JPS6133665B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spherical surface roughening machine for lenses, and specifically to a spherical surface roughening machine for lenses that can easily adjust the setting position of a spherical surface creation tool with respect to the lens to be processed. It is.

First, to explain the processing principle of a commonly used lens spherical surface roughening machine, as shown in Fig. 1a, the lens 1 to be processed is held at the tip of a lens holder 2 attached to a work shaft 3, and the axis line It is configured to rotate around A-A'.
As shown in the perspective view of FIG. 1b, the tip of the cup-shaped grindstone 4, which is a tool for creating a spherical surface, is brought into contact with the spherical surface of the lens 1 to be processed, as shown in FIG. It is configured so that it can grind the lens to be processed while rotating around . Here, axis line A in the figure
-A' and B-B' are on the same plane, but their intersection is O, and the size of AOB is θ. If certain points are P1 and P2 (see FIG. 1a), the points P1 and P2 are located symmetrically on the axis B-B', and the distance from the intersection O is 1=2. At this time, if the point P2 is on the axis A-A', the lens 3 to be processed will be created as a spherical surface with a radius of 2.

Therefore, in order to create a spherical surface with radius R, point P2 must be on axis A-A' and distance 2
It is sufficient if the condition =R is satisfied.

By the way, in order to adjust the setting position of the spherical surface generation tool with respect to the lens to be processed so as to satisfy the above conditions, the angle θ described above must be changed;
This is done by moving the grindstone 4, which is a tool for creating a spherical surface, in parallel in the direction perpendicular to the axis B-B', but as is well known, lens processing requires extremely high precision, and such adjustment is not easy. It's not something.
In other words, when changing the angle θ, since the center of rotation does not coincide with the intersection O, changing the angle θ only changes the value of 1, which should originally be kept constant. Point P2
The position will also deviate from the axis A-A'. Furthermore, when the axis B-B' is moved in parallel, the point P2 is also moved, and at the same time the intersection point O is also moved, and as a result, the length of 1 changes in the same way as above, and the setting of the spherical surface generation tool for the lens. It is very difficult to adjust the position to the above predetermined conditions. Conventionally, this type of adjustment has relied exclusively on manual work, resulting in long setup times and limited adjustment accuracy.

In order to cope with such circumstances, the present invention improves the structure of the lens spherical surface roughening machine so that setup time can be shortened by simple operation and high-precision adjustment can always be made. This is intended to ensure convenience. That is, the present invention provides a spherical surface roughening machine for lenses that rotates the lens to be processed and grinds it with a spherical surface creation tool that rotates around a quill shaft, and a cup-shaped grindstone that is a spherical surface creation tool is provided on the base. The opposing angle with respect to the lens to be processed is made variable by a rotating shaft, and the three axes of the quill shaft of the grinding wheel, the work shaft that rotates the lens to be processed, and the rotating shaft always intersect at one point. The present invention is characterized in that by arranging each part in such a manner that the above-mentioned adjustment can be made accurately and easily.

Hereinafter, specific embodiments of the present invention will be described with reference to FIG. This figure shows a partially sectional front view of a spherical surface roughening machine for lenses according to the present invention.
Note that parts corresponding to the same parts as in FIG. 1a are given the same numbers. In the figure, 11 is the base of the roughing machine. A slider 5 is provided at a predetermined position on the base 11, and is configured to be movable forward and backward in the direction of arrow E-E' in the figure. A work shaft 3 is attached to the slider 5, and a lens holder 2 is further provided at the tip of the work shaft 3. This lens holder 2 is located on the axis of the workpiece shaft 3 and is configured to be rotatably driven, and a lens, that is, a lens to be processed 1 can be attached to and detached from the tip of the lens holder 2. The X-O' line shown by a dashed line in the figure represents the axis of the workpiece shaft 3. On the other hand, reference numeral 8 is a rotating shaft which is erected at a predetermined position on the base 11 with a fixing member 15 such as a bolt. In the embodiment, this rotating shaft 8 is formed in the shape of a fixed pin, and a housing 9 is configured to rotate, which is fixed to this pin portion and is attached via a bearing 6 such as a ball bearing. . Note that 7 indicates a mounting nut. The axis of the rotating shaft 8 is represented by a dashed line YY' in the figure, and its upright position is set so as to perpendicularly intersect the axis X-O' of the workpiece shaft. Reference numeral 10 denotes a rotating table, one end of which is attached to the housing 9 with a fixture 14, and the other end, that is, a mounting table 10a.
A spindle 13 is placed on the slider 12 via a slider 12. The slider 12 is mounted on a mounting table 10 in the same way as the slider 5 provided on the work shaft 3 side.
It is configured to be able to move forward and backward with respect to a. Although such driving means capable of moving forward and backward is not shown, it is desirable to use, for example, a ball screw and a pulse motor to drive the ball screw, and to perform the movement quickly and accurately by numerical control. Of course, using Natsu and Screw, etc.
This may be done manually by operating the handle, or various other means may be freely used. In addition,
Although this type of driving means is not shown, the rotating table 1
It is desirable that the rotation means of 0 is similarly implemented.

Now, the tip of the spindle 13 described above is equipped with a tool for creating a spherical surface of the lens, but in the embodiment, the cup-shaped grindstone 4 described above is attached to the spindle 13.
Rotationally driven at 3. The center of rotation of this spindle 13 is eccentric with respect to its outer circumference, and this becomes a quill axis. The quill shaft (dotted chain line O'-X' line in Fig. 2) is positioned so as to intersect perpendicularly with the rotation axis Y-Y' line, and is at the same height as the axis X-O' line of the work shaft. The height is set to match. As a result, the axis of the quill shaft O′−
The X' line and the workpiece axis axis X-O' line exist on the same plane, and each of the three axes including the rotation axis Y-Y' line intersects at one point with O' as the intersection point. Therefore, even if the opposing angle of the grinding wheel 4 to the lens to be processed 1 is changed by rotating the rotating table 10 on which the spindle 13 is placed around the rotating axis 8, the above three lines will not intersect at O'. They intersect.

Therefore, when setting a tool for creating a spherical surface on a lens to be processed using the above-mentioned lens spherical surface roughening machine, the rotating table 10 is rotated about the rotation axis 8, and the tool for creating a spherical surface on the lens to be processed is set. The opposing angle, that is, the angle θ explained in FIG. 1 can be varied, and the positional relationship is set by mutual adjustment by the forward and backward movement of the spindle 13, the above-mentioned opposing angle θ, and the forward and backward movement of the work shaft 3. It is. Moreover, since the rotation means and the forward/backward driving means are numerically controlled using a pulse motor, a predetermined operation program can be created in advance. Note that the above-mentioned quill shaft is made eccentric with respect to the outer periphery of the spindle, but as a means for making this eccentric, there are methods using an eccentric spindle,
Alternatively, it can be constructed by providing a vertical position adjustment machine and using a spindle without eccentricity. In addition, although a cup-shaped grindstone has been described as an example of a tool for creating a spherical surface, it is not limited to this example, and it is also possible to use various other shapes and use other abrasive materials as necessary. It does not go beyond the scope of invention. Furthermore, although this embodiment describes the case of machining a convex lens, it is not limited to this, and the third method can also be used when a part of the prism has a convex spherical surface or when machining a concave lens.
By adjusting the arrangement as shown in the figure, it can be carried out in the same manner as in the case of the convex lens described above, and the lens material can be applied not only to glass but also to plastics and various other lens materials. It is possible. In addition, 1 in Figure 3
4a represents a lens to be processed, and 4a represents a cup-shaped grindstone.

Thus, according to the lens spherical surface roughening machine according to the present invention, the work shaft rotates the lens to be processed;
Since the axes of the rotation axes that change the opposing angle θ of this spherical surface creation tool with respect to the lens to be machined always intersect at one point, even if the angle θ is changed in the case of Fig. 1, the length changes to 1. does not occur. Therefore, the contact position of the spherical surface generation tool with respect to the lens to be processed can be adjusted extremely easily and with high precision.As a result, the setup time during work can be significantly shortened, and the processing quality of the lens itself can be improved. It can also greatly contribute to improvement.

Furthermore, the present invention has the advantage that it is possible to easily correct the radius of curvature during processing, and correct the protrusion-like unground portion formed at the center of the lens.

In addition, a pulse motor is used for the drive means that allows each part to move back and forth, and for the rotation means of the rotation axis, which allows numerical control to be performed, making it possible to speed up work and further improve machining accuracy. It has various characteristics.

[Brief explanation of the drawing]

Fig. 1a is a diagram explaining the principle of a general lens roughening machine, Fig. 1b is a perspective view showing an example of a spherical surface creation tool used in Fig. 1a, and Fig. 2 is a lens according to the present invention. Part 3 is a front partial cross-sectional view showing the configuration of the rough-sliding machine.
The figure is an explanatory diagram of main parts showing another embodiment according to the present invention. 1... Lens to be processed, 2... Lens holder,
3... Work shaft, 4... Spherical surface creation tool (cup-shaped grindstone), 5, 12... Slider, 6... Bearing, 8... Rotating shaft, 9... Housing, 10...
Rotating stand, 10a... Placement stand, 11... Base, 13
……spindle.

Claims (1)

[Claims] 1. In a lens spherical roughening machine that rotates the lens to be processed and grinds it with a spherical surface creation tool that rotates around a quill axis, the spherical surface creation tool is rotated by a rotating shaft provided on the base to grind the lens to be processed. The quill shaft of the spherical surface creation tool, the work shaft for rotating the lens to be processed, and the rotating shaft are arranged so that the axes thereof always intersect at one point. A spherical surface roughening machine for lenses.