JPH06170094A - Clothes dryer - Google Patents

Abstract

PURPOSE:To stably control a revolving speed of a ventilation means and a rotary drum by constituting them so as to be scarcely influenced by such a disturbance as a sudden variation of a power supply voltage, in the clothes dryer for drying clothes by allowing hot air to circulate into the rotary drum driven to rotate by a motor. CONSTITUTION:Hot air is allowed to circulate into a rotary drum 1 for drying clothes by a heat exchange type both blade fan, a PTC heater 3 is provided in a ventilation path to the inside of the rotary drum 1, and the rotary drum 1 and the heat exchange type both blade fan are driven to rotate by a motor 5. A revolving speed of the rotary drum 1 is detected by a revolving speed detecting means 91, and its variation is detected by a revolving speed variation detecting means 92. Based on an output of a revolving speed comparing means 94 for comparing an output of the revolving speed detecting means 91 and an output of a revolving speed setting means 93, a conduction time of a power semiconductor element 90 is controlled by proportional control, and it is formed so as to vary a proportional constant of the proportional control by the output of the revolving speed comparing means 94 and the output of the revolving speed variation detecting means 92.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clothes dryer which circulates warm air in a rotary drum which is driven by a motor to dry clothes.

[0002]

2. Description of the Related Art In recent years, household clothes dryers have mainly used a positive characteristic temperature sensitive heater (hereinafter referred to as PTC heater) as a heating means. However, since the PTC heater has a large inrush current and the heater current may be large at a low temperature and a home breaker may operate, a clothes dryer that powers down when the current exceeds 15 A has been proposed.

Conventionally, this type of clothes dryer has been disclosed in Japanese Utility Model No. 62.
It was constructed as shown in Japanese Patent Publication No.-90098. That is, the change in the current of the PTC heater is detected by the current measuring device, and the blowing capacity of the blowing fan is reduced as the current value increases.

[0004]

In such a conventional clothes dryer, the PTC heater current is detected to control the blowing capacity of the blowing fan, and the fan rotation speed is reduced when the PTC heater current is large. However, there is a problem that the rotation speed becomes unstable. In particular, the current change of the PTC heater is large for a few minutes immediately after the start of the drying operation, and if the fan rotation speed is controlled by the current change, the variable element of the control system becomes large and the fan rotation speed becomes unstable. It had a problem that it might stop.

The present invention solves the above conventional problems.
The object of the present invention is to suppress the influence of disturbance such as a sudden change in power supply voltage and to stably control the number of rotations of the blowing unit and the rotating drum.

[0006]

In order to achieve the above object, the present invention provides a rotating drum for drying clothes, an air blowing means for circulating warm air into the rotating drum, and an air blowing path into the rotating drum. A heating means provided in the motor, a motor for rotating the blower means or the rotary drum, a power semiconductor element connected in series to the motor to control the rotation of the motor, and a rotation speed of the rotary drum or the motor. Alternatively, a rotation speed detection unit that detects a rotation cycle, a rotation speed change amount detection unit that detects a rotation speed or a change amount of the rotation cycle of the rotating drum or the motor, and a rotation speed of the rotation drum or the motor. The rotation speed setting means for setting, the rotation speed comparing means for comparing the output of the rotation speed detecting means and the output of the rotation speed setting means, and the output of the rotation speed comparing means. And a conduction time control means for controlling the conduction time of the power semiconductor element by the output of the rotation speed change amount detection means to control the rotation speed of the rotary drum or the motor. There is.

The conduction time control means of the first problem solving means controls the conduction time of the power semiconductor element by proportional control based on the output of the rotation speed comparison means to control the rotation speed of the rotary drum or the motor. It is controlled that the proportional constant (gain) of the proportional control is changed by the output of the rotational speed comparison means and the output of the rotational speed change amount detection means.
Is used as a means for solving the problem.

In addition to the first problem solving means, a low speed rotation setting means for controlling the set rotation speed of the rotation speed setting means is provided, and the low speed rotation setting means is lower than a steady state when the motor is started. The third problem solving means is that the set rotation speed is set.

Further, in addition to the above-mentioned third problem solving means, there is provided a time measuring means for measuring the time from the start of operation of the rotary drum to a predetermined number of revolutions at the time of starting the motor, and the conduction time control means comprises A fourth problem solving means is that the number of rotations of the rotating drum or the motor is controlled based on the measurement result of the time measuring means.

[0010]

According to the first means for solving the problems of the present invention, the deviation between the rotational speed of the rotary drum detected by the rotational speed detecting means and the rotational speed set by the rotational speed setting means is calculated by the rotational speed comparing means. The rotation speed change amount detecting means calculates the rotation speed change amount of the rotary drum, and the conduction time control means operates the conduction time of the power semiconductor element based on the deviation with a proportional constant (gain) determined by the deviation and the change amount. Control the number of rotations. Therefore, the control of the rotation speed of the rotating drum and the blowing means can be stabilized, and at the same time, the breaker operates by setting the rotation speed of the rotating drum and the blowing means so as to keep the current consumption of the clothes dryer below a certain value. You can turn it off.

Further, according to the second means for solving the problem, the operation amount of the conduction time of the motor can be expressed by a linear expression of the deviation between the current rotation speed of the rotary drum and the set rotation speed. It becomes possible to easily control the number of rotations of the rotary drum and the blowing means by using such as. Since the proportional constant (gain) is changed based on the deviation between the current rotation speed and the set rotation speed and the amount of change in the rotation speed, stable rotation speed control that is not easily affected by disturbances such as voltage fluctuations is performed. realizable.

By the third means for solving the problems, the set rotational speed can be temporarily lowered and proportional control can be performed at the time of starting the motor, and particularly, the overshoot of the rotational speed when the power supply frequency is 60 Hz is reduced. be able to.

Further, the fourth problem solving means makes it possible to reduce the overshoot of the number of revolutions regardless of the amount of clothes in the rotating drum.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

As shown in the figure, the rotary drum 1 is for accommodating and drying an object to be dried (clothes), and hot air is circulated in the rotary drum 1 by a heat exchange type double-blade fan (blowing means) 2. The heat exchange type double-blade fan 2 circulates hot air in the rotating drum 1 and at the same time takes in air from the outside to cool the fan and dehumidify the circulating air in the rotating drum 1. P
The TC heater (heating means) 3 is provided in the air blowing path to the rotary drum 1, that is, in the circulating air intake, and heats the circulating air. The filter 4 is provided in the ventilation path of the heat exchange type double-blade fan 2, that is, in the air outlet of the rotary drum 1. If the filter 4 is clogged with lint, etc.,
The amount of air blown is reduced, the heating power of the PTC heater 3 is reduced, the drying time is lengthened, and the drying efficiency is also reduced. The motor 5 rotationally drives the rotary drum 1 and the heat exchange type double-blade fan 2. By controlling the rotation number of the motor 5, the rotation numbers of the rotary drum 1 and the heat exchange type double-blade fan 2 can be controlled.
The amount of heat generated by the C heater 3 can be controlled, and the current can be controlled.
The temperature detecting means 6 detects the temperature of the air sucked into the PTC heater 3. The rotation detection means 7 detects the rotation state of the rotary drum 1, and the magnet 8 is attached to the rotary drum 1.
3 to 6 are attached and a magnetic sensor (not shown) is fixed to the main body to detect the rotating state of the rotary drum 1.

The rotation control means 9 controls the rotation speed of the motor 5. The rotation of the rotary drum 1 is controlled by the power semiconductor element 90 such as a bidirectional thyristor connected in series with the motor 5 and the output of the rotation detection means 7. The number of revolutions detecting means 91 for detecting the number of revolutions, the number of revolutions changing amount detecting means 92 for detecting the amount of variation each time the number of revolutions of the rotating drum 1 is detected by the number of revolutions detecting means 91, and the number of revolutions of the rotating drum 1 are set. Rotating speed setting means 93, and rotating speed comparing means 94 for comparing the output of the rotating speed detecting means 91 and the output of the rotating speed setting means 93.
A conduction time control means 95 for proportionally controlling the conduction time of the power semiconductor element 90 by the output of the rotation speed change amount detection means 92 and the output of the rotation speed comparison means 94; and the rotation speed lower than a steady rotation speed when the motor 5 is started. The low speed rotation setting means 96 for setting the number of rotations, and the rotary drum 1 when the motor 5 is activated are also provided.
Is configured with a time measuring means 97 for measuring the time from the start of the operation until reaching a predetermined rotation speed (for example, 20 rpm).

In the rotation control means 9, the rotation speed detection means 91
The rotation speed comparison means 94 calculates the deviation between the rotation speed of the rotary drum 1 and the set rotation speed from the rotation speed setting means 93, while the rotation speed change amount detection means 92 changes the rotation speed of the rotary drum 1. The quantity is calculated and the conduction time control means 95
With the gain G (proportional constant) determined by the deviation and the change amount, the rotation time of the motor 5 is controlled by operating the conduction time of the power semiconductor element 90 by θ based on the deviation. Deviation and E _T becomes this as follows, if indicated by the formula.

Θ = G · E _T Here, an example of the gain table is shown in (Table 1).

[0019]

[Table 1]

Since the gain G is a value determined by the difference between the set rotational speed, the current rotational speed deviation, and the rotational speed change amount, the gain G is a value that includes a proportional element and a differential element, such as a sudden change in the power supply voltage. Responds well to external disturbances. In this example, generally, the gain is reduced when the deviation and the variation are small, and the gain is increased when the deviation and the variation are large. Phase control can be considered as the simplest conduction time control method. In the case of an inverter, not only the conduction time but also the frequency is controlled. By doing so, stable rotation control of the rotary drum 1 and the heat exchange type double-blade fan 2 can be realized. When the motor 5 is started, if the time measured by the time measuring means 97 is long, it is judged that there is a large amount of clothes, and if the time is short, it is judged that there is a small amount of clothes, and the low speed rotation setting means 96 causes the rotating drum 1 in the normal operation. Is set to a rotation speed lower than the rotation speed (36 to 45 rpm) (for example, 20 rpm), and is controlled, for example, twice when it is determined that there is a lot of clothes, and four times when it is not so that the overshoot at the time of startup is prevented. I try to make it smaller.

The current detecting means 10 is a current transformer 1.
1 and the current-voltage conversion circuit 12, detects the input current of the PTC heater 3, and outputs the output from the current comparison setting means 1.
Enter in 3. The current comparison setting means 13 compares the set current value of the PTC heater 3 with the output of the current detection means 10,
The output is input to the rotation speed setting means 93 to control the set rotation speed. Here, the set rotation speed set by the rotation speed setting means 93 is set so that the current of the PTC heater 3 becomes an air volume that does not exceed or fall below a predetermined current value. Further, the AC power supply 15 is connected in series to the PTC heaters 3a and 3b via the contacts 16a and 16b of the relay, respectively.

The operation of the above structure will be described with reference to FIGS. FIG. 3 is an operation flowchart of an embodiment of the present invention. After initial setting in step 30, the motor 5 is turned on in step 31, and the start-up sequence is executed in step 32. Next, in step 33, the PTC heater 3 is turned on, and in order to wait until the input current of the PTC heater 3 stabilizes, a constant time delay (for example, 1
Minutes). From step 35 to step 38, P
Current control (step 35) for controlling the set rotation speed so that the input current of the TC heater 3 becomes the set current value, and the rotation drum 1 is set to the set rotation speed every time the rotation detection signal is detected by the rotation detection means 7. The rotation control (step 37) is performed until the operation ends.

Next, the start-up sequence of step 32 will be described with reference to FIG.
The timer 1 which is the time measuring means 97 is started, and in step 41, the rotation detecting means 7 determines whether or not there is a rotation detecting signal. If there is a rotation detecting signal, in step 42,
The rotation speed detected by the rotation speed detection means 91 is 20 rpm.
It is determined whether or not the above. Rotation speed is 20r
If it is pm or more, the timer 1 is stopped in step 43, and the time measured by the timer 1 is discriminated in step 44. From step 45 to step 51, the setting Ts of the rotation cycle of the rotary drum 1 is set to a cycle T ₂₀ corresponding to 20 rpm, which is lower than the normal setting, and the rotation detection signal is detected by the rotation detection means 7. In addition, if the time measured by the timer 1 is 2 seconds or more, the rotation control is performed twice, and if the time is less than 2 seconds, the rotation control is performed only four times.

Next, the current control routine in step 35 will be described with reference to FIG. 5. First, in step 60, it is determined whether or not every second, and the following processing is performed every one second. In step 61, the current detection means 10 detects the current, and in step 62 the current comparison setting means 13 calculates the deviation from the current setting value. This calculation result is input to the rotation speed setting means 93, and in step 63, the rotation cycle of the rotary drum 1 is calculated from the calculation result. Then, the cycle Ts calculated in step 64 is set to the maximum cycle Tsmax (for example, 3
6 rpm equivalent cycle), the cycle Ts is the maximum cycle Ts
When it is larger than max, the process proceeds to step 65 and the maximum period Ts.
Let max be the set period. If the period Ts is smaller than the maximum period Tsmax, the process proceeds to step 66, where the period Ts is set to the minimum period Ts.
min (for example, a period corresponding to 45 rpm), and if the period Ts is smaller than the minimum period Tsmin, the process proceeds to step 67, and the minimum period Tsmin is set as the set period. When the period Ts is larger than the minimum period Tsmin, the process proceeds to the next step. Therefore, the set cycle Ts set by the rotation speed setting means 93
Is set to be smaller than the maximum period Tsmax and larger than the minimum period Tsmin.

Next, the rotation control routine of step 37 will be described with reference to FIG. 6. First, in step 70, the rotation cycle T is detected, and in step 71, the rotation cycle change amount ΔT is detected. In step 72, rotation speed comparison means 94
The deviation E between the set rotation cycle Ts and the current rotation cycle T
_T is calculated, and in step 73, the conduction time control means 95 determines the gain G (proportional constant) by the deviation E _T and the variation ΔT.
Then, the control phase of the power semiconductor element 90 is calculated and set based on the deviation E _T , and the rotational speed of the rotary drum 1 is controlled to the set rotational speed.

As described above, according to this embodiment, the deviation between the rotation speed of the rotary drum 1 detected by the rotation speed detection means 91 and the rotation speed set by the rotation speed setting means 93 is calculated by the rotation speed comparison means 94. On the other hand, the rotation speed change amount detection means 92 calculates the rotation speed change amount of the rotating drum 1, and the conduction time control means 95 calculates the power semiconductor element 90 based on the deviation by the gain G (proportional constant) determined by the deviation and the change amount. Since the rotation time of the motor 5 is controlled by operating the conduction time of 3 by θ, the control of the rotation speeds of the rotary drum 1 and the heat exchange type double-blade fan 2 can be stabilized, and the conduction time of the motor 5 The operation amount can be represented by a linear expression of the deviation between the current rotation speed of the rotary drum 1 and the set rotation speed, so that the rotation speeds of the rotary drum 1 and the heat exchange type double-blade fan 2 can be easily controlled. . Since the gain G is changed based on the deviation between the current rotation speed and the set rotation speed and the amount of change in the rotation speed, it is possible to realize stable rotation speed control that is not easily affected by disturbance such as voltage fluctuation. .

In this embodiment, the rotating drum 1 and the heat exchanging type double-blade fan 2 are driven by one motor 5, but a two-motor system having a motor for driving the same is also the same. Has the effect of.

[0028]

As is apparent from the above embodiments, according to the present invention, a rotating drum for drying clothes, an air blowing means for circulating warm air into the rotating drum, and an air blowing path into the rotating drum. A heating means provided in the motor, a motor for rotating the blower means or the rotary drum, a power semiconductor element connected in series to the motor to control the rotation of the motor, and a rotation speed of the rotary drum or the motor. Alternatively, a rotation speed detection unit that detects a rotation cycle, a rotation speed change amount detection unit that detects a rotation speed or a change amount of the rotation cycle of the rotating drum or the motor, and a rotation speed of the rotation drum or the motor. An output of the rotational speed setting means, a rotational speed comparison means for comparing the output of the rotational speed detection means and the output of the rotational speed setting means, and an output of the rotational speed comparison means. The rotating drum is detected by the rotation speed detecting means, since the rotation speed detecting means controls the conduction time of the power semiconductor element by the output of the rotation speed change amount detecting means to control the rotating speed of the rotating drum or the motor. The difference between the number of revolutions and the set number of revolutions from the number of revolutions setting means is calculated by the number of revolutions comparing means, while the amount of change in the number of revolutions of the rotating drum is calculated by the number of revolutions detecting means and the conduction time control means is calculated. The rotation speed of the motor can be controlled by operating the conduction time of the power semiconductor element by θ based on the deviation with a proportional constant determined by the deviation and the amount of change, and the control of the rotation speed of the rotating drum and the blowing means can be stabilized. At the same time, the breaker can be prevented from operating by setting the number of rotations of the rotating drum and the blowing means so as to keep the current consumption of the clothes dryer below a certain value. .

The conduction time control means controls the conduction time of the power semiconductor element by proportional control based on the output of the rotation speed comparison means to control the rotation speed of the rotating drum or the motor, and the rotation speed comparison means. Since the proportional constant (gain) of the proportional control is changed by the output of the motor and the output of the rotational speed change amount detecting means, the operation amount of the conduction time of the motor is
Since it can be expressed by a linear expression of the deviation between the current rotation speed of the rotary drum and the set rotation speed, the rotation speed of the rotary drum and the blowing means can be easily controlled even by a one-chip microcomputer, and the proportional constant Since the (gain) is changed based on the deviation between the current rotation speed and the set rotation speed and the amount of change in the rotation speed, it is possible to realize stable rotation speed control that is not easily affected by disturbance such as voltage fluctuation.

Further, since the low speed rotation setting means for controlling the set rotation speed of the rotation speed setting means is provided, and the low speed rotation setting means sets the set rotation speed lower than the steady state when the motor is started, When the motor is started, the set rotation speed can be temporarily lowered to perform proportional control, and in particular, the overshoot of the rotation speed when the power supply frequency is 60 Hz can be reduced.

Furthermore, when the motor is started, the rotating drum is provided with a time measuring means for measuring a time from the start of operation to a predetermined number of rotations, and the conduction time controlling means is based on the measurement result of the time measuring means. Alternatively, since the rotation speed of the motor or the like is controlled, the overshoot of the rotation speed can be reduced regardless of the amount of clothes in the rotating drum.

[Brief description of drawings]

FIG. 1 is a block diagram of a clothes dryer according to an embodiment of the present invention.

FIG. 2 is a sectional view of the clothes dryer.

FIG. 3 is a flowchart explaining the operation of the clothes dryer.

FIG. 4 is a flowchart illustrating an operation of a startup sequence of the clothes dryer.

FIG. 5 is a flowchart illustrating the operation of a current control routine of the clothes dryer.

FIG. 6 is a flowchart illustrating the operation of a rotation control routine of the clothes dryer.

[Explanation of reference numerals] 1 rotating drum 2 heat exchange type double-blade fan (blowing means) 3 PTC heater (heating means) 5 motor 90 power semiconductor element 91 rotation speed detection means 92 rotation speed change amount detection means 93 rotation speed setting means 94 rotation Number comparison means 95 Conduction time control means

Claims (4)

[Claims] 1. A rotary drum for drying clothes, a blower for circulating warm air into the rotary drum, a heating means provided in a blower path into the rotary drum, and the blower or the rotary drum. A motor that is rotationally driven, a power semiconductor element that is connected to the motor in series and that controls the rotation of the motor, a rotation speed detection unit that detects the rotation speed or the rotation cycle of the rotation drum or the motor, and the rotation drum. Alternatively, a rotation speed change amount detecting unit that detects a change amount of the rotation speed or the rotation cycle of the motor, a rotation speed setting unit that sets the rotation speed of the rotating drum or the motor, and an output of the rotation speed detecting unit. And the output of the rotational speed setting means, the rotational speed comparing means, the output of the rotational speed comparing means and the output of the rotational speed change amount detecting means A clothes dryer comprising: a conduction time control means for controlling the conduction time of the semiconductor element to control the rotation speed of the rotary drum or the motor. 2. The conduction time control means controls the conduction time of the power semiconductor element by proportional control based on the output of the rotation speed comparison means to control the rotation speed of the rotating drum or the motor, and the rotation speed comparison means. 2. The clothes dryer according to claim 1, wherein the proportional constant (gain) of the proportional control is changed according to the output of the control unit and the output of the rotation speed change amount detecting means. 3. A low speed rotation setting means for controlling the set rotation speed of the rotation speed setting means, wherein the low speed rotation setting means sets a set rotation speed lower than a steady state when the motor is started. 1. The clothes dryer according to 1. 4. A time measuring means for measuring the time from the start of operation of the rotating drum to a predetermined number of rotations at the time of starting the motor, and the conduction time controlling means, based on the measurement result of the time measuring means. The clothes dryer according to claim 3, wherein the number of rotations of the motor or the like is controlled.