JP2000346542A - Operation assisting apparatus and refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation assisting apparatus and a refrigerator using the former in which mechanical trouble caused by locking of speed reduction wheel train and motor is unlikely to occur and stable slip operation is ensured. SOLUTION: A protruded member 9 is provided for assisting operation of opening/closing operation by receiving driving force of a motor 7 through a gear wheel train 8 to slidably move and making contact with an opening/closing member 4. On the gear wheel train there is provided a worm 13 coupled integrally and rotatably with an output shaft 7a of the motor through a slip mechanism. The slip mechanism consists of a coiled spring 26 with one end engaged with the output shaft and with the other end serving as a free end, and a wall section 13e formed on the worm 13 such that frictional force is produced between the coiled spring and the section 13e when the coiled spring is rotated integrally with the output shaft 7a. When transmission torque from a motor side to a protruded member 9 side is less than a predetermined value, the output shaft 7a and the worm 13 are integrally rotated owing to frictional force, and, if the torque exceeds the predetermined value, the rotation of the output shaft is prevented from being transmitted to the worm 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an opening / closing member for opening or shutting off an internal space of a housing, such as a revolving door or a front surface of a drawer installed in a refrigerator or the like. The present invention relates to an operation assisting device for assisting the operation of the opening / closing member and a refrigerator using the device.

[0002]

2. Description of the Related Art Some home electric appliances and furniture having a revolving door or drawer have a front surface of the door or drawer held on a housing body side by using a magnetic action such as a magnet. Such a door or drawer (hereinafter referred to as an opening / closing member) is attracted to the housing body side by a magnetic attraction force of a magnet immediately before closing, so that it can be securely closed with a small force. The closed state is maintained with a constant closing force. Therefore, it is applied to many products because it can solve the inconvenience that the door or drawer opens naturally even if there is some vibration.

[0003] This kind of opening / closing member needs to satisfy both the element of securely holding the closed state and the element of easy opening operation. However, from the viewpoint of maintaining the closed state reliably, It is undeniable that it is necessary to have a certain closing force. Therefore, it is desired to provide an opening and closing mechanism which can be easily opened while having a certain closing force.

Accordingly, the present applicant has developed a motor actuator described in Japanese Patent Application Laid-Open No. 4-17548 as a device for making such a troublesome operation as easy as possible (see FIG. 6). The motor actuator includes a motor 51, a reduction mechanism 52 that reduces and transmits the driving force of the motor 51, a rod 55 having a rack 54 that meshes with a pinion 53 at the final stage of the reduction mechanism 52,
Position detecting means 56 for detecting the position of the rod 55
And a case 57 for storing these members. Note that the speed reduction mechanism 52 is provided with a worm 61 and a worm wheel 62 to increase the speed reduction ratio.

In this motor actuator, when a user touches a switch mechanism provided on a door (not shown), the motor 51 is energized and the rod 55 is slid forward by the driving force of the motor 51. The forward sliding movement of the rod 55 is used to assist the opening operation of the door disposed in front.

[0006]

However, in such a motor actuator, if the rod remains in the front after assisting the opening operation of the door, the door is closed when the user closes the door. The rod is pushed back into the case. Therefore, the sliding movement of the rod in the return direction tends to force the reduction gear train to rotate, and may cause damage to each gear of the reduction gear train.

Therefore, in such a device, a gear in the reduction gear train may be provided with a slip mechanism or a clutch mechanism in which the driving force is transmitted only in one direction (the direction in which the rod is advanced). Conceivable. If these are incorporated, even if the rod remaining in the front is pushed back into the case, the gears etc. will idle due to the incorporated slip mechanism etc., and the pushed force will escape, reducing the speed reduction gear train and motor And other internal mechanisms will not be damaged. In the motor actuator shown in FIG. 6, the motor 51 is rotated in both directions, the rod 55 is advanced, and then the motor 51 is rotated in the reverse direction to pull the rod 55 back.

However, the above-described clutch mechanism simply rotates the reduction gear train by idling the force from the protruding member that slides rearward when closing the door that is stopped forward (opened). This is a member that avoids locking such as when the force is applied from the protruding member side and at the same time the force is also applied from the motor side (when a force is generated from the opposite side during motor driving). Also, there is a fear that the reduction gear train and the like may be destroyed. That is, while driving the motor to move the protruding member forward,
If the protruding member is held down by a door or hand, and attempts to return in the opposite direction, the motor will continue to rotate against the force, causing the deceleration gear train and the motor to lock, and serious damage may occur. is there.

Such a problem also occurs in a motor actuator using a bidirectionally rotatable motor 51 as shown in FIG. Further, it is conceivable to provide a drive circuit for stopping the drive of the motor when an overload occurs as described above. However, the drive circuit becomes complicated, which not only tends to cause a failure, but also causes a failure in the motor. Another problem is that the cost increases.

The slip mechanism provided on the gear is a mechanism that slips due to an overload. When a force is applied from the protruding member side while a force is applied from the motor side, the gear slips and a deceleration wheel train or the like is damaged. However, the number of parts increases and the assemblability deteriorates. Moreover, it is difficult to keep the slip force constant, and the slip force tends to change with repeated operations.

According to the present invention, even if a force in the opposite direction is transmitted to the gear train by an opening / closing member while the projecting member is being moved forward by the driving of the motor, the speed reduction gear train and the motor are not moved. Provided are an operation assisting device capable of obtaining a stable slipping operation without causing a mechanical failure of a door, a protruding member, and an internal mechanism of the device without locking, and a refrigerator using the device. The purpose is to:

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, a motor can be slid by receiving driving force of a motor through a gear train so as to directly or indirectly contact an opening / closing member. A worm that has a protruding member and assists the operation of the opening and closing member by a sliding operation of the protruding member, the worm being connected to a gear train so as to be integrally rotatable with an output shaft of a motor via a slip mechanism. A coil spring having one end directly or indirectly locked to the output shaft and the other end being a free end, and a friction between the coil spring when the coil spring rotates integrally with the output shaft. When the transmission torque from the motor side to the projecting member side is equal to or less than a predetermined value, the output shaft and the worm unite due to frictional force. Rotating, if the load increases the transmission torque of the protruding member side exceeds a predetermined value the coil spring slips, the rotation of the output shaft of the motor is prevented is transmitted to the worm.

According to the operation assisting device described above, since the slip mechanism using the coil spring that slips by the transmission torque of a predetermined value or more is provided between the output shaft of the motor and the worm, the projecting member is moved in the opposite direction ( Push back direction)
When the force is applied, the force can be caused to idle at the slip mechanism. Therefore, in such a case, lock does not occur in the reduction gear train or the motor, and failure such as breakage of the gears can be prevented.

When the motor is driven to push the projecting member back in the reverse direction by an opening / closing member or a hand while the projecting member is slid forward, the motor is moved in the reverse direction from the projecting member side. The driving is continued against the force of, and the driving torque gradually increases. Although the conventional motion assist device is likely to fail due to such a situation, the motion assist device according to the present invention employs a coil spring that rotates integrally with the output shaft of the motor when the driving torque of the motor exceeds a predetermined value. The frictional force is reduced, and the coupling between the output shaft of the motor and the worm due to the frictional force is released. As a result, when such a situation occurs, the output shaft of the motor runs idle independently of the gear train, so that the reduction gear train and the motor do not lock, and the internal mechanism does not break. It will be.

[0015] Further, another invention provides, in addition to the above-described invention,
A hole is formed at one end of the worm, and an inner wall of the hole is used as a wall of the slip mechanism, and a coil spring is press-fitted into the inner wall of the hole to be fitted. Therefore, it is easy to assemble by press-fitting the slip mechanism portion of the operation assisting device having the above-mentioned operation, which enables the worm to be disengaged from the output shaft, into the hole formed in the worm with the coil spring slightly contracted. It is possible to be.

[0016] In addition, another invention provides, in addition to the above-described invention,
Release means for releasing the connection between the protrusion member and the motor after the protrusion member slides to a predetermined position, and protrusion member return means for returning the protrusion member released by the release means to the position before the slide movement. It has.

Therefore, in addition to the above-described operation of the slip mechanism, that is, the function that the internal mechanism is not locked even if a force is applied to the projecting member in the direction of pushing back during the sliding operation of the projecting member forward, During normal operation (except in cases where excessive force is applied during operation, or when the projecting member stops at a position halfway through the projecting due to failure of the motor, drive circuit, or other members)
Thus, the protruding member protruding forward can be returned to the original position after the operation is completed without relying on the opening / closing member, hand, motor drive, or the like. Therefore, the operation during normal use becomes smoother.

According to another aspect of the invention, there is provided a refrigerator comprising:
A door or drawer that is sucked and held using magnetic action on the refrigerator body, and the projecting member of the above-mentioned operation assisting device is attached so that the opening / closing member can be moved to a range where it does not operate by magnetic action. I have.

With this configuration, the refrigerator to which the present apparatus is attached can open the door and drawer with a small force, and in the closed state, can reliably trap cold air in the refrigerator. Moreover, even if the door is erroneously closed during the operation of the projecting member, the refrigerator does not break down. Furthermore, it is possible to easily return the protruding member protruding when the door or the like is opened to the home position without providing a complicated circuit or configuration, and simply closing the door or the like without causing a failure of the internal mechanism or the like. Thus, the cost can be reduced, and it can be easily attached to a narrow portion in the refrigerator.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An operation assisting device according to an embodiment of the present invention will be described below with reference to FIGS. Note that, in the present embodiment, the operation assisting device is described as being attached to a refrigerator, but the present invention, in particular,
It is not limited to the one attached to the refrigerator.

As shown in FIG. 1, the operation assisting device 1 is provided at a position facing the door 4 of the frame 3 of the refrigerator 2 as a housing. It is a device that assists the opening operation. Note that the door 4 is for opening / closing an open end portion of the refrigerator compartment 5 formed in the refrigerator 2, and one end is rotatably supported at a part of the open end of the refrigerator compartment 5. ing.

At the other end of the door 4, an attraction magnet 6 is provided. The attraction magnet 6 is used for attracting and holding the door 4 by utilizing a magnetic action at a part of the open end of the refrigerator compartment 5 of the refrigerator 2 when the refrigerator 4 is closed. 5 can be completely sealed.

As shown in FIGS. 2 and 3, the motion assisting device 1 includes a DC motor (hereinafter simply referred to as a motor) 7, a gear train 8 for transmitting the driving force of the motor 7, and a gear train 8. It has a projecting member 9 that can slide and contact the door 4 by the driving force of the motor 7 received therethrough, and a case 10 that stores these components inside.

The motor 7 is held in a motor holding section 11 formed in a case 10. The motor holding portion 11 is formed so as to surround the motor 7. The output shaft 7a of the motor 7 is connected to the case 1
0 protrudes into the internal space. The motor 7 is connected to an external control device (not shown) which also serves as a power supply and a control means by a plurality of lead wires 12, and is controlled and driven by this control device.

Motor holding portion 11 of output shaft 7a of motor 7
A worm 13 that constitutes a part of the gear train 8 is attached to a portion protruding from the gear wheel so as to be integrally rotatable via a slip mechanism. When the load on the worm 13 is equal to or less than a predetermined value, the slip mechanism rotates the output shaft 7a and the worm 13 integrally using the frictional force, and when the load on the worm 13 exceeds the predetermined value. The motor 7 does not run due to no integration due to frictional force. The detailed configuration will be described later.

The worm 13 is the first gear of the gear train 8. Therefore, during normal operation, when the motor 7 is driven, the output shaft 7a and the worm 1
3 rotate integrally, and the rotation is transmitted to the protruding member 9 via the gear train 8.

The gear train 8 includes a worm 13 that is the first stage, a first gear 15 having a large-diameter worm wheel 15a meshed with the worm 13, and a first gear 1
5, a large-diameter receiving gear 1 meshing with the small-diameter feed gear 15b
6a, a third gear portion 17 having a large-diameter receiving gear 17a meshing with a small-diameter feed gear 16b of the second gear portion 16, and a small-diameter feed gear 17b of the third gear portion 17 And a transmission gear 18 meshed with the rack teeth 9 a of the protruding member 9.

The worm 13 is connected to the motor 7 as described above.
, And a tip end portion is rotatably supported by a bearing portion 20 formed inside the side wall of the case 10. As shown in FIG. 4, the worm 13 has a shaft portion 13a having teeth 14 that engage with the worm wheel 15a, and a slip mechanism housing portion 13b formed at one end of the shaft portion 13a. The teeth 14 of the worm 13 have a lead angle α of about 20 degrees. Therefore, the worm 13 can rotate in the reverse direction by receiving the force in the reverse rotation direction from the worm wheel 15a input by pushing the projecting member 9 back into the case 10. The value of the advance angle α = 20 degrees can be variously changed, but the advance angle α
May be formed so large that the worm 13 can rotate in the reverse direction with respect to the force from the worm wheel 15a.

The slip mechanism storage section 13b includes a shaft section 13a.
And a large-diameter portion 13d continuous with the slope 13c. On the end face of the large-diameter portion 13d, there is provided a circular hole 13e that accommodates each member constituting the slip mechanism and that is itself a part of the slip mechanism. A small-diameter central hole 13f for accommodating the tip of the output shaft 7a is provided at the center of the bottom surface of the hole 13e.

In the hole 13e of the worm 13 having such a structure, the output shaft 7a of the motor 7 and the worm 13
Each member that constitutes a slip mechanism for connecting the members so as to be integrally rotatable is stored. The slip mechanism includes the above-described hole 13e, a disc-shaped connecting plate 25 inserted and fixed to the output shaft 7a of the motor 7 by press-fitting, and the like, and one end is locked to the connecting plate 25 and the other end is a free end. And a coil spring 26 fitted into the hole 13e of the worm 13 by press-fitting. The slip mechanism includes a coil spring 26 generated when the output shaft 7a of the motor 7 rotates.
Is used by utilizing the frictional force between the outer peripheral surface of the hole and the inner wall of the hole 13e.

That is, when the motor 7 is driven, the output shaft 7a rotates. Thus, the connecting plate 25 press-fitted and fixed to the output shaft 7a also rotates integrally with the output shaft 7a. The connecting plate 25 is provided with a locking groove 25a for locking one end of the coil spring 26. One end of the coil spring 26 locked in the locking groove 25a is also connected to the output shaft 7a and the connecting plate 25. Start to rotate in the same direction as. The coil spring 2
6 is wound in the same direction as the rotation direction of the output shaft 7,
As the output shaft 7a and the connecting plate 25 rotate integrally, one end is pulled and a force is applied in a direction to reduce the diameter.
However, the frictional force of the coil spring 26 with respect to the hole 13 e is set to be larger than the torque (force) of the motor 7 when the projecting member 9 is driven to assist the opening operation of the door 4. Therefore, the coil spring 26 does not slip during normal operation.

As a result, in normal operation, the worm 13 rotates integrally with the output shaft 7a of the motor 7 due to the frictional force between the inner wall of the hole 13e of the worm 13 and the outer peripheral surface of the coil spring 26. Therefore, the driving force of the motor 7 is transmitted to the projecting member 9 via the gear train 8 having the worm 13 as the first stage, and the projecting member 9 slides,
The opening operation of the door 4 can be assisted.

In this embodiment, the advance angle α of the teeth 14 of the worm 13 is set to 20 degrees as described above. Therefore, in the present embodiment, after the normal operation (the operation of sliding the protruding member 9 forward),
After the drive of the motor 7 is stopped, the projecting member 9 can be easily returned into the case 10 by the closing operation of the door 4 or the hand. At that time, the above-mentioned slip mechanism does not slip, and the worm 13 and the output shaft 7a of the motor 7 rotate integrally and reversely. In the case of such an operation of returning the protruding member 9 into the case 10 by a normal return operation (an operation such as closing the door 4 after the driving of the motor 7 is completed), the worm 13 and the output shaft 7a Therefore, no lock is generated in the internal mechanism because the rotation is performed in the same manner as the above gear.

On the other hand, the door 4 is closed while the projecting member 9 slides, or the projecting member 9 is manually moved.
When the operation of pushing back the tip of the gear into the case 10, that is, the abnormal return operation, is performed, the protruding member 9 is provided with a force for rotating each gear of the gear train 8 in the opposite direction. appear. At that time, the motor 7 continues to drive to rotate the gears of the gear train 8 in a normal direction against the force and push the protruding member 9 back. In such a state, lock of the gear train and the motor occurs in the conventional device, and there is a possibility that the gear train and the motor may be damaged. In response, the above-described slip mechanism operates to prevent the gear train 8 and the motor 7 from being locked.

That is, when an excessively reverse force is transmitted from the protruding member 9 to the motor 7 while the protruding member 9 is operated by driving the motor 7, the motor 7 resists the force. Then, the output shaft 7a and the connecting plate 25 are rotated while further increasing the torque. Then, the transmission torque from the motor 7 side to the protruding member 9 side, that is, the load on the worm 13 side is a predetermined value (the coil spring 26 and the hole 1
3e), the coil spring 26 starts to slip. Thereby, the output shaft 7a of the motor 7
Is not transmitted to the worm 13 side.

As a result, in the above-described situation, that is, in a situation in which a force that is pushed back into the case 10 is applied to the protruding member 9 during operation, the motor 7 idles due to the operation of the slip mechanism. The projecting member 9 is returned to a predetermined position in the case 10 (a position pushed back to the innermost position). for that reason,
Even in such a situation, a highly reliable device that does not destroy the internal mechanism can be provided.

The worm 1 is provided with the above-described slip mechanism.
Gear train 8 provided between the motor 3 and the output shaft 7a of the motor 7
During normal operation, when the motor 7 is driven, the worm 13 rotates integrally with the output shaft 7a, and the rotation thereof is the first,
The power is transmitted to the transmission gear 18, which is the final gear, via the second and third gear portions 15, 16, 17. When the transmission gear 18 rotates, the protruding member 9 is slid forward.
In addition, as shown in FIG.
1, the second gear unit 16 is attached to the second shaft 32,
7 are rotatably supported by the third shafts 33, respectively. The transmission gear 18, which is the last stage gear, is the case 1
The shaft is rotatably supported by a protruding shaft portion 50 provided at the center.

The protruding member 9 engages with the transmission gear 18 and receives the driving force of the motor 7 so that the case 10
Are guided by guide rails 37, 37 (see FIG. 3) formed above and below, and are slidable in the direction of arrow A in FIG. The protruding member 9 is slid in the direction of arrow A so that the distal end portion is
It projects from 0 to the outside. This case 1
The above-mentioned door 4 is arranged in a portion protruding from zero. That is, the projecting member 9 slides forward (in the direction indicated by arrow A in FIG. 2) by the driving force of the motor 7 to contact the door 4 and open the door 4 (in the direction indicated by arrow B in FIG. 2). It is something that sticks out.

The tip of the protruding member 9 is arranged so as to be substantially flush with the case 10 with the protruding member 9 retracted to the innermost part. The arrangement of the protruding member 9 is appropriately determined according to various relations such as an arrangement relation between the protruding member 9 and the door 4 and a relation of a time control from a start of the motor 7 to a contact of the protruding member 9 with the door 4. Can be changed. Further, in the present embodiment, the projecting member 9 can directly contact the door 4, but the projecting member 9 may be capable of indirectly contacting the door 4 via some member.

The movement assisting device 1 assists the door 4 in a predetermined range of the entire operation range by sliding the protruding member 9 forward. That is, the door 4 is pushed out by further sliding while the protruding member 9 collides with the inside of the door 4.
The door 4 is attracted to the refrigerator 2 body side by a magnetic attraction force, which is a magnetic action of the attraction magnet 6, but the operation assisting device 1 pushes the door 4 to a position where it is not attracted by the magnetic attraction force. In this embodiment, the door 4 is moved to a range where the door 4 does not operate due to the magnetic action as described above. However, the present invention is particularly applicable to a case where the door 4 is used for a door that uses the attraction force of a magnet. However, the present invention is not limited to this, and may be applied to a device that generates a closing force with a spring or the like, or a device that does not have a closing force such as a magnet or a spring.

As described above, by moving the projecting member 9 by the rotational driving force of the motor 7, the door 4 is released from the suction holding to the refrigerator 2 main body. The operation assisting device 1 is a device that operates the door 4 only in front of the refrigerator 2. Therefore, the door 4 is driven forward by the operation assisting device 1, and thereafter, after the user manually opens the door 4 and puts food or the like into and out of the refrigerator compartment 5, the user manually closes the door 4. It has become. Then, the projecting member 9 is returned to the original position before the slide movement by the closing operation.

The case 10 is, as shown in FIG.
Two case halves 10c and 10d are connected to four bolts 10e.
And the like, and has a box-like shape in which the motor 7, the gear train 8, the protruding member 9 and the like are housed as described above. That is, case 10
Has a surface (a surface serving as a bottom surface and a lid) for attaching each member, and a surface (side wall) surrounding each member.

A mechanism for rotatably supporting the respective gears of the gear train 8, specifically, fixed portions 10 f and 10 g for supporting both ends of the first shaft 31 are provided inside the case 10. Also, fixing portions 10h and 10j supporting both ends of the second shaft 32 and fixing portions 10k and 10m supporting both ends of the third shaft 33 are provided.

The operation assisting device 1 of the present embodiment configured as described above operates the door 4 of the refrigerator 2
It is detachably screwed and fixed to the frame 3 of the refrigerator 2. As shown in FIG. 1, the refrigerator 2 has a revolving door 4 at the front and a refrigerator 5 for storing food products such as beverage products which need to be refrigerated.
have. The door 4 is provided with a pull handle 35 for the user to grip and pull toward the front when the door 4 is opened, and a part of the pull handle 35 detects that the user has grasped the pull handle. A sensor 36 is provided.

The refrigerator 2 has a drawer 39 for storing frozen foods and the like, a storage space 40 for storing the drawers 39, a drawer 41 for storing foods such as vegetables, and the like. It has a storage space 42 for storing 41. That is, the refrigerator 2
Is a housing having three compartments, a refrigerator compartment 5, a freezing compartment and a vegetable compartment. And the refrigerator compartment 5 and the storage space 40
And a partition 44 is provided between the storage spaces 40 and 42, respectively.

Although the refrigerator 2 pushes the door 4 forward by the operation assisting device 1, the refrigerator 2 may be used to push the drawers 39 and 41 described above forward.

The refrigerator 2 has a housing having one door 4 and two drawers 39 and 41.
Or more than one drawer or three or more drawers. When two or more doors are provided or three or more drawers are provided, the motion assisting device 1 is arranged by the same number as the number of doors and the number of drawers, and all the doors and The drawers may be driven individually, or the operation assisting device 1 may be arranged to drive only some of the doors or the drawers.

In the present embodiment, the user operates the door 4
Although the sensor 36 is configured by a touch sensor in order to detect the opening of the touch panel, another detecting means such as a piezoelectric element or infrared detecting means may be provided instead of the touch sensor.

Next, the operation for assisting the operation of the door 4 of the refrigerator 2 using the operation assisting device 1 of the present embodiment will be described below. The door 4 is suction-held at the open end of the refrigerator compartment 5 by a suction magnet 6.

When the user grips the pull handle 35 to open the door 4 of the refrigerator 2, a sensor 36 provided on the pull handle 35 detects this contact, and a control device (not shown) receives a signal. From the control device to the motion assist device 1
Is supplied to the motor 7.

When electric power is supplied to the motor 7, the motor 7
Output shaft 7a rotates. This operation is a normal operation. At this time, since the transmission torque from the motor 7 to the worm 13 is equal to or less than a predetermined value, the output shaft 7a and the connecting plate 2
The coil spring 26 that rotates integrally through the coil 5 does not slip. Therefore, the worm 13 rotates integrally with the output shaft 7a of the motor 7 by the frictional force with the coil spring 26. When the worm 13 rotates, this rotation
The power is transmitted to the transmission gear 18 via the first, second, and third gear portions 15, 16, 17, and the transmission gear 18 rotates in the direction of arrow C in FIG.

The rotation of the transmission gear 18 in the direction of arrow C is transmitted to the rack teeth 9 a of the protruding member 9. Thereby, the protruding member 9 slides in the direction of arrow A, and pushes the door 4 in the direction of arrow A while the tip of the protruding member 9 collides with the door 4. As a result, the door 4 is moved forward against the holding force of the attraction magnet 6. The power supply to the motor 7 is performed for a predetermined time,
After the projecting member 9 has moved to the predetermined position, the supply of electric power to the motor 7 is stopped. Thus, a series of operations for assisting the opening operation of the door 4 by the protruding member 9 is completed.
The user manually opens the door 4 that is not affected by the holding force of the magnet, opens the door 4 with a light force, takes out an object inside the refrigerator compartment 5, and then closes the door 4 manually.

At this time, the protruding member 9 is in a state after the end of the operation of pushing out the door 4, that is, a state in which the front end portion is largely protruded forward from the case 10. Therefore, when the user closes the door 4, the door 4 hits the tip of the protruding member 9. As a result, the projecting member 9 slides in the opposite direction, and the force is transmitted to the transmission gear 18 to rotate the transmission gear 18 in the reverse direction. As a result, each gear of the gear train 8 rotates in the direction opposite to the direction in which the operation of the door 4 is assisted, but the lead angle α of the worm 13 is formed large as described above. Therefore, the worm 13 reversely rotates following the reverse rotation of the worm wheel 15a.

At this time, since the motor 7 has already been stopped as described above, no driving force is generated from the motor 7 side, and since it is a normal return operation, the projecting member 9 side Is also less than a predetermined value, the coil spring 26 in friction with the worm 13 does not slip, and the worm 13 and the output shaft 7a of the motor 7 rotate integrally. as a result,
Each gear of the gear train 8 and the motor 7 rotate in reverse with a small force without generating lock. For this reason, the user can push the protruding member 9 into the case 10 only by closing the door 4 with a light force, and the refrigerator 4 can be hermetically closed by the door 4.

If an abnormal operation such as an attempt to forcibly close the door 4 occurs during the protruding operation, the torque transmitted from the motor 7 to the protruding member 9 during driving exceeds a predetermined value. At this point, the coil spring 26 of the slip mechanism described above slips. That is, when the torque generated by the bidirectional force on the projecting member 9 side and the motor 7 side exceeds the frictional force of the coil spring 26, slip occurs. Therefore, the motor 7 runs idle. As a result, a failure in which the gear train 8 locks due to bidirectional forces on the protruding member 9 side and the motor 7 side and breaks the internal mechanism hardly occurs. When the hand is released from the door 4 in a state where the door 4 is forcibly closed, the transmission torque from the motor 7 to the protruding member 9 escapes from the abnormal state and returns to the normal state. Operation assistance will be resumed.

Although the above-described embodiment is an example of a preferred embodiment of the present invention, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. . For example, in the above-described embodiment, the movement assisting device 1 is attached to the refrigerator 2, but the present invention is not particularly limited to this, and other housings, for example, those having a sliding drawer such as a chest or a desk can be used. Or, it may be attached to a device having a revolving door such as a safe.

The operation assisting device 1 of the above-described embodiment
Is attached only to a position facing the upper end of the door 4 of the frame 3 of the refrigerator 2, but may be attached to a partition 43, for example, so that the upper and lower operation assisting devices 1 cooperate.

In the above-described embodiment, the coil spring 2 is indirectly connected to the output shaft 7a of the motor 7 via the connecting plate 25.
6, one end of the coil spring 26 may be directly engaged with the output shaft 7a. Further, in the above embodiment, the winding direction of the coil spring 26 is set to the same direction as the rotation direction of the output shaft 7a of the motor 7, and the rotation of the output shaft 7a applies a force in the direction in which the diameter of the coil spring 26 is reduced. However, the winding direction may be reversed, and a force may be applied in a direction in which the diameter of the coil spring 26 increases by the rotation of the output shaft 7a. In this case, a frictional wall portion on the worm 13 side is disposed inside the coil spring 26.

Further, the operation assisting device 1 of the above-described embodiment moves the protruding member 9 in the state where the front end portion protrudes from the case 10 after the operation of the door 4 is closed, to the original position by closing the door 4. As shown in FIG.
As shown in (5), a coil spring 46 as a projecting member return means may be provided in the case 10, and the projecting member 9 may be forcibly returned to the original position by the urging force of the coil spring 46.

That is, the configuration of the motion assisting device 1 shown in FIG. 5 is similar to that of the above-described embodiment, except that the motor 7, the gear train 8 with the worm 13 as the first stage, A protruding member 9 that engages with the last gear of the row 8 is provided, and a coil spring 46 for returning the protruding member 9 to the original position is provided. The protruding member 9 has a metal plate 48 to be held in the case 10 at the origin position (the position before the slide movement), and the case 10 has a magnet 47 for attracting and holding the metal plate 48. Each is provided. Then, the protruding member 9 which is returned to the origin position with vigor by the coil spring 46 is surely held at the origin position. However, there is no need to provide a configuration for maintaining the original position.

As shown in FIG. 5, the last stage gear of the gear train 8 is disengaged from the first section 49a engaging with the rack teeth 9a of the protruding member 9 and the rack teeth 9a. A second section 49b, wherein the first section 49a slides the projecting member 9 while engaging with the projecting member 9, and releases the engagement with the projecting member 9 in the second section 49b. An engagement / disengagement gear 49 serving as a release unit for releasing the connection state with the motor 7 may be used. If such a gear is used as the last gear, after the operation is assisted, the projecting member 9 can be returned to the original position by the urging force of the coil spring 46 smoothly without the load on the gear train 8. However, the last stage gear may be constituted by a gear such as the transmission gear 18 which is always engaged with the protruding member 9 as in the above-described embodiment.

The coil spring 46 is disposed at a position sandwiched between the case 10 and the protruding member 9, and has one end connected to the case 10.
Is locked to a protruding portion 10b protruding from the inner wall 10a on the side facing the door 4, and the other end of the protruding member 9 is
Abuts on a metal plate 48 serving as a yoke for the magnet 47 fitted into the magnet 47. Then, when the projecting member 9 is slid in the direction of arrow A ′ in FIG. 5, the coil spring 46 is pressed by the plate 48 and contracts, and exerts an urging force for returning the projecting member 9 to the home position. store. The torque required to contract the coil spring 46 is set to a torque lower than the normal torque of the motor 7, and the coil spring 46 is easily contracted by sliding the projecting member 9 by the motor 7. It has become something.

In a state where the coil spring 46 is contracted, the engagement between the projecting member 9 and the engagement / disengagement gear 49 is released, and the transmission of the driving force of the motor 7 is interrupted. As a result, the protruding member 9 is returned to the origin position. The projecting member 9 returned to the origin position is attracted to the magnet 47 arranged in the case 10 by the metal plate 48,
It is held at the origin position in the case 10. Note that the relationship between the plate 48 and the magnet 47 is reversed, that is, the projecting member 9 is provided with a magnet,
By disposing a metal plate on the protruding member 9, the protruding member 9 may be held at the origin position, or both may be magnets.

Further, the coil spring 46 may be configured not to contract and store the urging force by the sliding movement of the protruding member 9 forward, but to store the urging force in the contraction direction by expanding.

[0065]

As described above, according to the operation assisting device of the present invention, the slip mechanism using the coil spring that slips between the output shaft of the motor and the worm by a transmission torque of a predetermined value or more is provided. Therefore, when a force in the opposite direction (push-back direction) is applied to the protruding member, the force can be caused to idle at the slip mechanism portion, so that the reduction gear train and the motor are not locked. In particular, if the push-out member is pushed back in the opposite direction by an opening / closing member or a hand while the motor is being driven to slide the projecting member forward, failure of the internal mechanism occurs in the conventional configuration. Although it is easy to perform, in the operation assisting device of the present invention, even in such a situation, the output shaft of the motor idles independently of the gear train, so that no lock is generated in the reduction gear train and the motor, The internal mechanism will not be damaged.

Further, the coil spring is incorporated in the worm portion, which is a compact and simple structure, the number of parts is reduced, and the combination of the coil spring and the worm allows
An arbitrary and stable slip force can be obtained. Therefore, it is possible to easily obtain a slip force according to the torque of the motor and to obtain a stable slip force for a long period of time.

Therefore, even if the handling is somewhat rough, the operation assisting device is less likely to cause a failure and has high safety. Furthermore, if the internal mechanism of the apparatus is provided, various members such as a lock prevention mechanism such as a slip mechanism and a clutch mechanism, a control drive circuit for reversely rotating the motor, and a member for detecting the position of the protruding member are provided. This eliminates the necessity, and makes it possible to provide an inexpensive operation assisting device with reduced parts costs and assembly costs.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the appearance of a refrigerator to which an operation assisting device according to an embodiment of the present invention is attached.

FIG. 2 is a plan view showing an internal mechanism of the motion assist device shown in FIG.

FIG. 3 is a sectional development view showing an internal mechanism of the motion assisting device shown in FIG. 2;

FIG. 4 shows an internal mechanism of the motion assisting device shown in FIG. 2;
It is the figure which expanded and showed the worm and the slip mechanism, and the worm wheel.

FIG. 5 is a plan view showing a modification in which a means for returning the projecting member to the origin position and a means for releasing the connection between the projecting member and the gear train are added to the motion assisting device according to the embodiment of the present invention. It is.

FIG. 6 is a cross-sectional view showing a motor actuator as a conventional motion assist device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Operation assistance apparatus 2 Refrigerator 4 Door (opening / closing member) 6 Adsorption magnet 7 Motor 7a Output shaft 8 Gear train 9 Protruding member 13 Warm 13e Hole (having a wall which becomes a part of slip mechanism) 25 Connecting plate (Slip) Part of mechanism) 46 Coil spring (projection member return means) 49 Engagement gear (release means)

Claims (4)

[Claims] A sliding member that receives a driving force of a motor through a gear train and slides to directly or indirectly contact an opening / closing member; An operation assisting device for assisting the operation of the opening / closing member, comprising a worm connected to the gear train so that the output shaft of the motor can rotate integrally with the output shaft of the motor via a slip mechanism. A coil spring directly or indirectly locked to the output shaft, the other end of which is a free end, and a frictional force generated between the coil spring and the coil spring when the coil spring rotates integrally with the output shaft. The output shaft and the worm by the frictional force when the transmission torque from the motor side to the projecting member side is equal to or less than a predetermined value. Rotate integrally, and when the load on the projecting member side increases and the transmission torque exceeds a predetermined value, the coil spring slips so that the rotation of the output shaft of the motor is not transmitted to the worm. Characteristic motion assist device. 2. A hole is formed at one end of the worm, an inner wall of the hole is used as a wall of the slip mechanism, and the coil spring is fitted into the inner wall of the hole by press-fitting. The motion assisting device according to the above. 3. A releasing means for releasing the connection between the projecting member and the motor after the projecting member has slid to a predetermined position, and the projecting member released by the releasing means is moved before the sliding movement. 3. The motion assisting device according to claim 1, further comprising a projecting member returning means for returning to a position. 4. The operation assisting device according to claim 1, wherein the opening / closing member is a door or drawer that is suction-held on the refrigerator body by utilizing a magnetic action. Characterized in that the refrigerator is mounted so that it can be moved to a range where it does not operate by the magnetic action.