JPH051993Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention relates to a motor actuator that controls the position of a controlled object by a motor using a plurality of signals as input conditions.

BACKGROUND OF THE INVENTION For example, in a refrigerator equipped with a divided freezer compartment and refrigerator compartment, cold air cooled by a cooler is sent into the freezer compartment or the refrigerator compartment. Control of this cold air is performed by opening and closing a damper provided in a passage connecting the cooler and the freezing or refrigerating compartment, and a motor actuator is used as a driving source for opening and closing the damper. This motor actuator uses the temperature of the refrigerator compartment as an input condition to turn on and off, and also uses the open/closed state of the damper to be controlled as an input condition.

The drive source is an AC motor, and is equipped with an internal reverse rotation prevention mechanism. For this reason, AC
Even if the motor rotates in the reverse direction with a 1/2 probability when started, the rotation is instantly corrected to the normal rotation direction by the action of the reverse rotation prevention mechanism. The rotation of the AC motor generates a signal to stop the AC motor by means of a cam and a corresponding switch.

Because of this structure, when the cam rotates to push the switch, the AC motor is stopped, and then the AC motor is restarted, the AC motor instantly reverses, thereby causing the switch to stop. The on/off state may change.
In this way, when turning on and off an AC motor by switching a switch, or when detecting the position of a member such as a damper driven by an AC motor, the instantaneous reversal can cause malfunctions. Furthermore, if the AC motor stops instantaneously at the time the switch is switched, the switch will come into contact with the slope of the cam and stop in a neutral state, resulting in unstable operation. This is also a cause of malfunction.

Purpose of the invention Therefore, the purpose of the invention is to prevent malfunctions during startup of an AC motor with a reverse rotation prevention mechanism, that is, during reverse operation, and to obtain stable operating characteristics for this type of motor actuator. That's true.

SUMMARY OF THE INVENTION Therefore, in the present invention, the motor is stopped after the switch is set to a complete switching state by delaying the signal from the switch means for at least a certain period of time. Therefore, even if the motor temporarily reverses direction when the motor is restarted, the switch will not repeat unnecessary on/off operations during the time required to correct the rotation direction, and will not cause instability. It doesn't even become a state. This makes it possible to prevent an unstable state of the switch and malfunction of the control means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings.

This embodiment shows a motor actuator 1 of a refrigerator-freezer as an example.

First, FIGS. 1 and 2 show the mechanical structure of the motor actuator 1. FIG. A driven member to be controlled, that is, a damper 2 is driven by an AC motor 3 equipped with a reduction gear. That is, the damper 2 is plate-shaped,
It is rotatably supported on a frame 5 by a support shaft 4 at the lower end, and its air outlet 6 is opened and closed.

The AC motor 3 has a built-in mechanism that instantly returns to normal rotation even if the rotation is reversed at startup, and is fixed to the side surface of the frame 5, and its output shaft 3a connects the cam 7 and its eccentric pin. Rotate 8. By the way, such a so-called reversal prevention mechanism is disclosed in, for example, Utility Model Application No. 56-106046 and Utility Model Application No. 1983-106046.
This method is already known from, for example, No. 105170.

This cam 7 has a cam surface on its outer periphery that forms a high part and a low part with a center angle of 180 degrees as a boundary, and the on/off of the switch 9 is controlled by the contour of the cam surface. The cam 7 and the switch 9 constitute a switch means, and when the damper 2 is closed, the switch 9 is on, and when the damper 2 is open, the switch 9 is off. Further, the eccentric pin 8 is located inside a groove 10 formed on the side surface of the damper 2, and converts its revolution movement into a rocking movement, that is, an opening/closing movement, and transmits the same to the damper 2.

Next, FIG. 3 shows a temperature detection circuit 11 for detecting the temperature inside the refrigerator and generating an external signal A for driving the motor according to the temperature condition.

The power supply circuit 13 is connected to the AC power supply 12, and has a thermistor 14, a resistor 15,
16, and variable resistor 17, resistors 18, 19
a comparator 20 whose input is a change in the balance voltage of this bridge circuit;
Resistors 21, 22 and capacitor 23 are connected in sequence as shown. One end of the capacitor 23 and one end of the AC power supply 12 serve as power supply terminals 24 and 25, respectively, and the other end of the capacitor 23, that is, the output side of the comparator 20, serves as an output terminal 26 for the external signal A. .

Next, FIG. 4 shows the control means for the AC motor 3, that is, the control circuit 27.

The output terminal 26 is connected to one input terminal of an exclusive OR circuit 28, and also to one input terminal of a NAND circuit 30 via a NOT circuit 29, and directly to one input terminal of a NAND circuit 31. are connected to each.

On the other hand, the power supply terminal 24 is connected to ground 35 via a switch 9 and a resistor 33 connected in series, and one end of the switch 9 on the resistor 33 side is connected via a capacitor 36 and a resistor 37 to the ground 35. to ground 35, and also to capacitor 34 and resistor 32.
are connected to the power supply terminal 24, respectively. This switch 9 has on/off operation,
Generates stop signal B. And the above capacitor 3
The terminals of resistors 4 and 36 on the side of resistors 32 and 37 are respectively connected to the other input terminal of the NAND circuit 30 via a knot circuit 38, and to the other input terminal of the NAND circuit 31 via two knot circuits 39, respectively. ing. Further, the other ends of the capacitors 34 and 36 are connected to the other input end of the exclusive OR circuit 28. These NAND circuits 30, 31
The output terminals of the NAND circuits 40 and 40 are respectively connected to the input terminals of a NAND circuit 40, and the output terminal of the NAND circuit 40 is connected to the reset input terminal of a flip-flop 41 as a storage means by a NOT circuit 40a.

On the other hand, the exclusive OR circuit 28
The output terminal of is branched through a differential capacitor 42, connected to ground 35 by a resistor 43, and connected to the set input terminal of the flip-flop 41 through a not circuit 44, respectively. and,
The output terminal of this flip-flop 41 is branched through a not circuit 45 and a resistor 46, connected to the ground 35 through an integrating capacitor 47, and connected to the base of a switching transistor 50 through a not circuit 48 and a resistor 49. has been done. here,
The capacitor 47 and the resistor 46 are connected to the delay means 6
5. This delay means 65 is an important part of the present invention, and is located in the transmission path of the drive signal C, and gives a certain delay time to the transmission of the signal. The delay time of the delay means 65 is determined by the following equation: [time required for the switch 9 to rotate from one switching position to the other switching position in conjunction with the cam 7]>[delay time of the delay means 65]>[rotation of the motor 3] time required for direction correction].

This transistor 50 is connected in series with a resistor 51 between the gate of triac 52 and ground 35. This trial 52
together with the AC motor 3, the power terminal 24,
25 are connected in series.

Function of the invention Next, a series of functions of the motor actuator 1 will be explained.

The indoor temperature setting that should be used to control the temperature inside the refrigerator is
It can be set by adjusting the resistance value of the variable resistor 17, and the reference voltage corresponding to the set temperature is:
It is applied to one input terminal (+) of the comparator 20.

(1) When the indoor temperature in the room to be controlled rises above the set temperature, that is, when the temperature condition becomes the first state, the resistance value of the thermistor 14 decreases,
The voltage at the other input terminal (-) of the comparator 20 rises and becomes higher than the one input voltage, that is, the reference voltage, so the output of the comparator 20 is inverted and the external signal A at the output terminal 26 changes from the "H" level to " Changes to L” level.

At this time, if the driven member, that is, the damper 2 is closed, that is, in the first position, the switch 9 is on, so the switch 9 is turned on.
If the input signal, that is, the stop signal B, is closed at "H" level, that is, if it is in the first position,
Since the switch 9 is on, the input signal to the switch 9, that is, the stop signal B, is at the "H" level.

Therefore, exclusive OR circuit 2
Since both inputs to 8 change from the "H" level state to only one of the inputs to the "L" level, the output of the exclusive OR circuit 28 becomes "L" level.
level becomes “H” level, and the not circuit 4
An "L" level pulse is input to the set input terminal of the flip-flop 41 via the flip-flop 41. Therefore, the flip-flop 41 enters the set state, and an "H" level signal appears at its output terminal. This drive signal C is input to the not circuit 45, is given an appropriate delay time by the capacitor 47 of the delay means 65, is converted to an "H" level signal through the not circuit 48, and is applied to the base of the transistor 50. is applied to turn on transistor 50. As a result, the triax 52 becomes conductive, so the AC motor 3 starts rotating and rotates the damper 2 to the open state.

When the damper 2 is opened to a predetermined angle, the switch 9 is turned off.
Input signal from switch 9, that is, stop signal B
changes from "H" level to "L" level.
Therefore, the "H" level signal is input to the other input terminal of the NAND circuit 30 which is input via the NOT circuit 38, and the two NOT circuits 3
An "L" level signal is input to the other input terminal of the NAND circuit 31 through the input terminal 9.

On the other hand, at this time, the indoor temperature in the room to be controlled is higher than the set temperature, and the external signal A at the output terminal input 6 is at the "L" level, so one input terminal of the NAND circuit 30 is at the "H" level. A level signal is input, and an "L" level signal is input to one input terminal of the NAND circuit 31, respectively.

Therefore, since "H" level signals are input to both NAND circuits 30, their outputs are "L" level, and the NAND circuit 31 has
Since both signals are input at the "L" level, their outputs become the "H" level. As a result, the NAND circuit 40 outputs the "H" level signal, and the NAND circuit 54 outputs the "L" level signal. This signal is input to the reset input terminal of the flip-flop 41, and the flip-flop 41 enters the reset state. For this reason, the transistor 50
After an appropriate delay caused by the capacitor 47, the triax and the triax 52 are both turned off, and the AC motor 3 is stopped.

When the indoor temperature is higher than the set temperature and the damper 2 is open, the switch 9 is off and the stop signal B is at the "L" level. Therefore, the indoor temperature becomes lower than the set temperature. , until the external signal A at the output terminal 26 changes to the "H" level, the output from the exclusive OR circuit 28 remains at the "L" level, and the "L" level is applied to the set input terminal of the flip-flop 41. No pulse is input, and flip-flop 41 is not set. Therefore,
The AC motor 3 does not rotate, and the damper 2 remains in its open state.

(2) Next, when the indoor temperature in the room to be controlled falls below the set temperature, that is, when the temperature condition becomes the second state, the resistance value of the thermistor 14 increases, and the other input terminal (-) of the comparator 20 increases.
When the voltage decreases and becomes lower than one of the input voltages, that is, the reference voltage, the output of the comparator 20 is inverted, and the external signal A at the output terminal 26 changes from the "L" level to the "H" level.

At this time, if the damper 2 is open, that is, in the second position, the switch 9 is off, so the input signal to the switch 9, that is, the stop signal B, is at the "L" level.

Therefore, exclusive OR circuit 2
Since the inputs to the exclusive OR circuit 28 both change from the "L" level state to the "H" level state, the output of the exclusive OR circuit 28 becomes "H" level.
level, and an "L" level pulse is input to the set input terminal of the flip-flop 41 via the NOT circuit 44. As a result, flip-flop 41 enters the set state, turning on transistor 50. As a result, the triax 52 becomes conductive, so the AC motor 3
starts rotating, and the damper 2 is rotated to the closed state.

When damper 2 is closed, switch 9
is turned on, so the input signal from the switch 9, that is, the stop signal B, changes from the "L" level to the "H" level.
Change in level. Therefore, knot circuit 3
The "L" level signal is input to the other input terminal of the NAND circuit 30 which is input through 8, and
An "H" level signal is input to the other input terminal of the NAND circuit 31 which is input via two knot circuits 39.

On the other hand, at this time, the indoor temperature in the room to be controlled is lower than the set temperature, that is, the temperature condition is in the second state, so the external signal A at the output terminal 26 is at the "H" level, and the NAND circuit 3
An "L" level signal is input to one input terminal of the NAND circuit 31, and an "H" level signal is input to one input terminal of the NAND circuit 31.

Therefore, since "L" level signals are input to both NAND circuits 30, their outputs are "H" level, and since "H" level signals are input to both NAND circuits 31, ,
The output becomes "L" level, and as a result, an "H" level signal is output from the NAND circuit 40, and the "L" level signal is inputted to the reset input terminal of the flip-flop 41 via the NOT circuit 40a, and the transistor 50 and triax 52 are both turned off after a suitable delay by capacitor 47, and AC motor 3 is stopped.

When the indoor temperature is lower than the set temperature and the damper 2 is closed, the switch 9 is on and the stop signal B is at the "H" level. Therefore, the indoor temperature becomes higher than the set temperature. , until the external signal A at the output terminal 26 changes to the "L" level, the output from the exclusive OR circuit 28 remains at the "L" level, and the "L" level is applied to the set input terminal of the flip-flop 41. No pulse is input, and flip-flop 41 is not set. Therefore,
The AC motor 3 does not rotate, and the damper 2 remains in its closed state.

(3) Now, when the indoor temperature is lower than the set temperature, if you adjust the variable resistor 17 to lower the set temperature, the voltage at one input of the comparator 20 will gradually decrease, and the voltage from the thermistor 14 will decrease. When the voltage drops below the input voltage, comparator 2
The output of 0 changes from "H" level to "L" level. At this time, if the damper 2 is closed, the operation is the same as in the case (1) already described, so the damper 2 is in an open state. Further, if the damper 2 is open, the flip-flop 41 is not set, so the damper 2 remains open.

(4) Furthermore, when the indoor temperature is higher than the set temperature and the set temperature is increased by adjusting the variable resistor 17, the input voltage of one side of the comparator 20 gradually increases, and the voltage of the thermistor 14 increases. When the input level of the comparator 20 becomes higher than the input level on the side, the input of the comparator 20 changes from the "L" level to the "H" level.

At this time, if the damper 2 is open, the flip-flop 41 is set and the AC motor 3 is
The damper 2 is driven in the closing direction. Moreover, if the damper 2 is closed, the flip-flop 41
is not set, so damper 2 is
It remains open.

In this way, when the indoor temperature becomes higher or lower than the set value is detected by the rise or rise of the output of the comparator 20, and the on/off state of the AC motor 3 is controlled. On the other hand, the open/close position of the damper 2 is changed to an electric signal, that is, a stop signal B, by the cam 7 and the switch 9, and the output of the switch 9 indicates when the damper 2 changes from open to closed or from closed to open. The AC motor 3 is detected to stop the AC motor 3.

Other Embodiments of the Invention Next, FIG. 5 shows another embodiment of the control circuit 27. The output terminal 26 of the temperature detection circuit 11 is
It branches off via knot circuits 53 and 54, and connects directly to one input terminal of the NAND circuit 55, and also to the knot circuit 56.
is connected to one input end of the other NAND circuit 57. And this NAND circuit 55, 57
The output terminals of the flip-flop 58 are connected to the set input terminal and the reset input terminal of the flip-flop 58, respectively. Note that the output terminal of the knot circuit 54 is also connected to the input terminal of the knot circuit 53 via a resistor 59. A switch 9 and a resistor 33 are connected in series between the power supply terminal 24 and the ground 35. The output terminal of the flip-flop 58 and the connection point between the switch 9 and the resistor 33 are as follows.
Each is connected to an input end of an exclusive OR gate 60. The output terminal of this exclusive OR gate 60 is branched through a resistor 61 as a delay means 65, connected to the ground 35 by an integrating capacitor 62, and connected to the circuit through knot circuits 63 and 64. Similarly, it is connected to the base of transistor 50 by resistor 49. The output terminal of this knot circuit 63 is also connected to the other input terminals of the NAND circuits 55 and 57.

In this embodiment, the stop signal B from the switch 9 is
Corresponding to the fact that the level is only for one input signal of the exclusive or gate 60,
The input conditions of the flip-flop 58 are the output signal of the temperature detection circuit 11, the open/close state of the switch 9, and the set or reset conditions of the flip-flop 58, which are determined by the input conditions of the output of the flip-flop 58. . This control circuit 27 also provides the same functions as those described above.

Furthermore, in all of the embodiments described above, the necessary conditions are set by the logic circuit, but the function of the control circuit 27 is achieved by utilizing the control function of the microcomputer 66 as shown in FIG. This can be achieved by doing. In this case, the delay time is set programmatically within the microcomputer 66.

Further, in the above embodiment, the delay means 65 is configured by a time constant circuit, but this delay means 65
As illustrated in FIGS. 7 and 8, from the time when the output of the flip-flop 41 or the exclusive OR circuit 60, that is, the drive signal C, is input, the counter 67 controls the reference oscillation signal D1.
Alternatively, the frequency of the AC signal D2 may be counted and the drive signal C may be output when the count value corresponds to a certain delay time.

In any of the embodiments described above, the delay means 65 is provided after the flip-flops 41 and 58, but it is installed at the input side of the flip-flops 41 and 58, that is, when the external signal A and the stop signal B The stop signal B may be interposed only in the middle of the transmission path of the stop signal B, or at least at an appropriate position on the transmission path of the stop signal B.

In the above-described embodiment, the switch 9 is opened and closed in relation to the cam 7, but such a switch 9 may also be constructed of an optical switch or other proximity switch.

The control object of the present invention is not limited to refrigerators, but can also be used to control the damper of a car cooler, for example, and the external signal A, which is a driving premise, is not limited to temperature, but can also be used to detect, for example, the amount of frost. It can also be used for

Effects of the invention In the present invention, a delay means is provided in the control means, and at least the stop signal is
Since there is a delay of a certain delay time from the off point, the motor will stop for the first time after the above delay time has elapsed after the switch means is turned on or off, so when the motor starts after that, even if it is reversed,
As a result, the on/off state of the switch does not change, and malfunctions can therefore be prevented. In addition, since the motor continues to rotate for a certain delay time after the switch turns on or off, the switch is reliably turned on or off, eliminating the unstable stop of the switch in its neutral state. The operation becomes stable.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the mechanical part of the motor actuator of the present invention, Figure 2 is a side view showing the relationship between the driven member and the cam, Figure 3 is a circuit diagram of the temperature detection circuit, and Figure 4. is a circuit diagram of the control circuit, and FIGS. 5 to 8 are circuit diagrams of other control circuits. 1... Motor actuator, 2... Damper as a driven member, 3... AC motor, 7...
Cam, 9...Switch, 11...Temperature detection circuit,
14... Thermistor, 17... Variable resistor, 20
... Comparator, 27 ... Control circuit, 28 ...
Exclusive OR circuit, 41...Flip-flop, 50...Switching transistor, 52...Triack, 65...Delay means, 47, 62...Capacitor, 66...Microcomputer, 67...Counter.

Claims (1)

[Claims for Utility Model Registration] A motor 3 that operates a driven member and has a reverse rotation prevention mechanism, which corrects the rotation direction in the forward direction when the reverse rotation is started; a cam 7 having a cam surface formed with a lower portion and a lower portion; and a cam 7 that slides on the cam surface and transitions between the higher portion and the lower portion in accordance with different operating positions of the driven member. a switch 9 that generates a stop signal at the switch 9; and a control means 2 that outputs a drive signal for controlling the rotation of the motor 3 based on input of an external signal for driving the motor and the stop signal from the switch 9.
7, 66, 67, a delay means 65 is provided in the transmission path of the drive signal of the control means 27, 66, 67, and this delay means 65
[Time required for rotation of switch 9 from one switching position to the other switching position on cam 7]>[Delay time of delay means 65]>
A motor actuator 1 characterized in that the time required to correct the rotational direction of the motor 3 is set.