JPH0228378Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention relates to a motor actuator that controls a damper for opening and closing a passage through which gas passes and sends the gas into a desired room using the rotational force of a motor.

BACKGROUND ART For example, inside a refrigerator-freezer, a passage is formed for sending cold air from a cooler into a freezer compartment or a refrigerator compartment, and a damper is provided in the passage. This damper opens and closes depending on changes in temperature within the refrigerator, and functions to send cold air from the cooler into the freezer compartment or refrigerator compartment when necessary.

Incidentally, a solenoid or a stepping motor has conventionally been used as a drive source for this type of damper. Solenoid driven type,
Since current continues to flow during driving, power consumption is large and relatively loud operating noise is generated. Therefore, stepping motors have been used instead, but their use is limited because they are expensive.

Purpose of the invention Therefore, the purpose of the invention is to provide a relatively inexpensive AC
To provide a malfunction-free motor actuator that can also be used with a motor.

Summary of the invention Therefore, the present invention detects the amount of rotation of the motor using a switching means such as a cam or a switch, and accurately drives the motor by a predetermined amount of rotation based on the drive signal for driving the motor. I'm trying to make it possible.

Configuration of the invention Hereinafter, the configuration of the invention will be specifically explained based on the drawings.

First, FIG. 1 shows a controlled object, that is, a damper 2, which is controlled by a motor actuator 1 of the present invention. This damper 2 is attached to the tip of the arm 3 and is rotatably supported by a fixed shaft 4. The damper 2 corresponds to the opening surface of a cold air passage 5, which serves as a passage for sending cold air from a refrigerator (not shown) into a refrigerating room, so as to be openable and closable. Arm 3
A long hole 6 is formed in the middle of the cam 7, 8.
It fits loosely into a pin 9 formed on one of the cams.

These cams 7 and 8 are compatible with limit switch 1.
0, 11 as well as the first switch means and the second switch means.
Each of these constitutes a switch means. The first switch means is a switch for generating a stop signal to stop the drive of the motor when the damper 2 is in the open position and the closed position with respect to the cold air passage 5, respectively, and the second switch means is This is a switch that generates different signal outputs such as on or off when the damper 2 is in the open or closed position. These cams 7 and 8 are fixed to the output shaft 13 of a unidirectional rotating AC motor 12 such that the high portion 7b of the cam 7 is located approximately at the center of the high portion 8a of the cam 8. There is.

As shown in FIG. 2, one of the cams 7 constituting the first switch means is formed with two high portions 7a and 7b that protrude from the base circle on a certain diameter line.
In this part, when the corresponding limit switch 10 is hit, it is set to the OFF state.

Further, the other cam 8 constituting the second switch means, as shown in FIG. 3, integrally forms a high portion 8a which is higher than the base circle within a range of 180 degrees. When this high portion 8a hits the limit switch 11, the limit switch 11 similarly
Set to off state.

Next, FIG. 4 shows a control circuit 14 that controls opening and closing of the damper 2 by rotating the AC motor 12. The AC motor 12 and the triax 15 are connected in series to an AC power source 16. In addition, the limit switch 10
are connected in parallel to this triax 15. The control circuit 14 includes a limit switch 11 connected in series, a resistor 18, a resistor 19 connected in series, a thermistor 20,
Similarly, a variable resistor 21 and a resistor 22 connected in series are each connected in parallel. Above resistor 1
9, 22, thermistor 20 and variable resistor 21
constitutes a bridge, and the resistor 22 and the variable resistor 21 supply a reference voltage corresponding to the set temperature in the room into which cold air is sent, and the resistor 19
and thermistor 20 are connected to input voltages corresponding to the indoor temperature into which the cold air is sent into a comparator 23, that is, comparison means for comparing the indoor temperature and the set temperature. Further, the output terminal of the comparator 23 and the connection point between the limit switch 11 and the resistor 18 are respectively connected to the input terminal of an exclusive OR gate 24 as a motor drive signal generating means. The output terminal of this exclusive OR gate 24 is connected to the base of a switching transistor 25, and this transistor 25 is connected to the gate of the triac 15 and the DC power supply 17 via a resistor 26. Connected in series to the negative side.

Function of the invention Next, the function of the motor actuator 1 will be explained.

As already mentioned, the limit switch 10 is
It is in the off state when it corresponds to the high portions 7a and 7b of the cam 7, and is in the on state at other rotation angles. For this reason, the limit switch 10
are respectively at the open and closed positions of damper 2.
A stop signal is generated to stop the drive of the AC motor 12, and the AC motor 12
In other parts that do not correspond to a and 7b, they rotate in a self-holding state and do not stop in the middle, regardless of whether the triax 15 is on or off, that is, regardless of the output signal of the motor drive signal generating means. . On the other hand, the limit switch 11, which is the second switching means, generates different signal outputs when the damper 2 is in the open position or the closed position, and when the damper 2 is in the open position, the upper part of the cam 8 8a, a signal of "L" level is sent to one side of the exclusive OR gate 24,
Further, as shown in FIG. 1, the damper 2 is configured to send an "H" level signal to one side of the exclusive OR gate 24 when the damper 2 is in the closed position.

Now, the comparator 23 serves as a comparison means for detecting the indoor temperature indicating the indoor environmental condition of the refrigerator and comparing the indoor temperature and the set temperature.
This comparator 23 determines the level of temperature in the refrigerator compartment, that is, the resistance value of the thermistor 20, with respect to the voltage divided by the variable resistor 21 and the resistor 22, that is, the reference voltage value corresponding to the set temperature. When a change is detected and the indoor temperature is higher than the set temperature, the external signal A for driving the motor is set to the "L" level, and conversely, when it is lower than the set temperature, the motor drive external signal A is set to the "H" level.

Here, as shown in FIG. 1, a case will be described in which the indoor temperature becomes higher than the set temperature while the damper 2 is in the closed state.

When the damper 2 is closed and the indoor temperature becomes higher than the set temperature, as already explained, the motor drive external signal A from the comparator 23 becomes "L" level, and as shown in FIG. Since the limit switch 11 is on, the signal B from the limit switch 11 is at the "H" level. Therefore, the motor drive signal C generates an "H" level signal, the transistor 25 is turned on, and the triax 15 is also turned on, so the AC motor 12 starts rotating and the damper 2
Drive in the direction of opening.

Here, when the AC motor 12 starts rotating, the high part 7a of the cam 7 and the limit switch 10 are first separated, the limit switch 10 is turned on, and the AC motor 12 is turned on.
When the limit switch 10 is turned on, the motor 12 can obtain current directly from the AC power source 16.

From this state, the AC motor 12 further rotates,
When the cam 8 rotates approximately 90 degrees from the state shown in FIG. 1, the high portion 8a of the cam 8 presses the limit switch 11 and its contact becomes open, so that the signal B from the limit switch 11 becomes "L" level. Here, since the signal from the comparator 23, that is, the motor drive external signal A, is at the "L" level, the motor drive signal C is at the "L" level, and the triac 15
is turned off, and current no longer flows to the AC motor 12 via the triax 15. However, since the limit switch 10 is still in the on state, the AC motor is in a self-holding state and continues to rotate.

Next, the AC motor 12 further rotates, and the first
When the cam 7 is rotated approximately 180 degrees from the state shown in the figure, the high portion 7b of the cam 7 comes into contact with the limit switch 10, so the limit switch 10 is turned off and no current can be obtained from the AC power supply 16, so the AC motor 1
2 stops at this point.

In the above explanation, while the AC motor 12 is rotating, the indoor temperature becomes lower than the set temperature, and the output signal of the comparator 23, that is, the external signal A for driving the motor changes from the "L" level to the "H" level. Then, the AC motor 12 rotates 360 degrees from the initial state without stopping midway, and stops in the state shown in FIG. 1, setting the damper 2 in the closed state.

That is, when the AC motor 12 starts rotating and the high part 7a of the cam 7 and the limit switch 10 are separated, the cam 7 rotates approximately 180 degrees from the state shown in FIG. 1
Until it comes into contact with 0 and turns off, current can be obtained from the AC power source 16 via the limit switch 10, so the rotation continues without stopping midway. However, the AC motor 12 is approximately 180
When the cam 8 rotates, the high part 8a of the cam 8 pushes the limit switch 11, so that the signal B is output.
becomes the "L" level, and when the indoor temperature becomes lower than the set temperature, the comparator 23
Since the output signal of , that is, signal A changes from "L" level to "H" level, motor drive signal C
becomes "H" level, the triax 15 is turned on, and the current continues to flow to the AC motor 12, even if the high part 7b of the cam is in contact with the limit switch 10 and turned off, that is, even if a stop signal is generated. Even then, the AC motor 12 is in a self-holding state and continues to rotate. Then, until the high part 7b of the cam 7 separates from the limit switch 10 and the high part 7a of the cam 7 contacts the limit switch 10 again to generate a stop signal, the AC motor 12 continues to operate with the alternating current 16
It continues to rotate by drawing electric current from it.

Incidentally, in the above embodiment, a relatively inexpensive AC motor, for example, a unidirectional rotary AC (inductor) motor equipped with an internal reverse rotation prevention mechanism, was used as the motor. Although this motor always rotates in the same direction, this does not mean that it never rotates in opposite directions. The probability of whether this AC motor rotates forward or backward is 1/2, and if it reverses, the reversal prevention mechanism will work, and after a slight reversal, the reversal prevention mechanism will return the motor's rotation direction to the forward rotation direction. . When a switch or the like is operated by the rotation of the AC motor, if the switch is turned on or off even during this short reversal period, this can cause malfunction. In the above-mentioned embodiment, even under such conditions, it is possible to realize a predetermined function without malfunction.

That is, in this embodiment, when starting from the state shown in Fig. 1, it may begin to rotate in the opposite direction at the initial stage of startup. The limit switch 11 is activated by the cam 8 until the internal reverse rotation prevention mechanism works and the motor rotation returns to the normal rotation direction.
Since signal B from the motor is held at "H" level and motor drive signal C is held at "H" level,
It is possible to start a predetermined rotation in the forward direction without causing a malfunction that would result in a stop.

In the above embodiment, the unidirectional rotating AC
Although a motor is used as the drive source, the present invention is not limited to this, and other AC motors or DC motors may be used as the drive source.

Modified Example of the Invention Next, FIG. 5 shows an example in which the AC motor 12 is controlled only by the on/off state of the triax 15. In this embodiment, a limit switch 10 is connected in series with a resistor 18, the connection point of which is connected to one of the OR gates 28. The other input terminal of this OR gate 28 is connected to the exclusive OR gate 24, and the output side of the OR gate 28 is connected to the base of the transistor via a resistor 29.

In FIG. 5, when the limit switch 10 is in the on state, the output of the OR gate 28 is always at "H" level and can be in a self-holding state.Other operations are as shown in FIG. It will be the same as the one.

Effects of the Present Invention The present invention includes a motor, a damper for opening and closing a passage through which the gas passes to send the gas into a room, and stopping the drive of the motor at the open position and the closed position of the damper, respectively. a first switch means for generating a stop signal such as a stop signal; a second switch means for generating a different signal output when the damper is in an open position or a closed position; A comparison means for comparing the state and a set value, and an output signal of the comparison means and the second switch means are input, and the comparison means and the output signal of the second switch means are inputted. a motor drive signal generating means for generating a motor drive signal for driving the motor; an output of the motor drive signal generating means; and the first
Since the motor is configured to control the rotation of the motor using a switch, it is possible to provide a malfunction-free motor actuator without using a solenoid or stepping motor as a drive source for this type of damper. can.

[Brief explanation of the drawing]

Fig. 1 is a front view of the mechanical part of the motor actuator of the present invention, Figs. 2 and 3 are front views showing the correspondence between the cam and the limit switch, Fig. 4 is a circuit diagram of the control circuit, and Fig. FIG. 5 is a circuit diagram of a control circuit in another embodiment. 1... Motor actuator, 7, 8... Cam, 10, 11... Limit switch, 12...
AC motor, 14...control circuit, 23...comparator, 24...exclusive or gate, 28...or gate.

Claims (1)

[Claims for Utility Model Registration] A motor, a damper for sending the gas into a room by opening and closing a passage through which the gas passes, and the damper changing from a closed position to an open position or from an open position to a closed position. a first switch means for generating a stop signal for the motor when the damper is in the open position or a closed position; a second switch means for generating a different signal output when the damper is in the open position or the closed position; and a detected value of the environmental condition in the room. and a set value, and compares whether the detected value is higher or lower than the set value, the signal of the comparing means and the output signal of the second switching means are input, and the detected value is motor drive signal generating means for generating a drive signal for the motor when the detected value is higher than the set value and the damper is in the closed position, and when the detected value is lower than the set value and the damper is in the open position; A motor actuator comprising: a motor actuator configured to drive the motor by the output of the motor drive signal generating means and to stop the motor by the first switch means.