JPH05277282A - Washing machine - Google Patents

Abstract

PURPOSE:To properly detect the cloth quality of a wash put in a spin basket by lowering drive voltage applicable to a brushless DC motor to a zero level for the free running thereof, when the motor reaches a constant speed after the placement of the wash, and detecting a cloth volume from a motor speed reduction rate. CONSTITUTION:When a start switch is pressed, flat clutch discs are engaged to each other and a spin basket is thereby caused to rotate, together with a pulsator, on the operation of a brushless DC motor 5. When the angular velocity of the motor 5 reaches the predetermined value, upper arm transistors U1, V1 and W1, and lower arm transistors U2, V2 and W2 of an inverter circuit 17 are all turned off. The supply of drive voltage is thereby stopped and the motor 5 is caused to rotate on inertia. Concurrently, a software timer in a microcomputer 26 is reset and caused to start a counting process. When the angular velocity of the running motor 5 reaches a predetermined value, a cloth volume size is determined from a data table in the memory of the microcomputer 26 on the basis of the duration of a counted time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine having a small-sized and large-capacity washing tub by performing direct drive using a brushless DC motor, and particularly while utilizing the characteristics of the brushless DC motor. The present invention relates to a washing machine equipped with a unit for detecting the amount of laundry.

[0002]

2. Description of the Related Art A fully automatic washing machine that continuously and automatically performs washing operations such as washing, rinsing, and dehydrating treatments is performed by a user pushing a start button after putting laundry in a washing tub. After being supplied with water, these washing operations are started. Regarding the water supply amount, for example, three types are set according to the laundry amount, and before the user presses the start button, one of these three types may be selected in advance according to the laundry amount. However, in this case,
Since the user himself / herself selects the water supply amount according to the cloth amount, an accurate water supply amount corresponding to the cloth amount cannot be obtained.

For this reason, conventionally, before the water is supplied, the dehydration tank is raised to a preset constant number of rotations, and the sliding resistance of the rotary sliding portion, which is necessary for keeping the constant number of rotations, is changed by the change in the amount of cloth. There is a method in which the amount of cloth is detected from the change in the motor current value based on the change.

[0004]

However, in such a conventional washing machine, since the rate of change of the motor current value is extremely small, there is a problem that the amount of cloth cannot be accurately detected.

Therefore, an object of the present invention is to make it possible to accurately detect the amount of laundry put into the dehydration tub.

[0006]

In order to achieve the above object, the invention of claim 1 is an electric motor means for rotating a dehydration tub capable of accommodating laundry, and is rotationally driven by the electric motor means. With respect to the dehydration tank, a moment of inertia detecting means for detecting the moment of inertia of the electric motor means when the control current is controlled so that the driving in the rotating direction is stopped, and a desorption based on the moment of inertia detected by the moment of inertia detecting means. It is configured to have a cloth amount detecting means for detecting the cloth amount of the laundry stored in the water tank.

Further, the invention according to claim 2 is provided with a water flow generating means for generating a water flow at the bottom of the dehydrating tub for containing the laundry, and the electric motor means is connected to the water flow generating means for rotating the water flow generating means. And a clutch means for selectively connecting the rotation of the electric motor means to the dehydration tub so that the water flow generating means or the water flow generating means and the dehydration tub can be moved up and down according to the weight of the laundry stored in the dehydration tub. A resistance member, which is connected to an electric motor means via a drive shaft and receives resistance of water when rotating in a state where a predetermined amount of water is supplied to the water flow generating means or the dehydration tub, the resistance member is A load torque detecting means for detecting a load torque applied to the electric motor means when the water flow generating means or the water flow generating means and the dehydration tank is rotating while receiving resistance is provided. There be provided with a laundry amount detecting means for knowledge means detects the laundry weight of laundry contained in the dewatering tank according to the load torque sensing.

Further, according to the invention of claim 3, an elastic means for elastically supporting the washing tub containing the dehydration tub with respect to the main body of the washing machine, a vibration of the elastic means is damped, and the magnet and the magnet are energized when energized. A damper means including a coil on which a repulsive force acts, a distance detecting means for detecting a vertical distance of the washing tub with respect to the main body of the washing machine, and a distance detecting means when the coil of the damper means is de-energized. And a cloth quantity detecting means for detecting the cloth quantity of the laundry stored in the dehydration tub based on the distance detected by the means.

[0009]

According to the first aspect of the present invention, when the control current is controlled so that the driving in the rotation direction is stopped for the dehydration tank which is rotationally driven by the electric motor means, the electric motor means is rotated until now. The moment of inertia in the running direction is generated, and the amount of laundry stored in the dehydration tub is detected based on this moment of inertia.

According to the second aspect of the present invention, when the laundry is stored in the dehydration tub, the water flow generating means or both the water flow generating means and the dehydration tub descend according to the weight of the stored laundry. However, when the water flow generating means or both the water flow generating means and the dehydration tub rotate in this state, the resistance member receives the resistance of the water supplied in the washing tub by a predetermined amount, and the electric motor means according to the resistance force. The load torque applied to the load changes, and the amount of laundry stored in the dehydration tub is detected based on this load torque.

Further, according to the invention of claim 3, when the laundry is accommodated in the dehydration tub, the washing tub containing the dehydration tub descends against the elastic means with respect to the main body of the washing machine. The energization of the coil of the damper means is stopped. The distance detector detects the vertical distance of the washing tub with respect to the main body of the washing machine when the washing tub is lowered, and detects the amount of laundry stored in the dehydration tub based on the detected distance.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial sectional view showing the internal structure of a washing machine according to the first embodiment of the present invention. The washing machine shown in this embodiment has a small-sized, large-capacity washing tub that performs direct drive using a brushless DC motor, and uses the characteristics of the brushless DC motor to control the amount of laundry to be loaded. It has a function of accurately detecting, and it is possible to obtain an appropriate amount of water according to the amount of laundry by, for example, putting the laundry in the dehydration tub and simply pressing the start button.

First, a direct drive mechanism using a brushless DC motor will be described with reference to FIG. This washing machine is housed in an outer case 1 having an open upper part, and an openable / closable lid 14 is attached to the upper part of the outer case 1 so that the upper part can be closed. A washing tub 2 is provided inside the outer box 1, and a dehydration tub 3 is provided inside the washing tub 2. Washing tub 2
Is supported on the outer box 1 by four suspension rods 10 and suspensions 11 provided around the periphery at appropriate intervals. A brushless DC motor 5 as an electric motor means is attached to the bottom of the washing tub 2 via a mechanism 9 for rotating the washing tub 2 and the dehydration tub 3.

A drain hose 12 for draining the water in the wash tub 2 is attached to the bottom of the wash tub 2, and the drain hose 12 can be drawn out of the outer case 1. Although not shown, a drainage valve is provided between the drain hose 12 and the bottom of the washing tub 2 to which the drainage hose 12 is attached, and the drainage water in the washing tub 2 is drained by controlling the opening and closing of the drainage valve. Is ready for you. Furthermore, on the upper part of the washing tub 2 to which the lid 14 is attached,
Although not shown, a water supply valve is appropriately provided, and water can be supplied into the washing tub 2 by controlling opening / closing of the water supply valve.

A pulsator 4, which is a water flow generating means for generating a water flow in the water contained in the dehydration tank 3, is provided at the bottom of the dehydration tank 3, and the drive shaft of the brushless DC motor 5 (see FIG. A first transmission shaft 37 connected to the first transmission shaft 37
Penetrates through the bottoms of the mechanism section 9, the washing tub 2 and the dehydration tub 3 and extends to the pulsator 4 provided at the bottom of the dehydration tub 3, and the upper end of the first conduction shaft 37 of the pulsator 4 is Spline-fitted in the center, which allows brushless D
The pulsator 4 can be directly rotated by the C motor 5.

The mechanical portion 9 provided between the brushless DC motor 5 and the bottom of the washing tub 2 has a brushless DC motor 5
It has a clutch disk which is a clutch means for transmitting or shutting off the rotation of the dehydration tank 3 to the dehydration tank 3, a brake for forcibly stopping the dehydration tank 3, and the like. An actuator 16 is provided on the side of the mechanism unit 9. The actuator 16 actuates a flat clutch disk 57 provided in the mechanism unit 9 as will be described below, thereby causing a brushless operation. Switching control for transmitting the rotation of the DC motor 5 not only to the pulsator 4 but also to the dehydration tank 3 via the flat clutch disk 57 to rotate the dehydration tank 3 or to brake the dehydration tank 3 to stop it. Is used for. In addition, the balancer 13 is provided in the upper peripheral portion of the dehydration tank 3 so that when the dehydration tank 3 rotates, the rotation is performed stably.

Next, referring to FIG. 2, the internal structure of the mechanical section 9 will be described in detail. In FIG. 2, a cylindrical second conductive shaft 43 rotatable relative to the first conductive shaft 37 is fitted into a small diameter portion 37 a of the first conductive shaft 37 in a part of an outer peripheral portion of the first conductive shaft 37. Has been. The upper end of the second conduction shaft 43 is attached to the lower portion of the dehydration tank 3 to form the flange 4 shown in FIG.
It is attached through 5. A cutout surface 51 having a predetermined length in the axial direction is formed on the outer periphery of the second conductive shaft 43 from its lower end 47 to its upper end 49. On the other hand, a rectangular portion 55 is formed on the outer peripheral portion of the upper end of the large diameter portion 37b of the first conductive shaft 37, which is in contact with the lower end 47 of the second conductive shaft 43. The flat clutch disk 5 as a moving body that can be engaged with the notch surface 51 and the rectangular portion 55 and that transmits / blocks the driving force from the first transmission shaft 37 to the second transmission shaft 43.
7 is provided so as to be movable on the second conduction shaft 43 by several mm.

The flat clutch disk 57 has a disk portion 57a located at the lower portion and a cylindrical portion 57b located at the upper portion, and the second transmission shaft 43 penetrates these. The through hole 59 is formed in the cutout surface 51 of the second conductive shaft 43.
The second conductive shaft connecting portion 59a aligned with the first conductive shaft 37
The first conductive shaft connecting portion 59b aligned with the rectangular portion 55 of FIG. Disk part 5 of flat clutch disk 57
On the upper surface of 7a, a plurality of protrusions 61 are provided upward at equal intervals in the circumferential direction. Further, an annular groove 6 is formed on the outer periphery of the upper end of the cylindrical portion 57b of the flat clutch disc 57.
3 is provided.

Around the flat clutch disk 57, there is provided a brake disk 65 as a sliding body for exerting a braking force on the spinning dehydration tub 3. The brake disc 65 includes a turntable 67 and the turntable 67.
Lining material 73 attached to both the upper and lower outer peripheral sides
It consists of and.

The brake disc 65 is made up of the lining material 7
3 is supported from both upper and lower sides in a pressurized state by biasing springs 75 provided at four locations on the outer peripheral portion through brake pads 69 and 71 that serve as fixing portions for the washing tub 2.

The brake pads 69, 71 are fixed in the cover 41 of the mechanism section 9 as shown in FIG. First
The transmission shaft 37 and the second transmission shaft 43 are rotatable with respect to a bearing provided as a separate body (not shown).

On the inner peripheral side of the turntable 67, there is provided a concave portion 83 capable of engaging with the protrusion 61 of the flat clutch disc 57.
The same number is formed.

Annular groove 63 of flat clutch disk 57
Is engaged with an operation lever 77 having a projection at its tip, and a shaft 81 which is rotated by the actuator 16 shown in FIG. 1 is connected to the rear end of the operation lever 77. When the tip of the operating lever 77 is moved upward, the flat clutch disc 57
The plurality of protrusions 61 engage with the recesses 83 of the turntable 67.

The operation of the mechanical portion of the washing machine having the above structure will be described with reference to FIG. First, in the washing operation, when the flat clutch disc 57 is set to the upper position by the operation lever 77 as shown in FIG. 3A, the flat clutch disc 57 has the second transmission shaft connecting portion 59a notched. It is aligned with the surface 51 and is connected to only the second conduction shaft 43. Thereby, the first conduction shaft 3
The connection between 7 and the second conduction shaft 43 is cut off,
The rotation of the brushless DC motor 5 is transmitted only to the first transmission shaft 37 connected to the pulsator 4.

Next, in the dehydration operation, the operating lever 77
Is moved downward, and the state shown in FIG. 3 (c) is passed through FIG. 3 (a) to FIG. 3 (b). As a result, the flat clutch disc 57 has the second transmission shaft connecting portion 59.
a is connected to the cutout surface 51 of the second conductive shaft 43, and the first conductive shaft connecting portion 59b is connected to the rectangular portion 55 of the first conductive shaft 37, so that the first conductive shaft 37 and the second conductive shaft 43 are connected.
And are connected via the flat clutch disk 57. When the brushless DC motor 5 is operated in this state, the dehydration tub 3 connected to the second transmission shaft 43 rotates.

Further, in order to stop the rotating dewatering tank 31, the driving of the motor 5 connected to the first transmission shaft 37 is stopped, and the flat clutch disk 57 is moved by the operating lever 77 as shown in FIG. Set it in the same position as above. As a result, the flat clutch disc 57 is connected only to the second transmission shaft 43, and at the same time, the projection 61 engages with the recess 83 of the brake disc 65, and the second transmission shaft 4
3 rotates the brake disc 65 via the flat clutch disc 57. As the brake disc 65 rotates, it receives a braking force from the brake pads 69, 71, and the rotation of the dehydration tub 3 connected to the second transmission shaft 43 stops.

In this way, the second movement of the flat clutch disc 57, which is connected to the dehydration tub 3, by the slight movement of the flat clutch disc 57 in the vertical direction.
It is possible to switch between driving and braking of the transmission shaft 43. Therefore, the axial lengths of the clutch mechanism portion and the brake mechanism portion are shortened, and the dehydration tub can be performed without enlarging the outer case 1 of the conventional washing machine body. The volume of 3 can be increased, and the ratio of the washing capacity to the size of the outer box 1 can be increased.

The mechanical section 9 of the washing machine shown in FIG. 1 is constructed and operates as described above.
The operation of the C motor 5, the water supply / drainage unit, and other parts are as shown in FIG.
It is controlled by the circuit part shown in.

The circuit section shown in FIG. 4 is composed of, for example, a microprocessor and memories such as ROM and RAM, and an interface, and corresponds to the operation of the brushless DC motor 5 and the entire washing machine, that is, detection of the amount of laundry to be washed and the amount of laundry. It has a microcomputer 26 for controlling operations such as the amount of water supplied, the washing time and the setting of water flow. This microcomputer 26 uses a drive circuit 80 for brushless DC.
It controls the motor 5 and receives information such as the drive voltage or current of the brushless DC motor 5 from the brushless DC motor 5 via the filter 30 and the A / D converter 29, and also as described below.
The rotation speed information of the motor 5 is also received.

Further, the microcomputer 26 includes the above-mentioned flat clutch disk 57, the clutch mechanism 82 including the actuator 16, the water supply valve 84 and the drain valve 8.
6 is controlled.

Next, the drive circuit 80 for driving the brushless DC motor 5 under the control of the microcomputer 26 will be described with reference to FIG. Note that FIG. 5 showing the drive circuit 80 is shown in FIG. 5, in which the brushless DC motor 5, the microcomputer 26, the filter 30, and the A / D converter 2 are shown.
9 is also shown at the same time for the sake of explanation, but the portion excluding these circuit elements corresponds to the drive circuit 80.

As shown in FIG. 5, a brushless DC motor 5 having a three-phase armature U, V, W is used, and the brushless DC motor 5 is driven by a three-phase full-wave bridge type inverter circuit 17. Has been done. In the inverter circuit 17, 92 is a diode bridge for rectification, 93 is a smoothing capacitor, and the commercial AC power supply 91
After the AC voltage from is rectified by the diode bridge 92, it is smoothed by the smoothing capacitor 93 to obtain a DC voltage. And this input DC voltage is 3
It is designed to be converted into a three-phase alternating current at the phase full-wave bridge portion. That is, the three-phase full-wave bridge part has three
Six transistors U1, U2, V1, V2, W1 as switching elements are provided in three pairs of arms corresponding to the phases.
W2 is connected. Hereinafter, for convenience of description, the three arms on the side to which the transistors U1, V1, and W1 are connected are referred to as upper arms, and the three arms on the other side to which the other transistors U2, V2, and W2 are connected are referred to as lower arms. A free wheel diode 94 is connected in parallel to each of the six transistors U1 to W2, and three transistors of the upper arm and the lower arm are connected.
Three connection points are connected to the three-phase armature windings U, V, W in the brushless DC motor 5.

The brushless DC motor 5 includes, in addition to the armature windings U, V, and W, a rotor (not shown) formed of permanent magnets, and three Hall elements for detecting the rotational position of the rotor. 23a, 23b, 23c are provided.
The rotor position detection signals of the hall elements 23a, 23b, 23c are given to the motor control circuit 24.

The motor control circuit 24 is connected to the microcomputer 26 and has hall elements 23a, 23b, 23.
A rotation speed signal is generated from the rotor position detection signal from c and supplied to the microcomputer 26, and control signals such as a start / stop signal of the brushless DC motor 5 and a forward / reverse signal are received from the microcomputer 26.

The motor control circuit 24 also controls the upper arm transistors U1, V1, and V1 via the upper arm drive circuit 21.
W1 is driven to drive the lower arm transistors U2, V2 and W2 via the lower arm drive circuit 22. The rotor position detection signals from the Hall elements 23a, 23b, 23c are supplied to the motor control circuit 24, which uses the rotor rotation position detection signals to form the upper arm transistors U1, V1 constituting the inverter circuit 17. , W1 and the lower arm transistor U
The switching timing of 2, V2 and W2 is determined, and the upper arm drive circuit 21 and the lower arm drive circuit 22 are controlled so as to switch each transistor at this timing. Specifically, the Hall elements 23a, 23b, 23c
The rotor position detection signal from is subjected to logical conversion in the motor control circuit 24 and corresponds to the rotor position of the brushless DC motor 5, for example, the upper arm transistor U1 and the lower arm transistor V2, similarly the transistors V1 and W2, and the transistor V1 and W2. It is output as a drive signal for sequentially controlling ON of various combinations of transistors such as W1 and U2. Then, the DC voltage is converted into a three-phase AC by switching the transistor ON, and the brushless DC motor 5
A current sequentially flows through the armature windings U-V, V-W, and W-U, and the brushless DC motor 5 rotates in one direction. The forward and reverse rotations of the brushless DC motor 5 are performed by armature windings U, V,
It is carried out by reversing the order of the currents supplied to W, and the normal / reverse control is carried out via the motor control circuit 24 by the normal / reverse signals from the microcomputer 26.

The microcomputer 26 is supplied with the rotation speed signal of the brushless DC motor 5 created by the motor control circuit 24 based on the rotor position detection signals from the hall elements 23a, 23b, 23c, and this rotation speed is set to the set rotation speed. Create an on-duty signal such that
It is supplied to the oscillator 25 to control the on-duty of the PWM signal from the PWM oscillator 25.

The rotation speed of the brushless DC motor 5 is changed by variably controlling the applied DC voltage. To change the rotation speed, a PWM oscillator 25 is connected to the microcomputer 26 and the PWM oscillator 25 is connected. A microcomputer 26 supplies a PWM on-duty setting signal, which is a rotation control signal, to the oscillator 25. The output of the PWM oscillator 25 is connected to the upper arm drive circuit 21 via the chopper circuit 27, whereby the PWM oscillator 25 is turned on by a PWM on-duty setting signal from the microcomputer 26, for example, at a repetition frequency of 15 KHz. A PWM signal with a variable off-on duty is output, and this PWM signal is chopped by the chopper circuit 27 and passed through the upper arm drive circuit 21 to the upper arm transistors U1, V1, W1.
The DC voltage applied to the brushless DC motor 5 is changed, and the rotation speed of the brushless DC motor 5 is changed. There is. That is, as the on-duty ratio of the upper arm transistors U1, V1, W1 decreases, for example, the brushless D
The DC voltage applied to the C motor 5 becomes smaller and the rotation speed becomes slower. As the on-duty ratio becomes larger, the DC voltage applied to the brushless DC motor 5 becomes larger and the rotation speed becomes faster. ..

When the brushless DC motor 5 is stopped, a stop signal from the microcomputer 26 is sent by the motor control circuit 2.
4 is supplied to the upper arm transistors U1 and U1 of the inverter circuit 17 under the control of the motor control circuit 24.
V1, W1 and lower arm transistors U2, V2, W
This is done by turning off all two.

Further, one end of the smoothing capacitor 93 of the inverter circuit 17 and the lower arm transistors U2, V2, W2.
A resistor 28 is connected between the commonly connected emitters of the inverters, and the resistor 28 detects the inverter current flowing through the inverter circuit 17 as a voltage value. Since the detected voltage value is a pulse wave turned on and off at the inverter frequency, for example, 15 KHz,
A / D converter 29 for averaging through the filter 30
As a digital signal via the microcomputer 2
6, which allows the microcomputer 26 to identify the voltage value applied to the brushless DC motor 5.

The characteristics of the brushless DC motor 5 will be described in detail. As shown in FIG. 31, the relationship between the torque generated by the brushless DC motor 5 and the rotation speed n is inversely proportional such that the torque decreases as the rotation speed n increases, and this relationship is inversely proportional. The voltage Vdc applied to 5 changes as shown in the figure, and the torque generated by the brushless DC motor 5 increases as the voltage Vdc increases at the same rotation speed. Therefore, when the rotation speed n is constant, the relationship between the load torque applied to the brushless DC motor 5 and the voltage Vdc is proportional as shown in FIG. From this relationship, the brushless D which is the laundry
The load of the C motor 5 can be obtained from the voltage Vdc at the final rotation speed of the brushless DC motor 5.

When the supply voltage Vdc to the brushless DC motor 5 is constant, that is, when the capacity of the brushless DC motor 5 is constant, the brushless DC motor 5 is
Since the energy required for the number of revolutions to reach the predetermined target number of revolutions depends on the load torque, the time required to reach the target number of revolutions is as shown in FIG. Is almost proportional to. Therefore, the load of the laundry can also be obtained from the time required to reach the target rotation speed. Of course, the characteristic of FIG. 33 is that the load torque tends to be saturated when the arrival time is very long.

Further, FIG. 34 shows a brushless DC motor 5
FIG. 6 is a diagram showing a torque and a rotation speed applied to the brushless DC motor 5 when intermittent rotation is normally reversed. When the brushless DC motor 5 is about to start forward rotation or reverse rotation, the rotation speed gradually rises and finally reaches a constant target rotation speed ni at time tn, but this time tn is as described above. It changes depending on the load that is laundry. Further, the change dn of the rotation speed from the start of rotation to a predetermined time changes depending on the load which is the laundry. The torque applied to the brushless DC motor 5 increases at the start of rotation, and when the rotation speed becomes constant, the voltage Vdc applied to the brushless DC motor 5 becomes constant. Time tr is the time of normal rotation and reversal, and time ts is the time between normal rotation and reversal.

Since the voltage Vdc applied to the brushless DC motor 5 is proportional to the inverter current Idc flowing in the brushless DC motor 5, the inverter current can be used instead of the voltage Vdc, and the voltage Vdc can be used.
And the inverter current Idc is the microcomputer 26
PWM output from the PWM oscillator 25 under the control of
Since it is controlled by the on-duty ratio δ of the signal, the on-duty ratio δ instead of voltage and inverter current.
Can also be used.

FIG. 35 shows the relationship between the torque and the rotational speed of the brushless DC motor 5 in which the axes of the torque and the rotational speed are reversed in FIG. Shows the change of the inverter current I with respect to the change of. The inverter current thus changes almost in proportion to the torque.

Next, the detection of the amount of laundry put into the dehydration tub 3 in the thus constructed washing machine will be described.

In order to detect the amount of cloth, the microcomputer 26 controls the flat clutch disk 57 in the mechanism section 9 via the clutch mechanism 82 to transmit the rotation of the brushless DC motor 5 to the dehydration tank 3 as well. The first transmission shaft 37 and the second transmission shaft 43 are connected to each other so that the brushless DC motor 5 is rotated, whereby the dehydration tank 3 and the pulsator 4 are integrally rotated. It should be noted that this cloth amount detection operation is performed without putting water in the dehydration tub 3.

The amount of cloth is detected by converting it into the weight of the laundry, but the change information of the torque of the brushless DC motor 5 at the start or during the rotation of the dehydration tub 3 or the spinning tub 3 that is rotating. Load torque (Tj) of the dehydration tub 3 and the laundry from the electromotive force generated in the brushless DC motor 5 when the brake is stopped by the brake of the brushless DC motor 5.
Is detected and the weight of the laundry is calculated as the amount of laundry from this load torque, or the brushless DC motor 5 rotates the dehydration tub 3 containing the laundry at a constant speed, and then the brushless DC motor 5 is electrically braked. The brushless DC motor 5 is operated by setting the motor torque to zero after detecting the laundry amount from the electric power consumed by the electric brake or rotating the dehydration tub 3 containing the laundry at a constant speed.
Is run free and the amount of cloth is detected by the magnitude of the moment of inertia of the dehydration tank 3.

Next, a specific method for detecting the cloth amount will be described in detail.

The first method for detecting the amount of cloth is the brushless D
This is a method of detecting the cloth amount from the reduction rate of the rotation speed of the motor when the C motor 5 has a constant rotation speed and the drive voltage for the motor is set to 0 and the motor is free-run only by the moment of inertia.

More specifically, in the first cloth amount detecting method, when the dehydration tub 3 containing laundry is rotated, the torque applied to the brushless DC motor 5 becomes constant, that is, the brushless DC motor 5 is used. Changes the on-duty δ of the PWM signal from the PWM oscillator 25 so as to rotate at a constant rotation speed np to control the voltage Vdc applied to the brushless DC motor 5. And brushless D
At a certain point after the rotation speed of the C motor 5 becomes constant, all of the upper arm transistors U1, V1, W1 and the lower arm transistors U2, V2, W2 driving the brushless DC motor 5 are turned off, and the laundry is washed. The dehydration tub 3 containing is rotated only by inertia, and the state where the rotation speed is gradually decreased is monitored.

The decrease in the rotation speed in this case depends on the amount of cloth that is the laundry in the dewatering tub 3. The larger the amount of cloth due to the moment of inertia, the slower the decrease in the rotation speed and the smaller the amount of cloth. The lower the rotation speed, the faster. Therefore, starting from the time when all of the upper arm transistors U1, V1, W1 and the lower arm transistors U2, V2, W2 are turned off, the rotation speed n is the predetermined rotation speed n1.
The amount of cloth can be detected by counting the time until the temperature decreases by the microcomputer 26 and comparing the counted time T1 with preset data.

FIG. 6 is a graph showing the relationship between the time and the rotation speed in the first cloth amount detecting method. At the time t01 when the brushless DC motor 5 is rotating at a constant rotation speed np. At this point, the rotation of the brushless DC motor 5 is stopped, and the brushless DC motor 5 is free-run.
The C motor 5 continues to rotate while decreasing depending on the amount of laundry in the dehydration tub 3. In this case, when the amount of cloth is small, the rotation speed decreases quickly as shown by the curve 11a, and when the amount of cloth is medium, the rotation speed decreases moderately as shown by the curve 11b. When the amount of cloth is large, the rotation speed decreases slowly as shown by the curve 11c. Therefore, the time t1, t2, and the time until the rotation speed n decreases to the predetermined rotation speed n1.
The amount of cloth can be identified by counting t3.

FIG. 7 is a flow chart showing in detail the procedure of the first cloth amount detecting method described above. In the figure,
When the power of the washing machine is turned on and the start switch is pressed (steps 210, 220), the flat clutch disc 5
7 is connected (step 1210), and the dehydration tank 3 is rotated by the brushless DC motor 5 together with the pulsator 4 (step 1220). It is checked whether the rotation speed of the brushless DC motor 5, that is, the angular speed ω has reached a predetermined angular speed ωp (step 1230). When the predetermined angular speed ωp is reached, the upper arm transistors U1, V1, W1 of the inverter circuit 17 and All the lower arm transistors U2, V2, W2 are turned off, the supply of the drive voltage to the brushless DC motor 5 is stopped, the brushless DC motor 5 is rotated by inertia, and at the same time, the soft timer in the microcomputer 26 is reset. , And clocks (step 1240).

Then, it is checked whether or not the angular velocity ω of the brushless DC motor 5 which continues to rotate by the moment of inertia has reached a predetermined angular velocity ω1 (step 1250). When the angular velocity ω1 reaches the predetermined angular velocity ω1, software in the microcomputer 26 is reached. The time T1 measured by the timer is taken in, and the size of the cloth amount is determined from the data table preset in the memory of the microcomputer 26 based on the size of the counting time T1 (step 1260).

As shown in the table of step 1260 in FIG. 7, the cloth amount for the counting time T1 is determined to be large, medium, and small in proportion to the large, medium, and small counting times T1.

Next, a second method for detecting the amount of cloth will be described.

The second method for detecting the amount of cloth is a brushless DC motor 5 that rotates only by inertia when the brushless DC motor 5 is free run only by the moment of inertia after the brushless DC motor 5 reaches a constant rotation speed. This is a method of measuring the current flowing by the back electromotive force induced in the winding and detecting the amount of cloth by the time from the free run of the motor to the time when this current disappears.

In order to carry out the second cloth amount detecting method, as shown in the circuit of FIG. 8, a resistor 28a for current measurement is inserted between the emitters of the lower arm transistors V2 and W2 in the circuit of FIG. In addition to the filter 30 and the A / D converter 29 in the circuit of FIG. 5, a filter 30a and an A / D converter 29a for supplying the voltage across the current measuring resistor 28a to the microcomputer 26 are additionally provided.

In the circuit having such a configuration, when the brushless DC motor 5 is free-running, the counter electromotive force induced in the winding by the rotation of the brushless DC motor 5 due to inertia causes the current measuring resistor 28a to have a current. Figure 9
A current flows as indicated by an arrow at. Then, as shown in FIG. 10, this current decreases with time, that is, as the rotation of the brushless DC motor 5 decreases, and finally becomes zero. Therefore, the times t1 and t2 until the current becomes zero, The amount of cloth can be detected by measuring t3 with the soft timer of the microcomputer 26.

In FIG. 10, the curve shown by the dotted line is a plot of the peak value of the pulsating current.
If the amount of cloth indicated by 5a is small, the time is short and the curve 15
When the cloth amount shown by b is medium, the time is also medium, and when the cloth amount is large as shown by the curve 15c, the time is long.

FIG. 11 is a flowchart showing in detail the procedure of the second cloth amount detecting method described above. In the figure, the processing from steps 210 to 1230 is the same as the processing of the first cloth amount detecting method shown in FIG. That is,
After the washing machine is started, the flat clutch disc 57 is connected, and the dehydration tub 3 containing the laundry is rotated, it is determined that the angular velocity ω of the brushless DC motor 5 has reached a predetermined angular velocity ωp (step 210-1230).

After the angular velocity ω of the brushless DC motor 5 reaches a predetermined angular velocity ωp, the inverter circuit 17
The upper arm transistors U1, V1, W1 are all turned off, the lower arm transistors U2, V2, W2 are all turned on, and the brushless DC motor 5, and hence the dehydration tank 3 are rotated by inertia, and at the same time, The soft timer in the computer 26 is reset and clocked (step 1640).

Then, the voltage generated across the inverter current detection resistor 28a by the counter electromotive force induced in the winding of the motor by the rotation of the brushless DC motor 5 which continues to rotate by the moment of inertia is converted into an A / D converter 29.
And the respective output voltage V of the A / D converter 29a
The microcomputer 26 reads from 0 and V1 and calculates the current Ia flowing through the inverter current detecting resistor 28a from the difference between these voltages (step 1650).

Then, the microcomputer 26 determines whether or not the current Ia has become zero, that is, whether or not the current pulse has disappeared (step 1660), and when the brushless DC motor 5 enters the free-run state. The time T1 from when the current pulse disappears is counted by the soft timer in the microcomputer 26.
The size of the cloth amount is determined based on the size of 1 from the data table preset in the memory of the microcomputer 26 (step 1670).

The table of the cloth amount with respect to the counting time T1 shown in step 1670 is the same as that shown in step 1260 of FIG. 7, and the cloth amount is large or medium in proportion to the large, medium or small of the counting time T1. , Determined to be small.

Next, a third method for detecting the amount of cloth will be described.

In the third cloth amount detecting method, for example, the brushless DC motor 5 is rotated in the first direction of right rotation to reach a constant rotation speed, and then the brushless DC motor 5 is suddenly rotated in the opposite direction. When the voltage is controlled to rotate at the rotation speed, the brushless DC motor 5 tries to continue to rotate in the first direction due to inertia, so that the current due to the counter electromotive force and the control current for the reverse rotation generated in both directions. This is a method of measuring the added combined current and measuring the time from when the brushless DC motor 5 is rotated in the reverse direction until the combined current returns to the steady current to detect the cloth amount.

FIG. 12 is a graph showing the current flowing through the brushless DC motor 5 with respect to time when the brushless DC motor 5 is rotated in the reverse direction at time t01 in the third cloth amount detecting method. When the brushless DC motor 5 is rotated in the reverse direction at time t01, the increased combined current of the current due to the counter electromotive force and the control current for reverse rotation flows as the initial current io as described above. Of these, the current due to the back electromotive force is a component that depends on the inertia of the brushless DC motor 5, so it gradually decreases and eventually becomes zero, and the combined current becomes a steady current of only the control current for reverse rotation. Therefore, the amount of cloth is detected as described above by measuring the time when this steady current is reached.

In the reverse rotation of the brushless DC motor 5, the direction of the current flowing through the three-phase windings of the brushless DC motor 5 is "1 → 2 → 3 → 4 → 5 → as shown in FIG.
Assuming that the order is “6”, if a current of 3 is being supplied and a current is applied in the opposite direction, an opposite force will be applied. Therefore, control is performed so that a current of 4 is applied, and “4 → 3 → 2 → 1 → 6 →
This is achieved by passing current in the order of 5 → 4 ”.

FIG. 14 is a flow chart showing in detail the procedure of the above-mentioned third cloth amount detecting method. In the figure, the processing of steps 210 to 1230 is the same as the processing of the first and second cloth amount detecting methods. That is, it is determined that the angular velocity ω of the brushless DC motor 5 has reached a predetermined angular velocity ωp after the washing machine is started, the flat clutch disc 57 is connected, and the dehydration tub 3 containing the laundry is rotated. (Steps 210-1230).

After the angular velocity ω of the brushless DC motor 5 reaches the predetermined angular velocity ωp, the voltage across the inverter current detecting resistor 28 in the circuit of FIG.
The peak value of the inverter current flowing through the brushless DC motor 5 is fetched into the microcomputer 26 via the D converter 29 and stored as the voltage value V0 of the A / D converter 29 (step 1940). This voltage value V
0 corresponds to the above-mentioned steady current, and is stored for use in determining the time when the combined current drops to this steady current.

When the peak value V0 is saved, the brushless D
Brushless D through the inverter circuit 17 so that the C motor 5, and hence the dehydration tub 3 may have the same rotational speed in the opposite direction.
At the same time that the voltage of the C motor 5 is controlled, the soft timer of the microcomputer 26 is reset and the time counting operation is started (step 1950).

When the brushless DC motor 5 is rotated in the reverse direction, the above-mentioned combined current is generated. Therefore, the voltage corresponding to this combined current is taken into the microcomputer 26 via the filter 30 and the A / D converter 29.
The peak value V1 is detected (step 1960). Then, the peak value V1 is compared with the stored peak value V0 corresponding to the steady current (step 1970), and the time T1 until both are equal is determined by the microcomputer 2
The count is performed by the soft timer 6 and the cloth amount is determined from the data table preset in the memory of the microcomputer 26 based on the size of the count time T1 (step 1980).

The table of the cloth amount for the counting time T1 shown in step 1980 is the same as that shown in step 1260 of FIG. 7, and is proportional to the large, medium and small counting times.
The amount of cloth is determined to be large, medium and small.

When the cloth amount detecting operation is completed as described above, the wash water level corresponding to the detected cloth amount is determined from the data table stored in the memory of the microcomputer 26 in advance, and the predetermined amount of water is supplied. Is done.

FIG. 15 is a partial cross-sectional view showing the internal structure of the washing machine according to the second embodiment of the cloth amount detection of the present invention. In this embodiment, the pulsator 4 is provided with a plurality of resistance plates 4a as resistance members which receive resistance by water supplied by a predetermined amount at the time of rotation on the lower surface of the pulsator 4 and is elastically supported by the spring 101 while the first transmission shaft is being supported. The pulsator 4 is connected so as to be vertically movable with respect to 37, the laundry is put into the dehydration tub 3, and the pulsator 4 sinks. By the load torque of the DC brushless motor 5 corresponding to the resistance force received when the pulsator 4 rotates in this state. The amount of cloth is detected.

The first conduction shaft 3 near the bottom of the dehydration tank 3
A cup-shaped spring receiver 103 having an open upper portion is spline-coupled to 7, while a cup-shaped spring cover 4b having an open lower portion is integrally formed at the center of the pulsator 4. The inner diameter of the spring cover 4b is equal to the spring receiver 103.
Is formed larger than the outer diameter of. The spring 101 that biases the pulsator 4 upward is housed between the spring receiver 103 and the spring cover 4b.

In the spring cover 4b, a spline hole 4d is formed in a boss portion 4c formed at the center, and the first conduction shaft 37 is spline-coupled to the spline hole 4d.
In this state, the pulsator 4 is slidable with respect to the first transmission shaft 37 within a certain range in the axial direction. The resistance plate 4a extends from the outer peripheral portion of the spring cover 4b to the outer peripheral edge portion of the pulsator 4 and has a length B as shown in FIG. Other configurations include a brushless DC motor 5 and a mechanism 9 such as a clutch mechanism that transmits and blocks rotation of the brushless DC motor 5 to and from the dehydration tub 3, and a brake mechanism that forcibly stops and prevents rotation of the dehydration tub 3. Although the external shape is different from that of the embodiment of FIG. 1, the operation itself is the same as that of the embodiment of FIG. In addition, the mechanical unit 9 and the brushless DC
The operation of the motor 5, the water supply / drainage section and other sections are controlled by the circuit section shown in FIG.
The drive circuit 80 of FIG. 5 is used to drive the brushless DC motor 5.

In the washing machine having the above structure, FIG.
As shown in FIG. 7 or FIG. 18, first, when the laundry M is put into the dehydration tub 3, the spring 10 is caused by the weight W of the laundry M.
1 is contracted by a length x from the state before the laundry is loaded, the pulsator 4 moves downward, and stops in a state where the weight W of the laundry and the reaction force F of the spring 101 are balanced. Next, when the start button is pressed, water supply is started, and when the water level reaches L _W in FIG. 17 or 18, the water supply operation is temporarily suspended according to a preset program. At this time, the lower end of the resistance plate 4a is submerged in the water by a height h.

Next, when the brushless DC motor 5 is rotated with the clutch mechanism disengaged, the dehydration tank 3 whose drive force is interrupted by the clutch mechanism is stopped, and only the pulsator 4 to which the drive force is transmitted rotates. To do. Pulsator 4
When is rotated, the resistance plate 4a receives a resistance force by the supplied water, and the load torque T acts on the brushless DC motor 5 corresponding to the resistance force.

At this time, the microcomputer 26 determines that the rotation speed n of the pulsator 4 is a constant value, that is, the brushless DC, regardless of the load state that the resistance plate 4a corresponding to the torque applied to the brushless DC motor 5 receives by the wash water.
The on-duty ratio δ of the PWM signal is determined so that the motor 5 has a preset constant angular velocity ωp,
The voltage V _dc applied to the brushless DC motor 5 is controlled.
At this time, the load torque T generated in the brushless DC motor 5
If the amount of laundry M is constant, it is due to mechanical loss such as friction and the resistance force that the resistance plate 4a receives from the washing water. The microcomputer 26 changes the voltage V _dc applied to the brushless DC motor 5 to a value according to the load torque T in order to maintain the angular velocity at ωp regardless of the magnitude of the load torque T.

On the other hand, the contraction length x of the spring 101 is determined by the laundry M.
Is proportional to the weight W of the resistance plate 4a, the sinking height h of the resistance plate 4a in the wash water is proportional to the length x, and the area A (= B × h) immersed in water per resistance plate 4a is Proportional to height h.
Furthermore, the load torque T applied to the brushless DC motor 5
The water resistance is proportional to the area A, and the brushless D
The voltage V _dc applied to the C motor 5 is proportional to the load torque T. From the above, the voltage V applied to the brushless DC motor 5
_dc is a linear function of the weight W of the laundry M.

Therefore, when the brushless DC motor 5 maintains a constant angular velocity ωp, the load torque T applied to the brushless DC motor 5, that is, the brushless DC.
By detecting the voltage V _dc applied to the motor 5 or the inverter current I _dc generated by the voltage V _dc , the weight W of the laundry M, that is, the amount of cloth can be determined. To determine the weight W, table data showing the relationship between the weight M of the laundry M and the inverter current I _dc as shown in FIG. 19 is used.

The embodiment shown in FIG. 20 corresponds to the second embodiment of FIG.
Similar to the embodiment, the amount of cloth is detected by the load torque T of the brushless DC motor 5 corresponding to the resistance force received when the pulsator 4 rotates. In this embodiment, the dehydration tank 3
A plurality of resistance plates 3a as resistance members that receive resistance by water supplied by a predetermined amount at the time of rotation are formed on the lower surface of the.

The pulsator 4 is coupled to the upper end of the third conductive shaft 105 slidably fitted to the upper end of the first conductive shaft 37 within a certain range in the axial direction. On the other hand, in the dehydration tub 3, the second conductive shaft 43 is supported by the bearing case 109 that rotatably supports the third conductive shaft 105 via the bearing 107.
Is bound to. The lower end of the bearing case 109 is spline-engaged with the outer peripheral portion of the second conductive shaft 43 so as to be slidable in the axial direction by the same range as the sliding range of the third conductive shaft 105, and is formed on the outer peripheral portion. It is coupled to the bottom of the dehydration tub 3 via the mounting flange 109a. A spring 111 for urging the dehydration tub 3 together with the pulsator 4 upward is interposed between the mounting flange 109a and the spring receiver 2a on the bottom surface of the washing tub 2. Other configurations are as shown in FIG.
This is similar to the fifth embodiment.

In this embodiment, as shown in FIG. 22 or FIG. 23, when the laundry M is first put into the spin-drying tub 3, the weight W of the laundry M causes the spring 111 to move from the state before the laundry is loaded. The dehydration tub 3 moves downward together with the pulsator 4 by contracting by x, and the weight W of the laundry and the spring 111
Stop in a state where it is balanced with the reaction force F of. In this state,
When the start button is pressed, the water supply is started and the water supply operation is temporarily stopped when the water level reaches L _W , as in the embodiment of FIG. 15, and at this time, the lower end of the resistance plate 3a is submerged by the height h. It will sink.

Next, when the brushless DC motor 5 is rotated while the clutch mechanism is connected, the dehydration tub 3 to which the driving force is connected by the clutch mechanism rotates together with the pulsator 4, which is similar to the embodiment shown in FIG. In addition, the resistance plate 3a receives a resistance force due to the supplied water, and the brushless DC
The load torque T acts on the motor 5. Therefore, also in this embodiment, when the brushless DC motor 5 maintains a constant angular velocity ω, the load torque T applied to the brushless DC motor 5, that is, the brushless DC motor 5
By detecting the inverter current I _dc generated by voltage V _dc or voltage V _dc, according to, it becomes possible to detect the weight W of the laundry M by using the table data of FIG 19.

FIG. 24 is a sectional view showing the schematic internal structure of a washing machine according to the third embodiment of the cloth amount detection of the present invention. In this embodiment, a suspension 11 for supporting the dehydration tub 3 via a suspension rod 10 has a damper function, and a distance detecting means for measuring the distance between the bottom of the washing tub 2 and the bottom of the outer case 1 on the bottom of the washing tub 2. The ultrasonic range finder 113 is attached, and the amount of laundry loaded into the dehydration tub 3 is detected based on the measurement value of the ultrasonic range finder 113. In other words, when laundry is put into the dehydration tub 3, the dehydration tub 3 sinks due to the suspension 11, and the amount of cloth is determined according to this sinking amount.

By the way, in the washing machine in which the suspension 11 has the damper function, the spring and the damping action in the suspension mechanism have an effect of suppressing the vibration during the dehydration. In a general damper mechanism, a damping action is generated by friction between a cylinder and a piston inside the cylinder or friction between the piston and air. When the laundry is put into the empty dehydration tub, the dehydration tub sinks to a position where the force obtained by adding the spring force to the frictional force and the weight obtained by adding the dehydration tub and the cloth amount of the laundry are balanced. .. However, in this case, due to the frictional force, a linear depression with respect to the cloth amount cannot be obtained. Therefore, if a mechanism for canceling the damping action is provided at the time of measuring the cloth amount, a linear sinking with respect to the weight of the cloth that is thrown in occurs.

FIG. 25 shows a specific example of the mechanism capable of canceling the damping action. The suspensions 11 are arranged at the four corners of the washing tub 2, and the outer wall of the cylinder 115 is the washing tub 2.
It is fixed to the lower side wall of the. In the cylinder 115,
The suspension rod 10 is slidably inserted into the cylinder 115. A permanent magnet 117 is attached to the tip of the suspension rod 10, and a spring 119 that biases the permanent magnet 117 downward is interposed between the permanent magnet 117 and the upper inner wall of the cylinder 115. The lower end of the cylinder 115 is open, and the electromagnetic coil 121 is attached to this open part. The electromagnetic coil 121 is set so that a magnetic field is generated toward the permanent magnet 117 as shown in FIG.
On the other hand, the permanent magnet 117 is installed so that the N pole is on the lower side so that a reaction force is generated with respect to the magnetic field of the electromagnetic coil 121.

As a result, when the electromagnetic coil 121 is energized, a damping action occurs due to the repulsive action of the magnetic field generated in the electromagnetic coil 121 and the magnetic field of the permanent magnet, and the damping action is released by releasing the energization. Will be.

The ultrasonic distance meter 113 for measuring the distance between the bottom surface of the washing tub 2 and the bottom surface of the outer box 1 in a state where the damping action is released is shown in FIG. The ultrasonic oscillator 125 is connected to the ultrasonic oscillator 125, and the oscillation timing P of the ultrasonic oscillator 125 is controlled by the microcomputer 26.
As shown in FIG. 28, the ultrasonic oscillator 125 oscillates an ultrasonic transmission wave f ₁ in a pulsed manner, and the transmission wave f ₁ reflects the reception wave f ₂ reflected on the bottom surface of the outer box 1 by the same element. It is detected at the time of transmission, and the time t is measured from transmission to reception,
Convert this to distance.

FIG. 29 is a flow chart showing an example of the cloth amount detecting operation based on the distance measurement by the ultrasonic range finder 113 in the state where the damping action is released.

According to this, first, the power is turned on, and as an initial setting, the electromagnetic coil 121 is de-energized, and the ultrasonic distance meter 113 is used to wash the washing tub 2 before loading the laundry.
The distance L ₁ between the bottom of the outer box and the bottom of the outer box is measured as an initial value (step 2701). The measured distance L ₁ is stored in the memory.

Thereafter, while the user puts the laundry in the dehydration tub 2 (step 2703), the ultrasonic distance meter 113 measures the distance L ₂ (step 2705). Then, the distance L ₂ and the distance L ₁ are compared to obtain the difference (L ₂ −L ₁ ) and the product (L ₂ −L) of the spring constant of the spring 119 (in the case of considering four parallels) K L ₁ ) × K is calculated (step 2707), and the weight of the laundry, that is, the amount of laundry is determined based on the table data set in advance (step 2709).

FIG. 30 is a flow chart showing another cloth amount detecting operation using the ultrasonic distance meter 113. In this example, the distance L ₂ by the ultrasonic range finder 113 after the laundry is loaded
The operation up to step 2705 for measuring is the same as the operation shown in FIG. Then, the difference between the distance L ₁ and the distance L ₂ (L ₁
-L ₂ ) is greater than 0, that is, whether the laundry has been thrown in to some extent and the spring 119 has contracted (step 2707). If (L ₁ -L ₂ )> 0, the electromagnetic coil 121 is energized. (Step 270)
9). The applied current value I at this time is sufficiently small as δI.

Next, the ultrasonic distance meter 113 measures the distance again to update the value of the distance L ₂ (step 271).
1) The updated distance L ₂ and the distance L ₁ are compared to determine whether L ₂ −L ₁ = 0 (step 271).
3). Here, when L ₂ −L ₁ = 0 is not satisfied, the current applied to the electromagnetic coil 121 is increased by δI from the previous time to obtain I +.
Energize again as δI. Such energizing operation is performed by L ₂
Repeatedly until −L ₁ = 0. L ₂ -L ₁ = 0
Therefore, the distance L ₂ after the laundry is loaded is the distance L ₁ before the laundry is loaded.
When it becomes equal to, the weight of the loaded laundry is determined from the preset table data of the applied current value and the cloth weight value (step 2715).

[0099]

As described above, according to the present invention, the electric current when the control current is controlled so as to stop the driving in the rotation direction of the dehydration tank which is rotationally driven by the electric motor means. The moment of inertia of the motor means is detected, and the amount of laundry stored in the dehydration tub is detected according to this moment of inertia, so it is possible to detect the amount of laundry before water supply and set a small water level. Therefore, the cloth amount can be accurately detected.

Further, according to the second aspect of the present invention, when the laundry is put in the dehydration tub, the electric current is generated based on the resistance of the water when the water flow generating means or the resistance member provided in the dehydration tub is rotated. Since the load torque applied to the motor means is detected and the cloth amount of the laundry in the dehydration tub is detected according to the load torque, the cloth amount can be accurately detected.

Further, according to the third aspect of the present invention, the washing tub is supported by the damper means together with the elastic means, and the damper function of the damper means is released. Since the vertical distance is detected and the amount of cloth is detected based on this, a linear sinking occurs depending on the amount of laundry in the washing tub, and the amount of cloth can be detected accurately. it can.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an internal structure of a washing machine showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing an internal structure of a mechanism section used in the washing machine shown in FIG.

FIG. 3 is a cross-sectional view showing the operation of the mechanism section shown in FIG.

FIG. 4 is a block diagram showing a configuration of a circuit unit that controls the operation of the washing machine shown in FIG.

5 is a circuit diagram of a drive circuit used in the circuit unit shown in FIG.

FIG. 6 is a graph showing a relationship between time and rotation speed in a first cloth amount detection method by the washing machine of FIG.

FIG. 7 is a flowchart showing a procedure of a first cloth amount detecting method.

FIG. 8 is a circuit diagram in which the drive circuit of FIG. 5 is partially modified so that it can be used to implement the second cloth amount detection method.

FIG. 9 shows a brushless DC in the second cloth amount detecting method.
FIG. 9 is a circuit diagram showing a part of the circuit of FIG. 8 in which the current flowing by the electromotive force induced in the winding of the motor is indicated by an arrow.

FIG. 10 is a correlation diagram of time and change in current in the second cloth amount detection method.

FIG. 11 is a flowchart showing a procedure of a second cloth amount detection method.

FIG. 12 is an explanatory diagram showing the current flowing through the brushless DC motor with respect to time when the brushless DC motor is rotated in the reverse direction at time t01 in the third cloth amount detection method.

FIG. 13 shows a brushless D in the third cloth amount detecting method.
It is explanatory drawing which shows the direction and order of the electric current which flows into the winding of a brushless DC motor, when a C motor is reversely rotated.

FIG. 14 is a flowchart showing a procedure of a third cloth amount detection method.

FIG. 15 is a partial cross-sectional view showing the internal structure of the washing machine showing the second embodiment of the cloth amount detection of the present invention.

16 is an enlarged cross-sectional view of a main part of the washing machine of FIG.

17 is an explanatory diagram showing a cloth amount detection operation in the washing machine of FIG. 15. FIG.

FIG. 18 is an explanatory diagram showing a cloth amount detection operation in the washing machine of FIG. 15.

FIG. 19 is a correlation diagram between the laundry weight and the inverter current in the embodiment of FIG.

FIG. 20 is a partial cross-sectional view showing the internal structure of the washing machine showing another example of the second embodiment of the cloth amount detection of the present invention.

FIG. 21 is an enlarged cross-sectional view of a main part of the washing machine of FIG.

22 is an explanatory diagram showing a cloth amount detection operation in the washing machine of FIG. 20. FIG.

23 is an explanatory diagram showing a cloth amount detection operation in the washing machine in FIG. 20. FIG.

FIG. 24 is a schematic partial sectional view showing the internal structure of the washing machine showing the third embodiment of the cloth amount detection of the present invention.

25 is an enlarged cross-sectional view showing the internal structure of the suspension of the washing machine shown in FIG. 24.

FIG. 26 is an explanatory view showing the operation of the suspension shown in FIG. 25.

27 is a block diagram showing a circuit configuration for detecting the amount of laundry in the washing machine of FIG. 24.

FIG. 28 is a waveform diagram showing a transmission wave and a reception wave by the ultrasonic range finder for detecting the laundry amount of the washing machine shown in FIG. 24.

29 is a flowchart showing a method for detecting the amount of cloth in the washing machine shown in FIG. 24.

FIG. 30 is a flowchart showing another example of the laundry amount detection method for the washing machine in FIG. 24.

FIG. 31 is an explanatory diagram showing the relationship between the torque and the rotation speed of a brushless DC motor, using voltage as a parameter.

FIG. 32 is a correlation diagram between load torque and voltage applied to a brushless DC motor.

FIG. 33 is a correlation diagram between the load torque and the time required to reach the target rotation speed of the brushless DC motor when the capacity of the brushless DC motor is constant.

FIG. 34 is a time chart showing a torque, a rotation speed and a forward / reverse time applied to the brushless DC motor when the brushless DC motor is rotated in the normal direction and the reverse direction.

FIG. 35 is an explanatory diagram showing the relationship between the torque and the rotation speed of the brushless DC motor, using the voltage as a parameter, and showing the change in the inverter current with respect to the change in torque.

[Explanation of symbols]

 2 Washing tub 3 Dehydrating tub 4 Pulsator (water flow generating means) 3a, 4a Resistance plate (resistive member) 9 Mechanism part 17 Inverter circuit 21 Upper arm drive circuit 22 Lower arm drive circuit 24 Motor control circuit 25 PWM oscillator 26 Microcomputer 37th 1 Conduction Axis 43 Second Conduction Axis 57 Flat Clutch Disc 113 Ultrasonic Distance Meter (Distance Detection Means) 119 Spring (Elastic Means) 117 Permanent Magnet (Damper Means) 121 Electromagnetic Coil (Damper Means)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location H02P 6/00 8938-5K 7/00 L 9063-5H // G01M 1/10 (72) Inventor Kaichi Hatsukawa 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa, Ltd. Inside the Toshiba Housing and Spatial System Engineering Laboratory (72) Inventor Satoko Hasegawa 8-Shin-Sugita-cho, Isogo-ku, Yokohama, Kanagawa-ken, Ltd. In-house

Claims (3)

[Claims] 1. A control current is controlled for an electric motor means for rotating a dehydration tub capable of accommodating laundry and a dehydration tub rotationally driven by the electric motor means so as to stop the driving in the rotation direction. An inertia moment detecting means for detecting the moment of inertia of the electric motor means at this time, and a cloth amount detecting means for detecting the cloth amount of the laundry stored in the dehydration tub based on the inertia moment detected by the inertia moment detecting means. A washing machine characterized by having. 2. A water flow generating means for generating a water flow is provided at the bottom of a dehydration tub for containing laundry, and an electric motor means is connected to the water flow generating means for rotating the water flow generating means.
Clutch means for selectively connecting the rotation of the electric motor means to the dehydration tank is provided, and the water flow generating means or the water flow generating means and the dehydration tank are driven so as to be vertically movable according to the weight of the laundry stored in the dehydration tank. A resistance member, which is connected to an electric motor means via a shaft, receives resistance of water when rotating in a state where a predetermined amount of water is supplied to the water flow generating means or the dehydration tub, and the resistance member is a resistance of water. The load torque detecting means for detecting the load torque applied to the electric motor means when the water flow generating means or the water flow generating means and the dehydration tank are rotating while receiving the load torque is provided. Accordingly, the washing machine is provided with a cloth amount detecting means for detecting the cloth amount of the laundry stored in the dehydration tub. 3. An elastic means for elastically supporting a washing tub containing a dehydration tub with respect to a main body of a washing machine, and a vibration of the elastic means is attenuated so that a repulsive force acts between the magnet and the magnet when energized. Based on a damper means including a coil, a distance detecting means for detecting a vertical distance of the washing tub from the main body of the washing machine, and a distance detected by the distance detecting means when the coil of the damper means is de-energized. A washing machine, comprising: a laundry amount detecting means for detecting the laundry amount of the laundry stored in the dehydration tub.