JPH04173422A - Air-conditioning device for vehicle - Google Patents

Abstract

PURPOSE:To effectively prevent entrance of exhaust gas to the interior of a car room by expediting a timing of switching to an internal air introduction mode when a blower output exceeds a given reference value during switching of an open air introduction mode to an internal air introduction mode when gas concentration of the open air exceeds a given threshold. CONSTITUTION:Through automatic control of air-conditioning by means of a control unit 30 for an air-conditioning device 1, switching of the opening of an air mix damper 15 and a fan output, switching of introduction ports 12 and 13 and discharge ports 9-11 for air-conditioned air, and ON/OFF of a compressor 23 are decided based on detecting outputs from temperature sensors 42-45 and a solar radiation sensor 46. Actuators 20-22 are respectively driven and temperature is automatically controlled to the target set value of a temperature set volume 36. In this case, a gas sensor 41 to detect gas concentration of the open air is located, and when a detecting value is increased to a value higher than a given threshold, an open air introduction mode is switched to an internal air introduction mode. When a blower output is three stages or more, a given threshold is narrowly varied and a timing of switching to an internal air introduction mode is accelerated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle air conditioner, and particularly to one configured to switch the introduction mode of conditioned air according to the gas concentration of outside air.

[Prior art]

Generally, vehicles such as automobiles are equipped with an air conditioning system that maintains appropriate temperature and humidity inside the vehicle to improve livability and remove fogging from the front window to ensure good visibility.

Normally, the air conditioner has a defroster mode that blows out warm air from the defroster outlet, a heat mode that blows out warm air from the heat outlet, and a vent mode that blows cold air from the vent outlet depending on the conditions inside the vehicle. The system is configured so that multiple modes can be selected, and the air-conditioned air introduction mode can be selectively selected between an inside air introduction mode that circulates the inside air in the vehicle interior and an outside air introduction mode that introduces outside air. It is configured.

On the other hand, Japanese Unexamined Patent Publication No. 62-292521 discloses that a large amount of exhaust gas from preceding trucks, buses, etc. and exhaust gas filling the tunnel can be prevented from entering the vehicle interior and causing discomfort to the passengers. To do this, a sensor is installed to detect the gas concentration in the outside air, and when the gas concentration in the outside air exceeds a predetermined threshold, the outside air introduction mode is forcibly switched to the inside air introduction mode, and the exhaust gas is removed from the vehicle. An air conditioner configured to prevent intrusion into a room is described.

[Problem to be solved by the invention]

The air conditioner described in the above publication switches the conditioned air introduction mode to the inside air introduction mode when the gas concentration of the outside air becomes high, so it is possible to prevent a large amount of exhaust gas from entering the passenger compartment. This is set regardless of the threshold value or the blower output, so if the blower output is high, the amount of air being blown is large, and a large amount of exhaust gas will enter the passenger compartment before switching to inside air introduction mode. This may cause discomfort to the passengers.

On the other hand, by setting the threshold low, the intrusion of exhaust gas into the passenger compartment is suppressed even when the blower output is high, or in this case, the system is forcibly switched to the internal air introduction mode even at a slight gas concentration. However, the problem arises that it becomes difficult to control the air conditioning properly, causing discomfort to the occupants.

The purpose of the present invention is to make full use of regular air conditioning control while
An object of the present invention is to provide a vehicle air conditioner that can effectively prevent exhaust gas from entering a vehicle interior.

[Means to solve the problem]

A vehicle air conditioner according to a first aspect of the invention comprises: a mode switching means for selectively switching the introduction mode of the conditioned air between an outside air introduction mode and an inside air introduction mode; a detection means for detecting the gas concentration of the outside air; and a control means for controlling the mode switching means to change from the outside air introduction mode to the inside air introduction mode when the gas concentration of the outside air exceeds a predetermined threshold value in response to an output from the means. A blower output detection means for detecting a blower output of a blower blowing air into the vehicle interior is provided, and when the blower output is equal to or higher than a predetermined reference value upon receiving the output from the blower output detection means, the inside air introduction mode is set by the control means. A switching timing change means is provided for advancing the switching timing to the switching timing relative to the switching timing when the voltage is lower than the reference value.

A vehicle air conditioner according to a second claim is the vehicle air conditioner according to the first claim, wherein the switching timing changing means changes the predetermined threshold value to a small value to advance the switching timing. It is composed of

[Effect]

In the vehicle air conditioner according to the first aspect, the control means receives the output from the detection means for detecting the gas concentration of the outside air, and when the gas concentration of the outside air exceeds a predetermined threshold value, the control means switches the mode. The introduction mode of the conditioned air is switched from the outside air introduction mode to the inside air introduction mode by controlling the means, but before switching to the inside air introduction mode, the blower output detected by the switching timing changing means or the blower output detection means Accordingly, when the blower output is above a predetermined reference value, the timing of switching to the inside air introduction mode by the control means is earlier than the switching timing when the blower output is less than the predetermined reference value. is able to prevent exhaust gas from entering the passenger compartment while performing regular air conditioning control as much as possible.If the blower output exceeds a predetermined standard value, the switching timing is advanced to prevent large amounts of exhaust gas from entering the passenger compartment. can effectively prevent intrusion.

In the vehicle air conditioner according to the second aspect, the same effect as the vehicle air conditioner according to the first aspect can be obtained. In addition,
The switching timing changing means is configured to advance the switching timing by changing the threshold value to a small value when the blower output exceeds a predetermined reference value, so one detection means can be effectively used to perform switching. In addition to being able to set the timing, it is also possible to change the threshold value in multiple stages according to the blower output, making it easy to switch the introduction mode of the conditioned air more precisely.

〔Effect of the invention〕

According to the vehicle air conditioner according to the first aspect, as detailed in the [Operation] section above, when the blower output is less than a predetermined reference value, the air conditioner performs normal air conditioning control as much as possible while exhausting the air. It is possible to prevent gas from entering the vehicle interior, and when the proa output is higher than a predetermined reference value, the switching timing is advanced to effectively prevent large amounts of exhaust gas from entering the vehicle interior.

According to the vehicle air conditioner according to the second aspect, the same effects as the vehicle air conditioner according to the first aspect can be obtained. In addition, 1
Not only can the switching timing be set by effectively utilizing two detection means, but also the threshold value can be changed in multiple stages according to the blower output, making it easy to more precisely switch the introduction mode of the conditioned air.

〔Example〕

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

As shown in FIG. 1, an air conditioner l for an automobile includes an air conditioning unit 5 which is a unit of a proafan 2, an evaporator 3, a heater core 4, etc., a unit duct 6 as a casing of the air conditioning unit 5, and a unit duct 6. The main duct 7 is provided with a plurality of vent outlets 9 at the downstream end thereof, a defroster outlet 10 is provided in the middle of the differential duct 8, and the unit duct 6 is provided with a heat outlet. An air outlet 11 is provided, and the unit duct 6 near the suction part of the proafan 2 is provided with an inside air inlet 12 and an outside air inlet 13.

The air conditioning unit 5 includes an inside/outside air switching damper 1 that opens one of the inside air inlet 12 and the outside air inlet 13 and closes the other.
4, an air mix damper 15 provided in the upstream passage of the heater core 4, a sub-damper 16 provided in the downstream passage of the heater core 4, a vent damper 17 provided in the upstream part of the main duct 7, and a differential duct. 8 and a heat damper 19 provided in a passage upstream of the heat outlet 11. The inside/outside air switching damper 14 is selectively opened and closed by an actuator 20, The opening degrees of the differential damper 18 and the heat damper 19 are adjusted by actuators 21, and the opening degrees of the air mix damper 15 and sub-damper 16 are adjusted by actuators 22, respectively.

The air conditioner 1 includes an evaporator 3 and a compressor 2.
3, a condenser 24, and an expansion valve 25, a compressor 23 is connected to the output shaft 27 of the engine E via a pulley 26 equipped with an electromagnetic clutch, and refrigerant is circulated via a circulation pipe 28. As a result, the evaporator 3 is cooled.

The control unit 3o of the air conditioner l includes a first
As shown in the figure, there is a start switch 31 of the air conditioner 1, a mode selection switch 32 for selecting the outlet 9, 1o, 11 of the conditioned air such as vent mode, heater mode, and differential mode, and a mode selection switch 32 for selecting the outlet 9, 1o, 11 of the conditioned air such as vent mode, heater mode, and differential mode. an inside/outside air changeover switch 33 for selectively switching between an inside air introduction mode for introducing air and an outside air introduction mode for introducing outside air;
An auto mode switch 34 for automatically adjusting the temperature in the vehicle interior to a target set temperature, and an air volume setting switch 35 for switching the blower output in four stages from the lowest air volume (1 stage) to the highest air volume (4 stages). , switches such as a temperature setting volume 36 are connected, as well as a gas sensor 41 installed near the condenser 24 at the front of the vehicle, an inside air temperature sensor 42, an outside air temperature sensor 43, and a temperature sensor installed at the outlet of the evaporator 3. A sensor 44, an engine water temperature sensor 45, a solar radiation sensor 46, etc. are also connected, and furthermore, actuators 20, 21, 22, a fan motor 2a of the pro-afan 2, and an electromagnetic clutch of the pulley 26 are connected, respectively.

The resistance value of the gas sensor 41 changes according to the gas concentration in an atmosphere containing flammable (reducing) gases such as H, Co, and NOx, and the resistance value decreases as the gas concentration increases. It has the characteristics shown in .

The resistance value is determined by applying a predetermined voltage of, for example, 12 V from the control unit 30 to one terminal of the gas sensor 41 and detecting the voltage or current input from the other terminal.

The control unit 30 is mainly composed of a microcomputer, and other necessary A/D converters,
It is equipped with a drive circuit for the actuators 20, 21, 22, a drive circuit for the fan motor 2a, a drive circuit for the electromagnetic clutch, etc., and the ROM automatically controls the air conditioner 1 when the auto mode is selected. A control program for automatic air conditioning control, a control program for internal/external air switching control that is executed as an interrupt process during execution of this control program, and a map for calculating gas concentration based on the resistance value of the gas sensor 41. etc. are input and stored in advance.

The automatic air conditioning control described above is based on the detection outputs from the temperature sensors 42 to 45 and the solar radiation sensor 46, and switches the opening degree of the air mix damper 15 and the fan output, as well as the air conditioning air inlet 1.
2, 13 and air outlet 9, 10, 11 and 0N10FF of the compressor 23 are determined, and the actuator 2
This is an existing well-known device that is configured to automatically control the temperature inside the vehicle compartment to a target temperature set by a temperature setting volume 36 by driving an electromagnetic clutch.

By the way, in the above automatic air conditioning control, the outside air introduction mode is normally selected when the vehicle interior is not being rapidly cooled, so when driving behind a truck or bus or in a tunnel, a large amount of exhaust gas is It is introduced into the vehicle interior via the device 1.

In particular, when the blower output is high and the amount of air blown is large, a large amount of outside air is introduced into the vehicle interior, so that the gas concentration in the vehicle interior rapidly increases.

The air conditioner 1 of the present application includes a gas sensor 41 that detects the gas concentration of outside air, and when the gas concentration determined from the resistance value of the gas sensor 41 exceeds a predetermined threshold, the outside air introduction mode is changed to the inside air introduction mode. At the same time, if the blower output is 3 or more stages, the predetermined threshold value is changed to a smaller value to hasten the timing of switching to the inside air introduction mode and prevent exhaust gas from entering the passenger compartment. This is what I did.

Next, the above-mentioned internal/external air switching control will be explained with reference to the flowchart shown in FIG. 3. In addition, in the figure, Si (
i=1.2.3,...) is each step.

When the start switch 31 of the air conditioner 1 is turned on and the auto mode switch 34 is operated, automatic air conditioning control is started. Then, when the inside/outside air switching control is started as an interrupt process for this automatic air conditioning control, the resistance value of the gas sensor 41 is read, and the current number of stages B of the proa fan 2 set by the automatic air conditioning control and the conditioned air The introduction mode is read (S1), and the gas concentration G of the outside air is determined from the resistance value of the gas sensor 41 (S2).

Next, it is determined whether the air-conditioned air introduction mode is the outside air introduction mode (S3), and in the case of the outside air introduction mode, it is determined whether the number of stages B of the proa fan 2 is 3 or more stages (S4),
In the case of one stage or two stages, the threshold value α is a standard value St
(S5), and in the case of three or four stages, the threshold value α or a value Lo smaller than the standard value St is set (S6).

Next, it is determined whether the gas concentration G of the outside air is equal to or higher than the threshold value α (S7), and if No, the system returns to automatic air conditioning control, and if Yes, the internal air introduction mode is set (
S8), the outside air inlet 13 is closed by the inside/outside air switching damper 14 and the inside air inlet 12 is opened, flag F is set (S9), and the process returns to automatic air conditioning control. In other words, if the gas concentration in the outside air becomes high, such as when entering a tunnel with poor ventilation or when a preceding truck or bus starts,
The outside air introduction mode is switched to the inside air introduction mode to prevent exhaust gas from entering the vehicle interior. Moreover, the fourth
As shown in the figure, when the number of stages B of the proafan 2 is set to one or two stages and the amount of air conditioned air introduced is relatively small, the threshold value α is set to the standard value St. ,
This prevents frequent switching of the introduction mode due to slight fluctuations in gas concentration, and when the number of stages B of the proafan 2 is set to 3 or 4 and the amount of air conditioned air introduced is relatively large, the threshold A value Lo smaller than the value α or the standard value St
Therefore, the switching timing of the introduction mode is earlier than when the standard value St is used as the threshold value α, and the intrusion of exhaust gas into the passenger compartment is effectively prevented.

On the other hand, if it is determined No in S3, that is, if the inside air introduction mode is selected, it is determined whether the flag F is set (SlO), and the inside air is If the introduction mode is selected, the determination is Yes and the process moves to Sll; if the internal air is being circulated for rapid cooling, the determination is No and the process returns to automatic air conditioning control.

In Sll, it is determined whether the gas concentration G of the outside air is less than a predetermined threshold value β, and when the gas concentration G of the outside air becomes less than the predetermined threshold value β after passing through a tunnel, etc., the mode is set to be the outside air introduction mode. (3, 12), flag F is reset (
S13) If the gas concentration of the outside air is still higher than the threshold value β, such as while driving in a tunnel, the system returns to the automatic air conditioning control while remaining in the inside air introduction mode. Note that the threshold value α is set larger than the threshold value β to prevent frequent switching of the introduction mode due to slight fluctuations in the gas concentration G near the threshold value α.

As described above, according to the air conditioner 1 according to the above embodiment, by switching the threshold value α depending on whether the blower output is high or low, regular air conditioning control is performed when the blower output is less than 3 stages. While doing so as much as possible, it is possible to prevent exhaust gas from entering the passenger compartment.If the blower output is 3 or more stages, the switching timing is advanced to effectively prevent large amounts of exhaust gas from entering the passenger compartment. I can do it. Moreover, one gas sensor 41 can be effectively used to switch the introduction mode of the conditioned air.

In this embodiment, the inside/outside air switching control was executed as an interrupt process for automatic air conditioning control, but the inside/outside air changeover switch 33
Even when the outside air introduction mode is set by the operation, if the gas concentration of the outside air becomes high, the air conditioning air introduction mode may be switched in the same manner as described above.

In this embodiment, the internal/external air switching timing is set based on the output of one gas sensor 41, but the switching timing may be set using the outputs of two gas sensors with different sensitivities.

In this embodiment, the present invention was applied to an air conditioner that can change the air flow rate in four stages, but the present invention can be applied in substantially the same way to an air conditioner that can adjust the air flow rate in four stages or more or in a stepless manner. .

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Fig. 1 is an overall configuration diagram of an air conditioner, Fig. 2 is a characteristic diagram of a gas sensor, Fig. 3 is a flowchart of a routine for controlling inside/outside air, and Fig. 4 is a diagram of an air conditioner. It is a time chart showing the timing of changing the mind and the like. ■...Air conditioner, 2...Proa fan, 12...Inside air inlet, 13...Outside air inlet, 14...Inside and outside air switching damper, 20...Actuator, 30...Control unit, 33...Inside and outside air changeover switch,
41...Gas sensor. Figure 2 Gas concentration Figure 3

Claims (1)

[Claims] (1) A mode switching means for selectively switching the introduction mode of the conditioned air between an outside air introduction mode and an inside air introduction mode; a detection means for detecting the gas concentration of the outside air; In a vehicle air conditioner comprising: a control means for controlling a mode switching means to switch from an outside air introduction mode to an inside air introduction mode when a gas concentration exceeds a predetermined threshold; A blower output detection means for detecting the blower output is provided, and when the blower output is equal to or higher than a predetermined reference value in response to the output from the blower output detection means, the timing for switching to the inside air introduction mode by the control means is set to a time lower than the reference value. An air conditioner for a vehicle, characterized in that it is provided with a switching timing change means for advancing the switching timing compared to the current switching timing. (2) The vehicle air conditioner according to claim 1, wherein the switching timing changing means is configured to change the predetermined threshold value to a small value to advance the switching timing.