JPH0211280B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a clothes dryer that detects the degree of dryness of clothes and automatically stops the drying operation. This relates to a device that can perform a suitable automatic stop using an element (humidity sensor) whose resistance changes.

[Background of the invention]

Conventionally, clothes dryers with this type of automatic stop function were controlled by using a temperature sensor to capture the temperature that changes depending on the degree of dryness of the clothes, as described in Japanese Patent Publication No. 56-42320. Ta. However, it is necessary to compensate for the influence of outside temperature, which requires a complicated circuit. In addition, the drum exhaust temperature changes gradually when the drum is finished drying (drying rate is about 90% or more), making it difficult to precisely detect the degree of drying.

Another drying method involves directly touching the clothes being dried to detect how dry they are. Since this method detects the degree of dryness as a change in the electrical resistance of the sensor, it has the disadvantage that the degree of dryness cannot be accurately detected unless the clothes being dried are in reliable contact with the electrodes of the sensor. Also, cotton and synthetic fibers dry completely differently. Synthetic fibers dry quickly, but cotton takes a long time to dry. If cotton and synthetic fibers are dried together, the degree of dryness will vary depending on the fabric that touches the sensor electrode, making it difficult to accurately detect the degree of dryness. Furthermore, since the sensor electrodes are placed in a drum (drying room) that is hot and humid, long-term use can cause an oxide film to form, leading to a decline in the electrode's functionality.

[Purpose of the invention]

The present invention addresses the above-mentioned problems, and its purpose is to be able to precisely detect the degree of dryness of a dry finish, to have little deviation in dryness detection even when cotton and synthetic fibers are used together, and to reduce the temperature of the outside air. To provide a clothes dryer in which dryness detection accuracy does not change even after long-term use and is less affected by dryness.

[Summary of the invention]

The present invention comprises a clothes drying chamber such as a drum, a double-winged fan for heat exchange, a drying circulation air passage, a cooling air passage, and a heater that heats the air flowing through the drying circulation air passage and flowing into the clothes drying chamber. In addition, both wing fans have a fan part for drying air and a fan part for cooling air, and the drying air and cooling air are placed back to back.
In addition, it is configured to prevent mixed flows, with the suction side of the drying air fan part communicating with the exhaust side of the clothes drying chamber, the discharge side communicating with one side of the drying circulation air passage, and the other side of the drying circulation air passage communicating with the clothes drying room. In a clothes dryer in which the suction side and the discharge side of a fan section for cooling air are connected to the air intake side of the cooling air passage, respectively, a humidity sensor is installed to detect humidity and control the operation of the clothes dryer. A clothes dryer characterized in that it is installed between the exhaust side of a clothes drying room and the suction side of a drying air fan.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 9. FIG. 1 is a diagram showing the configuration of a clothes dryer, and FIG. 2 is a partially detailed diagram. To explain the structure, 1 is an outer frame, 19 is a back cover, and 22 is a door for putting in clothes. The drum 2 of the clothes drying room is rotatably supported in the frame formed by these.
is rotated by a driving motor 14 and a drum belt 15. 16 is a pulley located on the opposite side of the drum belt 15 of the motor 14;
A fan belt 17 is attached. The fan belt 17 is hung around a fan pulley 7a formed around the shaft, and drives a double-winged fan 7 for heat exchange. 2
0 is the shaft support. Reference numeral 8 denotes a fan casing for the double-wing fan 7, which guides air from an air passage hole 26 on the back side of the drum 2 (on the opposite side of the door 22) and communicates with the central duct 6 on the bottom surface of the drum. Further, the fan casing 8 has a partition plate 12 as a partition wall, and a ring 21 and a felt receiver 13 and a felt 9 provided on the outer periphery of the wing fan 7.
The structure is designed to keep the area substantially airtight. 11 is a drum airtight felt located between the drum 12 and the fan casing 8. 18 is a heater side duct, 3 is a heater serving as a heat source, 23 is an operator, 2
4 is clothing, 25 is an outside air introduction hole, 10 is a humidity sensor, 101 is an opening on the windward side through which air passes;
102 is a mounting foot, and 103 is a lead wire for signal transmission.

Here, the configuration of the air passage including the double-blade fan 7 for heat exchange will be explained in detail.

The double-winged fan 7 is a centrifugal double-sided fan with corrugations running radially. The part facing the drum 2 side is a dry air fan part, and the part facing the back cover 19 side is a cooling air fan part. The dry air fan section and the cooling air fan section are partitioned to prevent air from coming and going. Since the dry air fan section and the cooling air fan section are separated by a single wall, heat exchange is performed via this wall.

The outer periphery of the double-winged fan 7 forms a boundary between the dry air fan section and the cooling air fan section.
This boundary portion is formed by a felt receiver 13. The felt section 9, which has a V-shaped cross section and is supported by the felt receiver 13, has a sealing function that prevents air from flowing into the dry air fan section and the cooling air fan section from mixing.

Fan casing 8 in which both wing fans 7 are placed
has two casing chambers in which the dry air fan section and the cooling air fan section are located. A partition plate 12 that partitions the two casing chambers is provided on the inner peripheral surface of the fan casing 8 and serves as a partition wall. A ring 21 is attached to the inner peripheral end of the partition plate 12 and is placed so as to surround the outer periphery of both wing fans 7.

Since this ring 21 is placed so that it can slide airtightly on the outer periphery of the felt portion 9, the rotation of the double-winged fan 7 causes the dry air fan portion and the cooling air fan portion to move toward the outer periphery. This prevents the flowing air from mixing.

The suction port of the dry air fan is located near the center of the casing chamber of the dry air fan. Passing hole 26
The exhaust gas exhausted from the drum 2 flows through the suction port into the casing chamber of the dry air fan, and is blown toward the outer circumference by the fan's centrifugal force while exchanging heat with the double-winged fan 7. It is.
Since the humidity sensor 10 is provided at the suction port, it is possible to detect the humidity of the exhaust air before the heat is exchanged between the two-wing fans 7. The drying circulating air flow flowing from the drum 2 to the drying air fan section is indicated by a solid line a.

The casing chamber of the cooling air fan section is located on the back cover 1.
9 is partly responsible for this. Due to the suction action of the cooling air fan section, outside air passes through the intake port of the back cover 19, is directed toward the center of the cooling air fan section, and is blown toward the outer circumference by the centrifugal force of the fan while exchanging heat. Then, the air is exhausted from the exhaust port of the back cover 19. The cooling air path of the cooling air flowing into the cooling air fan section follows the flow of cooling air shown by arrow b.

In the double-wing fan 7, the exhaust air from the drum 2 is taken to the dry air fan part, and the cooling air from the outside is taken to the cooling air fan part, so that the hot and humid exhaust air is cooled by the dry air fan part. Moisture in the exhaust gas is removed as condensed water.

Condensed water is generated by the centrifugal force of the dry air fan.
It is blown away by the outer circumferential inner surface of the casing chamber and flows downward along the inner surface of the casing chamber. and the central duct 6 from the dry air outlet of the casing chamber.
It is discharged. The central duct, which forms part of the dry air circulation channel, has a drain outlet through which condensed water is drained to the outside. In addition, the dry air outlet of the casing chamber is connected to one side of the central duct 6, which serves as a dry air circulation path, so that the exhausted air discharged from the casing chamber, from which moisture has been removed, passes through the central duct 6 and is heated to the heater. It flows into the side duct 18. Then, it is heated again by the heater 3 and flows into the drum 2. In this way, the drying air circulates while drying the clothes in the drum 2.

To explain the operation based on these schematic configurations, the drum 2 and the double-winged fan 7 are driven by the motor 14. Drum 2 holds clothes 2 which are items to be dried.
The fan 7 on both sides pulls the air inside the drum 2 with the fan on the side of the drum 2, and while rectifying it on the way, it passes through the central duct 6 and the heater duct 18, and also passes through the heater 3, where it is heated. The heated air passes through the clothing 24, separates moisture, becomes humid, and returns to the passage hole 4. Further, the fan on the back cover 19 side pulls outside air through the outside air introduction hole 25, and the outside air is discharged from the upper part to the outside air again. The hot and humid air exhausted from the drum 2 is cooled in the outside air and taken out as condensed water. Water droplets as condensed water are collected in the central duct 6. In this way, both wing fans function as heat exchangers. The sensor 10 is located at a location before it is introduced into the passage hole 4 of the drum 2 and the fan 7, that is, the bell of the fan casing 8, to be exposed to humid and relatively high temperature air before compression. It is located at the mouse 5 (suction port). The dotted line labeled F is a filter. This filter captures dust such as lint and sand from clothing, and ideally the sensor should immediately capture the air that has passed through this filter. This is because the closer you get to the wing fans, the lower the air temperature is, and the more air is exchanged with air that is compressed and lowered in humidity, making it impossible to accurately measure the humidity from clothing. It is.

Next, the sensor 10 alone will be explained in detail. Third
The figure shows the sensor 10 alone, FIG. 4 is a perspective view of the sensor case, and FIGS. 5 to 7 are explanatory diagrams of the humidity sensing element alone. Accordingly, the sensor 10 is housed in the sensor case 100, and the sensor case 100 formed on the left and right sides at the hinge part 103 is box-shaped with an opening 101, and is opposed to this box-shaped shape. The lid 104 is the sensor case 1
It has a shallow box shape similar to 00. Hinge part 10
3 as a fulcrum and are engaged with the engagement pawl 112 and the engagement hole 108, thereby creating a box-shaped space. The humidity sensing element 101 is positioned in this space, and the lead storage groove 109 holds the signal transmission leads 302 and 303 pulled out from the humidity sensing element 101, and the lead holding projections 111 hold the leads 302 and 303. Along with the lead wire 5
A round terminal housing groove 109 for storing a round terminal 40 for electrical connection with the round terminal 40, a round terminal relief 114, and a caulked lead wire 50 are pulled out through the groove of the bent portion 110 and the lead wire guiding groove 115. Since the sensor 107 is used in humid conditions, it will malfunction if there is a leak between the terminals due to condensation or the like. The leak prevention protrusion 113 provided to prevent this danger is a corresponding protrusion engagement groove that ensures a distance between the terminals. 106 is a lead wire holder.

As described above, the moisture sensing element 30 has the lead 30
2, 303 are held by the lead storage groove 109 and the lead pressing protrusion 111 (these are overlapped with the hinge part 103 as a fulcrum and are locked by the engagement pawl 112 and the engagement hole 108). Both end surfaces of the round terminal 40 are protected against the pulling force or pushing force that may be applied to the wire in the round terminal storage part 105.
The lead 302,
303 and the humidity sensing element 30 in any way.

To explain the moisture sensing element 30 in detail, the substrate 309
Lead 302 is made of conductive material on one side of (ceramics),
There are a comb-shaped electrode A 306 and an electrode B 305 that are pulled out to 303 and form a moisture sensitive surface. lead 3
02, 303, electrode A 306, and electrode B 305 are connected by solder 307. Between the facing comb-shaped electrodes, a moisture sensitive agent 308 (polymer electrolyte) made of an organic polymer and whose conductivity changes according to changes in humidity is applied, and the moisture sensitive agent 308 (polymer electrolyte) is coated to prevent the moisture sensitive agent from flowing out.
A protective film 310 is coated to prevent dust from the outside, particularly conductive substances such as bases, from adhering and causing desired characteristic changes. However, this protective film must not be airtight because it is a sensor that is sensitive to the humidity of the outside air. It is a material with good permeability to water molecules. Silicone etc. are used, but they tend to crack or peel due to external forces, so for this purpose,
This means that it needs to be positioned in the box-shaped space of the sensor case 10 without touching the inner wall.

Furthermore, the moisture sensitive surface 310 is positioned with its opposite surface facing the opening 101. This has a filter that traps dust, but not all of it, allowing fine dust, especially sand, to pass through. If the filter is not of this quality, the drying efficiency will deteriorate significantly. This is because where the sensor 10 is located, air passes through the sensor at a high speed, and dust should not damage the protective film and shorten its lifespan.

In addition to sensors that consist of an organic polymer moisture-sensing agent and a protective film, there are also sensors that use ceramics, which obtain moisture-sensing properties by coating ceramic material on a comb-shaped electrode and then firing it. . A protective film such as silicone cannot be formed on this material. This is because ceramics after firing originally have a porous structure, and the degree of conductivity changes due to the adsorption of water molecules, which closes off the porous structure. Furthermore, even though it is made of ceramics, it is very weak against external forces, and its porous structure can be destroyed and its characteristics can easily deteriorate. be.

When looking at the humidity sensing element 30 from an electrical circuit perspective, as shown in FIG.
will have leads 302 and 303. The change in resistance value with respect to humidity change is shown in Figure 8.
As the humidity moves from low humidity to high humidity, the resistance value decreases approximately proportionally.

To explain these characteristics as a clothes dryer, see Figures 9 and 10. In the electric circuit shown in the block diagram, the power supply is branched into a power supply circuit with a transformer and rectifier. It is also connected to the motor and heater. Processing circuits such as microcomputers receive their driving source from the power supply circuit, and
The circuits for various signal inputs are on the right side. One has a humidity sensor at its tip, and enters the processing circuit via a detection circuit that converts and detects changes in electrical resistance, and a comparison circuit. The selection circuit is an input signal that allows the user to arbitrarily select the degree of dryness.For example, if you want to iron the product while leaving it damp, use the "Iron Cycle", for general drying, use the "Standard Cycle", or use the "Standard Cycle" for general drying. If you want to dry it, enter "careful cycle" etc. The display circuit is a circuit that performs these displays as well as displays such as whether the power is turned on or off.

Therefore, the motor and heater are driven by the input in the selection circuit, and the operation is started. In response to a signal input from the humidity sensor during operation, the processing circuit opens the drive circuit and automatically stops the operation. Figure 10 shows the resistance value change of the humidity sensor during operation depending on the sensor shape and mounting position of the present invention. For example,
A is for a small amount, B is for a medium amount, and C is for a rated capacity as indicated. Products such as clothes dryers generally experience these fluctuations in load, and if all of these fluctuations cannot be covered, the original automatic stop function will lose half its meaning. In the curve A, there are not many clothes, so the air heated by the heater 3 passes through the clothes and goes through the filters to the fans 7 on both sides without touching the clothes, so the humidity does not decrease much. Since it dries quickly, the resistance value increases quickly, and the degree of increase in resistance value near the completion of drying is very large. In the case of the rated capacity, the resistance value starts to decrease as soon as the operation starts, and the resistance value continues to decrease after a certain period of time, as shown in the curve shown in C. As the clothes dry, the resistance value begins to rise, becoming more gradual than curve A, but the degree of rise is more than sufficient for signal input to a comparison circuit or the like. B is drawing between A and C.

Now, when applying the above-mentioned "Iron Cycle" Standard Cycle and "Careful Cycle", the resistance value R is ₁ and it is determined as an "Iron Cycle". this is,
This is the resistance value when moderate moisture remains,
It is about to start rising rapidly. "Iron cycle"
If you select (b), the system will automatically stop at (a).
R ₂ was set as the "standard cycle". This is done near the middle of the ascent, and the automatic stop occurs at (b). The "careful cycle" is set to R ₃ , the resistance value in a sufficiently dry state, and stops at (c).

FIGS. 11 and 12 show an example of conventional automatic stopping means, which is performed by a humidity sensor 60. The first one shows the degree of temperature change.
In Figure 2, it rises at the start of operation, almost no change is observed during the process, and near the completion of drying, it rises significantly, similar to the change in resistance value of the humidity sensor mentioned above, and after complete drying, it continues to rise and remains almost constant. It becomes a constant curve. R ₁ in the resistance curve of the humidity sensor in Figure 10
_T1 to _T3 correspond to ~ _R3 .

The desired point on the curve as a control signal is the point where it starts to rise, and if we compare the humidity and temperature curves, the temperature curve is more gradual and difficult to grasp. In particular, there is little difference between T ₂ and T ₃ , making it difficult to distinguish. Furthermore, since it is necessary to have another means to eliminate the influence of ambient temperature, the signal is extracted based on the temperature, but after inputting the signal, there is a
The current situation is that we are driving with a margin of 20%.

The present invention solves the above-mentioned problems and provides an automatic stop function that eliminates unnecessary operation.

The moisture sensing element 30 will be explained in more detail.

Electrodes A306 and B305 are printed and provided on a substrate 309, and a moisture sensitive agent 308 is applied so as to fill the space between the electrodes A and B. The moisture sensitive agent 308 is then dried, and silicone is applied over it. After this, aging is performed in an atmosphere of high temperature and high humidity to stabilize the performance for a long time.

This humidity sensing element 30 is used at high temperatures. Therefore, changes in electrical resistance with respect to changes in humidity have good responsiveness and little systeresis, so changes in humidity in exhaust air can be detected quickly and accurately. Suitable for controlling the operation of clothes dryers.

〔Effect of the invention〕

As described above, the present invention provides a clothes drying chamber such as a drum, a double-blade fan for heat exchange, a drying circulation air path, a cooling air path, and a drying circulation air path that flows into the clothes drying room. The double-wing fan has a fan part for drying air and a fan part for cooling air, and is configured so that drying air and cooling air are placed back to back and do not mix. The suction side of the fan section is connected to the exhaust side of the clothes drying room, the discharge side is connected to one side of the drying circulation air path, and the other side of the drying circulation air path is connected to the intake side of the clothes drying room, and the cooling air In a clothes dryer in which the suction side and the discharge side of the fan are connected to cooling air passages, a humidity sensor that detects humidity and controls the operation of the clothes dryer is connected to the exhaust side of the clothes drying room and the dry air fan. It is characterized by being installed between the suction side of the

According to this configuration, the following advantages can be obtained.

(1) Between the exhaust side of the clothes drying room and the suction side of the drying air fan, the humidity of the exhaust air exhausted from the clothes drying room changes rapidly when the drying period comes. This rapidly changing humidity is detected by a humidity sensor and the drying timing is controlled, thereby ensuring accurate drying without changing the degree of drying.

(2) It is not a good idea to place the humidity sensor on the discharge side of the dry air fan. On the discharge side, the condensed water is removed and the humidity changes at this point during the drying stage are different from those on the suction side of the dry air fan section. There is almost no change in humidity until the clothes are completely dry. This shows a rapid drop in humidity after complete drying. Therefore, it is not possible to control the operation to achieve a desired degree of dryness. In addition, droplets of condensed water ride on the exhaust air and are discharged near the discharge port. These water droplets touch the humidity sensor and prevent accurate detection.

Due to these circumstances, it is necessary to provide a humidity sensor on the suction side of the dry air fan section in order to control the finishing operation to achieve the desired degree of drying.

(3) Since it detects humidity changes, it is not affected by outside temperature, and there is no difference in the degree of dryness even in summer and winter, where there is a large temperature difference.

(4) For devices that detect the degree of dryness by directly touching the clothes being dried, if fabrics such as cotton or synthetic fibers are dried together, the detected value will frequently change randomly, making it difficult to determine the degree of dryness at the end of drying. Hateful. Since the present invention detects the humidity of the exhaust gas, there is no random change in the detected value, and the degree of dryness at the end of drying can be accurately detected.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing the configuration of a clothes dryer;
The figure is an enlarged view of the main parts of Figure 1, Figure 3 is a detailed cross-sectional view of the sensor alone, Figure 4 is an open perspective view of the sensor case, Figure 5 is a perspective view of the moisture sensing element alone, and Figure 6 is Fig. 5 is an enlarged sectional view, Fig. 7 is a diagram replaced with an electric circuit, Fig. 8 is a diagram showing changes in resistance value with respect to changes in relative humidity, Fig. 9 is a block diagram explaining the control of a clothes dryer, Fig. 10 is a diagram showing a change curve of resistance value when a clothes dryer is operated, Fig. 11 is a cross-sectional view similar to Fig. 1 using a temperature sensor which is an example of a conventional example, and Fig. 12 is a diagram showing a change curve of resistance value when a clothes dryer is operated. It is a figure which shows the change of temperature corresponding to a figure. 2...Drum, 7...Double wing fan, 10...Sensor, 30...Moisture sensing element, 100...Sensor case,
310...Protective film.

Claims (1)

[Scope of Claims] 1. A clothes drying chamber such as a drum, a double-wing fan for heat exchange, a drying circulation air passage, a cooling air passage, and heating the air flowing through the drying circulation air passage and flowing into the clothes drying room. The double-wing fan has a fan section for drying air and a fan section for cooling air, and is configured so that the drying air and cooling air are placed back to back and do not mix. The suction side of the cooling air fan section is connected to the exhaust side of the clothes drying room, the discharge side is connected to one side of the drying circulation air path, and the other side of the drying circulation air path is connected to the intake side of the clothes drying room. In a clothes dryer in which the suction side and the discharge side are connected to cooling air passages, a humidity sensor that detects humidity and controls the operation of the clothes dryer is installed on the exhaust side of the clothes drying room and the suction side of the dry air fan. A clothes dryer characterized by being installed between the sides. 2. A clothes dryer according to claim 1, characterized in that a centrifugal fan is used as the double-blade fan for heat exchange. 3 In what is stated in claim 1,
A fan casing is provided in which a double-winged fan for heat exchange is placed, and a partition wall is provided inside the fan casing to separate drying air and cooling air so that they do not mix. A clothes dryer characterized in that a boundary part between a drying air fan part and a cooling air fan part is provided on the outer periphery of the clothes dryer, and a sealing means is interposed between this boundary part and a partition wall. 4 In what is stated in claim 3,
A clothes dryer characterized in that a sealing means is provided between the outer periphery of the boundary and the inner periphery of the partition wall. 5 In what is stated in claim 1,
The drying operation can be controlled in multiple drying states based on the detected value of the humidity sensor, such as a half-dry state when ironing, a dry state after careful drying, and a standard dry state between half-dry and dry. A clothes dryer characterized by: 6 In what is stated in claim 1,
1. A clothes dryer comprising a processing circuit such as a microcomputer that receives a detected value from a humidity sensor, and drying state selection means for receiving a drying state selection instruction signal to the processing circuit.