JP3186383B2 - Vehicle air conditioner - Google Patents

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 a vehicle which can set a bi-level mode in which warm air is blown out of a foot outlet and cool air is blown out of a vent outlet at the same time.

[0002]

2. Description of the Related Art Conventionally, there is provided an air mixing door for controlling the temperature of air by adjusting a mixing ratio of air passing through a heater core and air not passing through the heater core. 2. Description of the Related Art A vehicle air conditioner that blows air into a vehicle interior from a foot outlet is known. An air conditioner of this type is also known which has a bypass duct (bypass passage) for bypassing the air mix door, and through which the cooling air is directly led to a vent outlet. . In such a bypass duct, a bypass door for adjusting the amount of air passing through the bypass duct is usually provided (new vehicle manual Y32-119 issued by Nissan Motor Co., Ltd.).
June 1991).

When a bi-level (B / L) mode in which air is blown out from both the vent outlet and the foot outlet is set, relatively high-temperature air whose temperature has been adjusted by the air mix door is supplied to the foot. While being blown out from the air outlet, mixed air (relatively low-temperature air) of the air whose temperature has been adjusted and the air that has passed through the bypass duct is blown out from the vent air outlet, thereby heating the occupant's head and feet. At this time, the larger the opening degree of the bypass door is, the larger the amount of cooling air passing through the bypass duct is, and the lower the temperature of air blown from the vent outlet is.

[0004]

Conventionally, the opening of the bypass door when the B / L mode is set is determined according to the opening of the air mixing door. Estimates the actual blow-off temperature from a target blow-out temperature calculated based on the vehicle heat load, such as the outside air temperature, the vehicle interior temperature, and the amount of solar radiation. Based on the blow-out temperature, a heater characteristic as shown in FIG. , Which is obtained by back calculation, and there is a problem that the calculation is complicated. In addition, since the actual heater characteristics are not always constant as shown in FIG. 6 and slightly change according to the air volume of the blower fan, the air mix door opening calculated from the unique heater characteristics may include an error. However, in this case, the opening degree of the bypass door cannot be set to the optimum opening degree, and the optimum blowing temperature cannot be obtained.

An object of the present invention is to provide an air conditioner for a vehicle which can control a bypass door to an optimum opening by a simple method without requiring a complicated calculation.

[0006]

The present invention will be described with reference to FIG. 1 which is a diagram corresponding to claims.
A heater core 102 for heating the air introduced into 1;
An air mixing door 103 for controlling the temperature of the air by adjusting the mixing ratio of the air passing through the heater core 102 and the air not passing through the heater core 102, and passing the introduced air directly to the vent outlet 104 by bypassing the air mixing door 103. It has a bypass passage 105 for guiding and a bypass door 106 for adjusting the amount of air passing through the bypass passage 105. The air temperature-controlled by the air mixing door 103 is blown out from the foot outlet 107 and the air mixing door 103 The present invention is applied to a vehicle air conditioner capable of setting a bi-level mode in which mixed air of temperature-controlled air and air passing through a bypass passage 105 is blown out from a vent outlet 104. An interior temperature sensor 108 for detecting the interior temperature of the vehicle, an exterior temperature sensor 109 for detecting the outside air temperature, and a bypass door 106 based on the difference between the detected interior temperature and the outside air temperature when the bi-level mode is set. The opening degree control means 110 for controlling the opening degree is provided to solve the above problem. In particular, in the invention of claim 2, when the vehicle interior temperature is higher than the outside air temperature, the opening degree control is performed so that the opening degree of the bypass door 106 decreases as the difference between the two increases.

[0007]

According to the first aspect, when the bi-level mode is set, the bypass door is set based on the difference between the vehicle interior temperature and the outside air temperature.
Is controlled, and the outlet temperature from the vent outlet 104 is adjusted in accordance with the bypass door opening. In particular, in claim 2, when the vehicle interior temperature is higher than the outside air temperature,
As the difference between the two increases, the degree of opening of the bypass door 106 decreases, and the temperature of the air blown from the vent outlet 104 increases.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 2 is an overall configuration diagram of the vehicle air conditioner according to the present invention. As is well known, a blower fan 2
And an evaporator 3 for cooling the air from the blower fan 2, a heater core 4 for warming the air passing through the evaporator 3, and a mixing ratio of air passing through the heater core 4 and air not passing therethrough to control the temperature of the air. An air mixing door 5 is provided. Air mix door 5
It can be opened and closed between a fully open position indicated by a broken line and a fully closed position indicated by a two-dot chain line, and the amount of air passing through the heater core 4 is the largest at the fully open position and the smallest at the fully closed position.

The air conditioning duct 1 has a defroster duct 1 having a defroster outlet 11a, a foot duct 12 having a front foot outlet 12a and a rear foot outlet 12b, a driver seat side and a passenger seat side vent outlet 13a, A vent duct 13 having 13b is connected. The air from the defroster outlet 11a is blown toward the wind panel of the vehicle, and the foot outlet 1
The air from 2a, 12b is blown to the feet of the occupants in the front and rear seats, and the air from the vent outlets 13a, 13b is blown toward the upper body of the occupants in the driver's seat and the passenger's seat, respectively.

A defroster door 14, a foot door 15, and a vent door 16 (hereinafter collectively referred to as a mode door) are provided at boundaries between the ducts 11 to 13 and the air conditioning duct 1, respectively. The amount of air blown out from each outlet into the vehicle compartment is adjusted according to the opening degree.

Reference numeral 17 denotes a bypass duct for guiding a part of the cooling air passing through the evaporator 3 to the vent duct 13 by bypassing the air mixing door 5. Inside the bypass duct 17 is a bypass door 1
The amount of air passing through the bypass duct 17 is adjusted according to the degree of opening of the bypass door 18. The bypass door 18 can be opened and closed between a fully open position shown by a solid line in the drawing and a fully closed position shown by a two-dot chain line. At the fully open position, the amount of air passing through the bypass duct 17 is the largest.

In this embodiment, as the outlet mode, a vent mode in which air is mainly blown out from the vent outlets 13a and 13b, a foot mode in which air is mainly blown out from the foot outlets 12a and 12b, and a vent mode Exit 13a, 1
A bi-level mode (hereinafter, B / L mode) for blowing air from both the 3b and the foot outlets 12a and 12b, a defroster mode for mainly blowing air from the defroster outlet 11a, and the like can be set.

When the B / L mode is set, the mixed air (A + B) whose temperature is adjusted by the air mixing door 5 is blown out from the foot outlets 12a and 12b, while the mixed air and the air C passing through the bypass duct 17 are mixed. (A + B + C) is blown out from the vent outlets 13a and 13b. Accordingly, relatively high-temperature air is blown to the feet of the occupant and relatively low-temperature air is blown to the upper body, whereby the effect of head and foot heat is obtained.

FIG. 3 shows the configuration of a control system. A control circuit 21 for controlling the entire air conditioner includes an air mix door actuator 2 for adjusting the opening of the air mix door 5.
2, a mode door actuator 23 for adjusting the opening of each of the mode doors 14 to 16 and a bypass door actuator 24 for adjusting the opening of the bypass door 18
And the motor 2a of the blower fan 2 are connected. Further, an outside air temperature sensor 25 for detecting an outside air temperature TAMB, an indoor temperature sensor 26 for detecting a vehicle interior temperature TINC, a solar radiation amount QS
The solar radiation sensor 27 for detecting UN is also connected to the control circuit 21, and the detection output of each sensor is input to the control circuit 21.

The control circuit 21 calculates a target outlet temperature based on the detected outside air temperature TAMB, the vehicle interior temperature TINC, and the amount of solar radiation QSUN, and based on the target voltage, calculates a voltage applied to the blower fan motor 2a (the blower fan air volume). ), The degree of opening of the air mix door 5, the degree of opening of each of the mode doors 14 to 16 (outlet mode), and the like, and the opening of the bypass door 18 based on the difference between the vehicle interior temperature TINC and the outside air temperature TAMB. Control the degree.

Next, a detailed procedure of the control of the opening degree of the bypass door by the control circuit 21 will be described with reference to the flowchart of FIG. The routine in FIG. 4 is called periodically from a main routine (not shown). First, in step S1, it is determined whether or not the vent mode is set, and if it is, the process proceeds to step S2. Here, as described above, the outlet mode is determined according to the vehicle heat load. However, the vent mode is usually set when the outside air temperature TAMB exceeds 20 ° C. The air mix door opening is controlled so that cool air is blown out from 13a and 13b.

In step S2, the blower fan motor 2a
It is determined whether or not the voltage VF applied to is equal to the maximum value VMAX. In step S3, the target bypass door opening XF is set to 100% (fully open). on the other hand,
If it is determined in step S1 that the mode is not the vent mode,
If it is determined in step S2 that the applied voltage VF is not the maximum value VMAX, the process proceeds to step S4 to determine whether the B / L mode is set. If step S4 is denied, that is, in the case of the foot mode, the process proceeds to step S5, where the target bypass door opening XF is set to 0% (fully closed).
And Here, the foot mode is usually set when the outside air temperature TAMB is lower than 0 ° C. At this time, the opening of the air mix door is controlled so that warm air is blown out from the foot outlets 12a and 12b. Is done.

If it is determined in step S4 that the mode is the B / L mode, the process proceeds to step S6, where the room temperature sensor 2
6 and the outside air temperature sensor 25
ΔT from the outside air temperature TAMB detected at (ΔTIN−TAM)
B) Ask. Here, the B / L mode is usually set when the outside air temperature TAMB is about 0 ° C. to 20 ° C. At this time, the air mixing is performed so that hot air is blown out from at least the foot outlets 12a and 12b. The door opening is controlled.

Next, at step S7, a target bypass door opening XF corresponding to the difference ΔT is obtained from the characteristics shown.
According to this characteristic, when ΔT is less than 0 ° C., the target bypass door opening XF is 100%, and ΔT is 0 ° C. or more.
When the temperature is lower than 0 ° C., the target bypass door opening XF decreases between 100% and 0% as ΔT increases.
Above 0 ° C, it is 0%. After steps S3, S5, and S7, the process proceeds to step S8, where the bypass door actuator 2
4 is operated to obtain the target bypass door opening X determined above.
The bypass door 18 is driven so as to be F.

As described above, according to the present embodiment, when the B / L mode is set, the air mix door opening is controlled so that warm air is blown out from the foot outlets 12a and 12b. Difference Δ between temperature TINC and outside air temperature TAMB
When T is equal to or higher than 0 ° C. and lower than 30 ° C., the opening degree of the bypass door 18 decreases as ΔT increases. As the bypass door opening is smaller, the amount of air passing through the bypass duct 17 is reduced, and the temperature of air blown from the vent outlets 13a, 13b is increased.

More specifically, as shown in FIG. 5, for example, the opening of the air mix door is controlled in accordance with the above-described target blowing temperature, and the opening of the bypass door is determined in accordance with ΔT. Then, from the air mix door opening degree, the foot outlet temperature (the outlet temperature from the foot outlets 12a and 12b).
However, the vent outlet temperature (the outlet temperature from the vent outlets 13a and 13b) is determined from the air mix door opening and the bypass door opening. FIG. 5 shows a case where the vehicle interior temperature is constant, but as shown in FIG.
If the air temperature TAMB differs, the vent air temperature does not change so much even if the outside air temperature TAMB changes due to the above-described opening degree control of the bypass door 18. Therefore, even if the outside air temperature is significantly different, the occupant does not have a large difference in the air temperature received on the face, and does not feel discomfort due to the temperature difference. In addition, even when the outside air temperature is low, the temperature of the air blown from the vent air outlet does not become too low, so that a decrease in the heating performance can be prevented.

FIG. 5 shows a case where the temperature in the vehicle compartment is constant. However, even if the outside air temperature is the same, if the temperature in the vehicle compartment differs, the opening degree of the bypass door also changes. For example, assuming that the outside air temperature is 20 ° C., if the vehicle interior temperature is 25 ° C., the bypass door opening is 83% as shown in FIG. 5, but if the vehicle interior temperature is 20 ° C., the bypass door opening is 100%. %.
In other words, under the same outside air temperature, the lower the vehicle interior temperature, the larger the bypass door opening degree, and the lower the vent outlet temperature. Therefore, occupants who prefer a high cabin temperature,
Correspondingly, relatively hot air will be received on the face, and occupants who prefer cold vehicle interior temperatures will receive relatively cold air on their faces. That is, it is possible to obtain a vent outlet temperature suitable for each passenger's preference by the above-described bypass door opening control.

In the configuration of the above embodiment, the bypass duct 17 forms the bypass passage 105, and the control circuit 21 forms the opening control means 110.

Note that the characteristic diagram of step S7 in FIG. 4 is not limited to the one shown in the drawing, and that the degree of opening of the bypass door decreases as the difference between the two increases when the temperature in the vehicle compartment is higher than the outside air temperature. If it is, another form may be sufficient.

[0025]

According to the present invention, the degree of opening of the bypass door is controlled based on the difference between the cabin temperature and the outside air temperature. Therefore, the bypass door can be controlled by a simple method without requiring complicated calculations. It can be controlled to the optimal opening. For example, if the cabin temperature is higher than the outside air temperature, the opening degree of the bypass door is made smaller as the difference between the two is larger, so that even if the outside air temperature is greatly different, there is no great difference in the air temperature received by the occupant on the face, The occupant does not feel discomfort due to the temperature difference. In addition, even when the outside air temperature is low, the temperature of the air blown from the vent air outlet does not become too low, so that a decrease in the heating performance can be prevented. Furthermore, at the same outside air temperature, the lower the vehicle interior temperature, the larger the bypass door opening and the lower the vent air temperature, so occupants who prefer high vehicle interior temperatures should receive relatively high temperature air on their faces. Also, an occupant who prefers a low vehicle interior temperature will receive relatively cool air on the face. That is, according to the present invention, there is also obtained an effect that the vent outlet temperature suitable for each passenger's preference can be obtained by controlling the bypass door opening degree.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims.

FIG. 2 is a configuration diagram showing one embodiment of a vehicle air conditioner according to the present invention.

FIG. 3 is a block diagram showing a control system of the air conditioner.

FIG. 4 is a flowchart illustrating the operation of the embodiment.

FIG. 5 is a diagram illustrating a relationship between a bypass door opening and a vent outlet temperature controlled according to a difference between a vehicle interior temperature and an outside air temperature.

FIG. 6 is a diagram illustrating an example of a heater characteristic.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air-conditioning duct 2 Blower fan 3 Evaporator 4 Heater core 5 Air mix door 11 Defroster duct 12 Foot duct 12a, 12b Foot outlet 13 Vent duct 13a, 13b Vent outlet 14-16 Mode door 17 Bypass duct (Bypass passage) 18 Bypass door 21 control circuit (opening control means) 23 mode door actuator 24 bypass door actuator

Continued on the front page (72) Inventor Makoto Fukubayashi 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) B60H 1/00 103 B60H 1 / 00 102

Claims (2)

(57) [Claims] 1. A heater core for heating air introduced into an air conditioning duct, an air mix door for adjusting a temperature of the air by adjusting a mixing ratio of air passing through the heater core and air not passing therethrough, A bypass passage for bypassing the mixing door and directly leading the introduced air to the vent outlet; and a bypass door for adjusting an amount of air passing through the bypass passage. In a vehicle air conditioner capable of setting a bi-level mode in which a mixed air of air temperature-controlled by the air mixing door and air passing through the bypass passage is blown out from a vent outlet at the same time as blowing from an outlet, An indoor temperature sensor for detecting a temperature, an outside air temperature sensor for detecting an outside air temperature, and the detection when the bi-level mode is set. Air conditioning system characterized by comprising a opening control means for controlling the opening of the bypass door based on a difference between the vehicle interior temperature and the outside air temperature was. 2. The opening control means performs the opening control such that when the temperature in the vehicle compartment is higher than the outside air temperature, the opening of the bypass door decreases as the difference between the two increases. The vehicle air conditioner according to claim 1, wherein: