JP3313251B2 - Automatic ice machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic ice making machine for making ice in a refrigerator or the like.

[0002]

2. Description of the Related Art In recent years, many refrigerators have an automatic ice maker incorporated therein. This type of ice maker automatically supplies water to the ice tray, and after making the ice, rotates the ice tray to release the ice, drops the ice into an ice storage box provided below, and always stores an appropriate amount of ice. Things.

An automatic ice maker incorporated in a refrigerator is disclosed, for example, in Japanese Utility Model Publication No. 54-17137.

[0004] Hereinafter, the above-mentioned conventional automatic ice making machine is shown in FIG.
This will be described with reference to FIG. Conventional automatic ice maker,
The ice making machine comprises a mechanical main body 101, an ice tray 102, an ice storage box 103 for storing ice, and an ice detecting lever 104 driven by the mechanical main body 101.

[0005] Inside the mechanism body 101, a motor 105 and a reduction gear unit 106 are incorporated. The final gear of the final stage of the reduction gear unit 106 is the ice tray 102.
The ice tray 102 rotates together with the final gear. The ice detecting lever 104 is usually located in the ice storage box 103 and is driven by the reduction gear unit 106.

The rotation position of the ice tray 102 is detected by two switch means 107 for detecting an ice making position (horizontal position) and detecting an ice release position (maximum rotation position). Ice detection lever 10
The detection of the rotation position of No. 4 is performed by the switch means 108. Further, a harness from the motor 105 and a harness of the switch means 107 and 108 are provided in the mechanical main body 101.

In the automatic ice maker configured as described above, when the completion of ice making is detected, the ice tray 102 is rotated by the rotation of the motor 105, and the ice is separated from the ice tray 102 and falls into the ice storage box 103. I do. At this time, the ice detection lever 104
Swings with the ice tray 102. At this time, if there is ice, the ice detecting lever 104 does not return to its original position.

An automatic ice maker disclosed in Japanese Utility Model Laid-Open Publication No. 2-58669 is an extension of the above-described configuration.
In this automatic ice maker, the rotation position of the ice detecting lever 104 is detected by the switch means 108 as in the past, the horizontal position of the ice tray 102 is locked by the gear, and the motor lock current is detected to detect the horizontal position. Was to do.

[0009]

Problems to be Solved by the Invention
In the automatic ice maker disclosed in Japanese Patent Application Publication No. 7-107, two switch means 107 are required for detecting the position of the ice tray 102, and it is difficult to simplify the structure such as the number of assembling steps and harness processing. It is difficult to reduce costs.

Further, in the automatic ice maker disclosed in Japanese Utility Model Laid-Open Publication No. 2-58669, a switch for detecting the horizontal position of the ice tray 102 is unnecessary, but the motor and gears detect the horizontal position of the ice tray. Is locked and detected by the lock current, so that the mechanical damage of the gear is large and the brush life of the motor may be adversely affected.

In view of the above problems, the present invention does not lock the motor and gear for detecting the horizontal position of the ice tray, and detects the maximum rotation position of the ice tray and the position of the ice detecting lever by one switch means. It is an object of the present invention to provide an automatic ice maker which can be detected by the method.

[0012]

In order to achieve the above object, an automatic ice making machine according to the present invention forms a final stage of a gear train for transmitting forward and reverse rotations of a motor to an ice tray and forms a concave cam in a predetermined area. A final gear having a surface, an ice detection shaft having an arm biased to abut on the cam surface, rotatably supported in accordance with a change in the cam surface, and an ice detection shaft connected to the ice detection shaft. An ice detection lever that enters or exits the ice storage box before the ice tray reaches the maximum rotation position in conjunction with the rotation of the ice axis.
A detection switch that outputs a signal for reversing the motor or a signal for stopping the motor so that the ice tray returns to the horizontal position by operating due to the displacement of the switch lever; and A first projection provided on the final gear so as to be retractable and urged in a projecting direction at a position facing the switch lever when entering or exiting the ice storage box, and displacing the switch lever when projecting; A second protrusion provided on the final gear at a position facing the switch lever when the switch is at the maximum rotation position, and a second protrusion provided on the ice detection shaft for displacing the switch lever; A protruding portion that enters in the direction of displacement of the switch lever when entering the inside of the ice tray over a predetermined position, and disturbs the displacement of the switch lever; A toothless region provided in the final gear so that it does not mesh with a gear preceding the final gear when returning to the flat position, and when the final gear is no longer meshing with the preceding gear due to the toothless region. Urging means for urging the final gear in a direction in which the ice tray rotates in the ice releasing operation direction; and when the final gear rotates in the ice releasing operation direction of the ice tray, from the toothless region to the gear region. A first tooth that is the first tooth to be switched and has a greater tooth thickness than the other teeth; and the first gear that is provided at the gear end in the rotation axis direction of the first gear so as to contact the tip of the first tooth. And a notch formed in a specific portion of the circumferential portion so as to mesh with the first tooth.

Further, a final gear which constitutes the last stage of a gear train for transmitting the forward and reverse rotations of the motor to the ice tray and has a concave cam surface in a predetermined area is urged to abut on the cam surface. An ice detection shaft having an arm and rotatably supported in accordance with a change in the cam surface; and an ice tray connected to the ice detection shaft and reaching the maximum rotation position in conjunction with the rotation of the ice detection shaft. A signal for reversing the motor or a signal for stopping the motor so that the ice tray is returned to the horizontal position by operating the ice detecting lever which enters or exits the ice storage box beforehand, and which is operated by the displacement of the switch lever. And a detection switch for outputting the ice detection lever when the ice detection lever enters or exits the ice storage box. Sui A first projection for displacing the chiller, a second projection provided on the final gear at a position facing the switch lever when the ice tray is at the maximum rotation position, and displacing the switch lever; A projection provided on a shaft for intruding in the direction of displacement of the switch lever when the ice detection lever has entered the ice storage box by a predetermined position or more, and disturbing the displacement of the switch lever;
When the ice tray returns to the horizontal position, the toothless region provided in the final gear so that it does not mesh with the previous gear of the final gear, and the final gear rotates so that the ice tray returns to the horizontal position. A convex portion provided in the final gear at a position approaching the preceding gear when changing from the portion meshing with the preceding gear or the gear region to the missing tooth region; and a plane perpendicular to the rotation axis of the preceding gear. And a cam pin inserted into the cam groove, the final gear is rotated so that the ice tray returns to a horizontal position, and a portion meshing with the preceding gear or a gear region or the toothless region. And the final gear is rotated so that the ice tray rotates in the direction of the ice releasing operation, and the portion meshing with the previous gear or the missing tooth region Al wherein it when changing the gear area by moving the convex portion direction by the cam groove of having a abutting cam lever the protrusion.

[0014]

In the above configuration, the ice tray after the ice making is completed is
It is rotated by a motor and a gear train interlocked with the rotation of the motor. The ice detection shaft is rotated by the cam surface of the final gear, and the ice detection lever connected to the ice detection shaft enters the ice storage box before the ice tray reaches the maximum rotation position. At this time, if there is a predetermined amount of ice in the ice storage box, the ice detecting lever cannot enter the ice storage box beyond a predetermined position, so that the projection of the ice detecting shaft cannot enter in the displacement direction of the switch lever. The switch lever cannot be disturbed, the switch lever is displaced by the first projection, and the detection switch outputs a signal for reversing the motor so that the ice tray returns to the horizontal position.

If there is no predetermined amount of ice in the ice storage box,
The ice detecting lever enters the ice storage box at a predetermined position or more, and in conjunction with this, the protrusion of the ice detecting shaft enters in the direction of displacement of the switch lever to hinder the displacement of the switch lever. Therefore, the first projection retreats because the switch lever is not displaced, and the detection switch does not operate, and the rotation of the ice tray is continued. And
When the ice tray reaches the maximum pivot position, the ice in the ice tray falls into the ice bin, the switch lever is displaced by the second protrusion, and the detection switch reverses the motor so that the ice tray returns to the horizontal position. Output a signal for

When the ice tray returns to the horizontal position, the final gear connected to the ice tray does not engage with the previous gear due to the missing tooth region and does not rotate, so that the ice tray is held horizontally and the previous gear is moved to a predetermined position. After the idle running, the motor is stopped.

When the ice tray starts to perform the ice-removing operation again, the circumferential portion of the preceding gear is brought into contact with the tip of the first tooth of the final gear by the biasing means. However, even if the preceding gear rotates due to the rotation of the motor, the driving force of the preceding gear is not transmitted to the final gear. After a while, the notch in the circumferential part of the previous gear comes to the position of the first tooth of the final gear, and after the notch in the circumferential part of the previous gear meshes with the urging means, The front gear and the final gear gear area mesh with each other, the driving force of the front gear is transmitted to the final gear, and the final gear starts rotating in the direction of ice separation.

In another automatic ice making machine according to the present invention, when the ice making tray again starts the ice-releasing operation, the final gear is in the missing tooth region. Even if it rotates, the driving force of the preceding gear is not transmitted to the final gear. After a while, the cam lever of the gear at the preceding stage moves the cam lever in the direction of the convex portion of the final gear and comes into contact with the convex portion, and the cam lever pushes the convex portion to rotate the final gear in the direction of deicing, and the gear area of the final gear And the gear of the preceding stage mesh with each other, the driving force of the gear of the preceding stage is transmitted to the final gear, and the final gear starts rotating in the direction of ice separation.

As described above, the automatic ice maker according to the present invention can detect the horizontal position of the ice tray without locking the motor and gears, so that there is no mechanical damage to the gears and no adverse effect on the life of the motor. The detection of the maximum rotation position of the dish and the detection of the position of the ice detecting lever can be detected by one switch means.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an automatic ice making machine according to a first embodiment of the present invention will be described with reference to the drawings. In FIG.
1 is a mechanical unit of the ice making machine, 202 is an ice tray rotatably connected to the mechanical unit 201, 203 is a bearing for rotatably supporting the ice tray 202, 204 is ice storage for storing ice after ice making. The box is provided below the ice tray 202. An ice detecting lever 205 is driven by the mechanical unit 201 to enter the ice storage box 204 to detect the amount of ice storage.

Next, the internal structure of the mechanical unit 201 will be described with reference to FIGS. In the drawing, reference numeral 1 denotes a box-shaped housing, and a screw hole 3 for fastening a cover 2 fitted to the housing 1 is provided at a corner of the housing. Reference numeral 4 denotes a rib provided on the bottom surface 5 of the housing 1, into which a motor 7 as a driving source is fitted and fixed. A worm gear 9 is fitted into the shaft output shaft 8 of the motor 7 via a joint 8 a, and the tip of the worm gear 9 is carried by a bearing 10 extending from the bottom surface 5 of the housing 1.

A first gear 13 having a worm wheel portion 11 and a spur gear portion 12 at a position where it meshes with the worm gear 9
And a third gear 15 and a third gear 1 meshing with the second gear 14 and the second gear 14 meshing therewith.
A gear train is constituted by the final gear 16 meshing with the gear 5.

The final gear 16 comprises a gear portion 17, an outer peripheral cam 18 extending above the gear portion 17, and a shaft 26 extending below. The gear portion of the third gear 15 that meshes with the final gear 16 forms a circumferential portion 15a having an outer diameter slightly larger than the outer circumferential circle of the tooth tip of the gear portion at the gear end in the rotation axis direction, and a part of the circumferential portion 15a. And a notch 15b formed by extending the tooth bottom of the gear.

An arc-shaped concave portion 16d is provided around the shaft 26.
Is provided. The gear portion 17 is composed of a gear region 17a and a tooth missing region 17b. When the final gear 16 rotates in the direction of the ice removing operation of the ice tray, the first teeth 17c which are switched from the tooth missing region 17b to the gear region 17a are other. The first teeth 17c are larger than the teeth of the third gear 15 in the circumferential portion 1 of the third gear 15.
It is designed to mesh with the notch 15b of 5a.
A cam surface 20 is formed in the tooth width direction in the tooth missing area 17b, and the cam surface 20 includes an upper surface 20a, a lower surface 20b, and a slope 20c connecting these. Also, the lower surface 20b and the slope 20
and c constitute a concave cam surface.

The housing 1 is provided with a hole 1a through which the shaft 26 penetrates outward, and an arc-shaped convex portion 1d fitted around the hole 1a with the arc-shaped concave portion 16d of the final gear 16. The outer peripheral cam 18 is connected to the first projection 22 and the second projection 22.
And a third projection 24. Arc-shaped convex part 1d
Is set shorter than the arc-shaped concave portion 16d so that a space is formed when the two are fitted together, and the urging means 30 composed of a coil spring is disposed in this space.

Here, the second projection 23 and the third projection 24
Is formed integrally with the outer peripheral cam 18, but the first projection 22 is provided with a stepped rod-shaped rod 22a and a coil spring 22b.
In this state, the rod 22a is inserted into a through hole 18a provided in advance in the outer peripheral cam 18 and one end of the rod 22a is stopped by a retaining ring 22c, so that the rod 22a does not come off from the outer peripheral cam 18.

The first projection 22 is urged in the centrifugal direction by the coil spring 22b, but retreats when a predetermined external force is applied.

The shaft 26 has a protruding portion 27 protruding outside from a hole 1 a provided in the housing 1 and connected to an ice tray 202.

Reference numeral 36 denotes an ice detecting shaft for driving the ice detecting lever 205, which has a shaft portion 36a and a guide groove 36b for preventing axial deflection. A torque limiter 36c composed of a torsion coil spring is installed at the center, and
6 receives an abnormal torsional torque, the torque limiter 36c absorbs the abnormal torsional torque and prevents the ice detecting shaft 36 from being damaged. The shaft 36a is rotatably held by a bearing 39 provided on the housing 1. Ice detection lever 205
One end of the ice detecting shaft 36 on the side to be joined to the outside protrudes from a portion where the side wall of the housing 1 is cut out in a U-shape.

At one end of the ice detecting shaft 36, an arm 40 whose tip slides on the cam surface 20 of the final gear 16 and a projection 41 protruding in the axial direction are formed. The gear 16 is in contact with the cam surface 20.

A bias spring 42 urges the arm 40 of the ice detecting shaft 36 toward the cam surface 20 of the final gear 16.

Reference numeral 43 denotes a substrate, which is a groove 44 of the housing 1.
And is pressed and fixed to the cover 2 as well. The detection switch 45 is directly attached to the substrate 43.

Further, a test switch 49 for confirming a test operation of the automatic ice maker is provided on the substrate 43 at a position where the test switch 49 can be operated from outside.

The detection switch 45 is provided on the protrusion 2 of the outer peripheral cam 18.
It is in a position where it is turned on and off by the switch lever 47 by the switch levers 23, 23, 24. The switch lever 47 contacts the button 45a of the detection switch 45 to operate.

The projection 41 of the ice detecting shaft 36 is
When it rotates by a certain amount or more, it contacts the bent portion 47b of the switch lever 47 and is arranged at a position where the movement of the switch lever 47 can be prevented.

The ice storage amount is judged to be insufficient when the ice detection shaft 36 is rotated by a predetermined amount or more and the detection switch 45 does not output a signal. On the other hand, when the detection switch 45 outputs a signal without rotating the ice detection shaft 36 by a predetermined amount or more, it is determined that the ice storage amount is sufficient.

Here, the driving of the final gear 16 and the ice detecting shaft 36 will be described. The motor 7 is rotated by a de-icing start signal from a control unit (not shown). When the final gear 16 rotates forward (rotation in the de-icing direction), the arm 4 of the ice detecting shaft 36 is rotated.
0 is the upper surface 20a → the inclined surface 20c → the lower surface 20 on the cam surface 20
By making contact in the order of b → the slope 20 c → the upper surface 20 a, the ice detecting shaft 36 is rotated to lower and raise the ice detecting lever 205, and the ice tray 202 is rotated to the ice separating angle. This series of driving is referred to as first driving means.

Further, the motor 7 is rotated by the inversion signal from the control unit, and the final gear 16 is simultaneously rotated in the reverse direction while returning the ice tray 202 to the origin.
On the cam surface 20, the upper surface 20a → the inclined surface 20c → the lower surface 20b
By making contact in the order of the slope 20c and the upper surface 20a, the ice detecting shaft 36 is rotated to lower and raise the ice detecting lever 205. This series of driving is referred to as second driving means.

Further, the motor 7 is controlled by a de-icing start signal from the control unit.
When the final gear 16 rotates in the normal direction, the arm 40 of the ice detecting shaft 36 is moved from the upper surface 20a to the slope 2 on the cam surface 20.
By bringing the ice detection shaft into contact with 0c, the ice detection shaft 36 is rotated to lower the ice detection lever 205. When the ice detecting lever 205 does not drop below the predetermined position, the motor 7 rotates in the direction in which the final gear 16 rotates in the reverse direction. At this time, the arm 40 of the ice detecting shaft 36 is inclined on the cam surface 20. By making contact in the order of 20c → upper surface 20a, the ice detecting shaft 36 is rotated to raise the ice detecting lever 205. This series of driving is referred to as third driving means.

The operation of the automatic ice maker constructed as described above will be described. 7 to 9, the solid arrow indicates the rotation of the final gear 16 in the ice-removing direction, and the broken arrow indicates the direction in which the ice-making tray returns to the origin after the ice-releasing operation.

When the water supplied to the ice tray 202 by a pump (not shown) is frozen, and the thermistor, which is an ice making detecting means (not shown), detects a temperature lower than a set temperature and detects that the ice making is completed, When a signal is input from a control unit (not shown), the motor 7 is rotated in a direction in which the ice tray 202 separates from the ice, and the worm gear 9, the first, second, and third gears 13, 14, and 15 are sequentially decelerated and rotated. However, immediately after the start of rotation, the first teeth 17c of the gear region 17a of the final gear 16 are in contact with the circumferential portion 15a of the third gear 15, and the final gear 16 does not rotate (FIG. 7).

When the third gear 15 continues to rotate,
Notch 15b of third gear 15 and final gear 16
Are engaged with each other, and the rotation is transmitted to the final gear 16 (FIGS. 8 and 9).

When the final gear 16 starts to rotate forward, the arm 40 of the ice detecting shaft 36, which has first contacted the upper surface 20a of the cam surface 20 of the final gear 16 according to the first driving means, moves from the upper surface 20a. It moves along the slope 20c to the lower surface 20b. In conjunction with this, the ice detection shaft 36 rotates,
The ice detecting lever 205 is provided for the ice storage box 20 provided below the ice making machine.
It descends into 4. At this time, if ice has not been stored in the ice storage box 204, the ice detecting lever 205 descends to the lowest point, and the projection 41 of the ice detecting shaft 36 faces the detection switch 45 side of the free end 47b of the switch lever 47. When the first projection 22 of the outer peripheral cam 18 pushes the action point 47a downward, the action point 47a does not lower but the rod 22a of the first projection 22 retreats.
a cannot be operated. For this reason, since no signal is output from the detection switch 45, it is determined that the ice is insufficient.

At this time, the motor 7 continues to rotate in the reverse direction, the forward rotation of the final gear 16 continues, the ice detecting shaft 36 reaches the upper surface 20a of the cam surface 20 again, and the ice detecting lever 205 is moved to the ice storage box 2.
Pull up from 04. As long as the motor 7 continues to rotate in the reverse direction, it comes into contact with the upper surface 20a. Ice tray 2
02 is rotated to a position where the ice inside is twisted by a predetermined angle and the inner ice is released, the outer peripheral cam 18 of the final gear 16
Of the switch lever 47 at the action point 47
Since a is pushed downward, the switch lever 47 is pushed down, and the internal button 45a of the detection switch 45 operates to output a signal.

At this time, it is determined that the ice removal has been completed, and the motor 7 starts normal rotation to return the ice tray 202 to the home position.
Preparation for the next ice making operation is completed. Here, before returning to the origin position according to the second driving means, the ice detecting shaft 36 performs the ice detecting operation once again to confirm the amount of ice stored in the ice storage box 204 again.

Conversely, if there is ice in the ice storage box 204, the ice detecting lever 205 does not descend to the lowest point and stops halfway according to the third driving means, so that the arm 40 of the ice detecting shaft 36 is stopped. The floating state is maintained without reaching the lower surface 20b from the slope 20c of the cam surface 20. At this time, the projection 41 of the ice detecting shaft 36 does not come into contact with the free end 47b of the switch lever 47, and when the first projection 22 of the outer peripheral cam 18 pushes down the action point 47a, the switch lever 47 is also pushed down and the detection switch is pushed. The internal button 45a of 45 operates to output a signal. At this time, it is determined that there is ice, and the motor 7 rotates forward to return the ice tray 202 to the home position, and waits as it is.

Here, the final gear 16 is an ice tray 20.
After rotating reversely until 2 returns to the horizontal position of the origin, the third gear 1
5 comes into contact with the circumferential portion 15a of the gear region 17a at the first teeth 17c, so that the final gear 16 is stopped even when the third gear 15 is rotating (FIG. 7).

First gear 13, second gear 14, third gear 1
The motor 5 stops rotating when the motor 7 stops after the final gear 16 stops.

The stop timing of the motor 7 is determined by the ice tray 20.
The rotation of the second gear 2 is returned to the home position after the ice is removed, and the rotation is stopped after a predetermined time has elapsed, or the switch lever is pushed down by the third projection 24 of the outer peripheral cam 18 of the final gear 16 and the detection switch 45 outputs a signal. Is stopped after a predetermined time has passed.

As described above, the automatic ice making machine according to the present embodiment constitutes the final stage of the gear train for transmitting the forward rotation and the reverse rotation of the motor 7 to the ice tray 202 and has a concave cam surface 20 in a predetermined area. A gear 16, an ice detecting shaft 36 having an arm 40 urged to come into contact with the cam surface 20 and rotatably supported in accordance with a change in the cam surface 20; an ice detecting shaft connected to the ice detecting shaft 36; The ice-making tray 202 moves in and out of the ice storage box 204 before the ice-making tray 202 reaches the maximum rotation position in conjunction with the rotation of the ice-making tray 202, and the ice-making tray 202 is operated horizontally by the displacement of the switch lever 47. Motor 7 to return to position
A detection switch 45 for outputting a signal for reverse rotation of the motor or a signal for stopping the motor 7;
A first projection 22 biased in a projecting direction at a position facing the switch lever 47 when entering or exiting the ice storage box 204 and provided on the final gear 16 so as to be able to retreat and displace the switch lever 47 when projecting; , Ice tray 20
The second projection 23 provided on the final gear 16 for displacing the switch lever 47 and the ice detection lever 205 provided on the ice detection shaft 36 are provided at the position opposing the switch lever 47 when the 2 is at the maximum rotation position. A protruding portion 41 that enters the box 204 at a predetermined position or more and enters the direction of displacement of the switch lever 47 to hinder the displacement of the switch lever 47;
When the ice tray 202 returns to the horizontal position, the final gear 16 is formed by the toothless region 17b provided in the final gear 16 so that the final gear 16 does not mesh with the third gear 15 preceding the final gear 16, and the third gear 15 is formed by the toothless region 17b. The urging means 30 for urging the final gear 16 in a direction in which the ice tray 202 rotates in the direction of the ice releasing operation when the ice making tray 15 does not mesh with the final gear 15, and the final gear 16 rotates in the direction of the ice releasing operation of the ice tray 202. When the tooth missing area 17b is shifted to the gear area 1
The first tooth, which is the first tooth to be switched to 7a and has a larger tooth thickness than the other teeth, is provided at the gear end in the rotation axis direction of the third gear 15 so as to contact the tip of the first tooth 17c. 3
Since it has a circumferential portion 15a having an outer diameter equal to or slightly larger than the outer circumferential circle of the gear tooth tip of the gear 15, and a cutout portion 15b formed at a specific portion of the circumferential portion 15a so as to mesh with the first tooth 17c. The detection of the maximum rotation position of the ice tray 202 and the detection of the position of the ice detecting lever 205 can be detected by one switch means (detection switch 45), so that the configuration is simplified and the cost can be reduced. Further, since the horizontal position detection of the ice tray 202 is not performed by locking the motor 7 and the gear train as in the related art, the durability of the gears and the motor 7 is improved,
The life of the motor 7 can be extended. Further, since the horizontal position is determined by the mechanical contact between the circumferential portion 15a of the third gear 15 and the first teeth 17c of the final gear 16, the horizontal position accuracy can be improved. Further, the ice tray 202 returns to the horizontal position, and the portion of the final gear 16 that meshes with the third gear 15 is switched from the gear region 17a to the missing tooth region 17b, and
When the final gear 16 does not rotate despite the rotation of the gear 15, the ice tray 202 vibrates because the first teeth 17c of the final gear 16 do not collide with the gear tips of the third gear 15. No collision sound.

Next, a second embodiment of the automatic ice maker according to the present invention will be described with reference to FIGS. 10 to 15. The same reference numerals are given to the same components as those in the first embodiment, and the details thereof will be described. Description is omitted.

A first gear 13 having a worm wheel 11 and a spur gear 12 at a position where it meshes with the worm gear 9
Are provided, and the third gear 51 and the third gear 5 that mesh with the second gear 14 and the second gear 14
A gear train is constituted by the final gear 52 meshing with the one small gear portion 51a. Rotation shaft 51 of third gear 51
A cam groove 53 having a cam portion 53a in a part thereof is formed in a plane portion perpendicular to b.

Reference numeral 63 denotes a cam lever. A cam pin 64 provided at one end is fitted into the cam groove 53 of the third gear 51, and two openings 6 long in the longitudinal direction of the cam lever 63.
3a, 63c, the rotation shaft 51b of the third gear 51 is fitted in the opening 63a, the projection (not shown) of the cover 2 is fitted in the opening 63c, and the cam lever 63 is slidable. Has become.

The final gear 52 comprises a gear portion 54, an outer peripheral cam 55 extending upward and a shaft 56 extending downward. The gear portion 54 is constituted by a gear region 54a and a toothless region 54b. A cam surface 57 including an upper surface 57a, a lower surface 57b, and a slope 57c connecting them is formed in the tooth region 54b in the tooth width direction. The lower surface 57b and the inclined surface 57c constitute a concave cam surface. The housing 1 is provided with a hole 1a through which the shaft 56 passes. The outer peripheral cam 55 is connected to the first protrusion 58 and the second protrusion 58.
, A third projection 60 and a projection 61.

Here, the second protrusion 59 and the third protrusion 60
And the convex portion 61 are formed integrally with the outer peripheral cam 55,
The first projection 58 is formed by fitting a coil spring 58b into a rod-like rod 58a with a step and inserting the coil spring 58b into a through-hole 55a provided in advance in the outer peripheral cam 55 and stopping one end of the rod 58a with a retaining ring 58c. Rod 58
a is not detached from the outer peripheral cam 55.

The first projection 58 is urged in the centrifugal direction by the coil spring 58b, but retreats when a predetermined external force is applied.

The shaft 56 has a protruding portion 62 which protrudes outside from the hole 1 a provided in the housing 1 and is connected to the ice tray 202.

At one end of the ice detecting shaft 36, an arm 40 whose tip slides on the cam surface 57 of the final gear 52 and a projection 41 projecting in the axial direction are formed. It is arranged to be in contact with the cam surface 57 of the gear 52.

Reference numeral 42 denotes a bias spring which urges the arm 40 of the ice detecting shaft 36 toward the cam surface 57 of the final gear 52.

The detection switch 45 is provided with the protrusion 5 of the outer peripheral cam 55.
8, 59 and 60 are at positions where they are turned on and off via the switch lever 47. The switch lever 47 contacts the button 45a of the detection switch 45 to operate.

Here, the driving of the final gear 52 and the ice detecting shaft 36 will be described. The motor 7 is rotated by a de-icing start signal from a control unit (not shown), and when the final gear 52 rotates forward (rotation in the de-icing direction), the arm 4 of the ice detecting shaft 36 is rotated.
0 is the upper surface 57a → the inclined surface 57c → the lower surface 57 on the cam surface 57.
By contacting in the order of b → slope 57c → upper surface 57a, the ice detecting shaft 36 is rotated to lower and raise the ice detecting lever 205, and the ice tray 202 is rotated to the ice releasing angle. This series of driving is referred to as first driving means.

The motor 7 is rotated by an inversion signal from the control unit, and the final gear 52 is simultaneously rotated in the reverse direction while returning the ice tray 202 to the origin.
On the cam surface 57, the upper surface 57a → the inclined surface 57c → the lower surface 57b
By making contact in the order of the slope 57c and the upper surface 57a, the ice detecting shaft 36 is rotated to lower and raise the ice detecting lever 205. This series of driving is referred to as second driving means.

Further, the motor 7 is controlled by a de-icing start signal from the control unit.
When the final gear 52 rotates in the normal direction, the arm 40 of the ice detecting shaft 36 is moved from the upper surface 57a to the slope 5 on the cam surface 57.
7c, the ice detection shaft 205 is rotated to lower the ice detection lever 205. If the ice detection lever 205 does not drop below a predetermined position, the motor 7 rotates the final gear 52 in the reverse direction. In this case, the arm 40 of the ice detecting shaft 36 is brought into contact with the slope 57c → the upper surface 57a on the cam surface 57 in this order, whereby the ice detecting shaft 36 is rotated and the ice detecting lever 205 is rotated. To rise. This series of driving is referred to as third driving means.

The operation of the automatic ice maker configured as described above will be described. In FIGS. 13 to 15, the solid arrow direction indicates the rotation of the final gear 52 in the ice removing direction, and the broken arrow direction indicates the direction in which the ice tray returns to the origin after the ice removing operation.

When the water supplied to the ice tray 202 by a pump (not shown) is frozen and the thermistor, which is an ice making detecting means (not shown), shows the temperature below the set temperature and detects that the ice making is completed, A signal is input from a control unit (not shown), and the motor 7 is rotated in a direction in which the ice tray 202 is separated from the ice, and the worm gear 9, the first, second, and third gears 13, 14, and 51 are sequentially decelerated and rotated. However, immediately after the start of rotation, the toothless region 54b of the final gear 52 and the gear portion 51a of the third gear 51 are not meshed, so that the final gear 52 does not rotate (FIG. 13).

When the third gear 51 continues to rotate,
When the cam pin 64 fitted in the cam groove 53 of the third gear 51 is driven by the cam portion 53a, the cam lever 63 slides, and the contact portion 63b is formed on the outer peripheral cam 55 of the final gear 52 by the convex portion 61. Is pushed in the direction in which the final gear 52 rotates in the direction of ice separation, so that the gear portion 54a of the final gear 52 and the gear portion 51a of the third gear 51 mesh with each other, and the rotation is transmitted to the final gear 52 (FIG. 14,
(FIG. 15).

When the final gear 52 starts to rotate forward, the arm 40 of the ice detecting shaft 36, which first contacts the upper surface 57a of the cam surface 57 of the final gear 52 according to the first driving means, moves from the upper surface 57a. It moves along the lower surface 57b via the slope 57c. In conjunction with this, the ice detection shaft 36 rotates,
The ice detecting lever 205 is provided for the ice storage box 20 provided below the ice making machine.
It descends into 4. At this time, if ice has not been stored in the ice storage box 204, the ice detecting lever 205 descends to the lowest point, and the projection 41 of the ice detecting shaft 36 faces the detection switch 45 side of the free end 47b of the switch lever 47. When the first projection 58 of the outer peripheral cam 55 pushes the action point 47a downward, the action point 47a does not lower but the rod 58a of the first projection 58 retreats.
a cannot be operated. For this reason, since no signal is output from the detection switch 45, it is determined that the ice is insufficient.

At this time, the motor 7 continues to rotate in the reverse direction, the normal rotation of the final gear 52 continues, the ice detecting shaft 36 reaches the upper surface 57a of the cam surface 57 again, and the ice detecting lever 205 is moved to the ice storage box 2.
Pull up from 04. Then, as long as the reverse rotation of the motor 7 continues, the motor 7 comes into contact with the upper surface 57a. Ice tray 2
02 is rotated to a position where the ice inside is twisted by a predetermined angle and the inner ice is released, the outer peripheral cam 55 of the final gear 52
Of the switch lever 47 at the action point 47
Since a is pushed downward, the switch lever 47 is pushed down, and the internal button 45a of the detection switch 45 operates to output a signal.

At this time, it is determined that the ice removal has been completed, and the motor 7 starts normal rotation to return the ice tray 202 to the home position.
Preparation for the next ice making operation is completed. Here, before returning to the origin position according to the second driving means, the ice detecting shaft 36 performs the ice detecting operation once again to confirm the amount of ice stored in the ice storage box 204 again.

Conversely, if there is ice in the ice storage box 204, the ice detecting lever 205 does not descend to the lowest point and stops on the way according to the third driving means, so that the arm 40 of the ice detecting shaft 36 The floating state is maintained without reaching the lower surface 57b from the inclined surface 57c of the cam surface 57. At this time, the projection 41 of the ice detecting shaft 36 does not come into contact with the free end 47b of the switch lever 47, and when the first projection 58 of the outer peripheral cam 55 pushes down the action point 47a, the switch lever 47 is also pushed down and the detection switch is pushed. The internal button 45a of 45 operates to output a signal. At this time, it is determined that there is ice, and the motor 7 rotates forward to return the ice tray 202 to the home position, and waits as it is.

Here, the final gear 52 is an ice tray 20.
After the gear 2 is reversed until it returns to the horizontal position of the origin, the third gear 5
Since the first small gear 51a and the missing tooth region 54b face each other, the final gear 52 is stopped even when the third gear 51 is rotating.

First gear 13, second gear 14, third gear 5
The motor 1 stops rotating when the motor 7 stops after the final gear 52 stops.

The timing of stopping the motor 7 is determined by the ice tray 20.
2 starts rotation to return to the home position after ice release, and stops after a predetermined time has elapsed, or the switch lever is pushed down by the third protrusion 60 of the outer peripheral cam 55 of the final gear 52 and the detection switch 45 outputs a signal. Is stopped after a predetermined time has passed.

As described above, the automatic ice making machine of this embodiment forms the final stage of the gear train for transmitting the forward rotation and the reverse rotation of the motor 7 to the ice tray 202 and has a concave cam surface 57 in a predetermined area. A gear 52, an ice detecting shaft 36 having an arm 40 urged to abut on a cam surface 57 and rotatably supported in accordance with a change in the cam surface 57, and an ice detecting shaft connected to the ice detecting shaft 36. The ice-making tray 202 moves in and out of the ice storage box 204 before the ice-making tray 202 reaches the maximum rotation position in conjunction with the rotation of the ice-making tray 202, and the ice-making tray 202 is operated horizontally by the displacement of the switch lever 47. Motor 7 to return to position
A detection switch 45 for outputting a signal for reverse rotation of the motor or a signal for stopping the motor 7;
A first projection 58 is provided on the final gear 52 so as to be urged in a protruding direction at a position facing the switch lever 47 when entering or exiting the ice storage box 204, and is provided on the final gear 52 so as to displace the switch lever 47 when projecting. , Ice tray 20
The second projection 59 provided on the final gear 52 and displacing the switch lever 47 at a position opposing the switch lever 47 when the switch 2 is at the maximum rotation position, and the ice detection lever 205 provided on the ice detection shaft 36 are provided with ice storage. A protruding portion 41 that enters the box 204 at a predetermined position or more and enters the direction of displacement of the switch lever 47 to hinder the displacement of the switch lever 47;
When the ice tray 202 returns to the horizontal position, the toothless region 54b provided in the final gear 52 so as not to mesh with the third gear 51 preceding the final gear 52, and the final gear so that the ice tray 202 returns to the horizontal position. 52 rotates and the portion meshing with the third gear 51 in the preceding stage is the gear region 5.
4a to the missing tooth region 54b when the final gear 5
2, a convex portion 61 provided at a position approaching the third gear 51 of the preceding stage, a cam groove 53 formed on a plane perpendicular to the rotation axis of the third gear 51 of the preceding stage, and a cam groove 53.
The final gear 52 rotates so that the ice tray 202 is returned to the horizontal position with the cam pin 64 inserted into the third stage.
The third front and the final gear 52 is rotated so as and the ice tray 202 when the portion that meshes with the gear 51 is changed from the gear area 54a in the toothless region 54b is rotated in the ice removing operation direction
When the portion that meshes with the gear 51 changes from the toothless region 54b to the gear region 54a, the cam groove 53 moves in the direction of the convex portion 61 and has a cam lever 63 that comes into contact with the convex portion 61. Detection and ice detection lever 2
05 is detected by one switch means (detection switch 4
5), the configuration can be simplified, and the cost can be reduced. Further, since the horizontal position of the ice tray 202 is not detected by locking the motor 7 and the gear train as in the related art, the durability of the gears and the motor 7 is improved, and
Life can be extended. Further, although the ice tray 202 returns to the horizontal position and the portion of the final gear 52 that meshes with the third gear 51 is switched from the gear region 54a to the missing tooth region 54b, the third gear 51 is rotated.
When the final gear 52 is not rotating, the teeth of the final gear 52 do not collide with the gear tips of the third gear 51, so that the ice tray 202 does not vibrate and no collision sound is generated.

[0075]

As described above, the automatic ice making machine according to the present invention comprises a final gear having the final stage of a gear train for transmitting forward rotation and reverse rotation of a motor to an ice tray and having a concave cam surface in a predetermined area; An ice detecting shaft having an arm biased to abut on the cam surface and rotatably supported in accordance with a change in the cam surface; and an interlocked with the ice detecting shaft connected to the ice detecting shaft. Then, the motor is reversely rotated so that the ice tray returns to the horizontal position by operating the ice detecting lever that enters or exits the ice storage box before the ice tray reaches the maximum rotation position, and the switch lever is displaced. A detection switch for outputting a signal for stopping the motor or a signal for stopping the motor, and the detection lever is urged in a projecting direction at a position facing the switch lever when the ice detection lever enters or exits the ice storage box. The final can be retracted freely A first projection provided on the final gear and disposed on the final gear at a position opposed to the switch lever when the ice tray is at the maximum rotation position, the first projection being configured to displace the switch lever when protruded; And a projection provided on the ice detection shaft and projecting in the direction of displacement of the switch lever when the ice detection lever enters the ice storage box at a predetermined position or more, thereby obstructing the displacement of the switch lever. A toothless region provided in the final gear so that the ice making tray does not mesh with a gear preceding the final gear when the ice tray returns to the horizontal position; and Urging means for urging the final gear in a direction in which the ice tray rotates in the direction of the ice-releasing operation when the final gear is out of engagement; A) the first tooth that switches from the toothless region to the gear region when the ice tray rotates in the direction of the ice removal operation of the ice making tray, the first tooth having a larger tooth thickness than the other teeth, and the tip of the first tooth A circumferential portion having an outer diameter equal to or slightly larger than the outer peripheral circle of the gear tip of the gear of the preceding gear, which is provided at the gear end in the rotation axis direction of the preceding gear so as to contact with the first gear; As described above, since the notch is formed at a specific portion of the circumferential portion, the detection of the maximum rotation position of the ice tray and the position detection of the ice detecting lever can be detected by one switch means, so that the configuration is simplified and the cost is reduced. Can be realized. Further, since the detection of the horizontal position of the ice tray is not performed by locking the motor and the gear train as in the related art, the durability of the gears and the motor is improved, and the life of the motor can be extended. Further, since the horizontal position is determined by the mechanical contact between the circumferential portion of the preceding gear and the first tooth of the final gear, the horizontal position accuracy can be improved. Also, when the ice tray returns to the horizontal position and the portion that meshes with the previous gear of the final gear switches from the gear area to the missing tooth area, and the final gear does not rotate despite the previous gear rotating, Since the first tooth of the final gear does not collide with the gear tip of the preceding gear, the ice tray does not vibrate and no collision sound is generated.

The final gear of the gear train for transmitting the forward and reverse rotations of the motor to the ice tray has a final gear having a concave cam surface in a predetermined area, and is biased so as to contact the cam surface. An ice detection shaft having an arm and rotatably supported in accordance with a change in the cam surface; and an ice tray connected to the ice detection shaft and reaching the maximum rotation position in conjunction with the rotation of the ice detection shaft. A signal for reversing the motor or a signal for stopping the motor so that the ice tray is returned to the horizontal position by operating the ice detecting lever which enters or exits the ice storage box beforehand, and which is operated by the displacement of the switch lever. And a detection switch for outputting the ice detection lever when the ice detection lever enters or exits the ice storage box. Sui A first projection for displacing the chiller, a second projection provided on the final gear at a position facing the switch lever when the ice tray is at the maximum rotation position, and displacing the switch lever; A projection provided on a shaft for intruding in the direction of displacement of the switch lever when the ice detection lever has entered the ice storage box by a predetermined position or more, and disturbing the displacement of the switch lever;
When the ice tray returns to the horizontal position, the toothless region provided in the final gear so that it does not mesh with the previous gear of the final gear, and the final gear rotates so that the ice tray returns to the horizontal position. the final and the convex portion provided at a position closer to the front of the gear in the gear, the plane of rotation perpendicular to the axis direction of the front of the gear when the portion is engaged with the front of the gear change from the gear region in the toothless area The final gear is rotated so that the ice tray returns to a horizontal position, and a portion that meshes with the preceding gear is shifted from the gear region to the toothless region. the final gear is rotated portion the toothless regions engaged with the front gear as when and the ice tray rotates to the ice removing operation direction changes to And a cam lever which moves in the direction of the convex portion by the cam groove when coming into contact with the gear region, and detects the maximum rotation position of the ice tray and the position detection of the ice detecting lever by one switch. This makes it possible to realize a simple configuration and low cost. Further, since the detection of the horizontal position of the ice tray is not performed by locking the motor and the gear train as in the related art, the durability of the gears and the motor is improved, and the life of the motor can be extended. Also, despite the fact that the ice tray returns to the horizontal position and the part that meshes with the previous gear of the final gear switches from the gear area to the missing tooth area, despite the fact that the former gear is rotating,
When the final gear does not rotate, the teeth of the final gear do not collide with the gear tips of the preceding gear, so that the ice tray does not vibrate and there is no collision sound.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an automatic ice maker according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a mechanical unit of the automatic ice maker in the embodiment.

FIG. 3 is a partially cutaway plan view of a mechanical unit of the automatic ice maker in the embodiment.

FIG. 4 is a main part side view showing a final gear cam surface and an ice detection axis of the automatic ice making machine in the embodiment.

FIG. 5 is a schematic perspective view of a main part showing a meshing state of a final gear and a third gear of the automatic ice maker in the embodiment.

FIG. 6 is an essential part side view showing a meshing state between a final gear and a third gear of the automatic ice making machine in the embodiment.

FIG. 7 is a main part schematic plan view showing the meshing state of the final gear and the third gear when the ice tray of the automatic ice making machine in the embodiment is kept horizontal.

FIG. 8 is a main part showing the meshing state of the final gear and the third gear immediately before the ice tray of the automatic ice maker in the embodiment starts to rotate in the ice releasing direction or immediately before the ice tray returns to the horizontal position. Schematic plan view

FIG. 9 is a main part schematic plan view showing the meshing state of the final gear and the third gear when the ice tray of the automatic ice making machine in the embodiment is rotating.

FIG. 10 is an exploded perspective view of a mechanical unit of an automatic ice maker according to a second embodiment of the present invention.

FIG. 11 is a partially cutaway plan view of a mechanical unit of the automatic ice maker in the embodiment.

FIG. 12 is a main part side view showing a final gear cam surface and an ice detecting shaft of the automatic ice making machine in the embodiment.

FIG. 13 is a main part schematic plan view showing the meshing state of the final gear and the third gear when the ice tray of the automatic ice making machine in the embodiment is kept horizontal.

FIG. 14 is an essential part showing the meshing state between the final gear and the third gear immediately before the ice tray of the automatic ice maker in the embodiment starts to rotate in the ice releasing direction or immediately before the ice tray returns to the horizontal position. Schematic plan view

FIG. 15 is a main part schematic plan view showing the meshing state of the final gear and the third gear when the ice tray of the automatic ice making machine in the embodiment is rotating.

FIG. 16 is a sectional view showing a main part of a mechanical body of a conventional automatic ice maker.

FIG. 17 is a sectional view of an essential part showing an ice tray, an ice storage box, and an ice detecting lever of the conventional automatic ice machine.

[Explanation of symbols]

 7 Motor 15 Third Gear 15a Circumference 15b Notch 16 Final Gear 17a Gear Region 17b Missing Tooth Region 17c First Teeth 20 Cam Surface 22 First Projection 23 Second Projection 24 Third Projection 30 36 Ice detection shaft 40 Arm 41 Projection 45 Switch 47 Switch lever 51 Third gear 52 Final gear 53 Cam groove 53a Cam part 54a Gear area 54b Missing tooth area 57 Cam surface 58 First protrusion 59 Second protrusion 60 Third Projection 61 convex part 63 cam lever 64 cam pin 202 ice tray 204 ice storage box 205 ice detection lever

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-223779 (JP, A) JP-A-7-174443 (JP, A) JP-A 4-125173 (JP, U) JP-A 2-125779 58669 (JP, U) Jigyo Sho 51-3086 (JP, Y2) Jigyo Sho 54-17137 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25C 1/10 301

Claims (2)

(57) [Claims] 1. A final gear, which constitutes the last stage of a gear train for transmitting forward and reverse rotations of a motor to an ice tray and having a concave cam surface in a predetermined area, is urged to abut against the cam surface. An ice detection shaft having an arm and rotatably supported in accordance with a change in the cam surface; and an ice tray connected to the ice detection shaft and reaching the maximum rotation position in conjunction with the rotation of the ice detection shaft. the ice detecting lever to enter or exit into the ice box before - and said motor
The ice tray is twisted at a fixed angle
When the ice is turned to the position where the ice is released and the ice storage box
When there is ice inside and the ice detection lever does not descend and stops halfway
A switch lever that can be pushed down
When the chiller is pushed down, the motor rotates forward and
The ice tray is returned to the horizontal position, and after a predetermined time, the motor is turned on.
A detection switch for outputting a stop signal, and a final switch which is urged in a protruding direction at a position facing the switch lever when the ice detecting lever enters or exits the ice storage box, and is provided on the final gear. A first projection for displacing the switch lever when projecting, and a second projection provided on the final gear at a position facing the switch lever when the ice tray is at the maximum rotation position and displacing the switch lever. A projecting portion provided on the ice detecting shaft, which enters in the direction of displacement of the switch lever when the ice detecting lever enters the ice storage box at a predetermined position or more, and disturbs the displacement of the switch lever; A toothless area provided in the final gear so that when the plate returns to the horizontal position, the gear is prevented from meshing with a gear preceding the final gear; Biasing means for biasing the final gear in a direction in which the ice tray rotates in the direction of the ice releasing operation when the final gear is no longer meshed with the gear at the preceding stage due to the region; and The first tooth that is switched from the toothless region to the gear region when rotating in the direction of ice removal operation, the first tooth having a larger tooth thickness than the other teeth, and the first tooth is contacted with the tip of the first tooth. A circumferential portion provided at the gear end in the rotation axis direction of the preceding gear and having an outer diameter equal to or slightly larger than the outer circumferential circle of the gear tooth tip of the preceding gear; and the circumferential portion so as to mesh with the first tooth. Automatic ice making machine having a notch formed in a specific portion of the automatic ice making machine. 2. A final gear of a gear train for transmitting forward and reverse rotations of a motor to an ice tray, and a final gear having a concave cam surface in a predetermined area, and is biased to abut on the cam surface. An ice detection shaft having an arm and rotatably supported in accordance with a change in the cam surface; and an ice tray connected to the ice detection shaft and reaching the maximum rotation position in conjunction with the rotation of the ice detection shaft. the ice detecting lever to enter or exit into the ice box before - and said motor
The ice tray is twisted at a fixed angle
When the ice is turned to the position where the ice is released and the ice storage box
When there is ice inside and the ice detection lever does not descend and stops halfway
A switch lever that can be pushed down
When the chiller is pushed down, the motor rotates forward and
The ice tray is returned to the horizontal position, and after a predetermined time, the motor is turned on.
A detection switch for outputting a stop signal, and a final switch which is urged in a protruding direction at a position facing the switch lever when the ice detecting lever enters or exits the ice storage box, and is provided on the final gear. A first protrusion for displacing the switch lever when protruding, and a second protrusion provided on the final gear for displacing the switch lever at a position facing the switch lever when the ice tray is at the maximum rotation position. A projecting portion provided on the ice detecting shaft, for projecting in the direction of displacement of the switch lever when the ice detecting lever enters the ice storage box at a predetermined position or more, and disturbing the displacement of the switch lever; A toothless region provided in the final gear so that when the plate returns to the horizontal position, the gear does not mesh with a gear preceding the final gear; Where the portion dish and the final gear is rotated back to the horizontal position to mesh with the front gear approaches the front of the gear in the final gear when the teeth <br/> vehicle region changes to said toothless region The final gear so that the ice tray is returned to a horizontal position, comprising a convex portion provided on the front gear, a cam groove formed in a plane perpendicular to a rotation axis of the previous gear, and a cam pin inserted into the cam groove. When the final gear rotates and the ice making tray rotates in the direction of the ice removing operation when the portion that meshes with the previous gear changes from the toothed wheel region to the toothless region. automatic ice maker having said protrusion abutting cam lever portion meshing with front gear by moving the convex portion direction by the cam groove when changes to the gear region from said toothless region.