JPS5839613B2 - Table of Contents - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention separately electrically drives a cutting hob shaft and a table rotation shaft, and adjusts the rotation speed ratio and mutual phase relationship using electrical auxiliary means such as a pulse generator. This invention relates to a control method for the table rotation axis in a numerically controlled hobbing machine.

FIG. 1 is a control block diagram of a conventional numerically controlled hobbing machine, and 1 is a command value register that stores various input data from an NC tape.

2 is a unit movement amount determination circuit which inputs the data stored in the command value register and determines the unit movement amount ΔC of the table rotation axis; 3 stores the value determined by the unit movement amount determination circuit. This is a register for

A pulse generator 4 is coupled to the cutting hob shaft and controls the cutting hob shaft to maintain the rotation speed ratio and phase relationship between the cutting hob shaft and the table rotation shaft.

Reference numeral 5 designates an AND gate that passes the unit movement amount ΔC stored in the register 3 each time a pulse is output from the pulse generator.

6 is the unit movement amount △C that has passed through the AND gate
This is an arithmetic unit that inputs and adds the values fed back from the table rotation axis function generation circuit 7, which will be described later.

Reference numeral 7 denotes a table rotation axis function generation circuit for inputting the value output from the arithmetic unit and generating a function for driving the table rotation axis.

In such a numerically controlled hobbing machine, if the machine is stopped due to a power outage or gear dimension measurement, the phase relationship between the cutting hob axis and the table rotation axis will become unrelated, so it is necessary to restart cutting. The drawback was that it could not be done.

An object of the present invention is to control the table rotation axis in a numerically controlled hobbing machine in order to restore the mutual phase relationship between the cutting hob axis and the table rotation axis, which have become unrelated after the power is cut off or the machine is stopped, by means of phase difference correction means. The goal is to provide a method.

FIG. 2 is a control block diagram of the numerically controlled hobbing machine of the present invention, in which each element having exactly the same function as in FIG. 1 is given the same number.

8 is a phase difference correction device which is the main part of the present invention,
The detailed internal details of the first embodiment are shown in Figure 3, and the details of the second embodiment are shown in Figure 6.
As shown in the figure.

Reference numeral 9 denotes an AND gate that passes the unit movement amount ΔC stored in the register 3 according to the determination condition of the phase difference correction device 8.

Reference numeral 10 designates an AND gate for allowing the correction unit movement amount ΔC' to pass from the phase difference correction device 8 according to the judgment conditions of the phase difference correction device 8.

Reference numeral 11 is an OR gate for passing the output of AND gate 9 or 10.

FIG. 3 is a detailed block diagram of a first embodiment of the phase difference correction device 8 shown in FIG.

Here, 21 is connected to the cutting hob shaft, and the cutting hob shaft 1
It is an indexing signal generator that outputs one pulse per rotation.

Reference numeral 22 is a signal line connected to the command value register 1 of FIG. 2 and inputting the number n of teeth of the gear to be cut.

A counter 23 counts the number of output pulses from the index signal generator 21.

24 compares the number n of teeth input through the signal line 22 and the count number of the counter 23, and outputs 1'' until the count number matches the number n of teeth, and the count number is greater than the number n of teeth. This is a comparator that outputs "0" when

25 is an AND gate that allows the output pulse of the index signal generator 21 to pass only when the comparator outputs 1''.

26 is a memory write control circuit for receiving the output of the AND gate 25 and driving a memory unit 28, which will be described later, to write necessary data into the memory.

Reference numeral 27 is an AND gate that allows the current value of the table rotation axis to pass only when a repulse is issued from the index signal generator 21.

A memory unit 28 stores the current value of the table rotation axis that has passed through the AND gate 27 in response to a signal from the memory write control circuit 26, and is configured so that the contents will not be lost even if the power is turned off.

Reference numeral 29 denotes a memory read control circuit that drives the memory unit 28 using a pulse signal generated by the index signal generator 21 or a signal based on a determination condition of a phase difference determination circuit 32 (to be described later) to read stored data.

A register 30 stores the current value of the table rotation axis that has passed through the AND gate 27.

A subtracter 31 inputs and subtracts the value stored in the register and the data read out from the memory unit 28.

32 determines the output value of the subtracter 31, and when the output value is positive, it outputs '1' to the positive signal line to operate the memory read control circuit 29, and when the output value is zero, it outputs a zero signal. Output 1" to the line and open the AND gate 9 to allow the unit movement amount △C to pass. When the output value is negative, I output 1 to the negative signal line.
This is a phase difference determination circuit which outputs ", opens the AND gate 10, and passes a correction unit movement amount ΔC' which is an output of a sign inverter 35, which will be described later.

33 is a signal line into which the number N of pulses generated by the pulse generator 4 when the cutting hob shaft rotates once is inputted as a constant.

34 is a divider that divides the output of the subtracter 31 by the number N of pulses input from the signal line 33.

A sign inverter 35 inverts the sign of the output of the divider and outputs a correction unit movement amount Δd.

Next, the operation will be explained with reference to FIGS. 4 and 5.

FIG. 4 is an explanatory diagram when writing a booter into a memory unit.

51 is either clockwise or counterclockwise with respect to the base 52.
This table is also rotatable, and in this embodiment, it is rotated in the direction of the arrow as shown in the figure.

On the table, gears as shown in the figure are cut. Reference numeral 053 is a servo motor that rotates the table, and is driven based on the output of the table rotation axis function generation circuit 7 shown in FIG. be done.

Reference numeral 54 denotes an ab'nolute position detector that outputs the current position of the table corresponding to the reference point on the base 52 when the table rotates, and when the zero point on the table is relative to the reference point on the base 52, It is set to output zero output.

The output of the position detector is used for feedback of the servo system, and is also used as the current value of the table rotation axis when writing to and reading from the memory unit.

A on the table.

, A1.・・・・・・A1, point is index signal generator 2
1 indicates the table rotation axis positions that are sequentially written into the memory unit every time a signal is generated, and the number of table rotation axis positions that are written is equal to the number of teeth of the gear to be cut, and in this example, it is 12 as shown in the figure. It is individual.

Table rotation axis position A to be written first.

is an arbitrary position, for example 80° in this figure.

Since there are 12 teeth, the amount of movement for one pitch is 300,
Other table rotation axis position A1. A2.・・・・・・A
1□ has a value as shown in the figure.

To explain this based on FIG. 3, when the hob shaft is first rotated and a signal is issued from the indexing signal generator 21, the table rotation shaft position A.

passes through AND gate 27 and is input to memory unit 28 .

In this case, the counter 28 counts one pulse of the index signal.

On the other hand, the comparator 24 compares the number of teeth n = 12 inputted from the signal line 22 and the output of the counter 23, and determines that the number of index signals has not reached the number of teeth 12, and 1'' is output to the AND gate 25.

Therefore, the index signal obtained by first rotating the hob shaft passes through the AND gate 25 and drives the memory write control circuit 26, which drives the memory unit 28 and drives the AND gate 27. Table rotation axis position A that has passed.

is written to the memory unit 28.

Hereinafter, each time an indexing signal is issued, the same data is generated) and the rotational axis position AI + AL2,...Al
l is being written.

After the table rotation axis position All is written, when the next index signal comes, the output of the counter 23 becomes 13, the comparator 24 outputs “O” to the AND gate 25, and the index signal outputs the memory write control circuit 26. Prevent it from driving.

Therefore, writing to memory unit 28 is not performed.

FIG. 5 is an explanatory diagram when reading data from the memory unit.

After the writing to the memory unit is completed, as long as the cutting hob axis and table rotation axis are driven continuously, the current value of the table rotation axis when the indexing signal is issued is A.

, A2.・・・・・・) The position will be at one of the k1□ points, and the phase relationship between the cutting hob axis and the table rotation axis will be maintained, but if the power is turned off or the machine is once stopped, The table rotation axis stops immediately, but the cutting hob axis has inertia and moves several rotations.

Therefore, the phase relationship between the cutting hob shaft and the table rotation shaft is irrelevant.

This figure shows the above situation, that is, after the phase relationship has become irrelevant, the cutting hob shaft is rotated, and the current value of the table rotation axis happens to be P when a new indexing signal is issued.
Indicates that it is a point.

Considering the rotation direction of the table as shown, the table rotation axis position is corrected by α0 so that when the next indexing signal arrives, the nearest table rotation axis position A5 is determined.

After the correction, the cutting hob shaft and the table rotation shaft are driven while maintaining a normal phase relationship.

This is explained in Figure 3 (to explain this, after the machine has stopped, in order to restore the normal phase relationship between the cutting hob axis and the table rotation axis, a new indexing signal is first generated only for the cutting hob axis). Rotate.

When the index signal is issued, the memory read control circuit 2
9 is driven, and therefore the memory unit 28 is driven and the stored data is read out.

Therefore, the table rotation axis position A is already stored by the first indexing signal.

is input to the subtracter 31. On the other hand, the table rotation axis current value P is input to the register 30 through the AND gate 27, and the value of the register is also input to the subtracter 31.

Therefore, the subtracter 31 converts P to A.

and outputs the subtraction result P-Ao to the phase difference determination circuit 32.

The phase difference determination circuit determines that P-Ao is positive and issues an output "1" to the positive signal line.Therefore, the memory read control circuit 29 is driven again, and the memory unit 28 is completely read out. The next stored table rotation axis position A1 is input to the subtracter 31.

Similarly, the subtracter 31 subtracts A1 from P and outputs the subtraction result P-A1 to the phase difference determination circuit 32.

The phase difference determining circuit determines that P-A1 is positive and outputs an output 111 jj to the positive signal line.

In this way, A2, A3, and A4 are sequentially read out and arithmetic is performed, but when A is read out, the subtracter 3
The phase difference determination circuit 32 determines that the subtraction result P−A at 1 is negative, and therefore the phase difference α0 has been determined, and the positive The signal line outputs 0'', and the negative signal line outputs 1''.

Therefore, reading from the memory unit 28 ends, and the AND gate 10 and the OR gate 1
1 is opened and the correction unit movement amount ΔC' is output.

Therefore, when the correction unit movement amount △C' is output, the correction unit movement amount △C' passes through the AND gate 5 every time the pulse generator 4 outputs an output as shown in FIG. 6 and the table rotation axis function generation circuit 7, which ultimately drives the table rotation axis.

In this case, when the first index signal arrives, the data stored in the memory unit is repeatedly read and calculated, but since these operations are extremely fast, the reading and calculations are completed instantly. However, the I'ul table rotation axis will be driven.

In this manner, when the cutting hob shaft rotates once and the next indexing signal is issued, the current value of the table rotation shaft will be at point A5.

When this index signal is issued, the table rotation axis current value A passed through the AND gate 27 and was input into the register 30, and the table rotation axis position A was sequentially read out from the memory unit.

, A1. The subtractor 31 repeats the subtraction with A5, and finally the phase difference determination circuit 32 determines that the subtraction result is zero.

Therefore, the negative signal line, which has been outputting 1'', now outputs 0, and the zero signal line now outputs 1''.

Therefore, the AND gate 9 and the OR gate 11 are opened, and the normal unit movement amount ΔC is output.

Thereafter, unless the power is turned off or the machine is stopped, the table rotating shaft will be driven by the unit movement amount ΔC.

FIG. 6 is a detailed block diagram of a second embodiment of the phase difference correction device 8 shown in FIG.

Elements with the same numbers as those in the detailed block diagram of the first embodiment shown in FIG. 3 have the same functions, and therefore, description thereof will be omitted.

Reference numeral 41 is a signal line connected to the command value register 1 of FIG.

42 inputs the output of the subtracter 31 as an initial value, and as long as °1" is output to the positive signal line of the phase difference determination circuit 32,
This is a subtracter that sequentially subtracts the amount of movement of the gear l pitches from the initial value, and together with 43 registers constitutes an accumulator.

The output of the register 43 is output to the phase difference determination circuit 32 and the divider 34.

44 is a signal line that is connected to the command value register 1 of FIG. 2 and introduces the movement amount 360'/n of one gear pitch into the subtracter 42.

Next, the operation shown in FIG. 6 will be described with reference to FIGS. 4 and 5, which were used to explain the operation shown in FIG. 3.

However, in the second embodiment shown in FIG. 6, only one piece of data is required to be written to the memory unit, so A among the table rotation axis positions in FIG.

Only the points are needed, other A11A2,...Al1
Points are no longer needed.

Similarly, in Fig. 5, A14A2+...
, A1, points are no longer needed.

Regarding writing, in the first embodiment shown in FIG. 3, the data input from the signal line 22, which is one input of the comparator 24, has the number of teeth n1, that is, the numerical value 12, whereas in the second embodiment shown in FIG.
In the embodiment, a numerical value 1 is input to the signal line 41, which is one input of the comparator 24, and in short, data for only one tooth is written to the memory unit.

Regarding reading, in the first embodiment shown in FIG. 3, as long as there is an output "1" on the positive signal line of the phase difference determination circuit 32, data is read from the memory unit 28 and the table rotation axis current value P is read from the memory unit. In contrast, in the second embodiment shown in FIG. 6, only one piece of data is read from the memory unit 28, and the table rotation axis current value P is subtracted from the read table rotation axis position. The subtraction result becomes the initial value of the accumulator composed of the subtracter 42 and the register 43, and as long as the output IT 191 is on the positive signal line of the phase difference determination circuit 32,
'The amount of movement of one gear pitch is sequentially subtracted from the initial value.

To explain readout specifically, after the machine stops,
In order to restore the cutting hob shaft and table rotation shaft to normal conditions again, first, only the cutting hob shaft is rotated so that a new indexing signal is generated.

When the index signal is issued, the memory read control circuit 2
9 is driven, and therefore the table rotation axis position A is stored in the memory unit 28.

is input to the subtracter 31. On the other hand, the AND gate 27 is opened and the table rotation axis current value P is also input to the subtracter 31.

Therefore, the subtracter 31 converts P to A.

and outputs the subtraction result P-Ao to the subtracter 42.

The subtracter 42 outputs the P-Ao to the register 43, and the register 43 outputs the value to the phase difference determination circuit 32.

The phase difference determination circuit determines that P-Ao is positive, issues an output 111++ to the positive signal line, and instructs the subtracter 42 to perform a subtraction operation.

That is, 30° in this embodiment, which is the amount of movement of one gear pitch, is subtracted from P-Ao, which is input as the initial value.

This subtraction result P-Ao-30° passes through the register again and is output to the phase difference determination circuit 32.

The phase difference determination circuit determines that P-Ao-30° is positive, outputs "■" to the positive signal line, and subtracter 42
commands subtraction operation.

In this case, since the subtracter 42 and the register 43 constitute an accumulator, the output of the register 43, P-Ao-30°, is input to the subtracter 42, and this P
30° is further subtracted from -Ao-30'.

The result of this subtraction, P-Ao-60°, is input again to the phase difference determination circuit, and the subtraction is repeated until "O" is output to the positive signal line.

The subsequent operations are the same as those shown in FIG. 3 and will therefore be omitted.

As described above with respect to the two embodiments, according to the present invention, even if the phase relationship between one cutting hob axis and the table rotation axis becomes irrelevant due to a power outage or machine stoppage, it is possible to easily and instantaneously , it is possible to restore these relationships.

In addition, in the embodiments of the present invention, the rotation direction of the table rotation axis is limited to one direction in order to avoid complexity and facilitate understanding, but the rotation direction of the table rotation axis is limited to one direction. However, these do not depart from the spirit of the present invention.

[Brief explanation of the drawing]

Figure 1 is a control block diagram of a conventional numerically controlled hobbing machine;
The figure is a control block diagram of the numerically controlled hobbing machine of the present invention, and FIG. 3 is a detailed block diagram of a first embodiment of the phase difference correction device 8 shown in FIG. 2. FIG. 4 is an explanatory diagram when writing data to the memory unit, FIG. 5 is an explanatory diagram when reading data from the memory unit, and FIG. 6 is a detailed second implementation of the phase difference correction device 8 shown in FIG. 2. FIG. 2 is an example block diagram. 4... Pulse generator, 8... Phase difference correction device.

Claims (1)

[Claims] 1 The cutting hob shaft and the table rotation shaft are electrically driven separately, and the rotation speed ratio and mutual phase relationship are controlled using electrical auxiliary means such as a pulse generator, and the unit movement of the table rotation shaft is controlled. In a numerically controlled hobbing machine that outputs ΔC for each signal of the electrical auxiliary means to drive and control the table rotating shaft, the table rotates the number of teeth equal to the number of teeth of the gear to be cut based on the current value of the table rotating shaft. When the phase difference between the axis equidistant positions and the nearest position is determined, a correction unit movement amount Δσ of the table rotation axis obtained based on the phase difference is output for each signal of the electrical auxiliary means. the table rotation axis is driven and controlled, and when the phase difference becomes zero, the table rotation axis is driven and controlled by outputting a unit movement amount ΔC of the table rotation axis for each signal of the electrical auxiliary means. A control method for a table rotation axis in a numerically controlled hobbing machine, characterized by restoring the phase relationship between a cutting hob axis and a table rotation axis that have become unrelated.