JP2019026040A - Air conditioner - Google Patents

Abstract

To provide an air conditioner capable of preventing windows of a vehicle from getting fogged and so on while reducing a particle concentration in a vehicular cabin.SOLUTION: An air conditioner 10 comprises: an outside air introduction part 220 for introducing air to be supplied to an air conditioning part 260 from outside a vehicle; an inside air introduction part 210 for introducing air to be supplied to the air conditioning part 260 from inside the vehicular cabin; an inside/outside air switching door 230 for adjusting the amounts of the air introduced from the outside air introduction part 220 and inside air introduction part 210 respectively; a filter 240 for removing particles from the air supplied to the air conditioning part 260; and a blower 250 for sending the air out. A control part 120 adjusts the amount of the air introduced from the outside air introduction part 220 when performing particle reduction control as control to increase the flow rate of air passing through a filter 240.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an air conditioner mounted on a vehicle.

  An air conditioner mounted on a vehicle is a device that adjusts the temperature of air taken in from the inside of the vehicle interior or the outside of the vehicle and blows the air after temperature adjustment into the vehicle interior as conditioned air. In recent years, it has been studied to provide an air conditioner with a function of reducing the concentration of particles (for example, pollen and PM2.5) floating in the air in the passenger compartment.

  For example, in the air conditioner described in Patent Document 1 below, pollen concentration in the vicinity of the occupant's face can be reduced by blowing clean air that has passed through the filter toward the occupant's face.

Japanese Patent No. 4311270

  In the air conditioner described in Patent Literature 1, when performing control to blow clean air that has passed through the filter toward the face of the occupant, only the air taken in from the passenger compartment is blown into the passenger compartment, that is, to the inside air mode. Switching. Thereby, since the air containing many particles is not taken in from the exterior of a vehicle, cleaner air can be blown out into a vehicle interior.

  However, in a state in which only air inside the vehicle interior is circulated without any air from the outside of the vehicle being taken in, the humidity in the vehicle interior rises too much and fogging occurs in the vehicle window. There is. In addition, the carbon dioxide concentration in the passenger compartment may gradually increase, causing the passengers to feel uncomfortable.

  An object of the present disclosure is to provide an air conditioner that can prevent the occurrence of fogging in a vehicle window while reducing the particle concentration in the passenger compartment.

  An air conditioner according to the present disclosure is an air conditioner (10) mounted on a vehicle, and includes an air conditioner (260) that adjusts the temperature of air blown into the vehicle interior of the vehicle, and air supplied to the air conditioner. From the outside of the vehicle, the inside air introduction unit (210) for introducing the air supplied to the air conditioning unit from the interior of the vehicle, and the outside air introduction unit and the inside air introduction unit An inside / outside air adjusting unit (230) for adjusting the amount of air introduced, a filter (240) for removing particles from the air supplied to the air conditioning unit, and a blower (250) for sending air through the filter and the air conditioning unit ) And a control unit (120) for controlling the operations of the inside / outside air adjusting unit and the blower. 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 for increasing the flow rate of air passing through the filter.

  Such an air conditioner can execute particle reduction control. The particle reduction control is control for increasing 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, the particle concentration in the air in the passenger compartment can be reduced.

  When executing the particle reduction control, the control unit adjusts the flow rate of the air introduced from the outside air introduction unit. In other words, the control unit performs particle reduction control while introducing an appropriate amount of air (outside air) as needed from the outside air introduction unit, 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 from occurring in the vehicle window while reducing the particle concentration in the passenger compartment.

  According to the present disclosure, it is possible to provide an air conditioner that can prevent the occurrence of fogging in a vehicle window while reducing the particle concentration in the passenger compartment.

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

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

  An air conditioner 10 according to the present embodiment will be described with reference to FIG. The air conditioner 10 is a device that is mounted on a vehicle (the whole is not shown), and is configured as a device for adjusting the temperature of air in the vehicle interior of the vehicle, that is, performing air conditioning. The air conditioner 10 includes an air conditioner case 200, a blower 250, a filter 240, an air conditioner 260, a concentration detector 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 passenger compartment. Inside the air conditioning case 200, air flows in a direction from the left side to the right side in FIG. In the air conditioning case 200, an outside air introduction unit 220, an inside air introduction unit 210, a face duct 270, and a foot duct 280 are formed.

  The outside air introduction unit 220 is a portion that serves as an inlet for introducing air supplied to the air conditioning unit 260 described later into the air conditioning case 200 from the outside of the vehicle. The inside air introduction unit 210 is a part that serves 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 introduction part 210 and the outside air introduction part 220 are formed so as to line up in the upstream part of the air conditioning case 200.

  An inside / outside air switching door 230 is provided between the outside air introduction unit 220 and the inside air introduction 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 introduction unit 220 and the inside air introduction unit 210, and corresponds to the “inside / outside air adjustment unit” in the present embodiment. When the inside / outside air switching door 230 is operated, the flow rate of air introduced from the outside air introduction unit 220 and supplied to the air conditioning unit 260, and the flow rate of air introduced from the inside air introduction unit 210 and supplied to the air conditioning unit 260, The ratio of, is adjusted.

  Hereinafter, the air introduced from the outside air introduction unit 220 is also referred to as “outside air”. In addition, the air introduced from the inside air introduction unit 210 is also referred to as “inside air” below. As shown in FIG. 1, in the state where the outside air introduction unit 220 is completely closed, only the inside air is introduced into the air conditioning unit 260 and the 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.

  Both the face duct 270 and the foot duct 280 are outlets for guiding conditioned air into the vehicle interior. The face duct 270 and the foot duct 280 are formed in the downstream portion of the air conditioning case 200. The face duct 270 is connected to a face outlet (not shown) for blowing air conditioned air toward the passenger's face. The foot duct 280 is connected to a foot outlet (not shown) for blowing conditioned air toward the feet of the passenger.

  A face door 271 is provided at the entrance 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 entrance of the foot duct 280. When the foot door 281 is in the open state, the 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 sending air to the downstream side inside the air conditioning case 200. The air sent out by the blower 250 passes through the filter 240 and the air conditioning unit 260 in this order and is blown out into the vehicle interior. The number of rotations of the blower 250, that is, the amount of conditioned air blown out from the air conditioner 10 into the passenger compartment 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 at a position downstream of the inside air introduction unit 210 and the outside air introduction unit 220 and upstream of the blower 250. The particles removed by the filter 240 may be fine particles such as PM2.5, and may be pollen or dust.

  The air conditioning unit 260 is a part that adjusts the temperature of the air blown into the passenger compartment, thereby generating conditioned air. In the air conditioning unit 260, the temperature of the air is adjusted by heat exchange with a refrigerant or the like. The air conditioning unit 260 is provided at a position 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 air, a heater core for heating air, an air mix door for adjusting the flow rate of air passing through these, a compressor for circulating the refrigerant, and the like (Both 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 detector 291 is a sensor for detecting the particle concentration in the air in the passenger compartment. As shown in FIG. 1, one end of the introduction pipe 290 is connected to the air conditioning case 200 at a position downstream of the filter 240 and upstream of the blower 250. The other end of the introduction pipe 290 is open to the vehicle interior. The concentration detector 291 is provided at a position in the middle of the introduction pipe 290. When air is flowing inside the air conditioning case 200, air flows also in the introduction pipe 290 due to the negative pressure generated on the air conditioning case 200 side. That is, an air flow is generated from the passenger compartment through the introduction pipe 290 into the air conditioning case 200. The concentration detection unit 291 measures the concentration of particles contained in the air and transmits the concentration to the control device 100 using an electrical signal.

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

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

  The cloudiness determination unit 110 is a part 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 humidity value in the passenger compartment measured by the humidity sensor 141 described later is determined and used as it is as the cloudiness 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. Specific modes of control performed by the control unit 120 will be described 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 the control performed by the control unit 120 each time.

  Various switches and sensors provided in each part of the vehicle are connected to the control device 100. FIG. 1 shows an operation switch 140, a humidity sensor 141, and an in-vehicle camera 142 among these.

  The operation switch 140 is a switch operated by a vehicle occupant to start or end the execution of the particle reduction control. The particle reduction control is control for increasing 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 in response to the passenger's request, the particle concentration in the air in the passenger compartment can be reduced.

  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 taking a picture of the inside of the passenger compartment, and is, for example, a CMOS camera. An image photographed by the in-vehicle camera 142 is input to the control device 100 as image data. The control device 100 can grasp the number of occupants present in the passenger compartment, for example, by analyzing the image.

  Specific contents of the control executed by the control device 100 will be described with reference to FIG. A series of processes shown in FIG. 2 is a process that is repeatedly executed every time a predetermined control period elapses after an operation for starting execution of particle reduction control is performed on the operation switch 140. This process is repeatedly executed by the control device 100 until an operation for terminating the execution of the particle reduction control is performed on the operation switch 140.

  In first step S01, it is determined whether or not the particle concentration detected by the concentration detector 291 is equal to or higher than a threshold value TH2. The threshold value TH2 is a threshold value set in advance as a particle concentration value that requires execution of particle reduction control. If the particle concentration is greater than or equal to the threshold value TH2, the process proceeds to step S02.

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

  In step S <b> 03, the current opening degree of the inside / outside air switching door 230 and the current rotational speed of the blower 250 are acquired and 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 subsequent to step S04, processing for starting the particle reduction control described above is performed. Here, processing is performed to make the rotational speed of the blower 250 larger than the rotational speed up to that time. Moreover, the process which changes the opening degree of the inside / outside air switching door 230 is also performed. In the present embodiment, multiple types of control are executed in parallel as particle reduction control. Specific contents of each control will be described later.

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

  In step S07, it is determined whether or not the particle concentration detected by the concentration detector 291 is equal to or less than a threshold value TH1. The threshold value TH1 is a threshold value that is set in advance as a value of the particle concentration that is assumed to be sufficiently lower if the above-described predetermined period elapses while the particle reduction control is normally in effect. The value of the threshold value TH1 is smaller than the value of the threshold value TH2 and larger than the value of a threshold value TH0 described later.

  In step S07, when the particle concentration is equal to or lower than the threshold value TH1, it means that the particle reduction control is normally effective. For this reason, in this case, the series of processing shown in FIG. 2 is terminated without performing special processing.

  If the particle concentration exceeds the threshold value TH1 in step S07, the process proceeds to step S08. In step S08, it is determined whether or not the particle concentration detected by the concentration detector 291 is equal to or higher than a threshold value TH3. The threshold value TH3 is a threshold value set in advance as a minimum particle concentration value that is supposed to be detected when smoking is performed in the passenger 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 value TH3 in step S08, the process proceeds to step S09. The transition to step S09 means that the effect was not sufficiently exhibited despite the particle reduction control being performed in a situation where smoking is not performed in the passenger compartment. 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 the inside air is introduced and the outside air is not introduced. This prevents inflow of particles from the outside of the vehicle.

  In step S <b> 10 following step S <b> 09, processing for increasing the rotational speed of the blower 250 is performed by the control unit 120. Thereby, the flow rate of air passing through the filter 240 further increases, and the number of particles collected per unit time in the filter 240 increases.

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

  If the particle concentration is greater than or equal to the threshold value TH3 in step S08, the process proceeds to step S11. When the process proceeds to step S11, there is a high possibility that smoking is performed in the passenger compartment. In this case, even if the particle reduction control is continued, it is difficult to reduce the particle concentration in the passenger compartment only by the collection by 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 the outside air is introduced and the inside air is not introduced. As a result, particles in the passenger compartment are discharged out of the vehicle together with air, so that the particle concentration in the passenger compartment can be reduced to some extent.

  As described above, the control unit 120 according to the present embodiment is configured so that the flow rate of the air introduced from the outside air introduction unit 220 is maximized when the particle concentration exceeds the predetermined upper limit value (threshold value TH3). The air switching door 230 is controlled. As a result, in a situation where it is difficult to reduce the particle concentration in the passenger compartment only by collection by the filter 240, it is possible to prevent a situation in which the 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, in this embodiment, the process proceeds to step S08 as described above, and a process (step S09) for increasing the introduction amount of the inside air as necessary is performed. Is called. Instead of such an aspect, when the particle concentration exceeds the threshold value TH1 in step S07, the process of step S11 may always be performed.

  That is, if the particle concentration does not fall below a predetermined threshold (TH1) even after a predetermined period has elapsed since the start of particle reduction control, the flow rate of air introduced from the outside air introduction unit 220 by the control unit 120 It is also possible to control the inside / outside air switching door 230 so that is maximized. According to such control, in a situation where it is difficult to rapidly reduce the particle concentration, it is possible to prioritize clearing the fogging of the window rather than reducing the particle concentration. In this case, it is good also as interrupting execution of particle reduction control after that and notifying a passenger to that effect.

  If the particle concentration is less than the threshold value 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 a threshold value TH0. The threshold value TH0 is a threshold value set in advance as a particle concentration when the particle reduction control is ended (interrupted). As shown in FIG. 6, the value of the threshold value TH0 is lower than the value of the threshold value TH2.

  In step S12, when the particle concentration exceeds the threshold value TH0, the series of processing shown in FIG. 2 is terminated without performing any special processing. At this time, when the particle reduction control is being executed, the particle reduction control is continued.

  If the particle concentration is equal to or lower than the threshold value TH0 in step S12, the process proceeds to step S13. The transition to step S13 means that the particle concentration in the passenger compartment has been sufficiently lowered by the particle reduction control. Therefore, in step S13, the opening degree of the inside / outside air switching door 230 and the rotation 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 once ended, and the apparatus is on standby while performing normal air conditioning control.

  In step S14 following step S13, the value of the flag FL is returned to zero. Thereafter, the series of processes shown in FIG. In the subsequent period, when the particle concentration detected by the concentration detector 291 again becomes equal to or higher than the threshold value TH2, the process proceeds to step S05 through steps S01 to S04, and particle reduction control is resumed.

  Specific contents of the particle reduction control started in step S05 will be described. As already described, in the present embodiment, multiple 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 particle concentration in the passenger compartment is acquired by the concentration detector 291. In step S22 following step S21, a process of adjusting the opening degree of the inside / outside air switching door 230 based on the particle concentration is performed. 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 introduction unit 220 is reduced. As a result, the amount of particles flowing from the outside air introduction unit 220 is reduced as necessary, so that the particle concentration in the passenger 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 so that the flow rate of air introduced from the outside air introduction unit 220 decreases as the particle concentration increases.

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

  Another control executed as the 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 in the vehicle compartment is acquired by the humidity sensor 141. In step S32 following step S31, the cloudiness determination unit 110 determines the cloudiness index. As already described, in the present embodiment, the humidity value in the passenger compartment is used as it is as an upper cloudiness index.

  In step S33 subsequent to step S32, a process of adjusting the opening degree of the inside / outside air switching door 230 based on the cloudiness index is performed. Specifically, when the cloudiness index is large (that is, when window fogging is likely to occur), the control unit 120 changes the inside / outside air switching door 230 so that the flow rate of air introduced from the outside air introduction unit 220 increases. Adjust the opening. Thereby, since low-humidity air is introduced into the vehicle interior from the outside, it is possible to more reliably prevent the window from being fogged during the execution of the particle reduction control. The correspondence relationship between the cloudiness 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 map is set so that the flow rate of the outside air introduced from the outside air introduction unit 220 is the minimum necessary flow rate for preventing fogging.

  As the cloudiness index, the humidity measured by the humidity sensor 141 may be used as it is as in the present embodiment, but the cloudiness index may be calculated by another method. For example, the cloudiness index may be calculated to be larger as the number of passengers acquired by the in-vehicle camera 142 increases. Further, the cloudiness index may be calculated or corrected based on the operation state of the compressor of the air conditioning unit 260, the opening / closing state of the window, the temperature and humidity outside the vehicle, and the like.

  Another control executed as the 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 particle concentration in the passenger compartment is acquired by the concentration detector 291. In step S42 following step S41, it is determined whether or not the particle reduction control 3 currently being executed is the first time. Here, “it is the first time” refers to a period from the time of first transition from step S01 to step S02 to the transition from step S12 to step S13. That is, it refers to a period from when the particle reduction control 3 is first started until it is ended. When the execution of the particle reduction control 3 is the first time, the process proceeds to step S43.

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

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

  In step S42, when the execution of the particle reduction control 3 is not the first time, the process proceeds to step S44. In step S44, a process of setting the rotation speed of the blower 250 to the second rotation speed R2 is performed. Similar to the first rotation speed R1, the “second rotation speed R2” is not a fixed rotation speed but a rotation speed set according to the particle concentration obtained in step S41. Here, the second rotation speed R2 is set to a larger value as the particle concentration is higher. However, the second rotational speed R2 is set to a value smaller than the first rotational speed R1.

  FIG. 6A shows a change over time in the particle concentration in the passenger compartment when the particle reduction control 3 is being executed. FIG. 6B shows a change over time in the rotational speed of the blower 250 when the particle reduction control 3 is being executed.

  In the example shown in FIG. 6, the execution of particle reduction control is started at time t1, and the rotational speed of the blower 250 is set to the first rotational speed R1. After the time t1, the particle concentration is decreased by the particle reduction control, and is decreased to the threshold value TH0 at the time t2. For this reason, the process of step S13 of FIG. 2 is performed at the time t2, and the particle reduction control is once ended. As a result, after the 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 the time t2, the particle concentration in the passenger compartment gradually increases. Thereafter, when the particle concentration rises to the threshold value TH2 at time t3, the particle reduction control is started again. At this time, the rotational speed of the blower 250 is set to a second rotational speed R2 smaller than the first rotational speed R1.

  Thereafter, the particle concentration in the passenger compartment changes within the range from the threshold value TH0 to the threshold value TH2 by repeating the end and restart of the particle reduction control.

  As described above, during the 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 when the rotation speed increase control is performed for the first time. When executing the increase control, the rotational speed of the blower 250 is set to a second rotational speed R2 that is smaller than the first rotational speed R1.

  It is considered that the particle concentration in the passenger compartment is often high at the first execution of the rotation speed increase control. For this reason, it is preferable to increase the rotational speed of the blower 250 and increase the speed of reducing the particle concentration as described above.

  On the other hand, in the second and subsequent executions of the rotational speed increase control, the particle concentration in the passenger compartment is low and is about the threshold value TH2 at the maximum. For this reason, the necessity for increasing the rotational speed of the blower 250 is small. In the present embodiment, by reducing the rotation speed of the blower 250 at the second and subsequent executions, the noise in the passenger compartment accompanying the operation of the blower 250 is reduced, and the passenger is prevented from feeling uncomfortable. ing.

  Another control executed as the 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 particle concentration decrease rate measured by the concentration detector 291 is acquired. This rate of decrease can be calculated based on, for example, the slope of a measurement value sampled a plurality of times in a certain period up to the present time.

  In step S52 following step S51, it is determined whether or not the particle reduction control 4 currently being executed is the first time. Here, “it is the first time” refers to a period from the time of first transition from step S01 to step S02 to the transition from step S12 to step S13. That is, it means a period from when the particle reduction control 4 is first started until it is ended. When the execution of the particle reduction control 4 is not the first time, the series of processes shown in FIG. When the execution of the particle reduction control 4 is the first time, the process proceeds to step S53.

  In step S53, it is determined whether or not the reduction rate acquired in step S51 is smaller than a predetermined threshold value TR1. This threshold value TH1 is a threshold value set in advance as a minimum reduction rate expected in a state where the particle reduction control is normally effective. Note that the rate of decrease here is the rate of decrease in particle concentration, but the sign is positive.

  When the decrease rate is equal to or greater than the threshold value TR1, the series of processes illustrated in FIG. When the decrease rate is smaller than the threshold value TR1, the process proceeds to step S54.

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

  By performing the above processing, even when the effect of the particle reduction control is reduced for some reason, the particle concentration is more efficiently reduced. For this reason, the particle concentration is expected to decrease more rapidly thereafter.

  The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Those in which those skilled in the art appropriately modify the design of these specific examples are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in each of the specific examples described above and their arrangement, conditions, shape, and the like are not limited to those illustrated, and can be changed as appropriate. Each element included in each of the specific examples described above can be appropriately combined as long as no technical contradiction occurs.

10: Air conditioner 120: Control unit 210: Inside air introduction unit 220: Outside air introduction unit 230: Inside / outside air switching door 240: Filter 250: Blower 260: Air conditioning unit

Claims (10)

An air conditioner (10) mounted on a vehicle,
An air conditioning unit (260) for adjusting the temperature of the air blown into the passenger compartment of the vehicle;
An outside air introduction section (220) for introducing air supplied to the air conditioning section from the outside of the vehicle;
An inside air introduction section (210) for introducing air supplied to the air conditioning section from the vehicle interior;
An inside / outside air adjusting unit (230) for adjusting the amount of air introduced from each of the outside air introducing unit and the inside air introducing unit;
A filter (240) for removing particles from the air supplied to the air conditioning unit;
A blower (250) for sending air through the filter and the air conditioning unit;
A control unit (120) for controlling the operations of the inside / outside air adjusting unit and the blower,
The controller is
An air conditioner configured to adjust a flow rate of air introduced from the outside air introduction unit when performing particle reduction control, which is control for increasing the flow rate of air passing through the filter.   The air conditioner according to claim 1, further comprising a concentration detector (291) for detecting a particle concentration in the air in the passenger compartment. During the execution of the particle reduction control, the control unit,
The air conditioner according to claim 2, wherein when the particle concentration is high, a flow rate of air introduced from the outside air introduction unit is reduced. A cloudiness determination unit (110) for determining a cloudiness index indicating the likelihood of fogging in a window provided in the vehicle;
During the execution of the particle reduction control, the control unit,
The air conditioner according to claim 1, wherein when the cloudiness index is large, a flow rate of air introduced from the outside air introduction unit is increased.   The air conditioner according to claim 4, wherein the cloudiness determination unit uses humidity in the vehicle interior as the cloudiness index.   3. The air conditioner according to claim 2, wherein when the particle concentration is high, the control unit executes rotation speed increase control that is control for increasing the rotation speed of the blower. During the execution of the particle reduction control, the control unit,
When executing the rotation speed increase control in the first time, the rotation speed of the blower is set to the first rotation speed,
The air conditioner according to claim 6, wherein the rotation speed of the blower is set to a second rotation speed that is smaller than the first rotation speed when the rotation speed increase control is executed after the second time. The controller is
The air conditioner according to claim 6, wherein when the rate of decrease in 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 controller is
If the particle concentration does not fall below a predetermined threshold even after a lapse of a predetermined period from the start of the particle reduction control, the inside / outside is set so that the flow rate of air introduced from the outside air introduction unit is maximized. The air conditioner according to claim 2, wherein the air conditioner is controlled. The controller is
The air conditioner according to claim 2, wherein when the particle concentration exceeds a predetermined upper limit, the inside / outside air adjusting unit is controlled so that a flow rate of air introduced from the outside air introducing unit is maximized. .

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