JPH0767379A - Starting controller of motor - Google Patents

Abstract

PURPOSE:To drive a motor easily without changing a power supply voltage and coil windinq connection by starting the motor with 120-degree conduction sequence normally and with 180-degree conduction sequence whose average torque is higher than that of 120-degree conduction and whose torque minimum point differs when the motor cannot be driven even if a specific amount of time passes. CONSTITUTION:A motor control part 10 switches SWA and SWB when ON signal is received, controls a drive circuit 20 by a 120-degree drive circuit 16 of a drive sequence circuit 12 for starting a spindle motor 22, and at the same time sets a counter 32. Then, when a position signal generation circuit 24 outputs a position signal, the counter 32 is reset and at the same time the switch SWB is switched, thus shifting to the drive by a 120-degree drive circuit 18 based on the position signal. On the other hand, when the counter 32 is overflown while the position signal is not outputted, the switch SWA is switched for a certain amount of time for driving by a 180-degree drive circuit 14, thus returning to the drive by the 120-degree drive circuit 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a start-up control device for a motor that rotates a disk in a disk drive device for recording or reproducing information, and more specifically, an HD controller.
The present invention relates to a motor start-up control device suitable for a case where the load gradually increases like the magnetic head of D.

[0002]

2. Description of the Related Art As a magnetic head for an HDD, a floating head is usually used in order to avoid damage caused by contact with a disk. That is, although the magnetic head is in contact with the disk at startup,
The air flow generated by the rotation start of the disk causes the disk to float above the disk surface.

By the way, the magnetic head is a CSS (Contact
Repeated Start Stop), the load gradually increases. Then, for example, when the load exceeds the starting torque after about tens of thousands of times, which is several times the guaranteed value of performance,
It may be difficult to start. As a result, there is an inconvenience that the data becomes inaccessible and the data recorded on the disc is lost. In addition, even if the performance is several times as high as the guaranteed value, the CSS may not be activated even if the number of CSSs slightly exceeds the guaranteed value due to the influence of humidity or temperature.

The present invention has been made in view of these points.
Focusing on the advantage of 80-degree energization, it is an object of the present invention to provide a motor start-up control device capable of excellently starting a motor without changing a power supply voltage or a winding.

[0005]

In order to achieve the above object, the present invention provides a driving means including a plurality of switching elements for energizing each winding of a motor, a position information detecting means for obtaining rotational position information, and an initial stage. A first driving the switching element in a 120-degree conduction sequence based on a driving signal;
Drive sequence means, second drive sequence means for driving the switching element in a 180-degree conduction sequence based on an initial drive signal, and when the rotational position information is detected, the switching is performed based on the information. When the motor cannot be started within a predetermined time by the third driving sequence means for driving the element in a 120-degree energization sequence and the first driving sequence means, the motor is started by the second driving sequence. And a switching means for performing the switching.

[0006]

According to the present invention, the motor is normally started by energizing 120 degrees. Then, when the motor cannot be started even after a lapse of a predetermined time, the motor is driven by 180-degree energization this time.
The 180 degree energization has an average torque of 33 times that of the 120 degree energization.
%, And the minimum torque point is different, it is possible to start up easily without changing the power supply voltage or winding connection.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a motor starting control device according to the present invention will be described in detail below with reference to the accompanying drawings.

<120-degree energization and 180-degree energization> First,
In order to facilitate understanding of the present embodiment, 120-degree energization and 180-degree energization will be compared with reference to FIG. As shown in the figure, windings U, V, W of the three-phase spindle motor
It is assumed that each of the phases is star-connected. The resistance of each phase is R. As shown in (A) of the figure, when 120-degree conduction is applied, for example, two-phase conduction of the windings U and W is performed, and the total resistance is 2R.
Becomes Therefore, if the voltage is VE, the current is I120 = V
It becomes E / 2R.

As shown in FIG. 2B, when 180-degree energization is performed, for example, winding U and V, W are connected in parallel in three phases, and the total resistance is R + R.R / (R + R) = (3/2). R = 1.5R
Becomes Therefore, the current is I180 = VE / 1.5R.
Comparing the two, I180 / I120 = (VE / 1.5R) / (VE / 2R) = 4 / 3≈1.33, and the current at 180 degrees is 1.33 times that of 120 degrees. To increase. Therefore, the generated torque is 1.33
Doubled.

On the other hand, the sensorless control which does not require a position detecting means such as a hall element is a system in which the back electromotive voltage generated by the rotational driving is detected from the winding of the motor which is not energized and the drive is controlled. The control is performed by energizing 120 degrees. On the other hand, if the 180-degree energization is performed during the start-up, the counter electromotive voltage is not output, and there is a risk that the motor that has just started starting may be stopped. In this embodiment, such an inconvenience is prevented by limiting the energization time as described later.

The 180-degree energization and 120-degree energization are disclosed in, for example, Japanese Patent Laid-Open No. 58-29387.

<Structure of Embodiment> Next, the structure of this embodiment will be described with reference to FIG. In the figure, ON / O supplied from a system controller (not shown) of the HDD based on an instruction from an external computer system.
READ for completion of startup while accepting FF instruction
The initial drive signal output side of the motor control unit 10 that outputs the Y signal to the system controller is connected to the common input side of the switch SWA. Two switching output sides of the switch SWA are connected to the 180-degree drive circuit 14 and the 120-degree drive circuit 16 of the drive sequence circuit 12, respectively.

The drive sequence circuit 12 further includes 120
The 180 degree drive circuit 1 is provided with the 180 degree drive circuit 18.
The output side of the 4 and 120 degree drive circuit 16 and the output side of the 120 degree drive circuit 18 are connected to the switching input side of the switch SWB, respectively. The output side of the switch SWB is connected to the base of the transistor Tr of the drive circuit 20. The 180 degree drive circuits 14 and 12
The output side of the 0 degree drive circuits 16 and 18 is provided for each base of the transistor Tr of the drive circuit 20,
Although these can be switched by the switch SWB, they are simply shown by one line in the drawing.

Next, the drive circuit 20 has a structure in which a series circuit including two transistors Tr whose collectors are commonly connected is connected in parallel to the power supply E. The collectors of the transistors TrUP and TrUN are connected to the U winding of the spindle motor 22, the collectors of the transistors TrVP and TrVN are connected to the V winding, and the collectors of the transistors TrWP and TrWN are connected to each other. Is connected to the W winding. In addition, "P" in these TrUP, TrUN, ...
Represents a PNP type transistor, and "N" represents an NPN type transistor.

Next, each winding of the spindle motor 22 is
Comparators 26, 28, 30 of the position signal generation circuit 24
Are connected to one input side of each. The middle points of the spindle motor 22 are connected to the other input side of the comparators 26, 28 and 30, respectively. The output sides of the comparators 26, 28 and 30 are connected to the input side of the motor control unit 10, the input side of the 120 degree drive circuit 18 of the drive sequence circuit 12, and the reset side of the counter 32, respectively.

The output side of the initial drive signal of the motor control section 10 is connected to the count-up input side of the counter 32. In addition, FF indicating the end of counting by the counter 32
The (FullFlag) output side is connected to 10 input sides.
Further, the control input sides of the switches SWA and SWB are connected to the control output side of the motor control unit 10.

Among the above, the motor control unit 10 outputs the driving pulse signal in the initial stage when the back electromotive force is not output from the windings U, V, W of the spindle motor 22, and the position signal generation circuit 24 and the counter. It has a function of controlling switching of the switches SWA and SWB based on a signal input from 32. 18 of the drive sequence circuit 12
The 0-degree drive circuit 14 and the 120-degree drive circuit 16 have a function of outputting a pulse signal for driving the transistor Tr of the drive circuit 20 based on the initial drive signal supplied from the motor control unit 10. In addition, the 120-degree drive circuit 18
Has a function of outputting a pulse signal for driving the transistor Tr of the drive circuit 20 based on the position signal supplied from the position signal generation circuit 24.

The driving sequence of these transistors Tr by the 180-degree driving circuit 14 and the 120-degree driving circuits 16 and 18 is, for example, as shown in Tables 1 and 2 below.

[0019]

[Table 1]

[0020]

[Table 2]

Table 1 shows the relationship between ON and OFF of each transistor Tr in the case of 180 ° conduction.
Shows the relationship in the case of 120-degree energization. In each case, the six states indicated by are repeated.

The switch SWA is for the spindle motor 22.
Is a switch for selecting which sequence of the 180-degree drive circuit 14 and the 120-degree drive circuit 16 of the drive sequence circuit 12 is to be driven at the time of startup, and the switch SWB is a counter-electromotive force at the time of start-up and thereafter. It is a switch for switching the sequence after voltage generation. The position signal generating circuit 24 is for detecting the rotational position of the rotor with respect to the stator from the counter electromotive voltage generated in the winding of the spindle motor 22 based on the comparison result of the comparators 26, 28, 30. The signal is output. The counter 32 counts an initial drive signal output from the motor control unit 10 and measures a predetermined time.

<Operation of Embodiment> Next, the operation of the above embodiment will be described with reference to the flowchart of FIG. Turns on via an HDD system controller from an external computer to access the disk
Is supplied to the motor control unit 10, the motor control unit 10 causes the switch SWA to drive the drive sequence circuit 1.
2 is switched to the 120 degree drive circuit 16 side, the switch SWB is switched to the 180 degree drive circuit 14, 120 degree drive circuit 16 side, and further the initial drive signal is output. Therefore, each transistor T of the drive circuit 20
A pulse signal based on the sequence of the 120-degree drive circuit 16 is supplied to each r, and the spindle motor 22 is set to 1
It is activated by energizing 20 degrees (FIG. 3, step SA). At this time, since the initial drive signal is supplied to the counter 32,
The counter 32 counts up.

When the spindle motor 22 is properly rotated by this start-up and a counter electromotive voltage is generated from the windings U, V, W, a position signal is output from the position signal generating circuit 24 (Y in step SB). ). Then, the counter 32 is reset based on the position signal, the counting operation is stopped, the output of the initial drive signal is stopped by the motor control unit 10, and the switch SWB is moved to the 120-degree drive circuit 18 side of the drive sequence circuit 12. Can be switched. As a result, the operation started based on the position signal 1
According to the sequence of the 20 degree drive circuit 18, the drive circuit 20
The transistor Tr of is driven. That is,
The rotation drive is started by energizing 120 degrees based on the position signal (step SC).

Next, when the position signal is not obtained, the energization by the initial drive signal is continued. This energization is performed for at least one of the entire sequences of to in Table 2 for each phase of the winding of the spindle motor 22 (step S).
D). This is because it is not known in any of the sequences of Table 2 to obtain the maximum torque depending on the positional relationship between the rotor and the stator of the spindle motor 22, and it is necessary to try to energize the entire sequence.

After the energization, when the count advances with the passage of time, the counter 32 overflows and F
The F signal is output to the motor control unit 10 (step SE
Y). It should be noted that this count time is preferably in the range of about 4 to 8 seconds in the case of a 2.5-inch HDD, for example.
If it is too short, it will adversely affect the normal startup, while if it is too long, it will time out including the zero track detection by the magnetic head. In other words, the fact that the activation could not be performed properly is transmitted to the host side, and the access operation is stopped.

The motor control unit 10 determines that the activation by 120 ° energization was not properly performed within the predetermined time by the input of the FF signal. As described above, when CSS is repeated, the head load increases and the starting torque may not be obtained at 120-degree energization, so that it is impossible to start at 120-degree energization.

In this case, the motor control unit 10
The switch SWA is switched to the 180-degree drive circuit 14 side of the drive sequence circuit 12, and the drive pulse of the sequence shown in Table 1 is supplied to the drive circuit 20.
A start-up operation is performed by energizing 180 degrees (step S
F). The 180-degree energization has a torque as high as 33% as compared with the 120-degree energization as described above. Further, when the torque ripple is stopped at the minimum point, the minimum point becomes different in 180 degree energization. Therefore, it is highly possible that the spindle motor 22 can be started.

In this case, each of the sequences 1 to 3 shown in Table 1 is driven once (step SG). This is because, like step SD described above, it is not known which of the sequences (1) to (4) in Table 1 is to obtain the maximum torque, and therefore it is necessary to attempt energization for all of these sequences. However, in this case, if it can be activated by energizing 180 degrees, the sequence is activated in any sequence, so that each sequence of to is sufficient. After that, the switch SWA is switched to the 120-degree drive circuit 16 side of the drive sequence circuit 12 by the motor control unit 10 to return to the 120-degree energization.

The energization time corresponding to 180 degrees (one of) is preferably, for example, in the range of about 10 to 500 msec. If this time is too short, the required torque will not be produced, and if it is too long, it will time out including zero track detection. The optimum value of the 180-degree energization time is determined by examining the state of vibration of the motor in the HDD having a light head load and the state of separating the magnetic head from the disk in the HDD having a heavy head load.

<Effect of Embodiment> As described above, according to this embodiment, when the spindle motor 22 is started, the drive is performed in the 120-degree conduction mode based on the initial drive signal.
Then, when the back electromotive force is generated satisfactorily by the rotational drive, the drive is shifted to the 120-degree conduction mode based on the position signal. However, it does not rotate well after a predetermined time,
When the counter electromotive voltage is not obtained, driving is performed in the 180-degree conduction mode with high torque. Therefore, even if the load on the magnetic head increases due to the repetition of CSS, the spindle motor 22 can be favorably started without changing the power supply voltage or the winding, and the life of the HDD can be extended.

<Other Embodiments> The present invention is not limited to the above embodiments, and includes, for example, the following. (1) In the above embodiment, the sensorless control of the present invention is used.
The present invention is applied to the startup control of the DD spindle motor, but is applicable to any motor such as a motor using a Hall element as a position sensor as long as the load at the time of startup varies. It is possible. (2) Further, two 120 in the drive sequence circuit
The degree of drive circuit may be shared, the drive circuit may be formed of a thyristor, and a filter may be added to the position signal generation circuit.

[0033]

As described above, according to the motor start-up control device of the present invention, the 180-degree energization is performed when the start-up cannot be performed well even after the 120-degree energization for the predetermined time. There is an effect that it is possible to favorably start up without switching the winding of the motor or the motor.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a motor start-up control device according to the present invention.

FIG. 2 is an explanatory diagram showing the states of 120-degree energization and 180-degree energization.

FIG. 3 is a flowchart showing the operation of the embodiment.

[Explanation of symbols]

10 ... Motor control unit, 12 ... Drive sequence circuit, 14
... 180 degree drive circuit (second drive sequence means), 1
6 ... 120 degree drive circuit (first drive sequence means),
18 ... 120 degree drive circuit (third drive sequence means), 20 ... drive circuit (drive means), 22 ... spindle motor, 24 ... position signal generation circuit (position information detection means), 26, 28, 30 ... comparator, 32 ... Counter (switching means), E ... Power supply, SWA ... Switch (switching means), SWB ... Switch (third drive sequence means), Tr ... Transistor (switching element), U,
V, W ... Winding.

Claims (1)

[Claims] 1. A drive means including a plurality of switching elements for energizing each winding of a motor, a position information detecting means for obtaining rotational position information, and a sequence of energizing the switching elements for 120 degrees based on an initial drive signal. First to drive
Drive sequence means, second drive sequence means for driving the switching element in a 180-degree conduction sequence based on an initial drive signal, and when the rotational position information is detected, the switching is performed based on the information. Third drive sequence means for driving the element in a 120-degree energization sequence, and when the motor cannot be started within a predetermined time by the first drive sequence means, the motor is started by the second drive sequence. A start-up control device for a motor, comprising: a switching means for performing.