WASHING MACHINE

Abstract

 A washing machine includes: a plurality of water reservoir portions; a plurality of drain ports (18a, 18b) formed on bottom portions of each of the plurality of water reservoir portions; and a drain passage (21) through which water in the plurality of water reservoir portions is discharged outside the washing machine. The washing machine further includes: a plurality of drain pipes (19a, 19b) which communicably connect each of the plurality of drain ports (18a, 18b) to the drain passage (21); and one drain valve (27) disposed at a merging portion (24) where water flowing through each of the plurality of drain pipes (19a, 19b) firstly merges with each other. One drain valve (27) is configured to control stopping and discharging of the water from the plurality of drain ports (18a, 18b).

Description

TECHNICAL FIELD

[0001] The present invention relates to a washing machine which performs washing of fibrous products such as clothing.

BACKGROUND ART

[0002] In a conventional washing machine, there has been proposed a washing machine provided with a plurality of washing tubs. In general, such a washing machine is configured such that a pipe is connected to a drain port formed on each washing tub, drain water is introduced into the pipes, outlets sides of the respective pipes are joined to each other, and drain water is discharged to the outside of the washing machine through one hose (for example, see Patent Literatures 1 to 4).

[0003] In the conventional washing machine described in Patent Literature 1, water reservoir portions are formed by dividing a lower portion of a water tub into a plurality of regions, and drain valves are respectively mounted on bottom portions of respective water reservoir portions. Drain water which flows out from the respective drain valves is merged on a downstream side of the drain valves, and is discharged to the outside of the washing machine from one place through a drain hose.

[0004] A conventional washing machine described in Patent Literature 2 includes: a drain passage for a main tub and a drain passage for a sub tub which are connected to a bottom portion of an outer tub and a bottom portion of a sub washing tub respectively; and a common drain passage at which water which flows through the respective drain passages is merged on a downstream side of the respective drain passages. The drain passage for a main tub, the drain passage for a sub tub, and the common drain passage are respectively provided with a main drain valve, a sub drain valve, and an intermediate valve. At the time of draining water from the outer tub, the main drain valve and the intermediate valve are opened. At the time of draining water from the sub washing tub, the sub drain valve and the intermediate valve are opened.

[0005] In a conventional washing machine described in Patent Literature 3, only the draining of water from a washing tub is controlled by a drain valve mounted in a drain pipe. FIG. 10 is a perspective view showing an essential part of the conventional washing machine described in Patent Literature 3, and FIG. 11 is a cross-sectional view showing the essential part.

[0006] In FIG. 10 and FIG. 11, washing drain port 152 is formed on a bottom portion of washing tub 151, and spin-drying drain port 154 is formed on a bottom portion of spin-drying tub 153. Drain hose 157 is connected to a downstream side of connecting pipe 156 on which drain valve 155 is mounted. Washing drain port 152 of washing tub 151 is connected to washing drain portion 156a of connecting pipe 156 on an upstream side of drain valve 155. Spin-drying drain port 154 of spin-drying tub 153 is connected to spin-drying drain portion 156b of connecting pipe 156 on a downstream side of drain valve 155.

[0007] Partition plate 159 is formed on an intersecting portion between connecting pipe 156 and spin-drying drain portion 156b. The inside of connecting pipe 156 is partitioned by partition plate 159 into washing drain passage 158a through which water which flows into connecting pipe 156 from washing drain portion 156a flows and spin-drying drain passage 158b through which water which flows into connecting pipe 156 from spin-drying drain portion 156b flows. Due to such a constitution, draining of water is accelerated.

[0008] In a conventional washing machine described in Patent Literature 4, a drain valve which opens and closes a drain port of a washing tub is connected to a branched drain pipe arranged below a spin-drying tub, and water in the washing tub is discharged to the outside of the washing machine through a drain hose connected to the branched drain pipe. FIG. 12 is a cross-sectional view with a part broken away of an essential part of the conventional washing machine described in Patent Literature 4, and FIG. 13 is a cross-sectional view showing an essential part of the washing machine.

[0009] In FIG. 12 and FIG. 13, drain valve 163 is arranged below drain port 162 formed in a bottom portion of washing tub 161, and branched drain pipe 166 is arranged below drain port 165 formed in a bottom portion of spin-drying tub 164. Drain valve 163 and branched drain pipe 166 are connected to each other by pipe 167, and water is discharged to the outside of the washing machine through drain hose 168 connected to a downstream side of branched drain pipe 166.

[0010] Branched drain pipe 166 has an inlet port which is divided into inlet portion 169 through which water flows into branched drain pipe 166 from washing tub 161 and inlet portion 170 through which water flows into branched drain pipe 166 from spin-drying tub 164. Branched drain pipe 166 also has terminal outlet 171 of inlet portion 169 and terminal outlet 172 of inlet portion 170 which are arranged in parallel to each other. Due to such a constitution, drain water on a washing tub 161 side and drain water on a spin-drying tub 164 side are merged in parallel to each other.

[0011] However, in the conventional washing machines described in Patent Literatures 1, 2, when the plurality of drain ports are provided, draining of water is controlled by the plurality of drain valves provided on the drain ports respectively, and drain water is merged on a downstream side of the plurality of drain valves and is discharged. Accordingly, when the plurality of drain valves are opened simultaneously, the flows of drain water collide with each other in the merging portion thus giving rise to a drawback that it is difficult to smoothly drain water. Further, since the plurality of drain valves are mounted in a drain passage, there exists a drawback that the constitution of the washing machine becomes complicated.

[0012] Further, although a technique has been proposed to prevent the collision of the flows at a portion where the plurality of flows of drain water are merged, this technique has the following drawback. That is, in the conventional washing machine described in Patent Literature 3, the drain port of the spin-drying tub is connected to a downstream side of the drain valve. Accordingly, in the constitution where the drain port is formed on each of the plurality of water reservoir portions, the washing machine cannot be operated in a state where the respective drain ports are closed by one drain valve so that it is difficult to acquire the smooth flow of drain water.

[0013] Further, in the conventional washing machine described in Patent Literature 4, second valve 173 is mounted on a branched drain pipe connected to a downstream side of the drain valve of the washing tub on a side where drain water which flows into the branched drain pipe from the washing tub and the spin-drying tub respectively is discharged. However, second valve 173 opens and closes distal end outlet 172 on a washing tube side while always maintaining distal end outlet 171 on a washing tub side in an open state. In this case, the flows of drain water collide with each other in the branched drain pipe so that the smooth flow of drain water which passes through the branched drain pipe is obstructed.

Citation List

Patent Literature

[0014] 

PTL 1: Unexamined Japanese Patent Publication No. 2006-230956

PTL 2: Unexamined Japanese Patent Publication No. H10-43466

PTL 3: Accepted Japanese Utility Model Publication No. S62-15037

PTL 4: Unexamined Japanese Patent Publication No. S55-84199

SUMMARY OF THE INVENTION

[0015] The present invention has been made to overcome the conventional drawbacks, and it is an object of the present invention to provide a washing machine which can smoothly drain water in a plurality of water reservoir portions with the simple constitution.

[0016] A washing machine according to the present invention includes: a plurality of water reservoir portions; a plurality of drain ports which are formed on bottom portions of each of the plurality of water reservoir portions; and a drain passage through which water in the plurality of water reservoir portions is discharged outside the washing machine. The washing machine according to the present invention further includes: a plurality of drain pipes which communicably connect each of the plurality of drain ports to the drain passage; and one drain valve disposed at a merging portion where the water flowing through each of the plurality of drain pipes firstly merges with each other. One drain valve is configured to control stopping and discharging of the water from the plurality of drain ports.

[0017] Due to such a constitution, a control of discharging of water from the drain ports provided to the plurality of respective water reservoir portions can be performed using one drain valve and hence, a drain operation can be smoothly performed with the simple constitution.

[0018] The washing machine of the present invention can perform a drain operation of the plurality of water reservoir portions with the simplified constitution.

BRIEF DESCRIPTION OF DRAWINGS

[0019] 

FIG. 1 is a perspective view of a washing machine according to a first exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an essential part of the washing machine according to the first exemplary embodiment of the present invention as viewed from a front side.

FIG. 3 is a cross-sectional view showing an essential part of the washing machine according to the first exemplary embodiment of the present invention as viewed from a side.

FIG. 4 is a perspective view showing an essential part in the vicinity of a drain valve of the washing machine according to the first exemplary embodiment of the present invention.

FIG. 5 is a top plan view showing the essential part in the vicinity of the drain valve of the washing machine according to the first exemplary embodiment of the present invention.

FIG. 6 is a cross-sectional view of the washing machine according to the first exemplary embodiment of the present invention taken along a line 6-6 in FIG. 5.

FIG. 7 is a cross-sectional view showing an essential part of the washing machine according to the first exemplary embodiment of the present invention in a state where the drain valve is closed.

FIG. 8 is a cross-sectional view showing an essential part of the washing machine according to the first exemplary embodiment of the present invention in a state where the drain valve is opened.

FIG. 9 is a cross-sectional view showing an essential part of a washing machine according to a second exemplary embodiment of the present invention in a state where a drain valve is opened.

FIG. 10 is a perspective view showing an essential part of a conventional washing machine described in Patent Literature 3.

FIG. 11 is a cross-sectional view showing an essential part of the conventional washing machine described in Patent Literature 3.

FIG. 12 is a cross-sectional view with a part broken away of an essential part of the conventional washing machine described in Patent Literature 4.

FIG. 13 is a cross-sectional view showing an essential part of the conventional washing machine described in Patent Literature 4.

DESCRIPTION OF EMBODIMENTS

[0020] Hereinafter, exemplary embodiments of the present invention are described by reference to drawings. The present invention is not limited by these embodiments.

FIRST EXEMPLARY EMBODIMENT

[0021] FIG. 1 is a perspective view of washing machine 50 according to a first exemplary embodiment of the present invention. FIG. 2 is a cross-sectional view showing an essential part of washing machine 50 as viewed from a front side. FIG. 3 is a cross-sectional view showing an essential part of washing machine 50 as viewed from a side. FIG. 4 is a perspective view showing an essential part in the vicinity of a drain valve of washing machine 50. FIG. 5 is a top plan view showing an essential part in the vicinity of the drain valve of washing machine 50. FIG. 6 is a cross-sectional view of washing machine 50 taken along a line 6-6 in FIG. 5. FIG. 7 is a cross-sectional view showing an essential part of washing machine 50 in a state where a drain valve is closed. FIG. 8 is a cross-sectional view showing an essential part of washing machine 50 in a state where the drain valve is opened.

[0022] Washing machine 50 includes outer tub 1, housing 2, suspension mechanisms 3, first drum 4a, second drum 4b, drain pipe 19a, drain pipe 19b, connecting pipe 20, drain passage 21, merging portion 24, drain valve 27, drive device 28, and control part 30.

[0023] Outer tub 1 is resiliently supported by a plurality of suspension mechanisms 3 in the inside of housing 2 of washing machine 50. First drum 4a has first inlet port 6a through which laundry 5 to be stored in the inside of first drum 4a is put in or laundry 5 stored in first drum 4a is taken out from first drum 4a. First drum 4a is arranged in the inside of outer tub 1. First drum 4a is rotatable about rotary shaft 7. A large number of small discharge holes 9a are formed in peripheral wall 8a of first drum 4a.

[0024] First inlet port 6a is configured to be opened or closed by inner lid 10a which is mounted on a portion of peripheral wall 8a. First opening portion 11a of outer tub 1 which faces first inlet port 6a in an opposed manner is connected with housing 2 while ensuring an air-tightness using first packing 12a.

[0025] Second drum 4b is arranged in the inside of outer tub 1 coaxially with first drum 4a and in a rotatable manner about rotary shaft 7. Second drum 4b has second inlet port 6b through which laundry 5 is put in or taken out from second drum 4b, and a large number of small discharge holes 9b are formed in peripheral wall 8b of second drum 4b. Due to such a constitution, second drum 4b is constituted in the substantially same manner as first drum 4a, and has the substantially same volume as first drum 4a.

[0026] Second inlet port 6b is configured to be opened or closed by inner lid 10b which is mounted on a portion of peripheral wall 8b. Second opening portion 11b of outer tub 1 which faces second inlet port 6b in an opposed manner is connected with housing 2 while ensuring an air-tightness using second packing 12b.

[0027] First drum 4a and second drum 4b are arranged coaxially with each other in the horizontal direction using rotary shaft 7, and are respectively rotated in the normal and reverse directions in synchronism with each other by motor 13 arranged outside outer tub 1 on a second drum 4b side. Motor 13 is constituted of a brushless DC motor, and a rotational speed of motor 13 is freely changed by an inverter control.

[0028] At least a lower portion of outer tub 1 in which first drum 4a and second tub 4b are mounted in a rotatable manner is partitioned by outer tub partition member 14 so as to house a lower portion of first drum 4a and a lower portion of second drum 4b respectively. Outer tub partition member 14 extends upwardly from a bottom portion of outer tub 1 to an area in the vicinity of rotary shaft 7. Water reservoir portions 15a, 15b which are partitioned from each other by outer tub partition member 14 are formed on the bottom portion of outer tub 1 below first drum 4a and second drum 4b respectively. Due to outer tub partition member 14, water in first drum 4a and water in second drum 4b are not mixed with each other.

[0029] Water supply valve 16 is communicably connected to water reservoir portions 15a, 15b through water supply pipe 17. Water used in outer tub 1 passes through water supply valve 16 and water supply pipe 17, and is supplied to either one of or both of water reservoir portions 15a, 15b by a water supply change-over valve (not shown in the drawing).

[0030] Drain ports 18a, 18b are formed in bottom portions of the water reservoir portions 15a, 15b respectively, and drain pipes 19a, 19b are connected to the drain ports 18a, 18b respectively. Outlets of drain pipes 19a, 19b on a downstream side are communicably connected to merging portion 24 by way of connecting pipe 20. Connecting portion 20a which is formed into an approximately T shape is mounted on connecting pipe 20, and connecting pipe 20 is connected to outlet-side end portions of drain pipes 19a, 19b by way of connecting portion 20a. Merging portion 24 is connected to drain passage 21 through which drain water flows to the outside of the washing machine.

[0031] The inside of connecting pipe 20 is divided into first water passage 23a and second water passage 23b which are partitioned by partition plate 22 along the flowing direction of washing water. First water passage 23a is communicably connected to drain pipe 19a which is communicated with water reservoir portion 15a on an upstream side thereof, and second water passage 23b is communicably connected to drain pipe 19b which is communicated with water reservoir portion 15b on an upstream side thereof.

[0032] A downstream side of connecting pipe 20 is communicably connected to drain passage 21 through which water is discharged to the outside of the washing machine by way of the merging portion 24. Outlet-side end portions of first water passage 23a and second water passage 23b are connected to first inlet port 25a and second inlet port 25b of merging portion 24 respectively. Drain water flown out to drain pipes 19a, 19b respectively from respective drain ports 18a, 18b is merged at merging portion 24 for the first time.

[0033] First inlet port 25a and second inlet port 25b of merging portion 24 are formed such that first inlet port 25a and second inlet port 25b of merging portion 24 are arranged adjacent to each other on the same plane at an inlet port of merging portion 24. Further, a size of an opening portion of an outlet-side end portion of first water passage 23a and a size of an opening portion of an outlet-side end portion of second water passage 23b, that is, a cross-sectional area of a first water passage 23a and a cross-sectional area of second water passage 23b are set substantially equal to each other.

[0034] Merging portion 24 is configured such that a cross-sectional area of merging portion 24 is increased along the flowing direction of washing water from first inlet port 25a and second inlet port 25b of merging portion 24 toward inside 26 of merging portion 24. That is, cross-sectional area a1 of a water passage in inside 26 of merging portion 24 through which washing water flows is set larger than sum a2 of a cross-sectional area of first water passage 23a and a cross-sectional area of second water passage 23b.

[0035] Drain valve 27 which opens and closes first inlet port 25a and second inlet port 25b of merging portion 24 simultaneously and controls the passing of washing water which is drain water is mounted in merging portion 24. Drain valve 27 is driven by drive device 28 such as a motor, and drain valve 27 is operated in an advanceable and retractable manner with respect to first inlet port 25a and second inlet port 25b of merging portion 24.

[0036] Distal end portion 27a of drain valve 27 which faces first inlet port 25a and second inlet port 25b of merging portion 24 in an opposed manner is made of an elastic material such as rubber. In operating the washing machine, when washing water is to be reserved in water reservoir portions 15a, 15b of outer tub 1 as in the case of washing time, rinsing time or the like, as shown in FIG. 7, drain valve 27 is moved in the direction indicated by arrow A by drive device 28. Due to such an operation, first inlet port 25a and second inlet port 25b of merging portion 24 are closed by distal end portion 27a so that the flow of washing water is stopped.

[0037] When washing water is to be discharged to the outside of the washing machine as in the case of draining time, spin-drying time or the like, as shown in FIG. 8, drain valve 27 is moved in the direction indicated by arrow B so that distal end portion 27a is separated from first inlet port 25a and second inlet port 25b of merging portion 24 whereby these inlet ports are released. Due to such an operation, flow X of washing water and flow Y of washing water are merged in inside 26 of merging portion 24 thus forming flow Z and, thereafter, washing water is discharged to the outside of housing 2 through drain passage 21.

[0038] Openable and closeable door 29 is mounted on an upper surface of housing 2, and door 29 is opened when laundry 5 is put in and taken out from first drum 4a and second drum 4b.

[0039] Control part 30 which controls washing operation is arranged on an upper portion in the inside of housing 2. Control part 30 controls motor 13, water supply valve 16, drain valve 27 and the like, and suitably executes respective steps such as washing, rinsing and spin-drying.

[0040] The manner of operation and effects of the washing machine having the above-mentioned constitution are described hereinafter. Washing is sequentially performed by control part 30 in order of washing step, rinsing step and spin-drying step. The description is made with respect to the case where laundry 5 such as clothing is put in first drum 4a and second drum 4b and washing is performed.

[0041] Approximately the same amount of laundry 5 is put in both first drum 4a and second drum 4b. Thereafter, water supply valve 16 is opened in a state where drain valve 27 is closed, water is supplied to both water reservoir portions 15a, 15b which are formed on the bottom portion of the inside of outer tub 1 through water supply pipe 17, and a predetermined amount (same amount) of washing water which is set in advance is supplied to the respective water reservoir portions.

[0042] The washing step is performed by rotating first drum 4a and second drum 4b in the normal and reverse directions respectively about rotary shaft 7 by driving motor 13 at a rotational speed (for example, approximately 45rpm) with which a so-called beat washing operation can be performed. In the beat washing operation, laundry 5 is lifted up in the rotational direction and, thereafter, laundry 5 is made to fall.

[0043] When the beat washing operation is finished, washing water containing dirt and soils is drained. When drain valve 27 is moved by drive device 28 in the direction indicated by arrow B in FIG. 8, first inlet port 25a and second inlet port 25b of merging portion 24 which have been closed by distal end portion 27a are opened so that inside 26 of merging portion 24 and first water passage 23a and second water passage 23b are communicated with each other.

[0044] Washing water used in water reservoir portion 15a flows through drain pipe 19a from drain port 18a and arrives at connecting portion 20a, and flows through first water passage 23a formed by partitioning the inside of connecting pipe 20 along the flow direction of washing water toward merging portion 24.

[0045] On the other hand, washing water used in water reservoir portion 15b flows through drain pipe 19b from drain port 18b and arrives at connecting portion 20a, and flows through second water passage 23b formed by partitioning the inside of connecting pipe 20 in the flow direction of washing water toward merging portion 24.

[0046] Flow X of washing water flown out from drain port 18a of water reservoir portion 15a and flow Y of washing water flown out from drain port 18b of water reservoir portion 15b flow through first water passage 23a and second water passage 23b respectively in the same direction toward merging portion 24, and are flown out into inside 26 of merging portion 24 from first inlet port 25a and second inlet port 25b of merging portion 24 respectively and are merged for the first time.

[0047] First water passage 23a and second water passage 23b formed in connecting pipe 20 provide straightening portion 20b having a straight line shape between connecting portion 20a and merging portion 24. Flow X of washing water and flow Y of washing water are straightened parallel to each other by straightening portions 20b. Washing water which flows through straightening portions 20b in first water passage 23a and second water passage 23b are flown out to inside 26 of merging portion 24 in a state where the flows of washing water are straightened parallel to each other. Accordingly, the flow of water which flows into merging portion 24 from inlet port 25a and the flow of water which flows into merging portion 24 from inlet port 25b form flow Z without colliding with each other, and flow Z is guided to drain passage 21 and is smoothly flown out to the outside of the washing machine.

[0048] Cross-sectional area a1 of the water passage in inside 26 of merging portion 24 is set larger than sum a2 of cross-sectional areas of water passages in first inlet port 25a and second inlet port 25b of merging portion 24 through which washing water flows into inside 26 of merging portion 24 from first water passage 23a and second water passage 23b. Due to such a constitution, merging portion 24 plays a role of a buffer for drain water, and the draining operation can be smoothly performed with the simple constitution.

[0049] Further, first water passage 23a and second water passage 23b respectively have the end portions thereof on a downstream side opened in a state where the end portions are arranged adjacent to each other on the same plane at inlet ports 25a, 25b of merging portion 25 and hence, outlets of the plurality of water passages 23a, 23b can be opened and closed at the same timing. Accordingly, the flows of water which flow into merging portion 24 are smoothly flown out without colliding with each other.

[0050] Besides at the time of performing draining in the above-mentioned washing step, also at the time of performing draining in the rinsing step, the draining operation of washing water can be smoothly performed in the same manner. Further, also in an intermediate spin-drying step which is performed subsequent to the washing step as well as in a final spin-drying step which is performed subsequent to the rinsing step, the draining operation can be smoothly performed in the same manner.

[0051] When washing is performed in either one of first drum 4a and second drum 4b, the supply of water and the draining of water are performed only with respect to the drum where washing is performed.

[0052] As described above, washing machine 50 of this exemplary embodiment includes: the plurality of water reservoir portions 15a, 15b; the plurality of drain ports 18a, 18b formed on the bottom portions of each of the plurality of water reservoir portions 15a, 15b; and drain passage 21 for discharging water in the plurality of water reservoir portions 15a, 15b outside the washing machine. Further, washing machine 50 includes: the plurality of drain pipes 19a, 19b which communicably connect each of the plurality of drain ports 18a, 18b and drain passage 21; and one drain valve 27 disposed in merging portion 24 where water flowing through each of the plurality of drain pipes 19a, 19b is merged with each other for the first time. One drain valve 27 controls stopping and discharging of water from the plurality of drain ports 18a, 18b. Accordingly, the control of water flown from the plurality of drain ports 18a, 18b formed on the plurality of water reservoir portions 15a, 15b respectively is performed by one drain valve 27. Further, there exists no possibility that flows of water which flow into merging portion 24 from respective merging portion inlet ports 25a, 25b collide with each other so that water can be smoothly flown out and hence, the draining operation can be smoothly performed with the simple constitution.

[0053] Washing machine 50 of this exemplary embodiment is configured such that first drum 4a and second drum 4b are driven by motor 13 about same rotary shaft 7 in synchronism with each other. However, washing machine 50 may be configured such that first drum 4a and second drum 4b are driven by dedicated motors respectively. In this case, the plurality of drums 4a, 4b can be operated in different operation modes respectively.

[0054] Further, washing machine 50 of this exemplary embodiment is configured such that the cross-sectional area of the water passage in merging portion 24 is set larger than the sum of cross-sectional areas of water passages, in respective merging portion inlet ports 25a, 25b through which water flows into merging portion 24. Accordingly, merging portion 24 plays a role of a buffer for drain water and hence, the draining operation can be smoothly performed.

[0055] Washing machine 50 of this exemplary embodiment is configured such that the plurality of water reservoir portions 15a, 15b are formed on the bottom portion of outer tub 1 in which the plurality of drums 4a, 4b are mounted in a rotatable manner. Accordingly, even when the laundry is put in the plurality of drums 4a, 4b and a washing operation in drum 4a and a washing operation in drum 4b are performed simultaneously, water can be smoothly drained from respective water reservoir portions 15a, 15b and hence, the difference in time required for draining between draining of water from reservoir portions 15a and draining of water from reservoir portions 15b can be reduced.

[0056] Washing machine 50 of this exemplary embodiment further includes straightening portion 20b which makes water respectively flowing through the plurality of drain pipes 19a, 19b toward merging portion 24 flow in the same direction and hence, water which flows through the plurality of drain pipes 19a, 19b respectively flows into merging portion 24 through straightening portion 20b. Accordingly, the flows of water which flow into merging portion 24 from respective merging portion inlet ports 25a, 25b are guided to drain passage 21 without colliding with each other, and are smoothly flown out.

[0057] Washing machine 50 of this exemplary embodiment includes connecting pipe 20 which communicably connects the plurality of drain pipes 19a, 19b and merging portion 24 to each other, and connecting pipe 20 has the plurality of water passages 23a, 23b which are defined along the direction that water flows by the partition member. The plurality of water passages 23a, 23b are communicably connected to the plurality of drain pipes 19a, 19b on an upstream side thereof respectively, and are communicably connected to merging portion 24 on a downstream side thereof respectively, and the plurality of water passages 23a, 23b constituted straightening portion 20b. Accordingly, the flows of water which flow into merging portion 24 from respective merging portion inlet ports 25a, 25b are guided to drain passage 21 without colliding with each other, and are smoothly flown out.

[0058] Washing machine 50 of this exemplary embodiment is configured such that the plurality of water passages 23a, 23b respectively have downstream-side end portions thereof opened in a state where the end portions are arranged adjacent to each other on the same plane of merging portion inlet ports 25a, 25b. Due to such a constitution, the outlets of the plurality of water passages 23a, 23b are opened and closed at the same timing. Accordingly, there exists no possibility that the flows of water which flow into merging portion 24 collide with each other and hence, water can be smoothly flown out.

[0059] Water reservoir portions 15a, 15b are formed by partitioning the bottom portion of the outer tub 1 by outer tub partition member 14. However, washing machine 50 may be configured such that a plurality of outer tubs 1 are provided, and water reservoir portions 15a, 15b are formed in the plurality of outer tubs 1 respectively.

[0060] Water reservoir portions 15a, 15b are formed on the bottom portion of outer tub 1 and reserve washing water therein. However, water reservoir portions 15a, 15b may be formed on a bottom portion of the water reservoir portion for reserving washing water, the circulation portion for circulating washing water, the spin-drying portion or the like. In short, it is sufficient that draining can be performed at plural portions.

SECOND EXEMPLARY EMBODIMENT

[0061] FIG. 9 is a cross-sectional view showing an essential part of a washing machine according to a second exemplary embodiment of the present invention in a state where a drain valve is opened. This exemplary embodiment is characterized in that end portions of drain pipes 19a, 19b on a downstream side are connected to first inlet port 25a and second inlet port 25b of merging portion 24 respectively. Other constitutions of the second exemplary embodiment are equal to the corresponding constitutions of the first exemplary embodiment and hence, constitutional parts identical with the constitutional parts of the first exemplary embodiment are given the same symbols, and the detailed description of other constitutions of the second embodiment is omitted.

[0062] Straightening portion 20b having a straight-line shape where flows of water are directed in parallel to each other in the same direction toward merging portion 24 is provided to a merging portion 24 side of drain pipes 19a, 19b. As shown in FIG. 9, the direction of flow X of drain water which flows through drain pipe 19a and the direction of flow Y of drain water which flows through drain pipe 19b are directed opposite to each other on a drain ports 18a, 18b side. Drain pipes 19a, 19b are gently bent by 90 degrees at intermediate portions thereof respectively and are arranged parallel to each other thus forming straightening portion 20b. Accordingly, flow X and flow Y are straightened parallel to each other in straightening portion 20b. Drain water which flows through straightening portion 20b in drain pipes 19a, 19b is flown out into inside 26 of merging portion 24 from first inlet port 25a and second inlet port 25b of merging portion 24 in a state where the flows of drain water are straightened parallel to each other. Accordingly, these water flows form flow Z without colliding with each other, and flow Z is guided to drain passage 21.

[0063] By forming straightening portion 20b in drain pipes 19a, 19b, the connecting constitution which connects drain pipes 19a, 19b and merging portion 24 to each other can be simplified. Further, drain water can be made smoothly flow into straightening portion 20b having a straight-line shape through which drain water flow parallel toward merging portion 24. Accordingly, straightening effect can be enhanced.

INDUSTRIAL APPLICABILITY

[0064] As has been described heretofore, the washing machine according to the present invention can smoothly perform the draining operation of the plurality of water reservoir portions with the simple constitution. Accordingly, the washing machine according to the present invention is useful as a washing machine or the like provided with a plurality of water reservoir portions.

REFERENCE MARKS IN THE DRAWINGS

[0065] 

1

outer tub

2

housing

3

suspension mechanism

4a

first drum

4b

second drum

5

laundry

6a

first inlet port

6b

second inlet port

7

rotary shaft

8a, 8b

peripheral wall

9a, 9b

discharge hole

10a, 10b

inner lid

11a

first opening portion

11b

second opening portion

12a

first packing

12b

second packing

13

motor

14

outer tub partition member

15a, 15b

water reservoir portion

16

water supply valve

17

water supply pipe

18a, 18b

drain port

19a, 19b

drain pipe

20

connecting pipe

20a

connecting portion

20b

straightening portion

21

drain passage

22

partition plate

23a

first water passage

23b

second water passage

24

merging portion

25a

first merging portion inlet port

25b

second merging portion inlet port

26

inside

27

drain valve

27a

distal end portion

28

drive device

29

door

30

control part

50

washing machine

Claims

1. A washing machine comprising:

a plurality of water reservoir portions;

a plurality of drain ports which are formed on bottom portions of each of the plurality of water reservoir portions;

a drain passage through which water in the plurality of water reservoir portions is discharged outside the washing machine;

a plurality of drain pipes which communicably connect each of the plurality of drain ports to the drain passage; and

one drain valve disposed at a merging portion where the water flowing through each of the plurality of drain pipes firstly merges with each other, wherein

the one drain valve is configured to control stopping and discharging of the water from the plurality of drain ports.

2. The washing machine according to claim 1, wherein a cross-sectional area of a water passage in the merging portion is larger than a sum of cross-sectional areas of water passages, through which the water flows into the merging portion, at respective inlets to the merging portion.

3. The washing machine according to claim 1 or 2, wherein the plurality of water reservoir portions are formed on a bottom portion of an outer tub in which a plurality of drums are disposed in a rotatable manner.

4. The washing machine according to claim 1, further comprising:

a straightening portion which is configured to make the water flowing through each of the plurality of drain pipes toward the merging portion flow in the same direction,

wherein the water flowing through each of the plurality of drain pipes flows into the merging portion through the straightening portion.

5. The washing machine according to claim 4, further comprising:

a connecting pipe which communicably connects each of the plurality of drain pipes to the merging portion,

wherein the connecting pipe includes a plurality of water passages which are defined by a partition member along a direction that the water flows,

the plurality of respective water passages are communicably connected with the plurality of drain pipes on an upstream side thereof, and are communicably connected with the merging portion on a downstream side thereof, and

the plurality of water passages form the straightening portion.

6. The washing machine according to claim 5, wherein the plurality of water passages have end portions thereof on a downstream side opened in a state where the end portions are arranged adjacent to each other on the same plane at an inlet of the merging portion.

7. The washing machine according to claim 4, wherein the plurality of drain pipes have the straightening portion having a straight-line shape which causes flows of water flowing toward the merging portion to be directed parallel to each other in the same direction.

Drawing