JPS649138B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a crankshaft grinding wheel that has a shape different from the finished shape of a workpiece in order to grind a crankshaft, and its purpose is to grind a crankshaft. The purpose is to prevent the corners of the wheel from sagging during processing.

Generally, when grinding the pin part or journal part of the crankshaft, the corner part G2 of the grinding wheel G,
In the straight part G1, there is a large difference in the contact state with the workpiece. For example, as shown in FIG.
However, while the corner portion G2 is in contact with the shoulder portion W3 and the corner portion W2 of the workpiece W while the grinding wheel G strokes the distance L2, such a contact state Because of the difference, the corner portion G2 of the wheel is more likely to wear than the straight portion G1.

In particular, as shown in Fig. 2, the corner G2 of this grinding wheel G has a radius R1 (radius of about 3.5 mm) from the point of connection between the straight part G1 and this straight part to an angular position of 75 degrees.
A circular arc portion G4 bent at 75 on this circular arc portion G4
It consists of a tangent part G5 extending in the tangential direction of this circular arc part G4 from the angular position of 100 degrees, and when the shoulder part W3 has a large grinding allowance, the terminal part of this tangent part G5, that is, the tangent part G5 and the side surface G6. Significant wear or sagging occurs at the joints as shown by diagonal lines. This sag is directly transferred to the grinding surface of the workpiece, creating irregularities at the corner W2 of the workpiece, which has the disadvantage of making it impossible to grind into a uniform arc shape.

The present invention has been made in order to eliminate such problems in the conventional art. For example, as shown in FIG. This invention relates to a crankshaft grinding wheel that has a bulge G7 that gradually increases in thickness and does not protrude from the extension line to prevent the wheel from sagging during grinding.

An example of a grinding wheel correction device used for crankshaft grinding according to the present invention will be explained below with reference to FIGS. 4 and 5. In the figure, reference numeral 10 denotes a base;
A traverse table 11 is mounted so as to be slidable in a traverse direction parallel to the axis of the grinding wheel G, and a traverse cylinder device 12 mounted on a base 10
It is designed to be traversed by.
Reference numerals 13 and 14 are regulating members that regulate the forward end and the backward end of the traverse table 11, respectively.

A copying main body 15 is mounted on the traverse table 11 so as to be slidable in a copying direction perpendicular to the traverse direction. A ram 16 is installed on the copying main body 15 so as to be able to slide in the same direction as the copying main body 15. A tool stand 17 is integrally fixed to the tip of this ram 16, and a grinding wheel G is mounted on this tool stand 17. A correction roll 18 made of a diamond roll for correction is rotatably supported and rotationally driven by a motor 19. A cutting device 20 is attached to the rear end of the copying main body 15. A feed screw shaft 21 of this cutting device 20 is screwed to the rear end of the ram 16, and by rotating the feed screw shaft 21, the correction roll 18
It is designed to give cutting feed to.

Further, a support block 22 is integrally fixed to the rear lower end of the copying main body 15, and a stylus 24 that contacts the template T is fixed to the support block 22. Template T has the 6th
As shown in the figure, a straight section T1 is formed in the center according to the shape of the grinding wheel G to be corrected, and arcuate sections T4, T4 are formed at both end corners of the straight section T1, which are continuous with the arcuate sections T4, T4. Tangent line portions T5, T5 and guide portions T6, T6 are formed, and the stylus 24 is moved following this template T.

In order to control the contact state between the stylus 24 and the template T, a copy cylinder device 25 and a lift cylinder device 26 are fixed on the traverse table 11 as shown in FIG. This copying cylinder device 25 brings the stylus 24 into contact with the template T with a constant contact pressure. A piston 27 is slidably fitted into the cylinder device 25, and a piston rod 28 of the piston 27 is inserted into the cylinder device 25. Copying body 15
is connected to. Also, the lift cylinder device 2
6 is the straight line part T1 from the circular arc part T4 of the template T
In order to make it easier to ride the stylus 24 onto the template T, as shown by the solid line in FIG.
A piston 29 is slidably fitted into the lifting cylinder device 25, and the piston rod 30 is in contact with the piston 27 of the copying cylinder device 25. . An adjustment knob 31 for adjusting the piston stroke is screwed onto the other piston rod 30 of the lift cylinder device 26.
This adjustment knob 31 is used to adjust the lift position of the stylus 24. Further, a stop bolt 32 is provided opposite to this piston rod 30, and this stop bolt 32
The profiling forward end of the stylus 24 is regulated by the stylus 24.

Next, a wheel repairing process using the above-mentioned wheel repairing device will be explained.

First, in the original position, the stylus 24 is moved by the copying cylinder device 25 to the upper right side, away from the template T shown by the solid line in FIG. It is located in Therefore, when pressure oil is supplied to the traverse cylinder device 12 and the traverse table 11 is slid leftward in FIG. 4, the stylus 24 will eventually move to the template T.
It engages with the middle position of the circular arc part T4, and
4 to the straight section T1 smoothly.
Correcting roll 18 according to the movement of this stylus T
moves following the shape of the template T, and corrects a part of the circular arc portion G4 and the straight portion G1 of the grinding wheel G into the required shape. When the stylus 24 moves to the center position indicated by the imaginary line S1, the shift cylinder device 26 is switched in the opposite direction by a signal from a limit switch (not shown), and its piston 29 is moved until it comes into contact with the stopper bolt 32.

In this state, when the traverse table 11 is further moved to the left, the stylus 24 moves to the other arcuate portion T of the template T, as shown in FIG.
4, and the correction roll 18 corrects the circular arc portion G4 of the grinding wheel G into a predetermined shape by following this template shape. And the stylus 24 is S2
When the stylus 24 moves to a position immediately before the end of the arc portion G4, the piston 27 of the copying cylinder device 25 comes into contact with the piston rod 30 of the lift cylinder device 26, and the forward motion of the stylus 24 is stopped. In the case of normal copying motion of the stylus 24, the stylus 24 moves to the Sx position and the correction roll 18 moves to the Dx position, so that the cutting wheel G has the same shape as the stylus T, that is, as shown in FIG. However, as the stylus 24 stops moving forward, the tangential portion G5 becomes a radius R2 (radius) of the cross-sectional shape of the correction roll 18 as shown in FIG. As a result, the corners of the grinding wheel G have a maximum thickness of 0.09 to 0.1 mm on the side G6 side, as shown by the diagonal line, and the tangential part from this side G6 side. A bulge G7 is formed whose thickness gradually decreases toward G5. As described above, this bulge G7 prevents the grinding wheel G from drooping and improves the grinding performance.

After correcting the arcuate portion G4 on the left side of the grinding wheel G into the desired shape, the traverse table 11 further slides to the left in FIG. 4, and as a result, the stylus 24 separates from the template T as shown in FIG. It continues to move leftward to the S3 position, and at the same time, the correction roller 18 is also positioned to the D3 position. At the leftward end of the traverse table 11, the stylus 24 is lifted by the lift cylinder 26 to the S4 position in FIG.
It is located in the 4th position. After that, the traverse table 11 starts moving to the right, and the stylus 24 moves sequentially through the S5 and S6 positions again in the same manner as described above, and the correction roll 18 also moves sequentially through the D5 and D6 positions to touch the right corner of the grinding wheel G. It is corrected in the same way as the left corner of the grinding wheel G, and then returned to the original position shown by the solid line to complete the series of correction cycles.

By moving the wheel G corrected in the above correction step forward toward the workpiece W that is being rotated, as shown in FIG. The object W can be processed.

As mentioned above, in the present invention, a bulge is formed at the end of the side surface of the tangential part of the wheel, the thickness of which gradually increases from the tangent line toward the extension line of the side surface of the grinder, and which does not protrude from this extension line. This method has the advantage of preventing the occurrence of droop in the grinding wheel during grinding of the crankshaft, improving the profile accuracy of the workpiece, and significantly extending the life of the grinding wheel.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the state of grinding the pin portion of a crankshaft, Fig. 2 is an illustration showing the shape of the corner of a conventional crankshaft grinding wheel, and Fig. 3 is a diagram showing the shape of a corner of a conventional crankshaft grinding wheel. Diagram showing the shape of the corner part, 4th
The figure is a plan view showing an example of the device for forming a desired shape according to the present invention, FIG. 5 is a sectional view taken along the line -- in FIG. 4, and FIG. FIG. G...wheel, T...template, G7...
Bulge, 11...Traverse table, 15...
...Copying body, 16... Ram, 18... Correction roll.

Claims (1)

[Claims] 1 A straight line part parallel to the crankshaft processing surface,
A circular arc portion bent at a constant curvature from a connecting point with this straight portion, a tangent portion extending in a tangential direction of this circular arc portion from a predetermined angular position of this circular portion, and a connecting point with this tangent portion to the straight portion. In a wheel for grinding a journal or pin portion of a crankshaft having a grinding surface consisting of a side surface extending in a direction perpendicular to 1. A crankshaft grinding wheel, characterized in that a bulge is formed in which the bulge is increased and does not protrude from an extension line of the side surface.