Drum washing machine

Abstract

To provide a drum type washing machine capable of executing a dewatering operation according to the amount of clothing without making the time for a washing operation longer.SOLUTION: A drum type washing machine includes: a drum provided in a rotatable manner and for storing clothing; a motor for rotationally driving the drum; a current measurement part for measuring a motor current value which is the value of a motor current flowing in the motor; and a control part for controlling the rotation of the motor in the washing operation including the dewatering operation. The control part executes a balance control step which includes: a first control step of increasing the rotational frequency of the drum to first rotational frequency before performing the dewatering operation; and a second control step of lowering the rotational frequency of the drum from the first rotational frequency to second rotational frequency lower than the first rotational frequency. The control part can execute a first dewatering operation which is different from the normal dewatering operation, based on the motor current value measured in the balance control step.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a drum-type washing machine. [Background technology]

[0002] Patent Document 1 discloses a drum-type washing machine that efficiently corrects imbalances when spin-drying a small amount of laundry. This drum-type washing machine includes a drum, a water tub, a motor that rotates the drum, a laundry amount detection unit that detects the amount of laundry in the drum, and a control unit that controls the operation of the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-75477 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a drum-type washing machine that can execute a spin-drying operation according to the amount of laundry without providing a separate process for determining the control content of the spin-drying operation. [Means for solving the problem]

[0005] A washing machine according to the present disclosure includes a rotatable drum for storing clothes, a motor for driving the drum to rotate, a current measuring unit for measuring a motor current value, which is a value of a motor current flowing through the motor, and a control unit for controlling the rotation of the motor during a washing operation including a spin-drying operation. The control unit executes a balance control process including a first control step for increasing the rotation speed of the drum to a first rotation speed before the spin-drying operation, and a second control step for decreasing the rotation speed of the drum from the first rotation speed to a second rotation speed lower than the first rotation speed. The control unit is capable of executing a first spin-drying operation, which is different from a normal spin-drying operation, based on the motor current value measured in the balance control step. The first dehydration operation The rising gradient of the drum in the normal dehydration operation is gentler than the rising gradient of the drum in the normal dehydration operation. do. [Effects of the Invention]

[0006] The drum-type washing machine according to the present disclosure performs a spin cycle according to the amount of laundry using the motor current value measured in the balance control process, eliminating the need for a separate process for determining the control content for the spin cycle, and preventing the washing operation from taking too long. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a drum-type washing machine according to a first embodiment. [Figure 2] A block diagram showing the configuration of a control circuit of a ram-type washing machine according to a first embodiment. [Figure 3] FIG. 1 is a block diagram showing vector control in a control circuit of a drum-type washing machine according to a first embodiment. [Figure 4] 1 is a time chart showing the number of rotations of the drum in a balance control process of the drum-type washing machine according to the first embodiment. [Figure 5] Flowchart of balance control process and dehydration operation of drum type washing machine in embodiment 1 [Figure 6]Graph showing the relationship between the amount of laundry and the motor current value in the drum type washing machine according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

[0009] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0010] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS.

[0011] [1-1.Configuration] [1-1-1. Basic configuration of drum-type washing machine] FIG. 1 is a longitudinal cross-sectional view showing a schematic configuration of a drum-type washing machine 100 according to the first embodiment. As shown in FIG. 1, a cylindrical water tub 102 with a bottom is elastically supported by a suspension structure inside a housing 101, which is the washing machine body. A drum 103 for storing clothes is rotatably disposed inside the water tub 102. A plurality of water passage holes 104 are formed in the wall of the drum 103 to allow wash water to pass inside and outside the drum 103. A plurality of agitation protrusions are formed on the inner wall of the drum 103 to agitate the clothes. A rotating shaft 105 is provided at the rotation center of the drum 103, extending horizontally or in a direction inclined downward from the horizontal toward the rear. A motor 120, located near the rear side of the water tub 102, is connected to the rotating shaft 105 via a belt 106 and a pulley. The rotation of the motor 120 is controlled by a control unit 220 in the housing 101. The rotational driving force of the motor 120 is transmitted to the drum 103 via the belt 106 and the pulley, causing the drum 103 to rotate in the forward or reverse direction. The rotation speed of the drum 103 corresponds to the rotation speed of the motor 120 at a predetermined reduction ratio.

[0012] The housing 101 is provided with a door 109 at a position opposite to a clothing entrance 108 of the drum 103. With the door 109 open, a user can put clothes into or take clothes out of the drum 103 through the clothing entrance 108.

[0013] An operation display panel 110 is provided above a door 109 on the upper front surface of the housing 101. A user can operate the operation display panel 110 to set a desired operation course.

[0014] A fluid balancer 111 is provided on the front side of the drum 103. The fluid balancer 111 is divided into multiple storage chambers by multiple partition plates provided in the circumferential direction, and each partition plate has a communication hole. A liquid with a high specific gravity, such as a calcium chloride solution or a sodium chloride solution, is stored inside the fluid balancer 111. The liquid in the fluid balancer 111 can move from one storage chamber to the next through the communication hole. If the clothes in the drum 103 are unevenly distributed during the washing operation, an eccentric load is generated on the drum 103. The liquid in the fluid balancer 111 moves to the opposite side of the eccentric load, correcting the imbalance in the center of gravity and reducing vibration and noise of the drum 103.

[0015] The housing 101 also includes a water supply unit 130, a drainage unit 140, and a drying unit 150.

[0016] The water supply unit 130 has a water supply pipe 131 and a water supply valve 132 (shown in FIG. 2) provided in the water supply pipe 131. When the water supply valve 132 is opened, water is supplied into the water tank 102.

[0017] The drain unit 140 has a drain pipe 141 and a drain valve 142 (shown in FIG. 2) provided in the drain pipe 141. When the drain valve 142 is opened, water is drained out of the water tank 102.

[0018] The drying section 150 has a circulating air path 151, and further has, along the circulating air path 151, a heat pump 152 (shown in FIG. 2) consisting of a heating means such as a condenser, a blower fan 153 as a blowing means, and a filter 154 for removing foreign matter in the circulating air.

[0019] [1-1-2. Motor configuration] Motor 120 is a brushless motor. Motor 120 includes a permanent magnet that constitutes a rotor, a stator, and a rotor position detection unit 121. Rotor position detection unit 121 is composed of Hall IC 121a, Hall IC 121b, and Hall IC 121c. Hall IC 121a, Hall IC 121b, and Hall IC 121c detect position output reference signals every 60 electrical degrees from the relative position (rotor position) between the permanent magnet and the stator.

[0020] Motor 120 also has windings 122a, 122b, and 122c, which are three-phase windings of the stator. By controlling the supply of current to windings 122a, 122b, and 122c, motor 120 rotates at a predetermined rotation speed. The rotation of motor 120 is detected by rotation detector 107 on the back surface of motor 120.

[0021] [1-1-3. Control circuit configuration] Fig. 2 is a block diagram showing the configuration of a control circuit of drum type washing machine 100 according to the first embodiment. As shown in Fig. 2, the control circuit includes power supply introduction unit 200 connected to a commercial power source, rectifier 201, choke coil 202, smoothing capacitor 203, inverter circuit 210, load drive unit 204, and control unit 220. The AC voltage of power supply introduction unit 200 is rectified by rectifier 201. The rectified AC power is converted into a DC voltage by a smoothing circuit consisting of choke coil 202 and smoothing capacitor 203. The converted DC voltage is applied to inverter circuit 210.

[0022] The inverter circuit 210 is a three-phase full-bridge inverter circuit configured with an intelligent power module (hereinafter referred to as IPM) incorporating six insulated gate bipolar transistors (IGBTs) and anti-parallel diodes.

[0023] The control unit 220 is composed of a microcomputer, an inverter control timer (PWM timer) built into the microcomputer, a high-speed A / D conversion circuit, a memory circuit (ROM, RAM), and the like.

[0024] FIG. 3 is a block diagram showing vector control in the control circuit of drum-type washing machine 100 according to the first embodiment. In the control block of FIG. 3, current measurement unit 212 measures at least two-phase currents (Iu and Iv in FIG. 3) among currents Iu, Iv, and Iw supplied to motor 120. Current measurement unit 212 is configured with a shunt resistor. Control unit 220 detects the electrical angle from the position output reference signal of rotor position detection unit 121 and performs a three-phase / two-phase dq transformation to resolve the motor current value measured by current measurement unit 212 into a motor magnetic flux current Id, which is a current component corresponding to magnetic flux, and a motor torque current Iq, which is a current component corresponding to torque. Control unit 220 compares the converted Iq and Id with commanded Iq* and Id*, and then controls motor torque current Iq and motor magnetic flux current Id by using appropriate control gains P, I, etc. Furthermore, the control unit 220 performs a two-phase / three-phase dq inverse transformation to convert the voltage component Vd corresponding to the magnetic flux and the voltage component Vq corresponding to the torque into three-phase motor drive control voltages Vu, Vv, and Vw. The IGBT switching elements 211a to 211f are then PWM controlled through the drive circuit 221. As a result, the control unit 220 drives the motor 120 to rotate at a required rotation speed.

[0025] In addition, the control unit 220 controls the rotation drive of the motor 120 and the operation of the water supply valve 132, the drain valve 142, the heat pump 152, and the blower fan 153 via the load drive unit 204 based on operation instructions from the input setting unit 222, which sets the operation course, etc., and monitoring information, and controls a series of washing operation steps such as the washing step, rinsing step, and final spin-drying step.

[0026] [1-2. Operation and Control] [1-2-1. Basic operation of washing machine] The basic operation of the drum type washing machine 100 configured as above will now be described.

[0027] The washing operation is carried out in the following order: washing, rinsing, and final spin-drying. First, the user opens the door 109, puts clothes and detergent into the drum 103, and operates the operation display panel 110 to start the washing operation.

[0028] When the washing operation starts, the control unit 220 executes the washing cycle. In the washing cycle, the control unit 220 opens the water supply valve 132 to supply water from the water supply pipe 131 into the water tub 102, and closes the water supply valve 132 when the water level reaches a predetermined level. The control unit 220 then rotates the motor 120 to rotate the drum 103. As the drum 103 rotates, the clothes stored in the drum 103 are lifted in the direction of rotation by the agitation protrusions, and then dropped from an appropriate height and agitated. In this way, dirt is removed by beating the clothes by lifting them and dropping them. When a predetermined time has elapsed since the start of agitation, the control unit 220 opens the drain valve 142 to drain the washing liquid from the washing tub.

[0029] Next, the control unit 220 executes the rinsing process. In the rinsing process, an intermediate spin-drying operation is first performed. In the intermediate spin-drying operation, the rotation speed of the drum 103 is increased through a balance control process described below, thereby spinning out the washing liquid contained in the clothes. Then, the control unit 220 opens the water supply valve 132 to supply water into the water tub 102 again. Then, as the drum 103 rotates, the clothes stored in the drum 103 are lifted by the agitation protrusions and dropped, repeatedly undergoing an agitation operation, thereby rinsing the clothes. After a predetermined time has elapsed since the start of agitation, the control unit 220 opens the drain valve 142 to drain the washing liquid from the drain pipe 141. This rinsing process is performed twice.

[0030] Finally, a final spin cycle is performed. In the final spin cycle, the balance control cycle is performed, followed by a spin cycle. In the spin cycle, the drum 103 rotates at high speed to remove water from the clothes. After that, the drum 103 stops rotating, and the washing operation ends.

[0031] [1-2-2. Balance control process] The balance control process executed before the spin-drying operation will be described. Fig. 4 is a time chart showing the rotation speed of drum 103 in the balance control process of drum type washing machine 100 in embodiment 1. Fig. 5 is a flowchart of the balance control process and the spin-drying operation of drum type washing machine 100 in embodiment 1.

[0032] When there is only a small amount of laundry in the drum 103, if the small amount of laundry is unevenly distributed within the drum 103, large vibrations and noise may occur during the spin-drying operation. Therefore, a balance control process is performed to reduce the uneven distribution of the laundry within the drum 103.

[0033] As shown in FIG. 4, in the balance control process, the control unit 220 starts vector control of the rotation speed of the motor 120 by controlling the motor torque current Iq (S301).

[0034] The control unit 220 first controls the motor 120 to accelerate the rotation of the drum 103 from a stopped state at a predetermined acceleration α1 (e.g., 0.83 r / s^2) to a first rotation speed (e.g., 100 rpm) at which the clothes stick to the inner surface of the drum 103 (S302). The process of accelerating the rotation speed of the drum 103 from a predetermined rotation speed lower than the first rotation speed to the first rotation speed is referred to as the first control process. The control unit 220 then controls the motor 120 to rotate the drum 103 at the first rotation speed for a certain period of time (S303). Thereafter, the control unit 220 further performs a second control process of controlling the motor 120 to decelerate the rotation of the drum 103 to a second rotation speed (e.g., 70 rpm) that is lower than the first rotation speed and at which the clothes do not stick to the inner surface of the drum 103 but fall by gravity (S304).

[0035] Thereafter, the control unit 220 controls the motor 120 to rotate the drum 103 at the second rotation speed for a certain period of time (S305). The control unit 220 detects the vibration state of the drum 103 using a vibration sensor or the like, and if the vibration is greater than a predetermined value, performs the first control step and the second control step again. The first control step and the second control step are performed, for example, up to four times. This loosens the clothes in the drum 103, and reduces uneven distribution of the clothes in the drum 103.

[0036] In the balance control process, the current measurement unit 212 of the inverter circuit 210 measures a rising current value, which is the motor current value in the first control process, and a falling current value, which is the motor current value in the second control process (S302, S304). The control unit 220 calculates an average value Iq1 of the motor torque current at the rising time and an average value Iq2 of the motor torque current at the falling time measured by the current measurement unit 212, and calculates the total current value (S306).

[0037] If the total current value is equal to or less than a predetermined threshold, the control unit 220 determines that the laundry load is small (S307) and performs a first spin-drying operation, which is a spin-drying operation for a small amount of laundry (S308). If the total current value is greater than the predetermined threshold, the control unit 220 determines that the laundry load is not small and performs a normal spin-drying operation (S309). The specific method for determining whether the laundry load is small and the first spin-drying operation will be described in detail later. Then, the process proceeds to the next step (S310).

[0038] The balance control process is performed multiple times during a wash cycle, and the determination of whether the laundry load is small is performed for each balance control process. The control unit 220 controls the spin-drying operation based on the motor current value measured in the most recent balance control process. This allows the control unit 220 to control the spin-drying operation using the most recent determination result of whether the laundry load is small.

[0039] If the control unit 220 determines that the laundry load is small, it performs the first spin-drying operation, which is the spin-drying operation performed when the laundry load is small. Therefore, if the laundry is removed during the washing operation, it is possible to prevent the vibration and noise during the spin-drying operation from increasing. Furthermore, if the control unit 220 determines that the laundry load is not small, it performs the normal spin-drying operation even if the first spin-drying operation was performed previously. Therefore, it is possible to prevent the washing operation time from becoming longer or the spin-drying quality from becoming worse if the laundry is added during the washing operation or if it has once erroneously determined that the laundry load is small.

[0040] [1-2-3. How to calculate the amount of clothes from the motor current value] The number of pole pairs of the motor 120 is P, the interlinkage magnetic flux by the magnet is ψa, the d-axis inductance is Ld, When the q-axis inductance is Lq, the torque T of the motor 120 is expressed by the following equation 1.

[0041] [Equation 1] T=P(ψa×Iq+(Ld-Lq)×Iq×Id) In Equation 1, ψa×Iq represents the magnet torque, which is the main component of the torque generated by the rotation of the motor 120.

[0042] As can be seen from Equation 1, the torque T of the motor 120 can be controlled by controlling the motor torque current Iq and the motor magnetic flux current Id. Furthermore, because the d-axis inductance Ld and the q-axis inductance Lq change depending on the rotation state, there are cases where the torque T does not remain constant even if the motor torque current Iq and the motor magnetic flux current Id are controlled to be constant. Therefore, the motor magnetic flux current Id is set to 0, and the motor torque current Iq is controlled to be constant, thereby controlling the torque T of the motor 120 to be constant. In this case, Equation 2 holds.

[0043] [Equation 2] T=P×ψa×Iq Here, if the amount of clothes is m, the distance from the rotation axis 105 of the drum 103 to the center of gravity of the clothes is r, and the moment of inertia of the drum 103 and the motor 120 is Jd, the moment of inertia J of the rotation system including the cloth can be calculated using Equation 3. The amount of clothes refers to the mass of the clothes contained in the washing tub.

[0044] [Math 3] J=Jd+m×r^2 Furthermore, the torque motion equation of the rotation system when the drum 103 is accelerating is expressed as in Equation 4, where α is the acceleration, Tb is the friction torque, and J is the moment of inertia of the rotation system including the clothes.

[0045] [Equation 4] T-Tb=J×α From Equation 3 and Equation 4, Equation 5 is obtained.

[0046] [Number 5] T-Tb=α×Jd+m×r^2 From the above formulas 2 and 5, the relationship between the amount of clothes m and the motor torque current Iq can be expressed as formula 6.

[0047] [Math 6] P×ψa×Iq-Tb=α×(Jd+m×r^2) From Equation 6, when the distance r from the rotation axis 105 of the drum 103 to the center of gravity of the clothes is constant, the current value Iq is proportional to the amount of clothes m. In other words, the motor torque current Iq is large when the amount of clothes m is large and is small when the amount of clothes m is small. This proportional relationship between the motor torque current Iq and the amount of clothes m is utilized.

[0048] In Equation 6, if the motor torque current at the start-up in the balance control process is Iq1 and the angular acceleration of the motor 120 at the start-up is α1, the relationship between the amount of clothing m and the motor torque current Iq1 can be expressed by Equation 7.

[0049] [Math 7] P×ψa×Iq1-Tb=α1×(Jd+m×r^2) Similarly, in Equation 6, if the motor torque current at the time of falling is Iq2 and the angular acceleration of the motor 120 at the time of rising is α2, the relationship between the amount of clothes m and the motor torque current Iq2 can be expressed by Equation 8.

[0050] [Math 8] P×ψa×Iq2-Tb=α2×(Jd+m×r^2) When the component of friction torque Tb is eliminated from Equation 7 and Equation 8, Equation 9 is established.

[0051] [Number 9] P×ψa×(Iq1-Iq2)=(α1-α2)×(Jd+m×r^2) Here, Iq1 is called the rising current value, and Iq2 is called the falling current value. Since the torque T when decelerating from 0 is a negative value, the falling current value Iq2 is a negative value according to Equation 2. In other words, the difference Iq1-Iq2 between the rising current value Iq1 and the falling current value Iq2 is essentially the sum of the absolute values ​​of the rising current value Iq1 and the falling current value Iq2.

[0052] 6 is a graph showing the relationship between the amount of clothes m and the difference Iq1-Iq2 between the start-up current value and the end-down current value when the distance r from the rotation axis 105 of the drum 103 to the center of gravity of the clothes, the angular acceleration α1 during startup, and the angular acceleration α2 during shutdown are constant values ​​in Equation 9. As Equation 9 and FIG. 6 show, the amount of clothes m and the difference Iq1-Iq2 between the start-up current value and the end-down current value are proportional and independent of the friction torque Tb. Therefore, by storing the relationship between the amount of clothes m and the difference Iq1-Iq2 between the start-up current value and the end-down current value as a calculation table in the control unit 220, the amount of clothes m can be calculated from the start-up current value Iq1 and the end-down current value Iq2.

[0053] Here, m* is preset as the value of m at which vibration and noise are deemed to increase when the laundry load m is gradually decreased and the spin cycle is performed at a constant maximum rotation speed and a constant ramp rate. In Equation 9, by using the value of Iq1-Iq2(*) corresponding to m* as the threshold for determining whether the laundry load is small, the control unit 220 can determine whether Iq1-Iq2 is equal to or less than the threshold, thereby directly determining whether the laundry load is small. Note that the determination of whether the laundry load is small may be made after specifically determining the value of the laundry m.

[0054] By using the rising current value Iq1 and the falling current value Iq2, the control unit 220 can accurately determine the amount of laundry and perform a spin-drying operation according to the amount of laundry without relying on friction torque. Therefore, compared to using a single current value, a spin-drying operation according to the amount of laundry can be performed more accurately.

[0055] When the control unit 220 determines that the amount of laundry is small, it performs a first spin-drying operation that is different from a normal spin-drying operation. The first spin-drying operation is a spin-drying operation when the amount of laundry is small.

[0056] The maximum rotation speed of the drum 103 in the first spin-drying operation is lower than the maximum rotation speed of the drum 103 in the normal spin-drying operation. By lowering the maximum rotation speed of the motor 120 in the spin-drying operation, the maximum rotation speed of the drum 103 in the spin-drying operation can be lowered. This reduces vibration and noise generated in the spin-drying operation when there is a small amount of laundry.

[0057] Furthermore, the rising gradient of drum 103 during the first spinning operation is gentler than the rising gradient of drum 103 during the normal spinning operation. The rising gradient refers to the rate of increase in the rotation speed of drum 103, i.e., the slope of the upward-sloping straight line in FIG. 4. By making the rising gradient gentler, the movement of liquid within fluid balancer 111 is gradual, and the imbalance of the center of gravity is more accurately corrected. This reduces vibration and noise generated during the spinning operation when there is a small amount of laundry.

[0058] [1-3. Effects, etc.] As described above, in this embodiment, the drum type washing machine 100 includes the rotatable drum 103 for storing clothes, the motor 120 for driving the drum 103 to rotate, the current measuring unit 212 for measuring the motor current value flowing through the motor 120, and the control unit 220 for controlling the rotation of the motor 120 during a washing operation including a spin-drying operation. Before performing the spin-drying operation, the control unit 220 executes a balance control process including a first control step for increasing the rotation speed of the drum 103 to a first rotation speed, and a second control step for decreasing the rotation speed of the drum 103 from the first rotation speed to a second rotation speed lower than the first rotation speed. The control unit 220 controls the balance Based on the motor current value measured in the power control process, a first spin-drying operation that is different from the normal spin-drying operation can be performed.

[0059] As a result, the control unit 220 performs the spin-drying operation according to the amount of laundry using the motor current value measured in the balance control process. This eliminates the need for a separate process for determining the control content for the spin-drying operation, and prevents the washing operation from taking too long.

[0060] Furthermore, as in this embodiment, the current measurement unit 212 measures a rise current value, which is the motor current value in the first control process, and a fall current value, which is the motor current value in the second control process, and the control unit 220 may be capable of performing a first spin-drying operation that is different from a normal spin-drying operation based on the difference between the rise current value and the fall current value.

[0061] This allows the control unit to perform a spin cycle that corresponds to the amount of laundry, without relying on the friction torque, and therefore allows for a more accurate spin cycle that corresponds to the amount of laundry compared to when a single current value is used.

[0062] Furthermore, as in this embodiment, the maximum rotation speed of drum 103 in the first spin-drying operation may be set lower than the maximum rotation speed of drum 103 in the normal spin-drying operation.

[0063] This makes it possible to suppress vibrations and noise that occur during the dehydration operation when there is a small amount of laundry.

[0064] Furthermore, as in this embodiment, the rising gradient of drum 103 in the first spin-drying operation may be gentler than the rising gradient of drum 103 in the normal spin-drying operation.

[0065] This allows the liquid in the fluid balancer 111 to move slowly, and the imbalance of the center of gravity to be corrected more accurately, thereby suppressing vibrations and noise that occur during the spin-drying operation when there is a small amount of laundry.

[0066] Furthermore, as in this embodiment, the control unit 220 may execute the balance control process multiple times during the washing operation, and the control unit 220 may execute the first spin-drying operation based on the motor current value measured in the most recent balance control process.

[0067] This allows the machine to perform an appropriate spin-drying operation based on the latest laundry amount even if laundry is removed during the wash cycle, thereby preventing increased vibration and noise during spin-drying when laundry is removed during the wash cycle.

[0068] (Other embodiments) As described above, the first embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Therefore, other embodiments will be described below as examples.

[0069] In the first embodiment, the washing operation is performed in the following order: washing, two rinsing steps, and a final spin-dry step. Each step needs to be performed at least once. Therefore, each step may be performed two or more times, and the number of spin-drying operations and the associated balance control steps is not limited.

[0070] In the first embodiment, the control unit 220 measures the motor current value in the balance control step of the spin-drying operation, determines the amount of clothes, and controls the spin-drying operation. In addition to the balance control step, the measurement of the motor current value and the detection of the amount of clothes may be performed immediately after the start of the washing operation, for example. This allows the appropriate amount of water to be supplied in the washing step to be determined.

[0071] In the first embodiment, the first spin-drying operation is performed by both lowering the maximum rotation speed and gradual increasing the gradient. The first spin-drying operation may be performed when the laundry load is small, as long as it is a spin-drying operation that suppresses large vibrations and noise. Therefore, the first spin-drying operation may be performed by only one of lowering the maximum rotation speed and gradual increasing the gradient.

[0072] In the first embodiment, the control unit 220 determines whether the amount of water is low based on the latest motor current value and controls the spin-drying operation. This determination may be made by comprehensively considering not only the latest motor current value but also the previous motor current values. In this case, it is also possible to consider only some of the determination results from the washing operation rather than comprehensively considering all of them. This allows the determination of whether the amount of water is low to be made while taking into account the moisture content of the clothes, which changes each time the spin-drying operation is started. This allows the determination to be made more accurately, and the spin-drying operation to be performed appropriately.

[0073] Furthermore, when the control unit 220 executes the first step in a washing operation and executes the first spin operation in the first step, it may execute the first spin operation without executing the balance control step in the steps after the first step. The first step is one of the spin operations, excluding the last spin operation, among the multiple spin operations executed in the washing operation. The first step is, for example, the first spin operation executed in the washing operation. In this case, if it is determined that the amount of laundry is small in the first step, the first spin operation is executed in all subsequent spin operations. This makes it possible to omit the balance control step after the first step. This reduces the time required for the washing operation.

[0074] In the first embodiment, the determination of whether the current is small or not is based on the rising current value in the balance control process and the falling current value measured after the rising current value is measured. This determination may be made based on the sum of the absolute values ​​of the rising current value and the falling current value. Therefore, the motor current value used for this determination may be the falling current value and the rising current value measured after the falling current value is measured.

[0075] In the first embodiment, whether the current is small or not is determined using the average value Iq1 of the motor torque current at the time of rising and the average value Iq2 of the motor torque current at the time of falling, both measured by the current measurement unit 212. This determination can be made using the motor current value. Therefore, this determination may also be made using the motor current value when the number of rotations of the drum 103 reaches a predetermined number of rotations, or the integrated value, maximum value, and minimum value of the motor current value within a certain interval.

[0076] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents. [Industrial Applicability]

[0077] The present disclosure is applicable to drum-type washing machines that perform a balance control process, since it determines whether the amount of laundry is small in parallel with the balance control process. [Explanation of symbols]

[0078] 100 Drum washing machine 101 Case 102 Aquarium 103 Drums 104 Water vent 105 Rotational Axis 106 Belt 107 Rotation detection unit 108 Clothing Entrance 109 Door 110 Operation display panel 111 Fluid Balancer 120 motor 121 Rotor position detection unit 121a~121c Hall IC 122a~122c Winding 130 Water supply section 131 Water supply pipeline 132 Water supply valve 140 Drainage section 141 Drainage pipeline 142 Drain valve 150 Drying section 151 Circulation ventilation route 152 Heat Pump 153 Blower fan 154 filters 200 Power supply introduction section 201 Rectifier 202 Choke coil 203 Smoothing capacitor 204 Load drive unit 210 Inverter circuit 211a to 211f Switching elements 212 Current measurement section 220 Control Unit 221 Drive circuit 222 Input setting section

Claims

1. a rotatable drum for storing clothes; a motor that rotates the drum; a current measuring unit for measuring a motor current value that is a value of a motor current flowing through the motor; A control unit that controls the rotation of the motor during a washing operation including a spin-drying operation, the control unit executes a balance control process including a first control process of increasing the rotation speed of the drum to a first rotation speed before performing the dehydration operation, and a second control process of decreasing the rotation speed of the drum from the first rotation speed to a second rotation speed lower than the first rotation speed, The control unit is capable of executing a first spin-drying operation different from a normal spin-drying operation based on the motor current value measured in the balance control process, The rising gradient of the drum in the first dewatering operation is gentler than the rising gradient of the drum in the normal dewatering operation. Drum type washing machine.

2. A rotatable drum for storing clothes; a motor that rotates the drum; a current measuring unit for measuring a motor current value that is a value of a motor current flowing through the motor; A control unit that controls the rotation of the motor during a washing operation including a spin-drying operation, the control unit executes a balance control process including a first control process of increasing the rotation speed of the drum to a first rotation speed before performing the dehydration operation, and a second control process of decreasing the rotation speed of the drum from the first rotation speed to a second rotation speed lower than the first rotation speed, The control unit is capable of executing a first spin-drying operation different from a normal spin-drying operation based on the motor current value measured in the balance control process, the maximum rotation speed of the drum in the first dehydration operation is lower than the maximum rotation speed of the drum in the normal dehydration operation; Drum type washing machine.

3. A rotatable drum for storing clothes; a motor that rotates the drum; a current measuring unit for measuring a motor current value that is a value of a motor current flowing through the motor; A control unit that controls the rotation of the motor during a washing operation including a spin-drying operation, the control unit executes a balance control process including a first control process of increasing the rotation speed of the drum to a first rotation speed before performing the dehydration operation, and a second control process of decreasing the rotation speed of the drum from the first rotation speed to a second rotation speed lower than the first rotation speed, The control unit is capable of executing a first spin-drying operation different from a normal spin-drying operation based on the motor current value measured in the balance control process, The control unit executes the balance control step a plurality of times during the washing operation, The control unit is capable of executing the first spin-drying operation based on the motor current value measured in the latest balance control process. Drum type washing machine.

4. A rotatable drum for storing clothes; a motor that rotates the drum; a current measuring unit for measuring a motor current value that is a value of a motor current flowing through the motor; A control unit that controls the rotation of the motor during a washing operation including a spin-drying operation, the control unit executes a balance control process including a first control process of increasing the rotation speed of the drum to a first rotation speed before performing the dehydration operation, and a second control process of decreasing the rotation speed of the drum from the first rotation speed to a second rotation speed lower than the first rotation speed, The control unit is capable of executing a first spin-drying operation different from a normal spin-drying operation based on the motor current value measured in the balance control process, The control unit executes a first step in the washing operation, When the control unit executes the first spin-drying operation in the first step, the control unit executes the first spin-drying operation without executing the balance control step in steps after the first step. Drum type washing machine.

5. the current measurement unit measures a rising current value, which is the motor current value in the first control step, and a falling current value, which is the motor current value in the second control step; The control unit is capable of executing the first spin-drying operation based on a difference between the rise current value and the fall current value. The drum type washing machine according to any one of claims 1 to 4.

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