JP2020054785A - Washing machine - Google Patents

Abstract

To measure accurately in a short time an amount of laundry.SOLUTION: The washing machine comprises a controller 6 that controls a driving device 5 for rotating a drum 4 into which laundry is put by using a motor 51 and an inverter 52 and has a cloth amount measurement part 61 for measuring a weight of laundry put in the drum 4. The cloth amount measurement part 61 executes first measurement processing P1 for measuring acceleration for increasing speed during an increase in the speed of the drum 4 and second measurement processing P3 for measuring acceleration for decreasing speed of the drum 4 that is decelerated by inertial rotation and calculates a weight of the laundry based on each of the acceleration for increasing speed and the acceleration for decreasing speed.SELECTED DRAWING: Figure 5

Description

  The disclosed technology relates to a washing machine, and particularly relates to a technology for measuring an amount of input laundry.

  Most recent washing machines have automated processes such as washing, rinsing and dehydration. Water is automatically supplied in each of the washing and rinsing steps. At that time, in order to determine the amount of water to be supplied, the amount of laundry (clothes) inserted is automatically measured.

  For example, Patent Literature 1 discloses an example of a conventional method for measuring a cloth amount (amount of laundry) in a drum-type washing machine, and an improved method for improving the measurement accuracy.

  In the conventional method, a drum containing clothes is rotated at high speed by driving a motor, and the clothes are stuck around the drum by centrifugal force. The amount of cloth is measured using the fact that the time until the rotation of the drum stops is proportional to the amount of cloth.

  In the improved method, a process of rotating a drum containing clothes while accelerating and decelerating at a predetermined torque is performed three times or more. The angular acceleration at the time of each acceleration and the angular acceleration at the time of each deceleration are measured, and the cloth amount is measured based on these.

  Patent Literature 2 discloses that the torque constant of the motor is calculated before the weight of the laundry is measured to improve the measurement accuracy.

JP 2013-43030 A JP-A-2015-89435

  Usually, the measurement of the laundry amount (the weight of the laundry) is performed using the moment of the rotating drum. Therefore, at the time of measurement, it is necessary to stably adhere the laundry to the drum in a well-balanced manner. For that purpose, the drum must be rotated until it reaches a certain high rotational speed (for example, 150 rpm) or more.

  However, if the rotation of the drum is increased to such a rotation speed, the drum approaches the resonance point where the drum resonates with the washing machine, and as a result, the vibration of the drum tends to increase. As the vibration of the drum increases, the measurement accuracy decreases. Therefore, in order to perform high-accuracy measurement, it is preferable that after attaching the laundry to the drum, the rotation speed is reduced while maintaining the state, and the measurement is performed at the lowest possible rotation.

  On the other hand, in the above-mentioned conventional method, since the drum is rotating by inertia, the deceleration is slow and it takes time to perform highly accurate measurement. When the measurement is performed a plurality of times, it takes more time.

  On the other hand, in the above-mentioned improved method, since torque is applied during both acceleration and deceleration, measurement can be performed in a relatively short time.

  However, the improved method eliminates mechanical losses, such as rotational resistance, that constitute a measurement error by canceling both during acceleration and deceleration when torque is applied. The mechanical loss is not always the same during acceleration and deceleration, and the measured value is affected by torque. Therefore, the improved method cannot expect high measurement accuracy.

  In the improved method, the measurement accuracy is improved by performing the measurement a plurality of times, but the measurement is performed intermittently while the drum is stopped. Therefore, the improved method has room for improvement in terms of time reduction and stability.

  A main object of the disclosed technology is to measure the amount of laundry in a short time and with high accuracy.

  The disclosed technology relates to a washing machine.

  The washing machine includes a fixed tub installed inside a housing in a state where water can be stored, a rotary tub that is rotatably housed inside the fixed tub, and into which laundry is put, and the rotary tub. And a control device that controls the drive device and has a cloth amount measurement unit that measures the weight of the laundry put into the rotating tub.

  A first measurement process of measuring a speed-up acceleration at the time of speed-up by applying a predetermined speed-up torque to the rotary tub in a state where laundry is accommodated, and After the first measurement process, a second measurement process of measuring a deceleration at the time of deceleration by decelerating by inertia rotation is executed, and the weight of the laundry is determined based on each of the acceleration and the deceleration. Is calculated.

  In particular, the second measurement process is performed after a deceleration process that applies a predetermined deceleration torque to the rotating tank to reduce the rotation speed to a predetermined rotation speed, or is performed after the first measurement process, and the second measurement process is performed. After that, it is preferable to execute a deceleration process in which a predetermined deceleration torque is applied to the rotary tank to reduce the rotation speed to a predetermined rotation speed.

  According to this washing machine, the control device controls the drive device to rotate the rotary tub in which the laundry is put, using the motor and the inverter. Then, the cloth amount measurement unit of the control device performs a first measurement process of measuring the acceleration at the time of acceleration of the rotary tub and a second measurement process of measuring the deceleration of the rotary tub decelerated by the inertial rotation. Then, the weight of the laundry is calculated based on each of the acceleration and the deceleration.

  That is, in the first measurement process, after the acceleration of acceleration is measured in a state where the laundry is stuck to the rotating tub by centrifugal force, the deceleration is measured in a state where the rotating tub is coasted. Since the rotary tank is rotating by inertia, the deceleration based on the mechanical loss can be accurately measured without being affected by the torque.

  Before or after the second measurement process after the first measurement process, if a deceleration process of applying a predetermined deceleration torque to the rotary tub to perform deceleration is performed, the rotary tub can be lowered to a predetermined low rotational speed in a short time. it can.

  If the second measurement process is performed after the deceleration process, the measurement is performed at a low rotation speed, so that the influence of vibration is reduced and the measurement time is lengthened, so that more accurate measurement can be performed. On the other hand, in the case where the speed rapidly decreases even by the inertial rotation, if the deceleration process is executed first, there is a possibility that stable measurement cannot be performed. Therefore, in such a case, it is preferable to execute the second measurement process after the first measurement process. Then, even when the speed decrease due to the inertial rotation is large, a stable second measurement process can be performed.

  Since the weight of the laundry is calculated based on each of the acceleration and the deceleration, the weight of the laundry can be accurately measured in a short time.

  The washing machine also performs the first measurement process, the second measurement process, and the deceleration process a plurality of times continuously without stopping the rotation of the rotary tub, and The weight of the laundry may be calculated based on each of the plurality of accelerations and the decelerations.

  The measured acceleration and deceleration values vary statistically. Therefore, more accurate measurement can be performed by performing a plurality of measurements and calculating the weight of the laundry based on the plurality of measured values. In this case, it is necessary to continuously perform the cloth amount measurement processing including the first measurement processing and the second measurement processing. However, as described above, the cloth amount measurement processing can be performed in a short time. Can be measured in a short time.

  Further, in the case of this washing machine, since the cloth amount measurement process is continuously performed without stopping the rotation of the rotary tub, the measurement time is further reduced, and stable and accurate measurement can be performed.

  The washing machine is also configured such that when the cloth amount measuring unit executes the first measurement process from a state where the rotating tub is stopped, it rotates at a predetermined rotation speed at a constant speed before the first measurement process. In addition to performing the stabilization process, a process of obtaining a torque constant may be performed during the execution of the stabilization process, and the weight of the laundry may be calculated using the torque constant.

  When rotating the stopped rotating tank, a relatively large torque is required. Therefore, it takes a certain amount of time for the drive of the inverter and the rotation of the rotary tank and the motor to stabilize. On the other hand, in this washing machine, since the rotating tub is rotated at a constant speed prior to the first measurement process, it is possible to smoothly shift to the first measurement process, and highly accurate measurement can be performed in a short time.

  Motor characteristics have variations based on individual differences. Motor characteristics also vary with motor temperature. In order for the motor to generate a predetermined torque, a predetermined current corresponding thereto is supplied to the motor. However, when the motor characteristics change, the torque changes accordingly. Therefore, when the cloth amount measurement process is performed using a constant torque constant, high accuracy cannot be obtained.

  On the other hand, in this washing machine, each time a series of cloth amount measurement processing is executed, the torque constant is measured, and the weight of the laundry is calculated using the torque constant. Therefore, the weight of the laundry can be measured with high accuracy.

  The washing machine may be configured such that the cloth amount measuring unit adjusts the deceleration torque so that the voltage of the inverter does not rise to a predetermined value or more by a regenerative operation of the motor when the deceleration process is performed. Good.

  In the above-described deceleration processing, a predetermined deceleration torque is applied to the rotary tank to decelerate. That is, the motor is driven to rotate so that a torque opposite to the normal direction acts on the rotary tank. As a result, back electromotive force is generated in the motor, and a regenerative current flows through the inverter. When the regenerative current flows through the inverter, the voltage of the inverter increases, and the electric circuit may be damaged.

  Therefore, in this washing machine, during the deceleration process, the deceleration torque is adjusted so that the voltage of the inverter does not exceed the limit. Therefore, a failure of the inverter can be prevented.

  The washing machine may be configured such that the laundry amount measurement unit controls the driving of the inverter so that the motor does not output torque to the rotating tub when the second measurement process is performed.

  In general, in order to rotate the rotary tank by inertia, power supply to the inverter is stopped. However, in such a case, the electric state is likely to be unstable when the energization is restarted. Therefore, if the measurement is started immediately, an error may be caused. On the other hand, in this washing machine, the drive of the inverter is controlled so that the motor does not output torque to the rotating tub. Thereby, the power supply to the inverter is maintained even during the execution of the second measurement process, and a stable electrical state is ensured. Therefore, even if the measurement is started immediately, highly accurate measurement can be performed. Therefore, it is possible to immediately shift to the first measurement process, and then immediately start the measurement.

  The washing machine further includes a washing processing unit in which the control device performs a series of washing processes including a washing process, a rinsing process, and a dehydration process. A dry weight measurement process for measuring the weight of the laundry before and a wet weight measurement process for measuring the weight of the laundry immediately before the dehydration step may be executed.

  By doing so, it is possible to prevent a dehydration trouble caused by the laundry including waterproof clothing or the like by using the cloth amount measurement processing.

  In that case, the rotating tub is configured to rotate about an axis extending in a horizontal or inclined direction, and the cloth amount measuring unit uses the measurement result at the time of the dry weight measurement processing to thereby perform the wet weighing. The second measurement process during the weight measurement process may be omitted.

  That is, in the case of a drum type washing machine, unlike a vertical washing machine, the machine loss hardly changes even if the weight of the laundry changes, so that the deceleration obtained in the dry weight measurement process can be reused. By doing so, it is possible to shorten the time required for the wet weight measurement process as compared to the dry weight measurement process, while ensuring high detection accuracy.

  According to the disclosed technology, the amount of laundry can be measured with high accuracy in a short time, so that a washing machine that is excellent in water saving and easy to handle can be realized.

It is the schematic which shows the structure of the washing machine to which the technique disclosed is applied. It is the schematic which shows the structure of a drive device. It is a block diagram which shows a control apparatus and its main related apparatus. It is the schematic which shows the time-dependent change of the rotation of the drum in the cloth amount measurement process. It is the schematic which shows the relationship between the rotation speed and torque of a motor, and the voltage of an inverter in a part (initial stage) of a cloth amount measurement process. It is the schematic which shows the relationship between the number of times of measurement of a cloth amount measurement process, and measurement accuracy. It is a flowchart which shows the main flow of a washing process. It is a flowchart which shows the main flows of the cloth amount measurement processing. It is the schematic which shows the time-dependent change of rotation of a drum in a wet weight measurement process. It is a figure equivalent to FIG. 4 in the washing machine of a modification. It is a figure equivalent to FIG. 5 in the washing machine of a modification. It is a figure equivalent to FIG. 8 in the washing machine of a modification.

  Hereinafter, embodiments of the disclosed technology will be described in detail with reference to the drawings. However, the following description is merely an example in nature, and does not limit the present invention, its application, or its use.

<Washing machine>
FIG. 1 shows an example of a washing machine 1 to which the disclosed technology is applied. The washing machine 1 is a so-called drum type washing machine. The washing machine 1 is a so-called fully automatic washing machine, and is configured to automatically execute a series of washing processes including washing, rinsing, and dehydrating processes.

  The washing machine 1 mainly includes a housing 2, a tub 3 (fixed tub), a drum 4 (rotary tub), a driving device 5, a control device 6, and the like.

  The housing 2 is a box-shaped container including a panel and a frame, and forms an outer shell of the washing machine 1. On the front surface of the housing 2, a circular slot 2a is formed for taking in and out laundry. A door 2b having a transparent window is attached to the input port 2a. The inlet 2a is opened and closed by a door 2b. An operation unit 7 having a switch or the like operated by a user is installed above the input port 2 a in the housing 2.

  A tab 3 communicating with the insertion port 2a is housed inside the housing 2. The tub 3 is formed of a bottomed cylindrical water-storable container, and its opening is connected to the inlet 2a. The tab 3 is supported by a damper (not shown) provided inside the housing 2 so as to stabilize the tab 3 with its central axis J slightly inclined upward and forward.

  Above the tub 3, a water supply device 8 including a water supply pipe 8a, a water supply valve 8b, a medicine injection device 8c, and the like is provided. The upstream end of the water supply pipe 8a projects outside the washing machine 1 and is connected to a water supply source (not shown). The downstream end of the water supply pipe 8a is connected to a water supply port 3a opened at the top of the tub 3. The water supply valve 8b and the drug injection device 8c are installed in the water supply pipe 8a in this order from the upstream side.

  The medicine introduction device 8c accommodates medicines such as a detergent and a softener, and injects these medicines into the tub 3 by mixing the medicines with supplied water. A drain port 3b is provided below the tab 3. The drain port 3b is connected to the drain pump 9. The drain pump 9 discharges unnecessary water accumulated in the tub 3 to the outside of the washing machine 1 through the drain pipe 9a.

  The drum 4 is formed of a cylindrical container having a slightly smaller diameter than the tub 3, and is accommodated in the tub 3 with the center axis J coincident with the tub 3. In the front part of the drum 4, a circular opening 4a facing the charging port 2a is formed. The laundry is thrown into the drum 4 through the slot 2a and the circular opening 4a.

  On the side of the drum 4, a large number of dehydration holes 4b are formed over the entire circumference (only a part is shown in FIG. 2). Further, lifters 4c for stirring are attached to a plurality of locations inside the side portions. The front part of the drum 4 is rotatably supported by the charging port 2a.

  The driving device 5 is installed at the rear of the tub 3. The driving device 5 includes a motor 51, an inverter 52, and the like. The shaft 51 a of the motor 51 penetrates the rear part of the tab 3 and protrudes into the tab 3. The tip of the shaft 51a is fixed to the center of the bottom of the drum 4. That is, the rear portion of the drum 4 is supported by the shaft 51a, and the driving device 5 directly drives the drum 4 (so-called direct drive system). Thereby, the drum 4 rotates around the central axis J by the driving of the motor 51.

  FIG. 2 schematically shows the driving device 5. The motor 51 is, for example, a three-phase permanent magnet type motor, and has a stator 51b and a rotor 51c. The stator 51b includes a three-phase (U-phase, V-phase, and W-phase) coil group 51d and a cylindrical stator core 51e in which the coil groups 51d are integrally assembled. The rotor 51c has a rotor core 51f housed inside the stator 51b with a slight gap therebetween, and a plurality of permanent magnets 51g arranged around the rotor core 51f. The shaft 51a is fixed to the center of the rotor 51c.

  The inverter 52 is electrically connected to a commercial power supply PS outside the washing machine 1. Although not shown, the inverter 52 has a built-in converter. When the AC of the commercial power supply PS is input, the converter converts the AC into a predetermined DC voltage and outputs the DC voltage. The inverter 52 converts the DC voltage converted by the converter into a predetermined AC by performing PWM control or the like, and converts the DC voltage into three-phase (U-phase, V-phase, and W-phase) alternating currents (known in the art). )have.

  The electric circuit has a smooth line 52b and three arms 52c, 52c, 52c that are provided between the pair of buses 52a, 52a. A capacitor 52d is provided on the smoothing line 52b. In each arm 52c, two element units each including a switching element 52e and a free wheel diode 52f connected in anti-parallel are arranged in series. An output line 52g drawn from between the element units of each arm 52c is connected to each coil group 51d of the stator 51b.

  The switching element 52e of each arm 52c is turned on and off at a predetermined timing. As a result, alternating currents having different phases are supplied to the respective coil groups 51d, so that the motor 51 and the drum 4 rotate in synchronization with the alternating current. In the case of the washing machine 1, when rotating the drum 4 at a high speed, the control device 6 controls the inverter 52 to perform a field weakening control (publicly known) for supplying a predetermined control current to the motor 51.

  The control device 6 is installed on the upper part of the housing 2. The control device 6 comprehensively controls the operation of the washing machine 1. The control device 6 includes hardware such as a CPU and a memory, and software such as a control program and various data.

  FIG. 3 shows a main configuration of the control device 6. The control device 6 is electrically connected to a current sensor 12, a voltage sensor 13, a motor sensor 14, an operation unit 7, a driving device 5, a water supply valve 8b, a drainage pump 9, and the like. The current sensor 12 measures a current value output to the motor 51 and outputs the measured value to the control device 6. Voltage sensor 13 measures a voltage value input / output to inverter 52 and outputs the measured value to control device 6. The motor sensor 14 measures the rotation speed of the motor 51 and outputs the measured value to the control device 6. The operation unit 7 outputs to the control device 6 instruction information such as operation start and operation mode selection input by the user. The control device 6 controls the drive device 5, the water supply valve 8b, the drainage pump 9, and the like based on the measured values and the instruction information.

  The control device 6 includes a washing processing unit 61, a cloth amount measurement unit 62, an information storage unit 63, and the like. The washing processing unit 61 executes a series of washing processing including steps such as washing, rinsing, and dehydration according to an instruction. The cloth amount measuring unit 62 executes a process of measuring the weight of the laundry stored in the drum 4 (cloth amount measuring process). The information storage unit 63 stores information necessary for the washing process and the cloth amount measuring process, and outputs these information to the washing processing unit 61 and the cloth amount measuring unit 62.

<Clothes measurement processing>
The washing machine 1 is designed so that the cloth amount measurement process can be executed in a short time and with high accuracy. The details of the cloth amount measurement processing will be specifically described with reference to FIG.

  As shown in FIG. 4, in the cloth amount measurement processing, a predetermined acceleration torque is applied to the drum 4 in a state where laundry is stored and the drum 4 is rotated to measure acceleration during acceleration (acceleration acceleration). (First measurement process P1), after the first measurement process P1, a process of applying a predetermined deceleration torque to the drum 4 to reduce the rotation speed to a predetermined rotation speed (deceleration process P2), and after the deceleration process P2, A process (second measurement process P3) of measuring acceleration (deceleration) at the time of deceleration by decelerating the drum 4 by coasting rotation is executed.

  In this embodiment, a stabilization process P0 for auxiliary rotation of the drum 4 is performed when the first first measurement process P1 is performed, and thereafter, the first measurement process P1 is performed without stopping the rotation of the drum 4. , The deceleration process P2, and the second measurement process P3 are continuously performed three times. The weight of the laundry is calculated based on each of the acceleration and deceleration thus measured.

(Stabilization process P0)
When the cloth amount measurement process is performed from the state where the rotation of the drum 4 is stopped, the control device 6 (cloth amount measuring unit 62) rotates at a constant reference speed R0 (for example, 20 rpm) of 50 rpm or less in each case. The stabilization process P0 is performed. During the execution of the stabilization process P0, a process of measuring a torque constant used for calculating the weight of the laundry is also executed.

  When the stopped drum 4 is rotated, a relatively large torque is required, so that it takes some time until the drive of the inverter 52 and the rotation of the drum 4 and the motor 51 are stabilized. Therefore, in the washing machine 1, the drum 4 rotates stably, and the drum 4 rotates at a constant speed at a low reference rotation speed R0 at which the field weakening control is unnecessary (the rotation speed may be lower than the rotation speed at which the laundry sticks to the drum 4). (Initial stabilization period) is provided. As a result, it is possible to smoothly shift to the cloth amount measurement processing, and highly accurate cloth amount measurement processing can be performed.

  Motor characteristics have variations based on individual differences. Motor characteristics also vary with the temperature of the motor 51. In order for the motor 51 to generate a predetermined torque, a predetermined current corresponding thereto is supplied to the motor 51. However, when the motor characteristics change, the torque also changes accordingly. Therefore, when the cloth amount measurement process is performed using a constant torque constant, high accuracy cannot be obtained.

  Therefore, the washing machine 1 executes a process for obtaining a torque constant during the execution of the stabilization process P0.

  Specifically, in the latter half of the initial stabilization period, the voltage sensor 13 and the motor sensor 14 are used to sample a plurality of data in an interval of one cycle in which the motor 51 rotates. Calculate the torque constant.

  Equation (1): Kt = (Vq−ΔV−R × Iq) / ω

  Kt: torque constant, Vq: command value of q-axis voltage given to motor 51, ΔV: correction voltage, R: resistance value of coil group 51d, Iq: current value of q-axis current, ω: rotation speed of motor 51

  Therefore, in the washing machine 1, the influence of the variation in the torque constant can be reduced, so that a more accurate laundry amount measurement process can be performed.

(First measurement process P1)
The control device 6 accelerates the rotation of the drum 4 by applying a predetermined acceleration torque T1 to the drum 4 rotating at a low speed.

  As shown in FIG. 5, the speed-up torque T <b> 1 is, for example, a torque that can rotate the drum 4 even when the maximum amount of laundry is thrown into the drum 4, and is set in the information storage unit 63 in advance. ing. In the first measurement process P1, the control device 6 (cloth amount measuring unit 62) controls the inverter 52 to drive the motor 51 so that such a speed-up torque T1 acts on the drum 4.

  Normally, the amount of laundry that is sufficiently smaller than the maximum limit is input, so that the drum 4 is easily accelerated, and the laundry stably adheres to the drum 4 in a short time. Then, while the drum 4 makes several revolutions, the acceleration acceleration is measured using the motor sensor 14. Since the drum 4 is accelerated from the rotating state, the acceleration state of the drum 4 is stabilized in a short time, and can be measured immediately after the acceleration is started. Upon completion of the measurement, the flow shifts to deceleration processing P2.

  Therefore, the first measurement process P1 can be performed in a very short time.

(Deceleration processing P2)
In the deceleration process P2, a predetermined deceleration torque T2 is applied to the drum 4 to reduce the rotation speed to a predetermined rotation speed (measured rotation speed Rs). That is, the control device 6 (cloth amount measuring unit 62) controls the inverter 52 to rotate the motor 51 so that the torque opposite to the normal direction acts on the drum 4. As a result, the motor 51 performs a regenerative operation reverse to the normal operation, so that a counter electromotive force is generated in the motor 51. Thereby, a regenerative current flows from the motor 51 to the inverter 52 according to the deceleration torque T2.

  When a regenerative current flows from the motor 51 to the inverter 52, the voltage between the buses 52a increases as shown in FIG. As a result, the capacitor 52d may be damaged beyond an allowable amount. Therefore, in the washing machine 1, the upper limit voltage value V2 corresponding to the allowable limit of the capacitor 52d is set in the information storage unit 63 in advance. When the deceleration process P2 is performed, the voltage between the buses 52a, 52a is measured using the voltage sensor 13, and the controller 6 (cloth amount measuring unit 62) controls the voltage so that the voltage does not rise to the upper limit voltage value V2 or more. Adjusts the deceleration torque T2. Therefore, a failure of the inverter 52 can be prevented.

  Since the drum 4 is forcibly decelerated by the deceleration torque T2, the drum 4 can be decelerated to the measured rotational speed Rs in a short time. The measured rotation speed Rs is a low rotation speed at which the state in which the laundry adheres to the drum 4 can be maintained. The measured rotation speed Rs is determined by the specifications of the washing machine 1. Therefore, the measured rotation speed Rs is obtained in advance by a test or the like, and is set in the information storage unit 63.

  Since the measurement of the deceleration starts from the measured rotational speed Rs, it is preferable that the measured rotational speed Rs be as low as possible. The lower the measured rotation speed Rs, the farther the drum 4 resonates with the washing machine 1 from the resonance point, so that the influence of vibration causing errors can be reduced. Further, the lower the measured rotational speed Rs, the longer the deceleration time, so that stable measurement can be performed. Therefore, the measurement accuracy of the deceleration is improved.

(Second measurement process P3)
Then, when the rotation of the drum 4 reaches the measured rotation speed Rs, the control device 6 decelerates the drum 4 by inertial rotation. Specifically, the cloth amount measuring unit 62 controls the driving of the inverter 52 so that the motor 51 does not output torque to the drum 4.

  In order to cause the drum 4 to rotate by inertia, it is general to stop energizing the inverter 52 as shown by a two-dot chain line L3 in FIG. However, in such a case, the electric state is likely to be unstable when the energization is restarted. Therefore, if the measurement is started immediately, an error may be caused.

  On the other hand, in the washing machine 1, by changing the ON / OFF of each switching element 52 e in a state where the power to the inverter 52 is maintained, the cloth amount measuring unit 62 prevents the drive current from flowing to the motor 51 by the inverter 52. To control the drive of. As a result, even when the drum 4 is coasting, the voltage between the buses 52a, 52a is substantially constant, and a stable electric state is maintained.

  Under such a situation, the control device 6 measures the deceleration during deceleration. Specifically, while the drum 4 rotates several times, the deceleration is measured using the motor sensor 14. Since the drum 4 is rotating by inertia and the torque applied to the drum 4 corresponds to a mechanical loss, the torque caused by the mechanical loss can be measured with high accuracy.

  When the measurement is completed, the process immediately proceeds to the next first measurement process P1. Since the drum 4 is rotating at a low speed, the process can smoothly proceed to the first measurement process P1. Even during the execution of the deceleration process P2, the drive of the inverter 52 is controlled and the stable electrical state is maintained, so that even when the measurement is started almost simultaneously with the start of the first measurement process P1, highly accurate measurement can be performed. I can do it.

  By performing the same process three times, the control device 6 acquires three accelerations and three decelerations. The control device 6 averages each of the speed-up acceleration and the deceleration acceleration, and calculates the load amount (corresponding to the weight of the laundry) based on the following equation (2).

  Formula (2): Load amount = Torque constant / (Average value of accelerating acceleration−Average value of deceleration)

  As described above, a plurality of accelerations and decelerations are measured, and a load amount is obtained using a value obtained by statistically processing the accelerations, thereby improving measurement accuracy. That is, as shown in a simplified manner in FIG. 6, it was recognized that the measurement accuracy tended to increase as the number of measurements increased. And it was also recognized that the rate of improvement in measurement accuracy gradually decreased as the number of times increased.

  In the washing machine 1, three measurements are set as the number of measurements since three measurements were the most effective in terms of the effect of time. The number of times of measurement is set in the information storage unit 63, and can be arbitrarily changed.

<Operation control example of the washing machine 1>
FIG. 7 shows an operation control example of the washing machine 1.

  When the washing process is performed, first, the user puts laundry into the drum 4 (Step S1). In the case of this washing machine 1, at that time, a detergent or the like is also charged into the drug charging device 8c. Then, by operating the operation unit 7, an instruction to start washing is input to the control device 6 (step S2). As a result, the control device 6 (the washing processing unit 61) automatically executes a series of processing including steps such as washing, rinsing, and dehydration according to the instruction.

  Before the washing process, the control device 6 (cloth amount measuring unit 62) rotates the drum 4 into which the laundry is put and performs a cloth amount measurement process (dry weight measurement process) in order to set an appropriate water supply amount. Execute (step S3). That is, the weight of the laundry that is not wet is measured.

  When the dry weight measurement process is started, as shown in FIG. 8, the control device 6 determines whether or not the drum 4 is rotating (Step S31). When the drum 4 is not rotating, that is, when the drum 4 is stopped, the control device 6 drives the motor 51 under the control of the inverter 52 to execute the stabilization process P0 (step S32).

  During the execution of the stabilization process P0, the control device 6 executes the process of measuring the torque constant described above. When the control device 6 acquires the torque constant (Yes in step S33), the control device 6 immediately controls the inverter 52, applies the acceleration torque T1 to the drum 4, and starts the first measurement process P1 (step S34).

  Then, when the control device 6 measures the acceleration, and acquires the acceleration (Yes in step S35), it immediately controls the inverter 52, applies the deceleration torque T2 to the drum 4, and starts the deceleration process P2. (Step S36). When the rotational speed of the drum 4 reaches the measured rotational speed Rs (Yes in step S37), the control device 6 immediately sets the torque output to the motor 51 to “0” to coast the drum 4 by inertia. The second measurement process P3 is started by controlling the inverter 52 as described above (step S38).

  Then, when the control device 6 acquires the deceleration (Yes in step S39), the control device 6 determines whether or not the number of measurements has reached a predetermined number N (three times) (step S40). If the number of measurements has not reached three, the first measurement process P1, the deceleration process P2, and the second measurement process P3 are repeatedly executed (No in step S40).

  Then, when the number of measurements reaches three (Yes in step S40), the control device 6 calculates the weight of the laundry using each of the measured acceleration acceleration and deceleration acceleration (step S41). Thereafter, the control device 6 returns.

  As shown in FIG. 7, after calculating the weight of the laundry, the control device 6 supplies water based on the calculated weight of the laundry (Step S4).

  Specifically, in the information storage unit 63, water supply information that enables setting of an appropriate water supply amount corresponding to the weight of the laundry is set. The control device 6 selects an appropriate water supply amount by checking the calculated weight of the laundry with the water supply information. Then, the control device 6 controls the water supply valve 8b so that the tub 3 is supplied with the supplied water amount.

  When the water supply is completed, the control device 6 executes a washing step (Step S5). In the washing process, the drum 4 is reversely driven at a low speed for a predetermined time, and the laundry is stirred with the washing water. Thereafter, when the drainage valve 5a is controlled to drain the washing water from the tub 3, the washing process ends.

  When the washing process is completed, the control device 6 executes a rinsing step (Step S6). In the rinsing step, water supply, stirring, and drainage are performed as in the washing step. The rinsing step may be performed several times.

  When the rinsing step is completed, the control device 6 executes the cloth amount measurement process (wet weight measurement process) again (step S7). That is, in this wet weight measurement processing, the weight of the wet laundry is measured immediately before the dehydration step in order to prevent a dehydration trouble caused by the laundry including waterproof clothing and the like.

  The content of the wet weight measurement process is substantially the same as the content of the above-described dry weight measurement process, but in the wet weight measurement process, unlike the dry weight measurement process, the second measurement process P3 is omitted.

  Specifically, as shown in FIG. 9, when the deceleration processing P2 ends, the first measurement processing P1 is immediately executed. In FIG. 8, steps S38 and S39 are omitted. In this case, it is not always necessary to reduce the rotation speed to the measured rotation speed Rs.

  In the case of the drum type washing machine, unlike the vertical type washing machine, even if the weight of the laundry changes, the weight applied to the shaft 51a and its periphery hardly changes, so that the mechanical loss hardly changes. Conversely, in the case of a vertical washing machine, when the weight of the laundry changes, the weight acts on the shaft and its surroundings, so that the mechanical loss changes.

  Therefore, in the washing machine 1, the measurement result at the time of the dry weight measurement process, that is, the average value of the deceleration is reused. By doing so, the time required for the wet weight measurement processing is shortened while ensuring high detection accuracy.

  Specifically, based on the torque constant obtained in the stabilization processing P0 in the wet weight measurement processing, the average value of the acceleration acceleration obtained in the wet weight measurement processing, and the average value of the deceleration acceleration obtained in the dry weight measurement processing To calculate the weight of the wet laundry.

  In the information storage unit 63, information relating to a change in weight of the laundry (weight change information) when the dry laundry becomes wet after the rinsing process is set. The control device 6 determines whether there is any abnormality by comparing the calculated weight of the wet laundry with the weight change information (step S8).

  For example, if the laundry contains waterproof clothing and excess water remains on the drum 4, the presence or absence of such excess water can be determined based on the weight change information. If dehydration is performed in a state where excess water remains, there is a possibility that the dehydration troubles such as abnormal vibration or collapse of the washing machine 1 may be caused.

  Therefore, when the control device 6 determines that there is an abnormality in the weight of the wet laundry (Yes in step S8), it does not execute the dehydration process, but sounds an alarm buzzer to notify the abnormality (step S9). .

  On the other hand, when it is determined that there is no abnormality in the weight of the wet laundry (No in step S8), the control device 6 executes a dehydration process (step S10). In the dehydration step, the drum 4 is driven to rotate at a high speed for a predetermined time, and the laundry is dehydrated. Water accumulated in the tub 3 due to dehydration is discharged by a drain pump 9. When the spin-drying step is completed, the end of the washing is notified by sounding a predetermined buzzer or the like (step S11).

  As described above, the washing machine to which the disclosed technology is applied can measure the amount of laundry in a short time and with high accuracy, so that it is excellent in convenience and can save water effectively.

<Modification>
In the above-described embodiment, the application to the washing machine in which the drum 4 rotates around the inclined central axis J among the drum-type washing machines has been exemplified.

  However, in a washing machine or the like that rotates about a central axis J that extends substantially horizontally, when the drum 4 rotates, the laundry protrudes not only from the inner peripheral surface of the drum 4 but also from the circular opening 4a, and May stick to the surrounding area. The inlet 2a does not rotate, and a seal member for preventing water leakage is usually provided between the inlet 2a and the circular opening. Generally, a material such as rubber having a large frictional resistance is used for such a sealing material.

  Therefore, when the drum 4 rotates with the laundry stuck around the input port 2a, a large frictional resistance is generated. As a result, there is a case where the deceleration of the drum 4 that rotates by inertia becomes steep. In this case, if the deceleration process P2 is executed first, the second measurement process P3 may not be performed properly.

  Therefore, in the drum type washing machine (washing machine 1 ') of the present modified example, the second measurement process P3 is executed after the first measurement process P1 and subsequently to the first measurement process P1. Then, the deceleration process P2 is executed continuously after the second measurement process P3.

  FIG. 10 illustrates the contents of the cloth amount measurement process in the washing machine 1 '. Note that the basic configuration is the same as that of the washing machine 1 described above. Therefore, the same reference numerals are used for the components having the same contents, and the description is omitted.

  As shown in FIG. 10, in the washing machine 1 ′, after the execution of the first measurement process P <b> 1, the second measurement process P <b> 3 is continuously performed, and thereafter, the deceleration process P <b> 2 is further continuously performed.

  Also in the washing machine 1 ', when the first first measurement process P1 is executed, the stabilization process P0 is executed including the process of measuring the torque constant. Thereafter, without stopping the rotation of the drum 4, a series of processes including a first measurement process P1, a second measurement process P3, and a deceleration process P2 is repeatedly and continuously performed three times. The weight of the laundry is calculated based on each of the acceleration and deceleration thus measured.

  In the washing machine 1 ', in the first measurement process P1, the drum 4 is accelerated by accelerating the drum 4 by rotating the drum 4 a predetermined number of times (one rotation or several rotations, N rotations). Thereafter, while the drum 4 is rotated a predetermined number of times (one rotation or several rotations, N rotations), the second measurement processing P3 is performed by inertial rotation, and as soon as the second measurement processing P3 ends, the deceleration processing P2 is performed. Then, in a series of processing, the rotational speed is temporarily reduced to a predetermined rotational speed (reference rotational speed R0).

  In the washing machine 1 ', the second measurement process P3 is started immediately after the drum 4 rotates a predetermined number of times. That is, the control device 6 decelerates the drum 4 by inertial rotation. Specifically, as shown in FIG. 11, similarly to the washing machine 1, the cloth amount measuring unit 62 controls the driving of the inverter 52 so that the motor 51 does not output torque to the drum 4.

  Since the measurement is performed from a state where the rotation speed of the drum 4 is high, even if the drum 4 is rapidly decelerated, the state in which the laundry is stuck to the drum 4 can be maintained during the measurement period. When the measurement of the deceleration is completed (at the rotation speed Rx shown in FIG. 11), the process immediately proceeds to the deceleration process P2. Thereby, the drum 4 is forcibly decelerated by the deceleration torque T2, and can be decelerated to the reference rotation speed R0 in a short time.

  When the rotation speed of the drum 4 reaches the reference rotation speed R0 and the rotation speed of the drum 4 is stabilized, the process immediately proceeds to the next first measurement process P1. Since the drum 4 is rotating at a low speed, the process can smoothly proceed to the first measurement process P1. Even during execution of the deceleration processing P2, the drive of the inverter 52 is controlled and a stable electrical state is maintained, so that high-precision measurement can be performed even if measurement is started almost simultaneously with the start of the first measurement processing P1. I can do it.

  The same processing is performed three times as in the previous washing machine 1, and the control device 6 calculates the load amount (corresponding to the weight of the laundry).

<Operation control example of washing machine 1 ′>
FIG. 12 shows an example of the laundry amount measurement process (dry weight measurement process) of the washing machine 1 ′. FIG. 11 shows the relationship among the rotation speed, the torque, and the voltage of the drum 4.

  When the dry weight measurement process is started, the control device 6 determines whether or not the drum 4 is rotating as in the case of the washing machine 1 (step S51). When the drum 4 is stopped, the control device 6 drives the motor 51 under the control of the inverter 52 to execute the stabilization process P0 (step S52).

  During the execution of the stabilization process P0, the control device 6 executes the process of measuring the torque constant described above. When the control device 6 acquires the torque constant (Yes in step S53), the control device 6 immediately controls the inverter 52, applies the speed increasing torque T1 to the drum 4, and starts the first measurement process P1 (step S54).

  That is, the drum 4 is rotated a predetermined number of times (one rotation or several rotations, n rotations). In the meantime, the control device 6 measures the acceleration, and acquires the acceleration (Yes in step S55), the control device 6 immediately outputs the torque output to the motor 51 to cause the drum 4 to coast. Is controlled to be “0”, and the second measurement process P3 is started (step S56).

  Then, the drum 4 is rotated a predetermined number of times (one rotation or several rotations, n rotations). In the meantime, when the control device 6 acquires the deceleration (Yes in step S57), it immediately controls the inverter 52, applies the deceleration torque T2 to the drum 4, and starts the deceleration process P2 (step S58). When the rotation speed of the drum 4 reaches the reference rotation speed R0 (Yes in step S59), it is determined whether the number of times of measurement has reached a predetermined number N (three times) (step S60).

  If the number of times of measurement has not reached three, a series of processing including the first measurement processing P1, the second measurement processing P3, and the deceleration processing P2 is repeatedly executed (No in step S60). When the number of measurements reaches three (Yes in step S60), the control device 6 calculates the weight of the laundry using each of the measured acceleration and deceleration (step S61). Thereafter, the control device 6 returns.

  As described above, according to the washing machine 1 ', even when the drum 4 is rapidly decelerated by the inertial rotation, the cloth amount measurement process can be stably performed.

  Note that the washing machine according to the disclosed technology is not limited to the above-described embodiment, but also includes various other configurations. For example, in the embodiment, the drum type washing machine has been illustrated, but the present invention can be applied to a vertical type washing machine. The drive device is not limited to the direct drive system. A belt drive system driven by an endless belt may be used.

1 washing machine 3 tub (fixed tub)
4 drums (rotary tank)
Reference Signs List 5 Drive device 6 Control device 51 Motor 52 Inverter 61 Wash processing unit 62 Cloth amount measurement unit 63 Information storage unit J Central axis

Claims (9)

A washing machine,
A fixed tank installed inside the housing so that water can be stored,
A rotating tub that is rotatably housed inside the fixed tub and into which laundry is put;
A driving device for rotating the rotating tank using a motor and an inverter,
A control device that controls the driving device and includes a cloth amount measurement unit that measures the weight of the laundry put into the rotating tub,
With
The cloth amount measurement unit,
A first measurement process of measuring a speed-up acceleration at the time of speed-up by applying a predetermined speed-up torque to the rotary tub in a state where laundry is stored and rotating the rotary tub
A second measurement process of measuring a deceleration during deceleration by decelerating by inertial rotation after the first measurement process;
And calculating the weight of the laundry based on each of the speed-up acceleration and the deceleration. The washing machine according to claim 1,
The second measuring process is performed after a deceleration process in which a predetermined deceleration torque is applied to the rotating tub to reduce the rotation speed to a predetermined rotation speed. The washing machine according to claim 1,
The second measuring process is performed after the first measuring process, and after the second measuring process, a deceleration process of applying a predetermined deceleration torque to the rotating tub to reduce the rotation speed to a predetermined rotation speed is performed. . In the washing machine according to claim 2 or 3,
The cloth amount measuring unit continuously executes the first measurement process, the second measurement process, and the deceleration process a plurality of times without stopping the rotation of the rotary tub, and a plurality of the acceleration accelerations. A washing machine that calculates a weight of the laundry based on each of the deceleration and the deceleration. The washing machine according to any one of claims 2 to 4,
When performing the first measurement process from a state where the rotating tub is stopped, the cloth amount measurement unit performs a stabilization process of rotating at a predetermined rotation speed at a constant speed before the first measurement process. A washing machine that executes a process of obtaining a torque constant during execution of the stabilization process, and calculates a weight of the laundry using the torque constant. The washing machine according to any one of claims 2 to 5,
The washing machine, wherein the cloth amount measuring unit adjusts the deceleration torque so that a voltage of the inverter does not rise to a predetermined value or more by a regenerative operation of the motor when the deceleration process is performed. In the washing machine according to any one of claims 2 to 6,
A washing machine, wherein the cloth amount measuring unit controls the drive of the inverter so that the motor does not output torque to the rotating tub when the second measuring process is performed. The washing machine according to any one of claims 2 to 7,
The control device further includes a washing processing unit that performs a series of washing processes including each of a washing process, a rinsing process, and a dehydration process,
The cloth amount measurement unit,
Dry weight measurement processing for measuring the weight of the laundry before the washing step,
Wet weight measurement processing to measure the weight of the laundry immediately before the dehydration step,
Run, washing machine. The washing machine according to claim 8,
The rotary tank is configured to rotate around an axis extending in a horizontal or inclined direction,
A washing machine, wherein the cloth amount measurement unit omits the second measurement process in the wet weight measurement process by using a measurement result in the dry weight measurement process.

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