WO2019021681A1

WO2019021681A1 - Air conditioning device

Info

Publication number: WO2019021681A1
Application number: PCT/JP2018/023011
Authority: WO
Inventors: 政幸児玉; 竹田　弘; 佑太辻
Original assignee: 株式会社デンソー
Priority date: 2017-07-28
Filing date: 2018-06-15
Publication date: 2019-01-31
Also published as: JP2019026040A; CN110997374B; CN110997374A; JP6798440B2

Abstract

This air conditioning device (10) is provided with: an air conditioning unit (260) for regulating the temperature of air to be discharged into the interior of a vehicle; an outside air introduction unit (220) for introducing, from the outside of the vehicle, air to be supplied to the air conditioning unit; an inside air introduction unit (210) for introducing, from the interior, air to be supplied to the air conditioning unit; an inside air/outside air regulation unit (230) for regulating the amount of air to be introduced from each of the outside air introduction unit and the inside air introduction unit; a filter (240) for removing particles from air to be supplied to the air conditioning unit; a blower (250) for delivering air so that the air flows through the filter and the air conditioning unit; and a control unit (120) for controlling the operation of each of the inside air/outside air regulation unit and the blower. The control unit is configured so that, when particle reduction control for increasing the flow rate of air flowing through the filter is being performed, the control unit regulates the flow rate of air to be introduced from the outside air introduction unit.

Description

Air conditioner

Cross-reference to related applications

This application is based on Japanese Patent Application No. 201 7146621 filed on July 28, 2017 and claims the benefit of its priority, and the entire contents of the patent application are: Incorporated herein by reference.

The present disclosure relates to an air conditioner installed in a vehicle.

An air conditioner mounted on a vehicle is a device that adjusts the temperature of air taken in from the vehicle interior or the outside of the vehicle and blows out the temperature-adjusted air into the vehicle interior as conditioned air. In recent years, it has also been considered to provide an air conditioner with a function of reducing the concentration of particles (for example, pollen, PM 2.5, etc.) drifting in the air in a vehicle cabin.

For example, in the air conditioner described in Patent Document 1 below, it is possible to reduce the pollen concentration in the vicinity of the face of the occupant by blowing clean air that has passed through the filter toward the face of the occupant.

Patent No. 431270 gazette

In the air conditioner described in Patent Document 1, when performing control to blow clean air that has passed through the filter toward the face of the occupant, the mode that blows out only the air taken in from the vehicle compartment into the vehicle compartment, that is, the inside air mode Switching. As a result, since air containing a large amount of particles is not taken in from the outside of the vehicle, cleaner air can be blown into the vehicle compartment.

However, in the state where only the air in the vehicle compartment circulates without any air from the outside of the vehicle being taken in, the humidity of the vehicle compartment is excessively increased and fogging occurs on the window of the vehicle There is. In addition, the concentration of carbon dioxide in the passenger compartment may gradually increase, causing the occupants to feel uncomfortable.

An object of the present disclosure is to provide an air conditioner capable of preventing occurrence of fogging or the like on a window of a vehicle while reducing particle concentration in a vehicle interior.

An air conditioner according to the present disclosure is an air conditioner installed in a vehicle, and includes an air conditioning unit that adjusts a temperature of air blown out into a vehicle cabin of the vehicle, and an air supplied to the air conditioning unit from the outside of the vehicle. To adjust the amount of air introduced from each of the outside air introducing unit and the outside air introducing unit and the inside air introducing unit for introducing the air supplied to the air conditioning unit from the vehicle compartment A filter for removing particles from air supplied to the air conditioning unit, a blower for sending out the air so as to pass through the filter and the air conditioning unit, and a control unit for controlling the operation of the inside / outside air adjustment unit and the blower Prepare. The control unit is configured to adjust the flow rate of air introduced from the outside air introduction unit when performing particle reduction control, which is control to increase the flow rate of air passing through the filter.

Such an air conditioner can perform particle reduction control. The particle reduction control is control to increase the number of particles collected per unit time in the filter by increasing the flow rate of air passing through the filter. By performing such particle reduction control as necessary, it is possible to reduce the concentration of particles in the air in the vehicle compartment.

When performing particle reduction control, the control unit adjusts the flow rate of air introduced from the outside air introduction unit. That is, the control unit performs particle reduction control while introducing an appropriate amount of air (outside air) from the outside air introduction unit as needed, thereby preventing the humidity and carbon dioxide concentration in the vehicle compartment from becoming too high. can do. As a result, it is possible to prevent fogging and the like on the window of the vehicle while reducing the particle concentration in the vehicle compartment.

According to the present disclosure, it is possible to provide an air conditioner capable of preventing fogging and the like on the window of the vehicle while reducing the particle concentration in the vehicle interior.

FIG. 1 is a view schematically showing the overall configuration of the air conditioner according to the present embodiment. FIG. 2 is a flowchart showing the flow of processing executed by the control device. FIG. 3 is a flowchart showing the flow of processing executed by the control device. FIG. 4 is a flowchart showing the flow of processing executed by the control device. FIG. 5 is a flowchart showing the flow of processing executed by the control device. FIG. 6 is a diagram showing an example of the time change of each of the particle concentration and the blower rotation number. FIG. 7 is a flowchart showing the flow of processing executed by the control device.

Hereinafter, the present embodiment will be described with reference to the attached drawings. In order to facilitate understanding of the description, the same constituent elements in the drawings are denoted by the same reference numerals as much as possible, and redundant description will be omitted.

The air conditioner 10 which concerns on this embodiment is demonstrated, referring FIG. The air conditioner 10 is a device mounted on a vehicle (the whole is not shown), and is configured as a device for performing temperature control of air in a cabin of the vehicle, that is, air conditioning. The air conditioner 10 includes an air conditioning case 200, a blower 250, a filter 240, an air conditioning unit 260, a concentration detection unit 291, and a control device 100.

The air conditioning case 200 is a tubular member for guiding the air to be air conditioned into the vehicle compartment. Inside the air conditioning case 200, the air flows from the left side to the right side in FIG. In the air conditioning case 200, an outside air introducing unit 220, an inside air introducing unit 210, a face duct 270, and a foot duct 280 are formed.

The outside air introducing unit 220 is a portion serving as an inlet for introducing air supplied to the air conditioning unit 260 described later from the outside of the vehicle to the inside of the air conditioning case 200. The inside air introducing unit 210 is a portion serving as an inlet for introducing the air supplied to the air conditioning unit 260 from the vehicle interior to the inside of the air conditioning case 200. The inside air introducing unit 210 and the outside air introducing unit 220 are formed to be aligned in the upstream side portion of the air conditioning case 200.

An inside / outside air switching door 230 is provided between the outside air introducing unit 220 and the inside air introducing unit 210. The inside / outside air switching door 230 is a door for adjusting the amount of air introduced from each of the outside air introducing unit 220 and the inside air introducing unit 210, and corresponds to the “inside / outside air adjusting unit” in the present embodiment. By operating the inside / outside air switching door 230, the flow rate of air introduced from the outside air introducing unit 220 and supplied to the air conditioning unit 260, and the flow rate of air introduced from the inside air introducing unit 210 and supplied to the air conditioning unit 260, The ratio of, is adjusted.

The air introduced from the outside air introducing unit 220 is hereinafter also referred to as "outside air". Moreover, the thing of the air introduced from the inside air introduction part 210 is described also as "inner air" below. As shown in FIG. 1, when the outside air introduction unit 220 is completely closed, only inside air is introduced into the air conditioning unit 260 and outside air is not introduced. The operation of the inside / outside air switching door 230 is controlled by the control device 100 described later.

The actuator of the inside / outside air switching door 230 incorporates an opening degree sensor (not shown) for detecting the opening degree of the inside / outside air switching door 230 at the present time. The opening degree of the inside / outside air switching door 230 detected by the opening degree sensor is transmitted to the control device 100.

The face duct 270 and the foot duct 280 are both exhaust ports for introducing the conditioned air into the vehicle compartment. The face duct 270 and the foot duct 280 are formed on the downstream side of the air conditioning case 200. The face duct 270 is connected to a face outlet (not shown) for blowing conditioned air toward the face of the occupant. The foot duct 280 is connected to a foot outlet (not shown) for blowing conditioned air toward the feet of the occupant.

A face door 271 is provided at the inlet of the face duct 270. When the face door 271 is in the open state as shown in FIG. 1, conditioned air is supplied from the face duct 270 toward the face outlet. Similarly, a foot door 281 is provided at the inlet of the foot duct 280. When the foot door 281 is in the open state, conditioned air is supplied from the foot duct 280 toward the foot outlet. The operations of the face door 271 and the foot door 281 are controlled by the control device 100.

For example, the downstream side of the face duct 270 may be branched into two, and one of them may be connected to a defroster outlet (not shown) formed in the vicinity of the window.

The blower 250 is a blower for delivering air to the downstream side inside the air conditioning case 200. Air delivered by the blower 250 is blown out into the vehicle cabin through the filter 240 and the air conditioner 260 in order. The rotational speed of the blower 250, that is, the air volume of the conditioned air blown out from the air conditioner 10 into the vehicle cabin is controlled by the control device 100.

The filter 240 is a filter for removing particles contained in the air from the air supplied to the air conditioning unit through the air conditioning case 200. The filter 240 is provided on the downstream side of the inside air introducing unit 210 and the outside air introducing unit 220 and on the upstream side of the blower 250. The particles removed by the filter 240 may be, for example, fine particles such as PM 2.5, or may be pollen, dust, or the like.

The air conditioning unit 260 is a part that adjusts the temperature of the air blown out into the vehicle compartment and thereby generates the conditioned air. In the air conditioning unit 260, the temperature of air is adjusted by heat exchange with a refrigerant or the like. The air conditioning unit 260 is provided downstream of the blower 250 and upstream of the face duct 270 and the foot duct 280. The air conditioning unit 260 includes an evaporator for dehumidifying and cooling the air, a heater core for heating the air, an air mix door for adjusting the flow rate of the air passing through them, a compressor for circulating the refrigerant, and the like. (All not shown) are provided. In addition, since a well-known thing can be employ | adopted as a structure of such an air-conditioning part 260, the specific illustration and description are abbreviate | omitted.

The concentration detection unit 291 is a sensor for detecting the concentration of particles in the air in the vehicle compartment. As shown in FIG. 1, one end of an introduction pipe 290 is connected to a position downstream of the filter 240 and upstream of the blower 250 in the air conditioning case 200. The other end of the introduction pipe 290 is open to the passenger compartment. The concentration detection unit 291 is provided at a position in the middle of the introduction pipe 290. When the air is flowing inside the air conditioning case 200, the negative pressure generated on the air conditioning case 200 side also causes the air flow in the introduction pipe 290. That is, a flow of air from the vehicle interior to the inside of the air conditioning case 200 through the introduction pipe 290 occurs. The concentration detection unit 291 measures the concentration of particles contained in the air, and transmits the concentration to the control device 100 by an electrical signal.

The introduction pipe 290 may be a flow path formed to partition a part of the air conditioning case 200 by a wall.

Control device 100 is a device for controlling the overall operation of air conditioner 10. The control device 100 is configured as a computer system provided with a CPU, a ROM, a RAM, and the like. The control device 100 includes a fogging determination unit 110, a control unit 120, and a storage unit 130 as functional control blocks.

The fogging determination unit 110 is a portion that determines an index (hereinafter referred to as “cloudiness index”) indicating the likelihood of fogging in a window (not shown) provided in the vehicle. In the present embodiment, the value of the humidity in the vehicle compartment measured by the humidity sensor 141 described later is determined and used as it is as the above-mentioned fog index.

The control unit 120 is a part that controls the operation of the inside / outside air switching door 230, the blower 250, and the like. The specific aspect of the control performed by the control part 120 is mentioned later.

The storage unit 130 is a non-volatile storage device provided in the control device 100. The storage unit 130 stores information necessary for control performed by the control unit 120 each time.

The control device 100 is connected to various switches and sensors provided in each part of the vehicle. Among these, the operation switch 140, the humidity sensor 141, and the in-vehicle camera 142 are shown in FIG.

The operation switch 140 is a switch operated by an occupant of the vehicle to start or end the execution of the particle reduction control. The particle reduction control is control to increase the number of particles collected per unit time in the filter 240 by increasing the flow rate of air passing through the filter 240. By performing such particle reduction control according to the driver's request, it is possible to reduce the particle concentration in the air inside the vehicle compartment.

The humidity sensor 141 is a sensor for measuring the humidity in the passenger compartment. The humidity measured by the humidity sensor 141 is input to the control device 100 by an electrical signal.

The in-vehicle camera 142 is a camera for capturing an image of the interior of the vehicle, and is, for example, a CMOS camera. An image captured by the in-vehicle camera 142 is input to the control device 100 as image data. The control device 100 can grasp, for example, the number of occupants present in the vehicle compartment by analyzing the image.

The specific content of the control executed by the control device 100 will be described with reference to FIG. A series of processes shown in FIG. 2 are processes that are repeatedly performed each time a predetermined control cycle elapses after an operation for starting execution of particle reduction control is performed on the operation switch 140. The process is repeatedly performed by the control device 100 until an operation for ending the execution of the particle reduction control is performed on the operation switch 140.

In the first step S01, it is determined whether the particle concentration detected by the concentration detection unit 291 is equal to or higher than the threshold TH2. The threshold TH2 is a threshold set in advance as a value of the particle concentration that requires execution of particle reduction control. When the particle concentration is equal to or higher than the threshold TH2, the process proceeds to step S02.

In step S02, it is determined whether the value of the flag FL is 0 or not. The flag FL is a variable that is set to 1 when particle reduction control is being performed, and is set to 0 otherwise. If the value of the flag FL is 0, that is, if particle reduction control is to be started, the process proceeds to step S03. If the value of the flag FL is 1, that is, if the particle reduction control is already being executed, the process proceeds to step S05 described later.

In step S03, the opening degree of the inside / outside air switching door 230 at the present time and the rotation speed of the blower 250 at the present time are acquired, respectively, and these are stored in the storage unit 130.

In step S04 following step S03, 1 is set to the value of the flag FL. In step S05 following step S04, the above-described processing for starting the particle reduction control is performed. Here, processing is performed such that the number of rotations of the blower 250 is made larger than the number of rotations up to that point. Further, processing for changing the opening degree of the inside / outside air switching door 230 is also performed. In the present embodiment, a plurality of types of control are executed in parallel as particle reduction control. The specific content of each control will be described later.

In step S06 following step S05, it is determined whether a predetermined period has elapsed since the process of step S05 is performed. If the predetermined time period has not elapsed, the series of processes shown in FIG. 2 are ended. If the predetermined period has elapsed, the process proceeds to step S07.

In step S07, it is determined whether the particle concentration detected by the concentration detection unit 291 is equal to or less than the threshold TH1. The threshold value TH1 is a threshold value which is preset as a value of particle concentration which is assumed to be sufficiently lower if the above-mentioned predetermined period elapses in a state where the particle reduction control is normally effective. The value of the threshold TH1 is smaller than the value of the above-mentioned threshold TH2 and larger than the value of the below-mentioned threshold TH0.

In step S07, when the particle concentration is equal to or less than the threshold value TH1, it means that the particle reduction control is normally effective. Therefore, in this case, the series of processes shown in FIG. 2 are ended without performing any special process.

If the particle concentration exceeds the threshold TH1 in step S07, the process proceeds to step S08. In step S08, it is determined whether the particle concentration detected by the concentration detection unit 291 is equal to or higher than the threshold TH3. The threshold TH3 is a threshold set in advance as a value of the minimum particle concentration which is considered to be detected when smoking is performed in the vehicle compartment. As shown in FIG. 6, the value of the threshold TH3 is larger than the value of the threshold TH2.

If the particle concentration is less than the threshold TH3 in step S08, the process proceeds to step S09. Shifting to step S09 means that although the particle reduction control was performed in a situation where smoking was not performed in the vehicle interior, the effect was not sufficiently exhibited. Therefore, in step S09, the opening degree of the inside / outside air switching door 230 is adjusted by the control unit 120 so that only inside air is introduced and outside air is not introduced. This prevents the inflow of particles from the outside of the vehicle.

In step S10 following step S09, the control unit 120 performs a process of increasing the rotational speed of the blower 250. As a result, the flow rate of air passing through the filter 240 is further increased, and the number of particles collected per unit time in the filter 240 is increased.

By performing the processes of step S09 and step S10 as described above, particle reduction control can be performed more efficiently. For this reason, it is expected that the particle concentration will decrease more rapidly thereafter.

In step S08, when the particle concentration is equal to or higher than the threshold TH3, the process proceeds to step S11. When the process proceeds to step S11, there is a high possibility that smoking is being performed in the vehicle compartment. In this case, even if the particle reduction control is continued, it is difficult to reduce the particle concentration in the vehicle interior only by the collection with the filter 240. For this reason, in step S11, the opening degree of the inside / outside air switching door 230 is adjusted by the control unit 120 so that only outside air is introduced and inside air is not introduced. As a result, the particles in the passenger compartment can be discharged to the outside of the vehicle together with the air, so that the particle concentration in the passenger compartment can be reduced to some extent.

As described above, when the particle concentration exceeds the predetermined upper limit value (the threshold TH3), the control unit 120 in the present embodiment performs the inside and outside so that the flow rate of air introduced from the outside air introducing unit 220 becomes maximum. The air switching door 230 is controlled. As a result, in a situation where it is difficult to reduce the concentration of particles in the vehicle interior only by the collection by the filter 240, it is possible to prevent the situation where particle reduction control is continued while the amount of outside air introduced is small.

If the particle concentration exceeds the threshold value TH1 in step S07, the process proceeds to step S08 in the present embodiment as described above, and the process of increasing the introduction amount of inside air as necessary (step S09) is performed. It will be. Instead of such a mode, when the particle concentration exceeds the threshold TH1 in step S07, the process of step S11 may be performed at all times.

That is, if the particle concentration does not fall below the predetermined threshold (TH1) even if a predetermined period has elapsed since the start of the particle reduction control, the control unit 120 controls the flow rate of air introduced from the outside air introducing unit 220. The inside / outside air switching door 230 may be controlled such that According to such control, in a situation where it is difficult to reduce the particle concentration quickly, it is possible to give priority to clearing the window rather than reducing the particle concentration. In this case, the execution of the particle reduction control thereafter may be interrupted to notify the occupant of that effect.

If the particle concentration is less than the threshold TH2 in step S01, the process proceeds to step S12. In step S12, it is determined whether the particle concentration detected by the concentration detection unit 291 is equal to or less than the threshold TH0. The threshold TH0 is a threshold set in advance as the particle concentration at the time of ending (suspending) the particle reduction control. As shown in FIG. 6, the value of the threshold TH0 is lower than the value of the threshold TH2.

In step S12, when the particle concentration exceeds the threshold TH0, the series of processes shown in FIG. 2 are ended without performing any special process. At this time, when the particle reduction control is being performed, the particle reduction control is continued.

In step S12, when the particle concentration is equal to or less than the threshold TH0, the process proceeds to step S13. Moving to step S13 means that the particle concentration in the vehicle interior is sufficiently reduced by the particle reduction control. Therefore, in step S13, the degree of opening of the inside / outside air switching door 230 and the rotational speed of the blower 250 are returned to the values stored in the storage unit 130 in step S03. As a result, the particle reduction control is temporarily ended, and the air conditioning control as usual is performed and in a standby state.

In step S14 following step S13, the value of the flag FL is returned to 0. Thereafter, the series of processes shown in FIG. 2 are ended. In the subsequent period, when the particle concentration detected by the concentration detection unit 291 again becomes equal to or higher than the threshold TH2, the process proceeds to step S05 via steps S01 to S04, and the particle reduction control is restarted.

Specific contents of the particle reduction control started in step S05 will be described. As described above, in the present embodiment, a plurality of types of control are executed in parallel as particle reduction control. One of the controls (hereinafter also referred to as “particle reduction control 1”) will be described with reference to FIG.

In the first step S21 of the particle reduction control 1, the concentration detection unit 291 acquires the particle concentration in the vehicle interior. In step S22 following step S21, processing is performed to adjust the opening degree of the inside / outside air switching door 230 based on the particle concentration. Specifically, when the particle concentration is high, the control unit 120 adjusts the opening degree of the inside / outside air switching door 230 so that the flow rate of air introduced from the outside air introducing unit 220 is reduced. As a result, the amount of particles flowing in from the outside air introducing unit 220 is reduced as necessary, so that the concentration of particles in the vehicle compartment is prevented from becoming too high.

The correspondence between the particle concentration and the opening degree of the inside / outside air switching door 230 is stored in advance in the storage unit 130 as a map. For example, the map may be set such that the flow rate of air introduced from the outside air introducing unit 220 decreases as the particle concentration increases.

In the present embodiment, as described above, not only inside air is introduced during execution of the particle reduction control, but outside air is also introduced, and the flow rate of outside air introduced is adjusted by the control unit 120. Be done. This can prevent the humidity and the carbon dioxide concentration in the vehicle compartment from becoming too high. As a result, it is possible to prevent fogging or the like on the window of the vehicle while reducing the particle concentration in the vehicle interior.

Another control executed as particle reduction control (hereinafter also referred to as “particle reduction control 2”) will be described with reference to FIG.

In the first step S31 of the particle reduction control 2, the humidity sensor 141 acquires the humidity in the vehicle interior. In step S32 following step S31, the fogging determination unit 110 determines the fogging index. As described above, in the present embodiment, the value of the humidity inside the vehicle compartment is used as it is as the upper fog index.

In step S33 following step S32, processing is performed to adjust the opening degree of the inside / outside air switching door 230 based on the fogging index. Specifically, when the fog index is large (that is, when fogging of the window is likely to occur), the control unit 120 causes the inside / outside air switching door 230 to increase the flow rate of the air introduced from the outside air introducing unit 220. Adjust the opening of the. As a result, since low-humid air is introduced into the vehicle compartment from the outside, the occurrence of fogging of the window during execution of the particle reduction control can be more reliably prevented. The correspondence between the fog index and the opening degree of the inside / outside air switching door 230 is stored in advance in the storage unit 130 as a map. Here, it is preferable that the above-described map is set such that the flow rate of the outside air introduced from the outside air introducing unit 220 is the minimum flow rate necessary to prevent fogging.

Although the humidity measured by the humidity sensor 141 may be used as it is as the fogging index as in this embodiment, the fogging index may be calculated by another method. For example, the fog index may be calculated to be larger as the number of occupants acquired by the in-vehicle camera 142 is larger. In addition, the fogging index may be calculated or corrected based on the operating state of the compressor of the air conditioning unit 260, the opening and closing states of the windows, the temperature and humidity outside the vehicle, and the like.

Another control executed as particle reduction control (hereinafter also referred to as “particle reduction control 3”) will be described with reference to FIG.

In the first step S41 of the particle reduction control 3, the concentration detection unit 291 acquires the particle concentration in the vehicle interior. In step S42 following step S41, it is determined whether particle reduction control 3 currently executed is the first time. Here, "it is the first time" means a period from step S01 to step S02 for the first time, and step S12 to step S13. In other words, it refers to a period from the start of the particle reduction control 3 to the end. If the particle reduction control 3 is performed for the first time, the process proceeds to step S43.

In step S43, processing is performed to set the rotation speed of the blower 250 to the first rotation speed R1. The “first rotation number R1” is not a fixed rotation number, but is a rotation number set according to the particle concentration acquired in step S41. Here, as the particle concentration is higher, the first rotation speed R1 is set to a larger value.

As described above, when the particle concentration is high, the control unit 120 in the present embodiment executes control to increase the rotational speed of the blower 250. Such particle reduction control 3 corresponds to “rotational speed increase control” in the present embodiment. Since the rotation speed increase control increases the flow rate of air passing through the filter 240, the number of particles collected per unit time in the filter 240 also increases. As a result, particle concentration can be rapidly reduced.

If it is determined in step S42 that the particle reduction control 3 has not been executed for the first time, the process proceeds to step S44. In step S44, processing is performed to set the rotation speed of the blower 250 to the second rotation speed R2. Similar to the first rotation number R1, the “second rotation number R2” is not a fixed rotation number, but is a rotation number set according to the particle concentration acquired in step S41. Here, the second rotation speed R2 is set to a larger value as the particle concentration is higher. However, the second rotation speed R2 is set to a value smaller than the first rotation speed R1.

What is shown in FIG. 6A is the time change of the particle concentration in the passenger compartment when the particle reduction control 3 is being performed. What is shown in FIG. 6 (B) is the time change of the rotation speed of the blower 250 when the particle reduction control 3 is being performed.

In the example shown in FIG. 6, execution of particle reduction control is started at time t1, and the rotation speed of the blower 250 is set to the first rotation speed R1. After time t1, the particle concentration is reduced by the particle reduction control, and is reduced to the threshold TH0 at time t2. Therefore, the process of step S13 of FIG. 2 is performed at time t2, and the particle reduction control is temporarily ended. As a result, after time t2, the rotational speed of the blower 250 is returned to the initial rotational speed R0.

Since the particle reduction control is not performed after time t2, the particle concentration in the vehicle compartment is gradually increasing. Thereafter, when the particle concentration rises to the threshold TH2 at time t3, the particle reduction control is started again. The rotation speed of the blower 250 at this time is set to a second rotation speed R2 smaller than the first rotation speed R1.

Thereafter, the particle concentration in the vehicle compartment changes in the range from the threshold TH0 to the threshold TH2 by repeating termination and restart of the particle reduction control.

As described above, during execution of the particle reduction control, the control unit 120 of the present embodiment sets the rotation speed of the blower 250 as the first rotation speed R1 at the time of execution of the rotation speed increase control at the first time. At the time of execution of the increase control, the rotation speed of the blower 250 is set to a second rotation speed R2 smaller than the first rotation speed R1.

At the time of the first execution of the rotation speed increase control, it is considered that the particle concentration in the vehicle interior is often high. For this reason, it is preferable to increase the rotational speed of the blower 250 as described above and to increase the reduction rate of the particle concentration.

On the other hand, in the second and subsequent executions of the rotation speed increase control, the particle concentration in the vehicle compartment is low, and at most is about the threshold value TH2. Therefore, the need to increase the rotational speed of the blower 250 is small. In the present embodiment, by reducing the rotational speed of the blower 250 at the second and subsequent executions, the noise in the passenger compartment associated with the operation of the blower 250 is reduced to prevent the occupant from feeling unpleasant. ing.

Another control executed as particle reduction control (hereinafter also referred to as “particle reduction control 4”) will be described with reference to FIG.

In the first step S51 of the particle reduction control 4, the reduction rate of the particle concentration measured by the concentration detection unit 291 is acquired. The reduction rate can be calculated based on, for example, the slope of the measurement values sampled a plurality of times in a certain period up to the present time.

In step S52 following step S51, it is determined whether the currently executed particle reduction control 4 is the first process. Here, "it is the first time" means a period from step S01 to step S02 for the first time, and step S12 to step S13. That is, it refers to a period from when the particle reduction control 4 is first started to when it ends. If the particle reduction control 4 is not performed for the first time, the series of processes shown in FIG. 7 are ended. If the particle reduction control 4 is performed for the first time, the process proceeds to step S53.

In step S53, it is determined whether the reduction rate acquired in step S51 is smaller than a predetermined threshold value TR1. The threshold TH1 is a threshold set in advance as a minimum reduction rate expected in a state where the particle reduction control is normally effective. Here, the rate of decrease is the rate of decrease in particle concentration, but its sign is assumed to be positive.

If the reduction rate is equal to or higher than the threshold value TR1, the series of processes shown in FIG. If the decrease rate is smaller than the threshold value TR1, the process proceeds to step S54.

Moving to step S54 means that the effect of the particle reduction control is not sufficient, and the decrease rate of the particle concentration is small. Therefore, in step S54, the control unit 120 performs a process of increasing the rotational speed of the blower 250. As a result, the flow rate of air passing through the filter 240 is further increased, and the number of particles collected per unit time in the filter 240 is increased.

By performing the processing as described above, even when the effect of the particle reduction control is reduced for some reason, the particle concentration can be reduced more efficiently. For this reason, it is expected that the particle concentration will decrease more rapidly thereafter.

The present embodiment has been described above with reference to the specific example. However, the present disclosure is not limited to these specific examples. Those appropriately modified in design by those skilled in the art are also included in the scope of the present disclosure as long as the features of the present disclosure are included. The elements included in the above-described specific examples, and the arrangement, conditions, and shapes thereof are not limited to those illustrated, but can be appropriately modified. The elements included in the above-described specific examples can be appropriately changed in combination as long as no technical contradiction arises.

Claims

An air conditioner (10) mounted on a vehicle,
An air conditioning unit (260) for adjusting the temperature of the air blown out into the cabin of the vehicle;
An outside air introducing unit (220) for introducing air supplied to the air conditioning unit from the outside of the vehicle;
A room air introducing unit (210) for introducing air supplied to the air conditioning unit from the vehicle compartment;
An inside / outside air adjustment unit (230) for adjusting the amount of air introduced from each of the outside air introduction unit and the inside air introduction unit;
A filter (240) for removing particles from the air supplied to the air conditioning unit;
A blower (250) for delivering air through the filter and the air conditioning unit;
A control unit (120) for controlling the operation of the inside / outside air adjustment unit and the blower;
The control unit
An air conditioner configured to adjust the flow rate of air introduced from the outside air introduction unit when performing particle reduction control, which is control to increase the flow rate of air passing through the filter.
The air conditioner according to claim 1, further comprising a concentration detection unit (291) that detects a concentration of particles in air in the vehicle compartment.
During execution of the particle reduction control, the control unit
The air conditioner according to claim 2, wherein when the particle concentration is high, the flow rate of air introduced from the outside air introduction unit is reduced.
The vehicle further comprises a fogging determination unit (110) that determines a fogging index indicating the likelihood of fogging on a window provided in the vehicle.
During execution of the particle reduction control, the control unit
The air conditioner according to claim 1, wherein when the fogging index is large, the flow rate of air introduced from the outside air introducing unit is increased.
The air conditioner according to claim 4, wherein the fogging determination unit uses humidity in the vehicle cabin as the fogging index.
The air conditioner according to claim 2, wherein the control unit executes rotation number increase control, which is control for increasing the rotation number of the blower when the particle concentration is high.
During execution of the particle reduction control, the control unit
At the time of execution of the rotation speed increasing control at the first time, the rotation speed of the blower is taken as a first rotation speed,
The air conditioner according to claim 6, wherein when the rotation number increase control is executed for the second time and thereafter, the rotation number of the blower is set to a second rotation number smaller than the first rotation number.
The control unit
The air conditioner according to claim 6, wherein when the decrease rate of the particle concentration during execution of the rotation speed increase control is lower than a predetermined value, the rotation speed of the blower is further increased.
The control unit
If the particle concentration does not fall below a predetermined threshold even after a predetermined period of time has elapsed since the start of the particle reduction control, the inside and outside of the air are introduced such that the flow rate of air introduced from the outside air introduction portion becomes maximum. The air conditioner according to claim 2, which controls the air adjustment unit.
The control unit
The air conditioner according to claim 2, wherein when the particle concentration exceeds a predetermined upper limit value, the inside / outside air adjustment unit is controlled to maximize the flow rate of air introduced from the outside air introduction unit. .