JPH05305562A - Lens centering machine - Google Patents

Abstract

PURPOSE:To shorten the time of sudden access and sudden retreat or tact by changing the driving force of a driving device without laying the cutting directional movement of a grinding wheel along a cam when an optical material is suddenly approached to and suddenly retreated from the grinding wheel during one cycle working. CONSTITUTION:The cutting directional movement of a grinding wheel 7 to an optical material 9 is laid along the form of a cam 1 to grind the optical material 9. A driving device 13 for giving a driving force in the grinding wheel cutting direction is provided between a grinding wheel supporting slider 6 and an optical material carrying machine frame 16. When the rotating position of the cam 1 to conduct the sudden access and sudden retreat between the grinding wheel 7 and the optical element 9 is detected, the driving device 13 is operated to suddenly approach or suddenly retreat the grinding wheel 7 to the optical material 9 by its driving force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens centering machine using a cam drive device.

[0002]

2. Description of the Related Art A conventional radial (cutting direction) feeding mechanism in a lens centering machine using a cam driving device is a mechanism as shown in FIG.

Referring to FIG. 3, a workpiece 29 such as a lens or a filter is supported by a rotating work shaft 28 by a drive system (not shown). The work shaft 28
A Y-slider 26 is arranged in parallel with the Y-slider 26, and the Y-slider 26 is provided on the X-slider 24 with an arrow F by a bell cam (hereinafter referred to as a lateral feed cam) which is a lateral feed cam (not shown).
It is provided so that it can move in any direction. On the Y slider 26, a grindstone spindle 27a forcibly rotated by a driving means such as a motor (not shown) is rotatably supported by a sleeve (not shown), and is fixed to a grindstone holder 33 integrally arranged on the Y slider 26. Has been done. The grindstone 27 is integrally supported at the tip of the grindstone spindle 27a. The X slider 24 is a plate cam 2 that is a cam that controls the cutting amount of the grindstone that is forcibly rotated by a driving method (not shown).
1 by cam follower 22 and cam follower arm 2
Move through arrow 3 in the direction of arrow E. The cam follower arm 23 is slidable in the arrow H direction on the arm guide 31 integrally supported by the side surface of the X slider 24 by the feed screw 32. The compression spring 30 is configured to press the cam follower 22 against the plate cam 21 so that the X slider 24 follows the plate cam 21.

Next, the basic operation of one-cycle machining will be described with reference to FIG. The origin 0 ° shown in FIG. 4 indicates a portion where the apex of the plate cam 21 and the cam follower 22 shown in FIG. 3 are in pressure contact. From the origin 0 ° to A ° is a sharp approach in which the grindstone 27 follows the plate cam 21 and approaches the workpiece 29 such as a lens. From B ° to C °, the chamfering of the workpiece 29 such as a lens is performed on the plate cam 21 and the outer diameter is machined. The movement of the grindstone 27 is stopped by a radial stopper (not shown) at C °, and the plate cam 21 and the cam follower 22 are separated from each other. From C ° to D °, the workpiece 29 such as a lens performs a predetermined rotation without cutting the outer diameter. The grindstone 27 moves in the axial direction following the cam from the D ° by the lateral feed cam. The workpiece 29 such as a lens is chamfered right from E °, the Y slider 26 is stopped and the movement of the grindstone 27 is stopped by an axial stopper (not shown) at F °, and no axial cut is made up to G °. A work piece 29 such as a lens performs a predetermined rotation. Plate cam 21 from G °
The cam lift changes in a direction in which the grindstone 27 moves away from the work piece 29 such as a lens, and the grindstone 27 follows the plate cam 21 at H ° and moves in a direction away from the work piece 29 such as a lens and returns to the origin. At I °, the cam lift changes in the direction in which the lateral feed cam returns to the origin, and in J °, the grindstone 21 moves in the direction returning to the origin following the lateral feed cam.

The origin 0 ° to A °, C ° to D °, G °
Therefore, there is a case where the origin O ° receives a signal from a sensor (not shown) or the like, and the cam shaft is driven at high speed by an appropriate means such as inverter control.

[0006]

However, in the above-mentioned conventional example, since the sharp approach and the rapid retreat of the grindstone and the work piece are performed in accordance with the cam, the angle required for the rapid approach and the rapid retreat of the cam is not the same. Even if the camshaft drive is fed at high speed, it will be a waste of time. In addition, the steeply inclined projecting shape of the cam for causing the rapid approach and the rapid retraction has been difficult in designing and manufacturing the cam.

[0007]

According to the present invention, an object carrying a grindstone such as a fluid pressure cylinder, a linear motor or an electric motor, for example, a slider and an object carrying an optical material such as a workpiece, for example, is provided. By providing a drive device that generates a drive force for moving the grindstone between the machine frame and the work piece toward and away from the workpiece, and by operating this device, the rotational position of the cam can be adjusted regardless of the shape of the cam. When a sharp approach or a rapid retreat of the grindstone and the workpiece should be performed by detecting, the abrupt approach and the rapid retreat are performed by the driving force of the drive device.

[0008]

According to the present invention, when the optical material is ground in one cycle, the depth of cut is determined in accordance with the shape of the cam in order to perform the actual grinding. Different from the one that makes the sharp approach and the sudden retreat according to the shape, it is done by the driving force of the drive device provided when the sudden approach and the sudden retreat should be performed. ..

[0009]

【Example】

(Embodiment 1) FIG. 1 shows an embodiment showing a radial (cutting direction) feeding mechanism of the present invention. Referring to FIG. 1, a workpiece 9 such as a lens is supported by a rotating work shaft 8 by a drive system (not shown). The work axis 8
Is rotatably supported by a work shaft holder 8a fixed to the machine frame 16. The Y slider 6 is arranged in parallel with the work axis 8.
Is provided, and the Y slider 6 is X
It is provided on the slider 4 so as to be movable in the arrow B direction. On the Y slider 6, a grindstone spindle 7a forcibly rotated by driving means such as a motor (not shown) is rotatably supported by a sleeve (not shown).
Is fixed to a grindstone shaft holder 15 which is integrally arranged in the. The grindstone 7 is integrally supported at the tip of the grindstone spindle 7a. The X slider 4 slides in the direction of arrow A via the cam follower 2 and the cam follower arm 3 by the plate cam 1 which rotates in the direction of arrow C by a driving means (not shown). The cam follower arm 3 is an X slider 4
It is slidable in the direction of arrow D on the arm guide 11 which is integrally supported on the side by a feed screw 12 or the like. Further, the compression spring 10 presses the cam follower 2 against the plate cam 1, so that the X slider 4 always tries to slide toward the work shaft 8. Further, as a means for sliding the X slider 4 in the direction of arrow A, a machine frame 1 is provided integrally with the work shaft 8 by a fluid pressure cylinder 13 supported by the X slider 4.
The fixing portion 14 is fixed to 6 by an appropriate means such as a floating connector, the cylinder rod 13a of the fluid pressure cylinder 13 is connected, and the fluid pressure can be forcibly driven regardless of the cam drive.

Next, the basic operation of 1-cycle machining will be described with reference to FIG. At the origin of 0 °, the cam follower 2 is a pressing point for driving the plate cam 1 and the X slider 4.
Are separated by a hydraulic cylinder 13. From the origin 0 ° to A °, the fluid pressure cylinder 13 forcibly drives the X slider 4 so that the grindstone 7 rapidly approaches the workpiece 9 such as a lens. The cam follower 2 which is a pressing point for cam-driving the X slider 4 at A ° is brought into pressure contact with the plate cam 1, and the X slider 4 starts sliding by the cam driving. B °
For C °, the chamfering of the workpiece 9 such as a lens is performed on the plate cam 1 and the outer diameter is machined. The movement of the grindstone 7 is stopped by a radial stopper (not shown) at C °, the plate cam 1 and the cam follower 2 are separated from each other, and the workpiece 9 such as a lens is rotated in a predetermined rotation without cutting the outer diameter from C ° to D °. To do. From D °, the horizontal feed cam causes the Y slider 6 to follow the horizontal feed cam in the axial direction, whereby the grindstone 7 also starts moving. The chamfering of the workpiece 9 such as a lens is performed from E °, and the cam follower, which is a pressing point against the lateral feed cam (not shown), is separated by the lateral feed cam by the lateral stopper (not shown) at F °.
Is stopped, the movement of the grindstone 7 is stopped, and the workpiece 9 such as a lens is rotated by a predetermined amount without making an axial cut to G °. G °
Fluid pressure cylinder 13 supported by the X slider 4 at
As a result, the X-slider 4 moves in a direction away from the workpiece 9 such as a lens, so that the grindstone 7 separates from the workpiece 9 such as a lens. Also, the timing is slightly shifted from G °, and at H °, the Y slider 6 moves again following the transverse feed cam, and the grindstone 7 also returns to the origin. (Embodiment 2) In FIG. 1, instead of the compression spring 10, a fluid pressure is applied from the fluid port 13b of the fluid pressure cylinder 13 to a force corresponding to the pressure for pressing the plate cam 1 when processing the workpiece 9 such as a lens. That is, the compression spring 10 can be abolished by applying a pressure corresponding to the spring pressure used in the compression spring 10.

The compression spring 10 can be eliminated by using a similar idea even if another drive device such as a linear motor is used instead of the fluid pressure cylinder as the drive device. (Third Embodiment) In the first and second embodiments, the portion on the fixed side is pressed from the portion on which the fluid pressure cylinder is movable, but the movable portion may be pressed on the portion on the fixed side. That is, in FIG. 1, the fluid pressure cylinder is fixed to the movable side and the cylinder rod is fixed to the fixed side, but this may be reversed. (Embodiment 4) Although the inverter control is not described in Embodiments 1, 2, and 3, a section in which the camshaft may be fed at high speed in FIG. 2, for example, a section from C ° to D ° is detected by a sensor or the like not shown. The camshaft drive may be driven at high speed by a proper means capable of high speed feed, not limited to the inverter control, by taking a signal according to the rotational position.

As a matter of course, since the movement of the grindstone toward and away from the work piece is determined by the relative relationship between the two, the grindstone is on the moving side and the work piece is on the fixed side in the embodiment. However, this is not bad if it is reversed.

[0013]

As described above, by forcibly driving the driving device, for example, the fluid pressure cylinder, the sharp approach and the rapid retreat of the grindstone and the workpiece can be slid regardless of the cam drive. Sudden approach by cam (from O ° to A
°) The time during a sudden retreat (from G ° to O °), that is, the tact time is shortened. Further, since the shape of the cam is close to a circle, the cam can be easily manufactured. Further, since the compression spring can be eliminated, the mechanism can be simplified.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention.

FIG. 2 shows a processing cycle of the present invention.

FIG. 3 is an example of a conventional technique.

FIG. 4 shows a processing cycle in an example of a conventional technique.

[Explanation of symbols]

 1 Plate Cam 2 Cam Follower 3 Cam Follower Arm 4 X Slider 6 Y Slider 7 Grindstone 8 Work Axis 9 Workpiece such as Lens 10 Compression Spring 11 Arm Guide 12 Feed Screw 13 Fluid Pressure Cylinder 14 Floating Connector 15 Grindstone Axis Holder

Claims (3)

[Claims] 1. A lens centering machine that grinds an optical material such as a lens by a grindstone including a rapid approach and a rapid retreat of the grindstone and the optical material during one cycle of machining, in a cutting direction of the grindstone for grinding. In the case where the movement follows the shape of the cam, a drive device is provided between the object carrying the grindstone and the object carrying the optical material in the grindstone cutting direction, and the driving force is set according to the rotational position of the cam. Is configured so that it can be changed including the direction, when the grindstone abruptly approaches or retreats the optical material during one cycle machining, the movement of the grindstone in the cutting direction does not follow the cam, and the drive device The lens centering machine is characterized in that it is driven by forcibly driving the driving force of the lens. 2. The lens centering machine according to claim 1, wherein the drive unit is a fluid pressure cylinder. 3. The lens centering machine according to claim 1, wherein a pressure source applied to the cam in order to make the movement of the grindstone in the cutting direction follow the shape of the cam is constituted by a spring.