JPH0332551A - Machine origin offset regulation method - Google Patents

Abstract

PURPOSE:To set an offset value accurately and simply, by stopping the main shaft at a detection point when an 1 rotation signal is detected, and calculating the pulse of a position detector, and rotating the main shaft manually, and setting the specified position of the main shaft at a machine origin, and setting a calculation value thus obtained, as the offset value. CONSTITUTION:The main shaft 1 becomes rotatable manually by stopping the main shaft 1 at an 1 rotation signal position, and releasing the excitation of a main shaft motor 12. Thereupon, the main shaft 1 is rotated manually, and a machine origin position and a main shaft 1 specified position are made to agree. While the main shaft 1 is being rotated manually, a position pulse is generated from a position detector 16, and calculation is made at a register, and an indication is made at an indicator, so when the machine origin position and the main shaft 1 specified position has agreed, an offset value from the 1 rotation position to the machine origin position is indicated at the indicator. Then, an operator makes the value indicated at the indicator the offset value, and its numerical value is set from a key board or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the control of a spindle motor, and more particularly to an offset adjustment method for positioning a spindle at a machine origin.

Conventional technology When automatically replacing a tool attached to a spindle, the tool cannot be replaced automatically unless the spindle is stopped at a predetermined position (predetermined rotational position). For example, a specific position such as the keyway of the spindle is positioned at the machine origin position of the machine tool, a tool is taken out from the spindle into a tool magazine, the tool magazine is rotated, and the next tool to be installed is placed opposite the spindle position. It is necessary to attach the tool to the spindle by fitting the keyway of the spindle with the key of the tool.

Furthermore, there are cases where it is necessary to position the spindle, such as when starting machining from a predetermined position on a workpiece attached to the spindle.

Therefore, it is necessary to position the specific position of the spindle to the machine origin, but conventionally, the number of pulses required for the specific position of the spindle to reach the machine origin from the position of one rotation signal from the position detector that detects the spindle position. (The number of pulses from the position detector) is determined as an offset value, and this offset value is used to align the machine origin position with the specific position of the spindle to position the spindle. Figures 4 (a) to (C) are explanatory diagrams of the work to obtain this offset value, in which 1 is the main axis;
2 is a mark indicating the machine origin position, and 3 is a mark indicating a specific position of the spindle (for example, key clearance). First, as shown in Fig. 4(a), the spindle is positioned at a position where a one-rotation signal is detected from the position detector attached to the spindle, and the mark 3 representing the specific position of the spindle is set to the machine origin position 2. The main shaft 1 is rotated by inputting the number of offset setting pulses that are expected to coincide with each other (see FIG. 4(b)). If mark 2 at the machine origin position and mark 3 at the specific position of the spindle do not match, change the offset setting pulse number and input it.
Perform origin alignment again. When this operation is repeated and the machine origin and the specific position of the spindle match (Fig. 4 (C)
), the offset setting pulse number at that time is set as the offset value.

Problems to be Solved by the Invention As mentioned above, the work of determining the offset value for positioning the spindle at the machine home position is performed by trial and error, and the offset value cannot be determined in one operation, resulting in a time-consuming process. was on.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a machine origin offset value adjustment method that can obtain an offset value in one operation.

Means for Solving the Problems The present invention provides a first step of stopping the spindle at the detected point and de-energizing the spindle motor when a one-rotation signal is detected from a position detector that detects the spindle position; After it has stopped, the second machine counts the pulses generated from the position detector and manually rotates the spindle to align the specific position of the spindle with the machine origin.
The above problem was solved by a method consisting of the following steps and a third step of setting the count value obtained in the second step as an offset value.

Action First, stop the spindle at the position where the ↑ rotation signal is detected from the position detector. After that, the main shaft motor is de-energized. When the spindle motor is de-energized, the spindle can be freely rotated manually, so manually rotate the spindle and move a specific position (for example, mark 3 shown in Figure 4) on the spindle to the machine origin position (mark 3 in Figure 4). (position of mark 2 in Figure 4) (position of mark 2 in Figure 4)
Figure (C) state).

On the other hand, after the spindle stops at the one-rotation signal position, the number of pulses from the position detector is counted while the spindle is manually rotated and stopped at the machine origin position, and the counted value is set as an offset value. .

As a result, the offset value from the one-rotation signal detection position to the machine origin position is determined by the number of pulses from the position detector that are generated when the spindle actually moves, so the offset adjustment only needs to be performed once.

Embodiment FIG. 2 is a block diagram of main parts of an embodiment of the present invention, in which 10 is a numerical control device that controls a machine tool, etc., 11 is a spindle control circuit that controls a spindle motor 12, 1 is a spindle, It is driven by a main shaft motor 12 via a transmission means 14 such as a gear or a timing belt. 15 is a chuck for mounting the workpiece (or tool); 16 is an absolute position detector that detects the rotational position of the spindle 1; 17 is a counter that counts output pulses from the position detector 16; and 18 is a one-rotation rotation from the position detector i6. This is a latch circuit that latches the value of the counter 17 every time a signal is output.

In the above embodiment, the main shaft 1 is driven 17 through the transmission means ↓4, but it goes without saying that the main shaft 12 may be connected directly to the main shaft motor 12 to drive the main shaft.

In the above configuration, when an offset value calculation command is given via the numerical control device 10, the processor of the spindle control circuit 11 starts the process shown in FIG. , switch to position loop control (
In step S1), the value A of the counter 17 of the one-rotation signal currently latched in the latch circuit 18 is read, and the value B of the counter 17 is also read to determine the target value C (step S2).

That is, as shown in FIG. 3, the number of pulses PO between the value A currently latched in the latch circuit 18, the current value B stored in the counter 17, and one revolution signal (between one revolution of the main shaft)
to perform the next calculation (by S, the next 1 as the target value)
Calculate the movement 50 to the rotation signal.

C=A+PO-B Then, the processor sets the movement amount C to the target value and moves the main axis 1.
to the t rotation signal position (Step S3), de-energize the spindle motor 12 (Step S4), reset the register R4 provided in the spindle control circuit, and obtain feedback from the position detector. The position pulses are made countable and the value of the C register R is displayed on the display (step S5).

As a result of the above processing, the main work stops at the 1 rotation signal level as shown in Fig. 4 (2), and the main shaft motor 12 is de-energized. Therefore, as shown in Fig. 4(b), manually rotate the main shaft ↓, and align the machine origin position 3 and the specified position 2 of the main shaft as shown in Fig. 4(C). let

During this manual rotation of the main shaft 1, a position pulse is generated from the position detector 16, and is transmitted to the nozzle R.
The counted value is displayed on the display, so when the machine origin position 3 and the spindle specific position 2 match as shown in Figure 4(c), that is, the offset value from the 1 rotation position to the machine origin position. will be displayed on the display.

Therefore, the operator uses the value displayed on the display as an offset value and sets the value using a keyboard or the like. Alternatively, an offset value setting command may be provided to directly set the value of register R as the offset value.

Effects of the Invention With the present invention, the offset value setting only needs to be done once, and since the offset value is determined by the number of pulses actually detected by the position detector from the one-rotation signal position to the machine home position, the offset value can be set accurately. Offset value setting work can be done easily and in a short time.

[Brief explanation of drawings]

FIG. 1 is a processing flowchart of the processor of the spindle control circuit implemented in one embodiment of the present invention, FIG. 2 is a block diagram of the main part of the same embodiment, and FIG. 3 is an explanatory diagram of positioning to the one-rotation signal position. , FIG. 4 is an explanatory diagram of the work of offset value detection. K,...Main shaft, 2...Machine origin position mark, 3...
・Mark of specific position of spindle, 1o...numerical control device,
11... Spindle control circuit, 12... Spindle motor, 14
... 1 movement means, 16... position detector, 17...
Counter, 18...Latch circuit. Curse

Claims (1)

[Claims] A first step of stopping the spindle at the detected point and de-energizing the spindle motor when a one-rotation signal is detected from a position detector that detects the spindle position; A second process involves counting the pulses generated by the detector and manually rotating the spindle to align the specific position of the spindle with the machine origin; and a third process, which sets the count value obtained in the second process as an offset value. A machine origin offset adjustment method consisting of processes.