JPS6411422B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a grinding wheel that is movable along the axis of rotation of a workpiece and can be fed in a radial direction depending on the outer circumferential surface to be ground. This invention relates to a device that rotatably attaches a workpiece and grinds a rotationally symmetrical workpiece.

In profile grinding of a rotating body, a grinding wheel whose external shape corresponds to the contour to be ground has been conventionally used. Grinding wheels with a width similar to the contour to be ground are used under so-called line contact and must be ground while pressing with correspondingly strong radial forces, resulting in The drawback was that the coolant did not work optimally. In order to suppress the temperature rise of the workpiece, a relatively low grinding speed is generally used, partly due to the large weight of the grinding wheel, which results in a relatively long machining time, which reduces the cost of grinding the workpiece. The result was a considerable increase.

In addition, Japanese Patent Application Laid-open No. 55-5258 discloses that when the contact angle part of the grinding wheel that contacts the material to be ground wears out, the rotating shaft of the grinding wheel and the part of the material to be ground are A device has been disclosed that can change the angle of intersection of the material with the surface to be ground, but this device can only be used under line contact.

The object of the present invention is to provide a grinding method and device that allows all workpieces to be ground carefully and in a short time, and that, on the other hand, the grinding wheel wears uniformly in successive layers along its circumferential surface. The goal is to provide the following.

In order to achieve the above-mentioned object, in the method of the present invention, the grinding wheel is advanced along the axis of rotation of the workpiece and is displaced radially according to the circumferential contour to be ground. In a method of grinding a rotationally symmetrical workpiece fixed to a grinding machine so that it can rotate around a vertical axis, the inclined front surface of the grinding wheel engages and grinds the workpiece, and the generatrix of the grinding wheel and the workpiece The finished ground surface is formed by forming a relief angle with the circumference of the workpiece surface and making contact at a point that is in the area of the finished diameter of the workpiece and on a line perpendicular to the longitudinal axis of the workpiece. It was ground so that it was no longer captured by the grinding wheel, and when the grinding was finished the grinding wheel was in contact only at the points mentioned above.

In the grinding device for carrying out the above method, the grinding wheel has an inclined front surface that engages with the workpiece, the generatrix of the grinding wheel extends with a relief angle to the surface to be machined of the workpiece, and It is configured so that it contacts the finished surface in a dotted manner.

The relief angle described above can be formed by reshaping the grinding wheel into a conical shape. It can also be formed by modifying the grinding wheel into a cylindrical shape, with its axis at an angle greater than zero with respect to the longitudinal axis of the workpiece. Furthermore, it can also be formed by arranging the axis of the grinding wheel so as to be inclined horizontally and vertically to the axis of the workpiece.

Next, the present invention will be described in detail by way of examples based on the accompanying drawings.

The plan view of FIG. 1 shows a state in which a grinding body, which is a narrow grinding wheel 2, is grinding a workpiece 1, which is a rotationally symmetrical rotating body. The rotation axis 2a of this grinding wheel 2 is horizontally inclined by an angle β with respect to the axis 4 of the workpiece 1. The rotating shaft 2a of the grinding wheel 2 is connected to the workpiece 1
The angle α shown in the front view of FIG. 2 is obtained by tilting perpendicularly to the axis 4 of

How the inclination of the grinding wheel 2 with respect to the workpiece 1 functions during grinding will be explained with reference to FIGS. 3 and 4. In FIG. 3, which shows a case where the wear of the grinding wheel 2 is 10%, the grinding wheel 2 having a generally flat outer circumferential surface is working at a certain corner to remove a portion S of the workpiece 1. The grinding wheel 2 is initially formed with an inclined front surface F, with which it acts on the removed portion L of the workpiece 1. On the other hand, due to the above-mentioned special arrangement of the grinding wheel 2 with respect to the workpiece 1, there is a slight clearance between the linear generatrix M of the grinding wheel 2 and the circumferential line U where the grinding of the workpiece 1 has been completed, although it cannot be shown in the figure. Since the corners are formed, once the circumferential line U has completed grinding, it no longer comes into contact with the grinding wheel 2. In this case, a considerable part of the pressure of the grinding wheel 2 is transmitted in the axial direction through the portion L in FIG.
It acts on the workpiece 1 only at the points indicated by the reference numeral 1a in FIGS. The inclined front surface F of the grinding wheel 2 moves against the forward direction of the grinding wheel 2 and toward the free edge of the grinding wheel 2 due to wear caused by grinding, and the grinding wheel is worn down to 80% in the form of layers. In Figure 4, which shows the state,
It has moved to the point indicated by F ₁ .

Fig. 6 to Fig. 8 show wear of the grinding wheel and schematic diagrams. The relief angle formed between the linear generatrix M of the grinding wheel 2 and the circumferential line U of the workpiece 1 that has already been ground is not shown. U ₁ is the part of the workpiece that is about to be ground. According to FIG. 6, the inclined front face F of the grinding wheel 2 acts on the working layer B of the workpiece 1 in accordance with the desired grinding depth S. The two arrows indicate the radial infeed and axial movement of the grinding wheel 2 relative to the workpiece 1. In the process of grinding, the diameter of the workpiece 1 is reduced by twice the grinding depth S, and the grinding wheel 2 is sequentially worn in layers corresponding to the grinding depth S. During actual grinding, most of the grinding pressure acts in the axial direction;
The radial component of this force is transmitted from the grinding wheel 2 to the workpiece 1 exclusively at 1a. Since the grinding wheel 2 thus makes point contact with the workpiece 1 at the point 1a, the workpiece 1 itself is not subjected to a large radial pressure. Point 1a
is on a line perpendicular to the axis of the workpiece 1 and is at the position where the workpiece 1 has just finished being ground by the grinding wheel 2. The wear of the grinding wheel 2 is determined by the grinding depth S as described above.
occurs uniformly in the form of a layer corresponding to , so that the grinding wheel does not need to be reconditioned or replaced unless this layer has been completely removed. As long as portions X ₁ or X ₂ (see FIGS. 3 and 4) of the outer circumferential surface of the grinding wheel 2 are available for grinding, there is no need for constant reshaping, unlike in conventional grinding methods.

The proposal according to the invention makes it possible to carry out very careful high-speed profile grinding of workpieces. This is because, unlike the known cylindrical grinding method, where more than 90% of the force acts at right angles to the axis of the workpiece, the radial force is based on the point contact between the grinding wheel 2 and the workpiece 1 at point 1a; This is because it acts exclusively through this point, whereas most of the force is transmitted in the axial direction by the inclined front face F of the grinding wheel 2.

FIGS. 9 and 10 show schematic diagrams of the arrangement of the grinding wheel relative to the workpiece. According to FIG. 9, a clearance angle α is shown, as a result of which the part of the grinding wheel in the area of the finished diameter of the workpiece 1 no longer engages with the already cut surface. There is no. When the grinding wheel 2 is moved in the direction of the arrow shown in FIG. 9 with respect to the rotating workpiece, the grinding wheel 2 moves to the inclined front surface F.
It is clearly shown here that the wear is uniform in layers along the

The grinding wheel 2 acts exclusively on the workpiece 1 through point 1a to complete the finished diameter, while the remaining grinding force is applied via the inclined front face F of the grinding wheel 2 to the outer circumference of the workpiece to be removed. This effect is clearly seen in the illustration of FIG.

One method of profile grinding is shown in FIG. The twisted arrangement of the axis of rotation 2a of the grinding body and the axis 4 of the workpiece can be seen in this figure. In this case, a programmable computer numerically controlled grinding machine is used, with the axial and radial feed of the grinding wheel also being controlled by the computer 9 program. This makes it possible to guide the grinding wheel very precisely according to the desired contour.
The contour illustrated in FIG. 5 can be machined around the workpiece without much effort.

Describing the effects obtained by the present invention,
First, tool costs can be reduced, and grinding time can be significantly shortened (approximately 10 to 25%) with extremely low heat generation. When using a flat grinding wheel, cooling is much more intensive than before, which not only avoids heat build-up within the workpiece, but also avoids subjecting the workpiece to extreme radial grinding pressures. Firstly, the working surface of the grinding wheel that engages the workpiece per unit time is relatively small, and most of the grinding pressure is transmitted in the axial direction. Unlike conventional grinding, the force acting perpendicular to the axis is small, and this force only acts at one point on the workpiece's circumference, perpendicular to the workpiece's axis, making it possible to achieve relatively high cutting speeds. Can be used. Another advantage is that the grinding wheel wears evenly in a thin layer to one side. For this reason, it is numerically ascertained when a layer is removed from the periphery of the grinding wheel and it is time to reface it. If the grinding wheel is coated with borazon, the life expectancy is greatly increased.

By arranging the grinding wheel obliquely or torsionally with respect to the workpiece to be machined, a clearance angle is created between the generatrix of the grinding wheel and the circumferential line of the workpiece, so that the grinding wheel cuts only at predetermined points. It acts on the object, but other parts of the grinding wheel are not in contact and are empty, so it is impossible for the grinding wheel to re-grind areas that have already been ground during the subsequent grinding process. According to the invention, the inclined front face of the grinding wheel acts on the workpiece depending on the desired infeed depth, but the final diameter of the workpiece is ground by the grinding wheel exclusively in point contact.

[Brief explanation of drawings]

Figure 1 is a plan view with the rotational axis of the grinding wheel tilted horizontally to the vertical axis of the workpiece, and Figure 2 is a plan view with the rotational axis of the grinding wheel tilted perpendicular to the longitudinal axis of the workpiece. Figure 3 is a partial enlarged view of Figure 1 with the grinding wheel worn by 10%, Figure 4 is a partial enlarged view similar to Figure 3 with a higher degree of wear on the grinding wheel, and Figure 5 is a partial enlarged view of Figure 3 with the grinding wheel more worn. Schematic representation of a grinding wheel applied to a rotationally symmetrical workpiece; Figures 6, 7 and 8 are schematic plan views of various different plan views showing how the grinding wheel wears; Figure 9 is a diagrammatic representation of a grinding wheel applied to a rotationally symmetrical workpiece; FIG. 10 is a partial view of the workpiece and the grinding wheel in which the clearance angle α is created due to the inclination of the wheel, and FIG. 10 is a front view of the workpiece and the grinding wheel as seen from arrow A in FIG. 1... Workpiece, 2... Grinding wheel, 2a... Rotating axis of grinding wheel, 4... Vertical axis of workpiece, α... Clearance angle, S... Grinding depth, F... Inclined front surface of grinding wheel, M... Grinding wheel's Bus line,
U...Circumferential line of the grinding surface of the workpiece.

Claims (1)

[Claims] 1. Advance the grinding wheel along the rotation axis of the workpiece,
A method for grinding a rotationally symmetrical workpiece fixed to a grinding machine so as to be rotatable about the longitudinal axis of the workpiece by displacing it in the radial direction according to the peripheral ring to be ground, the grinding wheel The inclined front surface of the wheel engages and grinds the workpiece, forming a clearance angle between the generatrix of the grinding wheel and the circumferential line of the grinding surface of the workpiece, which is in the finished diameter area of the workpiece and By making contact at a point on a line perpendicular to the longitudinal axis, the finished ground surface is ground in such a way that it is no longer captured by the grinding wheel, and that at the end of grinding the wheel makes contact only at said point. A method for high-speed grinding of rotationally symmetrical workpieces. 2 Advance the grinding wheel along the rotation axis of the workpiece,
In a device for grinding a rotationally symmetrical workpiece fixed to a grinding machine so as to be rotatable about the longitudinal axis of the workpiece by displacing it in the radial direction according to the circumferential contour to be ground, the grinding wheel is characterized in that it has an inclined front surface that engages with the workpiece, and the generatrix of the grinding wheel extends with a clearance angle to the workpiece surface and contacts the finished surface of the workpiece in a point-like manner. A high-speed grinding device for rotationally symmetrical workpieces. 3. The high-speed grinding device according to claim 2, wherein the clearance angle is formed by reshaping the grinding wheel into a conical shape. 4. According to claim 2, the clearance angle is formed by reshaping the grinding wheel into a cylindrical shape and making the rotating axis of the grinding wheel at an angle greater than zero with respect to the longitudinal axis of the workpiece. High speed grinding equipment as described. 5. Claims 2 and 3, wherein the relief angle is formed by arranging the axis of the grinding wheel horizontally and vertically with respect to the axis of the workpiece.
Or the high-speed grinding device according to item 4.