JPH079843A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To provide a control device used in an air conditioner for vehicle which is provided with a variable displacement type refrigerant compressor. CONSTITUTION:This air conditioner is provided with a refrigerant circuit 10 which has a refrigerant compressor 11 equipped with an externally-controlled variable displacement control mechanism and which also has an evaporator 14 connected to the air intake chamber of the compressor, and a circuit controller 20 which controls the refrigerant circuit. The circuit controller is provided with a regulator to regulate a control point for the pressure of the air intake chamber. During operation, the control point for the pressure of the air intake chamber is regulated so that the temperature of flowing-out air from the evaporator is maintained at a preset temperature. While carrying out operation under an evaporator's static-thermodynamic condition, the control point for the pressure of the air intake chamber is regulated so that the temperature of flowing- out air from the evaporator is efficiently converged at the preset temperature with high efficiency. While carrying out operation under the evaporator's dynamic-thermodynamic condition, the control point is regulated so that the temperature of flowing-out air from the evaporator is converge at the preset temperature with high efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner. In particular, the present invention relates to a control device for a vehicle air conditioner having a variable capacity refrigerant compressor that is controlled externally.

[0002]

2. Description of the Related Art A control device for an air conditioning system for a vehicle having a variable capacity type refrigerant compressor controlled externally has been conventionally known.
well known. In the conventional example, the temperature of the evaporator outflow air (hereinafter, abbreviated as air temperature) while the vehicle air conditioner is operating is adjusted by adjusting the capacity of the refrigerant compressor.
It controls _Te . The air temperature T _e is a variable capacity control mechanism in which an electric signal having an amperage determined by proportional-integral-derivative control (hereinafter referred to as PID control) used in a conventional control device is controlled outside the compressor. To the set temperature T _set .

Generally, the operation of a vehicle air conditioner operates in a first state in which the vehicle air conditioner operates in the static thermodynamic state of the evaporator, and in the dynamic thermodynamic state of the evaporator in the vehicle air conditioner. It is divided into a second state of performing. In the first state, the heat load of the evaporator is, for example, a slight change in the electrical load of the vehicle battery or a slight change in the rotation speed of the evaporator blower caused by a slight change in the temperature of the air flowing into the evaporator. Depending on it, increase or decrease slightly. On the other hand, in the second state, the heat load of the evaporator is, for example, the change of the rotation speed of the evaporator blower, that is, the change of the flow rate of the air passing through the outer surface of the evaporator, or the indoor air circulation mode and the outdoor air. Immediately increase / decrease greatly in response to changes in the air conditioning mode of the vehicle such as switching of the intake mode.

[0004]

In the above conventional vehicle air conditioner, the coefficient of PID control of the control device is fixed to a certain value while the vehicle air conditioner is operating. However, if the coefficient of the PID control of the control device is set to a certain value in order to effectively control the first operating state of the vehicle air conditioner, the air temperature T _e will be much _larger than the set temperature T _set. Will exceed. Therefore, in the second operating state of the vehicle air conditioner, the time required to bring the air temperature T _e close to the set temperature T _set becomes long. Such a delay is indicated by the broken line in FIG. On the other hand, if the determined coefficients of the PID control of the control device to another constant value to effectively control the second operational state of the vehicle air conditioner, the air temperature T _e, the air conditioner for a vehicle 1 in operating conditions, the set temperature _{T set}
Can't be maintained. This is because the operation of the vehicle air conditioner is excessively controlled.

Therefore, an object of the present invention is to provide an air conditioning system for a vehicle, which is capable of appropriately air conditioning the interior of the vehicle.

[0006]

According to the present invention, a refrigerant circuit having a refrigerant compressor having a variable capacity control mechanism controlled from the outside and an evaporator connected to an intake chamber of the refrigerant compressor, A vehicle air conditioner having means for moving air through an exterior surface of an evaporator, and a circuit controller for controlling the refrigerant circuit, wherein the circuit controller detects a thermodynamic characteristic of the evaporator. Means, gradient determining means for determining a gradient of the thermodynamic characteristic over time, storage means for storing a relationship between the gradient of the thermodynamic characteristic and a coefficient, and a gradient determined by the gradient determining means And a relationship stored in the storage means, the coefficient determining means for determining a coefficient, the thermodynamic characteristic is monitored, and the thermodynamic characteristic and the predetermined thermodynamic characteristic are compared with each other. Feedback control means for comparing and determining a feedback calculation result for at least proportionally controlling the refrigerant circuit, and pressure of the intake chamber of the compressor according to the feedback calculation result and the coefficient determined by the coefficient determining means. There is provided a vehicle air conditioner characterized by including pressure adjusting means for adjusting the control point of.

Further, according to the present invention, a refrigerant circuit having a refrigerant compressor having a variable capacity control mechanism controlled externally and an evaporator connected to an intake chamber of the refrigerant compressor, and the outside of the evaporator. In a vehicle air conditioner having a blower that blows air along a surface, and a circuit control device that controls the refrigerant circuit, the circuit control device detects a temperature of air in the immediate downstream of the evaporator. A device, a gradient determining device that determines a thermal gradient of the temperature with time, a storage device that stores a relationship between the thermal gradient of the temperature and a coefficient, and a gradient that is determined by the gradient determining means. A coefficient determining device for determining a coefficient by comparing with the relationship stored in the storage means, the temperature is monitored, the temperature is compared with a predetermined temperature, and the refrigerant circuit is at least proportionally controlled. A feedback control device for determining a feedback calculation result for adjusting the pressure, and a pressure control device for adjusting a control point of the pressure of the intake chamber of the compressor according to the feedback calculation result and the coefficient determined by the coefficient determination device. A vehicle air conditioner including:

According to the invention, a vehicle including a refrigerant circuit having a compressor whose capacity is controlled according to a control signal and an evaporator connected to the compressor, and a circuit control device for controlling the refrigerant circuit. In the air conditioner for a vehicle, the circuit control device includes a detection unit that detects an actual thermodynamic property of the evaporator, a slope determination unit that determines a slope of the actual thermodynamic property with respect to time, and a predetermined unit. The coefficient to be used is determined by comparing the coefficient gradient characteristic storage means for storing the coefficient gradient characteristic representing the relationship between the gradient and the predetermined coefficient with the gradient of the actual thermodynamic characteristic with the coefficient gradient characteristic. A coefficient determining means, a first calculating means for executing a first predetermined calculation according to the actual thermodynamic characteristic and a predetermined thermodynamic characteristic to obtain a first calculation result; A control signal generating means for generating the control signal according to a coefficient and the first calculation result, wherein the control signal generating means has a second predetermined value according to the coefficient to be used and the first calculation result. Second arithmetic means for sequentially performing arithmetic operations to obtain a second arithmetic result;
And a signal processing for processing the addition result to generate the control signal, and an addition means for adding the operation result of the present operation and the operation result obtained before the operation result to obtain an addition result. A vehicle air conditioner characterized by including means.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a vehicle air conditioner according to the present invention has a refrigerant circuit 10 and a circuit controller 20 for controlling the operation of this refrigerant circuit. The refrigerant circuit 10 includes a refrigerant compressor 11, a condenser 12, and an expansion device 13.
And an evaporator 14, which are sequentially connected. The refrigerant compressor 11 includes a variable capacity control mechanism (hereinafter, abbreviated as capacity control mechanism) which is not shown but is controlled externally. Electromagnetic clutch 111
Is fixedly mounted on the compressor 11, and intermittently transmits power obtained from an external power source such as the engine 15 of the vehicle to the drive shaft of the compressor 10 to operate the compressor 10 intermittently. The refrigerant circuit 10 is
Further, a condenser blower 121, which is combined with the condenser 12 to allow air to pass along the outer surface of the condenser 12, and an evaporator 14, which is combined with the condenser 14,
Evaporator blower 14 that allows air to pass along the exterior surface of the
1 and. The condenser blower 121 and the evaporator blower 141 are installed in the engine compartment of the vehicle.
Electric power is obtained from the C battery 16.

The evaporator 14 is airtightly arranged inside a duct (not shown), and the inlet of the duct communicates with the inside of the vehicle and the outside of the vehicle via auxiliary ducts (not shown), respectively. A damper (not shown) is provided at the entrance of the duct. When the air inside the vehicle interior and the air outside the vehicle are introduced into the inlet of the duct through the auxiliary duct by the operation of the evaporator blower 141, the air inside the vehicle interior and the air outside the vehicle are mixed. Various air mixing ratios can be obtained by changing the pivot position of the damper. The air mixed at the inlet of the duct flows through the outer surface of the evaporator 14 and flows into the vehicle interior from the outlet of the duct.

The circuit controller 20 includes a temperature detector 17 and
Gradient calculator 21a, coefficient adjuster 21b, coefficient gradient characteristic storage device 21c, subtractor 22, set value generation device 2
3, a proportional calculator 24, an integral calculator 25, a derivative calculator 26, a first adder 27a, a second adder 27b,
It has a final arithmetic unit 28, a final storage device 29a, a final adder 29b, and an amplifier 30. These components will be described in detail below. Subtractor 22, setting value generator 23, proportional calculator 24, and integral calculator 25
, A differential calculator 26, a first adder 27a, a second adder 27b, a final calculator 28, and a final storage device 29a.
The final adder 29b and the amplifier 30 constitute a PID controller.

Temperature detector 1 in combination with evaporator 14
A first electric signal S ₁ for detecting the temperature T _e of the air flowing out of the evaporator 14 and a detected electric temperature T _e within a predetermined short time interval Δt of about 1 second, for example.
To generate. The temperature detector 17 is connected to a gradient calculator 21a which constitutes gradient determining means. Gradient calculator 21
a processes the _first electric signal S ₁ according to the following equation ( ₁ ).

[0013]

[Equation 1]

In the equation (1), the first term of the numerator is (n-
3) Air temperatures T _e (n−3) and (n−) detected at the third time
2) The average value with the air temperature _{Te (n-2)} detected at the second time, and the second term of the numerator is the air temperature _{Te (n-1)} detected at the (n-1) th time and ( _(n-1)). n) means the average value with the air temperature T _{e (n)} detected at the n-th time. Therefore, α _n
Represents the average temperature gradient of the detected air temperature _{Te for} the section from the (n-3) th detection time to the (n) th detection time, for example, for about 3 seconds. Therefore, in the first operating state of the vehicle air conditioner in which the heat load on the evaporator 14 slightly increases or decreases, that is, the detected air temperature T _e slightly increases or decreases, the temperature gradient α _n has a very small value. On the other hand, in the second operating state of the vehicle air conditioner in which the heat load on the evaporator 14 is significantly increased or decreased, that is, the detected air temperature T _e is greatly increased or decreased, the temperature gradient α _n has a very large value.

The gradient calculator 21a for generating the _second electric signal S ₂ representing the temperature gradient α _n is connected to the coefficient adjuster 21b constituting the coefficient determining means. Coefficient adjuster 21b
Is further connected to the coefficient gradient characteristic storage device 21c which stores the coefficient gradient characteristic shown in FIG. The coefficient gradient characteristic storage device 21c generates a _third electric signal S3 representing the coefficient gradient characteristic shown in FIG. The third electrical signal S ₃ is
It is sent from the coefficient gradient characteristic storage device 21c to the coefficient adjuster 21b.

Referring again to FIG. 2, when the temperature gradient α _n is greater than or equal to the predetermined first boundary value α _a , the coefficient A _n is maintained at the predetermined maximum value A _max . If the temperature gradient α _n is less than or equal to a second boundary value α _b that is smaller than _a predetermined first boundary value α _a ,
The coefficient A _n is maintained at a predetermined minimum value A _min . Furthermore, the temperature gradient α _n is smaller than the predetermined first boundary value α _a, but the second boundary value α _b
If larger, the coefficient An varies within a range between a predetermined maximum value A _max and minimum value A _min .

The coefficient adjuster 21b adjusts the coefficient A _n in accordance with the coefficient gradient characteristic shown in FIG. 2, so that the second electric signal S ₂ sent from the gradient calculator 21a and the coefficient gradient characteristic storage device 21c. The sent third electrical signal S
Process ₃ . The coefficient adjuster 21b adjusts the coefficient A _n according to the conditions defined by the following equations 2 and 3.

[0018]

[Equation 2]

[Equation 3]

In Equation 3, {(A _max −A _min ) /
(Α _a −α _b )} is the gradient of the straight line m shown in FIG.
(A _min · α _a −A _max · α _b ) / (α _a −α _b ) is the intercept on the ordinate of line m.

[0020]

[Equation 4]

Therefore, the coefficient A _n changes within the range of A _max to A _min according to the change of the temperature gradient α _n . The coefficient adjuster 21b adjusts A according to the change of the temperature gradient α _n.
A fourth electrical signal S ₄ is generated that represents the coefficient A _n that varies from _max to A _min . Further, the coefficient adjuster 21b
Is connected to the final computing unit 28 and sends the fourth electric signal S ₄ to the final computing unit 28. Furthermore, when the ordinal number n is smaller than 4, the temperature gradient α _n is
It is adjusted so that α _n is equal to α _b .

Subtractor 2 connected to temperature detector 17
2 receives the first electrical signal S ₁ . Setting value generator 2
3 is a set temperature T as one of predetermined thermodynamic characteristics.
Generate a _fifth electrical signal S ₅ representing _set . Subtractor 2
2 is sent from the set value generator 23 and the first electric signal S ₁ sent from the temperature detector 17 by subtracting the air temperature _{Te (n)} detected at the n-th time from the set temperature T _set. And processing the _fifth electrical signal S ₅ . This subtraction
It is shown by the following Equation 5.

[0023]

[Equation 5] In Expression 5, the symbol n indicates the ordinal number of the detected air temperature T _e . The subtractor 22 generates a _sixth electric signal S ₆ that represents the calculation result of Expression 5. The subtractor 22 is further connected to the proportional calculator 24, the integral calculator 25, and the derivative calculator 26.

The proportional calculator 24 processes the sixth electric signal S ₆ sent from the subtractor 22 according to the following equation (6).

[0025]

[Equation 6] In Expression 6, p is an arbitrary coefficient, and in this embodiment, p = 1 is selected. Therefore, Equation 6 can be rewritten as Equation 7 below.

[0026]

[Equation 7] Proportional calculator 24 generates a seventh electric signal S7 representing the operation result C ₇ of equation (7). The proportional calculator 24 is connected to the first adder 27a.

The integration calculator 25 processes the sixth electric signal S ₆ sent from the subtractor 22 according to the following equation (8).

[0028]

[Equation 8] In Equation 8, 1 / T _I is an arbitrary coefficient, and ΔT
Is a predetermined short operating interval equal to Δt. The integration calculator 25 generates an _eighth electric signal S ₈ representing the calculation result C ₈ of the equation (8). Integral calculator 25
Is also connected to the first adder 27a.

The first adder 27a by adding the operation result C7 and C8 of the equation (7) and equation (8), a seventh electrical signal S ₇ and the integral calculator sent from the proportional arithmetic unit 24 2
Process the _eighth electrical signal S ₈ sent from The first adder 27a generates a _ninth electric signal S ₉ representing the addition result executed there. The first adder 27a has a second
Is connected to the adder 27b.

The differential calculator 26 processes the sixth electric signal S ₆ sent from the subtractor 22 according to the following equation (9).

[0031]

[Equation 9] In Expression 9, T _D is an arbitrary coefficient. Differential operation unit 26 generates a tenth electric signal _{S 10} of which represent the operation result _{C 9} of equation (9). The differential calculator 26 is the second adder 2
It is also connected to 7b.

The second adder 27b is the first adder 27.
The ninth electric signal S sent from the first adder 27a is obtained by adding the addition result of a and the calculation result of the equation (9).
₉ and the tenth electrical signal S sent from the differential calculator 26
Process ₁₀ . Therefore, the addition result of the second adder 27b is expressed by the following expression (10).

[0033]

[Equation 10] Second adder 27b, for example, such feedback coefficients, to produce a eleventh electric signal _{S 11} representing the operation result _{C 10} number 10 formula. The subtractor 22, the proportional calculator 24, the integral calculator 25, the derivative calculator 26, the first adder 27a, and the second adder 27b together form a first calculating means.

Further, the second adder 27b is connected to the final arithmetic unit 28 as the second arithmetic means, and the final arithmetic unit 2
The eighth eleventh electrical signal S ₁₁ is sent out. Final calculator 2
8 processes the eleventh electric signal S ₁₁ sent from the second adder 27b and the fourth electric signal S ₄ sent from the coefficient adjuster 21b by executing the following formula 11.

[0035]

[Equation 11] The calculation result C 11 of the expression ₁₁ changes according to the value of the coefficient A _n and the change of the calculation result of the expression 10. Final calculator 28
Is a twelfth electrical signal S ₁₂ that represents the calculation result of Equation 11.
To generate. Further, the final computing unit 28 is the final storage device 2
9a and the final adder 29b and connected to the final storage device 2
The twelfth electrical signal S ₁₂ is sent to 9a and the final adder 29b.

The final storage device 29a stores (n-
1) Two twelfth electrical signals S ₁₂ representing the results of the 1st and (n) th operations are stored. The final adder 29b outputs the twelfth electrical signal S ₁₂ from the final storage device 29a, which represents the (n-1) th operation result of the equation (11), and the equation (n) of the equation 11 sent from the final calculator 28. ) According to the other twelfth electrical signal S ₁₂ representing the calculation result of the 10th time, the calculation result of the (n−1) th time of the formula 11 and the calculation result of the (n) th time of the formula 10 are added. That is, the final storage device 29a and the final adder 29b together function as an adding means. Therefore, the addition result of the final adder 29b is expressed by the following formula (12).

[0037]

[Equation 12] As the calculation result of Expression 11 changes, the calculation result of the right side of Expression 12 also changes. However, if the result of the operation on the right side of Equation 12 is less than or equal to the predetermined minimum value I _min , such as about 0 mA, the left side of Equation 12 is adjusted so that I _n = I _min. To be done. On the other hand, if the calculation result of the right side of the equation 12 is, for example, about 100
A predetermined maximum value I such as mA
If it is equal to or _larger than _max , the left side of the equation 12 is I _n = I
It is adjusted to be _max . The final adder 29b is
A thirteenth electrical signal S ₁₃ is generated, and the amperage of this signal is the same as the calculation result of the equation (12). Further, the final adder 29b is connected to the amplifier 30 as a signal processing means and sends the thirteenth electrical signal S ₁₃ to the amplifier 30. Amplifier 30, for example, to amplify the amperage of the thirteenth electric signal _{1S 13} to 10 · _{I n.} Current having the amperage 10 · I _n is supplied from amplifier 30 to the solenoid of the displacement control mechanism of the compressor. Final calculator 28, final storage device 29a, final adder 29b, and amplifier 30
Together constitute control signal generating means.

In this embodiment of the present invention, as the current supplied to the solenoid of the compressor displacement control mechanism increases, the pressure control point of the compressor intake chamber increases to a larger value. When the current supplied to the solenoid of the displacement control mechanism of the compressor decreases, the pressure control point of the compressor intake chamber decreases to a smaller value.

Next, the operation of the vehicle air conditioner according to the embodiment of the present invention will be described. Referring to FIG. 3, when it is attempted to cool the vehicle interior, the vehicle air conditioner operates in step 2
As shown at 01, it is switched on. When the vehicle air conditioner is switched on, a counter (not shown) that counts the number of times the air temperature T _e is detected is displayed in step 20.
It is reset to zero as shown in 2. The condenser blower 121 and the evaporator blower 141 are started in step 203, and at the same time, the control device 20 also starts operating.

As shown in step 204, when the control device 20 starts operating, the electromagnetic coil (not shown) of the electromagnetic clutch 111 is energized, and the operation of the compressor 11 starts. When the compressor 11 operates, the compressed gas-phase refrigerant flows into the condenser 12, where the first heat exchange is performed. Then, the condensed refrigerant agent from the condenser 12 is expanded by the expansion device 13, and then evaporated by the evaporator 14. The second heat exchange also takes place in the evaporator 14. Then, the vaporized refrigerant agent from the evaporator 14 returns to the compressor 11 again. The above operation is repeated while the compressor 11 is operating.

In step 205, the temperature detector 17 combined with the evaporator 14 detects the temperature T _e of the air flowing out of the evaporator 14 within a predetermined short time interval Δt. The temperature detector 17 detects the detected air temperature T
Generate a _first electrical signal S ₁ representing _e . The first electric signal S ₁ is sent from the temperature detector 17 to the subtractor 22 and the gradient calculator 21a.

In step 206, it is determined whether the number of times the air temperature T _e has been detected is 4 or more, that is, n ≧ 4. If the number of times the air temperature T _e has been detected is 4 or more, that is, n ≧ 4, the operation of the air conditioner proceeds to step 2
The procedure advances from 06 to step 207. On the other hand, if the air temperature T
_The number of times _e is detected is less than 4, that is, n <4
If so, operation proceeds from step 206 to step 209. In step 207, the calculation of Expression 1 is executed by the gradient calculation device 21a.

The operation results of step 207 are sorted in steps 208 and 210 as described below. In step 208, it is determined whether the temperature gradient α _n is less than or equal to α _b . If α _n is less than or equal to α _b , operation proceeds from step 208 to 209. In step 209, the coefficient A _n is adjusted by the coefficient adjuster 21b so that A _n = A _min . On the other hand, if α _n is greater than α _b , operation proceeds from step 208 to step 210. In step 210, it is determined whether α _n is less than α _a . If α _n is less than α _a , operation proceeds from step 210 to 211. In step 211, the calculation of Expression 3 is executed by the coefficient adjuster 21b. On the other hand, if α _n is greater than or equal to α _a , operation proceeds from steps 210 to 212. In step 212, the coefficient A _n is A _n =
It is adjusted by the coefficient adjuster 21b so that it becomes A _max .

Step 213 includes steps 209 and 21.
1 and 212. In step 213, the amperage I _n of the thirteenth electrical signal S ₁₃ adjusted by the calculation result of Expression 12 is 10
It is amplified I _n. Current having the amperage 10 · I _n is supplied from amplifier 30 to the solenoid of the displacement control mechanism of the compressor, and a compression control point of the compressor suction chamber.

Step 214 is a continuation of step 213. In step 214, it is determined whether a predetermined short time interval Δt has elapsed from the time when the air temperature _{Te (n)} was detected. If the predetermined short time interval Δt has elapsed since the time when the air temperature _{Te (n)} was detected, the operation proceeds from step 214 to step 215. In step 215, the number of times the air temperature T _e is detected is increased to n + 1. When the number of times the air temperature T _e is detected becomes n + 1, the operation returns from step 215 to step 205. The series of steps from step 205 to 215 is continued until the operation of the vehicle air conditioner is stopped.

FIG. 4 shows changes in the rotation speed of the evaporator blower 141, changes in the temperature T _e of the air flowing out of the evaporator 14, and the solenoid of the capacity control mechanism of the compressor during the operation of the vehicle air conditioner. a change of the current, indicating a change of the temperature gradient alpha _n of the detected air temperature T _{e (n).} In particular, in FIG. 4, except for the change in the rotation speed of the evaporator blower 141, the straight line shows the above change according to the embodiment of the present invention, and the dotted line shows the above change according to the conventional example.

Referring to FIG. 4, when the rotation speed of evaporator blower 141 is rapidly decelerated, for example, at time t ₁
If the speed is reduced from about 3500 rpm to about 1000 rpm, the flow rate of the air flowing along the outer surface of the evaporator 14 will also rapidly decrease sharply. Therefore, the heat load on the evaporator 14 is significantly reduced. As a result, the temperature T _e of the air flowing out of the evaporator 14 rapidly decreases, and the temperature gradient α _n of the detected air temperature T _{e (n)} increases to a large value. Therefore, the temperature gradient α _n exceeds the predetermined first boundary value α _a immediately after the time t ₁ and further exceeds the predetermined second boundary value α _b .

In this state, as long as the temperature gradient α _n is larger than the predetermined second boundary value α _b but smaller than the predetermined first boundary value α _a , the coefficient A _n is It is adjusted according to the calculation method of step 211 in FIG. As long as the temperature gradient α _n is equal to or greater than the predetermined first boundary value α _a , the coefficient A
_n is step 2 in FIG. 3 so that A _n = A _max .
It is adjusted by 12 calculation methods. Therefore, the value of the second term on the right side of Expression 12 increases to a large value. In particular, the number 1
The value of the second term on the right side of Equation 2 continues to increase as long as the temperature gradient α _n is equal to or greater than the predetermined first boundary value α _a . Therefore, the amperage supplied from the amplifier 30 to the solenoid of the displacement control mechanism of the compressor rapidly and drastically increases, and the pressure control point of the intake chamber pressure of the compressor greatly increases immediately after the time t ₁ . As a result, the decrease of the air temperature T _e from the set temperature T _set becomes flat in a low amount within a short time. Once the air temperature T
_When the decrease in _e is leveled off, the air temperature T _e rises toward the set temperature T _set according to the calculation result of Expression 11, and the T _e converges to the set temperature T _set . Air temperature T
_{When e} converges to the set temperature T _set , the air temperature T _e slightly increases or decreases according to the calculation method of step 209 in FIG.

As described above, even if the heat load on the evaporator 14 is drastically and drastically decreased by the drastic and rapid decrease of the rotation speed of the evaporator / blower 141, the air temperature T
The decrease of _{e from} the set temperature T _set leveled off in a low amount within a short time, and the decrease of the air temperature T _e rapidly stopped and started to rise. That is, the air temperature T _e efficiently converges to the set temperature T _set . Therefore, the evaporator blower 1
Even if the heat load on the evaporator 14 is rapidly and drastically reduced due to the drastic and rapid decrease of the rotation speed of 41, the air in the vehicle compartment is appropriately air-conditioned.

The above embodiment is applied to the operating condition of the vehicle air conditioner in which the heat load on the evaporator 14 is rapidly and significantly reduced due to the large and rapid decrease in the rotation speed of the evaporator blower 141. It However, the present invention is directed to other operating conditions of the vehicle air conditioner such that the thermal load on the evaporator rapidly and significantly increases due to a rapid change in the thermodynamic state of the evaporator, for example, from the indoor air circulation mode to the outside. By switching to the air intake mode, it is possible to apply to an operating state of a vehicle air conditioner in which the heat load on the evaporator rapidly increases significantly.

Further, in the above-described embodiment, the temperature T _e of the evaporator outlet air is detected as a thermodynamic characteristic of the evaporator. However, in the present invention, the pressure at the outlet of the evaporator is also detected as a thermodynamic characteristic of the evaporator.

Furthermore, although the PID control device is used in the above-mentioned embodiment, the present invention is not limited to this embodiment. For example, in another embodiment of the invention, a proportional-integral (PI) controller or a proportional (P) controller could be used instead of a PID controller.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the above description, and those skilled in the art can make various modifications without departing from the scope of the present invention. Needless to say, it can be modified.

[0054]

As described above, according to the present invention,
Even if the heat load on the evaporator is rapidly and significantly reduced due to the large and rapid decrease in the rotation speed of the evaporator blower,
Appropriate air conditioning of the air in the vehicle compartment is performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a vehicle air conditioner of the present invention.

FIG. 2 is a graph showing a relationship between a coefficient A _n and a temperature gradient α _n .

3 is a flowchart for explaining the operation of the vehicle air conditioner of FIG.

FIG. 4 is a graph showing a change in rotation speed of an evaporator blower and a temperature T of air flowing out from the evaporator during operation of the vehicle air conditioner.
and changes in _e, the change in the amount of current supplied to the solenoid of the externally controlled variable displacement mechanism of the compressor from the amplifier, mixed graph showing the relationship between the change of the temperature gradient alpha _n of the detected air temperature T _{e (n)} Is. In FIG. 4, the solid line shows the above change according to one embodiment of the present invention, and the dotted line shows the above change according to the conventional example, except for the change in the rotation speed of the evaporator blower.

[Explanation of symbols]

 10 Refrigerant Circuit 11 Refrigerant Compressor 12 Condenser 13 Expander 14 Evaporator 15 Engine 16 DC Battery 17 Temperature Detector 20 Circuit Controller 21a Gradient Calculator 21b Coefficient Adjuster 21c Coefficient Gradient Characteristic Storage Device 22 Subtractor 23 Set Value Generator 24 Proportional calculator 25 Integral calculator 26 Differential calculator 27a First adder 27b Second adder 28 Final calculator 29a Final storage device 29b Final adder 30 Amplifier 111 Electromagnetic clutch 121 Capacitor blower 141 Evaporator blower

Claims (13)

[Claims] 1. A refrigerant circuit having a refrigerant compressor having a variable capacity control mechanism controlled from the outside and an evaporator connected to an intake chamber of the refrigerant compressor, and air passing through an outer surface of the evaporator. In a vehicle air conditioner having a means for moving the refrigerant circuit and a circuit control device for controlling the refrigerant circuit, the circuit control device detects a thermodynamic characteristic of the evaporator, and the thermodynamic characteristic. Of the thermodynamic characteristics, storage means for storing the relationship between the gradient and the coefficient of the thermodynamic characteristic, the slope determined by the slope determination means and the storage means stored in the storage means. By comparing the relationship with a coefficient determining means for determining a coefficient, the thermodynamic characteristic is monitored, and the thermodynamic characteristic is compared with a predetermined thermodynamic characteristic to reduce the refrigerant circuit. Feedback control means for determining a feedback calculation result for proportional control, and pressure for adjusting a control point of the pressure of the intake chamber of the compressor according to the feedback calculation result and the coefficient determined by the coefficient determining means. An air conditioning system for a vehicle, comprising: an adjusting unit. 2. The vehicle air conditioner according to claim 1, wherein the feedback control means is a proportional control device. 3. The vehicle air conditioner according to claim 2, wherein the thermodynamic characteristic is a pressure at an outlet of the evaporator. 4. The vehicle air conditioner according to claim 1, wherein the feedback control means is a proportional-integral control device. 5. The vehicle air conditioner according to claim 4, wherein the thermodynamic characteristic is a pressure at an outlet of the evaporator. 6. The vehicle air conditioner according to claim 1, wherein the feedback control means is a proportional-integral-derivative control device. 7. The vehicle air conditioner according to claim 6, wherein the thermodynamic characteristic is a pressure at an outlet of the evaporator. 8. The vehicle air conditioner according to claim 1, wherein the thermodynamic characteristic is a temperature of air measured immediately downstream of the evaporator. 9. A refrigerant circuit having a refrigerant compressor having a variable capacity control mechanism controlled from the outside and an evaporator connected to an intake chamber of the refrigerant compressor, and air along the outer surface of the evaporator. In a vehicle air conditioner having a blower that blows air, and a circuit control device that controls the refrigerant circuit, the circuit control device is a temperature detector that detects the temperature of air immediately downstream of the evaporator, and the temperature. Of the thermal gradient with respect to the passage of time, a storage device for storing the relationship between the thermal gradient of the temperature and the coefficient, the gradient determined by the gradient determining means and the storage means stored in the storage means. And a coefficient determining device for determining a coefficient to monitor the temperature, compare the temperature with a predetermined temperature, and control the refrigerant circuit at least proportionally. A feedback control device that determines a back calculation result; and a pressure adjustment device that adjusts a control point of the pressure of the intake chamber of the compressor according to the feedback calculation result and the coefficient determined by the coefficient determination device. A vehicle air conditioner characterized by: 10. The vehicle air conditioner according to claim 9, wherein the feedback control device is a proportional control device. 11. The feedback control device is proportional-
The vehicle air conditioner according to claim 9, wherein the air conditioner is an integral control device. 12. The air conditioner for a vehicle according to claim 9, wherein the feedback control device is a proportional-integral-derivative control device. 13. A vehicle air conditioner including a refrigerant circuit having a compressor whose capacity is controlled according to a control signal and an evaporator connected to the compressor, and a circuit control device for controlling the refrigerant circuit. The circuit control device includes a detection unit that detects an actual thermodynamic characteristic of the evaporator, a slope determination unit that determines a slope of the actual thermodynamic characteristic with respect to time, a predetermined slope and a predetermined coefficient. A coefficient gradient characteristic storing means for storing a coefficient gradient characteristic representing a relationship with, and a coefficient determining means for determining a coefficient to be used by comparing the gradient of the actual thermodynamic characteristic with the coefficient gradient characteristic, First calculation means for performing a first predetermined calculation according to the actual thermodynamic characteristic and a predetermined thermodynamic characteristic to obtain a first calculation result; the coefficient to be used; and the first calculation means. And a control signal generating means for generating said control signal operation result in accordance with the control signal generating means, the coefficient first to the use
The second predetermined calculation is sequentially executed according to the calculation result of
A second calculation means for obtaining a second calculation result; and an addition means for obtaining the addition result by adding the second calculation result with the one obtained at the present time and the one obtained at a time earlier than that. When,
A vehicle air conditioner comprising: a signal processing unit that processes the addition result to generate the control signal.