JPH03245969A - Traverse grinding method - Google Patents

Abstract

PURPOSE:To perform finishing of a good surface roughness of a specular finishing, etc., in a short time, by varying the feeding speed of a traverse cut grinding time irregularly within a preset range. CONSTITUTION:When a grindstone is approached to the work face of a work by the rapid feeding command of NC and the traverse grinding command including an irregular feeding command is outputted from NC, a traverse grinding is performed by changing the feeding speed of a Z axial servomotor 4 at random with a random number being generated from a random number generation part 8, within the range set by a parameter at a setting part 7. Consequently, a good finishing face can be obtained in a short time without the need for a special technique.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a traverse grinding method for a grinding machine.

Conventional technology Conventionally, workpieces with severe restrictions on surface roughness, such as a mirror finish, are generally ground using the traverse cut method, and the feed rate at this time is a selected constant speed. was common knowledge.

Problems to be Solved by the Invention In the traverse cutting method described in the prior art, since the feed rate is constant, feed marks occur on the grinding surface in cylindrical and internal grinding, and the grindstone does not hit the workpiece in surface grinding. Slight scratches on the outer periphery of the grinding wheel that occur when the grinding wheel comes into contact with each other cause phenomena that impede surface roughness accuracy, such as feed marks appearing on the grinding surface with each revolution of the grinding wheel. However, there are problems in that it requires advanced technology and time.

The present invention was made in view of the above problems of the conventional technology, and its purpose is to provide a traverse grinding method that can obtain a good finished surface in a short time without requiring special techniques. It is intended to provide a method.

Means for Solving the Problems In order to achieve the above object, the traverse grinding method according to the present invention irregularly changes the feed rate during traverse cut grinding within a preset range.

When the grinding wheel approaches the machining surface of the workpiece due to a rapid feed command of action NG, and a traverse grinding command including an irregular feed command is issued from the NC, within the range set by the parameters,
Traverse grinding is performed by randomly changing the feed rate by generating random numbers.

Example An embodiment will be described with reference to FIGS. 1 and 2.

The first [ffl is a feed shaft (2
1 is a block diagram showing an embodiment of a servo system (axis), in which part A is a part related to the present invention, and other parts are the same as a general servo system.

Fig. 2 is an example of a program for executing irregular feed traverse, in which the first 001 specifies each element of the rapid traverse approach operation to the grinding start point of the grinding wheel, and G74
Each element of traverse grinding is specified in ``Got'', and each element of the rapid backward movement to a predetermined standby position of the grindstone is specified in ``Got''.

To explain each element in the 074 directive in more detail,
AS=O is the direct and indirect automatic chamber size, AF=0 is the continuous intermittent notch method, AT=Q is the grindstone reference position, Q F =0.0
0 designates the total depth of cut. Further Q
r=0. OO means intermittent cutting amount per one time, FF=0 means cutting speed fi/layer in (diameter display) TS=0 means spark out, T T =0.0 means tarry timesee
T○=0 specifies overfeed, ZN=00 specifies the left reversal position, zp=ooo specifies the right reversal position, and FT=0000 specifies the traverse speed m/win. The last M190 is an M code that specifies irregular feeding according to the present invention, and if this symbol is not present, a constant traverse speed specified by FT will be achieved.

Next, the contents of the Z-axis servo system will be explained using the block diagram shown in FIG.

The program memory 1 is a part that stores programs read from external devices such as a tape reader unit, floppy disk, beep chair, etc., and program contents input from a keyboard.The program interpretation unit 2 reads one block worth of part programs from the program memory. The position command calculation unit 3, which interprets this and sorts it into the necessary parts, uses the position command value sent from the program interpretation unit 2 and the two-axis servo motor 4.
This is a part that compares the current position output from the position detector 5 fixed concentrically with the current position and outputs a signal to the speed command calculation section 6. The speed change range setting section 7 is a section that determines the speed change range by setting an upper limit value and a lower limit value based on parameters that are previously input and stored with the speed command value sent from the program interpretation section 2. This is the part that generates random numbers within the range of the upper and lower limits determined by the range setting unit 7 and outputs a randomly changing target speed signal. If it is not output, both the speed change range setting section 7 and the random number generation section 8 are bussed so that they do not work, and the constant value of the speed command - target speed command output from the program interpretation section 2 is The speed command calculation unit 6 compares the current speed obtained by converting the output signal of the position detector 5 by the position-speed conversion unit 9 with the target speed output from the random number generation unit 8, and calculates the current command. A part that sends a signal to part IO.The current command calculation part is a part that compares the signal from the speed command calculation part and the detection xi from the two-axis servo motor 4 and outputs a signal to the power amplification part 11. 11 is a part that supplies drive current to the Z-axis servo motor.

Next, the operation of this embodiment will be explained with reference to the flowchart of FIG. 3 and the graph of FIG. 4.

In step S1, the contents of the traverse grinding command G74 issued from the program interpreter 2 are read, and in step S
In Step 2, the presence or absence of the irregular feed command M190 is confirmed, and if YES, in Step S3, the irregular feed command M190 is determined based on the speed command The shift range is determined by setting an upper limit value and a lower limit value. Next, in step S4, the random number generator 8 generates random numbers that do not fall outside the speed range, and randomly outputs different speed commands.

In step S5, the Z-axis servo motor 4 is irregularly driven by supplying electric power corresponding to the randomly changing speed command from the power amplifying section 11, and the upper limit (iAl and lower limit) are set as shown in the graph of FIG. Perform a traverse feed rate B that varies irregularly between values A2.

If the answer is NO in step S2, then in step S5 the shift range setting section 7. The Z-axis servo motor 4 is controlled by the speed specified by the FT that has passed the random number generator 8.
is driven to execute Z transport at a constant speed.

It should be noted that the traverse grinding method of the present invention is not limited to cylindrical grinding as in this embodiment, but is of course applicable to all grinding processes performed by the traverse grinding method, such as internal grinding and surface grinding. be.

Effects of the Invention Since the present invention is configured as described above, it produces the following effects.

Traverse grinding is performed by changing the feed rate during grinding irregularly within a preset range, eliminating the phenomenon that appears on the ground surface at regular intervals that impairs surface roughness accuracy, and using special technology. Finishing with good surface roughness, such as mirror finishing, can be achieved in a short time without the need for

[Brief explanation of drawings]

Fig. 1 is a block diagram of the Z-axis servo system of this embodiment, Fig. 2 is a partial diagram of a program sheet for executing irregular feed traverse grinding, and Fig. 3 is a flowchart showing the operation of this embodiment. , FIG. 4 is a graph showing the traverse feed speed which changes irregularly within the set speed change range.

Claims (1)

[Claims] (1) A traverse grinding method characterized by irregularly changing the feed rate during traverse cut grinding within a preset range.