JPH0578749B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a motor starting control device that controls the operation of a controlled member in a refrigerator.

[Summary of the Invention] The motor start control device of the present invention reliably starts the motor even if the environment in which the motor is used is at a very low temperature by restarting the motor after heating it for a certain period of time when the motor does not start. It is designed to start.

[Prior Art] For example, in a refrigerator equipped with a divided freezer compartment and a refrigerator compartment, cold air from a cooler is transferred to the freezing or refrigerator compartment by opening and closing a damper provided in a passage using the rotational force of a motor. This type of cold air control was developed, for example, in the 1980s.
This is shown in Publication No. 23673. In such refrigerators, when the temperature inside the refrigerator reaches a predetermined level or higher, the motor is started and the damper is opened to send in cold air.When the temperature inside the refrigerator reaches a predetermined level or lower, the motor is started and the damper is closed to release the cold air. It is configured not to send . Therefore, the motor is controlled to open and close the damper after reaching a certain temperature, and works to keep the temperature inside the refrigerator room constant.

However, in such a refrigerator, the temperature of the cold air from the cooler is very low, so there is a risk that the motor will be cooled by the cold air and the motor will not start even if the motor starting switch is turned on. To prevent this, a method has been adopted in which a heater is installed near the motor and the area around the motor is constantly warmed to start the motor.

[Problems to be Solved by the Invention] However, such a method of starting a motor creates a contradiction in that the motor, which is originally used to control the opening and closing of a damper and send cold air into the refrigerator compartment, is heated by a heater. There are problems in that it is necessary to prepare a new heater and power consumption increases.

The present invention has been made in response to such problems, and an object of the present invention is to provide a motor start control device that can reliably start the motor without preparing a heater.

[Means for Solving the Problems] In order to achieve the above object, the heater activation control device of the present invention includes a controlled member for controlling cold air sent into a refrigerator compartment, and a controlled member for controlling the operation of the controlled member. temperature detecting means for detecting the temperature of the refrigerator compartment; state change detecting means for detecting a change in state of the controlled member; switch means for applying starting power to the motor; motor start control means for controlling the switch means in response to a temperature detection signal from the detection means and a state change detection signal from the state change detection means;
The start control means energizes the motor for a set operation time to detect a change in the state of the controlled member, and when no change in state is detected during the set operation, the start control means energizes the motor for a set heating time. The gist is that it has the ability to extend.

[Operation] When a change in the state of a controlled member such as a damper is not detected for a predetermined period of time, power to the motor is stopped. Next, the motor is energized for a certain period of time to heat it. This allows the motor to be restarted.

[Embodiment] Fig. 1 shows an embodiment of the motor starting control device of the present invention, in which 1, 9, and 11 are resistors, 2 is a thermistor, 3 is a variable resistor, 4 is an A/D converter, and 5 is a cam, 6 is a photocoupler, 8 is an MPU (arithmetic element),
10 is a reed switch, 19 is an AC motor, 20
2 is a power source for starting the motor, and 22 is a bias power source.

In the above configuration, the thermistor 2 is installed in the refrigerating compartment of the refrigerator to detect the room temperature, and outputs a detected voltage _Vt corresponding to the temperature to the A/D converter 4.
Add to. Further, an arbitrarily set voltage of the variable resistor 3 is applied to the A/D converter 4 as a reference voltage Vs. The A/D converter 4 converts the applied detection voltage V _t and reference voltage V _s into digital signals and sends them to the MPU 8.
Output to. The MPU 8 preliminarily generates two types of voltages based on a reference voltage V _s , namely, a voltage V ₁ corresponding to a high temperature T ₁ and a voltage V ₂ corresponding to a low temperature T ₂ .
is set, the detection voltage V _t applied via the A/D converter 4 is compared with the above V ₁ and V ₂ , and the terminal
According to the voltage applied to Tx by reed switch 10, a control voltage is output from terminal _TY to control photocoupler 6. The reed switch 10 is configured to be turned on and off depending on whether a damper (not shown) is open or closed, and is turned on when the damper is open and turned off when the damper is closed. The reed switch 10 is controlled by a motor 19 via the cam 5, and is configured to be turned on and off once by one rotation of the cam 5. When the reed switch 10 is turned on, an L level signal (earth voltage) is applied to the terminal Tx of the MPU 8, and when it is turned off, an H level signal (bias potential) is applied to the terminal Tx.
When an L level signal is applied to the terminal Tx when the reed switch 10 is off, the MPU 8 controls the terminal _TY to be at the L level and turns on the photocoupler 6. The MPU 8 also has two types of functions: an operation timer and a heating timer. The operation timer is used to check whether the motor 19 has started within a predetermined time, and the heating timer is used to determine whether the motor 19 is heated. This is for setting.
When photocoupler 6 is turned on by the L level signal output from terminal _TY of MPU8, motor 1
A power source 20 for starting the motor is added to 9.

Next, the operation of this embodiment will be explained.

FIG. 2 is a flowchart showing the flow of the operation of the motor starting method according to the present embodiment, and FIG. 3 is a time chart showing signal waveforms in the flow. The following description will be made with reference to these drawings.

The necessary operation program is stored in the MPU8 in advance, and the second program can be started by turning on the refrigerator.
The MPU 8 starts the control operation so that the flowchart shown in the figure starts from block A.

First, when a detection voltage V _t is applied by the thermistor 2 to detect the temperature in the refrigerator compartment, the MPU 8 performs a comparison operation with the higher voltage V ₁ (that is, the higher temperature T ₁ ) of the two set voltages V ₁ and V ₂ . (Block B). As a result, if V _t >V ₁ (indoor temperature is above the specified temperature), the flow proceeds to block C, where it is determined whether the reed switch 10 is off (the damper is closed). If V _t <V ₁ , there is no need for cooling and the flow jumps to Block I, which will be described later. If the reed switch 10 is not turned off in block C, in this case the damper is open and cold air is being fed, so the process similarly moves to block I.

If the reed switch 10 is off in block C, the damper is not open in this state as shown in FIG. 3, so the process goes to block D and the motor 19 is turned on. This is the MPU8 terminal Tx
is detected by applying an L level signal to the terminal
This is because the motor starting power source 20 is applied to the motor 19 as a result of setting T _Y to the L level and turning on the photocoupler 6. Next, an operation timer is started in block E, and it is determined whether the reed switch 10 remains off (block F). If it is not off, that is, if the switch 10 is turned on, it means that the damper is released, so block G
to stop the motor rotation. If off, flow jumps to block Q, where a determination is made as to whether the operational timer has expired to detect if switch 10 is turned on within a predetermined period of time. In the case of termination, it means that the damper has not been opened even after the predetermined time has elapsed, and the heating timer is then started (block R). If the operating timer has not expired, the flow returns to block F to detect whether the damper is in the process of opening.

Next, after block R, it is determined in block S whether or not the reed switch 10 is off, and if it is still off, the process proceeds to block T, where it is determined whether the heating timer has ended. If it is not off, it means that the damper has been opened, so after the heating timer is turned off in block P, the flow proceeds to block G and the motor is turned off. If the heating timer has ended in block T, the motor 19 is turned off (block U). If not, the flow returns to block S again. After the motor is turned off, a delay operation is performed in block V, and the flow returns to block D again.

After block G, the operation timer is turned off (block H).

With the above, the comparison operation between V _t and V ₁ is completed,
When V _t >V ₁ , that is, the detected temperature is higher than the high temperature set temperature T ₁ , an operation is performed to start the operation timer and lower the detected temperature.

Next, a comparison operation between V _t and V ₂ is performed in the same manner (block I). If V _t <V ₂ , the flow proceeds to block J, where it is determined whether the reed switch 10 is on or not, and whether the damper is open or closed is detected. If V _t >V ₂ , the flow returns to block A. The same is true even when the reed switch 10 is not on, since the damper is closed. If it is on, the motor 19 is turned on (block K), and then an operation timer is started to see if the switch is turned off within a predetermined time (block L). It is determined in block M whether the reed switch 10 remains on, and if it is not on, that is, if it is off, the motor 1
9 is performed (block N). If it remains on, the process advances to block a within large block W, where it is determined whether the operation timer has expired or not.

If so, the heating timer is started (block b). If the operation timer has not expired, the process returns to block M again. Next, in block c, it is determined whether the reed switch 10 remains on. If it is on, it is determined in block e whether or not the heating timer has ended. If it is not on, that is, if it is detected that it is off and the damper is closed, block d is activated.
After the heating timer is turned off, the process returns to block N again. If the heating timer has ended in block e, the motor 19 is turned off (block f), then a delay operation is performed (block g), and then the process returns to block K.

If the heating timer has not ended, the process returns to block C again.

When the motor 19 is turned off in block N, the operation timer is turned off in block O, and then the flow returns to block B again.

As described above, a comparison operation between V _t and V ₂ is performed,
If V _t <V ₂ , that is, the detected temperature is below the low temperature set temperature T ₂ , an operation such as starting a heating timer to heat the motor 19 is performed. That is, if the motor 19 does not start within a predetermined time set by the operation timer, a heating timer is started, the energization time of the motor is extended by this time, and the motor is heated.

The time chart in FIG. 3 shows changes in signal waveforms corresponding to the flow chart in FIG.
At τ ₁ , a comparison is made between V _t and V ₁ , and by starting the motor 19 until τ ₂ , the damper is gradually opened via the cam 5 . Similarly, at τ ₃ , a comparison is made between V _t and V ₂ .
In this case, if the motor 19 does not start even if the motor starting power source 20 is applied by the operation timer until τ ₄ , the motor 19 is turned off by the motor starting power source 20 by the heating timer from τ ₄ to τ ₅ . Then, the motor 19 is heated, and thereafter, the application of the power source 20 for starting the motor is stopped until τ ₆ , and then the motor 19 is restarted. As a result, even if the outside temperature is below a certain temperature, the motor 19 is heated above the certain temperature and can be started. When the motor 19 starts, the damper is gradually closed. When the motor 19 does not start, the same operation is repeated again. When the motor 19 is started, the motor 19 is stopped at a predetermined position after confirming whether the reed switch 10 is on or off.

According to the embodiment of the present invention, when the motor 19 does not start, the heating power is applied to the motor 19.
Since the device 9 is restarted after a certain period of time after it has been heated, it can be reliably started even when the outside temperature is low. Furthermore, no heater is required, and the power source for starting the motor can be used as is for heating, so there is no need for a special power source, and there is no need to use an expensive motor.

Although each component in the embodiment has been described as being limited, the following various modifications are possible.

1. The motor 19 is a DC motor, a step motor, etc., and is combined with a DC power source.

2 Even if the heating timer is activated several times, the motor 19
If it does not start, the power supply is stopped and a failure display indicating that it does not start is displayed.

3 If you set the heating timer for a long time and the reed switch 10 does not turn over within this time,
The power is stopped and a failure is displayed.

[Effects of the Invention] As described above, according to the present invention, when the motor does not start, the motor is heated for a certain period of time and then restarted, so the outside temperature can drop to a certain level without using a heater. The motor can be reliably started even if the motor rotates.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a motor starting control device used to carry out the present invention, FIG. 2 is a flow chart explaining the operation of the present invention, and FIG. 3 is a time chart explaining the operation of the present invention. 2...Thermistor, 4...A/D converter, 5...
...Cam, 6...Photocoupler, 8...MPU (arithmetic element), 10...Reed switch, 19...Motor, 20...Motor starting power supply.

Claims (1)

[Scope of Claims] 1. A controlled member for controlling cold air sent into the refrigerator compartment, a motor for controlling the operation of the controlled member, a temperature detection means for detecting the temperature of the refrigerator compartment, and a controlled member for controlling the cold air sent into the refrigerator compartment. a state change detection means for detecting a state change of the control member; a switch means for applying starting power to the motor; a temperature detection signal from the temperature detection means; and a state change detection signal from the state change detection means. a motor starting control means for controlling the switching means in response to the setting operation, the starting control means energizing the motor for a set operation time to detect a change in the state of the controlled member; 1. A motor starting control device having a function of extending the energization time to the motor for a set heating time when a state change is not detected. 2. The activation control means further energizes the motor for a set heating time to detect a change in state of the controlled member, and when no change in state is detected within the set heating time, stops energizing the motor. 2. The motor starting control device according to claim 1, further comprising a function of re-energizing the motor after a certain period of time.