JP2013052127A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a washing machine capable of shortening operation time while keeping rinsing performance by shortening rest time of a circulation pump and improving drive rate.SOLUTION: The washing machine comprises a water circulation system which is provided in a circulation path and circulates washing water inside a rotary drum 4 by a circulation pump 20 with variable rotational speed. In a rinsing step, the circulation pump 20 is driven at a first predetermined rotational speed before water level detection means 10 detects a water level and, after water supply means 7a starts supplying water and the water level detection means 10 detects that a water level becomes a predetermined water level or higher, the circulation pump 20 is driven at a second predetermined rotational speed higher than the first predetermined rotational speed, so that drive rate of the circulation pump 20 is increased and the rinsing efficiency by a circulation shower is improved.

Description

  The present invention relates to a washing machine that performs a circulating shower.

  A conventional washing machine has a circulation pump in the middle and a circulation path for returning the water in the water tank taken out from the water outlet to the water tank so as to perform a circulation shower on the laundry (for example, a patent) Reference 1).

  In Patent Document 1, during a shower rinsing process in which a circulating shower is performed during the rinsing process, when the water level detected by the water level sensor rises to a preset driving start water level of the circulation pump in the water supply to the water tank The circulation pump has started to be driven. Further, when the water level detected by the water level sensor drops to the lower limit water level set at the lowest water level detectable by the water level sensor, the driving of the circulation pump is stopped. As a result, the drive rate of the circulation pump is increased to improve the shower rinsing effect, and air is prevented from being smeared.

JP 2010-46124 A

  However, in the above-described drum type washing machine, since the circulation pump is driven after supplying water to a predetermined water level in the water tank, the stationary time of the circulation pump becomes long. That is, since the onset of the rinsing effect by the circulation pump is delayed, there is a problem that the operation time becomes unnecessarily long to obtain the desired rinsing performance. The above problem becomes more conspicuous when the supply water flow rate at the installation site is low, or when the circulation pump is located near the lowest point in the circulation path and can circulate water with a very small amount of water. That is, when the feed water flow rate is low, it takes a long time for the water level in the water tank to reach the predetermined water level after the start of water supply, and as a result, the stationary time of the circulation pump becomes long. Moreover, the circulation pump is driven after supplying water to a predetermined water level in order to prevent air from flowing in the pump. However, the water level that the pump can drive without air is generally lower than the lower limit water level that can be detected by the water level detection means. Is also quite low. For this reason, although there is actually no problem even if the circulation pump starts driving, there is a problem that there is a time for waiting to start driving unnecessarily.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a washing machine capable of shortening the operation time while maintaining the rinsing performance by shortening the stationary time of the circulation pump and increasing the driving rate. And

  In order to solve the above-described conventional problems, a drum-type washing machine according to the present invention rotates a rotating drum formed in a bottomed cylindrical shape and the rotating drum from the front side to the back side which is the bottom. Rotating the rotating drum, a water tank disposed inside the shaft so as to be inclined horizontally or downward, a water supply means for supplying water into the water tank, a water level detecting means for detecting the level of washing water in the water tank, and A motor for driving, a water circulation system for circulating the washing water in the water tank through the circulation path connected to the water tank and circulating in the rotary drum by a circulation pump provided in the circulation path and having a variable rotation speed; and the motor And a control means for executing a rinsing step, and the control means sets the rotational speed of the circulation pump to a first predetermined speed before the water level is detected by the water level detecting means in the rinsing step. After starting water supply by the water supply means, after detecting that the water level detection means has reached a predetermined water level or higher, the rotation speed of the circulation pump is set to a second predetermined rotation higher than the first predetermined rotation speed. Drive at speed.

  With such a configuration, the circulating pump is driven before the water level detecting means detects the water level, so that the driving rate of the circulating pump can be increased. Further, by setting the rotational speed of the circulation pump to the first predetermined rotational speed and the second rotational speed higher than the first rotational speed, the laundry near the opening front side of the rotating drum and the back side of the rotating drum Circulating water can be supplied to both nearby laundry. As a result, since the circulating water can be uniformly supplied to the laundry inside the rotating drum for a longer time, the rinsing time can be shortened while maintaining the rinsing performance.

  The drum type washing machine of the present invention can shorten the operation time while maintaining the rinsing performance by shortening the stationary time of the circulation pump and increasing the driving rate.

Sectional drawing which shows schematic structure of the washing machine in Embodiment 1 of this invention. Block diagram of the washing machine Time chart showing the operation of the washing machine's rinsing process

  A washing machine according to a first aspect of the present invention has a rotating drum formed in a bottomed cylindrical shape, and the rotating drum has a rotating shaft that is horizontally or downwardly inclined from the front side to the bottom side toward the back side. A water tank disposed inside, a water supply means for supplying water into the water tank, a water level detection means for detecting the level of washing water in the water tank, a motor for rotationally driving the rotary drum, and the water tank in the water tank. A rinsing process is executed by controlling a water circulation system in which the washing water is circulated in the rotating drum through a circulation path connected to the water tank, and a rotation pump having a variable rotation speed, the motor, and the like. Control means for driving, at the rinsing step, the rotational speed of the circulation pump is driven at a first predetermined rotational speed before the water level detection by the water level detection means, and the water supply means After the start of the water supply, after the water level detection means detects the equal to or greater than a predetermined level, and drives the rotation speed of the circulation pump in the first higher than a predetermined rotational speed a second predetermined rotational speed.

  With such a configuration, since the circulation pump is driven before the water level detection means detects the water level, the drive rate of the circulation pump can be increased. Further, by setting the rotational speed of the circulation pump to the first predetermined rotational speed and the second rotational speed higher than the first rotational speed, the laundry near the opening front side of the rotating drum and the back side of the rotating drum Circulating water can be supplied to both nearby laundry. As a result, since the circulating water can be uniformly supplied to the laundry inside the rotating drum for a longer time, the rinsing time can be shortened while maintaining the rinsing performance.

  In the second invention, in particular, the control means of the washing machine according to the first invention drives the rotational speed of the circulation pump at the first predetermined rotational speed before the start of water supply by the water supply means in the rinsing step. Is.

  With such a configuration, since the circulation pump is driven before the start of water supply in the rinsing process, the drive rate of the circulation pump can be increased. Further, by setting the rotational speed of the circulation pump to the first predetermined rotational speed and the second rotational speed higher than the first rotational speed, the laundry near the opening front side of the rotating drum and the back side of the rotating drum Circulating water can be supplied to both nearby laundry. As a result, since the circulating water can be uniformly supplied to the laundry inside the rotating drum for a longer time, the rinsing time can be shortened while maintaining the rinsing performance.

  According to a third aspect of the invention, in particular, the control means of the washing machine of the first or second aspect of the invention is such that the water level detection means is less than or equal to the predetermined water level when the rotational speed of the circulation pump is the second predetermined rotational speed. When it is detected that the rotation speed has become, the rotation speed of the circulation pump is set to the first predetermined rotation speed.

  With such a configuration, it is possible to prevent the laundry from absorbing the circulating water and the like so that the water level in the water tank is lowered and the air from the circulation pump is generated. In addition, there is a method of stopping the circulation pump or intermittently driving when the water level is lower than a predetermined water level. However, in this case, not only the driving rate of the circulation pump is reduced, but also other problems occur. That is, when the motor of the circulation pump is intermittently driven, a change in the sound is accompanied when the start and stop are repeated, which may give the user a discomfort such as a roaring sound. If the circulating water is repeatedly discharged or not, it may be mistaken for a device failure. However, as described above, if the rotational speed of the circulation pump is lowered, no roaring noise is generated, and the user is not mistaken for a visual failure. Furthermore, since the circulating water is supplied to the laundry in the vicinity of the opening front side of the rotating drum, the rinsing effect by the circulating shower can be sufficiently obtained.

  Hereinafter, a washing machine according to an embodiment of the present invention will be described with reference to the drawings. The following embodiments are examples embodying the present invention, and do not limit the technical scope of the present invention.

(Embodiment 1)
Embodiment 1 of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view showing a schematic structure of a washing machine according to Embodiment 1 of the present invention. The configuration will be described below with reference to FIG.

  A water tub 3 is housed in the washing machine body 2 so as to be swingable. A rotating drum 4 is disposed in the water tub 3 so as to be rotatable around a rotation shaft 4a. The rotating shaft 4 a of the rotating drum 4 is directly connected to a motor 6 attached to the outside of the back surface of the water tank 3, and the rotating drum 4 is driven to rotate by this motor 6.

  The rotating drum 4 is provided with a plurality of through-holes 4e over the entire wall surface so that water can be passed and vented between the water tank 3 and the rotating drum 4. A plurality of stirring protrusions 4 b are provided on the inner surface of the wall surface of the rotating drum 4, and the laundry in the rotating drum 4 is lifted by the rotation of the rotating drum 4. Although the through hole 4e is provided over the entire wall surface 4c of the rotating drum 4, it may be partially formed on the wall surface 4c of the rotating drum 4. In short, the air permeability between the water tank 3 and the rotating drum 4 is essential. In addition, it should be set so that water permeability can be ensured and washing does not hinder drying.

  The rotating shaft 4a of the rotating drum 4 is inclined so as to face downward from the opening front side toward the back side as the bottom. Specifically, it is arranged to be inclined downward, for example, 20 ± 10 degrees from the horizontal direction. By tilting the rotary shaft 4a in this way, the opening 13 on the front side of the aquarium 3 can be arranged on the upper side, and the user can pass through the opening 13 of the aquarium 3 without taking a posture of bending greatly. The laundry in the rotating drum 4 can be taken out. Compared with the case where the rotating shaft 4a is set in the horizontal direction, the water supplied into the water tank 3 accumulates on the back side, and a deep water storage state can be obtained even with a small amount of water. In order to efficiently supply water to the laundry in the rotating drum 4, the water tank 3 is provided along the vicinity thereof with the same inclination as the rotating drum 4. If the amount of water supply is not taken into consideration, the rotating drum 4 may be horizontal or the inclination angle θ may be less than 10 degrees.

  A water supply system 7 having a water supply valve 7 a and a detergent container 7 b is provided at the upper part of the water tank 3. Water is supplied from the outside of the washing machine by opening and closing the water supply valve 7a. The supplied water is supplied into the water tank 3 together with the detergent in the detergent container 7b through the water supply path.

  In the lower part of the water tank 3, a drainage pipe 8 a having one end connected to the bottom of the water tank 3 and a drainage system 8 having a drainage valve 19 are provided. By opening and closing the drain valve 19, water in the water tank 3 is drained through the drain pipe 8a when necessary, such as at the end of the washing process or at the end of the rinsing process. Further, a drainage filter 8b that is removable from the outside of the washing machine main body 2 is disposed on the downstream side of the drainage pipe 8a, and collects yarn waste contained in the drainage. The drainage system 8 is connected to the lower part of the water tank 3 through a drain pipe 8a connected to the lower part of the water tank 3, as shown by a one-dot chain line at the end of the washing process or the end of the rinsing process by opening and closing the drain valve 19. After being collected and passed through a drainage filter 8b that can be removed from the outside, drainage can be performed.

  The drying system 9 circulates the air in the water tank 3 and the rotating drum 4 by the blower 12 as indicated by the broken line arrows in FIG. In the drying system 9, there are a filter (not shown) for collecting and removing dust from the lint, a dehumidifying part (not shown) for dehumidifying the introduced air after the dust removal, and a high temperature which is depleted by heating the dehumidified air. It has a heating part (not shown) etc. used as air.

  In addition to the above, the water circulation system 16 circulates the water in the water tank 3 as necessary during the washing process, the rinsing process, and the like, and has a function of improving the function of early dissolution of the detergent and easy washing. ing. The water circulation system 16 drives the circulation pump 20 so that the water in the water tank 3 passes through the drainage filter 8b through the drainage pipe 8a, the inflow side path 31a to the circulation pump 20 in the circulation path 31, and the circulation pump. 20 and the return path 31b from the circulation pump 20 of the circulation path 31 are repeatedly returned from the injection port 51 into the water tank 3.

  As shown in FIG. 1, the circulation pump 20 is fixed on a base plate, which is the bottom of the washing machine body 2, and sucks washing water and sends it to the circulation path 31. Here, the washing water includes washing water containing the detergent component in the washing step and rinsing water for removing the detergent component in the rinsing step from the laundry. The fed wash water is discharged into the rotary drum 4 from the opening 13 of the rotary drum 4 through the circulation path 31. In this way, a circulating shower is performed in which the water in the aquarium 3 is used to apply water to the laundry. Specifically, the discharge side path 31 b of the circulation path 31 is connected to the injection port 51 provided on the front end wall around the opening 13 of the water tank 3 from the outer surface. Washing water is fed between the inner surface of the front end wall of the water tank 3 and the outer surface of the front end wall of the rotating drum 4 corresponding thereto, and is injected into the rotating drum 4 through a flow path formed therebetween. To do. Since the injection port 51 is in a position where it does not come into contact with the laundry in the rotary drum 4, the laundry is caught and washed, and the behavior necessary for rinsing, rinsing, dehydration, drying and the like is not disturbed. Alternatively, it is possible to prevent the laundry from being damaged or torn. Furthermore, the appearance that looks good is not impaired.

  When washing water or rinsing water is simply sprayed into the rotating drum 4, much circulating water can be sprayed only to the local portion of the laundry in the rotating drum 4, and the circulation effect cannot be fully utilized. On the other hand, if a special injection nozzle is used to inject the circulating water over a wide area, the required pump pressure will increase and there will be a cost increase. Therefore, in the present embodiment, in order to circulate the water in the water tank 3 by the circulation pump 20, the flow rate and flow rate of the circulating water to be discharged are adjusted using, for example, a DC brushless motor capable of controlling the rotational speed. Thus, the vertical angle of the circulating water to be discharged and the degree of spread in the horizontal direction can be changed without employing a special injection nozzle. As a result, the circulating pump 20 can supply the circulating water evenly and optimally to the laundry in the rotating drum 4, and the washing performance and the rinsing performance can be improved. Moreover, since it is possible to avoid unnecessary supply of circulating water to the space where the laundry is not located, it is possible to suppress useless power consumption and to suppress abnormal foaming due to the detergent water.

  The rotational speed of the circulation pump 20 is such that it is discharged over a wide area from the vicinity of the opening front side of the rotating drum 4 to the vicinity of the back surface thereof as indicated by an arrow a in FIG. At this time, the rotation speed of the motor of the circulation pump 20 is set to about 3500 r / min, for example, and about 20 L / min of circulating water is supplied to the laundry in the rotating drum 4 to improve the washing performance and the rinsing performance. Plan. On the other hand, when the motor rotation speed of the circulation pump 20 is set to a relatively low rotation of, for example, 1600 r / min, discharge is made into the rotary drum 4 as indicated by an arrow b in FIG. By lowering the rotational speed of the circulation pump 20, the vertical angle at which the circulating water is discharged is made closer to the horizontal, and the extent of the lateral expansion is reduced. Thereby, when there is little laundry, the state where the discharged circulating water does not hit the laundry located in the downward direction in the rotating drum 4 can be avoided, and circulating water can be supplied efficiently. In this way, by controlling the rotational speed of the circulation pump 20, circulating water can be applied to the laundry lifted above the rotating drum 4 and the laundry on the front side and the back side. In addition, the injection port 51 is not limited to the lower portion, and may be arranged in any position as long as it does not contact the laundry in the rotating drum 4. Therefore, even if the injection port 51 is provided on the upper part of the rotating drum 4, the circulating water can be applied to the laundry lifted on the upper part of the rotating drum 4.

  In addition, in this Embodiment, it was set as the structure which installs the circulation pump 20 on the baseplate 2a which is the bottom part of the washing machine main body 2, However, It is not limited to this, The water in the water tank 3 is circulated. Alternatively, the circulation pump 20 may be installed in the lower part 3 b of the water tank 3.

  Further, the drum type washing machine according to the present embodiment is provided with a water level detection means 10 for detecting the amount of water supplied into the rotary drum 4. In this case, an air trap part and a pressure detection part arranged at a predetermined position near the lowest part of the water tank 3 are connected by a hose. The pressure detector is composed of a ferrite integrated with the bellows part that moves by pressure and a fixed coil that surrounds the outer periphery of the ferrite, and converts the moving stroke distance into the trap internal pressure using the change in inductance. . The water level detecting means 10 is in an open state when the cleaning water does not enter the air trap part, and the output is constant.

  As described above, the water level detection means 10 is generally sensing by air internal pressure measurement by an air trap mechanism, and measuring the time until the air internal pressure changes from the stable atmospheric open pressure affects the variation of the water level sensor. It is an appropriate calculation method that is not subject to

  The output of the water level detection means 10 changes depending on the rotation speed of the rotary drum 4 because the output changes depending on the rotation of the rotary drum 4 during the washing operation, such as whether or not the rotary drum 4 is rotating. Have multiple tables. That is, the water level can be recognized while the rotating drum 4 is stationary or rotating.

  Next, details of the control means 22 will be described with reference to FIG. FIG. 2 is a block circuit diagram of the washing machine according to Embodiment 1 of the present invention. The control means 22 is composed of a microcomputer. The control means 22 has a function of performing at least a washing process, a rinsing process, and a dehydrating process by automatically controlling the motor 6, the water supply valve 7 a, the drain valve 19, the circulation pump 20, and the like according to mode setting and a control program.

  The cloth amount detection for detecting the amount of laundry put into the rotating drum 4 is detected by using a rotation speed detecting means (not shown) for detecting the rotation speed of the rotating drum 4. An example of the cloth amount detection will be described below.

  First, the motor 6 is rotationally driven. At this time, the rotational speed of the rotating drum 4 is increased to a rotational speed at which the laundry is stuck to the inner side of the rotating drum 4, for example, about 100 to 140 r / min. After the rotation is maintained for a predetermined time, the energization of the motor 6 is turned off. Thereby, the inertial rotation of the rotating drum 4 is in a state where the motor 6 is rotated. At this time, the inertial rotational force of the rotating drum 4 gradually decreases due to the friction torque, and the rotating drum 4 eventually stops. The time from the stop of energization to the stop of the rotating drum 4 is long when the amount of laundry is large, and short when the amount of laundry is small. The amount of laundry is detected using the fact that the difference in time required for this stop is proportional to the amount of laundry.

  In addition, the drum type washing machine according to the present embodiment has a system that can manage all input / output control with a timer, including not only instructions for water supply / drainage and driving of the rotating drum 4, but also various sensor outputs such as the water level detection means 10. It is possible to know the time required for each operation and timing.

  In addition, selection of a mode such as an operation course and various functions is performed by inputting from an operation panel 21 provided at the upper front of the washing machine body 2. Based on the input information, the control means 22 displays on the display means 21b on the operation panel 21 to notify the user. At the same time, when the operation start is set by the input setting means 21 a on the operation panel 21, data is input from the water level detection means 10 for detecting the water level in the water tank 3 and the drive is started, and the drain valve 19 The operation of the water supply valve 7a, etc. is controlled to perform operations such as washing, rinsing, dehydration, and drying.

  The operation of the drum type washing machine configured as described above will be described below with reference to FIG. FIG. 3 is a time chart showing the operation of the rinsing process of the washing machine in the first embodiment of the present invention.

  First, when the laundry is put into the rotating drum 4 and the door is closed, the control means 22 detects the amount of the laundry. The control means 22 opens the water supply valve 7a and supplies water in the water tank 3 according to the amount of laundry. At this time, water is supplied through the detergent container 7 b and the detergent is also supplied into the water tank 3. When the water level detection means 10 detects that water has been supplied to the water level corresponding to the amount of laundry, the washing process is started. The control means 22 drives the motor 6 to rotate the rotating drum 4. The rotational speed of the rotating drum 4 is about 40 to 60 r / min, although it depends on the size of the rotating drum 4 and the amount and quality of the laundry. At this time, the rotating drum repeats forward and reverse rotation. As the rotating drum 4 rotates, the laundry is lifted by the stirring protrusions 4b, and tapping is performed. Further, by driving the circulation pump 20, the cleaning water is positively replaced, and the cleaning performance is increased.

  When the washing operation is performed for a predetermined time, drainage and dehydration are performed. The control means 22 operates the drain valve 19 to discharge the washing water in the water tank 3 out of the machine. The control means 22 increases the rotational speed of the rotary drum 4 to the rotational speed at which the washing water is dehydrated from the laundry. As a result, the washing water containing the dirt component is discharged from the laundry.

  When the dehydrating operation is performed for a predetermined time, the control means 22 stops the motor 6 and stops the rotation of the rotating drum 4. As shown in FIG. 3, when the driving of the motor 6 is stopped, that is, when the rotational speed of the rotating drum 4 starts to decrease, the driving of the circulation pump 20 is started. By doing in this way, since it does not keep waiting for water supply unnecessarily, the rinsing time can be shortened.

  However, if the circulating pump 20 is driven at a relatively high speed, for example, 3500 r / min before detecting the detectable lower limit water level A of the water level detecting means 10, there is a possibility that air leakage will occur. Therefore, in the present embodiment, the rotational speed of the circulation pump 20 is driven at 1600 r / min (first predetermined rotational speed), which is a relatively low speed. Thereby, a circulation shower can be performed quickly and efficiently without air. Further, the motor of the circulation pump 20 requires several seconds from the start of driving until it actually reaches the predetermined rotational speed. Therefore, before the water supply is started by the water supply valve 7a of the water supply system 7, in this embodiment, when the drive of the motor 6 is stopped, the drive of the circulation pump 20 is started.

  As in the conventional example, water supply is started by the water supply valve 7a of the water supply system 7 after the dehydration process after washing, and the circulating pump 20 is started to drive after the water level detecting means 10 detects the detectable lower limit water level A. In this case, it is necessary to wait for a long time before the circulation pump 20 is driven. This becomes significant when the water supply flow rate at the installation site is low. In other words, the dischargeable water level B of the circulation pump 20 is considerably lower than the detectable lower limit water level A when the rotation is relatively low, for example, 1600 r / min, and even if there is no water in the water tank 3 and the drainage system 8, Despite the fact that no gummy occurs, it will continue to wait unnecessarily for water supply.

  Therefore, in the present embodiment, before the water level detection means 10 detects the water level, the circulation pump 20 is driven at a relatively low rotation so that the water level is automatically detected when the circulating shower discharge start water level B of the circulation pump 20 is reached. Water can be discharged into the rotating drum 4 as indicated by an arrow b in FIG. Thus, when the rinsing water is supplied up to the circulating shower discharge start water level B, the circulating water is automatically discharged from the injection port 51. The circulating shower discharge start water level B is lower than the detectable lower limit water level A of the water level detection means 10. Thus, without waiting for the detection of the water level detection means 10, when the water level is such that the rinse water can be discharged, a circulating shower is automatically performed, and the rinse performance is further improved. That is, the time for obtaining the same rinsing performance is shortened.

  When the control means 22 starts to drive the circulation pump 20, the control means 22 opens the water supply valve 7a and starts water supply. When the water level detection means 10 detects that the predetermined water level is equal to or higher than the detectable lower limit water level A, the control means 22 drives the circulation pump 20 at a relatively high speed, for example, 3500 r / min (second predetermined rotation speed). To do. Thereby, water can be sprayed in a wide area from the vicinity of the front side of the opening 13 in the rotating drum 4 to the vicinity of the back surface thereof as indicated by an arrow a in FIG.

  As a result, since the circulating pump 20 is always driven after the predetermined water level is reached before the start of water supply, the circulating water is discharged as indicated by arrows b and a in FIG. The rinsing effect by the circulating shower can be exhibited. However, when the circulation pump 20 is driven at a high rotation, it can be discharged into the rotary drum 4 over a wide area, and the circulation amount per unit time is also large. For this reason, since the rinsing effect by the circulation shower is increased, it is desirable to drive the circulation pump 20 at a high speed for as long a time as possible.

  Thus, by setting the rotation speed of the circulation pump 20 to the first predetermined rotation speed and the second rotation speed higher than the first rotation speed, the laundry near the front side of the opening 13 of the rotary drum 4, Circulating water can be supplied to both the laundry in the vicinity of the opening side of the rotating drum 4 and the vicinity of the back side. As a result, since the circulating water can be uniformly supplied to the laundry inside the rotating drum for a longer time, the rinsing time can be shortened while maintaining the rinsing performance.

  When the rotation of the rotating drum 4 stops, the control means 22 starts the rotation of the rotating drum 4 again and performs rinsing. At this time, the rotating drum 4 rotates in one direction, and the rotating speed of the rotating drum 4 is such that the laundry is stuck to the inside of the rotating drum 4. Since the laundry is stuck inside the rotating drum 4, the rinsing effect by the circulating shower can be obtained more efficiently. Further, it is desirable that the rotational speed of the rotating drum 4 is a rotational speed lower than the resonant rotational speed. Thereby, vibration and noise due to resonance can be avoided. The rotation speed at this time is preferably about 100 r / min, for example.

  When the water level detection means 10 detects that the rinse water level has been reached, the control means 22 closes the water supply valve 7a and stops water supply.

  After that, when the laundry absorbs the rinsing water and the water level detection means 10 detects that the water level in the water tank 3 is equal to or lower than the predetermined water level, the control means 22 makes the rotational speed of the circulation pump 20 relatively low. For example, it is controlled to 1600 r / min. Thereby, air smearing can be reliably prevented. As a result, water can be discharged into the rotating drum 4 as shown by the arrow b in FIG. When the water level in the water tank 3 falls below a predetermined water level, there are also methods of stopping the circulation pump 20 or driving it intermittently. However, in that case, not only the driving rate of the circulation pump 20 is reduced, but also other harmful effects occur. That is, if the motor of the circulation pump 20 is intermittently driven, a change in sound feeling is accompanied when the start and stop are repeated, which may give the user a discomfort such as a roaring sound. If the circulating water is repeatedly discharged or not, it may be mistaken for a device failure. In the present embodiment, since the rotational speed of the circulation pump 20 is reduced, no roaring noise is generated, and the user is not mistaken for a visual failure. Further, since the circulation pump 20 is not stopped or intermittently driven, it is possible to prevent the drive rate of the circulation pump 20 from being lowered unnecessarily and the occurrence of a roaring sound due to the intermittent drive. Furthermore, since the circulating water is supplied to the laundry in the vicinity of the opening front side of the rotating drum, the rinsing effect by the circulating shower can be sufficiently obtained.

  When the rinsing operation is performed for a predetermined time, the control means 22 opens the drain valve 19 and starts draining. When rinsing is set a plurality of times, the same operation as the rinsing step is performed. When rinsing is performed once, the process proceeds to a dehydration process.

  In the dehydration process, as in the dehydration operation after the washing process, the control means 22 controls the motor 6 to increase the rotation speed of the rotary drum 4 to 900 r / min, and dehydrates the rinse water from the laundry. When the dehydrating operation is performed for a predetermined time, the control unit 22 stops the motor 6 and stops the rotation of the rotating drum 4. This completes the laundry.

  In the present embodiment, the configuration of the water circulation system 16 as shown in FIG. 1 is used to circulate the water in the water tank 3. However, the present invention is not limited to this, and the injection port 51 of the water circulation system 16 is used as the water tank. 3 may be formed on the outer periphery of the opening 13 with nozzles, and the same effect can be obtained.

  INDUSTRIAL APPLICABILITY The washing machine according to the present invention is effective as a washing machine that performs rinsing efficiently with a small amount of rinse water using a circulating shower.

2 Washing machine body 3 Water tank 4 Rotating drum 4a Rotating shaft 4b Stirring protrusion 4e Through hole 6 Motor 7 Water supply system 7a Water supply valve (water supply means)
7b Detergent storage section 8 Drainage system 8a Drainage pipe 8b Drainage filter 10 Water level detection means 13 Opening 16 Water circulation system 19 Drainage valve 20 Circulation pump 21 Operation panel 22 Control means 31 Circulation path 31a Inflow side path 31b Discharge side path 51 Injector

Claims (3)

A rotating drum formed into a bottomed cylindrical shape;
A water tank that is disposed inside the rotating drum so that the rotating shaft is inclined horizontally or downward from the opening front side toward the back side as the bottom;
Water supply means for supplying water into the water tank;
Water level detecting means for detecting the level of the washing water in the water tank;
A motor for rotating the rotating drum;
A water circulation system in which the washing water in the water tank is circulated in the rotary drum by a circulation pump provided in the circulation path through a circulation path connected to the water tank;
Control means for controlling the motor or the like and executing a rinsing step,
In the rinsing step, the control means drives the rotation speed of the circulation pump at a first predetermined rotation speed before the water level detection by the water level detection means, and after the water supply by the water supply means starts, the water level detection means A washing machine, wherein after detecting that the water level has been reached, the rotation speed of the circulation pump is driven at a second predetermined rotation speed higher than the first predetermined rotation speed. 2. The washing machine according to claim 1, wherein, in the rinsing step, the control unit drives the rotation speed of the circulation pump at a first predetermined rotation speed before water supply is started by the water supply unit. When the rotation speed of the circulation pump is the second predetermined rotation speed, the control means detects the rotation speed of the circulation pump when the rotation speed of the circulation pump is equal to or lower than the predetermined water level. The washing machine according to claim 1 or 2, wherein a rotational speed is set.

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