JP6706738B2 - Drum washing machine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum-type washing machine for washing laundry stored in a rotary drum by rotating the rotary drum.

Conventionally, this type of drum type washing machine has a configuration in which the rotation of the motor is transmitted to the drum pulley via a belt, and the rotating drum is normally or reversely rotated. For this reason, when the belt is cut or comes off, the rotary drum is not driven to rotate and the laundry such as clothes cannot be washed. Also, in the same type of washing machine that has a drying function, if the belt is cut or comes off, hot air is intensively applied to a part of the clothes in the rotating drum, which may cause discoloration of the clothes or damage to the clothes. There was a chance

As means for solving the above problems, for example, in a clothes dryer having a similar configuration, it is detected that the number of rotations of the motor is abnormally higher than the target number of rotations as in Patent Document 1. A configuration is disclosed in which, when the target number of revolutions is returned after a lapse of a predetermined time, it is determined that the belt has run out and an abnormality is notified. After that, when the target rotation speed is not returned, it is determined that the motor control is abnormal and the abnormality is notified.

However, according to the above configuration, the rotary drum rotates at an abnormal rotational speed for a predetermined time. For this reason, if the same detection method is used in the spin-drying operation of a washing machine that rotates the rotating drum at high speed, the rotating sound of the rotating drum and the motor becomes noise, causing the user to feel uneasy and, in some cases, turning on the motor and control circuit. It had a problem of causing it to break down.

In addition, in a washing machine in which the rotating drum rotates at high speed, for safety, it is general that the door is locked and the door is not opened until the number of rotations of the rotating drum becomes a predetermined number of rotations or less. If the belt breaks or comes off, the motor will stop immediately after the brake operation, but the rotating drum will continue to rotate for a long time due to inertia, so motor stop = rotating drum stop will not occur, and therefore belt breakage and detachment will be high. Detection accuracy is required.

In order to solve these problems, for example, as disclosed in Patent Document 2, the time until the rotation speed of a motor is detected by a rotation speed detection means and the rotation speed becomes a predetermined value or less when a brake operation is performed is longer than a predetermined time. When it is short, it is considered that the belt is broken or the belt is disengaged from the drum pulley, and in that case, the unlocking of the door is delayed.

JP-A-11-114294 JP2012-90831A

However, the above-mentioned conventional drum type washing machine and clothes dryer are based on the premise that the motor rotation speed can be correctly detected by the rotation speed detection means. There was a problem that it might happen.

In a DC brushless motor, in order to sequentially supply the drive current to the motor windings of each phase at the timing of a predetermined commutation operation for the motor windings of each phase, the relative rotation between the motor windings and the rotor is Since the positional information on the magnetic pole, that is, the magnetic pole position information, is required, the conventional drum type washing machine of this type is equipped with a rotor position detecting means including a Hall IC using a Hall element. It was possible to easily detect the rotation speed of the motor from the rotor position information that is switched.

On the other hand, the Hall element as described above has a temperature dependency, and in order to reduce the cost of parts, the motor control method is sensorless, that is, the current flowing through the motor instead of mounting the rotor position detecting means. Many controls for estimating the rotor position from the value have been proposed, and even in a washing machine for home use, a study of making sensorless is progressing.

In sensorless control, the rotor position may be erroneously detected due to the influence of noise, etc., and the rotation speed may continue to be erroneously detected as a trigger. ) And apply the brakes. Therefore, it is difficult to distinguish the abnormal rotation when the belt comes off during high-speed rotation from the abnormal rotation due to the above-mentioned step-out, and the number of rotations cannot be correctly detected during the step-out. Therefore, it is necessary to take safety measures such as delaying the unlocking of the door.

The present invention solves the above-mentioned conventional problems, and does not depend on the rotation speed detection means, that is, irregular conditions such as a failure of the rotation speed detection means, or the number of rotations when controlling a motor by a sensorless position estimation method. An object of the present invention is to provide a drum-type washing machine that detects a broken belt or a belt detachment with high accuracy even when a detection unit is not installed.

In order to solve the above-mentioned conventional problems, the present invention is directed to a rotary drum formed in a bottomed cylindrical shape, and the rotation axis direction is horizontal or inclined downward from the horizontal direction from the front side to the back side of the rotary drum. In this way, the water tank, the drum pulley fixed to the rotary shaft of the rotating drum, the motor fixed to the outer bottom of the water tank, the belt for transmitting the rotation of the motor to the drum pulley, and the motor. It has a current detection means for detecting a flowing current and a control means for executing each step such as washing, rinsing, dehydration, etc., and always calculates an induced voltage value from the output value of the current detection means while the motor is being driven. Then, the brake control of the motor is started when the rotation speed becomes higher than a predetermined value with respect to the target rotation speed of the motor in each step, and the induced voltage generated by the motor immediately before the brake control of the motor is performed. And the time from the start of the brake control until the output value of the current detection means reaches substantially zero, it is determined that the belt is broken or the belt is disengaged from the drum pulley. I decided to do it.

As a result, if the belt comes off or breaks while the motor is rotating, the motor speed will increase.Therefore, the abnormal rotation is detected and brake control is performed, and then the motor is The value of the induced voltage that is generated depends on the number of rotations of the motor. In sensorless position estimation control, it is difficult to correctly detect the value of the induced voltage when the motor is out of step, but the value of the current that flows in the motor. Pay attention to the fact that the current value flowing to the motor becomes almost zero when the rotation of the motor stops, and the value of the induced voltage generated by the motor immediately before the brake control and the motor current value from the start of the brake are almost zero. By making the above-mentioned determination based on the relationship with the time until it becomes, the motor is controlled without depending on the rotation speed detection means, that is, in an irregular situation such as a failure of the rotation speed detection means, or by a sensorless position estimation method. Even when the rotation speed detecting means is not installed, it is possible to detect the belt breakage or the belt detachment with high accuracy.

According to the present invention, the rotational speed detecting means is not mounted without depending on the rotational speed detecting means, that is, in an irregular situation such as a failure of the rotational speed detecting means or when controlling a motor by a sensorless position estimation method. Even in the case, the belt breakage or the belt detachment can be detected with high accuracy.

The longitudinal cross-sectional view of the drum type washing machine in Embodiment 1 of the present invention Rear view showing the internal structure of the drum type washing machine Circuit block diagram of the drum type washing machine Flowchart showing the flow of motor control from the start to the end of operation of the drum type washing machine Flowchart showing the flow of motor control when the brake end determination of the drum type washing machine The flowchart showing the flow of the motor control of the correction value update processing at the time of belt detachment determination of the same drum type washing machine. The flowchart showing the flow of the motor control of the correction value update process at the time of belt detachment determination in the production line of the drum type washing machine.

A first invention is a rotating drum formed in a bottomed cylindrical shape, and a water tank that encloses the rotating drum from the front side toward the back side such that the rotation axis direction is horizontal or inclined downward from the horizontal direction. A drum pulley fixed to the rotary shaft of the rotary drum; a motor fixed to the outer bottom of the water tank; a belt for transmitting the rotation of the motor to the drum pulley; and a current detection for detecting a current flowing through the motor. Means and a control means for controlling the motor with reference to a predetermined target rotation speed to perform drive control and brake control to perform steps such as washing, rinsing, and dehydrating, and driving the motor. Always calculates the induced voltage value from the output value of the current detection means, and when the rotation speed of the motor becomes higher than a predetermined value with respect to the target rotation speed of the motor in each step, the brake control of the motor is started, Due to the relationship between the value of the induced voltage generated by the motor immediately before the brake control of the motor and the time from the start of the brake control until the output value of the current detection means reaches substantially zero, the belt breaks. Or the belt is disengaged from the drum pulley.

As a result, it is possible to detect the belt breakage or the belt detachment with high accuracy without mounting the rotation speed detection means.

In a second aspect based on the first aspect, the value of the induced voltage generated by the motor immediately before the brake control of the motor and the output value of the current detection means after the brake control is started are substantially zero. It has a storage means for storing the relationship with the time to reach it as a judgment table, and when performing a braking operation, with respect to the induced voltage value immediately before the braking operation starts, the output value of the current detecting means from the braking operation start When the time to reach substantially zero is shorter than the time stored in the determination table and the difference is a predetermined value or more, the belt is broken or the belt is disengaged from the drum pulley. By determining that the belt breakage or the belt detachment can be efficiently detected with high accuracy without depending on the rotation speed detection means.

3rd invention has the cloth amount detection means which detects the amount of the clothes thrown in in the said rotary drum in the said 2nd invention, Comprising: The output value of the said electric current detection means is changed after starting brake control. By storing the time until reaching substantially zero as a relational expression having the induced voltage value generated by the motor and the output value of the cloth amount detection means as parameters, the time from the start of braking to the stop of motor rotation is Since it changes depending on the amount of clothes thrown into the rotary drum, it is possible to detect the belt breakage or the belt detachment with higher accuracy by previously storing the relationship between the amount of clothes and the time.

In a fourth aspect based on the second aspect, there is provided cloth amount detecting means for detecting the amount of clothes thrown into the rotary drum, and the output value of the current detecting means is changed after the brake control is started. By storing the relationship between the time required to reach substantially zero, the value of the induced voltage generated by the motor, and the output value of the cloth amount detecting means as a three-dimensional table, it is possible to detect the belt breakage or the belt detachment with higher accuracy. It can be detected with high accuracy.

A fifth invention is the invention of any one of the second to fourth inventions, wherein in the final dehydration step, an induced voltage value generated by the motor when the rotary drum rotates at a high speed at a predetermined rotation speed, and a brake. The time from the start of control until the output value of the current detecting means reaches substantially zero is measured, and the stored value is corrected and overwritten according to the measurement result, or a correction coefficient is stored. As a result, highly accurate belt breakage detection or belt detachment detection can be performed in response to individual variation of the drum type washing machine and secular change.

In a sixth aspect based on any one of the second to fourth aspects, at least when the rotating drum rotates at a high speed at a predetermined number of revolutions with no load, that is, the inside of the rotating drum is empty. The induced voltage value generated by the motor and the time from the start of the brake control until the output value of the current detection means reaches substantially zero are measured at the production factory, and the stored value is measured according to the measurement result. The time from the start of braking to the stop of motor rotation varies depending on the individual drum type washing machine by correcting and overwriting or storing the correction coefficient. It is possible to provide the user with the state in which the belt breakage or the belt detachment can be detected with higher accuracy by measuring and storing.

A seventh invention is the invention according to any one of the second to fourth inventions, wherein the induced voltage value generated by the motor and the output value of the current detection means after the brake control is started reach substantially zero. And the output value of the cloth amount detection means are measured for each washing operation, and the stored value is overwritten by correcting the stored value according to the average value of the measurement results for a plurality of times, or a correction coefficient is set. By storing, the time from the start of braking to the stop of motor rotation changes with the aging of the drum type washing machine such as belt tension change and deterioration of the performance of grease on the rotating shaft. By measuring and correcting these relationships, it is possible to detect the belt breakage or the belt detachment with high accuracy regardless of the secular change of the drum type washing machine.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to this embodiment.

(Embodiment 1)
1 is a vertical sectional view of a drum type washing machine according to a first exemplary embodiment of the present invention. The rotating drum 1 is formed in a cylindrical shape with a bottom, a large number of water passage holes 2 are provided in the outer peripheral portion of the side wall, and is rotatably arranged in a water receiving tank 3 (water tank). One end of a rotary shaft 4 provided in an inclined direction at the center of rotation of the rotary drum 1 is fixed, and a drum pulley 6 is fixed at the other end of the rotary shaft 4. The direction of the rotary shaft 4 is inclined downward from the horizontal direction from the front side of the drum type washing machine toward the back side which is the bottom. The direction of the rotary shaft 4 may be horizontal.

A motor 5 attached to the outer bottom of the water receiving tank 3 on the back side is connected to a drum pulley 6 by a belt 7, and the rotary drum 1 is configured to be normally or reversely rotated by the motor 5 and rotationally driven. Further, the inner wall surface of the rotary drum 1 is provided with several protrusions 8. Since the laundry is hooked at the time of rotation by the protrusions 8 and dropped from an appropriate height, the laundry can be washed with the effect of hitting and washing.

The water receiving tub 3 is suspended by a spring body 10 by a top plate of the washing machine body 9 so as to be swingable. The water receiving tank 3 has an opening on the front side of the rotary drum 1 covered with a lid 11 (lid) so as to be openable and closable. The lid lock device 12 locks the lid body 11 in a closed state, and locks the lid body 11 so that the lid body 11 is not opened while the rotary drum 1 is rotating. The lid lock device 12 prevents the fingers and the like from being caught in the laundry in the rotary drum 1.

One end of a drain hose 13 is connected to the lower part of the water receiving tank 3, and a drain valve 14 is provided at the other end of the drain hose 13. By opening the drain valve 14, the washing water in the water receiving tub 3 is drained. The water supply valve 15 is an electromagnetic valve for supplying water into the water receiving tank 3.

The control device 16 is composed of a control means 17 including a microcomputer that controls the operations of the motor 5, the drain valve 14, the water supply valve 15, and the like, and sequentially controls a series of steps such as washing, rinsing, and dehydrating.

The control device 16 is composed of a control means 17 including a microcomputer that controls the operations of the motor 5, the drain valve 14, the water supply valve 15, and the like, and sequentially controls a series of steps such as washing, rinsing, and dehydrating.

FIG. 2 is a rear view showing the internal structure of the drum type washing machine according to the first embodiment of the present invention. A belt 7 is suspended around the motor 5 and the drum pulley 6, and the rotating drum 1 can be rotated by driving the motor 5.

FIG. 3 is a circuit block diagram of the control device 16.

The commercial power supply 101 is input to the rectifier circuit 103 via the line filter 102 and converted into DC power. The rectifier circuit 103 constitutes a voltage doubler rectifier circuit as shown below. The AC voltage input to the rectifier circuit 103 is charged by the full-wave rectifier diode 103a into the capacitor 103b when the input voltage is a positive voltage and into the capacitor 103c when the input voltage is a negative voltage. As a result, a double voltage DC voltage is generated across the capacitors 103b and 103c connected in series, and the double voltage DC voltage is input to the inverter circuit 105 and the lid lock device 12.

The inverter circuit 105 is composed of a three-phase full-bridge inverter circuit composed of six power switching semiconductors and an antiparallel diode, and is integrally configured as an intelligent power module (hereinafter referred to as IPM) having a drive circuit and a protection circuit built therein. There is. The motor 5 is connected to the output terminal of the inverter circuit 105 to drive the rotating drum 1. The motor 5 is a DC brushless motor having electric saliency. Between the negative voltage terminal of the inverter circuit 105 and the negative voltage terminal of the rectifier circuit 103, a current detecting means 108 for detecting a current flowing through the inverter circuit 105 and a so-called shunt resistor is connected.

A drain valve 14 and a water supply valve 15 are connected between the output terminals of the line filter 102, and controlled by a switching means 112 composed of a solid-state relay such as a bidirectional thyristor or a mechanical relay. By pressing the power switch 113 arranged on the operation panel 18, electric power is supplied to the control device 16. The relay 115, which is a switch, is provided to retain electric power even after the power switch 113 is released, and the opening/closing of the relay 115 is controlled by the control means 17 via the relay drive circuit 114.

In the above configuration, the control device 16 pushes an operation switch (not shown) arranged on the operation panel 18 while the power is on, so that the control means 17 causes the lid lock device 12 to operate.
Is driven to lock the lid 11 in the closed state, and then the operation is started.

After the operation is started, the control device 16 controls the switching means 112 to control the operations of the drain valve 14, the water supply valve 15 and the like, and controls a series of steps of washing, rinsing, and dehydrating (detailed description of control operation). Is omitted), and the motor 5 is controlled (drive control and brake control) according to each stroke. In the washing process, the rotary drum 1 is rotated to the left and right, and mechanical force is applied to the clothes to clean the clothes. In the dehydration process, the rotary drum 1 is rotated at high speed, and the washing water used for washing is squeezed from the clothes. After a series of operations is completed, after confirming that the rotation of the rotary drum 1 is sufficiently reduced, the lid 11 is unlocked, the relay 115 is turned off, and all the operations are completed.

In addition, at the time of a power failure during operation and when a cut switch (not shown) or a temporary stop switch (not shown) arranged on the operation panel 18 is pressed, the motor 5 is braked/stopped and the rotary drum 1 is rotated. After confirming that the rotation is sufficiently reduced, the lid 11 is unlocked. At the time of a power failure or a stop by the off switch, the relay 115 is turned off after the lock is released, and all the operations are completed.

Hereinafter, details of the control of the motor 5 will be described with reference to FIGS. 4 to 7.

FIG. 4 is a flowchart showing a control flow from the start to the end of operation of the drum type washing machine according to the first embodiment of the present invention.

When the operation switch is pressed in step 1, the lid is locked and the operation is started. After that, the motor 5 is drive-controlled and brake-controlled according to each process. In steps 3 and 4, it is determined whether the temporary stop switch or the operation stop (off) switch is pressed. When each switch is pressed, a process according to the pressed switch is performed and the motor 5 is brake-controlled. The brake control is to cause the rotational energy of the motor 5 to be consumed within the motor by completely short-circuiting the IPM lower arm of the inverter circuit 105. The temporary stop switch is designed to be accepted only during operation.

In step 5, it is determined whether or not the brake control is being performed. If the brake is being applied, a brake end determination (details will be described later) is performed. If the brake is not being applied, the brake timer (t1) is reset and the process proceeds to step 6.

In step 6, it is determined whether or not it is the timing for driving the motor 5. If it is the timing for driving the motor 5, the process proceeds to step 7 to drive the motor 5. When the motor 5 is not driven, the routine proceeds to step 10, and if the rotation speed of the rotary drum 1 is 10 r/min or more, brake control is performed.

In step 7, the induced voltage generated by the motor 5 is measured, and the position of the rotor of the motor 5 and the rotation speed of the motor 5 are estimated based on the measured induced voltage. The rotation speed of the rotary drum 1 is calculated from the rotation speed of the motor 5 estimated in step 7 and the pulley ratio between the motor 5 and the rotary drum 1.

Calculation of the induced voltage is performed based on the following basic formula.

The control means 17 inputs the three-phase (U, V, W) current values of the motor 5 detected by the current detection means 108, performs uvw→dq(γδ) current conversion, and obtains iγ, iδ in the above equation. .. Vγ and Vδ are command voltages of the γ and δ axes (estimated d and q axes) from the control means 17. Ra, Ld, and Lq are treated as fixed values. Eγ is used to estimate the position of the rotor, and Eδ is used to detect the belt detachment in the brake end determination described later. The sensorless position estimation method used in the present embodiment is such that the estimated phase of the rotor is in the direction in which the error between the dq axis and the γδ axis (estimated dq axis) becomes zero, that is, the direction in which Eγ in the above equation becomes zero. This is a method of feedback controlling θ and the estimated angular velocity ω.

In step 8, rotational speed feedback control is performed so that the rotary drum 1 rotates at the target rotational speed. That is, if the estimated number of revolutions is less than the target number of revolutions, the amount of electricity to the motor 5 is increased, and if the estimated number of revolutions is greater than or equal to the target number of revolutions, the amount of electricity to the motor 5 is decreased. In FIG. 4, the target rotation speed is set to 800 r/min, but this value is an example, and differs depending on the process progress state such as washing, rinsing, and dehydration.

Further, at the beginning of the washing process, a control for determining the amount of cloth is performed, and the amount of clothes thrown into the rotary drum 1 is detected by the amount of cloth detecting means described later (not shown). The cloth amount determination is performed based on the following determination table (Table 1) from iq (q-axis current value) when the rotary drum 1 is stopped and accelerated up to 200 r/min with a predetermined acceleration.

By this control, the amount of clothes put in the rotary drum 1 is detected.

In step 9, abnormal rotation is determined. When the estimated rotation speed of the rotating drum 1 becomes 1000 r/min or higher, it is determined that some abnormality has occurred, and the braking process is performed. In the present embodiment, the abnormal rotation threshold value is set to 1000 r/min, but other rotation speeds may be used as long as they are higher than the target rotation speed.

FIG. 5 is a flow chart showing the flow of motor control when it is determined that the drum type washing machine has finished braking.

The brake end determination will be described with reference to FIG.

In the brake end determination, it is determined in step 11 whether all the three-phase current values (Iu, Iv, Iw) flowing in the motor 5 have become less than 0.1A. If any one of the phases is 0.1 A or more, it is determined that the motor 5 is still rotating, the brake control is continued, and at the same time, the brake timer (t1) is counted up. If all the three phases are less than 0.1 A, it is determined that the motor 5 has stopped or an abnormality such as a disconnection of the connection line with the motor 5 has occurred, and after the brake control is completed, step 12 The disconnection detection process is performed with. In the present embodiment, the IPM is controlled so that a predetermined current is supplied to each of the U, V, and W phases, and disconnection is detected depending on whether Iu, Iv, and Iw at that time have appropriate values. ing.

When it is determined in step 12 that the connection wire with the motor 5 is broken, the operation is terminated and the disconnection abnormality is displayed. In this case, since the rotary drum 1 may not be stopped, the lid lock is not released immediately, the lock release timer (t2) is counted up, and the lid lock is released after 5 minutes ( Step 13). In the present embodiment, the lock release timer is set to 5 minutes, but the present invention is not limited to this. Under the condition that the rotating drum 1 is rotating at high speed under the maximum load of the cloth amount and the belt 7 is disengaged, if the time between the starting and stopping of the rotating drum 1 is set, for example, 6 Minutes or 7 minutes.

If it is determined in step 12 that the wire is not broken, the process proceeds to step 14 to detect the detachment of the belt 7. It should be noted that even if the belt 7 is broken, the same phenomenon as the detachment of the belt 7 occurs, and therefore the detachment detection of the belt 7 will be described below. The detachment of the belt 7 is detected as follows.

The control means 17 has a non-volatile storage means 116, and shows the relationship between the induced voltage, the amount of cloth, and the time (t) from the start of braking until Iu, Iv, and Iw reach 0.1 A. It is stored in advance as a judgment table in the form shown in.

The induced voltage value measured immediately before the start of braking, that is, the induced voltage value measured in step 7, the time t1 measured during the brake control, and the result of the cloth amount determination are compared with Table 2, and t (seconds) in Table 2 On the other hand, when t1 is short and the difference is equal to or larger than a predetermined value, for example, less than half of t (seconds), it is determined that the belt 7 is broken or detached.

When the induced voltage value or the cloth amount is an intermediate value between the values specified in Table 2, the belt detachment is determined by comparing t (second) calculated by the proportional calculation and t1. For example, when the measured induced voltage value is 350 V and the cloth amount is 5 kg, the cloth amount is 3 kg and 6 kg t (second) at the induced voltage of 300 V in Table 2 and the cloth amount 3 kg and 6 kg t (second) at the induced voltage 400 V. ), first, t (second) when the induced voltage is 300 V and 400 V and the cloth amount is 5 kg is calculated by the following formula.

・T (second) at 300V, 5kg
=7.0+(10.0-7.0)×(5.0-3.0)÷(6.0-3.0)
= 9.0
・T (second) at 400V, 5kg
=11.0+(14.0-11.0)×(5.0-3.0)÷(6.0-3.0)
= 13.0
Next, from the t (second) at 5 kg at 300 V and 400 V obtained above, the t (second) at 5 kg at 350 V is calculated by the following formula.

・T(sec) at 350V, 5kg
=9.0+(13.0-9.0)×(350-300)÷(400-300)
= 11.0
In the present embodiment, the correction process is further performed on t (seconds) in Table 2, but the correction process will be described later. Here, for simplicity, the correction coefficient is “1” (=no correction). As explained.

If it is determined in step 12 that the belt 7 has come off, the operation is immediately terminated and an abnormality is displayed. Also in this case, the lid lock is not released immediately after the disconnection is detected, but the lid lock is released after 5 minutes.

If it is determined that the belt 7 is not disengaged, and if the brake is due to the end of operation or temporary stop, the lid lock is immediately released. If the operation is not completed or temporarily stopped, the correction value update process (details will be described later) is performed, and the process waits until the next operation.

FIG. 6 is a flowchart showing a flow of motor control of a correction value updating process at the time of belt detachment determination of the drum type washing machine in the first exemplary embodiment of the present invention.

The correction value updating process when the belt detachment is determined will be described with reference to FIG.

The correction value updating process is performed only at the end of the dehydration process. At step 101 in FIG. 6, it is determined whether or not it is the final dehydration step. If it is the final dehydration process, the process proceeds to step 102. If it is not the final dehydration step, the correction value updating process is terminated. Whether or not it is the final dehydration step is determined based on information from the control means 17 including a microcomputer that sequentially controls a series of steps.

Step 102 is a step of preventing the correction value from being updated with the value when the measurement result such as the induced voltage value this time is not standard, that is, when the measurement cannot be performed correctly due to some irregularity. First, the provisional correction coefficient Ktn for this time is calculated from t (seconds) calculated in the belt detachment detection process described above and t1 measured this time based on the following equation.
Ktn=t1÷t

If the difference between this Ktn and the current correction coefficient Kt (initial value is 1.0) is ±0.1 or more, it is determined to be an abnormal value, and the correction value update processing is terminated without performing the subsequent processing. ..

If the difference is less than ±0.1, Ktn is stored as the current correction coefficient.

The correction coefficient Kt is updated with an average value of a plurality of times, in the present embodiment, the average value of the correction coefficients Ktn of 50 times. In step 103, it is determined whether or not 50 or more Ktn's are stored. If 50 or more Ktn's are stored, the correction coefficient Kt is updated with the average value of the latest 50 Ktn's.

The correction coefficient Kt updated by the above method is used by multiplying t (second) calculated in the above-described belt detachment detection processing. For example, in the belt detachment detection process described above, t=11.0 (seconds) was calculated, but this value is further multiplied by the correction coefficient Kt, and t=11.0×Kt is set to determine the belt detachment.

FIG. 7 is a flowchart showing the flow of motor control of correction value update processing at the time of belt deviation determination in the production line of the drum type washing machine according to the first embodiment of the present invention.

In FIG. 6, the correction coefficient updating process during the washing operation has been described. In FIG. 7, the correction coefficient updating process performed on the production line of the factory before shipment will be described.

In the production line, it is general to perform performance measurement such as power consumption during operation in order to confirm product quality. In the present embodiment, the correction coefficient updating process is performed at the same time in the inspection process for measuring the dehydration performance.

At step 201, when the drum type washing machine on the production line receives the start signal from the inspection machine, it operates in the special mode for inspection. At the same time as driving the rotary drum 1 with the target rotation speed of 800 r/min, the induced voltage measurement similar to that of FIG. 4 is performed (step 202). When the inspection machine completes the measurement of the dehydration performance, the stop signal is input. When the stop signal is received from the inspection machine, the drum type washing machine performs brake control, counts up the brake timer (t1), and determines the brake end, as in FIG. The abnormality determination after step 12 in FIG. 5 is not performed. Finally, in step 203, Kt is updated with the current correction coefficient Ktn and stored.

Since the correction coefficient updating process in the production factory is intended to correct the individual variation of the drum type washing machine, it does not have to be performed with an average value of a plurality of times.

As described above, according to the present embodiment, while the motor 5 is being driven, the induced voltage value is constantly calculated from the output value of the current detection means 108, and the rotation speed is higher than the target rotation speed by a predetermined value or more. When the braking of the motor 5 is started, the value of the induced voltage generated by the motor 5 immediately before the braking control of the motor 5 and the output value of the current detection means 108 after the braking control is started are substantially zero. It is determined that the belt 7 is broken or the belt 7 is disengaged from the drum pulley 6 depending on the time required to reach

More specifically, the relationship between the value of the induced voltage generated by the motor 5 immediately before the brake control of the motor 5 and the time from the start of the brake control until the output value of the current detection means 108 reaches substantially zero is shown. The induced voltage value is calculated from the output value of the current detection means 108 at all times while the motor 5 is being driven, and the braking of the motor 5 is started when the rotation speed becomes higher than a predetermined value with respect to the target rotation speed. When performing a brake operation, the time from the start of the brake operation until the output value of the current detection means 108 reaches substantially zero is shorter than the stored time with respect to the induced voltage value immediately before the start of the brake operation. If the difference is equal to or more than a predetermined value, it is determined that the belt 7 is broken or the belt 7 is disengaged from the drum pulley 6. Therefore, when the belt 7 is disengaged or broken while the motor 5 is rotating, In addition to following the conventional operation of detecting an abnormal increase in the number of revolutions of 5 and performing brake control, further, without relying on the number of revolutions detecting means as in the past, that is, a failure of the number of revolutions detecting means, etc. It is possible to detect a broken belt or a detached belt with high accuracy even when the rotational speed detection means is not installed, such as in an irregular situation or when the motor 5 is controlled by the sensorless position estimation method.

Further, the relationship between the time from the start of the brake control until the output value of the current detection means 108 reaches substantially zero and the relationship between the induced voltage value generated by the motor 5 and the cloth amount is stored as a three-dimensional table, and the belt detachment is performed. Since it is used as a criterion for belt breakage, highly accurate determination is possible.

Although a three-dimensional table is used in the present embodiment, it is also possible to store these relationships as a relational expression instead of the table, and it is needless to say that the same effect can be obtained in that case. .

Furthermore, by the correction by the production line of the factory and the update of the correction value during operation, it is possible to make highly accurate determinations regardless of individual variation or aging.

As described above, the drum type washing machine according to the present invention is effective for a household drum type washing machine in which a rotary drum is driven at high speed via a belt, but the technique of the present invention is the same. It can also be used for vertical washing machines, clothes dryers, production equipment, etc.

1 rotating drum 2 water passage hole 3 water receiving tank (water tank)
4 Rotating Shaft 5 Motor 6 Drum Pulley 7 Belt 8 Projection Body 9 Washing Machine Main Body 10 Spring Body 11 Lid Body 12 Lid Lock Device 13 Drain Hose 14 Drain Valve 15 Water Supply Valve 16 Control Device 17 Control Means 18 Operation Panel 101 Commercial Power Supply 102 Line Filter 103 Rectifier circuit 103a Full-wave rectifier diode 103b Capacitor 103c Capacitor 105 Inverter circuit 108 Current detection means 112 Switching means 113 Power switch 114 Relay drive circuit 115 Relay (switch)
116 storage means

Claims (7)

A rotating drum formed in a bottomed cylindrical shape, a water tank that encloses the rotating drum from the front side to the back side such that the rotation axis direction is horizontal or inclined downward from the horizontal direction, and the rotation of the rotating drum A drum pulley fixed to the shaft, a motor fixed to the outer bottom of the water tank, a belt for transmitting the rotation of the motor to the drum pulley, a current detection means for detecting a current flowing through the motor, and the motor. A current control means for controlling the drive control and the brake control with reference to a predetermined target rotation speed to perform each step such as washing, rinsing, dehydration, etc. The induced voltage value is calculated from the output value of, and the brake control of the motor is started and the brake control of the motor is performed when the rotation speed becomes higher than a predetermined value with respect to the target rotation speed of the motor in each step. Depending on the relationship between the value of the induced voltage generated immediately before by the motor and the time from when the brake control is started until the output value of the current detection means reaches substantially zero, the belt is broken or the belt is A drum type washing machine, characterized in that it is determined that it is out of the drum pulley. The relationship between the value of the induced voltage generated by the motor immediately before the brake control of the motor and the time from the start of the brake control until the output value of the current detection means reaches substantially zero is stored as a determination table. When the braking operation is performed, the time from the start of the braking operation until the output value of the current detecting means reaches approximately zero is set to the determination table when the braking operation is performed. The time is shorter than the time stored in the table and the difference is equal to or more than a predetermined value, it is determined that the belt is broken or the belt is disengaged from the drum pulley. Drum type washing machine. The motor has a cloth amount detecting means for detecting the amount of clothes thrown into the rotating drum, and the motor generates a time from the start of brake control until the output value of the current detecting means reaches substantially zero. The drum type washing machine according to claim 2, wherein the induced voltage value and the output value of the cloth amount detecting means are stored as a relational expression having parameters. Having a cloth amount detecting means for detecting the amount of clothes thrown into the rotating drum, the time from the start of the brake control until the output value of the current detecting means reaches substantially zero, and the motor is generated. The drum type washing machine according to claim 2, wherein the relationship between the induced voltage value to be generated and the output value of the cloth amount detecting means is stored as a three-dimensional table. In the final dehydration step, the induced voltage value generated by the motor when the rotating drum rotates at a high speed at a predetermined rotation speed, and from the start of brake control until the output value of the current detecting means reaches approximately zero. The drum type according to any one of claims 2 to 4, wherein time is measured and the stored value is corrected and overwritten according to the measurement result, or a correction coefficient is stored. Washing machine. At least an unloaded state, that is, in a state where the inside of the rotating drum is empty, an induced voltage value generated by the motor when the rotating drum rotates at a high speed at a predetermined rotation speed, and the current detection means after starting brake control. The time until the output value of 0 reaches approximately zero is measured at the production factory, and the stored value according to claim 2 is corrected and overwritten according to the measurement result, or a correction coefficient is set. The drum-type washing machine according to claim 2, wherein the drum-type washing machine is stored. The induced voltage value generated by the motor, the time from the start of brake control until the output value of the current detection means reaches substantially zero, and the output value of the cloth amount detection means are measured for each washing operation. In addition, the stored value is corrected and overwritten according to an average value of the measurement results obtained a plurality of times, or a correction coefficient is stored, and the correction coefficient is stored. Drum type washing machine.

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