JPS58126051A - Compound rotary type surface grinder - Google Patents

Abstract

PURPOSE:To improve a working accuracy as well as a surface roughness by a method wherein a work is applied with rotation, in the surface grinder grinding the upper surface of the work chucked to the upper surface of a rotary table with a vertical shaft grinding stone. CONSTITUTION:The big table 4, supported to a base 8 by a bearing, is driven to rotate by a motor 13 through a reduction gear 12 and a belt 11. A plurality of small tables 5 are supported by the bearings on the circumference of the big talbe 4 and are driven to rotate by the motor 15 through another reduction gear 16, belt 17, gears 19, 20 and another belts 22. The works are attached to the upper surfaces of the small tables 5 through chucks 14 and the upper surface thereof are ground by the grinding stones arranged on the vertical shafts while being rotated and revolved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface grinding machine that grinds the upper surface of a workpiece chucked on a rotary table using a chamber-axis rotary grindstone.

FIG. 1 is a perspective view showing the principle of an example of a rotary table-type, chamber-axis grindstone type surface grinder that has been commonly used in the past. A plurality of (four in this example) chuck means 2.2 are provided on the rotary table 1. For convenience of explanation, the positions of the four chuck means are respectively referred to as A position,
Name them B position, C position, and D position.

A chamber shaft type rotary grindstone 3 is provided above the chuck means 2 at position A.

The workpieces are each chucked onto the chuck means 2.2, and the rotary table 1 is rotated at a fixed angle (90° in this example).
), the workpieces (not shown) are sequentially sent to position A below the grindstone 3 and are ground by the spindle-type rotary grindstone 3.

FIG. 2 shows an example in which two of the above-mentioned chamber shaft type rotary grindstones 't- are provided. With this configuration, the workpiece (not shown) is mounted on the chuck means 2 at the D position, for example, while the rotary table 1 is rotated counterclockwise intermittently by 90 degrees.
When the workpiece mentioned above is sent to position A, it is roughly ground by the rotary grindstone 3a, then when it is sent to the B position, it is finished ground by the rotary grindstone 3b, and when it is sent to the C position after finishing the finish grinding, it is chucked. By removing the workpiece from the means 2, a large number of workpieces can be surface ground continuously. Moreover, as shown in FIG. 2, the rotary table 1? Arrow E
, F, the workpiece (not shown) K is configured to be reciprocated in the horizontal direction and chucked by the chuck means 2, 2.
On the other hand, a surface grinding machine in which the rotary grindstones 5a and 5b are configured to move relatively horizontally and linearly has also been put into practical use.

In the conventional surface grinding machine as described above, during the period when the workpiece mounted on the rotary table 1 via the chuck means is being ground by sliding on the grindstones 5a and 3b, the workpiece is Since it is stationary or only moving in a straight line, almost parallel eyes are produced on the ground surface as shown in FIG. Since the grinding mechanism is as described above, the grinding accuracy is impaired due to the lack of parts.

(i) As is well known, when discussing grinding accuracy on the submicron order, the unique accuracy characteristics of each grinding machine are revealed due to extremely slight shape errors, bending, thermal deformation, etc. of the members that make up the grinding machine. As shown in FIG. 3, when a directional grinding surface is created by leaving tl parallel grinding marks, the above-mentioned accuracy characteristics appear on the ground surface as grinding errors up to t.

(iD) The above-mentioned grinding marks are fine irregularities, and the presence of such irregularities means that the surface roughness is not good.

The present invention has been made in view of the above circumstances, and by performing non-directional grinding on a workpiece in a two-dimensional plane, the above-mentioned accuracy characteristics can be offset, and the surface roughness, which is naturally determined by the grain size of the grinding wheel, can be improved. Another object of the present invention is to provide a surface grinding machine that can finish the surface with extremely high quality surface roughness.

The principle of the present invention is to continuously rotate the workpiece (hereinafter referred to as revolution) around a vertical axis located at a distance from the workpiece, and simultaneously rotate the workpiece around a vertical axis located at a distance from the workpiece in order to perform non-directional grinding. The workpiece is rotated (hereinafter referred to as "autorotation") around a vertical axis that passes through the surface of the workpiece or a vertical axis that is closest to the surface of the workpiece. By slidingly touching the surface and passing under it at a constant revolving circumferential speed, we constructed a device that can perform two-dimensional grinding in which the grinding lines in all directions are averaged and intersected in a mesh pattern, thereby achieving individual accuracy. This offsets the unevenness of the grinding marks and flattens them.

FIG. 4 is a principle explanatory diagram schematically depicting an example of a surface grinder according to the present invention.

The chamber-shaft rotary grindstone 3a for rough grinding and the chamber-shaft rotary grindstone 3b for finish grinding are the same components as those in the conventional grinding machine shown in FIG.

Reference numeral 4 denotes a rotary table, which is a component similar to the rotary table 1 in the conventional grinding machine shown in FIG. . For convenience of explanation, Jinre will hereinafter be referred to as large table 4. This large table 4 is continuously rotated in the direction of arrow G.

A plurality of (six in this example) small rotary tables 5, 5, . . . are installed along the circumference of the large table 40.

A hand R (both not shown) for chucking the workpiece is provided on the upper surface of each of the small rotary tables 5,5..., and the small rotary tables 5,5... Rotate it in the H direction.

In this case, each arbitrary point on the upper surface of the small rotary table 5 moves in a cycloidal curve.

Therefore, when looking at the workpiece (not shown) chucked on the upper surface of the small rotary table 5 as a reference, the axes I and J of the chamber-shaft type rotary grindstones 3m and 3b approach each other while moving in a spiral, As it passes, the upper surface of the workpiece is ground.

Figure 5 is a diagram schematically showing the grinding marks when grinding the surface of the workpiece at the initial stage when the axis of the rotary grindstone approaches the workpiece. It is also a rough expression.

The point in the figure is the first point at which the rotary grindstone approaches and contacts the workpiece 6. The point is the point at which the outer periphery of the rotary grindstone penetrates the most into the surface to be ground at the time when grinding is interrupted.

The trajectory of the foremost point on the outer periphery of the whetstone starts from point K,
As the large table 4 revolves, it gradually approaches the center of the surface to be ground, but at the same time, as the small rotary table 5 rotates, the direction of the arc-shaped scratches 7 forming the grinding marks changes. As a result, the frontmost point draws a spiral trajectory from K to L as indicated by the arrow.

Grinding continues in this way, and when the workpiece finishes passing under the rotary grindstone while rotating and revolving, individual arc-shaped grinding marks are distributed evenly in all directions within the grinding surface, as shown in Figure 6. It is distributed in a finely intertwined manner.

For example, as shown in Figure 3, when the axis of the rotary grindstone passes through the surface to be ground in the horizontal direction as shown by arrow M, and the arc-shaped grinding marks are aligned vertically, Assuming that it has a precision characteristic that is concavely distorted symmetrically with a line, if the arc-shaped grinding marks are evenly intersected and densely distributed as shown in Figure 6, the precision characteristic will be canceled out. It does not appear as distortion.

In addition, since the unevenness of the grinding marks is evened out, the surface roughness is significantly improved.

As shown in FIG. 4, a concrete example of a mechanical device that performs a composite rotation of autorotation and revolution is shown in FIGS. 7 and 8.

Figure 7 is a cross-sectional view of the practical machine completed by the inventors.
FIG. 8 is a diagram depicting only the complex rotation transmission member extracted from FIG. 7.

In FIG. 8, 8 is the pace of the apparatus, and 4 is a large table rotatably supported on the base via a bearing 9t.

A pulley groove 10 is formed on the large table 4 described above, and a belt 11 is formed. and is rotated by a revolution drive motor 16 via a reduction gear 12.

Small rotary tables 5, 5 are rotatably supported on a large table 4, and chuck means 14.14 are provided on the upper surface thereof. As the chuck means 14, any one such as an electromagnetic chuck or a vacuum chuck can be used.

15 is a motor for rotational driving. Its rotational output is the speed reducer 16. ■Transmission is transmitted to the rotating drive gear 19 via the belt 17 and the concentric shaft 18, and the rotating transmission gear 20 meshes with the rotating drive gear 19.
, 20'! l - Rotating transmission pulleys 21, 21 through
T-Rotate. The above-mentioned rotating transmission booleans IJ21, 21 are Cogpel) 22.22 and rotating driven pulleys 25, 25
The small rotary tables 5, 5 are rotated through the t-t.

In this embodiment, on top of the large table that rotates continuously as described above, a plurality of rotating small tables equipped with means for chucking the workpiece are arranged along the circumference of the large table. By doing so, the workpiece chucked on the small rotary table rotates together with the small rotary table, and as the large table rotates, the workpiece is configured to slide under the chamber shaft rotary grindstone and pass under it. It is.

In FIG. 7, a large table 4, a small rotary table 5, reducers 12, 16, a revolution drive motor 16, and a chuck hand #1.
14, the rotation drive motor 15, the concentric shaft 18, the rotation drive gear 19, the rotation transmission gear 20, the rotation transmission pulley 21, the rotation transmission cog belt 22, and the rotation driven pulley 23 are the components described with reference to FIG.

An electromagnetic clutch 24 is interposed and connected between the small table shaft 5a fixed to the small rotary table 5 and the rotating driven pulley 23, so that the rotation transmission of the small rotating table 5 can be freely connected/disconnected. The electric wire 25 for the electromagnetic clutch is pulled out through the slip ring 26 and inserted into the hollow part 1 formed in the concentric shaft 18.
Connect to the operation panel (not shown) through the 8a t-.

In this embodiment, an electromagnetic chuck is used as the chuck means 14, and excitation current is supplied through the slip rings 27 and 28t.

In this embodiment, the rotation speed of the large table 40 is 0.2~
The rotation speed of the small rotary table 5 can be adjusted within the range of 30 to 150 r, p, z. When the present invention is actually applied, it is desirable that the rotation speed is higher than the revolution speed (10 times or more) as in this embodiment. This results in perfect isotropy with respect to the grinding pattern, as explained for Figure 6.

(See Fig. 4) Chamber shaft rotary grindstone 3a in this embodiment,
The diameter of 5b is 205111. The rotation speed is 1900 r,
It is a two-stage switching between p, m, and 380Or, p, m. Further, vertical feeding is performed by a step motor (not shown), and the feeding amount per step is 0.25 μm.

The surface grinder of this example? If used, any method of operation is possible, either single-pass grinding or multi-pass grinding.

When performing one-pass grinding, the workpiece chucked onto the upper surface of the small rotary table 5 is rotated in the direction of the arrow H and revolved in the direction of the arrow G as described above, and as it revolves, it passes under the rough grinding wheel 3a. Then, it is passed under the finish grinding wheel 3b as it is.

With this operating method, a large number of workpieces can be rough-ground and finished-ground in sequence in assembly line operations, resulting in high efficiency.
Another advantage is that since the chuck is not released between the end of rough grinding and the start of finish grinding, there is less chance of error inflow. However, in order to perform grinding with submicron-order precision, there is a technical difficulty in that the positions of the two vertical rotary grindstones 5* and 3b in the feeding direction (vertical direction) must be aligned with ultra-high precision. . A solution to this problem will be described later.

When performing multi-pass grinding, first the feed of the rotary grindstone 6b for finish grinding is set backward (increased), and the small rotary table 5.5t that chucks the workpiece is rotated and revolved. Rough grinding is performed by repeatedly passing under the rotary grindstone 6a for rough grinding a plurality of times. Next, the rotary grindstone 5a' for rough grinding is moved backward (raised) in the feed direction, and the rotary grindstone 5bk for finish grinding is moved forward (lowered) in the feed direction, and while the workpiece is rotating, the rotary grindstone 3b for finish grinding is Finish grinding is performed by repeatedly passing the material several times while sliding it on the bottom surface. Even when performing all of the multi-pass grinding described above, the rotary grindstone 3b for finish grinding that was initially evacuated must be sent to the correct grinding position, so the positions of both the rough and finish grindstones 5a and 3b in the feed direction (up and down) are changed. There is a technical difficulty in that they must be aligned and interlocked with ultra-high precision.

In this embodiment, in order to align the above-mentioned two grinding wheels 5a, Sb with ultra-high precision, both grinding wheels 3a, ! By integrally fixing the feeding means (not shown) of the ib to the same base (not shown), both grinding wheels 3a and 3b can be strictly integrally fed in the vertical direction, Further, the individual grindstones 5a, 5bf are constructed so as to be able to move forward and backward in the feeding direction with respect to the above-mentioned base.

As a result, both grindstones are integrally connected via the base (not shown), and when the base is moved back and forth in the feeding direction, they move back and forth as one unit while maintaining alignment. Therefore, the individual grinding wheels 5h and 3b can be moved forward and backward by a minute amount with respect to the base, and the two grinding wheels can be used alternately with extremely high precision using the above-mentioned base as a reference.

The base may be a highly rigid slide base, or the electromagnetic drive feeding devices of both grinding wheels 3a, 3b may be electrically interlocked to perform the same function.

By providing a plurality of rotary grinding wheels as in this embodiment, it is possible to carry out any one of the above-described one-pass grinding or multi-pass grinding operations to perform surface grinding with high efficiency.

Further, as in this embodiment, the plurality of rotary grindstones for grinding may be connected mechanically or electromagnetically to perform an integral vertical feeding operation, or individually. If configured so as to be able to operate, the feed operations of the plurality of rotary grinding wheels can be aligned with each other with ultra-high precision, and a large number of workpieces can be surface ground in a continuous flow operation. can.

As mentioned above, when multiple rotating grindstones are connected and fed in an integrated manner, if the individual grindstones wear unevenly, alignment will be disrupted, so use a rotating grindstone with an extremely low wear rate (such as a diamond grinder). It is desirable to do so.

As explained above, the present invention provides a surface grinding machine in which the upper surface of a workpiece chucked onto the upper surface of a rotary table is ground using a spindle-type rotary grindstone. A plurality of small rotary tables equipped with means for chucking objects are arranged along the circumference of the large table, and the workpieces chucked on the small rotary tables are rotated together with the small rotary tables. As the large table revolves, it slides against the chamber-axis rotary grindstone and continuously passes under it, thereby applying two-dimensional isotropic grinding to the grinding surface of the workpiece. It has an excellent practical effect of being able to offset the f# degree characteristics and finishing with a surface roughness of much higher quality than the surface roughness naturally determined by the grain size of the grinding wheel.

[Brief explanation of drawings]

Figures 1 and 2 are each of a conventional surface grinder.
FIG. 6 is a schematic diagram of a grinding surface by a conventional surface grinder, and FIG. 4 is a perspective view schematically showing the principle of an embodiment of a compound rotary surface grinder according to the present invention. A schematic perspective view, and FIGS. 5 and 6 show the ground surface according to the above embodiment, FIG. 5 is a schematic diagram of the distribution of grinding holes at the initial stage of grinding, and FIG. 6 is a diagram at the end of grinding. FIG. FIG. 7 is a sectional view of an embodiment of a compound rotary type surface grinder according to the present invention. FIG. 8 is an explanatory diagram depicting a compound rotation transmission member extracted from FIG. 7. 3a... Chamber shaft rotary grindstone for rough grinding, 3b... Chamber shaft rotary grindstone for finish grinding, 4... Large table, 5... Rotating small table, 6... Workpiece, 7 ...Arc-shaped stop, 8...Base, 9...Pulley groove, 11, 17.
...V belt, 12.16...Reducer, 13...Revolution drive motor, 14...Chuck means, 15...Rotation drive motor, 18...Concentric shaft, 19...Rotation drive Gear, 20... Rotating transmission gear, 21... Rotating transmission pulley, 22... Cog belt, 23... Rotating driven pulley, 24... Electromagnetic clutch, 25... Electric wire for electromagnetic clutch, 26 ,27°28...Slip ring. Patent applicant Tokyo Seiki Kosakusho Co., Ltd. Agent Patent attorney Tadashi Akimoto Figure 1 Figure 2 Figure 3 33 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. In a surface grinding machine that grinds the upper surface of a workpiece chucked onto the upper surface of a rotary table using a rotary grindstone with an axis in all chambers, the workpiece is chucked onto a continuously rotating large table. A plurality of small rotary tables equipped with means are installed, and the workpiece chucked on the small rotary tables is rotated together with the small rotary tables and comes into contact with the chamber-axis rotating grindstone as the large table rotates. A compound rotary type surface grinding machine characterized by being configured so that the machine passes under the machine while rotating the machine. 2. The compound rotary type surface grinding machine according to claim 1, wherein a plurality of said rotary grindstones are provided. (v) The plurality of rotating grindstones are characterized by having a structure in which they can be interconnected and integrally fed in the vertical direction, and can also be fed individually in the vertical direction. A compound rotary surface grinder according to claim 2.