JPH02311266A - Form molding of grindstone on actual machine - Google Patents

Abstract

PURPOSE:To achieve time and cost effectiveness by using a rotational metal plate provided with a dressing face, and by performing dressing on a NC control grinding panel, with a grinding stone being held. CONSTITUTION:On the same base as a NC control grinding panel, a dressing device is mounted so as to rotate and drive a metal disc 1 as a dresser, while a grinding stone 4 is mounted on a rotational shaft of the grinding panel. A rotational shaft line A of the dresser 1 and a rotational shaft line B of the grinding stone 4 being put in parallel, a grinding face of the grinding stone 4 and a dressing face of the dresser 1 are made into contact with one another, and a central point is defined closer to a rotational shaft line of the grinding stone 4 based on the central point of a semicircular peripheral face of an original radius R1 of the dresser 1, as well as on the central point of a semicircular peripheral face of an original radius R3 of the grinding stone 4, while the central point on the dresser 1 being determined as a center, and on a semi-arc trajectory depicted by a radius, R1+R3, with the dresser 1 and the grinding stone 4 being rotated, and each rotational shaft line maintained in parallel, by moving the defined central point of the grinding stone 4, dressing is performed on this grinding face.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of forming a shape of a grinding wheel on an actual machine using a dressing device attached to an NO-controlled copy grinding machine such as a grinding center.

[Background Art] When a workpiece is to be grooved, a resin bond diamond or resin bond CBN grindstone is attached to an NC copy grinding machine such as a grinding center, and the groove is ground using NC copy control.

The rotary grinding surface of the resin-bonded diamond or resin-bonded CBN grinding wheel (hereinafter referred to as the grinding wheel) for groove grinding is usually R-shaped, and this is rotated back and forth with respect to the machined surface of the workpiece by NG control. Since the grinding wheel is moved laterally to perform the grinding process, uneven wear occurs on the grinding surface of the grinding wheel. In order to keep this uneven wear within an allowable range for grinding, it is necessary to perform a grinding surface modification process called dressing.

Conventionally, in order to dress a grinding wheel, the unevenly worn grinding wheel was generally removed from the grinding machine and a separate dressing device was used.
As disclosed in Publication i3-105888, a dressing device has already been proposed in which the dressing device itself is placed on the same base as the machining center, and dressing is performed on the actual machine, thereby reducing the time required for dressing the grinding wheel. .

[Problems to be Solved by the Invention] By the way, conventionally, in order to dress a grinding wheel for grinding a groove, a total amount dresser having a shape that is the basic shape of the grinding wheel is usually used, and the grinding wheel is modified by this dresser. However, this dresser itself causes uneven wear on the grinding surface due to repeated dressing of the grinding wheel, so if it is not replaced before the uneven wear exceeds the allowable range, the grinding wheel will be damaged. During the dressing process, run-out occurs and the grinding wheel does not have a predetermined original shape. And the dresser itself is quite expensive.

[Means for Solving the Problems] When using the NO control method, the grinding wheel for grinding the workpiece can at least draw a predetermined locus on a plane and move over time. Instead of preparing the entire dresser to be installed above, a dresser with an R-shaped outer circumferential surface is used, and the grinding wheel receiving the dressing and the rotating axis of the dresser are kept parallel and both are rotated. In this state, the grinding wheel is moved in a circular trajectory to be described later with a slight cut being made to the grinding surface of the grinding wheel, thereby dressing the grinding surface of the grinding wheel.

According to this method, it is only necessary to prepare a dresser whose outer circumferential surface is rounded in cross section, which is extremely economical compared to the conventional method of preparing a dresser with a total volume, and the dresser can be made in the same shape as the original. A completely unchanged ground surface can be easily obtained on the actual machine.

The present invention will be explained below with reference to an embodiment shown in FIG.

The figure shows a top view of each component on the same base as the grinder.

Reference numeral 8 indicates a motor for driving the workpiece, and 7 indicates a workpiece fixed to a rotating shaft 9 rotated by the motor 8, such as a carbide rolling roll that has grooves that have been deformed due to wear and requires correction. .

4 is a grinding wheel, 6 is a drive motor, and 4 is a grinding wheel mounted and fixed on a rotating shaft 5 rotated by the motor 6.

IO indicates a dresser device, 2 indicates a drive motor, 1 is attached to a rotating shaft 3 rotated by the motor 2,
Shows a fixed dresser.

The grinding wheel 4 is made of super abrasive diamond grains or CBN.
It is a disc-shaped resin-bonded grinding wheel in which boron nitride (boron nitride) grains are held in resin, and the grinding surface, which is the outer peripheral surface, has a semicircular cross section. The grinding surface 11 of the workpiece 7 is placed between the shaft 9 and the flat plate.
The grinding wheel 4 presses the surface to be ground 11 of the workpiece 7 which is also in the rotating state, and by moving the grinding wheel 4 in the X-axis direction and the Y-axis direction, the surface to be ground is A deformed groove having a semicircular cross section as shown at 11 is corrected. In this case, the movement of the grinding wheel is performed by NC control, although it will not be described here.

Since the grinding wheel 4 is worn out by grinding, the wear is measured or the number of rotations of the grinding wheel 4 is counted (not shown), and when the wear or deformation from the original shape exceeds the allowable limit. The grinding wheel 4 is moved toward the dresser device IO while being attached to the rotating shaft.

The dresser 1 is a disc made of a sticky metal such as mild steel, molybdenum, stainless steel, etc., in which chips of a workpiece are turned into sharp long pieces, and the semicircular outer peripheral surface of the dresser serves as a grinding surface.

FIG. 2 is an explanatory diagram of the dressing method. The same parts as in FIG. 1 are indicated by the same reference numerals.

As shown in the figure, the external shapes of the grinding wheel 4 and the dresser 1 are thick discs symmetrical to the rotational axes B and A, respectively, and their outer peripheral surfaces (grinding surfaces) are centered at their radial centers 0° and 0□, respectively.
is placed inside the grinding wheel 4 and dresser 1, radius R
It is formed by a semicircular rotating surface of 3.R. R3 below
, R, is called the original radius of the grinding wheel and dresser.

The figure shows that the rotational axes B and A of the grinding wheel 4 and the dresser 1 are parallel to each other, and that their thickness direction central planes P2 and Pl are on the same plane C, and their outer peripheral surfaces are in contact. ing. In other words, it shows that both are in contact at the outer periphery passing through the apex of the outer peripheral surface.

Assuming that there is no wear on the grinding wheel 4 and the dresser 1 and that the two vertices are in contact with each other, and keeping the rotational axis B parallel to A, the radius R3 of the grinding wheel is
The X-axis,
If the grinding wheel 4 is moved in the Y-axis direction, the radial center point of the dresser 1 that does not move will be 0. On the other hand, the radius center point 0□ of the grinding wheel 4 draws a semicircular locus T of R, 10R3=R2. In this case, the range in which the grinding wheel 4 can move is the range in which the semicircular grinding wheel surface and the dressing surface a of the dresser are formed so that both can come into contact with each other.

Assuming that there is no wear on the dressing surface a of the dresser 1, it is necessary to form a new grindstone surface with the original radius R3 on the grinding wheel surface of the grinding wheel 4 that has been worn, although it is exaggerated in the figure. , Assuming a radial center point O'2 slightly closer to the rotation axis B than the radial center point 0°, centering on the radial center point 01,
R1+R3” Both rotational axes A on the semicircular locus that becomes R2,
The rotating dresser 1 is moved by moving the assumed center point 0'2 of the grinding wheel 4 while keeping the wheels B parallel to each other.
Dressing is performed by bringing the grinding surface of the rotating grinding wheel 4 into contact with the dressing surface a of the grinding wheel 4.

At this time, the dressing progresses while the grinding wheel 4 is slightly pressed against the dresser 1.

In this way, the grinding surface of the grinding wheel 4, which has been repeatedly used and has suffered uneven wear, can be corrected and a new grinding surface of the original radius R3 can be formed.

In this case, the grinding surface of the grinding wheel 4, which has a slightly uneven surface due to repeated use, comes into contact with the dressing surface a of the dresser 1 with some pressure as described above. Since is a resin bonded grindstone, it has some elasticity, and when both are rotating, R, +
R3 = Even if the center point 0'2 is moved on the semicircular locus T regulated by R2, there will be no problem.For example, if the semicircular locus T is drawn from the starting point E of the dressing surface a of the dresser 1, By repeating the movement to the end point E' - times or repeating it, a new grinding surface of the grinding wheel 4 that is exactly the same as the original shape can be obtained.

The characteristic observed during this dressing is that the grinding surface of the grinding wheel 4 is in close to point contact with the dressing surface a of the dresser, and also comes into contact with a part of the dressing surface a that changes sequentially in the thickness direction. Therefore, dressing surface a is constantly updated. To do this, a dresser is required whose surface, that is, the radius R, is larger than the radius R3 compared to the thickness of the grinding wheel to be dressed.

As explained above, the dresser will be used repeatedly, so even though the grinding wheel to be dressed is made of diamond fine grains and CBN fine grains bonded with resin, wear is inevitable, so measurement of the dressing surface, Needless to say, it is necessary to make changes according to the usage time determined empirically, but one method is to use a graphite sample, grind the graphite with a grinding wheel that has been completely dressed, and then The dresser may be compared with the original shape using a magnifying projector, and if there is an unacceptable deviation from the original shape, the dresser may be replaced.

When using the dresser in consideration of wear, the above-mentioned R, + R3: When regulating R2, the original radius center point 02
In addition to assuming the shift to O'2, the wear of the dresser is also taken into account and corrected to further improve the rotational axis B.

Movement of the grinding wheel relative to the dresser, rotation control of the dresser and grinding wheel, semicircular trajectory movement of the grinding wheel due to the regulation of R1 + R3 = R2, etc. are all performed by NO control, and changes in the shape of the grinding wheel, the shape of the dresser, and the amount of wear Full automation is also possible by adding means for detecting etc.

In the above explanation, dressing of the grinding wheel was explained for rolling rolls, especially those with simple R-shaped grooves. It can also be applied to dressers for grinding wheels used in However, in this case, R3 of the grinding wheel needs to be RX>R3 compared to RX in the figure.

[Test Example NG] A dredging device was placed on the same base as the sub-control grinder, with the rotation axis aligned parallel to the rotation axis of the grinder.

Dresser rotation speed ND=GO-10Or, p, m, grinding wheel rotation speed ND=1000~[1000r, p,
m, R2 = R, + R3 semicircular trajectory motion speed F
D=5~100mm/min, Radius of dressing surface R+=5~10mm1 Radius of grinding wheel surface R2=3~1
The surface of the grinding wheel was corrected and molded by setting the incision (forming the original shape on the grinding wheel surface of the grinding wheel) to 5 to 20 μm.

As a result, the forming accuracy of the grinding wheel was ±0.02, making it possible to modify the surface of the grinding wheel with extremely high precision.

[Effects of the Invention] According to the present invention, the shape of the grinding wheel can be formed on the NC-controlled grinding machine while the grinding wheel is being held, that is, on the actual machine, without using a full-length dresser and having a dressing surface. This can be done by using a rotating metal plate, which saves dressing time and costs.

Further, there is no vibration that is likely to occur when the grinding wheel is attached or removed.

[Brief explanation of the drawing]

FIG. 1 schematically shows an apparatus for carrying out the invention. FIG. 2 shows an explanatory diagram for implementing the present invention. FIG. 3 shows one shape of an object that can be machined with a grinding wheel that can be shaped according to the invention. 1...Dresser, 2...Drive motor, 3...
・Rotating axis, 4... Grinding wheel, 5... Rotating axis, 6...
- Drive motor, 7... Workpiece, 8... Drive motor, 9... Rotating shaft.

Claims (1)

[Claims] (1) A metal disc is used as a dresser on the same base as the NC-controlled grinding machine, a dressing device that is rotationally driven is attached, and a grinding wheel is attached to the rotation axis of the grinder, and the rotation axis of the dresser and the grinding With the rotation axes of the grindstone parallel, the grinding surface of the grinding wheel and the dressing surface of the dresser are brought into contact, and the center point of the semicircular outer circumferential surface of the dresser with an original radius R_1 and the semicircular outer circumferential surface of the grinding wheel with an original radius R_3 are connected. Assuming a center point closer to the rotational axis of the grinding wheel than the center point, the dresser and the grinding wheel are rotated on a semicircular trajectory drawn with a radius of R_1 + R_3 around the center point of the dresser, A method for forming a shape on an actual machine of a grinding wheel, characterized by dressing the grinding surface of the grinding wheel by moving the assumed center point of the grinding wheel while maintaining parallel axes of rotation.