JPS5856130Y2 - Current position display device of the whetstone head - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a display device that displays the current position of a grindstone head based on the dimensions of a test-ground workpiece.

Conventionally, there have been display devices that display the current position of the grindstone head, but the position of the whetstone head is displayed based on the position of the tip of the grindstone dressing tool.

To explain this with reference to FIG. 1, the tip position of the dressing tool 3 provided on the headstock 2 is
Accurate position relative to the workpiece support center by both centers (
The dressing tool 3 is dressed by cutting the grindstone 4 by a predetermined amount into the dressing tool 3.
The current value displayed on the wheelhead position indicator 5 is set to the reference dimension, and the displayed value is changed for each unit movement amount of the wheelhead.

As a result, even if the position of the dressed grinding surface of the grinding wheel changes due to the feed of the grinding wheel head, the dimensions (diameter dimensions) of the workpiece to be machined by the grinding surface are displayed on the display 4.
The operator controls the feed of the grindstone head while looking at the displayed value, and when the finishing dimensions of the workpiece and the displayed value match, the worker stops feeding the grindstone head, and the workpiece with the regular dimensions can be finished.

In such conventional devices, when the tip position of the dressing tool changes due to wear, the change appears as a machining error.

For this reason, not only is it necessary to frequently reset the position of the tip of the dressing tool, but if there is an error in this setting, this will also be included in the machining error.

In addition, this method was effective for conventional grinding wheels, but in recent years, grinding wheels using hard abrasive grains such as cubic boron nitride have appeared, and it has become impossible to dress them with conventional dressing tools. It's here.

In a grindstone using such hard abrasive grains, for example, dressing may be performed using loose abrasive grains and a roller or the like that backs up the loose abrasive grains, and the surface of the roller is likely to wear.

For this reason, displaying the position of the grindstone head based on the dressing tool would result in large errors and would be impractical.

Instead of this, the present invention attempts to set the reference position using the dimensions of the trial-ground workpiece, and is characterized by a structure that allows the dimensions of the trial-ground workpiece to be easily set as the reference position.

In other words, in order to accurately measure the dimensions of the test-ground workpiece,
Alternatively, in order to ensure the safety of the measurement work, move the grindstone head back and forth quickly without changing the displayed value at the trial grinding position, measure the workpiece measurement dimensions in this retreated state, set the measured value on the display, and fast-forward. After moving forward by the same amount as the amount of retreat,
For the first time, the displayed value is changed according to the amount of movement of the grindstone head.

Therefore, the operability of setting the test-ground workpiece dimensions as a reference position is improved, and operational errors can be prevented.

The details of the present invention will be explained below based on the drawings.

FIG. 2 shows the feed mechanism of the grindstone head. A feed screw 13 is screwed into a nut fixed to the lower surface of the whetstone head 11 on which the whetstone 10 is rotatably mounted. One end of this feed screw 13 is connected to the bed 1.
It is supported by a slide base 15 mounted on a slide base 15 and connected to a feeding servo motor 16 via gears 17 and 18.

The rotation of this servo motor 16 is controlled according to the feed command pulse, and a pulse motor, a direct current motor, or the like can be used.

FIG. 3 shows a control circuit for controlling the rotation of this servo motor 16, and FIG. 4 shows an example of an operation panel.

As provided on the operation panel, 20 is a current position indicator, 21 is a setting device for the dimensions of the trial-ground workpiece, 22 is a set button thereof, 23 is a setting device for rapid forwarding and backward amount,
24 is a fast forward forward start button for the grinding wheelhead, 25 is a fast forward backward start button, and 26 is a manual pulse generator.

Control circuits not on the operation panel include a drive circuit for the servo motor 16 at 27, a fast-forward pulse generation circuit at 28, and a fast-forward pulse generation circuit at 29.
30 is an addition/subtraction counter connected to the current position indicator 20 and the work size setting device 21, and 30 is the setting device 23, counter 31. A fast forward stop detection circuit consisting of a comparator 32, 33
is a flip-flop that is set by the fast-forward forward button 24 and fast-forward backward button 25 and reset by the fast-forward/stop detection signal COM, and this flip-flop constitutes a fast-forward stop circuit that stops the transmission of fast-forward pulses.

Reference numeral 34 denotes a gate circuit that supplies command pulses to the addition/subtraction counter 29 except during fast forwarding.

The manual pulse generator 26 generates pulses proportional to the rotation angle by rotating the bundle 26a, but in addition to such a manual pulse generator, pulses at a preset frequency are transmitted while a button is pressed. It is also effective to provide a jog feed circuit.

The fast forward pulse generating circuit 28 is connected to the speed setting volume 2.
The voltage of 8a is applied to the voltage frequency converter 28C via the analog game (28b), and a fast forward pulse is generated from the output terminal.

Analog game) 28b is opened when the flip-flop 33 is set by the fast forward command button 24 or 25, and the voltage frequency converter 28C generates a pulse train with a frequency proportional to the applied voltage, and the fast forward forward command R,
If it is ADV, the gate 35 is opened and a forward command pulse is sent out.

If it is a fast forward backward command R, RET, the gate 36 is opened and a backward command pulse is sent out.

In either case, the gate 34 is in fast forward mode.
is not opened and no fast-forward pulse is given to the addition/subtraction counter 29, but the servo motor drive circuit 27 and the counter 31
is given to

The counter 31 is reset and starts counting when the signal A at the reset terminal becomes L due to the setting of the flip-flop 33.

When the set value of the setter 23 and the contents of the counter 31 match, a match signal COM is output from the comparator 32, the flip-flop 33 is reset, and fast forwarding is stopped.

By resetting the flip-flop 33, the counter 3
The signal A given to the reset terminal of No. 1 becomes H again,
Further, the H signal A is also applied to the gate 34.
Open 4.

Thereafter, when the bundle 26a of the manual pulse generator 26 is turned, a feed command pulse is given to the servo motor drive circuit 27 and the addition/subtraction counter 29.

Therefore, the current position according to the movement of the grinding wheel head 11 is displayed on the display 20.
will be displayed.

Incidentally, a pulse is also given to the counter 31, but since the signal A remains at H, the reset state is not released and no counting is performed.

Next, a procedure for setting the trial-ground machining dimensions as a reference position will be explained.

First, it is assumed that an appropriate value is set in the setting device 23 for the fast forward amount.

When the fast forward forward button 24 is pressed, the grindstone head 11 moves forward and stops just before it comes into contact with the workpiece.

Thereafter, the bundle 26a is rotated to feed the grindstone head and trial grind the workpiece.

The current position of the grindstone head after this trial grinding is displayed on the display 20, and this display value is temporarily set as Dl.

When the fast forward/reverse button 25 is pressed, the grindstone head 11 changes to the setting device 23.
Although the vehicle moves backward by a certain amount set in , the display value D1 does not change.

The dimensions of the test-ground workpiece are accurately measured using a micrometer, etc., and when the measured value D1' (D, +a) is set in the setting device 21 and the set button 22 is pressed, the measured value is preset in the addition/subtraction counter 29. , D1' is also displayed on the display 20 at the same time.

When the fast forward advance button 24 is pressed again, the grinding wheel head is rapidly moved forward by a certain amount and returns to the trial grinding position, and the displayed value D1' on the display 20 matches the current position of the grinding wheel head, which becomes the reference position.

As a result, when the grindstone head 11 is fed by turning the nozzle 26a, the dimensions of the work to be ground by the grindstone are always displayed on the display 20.

This kind of reference position setting operation can be performed when dressing the grinding wheel and is based on the test-ground workpiece dimensions, so there is no error in current position display due to setting error of the dressing tool as in the past. .

Furthermore, if the grindstone uses the hard abrasive grains, the wear of the grindstone is small, the workpiece is always machined to the dimensions displayed on the display 20, and there is an effect that almost no processing errors occur.

[Brief explanation of drawings]

Figure 1 shows a conventional example and is based on the position of the tip of the dressing tool. Figure 2 and the following diagrams show an embodiment of the present invention. Figure 2 shows the main part of the feeding mechanism of the grindstone head. A vertical sectional view, FIG. 3 is a block diagram of a control circuit, and FIG. 4 is a diagram showing an example of an operation panel. 11... Grindstone head, 16... Servo motor, 20...
・Current position indicator, 21... Trial grinding workpiece size setting device, 22... Set button, 23... Rapid traverse position setting device, 24... Rapid traverse forward start button, 25... Rapid traverse backward start button , 26... manual pulse generator, 28
...Fast forward pulse generation circuit, 34...Gate circuit.

Claims (1)

[Scope of utility model registration request] A servo motor that controls the feed of the grindstone in accordance with the feed command pulse, an addition/subtraction counter that counts the command pulses given to the servo motor, and a machining dimension setting device that sets the machining dimensions of the test-ground workpiece to the addition/subtraction counter. ,
a current position indicator that displays the count value of the addition/subtraction counter as the current position of the grinding wheelhead; a fast-forward pulse generating circuit that sends a fast-forward command pulse for the grinding wheel head; a setting device that sets a fast-forward movement amount; a fast-forward stop detection means that counts and compares the fast-forward movement amount set in the setting device and outputs a fast-forward stop signal; a fast-forward stop circuit that stops the transmission of the fast-forward pulse according to the output signal of the fast-forward stop detection means; A grinding wheel head comprising a manual feed pulse generating means for manually feeding the grinding wheel head, and a gate circuit for feeding only the command pulse given from the manual feeding pulse generating means to the servo motor to the addition/subtraction counter. current position display device.