JPH07185196A - Clothes dryer - Google Patents

Abstract

PURPOSE:To make the motor driving stop time for reversal rotation minimum as required to reduce the drying time by detecting the variation of load on the motor per 1 rotation of the drum. CONSTITUTION:When the clothes dryer operation is started, a heater 27 is powered on by a control circuit, a motor 11 rotates clockwise, a drum 4 is rotated in the same direction and clothes are dried by warm air supplied into the drum 4. In that condition, the control circuit judges whether the variation of the load on the motor 11 is more than a designated value or not, i.e., if the clothes to be dried are entangled each other or not. In other words, when an electric current flowing in the motor 11 per 1/4 rotations of the drum largely increases and then rapidly decreases, the circuit judges that the clothes are entangled each other, and, according to the judgement result, it transmits an instruction to rotate the motor in the reverse direction to eliminate the clothes entanglement quickly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called drum type clothes dryer.

[0002]

2. Description of the Related Art Conventionally, in a so-called drum type clothes dryer, the clothes to be dried are housed in a drum, and the drum is rotated by a motor, and at the same time, warm air is supplied into the drum, thereby the above-mentioned clothes are dried. It is designed to dry dry clothes. In this case, however, there is a problem in that clothes to be dried, especially large clothes to be dried such as sheets are entangled with the rotation of the drum, resulting in uneven drying. For this reason, during the drying operation, the drum is rotated relatively frequently to loosen the entangled clothes to be dried.

[0003]

However, when reversing the drum, it is necessary to stop the drum once each time, and the motor requires a drive stop time each time. Therefore, in the above-mentioned one, such reversing of the drum is required. Since it is performed regardless of whether or not the clothes to be dried are entangled, there is a drawback that the drying time is unnecessarily long when the clothes to be dried are not entangled.

The present invention has been made in view of the above circumstances, and therefore, the object thereof is that the drum can be reversed only when the clothes to be dried are actually entangled.
It is an object of the present invention to provide a clothes dryer capable of shortening the drying time as much as possible.

[0005]

In order to achieve the above object, in a clothes dryer of the present invention, a drum for containing clothes to be dried, a motor for rotating the drum in both forward and backward directions, and a drum are provided. A warm air supply device mainly including a fan for supplying warm air and a heater, comprising load fluctuation amount detection means for detecting a fluctuation amount of a motor load per one rotation of the drum, and detecting the load fluctuation amount. From the result, the motor is reversely rotated only when the variation amount of the motor load per one rotation of the drum is equal to or more than a predetermined value.

In this case, the load fluctuation amount detecting means may be any device that detects the fluctuation amount of the motor load per one rotation of the drum from the current flowing through the motor, the rotation speed of the motor, or both. When the motor is an AC motor, the load fluctuation amount detecting means may detect the fluctuation amount of the motor load per one rotation of the drum from the phase difference between the current flowing in the motor and the applied voltage. Good. Further, when the motor is a condenser motor, the load fluctuation amount detecting means may be one that detects the fluctuation amount of the motor load per one rotation of the drum from the voltage between the capacitor terminals of the motor.

[0007]

The load amount of the motor for rotating the drum depends on the degree of rotation of the drum, and the degree of rotation of the drum depends on the presence or absence of entanglement of the clothes to be dried. That is, if the clothes to be dried are not entangled, when the drum makes one rotation, the clothes to be dried are easily lifted from the lower part to the upper part of the drum, and the movement from the upper part to the lower part is normal, and the motor load per one rotation of the drum is large. Is small. On the other hand, if the clothes to be dried are entangled, it is difficult to lift the clothes to be dried from the lower part to the upper part of the drum when the drum makes one rotation, and the movement from the upper part to the lower part is rapid. The fluctuation amount of the motor load per rotation is large.

Therefore, the variation amount of the motor load per one rotation of the drum is detected, and the motor is rotated in reverse when the variation amount of the motor load per one rotation of the drum is equal to or more than a predetermined value. With this, the drum can be reversed only when the clothes to be dried are actually entangled. When the clothes to be dried are not actually entangled, it is possible to avoid reversing the drum. Therefore, it is possible to minimize the time required to stop the motor drive to reduce the drying time.

In this case, the variation amount of the motor load can be detected from the current flowing through the motor and also from the rotation speed of the motor. Particularly, if the variation of the motor load is detected from both of them, the variation can be detected more accurately. If the motor is an AC motor, the amount of change in the motor load can be accurately detected from the phase difference between the current flowing in the motor and the applied voltage. Further, if the motor is a capacitor motor, the amount of change in the motor load can be detected from the voltage across the capacitor terminals of the motor.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. First, FIG. 2 shows the overall structure of the clothes dryer, which has a clothes inlet / outlet 2 at the center of the front part of the outer box 1 and a door 3 for opening / closing the entrance / exit 2.

A drum 4 is arranged inside the outer box 1. The drum 4 has a front end plate having a large opening 5 fixed to a portion of the outer box 1 around the clothes inlet / outlet 2. The drum 7 is rotatably supported by a drum front support 6 provided thereon, and the shaft 7 provided at the center of the rear end plate is supported by a drum rear support 8 provided at a rear intermediate portion of the outer box 1. Also, this drum 4
A fan casing 9 is disposed between the drum rear support 8 and the drum rear support 8, and a fan 10 is rotatably attached to the shaft 7 of the drum 4 in the casing 9.

Here, the fan 10 has a double-blade shape having a front blade portion 10a and a rear blade portion 10b, and is made of a heat exchange material (heat transfer material), so that the fan 10 also functions as a dehumidifier as described later. The pulley 12 is driven by a motor 11 disposed in the upper part of the outer case 1 outside the drum 4 and rotatable in both forward and reverse directions.
Also, it is adapted to be rotationally driven via the belt 13. Further, the drum 4 is rotationally driven by the motor 11 via the pulley 14 and the belt 15.

In the rear half of the casing 9, the center portion is the outside air passage 16 formed in the drum rear support 8 and the outer case back plate 1.
An outside air intake port 18 formed in the central portion of 7 communicates with the outside of the machine, and a lower part thereof also communicates with the outside of the machine by an outside air return port 19 formed in a lower part of the outer case back plate 17. On the other hand, in the front half of the casing 9, the central portion communicates with the inside of the drum 4 via the filter 22 by the intake port 20 formed in the casing 9 and the exhaust port 21 formed in the rear central portion of the drum 4. , The lower part is a gas outlet 23 formed in the casing 9,
The drum 4 is communicated with the connecting duct 24 connected thereto, the heater duct 25 connected to the connecting duct 24, and the hot air outlet 26 formed at the lower front portion of the drum front support 6.

Therefore, when the fan 10 is rotated, the air in the drum 4 is discharged from the exhaust port 21 of the drum 4 to the casing 9
Through the intake port 20, the front half of the casing 9, the discharge port 23, the connecting duct 24, and the heater duct 25 in this order.
Returned inside. Further, from the rear outside the outer box 1, the air outside the machine passes from the outside air intake port 18 of the outer case back plate 17 to the outside air passage port 16,
It is returned to the outside of the outer case 1 through the latter half of the casing 9 and the outside air return port 19 in order.
Inside, the air inside the drum 4 and the air outside the outer box 1
The heat in the drum 4 is exchanged at the boundary of 0, and the air in the drum 4 is dehumidified. In the process of passing through the heater duct 25, the dehumidified air is heated by the heater 27 arranged in the heater duct 25 to become warm air, and is supplied into the drum 4 to be dried clothes (not shown). ).
Therefore, they function as a warm air supply device that supplies warm air into the drum 4.

On the other hand, FIG. 3 shows an electric circuit configuration of the dryer. In this electric circuit configuration, a commercial AC power supply 28 is provided via a transformer 29, an electronic circuit including a control circuit 31 and a power supply circuit 30 including a rectifying circuit, a smoothing circuit, a constant voltage circuit, etc. It outputs as a DC low voltage power supply for. The control circuit 31 functions as a load variation detection means and a control means, and is mainly composed of a microcomputer, and also includes various A / D converters (also not shown in detail).

The AC power supply 28 has a relay contact 3
The heater 27 is connected via 2a, and the motor 11 is connected via triacs 33 and 34. For the motor 11, a motor current detection circuit 35 is connected.
Is provided.

More specifically, the motor current detection circuit 35 includes the triac 33 on the forward rotation side of the motor 11 and the motor 1.
The current between 1 is detected by the current transformer 36,
The detected current is passed through the resistor 37 and the diode rectifier circuit 3
The voltage is converted into a voltage value by the resistor 8, the resistors 39 and 40, and the capacitor 41, and is input to the control circuit 31.

Further, the control circuit 31 includes a rotation detection circuit 42.
The rotation detection signal is input from. The rotation detection circuit 42 has a magnet 43 mounted at one location around the front end plate of the drum 4 shown in FIG. 2 and a reed switch 44 mounted on the inner surface of the front plate of the outer box 1 so as to face the magnet 43. The rotation detection signal is input to the control circuit 31 each time the drum 4 makes one rotation. The input of the rotation detection circuit 42 and the motor current detection circuit 35 are input.
The control circuit 31 detects the amount of change in the load of the motor 11 per one rotation of the drum 4 based on the input of. It should be noted that the motor 11 is an alternating-current motor, especially a single-phase induction motor, as shown in FIG. 3, and further comprises a capacitor motor.

In addition, the control circuit 31 receives a cloth amount signal and a dryness signal obtained by the contact of the clothes to be dried with the pair of contact electrodes 45 mounted on the lower part of the drum front support 6 facing the inside of the drum 4. , A key input signal is input from a key input circuit 47 including a course selection key, a start key, and the like. Based on a control program stored in advance, the control circuit 31 controls the operation of the relay coil 32b for opening and closing the relay contact 32a and the triacs 33 and 34, and thus the operation of the heater 27 and the motor 11, and at the same time, the display unit 48. It also controls the operation of.

Next, the operation of the above structure will be described. When the operation is started, the microcomputer of the control circuit 31 energizes the heater 27 and energizes the motor 11 in the forward direction as shown in FIG. 1 (step S).
1).

Then, the drum 4 is rotated in the forward direction,
Warm air is supplied into the drum 4, and in such a situation, the microcomputer next determines whether or not the variation amount of the load of the motor 11 per one rotation of the drum 4 is equal to or more than a predetermined value. Yes (step S2).

Motor 11 per one rotation of the drum 4
The load fluctuation amount is detected from the input of the rotation detection circuit 42 and the input of the motor current detection circuit 35 as described above. If the clothes to be dried are not entangled, as shown in (a) of FIG. In addition, when the drum 4 makes one rotation, the clothes to be dried can be easily lifted from the lower part to the upper part of the drum 4, and the movement from the upper part to the lower part is normal.
The current flowing through 1 increases slightly and then gradually decreases,
The change is small in ΔI, that is, the variation of the motor load is small.

On the other hand, if the clothes to be dried are entangled, as shown in FIG. 4 (b), when the drum 4 makes one revolution, the clothes to be dried are raised from the lower part to the upper part of the drum 4. It is difficult and the movement from the upper portion to the lower portion is rapid, and the current flowing through the motor 11 per one rotation of the drum 4 largely increases and then sharply decreases. Therefore, the change is larger than the above by ΔI ′, that is, the motor load. The fluctuation amount of is large.

Therefore, the predetermined value to be judged is ΔI
If the clothes to be dried are not entangled in step S2 by setting larger than ΔI ′,
It is determined that the variation of the load of the motor 11 per one rotation of the drum 4 is not more than the predetermined value, and if the clothes to be dried are entangled, the variation of the load of the motor 11 per one rotation of the drum 4 is the predetermined value. It is judged that it is above.

When it is determined in step S2 that the fluctuation amount of the load of the motor 11 per one rotation of the drum 4 is not more than the predetermined value, the operation is continued in the state up to that time, and the drum When it is determined that the variation amount of the load of the motor 11 per rotation is equal to or greater than a predetermined value, the operation temporarily stops the motor 11 to stop the drum 4 (step S4), and then the motor 11 Are reversed (step S5). By the reverse rotation of the motor 11, the drum 4 is also reversely rotated, and the entangled clothes to be dried are loosened.

Then, after that, it is judged whether or not it is time to end the drying operation (step S5), and while it is judged that it is not time to end, the process returns to step S2,
If it is determined in the returned step S2 that the variation amount of the load of the motor 11 per one rotation of the drum 4 is equal to or larger than a predetermined value, the process proceeds to steps S3 and S4 to reverse the motor 11 (in the reverse rotation state). If you return to the normal state). And
If it is determined in step S5 that it is time to end, the heater 27 is turned off and the motor 11 is turned off (step S6), and the operation is ended.

As described above, in this structure, the variation amount of the load of the motor 11 per one rotation of the drum 4 is detected, and the variation amount of the load of the motor 11 per one rotation of the drum 4 is determined from the detection result. The motor 11 is rotated in the reverse direction when the value is equal to or more than the value. In short, the drum 4 is rotated in the reverse direction only when the clothes to be dried are actually entangled, and the clothes to be dried are actually entangled. If not, the drum 4 will not be reversed.
Driving stop time of the motor 11 for reverse rotation (step S
It is possible to minimize 3) and reduce the drying time.

In contrast to the above, FIGS. 5 and 6 show a second embodiment of the present invention, in which the magnet 49 mounted on the peripheral portion of the rear end surface of the pulley 12 and the outer case back plate 17 facing the magnet 49 are disposed.
The reed switch 50 attached to the inner surface of the upper part of the drum 4 is incorporated into the rotation detection circuit 42 in place of the magnet 43 and the reed switch 44 described above, whereby one rotation of the drum 4 is detected, and The figure also shows that the change in the number of rotations of the motor 11 per rotation is also detected.

In this case, the control circuit 31 determines that the motor 1 per rotation of the drum 4 changes from the change in the number of rotations of the motor 11.
The load variation of 1 is detected, that is, if the clothes to be dried are not entangled, as described above, when the drum 4 makes one rotation, the clothes to be dried can be easily lifted from the lower part to the upper part of the drum 4, Since the movement from the upper part to the lower part is also normal, as shown in FIG. 6A, the number of rotations of the motor 11 per one rotation of the drum 4 slightly decreases and then gradually increases, so that the change is ΔN. Is small, that is, the fluctuation amount of the motor load is small.

On the other hand, if the clothes to be dried are entangled, as described above, when the drum 4 makes one revolution,
It is difficult to lift the clothes to be dried from the lower part to the upper part of the drum 4, and the movement from the upper part to the lower part is rapid. Therefore, as shown in FIG. 6B, the number of rotations of the motor 11 per one rotation of the drum 4 is increased. Is greatly reduced and then sharply increased, so that the change is larger than the above in ΔN ′, that is, the variation of the motor load is large.

Therefore, by setting the predetermined value to be judged in the previous step S2 to be larger than ΔN and smaller than ΔN ', the load of the motor 11 per one rotation of the drum 4 if the clothes to be dried are not entangled. It is determined that the amount of change in the load is not more than the predetermined value, the operation state up to that time is continued, and if the clothes to be dried are entangled, the amount of change in the load of the motor 11 per one rotation of the drum 4 is the predetermined When it is determined that the value is equal to or more than the value, the motor 11 is operated in reverse. Therefore, also in this case, the same effect as described above can be obtained.

Further, in this case, it is possible to detect the variation amount of the load of the motor 11 from both the current flowing through the motor 11 and the rotation speed of the motor 11, and according to this,
Since the amount of change in the load of the motor 11 can be detected more accurately, the actual presence or absence of entanglement of the clothes to be dried can also be detected more accurately, and it is possible to avoid the reverse rotation of the drum 4 when the clothes to be dried are not actually entangled. This can be performed reliably, and the drying time can be shortened more reliably.

7 and 8 show a third embodiment of the present invention, in which the diode rectifier circuit 5 is connected to the AC power supply 28.
1, the resistors 52 and 53, the transistor 54, and the resistor 5
A voltage detection circuit 56 composed of 5 is provided to detect the applied voltage of the motor 11 and to output the detection signal to the control circuit 3.
1 is input.

In this case, the control circuit 31 receives the input from the voltage detection circuit 56 and the motor current detection circuit 59 in which the capacitor 41 is replaced with the transistor 57 and the resistor 58.
Is used to detect the phase difference between the current flowing through the motor 11 and the applied voltage, and the amount of fluctuation of the motor load per rotation of the drum is detected from the detected phase difference.

That is, as long as the clothes to be dried are not entangled, as described above, when the drum 4 makes one revolution, the clothes to be dried can be easily lifted from the lower part to the upper part of the drum 4, and the movement from the upper part to the lower part is also normal. Therefore, as shown in (a) of FIG. 8, the phase difference between the current flowing through the motor 11 per one rotation of the drum 4 and the applied voltage is slightly decreased and then gradually increased. Is small in Δθ, that is, the amount of change in the motor load is small.

On the other hand, if the clothes to be dried are entangled, as described above, when the drum 4 makes one revolution,
It is difficult to lift the clothes to be dried from the lower part to the upper part of the drum 4, and the movement from the upper part to the lower part is rapid. Therefore, as shown in FIG. 8B, the current flowing through the motor 11 per rotation of the drum 4 is increased. Since the phase difference between the applied voltage and the applied voltage decreases greatly and then increases sharply, the change is greater than the above at Δθ ′.
That is, the fluctuation amount of the motor load is large.

Therefore, in this case as well, by setting the predetermined value to be judged in the previous step S2 to be larger than Δθ and smaller than Δθ ', if the clothes to be dried are not entangled, one rotation of the drum 4 is performed. It is determined that the amount of change in the load of the motor 11 is not greater than or equal to a predetermined value, the operation state up to that point is continued, and if the clothes to be dried are entangled, the load of the motor 11 per rotation of the drum 4 is reduced. It is determined that the variation amount is equal to or greater than the predetermined value, and the motor 11 is operated in the reverse direction. Therefore, also in this case, the same effect as described above can be obtained.

9 and 10 show a fourth embodiment of the present invention. A resistor 61, a diode rectifier circuit 62, and a resistor 6 are provided between both terminals of the capacitor 60 of the motor 11.
Voltage detection circuit 6 composed of 3, 64 and capacitor 65
6 is provided so that the voltage across the terminals of the capacitor 60 of the motor 11 is detected and the detection signal is input to the control circuit 31.

In this case, the control circuit 31 detects the fluctuation amount of the motor load per one rotation of the drum by the input from the voltage detection circuit 66, that is, if the clothes to be dried are not entangled, So drum 4 is 1
When rotating, the clothes to be dried are easily lifted from the lower part to the upper part of the drum 4, and the movement from the upper part to the lower part is also common.
As shown in (a) of FIG. 10, the voltage across the terminals of the capacitor 60 of the motor 11 per one rotation of the drum 4 is slightly decreased and then gradually increased. Therefore, the change is small at ΔVc, that is, The fluctuation amount of the motor load is small.

On the other hand, if the clothes to be dried are entangled, as described above, when the drum 4 makes one revolution,
It is difficult to lift the clothes to be dried from the lower part to the upper part of the drum 4, and the movement from the upper part to the lower part is rapid.
As shown in FIG.
Since the voltage across the terminals of the capacitor 60 of No. 2 decreases sharply and then increases sharply, the change is larger than the above at ΔV c ′,
That is, the fluctuation amount of the motor load is large.

Therefore, in this case as well, by setting the predetermined value to be judged in the previous step S2 to be larger than ΔVc and smaller than ΔVc ′, if the clothes to be dried are not entangled, one rotation of the drum 4 is performed. It is determined that the amount of change in the load of the motor 11 is not greater than or equal to a predetermined value, the operation state up to that point is continued, and if the clothes to be dried are entangled, the load of the motor 11 per rotation of the drum 4 is reduced. It is determined that the variation amount is equal to or greater than the predetermined value, and the motor 11 is operated in the reverse direction. Therefore, also in this case, the same effect as described above can be obtained.

[0042]

The clothes dryer of the present invention is as described above, and has the following effects. Firstly, in a device including a drum for containing clothes to be dried, a motor for rotating the drum in both forward and backward directions, and a warm air supply device mainly including a fan and a heater for supplying warm air into the drum. A load variation amount detecting means for detecting a variation amount of the motor load per one rotation of the drum, and when the variation amount of the motor load per one rotation of the drum is equal to or more than a predetermined value from the detection result, By controlling the motor to rotate in the reverse direction, it is possible to reverse the drum to loosen the entangled clothes to be dried only when the clothes to be dried are actually entangled. The drive stop time of the motor can be minimized as necessary, and the drying time can be shortened.

Secondly, since the load variation detecting means detects the variation of the motor load per one rotation of the drum from the current flowing through the motor, the variation of the motor load is detected, that is, Therefore, it is possible to relatively easily detect the actual presence or absence of the entanglement of the clothes to be dried.

Thirdly, the load fluctuation amount detecting means detects the fluctuation amount of the motor load per one rotation of the drum from the rotation speed of the motor. The detection, that is, the actual presence or absence of the entanglement of the clothes to be dried can be detected relatively easily.

Fourthly, the load change amount detecting means detects the change amount of the motor load per one rotation of the drum based on the current flowing through the motor and the rotation speed of the motor. Not only can the variation amount be detected relatively easily, but it can also be performed accurately.

Fifth, the motor is an AC motor, and the load fluctuation amount detecting means detects the fluctuation amount of the motor load per rotation of the drum from the phase difference between the current flowing through the motor and the applied voltage. As a result, similarly to the above, not only can the variation in the motor load be detected relatively easily, but it can also be performed accurately.

Sixth, the motor is a condenser motor, and the load fluctuation amount detecting means detects the fluctuation amount of the motor load per one rotation of the drum from the voltage across the capacitor terminals of the motor. Again, it is possible to detect the variation of the motor load relatively easily.

[Brief description of drawings]

FIG. 1 is a flowchart for explaining the operation of the first embodiment of the present invention.

FIG. 2 is a side view of the entire vertical section with a part broken away.

FIG. 3 is an electrical configuration diagram.

[Figure 4] Characteristic diagram

FIG. 5 is a view corresponding to FIG. 2 showing a second embodiment of the present invention.

FIG. 6 is a view corresponding to FIG.

FIG. 7 is a diagram corresponding to FIG. 3 showing a third embodiment of the present invention.

FIG. 8 is a view corresponding to FIG.

FIG. 9 is a view corresponding to FIG. 3 showing a fourth embodiment of the present invention.

FIG. 10 is a view corresponding to FIG.

[Explanation of symbols]

4 is a drum, 10 is a fan, 11 is a motor, 24 is a connecting duct, 27 is a heater, 31 is a control circuit (load fluctuation amount detecting means, control means), 35 is a motor current detecting circuit, 42
Is a rotation detection circuit, 43 is a magnet, 44 is a reed switch, 49 is a magnet, 50 is a reed switch, 56
Is a voltage detection circuit, 59 is a current detection circuit, 60 is a capacitor, and 66 is a voltage detection circuit.

Claims (6)

[Claims] 1. A drum including a clothes to be dried, a motor for rotating the drum in both forward and backward directions, and a warm air supply device mainly including a fan and a heater for supplying warm air into the drum. In addition, the load fluctuation amount detecting means for detecting the fluctuation amount of the motor load per one rotation of the drum is provided, and from the detection result, the fluctuation amount of the motor load per one rotation of the drum is equal to or more than a predetermined value. A clothes dryer characterized by comprising control means for controlling reverse rotation of the motor. 2. The clothes dryer according to claim 1, wherein the load fluctuation amount detecting means detects the fluctuation amount of the motor load per one rotation of the drum from the current flowing through the motor. 3. The clothes dryer according to claim 1, wherein the load fluctuation amount detecting means detects the fluctuation amount of the motor load per one rotation of the drum from the rotation speed of the motor. 4. The clothes drying apparatus according to claim 1, wherein the load variation detecting means detects the variation amount of the motor load per one rotation of the drum based on the current flowing through the motor and the rotation speed of the motor. Machine. 5. The motor is an AC motor, and the load fluctuation amount detecting means detects the fluctuation amount of the motor load per one rotation of the drum, from the phase difference between the current flowing through the motor and the applied voltage. The clothes dryer according to claim 1. 6. The motor according to claim 1, wherein the motor is a condenser motor, and the load fluctuation amount detecting means detects the fluctuation amount of the motor load per one rotation of the drum from the voltage across the capacitor terminals of the motor. Clothes dryer.