JPH08219618A - Electric refrigerator - Google Patents

Abstract

PURPOSE: To perform a time control of a high accuracy in response to the characteristics of a DC motor and its variation. CONSTITUTION: The rotating force of a DC motor 1 is converted into an opening/closing force of a damper plate 3 by a worm 5 and helical gear 6. Then, detecting means such as micro-switches 8, 9, etc., to detect a totally closed state and totally open state of a damper part 3 are provided, and a total opening driving period of time from a totally closed state to totally open state by normally rotating the DC motor, and a total closing driving period of time from the totally open state to totally closed state by reversing the DC motor are measured, and a unit opening period of time to open a unit opening angle, and a unit closing period of time to close the angle are obtained, and based on them, the opening angle of the damper part 3 is time- controlled. By periodically measuring the total opening driving period of time, and total closing driving period of time, the unit opening period of time and unit closing period of time are obtained, and the accuracy of the time control is increased by renewing and storing, and when a specified value is exceeded, it is informed as a failure of the damper in advance. For the helical gear 6, one part of the gear lacks to form a slip mechanism, and the helical gear 6 slips under the totally open state and totally closed state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of an opening angle of a damper at an opening of a cold air circulation path in an electric refrigerator.

[0002]

2. Description of the Related Art Conventionally, in a fan-type electric refrigerator, the temperature inside the refrigerator is controlled by controlling the number of rotations of a fan motor and the opening / closing of a damper according to the temperature inside the refrigerator to adjust the ventilation amount of cool air. are doing. Some dampers at the opening of the cold air circulation path are driven by a solenoid, and are generally driven by an AC motor.
As described in Japanese Patent Publication No. 073, a DC motor is used as a motor for driving a damper, and a worm transmission device is used as an opening / closing mechanism, which is proportional to a difference between a temperature of a refrigerating room detected by a temperature sensor and a set temperature. For example, there is one that controls the room temperature with high accuracy by rotating the DC motor only for the time and changing the opening angle of the damper plate.

[0003]

However, when it is attempted to control the opening angle of the damper by the drive time of the DC motor, the rotation characteristics of the DC motor vary, and even if the same voltage is applied, the rotation will be reversed from the normal rotation. There is a difference in the number of rotations with respect to the rotation, and these rotation characteristics change over time, which makes it difficult to perform precise time control.

Furthermore, when the damper plate is driven to the fully closed position, the damper hits the opening of the cold air circulation path and the damper is locked, and the DC motor and other parts are overloaded and malfunctions occur. I couldn't.

An object of the present invention is to solve these problems and to perform accurate time control of a damper by a DC motor.

[0006]

In the electric refrigerator of the present invention, the control circuit detects the room temperature of the refrigerating room to determine the opening angle of the damper for adjusting the ventilation of the cool air, and the time direct current motor corresponding to the opening angle. When controlling the opening and closing of the damper by driving the damper, the damper plate is driven to measure the fully open drive time from fully closed to fully open and the fully closed drive time from fully open to fully closed, and measure the specific unit angle. A detection unit such as a microswitch that detects the fully open state and the fully closed state to obtain the corresponding unit open time and unit close time is provided.The fully open drive time and the fully closed drive time are periodically set. The unit opening time and the unit closing time thus obtained are updated to improve the accuracy of time control and compared with their initial values to detect and notify an abnormality of the damper.

Further, by providing a sliding mechanism formed by cutting a part of gear teeth in a transmission portion composed of a worm and a helical gear for converting the rotational force of the DC motor into the opening / closing force of the damper plate, a fully open state is provided. Alternatively, even if the damper plate is locked when fully closed, the direct current motor can rotate freely by the action of the sliding mechanism.

[0008]

First, when the control circuit rotates the DC motor in the forward direction to open the damper plate, the micro switch detects the full open state and generates a full open signal.
When the forward rotation is further continued, the slip mechanism of the transmission portion operates to idle the DC motor and stop the DC motor after a predetermined time.

Next, when the DC motor is rotated in the reverse direction, the damper plate is immediately closed, and after a specific time, the fully open signal is cut off and the damper plate is still closed. When the fully closed state is reached, the micro switch detects it and fully closes it. Generate a signal. When the reverse rotation is further continued, the slip mechanism of the transmission portion operates similarly, the DC motor idles, and the DC motor is stopped after a predetermined time.
When the control circuit measures the time when the fully open signal is interrupted and the time when the fully closed signal is generated and calculates the difference, the fully closed drive time required from the fully open state of the damper plate to the fully closed state due to the reverse rotation of the DC motor is calculated. I want it.

Similarly, the fully open drive time from the fully closed state to the fully open state of the damper plate by normally rotating the DC motor is obtained. The fully closed drive time by the reverse rotation and the fully open drive time by the forward rotation are different from each other, Based on them, the unit closing time and unit opening time for the specific unit angle when opening and closing the damper plate are obtained respectively, and the opening angle of the damper according to the difference between the room temperature and the set temperature of the refrigerating room is determined by the DC motor. Depending on the driving time, it rotates in the reverse direction or in the forward direction, and the time is controlled for adjustment.

Since the fully closed drive time and the fully open drive time change over time, they are periodically measured and updated as new values, and when any one of them changes significantly, it is detected as a damper failure. Notify me.

[0012]

The present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the outline of the damper of the present invention. The rotational force of the DC motor 1 is converted into an opening / closing force by the transmission section 2, and the opening angle of the damper plate 3 is changed according to the room temperature of the refrigerating compartment. As a result, the air resistance of the opening 4 of the cold air circulation path is changed to control the inflow amount of cold air. The transmission portion 2 is composed of a worm 5 attached to the rotating shaft of the DC motor 1 and a helical gear 6 attached to a damper plate 3 meshing with the worm 5 and partially lacking teeth. The damper plate 3 corresponds to the opening 4. A totally closed cushioning material 7 made of a sponge-like elastic body having a thickness of about 3 mm is attached. And the damper plate 3
Is provided with a fully closed micro switch 8 for detecting the fully closed state and a fully open micro switch 9 for detecting the fully opened state. Further, a position of the damper plate 3 corresponding to the fully open micro switch 9 is about 3 mm. The full-open cushioning material 10 made of a sponge-like elastic body having a thickness of 1 is attached.

The DC motor 1 is driven by rotating it forward or backward, or by detecting the room temperature of the refrigerator and determining the opening angle of the damper plate 3 accordingly, the DC motor 1 is driven only for the time corresponding to the opening angle. A control circuit (not shown) for controlling the time by means of a circuit similar to that shown in FIG. 4 of JP-A-4-177073.

FIG. 2 is a cross-sectional view when the damper is fully open. When the DC motor 1 rotates forward from the intermediate opening angle, the rotational force of the worm 5 is transmitted to the helical gear 6 to open the damper plate 3. Then, in the fully open state, the fully open microswitch 9 detects it and generates a fully open signal. When the normal rotation is further continued, the helical gear 6 rotates to a position where the teeth are missing and the worm 5 no longer meshes with the worm 5 to rotate idly, so that the sliding mechanism operates. The DC motor 1 is stopped after a predetermined time has elapsed from the generation of the fully open signal. The predetermined time for actuating the sliding mechanism at the time of full opening is set to 400 msec.

At this time, the damper plate 3 is the fully opened cushioning material 10.
Since the first tooth of the helical gear 6 is pressed against the worm 5 because it is urged in the closing direction by the elastic force of, the helical gear 6 immediately rotates when the DC motor 1 reversely rotates and the damper plate 3 rotates. Start closing. Next, when the fully-open microswitch 9 is restored and the fully-open signal is cut off, the time at this time is measured and stored by the control circuit, and the closing is further continued.

FIG. 3 is a sectional view when the damper is in the fully closed state. If the DC motor 1 continues to rotate in the reverse direction and continues to close, the fully closed micro switch 8 detects it and generates a fully closed signal, so measure the time at this time with the control circuit. Remember. When the reverse rotation is further continued, the helical gear 6 is rotated to a position where the tooth opposite to that when the helical gear 6 is fully opened is missing, and the worm 5 is no longer engaged with the worm 5 and idles, so that the sliding mechanism operates. The DC motor 1 is stopped a predetermined time after the fully closed signal is generated.
The predetermined time during which the sliding mechanism operates when fully closed is set to 400 msec as in the fully opened state.

Here, if the difference between the time at which the fully closed signal is generated and the time at which the fully opened signal is interrupted is taken, the closing time, that is, the fully closed driving time due to the reverse rotation of the DC motor 1 is obtained. For example, in the case of the damper of the present invention, It was about 3.8 seconds.

Similarly, if the DC motor 1 is rotated in the forward direction from the fully closed state to the fully opened state, the fully open drive time by the forward rotation is obtained, which is 3.2 sec, which is different from the fully closed drive time by the reverse rotation. And a driving time difference due to reverse rotation occurs.

Further, if the DC motor is changed, even if the type is the same, the fully closed drive time by reverse rotation is 3.5 s.
ec, and full-open drive time due to forward rotation is 3.1 sec.
Therefore, there is a large variation in driving time due to the DC motor.

Therefore, in the present invention, as shown in the flowchart of FIG. 4, when the opening angle of the damper plate 3 is replaced with the drive time of the DC motor 1 to perform time control, the full open drive time required from the fully closed state to the fully open state is measured. (Step S
1) The unit opening time for opening the unit angle is calculated by dividing the maximum opening angle of the damper plate 3 by the value obtained by dividing the maximum opening angle by the subdivided unit angle for precisely controlling the room temperature. . For example, fully open drive time is 3.2se
When the maximum opening angle of the damper plate 3 is 30 ° in c and the unit angle for room temperature control is 3 °, the unit opening time for opening the unit angle is 320 msec (step S2). Data of the unit opening time is stored in the memory of the control circuit (step S3). Similarly, the fully closed drive time is measured (step S4), and the unit closing time for closing the unit angle is calculated (step S5).
Store in memory (step S6). In order to control the opening angle, when the damper plate 3 goes into a fully open state or a fully closed state, the time is controlled in consideration of the time for which the slip mechanism is operated.

Since the rotation characteristics of the DC motor have individual variations and deteriorate with the lapse of time, if the opening angle is controlled with a constant unit opening time or unit closing time over a long period of time, the accuracy of control will be improved. Is getting worse. Therefore, the present invention measures and stores the first fully open drive time and the fully closed drive time at regular intervals of every one or two months counted by the control circuit of the refrigerator after the measurement and storage, according to the flowchart of FIG. To update and store the data. At this time, especially when the fully open drive time or the fully closed drive time greatly changes and exceeds a predetermined time, the control circuit determines that the damper has failed and blinks the LED lamp or sounds the piezoelectric buzzer for warning. Notify me.

[0023]

According to the present invention, as described in claim 1, the full open drive time and the full close drive time of the damper are respectively measured, and the unit open time and the unit close time are calculated based on the measured values. The opening angle of the damper can be accurately time-controlled even if there is a difference in driving time due to forward rotation and reverse rotation of the DC motor when opening and closing the same opening angle.

Further, as described in claim 2, the fully open drive time and the fully closed drive time are periodically measured to obtain the unit opening time and the unit closing time, which are updated and stored. The opening angle of the damper can be accurately controlled over time even if there are variations in the motor rotation characteristics and changes over time.

Further, as described in claim 3, the fully open drive time and the fully closed drive time of the damper are periodically measured, and if they greatly differ from the initial value, it is judged as a failure and the alarm is issued. It is possible to know the deterioration of the engine at an early stage and prevent the damper failure. Further, according to the present invention, as described in claim 4, since the sliding mechanism by the helical gear having a part of the teeth is removed from the worm, which acts when the damper is fully opened or fully closed, the DC mechanism is simple. The damper can be opened and closed by reversing from the fully open state or the fully closed state without imposing a load on the motor.

[Brief description of drawings]

FIG. 1 is a sectional view showing an outline of a damper of the present invention.

FIG. 2 is a sectional view of the damper of the present invention when it is fully opened.

FIG. 3 is a cross-sectional view of the damper of the present invention when fully closed.

FIG. 4 is a flowchart for obtaining a unit opening time and a unit closing time of the damper of the present invention.

[Explanation of symbols]

 1 DC motor 3 Damper plate 5 Worm 6 Helical gear 7 Fully closed cushioning material 8 Fully closed micro switch 9 Fully opened micro switch 10 Fully opened cushioning material

Claims (4)

[Claims] 1. An electric refrigerator in which a damper in a cold air circulation path is driven by a DC motor to control the room temperature by adjusting an opening angle, and a detection unit such as a micro switch for detecting a fully open state and a fully closed state of the damper is provided. Provided, the forward rotation of the direct-current motor to measure the fully open drive time from the fully closed state to the fully open state of the damper and the reverse rotation to the fully closed drive time from the fully open state to the fully closed state, the fully open drive time and the Based on the fully closed drive time, the unit opening time by the forward rotation and the unit closing time by the reverse rotation of the DC motor for opening the damper only by the unit angle are obtained, and the unit opening time or the unit closing time is used as the basis. An electric refrigerator characterized in that the opening angle of the damper is controlled by controlling the time. 2. The electric refrigerator according to claim 1, wherein the fully-open drive time and the fully-close drive time are regularly measured, and the unit opening time and the unit closing time obtained from the measurement result are updated. An electric refrigerator characterized by being stored in memory. 3. The electric refrigerator according to claim 1, wherein the fully-open drive time and the fully-close drive time are periodically measured, and when either of them is significantly different from an initial value, a notification of a damper failure is given. An electric refrigerator characterized by: 4. An electric refrigerator for controlling a room temperature by driving a damper of a cold air circulation path by a DC motor to adjust an opening angle, and a worm and a tooth for converting a rotational force of the DC motor into an opening / closing force of the damper. A transmission part consisting of a helical gear lacking a part of is provided, and when the damper is fully open or fully closed, the helical gear is arranged so that the meshing of the worm is the part where the teeth are missing, and the fully open or fully open state. An electric refrigerator characterized in that a transmission mechanism is provided with a sliding mechanism in which the worm idles so that the damper does not open and close even when the DC motor continues to rotate forward or backward in the closed state.