JP2014084074A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner for a vehicle in which an operating period of a compressor can be secured sufficiently, even in a situation that it is difficult to suppress recirculation of a cooling wind for a condenser.SOLUTION: When a three-dimensional object in front of a vehicle 1 is recognized by a stereo-image recognition device 4 based on image information imaging an environment outside the vehicle, a three-dimensional object the projection area of which is a set value or more exists in front of the vehicle 1 and the distance d from the vehicle 1 to the three-dimensional object is a set threshold value D1 or less, then a discharge capacity of a compressor 25 is controlled to a value lower than a value to be set depending on cooling demanding load in an A/C_ECU7. Herewith, even in a situation where it is difficult to suppress recirculation of a cooling wind to a condenser 26, abrupt rising of a high-pressure-side pressure of a coolant is prevented and operating time of a compressor 25 can be secured sufficiently.

Description

  The present invention relates to a vehicle air conditioner that radiates heat from a condenser by running wind introduced through a grill opening.

  In general, a condenser of a vehicle air conditioner is disposed in an engine room so as to be opposed to a grille opening that opens at the front of the vehicle body. A radiator is disposed behind the condenser so as to be in series with the air flow from the grill opening.

  These condensers and radiators are cooled by running wind (cooling wind) introduced from the grill opening when the vehicle is running at a predetermined speed or higher. Further, for example, when a sufficient amount of traveling airflow cannot be expected, such as when driving at low speed or when stopping (when idling), a cooling fan disposed behind the radiator is operated as appropriate, and this cooling fan is generated. The condenser and the radiator are cooled by the cooling air.

  By the way, when the vehicle is stopped, the cooling capacity of the condenser may be reduced more than the reduction of the cooling capacity due to the decrease in the cooling air volume. This is due to the fact that when the cooling air speed due to traveling is low, such as when the vehicle is stopped, the cooling air (hot air) after passing through the cooling fan circulates upstream of the condenser and is recirculated. And when the fall of the cooling capacity by such recirculation of cooling air generate | occur | produces, control, such as increasing the discharge capacity of the compressor interposed in the refrigerating cycle, is performed in an air conditioner.

  As a technique for preventing an increase in the discharge capacity of the compressor due to such recirculation of cooling air, for example, in Patent Document 1, at least when the speed of air flowing toward the condenser is equal to or lower than a predetermined speed, A technique is disclosed in which a communication path is provided that bypasses a part of the air that flows backward to the condenser side through the engine room after passing through the cooling fan from the condenser and the radiator.

JP 2005-254934 A

  However, even in the configuration in which a communication path or the like is provided as in the technique disclosed in Patent Document 1 described above, it may be difficult to sufficiently suppress the recirculation of the cooling air. For example, when the host vehicle is stopped with the grille opening approaching the wall of the building, etc., or when the host vehicle is following the large vehicle at a very low speed with a small inter-vehicle distance, In addition to these conditions, if there are overlapping conditions that are unfavorable for the introduction of cooling air from the grill opening, such as when a tailwind is blowing from the rear of the vehicle body to the front, In some cases, it is difficult to sufficiently suppress the recirculation of the cooling air with respect to the above, or the ambient temperature itself around the vehicle rises, and the same fan output may not provide sufficient cooling capacity.

  For example, when the recirculation of the cooling air is continued in an environment where the outside air temperature is 40 ° C. or higher and the increase control of the discharge capacity of the compressor is continuously performed for a long time, the pressure on the high pressure side of the refrigeration cycle Reaches the cycle protection pressure (for example, 3 MPa), and the compressor may be controlled to stop. When such compressor stop control is performed, it becomes difficult to supply cold air into the passenger compartment, and there is a risk of causing an uncomfortable feeling to the passenger or the like due to a sudden rise in the temperature of the blowout air.

  The present invention has been made in view of the above circumstances, and provides a vehicle air conditioner that can sufficiently ensure the operation period of a compressor even in a situation where it is difficult to suppress recirculation of cooling air to the condenser. For the purpose.

  A vehicle air conditioner according to an aspect of the present invention includes a variable displacement compressor and a discharge that calculates a cooling demand load based on a preset condition and variably controls the discharge capacity of the compressor according to the cooling demand load. In the vehicle air conditioner including the capacity control means, a three-dimensional object recognition means for recognizing a three-dimensional object in front of the host vehicle based on image information obtained by imaging an environment outside the vehicle, and a projection area is set in front of the host vehicle. When the three-dimensional object equal to or greater than the value is present and the distance from the host vehicle to the three-dimensional object is less than or equal to a set threshold, the discharge capacity of the compressor is lower than a value set according to the cooling demand load Discharge capacity limiting means for limiting to a value.

  According to the vehicle air conditioner of the present invention, it is possible to sufficiently ensure the operation period of the compressor even in a situation where it is difficult to suppress the recirculation of the cooling air to the condenser.

Schematic configuration diagram showing the main parts of a driving support device and an air conditioner mounted on a vehicle Air conditioning unit schematic configuration diagram Flow chart showing compressor control routine Flowchart showing compressor discharge capacity limit value setting routine Map for judging obstacles ahead Map for setting limit values Time chart showing changes in pressure in the refrigeration cycle

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings relate to an embodiment of the present invention, FIG. 1 is a schematic configuration diagram showing a main part of a driving support device and an air conditioning device mounted on a vehicle, FIG. 2 is a schematic configuration diagram of the air conditioning device, and FIG. 3 is a compressor control routine. 4 is a flowchart showing a compressor discharge capacity limit value setting routine, FIG. 5 is a map for determining a front obstacle, FIG. 6 is a map for setting a limit value, and FIG. 7 is a time showing a pressure transition in the refrigeration cycle. It is a chart.

  In FIG. 1, reference numeral 1 indicates a vehicle (own vehicle) such as an automobile on which the air conditioner 20 is mounted. The vehicle 1 is more likely to collide with an object to be controlled such as an obstacle or a preceding vehicle. In some cases, the vehicle driving support device 2 having a collision prevention function for preventing collision by performing braking control by intervention of automatic braking independent of the driver's braking operation is mounted.

  The driving support device 2 includes a stereo camera 3, a stereo image recognition device 4, a travel control unit 5, and the like, and its main part is configured.

  The stereo camera 3 is composed of a pair of left and right CCD cameras using an individual image sensor such as a charge coupled device (CCD), for example. Each of these sets of CCD cameras is attached to the front of the ceiling in the vehicle interior with a fixed interval, and subjects the object outside the vehicle to stereo imaging from different viewpoints, and outputs the captured image information to the stereo image recognition device 4.

  The stereo image recognition device 4 receives the image information from the stereo camera 3 and the vehicle speed V from the vehicle speed sensor 6. Based on these pieces of information, the stereo image recognition device 4 recognizes forward information such as three-dimensional object data and white line data ahead of the host vehicle 1 on the basis of image information from the stereo camera 3, and based on these recognition information and the like. Estimate the vehicle travel path. Further, the stereo image recognition device 4 checks whether or not a three-dimensional object is present on the traveling road of the vehicle, and if it is present, recognizes the latest one as a control object for collision prevention control by braking.

  Here, the stereo image recognition device 4 performs processing of image information from the stereo camera 3 as follows, for example. First, distance information is generated on the basis of the principle of triangulation from a corresponding positional shift amount for a pair of stereo images obtained by capturing the traveling direction of the host vehicle with the stereo camera 3. Then, a well-known grouping process is performed on the distance information, and by comparing the grouped distance information with preset three-dimensional road shape data, solid object data, etc., white line data, road Sidewall data such as guardrails and curbs, and three-dimensional object data such as vehicles are extracted along the way. Further, the stereo image recognition device 4 estimates the own vehicle traveling path based on the white line data, the side wall data, the estimated traveling path of the own vehicle, and the collision prevention control of the nearest three-dimensional object existing in front of the own vehicle traveling path. It is extracted (detected) as an obstacle to be controlled.

  When an obstacle to be controlled is detected, the relative distance d between the own vehicle 1 and the controlled object, the moving speed Vf of the controlled object (= (change in relative distance d) is detected as the obstacle information of the controlled object. Ratio) + (own vehicle speed V)), the deceleration af of the control target (= the differential value of the movement speed Vf of the control target) and the like.

  Thus, the stereo image recognition device 4 realizes a function as a three-dimensional object recognition means together with the stereo camera 3. That is, in the present embodiment, the stereo image recognition device 4 recognizes the size of the three-dimensional object in the real space by recognizing the three-dimensional object based on the pair of images captured in stereo, and up to the three-dimensional object. It is possible to recognize the distance. Note that the stereo camera 3 and the stereo image recognition device 4 can continue to operate even when driving support control such as collision prevention control in the travel control unit 5 described later is turned off, and can recognize the environment outside the vehicle. It has become.

  The traveling control unit 5 is connected so that various control units such as an engine control unit (E / G_ECU 5a: see FIG. 2) and a brake control unit (not shown) can communicate with each other through an in-vehicle communication line such as a CAN (Controller Area Network). As a result, the main part is configured. Various types of control information to be controlled recognized by the stereo image recognition device 4 are input to the traveling control unit 5. In addition, for example, the vehicle speed V is input to the travel control unit 5 from the vehicle speed sensor 6.

  The traveling control unit 5 then, for example, predicts a collision time TTC (Time To Collision: a value obtained by dividing the relative distance d between the host vehicle 1 and the control target by the relative speed) until the host vehicle 1 collides with an obstacle. Compared with a preset threshold (for example, 0.8 seconds), and when the collision prediction time TTC is shorter than the threshold, through the throttle control of the engine 10 and the control of the automatic brake control device 9, etc. A preset deceleration is generated.

Next, the configuration of the air conditioner 20 mounted on the vehicle 1 will be described.
As shown in FIG. 2, the air conditioner 20 includes a refrigeration cycle 21, and the refrigeration cycle 21 includes a compressor 25, a condenser 26, an expansion valve 27, and an evaporator 28 that are annularly arranged via a refrigerant circulation path 29. The principal part is comprised by communicating with.

  The compressor 25 is connected to the output shaft of the engine 10 via, for example, a drive belt 25a (see FIG. 1), and is operated by a driving force from the engine 10. The compressor 25 is constituted by, for example, a swash plate type variable capacity compressor. That is, the compressor 25 incorporates a well-known swash plate (none of which is shown) that is operated by, for example, a solenoid valve type variable mechanism. For example, a solenoid type variable mechanism is connected to the swash plate, and the solenoid valve of the variable mechanism is duty-controlled by an air conditioner control unit (A / C_ECU) 7 described later. The inclination angle of the swash plate can be changed. Then, a piston stroke (not shown) is changed according to the inclination angle of the swash plate, so that the discharge capacity of the compressor 25 is variably controlled.

  The condenser 26 is connected downstream of the compressor 25. The capacitor 26 is disposed in the engine room of the vehicle 1 so as to face the grill opening 1 a that opens at the front of the vehicle body. A radiator 31 is disposed behind the condenser 26 so as to be in series with the air flow from the grill opening 1 a, and a cooling fan 32 is disposed downstream of the radiator 31. The condenser 26 cools the refrigerant in the superheated gas phase discharged from the compressor 25 to the condensation point by the cooling air introduced from the grill opening 1a when the host vehicle 1 runs or the cooling fan 32 is driven. Phase state.

  The expansion valve 27 is disposed downstream of the condenser 26 and depressurizes the liquid-phase refrigerant that has flowed out of the condenser 26 to a low-pressure liquid-phase state.

  The evaporator 28 is configured to evaporate the low-pressure liquid-phase refrigerant that has flowed out of the expansion valve 27 to a low-pressure gas-phase state. The evaporator 28 is disposed in an air conditioning duct 35 that communicates with the outside of the vehicle interior, and cools the air conditioning air by exchanging heat with the air conditioning air flowing through the air conditioning duct 35.

  Here, the air conditioning duct 35 has, on the upstream side, an outside air inlet 36 for sucking in air from the outside of the host vehicle 1 and an inside air inlet 37 for sucking and circulating air in the vehicle interior. . Further, an inside / outside air switching damper 38 for selectively opening and closing these is disposed downstream of the outside air inlet 36 and the inside air inlet 37, and a blower driven by a blower motor 39a is disposed downstream of the inside / outside air switching damper 38. A fan 39 is provided. Further, an evaporator 28 is disposed downstream of the blower fan 39, and a water temperature type heater core 40 that uses cooling water from the radiator 31 as a heat source is disposed downstream of the evaporator 28. An air mix damper 41 is disposed upstream of the heater core 40, and the flow rate of the air conditioning air flowing through the heater core 40 is adjusted according to the opening degree of the air mix damper 41. Further, various air outlets 42 are opened downstream of the heater core 40, and a switching damper 43 is provided at the air outlets 42 to switch the air outlet mode.

  The A / C_ECU 7 includes an evaporator air temperature from an evaporator air temperature sensor 45 disposed in the vicinity of the air outlet side of the evaporator 28, a water temperature from a water temperature sensor 46 that detects the water temperature of the radiator 31, and an outside air temperature from an outside air temperature sensor 47. Various information indicating the vehicle interior temperature from the vehicle interior temperature sensor 48, the solar radiation amount from the solar radiation sensor 49, and the like are input. Various signals indicating the set temperature, the operation mode, and the like from the operation panel 50 are input to the A / C_ECU 7. Further, the A / C_ECU 7 receives various information such as the engine speed and the own vehicle speed V from the E / G_ECU 5a and various information related to the front three-dimensional object recognized by the stereo image recognition device 4.

  The A / C_ECU 7 performs switching control of the dampers 38, 41, 42, drive control of the blower motor 39a, discharge capacity control of the compressor 25, and the like based on these various pieces of input information. Thus, air-conditioning air corresponding to the set temperature set by the passenger is supplied from the air outlet 42 into the vehicle interior in a predetermined mode.

  Here, when controlling the discharge capacity of the compressor 25, the A / C_ECU 7, for example, information from various sensors of the air conditioning system such as the outside air temperature, the passenger compartment temperature, and the amount of solar radiation, the set temperature set by the occupant, etc. Based on the above, the target evaporator outlet temperature is calculated. The A / C_ECU 7 basically calculates the required cooling load based on the relationship between the target evaporator outlet temperature and the evaporator outlet temperature, and variably controls the discharge capacity of the compressor 25 based on the required cooling load. .

  At that time, the A / C_ECU 7 determines whether or not the current environment outside the vehicle is difficult to introduce the cooling air from the grill opening 1a based on the three-dimensional object information input from the stereo image recognition device 4. Determine whether. That is, when the A / C_ECU 7 determines that there is a three-dimensional object with a projected area equal to or larger than the set value in front of the host vehicle 1 and the distance d from the host vehicle 1 to the three-dimensional object is equal to or less than the set threshold value D1, It is determined that it is difficult to introduce cooling air having a sufficient flow rate from the grill opening 1a. When it is determined that it is difficult to introduce cooling air with a sufficient flow rate from the grill opening 1a, the A / C_ECU 7 sets the discharge capacity of the compressor 25 to a value set according to the cooling demand load. Limit to low values.

  Thus, in this embodiment, A / C_ECU7 implement | achieves each function as a discharge capacity control means and a discharge capacity restriction means.

  Next, the compressor control executed in the A / C_ECU 7 will be described according to the flowchart showing the compressor control routine shown in FIG. This routine is repeatedly executed every set time. When the routine starts, the A / C_ECU 7 first sets the target evaporator outlet temperature in step S101. That is, the A / C_ECU 7 is configured based on information from various sensors of the air conditioning system such as outside air temperature, vehicle interior temperature, and solar radiation amount, a preset temperature set by the occupant, and the like. The target evaporator blowout temperature is calculated with reference to FIG.

  When the process proceeds from step S101 to step S102, the A / C_ECU 7 calculates the cooling request load based on, for example, the relationship between the target evaporator outlet temperature and the evaporator outlet temperature. For example, the A / C_ECU 7 calculates a discharge capacity required for the compressor 25 based on the cooling required load, and calculates a compressor control current as a control current corresponding to the discharge capacity.

  When the process proceeds from step S102 to step S103, the A / C_ECU 7 calculates a duty ratio for the solenoid valve of the variable mechanism based on the compressor control current.

  When the process proceeds from step S103 to step S104, the A / C_ECU 7 checks whether or not a limit value for limiting the discharge capacity of the compressor 25 is set in a compressor discharge capacity limit value setting routine described later.

  If it is determined in step S104 that the limit value is set, the A / C_ECU 7 proceeds to step S105, and after correcting the duty ratio calculated in step S103 with the limit value over a predetermined time constant τ, Proceed to step S106. In the present embodiment, as the limit value, for example, a coefficient for reducing the duty ratio to a predetermined ratio by multiplying the duty ratio according to the cooling required load is set.

  On the other hand, if it is determined in step S104 that the limit value is not set, the A / C_ECU 7 proceeds directly to step S106.

  When the process proceeds from step S104 or step S105 to step S106, the A / C_ECU 7 outputs the PWM waveform to the solenoid valve based on the currently set duty ratio, and then exits the routine.

  Next, the compressor output level limit value setting executed in the A / C_ECU 7 will be described with reference to the flowchart of the limit value setting routine shown in FIG. This routine is repeatedly executed every set time. When the routine starts, the A / C_ECU 7 first checks in step S201 whether or not the outside air temperature is equal to or higher than a preset threshold value.

  Here, when the outside air temperature is low, it is unlikely that the discharge capacity of the compressor 25 is controlled to a high value due to an increase in the required cooling load, and there is no necessity to limit the discharge capacity. Therefore, if the outside air temperature is less than the threshold, the A / C_ECU 7 proceeds to step S206 to cancel the setting of the limit value.

  On the other hand, if it is determined in step S201 that the outside air temperature is equal to or higher than the threshold value, the A / C_ECU 7 proceeds to step S202 and checks whether or not the water temperature of the radiator 31 is equal to or higher than a preset threshold value.

  Here, the case where the water temperature of the radiator 31 is low means that the engine 10 is not warmed up and the temperature in the engine room is low, so that the cooling load of the compressor 25 is increased due to an increase in cooling demand load caused by insufficient cooling capacity of the condenser. The possibility that the discharge capacity is controlled to a high value is low, and there is no necessity to limit the discharge capacity. Therefore, if the water temperature is lower than the threshold value, the A / C_ECU 7 proceeds to step S206 to cancel the setting of the limit value.

  On the other hand, if it is determined in step S202 that the water temperature is equal to or higher than the threshold, the A / C_ECU 7 proceeds to step S203 and checks whether the vehicle speed V is equal to or lower than a preset threshold.

  Here, when the host vehicle speed V is high, a predetermined amount or more of traveling wind is introduced through the grill opening 1a, so that the discharge capacity of the compressor 25 is increased due to an increase in cooling demand load caused by insufficient cooling capacity of the condenser. Is not likely to be controlled to a high value, and there is no necessity to limit the discharge capacity. Therefore, if the host vehicle speed V is higher than the threshold value, the A / C_ECU 7 proceeds to step S206 in order to cancel the limit value setting.

  And if it progresses to step S206 from step S201, step S202 or step S203, A / C_ECU7 will progress to step S211 after clearing the timer t mentioned later.

  On the other hand, if it is determined in step S203 that the vehicle speed V is equal to or lower than the threshold value, the A / C_ECU 7 proceeds to step S204, increments the timer t, and then proceeds to step S205.

  Here, the timer t is a timer indicating the duration of the state in which the outside air temperature is equal to or higher than the threshold, the water temperature is equal to or higher than the threshold, and the vehicle speed V is equal to or lower than the threshold, and the A / C_ECU 7 If it is greater than or equal to the threshold, the process proceeds to step S207, and if the count of the timer t is less than the threshold, the process proceeds to step S211.

  In addition, although the process shown from the above-mentioned step S201 to step S206 is for avoiding the setting of an unnecessary limit value, in these processes, as the parameters for determining the duration, the outside air temperature, the water temperature, and It is not necessary to determine all the vehicle speeds and can be omitted as appropriate. Also, other parameters can be added as appropriate as parameters for determining the duration. Furthermore, the processing itself shown in steps S201 to S206 described above can be omitted.

  When the process proceeds from step S205 to step S207, the A / C_ECU 7 is a three-dimensional object with a projected area equal to or larger than a set value (for example, equal to or larger than a projected area of a general passenger car) in front of the host vehicle 1 (immediately before). To see if exists.

  If it is determined in step S207 that there is no three-dimensional object whose projected area is equal to or larger than the set value in front of the host vehicle 1, the A / C_ECU 7 proceeds to step S211.

  On the other hand, if it is determined in step S207 that there is a three-dimensional object with a projected area equal to or larger than the set value in front of the host vehicle 1, the A / C_ECU 7 proceeds to step S208, and the distance d to the three-dimensional object is equal to or less than the set value D1. It is checked whether or not (for example, D1 = 1 m or less).

  If it is determined in step S208 that the distance d to the three-dimensional object is greater than D1, the A / C_ECU 7 proceeds to step S211.

  On the other hand, when it is determined in step S208 that the distance d to the three-dimensional object is equal to or less than D1, that is, there is a three-dimensional object with a projected area equal to or larger than the set value in front of the host vehicle 1, and When it is determined that the distance d is equal to or less than D1, the A / C_ECU 7 determines that the front three-dimensional object can be an obstacle that inhibits the introduction of the cooling air from the grill opening 1a, and proceeds to step S209.

  When proceeding from step S208 to step S209, the A / C_ECU 7 determines a level (inhibition level) at which the front three-dimensional object (obstacle) can inhibit the introduction of the cooling air from the grill opening 1a. Specifically, the A / C_ECU 7 determines the inhibition level of the front obstacle with reference to, for example, a map shown in FIG. In the map shown in FIG. 5, for example, any one of level A to level E is determined as the inhibition level. That is, on the map, as the projected area of the obstacle, for example, small (equivalent to the projected area of a general passenger car), medium (equivalent to the projected area of a large vehicle), large (equivalent to the projected area of a building, etc.) Three sections are set, and the distance to the obstacle is D1 ≧ d> D2, D2 ≧ d> D3, D3 ≧ d (where D1 = 1 m, D2 = 0.7 m, D3 = 0.5 m) These three categories are set. In this map, the higher inhibition level is determined as the projected area of the obstacle is larger, and the higher inhibition level is determined as the distance to the obstacle is shorter.

  When the process proceeds from step S209 to step S210, the A / C_ECU 7 sets the limit value (coefficient) of the compressor discharge capacity and the time constant τ according to the determined inhibition level, and then exits the routine. More specifically, the A / C_ECU 7 sets a limit value and a time constant τ of the compressor discharge capacity with reference to, for example, a map shown in FIG. That is, for example, when the inhibition level is A, the A / C_ECU 7 sets the limit value to “0.5” and the time constant τ to “60 sec”, and when the inhibition level is B, the A / C_ECU 7 If the value is set to “0.6”, the time constant τ is set to “50 sec”, and the inhibition level is C, the limit value is set to “0.7”, the time constant τ is set to “40 sec”, and the inhibition is performed. When the level is D, the limit value is set to “0.8” and the time constant τ is set to “20 sec”. When the inhibition level is E, the limit value is set to “0.9” and the time constant is set. τ is set to “10 sec”. As a result, in step S105 described above, the discharge capacity (duty ratio) of the compressor 25 is limited as the projected area of the obstacle increases and is limited as the distance from the obstacle decreases.

  On the other hand, when the process proceeds from step S205, step S206, step S207, or step S208 to step S211, the A / C_ECU 7 exits the routine after releasing the limit value of the compressor discharge capacity.

  Next, an example of the transition of pressure in the refrigeration cycle 21 of the air conditioner 20 in which such control is performed will be described with reference to FIG. The time chart shown in FIG. 7 is a change in pressure after the host vehicle 1 that was traveling at a predetermined vehicle speed V (for example, V = 100 Km / h) is stopped at the timing T1 with the mode of the air conditioner 20 set to the inside air circulation mode. Is shown together with outside air temperature and blowing temperature.

  As shown in FIG. 7, after the host vehicle 1 stops, the traveling wind is not introduced from the grill opening 1 a and the cooling fan 32 operates appropriately. However, the cooling fan 32 introduces cooling introduced from the grill opening 1 a. Since the amount of wind is smaller than that due to traveling wind, the temperature around the condenser 26 gradually increases, and accordingly, the required cooling load increases. When the cooling requirement load increases, the discharge capacity of the compressor 25 is controlled to the increase side, and the high pressure side pressure and the low pressure side pressure of the refrigerant circulating in the refrigeration cycle 21 are increased.

  Next, for example, when the mode of the air conditioner 20 is switched from the inside air circulation mode to the outside air introduction mode at the timing T <b> 2, outside air is introduced into the air conditioning duct 35 via the outside air inlet 36. Since the outside air introduced in this way is easily affected by the heat in the engine room when the vehicle is stopped, the evaporator blowout temperature rises, and the cooling demand load further increases accordingly. When the cooling requirement load further increases, the high pressure side pressure and the low pressure side pressure of the refrigerant circulating in the refrigeration cycle 21 further increase.

  Next, for example, when a tail wind from the rear of the host vehicle 1 is applied at the timing T3, and a partition is installed as an obstacle immediately before the host vehicle 1 at the timing T4, the cooling air is regenerated in the engine room. A large amount of circulation occurs, and the cooling demand load further increases.

  On the other hand, when the stereo image recognition device 4 recognizes a partition and recognizes this partition as a three-dimensional object (obstacle) that inhibits the introduction of cooling air from the grill opening 1a, a limit value is set in the A / C_ECU 7. The discharge capacity from the compressor 25 is limited by this limit value. Thereby, the rapid and excessive rise of the high-pressure side pressure and low-pressure side pressure of the refrigerant circulating in the refrigeration cycle 21 is suppressed. Therefore, the high pressure side pressure of the refrigerant is suppressed from rising to the cycle protection pressure, and the cooling function is maintained. In this case, the temperature of the blowout gradually increases so as not to give the passenger a sense of incongruity.

  Here, as a comparative example, characteristics when the discharge capacity of the compressor 25 is not suppressed are indicated by broken lines in FIG. As is clear from the figure, when the high-pressure side pressure after the screen is set up rapidly and reaches the cycle protection pressure, the cooling function is impaired, and the outlet temperature also rises rapidly.

  According to such an embodiment, the stereo image recognition device 4 recognizes a three-dimensional object in front of the host vehicle 1 based on image information obtained by imaging the environment outside the vehicle, and the projected area is greater than or equal to a set value in front of the host vehicle 1. When the three-dimensional object is present and the distance d from the host vehicle 1 to the three-dimensional object is equal to or less than the set threshold value D1, the discharge capacity of the compressor 25 is set to a value set according to the cooling demand load in the A / C_ECU7. By limiting the cooling air to a low value, even when it is difficult to suppress the recirculation of the cooling air to the condenser 26, the high pressure side pressure of the refrigerant circulating in the refrigeration cycle 21 is prevented from rising rapidly, and the operating time of the compressor 25 is reduced. Can be secured sufficiently.

  In this case, the larger the projected area of the front three-dimensional object, the higher the ratio that restricts the discharge capacity of the compressor 25, so that an appropriate restriction amount according to the inhibition level with respect to the introduction of the cooling air from the grill opening 1 a. Thus, the discharge capacity of the compressor 25 can be limited. Therefore, it is possible to balance the securing of the operation time of the compressor 25 and the suppression of fluctuations in the discharge temperature in a balanced manner.

  Further, as the distance from the host vehicle 1 to the front three-dimensional object becomes shorter, the ratio of restricting the discharge capacity of the compressor 25 is increased, so that an appropriate restriction according to the inhibition level with respect to the introduction of the cooling air from the grill opening 1a. The discharge capacity of the compressor 25 can be limited by the amount. Therefore, it is possible to balance the securing of the operation time of the compressor 25 and the suppression of fluctuations in the discharge temperature in a balanced manner.

  Further, by using the three-dimensional object information acquired in the driving support device 2 for air conditioning control, it is possible to take measures against recirculation of the cooling air with a simple configuration without adding a new configuration.

  Here, in order to eliminate the recirculation of the cooling air at an early stage, for example, when the A / C_ECU 7 determines the restriction on the discharge capacity of the compressor 25, the inter-vehicle distance is secured to the driver together with the discharge capacity restriction control. It is also possible to provide voice guidance that prompts the user.

  In addition, this invention is not limited to each embodiment described above, A various deformation | transformation and change are possible, and they are also in the technical scope of this invention. For example, in the above-described embodiment, an example of setting a limit value for the duty ratio for controlling the variable mechanism of the compressor 25 has been described as an example of control for limiting the discharge capacity of the compressor 25. Of course, for example, a limit value for the cooling demand load or the discharge capacity itself required for the compressor 25 may be set. In addition, by replacing device control that improves cooling performance, for example, discharge capacity control with cooling fan duty control, etc., it is possible to secure a time delay until the pre-capacitor air temperature rises to an extreme, and achieve a certain level of effect. It is possible.

  In the above-described embodiment, an example of recognizing a three-dimensional object based on image information from the stereo camera 3 has been described. However, the present invention is not limited to this, and for example, image information from a monocular camera. Of course, a three-dimensional object may be recognized based on a combination of image information from a monocular camera and distance information from a millimeter wave radar or the like.

1 ... Vehicle (own vehicle)
DESCRIPTION OF SYMBOLS 1a ... Grill opening part 2 ... Driving support apparatus for vehicles 3 ... Stereo camera (three-dimensional object recognition means)
4 ... Stereo image recognition device (three-dimensional object recognition means)
DESCRIPTION OF SYMBOLS 5 ... Traveling control unit 6 ... Vehicle speed sensor 7 ... Air-conditioner control apparatus (discharge capacity control means, discharge capacity restriction means)
DESCRIPTION OF SYMBOLS 9 ... Automatic brake control apparatus 10 ... Engine 20 ... Air conditioner 21 ... Refrigeration cycle 25 ... Compressor 25a ... Drive belt 26 ... Condenser 27 ... Expansion valve 28 ... Evaporator 29 ... Refrigerant circulation path 31 ... Radiator panel 32 ... Cooling fan 35 ... Air conditioning Duct 36 ... Outside air inlet 37 ... Inside air inlet 38 ... Inside / outside air switching damper 39 ... Blower fan 39a ... Blower motor 40 ... Heater core 41 ... Air mix damper 42 ... Outlet 43 ... Switching damper 45 ... Evaporator outlet temperature sensor 46 ... Water temperature sensor 47 ... Outside air temperature sensor 48 ... Interior temperature sensor 49 ... Solar radiation sensor 50 ... Operation panel

Claims (6)

A vehicle air conditioner comprising: a variable displacement compressor; and a discharge capacity control unit that calculates a cooling demand load based on a preset condition and variably controls the discharge capacity of the compressor according to the cooling demand load In
A three-dimensional object recognition means for recognizing a three-dimensional object in front of the host vehicle based on image information obtained by imaging an environment outside the vehicle;
When the three-dimensional object whose projected area is equal to or larger than a set value exists in front of the host vehicle and the distance from the host vehicle to the three-dimensional object is equal to or less than a set threshold value, the discharge capacity of the compressor is set to the cooling required load. A vehicle air conditioner comprising discharge capacity restriction means for restricting to a value lower than a value set accordingly.   2. The vehicle air conditioner according to claim 1, wherein the discharge capacity limiting unit increases the ratio of limiting the discharge capacity of the compressor as the projected area of the three-dimensional object increases.   3. The vehicle air conditioning according to claim 1, wherein the discharge capacity limiting unit increases the ratio of limiting the discharge capacity of the compressor as the distance from the host vehicle to the three-dimensional object decreases. apparatus.   The discharge capacity limiting means has an outside air temperature in advance even when the three-dimensional object having a projected area equal to or larger than a set value is present in front of the host vehicle and the distance from the host vehicle to the three-dimensional object is equal to or less than a set threshold value. The vehicle air conditioner according to any one of claims 1 to 3, wherein the compressor discharge capacity is not limited when a state equal to or greater than a set threshold value has not continued for a set time or longer. .   The discharge capacity limiting means is configured to provide a cooling water temperature of the engine even when the three-dimensional object whose projected area is equal to or larger than a set value exists in front of the host vehicle and the distance from the host vehicle to the three-dimensional object is equal to or less than a set threshold value. 5. The vehicle according to claim 1, wherein a discharge capacity of the compressor is not limited when a state equal to or greater than a preset threshold value does not continue for a set time or more. Air conditioner.   The discharge capacity limiting means is configured so that the vehicle speed is predetermined in advance even when the three-dimensional object having a projection area equal to or larger than a set value exists in front of the host vehicle and the distance from the host vehicle to the three-dimensional object is equal to or less than a set threshold value. The vehicle air conditioner according to any one of claims 1 to 5, wherein the compressor discharge capacity is not limited when a state equal to or less than a set threshold value has not continued for a set time or longer. .

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