JPH04285599A - Clothes drying machine - Google Patents

Abstract

PURPOSE:To prevent overdrying and overheating and preclude a resin product from deformation by connecting a drying wind circulation path with a drum, installing in this circulating route, providing a lint filter, a heater with pos. temp. resistance characteristic, dehumidifying device, and temp. sensor, controlling the drying process with a drying control means, and equipping an altering part to alter the control temp. difference, etc., in accordance with clogging condition of the lint filter. CONSTITUTION:A clothes cast-in hole 2 is furnished in the center of the front of the frame 1 of a clothes drying machine according to the invention, while an external air lead-in hole 3 and lead-out hole 4 are provided at the rear of the machine frame 1. A drum 5 is installed within the frame 1, and an outlet 13 leading to a fan casing 9 is provided in a supporting plate 8 and the rear surface of this drum 5, wherein the fan casing 9 together with a fan 10 constitutes a dehumidifying device. A heater 15 of pos. temp. resistance characteristic is mounted in a circulation path 12 soon before the inlet 11, and a lint filter 17 covering the outlet 13 is mounted within the drum 5. A drying control means includes an altering part, which alters and sets the upper limit temp. and limit temp. difference according to the clogged condition of the lint filter 17, and thereby overdrying and overheating are precluded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention connects a drying air circulation path to the outlet and inlet of a drum containing clothes, arranges a lint filter near the outlet, and has a positive temperature resistance characteristic on the inlet side. A honeycomb-shaped heater is arranged, a dehumidifier for dehumidifying dry air is arranged between the heater and the drum outlet, and first and second temperatures are used to detect the temperature of the dry air before and after dehumidification by the dehumidifier. A detector is provided, and the drying control means controls the drying work based on a comparison between the difference in drying air temperature before and after dehumidification and the control temperature difference, and also controls the drying operation when the detected temperature of the drying air by the first temperature sensor reaches a predetermined value. The present invention relates to a clothes dryer that stops heating drying air when an upper limit temperature is reached.

0002

[Prior Art] This type of clothes dryer, for example,
In Publication No. 2-6836, normal drying work is controlled by a drying air temperature difference signal generated depending on the type and amount of clothing (load), and in rare cases, a specified upper limit temperature (85°C
), it is determined that there is a small load or no load, and heating by the dry air heater is stopped to cool down the drum. However, this control is possible under normal conditions when the lint filter is not clogged, but when it is clogged, the drying air temperature difference signal for ending is not output, the drying air temperature does not reach the upper limit temperature, and it is not possible to actually Even if the product was dry, the drying process continued sluggishly, resulting in overdrying.

Therefore, in Japanese Patent Application Laid-Open No. 63-260596, a third temperature sensor is provided at the heater outlet (drum inlet), and the temperature detected here is compared to the temperature detected by the first and second temperature detectors. The clogging of the lint filter and heater is determined by processing together with the temperature, and the drying air temperature difference signal is corrected based on the determination result to prevent overdrying.

0004

[Problem to be solved by the invention] However, this Japanese Patent Application Publication No. 6
In the publication No. 3-260596, for filter clogging,
If the ambient temperature is very high or the load is low, control of the end of drying may be delayed or impossible. In particular, with this type of heater, even if the air flow is extremely reduced, the temperature near the heater outlet will reach a maximum of 250°C, so if the termination control is delayed under conditions of extremely high ambient temperature. In some cases, doors and the like, which are often made of resin, may be thermally deformed due to the reflection of high-temperature dry air.

The present invention aims to prevent overdrying and overheating by automatically controlling drying in response to filter clogging and ambient temperature.

[0006]

[Means for Solving the Problems] The present invention provides a control temperature difference that is compared with a difference in drying air temperature before and after dehumidification in order to control the completion of drying depending on the clogging state of a lint filter;
This configuration includes a changing unit that changes the temperature indicating the upper limit of the drying air temperature detected at the drum outlet.

The present invention also provides a control temperature difference that is compared with the difference in drying air temperature before and after dehumidification in order to control the end of drying, and an upper limit of the drying air temperature detected at the drum outlet, depending on the ambient temperature. This configuration includes a changing section that changes the temperature indicated by the temperature.

[0008]

[Operation] That is, clogging of the filter is determined based on the temperature detected by each temperature sensor, the temperature difference, the heater current, etc.
Further, the ambient temperature is determined by the dry air temperature at the heater inlet (proportional to the ambient temperature) and a separately provided temperature sensor, and the changing section changes the control temperature difference and upper limit temperature in accordance with the results of these determinations. For example, when filter clogging progresses, the control temperature difference and upper limit temperature are lowered, and even when the ambient temperature is high, the control temperature difference and upper limit temperature are lowered to suppress the occurrence of overheating.

[0009]

[Embodiment] To explain an embodiment based on the drawings, a machine frame 1 of a clothes dryer has a clothes inlet 2 in the center of the front part, and an external air inlet 3 and an outlet in the rear part. There are 4. Inside the machine frame 1, a transverse shaft-shaped drum 5 made of resin is rotatably supported at its front inner edge on the outer edge of an annular drum support plate 6 via felt, etc., and at its rear center. It is rotatably supported on a shaft 7.

The drum support plate 6 is fixed to the mouth edge of the input port 2, and the support shaft 7 is fixed to the rear part of the machine frame 1 and a support plate 8 installed laterally inside thereof. .

Located between the support plate 8 and the rear surface of the machine frame 1,
A fan casing 9 partially utilizing these has a centrifugal fan 10 having blades on the front and rear surfaces rotatably supported on a support shaft 7, and the drum support plate An entrance 11 to the drum 5 opened on one side of the bottom of the drum 6
The circulation path 12 leading to the . An outlet 13 communicating with the fan casing 9 is provided on the rear surface of the drum 5 and on the support plate 8, and the outlet 13 is surrounded by a sealing material 14. The cooling side of the rear surface of the fan 10 communicates with the outside of the machine frame 1 via an inlet 3 and an outlet 4. The fan casing 9 and the fan 10 constitute a dehumidifying device that dehumidifies dry air by exchanging heat with outside air.

In the circulation path 12 just before the inlet 11, there is a heater 15 made of a honeycomb ceramic material and having positive temperature resistance characteristics.
A plurality of lint filters are provided in horizontal rows, and a drain port 16 communicating with the outside of the machine frame 1 is provided at the lowest part of the circulation path 12, and a lint filter 17 that covers the outlet 13 is removably provided in the drum 5. The rotational force of a motor 18 is transmitted to the drum 5 and fan 10 via a pulley belt. The input port 2 is opened and closed by rotating the resin door 19 in the left-right direction.

Lint filter 17 and drum outlet 13
A first temperature sensor 20 for detecting the temperature of the dry air before dehumidification is arranged on the support plate 8 on the downstream side of the circulation path 1.
A second temperature detector 21 is disposed upstream of the heater 15 in the circulation path 12 to detect the temperature of the dry air after dehumidification through heat exchange with outside air. Inlet 1 downstream
A third temperature detector 22 for detecting the temperature of the reheated dry air is arranged near the first temperature detector 22 .

As shown in FIG. 2, the drying control means 23 consisting of a general microcomputer includes a temperature sensor 20.
, 21 and 22 are input as the drum outlet temperature K1, heater inlet temperature K2, and heater outlet temperature K3,
A temperature difference T1 is calculated from the two temperatures K1 and K2, and a temperature difference T2 is calculated from the two temperatures K2 and K3. As shown in Figure 4, the ambient temperature is proportional to the heater inlet temperature, so
The heater inlet temperature K2 can be used instead. This drying control means 23 is set with a program for controlling the entire drying work, and several types of upper limit temperatures KM and limit temperature differences TM are set, and these upper limit temperatures KM and limit temperature differences TM are A changing unit 24 is provided that changes (selects) based on a fuzzy rule that receives the difference T2 and the heater inlet temperature K2 (if the ambient temperature is detected by a separate temperature detector, the ambient temperature). ing.

[0015] Thus, when the start key is operated,
The drying control means 23 operates the drum 5 and the fan 10 with the motor 18 and heats it with the heater 15. The drying air inside the drum 5 is passed through a lint filter 17, an outlet 13,
Circulation side of fan 10, circulation path 12, heater 15, inlet 1
The external air (outside air) flows through the inlet 3, the cooling side of the fan 10, and the outlet 4 in this order. Most of the lint produced during the drying operation within the drum 5 is removed by the filter 17. Fan 1 blows out hot and humid dry air.
It exchanges heat with outside air at 0, is cooled and condenses moisture, is then reheated by a heater 15, and continues to be supplied to the drum 5. Condensed water is discharged from the drain port 16.

As shown in FIG. 3, in controlling such drying work, first a time count is started, and when a predetermined value B is reached by 15 de
g, and turn on the heater 15 and motor 18. When the drum outlet temperature K1 from the first temperature sensor 20, the heater inlet temperature K2 from the second temperature sensor 21, and the heater inlet temperature K3 from the third temperature sensor 22 are input, the temperature difference T1, T2 Calculate. During work, the changing section 24 changes and sets the upper limit temperature KM and the limit temperature difference TM at all times based on the following four fuzzy rules.

■When T2 is large and K2 is small, K
Put M and TM inside.

■When T2 is small and K2 is small, K
Increase M and TM.

■When T2 is large and K2 is large, K
Lower M and TM.

■When T2 is small and K2 is large, K
Increase M and TM.

[0021] If the temperature difference T2 is large, the filter
17, if it is small, it indicates normality; if the heater inlet temperature K2 is large, it indicates that the ambient temperature is high, and if it is small, it indicates that it is low. In this embodiment, the clogging and the ambient temperature are comprehensively judged and changed, but the changes can be made in accordance with the clogging and the ambient temperature individually.

Furthermore, during the drying operation, the drying control means 23 compares and determines whether the drum outlet temperature K1 exceeds the upper limit temperature KM, and then determines whether the temperature difference T1 or this exceeds the upper limit temperature KM by 15 deg.
A comparison is made to determine whether the added value of g exceeds the limit temperature difference TM, and priority is given to control based on these. Normally, in general control, for example, the temperature difference T1 in 15 minutes is stored as the reference value A, and a predetermined value B (15 deg) is added to this to make the reference temperature difference (A+B), and thereafter the temperature difference T1 is A comparison is made to determine whether this reference temperature difference (A+B) is exceeded. That is, the drying control means 23 sets both the limit temperature difference TM and the reference temperature difference (A+B) as the control temperature difference.
It is compared with 1.

[0023] If the result of any comparison judgment is that it exceeds the limit, cold air operation (cooler operation) in which only the heater 15 is turned off is performed.
(download) for a predetermined period of time, and then terminates.

In this way, drying is usually controlled depending on whether the temperature difference T1 exceeds the reference temperature difference (A+B), but clogging,
When control is not possible with the reference temperature difference (A+B) due to the ambient temperature, drying can be controlled with the upper limit temperature KM and the limit temperature difference TM.

It should be noted that if the calculation result of the temperature difference T2 is larger than an existing predetermined value, the upper limit temperature KM and the limit temperature difference TM
In addition to changing the filter, it is also desirable to display and warn that the filter is clogged in order to eliminate the cause of overheating.

[0026] When changing the limit temperature difference TM, it is also possible to change the previously set predetermined value B (15 degrees).

In the case of the heater 15 having a positive temperature resistance characteristic, when the filter 17 is clogged and the amount of ventilation decreases, the input current decreases, so this change in current is detected by a current transformer or the like to prevent the clog. You can also look it up.

[0028]

Effects of the Invention According to the present invention, automatic drying control is performed in response to filter clogging and ambient temperature with high accuracy.
It is possible to provide a highly safe clothes dryer that hardly causes overdrying or overheating and prevents thermal deformation of resin products and the like.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a clothes dryer according to the present invention.

FIG. 2 is a control block diagram as well.

FIG. 3 is a flowchart for explaining the operation.

FIG. 4 is a characteristic diagram of heater inlet temperature and ambient temperature.

[Explanation of symbols]

1 Machine frame 5 Drum 9 Fan casing 10 Fan (dehumidifier) 12 Circulation path 13 Exit 15 Heater 17 Lint filter 19 Door 20 First temperature detector 21 Second temperature sensor 22 Third temperature detector 23 Drying control means 24 Modification means

Claims (2)

[Claims] Claim 1: A drying air circulation path is connected to the outlet and inlet of the drum containing clothes, a lint filter is arranged near the outlet, and a honeycomb-shaped heater with positive temperature resistance characteristics is installed on the inlet side. A dehumidifying device for dehumidifying the drying air is placed between the heater and the drum outlet, and first and second temperature detectors are provided to detect the temperature of the drying air before and after dehumidification by the dehumidifying device. The control means controls the drying operation based on a comparison between the difference in drying air temperature before and after dehumidification and the control temperature difference, and when the detected temperature of the drying air by the first temperature sensor reaches a predetermined upper limit temperature. What is claimed is: 1. A clothes dryer that stops heating the drying air, the clothes dryer comprising a changing section that changes the control temperature difference and upper limit temperature depending on the clogging state of the lint filter. 2. A drying air circulation path is connected to the outlet and inlet of the drum containing clothes, a lint filter is arranged near the outlet, and a honeycomb-shaped heater with positive temperature resistance characteristics is installed on the inlet side. A dehumidifying device for dehumidifying the drying air is placed between the heater and the drum outlet, and first and second temperature detectors are provided to detect the temperature of the drying air before and after dehumidification by the dehumidifying device. The control means controls the drying operation based on a comparison between the difference in drying air temperature before and after dehumidification and the control temperature difference, and when the detected temperature of the drying air by the first temperature sensor reaches a predetermined upper limit temperature. What is claimed is: 1. A clothes dryer that stops heating drying air, the clothes dryer comprising a changing section that changes the control temperature difference and upper limit temperature according to ambient temperature.