JP2010058660A - Vehicular air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress rapid temperature variation of the temperature of air passing through an evaporator when a feeding amount of air passing through the evaporator is varied, thereafter to transfer it to proportional integration control according to the system state, and to smoothly perform transferring to the stable state that the temperature of air passing through the evaporator is made coincident to the target temperature. <P>SOLUTION: The vehicle air conditioner varies an outside control signal by an operation equation having a proportional member based on variance of the temperature of air after evaporator detected by an air temperature detection sensor after the evaporator and the target temperature and an integration member by time accumulation of remained variance of the temperature of air after the evaporator relative to the target temperature to vary a coolant delivery amount of a compressor. An air amount correction amount is added/reduced relative to the integration member according to increase/reduction of the feeding amount of air passing through the evaporator. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention has a compressor in the refrigeration cycle in which the refrigerant discharge amount can be varied by an external control signal, and the temperature of the air that has passed through the evaporator by varying the refrigerant discharge amount of the compressor, and hence the blowout into the passenger compartment. The present invention relates to a vehicle air conditioner that controls an air temperature.

  Various types of conventional vehicle air conditioners of this type have been proposed in which the refrigerant discharge amount of the compressor is feedback-controlled so that the air temperature that has passed through the evaporator matches the target temperature. The feedback control method includes a proportional term based on the deviation between the air temperature that has passed through the evaporator (hereinafter referred to as the air temperature after the evaporator) and the target temperature, and the time of the residual deviation of the air temperature after the evaporator relative to the target temperature. Conventionally known are PI control based on an arithmetic expression composed of an integral term by integration, or PID control based on an arithmetic expression composed of a proportional term and an integral term and a differential term based on time differentiation between residual deviations (PID control). (See Patent Document 1).

  In PI control and PID control, if each operation is strengthened (the operation constant is large), control responsiveness is improved, but control stability is deteriorated. Conversely, if each operation is weakened (the operation constant is small), stability is improved, but control responsiveness is deteriorated. Therefore, in the PI control and the PID control, each operation constant is determined so as to balance the response and stability. However, when the operation constant is determined in such a manner that the control response and stability are harmonized, a rapid temperature change in the post-evaporator air temperature that occurs when the air flow to the evaporator changes cannot be suppressed.

  In view of this, there has been proposed a method in which a switching compensation amount is added to a control output to the compressor for a predetermined time when the air flow to the evaporator is changed (see Patent Document 2).

According to this, the rapid temperature change of the air temperature after the evaporator at the time of the air volume change can be suppressed.
Japanese Patent Laid-Open No. 5-85142 Japanese Patent Publication No. 7-6503

  However, in the conventional example, the switching compensation amount disappears from the control output to the compressor after a lapse of a predetermined time from the time when the air flow to the evaporator is changed. Then, even after the predetermined time, even if the post-evaporator air temperature is stable, it fluctuates, and correction by PI control or PID control is required again. Therefore, there is a problem that the transition to the stable state in which the post-evaporator air temperature matches the target temperature cannot be smoothly performed.

  Therefore, the present invention can suppress a rapid temperature change of the air temperature that has passed through the evaporator when the amount of blown air that has passed through the evaporator changes, and then shifts to proportional-integral control according to the system state. An object of the present invention is to provide a vehicle air conditioner that can smoothly transition to a stable state in which the air temperature that has passed through the evaporator matches the target temperature.

  The invention according to claim 1, which achieves the above object, is a compressor capable of changing a refrigerant discharge amount by an external control signal, a radiator for radiating high-temperature and high-pressure refrigerant discharged from the compressor, and a refrigerant radiated by the radiator. A refrigeration cycle having a decompression means for decompressing the refrigerant, an evaporator for cooling the air by exchanging heat between the refrigerant decompressed by the decompression means and the air sent to the vehicle interior, and passing the evaporator to the vehicle interior A post-evaporator air temperature detected by the post-evaporator air temperature detecting means is provided with a blower that generates blast and a post-evaporator air temperature detecting means that detects the post-evaporator air temperature that is the temperature of the air that has passed through the evaporator. And a proportional term based on the deviation of the target temperature and an integral term based on the time accumulation of the residual deviation of the post-evaporator air temperature with respect to the target temperature. Variable To an air conditioner for a vehicle, characterized by subtracting the air flow rate correction amount to the integral term in accordance with the blowing amount of increase or decrease passing through the evaporator.

  A second aspect of the present invention is the vehicle air conditioner according to the first aspect, wherein a threshold value is set for an increase / decrease amount of the air flow passing through the evaporator to determine whether or not to perform correction by the air flow correction amount. It is characterized by that.

  A third aspect of the present invention is the vehicle air conditioner according to the first or second aspect, wherein the air volume correction amount to be added to or subtracted from the integral term is in accordance with the amount of change in the air flow rate passing through the evaporator. It is characterized by being variable.

  A fourth aspect of the present invention is the vehicle air conditioner according to any one of the first to third aspects, wherein the air volume correction amount to be added to or subtracted from the integral term is as long as the air temperature before passing through the evaporator is large. The larger the value, the larger the amount.

  A fifth aspect of the present invention is the vehicle air conditioner according to any one of the first to third aspects, wherein when the amount of air passing through the evaporator changes in a decreasing direction, the evaporator A threshold value is set for the deviation between the rear air temperature and the target temperature. If the deviation is larger than the threshold value, the air flow correction amount is not subtracted. If the deviation is smaller than the threshold value, the air flow correction amount is set. The subtraction is performed.

  According to the first aspect of the present invention, the refrigerant discharge of the compressor is performed by the external control signal based on the arithmetic expression having the proportional term based on the deviation of the air temperature that has passed through the evaporator and the target temperature and the integral term due to the time accumulation of the residual deviation. In order to vary the amount, it is possible to control the temperature of the air that has passed through the evaporator to match its target temperature. When the air flow passing through the evaporator changes, the air flow correction amount is added to or subtracted from the integral term of the arithmetic expression according to the increase or decrease of the air flow, so that a rapid temperature change of the air temperature passing through the evaporator is suppressed. it can. After that, it shifts to proportional integral control according to the system state, in other words, it shifts to proportional integral control etc. in which the air flow correction amount is absorbed as an integral term, and the air temperature that has passed through the evaporator is stabilized to match its target temperature. Transition to the state can be performed smoothly. From the above, it is possible to speed up the responsiveness to changes in the air flow without impairing the normal stability.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, the control stability is improved by adding / subtracting the air flow correction amount to / from the integral term only for the air flow change that cannot be handled by proportional integral control or the like. Can be planned.

  According to the invention of claim 3, in addition to the effect of the invention of claim 1 or claim 2, since correction according to the change in the air volume can be performed, both control responsiveness and stability can be achieved.

  According to the invention of claim 4, in addition to the effects of the inventions of claims 1 to 3, it is possible to perform correction in consideration of the temperature load in the air volume change, and thus it is possible to achieve both responsiveness and stability. . In addition, when the cooling load is low, the correction is canceled, so that unnecessary operation can be prevented.

  According to the invention of claim 5, in addition to the effects of the inventions of claims 1 to 3, if the air temperature after the evaporator is not cooled, the correction is canceled because there is no risk of freezing. Delays can be avoided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
1 to 3 show a first embodiment of the present invention, FIG. 1 is a schematic configuration diagram of a vehicle air conditioner, FIG. 2 is a control flow chart of refrigerant discharge amount of a compressor, and FIG. It is an output time chart.

  As shown in FIG. 1, the vehicle air conditioner A has a refrigeration cycle 1. The refrigeration cycle 1 includes a compressor 2 that compresses refrigerant, a radiator 3 that radiates high-temperature and high-pressure refrigerant discharged from the compressor 2, a decompression unit 4 that decompresses refrigerant that has passed through the radiator 3, An evaporator 5 that evaporates the refrigerant depressurized by the depressurizing means 4 and cools the air guided to the vehicle interior, and is connected to the downstream of the evaporator 5, separates the refrigerant into a gas and liquid, and converts only the gas refrigerant into the compressor 2. And an accumulator 6 that is sent to the pipes 7a to 7e.

  The compressor 2 is configured to receive a driving force from the vehicle engine 8 and to vary the refrigerant discharge amount by an external control valve (ECV) 9. The external control valve 9 varies the refrigerant discharge amount of the compressor 2 by an external control signal from the control unit 20.

  The evaporator 5 is disposed in a blower air passage 10 that leads into the passenger compartment. A blower 11 is arranged upstream of the evaporator 5 in the blower passage 10. The air volume of the blower 11 is varied by a control voltage (4V to 12V) from the control unit 20. In addition, an outside air inlet (not shown) and an inside air inlet (not shown) are opened in the uppermost stream of the air passage 10, and a blowout outlet (not shown) to the vehicle interior is provided in the most downstream of the air passage 10. ) Is opened. Outside air and inside air are sucked into the air passage 10 by the suction force of the blower 11, and the sucked air passes through the evaporator 5 and the like and then blows out into the vehicle interior through the outlet.

  Further, a post-evaporator air temperature detection sensor S1, which is a post-evaporator air temperature detection means, is disposed immediately downstream of the evaporator 5 in the air passage 10. The post-evaporator air temperature detection sensor S1 detects the air temperature that has passed through the evaporator 5 (hereinafter referred to as post-evaporator air temperature Tint). This detection output is output to the control unit 20.

  The control unit 20 includes an ECV adjustment function unit 20a, an air volume adjustment function unit 20b, and a necessary capacity determination function unit 20c. The ECV adjustment function unit 20a controls the external control valve 9 according to a command from the necessary capacity determination function unit 20c. Specifically, the ECV adjustment function unit 20a controls the external control valve 9 according to the output duty ratio. The external control valve 9 controls the refrigerant discharge amount of the compressor 2 in proportion to the output duty ratio. That is, the compressor 2 is controlled to increase the refrigerant discharge amount as the output duty ratio increases, and to decrease the refrigerant discharge amount as the output duty ratio decreases.

  The air volume adjustment function unit 20b controls the blower 11 according to a command from the necessary capacity determination function unit 20c. Specifically, it is controlled by the voltage (4V to 12V) output to the blower 11. In addition to the post-evaporator air temperature detection sensor S1, sensor outputs from the outside air temperature detection sensor S2, the vehicle interior temperature detection sensor S3, the solar radiation sensor S4, and the like are input to the necessary capacity determination function unit 20c. Various data such as a target temperature Ttarget of the passed air temperature and an air volume setting of the blower 11 are input. The target temperature and the air volume may be set by a user operation or automatically by an environmental change. The necessary capacity determination function unit 20c controls the refrigerant discharge amount of the compressor 2 via the ECV adjustment function unit 20a based on the flowchart of FIG.

  Here, the necessary capacity determination function unit 20c calculates the refrigerant discharge amount of the compressor 2 based on the deviation between the air temperature that has passed through the evaporator 5 (hereinafter referred to as the post-evaporator air temperature Tint) and the target temperature Ttarget. In general, feedback control (PI control) is performed by a proportional-integral calculation method. Specifically, the proportional term (Kp × e (t)) based on the deviation e (t) between the post-evaporator air temperature Tint and the target temperature Ttarget, and the time of the residual deviation of the post-evaporator air temperature Tint with respect to the target temperature Ttarget Based on an arithmetic expression consisting of an integral term (E (t) = Ki × e (t) + E (t−Δt)) based on accumulation, an air volume change correction term F (t) is added to or subtracted from the integral term E (t). . Here, e (t), E (t), and F (t) indicate numerical values of each term at time t, and Δt indicates a calculation unit time. Kp represents an operation constant of the proportional term, and Ki represents an operation constant of the integral term. The contents of the airflow change correction term F (t) will be described in detail in the following control operation.

  Next, the control operation of the refrigerant discharge amount of the compressor 2 will be described. In FIG. 2, the routine shown below is executed every calculation unit time of 100 ms. This will be described below.

  First, it is checked whether or not the compressor 2 is operating (step S0). If the compressor 2 is in operation, the current post-evaporator air temperature Tint of the post-evaporator air temperature detection sensor S1 is input, and the deviation e (t) between the post-evaporator air temperature Tint and the target temperature Ttarget is calculated. Calculate (step S1).

  Next, it is checked whether there is a change in the air volume of the blower 11 (step S2). If there is a change in the air volume and it is an increase in the air volume (step S4), the air volume change correction term is set to F (t) = 8% (step S41). If the air volume is decreased (step S4), the air volume change correction term is set to F (t) = − 8% (step S42). Here, when it is determined that there is a change in the air flow, the subsequent change in the air flow is checked using the air flow value determined to be changed as the air flow reference value. As a result, the airflow change correction term is corrected only once for a single airflow change.

  If there is no change in the air flow, the air flow change correction term is set to F (t) = 0% (step S43). In this first embodiment, the value of the airflow change correction term is a value that changes the output duty to the external control valve 9 by ± 8%. However, when the airflow changes, the abrupt temperature change of the post-evaporator air temperature Tint occurs. Is appropriately determined to a value that can suppress as much as possible.

  Next, the integral term E (t) = Ki × e (t) + E (t−Δt) + F (t) is calculated based on the value of the airflow change correction term F (t) (step S50).

  That is, when the air volume of the blower 11 has changed, the integral term E (t) is calculated by adding or subtracting the air volume change correction term F (t).

  Next, an output = Kp × e (t) + E (t) is calculated based on the calculated value of the integral term E (t) (step S60). Based on the output calculated in this way, the ECV adjustment function unit 20a outputs an external control signal to the external control valve 9, and the refrigerant discharge amount of the compressor 2 is varied.

  That is, as shown in FIG. 3, when the air flow rate of the blower 11 decreases, the evaporator 5 tends to overcool the air flow, but the refrigerant discharge amount of the compressor 2 decreases, and consequently the refrigerant of the evaporator 5. Since the flow rate is reduced, there is no overcooling. Further, when the air flow rate of the blower 11 is increased, the evaporator 5 tends to be undercooled, but the refrigerant discharge amount of the compressor 2 is increased and the refrigerant flow rate of the evaporator 5 is increased. There is no shortage. Thus, when there is a change in the amount of air blown from the blower 11, it is possible to suppress a rapid temperature change in the air temperature that has passed through the evaporator 5. Then, the process proceeds to proportional integral control according to the system state, in other words, the process proceeds to proportional integral control in which the airflow correction amount is absorbed as an integral term, and the air temperature that has passed through the evaporator 5 is matched with the target temperature. Transition to the state can be performed smoothly.

  On the other hand, if the compressor 2 is not in operation (step S0), the integral term E (t) = 0 is set (step S51), and the output = 0 is set (step S61).

  As described above, the vehicle air conditioner A includes the proportional term based on the deviation e (t) between the post-evaporator air temperature Tint detected by the post-evaporator air temperature detection sensor S1 and the target temperature Ttarget, and the target temperature. The refrigerant discharge amount of the compressor 2 is varied by changing the external control signal by an arithmetic expression having an integral term by the time accumulation of the residual deviation of the post-vaporizer air temperature Tint with respect to Ttarget, and passes through the evaporator 5. The air flow correction amount is added to or subtracted from the integral term according to the increase or decrease of the air flow to be performed. Therefore, since the refrigerant discharge amount of the compressor 2 is basically controlled by feedback control based on proportional-integral calculation, it is possible to control the air temperature that has passed through the evaporator 5 to match the target temperature. When the amount of air flowing through the evaporator 5 changes, the air amount correction amount is added to or subtracted from the integral term of the arithmetic expression in accordance with the increase or decrease of the amount of air flow. Can be suppressed. After that, the process shifts to proportional-integral control according to the system state, in other words, shifts to proportional-integral control in which the airflow correction amount is absorbed as an integral term, and the stable state in which the air temperature passing through the evaporator 5 matches the target temperature. The transition to can be done smoothly. From the above, it is possible to speed up the responsiveness to changes in the air flow without impairing the normal stability.

(Second Embodiment)
4 and 5 show a second embodiment of the present invention, FIG. 4 is a control flow chart of the refrigerant discharge amount of the compressor, and FIG. 5 is a time chart of each output when the air volume changes.

  Compared with the first embodiment, the second embodiment is different from the first embodiment only in a part of the flowchart for controlling the refrigerant discharge amount of the compressor. explain. In addition, since the schematic block diagram of the vehicle air conditioner A is the same as 1st Embodiment, FIG. 1 is utilized.

  As shown in FIG. 4, in this 2nd Embodiment, the threshold value is provided in the air volume change of the air blower 11 (step S3). Then, if the change in the air volume is 3 V / 4 seconds or more, the flow rate is changed, and if it is less than that, a step (step S3) for determining that there is no air volume change is inserted. As shown in FIG. 5, the refrigerant discharge amount of the compressor 2 is not changed unless the change in the air volume is 3 V or more in 4 seconds.

  In the second embodiment, since a threshold value is set for the increase / decrease amount of the air flow passing through the evaporator 5 and it is determined whether or not to perform the correction by the air flow correction amount, the air flow change that cannot be handled by the proportional integral control is determined. The stability of the control can be improved by adding or subtracting the airflow correction amount.

  Although the threshold value is 3 V / 4 seconds in the second embodiment, the threshold value is appropriately determined depending on whether or not the air volume correction value can be dealt with by normal proportional integral control when the air volume changes. . More specifically, it is preferable to determine whether or not freezing prevention due to undershoot can be performed without disengaging the clutch, and whether window fogging or odor generation due to overshoot can be prevented.

(Third embodiment)
6 and 7 show a third embodiment of the present invention, FIG. 6 is a control flow chart of the refrigerant discharge amount of the compressor, and FIG. 7 is a time chart of each output when the air volume changes.

  Compared with the second embodiment, the third embodiment is different from the second embodiment only in a part of the flowchart for controlling the refrigerant discharge amount of the compressor. explain. In addition, since the schematic block diagram of the vehicle air conditioner A is the same as 1st Embodiment, FIG. 1 is utilized.

  That is, as shown in FIG. 6, the calculation formula of the airflow change correction term F (t) is different (steps S44 and S45). When the airflow change amount is increased, the airflow change correction term F (t) = 8 + (| change amount | −3) / 2%, and when the airflow change amount is decreased, the airflow change correction term F (t ) = − 8− (| change amount | −3) / 2%. Here, the change amount is a change value of the output voltage of the blower 11. As shown in FIG. 7, the output duty to the external control valve 9 changes according to the magnitude of the change in the air volume. As a result, the refrigerant discharge amount of the compressor 2 changes according to the change in the air volume.

  In the third embodiment, the amount of correction to be added to or subtracted from the integral term is varied according to the amount of change in the amount of air passing through the evaporator 5, so that correction according to the change in air volume can be performed. Both responsiveness and stability can be achieved.

  The air flow correction value corresponding to the air flow change is (| change amount | −3) / 2% in the third embodiment, but is determined as appropriate under the control responsiveness and stability.

(Fourth embodiment)
FIG. 8 is a control flowchart of the refrigerant discharge amount of the compressor according to the fourth embodiment of the present invention.

  Compared with the third embodiment, the fourth embodiment is different from the third embodiment only in part of the flowchart for controlling the refrigerant discharge amount of the compressor. explain. In addition, since the schematic block diagram of the vehicle air conditioner A is the same as 1st Embodiment, FIG. 1 is utilized.

  That is, as shown in FIG. 8, whether or not the air temperature before passing through the evaporator 5 (hereinafter referred to as pre-evaporator air temperature Tsuc) exceeds 15 ° C. after the calculation of the airflow change correction term F (t). Is checked (step S90). If the pre-evaporator air temperature Tsuc exceeds 15 ° C., the air volume change correction term F (t) = F (t) * {1+ (Tsuc−25) / 25} is calculated (step S91). That is, when the pre-evaporator air temperature Tsuc exceeds 25 degrees, a large air amount correction amount is corrected for the integral term, and when it is less than 25 degrees, a small air amount correction amount is corrected for the integral term.

  If the pre-evaporator air temperature Tsuc is equal to or lower than 15 ° C., the air volume change correction term F (t) = 0 is set (step S92). Here, the pre-evaporator air temperature Tsuc is determined by estimating the detection temperature of the vehicle interior temperature detection sensor S3 when the inside air is introduced, and the detection temperature of the outside air temperature detection sensor S2 when the outside air is introduced. Of course, a pre-evaporator temperature detection sensor may be provided immediately upstream of the evaporator 5 in the air passage 10.

  In this fourth embodiment, the air volume correction amount to be added to or subtracted from the integral term is set to be large when the value of the pre-evaporator air temperature is large, and small when it is small. Since the correction can be performed in consideration of the load, both responsiveness and stability can be achieved. In addition, when the cooling load is low, the correction is canceled, so that unnecessary operation can be prevented. In the fourth embodiment, the pre-evaporator air temperature Tsuc is divided into large and small with 25 ° C. as a boundary. However, the larger the pre-evaporator air temperature, the larger the amount may be set linearly.

  In the fourth embodiment, the criterion for determining the pre-evaporator air temperature Tsuc is 15 ° C., and the air volume change correction term when the pre-evaporator air temperature Tsuc is exceeded is F (t) = F (t) × {1+ (Tsuc−25). ) / 25}, but is determined as appropriate under the control responsiveness and stability.

(Fifth embodiment)
FIGS. 9 and 10 show a fifth embodiment of the present invention, FIG. 9 is a control flow chart of the refrigerant discharge amount of the compressor, and FIG. 10 is a time chart of each output when the air volume changes.

  Compared with the second embodiment, the fifth embodiment is different from the second embodiment only in a part of the flowchart for controlling the refrigerant discharge amount of the compressor, and the other parts are the same. explain. In addition, since the schematic block diagram of the vehicle air conditioner A is the same as 1st Embodiment, FIG. 1 is utilized.

  That is, as shown in FIG. 9, when the air volume of the blower 11 is decreasing (step S4), the deviation e (t) between the evaporator post-air temperature Tint and its target temperature Ttarget is less than 7 ° C. It is checked whether or not there is (step S400). Only when the deviation e (t) is less than 7 ° C., the airflow change correction term is set to F (t) = − 8% (step S42). When the deviation e (t) is 7 ° C. or higher, the airflow change correction term is set to F (t) = 0% (step S43). That is, as shown in FIG. 10, when the amount of air passing through the evaporator 5 is changing in the decreasing direction, the difference e (t) between the post-evaporator air temperature Tint and its target temperature has a threshold value ( (7 ° C.) is set, and if it is equal to or greater than the threshold value, the air volume correction amount is not subtracted, and if it is less than the threshold value, the air volume correction amount is subtracted.

  According to the fifth embodiment, when the post-evaporator air temperature Tint is not cooled, no correction is performed because there is no fear of freezing. Thereby, a cooling delay etc. can be avoided.

  Note that the reference value of the deviation e (t) for determining whether or not to perform correction in accordance with the change in the air volume is 7 ° C. in the fifth embodiment, but is appropriately determined under control responsiveness and stability. .

  In the fifth embodiment, different processing is performed separately for the case where the threshold is the threshold or more and the case where the threshold is less than the threshold, but depending on the threshold to be set. Different processing may be performed separately for a value exceeding the threshold value and for a value equal to or less than the threshold value.

(Other)
The compressor applicable to the present invention is not limited as long as the refrigerant discharge amount can be varied by an external control signal. For example, a swash plate compressor or an electric motor that can vary the refrigerant discharge amount by changing the angle of the swash plate. It is an electric compressor that compresses the refrigerant. In the case of an electric compressor, the number of revolutions of the electric motor is controlled by an external control signal, thereby changing the refrigerant discharge amount.

  In each of the above embodiments, PI control based on proportional-integral calculation is employed as a control method for feedback control of the refrigerant discharge amount of the compressor, but PID control based on proportional-integral-derivative calculation may be used. In other words, the present invention provides an arithmetic expression having at least a proportional term based on a deviation between the post-evaporator air temperature Tint and its target temperature Ttarget, and an integral term by time accumulation of the residual deviation of the post-evaporator air temperature Tint with respect to the target temperature Ttarget. It can be applied if it is controlled by.

1 is a schematic configuration diagram of a vehicle air conditioner according to a first embodiment of the present invention. It is a control flowchart of the refrigerant | coolant discharge amount of a compressor which shows 1st Embodiment of this invention. It is a time chart of each output which shows 1st Embodiment of this invention and an airflow change. It is a control flowchart of the refrigerant | coolant discharge amount of a compressor which shows 2nd Embodiment of this invention. It is a time chart of each output at the time of air volume change, showing a second embodiment of the present invention. It is a control flowchart of the refrigerant | coolant discharge amount of a compressor which shows 3rd Embodiment of this invention. It is a time chart of each output which shows 3rd Embodiment of this invention and the air volume change. It is a control flowchart of the refrigerant | coolant discharge amount of a compressor which shows 4th Embodiment of this invention. It is a control flowchart of the refrigerant | coolant discharge amount of a compressor which shows 5th Embodiment of this invention. It is a time chart of each output at the time of an air volume change, showing a 5th embodiment of the present invention.

Explanation of symbols

A Vehicle air conditioner 1 Refrigeration cycle 2 Compressor 3 Radiator 4 Pressure reducing means 5 Evaporator 11 Blower S1 Evaporator air temperature detection sensor (Evaporator air temperature detection means)

Claims (5)

Heat is dissipated by the compressor (2) whose amount of refrigerant discharge can be varied by an external control signal, a radiator (3) that radiates high-temperature and high-pressure refrigerant discharged from the compressor (2), and the radiator (3). A refrigeration system comprising a decompression means (4) for decompressing the refrigerant, and an evaporator (5) for exchanging heat between the refrigerant decompressed by the decompression means (4) and the air sent into the passenger compartment to cool the air. Cycle (1);
A blower (11) that generates air flow that passes through the evaporator (5) and is guided into the vehicle interior;
A post-evaporator air temperature detection means (S1) for detecting the post-evaporator air temperature that is the temperature of the air that has passed through the evaporator (5),
A proportional term based on the deviation between the post-evaporator air temperature and the target temperature detected by the post-evaporator air temperature detecting means (S1), and an integral term based on time accumulation of the residual deviation of the post-evaporator air temperature with respect to the target temperature. A vehicle air conditioner (A) that varies the external control signal according to at least an arithmetic expression to vary the refrigerant discharge amount of the compressor (2),
A vehicle air conditioner (A), wherein an air flow correction amount is added to or subtracted from the integral term in accordance with an increase or decrease in an air flow amount passing through the evaporator (5). The vehicle air conditioner (A) according to claim 1,
A vehicle air conditioner (A) characterized in that a threshold value is set for an increase / decrease amount of air flow passing through the evaporator (5) to determine whether or not to perform correction based on the air flow correction amount. The vehicle air conditioner (A) according to claim 1 or 2,
The vehicle air conditioner (A) characterized in that the air volume correction amount to be added to or subtracted from the integral term is varied according to the amount of change in the air flow rate passing through the evaporator (5). The vehicle air conditioner (A) according to any one of claims 1 to 3,
The vehicle air conditioner (A) is characterized in that the air flow correction amount to be added to or subtracted from the integral term is set to a larger amount as the air temperature before passing through the evaporator (5) increases. The vehicle air conditioner (A) according to any one of claims 1 to 3,
When the amount of air passing through the evaporator (5) changes in a decreasing direction, a threshold value is set for the deviation between the post-evaporator air temperature and its target temperature, and the deviation is larger than the threshold value. In this case, the air conditioning apparatus (A) is characterized in that the air volume correction amount is not subtracted and the air volume correction amount is subtracted when the deviation is smaller than a threshold value.

Images