JP2003348879A - Motor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor device which works both for indexing and main- shaft operation and is capable of generates a large torque required for indexing while reducing the effect of a counterelectromotive force on a current amplifier circuit during operation of a main-shaft. <P>SOLUTION: Excitation coils of respective phases are divided into three: 1a-1c, 2a-2c, and 3a-3c. A part or entire excitation coil which has been divided is supplied with a current for indexing or main-shaft operation by switches 4a, 4b, and 4c, with the use of two current amplifying circuits 6 and 7 with different characteristics for indexing and main-shaft operation. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor device for performing both spindle operation and indexing in a processing apparatus.

[0002]

2. Description of the Related Art When the purpose of use such as the spindle operation and the indexing operation is different, it is common to use the motor unit as it is or to use a different motor unit. As shown in FIG. 4, in the case of a three-phase motor, a current amplification circuit having a current amplification circuit for three phases is connected. In FIG. 4, 9 is a control circuit, 11 is a low-resolution high-speed encoder, 12 is a high-resolution low-speed encoder, 14 d is a three-phase current amplifier circuit, 15 is a U-phase excitation coil, 16 is a V-phase excitation coil, and 17 is This is a W-phase excitation coil.

[0003]

However, when two different motor units are prepared for spindle operation and indexing, there is a problem in that the size of the apparatus becomes large when two are attached to the processing machine. In the case of replacement and replacement, the replacement time and the mounting accuracy at the time of replacement become problems.

In the indexing operation, the motor must have a large maximum torque in order to keep the rotary table at an arbitrary position under control. To increase the motor torque, either increase the motor torque constant or
It is necessary to supply a large current to the motor coil. However, flowing a large current through the motor coil section during precision machining has a significant heat generation problem, and therefore it is necessary to increase the torque constant of the motor.

However, when the same motor is used for both the spindle operation and the indexing operation, when the spindle is operated at high speed, the number of turns of the motor coil is proportional to the interlinkage magnetic flux at the time of rotation. Voltage is generated. In order to use the motor at a high speed, if the torque constant of the motor is large, a counter electromotive force is large and an output voltage of the driver must be very high. Is determined in consideration of both the spindle operation and the indexing operation, and it is difficult to select a torque constant that can exhibit the maximum performance in both operation modes.

Accordingly, an object of the present invention is to provide a motor device which solves the above problems.

[0007]

SUMMARY OF THE INVENTION The present invention focuses on the fact that the motor torque during the spindle operation is smaller than the torque required for the indexing operation. The number of turns n of the coil is determined, and when the number of turns is n, the exciting coil is divided and wound. As a method of dividing the exciting coil, two or more m wires are wound together n / m times to form a parallel coil, or a normal single coil is divided and wound, and each divided coil is wound. There is a method in which an independent input terminal is taken out from the device and the connection method is wound in parallel or in series by input switching means.

In order to generate a large torque constant required for the motor at the time of indexing, a current amplifier circuit that can simultaneously supply current to all of the divided exciting coils is connected. A high torque is required at the time of indexing, but low-speed rotation is sufficient, so the back electromotive force generated in the coil is low.When used as a high torque motor, a current amplifier circuit that can flow a high current at a low voltage is used. Connecting.

During operation of the main shaft, the connection is changed so that only a part of the windings of the divided excitation coil is energized, and the energization is performed. At this time, the connected current amplifier circuit is connected to a high-voltage amplifier circuit capable of generating a voltage higher than the back electromotive force generated during the spindle operation. Since the torque required to stabilize the speed during spindle operation is smaller than that during indexing operation, it is possible to rotate the motor with a small torque constant by using a part of the excitation coil. By reducing the size, it is possible to reduce the back electromotive force generated during the operation of the spindle.

That is, according to the first aspect of the present invention, in a rotary motor which forms a winding of each phase by a plurality of exciting coils and performs an indexing operation and a main shaft operation, a plurality of current amplifying circuits and the plurality of the current amplifying circuits are divided. Switching means for supplying a current from any one of the plurality of current amplifying circuits to only any one of the exciting coils; and controlling the switching means in accordance with the indexing operation or the spindle operation to divide the plurality of exciting coils into the plurality of exciting coils. And a control circuit for supplying a current from a current amplification circuit selected from the plurality of current amplification circuits to an arbitrary number of the excitation coils.

According to a second aspect of the present invention, in the first aspect, the excitation coil divided into a plurality of coils is formed by winding a plurality of parallel wires in one set, and the switching means is provided in the one set. The present invention is characterized in that an arbitrary number is selected from among the plurality of wires wound in step (a) and connected to the current amplifier circuit.

According to a third aspect of the present invention, in the first aspect, the plurality of current amplifying circuits are connected to the exciting coil connected to the exciting coil divided at the time of main shaft operation at a predetermined maximum number of rotations. The first current amplification circuit capable of outputting a voltage output equal to or greater than the generated back electromotive force, and the current amplification circuit connected to the excitation coil divided at the time of the indexing operation supplies current to all of the divided excitation coils, and a predetermined maximum A second current amplifying circuit for generating torque.

[0013]

(Embodiment 1) FIG. 1 shows a first embodiment of the present invention.

This embodiment uses a DC brushless motor for Y.
It is a connected three-phase motor. Fig. 1
The U-phase excitation coil is divided into three parts, and three divided coils having a common ground like the excitation coils 1a, 1b, and 1c are arranged in parallel. The excitation coil is divided into three parts by winding three parallel wires at the same time, and is divided equally into three parts when used in combination with separately wound coils. The input terminal of the U-phase has a changeover switch 4a, and the changeover switch 4a simultaneously switches input terminals to the excitation coils 1a, b, and c which are divided into three and arranged in parallel. By the changeover switch 4a, U
The excitation coils 1a, 1b, 1c divided into three phases are connected to a current amplifier circuit 6 for indexing or a current amplifier circuit 7 for the main shaft by wirings 8a and 8d. Similarly, V-phase split excitation coils 2a to 2c and W-phase split excitation coils 3a to 3a
Similarly, the switch c is connected to the indexing current amplifier circuit 6 or the main shaft current amplifier circuit 7 by the changeover switches 4b and 4c. The changeover switches 4a to 4c are connected to a changeover signal line 10a
The connection is switched according to signals from .about.c. The current amplification circuit 6 for indexing is a high current output type current amplification circuit.
In order to output currents independently for the U, V, and W phases, three current amplifier circuits are built in.
c, when connecting to the divided excitation coils 1 to 3 through U, V, and W phases,
c Connected to all coils. The main shaft current amplifying circuit 7 is a high voltage output type current amplifying circuit, and when connected to the divided excitation coils 1 to 3 via the changeover switches 4a to 4c, the U, V, and W phases are divided. Excitation coils 1-3
A and b in each of the U to W phases of the divided excitation coils
And only c is not connected.

Further, as an encoder serving as a detection system, a low-resolution high-speed encoder 11 used during spindle operation and a high-resolution low-speed encoder 1 used during indexing operation.
2 is connected to the control circuit 9 through the detection signal lines 13a and 13b. Both encoders are connected to a mover using permanent magnets (not shown) and measure the movement of the motor.

In such an arrangement, during an indexing operation in which a large torque is required, the control circuit 9 uses the coil changeover switch signal 10 to control the U-, V-, and W-phase excitation coils a to switch 4 so that the connection to c is connected to the current amplification circuit 6 for indexing.
Switch between a, b, and c. The control circuit 9 supplies a drive signal having a U-, V-, and W-phase phase shift of 120 degrees to the index current amplification circuit 6 through the wiring 8a. The current amplifying circuit 6 for indexing supplies current to the ac excitations of the divided excitation coils 1 to 3 of the U, V and W phases in accordance with a command given from the control circuit 9. As a result, current is supplied to all of the divided excitation coils via the changeover switches 4a to 4c arranged in the U, V, and W phases, respectively. The mover (not shown) is rotated by the supplied current, and the connected encoders 11 and 12 are rotated. At the time of indexing, the output of the high-resolution low-speed encoder 12 is detected. Using this as a feedback signal, the control circuit 9 adjusts a command value for the current amplification circuit 6 for indexing and positions the mover. At this time, the current supplied by the indexing current amplifier circuit 6 is supplied to the ac coils of the exciting coils 1 to 3 which are divided into three in each phase and connected in parallel.
For each of the U, V, and W phases, the current amplification circuit for determining a current value that is three times the value of the current flowing through one divided excitation coil is output to each phase.

When the spindle is operating at a high speed, the control circuit 9 uses the coil changeover switch signals 10a and 10b to control the U, V and W phases of the divided excitation coils 1 respectively.
The switching is performed so that the input terminals a and b of the a to c of the a to b are connected to the main shaft current amplifier circuit 7. The control circuit 9 supplies the main shaft current amplifying circuit 7 with drive signals having U, V, and W phases that are shifted by 120 degrees. The main shaft current amplifier circuit 7
Three current amplifier circuits are built in to output currents independently for the U, V, and W phases. The current amplifying circuits are divided into U, V, and W phases. The current is supplied according to a command given from the control circuit 9. As a result, the divided excitation coils 1 through 1 are switched via the changeover switches 10a and 10b disposed in the U, V, and W phases, respectively.
Current is supplied only to a and b in a to c of FIG. The mover (not shown) is rotated by the supplied current, and the connected encoders 11 and 12 are rotated. During operation of the spindle, the rotor rotates at a high speed (about 6000 rpm to 10000 rpm), and among the divided excitation coils, the coils a and b of the excitation coils 1 to 3 a to c connected to the current amplifier have a mover. The back electromotive force is generated by the rotation. However, the main shaft current amplifier circuit 7 receives only the back electromotive force generated by a and b of the first to third a to c of the inner divided excitation coil. On the other hand, since the back electromotive force is 2/3, the maximum output voltage of the main shaft current amplifier circuit may be 2/3. On the other hand, the maximum torque is one of 1 to 3 a to c of the divided excitation coils,
Since the current is supplied only to a and b, it is 2/3 as compared with the case of using an indexing current amplifier that supplies current to all of the excitation coils 1 to 3c. Since no large torque is required in operation, no problem occurs. At the time of spindle operation, the high-resolution low-speed encoder 12 has too high a rotation speed and cannot be detected. Therefore, the output of the low-resolution high-speed encoder 11 is detected, and the feedback signal is used as a feedback signal by the control circuit 9 to control the current amplification for the spindle. The command value for the circuit 7 is adjusted to position the mover. At this time, the current supplied by the main shaft current amplifying circuit 7 is supplied to two parallel-connected exciting coils of each of the three divided phases.
In both the V and W phases, a current that is twice as large as the current flowing through one of the divided excitation coils is output.

(Embodiment 2) FIG. 2 shows a second embodiment of the present invention.

This embodiment uses a DC brushless motor for Y
It is a connected three-phase motor. Fig. 2
The U-phase excitation coil is divided into three, and three coils having a common ground, such as the excitation coils 1a, 1b, and 1c, are arranged in parallel. The excitation coil is divided by winding three parallel wires at the same time. The excitation coils of a, b, and c of the excitation coils 1 to 3 of each phase which are divided into three are connected to different current amplifier circuits 14a to 14c via changeover switches 4d to 4f. The switching switches 4d to 4f are connected to or disconnected from the current amplification circuits 14a to 14c by the switching signals 10d to 10f, respectively. Switching between the two patterns.

Further, as an encoder serving as a detection system, a low-resolution high-speed encoder 11 used during spindle operation and a high-resolution low-speed encoder 12 used during index operation are used.
Is connected to the control circuit. Both encoders are connected to a mover using permanent magnets (not shown) and measure the movement of the motor.

With such a configuration, at the time of the indexing operation in which a high torque is required, the control circuit 9 uses the coil changeover switch signals 10d to 10f to control the U, V, and W phases of the divided excitation coils 1 to 3, respectively. The switches are switched so that the connections to ac are connected to the current amplifier circuits 14a to 14c, respectively. The control circuit 9 includes a current amplification circuit 14
The drive signals a to c are shifted by 120 degrees in U, V, and W phases. The current amplifying circuits 14a to 14c are respectively connected to the ac excitations of the divided excitation coils 1 to 3 of U, V, and W phases.
The current is supplied according to a command given from the control circuit 9. As a result, current is supplied to all of the divided excitation coils via the changeover switches 4d to 4f arranged in the U, V, and W phases, respectively. The mover (not shown) is rotated by the supplied current, and the connected encoder 11 is rotated.
And 12 rotate. At the time of indexing, the control circuit 9 detects the output of the high-resolution low-speed encoder 12 and uses the output as a feedback signal to adjust command values for the current amplifier circuits 14a to 14c to position the mover. At this time, the current supplied by the current amplifier circuits 14a to 14c is a current of the excitation coils 1 to 3 in which each current amplifier circuit is divided into three and connected in parallel.
To c individually.

When the spindle is operating at a high speed, the control circuit 9 uses the coil changeover switch signals 10d to 10f to separate the excitation coils 1 of the U, V, and W phases.
The connection between the input terminals of a to c and the current amplification circuits 14a to 14c is changed. At this time, the connection switching signals 10d-e
Therefore, among the changeover switches 4d to 4f, f is released, and only the coils a and b are used among the divided excitation coils 1 to 3 a to c. The control circuit 9 provides the current amplifier circuits 14a and 14b with drive signals of U, V, and W phases that are shifted by 120 degrees. The current amplifying circuits 14a and 14b are respectively divided into excitation coils 1 to 3 of U, V, and W phases.
Are supplied in accordance with the instruction given from the control circuit 9 to a and b. As a result, current is supplied only to a and b of the divided excitation coils 1 to 3 through the changeover switches 4d and 4e disposed in the U, V, and W phases, respectively. The mover (not shown) is rotated by the supplied current, and the connected encoders 11 and 12 are rotated. High speed (6000 rpm-100
(Approximately 00 rpm), and among the divided excitation coils, the back electromotive force is generated by the rotation of the mover in the coils of a and b of the excitation coils 1 to 3 connected to the current amplification circuits 14a and 14b. . However, since only the back electromotive force generated by the inner split 1 and 2 of the exciting coil is applied to the main shaft current amplifier, the exciting coil is divided and used, whereas the back electromotive force is 1/3. Therefore, the maximum voltage that can be output from the main shaft current amplifier may be 1/3. On the other hand, the maximum torque is 2/3 as compared with the case of using an indexing current amplifier for supplying current to all 1 to 3 because the current is supplied only to 1 and 2 of the divided excitation coils. Unlike the indexing operation, the spindle operation does not require a large torque, so that no problem occurs. At the time of spindle operation, the high-resolution low-speed encoder 12 has an excessively high rotation speed and cannot be detected. Therefore, the output of the low-resolution high-speed encoder 11 is detected. Adjust the value and position the mover.

(Embodiment 3) FIG. 3 shows a third embodiment of the present invention.

In this embodiment, a DC brushless motor is used.
It is a connected three-phase motor. The difference from the second embodiment is that
The coil is divided into two parts, and the connection of the divided excitation coils is in series. By the changeover switches 4g and 4h, a current is passed through the two series-connected coils during the indexing operation, and the series is formed during the main shaft operation. That is, control is performed by the control circuit 9 so that current flows through only one of the two coils.

(Embodiment 4) When the parallel wires of the embodiment 1 are integrally wound, the separately wound coils can be combined and divided evenly.
About 20 parallel wires are wound together. On this occasion,
A coil having the same width as the integrated parallel wiring is manufactured by winding the parallel wiring so that each of the wirings always overlaps itself. In this case, compared with the case where one coil is wound around the bobbin, since no folded portion occurs at both ends in the width direction of the coil, the coil can be more evenly divided and wound without disturbance. Even if the number of poles is increased by using the coil manufactured as described above, the same method as in the first embodiment can be used.

[0026]

As described above, according to the present invention, the excitation coil, which is supposed to be constituted by a single motor of the rotary motor, is divided, and the connection with a plurality of current amplifier circuits is switched.
By using a current amplifying circuit with different characteristics for the spindle and indexing to supply current to a part or all of the divided exciting coil, compared with the case where the exciting coil is not divided,
Compared to when the motor is not shared, there is no need to have two separate spindles and indexing shafts, and the necessary high torque is generated at the time of indexing, and at the same time, the back electromotive force generated in the current amplifier circuit during spindle operation The drive motor can reduce the influence of the drive motor.

Further, by dividing the winding excitation coil by integrating a plurality of parallel wirings, the characteristics of the divided excitation coil can be equalized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing a conventional example.

[Explanation of symbols]

1a-c U-phase excitation coil divided into three 2a-c V-phase excitation coil divided into three 3a-c W-phase excitation coil divided into three 4a-f switch 5a-f Current supply wiring 6. Three-phase current amplifier for indexing 7a-c Three-phase current amplifier circuit for spindle 8a-f Current command 9 Control circuit 10a-g switching signal 11 Low-resolution high-speed encoder 12 High resolution low speed encoder 13a, b Encoder detection signal 14a-d Three-phase current amplifier circuit 15 U-phase excitation coil 16 V phase excitation coil 17 W phase excitation coil

Claims (3)

[Claims] 1. A rotary motor in which each phase winding is constituted by a plurality of divided excitation coils and performs an indexing operation and a spindle operation, wherein a plurality of current amplification circuits; and an arbitrary excitation coil of the plurality of divided excitation coils Switching means for supplying a current from any one of the plurality of current amplifier circuits only to the plurality of current amplification circuits; and an arbitrary number of the plurality of exciting coils divided by controlling the switching means in accordance with the indexing operation or the spindle operation. And a control circuit for supplying a current from a current amplifier circuit selected from the plurality of current amplifier circuits to the exciting coil of (1). 2. The plurality of exciting coils according to claim 1, wherein the plurality of exciting coils are coils formed by winding a plurality of parallel wires in a set, and the switching unit includes a plurality of the coils wound in the set. A motor device, wherein an arbitrary number of lines are selected and connected to a current amplifier circuit. 3. The back electromotive force generated in the excitation coil connected to the excitation coil connected to the excitation coil divided during the operation of the spindle at a predetermined maximum rotation speed, wherein the plurality of current amplification circuits are connected to each other. The first current amplifying circuit capable of outputting the above voltage output and the current amplifying circuit connected to the exciting coil divided at the time of the indexing operation supply current to all the divided exciting coils to generate a predetermined maximum torque. 2. A motor device, comprising: