JPH0277297A - Operation control method for dewatering machine - Google Patents

Abstract

PURPOSE:To prevent the movement of water in a tank from being made into an eccentric load in synchronizing with the rotating speed of a dewatering layer and to prevent the dewatering tank from being widely vibrated by intermittently rotating the dewatering tank at the rotating speed at a low speed equal to an inherent frequency or below in the early stage of a dewatering operation and discharging the water in the tank. CONSTITUTION:Based on the voltage waveform of a speed generator 13, a rotating speed W2 of a dewatering motor 7 is always detected, the rotating speed W2 is compared with an inherent frequency W1 by a controller 14, and when the rotating speed W2 reaches the vicinity of the inherent frequency W1, a current flowing to the dewatering motor 7 is automatically turned off. After a stop time set beforehand passes, the current flowing to the dewatering motor 7 is executed again, the dewatering tank is rotated at a low speed, and a drain is executed. the rotation and stop of the dewatering tank by the rotating speed W2 in a low speed equal to the inherent frequency W1 on below is repeated plural times, and the water in the dewatering tank is discharged in the early stage of the dewatering operation. After such an intermittent dewatering is executed, the dewatering motor 7 is successively energized, and a shift to a full speed dewatering is executed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for controlling the operation of a dehydrator in a two-tub washing machine, which is equipped with a washing tub and a dehydrating tub, and performs washing operation and dehydrating operation in the dehydrating tub. 9 [Prior art] A two-tub washing machine that is equipped with a washing mechanism and a dewatering mechanism is
As shown in Figure 6, a washing tub (2) and a dehydrating tub (3) are installed adjacent to each other in an outer box (1).
) is installed inside the dewatering tank (4) as shown in Fig. 7.

Then, the rotation shaft (8) of the dehydration motor (7) attached to the bottom frame (5) via the vibration isolation spring (6) and the dehydration shaft (9) protruding from the bottom of the dehydration tank (3) are connected to the cup. ring (10)
The dehydration motor (7) rotates the dehydration tank (3). In the figure (11) is the rotation shaft (8).
) and are screws for fixing the dehydration shaft (9) to the coupling (10), respectively, and the dehydration tank (3) has a dehydration hole (12) for drainage in the side wall around it. .

As a method of controlling the dehydration operation in the dehydration tank (3), there is a conventional method disclosed in, for example, Japanese Utility Model Publication No. 49-25491. This method uses a strong rotational force to dehydrate fabrics with a poor dehydration rate, and dehydrates fabrics with a good dehydration rate at a low rotational speed for an appropriate amount of time. , its control circuit will be explained with reference to FIG.

(7) is the dehydration motor, (25) is the induction coil, (26
) is the starting capacitor connected to one end of the induction coil (25), (27) is the time switch, and (28) is the power supply (
29) is a time contact of the time switch (27) connected in series, and (30) is a time contact provided by branching off the fixed contact side of the time contact (28), which has an arcuate part and a toothed part. It is interlocked with an intermittent interlocking mechanism consisting of a cam (31) and the like. (
32) is a control circuit changeover switch that connects fixed contact A, which is branched on the fixed contact side of time contact (28), and time contact (28).
30) and the fixed contact B to be connected.

To perform dehydration operation with a dehydrator with this type of structure, a dehydration tank (
3) Place the laundry inside, set an arbitrary time, close the time contact (28), and connect the changeover switch (32y to the fixed contact A).
If you connect it to the dehydrating motor (7) and energize the dehydrating motor (7), the dehydrating tank (
3) starts to rotate, and due to the centrifugal force of the rotation, water contained in the laundry flows out of the dehydration tank (3) through the dehydration hole (12) provided in the dehydration tank (3) and is dehydrated. .

At this time, as shown by curve (a) in FIG. 9, the rotational speed increases with the passage of time, and a strong dewatering force can be obtained. Further, when the changeover switch (32) is connected to the fixed contact B, the cam (31) is driven and the interlocking mechanism slides on the arc portion. That is, as shown in the curve (b), the time contact (3o) is closed until the rotation speed of the dehydration motor (7) reaches about 150 rpm from 0, and then the time contact (3o) is closed every few seconds by the teeth. By repeatedly opening and closing, it continues to rotate at a stable low speed once it reaches a certain number of rotations, producing a weak rotational force.

By the way, the angular velocity and the amount of vibration when rotating the dehydration tank (3) are as shown in Figure 10. If the horizontal axis is the angular velocity W and the vertical axis is the vibration amount, the amount of vibration increases with the angular velocity W. The frequency of the vibration isolation system, which includes the dehydration tank (3), rotating shaft (8), dehydration shaft (9), dehydration motor (7), screws (11), vibration isolating spring (6), etc. It reaches a maximum at point W1, then decreases, and becomes constant at a certain value.

This relationship between the angular velocity and the amount of vibration vJ also applies to the conventional example, and as shown in FIG.
) starts rotating from a stopped state, the initial angular acceleration is (d
Wl/dT1) = α, and this angular acceleration α1 is the same whether the dehydrator is operated at full speed or intermittently, and the maximum amount of vibration occurs near the natural frequency of the dehydrator.

On the other hand, when the amount of laundry is small, this dehydration tank (3) may perform not only dehydration operation but also washing operation, and in the dehydration operation that follows the washing operation, the water used for washing is used in this dehydration process. As with dewatering, the dehydrating motor (7) is energized to rotate the dehydrating tank (3), and the centrifugal force of the rotation is used to remove water from the dehydrating tank (3). The water in the dehydration tank (3) is discharged to the outside from the dehydration hole (12).

[Problem to be solved by the invention]

When washing is performed in the washing tub and then the laundry is dehydrated in the spin-drying tank, the center of gravity of the spin-drying tank is determined to some extent when the clothes are placed in the spin-drying tank, as the clothes are simply thrown into the spin-drying tank. This center of gravity position hardly changes even during dehydration operation. Therefore, as the rotation speed of the dehydration tank increases after the start of dehydration operation, the moisture contained in the clothes is gradually discharged, and the rotation speed decreases to full rotation in the case of full-speed operation, or to a predetermined rotation speed in the case of intermittent operation. Each can stand up smoothly.

However, if you perform washing operation on the dehydration tank side, then perform dehydration operation in the same dehydration tank, and then drain the water used for washing in this dehydration process, rotating the dehydration tank will drain the water in the tank. It moves due to rotation, and the movement of this water causes the position of the center of gravity of the dehydration tank to change significantly as it rotates, and this change in the center of gravity acts on the dehydration tank as an eccentric load.

As a result, the dehydration tank shakes and collides with the dehydration receiving tank, resulting in an inconvenience in that the dehydration tank cannot smoothly reach a full rotation or a predetermined rotation.

This eccentric load is not so large when the dehydration tank and the water inside are slipping, that is, when the internal water cannot follow the acceleration of the dehydration tank, but the rotational speed of the internal water is When it catches up with the rotational speed of the aquarium, it becomes a fairly large eccentric load.

Furthermore, as mentioned above, the shaking of the dehydration tank reaches its maximum at its natural frequency, but during the dehydration operation that follows the washing operation in the dehydration tank, the overall weight of the dehydration tank increases due to the water in the tank. Therefore, it takes a certain amount of time to pass around the natural frequency. As a result, there was a risk that the dehydration tank would shake particularly strongly around this natural frequency and collide with the dehydration receiving tank.

The purpose of the present invention is to eliminate the disadvantages of the conventional example, and to provide a system in which, when a dehydration operation is performed following a washing operation in a dehydration tank, the movement of water in the tank is synchronized with the rotational speed of the dehydration tank, resulting in an eccentric load. To provide a method for controlling the operation of a dehydrator, which prevents the dehydration tank from shaking significantly by causing the dehydration tank to quickly pass through the vicinity of the natural frequency, and can smoothly reach rotation at a predetermined rotation speed. There is a particular thing.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a two-tub washing machine that is equipped with a washing tub and a spin-drying tank and performs a washing operation and a spin-drying operation in the spin-drying tank. At this stage, the dehydration motor is rotated at a low speed by applying electricity at a pseudo frequency lower than the power supply frequency, and the rotation speed of the dehydration motor detected by the means for detecting the rotation speed of the dehydration motor during the low speed rotation is the rotation speed of the dehydration motor as a whole. When the frequency reaches around the natural frequency, the power to the dehydration motor is stopped, and after a predetermined stop time, the dehydration motor is energized again at a low pseudo frequency, and after repeating this cycle multiple times,
The gist of this is to energize the dewatering motor at full speed.

[Effect]

According to the present invention, when performing a dehydration operation of the same type after a washing operation in a dehydration tank, in the initial stage of the dehydration operation, the dehydration motor is first energized for a short time at a pseudo frequency lower than the power supply frequency. Rotate at low speed to drain water. During this low-speed rotation during drainage, when the rotational speed of the dehydration motor reaches around the natural frequency of the entire vibration system, this is detected and the energization to the dehydration motor is temporarily stopped, after which the dehydration motor is energized again at a low pseudo frequency. Drain water at low speed. Therefore, during drainage due to this low-speed rotation, the rotational speed of the dehydration motor does not reach the natural frequency, so the dehydration tank does not vibrate significantly during drainage. After repeating this operation several times, the dewatering motor is continuously energized at full speed to perform dewatering. At this time, the rotational speed of the dehydration tank passes through the natural frequency, but since the remaining water in the dehydration tank has been reduced by the drainage, large vibrations do not occur.

〔Example〕

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

FIG. 1 is a characteristic curve diagram showing the relationship between energization time and angular velocity when using the dehydrator operation control method of the present invention, and the basic structure of the dehydrator used in the method of the present invention is the same as that of the conventional Since this is the same as the example, detailed explanation will be omitted here.

In the method of the present invention, in addition to the structure of the dehydrator, a speed generator (13) as shown in FIG. Attach to the side. This speed power generation i (13) is composed of a coil (13a) and a magnet (13b).
The output of the speed generator (13) was introduced into a controller (14) using a microcomputer, etc., which will be described later.

FIG. 4 is a circuit diagram for controlling dehydration, in which (15) is an on switch and (16) is a starting capacitor, which generates a rotating magnetic field that rotates the dehydration motor (7).

In the figure, (14) is the controller, and (17) and (18) are the dewatering motors that are operated by the output of the controller (14), respectively.
7) shows the right rotation switch and left rotation switch.

Here, to explain the power supply circuit to the controller (14), when the on switch (15) is pressed, AC voltage is applied from the commercial AC power supply (29) to the transformer (19), and this transformer (19) The voltage reduced to one-tenth is supplied to a rectifier (20) such as a diode bridge, where it is full-wave rectified. And then the smoothing capacitor (21
) as a stable DC voltage that is smoothed by the controller (1
4).

The controller (14) to which voltage is applied in this way operates according to a preset program, but when the dehydration motor (7) rotates, it generates speed m (1
3) generates electricity, and a voltage as shown in FIG. 5 is generated. This voltage waveform is, for example, a two-pitch sine wave output when the dehydration motor (7) makes one rotation, and this two-pitch sine wave is converted by the transistor (23) into a rectangular wave as a digital output, and then the controller ( 14) entry capo)
(22) is output. Then, by counting this rectangular wave, the rotation speed of the dehydration motor (7) is detected.

The operation control method of the present invention is performed by the controller (14) to which a voltage is applied in this way, and then the dehydration tank (3
), and then the dehydration tank (3)
This section explains how to perform drainage and dewatering operations.

When the dehydration switch (not shown) is pressed, the clockwise rotation switch (1) is activated by the output from the controller (14) according to the program.
7) is turned on, the dehydration motor (7) is energized, the dehydration tank (3) rotates, and the water in the dehydration tank (3) is discharged.

At this time, the right rotation switch (17) turns on and off at high speed,
As a result, a voltage is applied to the dehydration motor (7) at a pseudo frequency as shown in FIG. Note that in order to obtain such a pseudo frequency, although not shown in the drawings, one obtained from an AC commercial power source via a frequency converter may be applied to the dewatering motor (7). The pseudo frequency in this case is 1/3 of the applied frequency, so the dehydration motor (
7) rotates at low speed at 1/3 of the rotation speed of normal full-speed dehydration.

The rotation speed during this low-speed rotation is determined by the rotation of the dehydration motor (7), which generates electricity from the speed generator i (13), and the waveform converted into a rectangular wave by the transistor (23), which is transmitted to the controller (
14) is input to the input capo-1-(22), and is calculated based on the time between pulses of the waveform input by the controller (14).

As long as the stable rotational speed W2 during this low-speed rotation is smaller than the natural frequency W1, the dehydration tank (3) does not vibrate significantly. However, since this rotation speed W2 is determined by balancing the load torque of the dehydration tank (3) with the operating torque of the dehydration motor (7), the water in the dehydration tank (3) is discharged and dehydrated. If the overall weight of the water tank (3) becomes lighter, there is a possibility that Wl<W, and in such a case, the dehydration tank (3) will resonate and will not be able to start up its rotation smoothly.

Therefore, in the method of the present invention, the speed generator (1
The rotation speed Wt of the dehydration motor (7) is constantly detected based on the voltage waveform in step 3), and the controller (14) controls the rotation speed W2.
is compared with the natural frequency W1, and the rotation speed W2 is the natural frequency W1.
When the temperature reaches around l, the power to the dehydration motor (7) is automatically turned off. Then, after the preset stop time has elapsed,
Turn on the power to the dehydration motor (7) again and run the dehydration tank (3) at low speed.
Rotate to drain water. The rotation and stopping of the dehydration tank (3) at a low rotational speed W2 below the natural frequency W1 is repeated multiple times to drain the water in the dehydration tank (3) at an early stage of the dehydration operation. Drainage due to this low-speed rotation is performed below the natural frequency W, so during this time the dewatering tank (3
) does not vibrate significantly.

After performing such intermittent dehydration, the dehydration motor (7) is continuously energized to shift to full speed dehydration. Dehydration tank at this point (3
) is decreasing because it is drained by the above-mentioned intermittent dehydration, and the weight of the entire dehydration tank (3) is small, so the flow velocity angle during full speed dehydration is the acceleration angle during intermittent dehydration. The dewatering tank (3) is larger than the above, and can pass through the vicinity of the natural frequency in a short time, and since there is not a large amount of water in the tank, eccentric loads will not occur and act on the dehydration tank (3).

〔Effect of the invention〕

As described above, in the dehydrator operation control method of the present invention, when a washing operation and a subsequent dehydration operation are performed in the dehydration tank of a two-tub washing machine, the natural vibration frequency is set at the initial stage of the dehydration operation. Since the dehydration tank is rotated intermittently at the following low rotational speeds to drain the water in the tank, there is a risk that the rotation of the dehydration tank and water will be synchronized and a large eccentric load will be applied to the dehydration tank. Furthermore, since the dehydration tank can pass through the vicinity of the natural frequency of the dehydration tank in a short time, there is no risk that the dehydration tank will shake greatly and hit the dehydration receiving tank, and as a result, it can smoothly reach full speed rotation.

[Brief explanation of the drawing]

Fig. 1 is a characteristic curve diagram showing the relationship between the energization time and the rotation speed of the dehydrating motor showing an embodiment of the dehydrating machine operation control method of the present invention; Fig. 2 is a voltage waveform diagram of the same dehydrating motor;
Figure 3 is a front view of the speed generator, Figure 4 is an electric circuit diagram for dehydration control, Figure 5 is a voltage waveform diagram of the speed generator, Figure 6 is an overall perspective view of the two-tub washing machine, Figure 7 The figure is a vertical sectional side view of the dehydrator, which is the main part of the same as above, Figure 8 is a conventional dehydration control circuit diagram, and Figure 9 is a conventional dehydrator control circuit diagram.
The figure is a characteristic curve diagram showing the relationship between the energization time and the rotation speed of the dehydration tank, and FIG. 10 is a characteristic curve diagram showing the relationship between the vibration amount and angular velocity of the dehydration tank. (1)...Outer box (2)...Washing tub (3
)...Dehydration tank (4)...Dehydration tank (5)
... Bottom frame (6) ... Anti-vibration spring (7)
... Dehydration motor (8) ... Rotating shaft (9) ...
Dehydration shaft (10)... Campling (11)
...Screw (12) ...Dehydration hole (13)
-...Speed generator (13a)...Coil (13
b)... Magnet (14)... Controller (15
)...Large switch (16)...Starting capacitor (17)...Right rotation switch (18)...Left rotation switch (19)...Transformer (20
)... Rectifier (21)... - Smoothing capacitor (22
)...Manpower port (23)...Transistor (
25)...Induction coil (26)...Starting capacitor (27)...Time switch (28)...Time contact (29)...Power supply (30)...Time contact (31) ... Cam (32) ... Changeover switch agent Patent attorney Tenant Masuo Figure 1 Figure 7 Figure 8 Figure 9 - akii Figure 10

Claims (1)

[Claims] In a two-tub washing machine that is equipped with a washing tub and a spin-dry tub, and the spin-dry tub performs washing and spin-drying operations, the spin-drying motor is rotated at low speed by energizing at a pseudo frequency lower than the power supply frequency during the initial stage of spin-driving operation. When the rotation speed of the dehydration motor detected by the means for detecting the rotation speed of the dehydration motor during the low speed rotation reaches around the natural frequency of the entire vibration isolation system, the power supply to the dehydration motor is stopped and a predetermined stop is performed. After a period of time has elapsed, the dehydrating motor is energized again at a low pseudo frequency, and after repeating this cycle multiple times, the dehydrating motor is energized at full speed.