JPH01233603A - Orientation stopping controller - Google Patents

Abstract

PURPOSE:To shorten duration from a command to a stop by speed-reducing a rotational shaft to a high speed first stage slow speed turning it rapidly in this condition until a rotational direction position approaches a control zone, switching it to a second slow speed and switching a control system from speed control to position control when the orientation stopping point of the rotational shaft comes inside the control zone. CONSTITUTION:A slow speed is set to the two stages of a first stage appropriate intermediate slow speed and a low speed appropriate second slow speed and a pulse signal A to output a switching timing from the first stage slow speed to the second stage slow speed from a rotational direction position detecting means 5 of a rotational shaft 4 is counted and is set. Then, the rotational shaft 4 which is rotating at a high speed (6,000rpm, for instance) is speed-reduced to the first stage slow speed (300rpm, for instance) once based on an orientation command, is turned in this condition until the rotational direction position of the rotational shaft 4 approaches a control zone appropriately, and is switched to the second slow speed (60rpm same as a usual instance, for instance). Thus, duration from the orientation command to a stop can be shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a control device for stopping the main axis of a machine tool driven by a motor in a fixed position, and can shorten the predetermined time from an orientation command to stopping. Concerning what was done.

[Conventional technology]

As shown in Fig. 5, in the fixed position stop control device, the motor, which is rotating at high speed (6000 rpm in the figure), is stopped at a constant slow speed (600 rpm in the figure) based on the orientation command.
rpm), and after reaching a slow speed, when the rotational direction position of the rotary shaft reaches the control zone as shown in Figure 6, the control system is switched from speed control to position control and stopped at a fixed position. was. In this case, the slow speed is generally 1
For example, 60r
It was set to a low speed of pm.

[Problem to be solved by the invention]

In the above structure, since the slow speed is low, the time t required from when the rotating shaft reaches the slow speed until it reaches the control zone is
The disadvantage is that 1 becomes long.

In order to eliminate the above-mentioned drawbacks, it is an object of the present invention to provide a fixed position stop control device that can shorten the time required from an orientation command to a stop.

[Means to solve the problem]

In order to achieve the above object, the present invention reduces the rotational speed of the motor 3 from high speed to slow speed by the output signal of the slow speed switching circuit 2 via the slow speed command circuit 1 in response to the input of the orientation command signal G. , in a control device that switches the control system from speed control to position control and stops at a fixed position when the rotational direction position of the rotary shaft 4 reaches a control zone after reaching a certain slow speed; The timing of switching from the first stage slow speed to the second stage slow speed is determined by the rotation direction of the rotary shaft 4. The pulse signal A outputted from the position detection means 5 is counted and set.

[Operation] The rotating shaft 4, which is rotating at a high speed (for example, 6000 rpm), is once decelerated to the first stage slow speed (for example, 300 rpm) based on the orientation command, and in this state, the rotating shaft 4 is rotated at a high speed (for example, 6000 rpm).
Rotate until the position in the rotational direction approaches the control zone, and then start the second stage slow speed (for example, 60 rpm, same as the conventional example).
Since the switching is made so that the time required from the orientation command to the stop can be shortened.

〔Example〕

FIG. 1 shows an embodiment of the present invention, in which an AC motor 3 that rotationally drives a main shaft 6 of a machine tool is speed controlled by an inverter (not shown), etc., and a magnet (magnetic body) attached to the outer periphery of the tip of the main shaft 6. A sensor 8 for detecting the rotational direction position of the main shaft 6 and a detection means (not shown) are provided opposite to the main shaft 7 . The motor 3 includes a detection means 5 that generates a pulse signal A as the rotation shaft 4 rotates and detects the rotational direction position of the rotation shaft 4. The pulse signal A outputted from the detection means 5 is sent to a counter 9 and a digital comparator. It is input to the slow speed command circuit 1 consisting of 10 etc. The pulse signal A outputs, for example, 256 solenoid pulses as shown in FIG. 2 when the rotating shaft 4 rotates once.
The number of pulses is counted and displayed in 7 segments 11, and the rotation angle of the rotating shaft 4 is calculated and input as an 8-bit signal C to the digital comparator 10. The counter 9 is reset to zero when the fixed position stopping point of the rotary shaft 4 enters the control zone and the control zone signal B becomes H level.

The digital comparator 10 is configured to input the slow speed switching angle set value d set as an 8-bit signal by two digital switches 2 and compare it with the signal C representing the actual value of the rotation angle of the rotating shaft 4. When the main shaft 6 and the rotary shaft 4 are gear-coupled and the gear ratio is 1:1, the slow speed switching angle can be set approximately every 1.4 degrees. The signal C representing the actual rotation angle of the rotating shaft 4 is compared with the slow speed switching angle setting value d, and if the signal C is larger, the switching angle attainment signal e output from the digital comparator 10 becomes H level and the flip-flop is activated. input into step 13.

On the other hand, the slow speed is an appropriate intermediate slow speed of the first stage (for example, 300
rpm) and an appropriate second stage slow speed (for example, 60 rpm, which is the same as in the conventional example). 6000r
pm), the rotating shaft 4 decelerates and reaches the first stage slow speed, the first stage slow speed attainment signal F goes to H level and is the output from the flip-flop 13 which inputs this, which is the slow speed switching. The signal m becomes H level and is latched. The first stage slow speed is set to a high speed several times the second stage slow speed,
The orientation command signal G input to the flip-flop 13 is reset when the slow speed switching signal m becomes H level.

The slow speed switching signal m is input to the AND gate 14,
The AND gate 14 outputs the second stage slow speed command signal at H level under the AND condition with the orientation command signal G. When the second stage slow speed command signal reaches H level, the contact 15 in the slow speed switching circuit 2 is closed and the second stage slow speed setting value j set by the volume 16 is sent as a command signal from the operational amplifier circuit 17. As shown in FIG. 3, the rotating shaft 4 is decelerated once to the first stage slow speed (for example, 30 rpm), and then further decelerated to the second stage slow speed (for example, 60 rpm), and then As shown in the figure, the rotating shaft 4 is rotated at a low speed until the rotational direction position reaches the control zone. When the fixed position stopping point of the rotary shaft 4 enters the control zone, the control system is switched from speed control to position control using a stop position command circuit (not shown) or the like to stop the rotary shaft 4 at the fixed position. The first stage slow speed is AND gate 14.
When the second stage slow speed command signal i is at L level, the AND gate 14 outputs the first stage slow speed command signal i via the inverter gate 18, thereby closing the contact 19 in the slow speed switching circuit 2. A command signal is sent from the operational amplifier circuit 17 to the first stage slow speed setting value k set with the volume 20! This is done by closing and outputting. Furthermore, the slow speed switching angle setting value d
is set by checking the signal C of the actual value of the rotation angle when the rotating shaft 4 is rotated once through the 7 segments 11, and calculating the signal C/360° of d=switching angle×11 rotations.

According to the embodiment described above, the rotary shaft 4 rotating at high speed is decelerated once to a fairly high speed first stage slow speed based on the orientation command to stop at a fixed position, and in this state, the rotational direction position of the rotary shaft 4 is in the control zone. Since the rotating shaft 4 is rapidly rotated until it approaches the speed appropriately and then switched to the second stage slow speed, the time (tz+ts) required from when the rotating shaft 4 reaches the slow speed until it reaches the control zone is shorter than that of the conventional example. The required time t explained above can be further shortened, thereby making it possible to shorten the time required from the orientation command to the stop.

〔Effect of the invention〕

According to this invention, in a fixed position stop control device for a rotary shaft, the rotary shaft that is rotating at high speed is first decelerated to a relatively high first stage slow speed based on an orientation command, and in this state, the rotational direction position of the rotary shaft is The control system is rotated rapidly until it approaches the control zone, then switches to the second stage slow speed, and when the fixed position stopping point of the rotating shaft enters the control zone, the control system is switched from speed control to position control. Therefore, an effect can be obtained in that the time required from the orientation command to the stop can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of main parts of an embodiment of the present invention, FIG. 2 is a time chart of each signal in FIG. 1, FIGS. 3 and 4 are operation explanatory diagrams of FIG. 1, and FIGS. FIG. 6 is an explanatory diagram of the operation of the conventional example. 1... Slow speed command circuit, 2... Slow speed switching circuit, 3...
... Motor, 4... Rotating shaft, 5... Detection means, A,
f...Signal Fig. 1 Fig. 2 Fig. 3 Fig. 5

Claims (1)

[Claims] 1) When the orientation command signal is input, the rotational speed of the motor is reduced from high speed to slow speed by the output signal of the slow speed switching circuit via the slow speed command circuit, and after reaching a certain slow speed, the rotation direction of the rotating shaft is changed. When the position reaches the control zone, the control system is switched from speed control to position control 1 to stop the control system at a fixed position. A two-stage slow speed is set, and the switching timing from the first stage slow speed to the second stage slow speed is set by counting the pulse signal output from the rotational direction position detection means of the rotating shaft. A fixed position stop control device characterized by: