JP2901922B2 - Washing control method of direct drive type vibration basket washing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing control method for a direct drive type vibration basket washing machine, and more particularly to a direct drive type vibration basket washing machine. The present invention relates to a washing control method for a direct-drive type vibrating basket washing machine that can appropriately control the rotation of the washing tub according to the rotation direction of the washing tub to prevent the vibration of the external tub during washing.

[0002]

2. Description of the Related Art FIG. 3 is an explanatory view showing the structure of a directly driven vibration basket washing machine. The vibration basket washing machine of the direct drive type includes a washing machine case 1 which is an outer case for protecting the washing machine, an external bathtub 2 provided inside the washing machine case 1, and a damper spring at the tip end. A damper 3 hooked to the washing machine case 1 by 3a;
Internal tub 4 which is a washing tub arranged inside external tub 2
And a rotating plate (P) integrally formed on the bottom surface of the internal bathtub 4.
ulsator) 13 brushless D transmitting torque
C motor (hereinafter referred to as motor) M1 and motor M1
And a control unit 5 for controlling the driving of. Here, the motor M <b> 1 includes a stator 14 and a rotor 15, and the stator 14 is controlled by the control unit 5.

FIG. 4 is a block diagram of the control unit 5. The control unit 5 includes, as shown in FIG. 4, a converter unit 6 for converting an external AC power supply to a DC power supply, an inverter unit 7 for applying the DC power supply of the converter unit 6 to the motor M1, and a rotor 15 for the motor M1. A rotor position detecting section 8 for detecting a position change; an overcurrent protection section 9 connected to both ends of an overcurrent sensing resistor Rs between the converter section 6 and the inverter section 7 to protect the above sections from overcurrent; A gate driving unit 10 for driving transistors Q1-Q6, which are switching elements of the unit 7, and a PWM (Pulse Width)
The microcomputer 11 controls the motor M1 by appropriately outputting a modulation (Modulation) signal and a gate signal according to the position of the rotor 15, and a modulation and buffer unit 12 that modulates and amplifies various control signals from the microcomputer 11. It is configured.

FIG. 5 is a plan view showing a twisted state of an external bathtub and a damper during a washing process in a conventional direct drive type vibration basket washing machine.

[0005] In the conventional washing machine constructed as described above, when washing is performed, the motor M1 is controlled in accordance with the control of the control unit 5.
Is driven, the rotor 15 rotates. At this time, the stator 14 receives a force in the opposite direction to the rotor 15 due to the reaction. This force is transmitted to the external tub 2 and the damper 3 because the stator 14 is fixed to the lower part of the external tub 2, and as shown in FIG. Direction), the development occurs in which the external bath 2 supported by the damper 3 is pushed.

On the other hand, when the motor M1 is driven in the opposite direction from the state shown in FIG. 5A, the state changes to the state shown in FIG. 5B. At this time, the displacement d1 of the damper 3 and the displacement Vibration shock occurs in the external bathtub 2 according to the time t1. The vibration and shock are also transmitted to the washing machine case 1. Here, the vibration impact appears in proportion to the displacement amount (d1) / displacement time (t1).

FIG. 6 is a flowchart of a washing process in a conventional direct-drive vibration basket washing machine.
Hereinafter, the relationship between the above-described series of operations will be described with reference to the flowchart of FIG.

First, the microcomputer 11 generates a gate drive signal via the modulation / buffer unit 12 and the gate drive unit 10 according to the detection signal of the rotor position detection unit 8. FIG. 7 is an operation timing chart of a conventional direct drive type vibration basket washing machine. As shown in FIG. 7, the gate drive signal includes an upper gate drive signal P1 applied to upper switching elements Q1, Q3, and Q5 of the inverter unit 7, and lower switching elements Q2, Q4, and Q5.
6 is applied to the lower gate drive signal P4.
There are other possible combinations for generating the respective gate drive signals, but here, the case of P1 and P4 has been described as an example.

Next, PWM is performed according to the rotation of the motor M1.
When the duty cycle is increased, the voltage applied to the motor M1 (PWM duty cycle × VDC) increases, so that the speed of the motor M1 increases (S10).

At this time, the duty cycle of the final target value D0 varies depending on the revolutions per minute (RPM). 8 and 9 show the PWM duty cycle during the washing process of the direct-drive vibrating basket washing machine,
4 is a graph showing a relationship between a drive current waveform and a rotation speed per minute (RPM). The PWM duty cycle has a constant slope S2
When the final target value D0 is attained after the increase in (1), the state is maintained (S11).

Here, the PWM duty cycle, the number of revolutions per minute (RPM), and the drive current waveform in the above operation are as follows:
As shown in FIG. The amount of rotation of the motor M1 is checked from the position detection signal of the rotor 15, and if it is determined that the motor M1 is rotating at a constant rotational speed, the PWM duty cycle is reduced at a constant slope S2 ', and then a predetermined time tof
The operation of the motor M1 is turned off only during the period f (S12-S
14).

After the elapse of the off-time toff, the motor M1 is driven in the opposite direction, but the PWM duty cycle is increased from 0 to the target value D0 at a constant slope S2, and the PWM duty cycle is increased.
The duty cycle is maintained at the target value D0. When the motor M1 is rotated at a constant rotation speed, PW
After decreasing the M duty cycle with a slope of S2 ',
The drive according to the forward / reverse rotation at the time of washing is controlled by a method of turning off the operation of the motor M1 for a fixed time toff (S15-S19).

The target value D0 of the PWM duty cycle is determined by the target revolutions per minute (RPM), and the increase S2 and the decrease S of the PWM duty cycle are determined.
2 'is determined experimentally. The rotation direction of the motor M1 is
It is identified by the rotor position detection signal detected by the rotor position detector 8.

[0014]

However, in the conventional washing machine constructed and operated as described above, the forward and reverse rotations of the motor are irrespective of the forward drive of the motor and the rotation speed per minute (RPM). Instead, the PWM duty cycle must be increased with a constant slope S2. Also,
Upper switching elements Q1, Q3, Q of inverter section 7
The gate drive signal P1 applied to 5 is a signal modulated by a signal (PWM0) output from the microcomputer 11. On the other hand, the lower switching element Q
2, Q4 and Q6 are applied to the gate drive signal P4 output from the microcomputer 11 (PWM0).
), The signal is not modulated.
The drive current for driving the motor M1 sharply increases during a period in which the rotation direction of the motor M1 is changed from the forward direction to the reverse direction, that is, during a period t1 in FIG. On the other hand, even if the motor is stopped at the time of actual washing, the rotation speed gradually decreases because the inertia of the internal bathtub itself is large, and therefore, when the internal bathtub is driven again in the opposite direction, the driving current sharply increases. . Therefore, a sudden increase in the drive current is a problem that always occurs during both forward and reverse rotations.

[0015] Since the rotational force of the motor is usually proportional to the supply current, a sudden change in the drive current results in a sudden change in the rotational force. This corresponds to the displacement time t in FIG.
1 becomes shorter, and conversely, the displacement d1 becomes larger, which means that the vibration of the external bathtub becomes larger. The amount of this vibration is proportional to the number of revolutions per minute (RPM) at the beginning of the reverse rotation, and such vibration causes fatigue in the damper 3, the external bathtub 2, the washing machine case 1, etc. There is a problem that it directly affects the service life of the washing machine.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to simultaneously PWM-modulate gate drive signals applied to upper and lower switching elements of an inverter unit, to thereby reduce the sudden rotational force of a motor. It is an object of the present invention to provide a washing control method of a direct drive type vibration basket washing machine capable of reducing a change and preventing a vibration impact during washing.

Another object of the present invention is to suppress a sudden increase in drive current at a point in time when the forward rotation and the reverse rotation of the motor are converted by PWM modulation of each gate drive signal. It is an object of the present invention to provide a washing control method for a direct drive type vibration basket washing machine capable of preventing mechanical vibration and shock during forward / reverse drive and thereby improving the life of the washing machine.

[0018]

According to the washing control method of the vibration basket washing machine of the direct drive type according to the present invention, a motor for a rinsing machine and an inverter section connected to the motor and applying a gate drive pulse to the motor. And a first step of determining whether the driving direction of the motor coincides with the rotating direction of the motor in the washing control method of the vibration basket washing machine of the direct drive type provided with a PWM generator for supplying a PWM signal. And a second step of simultaneously PWM-modulating the gate drive pulses respectively applied to the upper and lower switching elements of the inverter unit to a predetermined pulse width when the driving direction of the motor does not match the rotation direction of the motor. , The first and second PWM duty cycles (Dr1, Dr2) are determined by sensing the initial revolutions per minute of the motor. A step, a fourth step of increasing the first PWM duty cycle (Dr1) to a target value at a slope S1 until the driving direction of the motor coincides with the rotation direction of the motor, and a driving direction of the motor and a rotation direction of the motor. And the second PWM duty cycle (Dr2) is sloped S2 such that only one of the gate drive pulses is modulated into the PWM signal.
And the fifth step of raising and maintaining the target value at the same time, and when the motor starts rotating at a constant speed, the second PWM
A sixth step of reducing the duty cycle (Dr2) to the zero level with the slope S2 ', and after stopping the motor for a predetermined time, it is determined again whether the driving direction of the motor coincides with the rotation direction of the motor. Then, after sequentially performing the seventh step of driving the motor in a predetermined direction and the first to seventh steps, an eighth step of sequentially repeating the second to sixth steps is performed. With this configuration, when the driving direction of the motor and the rotation direction of the motor do not match, the gate driving pulses applied to the upper and lower switching elements of the inverter unit are simultaneously specified. A sudden change in the rotational force of the motor that modulates the pulse width can be suppressed to prevent vibration and impact during washing. Therefore, the life of the washing machine can be extended by appropriately controlling the mechanical vibration and shock caused by the sudden increase in the driving current generated when the washing machine is driven forward and backward.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a washing control method for a direct drive type vibration basket washing machine according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a flow chart for carrying out a washing process by a washing control method of a direct drive type vibration basket washing machine according to the present invention, and FIG. 2 is a driving current by a PWM modulation method for carrying out the present invention. It is a waveform diagram which shows an increase state.

The washing control method of the vibration basket washing machine of the direct drive type according to the present invention is performed by the washing machine shown in FIG. In order to reduce the generated vibration and shock during the period in which the forward and reverse directions of the motor are changed during forward and reverse drive of the washing machine, a sudden change in the rotational force of the motor (increase or decrease in drive current) is required to reduce the vibration and shock generated. Should be avoided. Therefore, in order to suppress a sudden increase in the driving current at the time when a sudden change in the rotational force occurs, that is, at the time when the forward rotation and the reverse rotation of the motor are converted, it is shown in FIG. It is preferable to appropriately control the drive current increase state in accordance with the PWM modulation method.

More specifically, when the inverter unit 7 is driven, the upper switching elements Q1, Q3, and Q5 and the lower switching elements Q2, Q4, and Q6 are simultaneously subjected to PWM modulation, so that the rotation of the motor in the reverse direction is reversed. It is possible to suppress an abrupt increase in drive current at the time point when the rotation in the direction is converted. Hereinafter, the process will be described with reference to the flowchart of FIG.

First, before driving the motor M1, it is determined whether or not the reverse rotation Mr and the forward rotation Mc of the motor coincide with each other. If the rotations coincide with each other, the motor is rotated according to the conventional one-side PWM modulation method. Drive M1 (S20-S2
2).

On the other hand, if the rotations do not match, "Hig" output from the microcomputer 11 in FIG.
h ″ pulse control signal Pc ′ is
Is applied to the motor, the modulation and buffer unit 12 operates in a state where the gate drive signal output from the gate drive unit 10 is constantly PWM-modulated, and the rotation speed of the motor (R
PM) to determine initial first and second duty cycles Dr1 and Dr2, respectively (S20-S2).
3). At this time, a comparison table of the duty cycles Dr1 and Dr2 based on the rotation speed per minute (RPM) in the reverse direction when the motor is driven is as shown in Table 1 below.

[0025]

[Table 1] Here, the number of revolutions per minute (RPM) is...>R1>R2> R
3>, and the first duty cycle is: <Dr1
(1) <Dr1 (2) <Dr1 (3) <...
The duty cycle is: <Dr2 (1) <Dr2
(2) <Dr2 (3) <... The first duty cycle Dr1 is determined so as to be in a state that does not affect the life of the washing machine (an appropriate level of vibration and impact), and the second duty cycle Dr2 is determined to be a time point at which the drive current continuously increases. To decide.

After setting the PWM duty cycle to the first duty cycle Dr1, the motor starts to rotate in the forward direction Mc, and the PWM duty cycle is increased by the slope S1 to appropriately generate the rising slope of the drive current. Is changed to Mr = Mc, the PWM duty cycle is set to the second duty cycle Dr2. In response, the microcomputer 11 outputs the pulse control signal Pc ′ to “Low” (see FIG. 7), and
After the duty cycle is increased again to the target duty cycle D0 at the slope S2, the state is maintained (S
24-S27). Here, the gate drive signal of the switching element corresponding to the pulse control signal Pc 'of the microcomputer 11 is the same as Q4' shown in FIG.

When the rotation speed of the motor M1 reaches a certain speed, the PWM duty cycle is reduced to 0 with a slope S2 '. When the rotation speed of the motor M1 reaches 0, the motor M1 is stopped for a certain time Loff. Positive rotation Mc of
Is converted into a rotation Mr in the opposite direction, and the above operation is repeated (S28-S33).

On the other hand, during the operation control as described above, the PWM duty cycle, the drive current waveform, and the number of revolutions per minute (RP
9), as shown in FIG. 9, the slope of the rise of the drive current during the period in which the forward rotation Mc and the reverse rotation Mr, which has been a problem in the related art, are different from each other, is described above. By appropriately controlling according to the control operation and reducing the displacement amount (d1) / displacement time (t1) in the damper 3, the vibration and shock applied to the external bathtub 2 and the washing machine case 1 are reduced as a result.

[0029]

As described above, according to the washing control method of the direct drive type vibration basket washing machine according to the present invention, the gate drive signals applied to the upper and lower switching elements of the inverter unit are simultaneously PWM-controlled. Since the modulation is performed, a sudden change in the rotational force of the motor can be suppressed, and the vibration and impact during washing can be prevented.

Therefore, according to the washing control method of the direct drive type vibrating basket washing machine of the present invention, the mechanical vibration impact caused by the sudden increase of the driving current generated when the washing machine is driven forward / reversely can be appropriately controlled. By controlling, the life of the washing machine can be extended.

[Brief description of the drawings]

FIG. 1 is a flowchart for performing a washing process according to a washing control method of a direct-drive vibration basket washing machine according to the present invention.

FIG. 2 is a waveform diagram showing a drive current increase state by a PWM modulation method for implementing the present invention.

FIG. 3 is an explanatory view showing a configuration of a directly driven vibration basket washing machine.

FIG. 4 is a block diagram of a control unit 5;

FIG. 5 is a plan view showing a twisted state of an external tub and a damper during a washing process in a conventional direct drive type vibration basket washing machine.

FIG. 6 is a flowchart of a washing process in a conventional direct-drive vibration basket washing machine.

FIG. 7 is an operation timing chart of a conventional direct drive type vibration basket washing machine.

FIG. 8 is a graph showing a relationship between a PWM duty cycle, a drive current waveform, and a revolutions per minute (RPM) during a washing process of a vibration basket washing machine of a direct drive system.

FIG. 9 is a graph showing a relationship between a PWM duty cycle, a drive current waveform, and a rotation speed per minute (RPM) during a washing process of a vibration basket washing machine of a direct drive system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Washing machine case 2 External tub (Outer Tub) 3 Damper 3a Damper spring 4 Internal tub (Inner Tub) 5 Control part 6 Converter part 7 Inverter part 8 Rotor position detection part 9 Overcurrent protection part 10 Gate drive part 11 Microcomputer 12 Modulation and buffer unit 13 Rotating plate (Pulsator) 14 Stator 15 Rotor M1 motor (brushless DC motor)

Claims (2)

(57) [Claims] 1. A direct drive type vibration basket washing machine comprising: a motor for a washing machine; an inverter connected to the motor for applying a gate drive pulse to the motor; and a PWM generator for supplying a PWM signal. In the washing control method for a machine, a first step of determining whether a driving direction of the motor matches a rotation direction of the motor; and a step of determining whether the driving direction of the motor does not match the rotation direction of the motor. A second step of simultaneously PWM-modulating a gate drive pulse applied to each of the upper and lower switching elements of the inverter unit to a predetermined pulse width; and And the second
A third step of determining each of the PWM duty cycles (Dr1, Dr2); and the first PWM duty cycle (D2) until the driving direction of the motor and the rotation direction of the motor match.
r1) is increased to a target value at a slope S1, and when the driving direction of the motor and the rotation direction of the motor match, only one of the gate driving pulses is modulated into a PWM signal. The second P
A fifth step of increasing and maintaining the WM duty cycle (Dr2) to a target value with a slope S2, and when the motor starts rotating at a constant speed, the second PWM duty cycle (Dr2) is sloped S2 '.
A sixth step of reducing the level to 0 level, and after stopping the motor for a predetermined time, it is determined again whether the driving direction of the motor coincides with the rotation direction of the motor, and the predetermined direction is determined. A seventh step of driving the motor, and an eighth step of sequentially performing the first to seventh steps and then repeatedly repeating the second to sixth steps. And a washing control method for a directly driven vibration basket washing machine. 2. The washing control method for a directly driven vibration basket washing machine according to claim 1, wherein said first PWM duty cycle (Dr) in said third step is performed.
1) is determined when the rotation direction of the motor is changed, and the second PWM duty cycle (Dr2) is determined at a time when the drive current increases continuously, wherein the vibration basket washing machine of the direct drive type is characterized in that: Washing control method.