JP2010017331A - Washing/drying machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve drying of a laundry by a heat pump and thoroughly restrict the inflow of liquid refrigerant and oil into a compressor to achieve a desired reduction in size and weight even if an accumulator is downsized. <P>SOLUTION: The flow of refrigerant into an evaporator from a condenser is blocked at the time the operation of the heat pump is started by activating the compressor while a wringer is closed (S3-S6) when the operation of the heat pump is started. Also the refrigerant and oil remaining in the evaporator is sucked (resumed) into the compressor 18 by activating the compressor and the pressure of the evaporator is decreased. By this, the inflow of refrigerant and oil into the accumulator from the evaporator thereafter can be reduced and the inflow of liquid refrigerant, and oil into the compressor can thoroughly be restricted even the accumulator is downsized to achieve a desired reduction in size and weight. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laundry dryer for drying laundry with a heat pump.

  2. Description of the Related Art Conventionally, in a washing / drying machine, a machine provided with a heat pump for drying laundry has been attracting attention as having good drying performance and being effective in saving energy. In the washing / drying machine equipped with this heat pump, the air in the washing tub containing the laundry is circulated through the ventilation path of the heat pump, in which an evaporator and a condenser connected in a cycle are arranged. , Of which the air is cooled and dehumidified with an evaporator, the air is heated with a condenser, the air is fed into the washing tub successively, and the air deprived of moisture is passed through the air passage. Thus, the laundry is gradually dried.

  Therefore, the moisture generated when the laundry is dried is collected by the evaporator, the latent heat collected in the folding is converted into a high-temperature refrigerant state by the compressor, and reused as energy for heating the air by the condenser. In this way, the energy can be reused without losing almost any energy except for a slight heat loss outside. Therefore, efficient drying can be realized (see, for example, Patent Document 1).

  However, since the heat pump unit is larger and heavier than that for drying laundry with warm air generated by an electric heater, downsizing and weight reduction are important solution issues. In the heat pump unit, the compressor includes an accumulator at the refrigerant inlet portion, and reducing the height of the compressor leads to compactness. Of these, downsizing of the compressor requires downsizing of the drive motor and reduction of the volume of other mechanical parts, and reduction of the amount of oil that contributes to lubrication and cooling of the internal mechanical parts of the compressor. It becomes. On the other hand, in order to make the accumulator compact, it is necessary to reduce the internal volume of the accumulator.

Among them, the former leads to a reduction in the performance of the compressor, that is, the compression capacity and the refrigerant transport capacity, by reducing the size of the drive motor, and the lubrication and cooling capacity of the internal mechanism of the compressor is reduced by reducing the amount of oil inside the compressor. A reduction may be caused, and the function of the compressor which performs rotational movement may be impaired.
In the latter case, the original function of the accumulator is to restrict the flow of liquid refrigerant into the compressor mechanism, but the adjustment function may break down by making the accumulator compact. If it breaks down, liquid refrigerant flows into the compressor mechanism and compresses it, which may damage the compressor mechanism.

  In addition, the refrigerant | coolant said here includes the case where it has a property compatible with oil, and the thing in which the refrigerant | coolant was contained in oil shall also be considered as a liquid refrigerant | coolant (liquid refrigerant). In particular, before the start of operation, when refrigerant or oil remaining in the evaporator or condenser returns to the compressor in about 1 to 3 [minutes] immediately after startup, liquid refrigerant that is more than allowable may temporarily return. There is a risk of damaging the mechanical part of the compressor.

  There are two types of oil: compatible oils that are easily soluble in refrigerants and incompatible oils that do not dissolve in refrigerants. Dehumidifiers, etc. use incompatible oils to reduce the size of accumulators. There is an example. With compatible oils, there are almost no examples of downsizing of accumulators. The reason is that at the start of operation, the liquid refrigerant and oil remaining in the evaporator try to return to the accumulator at once, so if the accumulator is not of a certain size, the liquid refrigerant and oil return to the compressor and the compressor This is because there is a possibility that the above-mentioned adverse effect is exerted on the mechanism portion.

  On the other hand, it is conceivable to reduce the amount of liquid refrigerant and oil accumulated in the evaporator or condenser by reducing the outflow of oil from the compressor. One of them is to provide a tank for separating the oil and the refrigerant dissolved in the oil at the refrigerant discharge port portion of the compressor, and to provide a path for returning the separated oil and the refrigerant to the compressor.

Also, as a different one, the refrigerator uses two evaporators, and there is a technique of recovering the refrigerant of one evaporator for improving the efficiency of the cooling system (see, for example, Patent Document 2).
JP 2006-87484 A JP 2001-133113 A

  As described above, providing a tank or a path at the refrigerant discharge port portion of the compressor requires an additional device around the compressor, which goes against compactness and weight reduction. Moreover, the flow of liquid refrigerant into the compressor cannot be limited by the technique of simply collecting the refrigerant.

  The present invention has been made in view of the above circumstances. Therefore, even if the accumulator is made compact, it is possible to limit the inflow of liquid refrigerant and oil into the compressor, and to achieve the desired purpose. The object is to provide a washing and drying machine that can be made compact and light.

In order to achieve the above object, in the washing / drying machine of the present invention, a washing tub, an air circulation device for performing circulation for returning the air in the washing tub to the washing tub through a ventilation path outside the washing tub, and this By arranging an evaporator and a condenser in the ventilation path of the air circulation device and connecting them with a compressor and a throttle, the refrigerant is circulated through the compressor, the condenser, the throttle and the evaporator. A refrigeration cycle is provided, and a heat pump having an accumulator at the refrigerant inlet of the compressor is provided. In addition to washing and dewatering the laundry, the laundry is dried by operating the air circulation device and the heat pump. In things,
First, at the start of operation of the heat pump, the compressor is driven with the throttle being closed or slightly opened (invention of claim 1).

In the laundry dryer of the present invention, secondly, the rotation speed of the compressor can be changed by frequency control, and the drive frequency of the compressor is reduced to the lowest frequency immediately before the end of the drying operation. (Invention of claim 2).
In the washing / drying machine of the present invention, thirdly, immediately before the completion of the drying operation, the throttle is controlled so that the refrigerant is gasified at the refrigerant outlet of the evaporator ( Invention of Claim 3).

In the washing / drying machine of the present invention, fourthly, the compressor is driven in a state in which the expansion device is closed immediately before the end of the drying operation (invention of claim 4).
In the washing / drying machine of the present invention, fifthly, the circulation fan of the air circulation device is driven even after the drying operation is finished (invention of claim 5).
In the washing / drying machine of the present invention, sixthly, immediately after completion of the drying operation, the throttling device is fully opened (invention of claim 6).

  According to the first means (invention of claim 1), at the start of operation of the heat pump, by driving the compressor with the throttle closed or slightly opened at the start of operation of the heat pump, The refrigerant flow from the condenser to the evaporator is interrupted or made slightly. In the evaporator, when the compressor is driven, the remaining refrigerant and oil are sucked (recovered) into the compressor and the pressure is increased. Is lowered. Thus, the subsequent inflow of refrigerant and oil from the evaporator to the accumulator is reduced. Thus, even if the accumulator is made compact, the inflow of liquid refrigerant and oil to the compressor can be limited. Thus, the desired compactness and weight reduction can be achieved.

  According to the second means (the invention of claim 2), the compressor can change the rotational speed by performing frequency control, and the drive frequency of the compressor is set to the lowest frequency immediately before the end of the drying operation. This reduces the rotational speed of the compressor and reduces the amount of liquid refrigerant and oil discharged from the compressor to the condenser and evaporator. Therefore, the flow of refrigerant and oil from the evaporator to the accumulator at the start of the next drying operation is reduced, thus limiting the flow of liquid refrigerant and oil to the compressor even if the accumulator is made compact. It can be cut and the desired compactness and weight reduction can be achieved.

  According to the third means (the invention of claim 3), immediately before the end of the drying operation, the end of the drying operation is completed by controlling the throttle so that the refrigerant is gasified at the refrigerant outlet of the evaporator. Immediately before, the refrigerant is gasified in the evaporator, the liquid refrigerant and oil are not retained in the evaporator, and the inflow of refrigerant and oil from the evaporator to the accumulator at the start of the next drying operation is reduced. . Thus, even if the accumulator is made compact, the inflow of liquid refrigerant or oil to the compressor can be limited and the desired compactness and weight can be achieved.

  According to the fourth means (the invention of claim 4), the refrigerant and oil in the evaporator are recovered by the compressor by driving the compressor with the throttle closed, immediately before the end of the drying operation. . Therefore, even if the throttle is opened after that, the compressor stops and is not compressed, so the inflow and retention of the refrigerant to the evaporator decreases, and the accumulator from the evaporator at the start of the next drying operation. Inflow of refrigerant and oil into the tank is reduced. Thus, even if the accumulator is made compact, the inflow of liquid refrigerant or oil to the compressor can be limited and the desired compactness and weight can be achieved.

  According to the fifth means (the invention of claim 5), even after the drying operation is completed, the evaporator is heated by the residual heat of the circulating air by driving the circulation fan of the air circulation device, and the refrigerant is gasified. Therefore, the liquid refrigerant and oil do not stay in the evaporator, and the inflow of refrigerant and oil from the evaporator to the accumulator at the start of the next drying operation is reduced. Thus, even if the accumulator is made compact, the inflow of liquid refrigerant or oil to the compressor can be limited and the desired compactness and weight can be achieved.

  According to the sixth means (invention of claim 6), immediately after the drying operation is completed, the throttle is fully opened, whereby the refrigerant and the oil flow from the condenser to the evaporator through the throttle. On the other hand, the amount of refrigerant and oil flowing to the accumulator through the compressor decreases, and the amount of refrigerant and oil remaining in the accumulator during the next drying operation decreases. Thus, even if the accumulator is made compact, the inflow of liquid refrigerant or oil to the compressor can be limited and the desired compactness and weight can be achieved.

Hereinafter, a first embodiment (first embodiment) of the present invention will be described with reference to FIGS.
First, as shown in FIG. 2, the front part (the left part in FIG. 2) of the outer box 1 that forms the outer shell of the entire washing and drying machine has a laundry entrance 2, which is opened and closed by a door 3. Like to do.

  Inside the outer box 1, a water tub 4 is arranged in a horizontal axis shape with an upwardly inclined shape by a plurality of elastic support devices (not shown), and inside the water tub 4 is a drum 5 which is a washing tub. Are arranged parallel to the water tank 4 and concentrically. The drum 5 has a porous shape having a large number of holes 6 in the almost entire area of the peripheral wall (only a part of the holes 6 are shown), and a motor that is a drive device that directly rotates the drum 5 with a rotating shaft 7a. 7 is attached to the back of the water tank 4.

  A ventilation case 8 is disposed below the water tank 4, and the front part of the ventilation case 8 is formed in the upper part of the front part of the water tank 4 via a suction duct 9 having a flexible part 9 a. Tens. On the other hand, the rear part of the ventilation case 8 is connected to the inlet 12 formed in the upper part of the inner part of the water tank 4 through the discharge duct 11 having the flexible part 11a. The suction duct 9, the ventilation case 8, And the discharge duct 11 connects the air outlet 10 and the air inlet 12 of the water tank 4 to form a ventilation path 13. Therefore, the ventilation path 13 is located outside the water tank 4 (outside the drum 5).

  Thus, the evaporator 14 is disposed on the suction duct 9 side and the condenser 15 is disposed on the discharge duct 11 side in the ventilation path 13, particularly inside the ventilation case 8. Although not shown in detail, the evaporator 14 and the condenser 15 are both of a finned tube type in which a large number of heat transfer fins made of, for example, an aluminum plate are attached to a meandering, eg, copper refrigerant circulation pipe. Therefore, air passing through the ventilation case 8 as described below flows between the heat transfer fins.

  Further, a circulation fan 16 is disposed on the discharge duct 11 side further than the condenser 15 in the ventilation case 8. The circulation blower 16 circulates the air in the drum 5 through the ventilation path 13 and then returns to the drum 5 by the air blowing action as shown by arrows in FIG. Thus, the air circulation device 17 that circulates the air in the drum 5 is constituted by the ventilation path 13 and the circulation fan 16.

  The evaporator 14 and the condenser 15 are a compressor 18 and a throttle (in this case, in particular, an electronic expansion valve [PMV: Pulse Motor Valve] shown in FIG. 3, and adjust the cross-sectional area of the refrigerant passage, The refrigerant flow rate can be changed actively. In short, the opening degree can be adjusted.) 19 and the heat pump 20 are configured. In the heat pump 20, the connection pipe 21 The compressor 18 -the condenser 15 -the throttle 19 -the evaporator 14 -the compressor 18 are cycle-connected in this order (refrigeration cycle), and the refrigerant enclosed in the cycle is circulated when the compressor 18 is operated. It is like that.

The compressor 18 is a rotary type, and compatible oil is used as oil that contributes to lubrication and cooling of the internal mechanism. The compressor 18 and the restrictor 19 are disposed outside the ventilation duct 8 (not shown in FIG. 2).
FIG. 3 schematically shows the water tank 4 and the ventilation path 13 (the suction duct 9, the ventilation case 8, and the discharge duct 11) together with the heat pump 20, and in addition to the refrigerant inlet portion of the evaporator 14. The temperature sensors 22 and 23 provided in the refrigerant outlet part, the temperature sensor 24 provided in the middle part of the condenser 15, and the temperature sensor 25 provided in the refrigerant outlet part of the compressor 18 are shown.

  An accumulator 26 is provided at the refrigerant inlet of the compressor 18. 4 shows the structure of the accumulator 26. The accumulator case 27 has a refrigerant inlet pipe 28 in the upper part, and the accumulator case 27 has a refrigerant outlet pipe 29 in the outer lower part. Among these, the refrigerant inlet pipe 28 is connected to the refrigerant outlet portion of the evaporator 14, and the refrigerant outlet pipe 29 is connected to the refrigerant inlet portion of the compressor 18.

  FIG. 4 shows a filter 30 provided between the refrigerant inlet pipe 28 and the refrigerant outlet pipe 29 inside the accumulator case 27, and also shows the liquid refrigerant H and the liquid level H of the oil inside the accumulator case 27. As shown in the figure, the liquid refrigerant H and oil liquid level H inside the accumulator case 27 must be kept lower than the upper end of the refrigerant inlet pipe 28 in order to avoid the inflow of the liquid refrigerant and oil into the compressor 18. . An oil return hole 31 is present at the lower portion of the refrigerant outlet pipe 29.

FIG. 5 shows the control device 32. The control device 32 is composed of, for example, a microcomputer, and is located in the outer box 1 and functions as control means for controlling the overall operation of the washing / drying machine.
Various control signals are input to the control device 32 from an operation input unit 33 including various operation switches provided on an operation panel (not shown), and from a water level sensor 34 provided to detect the water level in the water tank 4. A water level detection signal is input, and temperature detection signals are input from the inlet side temperature sensor 22 of the evaporator 14, the outlet side temperature sensor 23, the temperature sensor 24 of the condenser 15, and the temperature sensor 25 of the compressor 18, respectively. It has become so.

  And the control apparatus 32 is based on the input of the said various signals, and the control program memorize | stored previously, The water supply valve 35 provided so that the water tank 4 may be supplied with water, the said motor 7, the ventilation fan 16, and the compressor 18 The drain valve 36 provided to open and close the throttle port 19 and the drain port of the water tank 4 is controlled via a drive circuit 37.

  The drive circuit 37 includes inverter devices 38 and 39 that are frequency output variable devices. The inverter device 38 controls the frequency of the motor 7 and the inverter device 39 controls the compressor 18 (particularly, the compressor 18). The frequency of each of the drive motors is controlled to change the rotation speed. Therefore, the rotational speed of the motor 7 and the drive motor of the compressor 18 can be changed by frequency control.

Next, the operation of the above configuration will be described.
First, a schematic operation of the washing / drying machine will be described. When an operation panel (not shown) is operated by the user to set a course of driving and an instruction to start driving is given, the washing / drying machine performs a washing operation, a drying operation, or both according to the set driving course. A washing / drying operation is performed in which the operation is continued. As one of them, when the execution of the washing and drying operation is started, the washing process, the dehydrating process, and the drying process are executed in order.

  In the washing process, after the water supply valve 35 is opened to supply water into the water tank 4, an operation of rotating the drum 5 at a low speed is performed. In the dehydration process, after the drain valve 36 is opened and the water in the water tank 4 is discharged, the drum 5 is rotated at a high speed. In the drying process, an operation of supplying hot air into the drum 5 is performed while rotating the drum 5 at a low speed.

  The operation of supplying warm air into the drum 5 is performed in detail as follows. That is, after the circulation blower 16 is operated, the air in the drum 5 flows into the ventilation case 8 from the air outlet 10 of the water tank 4 through the suction duct 9 of the ventilation path 13, and then in the ventilation case 8 and It passes through the discharge duct 11 in order and returns to the drum 5 from the inlet 12 of the water tank 4.

  At this time, the heat pump 20 drives the compressor 18. Thereby, the refrigerant (gas) is compressed by the compressor 18 to become high temperature and high pressure, and the high temperature and high pressure refrigerant flows into the condenser 15 and exchanges heat with the air passing through the ventilation case 8. As a result, the air passing through the ventilation case 8 is heated, and conversely, the temperature of the refrigerant is lowered and liquefied. The liquefied refrigerant is then depressurized through the restrictor 19 and then flows into the evaporator 14 to be vaporized. At this time, the behavior of the refrigerant is detected from the detected temperatures of the inlet side temperature sensor 22 and the outlet side temperature sensor 23 of the evaporator 14, and the throttle 19 is throttled according to the detection result.

  The refrigerant evaporated in the evaporator 14 cools the air passing through the ventilation case 8. The refrigerant that has passed through the evaporator 14 returns to the compressor 18 via the accumulator 26. As a result, the air flowing from the drum 5 into the ventilation case 8 is cooled by the evaporator 14 and dehumidified, and then heated by the condenser 15 to be warmed. Then, the warm air passes through the discharge duct 11 and is supplied into the drum 5 from the inlet 12 of the water tank 4.

  Thus, the hot air supplied into the drum 5 deprives the laundry of moisture, and then flows into the ventilation case 8 from the air outlet 10 of the water tank 4 through the suction duct 9. Thus, the air in the ventilation case 8 having the evaporator 14 and the condenser 15 circulates between the drum 5 and the laundry in the drum 5 is dried.

  FIG. 1 shows the contents of control by the control device 32 in this drying process. As is apparent from FIG. 1, when starting the drying process (step S1), the control device 32 first enters the refrigerant recovery mode, sets the refrigerant recovery time in the same mode, and starts counting the time. (Step S2). Next, the diaphragm 19 is closed (step S3).

  Thereafter, the compressor 18 is activated and the circulation fan 16 is activated (step S4). Next, the rotation speed of the compressor 18 is increased to a predetermined rotation speed at a predetermined increase speed (step S5). Then, it is determined whether or not the time at which the counting is started in step S2 has reached the end of the refrigerant recovery time (for example, 1 [minute] or 2 [minute]) set in step S2 (step S6). If not reached (NO), the process returns to step S5.

  On the other hand, if it is determined in step S6 that it has reached (YES), the refrigerant recovery mode is canceled, the refrigerant recovery operation so far is terminated, and the normal drying operation is started (step S7). Thereafter, the expansion device 19 is opened to the opening of the normal drying operation (step S8), the time for the normal drying operation is set, and the time counting is started (step S9).

  Next, the opening degree of the restrictor 19 is adjusted by the difference (temperature difference Δt) in the detected temperature result between the inlet side temperature sensor 22 and the outlet side temperature sensor 23 of the evaporator 14 (step S10). When the detected temperature result of the temperature sensor 25 or the detected temperature result of the temperature sensor 24 of the condenser 15 reaches a predetermined temperature, the rotational speed of the compressor 18 is reduced by a predetermined amount (step S11).

  Then, it is determined whether or not the time when the counting is started in step S9 has reached the end of the normal drying operation time set in step S9 (step S12), and it is determined that the time has not been reached (NO). If so, the process returns to step S10, but if it is determined that it has reached (YES), the drying process is terminated (step S13).

  As described above, in this configuration, when the operation of the heat pump 20 in the drying process is started, the compressor 19 is closed and the compressor 18 is driven (steps S3 to S6), thereby starting the operation of the heat pump 20. At this time, the flow of the refrigerant from the condenser 15 to the evaporator 14 is interrupted, and in the evaporator 14, the compressor 18 is driven so that the remaining refrigerant and oil are sucked (recovered) into the compressor 18. And the pressure is reduced. Therefore, the inflow of refrigerant and oil from the evaporator 14 to the accumulator 26 at the start of the subsequent normal drying operation is reduced. Thus, even if the accumulator 26 is made compact, the inflow of liquid refrigerant or oil into the compressor 18 is limited (the liquid refrigerant and oil liquid level H inside the accumulator case 27 shown in FIG. The pipe 28 can be kept lower than the upper end of the pipe 28, and the inflow of liquid refrigerant and oil into the compressor 18 can be avoided), and the desired compactness and weight reduction can be achieved.

  6 to 10 show second to fifth examples (second to fifth embodiments) of the present invention, and the same parts as those of the first example are the same. A description will be omitted with reference numerals, and only different parts will be described.

[Second Embodiment]
In the second embodiment shown in FIG. 6, instead of closing (full closing) the restrictor 19 in step S3 of FIG. 1, the restrictor 19 is slightly opened (step S101). The same as one embodiment.

FIG. 7 shows the relationship between the opening degree of the restrictor 19 and the flow rate, and it can be seen that the flow rate increases as the opening degree of the restrictor 19 increases. In FIG. 7, the opening degree _OL is the lower limit opening degree that is normally used by the restrictor 19, and the slight opening of the restrictor 19 in step S <b> 101 is the lower limit opening degree that is normally used by the restrictor 19. O is that the opening of a small opening area than _L.

  As described above, in the second embodiment, at the start of operation of the heat pump 20 in the drying process, the compressor 18 is driven with the throttle 19 slightly opened (steps S101 to S6). The refrigerant flow from the condenser 15 to the evaporator 14 at the start of operation of the heat pump 20 is slightly reduced until it is not blocked, and the evaporator 18 drives the compressor 18 as in the first embodiment. Thus, the remaining refrigerant and oil are sucked (recovered) into the compressor 18 and the pressure is reduced. Therefore, the inflow of refrigerant and oil from the evaporator 14 to the accumulator 26 at the start of the subsequent normal drying operation is reduced. Thus, in this case as well, even if the accumulator 26 is made compact, the inflow of liquid refrigerant or oil into the compressor 18 can be limited, and the desired compactness and weight reduction can be achieved.

[Third embodiment]
In the third embodiment shown in FIG. 8, the step S1 is followed by the step S4 and further through the step S8. Thereafter, the normal drying operation time is set, and the time for reducing the drive frequency of the compressor 18 by the inverter device 39 (Hz down time, for example, 5 to 10 minutes) is set. Counting is started (step S201), and then the steps S10 and S11 are performed.

  Then, after that, it is determined whether or not the time at which the counting is started in step S201 has reached a time obtained by subtracting the Hz down time set in step S201 from the normal drying operation time set in step S201. However, if it is determined that it has not been reached (NO), the process returns to step S10. That is, the normal drying operation is performed with the Hz down time remaining after the start of the drying process.

  If it is determined in the above step 202 that it has reached (YES), the drive frequency of the compressor 18 by the inverter device 39 is reduced to the lowest frequency (step S203). The minimum driving frequency of the compressor 18 is a driving frequency at which the rotational speed of the compressor 18 is 30 to 40 [rps].

  Thereafter, the opening degree of the throttle 19 is adjusted by the difference (temperature difference Δt) in the detected temperature results between the inlet side temperature sensor 22 and the outlet side temperature sensor 23 of the evaporator 14 (step S204). At this time, the opening degree of the restrictor 19 is adjusted so that the detected temperature of the outlet side temperature sensor 23 is, for example, 10 ° C. or more higher than the detected temperature of the inlet side temperature sensor 22 of the evaporator 14. Therefore, the refrigerant is completely gasified at the refrigerant outlet portion of the evaporator 14. That is, at this time, the restrictor 19 is controlled so that the refrigerant is completely gasified at the refrigerant outlet of the evaporator 14.

  Then, the process proceeds to step S12. If it is determined that the value has not been reached (NO) in step S12, the process returns to step S204. If it is determined that the value has been reached (YES), the compressor 18 and the circulation unit are returned. While stopping the driving of the blower 16, the throttle 19 is fully opened (step S205), and the process proceeds to step S13 (end of the drying process).

  As described above, in the third embodiment, the driving frequency of the compressor 18 is set to, for example, 5 to 10 minutes (Hz down time) immediately before the end of the operation of the heat pump 20 in the drying process, that is, immediately before the end of the drying operation. Therefore, the frequency is reduced to the lowest frequency (steps S203 to S12), whereby the rotational speed of the compressor 18 is reduced, and the amounts of liquid refrigerant and oil discharged from the compressor 18 to the condenser 15 and the evaporator 14 are reduced. Reduced. Therefore, the inflow of refrigerant and oil from the evaporator 14 to the accumulator 26 at the start of the next drying operation is reduced. Thus, even if the accumulator 26 is made compact, the inflow of liquid refrigerant and oil to the compressor is reduced. The desired size and weight can be reduced.

Further, in the third embodiment, immediately before the end of the drying operation, the throttle 19 is controlled so as to gasify the refrigerant at the refrigerant outlet of the evaporator 14 (steps S204 to S12). As a result, immediately before the end of the drying operation, the refrigerant is completely gasified in the evaporator 14, and the liquid refrigerant and oil are not retained in the evaporator 14, and the evaporator at the start of the next drying operation. Inflow of refrigerant and oil from 14 to the accumulator 26 is reduced. Thus, in this case as well, even if the accumulator is made compact, the flow of liquid refrigerant or oil into the compressor can be limited, and the desired compactness and weight reduction can be achieved.
Note that the two controls in the third embodiment may be performed independently.

[Fourth embodiment]
In the fourth embodiment shown in FIG. 9, after steps S1 to S12 of the first embodiment, the drive frequency of the compressor 18 by the inverter device 39 is reduced to the lowest frequency, and the time for fully closing the throttle 19 is set. Setting is made (step S301). Then, it performs (step S302).

  Thereafter, it is determined whether or not the time when the counting is started in step S302 has reached the end of the time for fully closing the diaphragm 19 set in step S301 (step S303). If it is determined (NO), the process returns to step S302, but if it is determined that it has been reached (YES), step S205 (stop driving of the compressor 18 and the circulation fan 16 and full opening of the throttle 19) is performed. Then, it progresses to step S13 (end of a drying process).

As described above, in the fourth embodiment, the compressor 18 is driven with the throttle 19 closed immediately before the end of the drying operation, so that the refrigerant and oil in the evaporator 14 are discharged from the compressor. 18 recovered. Therefore, even if the throttle 19 is opened after that, the compressor 18 stops and is not compressed, so the inflow and stagnation of the refrigerant into the evaporator 14 is reduced, and the evaporation at the start of the next drying operation is performed. Inflow of refrigerant and oil from the vessel 14 to the accumulator 26 is reduced. Thus, in this case as well, even if the accumulator 26 is made compact, the inflow of liquid refrigerant or oil into the compressor 18 can be limited, and the desired compactness and weight reduction can be achieved.
In the fourth embodiment, steps S2 to S6 (refrigerant recovery operation at the start of drying operation) may be omitted.

[Fifth embodiment]
In the fifth embodiment shown in FIG. 10, after passing through the steps S1, S4, and S8 in order, the normal drying operation time is set and the air circulation operation time is set after the drying operation is completed. Is started (step S401), and then the steps S10 and S11 are performed.

  Then, the process proceeds to step S12. If it is determined in step S12 that it has not been reached (NO), the process returns to step S10. If it is determined that it has been reached (YES), the compressor 18 is driven. The stop 19 is stopped and the throttling device 19 is fully opened, but the driving of the circulation fan 16 is continued (step S402).

Thereafter, it is determined whether or not the time when the counting is started in step S401 has reached the time obtained by adding the air circulation operation time set in step S401 to the normal drying operation time set in step S401. (Step 403) If it is determined that it has not been reached (NO), Step S403 is repeated, and if it is determined that it has been reached (YES), the driving of the circulation fan 16 is stopped (Step 404). That is, from the end of the drying operation in step S402, the circulation fan 16 is continuously driven and the circulation of the air in the drum 5 through the ventilation path 13 is continued.
Moreover, after the completion of the drying operation, the restrictor 19 remains fully open.
Then, it progresses to step S13 (end of a drying process).

  As described above, in the fifth embodiment, the circulation fan 16 of the air circulation device 17 is driven even after the drying operation is finished, whereby the evaporator 14 is heated by the residual heat of the circulation air, Since the refrigerant is gasified, the liquid refrigerant and oil do not stay in the evaporator 14, and the inflow of refrigerant and oil from the evaporator 14 to the accumulator 26 at the start of the next drying operation is reduced. Thus, in this case as well, even if the accumulator is made compact, the flow of liquid refrigerant or oil into the compressor can be limited, and the desired compactness and weight reduction can be achieved.

  Further, in the fifth embodiment, the throttle 19 is fully opened immediately after the end of the drying operation. On the other hand, in the case where the throttle 19 is fully closed immediately after the end of the drying operation, The flow of refrigerant and oil from the condenser 15 to the evaporator 14 through the throttle 19 is interrupted, and much refrigerant and oil flow from the condenser 15 to the accumulator 26 through the compressor 18 in the opposite direction. As described above, the throttle 19 is fully opened immediately after the end of the drying operation, so that the flow of the refrigerant and oil from the condenser 15 to the evaporator 14 through the throttle 19 is not blocked, and the condensation is performed. The amount of refrigerant and oil flowing from the condenser 15 to the evaporator 14 through the restrictor 19 and the amount of refrigerant and oil flowing from the condenser 15 to the accumulator 26 through the compressor 18 is reduced. The amount of the refrigerant and the oil remaining on the accumulator 26 is reduced.

Thus, in this case as well, even if the accumulator 26 is made compact, the inflow of liquid refrigerant or oil into the compressor 18 can be limited, and the desired compactness and weight reduction can be achieved.
The above two controls in the fifth embodiment may be performed independently.

  In addition, the present invention is not limited only to the embodiment described above and shown in the drawings. In particular, the washing and drying machine as a whole is not limited to the drum type, and is a vertical type having a water tub or a washing tub in the shape of a vertical axis. The present invention can be carried out with appropriate modifications within a range not departing from the gist, such as a washing / drying machine.

The flowchart for explaining the operation of the first embodiment of the present invention. Longitudinal side view of washer / dryer Schematic configuration diagram of washing dryer internal structure Front view of accumulator Electrical configuration block diagram FIG. 1 equivalent view showing a second embodiment of the present invention. Diagram showing the relationship between the opening of the restrictor and the flow rate FIG. 1 equivalent view showing a third embodiment of the present invention. FIG. 1 equivalent view showing a fourth embodiment of the present invention. FIG. 1 equivalent view showing a fifth embodiment of the present invention.

Explanation of symbols

  In the drawings, 5 is a drum (washing tub), 13 is a ventilation path, 14 is an evaporator, 15 is a condenser, 16 is a circulation fan, 17 is an air circulation device, 18 is a compressor, 19 is a throttle, and 20 is A heat pump, 26 is an accumulator, 32 is a control device, and 39 is an inverter device.

Claims (6)

A washing tub,
An air circulation device that performs circulation to return the air in the washing tub to the washing tub through a ventilation path outside the washing tub;
By arranging an evaporator and a condenser in the ventilation path of this air circulation device and connecting them with a compressor and a throttle, the refrigerant is circulated through the compressor, the condenser, the throttle and the evaporator. Comprising a heat pump comprising an accumulator at the refrigerant inlet of the compressor,
In addition to performing washing and dehydration of the laundry, the laundry is dried by the operation of the air circulation device and the heat pump.
The washing and drying machine, wherein the compressor is driven in a state where the throttle is closed or slightly opened at the start of operation of the heat pump. A washing tub,
An air circulation device that performs circulation to return the air in the washing tub to the washing tub through a ventilation path outside the washing tub;
By arranging an evaporator and a condenser in the ventilation path of this air circulation device and connecting them with a compressor and a throttle, the refrigerant is circulated through the compressor, the condenser, the throttle and the evaporator. Comprising a heat pump comprising an accumulator at the refrigerant inlet of the compressor,
In addition to performing washing and dehydration of the laundry, the laundry is dried by the operation of the air circulation device and the heat pump.
The rotation speed of the compressor can be changed by frequency control,
A washing and drying machine characterized in that the drive frequency of the compressor is reduced to the lowest frequency immediately before the end of the drying operation. A washing tub,
An air circulation device that performs circulation to return the air in the washing tub to the washing tub through a ventilation path outside the washing tub;
By arranging an evaporator and a condenser in the ventilation path of this air circulation device and connecting them with a compressor and a throttle, the refrigerant is circulated through the compressor, the condenser, the throttle and the evaporator. Comprising a heat pump comprising an accumulator at the refrigerant inlet of the compressor,
In addition to performing washing and dehydration of the laundry, the laundry is dried by the operation of the air circulation device and the heat pump.
Immediately before the end of the drying operation, the washer / dryer is subjected to throttling control so that the refrigerant is gasified at the refrigerant outlet of the evaporator. A washing tub,
An air circulation device that performs circulation to return the air in the washing tub to the washing tub through a ventilation path outside the washing tub;
By arranging an evaporator and a condenser in the ventilation path of this air circulation device and connecting them with a compressor and a throttle, the refrigerant is circulated through the compressor, the condenser, the throttle and the evaporator. Comprising a heat pump comprising an accumulator at the refrigerant inlet of the compressor,
In addition to performing washing and dehydration of the laundry, the laundry is dried by the operation of the air circulation device and the heat pump.
Immediately before the end of the drying operation, the washer / dryer is driven with the compressor closed. A washing tub,
An air circulation device that performs circulation to return the air in the washing tub to the inside of the washing tub through a ventilation path outside the washing tub with a circulation fan;
By arranging an evaporator and a condenser in the ventilation path of this air circulation device and connecting them with a compressor and a throttle, the refrigerant is circulated through the compressor, the condenser, the throttle and the evaporator. Comprising a heat pump comprising an accumulator at the refrigerant inlet of the compressor,
In addition to performing washing and dehydration of the laundry, the laundry is dried by the operation of the air circulation device and the heat pump.
The laundry dryer is characterized in that the circulation fan is driven even after the drying operation is completed. A washing tub,
An air circulation device that performs circulation to return the air in the washing tub to the washing tub through a ventilation path outside the washing tub;
By arranging an evaporator and a condenser in the ventilation path of this air circulation device and connecting them with a compressor and a throttle, the refrigerant is circulated through the compressor, the condenser, the throttle and the evaporator. Comprising a heat pump comprising an accumulator at the refrigerant inlet of the compressor,
In addition to performing washing and dehydration of the laundry, the laundry is dried by the operation of the air circulation device and the heat pump.
Immediately after completion of the drying operation, the washer and dryer are fully opened.

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