JPS60177853A - Spherical grinder - Google Patents

Abstract

PURPOSE:To efficiently realize a desirable grinding-finished surface by adding the finishing-work depth condition onto working conditions. CONSTITUTION:Several dimensions of a worked lens, data of radius of curvature to be obtained after finishing grinding, working amount data in finishing grinding shape data of diamond grindstones 8 and 9, etc. are input into an NC control unit 22, and the position of the diamond grindstone 9 in finishing grinding is calculation-treated, and the position of the grindstone 8 in rough grinding is calculation-treated, and in orer to obtain the equal finishing-work depth (c) over the all surface of a workpiece, the spherical radius of curvature (a) in rough grinding is set so as to be equal to the radius of curvature (b) after finishing grinding plus finishing-work portion (c) in case of convex surface, and so as to be equal to the radius of curvature (b) minus finishing-work portion in case of concaved surface. The workpiece is set into an autohand 18, and a series of grinding works are carried-out by a rotary index 20.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a spherical grinding machine for optical parts such as optical lenses and mirrors.

Structure of conventional example and its problems In the conventional spherical grinding machine, as shown in FIG. A diamond grindstone 7 rotates at a high speed and is attached to a high-speed rotating spindle 6 which is tilted at a predetermined angle by a shaft 4 and placed in a predetermined position by a parallel slide shaft 6.
The spherical surface is ground by In this case, the glass material is brought into the collet chuck 1 by hand by an operator or brought in and held by an autoloader, and the same applies to removal after processing.

In addition, the diamond whetstones commonly used are metal bond 4f100~#4oO, and Rmax2~
The finished surface roughness is 6μ. In the subsequent process, smoothing is performed using diamond metal bond pellets and resinoid bond pellets, and further, in the subsequent process, boring is performed using an abrasive material such as CeO2.

However, in the above-mentioned device, the lens 3 held by the collector chuck 1 can only be ground with one diamond grindstone 7, and when finishing grinding it, the grindstone must be completely replaced or another spherical grindstone must be used. Although it is necessary to transfer the lens to the processing device, re-holding the lens with a collet chuck requires changing the holding posture of the lens and increasing the machining allowance for finish grinding. However, it is difficult to perform rough grinding and finish grinding efficiently.
In addition, the machining depth during finish grinding is determined by the microcracks generated in the previous process, that is, the rough grinding process.

It must be in an order that completely removes the layer, but
In order to make this machining depth uniform over the entire surface of the lens, the amount of machining required during finish grinding is anticipated, a spherical shape is assumed during rough machining, and conditions are set to ensure this shape throughout. It is necessary to carry out this process, which requires experience, and conventional methods for carrying out this process have drawbacks such as being time-consuming.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned drawbacks and efficiently realizes a good polished surface.

Composition of the Invention The spherical grinding machine of the present invention includes a holder that holds a workpiece, a work shaft that rotates the workpiece and feeds the workpiece in the axial direction, and processes the workpiece into a predetermined spherical shape. The workpiece shaft and the processing tool each have one for rough machining and one for finishing machining, and a holder that holds the workpiece. is transferred to the work shaft for rough machining and the work shaft for finishing machining, and the workpiece is machined. In addition, in order to make the finishing machining depth uniform over the entire surface of the workpiece, the position and posture conditions of the processing tool for rough machining are set so that when the rough machining radius of curvature is a convex surface, the finishing curvature radius plus the finishing machining depth is applied. In addition, in the case of a concave surface, it is equipped with an NC control unit that performs calculation processing and automatically sets the finish machining depth so that the finish curvature radius - 2 minus the finish machining depth.It instantly realizes the setting of conditions to make the finish machining amount uniform over the entire surface of the workpiece. A good grinding finish surface can be achieved efficiently.
Post-processing can be simplified, which is extremely advantageous in terms of quality control and cost reduction.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a specific example, and is a perspective view of a spherical surface grinding machine, and FIG. 3 is a sectional view of a lens to be processed. In the figure, 8 is a diamond grinding wheel for rough machining and # of metal bond.
Use approximately #100 to #400. Reference numeral 9 is a diamond grindstone for finishing, and metal bond size #600 to #1500 is used. Reference numerals 10 and 11 are the rotation spindle μ of each of the grindstones, and 12 and 13 are the drive motors thereof.
4.15 is a slide drive DC servo motor that moves the grindstone to a predetermined position, and a drive D (not shown)
The C servo motor tilts the grindstone at a predetermined angle around the tip of the grindstone. 16.17 is a lens to be processed, which is held by a chuck unit (not shown), and is held at 6 to 50 r.
It rotates at a speed of about pm, and is sent to the grinding wheels 8 and 9 by a DC servo motor to be ground into a spherical surface. 18
In order to take the lens material 19 into this spherical grinding machine,
Alternatively, it is an automatic hand for taking out the lens after finishing grinding. 2o is a rotary index, and the lenses 16, 17, and 19 to be processed are indexed at a predetermined position while being held by the chuck unit. 21
is the main page. 22 is a 14°15 DC servo motor that places an 8°9 diamond grindstone in a predetermined position, a DC servo motor that provides a predetermined inclination, 16.1
This is an NC control unit that performs arithmetic processing and controls condition settings for all six axes, including a DC servo motor that feeds the lens to be processed No. 7 to the diamond grindstones No. 8 and 9.

The operation of the spherical surface grinding machine constructed as described above will be explained below.

First, operate the N'C control unit No. 22 and input the specifications of the lens to be machined, the curvature data you want to obtain in finish grinding, the processing amount data in finish grinding, the shape data of the 8°9 diamond grindstone, etc. death.

The position of the diamond grindstone 9 during finish grinding is calculated, and the position of the diamond grindstone 8 during rough grinding is calculated. At this time, in order to make the finishing depth C equal over the entire surface of the workpiece, the radius of curvature aid of the spherical surface processed by rough grinding, the radius of curvature b plus the radius of curvature obtained by finishing grinding in the case of a convex surface, and the finishing allowance C. In addition, in the case of a concave surface, conditions are added so that there is a negative finishing machining allowance. Based on this calculation data, the diamond grindstone 8.9 is placed at a predetermined position by NC control. Thereafter, the lens to be processed is brought in by the automatic hand 18, and the chuck unit holding it is sent to the rough grinding position by the rotary index 20. After the rough grinding is completed, the lens is further sent to the finish grinding position to perform the finish grinding, after which the lens is further indexed, returns to its original position, and is taken out from the spherical grinding machine by the 18 automatic hand. A series of operations as described above are performed continuously at the same takt time.

As described above, according to this embodiment, the takt time is 20 to 3
Rmaxo, 0 during finish grinding in about 0 sec.
A thickness of about 5 μm can be easily obtained with a minimum amount of processing, and the initial conditions can be set in a short time.

Effects of the Invention As described above, the spherical grinding machine of the present invention has a work shaft and a processing tool for rough processing and finishing processing, and the position and position of the processing tool for processing into a desired spherical shape. It has the ability to add the condition that the finish machining depth CL is uniform over the entire surface of the workpiece to the condition settings such as posture, process this, and perform NC control based on this data. During finish grinding, the entire surface of the lens to be processed can be processed with a uniform amount of grinding, and a good ground surface can be achieved efficiently and in a short time. Post-process smoothing and polishing can be simplified, and in the future, automation is also possible. It's possible.

It becomes easier to maintain quality and reduce costs.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the specific configuration of a conventional spherical grinding machine, Fig. 2 is a perspective view showing a spherical grinding machine according to an embodiment of the present invention, and Fig. 3 is a sectional view of a lens to be processed. It is. 7.8.9...Diamond grindstone, 3,16°17...Workpiece (lens), 18...
Auto = y)", 2 o-rotary index, 6,10°11... Grinding wheel rotation spindle, 2
2...NC control unit. Name of agent: Patent attorney Toshio Nakao and 1 other person
2 Figure f53

Claims (1)

[Claims] A holder that holds a workpiece, a workpiece shaft that rotates the workpiece and feeds it in the axial direction, and is arranged inclined at a predetermined angle in order to process the workpiece into a predetermined spherical shape. The work shaft and the machining tool have one for rough machining and one for finishing machining, respectively, and the position and orientation conditions of the machining tool for rough machining are adjusted to the depth of the subsequent finishing machining. In order to make the curvature uniform over the entire surface of the object, if the rough machining radius is a convex surface, it will be the finishing curvature radius plus the finishing machining depth, and if it is a concave surface, it will be the finishing curvature radius minus the finishing machining depth. A spherical grinding machine equipped with