JPH0361099B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a control device for an individual air conditioner that introduces outside air.

Conventional Technology Conventionally, an individual air conditioner that introduces outside air and is installed in a perimeter zone such as a building has a damper installed in the outside air intake path constructed inside the main body, and the damper is opened during heating and cooling operation. outside air was introduced into the engine, and the damper was closed when the engine was stopped.

The control circuit for this damper will be explained with reference to FIG. The compressor 4, indoor blower 5, outdoor blower 6, and four-way valve 8 are each connected to a power source 1 via an operating switch 2. Note that 13 is a lead wire for energizing, and a heating/cooling changeover switch is inserted into the energizing circuit of the four-way valve 8. Further, a first limit switch 10, a second limit switch 11, and a damper motor 12 are connected in series to the power source 1. Note that 9 and 13 are lead wires for power supply.
The lead wire 3 connected to one terminal C of the operation switch is connected between the mutually connected terminals E and G of the first limit switch 10 and the second limit switch 11, and is led out from the other terminal B of the operation switch 2. The lead wire 14 is connected between the terminals F and H of the first limit switch 10 and the second limit switch 11, which are connected to each other.

The conventional air conditioner control device is configured in this manner, and when the operation switch 2 is set between A and C, the compressor 4, indoor blower 5, and outdoor blower 6 are connected via the lead wire 3 to OFF during cooling. , ON during heating
An energizing circuit for the four-way valve 8, lead wire 15, and power source 1, which is turned ON during heating, is formed and operated via the cooling/heating changeover switch 7. Then, in order to open the damper (not shown) provided in the outside air introduction flow path and introduce outside air during heating and cooling, the operating switch 2 is connected between A and C as described above, and the lead wire 3 Electricity is applied between the first limit switch 10 and the second limit switch 11, and then electricity is applied between I and G of the second limit switch 11 to energize the damper motor 12, which rotates the damper and opens it to introduce outside air. Ta.

Problems to be Solved by the Invention Incidentally, in the above control operation, the damper motor 12 is always energized during both cooling and heating operations, so that the damper is always open and outside air is introduced into the room. For this reason, especially during the heating operation season, when the difference between the outside air temperature and the indoor temperature is large, the indoor heating effect is impaired due to the cold air introduced by the outside air, which increases the indoor load due to the introduction of the outside air cold air, and the outside air temperature becomes low. I see that there was a problem in that it was severely damaged.

The present invention solves these problems,
An object of the present invention is to obtain a control circuit for an air conditioner that does not cause a significant decrease in heating effect.

Means for Solving the Problem In order to solve this problem, the present invention provides a single-pole, double-throw type relay switch that opens and closes according to changes in pressure on the low pressure side of the refrigeration cycle of an air conditioner, and a damper. A single-pole, double-throw type first limit switch that is switched by the required rotation of the motor; and a single-pole, double-throw type second limit switch that is connected in series with the damper motor and is switched by the required rotation of the damper motor. , the relay switch and the first limit switch are connected to a power source and a second limit switch, respectively.
When the pressure on the low pressure side of the refrigeration cycle decreases during heating operation of the air conditioner, the relay switch is switched to rotate the damper motor as required and close the damper, and then the first and second limit switches are connected. This is a control device for an air conditioner in which the damper motor is switched off, and when the relay switch returns, the damper motor is driven via the first limit switch.

Function With this circuit configuration, during normal heating operation, the damper motor is energized from the second limit switch through the contacts of this relay switch to open the damper, and when the outside air temperature falls and the low pressure drops to a certain pressure. The pressure switch is turned off,
The introduction of outside air is stopped by energizing the damper motor from the contact point of the relay switch via the second limit switch to rotate and close the damper.

Embodiment An embodiment of the present invention will be described based on FIGS. 1 to 3. Figure 2 shows the configuration and air flow of an individual air conditioner. In FIG. 2, a main body 20 is provided with an outdoor heat exchanger 21, an outdoor blower 22, an indoor heat exchanger 23, and an indoor blower 24, and a total heat exchange unit 2 is provided in the center.
5 and a total heat exchanger 26. The air flow is composed of an outdoor flow path A shown as a flow path and an indoor circulation flow path B that circulates indoors, an exhaust flow path 27 that exhausts indoor air, and an outside air introduction flow path 28 that introduces outside air. and the outside air introduction channel 28
A damper motor 29 and a damper 30 are provided in the middle of the total heat exchange unit 25 to open or close the introduction of outside air. FIG. 3 shows a refrigeration cycle, in which refrigerant compressed by a compressor 31 passes through a four-way valve 32 and flows to an outdoor heat exchanger 21 during cooling, is depressurized by a pressure reducing mechanism 33, and evaporates in the outdoor heat exchanger 23. The four-way valve 32 returns to the compressor 31 via the low pressure pipe 34. This low pressure pipe 34 is provided with a pressure switch 36 which is opened and closed by low pressure via a pressure detection pipe 35.

FIG. 1 shows the control circuit of this air conditioner. As shown in the figure, an energizing circuit including a power source 40, an operating switch 41, a lead wire 42, a pressure switch 36, a relay 43, a lead wire 44, and the power source 40 is formed.
A compressor 31, an outdoor blower 22, and an indoor blower 23 are connected to the lead wires 42 and 44 forming the power supply line, respectively, and a four-way valve 32 is connected via a cooling/heating switch 45 that is turned on during heating. ing. On the other hand, from the power supply 40 to the lead wire 4
6 to the single-pole double-throw contact 43a of the relay 43
, connect to this contact 43a, and connect this contact 4
3a, the lead wire 47 and the lead wire 48 are connected to the first limit switch 49 and the second limit switch 50.
is connected between. The first limit switch 49 and the second limit switch 50 are connected in series and connected to a damper motor 29, the other end of which is connected to a power source 40 via a lead wire 51.

In the above configuration, the control circuit shown in FIG. 1 shows when the operation of the air conditioner is stopped, and when the operation switch 41 is turned on to start heating operation, the compressor 31, outdoor blower 22, indoor blower 23, Valve 32 (cooling/heating selector switch 45 is ON)
energized and normal heating operation is performed. Here, the pressure switch 36 is turned on because the pressure in the low pressure pipe 34 (Fig. 3) is within the normal operating range, and the relay 43 is turned on by the lead wire 44 and the lead wire 42.
is energized, and the contact 43a is switched between J and K. By switching between J and K, current is applied from the lead wire 46 to the contact 43a at JK, and from the lead wire 48 to the P to R of the second limit switch 50.
energizes the damper motor 29. The damper motor 29 then starts rotating, and the damper 30 shown in FIG. 2 is in the open position (dotted line). At this time, a cam (not shown) provided in contact with the shaft of the damper motor 29 switches the first limit switch 49.
switches between M and N, and the second limit switch 5
0 switches between R and Q, damper motor 29
is temporarily stopped, and the damper 30 is stopped at the open position, thereby allowing outside air to be introduced.

Next, when the outside air temperature drops significantly and the temperature difference between indoors and outdoors becomes large, and the indoor heating effect is greatly impaired by introducing outside air, the low pressure pipe 34 of the refrigeration cycle shown in FIG. The pressure decreases, and upon detecting this decreased pressure, the pressure switch 36 is turned off. This causes relay 4
3 is cut off, the contact 43a switches between J and L to energize the lead wire 47, and energizes between Q and R of the second limit switch 50 to drive the damper motor 29.
energize. This energization causes the damper motor 29
starts rotating, and the damper 30 (Fig. 2), which has been in the open position until now, is moved to the solid line position to close it again. When the damper 30 is closed, the shaft of the damper motor 29 is A cam (not shown) provided in contact with the first limit switch 49
is between M-O, and the second limit switch 50 is between R-
P, the damper motor 29 stops, the damper 30 closes, and the introduction of outside air is stopped, thereby preventing a decrease in the heating effect.

Effects of the Invention As is clear from the description of the embodiments, according to the present invention, during heating operation, when the outside air temperature decreases and the low pressure of the air conditioner decreases accordingly, the pressure switch energizes the relay. When the damper is stopped, the contact of the relay is returned, and the damper motor is energized via the second limit switch to return the damper to the closed position, when the outside air temperature drops significantly during winter heating, the introduction of outside air is stopped. Heating operation can be continued without impairing the indoor heating effect, and a decrease in the heating effect can be prevented.

[Brief explanation of drawings]

Figure 1 is a circuit diagram of a control device for an air conditioner according to an embodiment of the present invention, Figure 2 is a configuration diagram of the air conditioner, Figure 3 is a refrigeration cycle diagram of the air conditioner, and Figure 4 is a diagram of the air conditioner's refrigeration cycle. FIG. 1 is a circuit diagram of a conventional air conditioner control device. 40...power supply, 41...operation switch, 36...
...pressure switch, 43...relay, 43a...contact, 49...first limit switch, 50...second limit switch, 29...damper motor.

Claims (1)

[Claims] 1. The main body is provided with an outdoor flow path A, an indoor circulation flow path B, an outside air introduction flow path 28 in the outdoor flow path A, and a damper 30 that is opened and closed by a damper motor 29 is provided in the outside air introduction flow path 28. A relay 43 is connected between the power sources 40 via a pressure switch 36 that opens and closes by detecting a change in pressure on the low pressure side of the refrigeration cycle of the main body, and a single-pole double-throw type relay 43 that is opened and closed by this relay 43. Contact 43a and damper motor 29
a single-pole, double-throw type first limit switch 49 that is switched by the required rotation of the damper motor 29; and a single-pole, double-throw type second limit switch that is connected in series with the damper motor 29 and is switched by the required rotation of the damper motor 29. 50, the contact 43a and the first limit switch 49 are connected to the power source 4, respectively.
0 and the second limit switch 50,
When the pressure on the low pressure side of the refrigeration cycle decreases during heating of the air conditioner, the pressure switch 36 is switched, the contact 43a is switched via the relay 43, the damper motor 29 is rotated as required, and the damper motor 29 is closed. A control device for an air conditioner configured to turn off electricity to a damper motor 29 by switching a two-limit switch 50, and drive the damper motor 29 via a first limit switch 49 when the pressure switch 36 returns.