JPH0493169A - Polishing spindle - Google Patents

Abstract

PURPOSE:To enable the polishing of a general spherical face and nonspherical face not only a Toric face by providing a polishing tool that a polishing member of a 1st elastic body having a bag shape at the tip of a hollow spline shaft is air-tightly installed to a joint part. CONSTITUTION:A polishing member 7 which is a 1st elastic body having a bag shape is expanded with its internal pressure being increased by a compression fluid to press the surface of the body (1a) to be worked subjected to grinding in advance. As it is difficult to control the deformation quantity of the elastic body polishing member 7 and its spot pressure quantitatively, only be controlling the internal pressure of this elastic body polishing member 7, the contact area with the body (1a) to be worked is kept constant with a 2nd elastic body 31 pressing the polishing member 7 which is a 1st elastic body to the body (1a) to be worked together with a hollow spline shaft 10 further, and simultaneously the spot pressure generated at a work point is kept constant.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a polishing spindle for a polishing apparatus used in a polishing process for all types of lenses, such as spherical and aspherical surfaces, the so-called polishing process.

In the conventional lens polishing process, various processing methods have been used for spherical and aspheric surfaces.

In recent years, not only spherical but also aspherical optical glass lenses have been used in optical equipment to make equipment smaller and lighter.

We are promoting higher functionality. For example, toric lenses used in laser beam printers require a special shape, and the desired shape is obtained by first grinding the workpiece into a spherical surface with an approximate radius of curvature, then changing the processing tool and polishing it again. was. -For example, JP-A-63
The configuration shown in FIG. 3 described in Japanese Patent No. 216664 was used.

This will be explained below with reference to the drawings. FIG. 3(a) is a side sectional view of a conventional polishing apparatus, and FIG. 3(b) is a front view.

A workpiece 1 is attached to the outer periphery of a rotatable wheel 2, and a female jig 3 made of iron, cast iron, stainless steel, or the like is formed with a concave toric surface on the outer circumferential machined surface of the workpiece 1. Press with a predetermined force F, and in this state, press wheel 2.
At the same time, the female jig 3 is rotated perpendicularly to the direction of rotation of the wheel 10 while supplying abrasives such as wire-based silicon carbide abrasive grains #6o○ to #4000 between the female jig 3 and the processing surface. The lapping process is performed by swinging the abrasive grains in the direction of 1 μm and successively reducing the particle size of the abrasive grains, and in the finishing process, a polysoher such as polyurethane is applied to the female jig 3, and oxidation with a particle size of about 1 μm is applied. Cerium abrasive grains were supplied and polishing was performed in the same manner. The female jig 3 has an appropriate length, and is supported so as to be swingable in the width direction by engaging the tips of a pair of pressing needles 4 at both ends thereof. 4 are fixed to both ends of a swing frame 5 that is swingable in the longitudinal direction of the female jig 3, so that it is supported swingably in the longitudinal direction as well. Further, the swing frame 6 is urged toward the axis of the wheel 2,
and an actuating arm 6 that can be driven reciprocatingly in the axial direction of the wheel 2.
It is swingably mounted on the

Problems to be Solved by the Invention However, in such a lapping and polishing method, since the direction of the swinging force of the female jig 3 is naturally the same at any position in the longitudinal direction, the swinging surface S at the center is not the same as the wheel. Even if the radial direction T of the wheel 2 coincides with the radial direction T of the wheel 2, the swinging surface S at both ends will be inclined by an angle θ with respect to the radial direction T of the wheel 2. In principle, the curvature of the curved surface will not match that of the toric surface. Therefore, in reality, with such a processing method, it is extremely difficult to process the toric surface with high accuracy, and it is also difficult to maintain the accuracy of the toric surface of the female jig 3, and high-precision machining requires manual processing. This method requires intuition and skilled skills, resulting in extremely low productivity and high costs. Furthermore, regarding this problem, JP-A-63-216
Publication No. 664 attempts to improve precision and efficiency by causing the processing point of the processing tool to move in an hourglass-shaped trajectory with a radius of curvature equal to the radius of curvature of one of the toric surfaces to be processed. The main body of the device is complicated and high precision is required, and although it is suitable as a grinding device, it is not reasonable as a polishing device.

Polishing methods using an elastic body with internal pressure have also been proposed, but controlling the internal pressure alone limits the amount of deformation of the elastic body, and the contact area with the workpiece fluctuates, causing the pressing force per unit area to decrease. Due to the unevenness, the amount of processing could not be quantitatively determined, and a highly accurate polished surface could not be obtained.

In view of the above problems, it is an object of the present invention to provide a polishing spindle that has a simple structure, high precision, and is capable of polishing not only toric surfaces but also general spherical and aspheric surfaces.

Means for Solving the Problems In order to achieve the above objects, the polishing spindle of the present invention includes a first bag-shaped shaft at the tip of the hollow spline shaft.
A polishing tool having a joint part completely fitted with a polishing member that is an elastic body (hereinafter sometimes simply referred to as an elastic polishing member);
means for supplying compressible fluid to the other end of the hollow spline shaft via a rotary joint; means for rotatably supporting a nut that engages with the hollow spline shaft; means for rotating the hollow spline shaft; and a second elastic body provided in the direction of the rotation axis so that the polishing member is pressed against the workpiece at a constant pressure. Furthermore, a pressure detector is provided to detect a pressure drop in the compressible fluid due to damage to the bag-shaped first elastic polishing member.

According to the above-described configuration, the polishing member, which is the first elastic body having a bag shape, expands by increasing the internal pressure with the compressed fluid, and grinds the surface of the workpiece that has been previously ground. Press. Since it is difficult to quantitatively control the deformation amount and pressing force of the elastic polishing member by simply managing the internal pressure of the elastic polishing member, it is difficult to quantitatively control the deformation amount and pressing force of the elastic polishing member. By pressing the entire hollow spline shaft against the workpiece, the contact area with the workpiece can be kept constant, and at the same time, the pressing force generated at the processing point can be kept constant. Therefore, the pre-ground workpiece maintains its shape and has a surface roughness of Rmax-0, 5 to 0.01.
Polishing finish on the order of μm can be achieved. By using this polishing spindle, the structure of the device is simplified,
The accuracy of the device is also allowed to be about 0.1 indentation, the axis can be easily adjusted, and a polishing device that can perform polishing with higher precision can be realized.

Next, according to the second invention, in preparation for an abnormality such as occurrence of damage due to wear of the first elastic polishing member, when the internal pressure of the elastic polishing member decreases due to compressed air, etc. By detecting a pressure drop with a pressure detector and generating an abnormality signal, it becomes possible to immediately respond to the occurrence of an abnormality, such as issuing an alarm or stopping the device.

EXAMPLE Hereinafter, a polishing spindle according to an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a longitudinal cross-sectional view of a polishing nubindle in an embodiment of the first invention. In the figure, 1a is a workpiece, which is held by a rotatable wheel 2a. Reference numeral 7 denotes a polishing member which is a first elastic body, and a marsupial-shaped polishing tool 3 is arranged so that a compressible fluid C is sealed between a case 78 and a case 9.
5. This polishing tool 35 is attached to the tip of the hollow spline shaft 10.
A rotary joint 24 is provided at the other end of the rotary joint 24 via a bearing 23, and is connected to a compressible fluid source 26 via a conduit 25. On the other hand, the hollow spline shirt 10 is a so-called hollow spline shaft that is integrated with the nut 11 of the bearing portion and can transmit rotational motion and can also slide in the axial direction. This nut 11 is rotatably supported by a spindle case 15 via a bearing 12a and a bearing 12b, and the bearing 12a can generate axial pressurization by a bearing inner ring holder 13 and a bearing outer ring holder 14. Further, the nut 11 is interlocked with a rotational drive device 22 via a pulley 19, a pulley 21, and a belt 20. These spindle case 16 and rotary drive device 22 are fixed to a slide base 16 that slides on a rail 1 attached to the polishing machine main body 18 and allows the workpiece 1a and the polishing tool 35 to come into contact with and separate from each other. . The stopper 34 positions the slide base 16 and determines the contact state between the polishing tool 35 and the workpiece 1d.

Further, a ring 27 is fixed to the hollow spline shaft 10, and a thrust bearing 28 is connected to the ring 27 and the bush 29.
A stopper ring 30 held by the bushings 29 is arranged so that the pressing force of a spring 31, which is a second elastic body, can be adjusted. During actual machining, use polishing liquid 3.
3 is supplied to the pressure contact point between the workpiece 1a and the elastic polishing sweetener through a nozzle 32 or the like.

The operation of the polishing spindle configured as described above will be described below.

First, although not shown in the figure, the workpiece 1 is placed on the polishing machine main body 18.
The polishing spindle main body is lowered in the direction of the arrow to the position set by the stopper 34 by means of elevating means that brings the slide base 16 into and out of contact with a. The polishing tool 35 receives compressed fluid C from the compressible fluid source 26, and the internal pressure of the elastic polishing member 7 increases to high pressure, expands uniformly, and comes into contact with the surface of the workpiece 1a to be machined. . The polishing tool 35 is attached to a hollow spline shaft 10, and the hollow spline shaft 10 receives the rotational driving force transmitted to the nut 11 by the rotational drive device 22 via the pulley 19, 21 and the belt 20 in the direction of arrow B. It rotates at a rotation speed of approximately 10 to 200 Orpm. Therefore, the polishing tool 36 also moves in the same direction B.
It will rotate to . The other end of the hollow spline shaft 10 is connected to a compressible fluid source 26 through a conduit 26, but a rotary joint 24 is interposed between the hollow spline shaft 10 and the conduit 26, and the rotary joint 24 is a slider. Since rotation is restricted by the base 16, the conduit 25 is not twisted.

At this time, the naso l-11 is rotatably held by a spindle case 15 fixed to a slide base 16 by bearings 12a, 12b, so that the hollow spline shaft 10 that engages with this nand 11 can rotate.

11. On the other hand, a bush 29 is attached so that a thrust bearing 28 is held between a ring 27 fixed to the hollow spline shaft 10.
is inserted, and the compressed length of the spring 31, which is the second elastic body, is adjusted and fixed by a stopper ring 30 provided on the outer periphery of the bushing 29, thereby generating a compressive force in the spring compression part 36. The compressive force generated between the slide pace 16 and the stopper ring 3Q is caused by the bushing 29. Thrust bearing 28
゜Ring 27. The force is transmitted to the elastic polishing member 7 of the polishing tool 35 via the hollow spline shaft 10, so that a pressing force can be applied to the workpiece 1a. Therefore, even if the elastic polishing member 7 makes only the internal pressure uniform, the contact area of aspherical lenses with uneven distances to the workpiece 1a fluctuates, and the blood pressure is also unstable. The elastic body No. 2 keeps the pressing area of the polishing part against the workpiece 1a constant, so it is possible to actively promote stabilization and uniformity of the amount of processing, and the range of pressing force is expanded, making management easy. Therefore, it exhibits the important feature of being able to control the amount of processing quantitatively.

Further, in the second invention, as shown in the compressible fluid circuit diagram shown in FIG. 2, a pressure gauge 37. Pressure detector 38, pressure reducing valve 39. If the elastic polishing member 7 is damaged due to abrasion of the polishing tool 36 or damage due to foreign matter when the pulp 40 or the like is provided,
If the internal pressure is low and it can be detected by the pressure detection gg3s, it will be possible to take immediate measures such as reporting an abnormality in the main polishing spindle or stopping the device 1q.
It is possible to achieve great effects such as "improving equipment efficiency" while avoiding adverse effects on "a".

Effects of the Invention As described above, according to the present invention, glass lenses having not only spherical surfaces but also aspherical surfaces can be polished easily and with high precision, and the polishing apparatus can be made lower in price and smaller in size. Furthermore, it can also be used to reduce the cost of workpieces.

In addition, if the polishing spindle of the present invention is equipped with a pressure detector that detects a pressure drop in the compressible fluid due to damage to the polishing part, it will have a significant effect on improving the functionality of the polishing equipment and improving the operating rate. Demonstrate.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a polishing spindle in an embodiment of the first invention, FIG. 2 is a circuit diagram of the compressible fluid of the polishing spindle in an embodiment of the second invention, and FIG. 3(a) is a conventional A side sectional view of the polishing device, and FIG. 3(b) is a front view of the same device. 1a...Workpiece, 2a...Wheel,
7...Elastic polishing member, 10...Hollow spline shaft, 11...Nut, 16...
...Slide base, 17...Rail, 1
9,21...7" -1,1-120...
...Belt, 22...Rotary drive device, 24...
...Rotating joint, 25...Pipeline, 26...
... Compressible fluid source, 31 ... Spring. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (2)

[Claims] (1) A polishing tool in which a polishing member, which is a bag-shaped first elastic body, is airtightly attached to the tip of a hollow spline shaft, and a compressible fluid is connected to the other end of the hollow spline shaft through a rotary joint. means for rotatably supporting a nut that engages with the hollow spline shaft; means for rotating the hollow spline shaft; means for moving the shaft in the direction of the rotation axis; A second shaft is provided in the direction of the rotation axis so as to press the
Polishing spindle with elastic body. (2) The polishing spindle according to claim 1, further comprising a pressure detector for detecting a pressure drop in the compressible fluid due to damage to the polishing member.