JPH0763558B2 - Clothes dryer - Google Patents

Description

TECHNICAL FIELD The present invention relates to, for example, a clothes dryer used in general households, and more particularly to a clothes dryer including a heater having a positive temperature characteristic.

(Prior Art) Generally, this kind of clothes dryer is provided with an upper motor (2) of a housing (1) as shown in FIG. 4, and the motor (2) and the rear side of the housing (1) are provided. Belts (5) and (6) are stretched between a fan (3) provided and a rotating drum (4) provided in front of the fan (3), and the fan (3) is driven by a motor (2). ) And the rotating drum (4) are rotated, and a heater (7) made of a semiconductor having a positive temperature characteristic is disposed on the front side of the housing (1) and is further housed in the rotating drum (4). The fan (3) has a structure in which a filter (8) for collecting lint generated from the dried material (clothes) thus dried is installed in the rear opening of the rotary drum (4) facing the fan (3). Is heated by the rotation of the heater (7). The heated hot air is introduced into the rotary drum (4), and the material to be dried in the rotary drum (4) is heated and dried by this (problems to be solved by the invention). In the above, there is a risk that the motor (2) will be locked for some reason, causing abnormal overheating, and eventually igniting. In this case, even if the motor (2) is provided with a safety device such as a temperature fuse, the rotating drum (4) is in a stopped state until the safety device operates, so that the area to be dried near the heater (7) is dried. There is a problem that things are overheated and burnt.

Further, if a large amount of lint adheres to the filter (8) and becomes clogged, there is a problem that the drying efficiency is significantly reduced.

The present invention is to solve such problems,
For example, it is an object of the present invention to improve safety when the motor is locked as described above and to notify the user that the filter should be cleaned when the filter is clogged.

(Means for Solving Problems) The characteristic configuration of the present invention for solving these problems is as follows.
A heater made of a semiconductor having a positive temperature characteristic, a rotary drum for containing and rotating and agitating an object to be dried, a fan for introducing hot air heated through the heater into the rotary drum, and this fan and A motor that drives the rotating drum, a filter that is installed in the ventilation path of the heated hot air and that collects lint generated from the material to be dried,
Current detection means for detecting a total value of currents flowing through the heater and the motor, and a current value detected by the current detection means having a first set value and a second set value, and the set value are compared to determine And a determination operation means for performing an operation, wherein the determination operation means determines that the motor is in a locked state when the current value detected by the current detection means is smaller than the first set value,
When it is smaller than the second set value, it is determined that the filter is in a clogged state.

(Operation) For example, when the current value detected by the current detection means is smaller than the predetermined current value, when the motor is in the locked state or when the filter is clogged and the fan cannot operate normally. is there. Therefore, the judgment operation means compares the two current values to judge the presence / absence of ventilation to the heater, for example, to stop the energization of the heater and the motor or to notify the clogging state of the filter. By performing the above, it is possible to prevent a dangerous state and improve the safety.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing.
The basic structure of the clothes dryer according to this embodiment is the same as that of the dishwasher having the structure described with reference to FIG. 4, and the description thereof will be omitted to avoid duplication. It is to be noted that the reference numerals of the components used in this embodiment are the same as those shown in FIG.

In the block diagram of FIG. 1, (11) is a microcomputer having a built-in judgment operation means, and (12) is current control to a motor (2) and a heater (7) according to a control signal output from the microcomputer (11). The current control circuit (13) for performing the above is a current detection means for constantly detecting the value of the current flowing through the motor (2) and the heater (7).

In FIG. 2, when the current flowing through the motor (2) during normal operation of the clothes dryer is I _M and the current flowing through the heater (7) is I _H , the current I detected by the current detecting means (13) is shown.
Is, the I = I _M + I _H.

In contrast, the current flowing in the motor (2) during a state where the wind through the heater (7) hardly flows for some reason ▲ I _^'M ▼, the current flowing through the heater (7) ▲ ^I' _H
▼ and when the heater (7) because it has a positive temperature characteristic, the ^{_{▲ I 'H ▼ "I H}} . Current I detected by this time, the current sensing means (13) _{^{'is, I' = ▲ I 'M}} ▼ + ▲ I' H ▼ , and this current I 'is smaller than the current I at the time of normal operation.

In this case, in the microcomputer (11), an intermediate value I ₁ between the current value I and the current value I ′ is set as the current value flowing through the motor (2) and the heater (7), and the current detection means (13) The current detected by the
The presence or absence of ventilation to the heater (7) can be determined by comparing with I ₁ .

Now, when the motor (2) is locked for some reason, the current I detected by the current detection means (13) during normal operation corresponds to point (a). The _{'to M} ▼ normal current I _M, ▲ _^I' current ▲ ^I in the locked state of the motor (2) _M ▼> becomes a I _M, a heater (7) to the current flowing ▲ ^I _'H ▼ reverse _{^{to, ▲ I 'H ▼ "I}} H
Becomes This is because the heater (7) is made of a semiconductor having a positive temperature characteristic, so that the fan (3) does not rotate and air does not flow through the heater (7). Therefore, the current I'detected by the current detection means (13) has a value at point (b) which is smaller than the current I under normal conditions. Therefore, as the set value I ₁ in the microcomputer (11), an intermediate value (I ′ <I ₁ <which is smaller than the point (a) and larger than the point (b).
It is possible to detect the locked state of the motor (2) by selecting I) and comparing the current detected by the current detecting means (13) in the microcomputer (11) with the set current value I _{1 at} all times. . In this case, the current I '<I
In this case, the current control circuit (12) can stop energization of the motor (2) and the heater (7) to improve safety.

Next, a case where the filter (8) is used for detecting clogging will be described. In FIG. 3, the and in normal operation as well, the current I detected by the current detector (13) is I = I _M + I _H next, corresponding to point (c). When a large amount of lint adheres to the filter (8) and becomes clogged and the amount of air passing through the heater (7) is extremely reduced, the current ▲ I ^′ _M ▼ flowing through the motor (2) is ▲ ^I _'M ▼ = but it changes is not a I _M, a current flowing through the heater (7) ▲ _{^I' H} ▼ by the temperature characteristic of the heater (7), the ^{_{▲ I 'H ▼ <I H}} . Accordingly, the current detected by the current detecting means (13) I '(I' = ▲ I 'M
▼ + ▲ ^I _'H ▼) is I to normal when the current _{I (I = I M + I} H)'<I , and the corresponding to point (d). In this case also, in the same manner as above, in the microcomputer (11),
The set value I ₂ is set so that I ′ <I ₂ <I, and the current detection means (1
By constantly comparing the current detected in 3) with I ₂ ,
The clogging state of the filter (8) can be detected. When I ′ <I ₂ , the drying time becomes abnormally long if a notification device (not shown) is provided to notify the user to clean the filter (17). Prevent it.

(Effects of the Invention) As described above, according to the present invention, the judgment operation means for comparing the current value detected by the current detection means with a predetermined current value to judge whether or not the heater is ventilated. Since it is possible to improve the safety when the motor is locked or to notify when the filter is clogged, it is possible to obtain a safe and convenient clothes dryer. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a clothes dryer according to the present invention, FIG. 2 is a view showing a relationship of current values when it is used as lock detection of a motor, and FIG. 3 is another embodiment. FIG. 4 is a diagram showing the relationship between current values when used as a filter clogging detection, and FIG. 4 is a vertical sectional view showing a general clothes dryer. (2) ... motor, (3) ... fan, (4) ... rotating drum, (7) ... heater, (8) ... filter,
(11) …… Judgment operation means, (13) …… Current detection means.

Claims (2)

[Claims] 1. A heater made of a semiconductor having a positive temperature characteristic, a rotary drum for containing and rotating and stirring an object to be dried, and a fan for introducing hot air heated through the heater into the rotary drum. , A motor that drives this fan and a rotating drum, a filter that is installed in the ventilation path of heated hot air and that collects lint generated from the material to be dried, and a current that detects the total value of the current that flows in the heater and the motor. The determination operation includes: detection means; determination operation means having a first set value and a second set value and performing a determination operation by comparing the current value detected by the current detection means with the set value. The means determines that the motor is in the locked state when the current value detected by the current detection means is smaller than the first set value, and determines that the motor is in the filter clogging state when the current value is smaller than the second set value. Clothes dryer. 2. The clothes dryer according to claim 1, wherein when the judging operation means judges that the motor is in a locked state, the energization of the heater and the motor is stopped.