Patent Publication Number: US-10316449-B2

Title: Washing machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage application under 35 U.S.C. § 371 of International Application No. PCT/KR2016/002768, filed Mar. 18, 2016, which claims the benefit of Korean Application No. 10-2015-0038754, filed on Mar. 20, 2015. The disclosures of the prior applications are incorporated by reference in their entirety. 
     TECHNICAL FIELD 
     The present invention relates to a washing machine, and more particularly, to a washing machine in which a door structure is improved to prevent vibration and noise generated in a tub when the washing machine is operated from being delivered to a case of the washing machine. 
     BACKGROUND ART 
     Generally, a washing machine is an appliance that removes various contaminants attached to clothes, bedding, etc. by using an emulsification process of detergent, or friction of a water flow according to a pulsator or drum, and impact applied to laundry. 
     A full automatic washing machine which has been recently developed automatically performs a series of strokes such as a washing course, a rinsing course and a dehydrating course without manipulation of a user. 
     Also, demands of a drum type washing machine are gradually being increased, in which tangle and wrinkling of laundry little occur and a whole height is reduced as compared with a pulsator washing machine of which washing tub is rotated in a standing state. 
     A structure of the aforementioned drum type washing machine  10  will be described in brief with reference to the accompanying drawing. 
     As shown in  FIG. 1 , the drum type washing machine  10  includes a main body cabinet  11  forming an external appearance, a tub (not shown) arranged inside the main body cabinet  11  and supported by a damper (not shown) and a spring (not shown), in which washing water is stored, and a cylindrical drum  15  arranged inside the tub to put laundry therein, wherein a driving force is delivered to the drum  15  by a driving unit  17  for washing laundry put into the drum  15 . 
     Such a drum type washing machine  10  according to the related art is necessarily provided with a gasket  19  between an opening of a tub  13  and the main body cabinet  11  to prevent leakage of washing water stored in the tub  13  from occurring. 
     Meanwhile, the washing machine  10  according to the related art necessarily causes vibration due to factors such as a rotational force of the drum  15  and eccentricity of laundry when the drum  15  is rotated to wash and dehydrate laundry put into the drum  15 , wherein the vibration generated by rotation of the drum  15  is delivered to the outside through the tub  13  and the cabinet  11 . 
     In this case, vibration and nose delivered to the tub  13  are delivered to the cabinet  11  through the gasket  19  that maintains water density between the cabinet  11  and the tub  13 , whereby a problem occurs in that vibration and noise are generated in the cabinet  11 . 
     Also, in case of the washing machine  10  according to the related art, laundry is interposed between a door  12  for closing the tub  13  and the drum  15  which is rotated. To prevent laundry from being interposed between the door and the drum, an inner side of the door  12  is protruded toward an inner side of the opening of the tub  13  or the opening of the drum  15 . However, such a protrusion structure of the door  12  occupies washing capacity, whereby a problem occurs in that substantial washing capacity is deteriorated. 
     DISCLOSURE 
     Technical Problem 
     An object of the present invention is to provide a washing machine that improves a structure between the tub and the cabinet to prevent vibration of a tub from being delivered to a cabinet through a gasket, thereby preventing vibration and noise of the tub from being delivered to the cabinet. 
     Another object of the present invention is to provide a washing machine that improves an inner structure between a cabinet and a tub to increase tub capacity as compared with the related structure. 
     Other object of the present invention is to provide a washing machine that includes a cabinet door for opening or closing a cabinet and a tub door for opening or closing a tub to allow the cabinet door and the tub door to interwork with each other when the cabinet door and the tub door are opened or closed. 
     Technical Solution 
     To achieve these objects and other advantages and in accordance with the purpose of the invention, a washing machine according to one embodiment of the present invention comprises a cabinet having a first insertion hole; a tub provided in the cabinet, having a second insertion hole aligned with the first insertion hole; a cabinet door provided in the cabinet, opening or closing the first insertion hole; a tub door provided in the tub, opening or closing the second insertion hole; a hinge unit for elastically supporting the tub door in the opening direction of the second insertion hole; and an anti-friction member provided on one among surfaces where the tub door and the cabinet door face each other, for preventing a direct friction between the tub door and the cabinet door. 
     Preferably, the washing machine further comprises an unlocking unit for releasing a locking state of the tub door when the cabinet door is opened. 
     Preferably, the cabinet includes a cabinet door lock for maintaining a locking state of the cabinet door, and the tub includes a tub door lock for maintaining a locking state of the tub door. 
     Preferably, the unlocking unit includes a release lever provided in a grip portion of the cabinet door; a release switch for sensing opening of the cabinet door in accordance with an operation of the release lever; and a tub door lock releaser for releasing the tub door lock in accordance with sensing of the release switch. 
     Preferably, the unlocking unit includes a release lever provided in a grip portion of the cabinet door; a release switch for sensing opening of the cabinet door in accordance with an operation of the release lever; and a tub door lock for releasing the locking state of the tub door in accordance with sensing of the release switch. 
     Preferably, the cabinet door is fixed to the hinge unit to have a rotational shaft to be spaced apart from the hinge unit. 
     Preferably, the cabinet door is opened by interworking with the tub door as the tub door is opened. 
     Preferably, the anti-friction member pressurizes the cabinet door to open the first insertion hole as the tub door is opened. 
     Preferably, the tub door is closed by interworking with the cabinet door as the cabinet door is closed. 
     Preferably, the cabinet door pressurizes the anti-friction member to close the first insertion hole as the cabinet door is closed. 
     Preferably, the anti-friction member includes a pressurizing roller provided at an outer side of the tub door to pressurize the cabinet door to be adjacent to an inner side of the cabinet door. 
     Preferably, the tub includes a tub door lock for maintaining the locking state of the tub door, and the tub door lock switches the tub door to a locking state as the cabinet door is rotated in a closing direction. 
     Preferably, the cabinet includes a cabinet door lock for maintaining the locking state of the cabinet door, and the tub door lock switches the tub door to a locking state after the cabinet door is switched to the locking state by the cabinet door lock. 
     Preferably, the cabinet door lock moves the cabinet door to be spaced apart from the tub door after the tub door is switched to the locking state. 
     Advantageous Effects 
     According to the washing machine of the present invention, a structure between a tub and a cabinet is improved to prevent vibration and noise of the tub from being delivered to the cabinet, whereby vibration and noise generated in the cabinet may be reduced, and thus unpleasant vibration and nose may be prevented from being delivered to a user. 
     Also, according to the washing machine of the present invention, it is possible to increase tub capacity by improving the structure between the tub and the cabinet. 
     Also, according to the washing machine of the present invention, a cabinet door for opening or closing a cabinet and a tub door for opening or closing a tub may interwork with each other when the cabinet door and the tub door are opened or closed, whereby convenience may be provided to a user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a brief view illustrating a washing machine according to the related art. 
         FIG. 2  is a perspective view illustrating a washing machine according to the present invention. 
         FIG. 3  is a perspective view illustrating the state that each door of a washing machine according to the present invention is opened. 
         FIG. 4  is a perspective view illustrating an arrangement state of a cabinet door and a tub door which are main parts of a washing machine according to the present invention. 
         FIG. 5  is an exploded perspective view illustrating an arrangement state of a cabinet door and a tub door which are main parts of a washing machine according to the present invention. 
         FIG. 6  is a detailed exploded perspective view illustrating a cabinet door of a washing machine according to the present invention. 
         FIG. 7  is a cross-sectional view illustrating an unlocking unit of a washing machine according to the present invention. 
         FIG. 8  is an exploded perspective view illustrating a cabinet door locking unit of a washing machine according to the present invention. 
         FIG. 9  is a perspective view illustrating a tub and a tub door of a washing machine according to the present invention. 
         FIG. 10  is an exploded perspective view illustrating a tub door of a washing machine according to the present invention. 
         FIG. 11  is an exploded perspective view illustrating a pressurizing roller of a tub door of a washing machine according to the present invention. 
         FIG. 12  is a conceptual view illustrating an unlocking unit of a washing machine according to the present invention. 
         FIGS. 13 and 14  are plane and cross-sectional views illustrating a locking unit of a washing machine according to the present invention. 
         FIG. 15  is a plane and cross-sectional view sequentially illustrating a locking state of a washing machine according to the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, a washing machine according to one embodiment of the present invention will be described with reference to the accompanying drawings. 
     Titles of respective elements are defined in description of the present invention in consideration of their functions in the present invention and therefore it is not to be understood that the titles restrict technical elements of the present invention. Also, the titles defined in the respective elements may be referred to as other titles. 
     First of all, a washing machine according to one embodiment of the present invention will be described in brief with reference to the accompanying drawings.  FIG. 2  is a perspective view illustrating a washing machine according to the present invention.  FIG. 3  is a perspective view illustrating the state that each door of a washing machine according to the present invention is opened. 
     As shown in  FIGS. 2 and 3 , the washing machine  1  according to one embodiment of the present invention comprises a cabinet  100  for forming an external appearance, a tub  200  supported by a suspension (not shown) such as a damper and spring inside the cabinet, in which washing water is stored, a drum  400  rotatably provided inside the tub  200  to allow laundry to be loaded therein, and a driving unit (not shown) for rotating the drum. 
     The cabinet  100  may include a front cabinet  110  for forming the front of the washing machine, a horizontal cabinet  130  for forming left and right sides of the washing machine, and an upper cabinet  120  for forming a top surface of the washing machine. 
     A first insertion hole  114  for allowing laundry to put in a loading space of the drum  400  is formed at the center of the front cabinet  110 , and is provided with a cabinet door  160  for opening or closing the first insertion hole  114 . 
     A control panel  112  that includes a manipulation unit and a display unit for controlling and displaying an overall operation of the washing machine  1  may be provided on a top portion of the first insertion hole  114 . 
     A second insertion hole  210  opened to allow laundry put in the first insertion hole  114  to be loaded in the drum  400  is formed at the front of the tub  200 , and includes a tub door  230  for opening or closing the second insertion hole  210 . 
     The present invention relates to a cabinet door  160  and a tub door  230 , and description of the other elements (for example, drum, suspension, water supply unit, drainage unit, etc.) will be omitted. 
     Hereinafter, the front cabinet and the tub which are main parts of the present invention will be described in detail with reference to  FIGS. 4 and 5 .  FIG. 4  is a perspective view illustrating an arrangement state of a cabinet door and a tub door which are main parts of a washing machine according to the present invention, and  FIG. 5  is an exploded perspective view illustrating an arrangement state of a cabinet door and a tub door which are main parts of a washing machine according to the present invention. 
     As shown in  FIGS. 4 and 5 , a cabinet hinge coupling unit  116  to which the cabinet door  160  is rotatably hinge-coupled is formed to be recessed at one side of the first insertion hole  114  formed in the front cabinet  110 , and a cabinet door lock coupling unit  118  for setting a locking state of the cabinet door  160  is formed at the other side of the cabinet hinge coupling unit  116 . 
     A cabinet door lock  180  is provided inside the cabinet door lock coupling unit  118  so as not to be exposed to the outside of the front cabinet  110 . Also, a grip portion  164  for opening the cabinet door  160  is formed at the other side of the cabinet door  160 . 
     An unlocking unit  140  for locking or unlocking the cabinet door  160  and the tub door  230  is provided inside the grip portion  164 . The unlocking unit  140  is provided to simultaneously unlock the cabinet door lock  180  which locks the cabinet door  160  and the tub door lock  260  which locks the tub door  230  by a single operation of a user. The unlocking unit  140  will be described together with the cabinet door  160 . 
     The cabinet door  160  is rotatably provided in the first insertion hole  114  of the front cabinet  110  to open or close the first insertion hole  141  as shown in  FIG. 6 , and includes a first outer frame  161  forming an outer side of the cabinet door  160 , a first inner frame  164  forming an inner side of the cabinet door  160 , and a first hinge unit  168  rotatably supporting the cabinet door  160 . 
     The first outer frame  161  and the first inner frame  164  are coupled to each other by a coupling member (not shown) such as a bolt, and may be formed of a transparent material to allow a user to identify an inner operation state of the washing machine  1 . 
     Meanwhile, an outer side (that is, outer side of the first outer frame  161 ) of the cabinet door  160  is preferably formed on an extension surface of the front cabinet  110  along an external appearance of the front cabinet  110 , and the grip portion  164  for opening the cabinet door  160  is formed at an opposing side of the first hinge unit  168 . 
     A plurality of reinforcing ribs  162  for reinforcing strength of the first outer frame  161  may be formed at the inner side of the first outer frame  161 . A roller pressurizing surface  165  with which a pressurizing roller  250  of the tub door  230  is in contact is formed at an inner side (that is, outer side of the first inner frame  164 ) of the cabinet door  160 . The pressurizing roller  250  will be described later. 
     When the cabinet door  160  is pressurized and closed by a user, the roller pressurizing surface  165  pressurizes the pressurizing roller  250  of the tub door  230 , whereby the cabinet door  160  and the tub door  230  may be closed by interworking with each other. 
     The first hinge unit  168  provided in the cabinet hinge coupling unit  116  formed in the first insertion hole  114  to rotatably support the cabinet door  160  is provided at one side of the cabinet door  160 . 
     The unlocking unit  140  fixed to be held in the cabinet door lock  180  when the cabinet door  160  closes the first insertion hole  114 , unlocking the cabinet door lock  180  by means of an operation of a user is provided at the inner side of the grip portion  164  formed in the first outer frame  161 . The unlocking unit  140  will be described together with the cabinet door lock  180 . 
     A protrusion  163  for providing the first hinge unit  168  is formed in the first outer frame  161 , and a protrusion  166  is formed at one side of the first inner frame  168  to correspond to the protrusion  163  of the first outer frame  161 . 
     A pair of recesses  167  to which upper and lower rotational portions  171  and  173  of the first hinge unit  168  are inserted are formed at upper and lower sides of the protrusion  166  formed in the first inner frame, and a pair of brackets  176  for fixing upper and lower rotational shafts  172  and  174  of the first hinge unit  168  are respectively coupled to the pair of recesses  167 . The upper and lower rotational portions  171  and  173  and the upper and low rotational shafts  172  and  174  will be described later. 
     The protrusion  166 , the recesses  167  and the brackets  176 , which are formed in the first inner frame  168 , are shielded by the protrusion  163  formed in the first outer frame  161  when the first outer frame  161  and the first inner frame  168  are coupled to each other. 
     The first hinge unit  168  includes a hinge body  169  fixed to the cabinet hinge coupling unit  116  formed in the first insertion hole  114  of the front cabinet, the upper and lower rotational portions  171  and  173  extended from upper and lower portions of the hinge body  169 , and the upper and lower rotational shafts  172  and  174  extended respectively from ends of the upper and lower rotational portions  173 . 
     It is preferable that the upper and lower rotational portions  171  and  173  formed in the hinge body  169  of the first hinge unit  168  are formed to be spaced apart from each other at a predetermined interval. These upper and lower rotational portions  171  and  173  are spaced apart from each other at a predetermined interval to avoid a structural overlap with a second hinge unit  242  of the tub door  230 , which will be described later. The second hinge unit  242  is arranged between the upper and lower rotational portions  171  and  173 . 
     The cabinet door lock  180  which is locked by insertion of a cabinet door hook  142  of the unlocking unit  140  to the inner side of the front cabinet  110  is provided in the cabinet door lock coupling unit  118  formed at the other side of the first insertion hole  114  of the front cabinet  110 . 
     Hereinafter, the unlocking unit  140  and the cabinet door lock  180  according to the present invention will be described with reference to  FIGS. 7 and 8 .  FIG. 7  is a cross-sectional view illustrating an unlocking unit of a washing machine according to the present invention, and  FIG. 8  is an exploded perspective view illustrating a cabinet door locking unit of a washing machine according to the present invention. 
     As shown in  FIG. 7 , the unlocking unit  140  is located inside the grip portion  164  to unlock the cabinet door lock  180  by pressurization of a user when the user grips the grip portion  164  to open the cabinet door  142 . 
     The unlocking unit  140  includes a locking release lever  141 , a cabinet door hook  142  fixed by the cabinet door lock  160  when the first insertion hole  114  of the cabinet door  160  is closed and released from the cabinet door lock  180  when the release lever  141  is pressurized, and a pressurizing spring  143  exerting an elastic force to always fix the cabinet door hook  142  to the cabinet door lock  180 . 
     The cabinet door lock  180  is intended to control the locking state of the cabinet door  160  provided in the first insertion hole  114  as shown in  FIGS. 7 and 8 , and includes a hook holder  181  fixed into the cabinet door lock coupling unit  118  of the front cabinet  110 , a hook insertion unit  183  movably fixed to the hook holder  181  in an insertion direction of the cabinet door hook  142  outside the cabinet door lock coupling unit  118 , an elastic support unit  184  elastically supporting the hook insertion unit  183  in an opposite direction of the insertion direction of the cabinet door hook  142  by means of an elastic body such as spring, and an unlocking switch  143  for sensing an operation of the cabinet door hook  142  when a locking state of the cabinet door hook  142  fixed to the hook holder  181  is released. The unlocking switch  143  generates an electric signal for an operation of a tub door releaser  220  which will be described later. 
     The cabinet door lock  180  further has a spare moving space where the hook insertion unit  183  is elastically supported by the elastic support unit  184  after the cabinet door hook  142  is fixed by the hook holder  181  when the cabinet door  160  is closed. By the spare moving space, the cabinet door  160  further pressurizes the tub door  230  after being fixed to the hook holder  181  of the cabinet door lock  180  to close the tub door  230 . An interworking configuration of the cabinet door  160  and the tub door  230  will be described in detail when the operation of the cabinet door  160  and the tub door  230  is described. 
     Hereinafter, the tub door will be described in detail with reference to  FIGS. 9 and 10 .  FIG. 9  is a perspective view illustrating a tub and a tub door of a washing machine according to the present invention, and  FIG. 10  is an exploded perspective view illustrating a tub door of a washing machine according to the present invention. 
     As shown in  FIGS. 9 and 10 , a second insertion hole  210  for loading of laundry is formed at the front of the tub  200  to be extended from the first insertion hole  114  in a state that it is spaced apart from the first insertion hole  114  of the cabinet  100 . A weight balancer  270  for preventing vibration of the tub  200  from occurring by increasing mass of the tub  200  is provided outside the second insertion hole  210 , and the tub door  230  spaced apart from the cabinet  100  to open or close the second insertion hole  210  of the tub  200  is provided at one side of the second insertion hole  210  formed at the front of the tub  200 . 
     The second insertion hole  210  formed at the front of the tub  200  is provided with a ring shaped rim portion  212  provided toward the front cabinet  110 , and a second hinge coupling unit  214  provided with a second hinge unit  242 , which will be described later, is formed to be protruded at one side of the rim portion  212 , and a tub door lock coupling unit  216  provided with the tub door lock  260  for setting the locking state of the tub door  230  for opening or closing the second insertion hole  210  is provided at the other side of the rim portion  212 . 
     The second hinge unit  242  for allowing the tub door  230  to open or close the second insertion hole  210  by rotatably supporting the tub door  230  is provided at one side of the front of the tub  200 , and the tub door lock  260  for setting the locking state of the tub door  230  is provided at the other side of the front of the tub  200 . Also, the tub door lock releaser  220  for releasing the locking state of the tub door lock  260  is provided at an upper portion of the tub door lock  260 . 
     The aforementioned tub door  230 , tub door lock  260  and tub door lock releaser  220  are not connected with the cabinet  100  structurally, and the tub  200  is structurally connected with the cabinet  100  and independently supported by a suspension (not shown). 
     That is, since a gasket except the suspension is not provided between the tub  200  and the cabinet  100  unlike the washing machine  1  of the related art, the suspension is only supported, whereby delivery of the vibration of the tub  200  to the cabinet  100  may be reduced remarkably. 
     The tub door  230  includes a second outer frame  231  forming an outer side of the tub door  230 , a ring shaped second inner frame  235  forming an inner circumference of the tub door  230 , provided with a hollow portion, a ring shaped ring sealer  241  interposed between the second outer frame  231  and the second inner frame  235 , for sealing between the second insertion hole  210  of the tub  200  and the tub door  230 , and a light transmissive frame  239  inserted into the hollow portion of the second inner frame  235  to identify the inside of the tub  200  or the drum  400 . 
     A protrusion  236  to which the second hinge unit  242  is coupled is formed at one side of the second inner frame  235 , and a recess  237  to which upper and lower rotational portions  244  and  246  and a rotational spring  248  are inserted is formed in the protrusion  236 . The upper and lower rotational portions  244  and  246  and the rotational spring  248  will be described later. 
     Also, a fixed bracket  238  for rotatably fixing the upper and lower rotational portions  244  and  246  and the rotational spring  248  fixed to the recess  237  is provided at an inner side of the second inner frame  235 . Meanwhile, a tub door hook  249  inserted to the tub door lock  260 , which will be described later, maintaining a locking state of the tub door  230  is provided at the other side of the second inner frame  235 . 
     A protrusion  234  for covering the protrusion  236  formed in the second inner frame  235  is formed at one side of the second outer frame  231 , and a pressurizing roller  250  for opening the cabinet door  160  by pushing the cabinet door  160  in contact with the roller pressurizing surface  165  of the cabinet door  160  located outside the tub door  230  when the tub door  230  is rotated in an opening direction is provided at a predetermined portion of the outer side of the second outer frame  231 . 
     The pressurizing roller  250  is intended to prevent the cabinet door  160  or the tub door  230  from being damaged by friction between the cabinet door  160  and the tub door  230  when the tub door  230  is opened by the rotational spring  248  of the second hinge unit  242 , and, as shown in  FIG. 12 , includes a fixed unit  251  fixed to a roller insertion unit  232  provided in the second outer frame  231  of the tub door  230 , a movable unit  253  movably fixed to the fixed unit  251  at a predetermined spacing with respect to the fixed unit  251 , and a roller  256  having a rotational shaft parallel with the rotational shafts of the cabinet door  160  and the tub door  230  is provided inside the movable unit  253 . 
     A plurality of protrusions  252  for restricting a moving distance of the movable unit  253  are formed at each corner of the fixed unit  251 , and the movable unit  253  is held in the protrusions  252  of the fixed unit  251  to be prevented from being detached from the fixed unit  251 . Also, a spring  255  for allowing the movable unit  253  to be spaced apart from the fixed unit  251  at a predetermined elastic force is provided between the fixed unit  251  and the movable unit  253 . Meanwhile, a roller groove  254  to which the roller  256  is rotatably fixed is formed inside the movable unit  253 . 
     When the tub door  230  is opened by the pressurizing roller  250 , the pressurizing roller  250  opens the cabinet door by pushing the cabinet door  160  in an opening direction in contact with the roller pressurizing surface  165  formed in the first inner frame  168  of the cabinet door  160 . 
     It has been described that the aforementioned pressurizing roller  250  is located outside the tub door  230  and the pressurizing surface  165  is formed inside the cabinet door  160  as an example. However, the pressurizing roller  250  may be located inside the cabinet door  160  and the pressurizing surface  165  may be formed outside the tub door  230 . 
     The second hinge unit  242  is fixed to the second hinge coupling unit  214  formed at one side of the rim portion  212  of the second insertion hole  210  to rotatably support the tub door  230  and at the same time provide a predetermined elastic force in a direction that the tub door  230  always opens the second insertion hole  210 . 
     The second hinge unit  242  includes a hinge body  243  fixed to the second hinge coupling unit  214 , upper and lower rotational portions  244  and  246  protruded and extended from upper and lower portions of the hinge body  243 , upper and lower rotational shafts  245  and  247  provided at ends of the upper and lower rotational portions  244  and  246  and rotatably fixed to the recess  237  of the second inner frame  235  of the tub door  230 , and a rotational spring  248  having the same rotational shaft as the upper and lower rotational shafts  245  and  247  and providing an elastic force to the tub door  230  in an opening direction of the tub door  230  with respect to the second insertion hole  210 . 
     It is preferable that the rotational portions  244  and  246  provided in the second hinge unit  242  are formed to be smaller than the distance between the upper and lower rotational portions  171  and  173  of the first hinge unit  168 . 
     That is, the first hinge unit  168  and the second hinge unit  242  rotatably support the cabinet door  160  and the tub door  230  in a state that they have their respective rotational shafts different from each other. In this respect, to prevent the rotational shafts of the first and second hinge units  168  and  242  from interfering with each other, centers of the rotational shafts are spaced apart from each other and at the same time detached from each other, whereby interference of the first and second hinge units  168  and  242  is avoided. 
     The tub door lock coupling unit  216  formed at the other side of the second insertion hole  210  of the tub  200  includes the tub door lock  260  locked by insertion of the tub door hook  249  of the tub door  230 , and the tub door lock releaser  220  provided to adjoin the second insertion hole  210 , releasing the locking state of the tub door lock  260  by interworking with the unlocking unit  140 . 
     The tub door lock releaser  220  is intended to release the locking state of the tub door lock  260  by means of an unlocking signal generated by a release switch  186  of the unlocking unit  140 , and includes a solenoid  226  operated in accordance with the signal generated by the release switch  186 , a rotational portion  222  rotated in accordance with the operation of the solenoid  226 , and a tensile cable  224  for delivering a rotational force of the rotational portion  222  to the tub door lock  260  in accordance with rotation of the rotational portion  222 . 
     The tub door lock  260  is intended to control the locking state of the tub door  230  provided in the second insertion hole  210 , and includes a hook holder  181  fixed to the tub door lock coupling unit  216  to be adjacent to the second insertion hole, and a cable interlocking unit  261  connected to the tensile cable  224  of the tub door lock releaser  220  to be adjacent to the hook holder  181 . 
     In the aforementioned description, although the tub door lock releaser  220  and the tub door lock  230  have been described respectively, the solenoid  226  of the tub door lock releaser  220  may directly be provided in the tub door lock  260  to release the tub door lock  260  by using the signal of the release switch  186  of the cabinet door lock  180 . 
     The operation of the washing machine according to one embodiment of the present invention will be described in detail with reference to the accompanying drawings. The respective elements described hereinafter should be understood with reference to the aforementioned description and drawings. Meanwhile, the main subject of the present invention lies in locking and unlocking of the cabinet door  160  and the tub door  230 . Therefore, description of general operation (for example, washing stroke, rinsing stroke, dehydrating stroke, etc.) of the washing machine  1  will be omitted. 
     Prior to description of opening operation of the cabinet door  160  and the tub door  230 , closing states of the cabinet door  160  and the tub door  230  will be described. The cabinet door  160  maintains a locking state as its cabinet door hook  175  is fixed to the cabinet door lock  180 , and the tub door  230  maintains a locking state as its tub door hook  249  is fixed to the tub door lock  260 . 
     First of all, an opening operation of the cabinet door  160  and the tub door  230  will be described with reference to the accompanying drawings.  FIG. 12  is a conceptual view illustrating an unlocking unit of a washing machine according to the present invention, and  FIGS. 13 and 14  are plane and cross-sectional views illustrating a locking unit of a washing machine according to the present invention. 
     To open the cabinet door  160 , a user grips the grip portion  164  formed in the cabinet door  160  of the front cabinet  110  and then pressurizes the grip portion  164  in an opening direction of the cabinet door  160 . In this case, a release lever  141  of the unlocking unit  140  provided inside the grip portion  164  is rotated, whereby the locking state of the cabinet door hook  142  is released, and the release switch  186  of the cabinet door lock  180  senses the locking release of the cabinet door hook  142 . 
     The solenoid  226  of the cabinet door lock releaser  150  is operated in accordance with sensing of the release switch  186  to operate the rotational portion  222 , and the cable interlocking unit  261  of the tub door lock  260 , which is connected to the tensile cable  224  of the rotational portion, is operated in accordance with rotation of the rotational portion  222 , whereby the locking state of the tub door hook  249  fixed to the hook holder  181  of the tub door lock  260  is released, and at the same time the locking states of the cabinet door  160  and the tub door  230  are released. 
     As the locking states of the cabinet door  160  and the tub door  230  are released, the tub door  230  is rotated in its opening direction by the rotational spring  248  provided in the second hinge unit  242  of the tub door  230 , and the pressurizing roller  250  provided in the second outer frame  231  of the tub door  230  pressurizes the roller pressurizing surface  165  formed in the first inner frame  168  of the cabinet door  160  and at the same time pressurizes the cabinet door  160  in an opening direction of the cabinet door  160 , whereby the cabinet door  160  is opened simultaneously with the tub door  230  by the tub door  230 . 
     Hereinafter, a closing operation of the cabinet door  160  and the tub door  230  will be described with reference to the accompanying drawing.  FIG. 15  are plane and cross-sectional views sequentially illustrating a locking state of a washing machine according to the present invention. 
     As shown, when the cabinet door  160  and the tub door  230  are closed, as a user rotates the cabinet door  160  in a closing direction, the roller pressurizing surface  165  formed in the first inner frame  168  of the cabinet door  160  adjoins the pressurizing roller  250  provided in the second outer frame  231  of the tub door  231 , and the cabinet door  160  and the tub door  230  are rotated in their closing direction while overcoming an elastic force of the rotational spring  248  provided in the second hinge unit  242  of the tub door  230 . 
     As the cabinet door  160  and the tub door  230  are rotated, the cabinet door hook  175  of the cabinet door  160  is inserted into the cabinet door lock  180 , and at the same time the tub door hook  249  of the tub door  230  is inserted into the tub door lock  260  (see  FIG. 15( a ) ). 
     As the cabinet door  160  is closed by the user, when the cabinet door hook  175  of the cabinet door  160  is inserted into the cabinet door lock  180 , since the hook insertion unit  183  into which the cabinet door hook  175  is inserted is elastically supported by the spring, the cabinet door lock  180  is pressurized by rotation of the cabinet door  160 , whereby the cabinet door hook  175  is fully fixed to the cabinet door lock, and the tub door is further moved as much as a moving distance of the hook insertion unit of the cabinet door lock and then fixed to the tub door lock (see  FIG. 15( b ) ). 
     A pressurizing force of the user, which is applied to the cabinet door, is removed, and the hook insertion unit  183  of the cabinet door lock  180  returns to its original position by an elastic force of the spring for supporting the hook insertion unit  183 . The cabinet door  160  fixed to the cabinet door lock  180  by the returning force of the hook insertion unit returns to a position spaced apart from the tub door  230 , whereby closing of the cabinet door and the tub door is completed (see  FIG. 15( c ) ). 
     As described above, when the cabinet door  160  and the tub door  230  according to the washing machine according to the present invention are closed, they are maintained to be spaced apart from each other, whereby vibration of the tub is prevented from being directly delivered to the cabinet during the washing operation. 
     It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential characteristics of the invention. Thus, the above embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the invention should be determined by reasonable interpretation of the appended claims and all change which comes within the equivalent scope of the invention are included in the scope of the invention.