JP3169063B2 - 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, and more particularly to an air conditioner for automatically switching between an inside air mode and an outside air mode in response to contamination of outside air.

[0002]

2. Description of the Related Art A conventional air conditioner for a vehicle as described above is disclosed in JP-A-60-100749. In this conventional device, a gas sensor for detecting dirt in the outside air is provided outside the vehicle compartment, and a detection signal of the gas sensor is compared with a predetermined determination level to determine whether or not the outside air is dirty. If it is determined that the air conditioner is in operation, the inside / outside air mode is switched to the inside air mode.

[0003] In the conventional apparatus, as a human sensation to the smell of the outside air, attention is paid to the fact that even if the contamination of the outside air increases slowly, it is not so uncomfortable, but it is uncomfortable if the outside air smear increases rapidly. However, when the dirt of the outside air is increasing slowly,
While having a predetermined difference d from the detection signal of this gas sensor,
It is configured to increase or decrease following this detection signal.

Further, in the above-described conventional apparatus, an upper limit value and a lower limit value of the determination level are provided to set whether the outside air is dirty or clean regardless of a change in the detection signal of the gas sensor.

[0005]

However, in the above-mentioned conventional device, even if the upper limit value of the determination level is provided, there are the following problems. For example, if the outside air travels for a long time in a dirty tunnel and the interior air mode is set, and the contamination in the tunnel continues to increase, the above-described determination level increases accordingly.

Therefore, if the detection signal of the gas sensor drops in the tunnel to the extent that the occupant feels uncomfortable and the outside air is contaminated, for example, near the exit in the tunnel, the mode is switched to the outside air mode. However, there is a problem that dirty outside air enters the vehicle cabin and does not fit the occupant's feeling. Conversely, if the vehicle is running in a clean place where the outside air is in the outside air mode, there is a problem that even a slight change in the dirt of the outside air is switched to the inside air mode, which does not suit the occupant's feeling.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle air conditioner in which a determination level is changed in accordance with a detection signal of a gas sensor and in which a determination level suitable for an occupant's feeling can be set.

[0008]

In order to achieve the above object, the amount of increase / decrease of the judgment level (Lsm) is determined by using a dirt signal (VDGS
) Is limited to a predetermined range smaller than the increase / decrease amount. As a result, for example, if the outside air travels in a dirty tunnel for a long time and, as a result, the inside of the tunnel continues to increase in the case where the air inside the vehicle is introduced into the air-conditioning case, the determination level follows this. However, the amount of increase is limited within a predetermined range, and becomes smaller than before.

Thus, for example, when the outside air is contaminated to such an extent that the occupant feels uncomfortable in a tunnel, it is possible to prevent the inside / outside air mode from being switched even with a slight change in the contamination signal. As a result, it is possible to perform the inside / outside air automatic control according to the occupant's feeling. In addition, for example, as a result of traveling in a place where the outside air is clean, when the outside air of the vehicle interior is introduced into the air conditioning case, if the dirt of the outside air keeps decreasing, the determination level decreases accordingly. The amount of increase is limited within a predetermined range and becomes smaller than before.

Thus, for example, in a place where the outside air is very clean, it is possible to suppress the switching between the inside and outside air modes even if the dirt signal slightly changes. As a result, it is possible to perform the inside / outside air automatic control according to the occupant's feeling. Further, the invention according to claim 2 is characterized in that the judgment level (Lsm) is updated based on at least a difference between a preset initial set value (Lsml) and a stain signal (VDGS).

[0011] Thus, from the time when the vehicle air conditioner is first mounted on the vehicle and started, the inside and outside air can be automatically controlled in accordance with the dirt of the outside air. According to the third aspect of the present invention, when the start signal for enabling the vehicle to run is generated, the determination level (Lsm) is set to the initial set value (Lsml).
It is characterized by the following.

This makes it possible to set a judgment level according to environmental conditions.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. First, the overall configuration of the present embodiment will be described with reference to FIG. The vehicle air conditioner 1
An air-conditioning case 2 forming an air passage to the passenger compartment;
A blower 3 for introducing air into the vehicle and blowing air into the passenger compartment, an evaporator 4 as a heat exchanger for cooling, a heater core 5 as a heat exchanger for heating, and an air conditioner control device (air conditioner EC)
U) 6.

Branch cases 2a to 2c are connected to the air downstream side of the air conditioning case 2. The tip of the branch case 2a is connected to a defroster outlet 7 for blowing air toward the inner surface of the window glass 10 of the vehicle, and the tip of the branch case 2b is for blowing air toward the upper body of the occupant. Branch case 2 connected to face outlet 8
The tip of c is connected to a foot outlet 9 for blowing air toward the feet of the occupant.

Each of the outlets 7 to 9 has a branch case 2a to 2c.
It is opened and closed by the outlet switching doors 11 and 12 provided at the upstream opening of the air conditioner. The outlet switching doors 11 and 12 are
It is driven by a servo motor (not shown) via a link mechanism (not shown). Thus, in the present example, a well-known blowing mode for changing a blowing part of the conditioned air in the vehicle compartment can be selected. The blow mode includes a face mode in which conditioned air is blown out of the face outlet 8, a bi-level mode in which conditioned air is blown out from both the face outlet 8 and the foot outlet 9, and a foot level of the foot outlet 9 and the defroster outlet 7. This is a foot mode in which air-conditioning air is blown from both sides.

The blower 3 includes a blower case 3a, a centrifugal fan 3b, and a blower motor 3 as a driving means thereof.
The air flow rate of the conditioned air is determined according to the voltage (blower voltage) applied to the blower motor 3c. At the air inlet of the blower case 3a, two inside air inlets 14 for introducing vehicle interior air (hereinafter, inside air) into the air conditioning case 2 are provided.
And an inside / outside air switching box 50 in which an outside air introduction port 15 for introducing outside air (hereinafter, outside air) into the air conditioning case 2 is formed. Further, the outside air inlet 15 is actually connected to an outside air inlet (not shown) opened to the upper cowl of the vehicle by an outside air introduction duct (not shown).

The inside / outside switching box 50 is provided with two inside / outside air switching doors 16 driven by a servomotor 17 as a driving means. Air flow introduced into the air, and the air conditioning case 2 from the outside air inlet 15
The amount of outside air introduced into the inside is controlled. In this example, an inside air circulation mode (hereinafter, inside air mode) in which vehicle interior air is introduced into the air conditioning case 2 by opening the inside air introduction port 14 and closing the outside air introduction port 15 with the inside / outside air switching door 16. By closing the inside air introduction port 14 with the inside / outside air switching door 16 and opening the outside air introduction port 15, it is possible to switch between the outside air introduction mode (hereinafter, outside air mode) for introducing the air into the air conditioning case 2. .

The evaporator 4 forms an evaporator of a refrigeration cycle (not shown) mounted on the vehicle. The refrigeration cycle includes a refrigerant compressor, a refrigerant condenser, a receiver, a decompression device (not shown), and the evaporator 4. Is a well-known one. The evaporator 4 is arranged in the air conditioning case 2 and cools the low-temperature low-pressure refrigerant by evaporating the low-temperature low-pressure refrigerant by heat exchange with air from the blower 3.

The heater core 5 is disposed downstream of the evaporator 4 in the air conditioning case 2 and heats the air in the air conditioning case 2 using the engine cooling water as a heat source. The heater core 5 is disposed in the air conditioning case 2 such that the cool air from the evaporator 4 forms a bypass passage 30 that bypasses the heater core 5. Then, of the cold air, the amount of air passing through the heater core 5 and the bypass passage 30
Is adjusted by the position of the air mix door 31 provided on the upstream side of the heater core 5 in the air. The air mix door 31 is driven by a servo motor 31 as a driving unit via a link mechanism (not shown).

The air conditioner control device 6 includes a microcomputer in which a control program relating to air conditioning control and various arithmetic expressions are stored, a ROM, a RAM, an I / O port,
The servo motor 17 includes a / D converter and the like (both not shown), based on an operation signal output from the air conditioner operation panel 33 and detection signals from various sensors described later, 31 and blower motor 3
and outputs a control signal to a motor drive circuit 34 for driving the control signal c.

The various sensors include an inside air temperature sensor 36 as a means for detecting the temperature in the vehicle interior, an outside air temperature sensor 37 as a means for detecting the temperature outside the vehicle interior, and the amount of solar radiation radiated into the vehicle interior. A solar sensor 38, a post-evaporator sensor 39 for detecting the air temperature immediately after passing through the evaporator 4, and a water temperature sensor 40 attached to the outer surface of the heater core 5 and detecting the engine cooling water temperature. Used. The vehicle speed sensor 41 is configured by a well-known electromagnetic pickup type wheel speed sensor.

In this embodiment, a gas sensor 42 serving as a means for detecting dirt in the outside air is connected to the air conditioner control device 6 as the various sensors. The gas sensor 42 is for performing the inside / outside air automatic control described later, and is arranged in a vehicle engine room (not shown). In this example, the gas sensor 42 has a semiconductor element (for example, SiO ₂ ) that reacts with a harmful gas such as carbon monoxide (CO) or nitrogen carbide (HC), and an electric heater that heats the semiconductor element. The gas sensor 42 constitutes a dirt signal generating means for generating a dirt signal according to the dirt outside the vehicle compartment according to the present invention. As the concentration of the harmful gas (dirt of the outside air) increases, the output value (output voltage) VDGS increases. Is configured to be low.

The air conditioner operation panel 33 is provided on an instrument panel (not shown) in the vehicle compartment, and switches a well-known blowing mode by operating a temperature setting device (not shown) for setting a set temperature in the vehicle compartment or an occupant. A blow mode setting switch (not shown) is provided. Further, the air conditioner operation panel 33 is provided with an inside / outside air switch (not shown) for switching between inside / outside air modes by an occupant's operation.

The vehicle air conditioner 1 of this embodiment is automatically controlled by the air conditioner control device 6 so that the temperature in the passenger compartment becomes the set temperature set by the temperature setting device. I have. Next, automatic control of the inside and outside air by the gas sensor 42, which is a main part of the present invention, will be described with reference to FIGS.

When the ignition switch of the vehicle is turned on and power is supplied to the air conditioner control device 6, first, at step S10, the gas sensor 42 is warmed up. Here, the warm-up is to heat the semiconductor element by the electric heater to increase the reaction speed of the reaction element. In this example, this heating is performed for about 30 times, during which time the inside / outside air mode becomes the inside air mode.

When the warm-up is completed, in step S20, a reference value VCLR for detecting the concentration of the harmful gas (the size of the outside air, hereinafter simply referred to as the exhaust gas concentration) by the gas sensor 42 is set. I do. Here, the detection accuracy of the gas sensor 42 varies depending on the semiconductor element, and the detection value fluctuates depending on the humidity. Therefore, it is difficult to detect the gas concentration as an absolute value.
Therefore, in the present embodiment, the magnitude of the dirt in the outside air is detected based on the amount of change with respect to the reference value VCLR. The reference value VCLR is an absolute value of dirt detected by the gas sensor 42.

Then, in step S20, the reference value VCLR is determined by the following equation (1).

[0028]

## EQU1 ## Reference value VCLR ← max (VCLR, VDDS) Here, VDDS is the dirt (absolute value) of the gas sensor 42 which is actually detected. As shown in the above equation 1, the reference value V
CLR is the exhaust gas concentration VDGS in the place where the outside air is clean when this flowchart is executed.

Next, in step S30, step S20
The exhaust gas concentration VDGS, which is the detection value of the gas sensor 42, which is read by the above, is read. Further, in step S40, a processing value Ln used for processing of the inside / outside air automatic control described later is calculated. This processing value Ln is calculated by the following equation (2).

[0030]

## EQU2 ## Processing value Ln = gas concentration VDDS / reference value VCLR That is, as described above, this equation 2 can be used as the reference value VCL.
The amount of change with respect to R, which corresponds to the degree of contamination of the outside air. Also, if the outside air is polluted and the size of the dirt is large,
The exhaust gas concentration VDGS and the processing value Ln decrease. Accordingly, it is possible to calculate the size of the dirt in the outside air regardless of the variation in the detection accuracy and the variation in the detection value due to the humidity.

Subsequently, in step S50, a determination level Lsm to be compared with the processing value Ln is calculated. In addition,
The contents of step S50 will be described later in detail. Then, in step S60, the processing value Ln
Is the determination level Ls calculated in step S50.
It is determined whether or not: As described above, if the outside air is contaminated and the dirt is large, the exhaust gas concentration VDGS becomes small. Therefore, when the processing value Ln is smaller than the determination level Lsm, the occupant is contaminated with the outside air being larger than a predetermined reference value. Is when they feel discomfort. Then, in this case, the process proceeds to step S70, and the inside / outside air mode is set to the inside air mode. As a result, the inside / outside air mode is switched to the inside air mode, and dirty outside air is prevented from entering the vehicle interior, so that the occupant does not have to feel uncomfortable.

On the other hand, in step S60, the processing value L
When n is greater than the determination level Lsm, the outside air is not so contaminated, the contaminant degree is smaller than a predetermined reference value, and the occupant does not feel uncomfortable. In step S64, the inside / outside air mode is set to the outside air mode. Next, the contents of step S50 will be described.

The judgment level Lsm is updated based on at least a difference between a preset initial set value Lsml and a dirt signal VDGS. In this example, the following equation (3) is used. Calculation).

[0034]

Lsm = (T-1) / T * Lsm (old) + [(V
DGS-Lsml) * k + Lsml] / T] where T is a time constant for setting a time delay, Lsm (old) is a judgment level one control cycle before, and Lsml is a judgment level stored in the control device 20 in advance. And k is a coefficient.

The function of the equation (3) will be described. It is assumed that a vehicle ignition switch (not shown) is turned on and the engine is started, that is, a start signal for enabling the vehicle to run is generated. In this case, since Lsm (old) is 0, the judgment level Lsm is [(VDDGS-Lsml) * k + Lsml] /
T]. Therefore, when VDGS is larger than Lsml, the latest judgment level Lsm becomes smaller than Lsml,
If VDGS is smaller than Lsml, the latest judgment level L
sm is greater than Lsml.

As a result, the determination level Lsm is updated by increasing or decreasing in accordance with the increase or decrease of VDGS which is the dirt signal. In addition, by setting the initial set value Lsml in Equation 3 as described above, the above-described inside / outside air automatic control is performed according to the dirt of the outside air from the time of starting the engine, thereby setting the determination level according to the environmental conditions of the traveling. Becomes possible. In this example, the increase / decrease amount of the determination level Lsm is determined by the coefficient k.
It is limited to a predetermined range smaller than the increase / decrease amount of VDGS.
Incidentally, (VDGS-Lsml) × k corresponds to the increase / decrease amount limiting means. That is, the coefficient k needs to be 0 <k <1 (0.7 in this example). According to the study of the present inventors, if the coefficient k is 1 or more, as in the above-described conventional device, The determination level follows the dirt signal VDGS too much, and the above-described problem occurs.

Therefore, in this example, since the coefficient k is set to a value of 0.7 smaller than 1, the amount of increase / decrease of the determination level Lsm is limited to a predetermined range smaller than the amount of increase / decrease of VDGS. According to the study by the present inventors, it has been found that the above problem can be solved. FIG. 3 shows a change in the determination level Lsm due to the difference in the coefficient k.
The judgment level Lsm changes in the same manner as the change in the dirt signal VDDGS. However, when k = 0.7, the increase / decrease amount of the judgment level Lsm becomes smaller than the increase / decrease amount of VDDGS.

Therefore, for example, when the outside air travels in a dirty tunnel for a long time and the inside and outside air mode is the inside air mode and the inside of the tunnel keeps increasing, the determination level Lsm follows this. However, the amount of increase is small because it is limited within a predetermined range by a coefficient k. Thus, when the outside air is dirty to the extent that the occupant feels uncomfortable in the tunnel, it is possible to suppress switching between the inside and outside air modes even if the outside air is slightly changed. As a result, it is possible to perform the inside / outside air automatic control according to the occupant's feeling.

Further, for example, when the inside and outside air mode is the outside air mode as a result of running in a place where the outside air is clean, if the outside air dirt continues to decrease, the above-described determination level Lsm decreases accordingly. The amount of increase is limited to a predetermined range by a coefficient k, so that the amount of increase is smaller than in the related art. Thus, for example, in a place where the outside air is very clean, it is possible to suppress switching between the inside and outside air modes even if the outside air is slightly changed. As a result, it is possible to perform the inside / outside air automatic control according to the occupant's feeling.

In FIG. 3, the line representing the change in the judgment level Lsm is delayed with respect to the line representing the change in VDGS, but is delayed by the time constant T. is there. (Modification) In the above embodiment, the inside / outside air switching door 16 is configured by a plate-shaped plate door, but may be a rotary door or a film-shaped member.

In each of the above embodiments, whether the outside air is contaminated is determined by comparing the processing value Ln, which is the rate of change of the exhaust gas concentration, with the determination level Lsm. The determination level Lsm may be compared.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle air conditioner according to an embodiment of the present invention.

FIG. 2 is a flowchart showing control contents of the vehicle air conditioner in the embodiment.

FIG. 3 illustrates a change update of a determination level Lsm in the embodiment.

[Explanation of symbols]

2 ... air-conditioning case, 6 ... air-conditioning ECU, 42 ... gas sensor.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masafumi Kawashima 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Co., Ltd. (72) Inventor Tomoyuki Kako 1-1-1, Toyota-cho, Toyota-shi, Aichi Pref. In-company (56) References JP-A-5-294133 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60H 1/00 103

Claims (3)

(57) [Claims] An air-conditioning case (2) forming a ventilation path to a vehicle interior; a dirt signal generating means (42) for generating a dirt signal in accordance with dirt of the air outside the vehicle; and a dirt signal (VDGS). Determining means (S60) for determining whether or not the air outside the vehicle compartment is dirty based on the determination level (Lsm). Then, the vehicle interior air is introduced into the air conditioning case (2), and when the determination means (S60) determines that the vehicle exterior air is clean, the vehicle interior air is introduced into the air conditioning case (2). An air-conditioning system for a vehicle which performs automatic control of inside and outside air for introducing air, and further increases and decreases the determination level (Lsm) in accordance with increase and decrease of the dirt signal (VDGS). An apparatus, wherein the amount of increase or decrease of the determination level (Lsm) is The dirt signal (V
A vehicle air conditioner characterized in that the air conditioner is limited to a predetermined range smaller than the amount of increase or decrease of DGS). 2. The method according to claim 1, wherein the determination level is updated based on at least a difference between a preset initial value (Lsml) and the dirt signal (VDGS). Vehicle air conditioners. 3. The air conditioner for a vehicle according to claim 2, wherein the determination level (Lsm) is set to the initial set value (Lsml) when a start signal for enabling the vehicle to run is generated.