JPH05229335A - Car air conditioner - Google Patents

Abstract

PURPOSE:To keep off any overcoolness in a portion being exposed to air down out of a duct, without varying a temperature in the vehicle interior. CONSTITUTION:A control circuit 22 of a car air conditioner 1 raises a blowoff temperature as far as five degrees when interior temperature is stabilized and such a state that the blowoff temperature out of a duct 2 is less than 5 deg. is continued as long as ten minutes, while it increases an air quantity by an air blower 4 in order to keep a blowoff heating value constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for cooling operation.

[0002]

2. Description of the Related Art An air conditioner is generally used for cooling a passenger compartment by blowing out air having a lower temperature from a duct outlet.

[0003]

In the summer or when the sunlight is strong, the air having a low temperature is continuously blown out from the air outlet to cool the room. Then, the vehicle occupant is exposed to cold air for a long period of time, which causes a problem that the part on which the air is applied (for example, a shoulder or a hand) is too cold and becomes uncomfortable.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an air conditioner for a vehicle, which can prevent excessive cooling of a portion exposed to the wind blown from a duct without changing the temperature inside the vehicle.

[0005]

The vehicle air conditioner of the present invention employs the following technical means. An air conditioner for a vehicle is provided with a duct for sending air toward a passenger compartment, a blower for generating an air flow toward the passenger compartment in the duct, and a duct disposed in the duct to cool air blown into the passenger compartment. And a control circuit for controlling the temperature and air volume of the air blown into the vehicle compartment from the duct. Then, the control circuit performs the cooling operation in which the blowout temperature and the air volume are increased when the cooling operation for cooling the vehicle interior continues for the set time.

[0006]

When the cooling operation for cooling the vehicle interior is continuously performed for the set time, the control circuit performs the cooling operation in which the blowing temperature and the air volume are increased. By increasing the temperature of the blowout air, the cold air blown out from the duct hits and cools the cold portion, and it is possible to prevent overcooling. At this time, since the air volume also increases, the amount of heat blown out is maintained and the temperature rise in the vehicle compartment is prevented. That is, it is possible to prevent an excessively cold portion of the air blown from the duct from coming into contact with the vehicle without increasing the temperature inside the vehicle.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a vehicle air conditioner of the present invention will be described based on an embodiment shown in the drawings. [Configuration of Embodiment] FIG. 1 is a schematic configuration diagram of a vehicle air conditioner. The vehicle air conditioner 1 includes a duct 2 that forms an air passage that sends air toward the passenger compartment. The duct 2 is arranged in the vehicle compartment, and one end of the duct 2 is connected to a blower 4 having an inside / outside air switching unit 3. The inside / outside air switching means 3 communicates with the inside of the vehicle and is the air inside the vehicle (inside air).
And an outside air introduction port 6 communicating with the outside of the vehicle compartment to introduce air (outside air) outside the vehicle compartment. The inside / outside air switching unit 3 includes an inside / outside air switching damper 7,
The inside / outside air switching damper 7 can switch the air introduced into the duct 2 between the inside air and the outside air. The blower 4 includes a fan case 8, a fan 9, and a motor 10. The motor 10 rotationally drives the fan 9 according to the applied voltage and sends an air volume according to the applied voltage into the vehicle interior.

At the other end of the duct 2, there are formed a face outlet 11 and a foot outlet 12 for blowing out the air passing through the duct 2 to the upper body of the vehicle occupant and the feet of the occupant. And the face outlet 1 is in the duct 2.
A blower outlet switching damper 13 for adjusting the flow rate of the air blown from the air outlet 1 or the foot blower outlet 12 is provided.

A cooling means 14 is provided upstream of the duct 2. This cooling means 14 is provided in the duct 2
It is a refrigerant evaporator of a refrigeration cycle that cools the air passing through it. Further, the heating means 15 is provided downstream of the cooling means 14.
Is provided. The heating means 15 is a cooling means 14.
It is a heater core that uses engine cooling water (hot water) to heat the air that has passed through. Further, a bypass passage 16 that bypasses the heating means 15 is provided in the duct 2, and the ratio of air passing through the heating means 15 and air passing through the bypass passage 16 is adjusted by the air mix damper 17.

A drive circuit 18 for driving the motor 10 of the blower 4 and a servo motor 1 for driving the inside / outside air switching damper 7.
9. Servo motor 2 for driving the outlet switching damper 13
0, and the servo motor 21 that drives the air mix damper 17 receives the control signal from the control circuit 22 and drives the above-mentioned units. The control circuit 22 detects a temperature setter 23 operated by the user, an operation switch 24 of the automatic air conditioner, an inside air sensor 25 for detecting the temperature of the air inside the vehicle, and an outside air temperature as input signals for performing air conditioning control. An outdoor air sensor 26, a solar radiation sensor 27 that detects the amount of solar radiation,
Outlet temperature sensor 2 for detecting the temperature downstream of the cooling means 14.
8. Input signals from a water temperature sensor 29 for detecting the temperature of hot water supplied to the heating means 15, an opening sensor 30 for detecting the opening of the air mix damper 17, and the like. Then, the control circuit 22 reads various input signals via the A / D converter 31, and the CPU 33 determines the operation amount of each unit based on the read signals and the program stored in the ROM 32.
The arithmetic processing is performed by the output unit 34 and the control signal according to the calculation result is output.
From the above to each of the above parts to perform air conditioning control. Reference numeral 35 is a crystal oscillator for oscillating a reference clock to execute arithmetic processing.

Next, the air conditioning control executed by the control circuit 22 will be described with reference to the flowchart of FIG. Auto air conditioning (automatic air conditioning) by operating switch 24
When is selected (start), in step S1, flags and counters used for execution of subsequent processing are initialized.
Then, in step S2, the environmental condition of the vehicle is read from various signals such as the set temperature, the inside temperature, the outside temperature, and the amount of solar radiation. In the next step S3, the target outlet temperature TAO blown out from the outlet is calculated by the following mathematical formula 1 so that the temperature inside the vehicle interior maintains the temperature set by the temperature setter 23.

## EQU1 ## TAO = Kset.Tset-Kr.Tr-Kam ..
Tam-Ks.Ts + C (Kset is a temperature setting gain, Tset is a temperature setting signal of the temperature setter 23, Kr is an inside air temperature gain, Tr is a temperature signal of the inside air sensor 25, Kam is an outside air temperature gain, and Tam is a temperature gain.
Is the temperature signal of the outside air sensor 26, Ks is the solar gain, Ts
Is a solar radiation signal of the solar radiation sensor 27, and C is a correction constant).
Subsequently, in step S4, the target opening degree θ of the air mix damper 17 is calculated by the following mathematical expression 2 in order to realize the target outlet temperature TAO.

## EQU2 ## θ = {(TAO-Te) / (Tw-Te)} × 100 (where Te is the temperature signal of the outlet temperature sensor 28 and Tw is the temperature signal of the water temperature sensor 29). Also, step S4
Then, the air volume of the blower 4 (the voltage applied to the motor 10) is determined by the target outlet temperature TAO as shown in FIG. 4, and the outlet mode is set as the target outlet temperature TAO as shown in FIG.
And the inside / outside air mode is also determined by the target outlet temperature TAO. Then, in step S5, it is determined whether or not the temperature inside the vehicle is stable. Specifically, | Tset
It is determined whether or not −Tr | ≦ A (A is a set value, for example, 2 °). If the result of this determination is YES, the target outlet temperature TAO is the set value B (for example, 5 ° C.) in step S6.
It is determined whether it is lower than. If the result of this determination is YES, it is determined in step S7 whether or not the room temperature is stable and the target outlet temperature TAO is lower than the set value B for a set time (for example, 10 minutes). If the result of this determination is YES, in step S8, a correction process is performed to perform the cooling operation in which the blowout temperature and the airflow amount are increased so that the blowout heat amount does not change.

The control of step S8 will be described with reference to FIG. First, in step S81, the target outlet temperature TAO
Is corrected. That is, the corrected target temperature TAO after correction is obtained by adding the correction temperature α (for example, 5 °) to the target outlet temperature TAO.
Let O1. Subsequently, in step S82, the applied voltage V of the motor 10 is corrected to the corrected applied voltage V1 by the following mathematical formula 3 in order to compensate for the shortage of the cooling capacity due to the rise of the blowout temperature.

## EQU3 ## V1 = V + {-. Alpha..multidot.V / (TAO1 -Tr)} In the next step S83, the corrected target outlet temperature TAO1
Then, the target opening degree θ of the air mix damper 17 is calculated again from the above equation 2, and the routine proceeds to step S9. In step S9, according to the calculation results calculated in the above steps,
Servo motor 1 for drive circuit 18 and inside / outside air switching damper 7
9. A motor voltage control signal, an inside / outside air switching control signal, an outlet switching control signal, and an air mix damper opening control signal are output to the servo motor 20 of the outlet switching damper 13 and the servo motor 21 of the air mixing damper 17, respectively. Then, the process returns to step S2. If the result of the determination in steps S5, S6, S7 is NO, the timer for counting the elapsed time is cleared in step S10.
Then, it progresses to step S9.

[Operation of Embodiment] Next, the operation of the above embodiment will be briefly described. When the automatic air conditioner is selected by the operation switch 24, the temperature inside the vehicle compartment is set to the temperature setter 23.
The blowout temperature, the air flow rate, etc. are controlled so that the temperature is set at. In the summer or when the sunlight is strong, in order to maintain the indoor temperature Tr at the set temperature Tset, low temperature air is continuously blown out from the air outlet. The room temperature Tr is stable, the target outlet temperature TAO is 5 ° C or less, and the set temperature Tse
If the difference between t and the room temperature Tr is within 2 ° for more than 10 minutes, the target blowout temperature TAO is increased by 5 ° and the blower heat is kept constant so that the room temperature Tr does not change. Increase the air volume by 4. In addition, when the user switches the mode (sets the temperature, sets the air volume, and switches the outlet mode), the correction of the target outlet temperature TAO is canceled.

[Effects of Embodiment] When the automatic air conditioner is selected, in order to set the room temperature Tr to the set temperature Tset,
The outlet temperature, air volume, outlet, etc. are automatically set. With conventional auto air conditioners, the set temperature remains constant,
Because it is not possible to control the blowing temperature and air volume, low temperatures may constantly hit the hands, shoulders, etc. in the summer and in the case of strong sunlight, causing cold. However, by applying the present embodiment, it is possible to prevent the low temperature from constantly hitting the parts such as the hands and shoulders continuously without changing the indoor temperature Tr, and prevent the parts to which the blowing air is applied from being too cold. Can be prevented. In addition, since the air having a temperature lower than that of the air outlet is blown out for a certain period of time at the beginning, the user is given a high cooling sensation in the initial stage, and the user is not made uncomfortable with the increase in the blowout temperature.

[Modification] In this embodiment, an example in which an air mix damper is used to control the blowing temperature is shown. However, a variable capacity type refrigerant compressor is used in the refrigeration cycle, and the capacity is varied to blow out the refrigerant. Other means may be used as long as they affect the blowout temperature, such as operating the temperature and increasing the heating amount of the heating means. In the present embodiment, as an example of the case where the cooling operation for cooling the vehicle interior continues for a set time, when the room temperature is stable and the blowout temperature is equal to or lower than the set temperature for the set time, the blowout temperature and the air volume are increased. It was Then, although the blowout temperature is detected from the target blowout temperature TAO, the actual blowout temperature may be detected by a sensor or the opening of the air mix damper. In the present embodiment, since the blowing temperature and the air volume are increased after the set time elapses, the passenger may feel uncomfortable. Therefore, the blowing temperature and the air volume may be gradually increased.
After increasing the blowout temperature and the air flow rate, the blowout temperature and the air flow rate may be lowered again, and the raising and lowering may be repeated. The numerical values shown in the examples are used to facilitate understanding of the examples, and the present invention is not limited to these numerical values. In this embodiment, an example in which the present invention operates when the automatic air conditioner operates is shown, but the present invention may be applied even when operating manually.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a vehicle air conditioner.

FIG. 2 is a flowchart showing a basic operation of a control circuit.

FIG. 3 is a graph showing a relationship between a target outlet temperature and an outlet mode.

FIG. 4 is a graph showing a relationship between a target outlet temperature and a voltage applied to a blower.

FIG. 5 is a flowchart for performing a rise temperature and air volume increase correction.

[Explanation of symbols]

 1 Vehicle Air Conditioner 2 Duct 4 Blower 14 Cooling Means 22 Control Circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Ito 1-1, Showa-cho, Kariya city, Aichi Nihon Denso Co., Ltd. (72) Inventor Katsuhiko Samukawa 1-1-1-1, Showa-cho, Kariya city, Aichi prefecture Within the corporation

Claims (1)

[Claims] 1. A duct for sending air toward a vehicle interior, a blower for generating an air flow toward the vehicle interior in the duct, and a cooling arranged in the duct for cooling air blown into the vehicle interior. In a vehicle air conditioner comprising means and a control circuit for controlling the temperature and air volume of the air blown from the duct into the vehicle compartment, the control circuit is configured such that the cooling operation for cooling the vehicle interior continues for a set time. In this case, the vehicle air conditioner is characterized by performing cooling operation in which the blowout temperature and the air volume are increased.