Refrigerator

A refrigerator includes: a cabinet; a door rotatably connected to the cabinet by a hinge; and a door opening device for opening the door. The door opening device includes a driving motor and a push member configured to move in the forward/backward direction. The push member includes a first end portion positioned close to the front surface of the cabinet and a second end portion positioned on the opposite side of the first end portion. The cabinet includes a cabinet side wall positioned close to the hinge. The door includes a door side wall positioned close to the hinge. When the door is closed, the horizontal distance between the first end portion and the cabinet side wall or the door side wall is smaller than the horizontal distance between the second end portion and the cabinet side wall or the door side wall.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage application under 35 U.S.C. § 371 of International Application No. PCT/KR2018/004751, filed on Apr. 24, 2018, which claims the benefit of Korean Patent Application No. 10-2017-0052455, filed on Apr. 24, 2017. The disclosures of the prior applications are incorporated by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a refrigerator.

BACKGROUND ART

In general, a refrigerator is a home appliance that can keep objects such as food in a storage chamber that is opened or closed by a door at a low temperature.

The storage chamber may be surrounded by an insulation wall such that the internal temperature of the storage chamber is maintained at a temperature lower than an external temperature. The storage chamber may be referred to as a refrigerating compartment or a freezing compartment according to the temperature range of the storage chamber.

The user opens the door in order to put objects into the storage chamber or take objects out of the storage chamber. In some examples, the door is rotatably provided on the cabinet and a gasket is provided between the door and the cabinet.

In some cases, in a state of closing the door, the gasket is closely adhered between the door and the cabinet to prevent leakage of cool air from the storage chamber. As adhesion force of the gasket increases, the effect of preventing leakage of cool air may increase.

In order to increase adhesion force of the gasket, the gasket may be formed of, for example, a rubber magnet or a magnet may be provided in the gasket. However, if adhesion force of the gasket increases, a large force may be required to open the door.

Recently, refrigerators having an auto closing function have been provided.

A method for opening a door of a refrigerator is disclosed in Korean Patent Registration No. 10-1658668 that is a prior art document.

According the prior art document, in order to open the door of the refrigerator, a driving motor rotates to allow the push rod that is gear-coupled to a rotation shaft of the driving motor to advance so as to open the door. Also, when it is confirmed that the push rod reaches a set position, at which the door is opened, by a position detection member configured to detect a position of the push rod, the driving motor reversely rotates so that the push rod returns to its initial position.

Also, the push rod receives driving force generated from the driving motor by a plurality of gears to move.

According to the prior art document, since two push rods operate by using one driving motor, each of the push rods is disposed at a position far from a hinge of the door to smoothly receive power of the driving motor. That is, each of the push rods are disposed adjacent to a boundary of two doors that are adjacent to each other.

Thus, when the door is opened by using the push rod, there is a disadvantage that an opening angle of the door per unit length of the push rod is low. Thus, in order to increase in opening angle of the door, the push rod has to increase in length. In this case, a portion of the push rod, which is exposed to the outside, is lengthened, which cause deterioration of aesthetics.

Also, there is a limitation when a user closes the door after increasing in opening angle of the door before or after the push rod advances to move to the set position. In detail, an impact caused by emergency return of the door is transmitted to the plurality of gears through the push rod, and thus, the push rods and/or the gears are damaged.

DISCLOSURE OF THE INVENTION

Technical Problem

An object of the prevent invention is to provide a refrigerator in which an opening angle of a door per unit length of a push member increases while the push member increases in length so as to increase in opening angle of the door.

Also, an object of the present invention is to provide a refrigerator in which a push member is capable of urgently returning to detect whether door is opened by external force and prevent the push member from being damaged.

Technical Solution

A refrigerator according on one aspect includes a cabinet having a storage chamber; a door configured to open and close the storage chamber, the door being rotatably connected to the cabinet by a hinge; and a door opening device configured to open the door.

The door opening device includes a driving motor and a push member configured to receive power of the driving motor to move forward and backward.

The push member includes a first end portion disposed close to a front surface of the cabinet and a second end portion disposed at an opposite side of the first end portion.

The cabinet includes a cabinet sidewall disposed close to the hinge, and the door includes a door sidewall disposed close to the hinge.

In a state in which the door is closed, a horizontal distance between the cabinet sidewall or the door sidewall and the first end portion may be less than that between the cabinet sidewall or the door sidewall and the second end portion.

When the push member moves to open the door, the first end portion and the second end portion may move to approach the cabinet sidewall or the door sidewall.

A length between the first end portion and the second end portion of the push member may be greater than a thickness of the door in a front and rear direction.

The push member may include a push rack comprising a rack gear configured to receive the power of the driving motor, the push rack may include a first side surface and a second side surface, the first side surface may be disposed closer to the cabinet sidewall or the door sidewall than the second side surface, and the rack gear may be disposed on the first side surface.

The push rack may further include a top surface and a bottom surface, a groove may be defined in one or more of the top surface and the bottom surface, and the groove may be disposed closer to the first side surface than the second side surface.

The driving motor may be disposed in a region between the first side surface and the cabinet sidewall.

The door opening device may be installed on an installation bracket provided in the cabinet, the installation bracket may include a wire guide configured to guide a wire connected to the door, and the driving motor may be disposed behind the wire guide.

The push member may further include: a push rack including a rack gear configured to receive power of the driving motor; and a rack cover rotatably connected to the push rack while the door is opened, the rack cover being configured to contact a front surface of the cabinet or a rear surface of the door.

The push rack may include a first side surface, a second side surface, and a connection surface configured to connect the first side surface to the second side surface, and a cover coupling part coupled to the rack cover may be disposed on the connection surface.

The rack cover and the cover coupling part may be relatively rotatably coupled to each other by a shaft.

The cover coupling part may protrude from the connection surface, the cover coupling part may be spaced apart from each of top and bottom surfaces of the push rack, the rack cover may include a contact surface configured to contact the cabinet or the door and a slot surface that is an opposite surface of the contact surface, and a slot, into which the cover coupling part is accommodated, may be defined in the slot surface.

The connection surface may include an inclined surface that is spaced apart from the slot surface of the rack cover in a state in which the contact surface is disposed to face the front surface of the cabinet or the rear surface of the door at an initial position of the push member in the state in which the door is closed.

When an opening angle of the door increases while the push member moves to open the door, the push rack and the rack cover may relatively rotate so that the inclined surface contacts the slot surface.

The refrigerator may further include: a magnetic field generation device installed in the door opening device; and a reed switch assembly configured to operate by the magnetic field generation device.

One of the magnetic field generation device and the reed switch assembly may be disposed in the cabinet, and the other is disposed in the door.

For example, the magnetic field generation device may be installed in the push member.

In the door opening device, the push member may be disposed in the cabinet to move toward the door, and the reed switch assembly may be disposed on the door adjacent to the push member.

The reed switch assembly may include a pair of reeds disposed to contact each other by the magnetic field generation device.

When one end of the push member is separated from the door, the pair of reeds may be spaced apart from each other.

When the pair of reeds are spaced apart from each other, the refrigerator may further include a controller that controls the motor so that the push member is inserted into or returns to the initial position.

The push member may include a linear push rack having a rack gear on one side thereof.

For another example, in the door opening device, the push member may be disposed in the door to move toward the cabinet, and the reed switch assembly may be disposed on the cabinet adjacent to the push member.

The push member may include a rack cover disposed to be exposed to the outside of the cabinet, and the magnetic field generation device may be disposed on the rack cover.

The reed switch assembly may be disposed adjacent to the rack cover to recognize magnetic fields generated by the magnetic field generation device.

The reed switch assembly may include a pair of reeds. When the door rotates by the door opening device, the pair of reeds contact each other by the magnetic field generation device, and when the door rotates by external force, the pair of reeds may be spaced apart from each other.

The magnetic field generation device may be a magnet.

A refrigerator according to another aspect includes: a cabinet having at least one storage chamber therein; a door disposed at one side of the cabinet to open and close the storage chamber; a door opening device configured to operate so that the storage chamber is opened by driving force of a motor; a magnetic field generation device installed in the door opening device; and a reed switch assembly configured to operate by the magnetic field generation device, wherein one of the magnetic field generation device and the reed switch assembly is disposed in the cabinet, and the other is disposed in the door.

Advantageous Effects

According to the proposed embodiments, the opening angle of the door per unit length of the push member may increase while the push member increases in length so as to increase in opening angle of the door.

Also, according to the present invention, the push member may urgently return to detect whether door is opened by the external force and prevent the push member from being damaged.

Also, when the door opening device is installed in the cabinet, the structure configured to couple the door opening device to the outer case may not be directly provided, but the door opening device may be installed on the installation bracket after the installation bracket is coupled to the outer case.

Therefore, the position of the door opening device may be fixed with respect to the cabinet without changing the structure of the mold configured to manufacture the outer case according to the related art.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying drawings. Exemplary embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. It is noted that the same or similar components in the drawings are designated by the same reference numerals as far as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted to avoid making the subject matter of the present invention unclear.

In the description of the elements of the present disclosure, the terms first, second, A, B, (a), and (b) may be used. Each of the terms is merely used to distinguish the corresponding component from other components, and does not delimit an essence, an order or a sequence of the corresponding component. It should be understood that when one component is “connected”, “coupled” or “joined” to another component, the former may be directly connected or jointed to the latter or may be “connected”, coupled” or “joined” to the latter with a third component interposed therebetween.

FIG. 1is a perspective view of a refrigerator according to a first embodiment of the present invention.

Referring toFIG. 1, a refrigerator10according to an embodiment of the present invention may include a cabinet11and at least one refrigerator door12, which define an outer appearance thereof.

At least one storage chamber is provided in the cabinet11. The refrigerator door12is rotatably and slidably connected to a front surface of the cabinet11to open and close the storage chamber. Here, since a user uses the refrigerator10in front of the refrigerator10, the refrigerator door12may be disposed in front of the cabinet11.

In detail, the storage chamber may include at least one of the refrigerating compartment111or the freezing compartment112. Although the storage chamber includes one refrigerating compartment111and on freezing compartment112inFIG. 1, this is merely an example, and the refrigerating compartment111and the freezing compartment112may be provided in plurality. Also, the refrigerating compartment111and the freezing compartment112may be partitioned by a partition wall. Alternatively, the storage chamber may include only one of the refrigerating compartment111and the freezing compartment112.

The refrigerator door12may include at least one refrigerating compartment door13that opens and closes the refrigerating compartment111, and at least one freezing compartment door16that opens and closes the freezing compartment112.

Also, the refrigerator door12may be a pivotable door provided to be rotatable through a door hinge30. That is, the refrigerator door12may rotate with respect to the cabinet11through the door hinge30.

Also, the refrigerating compartment door13may include a pair of doors14and15, which are rotatably connected to left and right edges of the front surface of the cabinet11, respectively. That is, the refrigerating compartment door13may include a first refrigerating compartment door14and a second refrigerating compartment door15.

Also, the freezing compartment door16may include a pair of doors17and18, which are rotatably connected to left and right edges of the front surface of the cabinet11, respectively.

This is merely an example. For example, each of the refrigerating compartment door13and the freezing compartment door16may be provided in various forms such as a drawer type door that opens and closes the freezing compartment in a sliding manner.

Also, as illustrated inFIG. 1, in this embodiment, a bottom freezer type refrigerator is disclosed. However, this is merely an example. For example, the refrigerator10may be provided in various forms such as a top mount type refrigerator, a side by side type refrigerator, a refrigerator having only one storage chamber and one door, and the like.

FIG. 2is a plan view of the refrigerator according to the first embodiment.

Referring toFIG. 2, the refrigerator10may further include a door opening device20that operates to open the refrigerator door12without external force by the user.

That is, the refrigerator10may include a door opening device20that is capable of automatically opening the refrigerator door12.

Also, the door opening device20may open each of the refrigerator doors12that need to be opened. For example, in order to open the refrigerating compartment door13, the door opening device20may open each of a first refrigerating compartment door14and a second refrigerating compartment door15.

Hereinafter, a case in which the first refrigerating compartment door14of the refrigerator door12is automatically opened by the door opening device20will be described. In addition to the first refrigerating compartment door14, other refrigerator doors12may also be automatically opened by a structure and manner that will be described below.

As described above, the first refrigerating compartment door14is connected to the cabinet11by the door hinge30. That is, the first refrigerating compartment door14may rotate by using a hinge shaft32(seeFIG. 3) provided on the door hinge30as a rotational center.

As illustrated inFIG. 2, the door opening device20may be installed in the first refrigerating compartment door14.

Also,FIG. 2illustrates a top surface of the refrigerator10so as to show a case in which the door opening device20is installed in an upper portion of the first refrigerating compartment door14. This is merely an example. For example, the door opening device20may be installed in a lower portion of the first refrigerating compartment door14.

Hereinafter, various devices, which automatically open the first refrigerating compartment door14, such as the door opening device20will be described in detail.

FIG. 3is an enlarged view of a portion A ofFIG. 2, andFIG. 4is a view illustrating a state in which the door rotates inFIG. 3. Hereinafter, the first refrigerator door14is referred to as a ‘door’. Also, in order to illustrate the door opening device20and the like in detail, an upper configuration of the door opening device20and the like, for example, an upper cap of the door14will be omitted.

Referring toFIGS. 3 and 4, the door opening device20may be disposed in the upper portion of the door14.

The door14may be provided with a predetermined space in which the door opening device20is accommodated.

The door opening device20includes a housing21and a motor (not shown) and a push member22, which are installed in the housing21. The push member22is installed to be withdrawn from and inserted into the housing21by driving force of the motor.

Also, the door opening device20may further include a power transmission device28that transmits the driving force of the motor to the push member22. That is, the driving force of the motor is transmitted to the push member22through the power transmission device28. Thus, the push member22is withdrawn from the housing21by the driving of the motor in one direction and is inserted into the housing21the housing21by the driving of the motor in the other direction.

InFIG. 3, the push member22is inserted into the housing21, and inFIG. 4, a push rack22is withdrawn from the housing21. As illustrated inFIG. 3, a portion of the push member22may protrude to the outside of the housing21in a state in which the push member22is inserted into the housing21.

The power transmission device28may include at least one gear. In the present invention, the number of gears is not limited as long as the power transmission device28is capable of transmitting the power of the motor to the push member22. For example, the power transmission device28may include a plurality of reduction gears.

The push member22includes a rack gear26engaged with at least one power transmission device28. The driving force of the motor is transmitted to the push member22through the engagement between the power transmission device28and the rack gear26.

The push member22may be provided in a curved shape so that an opening angle of the door14per unit length increases and also be provided in an arc shape around the hinge shaft32of the door hinge30.

Also, the push member22may be disposed adjacent to the hinge shaft32so that the opening angle of the door14per unit length increases.

That is, in the door14, the push member22is disposed close to the a first side surface between the first side surface adjacent to the hinge shaft32and a second side surface adjacent to the other door as an opposite surface of the first surface.

Also, the push member22may include a rack cover24coupled to a distal end thereof. As illustrated inFIGS. 3 and 4, the rack cover24is disposed to contact the front surface of the cabinet11. This is merely an example. For example, the rack cover24may be disposed to be spaced a predetermined distance from the cabinet11.

That is, as a length by which the push member22is withdrawn to the outside of the housing21increases, the rack cover24contacts the front surface of the cabinet11to apply force to the cabinet11. Accordingly, the cabinet11and the door14may be separated from each other, and the storage chamber may be opened.

The rack cover24may be made of an elastic material because the rack cover24contacts the cabinet11. For example, the cabinet11may be made of a material that is elastically deformable, such as a rubber material or a silicon material, to prevent the breakage when external force is applied to the cabinet11.

A process of automatically opening the storage chamber by the rotation of the door14due to the driving of the door opening device20will be described.

First, an opening signal that is required for opening the storage chamber is generated. For example, a signal may be generated through a voice or a human body sensor. That is, the user may generate the opening signal by recognizing the voice or a relatively free foot to the sensor while holding an object in both hands thereof.

When the opening signal is generated, the motor is driven to transmit the driving force to the push member22through the power transmission device28. The push member22is withdrawn to the outside of the housing21by the driving force.

Accordingly, the rack cover24applies external force to the cabinet11, and thus, the door14rotates. That is, while the state ofFIG. 3is changed into the state ofFIG. 4, the door14opens the storage chamber provided in the cabinet11.

Therefore, the user may approach the storage chamber without applying the external force to take out food or inject food into the storage chamber.

Here, the door opening device20is provided to allow the door14to rotate at a predetermined angle and up to a predetermined position (hereinafter, opening position). For example, the door opening device20may allow the door14to rotate so that the door14is in the opening position having an opening angle of approximately 40 degrees.

Also, in the door opening device20, after a predetermined time is elapsed, the motor of the door opening device20may be driven in the other direction, and thus, the push member22may be inserted into the housing21.

That is, the motor is driven so that the push member22returns to the housing21. The door14in which the external force by the push member22is removed may rotate by a self-weight of the refrigerator10to close the storage chamber.

This corresponds to a case in which the user does not apply external force at all to the door14. However, in some cases, the user may apply external force to the door14so that the door14rotates.

For example, while the door14rotate by the door opening device20, that is, before the door14reaches a predetermined opening position, the user applies external force so that the door14rotates to open the storage chamber.

Alternatively, the user applies external force to the door14that rotates by the door opening device20so that the door14further rotates at a predetermined angle.

Here, the user may apply external force again to allow the door to rotate so as to close the storage chamber by the door14. In this case, if the push member22is in the withdrawn state, the door opening device20such as the push member22and the power transmission device28may be damaged.

Therefore, the refrigerator10according to the present invention may further include a part for detecting the case when the user applies the external force to the door14so that the door14rotates.

For example, the refrigerator10may further include a magnetic field generation device50and a reed switch assembly40that operates by the magnetic field generation device50.

The reed switch assembly40may include a case42, a sensor44, and a wire46.

The case42is provided with an inner space in which the sensor44is accommodated. Also, the case42may be provided with a constituent that supports or fixes the sensor44.

The sensor44is constituted by a container defining a predetermined accommodation space and a reed disposed inside the container. The reeds are provided in a pair that are spaced apart from each other by their elasticity, When magnetic fields are detected, the reeds contacts each other. That is, the reeds may be made of a magnetic material and thus may contact each other only when the magnetic fields are detected.

The wire46is connected to the sensor44to extend to the outside of the case42. In particular, the wire46is coupled to each of the pair of reeds. For example, the wire46and the reed may be bonded to each other through soldering or the like.

The wire46may extend to the outside of the case42so as to be connected to the controller. For example, the wire46may extend to the hinge shaft32.

The magnetic field generation device50may be provided as a magnet. For example, the magnetic field generation device50may be provided as a plurality of magnets having different polarities to generate the magnetic fields.

The magnetic field generation device50may be installed in the door opening device20. For example, the magnetic field generation device50may be installed at one end of the push member22, i.e., the rack cover24.

As illustrated inFIG. 3, the magnetic field generation device50is installed in the rack cover24, and the reed switch assembly40is installed in the cabinet11adjacent to the rack cover24.

That is, the magnetic field generation device50is installed in the door14, and the reed switch assembly40is installed in the cabinet11. However, since the magnetic field generation device50is installed in the rack cover24contacting the cabinet11, the magnetic field generation device50and the reed switch assembly40are adjacent to each other.

Thus, the reed switch assembly40may recognize the magnetic fields generated by the magnetic field generation device50. That is, the pair of reeds of the reed switch assembly40are connected to each other by the magnetic field generation device50.

As illustrated inFIG. 4, when the door14rotates by the door opening device20, the pair of reeds of the reed switch assembly40is continuously maintained in the connected state by the magnetic field generation device50.

However, when the door14rotates by the user, the rack cover24and the cabinet11is separated from each other. That is, the magnetic field generation device50and the reed switch assembly40are away from each other. Thus, the pair of reeds of the reed switch assembly40do not recognize the magnetic fields and thus are spaced apart from each other by their elasticity.

The separation of the pair of reeds is transmitted to the controller through the wire44. Thus, the controller determines that the user has opened the door14by applying the external force, and then drives the motor so that the push member22is inserted into the housing21.

In summary, whether the user applies the external force to allow the door14to rotate may be recognized through the magnetic field generation device50installed in the rack cover24and the reed switch assembly40installed in the cabinet11. When it is determined that the user has opened the door14by applying the external force, the motor may be driven to insert the push member22into the housing21, thereby preventing the door opening device20from being damaged.

In the above, the case in which the magnetic field generation device50is installed in the door14, and the reed switch assembly40is installed in the cabinet11has been described. However, the above-described operation may be performed in all of cases in which one of the magnetic field generation device50and the reed switch assembly40may be disposed in the cabinet11, and the other is disposed in the door14.

That is, even when the door opening device20is installed in the cabinet11, and the reed switch assembly40is installed in the door14, the same operation may be performed.

Hereinafter, the refrigerator according to this embodiment will be referred to as a refrigerator according to a second embodiment and will be described in detail. Also, the same reference numerals are used for the same components as those described above, and only the differences will be described.

FIG. 5is a plan view of a refrigerator according to a second embodiment,FIG. 6is an enlarged view of a portion B ofFIG. 5, andFIG. 7is a view illustrating a state in which a door rotates inFIG. 6.

Referring toFIGS. 5 to 7, a door opening device20aaccording to this embodiment may be installed in a cabinet11.FIG. 5illustrates a top surface of a refrigerator10so as to show a case in which the door opening device20ais installed in an upper portion of a first refrigerating compartment door11. This is merely an example. For example, the door opening device20amay be installed in a lower portion of the cabinet11.

Hereinafter, the first refrigerator door14is referred to as a ‘door’. Also, in order to illustrate the door opening device20aand the like in detail, an upper configuration of the door opening device20aand the like, for example, upper caps of the door14and the cabinet11will be omitted.

The door opening device20amay include a housing21and a motor (not shown), a push member22, and a power transmission device28, which are installed in the housing21.

The push member22is installed to be withdrawn from and inserted into the housing21by driving force of the motor.

As the push member22is withdrawn to the outside of the housing21, a rack cover24applies external force to the door14. Accordingly, the cabinet11and the door14may be separated from each other, and the storage chamber may be opened.

Also, the refrigerator10may include a magnetic field generation device50and a reed switch assembly40athat operates by the magnetic field generation device50.

The reed switch assembly40amay include a case42, a sensor44, and a wire46.

As illustrated inFIGS. 6 and 7, the magnetic field generation device50is installed in the rack cover24, and the reed switch assembly40ais installed in the door14adjacent to the rack cover24.

That is, the magnetic field generation device50is installed in the cabinet11, and the reed switch assembly40ais installed in the door14. However, since the magnetic field generation device50is installed in the rack cover24contacting the door14, the magnetic field generation device50and the reed switch assembly40aare adjacent to each other.

As illustrated inFIG. 7, when the door14rotates by the door opening device20a, the pair of reeds of the reed switch assembly40ais continuously maintained in the connected state by the magnetic field generation device50.

However, when the door14rotates by the user, the rack cover24and the cabinet11is separated from each other. That is, the magnetic field generation device50and the reed switch assembly40aare away from each other. Thus, the pair of reeds of the reed switch assembly40ado not recognize the magnetic fields and thus are spaced apart from each other by their elasticity.

The separation of the pair of reeds is transmitted to the controller through the wire44. Thus, the controller determines that the user has opened the door14by applying the external force, and then allows the push member22to return to the housing21.

In the first and second embodiments, embodiments in which the door opening device and the magnetic field generation device are different in the same refrigerator have been described. Hereinafter, in a third embodiment, a refrigerator and door opening device having a different shape will be described.

FIG. 8is a perspective view of a refrigerator according to a third embodiment of the present invention, andFIG. 9is a plan view of the refrigerator according to the third embodiment.

Referring toFIGS. 8 and 9, a refrigerator10aaccording to this embodiment may include a cabinet11ahaving a storage chamber and a refrigerator door12athat opens and closes the storage chamber.

The storage chamber may include one or more of a refrigerating compartment111aand a freezing compartment112a.

The refrigerator door12amay include one or more of a refrigerating compartment door13athat opens and closes the refrigerating compartment111aand a freezing compartment door16athat opens and closes the freezing compartment112a.

Also, the refrigerating compartment door13amay include a first refrigerating compartment door14aand a second refrigerating compartment door15a. Also, the freezing compartment door16amay include a pair of doors17aand18a.

Hereinafter, the first refrigerator door14awill be described as an example and will be referred to as a ‘door’.

The door14amay include an inner door142contacting a front surface113aof the cabinet11aand an outer door141disposed on a front surface of the inner door142.

That is, the cabinet11a, the inner door142, and the outer door141may be sequentially arranged.

A separate accommodation space, which is separated from the storage chamber, may be defined between the inner door142and the outer door141.

Also, the door14amay be a pivotable door that is provided to be rotatable through a first hinge60. Also, the outer door141is rotatably connected to the inner door142through a second hinge64.

That is, the first hinge60is provided to connect the inner door142to the cabinet11, and the second hinge64is provided to connect the inner door142to the outer door141.

The door14aincluding the inner door142and the outer door141rotates about a hinge shaft62of the first hinge60to open the storage chamber.

Also, the refrigerator10amay include various devices that automatically open the door14asuch as a door opening device100and a reed switch assembly40b.

Here, the door opening device100allows the door14aincluding the inner door142and the outer door141to rotate about the hinge shaft62of the first hinge60.

As described above, the door opening device100may be installed in the cabinet11a, and the reed switch assembly40bmay be installed in the door14a.

Since the cabinet11ahas an area greater than that of the door14a, when the door opening device20ais installed in the cabinet11a, a spatial limitation may be relatively less.

FIG. 10is an enlarged view of a portion C ofFIG. 9, andFIG. 11is an exploded perspective view of the door opening device according to the third embodiment of the present invention.

Referring toFIGS. 9 to 11, the door opening device100is disposed in an upper portion of the cabinet11a.

The door opening device100may include a push member150that pushes the door14ato open the door14a.

InFIG. 10, a position of the push member150may be referred to as an initial position. However, in this specification, the position of the push member150when the opening of the door14ais completed by the push member150may be referred to as a door opening position.

Since the door opening device100is disposed in the cabinet11a, the push member150may increase in length when compared to a case in which the door opening device100is disposed in the door14a. When the push member150increase in length, an opening angle of the door14amay increase.

The push member150may be disposed to be inclined with respect to a first virtual line A1that is perpendicular to the front surface113aof the cabinet11aand extends forward and backward.

The push member150may include a first end portion158aand a second end portion158b.

The first end portion158ais an end portion of the push member150, which is disposed close to the front surface113aof the cabinet11a(or a boundary146between the cabinet11aand the door14a), and the second end portion158bis an end portion disposed at a side opposite to the first end portion158a.

A length from the first end portion158ato the second end portion158bof the push member150may be greater than a thickness of the door14a(a thickness in an extension direction of the first virtual line A1or a second virtual line A2to be described later).

When the length of the push member150is greater than the thickness of the door14a, the opening angle of the door14amay increase.

In this embodiment, the first end portion158aof the push member150is disposed close to a sidewall113of the cabinet11a(or referred to as a “cabinet sidewall”) that is adjacent to a portion at which the first hinge60is installed or the second virtual line A2when compared to the second end portion158bso that the opening angle of the door14aper unit length of the push member150increases.

Here, the second virtual line A2is a virtual line that extends from the sidewall113of the cabinet11aand is parallel to the first virtual line A.

The second virtual line A2may be parallel to the door sidewall14cdisposed close to the portion of the door14aat which the first hinge60is installed or may be disposed on the door sidewall14c.

In the closed state of the door14aor the initial position of the push member150, the push member150is disposed so that a horizontal distance L1between the first end portion158aand the sidewall113of the cabinet11ais less than a horizontal length L2between the second end portion158band the sidewall113of the cabinet11a.

In this embodiment, the horizontal distance represents a distance in the normal direction of the sidewall113.

The opening angle of the door14aper unit length of the push member150may increase due to the above-described arrangement of the push member150. Therefore, there is an advantage that the length of the push member150required to open the door14aat a predetermined angle may be reduced.

Also, the first end portion158amay be disposed adjacent to a first side surface among the first side surface disposed close to the first hinge60and a second side surface opposite to the first side surface of both sides of the door14a.

The door opening device100may further include a driving device180.

The driving device180may further include a driving motor182that drives the push member150, and a power transmission part that transmits power of the driving motor182to the push member150.

The power transmission part may include, but not limited to, a plurality of gears.

The power transmission part includes a driving gear183connected to a shaft of the driving motor182, a reduction gear184connected to the driving gear183, a transmission gear connected to the reduction gear184, and a driven gear189connected to the transmission gear188to transmit the power to the push member150.

Referring toFIG. 9, force required by the user to directly open the door14ais F1. InFIG. 9, a portion at which the force F1acts is a handle.

Force required by the push member150to push and open the door14ais F2.

Here, since the push member150is disposed closer to the hinge shaft62than the handle, the force F2is greater than the force F1.

That is, the user has to push the push member150with force greater than the required force so as to directly open the door14a.

The more the push member150approaches the hinge shaft62, the more the force required by the push member150to open the door14aincreases.

Therefore, in this embodiment, the reduction unit184may include a plurality of reduction gears185,186, and187so that the force transmitted to the push member150increases when the driving motor182operates.

The push member150may include a push rack151having a rack gear153that receives the power of the driving motor182.

The rack gear153may be engaged with the driven gear189. The driven gear189may have a height greater than that of the rack gear153so that rotational force of the driven gear189is smoothly transmitted to the rack gear153.

The push rack151may include a first side surface152adisposed close to the sidewall113of the cabinet11aand a second side surface152bdisposed opposite to the first side surface152a. The rack gear153may be disposed on the first side surface152a.

When the rack gear153is disposed on the first side surface152alike this embodiment, when the push member150protrudes forward from the cabinet11ato open the door14a, exposure of the rack gear toward the user may be prevented.

For example, when the door14ais the right door among the doors arranged at the left and rights, the user may stand close to the left door so as not to collide with the right door when the right door is opened.

In this case, when the push member150protrudes forward from the cabinet11awhile the right door is opened, the user faces the second side surface152bof the push member150.

In this embodiment, since the rack gear153is disposed on the first side surface152aof the push member150, even if the push member150protrudes forward from the cabinet11a, the rack gear153may not be visible to the user.

The push member150may further include a rack cover170coupled to an end portion of the push rack151.

The rack cover170may directly contact the door14a. The rack cover170may be made of a material such as urethane rubber or a silicon material.

Accordingly, the first end portion158aof the push member150described above may actually be the end portion (contact surface171to be described later) of the rack cover170.

The door opening device100may further include a housing that accommodates the push member150and guides the movement of the push member150.

The housing may include, but is not limited to, an upper housing130and a lower housing110.

The power transmission part may be disposed in a space defined by the upper housing130and the lower housing110, and the driving motor182may be connected to the driving gear183outside the housing.

The lower housing110may have a seating part112on which the power transmission part is seated. A shaft114on which the plurality of gears constituting the power transmission part are rotatably installed may be disposed on the seating part112.

A guide116that guides the movement of the push member150may be disposed on each of the upper housing130and the lower housing110.

For example, the driving motor182may be installed in the lower housing110. The motor cover190may be coupled to the lower housing110so that the motor cover190surrounds the driving motor182in the state in which the driving motor182installed in the lower housing110.

The door opening device100may further include an opening detection part that detects whether the door14ais manually opened.

The opening detection part may include a magnetic field generation device50and a reed switch assembly40b.

The magnetic field generation device50(e.g., a magnet) may be provided, for example, in the push member150. The magnetic field generation device50may be provided in the rack cover170, and the reed switch assembly40bmay be provided in the door14a.

Since the structure and operation of the reed switch assembly40bare the same as those described in the second embodiment, detailed description thereof will be omitted.

A vibration-proof member200may be coupled to the housing. Fixing parts120and134coupled to the vibration-proof member200may be disposed on one or more of the lower housing110and the upper housing130.

FIG. 11, for example, the fixing parts120and134are respectively provided on the lower housing110and the upper housing130. In this case, the vibration-proof member200may be coupled to the fixing parts120and134of each of the lower housing110and the upper housing130.

A structure of the vibration-proof member200and a method for coupling the vibration-proof member200to the housing will be described later.

FIG. 12is a plan view of the push rack according to the third embodiment of the present invention,FIG. 13is a view of a cover coupling part provided on the push rack according to the third embodiment of the present invention,FIG. 14is a view illustrating a state in which the rack cover is coupled to the cover coupling part ofFIG. 12, andFIG. 15is a view illustrating constituents ofFIG. 14when viewed in a direction D.

Referring toFIGS. 12 to 15, the push rack151may include a top surface152cand a bottom surface152d.

A protrusion or groove that enhances strength of the push rack may be disposed on/in one or more of the top surface152cand the bottom surface152d.

InFIGS. 13 to 15, for example, the groove is defined in each of the top surface152cand the bottom surface152dof the push rack151.

That is, a top surface groove154recessed downward may be defined in the top surface152cof the push rack151, and a bottom surface groove155recessed upward may be defined in the bottom surface152dof the push rack151.

Although not limited, the top surface groove154and the bottom surface groove155may be lengthily provided in a longitudinal direction of the push rack151.

Here, the top surface groove154and the bottom surface groove155may be disposed to overlap each other in the vertical direction. Therefore, the vertical cross-section of the push rack151may have a shape such as “H”.

Since a portion at which the rack gear153is disposed receives force of the power transmission part, the top surface groove154and the bottom surface groove155may be defined closer to the first side surface152athan the second side surface152bof the push rack151so that strength of the portion at which the rack gear153is disposed increases.

That is, a distance D1between the top surface groove154and the first side surface152ais less than a distance D2between the top surface groove154and the second side surface152b. A distance D1between the bottom surface groove155and the first side surface152ais less than a distance D2between the bottom surface groove155and the second side surface152b.

The push rack151may further include a connection surface156aconnecting one end of the first side surface152ato one end of the second side surface152b. The connection surface156amay connect the top surface152cto the bottom surface152dof the push rack151.

A cover coupling part160coupled to the rack cover170may be provided on the connection surface156a. The cover coupling part160may protrude from the connection surface156a.

A vertical length H2of the cover coupling part160may be less than a vertical length H1of the push rack151. For example, the cover coupling part160may be disposed to be spaced apart from each of the top surface152cand the bottom surface152dof the push rack151.

Also, a shaft hole162through which the shaft178coupled to the rack cover170passes may be defined in the cover coupling part160.

The rack cover170may be rotatably coupled to the cover coupling part160by the shaft178.

The rack cover170may have substantially a rectangular parallelepiped shape. The rack cover170may include a contact surface171contacting the door14a.

In the rack cover170, a slot174into which the cover coupling part160is inserted may be defined in an opposite surface of the contact surface171. In this embodiment, the opposite surface of the contact surface171in the rack cover170may be referred to as a slot surface173.

Also, a shaft hole162through which the shaft coupled to the cover coupling part160inserted into the slot174passes may be defined in the rack cover170.

The connection of the push rack151may include an inclined surface156bso that the rack cover170and the push rack151are rotatable without interfering with each other in the state in which the rack cover170is coupled to the cover coupling part160.

Specifically, in a state in which the initial position of the push member150and the contact surface171of the rack cover170are disposed to face the door14a, at least a portion of the connection surface156ais disposed to be inclined on the rack cover170with respect to the slot surface173.

Thus, the inclined surface156bis spaced apart from the slot surface173on the connection surface156a, and a gap is defined between the inclined surface156band the slot surface173.

The shaft hole162may be disposed close to one side surface of both side surfaces of the rack cover170.

Referring toFIG. 14, one side surface of the rack cover170is a left surface. The inclined surface156bof the connection surface156amay be inclined away from the slot surface173from the left surface to the right surface of the rack cover170.

In this embodiment, since the rack cover170contacts the door14a, a surface of the door14amay be prevented from being damaged by the push rack151.

FIG. 16is a view illustrating a state in which an installation bracket is installed on the cabinet according to the third embodiment of the present invention, andFIGS. 17 and 18are perspective views of the installation bracket according to the third embodiment of the present invention.

FIG. 19is a view illustrating the fixing part of the lower housing according to the third embodiment of the present invention,FIG. 20is a view illustrating a state in which the vibration-proof member is fixed to the fixing part,FIG. 21is a view illustrating a state in which the vibration-proof member is coupled to a coupling protrusion of the installation bracket, andFIG. 22is a sectional view taken along line A-A ofFIG. 21.

Referring toFIGS. 10 and 16 to 22, the door opening device100according to this embodiment may be installed in an installation bracket300installed in the cabinet11ain the upper portion of the cabinet11a.

The cabinet11amay include an outer case defining an outer appearance, an inner case disposed inside the outer case to define the storage chamber, and a heat insulation material disposed between the inner case and the outer case.

The installation bracket300may be fixed to the outer case inside the outer case. In this embodiment, a top surface of the outer case will be described as an upper wall115of the cabinet11a.

For example, the installation bracket300may be attached to a bottom surface of the upper wall115of the cabinet11aby a coupling part such as an adhesive or a tape. That is, the installation bracket300may contact the outer case in a space between the outer case and the inner case.

In the state in which the installation bracket300is fixed to the outer case, a foaming solution for forming an insulation material may be filled into the space between the outer case and the inner case.

The adhesion between the installation bracket300and the outer case may be improved by the expansion of the foaming solution in a process of cooling the foaming solution.

According to this embodiment, the installation bracket300may be coupled to the outer case, and then, the door opening device100may be installed on the installation bracket300without directly providing a structure that couples the door opening device100to the outer case.

Thus, there is an advantage in that the position of the door opening device100is fixed to the upper portion of the cabinet11awithout changing the conventional mold structure for manufacturing the outer case.

Also, there is an advantage in that a structure of a foaming jig holding the outer case to fill the foaming solution into the outer case is used as it is without being changed in structure.

The installation bracket300may include a first bracket310, a second bracket320spaced apart from the first bracket310, and a connection part330connecting the first bracket310to the second bracket320.

One or more of the first bracket310and the second bracket330may include one or more installation parts314for installing the door opening device100.

Each of the first bracket310and the second bracket320may include one or more installation parts314to firmly fix the position of the door opening device100.

The first bracket310may further include a motor accommodation part312in which the driving motor182generating power for driving the push member150is accommodated.

For example, the motor accommodation part312may be provided by recessing one surface of the first bracket310downward.

In the first bracket310, the installation part314may include a recess part defined by recessing the one surface of the first bracket310downward.

For example, the installation part314may include a bottom surface314aand a circumferential surface314b.

A coupling protrusion315to which the vibration-proof member200coupled to the door opening device100is coupled may be disposed on the bottom surface314aof the installation part312.

The coupling protrusion315protrudes upward from the bottom surface314aand is connected to the circumferential surface314b. For example, the coupling protrusion315is integrated with the bottom surface314aand the circumferential surface314b.

According to this embodiment, since the coupling protrusion315is integrated with the circumferential surface314band the bottom surface314a, a phenomenon in which the coupling protrusion315is damaged by reaction force applied to the push member150may be prevented.

A coupling groove316to which the coupling member is coupled may be defined in the coupling protrusion315.

Although not limited, the plurality of installation parts314may be provided on the first bracket310, and the motor accommodation part312may be disposed between the plurality of installation parts314.

A rib317for reinforcing strength may be disposed on the bottom surface of the first bracket310. The rib317may prevent the first bracket310from being deformed by the force applied to the first bracket310when the foaming solution is expanded.

Although not limited, the rib317may be provided in a lattice shape on the first bracket310.

Since the structure of the installation part314provided on the second bracket320is the same as that of the installation part314provided on the first bracket310, a detailed description thereof will be omitted.

In this embodiment, since the installation part314and the motor receiving unit312are provided to be recessed downward in the first bracket310and the second bracket320, a protruding height of the door opening device100from the upper wall115of the cabinet11amay be minimized in the state in which the door opening device100is installed on the installation bracket300.

The installation bracket300may further include a wire guide322guiding a wire. The wire guide322may guide the wire to be inserted into the door14a.

For example, the wire guide322may be provided in the second bracket320. The wire guide322may be provided in the form protruding from the second bracket320.

The installation bracket300may be disposed so that the second bracket322is disposed closer to the front surface of the cabinet11a(or the door14a) than the first bracket310.

Also, the wire guide322may be disposed closer to the sidewall113of the cabinet11athan the installation portion314of the second bracket320.

Thus, at the initial position of the push member150, the wire guide322may be disposed in a region between the first side surface152aof the push rack151and the sidewall113of the cabinet11a.

In order to prevent ween the wire guide322and the driving device180from interfering with each other, the wire guide322and the driving device180may be arranged in a front and rear direction.

Here, the wire guide322may be disposed in front of the driving device180.

The driving device180may be disposed in a region between the first side surface152aof the push rack151and the sidewall113of the cabinet11aso that the power is smoothly transmitted to the rack gear153disposed on the first side surface152aof the push rack151.

Since the installation bracket300is disposed below the upper wall115of the cabinet11a, a plurality of openings may be defined in the upper wall115of the cabinet11aso that the door opening device100is installed on the installation bracket300above the upper wall of the cabinet11a.

The plurality of openings may include a first opening116through which the installation part314provided on the first bracket310and the motor accommodation part312are exposed to the outside and a second opening117through which the installation part314provided on the second bracket320and the wire guide322are exposed to the outside.

One portion of the vibration-proof member200coupled to the door opening device100and the driving motor182may pass through the first opening116.

The other portion of the vibration-proof member200coupled to the door opening device100may pass through the second opening117. Also, the wire guide322may protrude upward from the upper wall115through the second opening117. The wire guide322protruding upward from the upper wall115may be covered by the first hinge60.

As described above, the fixing part120and134having the same structure may be disposed on the lower housing110and the upper housing130, respectively.

Hereinafter, the structure of the fixing part120provided on the lower housing110will be described.

The fixing part120may protrude downward from the bottom surface110aof the lower housing110. This is done for a reason in which the vibration-proof member200coupled to the fixing part120passes through the openings116and117of the cabinet11aso as to be installed on the installation part314.

The fixing part120includes a space part122in which the vibration-proof member200is disposed and a fixed rib124which is exposed to the space part122and to which the vibration-proof member200is fixed.

Although not limited, the fixing rib124may be provided in a shape such as “U” when viewed from above.

The vibration-proof member200may be made of a material capable of absorbing vibration. For example, the vibration-proof member2000may be made of a rubber material.

The vibration-proof member200may be provided, for example, in a shape such as “U”. That is, when the vibration-proof member200is viewed from above, one side thereof may be opened.

The vibration-proof member200may include an inner circumferential surface201and an outer circumferential surface202. A slot203into which the fixing rib124is accommodated may be defined in the outer circumferential surface202of the vibration-proof member200.

Thus, the vibration-proof member200may be slidably coupled to the fixing rib124so that the fixing rib124is fitted into the slot203of the vibration-proof member200.

A coupling hook126may be disposed on the fixing rib124to prevent the vibration-proof member200from being separated from the fixing rib124in the state in which the fixing rib124is fitted into the slot203of the vibration-proof member200. A hook insertion part204into which the coupling hook126is inserted may be defined in the vibration-proof member200.

For example, the hook insertion part204may be recessed toward the inner circumferential surface201in the slot203.

Since the vibration-proof member200is provided in a “U” shape, the inner circumferential surface201of the vibration-proof member200defines a space205in which the coupling protrusion315is accommodated.

The housing may be installed on the installation bracket300in the state in which the vibration-proof member200is coupled to the fixing parts120and134of the housing.

In the process of opening the door14aby the push member150, the reaction force acts on the push member150from the door14a, and the reaction force acting as the push member150is transmitted to the housing.

Here, the reaction force acting on the fixing part120or134, which is disposed closest to the door14a, among the fixing parts120and134provided on the housing may be largest.

Thus, the housing may further include a reinforcement rib127integrated with a portion of the whole of the fixing parts120and134. For example, the reinforcement rib127may be integrated with the side surface120aof the fixing part120and the bottom surface110aof the lower housing110. The reinforcement rib127may include an inclined surface128so as not to interfere with surrounding structures.

A motor accommodating groove119accommodating the driving motor182may be defined in a bottom surface of the lower housing110. The motor cover190may be coupled to the lower housing110in the state in which the driving motor182is accommodated in the motor accommodating groove119.

A process of installing the door opening device100on the installation bracket300will be described.

The coupling protrusion315of the installation bracket300and the vibration-proof member200of the door opening device100are aligned, and then, the door opening device100moves toward the upper wall115of the cabinet11aso that the coupling protrusion315is fitted into the vibration-proof member200.

The coupling protrusion315is fitted into the space205of the vibration-proof member200, and the vibration-proof member200is seated on the bottom surface314aof the installation part314.

The housing is spaced apart from the bottom surface314ain the state in which the vibration-proof member200is seated on the bottom surface314aof the installation part314.

The coupling member may be coupled to the coupling protrusion315in the state in which the coupling protrusion315is fitted to the vibration-proof member200.

Hereinafter, an operation of the door opening device will be described.

FIG. 23is an enlarged view illustrating a portion E ofFIG. 11,FIG. 24is a view illustrating a state in which the refrigerator door is opened by the door opening device according to the third embodiment of the present invention, andFIG. 25is an enlarged view of a portion F ofFIG. 24.

Referring toFIGS. 8 to 24, when the refrigerator10is turned on, a controller (not shown) waits for an input of a door opening command.

At the initial position of the push member150, the rack cover170is spaced apart from a surface144of the door14a(a surface facing the front surface113aof the cabinet11a, i.e., referred to as a rear surface of the door), and the contact surface171of the rack cover170is disposed to face the door14a.

If it is determined that the door opening command is inputted, the controller controls the driving motor182so that the driving motor182rotates in a first direction to allow the push member150to move from the initial position to the door opening position.

When the driving motor182rotates in the first direction, the power transmission part transmits the rotational force of the driving motor182to the push member150in the first direction, and thus, the push member150pushes the door14ato allow the door14ato rotate.

Since the rack cover170is spaced apart from the door14aat the initial position of the push member150, the rack cover170moves together with the push rack151at the initial operation of the driving motor182, and thus, the contact surface171of the rack cover170contacts the surface144of the door14a.

In this state, when the protruding length of the push rack151(for example, the length protruding forward from the cabinet11aor the length protruding outward from the housing) increases, the push member150may press the surface144of the door14ato open the door14a.

In this embodiment, since the rack cover170is rotatably coupled to the cover coupling part160, when the opening angle of the door14aincreases in the state in which the push rack151protrudes from the housing to allow the contact surface171of the rack cover170to contact the surface144of the door14a, the rack cover170relatively rotates with respect to the push rack151.

Then, the rack cover170rotates in a direction in which the slot surface173of the rack cover170and the inclined surface156bof the connection surface156aapproach each other, and the inclined surface156bof the connection surface156acontacts the slot surface173of the rack cover170in the state in which th door14ais opened at a predetermined angle.

As described above, the contact surface of the rack cover170is not slid on the surface144of the door14ain the state in which the contact surface171of the rack cover170contact the door14auntil the inclined surface156bof the connection surface156acontacts the slot surface173of the rack cover170.

Accordingly, friction between the rack cover170and the surface144of the door14amay be minimized to minimize surface damage of the rack cover170and/or the door14a.

Also, the first end portion158aand the second end portion158bof the push member150move together by the operation of the driving motor182.

Here, in the process of moving the push member150to open the door14a, the first end portion158aand the second end portion158bof the push member150move to approach the second virtual line A2.

The controller determines whether the push member150reaches the door opening position in the rotation process of the driving motor182in the first direction.

The controller may determine whether the push member150reaches the door opening position by using a sensor (not shown). Alternatively, the controller may determine that the push member150reaches the door opening position when cumulative rpm of the driving motor182reaches reference rpm.

The controller may stop the rotation of the driving motor182when it is determined that the push member150moves to the door opening position.

In a state in which the door14arotates at a predetermined angle, the user may manually increase the opening angle of the door14a.

On the other hand, when the manual opening of the door14ais detected by the opening detection part in the state in which the driving motor182is stopped while the door14ais opened or after the door14ais opened, the controller may allow the driving motor181to rotate in a second direction opposite to the first direction so that the push member150returns to the initial position.

The controller determines whether a predetermined time is elapsed when the push member150moves to the door opening position, and the driving motor182is stopped.

If it is determined that a predetermined time is elapsed at a time point at which the driving motor182is stopped, the control unit allows the driving motor182to rotate in the second direction so that the push member150returns to the initial position.

Also, the controller determines whether the push member150returns to the initial position, and when it is determined that the push member150returns to the initial position, the driving motor182is stopped.

In the third embodiment, the door opening device is installed in the cabinet. However, alternatively, the door opening device may be installed in the door. In this case, relationships between the push member and the first and second virtual lines may be the same.

For example, the push member may be disposed to be inclined with respect to the first virtual line perpendicular to the front surface of the cabinet and extending in the front and rear direction.

Also, the push member may include a first end portion and a second end portion. The first end portion is an end portion disposed close to the front surface of the cabinet in the push member, and the second end portion is an end portion disposed opposite to the first end portion.

A length of the first end portion and the second end portion of the push member may be greater than a thickness (in the front and rear direction) of the door.

The first end portion of the push member may be disposed closer to the sidewall14cof the door14aadjacent to the portion at which the first hinge is installed than the second end portion.

That is, in the state in which the door is closed or at the initial position of the push member, the push member may be disposed so that a horizontal distance from the first end portion to the sidewall14cof the door is less than a horizontal distance from the second end portion to the sidewall14cof the door.

In this case, the horizontal distance represents a distance in a normal direction of the sidewall of the door.