SU1703396A1 - Method of depth grinding with dressing of grinding wheel - Google Patents

Abstract

The invention relates to mechanical engineering, and more specifically to metal cutting. The purpose of the invention is to increase productivity and accuracy of processing. The right diamond roller 6, mounted on the spindle 5 of the carriage 4, is set to the distance Lot working surface of the grinding wheel 3 mounted on the spindle 2 of the grinding headstock 1. Table 7. on which the workpiece 9 is attached to the tool 8 is attached to the speed longitudinal feed UD. When the grinding wheel 3 is embedded in the part 9 at the moment when the distance from the lower point A on the grinding wheel 3 forming the final surface of the part 9 to its face 13 is a, the carriage 4 with the diamond roller 6 is moved. at a set depth of edits. Spacing a d (vfl / S06 n) + s. where a is the distance from the lower point A of the grinding wheel 3 to the end surface 13 of the part 9, on reaching which include the supply of the right tool, mm; S06 feed right diamond roller 6 per revolution of the grinding wheel 3 mm / rev; n is the frequency of rotation of the grinding wheel 3, rpm; c is the error determined by the characteristics of the tracking drive drive system of the right-handed tool, mm. Simultaneously with the movement of the carriage 4, the grinding headstock 1 descends with the feed Y set by the CNC to the amount of wear of the grinding wheel 3. Thus, point A is at a constant distance from the surface of the table 7. When the point A reaches the face of the part 9, the carriage 4 is fed disconnect. Next, the part 9 is machined with a filled grinding wheel, which forms the final profile. 4 il. ate with 4 o ca cj o o

Description

The invention relates to mechanical engineering and can be used in the processing of shaped parts of the exact profile using the methods of plunge grinding.

The aim of the invention is to increase the productivity and accuracy of processing.

FIG. 1 shows the processing scheme before the start of the working stroke; in fig. 2 - the same at the time of the start of editing; in fig. 3 - formation of the surface of the part; 4 shows the profile of the machined part.

To carry out the proposed method, the grinding headstock 1 contains a spindle 2 with a grinding wheel 3 and a carriage 4 with a spindle 5, on which a right-hand diamond roller 6 is fixed. On the table 7 of the machine there is a fixture 8 with the workpiece 9 having a length d. The maximum value of the stock of the part 9 is t. In this case, the calculated length of the contact arc of the grinding wheel 3 with part 9 is defined as

1kR, where DK is the diameter of the grinding wheel.

However, with a small length d, as well as in the process of embedding and exiting, the actual length of the contact arc (to the grinding wheel 3 with part 9 is less than the calculated one. Before grinding, the part 9 has flat surfaces 10. At the beginning of the working stroke of the table 7, the correct diamond roller 6 is set to distance Dog of the surface of the grinding wheel 3. The value of A is determined by the release of the spindle 2 when machining the grinding wheel 3 with parts 9. On the working surface of the wheel 3, for example, when it is replaced, a profile must be formed that corresponds to the profile the surface 11 of the finished part 9. The movement of the grinding headstock 1, the carriage 4 with the right-hand roller b and the angle 7 with the part 9 fixed on it is carried out from a numerical control unit (CNC) in accordance with the commands specified in the control program frame.

Table 7 is attached to the speed of the longitudinal feed beats. A coolant is supplied through the nozzle 12 to cool the treatment zone.

As the part 9 is pushed into the flat surface 10, the circle 3 wears out, its profile loses its accuracy, and the grinding forces and elastic deformation of the spindle 2 increase at the same time, due to which the grinding wheel 3 is brought to contact with the diamond roller 6. The CNC controls the position of the table 7, at the moment when the distance from the end surface 13 of the part 9 to the lower point A of the grinding wheel 3

becomes equal to a, turns on the drive / moving carriage 4 with a diamond roller 6 in the direction of the grinding wheel 3 by the amount of dressing depth specified in the control program frame. At the same time

with the movement of the carriage 4 of the CNC, controlling the current diameter D of the grinding wheel 3, lowers the grinding headstock 1 with a feed of Y equal to the value of the carriage of the carriage 4 5o- Thus, the lower point A

on the working surface of the grinding wheel 3, in which the final surface 11 of the part 9 is formed, remains at a constant distance b from the base surface of the table 7.

The distance a is chosen from the following considerations. In order to avoid occurrence of a surface 11 that is not uniform in quality, the part 9 must be corrected before its formation. Besides,

when forming the surface 11, the circle 3 must be worn as little as possible, therefore, before the beginning of the straightening, from the part 9 it is necessary to remove the maximum amount of the stock material. Therefore, the feed of the carriage 4 must stop at the moment when the point A of the grinding wheel 3 touches the end surface 13 of the part 9. The moment of turning on the drive of the feed of the carriage 4 is determined by the time t

to edit the grinding wheel 3 by the value of d. The signal to turn on the drive of the carriage 4 gives the CNC, which constantly controls the position of the table 7. The CNC gives a signal to the movement of the carriage 4 when

the table 7 reaches a certain position in which the distance from the end surface of the part 9 to the point A of the grinding wheel 3 is equal to a g beats + c,

where g is the time of editing, min;

St. - longitudinal feed parts, mm / min; c is the error determined by the characteristics of the carriage 4 feed drive with the right diamond roller 6, mm.

Editing time can be calculated as

g- "

Soen

where d is the thickness of the layer of material removed during dressing from the grinding wheel 3. mm;

S06 - carriage feed 4 per revolution of the grinding wheel 3, mm / rev;

n is the frequency of rotation of the grinding wheel 3, rpm.

We finally have

VA

+ C.

Goiter g

After the end of the straightening, at the moment when the point A of the grinding wheel 3 contacts the face of the part 9, the carriage 4 stops, while the diamond roller 6 is in contact with the circle 3. micro-correction of its working surface is performed. The final surface 11 is formed by an unworn grinding wheel 3, therefore the machining accuracy is improved. When the grinding wheel 3 comes out of contact with the workpiece 9, the grinding force gradually decreases. The grinding wheel 3 is moved away from the diamond roller by the elastic force. At the end of processing, the distance L is set from it. Before processing the next part, it is not necessary to edit the grinding wheel, as there is no great demands on the accuracy of the profile.

In the known machines, when the working body is accelerated, the CNC Unit generates a gradually increasing speed setting, and when braking it gradually decreases. The acceleration (deceleration) time is selected when the machine is tuned by setting the jumper pin.

For the LS-220 machine in the range of carriage feeds up to 25 mm / min, the time setting is 0.0008 minutes. The total time required to accelerate and decelerate the carriage is Tr. 2ty 0,0016 min. The value с is defined as the distance that the table will cover during the time t gr .:

C Tr. Ud.

/

-

So, for the case of machining a part with a table speed UD 150 mm / min: n 1000 rpm; Goiter 0.002 mm / rev and when moving the carriage equal to the depth of the edit (3 0.1 mm. On the machine

Claims (1)

5 times the joint time of 0.0008 minutes, the value of 7.74 mm, the value of c - 2.0,0008.150 0.24 mm. The invention of the method of deep grinding with grinding wheel for one working 10 the table travel, at which the grinding wheel is fed to the plunge, and the right tool is set relative to the grinding wheel with a gap defined by the value before machining. 15 elastic displacement of the wheel during grinding, characterized in that, in order to increase productivity and machining accuracy, the grinding wheel is edited at the end of the cutting process 20 into the part, for which the supply of the right tool in the direction of the grinding wheel includes when the table reaches a position at which the distance a from the lower point of the grinding wheel to the face of the part 25 equals a + c, Bob n and turn off when the butt reaches the detail of the lower point of the circle, where g is the specified amount of depth, mm; UD - longitudinal table feed, mm / min; 5Ob the right tool feed per revolution of the grinding wheel, mm / rev; 35p is the rotational speed of the grinding wheel, rpm; c is the error determined by the characteristics of the drive drive of the right tool, mm. thirty