JP2008073089A - Clothes dryer - Google Patents

Abstract

A water level sensor that dries clothing using a heat pump, detects clogging of a dew filter that filters dew falling from the evaporator of the heat pump, and that detects the water level of a dew tank. The air blower for drying clothes can be used.
A dew that is generated and dropped by an evaporator 15 of a heat pump is filtered by a dew filter 24 and stored in a dew tank 22, and the stored water level is determined by the self-heating water level sensor 25 using air and water. In this case, a part of the air passing through the ventilation path 14 is supplied to the detention tank 22 through the dew filter 24, so that the dew filter 24 is not clogged. The water level sensor 25 detects the difference in heat diffusion with respect to the air at the time of clogging and the air at the time of clogging.
[Selection] Figure 1

Description

  The present invention relates to a clothes dryer for drying clothes using a heat pump.

2. Description of the Related Art Conventionally, clothes dryers that use a heat pump to dry clothes are known (see, for example, Patent Document 1). This product is designed to dry clothes by circulating the air in the drying room with a blower through an air passage provided with an evaporator and a condenser connected to the compressor of the heat pump. Moisture to be recovered is recovered by an evaporator, and the latent heat recovered in the fold is converted into a high-temperature refrigerant state by a compressor and reused as energy for heating air by a condenser. By doing so, it can be reused without losing almost any energy except for a slight heat loss outside, and thus efficient drying can be realized.
JP 2003-265879 A

  In the case of drying clothes using the above-described heat pump, specifically, the evaporator condenses and removes water that is emitted from the clothes such as laundry after washing and cools moisture contained in the air. In the process, dew is generated on the surface of the evaporator. The dew generated on the surface of the evaporator flows and drops on the surface of the evaporator, is received and stored in the dew tank, and is discharged from the dew tank by a drain pump or the like. Yes.

  In addition, an air filter is provided in the ventilation path for circulating the air in the drying chamber at a portion above the evaporator, and the air filter removes lint that is scattered from the clothing and carried to the circulating air. It is designed to capture the first foreign object. Therefore, the size of the foreign matter captured by the air filter is determined by the size of the air filter, and the smaller the size, the smaller lint can be captured. However, if the eyes of the air filter are made too small, the passage of air in the ventilation path is deteriorated, and consequently the drying performance of the clothes is deteriorated. For this reason, the eyes of the air filter are kept to an appropriate size, and extremely small foreign matters cannot be captured.

Therefore, the extremely small foreign matter passes through the air filter and reaches the dew tank along with water dripped from the evaporator. The foreign matter that has reached the dew tank is drained by a drain pump that drains the dew tank. The functional part may become clogged and drainage abnormalities may occur. For this reason, a dew filter having a smaller mesh size than the air filter is provided in a portion where dew of the dew tank is placed, and foreign substances that have passed through the air filter are captured by the dew filter.
However, if the foreign matter is continuously captured by the dew filter, the dew filter will eventually become clogged, so that the dew dropped from the evaporator cannot pass through the dew filter and flows down to the periphery.

  The present invention has been made in view of the above-mentioned circumstances, and therefore the object thereof is to detect clogging of a dew filter, and it can detect the water level of a dew tank, and to dry clothes. It is in providing the clothes dryer which can be utilized using the air blower which ventilates.

In order to achieve the above object, in the clothes dryer of the present invention, the clothes are dried by circulating the air in the drying chamber through an air blower provided with an evaporator and a condenser of a heat pump by a blower. The dew generated and dripped by the evaporator is filtered through a dew filter and stored in a dew tank, and the water level of the dew tank is determined by the self-heating type water level sensor provided in the dew tank. In what is detected by the difference in thermal diffusion with water,
By supplying a part of the air passing through the ventilation path to the detention tank through the dew filter, the dew filter is clogged with respect to the air at the time of non-clogging and the air at the time of clogging. Detection is based on a difference in thermal diffusion (invention of claim 1).

  According to the above means, the clogging of the dew filter can be detected using the water level sensor for detecting the water level of the dew tank and the blower for ventilating the clothes.

Hereinafter, the present invention is applied to a washing and drying machine, and one example (one embodiment) thereof will be described with reference to the drawings.
First, FIG. 1 schematically shows the overall configuration of a washing / drying machine. An outer box 3 having a laundry doorway 2 opened and closed by a door 1 on the front surface (left side in the figure) is used as an outer shell. In addition, the water tank 4 is arranged in the shape of a horizontal axis and in an upwardly inclined manner. Inside the water tank 4, a drum 5 is disposed in parallel and concentrically with the water tank 4, and a motor 7 that rotates the drum 5 with a rotating shaft 6 is attached to the back of the water tank 4. The drum 5 has a porous shape (only a part of the holes are illustrated), and the inside 5a functions as a laundry room, functions as a dehydration room, and functions as a drying room.

  A ventilation case 8 is disposed below the water tank 4, and the front part of the ventilation case 8 is connected to an exhaust port 10 formed in the upper part of the front wall part of the water tank 4 via a suction side duct 9. Yes. On the other hand, the rear part of the ventilation case 8 is connected to the air supply port 13 formed in the upper part of the back wall part of the water tank 4 via the casing 11a and the discharge side duct 12 of the blower 11, and these suction side ducts 9, The ventilation case 14, the casing 11 a of the blower 11, and the discharge-side duct 12 constitute a ventilation path 14 through which the air in the water tank 4 and thus the air in the interior 5 a of the drum 5 pass.

  Thus, the evaporator 15 is disposed at the front and the condenser 16 is disposed at the rear in the ventilation path 14, particularly inside the ventilation case 8. As shown in FIG. 2, the evaporator 15 and the condenser 16 compose a heat pump 19 with a compressor 17 and a throttle valve (in particular, an electronic throttle valve in this case) 18 as a throttle. In this heat pump 19, a compressor 17-condenser 16-throttle valve 18-evaporator 15-compressor 17 are connected in this order by a connecting pipe 20, thereby constituting a refrigeration cycle. A refrigerant (not shown) is enclosed in the cycle. Although not shown in FIG. 1, the compressor 17 and the throttle valve 18 are disposed outside the ventilation case 8 (inside the outer box 3).

  Further, an air filter 21 is interposed in the ventilation path 14 at a position directly above the front portion of the ventilation case 8, particularly the windward portion of the evaporator 15. The air filter 21 is, for example, a mesh-like one having eyes that can capture foreign matter (excluding extremely small items) such as lint that scatters from the laundry (clothing). 3 is detachably mounted so that it can be pulled out from the front.

  Further, a dew tank 22 is disposed in the ventilation path 14 from the lower side to the side of the partial zone where the evaporator 15 of the ventilation case 8 is disposed. As shown in FIGS. 3 and 4, the dew tank 22 is composed of a relatively flat rectangular parallelepiped container, and has an opening 23 in the upper part of one side (left side) of the lower side in FIG. A dew filter 24 is disposed above. The dew filter 24 is, for example, a mesh-shaped filter body 24a located immediately above the opening 23 having an eye that can capture very small foreign matter that cannot be captured by the air filter 21. Similarly to the air filter 21, it is detachably mounted so that it can be pulled out from the front of the outer box 3.

  A water level sensor 25 is attached to the middle of the one side of the dew tank 22 from above the ventilation case 8 inward. In this case, the water level sensor 25 is composed of a thermistor having a negative characteristic, and the lowermost part located in the detected water level portion in the dew tank 22 is a detection unit 25a.

  Further, a drain pipe 26 is attached to a portion of the dew tank 22 opposite to the opening 23 on the one side (right side), and the dew tank between the drain pipe 26 and the water level sensor 25 is installed. A partition wall 27 is provided in the interior 22. The partition wall 27 isolates the drain pipe 26 side and the water level sensor 25 side in the dew tank 22 from each other, but is separated from the other side (upper side in FIG. 3) of the dew tank 22. (The drain pipe 26 side in the dew tank 22 and the water level sensor 25 side are communicated).

  As shown in FIGS. 5 and 6, a drainage pump 28 is connected to the drainage pipe 26 outside the dew tank 22. In addition, a base end portion of a dew pipe 29 is connected to a lowermost portion of the side wall of the dew filter 24 where the evaporator 15 of the ventilation case 8 is disposed. It faces the filter body 24a of the dew filter 24, and further faces the opening 23 of the dew tank 22 through the filter body 24a.

  Here, the blower 11 has a blower blade 11b (see FIG. 1) disposed in the casing 11a, and the blower blade 11b is rotationally driven by a motor 11c disposed outside the casing 11a. There, the base end portion of the communication pipe 30 is connected to the casing 11a, and the tip end portion of the communication pipe 30 is connected to an intermediate portion near the base end portion of the exhaust pipe 29.

  FIG. 7 shows a water level detection circuit mainly composed of the water level sensor 25. In this water level detection circuit, the water level sensor 25 is connected in series with a load resistor 31 between, for example, a 12 [V] power source and the ground, and a voltage Vout obtained by voltage division with the load resistor 31 is converted into an impedance. The conversion circuit 32 converts the detection voltage signal Vth into a detection voltage signal Vth (for example, 0 to 3 [V]) and inputs it to the microcomputer 33. The microcomputer 33 functions as control means for controlling the overall operation of the washing / drying machine, as well as making judgments and controlling as described later based on the input.

Next, the operation of the above configuration will be described.
When a standard driving course is selected, the microcomputer 33 first starts a washing (washing and rinsing) operation. In this washing operation, an operation of supplying water into the aquarium 4 is performed, and then the drum 5 is alternately rotated by the motor 7 in both forward and reverse directions at a low speed. The laundry accommodated in the drum 5 is washed by being beaten thereby.

  When the washing operation is completed, the dehydration operation is then started. In this dehydration operation, after the water in the water tank 4 is discharged, the operation of rotating the drum 5 in one direction at a high speed by the motor 7 is performed. Thereby, the laundry in the drum 5 is centrifugally dehydrated.

  When the dehydration operation is completed, the drying operation is started next. In this drying operation, the blower 11 is operated while rotating the drum 5 in the forward and reverse directions at a low speed by the motor 7. The operation of the blower 11 is to rotationally drive the blower blades 11b with a motor 11c, and the air in the drum 5 is blown from the exhaust port 10 of the water tank 4 by the air blowing action, thereby the suction side duct 9, the ventilation case 8, Through the discharge side duct 12, that is, through the ventilation path 14, circulation is performed so as to be returned from the air supply port 13 of the water tank 4 into the drum 5.

  At this time, the compressor 17 is operated by the heat pump 19 so that the refrigerant is compressed into a high-temperature and high-pressure refrigerant (gas), and the high-temperature and high-pressure refrigerant flows into the condenser 16, Exchange heat with air. As a result, the air in the ventilation case 8 is heated, and conversely, the temperature of the refrigerant is lowered and liquefied. The liquefied refrigerant then passes through the throttle valve 18 and is depressurized, and then flows into the evaporator 15 and vaporizes. Thereby, the evaporator 15 cools the air in the ventilation case 8. Then, the refrigerant that has passed through the evaporator 15 returns to the compressor 17.

As a result, the air flowing from the drum 5 into the ventilation case 8 through the suction duct 9 is cooled by the evaporator 15 and dehumidified, and then heated by the condenser 16 to be warmed. Then, the warm air is supplied into the drum 5 through the discharge side duct 12.
The warm air supplied into the drum 5 deprives the laundry of moisture and then flows into the ventilation case 8 through the suction side duct 9.
Thus, air circulates between the ventilation case 8 in which the evaporator 15 and the condenser 16 are disposed and the drum 5 so that the laundry in the drum 5 is dried. Accordingly, at this time, the interior 5a of the drum 5 functions as a drying chamber.

  Now, during this drying operation, foreign matter such as lint scattered from the laundry in the drum 5 is carried to the circulating air, and the circulating air passes through the air filter 21 on the wind of the evaporator 15. A large amount is captured by the air filter 21 by being filtered.

  Further, in the evaporator 15, the air passing through the ventilation case 8 contacts the surface of the evaporator 15 and is cooled and dehumidified. As a result, dew condensation occurs on the surface of the evaporator 15, and the dew is evaporated. It flows on the surface of the vessel 15 and drops. The dew dropped from the evaporator 15 passes through the dew pipe 29 and further passes through the dew filter 24 and falls into the dew tank 22 from the opening 23 of the dew tank 22 and is stored. At this time, the foreign matter that has passed through the air filter 21 flows into the dew that passes through the dew tube 29, and is filtered by the dew filter 24 when the dew is filtered through the dew filter 24. .

  The dew that has fallen and stored in the dew tank 22 gradually raises the water level throughout the dew tank 22. On the other hand, during this drying operation, the drainage pump 28 is operated at predetermined time intervals at predetermined time intervals (for example, every 40 minutes). Thereby, the dew stored in the dew tank 22 is sucked up through the drain pipe 26 and discharged to a predetermined drainage part (for example, a drain outlet of a house).

  As described above, the dew stored in the dew tank 22 is discharged by the drain pump 28 at predetermined time intervals. However, when there is a large amount of dew generated and dripped in the evaporator 15, the drain pump 28 Before reaching the time at which the operation is started, the water level in the dew tank 22 may reach the height at which the detection unit 25a of the water level sensor 25 is located. In such a case, water (dew) comes into contact with the detection unit 25 a of the water level sensor 25 in the dew tank 22.

  The water level sensor 25 is a self-heating type that continues to generate heat during energization, and when water comes into contact with the detection unit 25a of the water level sensor 25 that has generated heat, heat in a state where air has been in contact with the water level sensor 25 is used. A change appears in the voltage Vout obtained by the partial pressure with the load resistor 31 due to the difference (difference) in thermal diffusion due to the contact of water with respect to the diffusion.

  Specifically, the thermal diffusion of the water level sensor 25 is larger due to the contact of water than in the situation where the air is in contact with the detection unit 25a, and thereby the water level sensor 25 (negative characteristic thermistor). As the temperature decreases and the resistance value increases, the voltage Vout obtained by voltage division with the load resistor 31 decreases, and the detection voltage signal Vth converted by the impedance conversion circuit 32 and input to the microcomputer 33 also decreases. .

  FIG. 8 is a graph showing the difference in the divided voltage Vout between the situation in which air is in contact with the detection unit 25a of the water level sensor 25 (in the air) and the situation in which water is in contact (underwater). In the atmosphere of the normal use environment temperature of 0 to 40 [° C.], the latter (the divided voltage Vout in a state where the air contacts the detection unit 25a of the water level sensor 25) is used, and the latter (the detection unit 25a of the water level sensor 25). It can be seen that the divided voltage Vout in the situation where water is in contact with the water is small.

  The microcomputer 33 has a threshold value programmed in the middle of the above two. Therefore, when water comes into contact with the detection unit 25a of the water level sensor 25 and the divided voltage Vout becomes lower than the threshold value, It is determined that the water level in the dew tank 22 has reached the height at which the detection unit 25a of the water level sensor 25 is positioned, and the drain pump 28 is operated without waiting for the set operation time of the drain pump 28 to dew tank 22 Drain the water inside.

  FIG. 9 shows the operation of the drain pump 28 at a predetermined time interval and the operation when it is determined that the water level in the dew tank 22 has reached the height at which the detection unit 25a of the water level sensor 25 is located. This is shown over time, and when the drainage pump 28 is operated at predetermined time intervals T, when it is determined that the water level in the dew tank 22 has reached the height at which the detection unit 25a of the water level sensor 25 is located (time) In t), it can be seen that the drain pump 28 is operated without waiting for the set operation time of the drain pump 28.

  It should be noted that the dew sucked up through the drain pipe 26 by the drain pump 28 is returned to the drain pump 28 by the stop of the drain pump 28, and water splashes occur in the dew tank 22. On the other hand, there is a partition wall 27 in the dew tank 22 so that the splashed water does not contact the detection unit 25a of the water level sensor 25 and cause the water level sensor 25 to malfunction.

On the other hand, during such a drying operation, a part of the air passing through the ventilation path 14 enters the exhaust pipe 29 from the casing 11a of the blower 11 through the communication pipe 30 and the dew filter along with the dew passing through the exhaust pipe 29. It flows into dew tank 22 through 24. For this reason, when the water in the dew tank 22 is not in contact with the detection unit 25a of the water level sensor 25 located in the dew tank 22, the air flowing into the dew tank 22 contacts as wind. To do.
In this way, if the wind comes into contact with the detection unit 25a of the water level sensor 25, the divided voltage is derived from the difference in thermal diffusion caused by the contact of the wind with respect to the thermal diffusion in the situation where the static air has been in contact so far. A change appears in Vout.

  Specifically, the thermal diffusion of the water level sensor 25 is greater when the wind is in contact with the detection unit 25a than when the static air is in contact with the detection unit 25a, thereby lowering the temperature of the water level sensor 25. As the resistance value increases, the voltage Vout obtained by voltage division with the load resistor 31 decreases, and the detection voltage signal Vth converted by the impedance conversion circuit 32 and input to the microcomputer 33 also decreases.

  FIG. 10 is a graph showing the difference in detection voltage signal Vth between a situation where still air is in contact with the detection unit 25a of the water level sensor 25 (blower stop situation) and a situation where the wind is in contact (blower operating situation). From the former (detection voltage signal Vth when static air is in contact with the detection unit 25a of the water level sensor 25), the latter (detection voltage signal Vth when the wind is in contact with the detection unit 25a of the water level sensor 25) is I understand that it is small.

  For this reason, as shown in the previous FIG. 9, at the beginning of the drying operation, the divided voltage Vout is lowered due to the start of the operation of the blower 11. In this situation, the dew tank 22 is depleted by the water level sensor 25. The water level is detected (at the end of the drying operation, the divided voltage Vout is raised and restored due to the suspension of the blower 11).

  The air that has flowed into the dew tank 22 flows into the dew tank 22 through the dew filter 24 as described above. The dew filter 24 captures foreign matter that has passed through the air filter 21, and the amount of foreign matter that is captured increases over a long period of time, resulting in clogging. When the dew filter 24 is clogged, the amount of air flowing into the dew tank 22 through the dew filter 24 is reduced, and the amount of wind coming into contact with the detection unit 25a of the water level sensor 25 is reduced.

  Then, the thermal diffusion of the water level sensor 25 decreases, the temperature of the water level sensor 25 rises and the resistance value decreases, so that the divided voltage Vout increases and the detection voltage signal Vth also increases. For this reason, the difference with respect to the detection voltage signal Vth due to thermal diffusion in the situation where the still air is in contact is smaller than that due to thermal diffusion in the situation where the dew filter 24 is not clogged (when not clogged). Become.

FIG. 10 also shows the difference, in the situation where the dew filter 24 is not clogged (no clogging) with respect to the detection voltage signal Vth due to thermal diffusion in the situation where the previous still air is in contact. From the difference ΔV ₁ of the detection voltage signal Vth ₁ due to thermal diffusion, the difference ΔV ₂ of the detection voltage signal Vth ₂ due to thermal diffusion when the dew filter 24 is clogged (clogged) is smaller.

The microcomputer 33 has a threshold value programmed in accordance with the latter of the above differences ΔV ₁ and ΔV ₂ , so that the dew filter 24 is clogged when the difference is less than the threshold value. The display device, for example, a display lamp is activated to display a message prompting the user to clean the dew filter 24.

  FIG. 11 shows the relationship between the divided voltage Vout and the rotational speed of the blower blade 11b of the blower 11 at a certain temperature, and consequently the amount of wind generated by the rotation of the blower blade 11b (wind volume), and a predetermined voltage Vout. When the rotational speed is less than R (in this case, for example, 1800 [rpm]), the variation of the divided voltage Vout is large, but when the rotation speed is higher than that, the divided voltage Vout does not vary and is stable. The clogging detection is performed in a state where the blower blades 11b are rotating at a speed equal to or higher than the predetermined rotation speed R.

  As described above, in the present configuration, clogging of the dew filter 24 can be detected, so that dew dropped from the evaporator 15 cannot pass through the dew filter 24 and does not flow down to the periphery. it can. In addition, clogging of the dew filter 24 can be performed using the water level sensor 25 for detecting the water level of the dew tank 22 and the blower 11 for ventilating the clothes. Therefore, it is possible to provide the sensor and the blower separately at a low cost.

  In addition, the clogging of the dew filter 24 is detected in a situation where the blower blades 11b of the blower 11 are rotating at a speed equal to or higher than a predetermined rotation speed R, whereby the detection voltage signal does not fluctuate. Since it is stable, detection performance can be obtained stably.

  In addition, this invention is not limited only to the Example mentioned above and shown in drawing, Especially as the whole washing-drying machine, it is not restricted to the above-mentioned horizontal axis shape, A water tank and a rotation tank are made into a vertical axis | shaft shape. It may be in the form of a vertical axis, and the drying chamber may not rotate. In addition, the present invention is not limited to a washing and drying machine having both a washing function and a drying function, and can be applied to a clothes drying machine having only a drying function, as appropriate without departing from the scope of the present invention. obtain.

FIG. 1 is a schematic longitudinal side view of the whole showing a first embodiment of the present invention. Cycle diagram of heat pump Top view of dew tank Vertical side view of dew tank Perspective view of the part from the ventilation case to the dew tank Top view of the part from the ventilation case to the dew tank Schematic configuration diagram of water level detection circuit Figure 1 showing the characteristics of the water level sensor The figure which shows the state (a) of the water level detection and the state (b) of the operation of the drain pump over time. Figure 2 showing the characteristics of the water level sensor Figure 3 showing the characteristics of the water level sensor

Explanation of symbols

  In the drawings, 5a is the inside of the drum (drying chamber), 11 is a blower, 11b is a blower blade, 14 is a ventilation path, 15 is an evaporator, 16 is a condenser, 19 is a heat pump, 22 is a dew tank, and 24 is a dew tank. A filter, 25 is a water level sensor, 30 is a communication pipe, and 33 is a microcomputer (control means).

Claims (2)

The air in the drying chamber is circulated by a blower through a ventilation path provided with an evaporator and a condenser of a heat pump to dry clothes, and the dew generated and dripped by the evaporator is filtered by a dew filter. Stored in a dew tank, and the water level of the dew tank is detected by the difference in thermal diffusion between air and water in the self-heating water level sensor provided in the dew tank,
By supplying a part of the air passing through the ventilation path to the detention tank through the dew filter, the dew filter is clogged with respect to the air at the time of non-clogging and the air at the time of clogging. A clothes dryer characterized by detecting the difference in thermal diffusion.   The blower detects the clogging of the dew filter in a situation where the air in the drying chamber is circulated through the air passage by the rotating blower blades, and the blower blades are rotating at a speed equal to or higher than the predetermined rotation speed. The clothes dryer according to claim 1, which is configured as described above.

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