JPS6236644Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a control device for a vehicle air conditioner.

A conventional vehicle air conditioning system is generally known as shown in Fig. 1 and Fig. 2. In Fig. 1, 1 denotes a compressor, 3 denotes a condenser, 5 denotes an evaporator, and 7 denotes a fan. The compressor 1, condenser 3, and evaporator 5 are connected by a pipe 9, and the refrigerant gas sucked and compressed by the compressor 1 is forcibly cooled by the condenser 3 to become a high-pressure liquid and is sent to the evaporator 5. At this time, the evaporator 5 removes the latent heat of evaporation from the surrounding air through fins 5a to produce cooling air. The cooling air is blown into the passenger compartment 8 by the fan 7. Meanwhile, the refrigerant gas that has finished its work is regenerated by the compressor 1, and the same cycle as above is repeated. Reference numeral 11 denotes a liquid tank that removes moisture and dust contained in the refrigerant,
Reference numeral 12 denotes an expansion valve, and reference numeral 13 denotes a cooling unit case.

FIG. 2 shows an electric circuit diagram of the air conditioner, and 15 is a power supply circuit connected to the battery V;
17 is a fan motor circuit having a fan motor M and a manual fan switch 19; 21 is a compressor circuit having a compressor 1 and a manual air conditioner switch 23. In the fan motor circuit 17, S is an off contact, _S1 is a low (weak) contact, and _S4 is a high (strong) contact, which are connected to the resistor R, and 19a slides between each contact S and _S4 . The actuator is shown moving. In addition, the compressor circuit 21
, L indicates an indicator lamp, and 23a indicates an air conditioner relay of the air conditioner switch 23. Further, in the power supply circuit 15, N indicates an ignition ACC switch, and n indicates an ACC relay.

In the control device with such a configuration, the compressor circuit 21 is grounded via the fan switch 19, so that the operating state of the fan motor M, that is, the actuator 19a of the fan switch 19 is located at either contact point S ₁ or S ₄ It can only be activated when it is turned on.

Therefore, when the fan switch 19 is turned off,
Since the air conditioner switch 23 is not grounded even when the air conditioner switch 23 is turned on, the compressor circuit 21 does not operate and the evaporator 5 does not freeze.
This conventional circuit has the inconvenience that the cooling function cannot be activated even if the air conditioner switch 23 is directly turned on, since the cooling function starts after the two steps of turning on the fan switch 19 and then turning on the air conditioner switch 23.

Therefore, the object of this invention is to provide a new control device which allows the compressor circuit 21 to operate even when the fan motor circuit 17 is disconnected while the vehicle is running, and which does not cause the evaporator to freeze.

In order to achieve this purpose, this invention includes an evaporator whose outlet faces into the vehicle interior and removes the latent heat of evaporation from the surrounding air through fins, and a device that sends cooling air cooled by the evaporator to the outlet. In an air conditioner comprising a fan, a compressor that takes in and compresses refrigerant gas that has finished its work in an evaporator, and a condenser that forcibly cools the refrigerant gas sent out from the compressor, a fan motor circuit having a fan motor of the fan and a A power supply circuit is connected to the fan motor circuit and a compressor circuit having an independent compressor, the fan motor circuit is provided with a manual fan switch for disconnecting and connecting the circuit, and the compressor circuit is connected to the upper side or lower side of the evaporator. The air conditioner switch is equipped with a sensor relay switch that is normally disconnected from the airflow sensor installed in the airflow sensor and connected to the airflow sensor when the airflow sensor is turned on, and an air conditioner switch that is manually disconnected and connected.

Hereinafter, one embodiment of this invention will be described in detail with reference to the drawings of FIGS. 3 and 4. Note that the same members as in the conventional example will be described with the same reference numerals.
In FIG. 3, reference numerals 1, 3, and 5 indicate a compressor, a condenser, and an evaporator having a large number of fins 5a, and since these functions are the same as those of the conventional example, detailed explanations thereof will be omitted here.

In FIG. 4, 15 is a power supply circuit, 17 is a fan motor circuit, and 21 is a compressor circuit. The fan motor circuit 17 and the compressor circuit 21 are connected in parallel to the power supply circuit 15 and have independent circuit configurations.

The power supply circuit 15 is provided with an ignition ACC relay n which is normally disconnected from the battery power supply V and connected when the ACC switch N is turned on.

The fan motor circuit 17 is provided with a fan motor M for driving the fan and a manual fan switch 19. The fan switch 19 includes an actuator 19a that slides each contact S, S ₁ ... S ₄ with the rotation axis 0 as a fulcrum, and a resistor R connected to each contact S ₁ ... S ₄ , and the contact S is connected to the circuit 17. It is an off contact that disconnects the power. On the other hand, the contacts S ₁ ...S ₄ are fan switching contacts that connect the circuit 17. The contact S ₁ is in the (weak) position where all resistance is applied, and the contact S ₄ is in the high (high) position where no resistance is applied.

The compressor circuit 21 also includes a manual air conditioner switch 23 and a relay switch 2 that is normally disconnected and connected when the air conditioner switch 23 is turned on (connected).
3a and a sensor relay switch 27 that is normally disconnected from the airflow sensor 25 that detects the airflow while driving, but is connected when the airflow sensor 25 is turned on;
The airflow sensor 25 is installed on the upper side of the cooling unit case 13 of the evaporator 5. The sensor capability of the airflow sensor 25 in this embodiment is set based on the low position of the fan motor M.

Note that L is an indicator lamp.

Next, the operation will be explained. When the relay contact n of the power supply circuit 15 is in the closed state, the fan 7 is operated by positioning the actuator 19a from the off contact S to the fan switching contact _S1 , for example. As a result, the air volume sensor 25 is turned on, and the sensor relay switch 27 is brought into contact, making the compressor circuit 21 ready for operation. Next, when the air conditioner switch 23 is turned on (dashed line), the air volume sensor 25 and sensor relay switch 27 are energized, and the compressor circuit 21 is turned on by connecting the relay switch 23a.
becomes active.

Next, when the actuator 19a is in the OFF contact S position while driving, an air volume corresponding to the low position of the fan motor M is sent to the evaporator 5, the air volume sensor 25 is activated, and the sensor relay switch 27 is activated.
is connected to put the compressor circuit 21 into an operable state. In the above state, air conditioner switch 2
3, the compressor circuit 21 is activated and the cooling air is blown into the passenger compartment 8 through the outlet 13. In this case, freezing of the evaporator 5 does not occur.

FIG. 5 shows an embodiment in which a thermoswitch 29 (temperature switch) for sensing the outside temperature is added to the first embodiment. The thermo switch 29 turns on the compressor circuit 21 when the outside temperature approaches freezing.
Evaporator 5
, and is connected in series between the thermo-relay switch 27 and the switch relay 23a. It should be noted that the same reference numerals as those in FIG. 4 have the same parts and functions, so detailed explanations will be omitted.

In the case of this embodiment, it functions depending on the outside temperature and the presence or absence of air volume. For example, when the outside temperature drops below freezing, if the function of the thermoswitch 29 is activated with a significant delay or does not function at all, the fins 5a of the evaporator 5 will begin to freeze, but at the same time, the air volume will decrease due to freezing. Since the sensor 25 senses and cuts off the compressor circuit 21,
Freezing of the evaporator 5 is avoided. Therefore, in this embodiment, reliability for freezing prevention can be improved.

As explained above, according to the control device of this invention, even when the fan motor is off, if the evaporator obtains a specified air volume, it can operate as a cooling function. Moreover, the airflow sensor does not operate unless the evaporator receives the specified airflow.
It functions to prevent the evaporator from freezing and prevents accidents. Furthermore, since the fan motor is not driven during cooling due to the wind pressure while traveling, it is advantageous in terms of fuel efficiency.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of an air conditioner showing a conventional example, Figure 2 is an electric circuit diagram of the same as above, Figure 3 is an explanatory diagram of an air conditioner according to this invention, and Figure 4 is an electric circuit diagram of the same as above. , FIG. 5 is an electrical circuit diagram showing another embodiment. Explanation of main drawing symbols, 1...compressor, 3...condenser, 5...evaporator,
7... Fan, 8... Vehicle interior, 13a... Air outlet, 15... Power supply circuit, 17... Fan motor circuit, 19... Fan switch, 25... Air volume sensor, 27... Sensor relay switch, M ...Fan motor.

Claims (1)

[Scope of utility model registration request] An evaporator whose outlet faces the interior of the vehicle and removes the latent heat of evaporation from the surrounding air flowing by the wind pressure or fan when the vehicle is running through the fins, a compressor that sucks in and compresses the refrigerant gas that has finished its work in the evaporator, and sends it out from the compressor. In a vehicle air conditioner comprising a condenser that forcibly cools refrigerant gas, a power supply circuit is connected to a fan motor circuit having a fan motor of the fan and a compressor circuit having a compressor independent of the fan motor circuit; A manual fan switch is provided in the fan motor circuit to connect and disconnect the circuit, and the compressor circuit is provided on the upper side or lower side of the evaporator, and when a specified air volume is detected that does not cause the evaporator to freeze during the refrigeration cycle. An airflow sensor that is turned on is connected in series with a sensor relay switch that is normally disconnected and connected when the airflow sensor is turned on, and an air conditioner switch that is manually disconnected. 1. A control device for a vehicle air conditioner, characterized in that the compressor circuit is energized when the current flows.