JP2007068994A - Driving mechanism and driving method of washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the driving mechanism and the driving method of a washing machine which make a motor drive method differ according to the operating condition of the washing machine. <P>SOLUTION: In order to drive a motor in an optimum condition according to the condition of torque and noise, the driving mechanism and its method of a washing machine have a memory where a reference signal is stored, a control section which calls the reference signal which is different each other according to the stroke of the washing machine and generates a switching signal compared to a carrier signal, an inverter which generates a motor drive signal where an external power source is switched by the switching signal, a motor which is rotated by the motor drive signal, and the rotator of the washing machine which is activated by the motor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a driving device and a driving method of a washing machine, and more specifically, a washing machine that enables a motor of a washing machine to be operated in an optimum state so as to match the operating state of the washing machine. The present invention relates to a driving device and a driving method. More specifically, the present invention relates to a washing machine driving apparatus and a washing machine for rotating a washing machine rotating body in an optimum state in accordance with the operating state of the washing machine and the taste of the user. It relates to a driving method.

  Washing machines have become popular in homes as a device for washing clothes and the like. Such a washing machine has a so-called drum washing machine in which clothes are dropped by rotation of the drum and the clothes are washed by an impact force between the clothes and washing water, and the clothes and washing are performed by rotating the pulsator at the bottom of the drum. So-called pulsator washing machine in which washing is carried out by friction between water and so-called pulsator washing machine, and so-called washing is carried out by friction force between clothes and washing water in such a way that a forced water flow is generated by an azotator protruding inside the washing tub There is an azotator washing machine. By the way, it goes without saying that any type of washing machine described above performs washing by a process in which a rotating body corresponding to a drum, a pulsator, or an azotator is rotated by a rotational force transmitted by a motor.

  And, when the functions of the washing machine and the dehydrator are adopted in a single washing machine, the drum is rotated at a high speed when the dehydration process proceeds so that the moisture of the laundry is removed by centrifugal force. Is carried out by the washing machine. In these days, it is common that the function of the washing machine and the function of the dehydrator are performed simultaneously by a single device.

  Under these circumstances, the various types of washing machines operate such that the drum, the pulsator or the agitator rotates in the opposite direction at a low speed to rotate the washing water or stir the clothes when the washing process is performed. Carried out. When the dehydration process is performed, the drum in which the garment is entirely accommodated is rotated at a high speed in a general direction so that a centrifugal force is applied to the garment, and the water wet on the garment is released by the centrifugal force. Like that. As described above, the washing machine is a device that not only performs low-speed rotation but also simultaneously performs high-speed rotation.

  On the other hand, the method of driving the motor of the washing machine is generally driven by a PWM (Pulth Width Modulation) control method. In the PMW control method, a carrier signal that is a triangular wave and a reference signal that is a sine wave are input to a comparator and compared together, and a PWM signal in a specific form is output. The output PWM signal controls the switching of the inverter, and the motor drive signal output from the inverter is input to each coil of the motor to induce the rotational force of the motor. In such PWM control, the rotational speed of the motor is changed by changing the frequency of the triangular wave and the sine wave.

  However, the conventional PWM signal output by comparing the triangular carrier signal and the sine reference signal has a problem that it cannot be applied to a washing process requiring high torque because the utilization rate of DC-link is low. . In other words, since a lot of electric power in the input DC power cannot be used as the electromotive force of the motor, there is a problem that the torque of the motor becomes weak. To this end, it is necessary to amplify the DC input voltage or increase the reverse torque when designing the motor. However, such a structural change increases the size of the motor or increases the manufacturing cost of the motor. Not desirable.

  The present invention has been proposed in order to improve the above-described problems, and an object of the present invention is to propose a washing machine driving apparatus and a driving method in which the motor driving method is varied according to the operating state of the washing machine. To do.

  Further, according to the present invention, the operation state of the washing machine motor is optimally controlled according to the rotation speed of the high-speed rotation and the low-speed rotation according to the appropriate rotation speed of the rotating body such as the drum of the washing machine. An object of the present invention is to propose a washing machine driving apparatus and a washing machine driving method.

  Furthermore, the present invention provides a washing machine driving apparatus and washing machine that allows a motor of the washing machine to be operated in an optimum state in accordance with a required torque and a required noise state in many processes of the washing machine. The purpose of this is to propose a driving method.

  According to an aspect of the present invention, the driving apparatus for the washing machine according to the present invention provides a memory in which a reference signal is stored, a reference signal different from each other according to a process of the washing machine, and a switching signal compared to a carrier signal. A controller for generating, an inverter for generating a motor drive signal by switching an external power source according to the switching signal, a motor rotated by the motor drive signal, and a rotating body of a washing machine operated by the motor are included.

  The driving method of the washing machine according to another aspect of the present invention includes a single rotating body that performs at least high-speed rotation and low-speed rotation in a state where laundry is accommodated, and a single motor that rotates the rotating body. In the washing machine, the rotation request state of the washing machine is determined, and when the rotation request state of the washing machine is high speed rotation, the motor is driven in three phases for at least a certain period to obtain low noise. If the rotation request state of the washing machine is low speed rotation, the motor is driven in two phases for at least a certain period in order to obtain a high torque.

  According to another aspect of the present invention, there is provided a method for driving the washing machine in which a rotating body of a washing machine in which laundry is accommodated rotates at a high speed to remove moisture from the laundry in a state in which the laundry is accommodated. In this case, the motor for driving the rotating body is driven in the SPWM method at least for a certain period, and the laundry is kept at a low speed so as to remove the waste while the laundry and water are contained. When rotating, the motor is driven in a DPWM system for at least a certain period.

  According to another aspect of the present invention, there is provided a method for driving a washing machine, wherein a step of determining a stroke in the washing machine, a step of determining a rotation state of a drum adapted to the determined stroke, and generating a PWM signal. The reference signal is called, the reference signal and the carrier signal are compared, a PWM signal is generated and input to the inverter, a motor drive signal is generated by the inverter, and the motor is driven by the motor drive signal. The reference signals that are called when the rotation is performed are different from each other according to the rotation state of the drum.

  According to the proposed present invention, since the motor of the washing machine can be operated in an optimum state according to the process of the washing machine, the operation performance of the washing machine can be improved and the user's taste can be enhanced. There is an advantage.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The concept of the present invention may be more clearly understood with reference to the accompanying drawings.

  FIG. 1 is a block diagram of a washing machine driving apparatus according to the idea of the present invention.

  Referring to FIG. 1, a washing machine driving apparatus according to the present invention includes a power supply unit 1 to which an AC power is input, a rectification unit 2 that rectifies the AC power input through the power supply unit, and a rectification unit. A smoothing unit 3 that smoothes the rectified DC power source, an inverter 4 that switches the power source smoothed by the DC power source to generate a motor drive signal, and a motor 5 that is driven by the output power source of the inverter are included.

  Further, a control unit 6 that generates a switching signal for controlling the power source of the inverter 4 and inputs the switching signal, and a memory 7 that stores information necessary for the operation of the control unit 6 are included.

  As one feature of the present invention, at least two kinds of reference signals are recorded in the memory 7 in the form of a look-up table, so that appropriate reference signals are called for each operation state of the motor. For example, one of the reference signals is a first lookup table necessary for two-phase driving of the motor, and the other is a second lookup table for three-phase driving of the motor. It has already been explained that the reference signal is compared with the carrier signal to generate the switching signal necessary for the operation of the inverter 4. The PWM signal generated by the inverter is naturally input to the motor 5 and used as a motor drive signal.

  The washing machine driving method according to the present invention will be briefly described based on the proposed washing machine driving apparatus.

  First, many processes that are performed in the washing machine are divided into processes that require motor rotation and processes that do not require motor rotation. For example, the process requiring the motor rotation is a process in which the drum / pulsator / ezo data is rotated in the washing / rinsing / dehydrating process, and the process not requiring the motor rotation is a water supply / drainage process. If the motor needs to rotate during the above-described process, it is determined whether the process currently being performed is a high-speed rotation process or a low-speed rotation process. The high-speed rotation or the low-speed stroke is determined in advance according to the operating state of the washing machine. For example, washing and / or rinsing is a low-speed stroke, and the dewatering stroke is a high-speed stroke.

  Here, if the high-speed rotation stroke proceeds, the motor is driven in three phases. The reason why the motor is driven in three phases in such a high-speed rotation process is that since a relatively large amount of noise is generally generated if the motor is rotated at a high speed, the noise is low even if the torque is weak. The motor is driven by a three-phase drive system. On the other hand, when the low-speed rotation stroke is advanced, the motor is driven in two phases. The motor is driven in two phases in such a low-speed rotation process. In general, when the motor is rotated at a low speed, water and clothes are contained in the drum as in the washing process. This is because the direction of rotation of the motor is frequently changed and many resistances are added to the rotation of the motor. Therefore, the motor is driven in two phases with strong torque in the low speed rotation stroke. Here, even when the motor is driven in two phases, a certain amount of noise is generated. However, this noise is absorbed by the noise generated when the clothes are agitated and does not give the user any additional discomfort.

  The motor two-phase driving method and three-phase driving method described above will be described in more detail later.

  Then, after a certain stroke of the washing machine is finished, it is determined what the next stroke is performed continuously. If it is a low-speed rotation stroke, a two-phase drive method is applied, and a high-speed rotation stroke is applied. If this is the case, a three-phase driving method is applied and the driving process of the next washing machine proceeds.

  On the other hand, the data stored in the memory 7 is called up and used as data necessary for the two-phase driving method or the three-phase driving method of the motor. When the two-phase driving method is applied, the first look-up table is called and used as a reference signal, and when the three-phase driving method is applied, the second look-up table is called and used as a reference signal. The called look-up table information is compared with the carrier signal by the control unit 6, and the signal output after the comparison is input to the inverter 4 and used as a switching signal.

  The driving method of the washing machine as described can be clearly understood by the flow diagram illustrating the driving method of the washing machine presented in FIG.

  If the driving method of the washing machine is described in detail with reference to FIG. 2, it is first determined whether or not the motor is driven (ST1). The stage where the motor is driven is classified into a washing process, a rinsing process, and a dehydrating process as a direct process, and is classified into a drum, a pulsator, and an azotator as a process rotated for washing. There is a distinction between a process in which the motor is rotated at a low speed for the rinsing process and a stage in which the motor is rotated at a high speed for the dewatering process.

  Next, it is determined whether or not the motor is rotating at a high speed (ST2). If it is determined that the motor is in the high speed rotation mode, the motor is driven in three phases (ST3), and the low speed rotation mode is not the high speed rotation mode. In this case, the motor is driven in two phases (ST4). Whether the motor is rotating at high speed can be determined in advance according to a series of stroke states stored in the memory in advance according to the progress of the washing machine.

  The reason why the operation method of the motor changes according to the process of the washing machine is to operate the washing machine under the optimum torque condition and noise condition according to the process of the washing machine. In particular, when the motor is driven in two phases, a high torque is generated because the DC-link utilization rate of the motor is close to 100%. However, since many harmonics are generated, noise is generated during driving. A lot is generated. When the motor is driven in three phases, the DC-link utilization rate is approximately 87% lower than that in the two-phase drive state, but the torque is low, but it is preferably applied when low noise operation is required due to less harmonics. Can.

  FIG. 3 is a drawing showing an example of a three-phase driving method, and FIG. 4 is a drawing showing no example of a two-phase driving method. The three-phase driving method is a sinusoidal pulse width modulation method (hereinafter referred to as SPWM), and the two-phase driving method is a dead-band sinusoidal pulse width modulation method (hereinafter referred to as DPWM). It can be embodied by.

  Referring to FIGS. 3 and 4, FIGS. 3 (a) and 4 (a) illustrate alternating states of the carrier signals 11 and 21 and the reference signals 21 and 22, and one of the carrier signals that are triangular waves. The reference signal, which is a sine wave, is shown in comparison with each other. The line-to-neutral switching pattern output after the two signals are compared by the comparator is shown in FIGS. 3B and 4B. ing. 3 (c) and FIG. 4 (c) show a state where the signals of FIG. 3 (b) and FIG. 4 (b) are subjected to Fourier transform and subjected to frequency analysis in the frequency domain.

  Referring to FIG. 3B and FIG. 4B, when the carrier signals 11 and 21 are equal and the reference signals 12 and 22 are compared, the reference signal 12 is a continuous sine in SPWM. On the other hand, in the DPWM, the reference signal 22 is a discontinuous sine wave, and 120 of the entire 360 has no signal in DPWM. Therefore, in SPWM, a drive signal continuously PWM-modulated is input to all three phases of the motor 5, but in DPWM, ON (ON) that is not modulated by the carrier signal 21 through one phase alternated at intervals of 120. ) Signal is input. In the case of the DPWM, since the reference signal 22 is not input at 120, this region is called a dead-band. By such a method, the DPWM is always inputted with a motor drive signal modulated only for two phases, and for this reason, the DPWM is driven by a two-phase drive method.

  Further, referring to FIG. 3C and FIG. 4C, the two-phase driving method generates more harmonics than the three-phase driving method, and the motor is driven by the harmonics. It can be seen that many roaring sounds are generated.

  3 (d) and FIG. 4 (d) illustrate the output waveforms between the lines in the SPWM method and the DPWM method, respectively, and FIG. 3 (e) and FIG. 5D is a diagram of a state in which the signal of FIG. 4D and the signal of FIG. 4D is subjected to Fourier transform and subjected to frequency analysis in the frequency domain.

  Referring to FIG. 3D and FIG. 4D, the DPWM method is applied because the duty cycle of the DPWM method is increased and the utilization rate of the DC-link is higher than that of the SPWM method. It can be easily understood that high torque is generated by the two-phase driving.

  Referring to FIG. 3E and FIG. 4E, since the DPWM system generates more harmonics than the SPWM system, there are many problems in the two-phase drive to which the DPWM system is applied. It can be easily understood that sound is generated.

  The motor drive systems described can be applied differently according to the process of the washing machine. More specifically, it is desirable to apply a two-phase drive system of a motor operated by the DPWM method in a washing process and / or a rinsing process in which a high torque is required during the operation process of the washing machine. This is because high torque can be obtained even if noise is generated to some extent. In addition, in the washing process and / or rinsing process, even if a noise is generated by a motor, it is less likely to cause discomfort to the user when mixed with a noise generated when stirring laundry such as clothes. is there. Further, although the washing process and the rinsing process are rotating at a low speed, the two-phase driving system operated by the DPWM system in which a high torque is generated is more suitable because the rotation direction is rapidly changed.

  Further, in the dehydration process that rotates at high speed during the operation process of the washing machine, the three-phase drive system of the motor operated by the SPWM system is desirable because a low noise operation state can be obtained even if the torque is small. In the dehydration process, the rotation direction is not changed even if it rotates at high speed, and a large torque is not required in the rotating state, so that sufficient power can be obtained even at low torque. The three-phase drive system of this motor is more suitable.

  Referring to FIG. 2 again, if it is determined that the low-speed rotation mode is selected (ST2) and the two-phase driving of the motor is performed (ST5), first, the first lookup table is called in the memory 7 (ST6). ), The control unit 6 compares the reference signal of the first lookup table with the carrier signal to generate a switching signal (ST7). Then, the switching signal is used as a switching signal of the inverter 4, and a direct motor drive signal is generated in the inverter 4 and supplied to the motor 5, and the motor is rotated (ST8).

  In the high-speed rotation mode determination step (ST2), if the high-speed rotation mode is determined and the motor is driven in three phases (ST3), the second look-up table is first called in the memory 7 (ST4). ), The control unit 6 compares the reference signal of the second lookup table with the carrier signal to generate a switching signal (ST7). Then, the switching signal is used as a switching signal of the inverter 4, and the inverter 4 generates a motor drive signal and supplies it to the motor 5 to rotate the motor (ST8).

  According to the proposed invention, especially when performing a stroke such as a dehydration stroke that requires operation in a low noise state, the motor is driven in three phases by the SPWM method, so that the torque is small. In other words, the washing machine can be driven with the necessary low noise. In particular, when performing a washing process or a rinsing process that requires high-torque operation, it is necessary to say that low noise is generated to some extent by allowing the motor to be driven in two phases by the DPWM method. There is an advantage that the washing machine can be driven in a high torque state.

  As described above, according to the method for driving a washing machine according to the present invention, the DPWM method can be realized by storing two types of lookup tables in the memory 7 without adding a complicated hardware configuration. It is possible to implement a two-phase motor drive system using the SPWM and a three-phase motor drive system using the SPWM system. Therefore, it is possible to obtain an advantage that the driving system of the washing machine can be adapted according to the process of the washing machine, without consuming additional circuits or additional costs.

  The proposed specific embodiments of the present invention can be applied to other embodiments that are changed within the scope of the present application, and therefore, such changeable embodiments will be described below. To do.

  First of all, the main idea of the present invention is the washing and rinsing process in which the requirements for noise are low while requiring torque, in other words, according to the operating state of the washing machine in which washing, rinsing and dewatering are performed by a single rotating body. In a dehydration process where torque requirements are low while low noise is required, the washing machine motor is rotated in different ways. By performing the operation of the washing machine in this way, it is possible to increase the satisfaction of the user due to low noise according to the operation state of the washing machine, or to obtain the operational safety of the washing machine by its torque, There is an advantage that the washing performance can be improved. Also, there is no additional hardware configuration, and a small amount of information that is applied differently to the number and type of motor operable phases, such as multiple lookup tables, is added to the memory. The effect can be achieved only by doing so, and there is an advantage that the manufacturing cost is reduced.

  Further, the reference signal and carrier signal used in the DPWM method are not limited to those presented, and signals in which various forms are combined can be used. However, such a DPWM system also has a dead zone at regular intervals, and of course the motor is operated in two phases. It should be readily understood that the use of various types of reference signals and carrier signals is the same in the three-phase driving of the motor. And the motor drive system that can meet the requirements of noise and torque depending on the motor drive system should be able to propose various phases, but compared with the case where high torque is required When low noise is required, it is more desirable to apply a drive system with a large number of phases.

  As another example, when a specific process is performed according to a process of the washing machine, the motor may be driven in two phases in a certain section, and the certain section may be driven in three phases. It should be included in the scope of thought. However, it is naturally preferable in the idea of the present invention that the two-phase drive is preferably driven by only two phases as a whole and the three-phase drive is driven by only three phases as a whole.

  Also, in terms of equipment, it is possible to save two lookup tables according to the motor drive system and call them up whenever necessary, but according to the progress of the continuous process in the washing machine, It is also possible to store more than one lookup table and call and use a more suitable lookup table as needed. Furthermore, it is possible to generate a necessary reference signal every time by an arithmetic method instead of a method of storing a table in a memory. In order to improve the responsiveness of the system, it is more desirable to call and use it every time necessary things occur in a state where the lookup table is stored in advance.

  The present invention can be applied to various types of washing machines such as a drum, a pulsator, an ezotator and the like in various types of washing machines. More preferably, it applies to the driving of drums in drum washing machines that act equally.

  In the proposed invention, it is an advantage that it is possible to drive the washing machine in which the characteristics of the stroke are adapted so that the driving methods of the inverter and the motor are different according to the stroke state of the washing machine.

  Since the two-phase motor driving method and the three-phase motor driving method are selectively applied according to the appropriate rotation speed and noise state of the rotating body such as a drum of a washing machine, operation with low noise is especially performed during dehydration. In addition, it is possible to obtain an advantage that a high torque operation is possible during washing and rinsing.

  Furthermore, it is possible to operate the washing machine as desired simply by storing a plurality of reference signals for individual operation of the inverter in an already installed memory, so an additional configuration is required. Not only that, but you can get the advantage of not spending money.

It is a block diagram of the drive device of the washing machine concerning the present invention. It is a flowchart explaining the drive method of the washing machine which concerns on this invention. 1 is a diagram illustrating an example of a three-phase driving method of a motor according to the present invention. 1 is a diagram illustrating an example of a two-phase driving method of a motor according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply part 2 Rectification part 3 Smoothing part 4 Inverter 5 Motor 6 Control part 7 Memory

Claims (14)

A memory in which the reference signal is stored;
A control unit that calls the reference signals different from each other according to the process of the washing machine and generates a switching signal compared to the carrier signal;
An inverter that generates a motor drive signal by switching an external power supply according to the switching signal;
A motor rotated by the motor drive signal;
A rotating body of a washing machine operated by the motor;
A drive device for a washing machine, comprising:   The washing machine driving apparatus according to claim 1, wherein the reference signal includes at least a reference signal for two-phase driving of the motor and a reference signal for three-phase driving of the motor.   The reference signal for three-phase driving of the motor is a continuous sine wave signal, and the reference signal for two-phase driving of the motor is a sine wave signal having a dead band. A washing machine drive.   The driving device of the washing machine according to claim 1, wherein the motor driving signal is a two-phase driving signal or a three-phase driving signal determined according to the reference signal.   The driving apparatus of the washing machine according to claim 1, wherein the reference signal is stored in the memory in the form of a plurality of look-up tables.   The driving device of the washing machine according to claim 1, wherein the plurality of reference signals are called different reference signals according to a process of the washing machine.   The driving device of the washing machine according to claim 6, wherein, when the process of the washing machine is a dehydration process, a reference signal for causing the motor to be driven in three phases is called.   The driving device of the washing machine according to claim 6, wherein when the process of the washing machine is a washing and / or rinsing process, a reference signal for causing the motor to be driven in two phases is called. In a washing machine including a single rotating body that performs at least high-speed rotation and low-speed rotation in a state in which laundry is accommodated, and a single motor that rotates the rotating body,
Determining a rotation request state of the washing machine;
When the rotation request state of the washing machine is high-speed rotation, the motor is driven in three phases for at least a certain period to obtain low noise, and when the rotation request state of the washing machine is low-speed rotation, high torque is obtained. The motor is driven in two phases for at least a certain period of time,
A method for driving a washing machine, comprising:   The method for driving a washing machine according to claim 9, wherein when the rotating body is rotated at a high speed, a dehydration process of the washing machine is performed.   The method for driving a washing machine according to claim 9, wherein when the rotating body is rotated at a low speed, the washing process is a washing process and / or a rinsing process.   The method for driving a washing machine according to claim 9, wherein the motor is driven by an inverter.   The method of driving a washing machine according to claim 12, wherein when the rotating body is rotated at a high speed, the switching signal of the inverter is generated by an SPWM method.   The method of driving a washing machine according to claim 12, wherein when the rotating body rotates at a low speed, the switching signal of the inverter is generated by a DPWM method.

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