JPH0545865B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an air conditioner for an automobile, which is equipped with an electric blower to cool a condenser in a refrigeration cycle, and whose rotational speed of the blower can be changed by the high pressure of the refrigeration cycle. .

[Conventional technology]

Conventionally, as disclosed in Japanese Utility Model Application Publication No. 57-79010, the rotational speed of the cooling fan of the condenser is adjusted according to the high pressure of the refrigeration cycle to prevent the high pressure from rising and to properly condense the refrigerant. At the same time, there have been attempts to reduce the power consumption of electric blowers.

[Problem to be solved by the invention]

If the rotational speed of the electric blower is adjusted according to the high pressure as in the above-mentioned conventional technology, the refrigerant condensing ability can be improved, especially when the high pressure becomes high. However, on the other hand, when the refrigeration cycle is started, the high pressure is low and the electric blower is rotated at a low speed. For this reason, when starting up the refrigeration cycle, which requires especially large cooling capacity, the high pressure rises and it takes a considerable amount of time for the electric blower to rotate at high speed, preventing the refrigerant from condensing properly and impairing the cool-down characteristics. There was a problem.

In view of the above-mentioned problems, the present invention provides an automotive air conditioner that can strongly condense refrigerant immediately after a command to start a refrigeration cycle is issued, and can exhibit excellent cool-down characteristics. The purpose is to

[Means to solve the problem]

In order to achieve the above object, the present invention provides an electric blower that cools a condenser in a refrigeration cycle, and a rotation speed of the electric blower that is adjusted according to the high pressure of the refrigeration cycle, and the rotation speed is increased when the high pressure is high. and a first control means for reducing the rotation speed when the high pressure is low, a command means for commanding the start-up of the refrigeration cycle; and a command means for commanding the start-up of the refrigeration cycle by the command means. Immediately after the command is issued, the rotational speed of the electric blower is adjusted to be higher than the rotational speed corresponding to the high pressure, and then the rotational speed of the electric blower is adjusted by the first control means. The technical means of providing two control means is adopted.

[Effect]

According to the configuration of the present invention described above, the rotational speed of the electric blower is adjusted by the first control means in accordance with the high pressure of the refrigeration cycle. When a command to start the refrigeration cycle is issued by the command means, the rotational speed of the electric blower is immediately adjusted by the second control means. Moreover, this rotational speed is adjusted to be higher than the rotational speed corresponding to this high pressure, regardless of the high pressure at the time of startup.

Therefore, according to the device of the present invention, the rotational speed of the electric blower is maintained at a high level immediately after the command to start the refrigeration cycle is issued, regardless of the high pressure.
After that, the rotation speed is adjusted according to the high pressure.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to appropriately condense the refrigerant by adjusting the rotational speed of the blower that cools the condenser according to the high pressure of the refrigeration cycle. Regardless, since the rotational speed is adjusted high, the refrigerant can be appropriately condensed immediately after the refrigeration cycle is started, and the cool-down characteristics can be improved.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment to which the present invention is applied,
0 is battery terminal, 1 is key switch (IG), 2
is an air conditioning fan relay, 3 is a manually or automatically operated fan switch, 4 is an air conditioning blower, 5 is
is the resistance for speed adjustment, 6 is the air conditioner switch,
7 is a thermostat, and 8 is an electromagnetic clutch that connects the compressor 8A to the engine (not shown). Here, when switch 1 is closed, if fan switch 3 is turned on to low speed (Lo), medium speed (Me), or high speed (Hi), the contact of relay 2 closes and the fan 4 moves to the position of fan switch 3. Rotates at a speed corresponding to Furthermore, when the air conditioner switch 6 is turned on, the compressor 8A starts a refrigeration cycle (not shown), causing the condenser to radiate heat and the evaporator to absorb heat. The thermostat 7 opens when the evaporator becomes supercooled and adjusts the temperature to stop absorbing heat.

9 is an electric blower for cooling the condenser, which also serves to cool the engine radiator if necessary. This blower 9 is connected in parallel with the clutch 8, and is energized to rotate when the refrigeration cycle is activated, thereby cooling the condenser. 11 is a speed switching relay for the blower 9, 1
Reference numeral 2 denotes a speed adjusting resistor, and when the contact of the relay 11 is closed, the blower 9 rotates at high speed, and when it is open, the blower 9 rotates at a low speed due to the pressure reducing action of the resistor 12.

Therefore, the condenser cooling blower 9 is connected to a pressure switch 13 installed in the high pressure piping (between the receiver and the expansion valve) in the refrigeration cycle.
Therefore, when the pressure exceeds the set pressure (for example, 15 Kg/cm ² ), the relay 11 operates and closes the contacts, so it operates at high speed, and when the pressure falls below the set pressure (for example, 10 Kg/cm ² ), the relay 11 deactivates and operates at low speed. do. This is because when the cooling load is large and the high pressure rises, the condenser cooling fan 9 is operated at high speed to improve the cooling capacity and lower the high pressure. Note that hysteresis is provided to the operating set point of the pressure switch 13 if necessary.

Here, when starting the air conditioner, it takes time for the high pressure to rise, so when particularly rapid cooling is required, such as after parking in the hot summer sun, the condenser cooling fan 9 does not operate at high speed. , the cooling capacity will be insufficient because it will operate in Lo for a while. Therefore, this device is equipped with a timer circuit 10, and when the air conditioner switch 6 is turned on, the output line 10A is set to the ground level for a predetermined period of time, and the relay 11 is forcibly activated to turn on the blower 9. It operates at high speed. In the above embodiment, the speed switching relay 11, the speed adjustment resistor 12, and the pressure switch 13 constitute the first control means, and the timer circuit 10, the speed switching relay 11, and the output line 10A constitute the first control means. The air conditioner switch 6 constitutes a command means.

FIG. 2 shows a second embodiment of the invention, in which a microcomputer 15 is used.
FIG. 3 is a flowchart of the microcomputer 15. First, in step 101 (processed by timer interrupt if necessary), the status of each switch input and high pressure is read. Next, the process proceeds to step 102, where flag F is set to 1. In step 103, it is determined whether the air conditioner switch 6 is on or off. If the air conditioner switch 6 is off, the process proceeds to step 112, where the relay 14A is turned off to stop the blower 9, and the relay 14B is turned off to disconnect the clutch 8 and stop the compressor.

If air conditioner switch 6 is on, step
Proceed to 104. In step 104, it is determined whether flag F is set. Not set F=
If it is 0, the process goes to step 109, and if F=1, the process goes to step 105, where the relay 11 is turned on to operate the blower 9 at high speed, and the relays 14A and 14B are turned on to close the clutch 8. Connect and operate the compressor 8A.

Next, the process proceeds to step 106, where the built-in timer counter is activated and waits until the value reaches a predetermined value A or more.
Step starts when the timer count value exceeds the specified value.
Proceed to step 108 and reset flag F (F=0).
Next, the process proceeds to step 109, and when it is determined that the high pressure value of the refrigeration cycle is equal to or higher than the predetermined value C and is high speed (Hi), the process proceeds to step 110. Further, when the high speed pressure gradually decreases to a pressure B lower than the predetermined value C, it is determined that the speed is low (Lo) and the process proceeds to step 111. In step 110, the blower 9 is operated at high speed, and the clutch 8 is connected to operate the compressor 8A. Further, in step 111, the blower 9 is operated at a low speed, and the clutch 8 is connected to operate the compressor 8A.

Note that when the blower 9 also serves to cool the engine radiator, the signal from the engine coolant temperature sensor is input to the microcomputer 15, and at step 109, the value of the coolant temperature is also determined. 9 high and low speeds may be determined. In this case, in order to save power, the conditions should be set such that the engine operates at high speed when the engine water temperature or high pressure side pressure exceeds a predetermined value, and operates at low speed only when both water temperature and pressure fall below a predetermined value.

Further, the time counted by the timer can be changed depending on the temperature inside the vehicle interior or the temperature outside the vehicle interior. In the second embodiment, step 110 and step 111 constitute the first control means, and step 105, step 106, step 107,
and configuring the second control means in step 108,
Step 103 and step 104 constitute a command means.

[Brief explanation of drawings]

FIG. 1 is an electrical wiring diagram of the first embodiment of the present invention, FIG. 2 is a configuration diagram of the second embodiment, and FIG. 3 is an explanatory diagram of a control program of the second embodiment. 6...Air conditioner switch, 8...Clutch, 9
...Electric blower for capacitor cooling, 10...Timer circuit, 11...Relay, 12...Resistance for speed adjustment, 13...Pressure switch, 14A, 14B...
Relay, 15...microcomputer.

Claims (1)

[Scope of Claims] 1. An electric blower that cools a condenser of a refrigeration cycle, and a rotation speed of the electric blower is adjusted according to a high pressure of the refrigeration cycle, and when the high pressure is high, the rotation speed is set to high, and the high pressure an air conditioner for an automobile, comprising: a first control means for reducing the rotational speed when the rotational speed is low; a command means for commanding the start-up of the refrigeration cycle; immediately after that, the rotational speed of the electric blower is adjusted to be higher than the rotational speed corresponding to the high pressure, and the second control means causes the first control means to adjust the rotational speed of the electric blower. An air conditioner for an automobile characterized by comprising: 2 The second control means controls the rotational speed of the electric blower for a predetermined period of time immediately after the command means issues a command to start the refrigeration cycle. 2. The air conditioner for an automobile according to claim 1, wherein the rotation speed is adjusted to be higher than the rotation speed corresponding to the high pressure when the air conditioner is turned on.