JP3133284B2 - Ice tray drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an apparatus for driving an ice tray of a refrigerator.

[0002]

2. Description of the Related Art In this type of automatic ice making device, the presence or absence of ice in an ice storage compartment is detected by an ice detecting lever. For this reason, the ice detecting bar is rotatably supported by the driving device of the ice tray at the upper part of the ice storage chamber, and at the time of ice detecting, by a transmission means such as a motor or a cam gear for rotating the ice tray, It is designed to be driven. However, when an external force is applied to the ice detecting bar when ice is taken in and out of the ice storage room, the force is also transmitted to transmission means such as a motor and a cam gear. At this time, the transmission means is in a reverse drive state, cannot withstand external force, and is likely to be damaged.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent the transmission means from being broken by an external force.

[0004]

According to the present invention, there is provided an ice tray provided rotatably, a driving circuit for rotating the ice tray, a motor driven by the driving circuit, and a motor for driving the ice tray. Transmission means for reducing the rotation of the transmission to the ice tray, a cam gear provided in the transmission means,
An ice tray is driven by the cam gear and performs an ice detecting operation to form an ice tray driving device. In particular, a load greater than or equal to a predetermined value is applied to the ice detecting bar between the ice detecting bar and the motor. When a shock is applied, a shock absorber for damping this load is incorporated. The shock absorber is provided between the ice detection bar and the cam gear.

[0005]

1 and 2 show the overall structure of a driving device 1 for an ice tray. The ice tray driving device 1 is mounted on an ice storage container in an ice-making room of a refrigerator to turn the ice tray 2 and swing the ice detection bar 3.

[0006] The ice tray 2 is of a rectangular top opening type, and has a driven side fixed to the drive unit 4 of the ice tray driving device 1 on one side and fixed to the machine frame 6 of the refrigerator on the other side. It is supported in a reversible state with respect to the shaft 5, and at the time of reversal, that is, at the time when the state changes from the upward state to the downward state, for example, by hitting the contact piece 7 fixed to the machine frame 6, torsional deformation Then, the ice inside is released and dropped into the ice storage container below.

The ice detecting bar 3 is attached to the ice detecting shaft 10 at a position lateral to the split cases 8 and 9 of the driving device 1, and requires a required angle from a horizontal position, for example, a maximum operating angle of 37 degrees. By pivoting to the extent, it comes into contact with or not in contact with the ice in the ice storage chamber, and its amount is detected.

FIGS. 3 to 8 show the structure of a cam gear 11, an ice detecting lever 12, a switch operating lever 13, and a switch 14 incorporated in the cases 8, 9, and a DC motor for driving them. 15 and the like are shown. As shown in FIG. 8 in addition to FIG. 3, the motor 15 is fixed inside the case 8 together with the printed circuit board 37, and the rotation thereof is transmitted to the ice tray 2 by reducing the rotation of the motor 15. The power is transmitted to the cam gear 11 via transmission means, that is, a reduction worm 16, a worm wheel 17, and gears 18 and 19.

As shown in FIGS. 4, 6 and 7, the cam gear 11 is provided with a case 8, 9 by an integral shaft 20.
The first cam 21 is formed by the contour of one side surface, and the second cam 22 is formed by the other discontinuous ridge. , A stopper 23 for regulating the rotation angle of the cam gear 11, and a projection 24 for driving the lock lever 25. Note that a part of the shaft 20 is
, And protrudes to form an oval-shaped drive section 4.

The stopper 23 corresponds to the stopper receivers 26 and 27 formed on the case 8 to regulate the rotation angle of the cam gear 11 as shown in FIG. Is regulated. The lock lever 25 corresponds to the stepped portion 47 formed on the boss portion of the worm 16 at the tip of the claw as shown in FIG. 4. , The motor 15 and the worm 16 are forcibly stopped.

The first cam 21 is in contact with the cam follower 28 of the ice detecting lever 12 at the contour as shown in FIGS. 3 and 6, and forms a displacement allowable area 29 at the recess. ing. As shown in FIG. 7, the second cam 22 is in contact with the cam follower 30 of the switch operating lever 13 on the outer peripheral wall.
, A displacement permissible range 32 corresponding to the displacement permissible range 29, and a displacement permissible range 33 corresponding to the end of rotation of the cam gear 11.

As shown in FIG. 8, the switch operating lever 13 and the lock lever 25 are both rotatably supported on a lever shaft 34 integral with the case 8, and a pull spring provided therebetween. 35 are urged in mutually different rotational directions. Switch operating lever 1
Numeral 3 is provided with, for example, a permanent magnet 36 at the tip portion, and makes the magnetic flux of the permanent magnet 36 correspond to a switch 14 such as a Hall element mounted on a printed circuit board 37.

As shown in FIG. 3, the ice detecting lever 12 is rotatably supported at one end with respect to a lever shaft 39 integral with the case 8, and intersects the shaft 20 at a slot 40. ,
It is engaged with the ice detection shaft 10 directly at the tip end portion or with a slider 41 interposed as seen in this embodiment. That is, the slider 41 is fitted in a movable state inside the slide guide 42 formed on the ice detecting lever 12, and the spring receiver 44 of the slider 41 and the spring receiver 45 of the ice detecting lever 12 are provided.
, And is engaged with an engagement piece 48 integral with the ice detection shaft 10 by two engagement projections 46 at the tip.

As shown in FIG. 5, the ice detecting shaft 10 is always urged clockwise in FIG. 5 by a pulling spring 49 hung on the case 8 at a lower portion. As a result, the ice detecting bar 3 is always urged counterclockwise in FIG. 2, and the ice detecting lever 12 is
9, the force is constantly applied in the clockwise direction in FIG. 3, that is, the direction in which the cam follower 28 comes into contact with the contour of the first cam 21.

The ice detecting lever 12 is a switch operating lever 1.
3 is provided with a displacement prevention portion 50, which is brought into contact with a part of the switch operation lever 13, for example, a displacement prevention piece 51 integral with the switch operation lever 13, so that the rotation range of the switch operation lever 13 can be adjusted. Regulate.

Next, FIG. 9 shows a control system of the motor 15. The controller 52 incorporates an operation program, and gives an operation command to the drive circuit 53 by using various command signals, an output signal from the switch 14 and the like as inputs. The driving circuit 53 rotates the motor 15 with a necessary torque by flowing a forward current through the diode 54 in order to drive the motor 15 in the forward direction during the ice detecting operation and the ice releasing operation. At the time of the ice operation or the return operation after the ice separation, a current smaller than the current at the time of normal rotation is caused to flow through the resistor 55 by flowing a current in the reverse direction to the diode 54, and the motor 15 is driven in the reverse direction with a small torque. Rotate to. Thus, the diode 5
Reference numeral 4 denotes a power supply path between the drive circuit 53 and the motor 15, which is interposed as a forward direction with respect to the normal rotation direction of the motor 15, and a resistor 55 is connected in parallel with the diode 54.

Next, FIG. 10 shows a series of operations of the ice tray driving device 1. In response to a periodic operation command from the operation program or a compulsory operation command from the outside, the controller 52 drives the motor 15 in the forward direction with a necessary torque via the drive circuit 53, and the cam gear 11
Is slowly rotated in the counterclockwise direction in FIGS. 3, 6, 7, and 8. The time required for the cam gear 11 to rotate 170 degrees is set to about 10 seconds.

The ice tray 2 slowly rotates in the reverse direction by rotating the cam gear 11 and the drive unit 4 integral with the shaft 20 counterclockwise in FIG. At the same time, the first cam 21 rotates in the same direction, and the cam follower 28 of the ice detecting lever 12 is depressed by the elasticity of the pulling spring 49, that is, falls into the displacement allowable area 29. Then, the ice detecting shaft 10 is rotated clockwise about the lever shaft 39 and rotated clockwise in FIG. This ice detection axis 10
Rotates the ice detecting bar 3 counterclockwise in FIG.

When the ice storage amount is insufficient, the ice detecting bar 3 is rotated to the maximum operation angle, so that the ice detecting lever 12 is displaced to a deep position in the displacement allowable area 29 in conjunction with the rotation, and FIG. As shown in FIG. 8, the displacement preventing portion 50 is
Move to the direction approaching 1. However, when the ice storage amount is sufficient, the ice detection bar 3 hits the ice and stops halfway, so that the ice detection axis 10 does not rotate beyond the full ice detection level. Therefore, the ice detecting lever 12 is not displaced to the position where the displacement preventing portion 50 contacts the displacement preventing piece 51 in conjunction with the ice detecting lever 12.

In a range where the cam gear 11 rotates from 55 degrees to 85 degrees, the ice detecting lever 12 returns to the original position. Thereafter, the ice detecting lever 12 is set in a state in which the ice detecting lever 12 does not rotate since it comes into contact with the arc-shaped contour portion of the first cam 21.

On the other hand, in the portion of the second cam 22, an allowable displacement range 31 in the range of -12 to 11 degrees, an allowable displacement range 32 in the range of 33 to 47 degrees, and an allowable range of 32 in the range of 170 to 190 degrees. Since the displacement permissible area 33 is formed, the switch actuating lever 1 is provided in these displacement permissible areas 31, 32, and 33.
When the three cam followers 30 correspond, the switch operating lever 13 displaces the permanent magnet 36 in a direction away from the switch 14.

The switch 14 generates an "H" level output when the switch 14 is separated from the permanent magnet 36, but changes to an "L" level signal when the switch 14 is opposed to and close to the permanent magnet 36. Therefore, the output signal of the switch 14 is
Corresponding to the displacement permissible areas 31, 32, and 33, the signals are an "H" level original position signal, an ice detection signal, and an ice release signal, which are input to the controller 52.

As described above, when the controller 52 receives the operation command, the controller 52 generates an output for rotating the motor 15 in the normal rotation direction.
When the output signal of the switch 14 changes from the “L” level to the “H” level, that is, when the ice detection signal or the ice removal signal is generated, the controller 52 causes the motor 15 to rotate in the reverse rotation time. This reverse rotation time is determined by the cam gear 1
For example, it is set to about 16 seconds as a time in which 1 can be turned by [170 degrees + the margin angle].

The controller 52 rotates the motor 15 in the reverse direction, stops the motor 15 after the reverse rotation time has elapsed, returns the motor 15 to the origin of -1 degree, and then rotates the cam gear 11 in the normal forward direction, thereby rotating the cam gear 11. Return to ice making position.
In this operation, the stopper 23 of the cam gear 11 is securely applied to the stopper receiver 26, and the return operation is performed without the stress of the drive system by the forward rotation of the motor 15 corresponding to a short time after the mechanical positioning. Set to end.

When the ice storage operation is insufficient due to the ice detecting operation, the ice detecting lever 12 is largely displaced, and the displacement preventing portion 50 approaches the displacement preventing piece 51 of the switch operating lever 13. Therefore, at the initial stage of the rotation, the switch operating lever 13 is displaced by the displacement allowable range 31, and the original position signal as the output of the "H" level of the switch 14 changes to the "L" level.
Attempts to fall into the next allowable displacement range 32.

However, when the displacement preventing piece 51 of the switch operating lever 13 is displaced, the displacement preventing portion 50 of the ice detecting lever 12 is displaced.
, The switch operating lever 13 does not fall into the displacement allowable range 32. Therefore, when the ice storage amount is insufficient, the output of the switch 14 remains at the “L” level,
No "H" level ice detection signal is output.

Therefore, the controller 52 rotates the motor 15 and rotates the cam gear 11 to an ice-separation position of about 170 degrees until an ice-separation signal is obtained as an output signal of "H" level. As a result, the ice tray 2 is turned over, and immediately before being completely turned over, hits the contact piece 7 to be torsionally deformed, thereby releasing the ice inside and dropping it into the ice storage container.

When the cam gear 11 rotates to the ice release position,
When the switch operating lever 13 falls into the displacement allowable range 33, the signal of the switch 14 changes from the "L" level to the "H" level, and the ice release signal is obtained, the controller 52 causes the motor 15 to rotate in the reverse rotation time. The cam gear 11 is returned to the origin of -1 degree by rotating the cam gear 11 in the reverse direction (about 16 seconds), and the stopper 23 of the cam gear 11 is brought into contact with the stopper receiver 26 to stop and instantaneously rotate forward.
Turn to 0 degree ice making position to eliminate the stress on the drive system.

At the time of this reverse rotation, the diode 54
5, the current limited by the resistor 55 passes through the motor 15 in order to prevent the flow of the motor current in the reverse direction, so that the output torque of the motor 15 becomes 1 / It is kept low from about 2 to 1/4. As a result, the required return operation can be ensured with low power, and more than necessary force does not act, thereby protecting the drive system. During the reverse rotation operation, an ice detection operation is performed, and when the ice is full due to ice separation, an ice detection signal is output. The ice detection signal at this time is not related to the reverse rotation operation of the motor 15. .

Next, at the time of the ice detecting operation, when the amount of ice storage is full, the rotation amount of the ice detecting bar 3 is reduced.
In conjunction with this, the ice detecting lever 12 is within the range of the full ice detection level, and does not move the displacement prevention unit 50 to a position where it comes into contact with the displacement prevention piece 51 of the switch operating lever 13.

Accordingly, the cam gear 11 has a rotation angle of 33 degrees to 47 degrees.
The cam follower 30 of the switch operating lever 13 falls into the displacement allowable range 32 in the rotation range up to
6 is changed from a position facing the switch 14 to a position not facing the switch 14. As a result, the switch 14 outputs an "H" level ice detection signal.

Therefore, the controller 52 operates the switch 1
4 is detected from the "L" level to the "H" level, and the motor 15 is rotated in the reverse direction for the reverse rotation time (about 16 seconds).
And stop by the contact relationship with the stopper receiver 26, and then immediately rotate forward to return to the 0 degree ice making position.

At this time, the rotation angle required for the return of the cam gear 11 is about 34 degrees in the reverse rotation direction, which may be sufficiently smaller than about 171 degrees at the time of the above-described ice-removing operation. Therefore, the rotation stop state of the motor 15 continues for most of the reverse rotation time while the power to the motor 15 is kept energized. However, since the current at the time of the reverse rotation is kept low by the resistor 55, No adverse effects appear.

The movement of the ice detecting lever 12 is indirectly controlled via the slider 41 and the spring 43.
A shock absorber is added so as to be transmitted to the vehicle. In this embodiment, the shock absorber is constituted by a slider 41 and a spring 43. Therefore, even if an external force is applied to the ice detecting bar 3 and the ice detecting shaft 10 rotates in a reverse drive state, the force is absorbed by the deflection of the spring 43 accompanying the displacement of the slider 41. For this reason, it is not transmitted to the ice detecting lever 12, and thereby the destruction of the ice detecting lever 12 and transmission means such as gears related thereto can be prevented.

In the process of rotating the cam gear 11 in the normal rotation direction, even if the cam gear 11 does not stop rotating by more than 170 degrees due to an abnormality, the projection 24 of the cam gear 11 is rotated at 180 degrees.
Hits the lock lever 25 and turns it counterclockwise in FIG. 8.
As described above, the motor 15 is forcibly stopped in the state of being energized while being brought into contact with the step portion 47 of the worm 16 to be in a locked state. Therefore, the cam gear 11 does not rotate more than 180 degrees, and therefore, the ice tray 2 and the internal components related to the cam gear 11 are not destroyed by receiving a large force. Since the worm wheel 17 is rotating at high speed and has a small torque, the worm wheel 17 is forcibly stopped with a relatively small force due to the engagement between the lock lever 25 and the step 47.

Next, FIG. 11 shows another embodiment. In the embodiment of FIG. 10, the reverse rotation time of the motor is set to 16 seconds, and the time is commonly given to both the return operation after the ice removing operation and the return time after the ice detecting operation. In consideration of variations in the rotation characteristics of the DC motor 15 and fluctuations in the drive voltage, the reverse rotation time must be set large enough. If the reverse rotation time increases, the cam gear 11 returns to the original position by the reverse rotation when the rotation is reversed from the time of the ice detection, and the state where the motor 15 is not energized and the motor 15 is not rotated continues for a long time, which is not preferable.

Therefore, in the embodiment of FIG. 11, in the course of the reverse rotation of the cam gear 11, the output signal level of the switch 14 is first reversed without time limitation until it first changes from the "L" level to the "H" level. If the ice storage is full due to ice removal, when the ice detection signal is issued, or the ice storage is still insufficient, regardless of ice removal, or the ice storage is full at the time of ice detection. If there is, when the original position signal is output, the stopper 23 of the cam gear 11 is brought into contact with the stopper receiver 26 by rotating the cam gear 11 for a required time period, for example, 5 seconds from the time of occurrence, to stop the cam gear 11. It is.

In this case, since the rotation angle corresponding to the time limit of the cam gear 11 is a maximum of about 48 degrees from 47 degrees to -1 degree, the time limit reverse rotation time required is about 5 seconds even if there is a margin. Is enough. Therefore, the motor 1
While the power supply 5 is set to the energized state, the time during which the motor 5 does not rotate in the reverse direction can be shortened, and a wasteful operation of the energized state can be avoided.

Next, FIG. 12 shows that the second cam 22
This is an example in which a displacement allowable area 38 is formed in a section of degrees to 84 degrees, and an identification signal is generated by the switch 14 in this section. The controller 52 sets a timer for 3 seconds after the motor 15 starts, and determines that the ice is full when the ice detection signal is generated during the timer time. Therefore, at this time, the controller 52 rotates the motor 15 in the reverse direction,
After this, if the output of the switch 14 changes, that is, if the home position signal is output, after 1.5 seconds of the timer time, the motor 1
Stop 5. This ensures that the cam gear 11 returns to its original position.

When the ice detection signal is not generated during the three-second timer period after the start, the controller 52 determines that the ice storage amount is insufficient, and after confirming the first signal level change, that is, the identification signal, performs the second time. , The motor 15 is rotated in the reverse direction. Since the first change in the signal level after the reverse rotation is the identification signal, a timer is applied for 3 seconds from the time when the identification signal disappears, and the rising change of the output signal during this timer time is ignored. Thereby, the ice detection signal can be invalidated.

After the elapse of the timer time, the controller 52 detects the original position signal based on the first rise of the output signal, and stops the motor 15 1.5 seconds after the detection of the home position signal. As a result, as described above, the cam gear 11 is reliably returned to the original position, and the motor 15 in a state where the stopper 23 and the stopper receiver 26 are in contact with each other.
Can be suppressed to a minimum of, for example, 1 second or less.

In the above embodiment, the ice detecting lever 12 and the switch operating lever 13 are configured to be of a rotary type. However, these displacements may be linear displacements. And a linear guide mechanism. Further, the switch 14 is not limited to a Hall element or the like, and can be configured as a contact type. Therefore, the combination of the switch operating lever 13 and the switch 14 is appropriately changed depending on the type of the switch.

[0043]

According to the present invention, when a load exceeding a predetermined value is applied to the ice detecting bar between the ice detecting bar and the motor, a buffer device for buffering the load is provided. When an external force is applied, the external force is not transmitted to transmission means such as a motor and a cam gear, so that damage or breakage of the transmission means can be prevented.

In the embodiment in which the shock absorber is provided between the ice detection bar and the cam gear, the shock absorber is provided between the ice detection bar and the cam gear, in other words, where the load is large. As a result, the allowable value of the load on the shock absorber can be made large and can cope with many external forces. In general, if a buffer device is to be incorporated into the transmission means, the device becomes complicated. However, as described above, the buffer device is provided between the ice detection bar and the cam gear, so that the buffer device is installed. It will be easier.

[Brief description of the drawings]

FIG. 1 is an overall plan view of a driving device of an ice tray.

FIG. 2 is an overall side view of an ice tray driving device.

FIG. 3 is an enlarged rear view, partially broken away, of a main part of a driving device for an ice tray.

FIG. 4 is an enlarged horizontal cross-sectional view of the cam gear portion viewed from below.

FIG. 5 is an enlarged sectional view of a driving portion of the ice detecting shaft.

FIG. 6 is an enlarged front view of a first cam of the cam gear.

FIG. 7 is an enlarged horizontal sectional view of a second cam of the cam gear.

FIG. 8 is an enlarged plan view of a correspondence relationship between a switch operation lever and a lock lever corresponding to a cam gear.

FIG. 9 is a block diagram of a control system.

FIG. 10 is a time chart during operation.

FIG. 11 is a time chart during operation of another embodiment.

FIG. 12 is an enlarged plan view of a second cam according to another embodiment.

FIG. 13 is a time chart of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ice tray driving device 2 Ice tray 3 Ice detecting bar 4 Drive unit 5 Driven shaft 6 Machine frame 7 Contact piece 8 Split type case 9 Split type case 10 Ice detecting shaft 11 Cam gear 12 Ice detecting lever 13 Switch operation Lever 14 Switch 15 Motor 16 Worm 17 Worm wheel 18 Gear 19 Gear 20 Shaft 21 First cam 22 Second cam 23 Stopper 24 Projection 25 Lock lever 26 Stopper receiver 27 Stopper receiver 28 Cam follower 29 Allowable displacement area 30 Cam follower 31 Allowable displacement area 32 Allowable displacement area 33 Allowable displacement area 34 Lever shaft 35 Pull spring 36 Permanent magnet 37 Printed circuit board 38 Allowable displacement area 39 Lever shaft 40 Long hole 41 Slider 42 Slide guide 43 Spring 44 Spring receiver 45 Spring receiver 46 Mating projection 47 step portion 48 engaging piece 49 pulling spring 50 displacement prevention section 51 displacement prevention piece 52 controller 53 drive circuit 54 diode 55 resistor

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F25C 1/10 F25C 5/18

Claims (2)

(57) [Claims] 1. An ice tray provided rotatably, a drive circuit for rotating the ice tray, a motor driven by the drive circuit, and a rotation of the motor reduced to be transmitted to the ice tray. A transmission means, a cam gear provided in the transmission means, and an ice detection bar which rotates by the cam gear to perform ice detection, and an ice detection bar is provided between the ice detection bar and the motor. A driving device for an ice tray, comprising: a buffer device for buffering a load equal to or more than a predetermined value. 2. The driving device for an ice tray according to claim 1, wherein the shock absorber is provided between the ice detecting bar and the cam gear.