JPS60145199A - Clothing drier - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a clothes dryer equipped with an improved drying end detection mechanism.

Structure of conventional examples and their problems In recent years, with the spread of clothes dryers, various methods have been devised to detect the end of drying, which automatically ends the operation when the degree of dryness of the clothes to be dried reaches an appropriate state. It has been.

However, conventionally devised devices lacked sufficient precision or had problems in construction.

For example, one conventional method attempts to detect the end of drying only based on the exhaust temperature at the drum outlet. However, with this method, when the clothes to be dried are very short, the hot air heated by the heater is directly exhausted without touching the clothes and is detected as a relatively high temperature. The accuracy is poor. Furthermore, the accuracy is greatly affected by the ambient temperature.

Next, there is a method of directly detecting the resistance value of clothing by providing a pair of electrodes within the drum, but this method has the following problems in terms of accuracy and construction.

First, the resistance value of clothing hardly changes in the final stages of drying, and detailed judgments at drying rates of 90 to 95% or higher are not necessary, and some kind of correction means is required. In addition, the accuracy of dryness detection using this electrode depends on the frequency of contact between the clothes and the electrode, and the drying rate of the clothes to be dried varies greatly at each detection time.
Even if a correction means is provided, there is still a limit to accuracy. Second
Another problem is that the resistance value of clothing is very high even when it contains moisture. That is,
In order to perform high resistance detection, it is necessary to provide sufficient insulation between elements on the control circuit, and it is also necessary to apply a relatively high voltage between the electrodes. Since such insulation between elements, moisture proofing of the circuit, and safety measures are very important in this resistance detection method, it is also disadvantageous in terms of cost.

OBJECTS OF THE INVENTION The present invention aims to solve the above-mentioned problems regarding accuracy and structure, and to realize accurate drying end detection safely and inexpensively.

Structure of the Invention In order to achieve the above object, the present invention provides a heat exchanger for dehumidifying the highly humid air that has taken moisture from clothing; In a clothes dryer having an outflow path through which air dehumidified by a heat exchanger flows out, a temperature sensor is provided in each of the inflow path and the outflow path, and the inflow path and the inflow path are detected by these temperature sensors. Conditions including at least one of the humidity difference with the outflow path and the time change of this temperature difference are independent, or the conditions include at least one of the temperature of the inflow path and the temperature of the outflow path and their change over time. The clothes dryer is characterized in that it includes a control circuit for substantially terminating the operation of the clothes dryer when a predetermined level is reached.

DESCRIPTION OF EMBODIMENTS FIG. 1 shows the basic configuration of an embodiment of the present invention, in which (1) is a heat exchanger, (2) is an inflow path to the heat exchanger,
(3) is the outflow path from the heat exchanger, and (4).

(5) is a temperature detector placed in the inflow and outflow paths (2) and (3), (6) is a blower means such as a fan driven by a motor, and (7) is the same as that for the fan. Or a clothes storage consisting of a drum or the like driven by a dedicated motor. (8) is a heater. In addition, the black arrows in the figure indicate the flow of air, which is the direct medium for drying the clothes to be dried, and the white arrows indicate the flow of air, which is the direct medium for drying the clothes to be dried.
) is a flow of outside air for cooling to dehumidify the tank.

The air heated by the heater (8) is sent to the blowing means (6).
The air is blown to the clothes storage (7) by the clothes storage (7).
) The air becomes highly humid by removing moisture from the clothes to be dried. This highly humid air is sent through the inlet path (2) to the heat exchanger (1), where it exchanges heat with the outside air to condense moisture and dehumidify it. This dehumidified air returns to the heater (8) through the outflow path (3). The clothes to be dried are dried through this air cycle. A temperature sensor (4) detects the temperature of the inflow path (2), and a temperature sensor (5) detects the temperature of the outflow path (3).

A feature of the present invention is that the temperature difference between the humidity in the inflow path (2) to the heat exchanger () and the humidity in the outflow path (3) from the heat exchanger (1) is used as a reference for detecting the end of drying. It is. The present invention is capable of terminating the drying operation or switching to cold air operation by turning off only the heater (8) when this temperature difference, its time change, or a combination of these reaches a predetermined level. , to achieve ideal dry conditions. Also, in some cases, a temperature sensor (4)
.

(5) The inflow route (2) or the outflow route (
The temperature of 3) may be used alone, and the predetermined level described above may be corrected depending on the temperature, its change over time, or a condition consisting of a combination thereof.

4. In FIG. 1, the order of the temperature detector (4) and the blower means (6) in the inflow path (2) may be interchanged. Furthermore, although the configuration shown in FIG. 1 is for a circulation-type clothes dryer, the present invention can also be implemented in exhaust-type clothes dryers if a small-scale heat exchanger is provided exclusively for detecting the completion of drying. is considered possible.

Next, specific embodiments of the present invention will be described with reference to FIGS. 2 and 3. In FIG. 2, the arrangement of parts using the same reference numerals as in FIG. 1 is the same as in FIG.

In this embodiment, the heat exchanger (1) is placed at the rear of the device, and uses a double-blade heat exchange fan that also serves as the air blowing means (6) in FIG. The inflow path to this heat exchanger (1) (
2) is the front center of the heat exchange fan (in Fig. 2,
The outflow path (3) from the heat exchanger (1) is formed from the lower end of the outer periphery of the fan to the front of the device, and is equipped with temperature detectors (4) and (5), respectively. There is. The clothing storage (7) is equipped with a heater (8) at the connection port (hot air inlet) with the outflow path (3) at the bottom of the front.
The storage compartment itself consists of a rotating doze (9). In addition, the motor (00) on the top of the device drives the heat exchanger (1), the door (11) on the device i1E is used to take in and take out the clothes to be dried, and the threshold (threshold) on the bottom of the device drives the heat exchanger (1). 1), which discharges moisture condensed outside the machine.The black arrow shown in Figure 2 indicates the flow of circulating air, and the self-arrow indicates the flow of circulating air that cools the circulating air in the heat exchanger (]). The figure shows the flow of cooling air that is dehumidified.

311+ shows electrical connections regarding the control circuit of this embodiment. The temperature detectors (4L (5)) in the route leading to the heat exchanger (1) described above are composed of, for example, thermistors.
), (5) as input, and controls the operation of the heater (8) and motor 00) as described below.

That is, in the control circuit section, '(+4) is a microcomputer, and (15) and (10) are temperature detectors (4), respectively.

A pair of input converters including, for example, an A/D converter for inputting the temperature detected by (5) to the microcomputer θ4), and (17) and (18) respectively A pair of actuators for energizing or stopping the heater (8) and the motor α0) in response to the output of the actuator, and is composed of a control switching element such as a triac. In the q configuration of such a circuit, the microcomputer (14) inputs the heat exchanger inflow path (2 ) and the humidity in the outflow path (3), and when a predetermined condition described later is reached, the heater (8) and motor 00) are stopped.

Next, a drying completion detection method determined within the microcomputer 044) will be described. In Figure 4 (0), the solid line represents the humidity in the inflow path (2) to the heat exchanger (1), and the humidity in the outflow path (
The temperature in 3) is shown by a broken line. Figure 4 (1)) shows those 2
This indicates the difference in humidity (hereinafter referred to simply as temperature difference). This temperature difference △T increases during the preheating period immediately after turning on the heater, becomes almost constant during the constant rate drying period when substantial drying begins and water evaporation energy and heating energy are balanced, and as drying progresses, the amount of water evaporation (endothermic During the drying period, the lapse rate (energy) decreases and then increases again.

To put this in thermodynamic terms, as drying approaches the end, the absolute humidity of the circulating air passing through the heat exchanger (1) decreases, and the specific heat decreases accordingly. This is because the temperature difference created by passing through the exchanger (1) increases. The drying end detection method in the present invention is performed based on this temperature difference ΔT.

First, when the drying operation is started, the temperature at the outlet of the drum (9), that is, in the inflow path (2) (solid line in Figure 4 (a)) increases by 1, but this temperature increases over time. It is determined when the rate becomes constant (t+ in FIG. 4(a)), and it is determined that the constant rate drying period has started.

Therefore, after this point (tl), as shown in FIG.
The time when the temperature difference ΔT/Δt (time differential) reaches the predetermined value (ΔT/Δ1)+ is set as 12, and the temperature difference ΔT■ at time t2 shown in Fig. 4 is used as the reference. Let it be the humidity difference. As the drying progresses, this temperature difference △T further increases, but there is a point at which this temperature difference △T further increases by 1゛2 from the reference temperature difference △T1 to a predetermined value (in Fig. 4).
ta) is reached. In this embodiment, this point is determined to be the end of drying, and as described above, the microcomputer (14) operates to stop the operation of the heater (8) and motor 00).

FIG. 5 shows the relationship between the temperature difference ΔT minus the reference temperature difference ΔT1 (ΔT−ΔT+) and the progress of drying the clothes to be dried. Figure 5 shows the change in (△T-△T+) with respect to time.
The solid line indicates the room temperature (30° C., the broken line indicates 5° C.), and the marks on the graph indicate when the drying rate reached each value. Fifth
As is clear from the figure, the drying rate is almost constant for the value of (ΔT−ΔT+) regardless of the room temperature and the amount of cloth. In other words, the reference temperature difference △T1 of T to the temperature difference mentioned above
If the operation of the dryer is stopped when the increment from ΔT2 reaches a predetermined value of ΔT2, a desired drying rate can be obtained with less variation.

Effects of the Invention As mentioned above, the present invention basically uses only two temperature detectors as sensors, and does not require higher voltage than the conventional method of detecting the resistance value of clothing using electrodes. figure,
Also, there is no need for insulation and moisture proofing of the control circuit. Furthermore, compared to a method that detects only the temperature of the drum exhaust, it is possible to detect the completion of drying with high accuracy even when there is a very small amount of clothes to be dried, and there is almost no influence from the ambient temperature.

Furthermore, even if the overtemperature prevention system operates and the temperature is adjusted, if the completion of drying is detected based on only one temperature, it may become impossible to determine the end of drying, or the difference in temperature shown in the present invention may be affected by the overtemperature prevention system. Since this does not occur, it is possible to effectively detect the end of drying in any case.

Furthermore, if the user is allowed to set the predetermined value ΔT2 of the increment of the temperature difference Δ′1゛ from the reference temperature difference ΔT1 mentioned above, the operation can be terminated at an arbitrary drying rate at the final stage of the drying operation. You can also do it.

As described above, the present invention realizes a very effective and powerful detection of the end of drying, and is also advantageous in terms of cost, so it is considered to be of great significance.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of the present invention, FIG. 2 is a vertical sectional view showing the structure of a specific embodiment thereof, FIG. 3 is an electrical connection diagram regarding the control circuit of the embodiment, and FIG. ), (b)
, (C) is a graph showing the temperature change of the inflow route and the outflow route with respect to time, the change in the temperature difference between them, and the change in the time change (time derivative) of the temperature difference, and Figure 5 is (
It is a graph showing the relationship between (humidity difference) - (reference Wilt degree difference) and drying rate. (1)・・・・・・・・・・・・Heat exchanger (2)
・・・・・・・・・・・・Inflow route (3)...
・・・・・・・・・Outflow route (4), (5)−
・・−・−・・Temperature detector (6)・・・・・
......Blower means (7)...
・・・・・・Clothing storage (8)・・・・・・・・・・・・
・・・・・・Heater (9)・・・・・・・・・－・・・・・・
・Drum Qo)...Motor (+)...Door (B)...-
・−・・・・・・・Discharge port (13) ・−・−・−・
--- Control circuit section (14) ----
・Micro 6 computer 05), (16)...-
・−・−・−・・Conversion part (17)! (+8) ・−
−−−−−−・Four Actuator Patent Applicant Matsushita Electric Industrial Co., Ltd. Agent Kenji Arata (1 other person) Figure 3

Claims (2)

[Claims] (1) A heat exchanger that dehumidifies the highly humid air that has taken moisture from clothing, an inlet path that allows the highly humid air to flow into the heat exchanger, and an outlet through which the air dehumidified by the heat exchanger flows out. In the clothes dryer having an outflow path, a temperature detector is provided in each of the inflow path and the outflow path, and the temperature difference between the inflow path and the outflow path detected by these temperature detectors and this temperature difference. When a condition including at least one of the time changes of the above reaches a predetermined level alone or in relation to at least one of the temperature of the inflow path and the temperature of the outflow path and their time changes. A clothes dryer characterized by comprising a control circuit section for substantially terminating the operation of the clothes dryer. (2) The control circuit section determines the point in time when the time change in the temperature difference between the inflow path to the heat exchanger and the outflow path from the heat exchanger reaches a predetermined value after the start of the constant rate drying period. Recognized,
The temperature difference at this point is set as a reference temperature difference, and when the increment of the humidity difference with respect to the reference temperature difference reaches a predetermined value, the operation is terminated or a corresponding control operation is performed. A clothes dryer according to feature 31 and claim (1).