JP2018119759A - Drawer opening/closing mechanism for refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic opening/closing mechanism capable of preventing generation of resistance due to a drive machine and preventing load from being applied to the drive mechanism, in a case of manually opening/closing a drawer with respect to a refrigerator body, in a refrigerator including the automatic opening/closing mechanism.SOLUTION: A drawer opening/closing mechanism includes a refrigerator body, a drawer provided in the refrigerator body, and an automatic opening/closing mechanism 200 configured to open/close the drawer. The automatic opening/closing mechanism 200 includes a drive mechanism 210, and a power transmission mechanism 220 configured to transmit power of the drive mechanism 210 to the drawer. The power transmission mechanism 220 includes a switching mechanism 230 configured to switch to any one of a power transmission state of connecting the power transmission mechanism 220 to the drive device 210, and a power non-transmission state of not connecting the power transmission mechanism 220 to the drive device 210.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a drawer opening / closing mechanism for a refrigerator.

  As a conventional refrigerator, it is used in vegetable compartments and freezer compartments, and it is a drawer for reducing the burden on the user in drawing out the drawer for a large-capacity drawer containing a relatively large and heavy container. Some have a mechanism that automatically opens and closes.

  As the conventional refrigerator, Patent Document 1 discloses a refrigerator including a refrigerator main body and a drawer provided in the refrigerator main body, wherein a rack is provided on a fixed rail of the refrigerator main body, a pinion is provided on a moving rail of the drawer, and the rack A device that automatically opens and closes a drawer with respect to a refrigerator main body by rotating the pinion by a drive motor in a state where the pinion and the pinion are connected is disclosed.

  However, in the refrigerator disclosed in Patent Document 1, since the drive motor and the pinion are always connected, when the drawer is manually opened and closed with respect to the refrigerator body, Therefore, a large force has to be applied to open and close the drawer, which in turn is a burden on the user, and a load is applied to the drive motor, causing a problem of the drive motor. .

US Pat. No. 8,074,468

  Therefore, the present invention provides a refrigerator drawer opening / closing mechanism in which when the drawer is manually opened and closed with respect to the refrigerator body, resistance by the driving mechanism does not occur and no load is applied to the driving mechanism. Is the main issue.

  That is, the refrigerator drawer opening and closing mechanism according to the present invention is a refrigerator drawer opening and closing mechanism including a refrigerator body, a drawer provided in the refrigerator body, and an automatic opening and closing mechanism for opening and closing the drawer, and a drive mechanism, A power transmission mechanism for transmitting the power of the drive mechanism to the drawer; and a switching mechanism interposed between the drive mechanism and the power transmission mechanism, wherein the switching mechanism transmits the power of the drive mechanism to the drawer. Switching between a power transmission state in which the power transmission mechanism is transmitted and a power non-transmission state in which the power of the drive mechanism is not transmitted to the power transmission mechanism is provided.

  In such a case, when the drawer is manually opened and closed with respect to the refrigerator main body, it can be switched to the power non-transmission state by the switching mechanism. Therefore, when the drawer is moved, The resistance is reduced, and accordingly, the drawer can be moved with a small force. Further, a load is not applied to the drive mechanism, and a failure of the drive mechanism can be prevented.

  As a specific configuration of the switching mechanism, the switching mechanism includes at least one connection mechanism that repeats a connected state and a non-connected state with respect to the power transmission mechanism, and the switching mechanism is connected to the power transmission mechanism. For example, the power transmission state in which the connection mechanism is connected and the power non-transmission state in which the connection mechanism is not connected to the power transmission mechanism are included. A connection mechanism, wherein the switching mechanism connects one connection mechanism to the power transmission mechanism and does not connect the other connection mechanism; and the other connection mechanism to the power transmission mechanism. Switch between the power transmission state in which one connection mechanism is not connected and the power transmission state in which both connection mechanisms are not connected to the power transmission mechanism. Configuration, and the like.

  In such a case, since the power transmission mechanism and the drive mechanism are not connected in the power non-transmission state, this allows the drive mechanism to be manually opened and closed with respect to the refrigerator body. It can be moved with a small force without receiving resistance.

  In the refrigerator drawer opening and closing device, the switching mechanism switches to the power transmission state when the drive mechanism is driven, and switches to the power non-transmission state when the drive mechanism is not driven. It may be.

  In such a case, when the power is not supplied to the refrigerator due to a power failure or the like, and the drawer must be manually opened and closed, the drive mechanism is stopped, and the switching mechanism is automatically operated accordingly. Automatically switches to the power non-transmission state.

  As a specific configuration of the drive mechanism and the power transmission mechanism, the drive mechanism is a drive motor, and the power transmission mechanism is a rack installed on either the drawer or the refrigerator main body and the other. A power transmission state in which the switching mechanism is interposed between the drive motor and the pinion and transmits the power of the drive motor to the pinion, and the power of the drive motor is transmitted to the pinion. The thing of the structure switched to the power non-transmission state which is not transmitted to a pinion is mentioned.

  With such a configuration, the power transmission state and the power non-transmission state can be mechanically switched without using an electrical connection such as a switching element.

  Further, the specific configuration of the switching mechanism includes a center gear connected to the drive motor, and at least one connection mechanism having a gear meshing with the center gear, and the drive motor rotates in one direction. When the connection mechanism is connected to the pinion and enters a power transmission state, and when the drive motor rotates in the other direction, the connection mechanism is connected to the pinion and enters a power transmission state, and the drive motor rotates. In the case where the two connection mechanisms are not connected to the pinion, the power is not transmitted.

  With such a configuration, the connection mechanism can be moved between the power transmission position and the power non-transmission position by moving the connection mechanism along a plane perpendicular to the rotation axis of the center gear by the switching mechanism. Therefore, a clutch mechanism for moving the gear in the height direction is unnecessary, and the switching mechanism can be made compact in the height direction. Moreover, since the connection mechanism moves in conjunction with the rotation of the center gear, the connection mechanism can be moved by the power of the motor, and a dedicated actuator for switching between the power transmission state and the power non-transmission state can be eliminated. it can.

  Further, as a more specific configuration of the switching mechanism, the switching mechanism includes a turning mechanism that has the same rotation shaft as the center gear and turns the at least one connection mechanism around the rotation shaft, The turning mechanism may be configured to turn by its own weight and switch to the power non-transmission state when the drive motor is not rotating.

  If it is such, since a turning mechanism can be switched to a power non-transmission state, without adding components with respect to a switching mechanism, productivity can improve and cost and failure risk can also be reduced. .

  In addition, as a connection structure between the drive motor and the center gear, a torque limiter is interposed so that when the torque more than a threshold is applied to the center gear, the center gear is idled with respect to the drive motor. Also good.

  In such a case, when the drawer is automatically opened and closed in the power transmission state, if a strong external force is applied to the drawer and a large load is applied to the center gear, the torque limiter acts on the center gear. The load is not transmitted to the drive motor, and damage to the drive motor can be prevented.

  In any one of the refrigerator drawer opening / closing mechanisms, the refrigerator body includes a fixed rail that slides the drawer, and the drawer includes a movable rail attached to the fixed rail, and the fixed rail or the movable rail. One of them may have one of the rack or the pinion, and one of the fixed rail or the movable rail may have the other of the rack or the pinion.

  If this is the case, the automatic opening / closing mechanism can be incorporated into the slide rail that has been used as a drawer slide mechanism for the refrigerator main body, so that it can be installed in a small space and the drawer capacity can be increased. it can.

  According to the drawer drawer opening and closing mechanism according to the present invention configured as described above, when the drawer is manually opened and closed with respect to the refrigerator body, no resistance is generated by the driving mechanism, and no load is applied to the driving mechanism. Can not be.

It is the fragmentary sectional view which showed the refrigerator which concerns on Embodiment 1. FIG. FIG. 3 is a partially omitted cross-sectional view illustrating a relationship between a fixed rail and a moving rail of the refrigerator according to Embodiment 1 and an automatic opening / closing mechanism. FIG. 3 is a partially omitted cross-sectional view illustrating a relationship between a fixed rail and a moving rail of the refrigerator according to Embodiment 1 and an automatic opening / closing mechanism. FIG. 3 is an exploded cross-sectional view showing a turning mechanism according to the first embodiment. It is explanatory drawing which shows operation | movement of the turning mechanism with respect to the shaft gear which concerns on Embodiment 1. FIG. It is explanatory drawing which shows operation | movement of the turning mechanism with respect to the shaft gear which concerns on Embodiment 2. FIG.

  Below, the refrigerator provided with the drawer open / close mechanism for refrigeration which concerns on this invention is demonstrated based on drawing.

<Embodiment 1>
As shown in FIG. 1, the refrigerator 100 according to the present embodiment has a drawer 30 inserted in a lower space 20 provided in the lower portion of the refrigerator body 10. The lower space 20 has an opening 21 toward the front, and fixed rails 40, 40 are installed on both inner side surfaces so as to extend in the front-rear direction (horizontal direction).

  The drawer 30 is installed so as to span between the door plate 31 that closes the opening 21 that faces the front of the lower space 20, the pair of movable rails 50 that extend rearward from both sides of the back surface of the door plate 31, and both the movable rails 50. The storage case 60 is provided. The storage case 60 holds a storage item. The drawer 30 can slide in the front-rear direction with respect to the lower space 20 by attaching the movable rails 50 to the corresponding fixed rails 40 respectively.

  The attachment structure of the fixed rail 40 and the movable rail 50 will be described in detail. 2A is a cross-sectional view taken along the line AA in which the long portions of the fixed rails 40 and the movable rails 50 in FIG. 1 are omitted, and FIG. 2B is a cross-sectional view of the fixed rails 40 in FIG. It is the BB cross section which abbreviate | omitted the elongate part of both the movable rails 50. FIG. 3A is a CC cross section in FIG. 2A, and FIG. 3B is a DD cross section in FIG. 2B. Is shown.

  As shown in FIG. 2 and FIG. 3, the fixed rail 40 is a long fixed plate 41 fixed to the side surface of the refrigerator main body 10, and the side of the refrigerator main body 20 from the upper side and the lower side of the fixed plate 41. And a pair of inner rail pieces 42 rising vertically. The lower inner rail piece 42b is provided with a rack 221 constituting an automatic opening / closing mechanism 200, which will be described later, on a surface facing the upper inner rail piece 42a.

  The movable rail 50 includes a reinforcing plate 51 positioned so as to face the fixed plate 41 of the fixed rail 40 in a state where the drawer 30 is inserted into the lower space 20, and the fixed rail 40 from the upper side and the lower side of the reinforcing plate 51. A pair of outer rail pieces 52 bent so as to face, and an auxiliary plate 53 (see FIG. 3) attached to a surface of the reinforcing plate 51 facing the fixed rail 40 and partially protruding from the rear end side of the reinforcing plate 51; It has. Further, a connecting bar 54 is stretched over the movable rail 50 on the rear end side of each reinforcing plate 51.

  When the movable rail 50 is attached to the fixed rail 40, the fixed rail 40 is inserted between the outer rail pieces 52 of the movable rail 50, and the upper inner and outer rail pieces 42a and 52a are brought into contact with each other. The lower inner and outer rail pieces 42b and 52b are brought into contact with each other. As a result, the fixed rail 40 and the movable rail 50 can slide back and forth while maintaining the state in which the upper inner and outer rail pieces 42a and 52a and the lower inner and outer rail pieces 42b and 52b are in contact with each other. become.

  Next, as shown in FIG. 3, the automatic opening / closing mechanism 200 is interposed between the drive mechanism 210, the power transmission mechanism 220 that transmits the power of the drive mechanism to the drawer 30, and the drive mechanism 210 and the power transmission mechanism. And a switching mechanism 230.

  The drive mechanism 210 includes a drive motor (not shown) serving as a power source. The drive motor is housed in a box 211 fixed to a connecting bar 54 that spans the reinforcing plates 51 of both movable rails 50 and 50, and a torque limiter (not shown) housed in the box 211 is also used. To the power transmission mechanism 220. The specific configuration of the torque limiter is a rotating shaft that is interposed between the drive motor and the power transmission mechanism 220 when a load (torque) that is equal to or greater than a threshold acts on the drive motor side via the power transmission mechanism 220. Is configured to idle.

  The power transmission mechanism 220 includes a rack 221 provided on the both fixed rails 40 and a pinion 222 that is rotatably fixed to the auxiliary plate 53 of both movable rails 50, and between the drive motor and the pinion 222. The switching mechanism 230 is interposed between the two.

  Both pinions 222 and 222 are fixed to a shaft 223 that spans the auxiliary plate 53 of both movable rails 50 and 50, and rotates about the shaft 223 as a rotation axis. Further, a shaft gear 224 that rotates about the shaft 223 as a rotation axis is fixed to the shaft 223 so as to be adjacent to one pinion 222 as in the case of both pinions 222 and 222. In the state where the movable rail 50 is attached to the fixed rail 40, both the pinions 222 are engaged with the rack 221.

  As shown in FIGS. 2 and 3A, the switching mechanism 230 has a center gear 231 that rotates in conjunction with the drive motor and a pair of idle gears 241 (a pair of connection mechanisms) that mesh with the center gear 231. Mechanism 240. The center gear 231 is fixed to a shaft body 212 that rotates in conjunction with the drive motor, and the turning mechanism 240 is rotatably attached to the shaft body 212.

  The pair of idle gears 241 is arranged with respect to the turning mechanism 240 so as to sandwich a straight line connecting the rotation shaft of the center gear 231 and the rotation shaft of the shaft gear 224, and rotates in conjunction with the center gear 231.

  As shown in FIG. 4, the turning mechanism 240 has a flat plate-like turning plate 242 that supports a pair of idle gears 241. The swivel plate 242 has a through hole 243 into which the shaft body 212 is inserted, and a pair of idle gear mounting shafts 244 are provided so as to sandwich the through hole 243, and the pair of idle gear mounting shafts. An idle gear 241 is rotatably attached to 244. Note that a rotational load member 245 interposed between the idle gear 241 and the swivel plate 242 is passed through the pair of idle gear mounting shafts 244.

  The rotation load member 245 applies a load to the rotation of the idle gear 241 and generates torque for turning the pair of idle gears 241 around the rotation axis of the center gear 231. The rotation load member 245 follows the rotation axis with respect to the idle gear 241. An elastic member such as a spring that applies a force in the direction is used.

  Specifically, the rotary load member 245 is passed through the idler gear mounting shaft 244, the idler gear 241 is passed from above, and the rotary load member 245 is fixed through a pressing plate 246 that presses the idler gear 241 from above. A force is applied from 245 to the idle gear 241 in a direction along the rotation axis. The pressing plate 246 is fitted and fixed in the concave groove 247 along the circumferential direction of the outer peripheral surface of the idle gear mounting shaft 244.

  As shown in FIG. 5, the turning mechanism 240 configured as described above can turn the pair of idle gears 241 around the rotation axis (shaft body 212) of the center gear 231 along the rotation direction of the center gear 231. It has become. More specifically, when the shaft body 212 rotates in one direction as the drive motor is driven, as shown in FIG. 5A, the turning plate 242 also turns in one direction by the action of the torque of the rotary load member 245. One idle gear 241 a meshes with the shaft gear 224. On the other hand, when the shaft body 212 rotates in the direction as the drive motor is driven, as shown in FIG. 5B, the turning plate 242 also turns in the other direction by the action of the torque of the rotary load member 245, and the other idler The gear 241b meshes with the shaft gear 224.

  In addition, when the turning mechanism 240 is in a state where it can freely rotate about the rotating shaft (shaft body 212) extending in the horizontal direction, the turning mechanism 240 turns by its own weight and has a center of gravity so that both the idle gears 241 are separated from the shaft gear 224. Is set. Therefore, it is preferable to set the center of gravity of the turning mechanism 240 to be lower along the direction of gravity with respect to the rotation axis. As a result, when the drive motor stops and the shaft body 212 interlocked with the drive motor can freely rotate, as shown in FIG. 5C, the turning mechanism 240 turns so as to maintain the weight balance. Then, both the idle gears 241 are separated from the shaft gear 224.

  The refrigerator drawer opening / closing mechanism has a control unit (not shown), and the control unit is connected to an input means including an open button and a close button provided on an outer wall surface of the refrigerator 100 or the like. The control unit is constituted by a so-called computer having a CPU, a memory, an A / D / D / A converter, an input / output means, etc., and a program stored in the memory is executed, and various devices cooperate. The function is realized by working. Specifically, when the open / close button of the input means is pressed, the control unit exhibits a function of automatically opening and closing the drawer 30 by the automatic opening / closing mechanism 200.

  Next, the operation of the refrigerator drawer opening / closing mechanism will be described.

  First, when the open button of the input means is pressed, as shown in FIG. 5A, the control unit drives the drive motor to rotate forward, and the center gear 231 is interlocked with the forward rotation of the drive motor. Is rotated in one direction (counterclockwise in FIG. 5A), and accordingly, the turning mechanism 240 is also rotated in one direction by the load of the rotation load member 245. Thereby, the pair of idle gears 241 of the turning mechanism 240 turns in one direction around the rotation axis of the center gear 231, and one idle gear 232 a meshes with the shaft gear 224. Therefore, the drive mechanism 210 and the power transmission mechanism 220 are connected to each other via the switching mechanism 230, and the power of the drive mechanism 210 is transmitted to the power transmission mechanism.

  Specifically, the forward rotation of the drive motor is transmitted from the center gear 231 to the shaft gear 224 via one idler gear 241a, and both pinions 222 fixed to both ends of the shaft 223 as the shaft gear 224 rotates. As a result, both pinions 222 move forward relative to the rack 221 provided on the fixed rail 40 of the refrigerator main body 10, and the drawer 30 is automatically opened. When the drawer 30 moves forward to a predetermined position, a position detection sensor (not shown) detects this, and the control unit that receives the signal from the position detection sensor stops driving the drive motor.

  On the other hand, when the close button of the input means is pressed, as shown in FIG. 5B, the control unit drives the drive motor to rotate in the reverse direction, and the center gear is interlocked with the reverse rotation of the drive motor 210. 231 rotates in the other direction (clockwise in FIG. 5B), and accordingly, the turning mechanism 240 also rotates in the other direction by the load of the rotation load member 245. As a result, the pair of idle gears 241 a of the turning mechanism 240 turns in the other direction around the rotation axis of the center gear 231, and the other idle gear 241 b meshes with the shaft gear 224. Therefore, the drive mechanism 210 and the power transmission mechanism 220 are connected to each other via the switching mechanism 230, and the power of the drive mechanism 210 is transmitted to the power transmission mechanism 220.

  Specifically, the reverse rotation of the drive motor is transmitted from the center gear 231 to the shaft gear 224 via the other idler gear 241b, and both pinions 222 fixed to both ends of the shaft 223 as the shaft gear 224 rotates. As a result, both pinions 222 are moved backward with respect to the rack 221 provided on the fixed rail 40 of the refrigerator body 10, and the drawer 30 is automatically closed. Further, when the drawer 30 is retracted to a predetermined position, a position detection sensor (not shown) detects this, and the control unit that has received a signal from the position detection sensor stops driving the drive motor.

  When the control unit stops driving the drive motor, the shaft body 212 is in a free rotating state, and accordingly, the turning mechanism 240 can freely rotate. Thereby, the turning mechanism 240 turns around the shaft body 212 so as to maintain a balance, and both the idle gears 241 are separated from the shaft gear 224. As a result, the drive mechanism 210 and the power transmission mechanism 220 are not connected to each other through the switching mechanism 230, and the power of the drive mechanism 210 is not transmitted to the power transmission mechanism 220. When the drawer 30 is manually moved with respect to the refrigerator main body 10 in this state, the drive mechanism 210 and the power transmission mechanism 220 are separated from each other, so that the load is not applied to the drive mechanism 210 and the resistance by the drive mechanism 210 is reduced. The drawer 30 can be moved with a relatively small force.

  In addition, even if a large external force is applied in the direction opposite to the opening / closing direction of the drawer 30 in the power transmission state, and even if a load is applied to the power transmission mechanism 220, the drive mechanism 210 (drive motor) is not limited to the torque limiter. Since the power transmission mechanism 220 is connected to the power transmission mechanism 220 via the power transmission mechanism, idling occurs between the power transmission mechanism 220 and the drive mechanism 210 when the load is equal to or greater than the threshold value, and the damage to the drive mechanism 210 can be prevented.

<Embodiment 2>
The second embodiment is a modification of the switching mechanism in the first embodiment. The switching mechanism 230 of the present embodiment includes a center gear 231 that rotates in conjunction with the drive motor, and a turning mechanism 240 that has one idle gear 241 (connection mechanism) that meshes with the center gear 231.

  With this configuration, when the shaft body 212 rotates in one direction as the drive motor is driven, as shown in FIG. 6A, the revolving plate 242 also revolves in one direction, and the idler gear 241 becomes the shaft gear. 224 meshes. On the other hand, when the shaft body 212 rotates in the other direction as the drive motor is driven, as shown in FIG. 6B, the revolving plate 242 also revolves in the other direction, and the idle gear 241 meshes with the shaft gear 224.

  Further, when the turning mechanism 240 can freely rotate around the rotation shaft (shaft body 212), the center of gravity is biased toward the idle gear 241. Therefore, the idle gear is along the direction of gravity with respect to the rotation axis. It turns by its own weight so as to be positioned below. Therefore, when the shaft body 212 interlocked with the drive motor becomes freely rotatable with the stop of the drive motor, as shown in FIG. 6C, the turning mechanism 240 turns to maintain the weight balance. The idle gear 241 is separated from the shaft gear 224.

  In each of the above embodiments, the switching mechanism 230 is switched to the power non-transmission state due to the weight balance of the turning mechanism 240, but the invention is not limited to this, and the turning mechanism 240 is made of an elastic member such as a spring. You may comprise so that the switching mechanism 230 may be in a power non-transmission state by pulling in a predetermined direction by an urging means.

  In the embodiment, the drawer is opened and closed by pressing a button provided on the input means. However, the drawer may be opened by voice input. If the drawer can be opened and closed by voice input, the drawer can be opened and closed even when both hands are closed.

  In the above embodiment, the rotation of the drive motor is transmitted to the pinion 222 by meshing the idle gear 241 with the shaft gear 224. However, the idle gear 241 may be meshed directly with the pinion, for example. Further, the idle gear 241 may be directly meshed with the rack 221. In this case, the rack 221 becomes the power transmission mechanism 210. The rack 221 may be provided on the upper inner rail piece 42a, and the switching mechanism 230 may be connected to the rack 221 from below. Each mechanism and each member constituting each mechanism may be connected directly or indirectly.

  In the above embodiment, an elastic member is used as the rotation load member 245. However, any member may be used as long as it generates a load between the swivel plate 242 and the idle gear 241. For example, the idle gear attachment shaft 244 is provided. A cylindrical friction member that generates friction between the rotary gear 241 and the idle gear 241 may be used.

  In addition, it goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 Refrigerator 10 Refrigerator main body 30 Drawer 40 Fixed rail 50 Movable rail 200 Automatic opening / closing mechanism 210 Drive mechanism 220 Power transmission mechanism 221 Rack 222 Pinion 230 Switching mechanism 231 Center gear 240 Turning mechanism 241 Idle gear

Claims (9)

A refrigerator drawer opening / closing mechanism comprising a refrigerator body, a drawer provided in the refrigerator body, and an automatic opening / closing mechanism for opening and closing the drawer,
The automatic opening and closing mechanism includes a drive mechanism, a power transmission mechanism that transmits power of the drive mechanism to the drawer, and a switching mechanism that is interposed between the drive mechanism and the power transmission mechanism;
The refrigerator is characterized in that the switching mechanism switches between a power transmission state in which the power of the driving device is transmitted to the power transmission mechanism and a power non-transmission state in which the power of the driving device is not transmitted to the power transmission mechanism. Drawer opening and closing mechanism. The switching mechanism includes at least one connection mechanism that repeats a connected state and a disconnected state with respect to the power transmission mechanism,
The switching mechanism is
The power transmission state connecting the connection mechanism to the power transmission mechanism;
The drawer opening / closing mechanism for a refrigerator according to claim 1, wherein the power transmission mechanism is switched to the power non-transmission state in which the connection mechanism is not connected. The switching mechanism includes a pair of connection mechanisms,
The switching mechanism is
The power transmission state in which one connection mechanism is connected to the power transmission mechanism and the other connection mechanism is not connected,
Connecting the other connection mechanism to the power transmission mechanism and not connecting one connection mechanism;
The drawer opening / closing mechanism for refrigerators according to claim 1 or 2 which switches to said power non-transmission state which does not connect both connection mechanisms to said power transmission mechanism. 4. The switch according to claim 1, wherein the switching mechanism switches to the power transmission state when the drive mechanism is driven, and switches to the power non-transmission state when the drive mechanism is not driven. 5. A drawer opening and closing device for refrigerators. The drive mechanism is a drive motor;
The power transmission mechanism further comprises a rack installed on either the drawer or the refrigerator body and a pinion installed on the other,
A power transmission state in which the switching mechanism is interposed between the drive motor and the pinion and transmits the power of the drive motor to the pinion; and a power non-transmission state in which the power of the drive motor is not transmitted to the pinion. The drawer opening / closing mechanism for refrigerators according to any one of claims 1 to 4, wherein The switching mechanism includes a center gear interlocked with the drive motor, and at least one connection mechanism having a gear meshing with the center gear;
When the drive motor rotates in one direction, the connection mechanism is connected to the pinion and is in a power transmission state.
When the drive motor rotates in the other direction, the connection mechanism is connected to the pinion and is in a power transmission state.
The drawer opening / closing mechanism for a refrigerator according to claim 5, wherein when the drive motor is not rotating, the connection mechanism is not connected to the pinion and is in a power non-transmission state. The switching mechanism has the same rotation axis as the center gear, and includes a turning mechanism for turning the at least one connection mechanism around the rotation axis;
The drawer opening / closing mechanism for a refrigerator according to claim 6, wherein the turning mechanism turns by its own weight and switches to the power non-transmission state when the drive motor is not rotating. A torque limiter is provided between the drive motor and the center gear,
The drawer opening / closing mechanism for a refrigerator according to any one of claims 6 and 7, wherein the torque limiter causes the center gear to idle with respect to the drive motor when a torque of a threshold value or more is applied to the center gear. The refrigerator body includes a fixed rail that slides the drawer,
The drawer comprises a movable rail attached to the fixed rail;
One of the fixed rail or the movable rail has one of the rack or the pinion,
The drawer opening / closing mechanism for a refrigerator according to any one of claims 1 to 8, wherein the other of the fixed rail and the movable rail has the other of the rack and the pinion.