JP2008107058A - Control device of variable capacity compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of a variable capacity compressor capable of resolving the shortage of initial cooling capacity at a high temperature when the variable capacity compressor is restarted after stopped. <P>SOLUTION: This control device of the variable capacity compressor for deciding an output value on the basis of a proportional value and an integrated value to the temperature difference between an actual temperature and a target temperature, and outputting the decided output value to a variable capacity actuator in operating the variable capacity compressor 1, is provided with a means having a variable capacity compressor start control portion (steps S8-S15 in Fig.4) for storing an output value to the variable capacity actuator in stopping as an output storage value (step S7) in starting the variable capacity compressor 1, applying a restart starting output value to the variable capacity actuator as the output storage value in starting the restart of the variable capacity compressor 1, and applying a value obtained by subtracting a proportional initial value from the output storage value as an integrated initial value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control apparatus for a variable capacity compressor that controls an output value based on a proportional value and an integrated value with respect to a difference between an actual temperature and a target temperature during operation of the variable capacity compressor.

Conventionally, as a control device for a variable displacement compressor, a control duty is obtained based on an expression of {proportional coefficient × differential temperature + (integral coefficient × differential temperature + integrated value up to the previous time)}, and variable capacity is determined by an output duty signal. One that performs compressor capacity control is known (see, for example, Patent Document 1).
JP-A-4-38223

  However, in the conventional variable displacement compressor control device, when the variable displacement compressor is started, the accumulated value accumulated up to that time is always cleared. Therefore, after the air conditioner switch is turned off, the air conditioner is turned on again. When the switch is turned on, there is a problem that the output control duty starts only from the proportional control of (proportional coefficient × differential temperature), and the initial cooling capacity at high temperature becomes insufficient.

  For example, if the air conditioner switch is turned on when the air conditioner switch is turned on while only a short time has passed since the air conditioner switch was turned off and the actual temperature detected by the evaporator outlet temperature sensor is still low, the evaporator has already cooled down. The output duty is lower than the originally required output duty.

  The present invention has been made paying attention to the above problems, and provides a control device for a variable displacement compressor that can solve the initial shortage of cooling capacity at high temperatures when the variable displacement compressor is stopped and then restarted. The purpose is to do.

In order to achieve the above object, according to the present invention, when the variable displacement compressor is operated, an output value is determined by a proportional value and an integrated value with respect to the difference between the actual temperature and the target temperature, and the determined output value is output to the variable displacement actuator. In a control apparatus for a variable displacement compressor having compressor control means for
An output value storage means for storing an output value for the variable displacement actuator when the variable displacement compressor is started and then stopped as an output storage value;
When the restart of the variable displacement compressor is started, the compressor control means sets the restart start output value for the variable displacement actuator to the output stored value, and sets the value obtained by subtracting the proportional initial value from the output stored value as the integrated initial value. And a variable capacity compressor starting control unit.

  Therefore, in the control apparatus for the variable displacement compressor of the present invention, when the restart of the variable displacement compressor is started, the restart start output value for the variable displacement actuator is set as the output storage value. In other words, since the value (output stored value) according to the cooling capacity request at the time of stopping the variable capacity compressor is output at the start of restarting, if the output value becomes a low value only for proportional control, the cooling capacity The initial response for starting the restart is secured.

  In addition, when the restart of the variable capacity compressor is started, a value obtained by subtracting the proportional initial value from the output stored value is set as the integrated initial value. That is, when the restart of the variable capacity compressor is started with the output stored value, the integral control with the integrated initial value is started together with the proportional control from the next control cycle, so that the lack of cooling capacity at the start of the restart is resolved.

  By the way, the output value for driving and controlling the variable capacity compressor is determined by the proportional control amount + the integral control amount. The integral control amount is added to the proportional control amount to + α minutes, and the cooling capacity becomes insufficient due to this integral control amount. It is for covering. Therefore, in the case of the prior art that does not have an integration initial value, a calculation delay due to the integration time until the integral control is generated occurs, and this calculation delay causes a lack of cooling capacity when the variable capacity compressor is restarted. .

  As a result, when the variable capacity compressor is stopped and then restarted, it is possible to solve the initial lack of cooling capacity at high temperatures.

  Hereinafter, the best mode for realizing a control apparatus for a variable displacement compressor according to the present invention will be described based on a first embodiment shown in the drawings.

First, the configuration will be described.
1 is an overall view showing an externally controlled compressor system to which a control device for a variable displacement compressor according to a first embodiment is applied. FIG. 2 is a cross-sectional view showing an example of a high-pressure valve for controlling the displacement of the variable displacement compressor according to the first embodiment. FIG. 3 is a time chart showing an example of a current waveform and a voltage waveform of the control duty signal applied to the coil of the high-pressure valve shown in FIG.

  The external control compressor system shown in FIG. 1 electrically changes the capacity of the variable displacement compressor 1 and controls the evaporator outlet temperature in a predetermined temperature range (for example, a range of 3 ° C. to 10 ° C.). In order to reduce the electrical load, the condenser fan control is also performed at the same time.

  As shown in FIG. 1, the variable capacity compressor 1 according to the first embodiment is provided as a component of a refrigeration cycle including an evaporator 3 disposed in an air conditioning unit 2 of a vehicle.

The refrigeration cycle is a cycle in which the refrigerant circulates by repeating four state changes of evaporation → compression → condensation → expansion, and at the time of the evaporating action, the refrigerant takes heat from the surroundings and exhibits cooling performance.
As shown in FIG. 1, the refrigeration cycle includes an evaporator 3 (evaporator), a variable capacity compressor 1 (compressor), a condenser 4 (condenser), a receiver 5 and an expansion valve. 6 are provided.

The evaporator 3 is an evaporator that produces cold air by evaporating the refrigerant. The evaporator 3 is provided at a downstream position of the blower 7, and the cold air that has passed through the evaporator 3 passes through an air mix door, a heater core, and the like that are not illustrated. Then, the air is blown out from the air outlet into the passenger compartment.
As shown in FIG. 1, an evaporator outlet temperature sensor 8 (evaporator outlet temperature detecting means) for detecting an evaporator outlet temperature is provided at a position immediately after the downstream side of the evaporator 3.

The variable capacity compressor 1 increases the temperature of the refrigerant so that it can be liquefied even at a relatively high outside air temperature, and has a high-pressure valve 9 that controls the flow rate of the discharged refrigerant.
As shown in FIG. 2, the high-pressure valve 9 includes a valve controller 92 and a lift amount of the ball valve 90 determined by a pressure load F (Ps), a spring load F (K), and a magnetic force F (I) acting on the diaphragm 91. To control the flow rate of the refrigerant discharged.
In FIG. 2, 93 is a set spring, 94 is a coil, Ps is a suction chamber pressure, Pc is a crank chamber pressure, and Pd is a discharge chamber pressure.

The pressure load F (Ps) is expressed by F (Ps) = Ps × diaphragm effective diameter.
The spring load F (K) is a load by the set spring 93.
The magnetic force F (I) is a force generated by the coil 94.
The relationship between these forces is F (K) = F (I) + F (Ps), and the spring load F (K) acts in the upward direction in FIG. 9, and the magnetic force F (I) and the pressure load F (Ps) acts in the downward direction of FIG.
In the relational expression of the force, a coil 94 that electrically changes the magnetic force F (I) acting on the diaphragm 91 of the high-pressure valve 9 is a variable capacity actuator, and the voltage waveform characteristics of FIG. As shown in FIG. 4, a 400 Hz duty control signal is given, and an effective current corresponding to the duty ratio is applied as shown in the current waveform characteristics of FIG.
Note that the duty ratio (%) is expressed by an expression of duty ratio = T1 / (T1 + T2) × 100.

  Incidentally, when the duty ratio is low (in the case of low effective current), the ball valve 90 is opened by the spring load F (K), and the refrigerant flows from the discharge chamber to the crank chamber, so that the compressor capacity can be kept low. On the other hand, the higher the duty ratio (the higher the effective current), the stronger the magnetic force F (I), and the ball valve 90 that has been opened by the spring load F (K) moves to the closed side, causing the crank from the discharge chamber. By suppressing the flow of the refrigerant into the chamber, the compressor capacity increases as the duty ratio increases.

  The condenser 4 condenses and liquefies the refrigerant. A radiator 10 is disposed on the front side of the condenser 4 in the vehicle, and a condenser fan 11 having a motor fan structure is disposed on the rear side of the condenser 4 on the vehicle. Yes.

  The externally controlled compressor system includes an ECV controller 12 as an arithmetic processing unit, an evaporator outlet temperature sensor 8 that provides input information to the ECV controller 12, an air conditioner switch 13, a blowing temperature setter 14, and the like, A variable capacity compressor control system is configured by the high pressure valve 9 (coil 94) whose effective current is controlled by a control command (duty signal).

  The external control compressor system also includes an ECV controller 12 as an arithmetic processing unit, an engine coolant temperature sensor 15 and a pressure transducer 16 that provide input information to the ECV controller 12, and control commands (from the ECV controller 12). The condenser fan 11 whose rotation is controlled by the motor driving current) constitutes a condenser fan control system for reducing the electrical load.

  FIG. 4 is a flowchart showing the flow of the compressor control process executed by the ECV controller 12 of the first embodiment. Hereinafter, each step will be described (compressor control means).

Step S1 is a step of determining whether or not the air conditioner switch 13 is switched from OFF to ON for the first time.
If it is determined as Yes in step S1, the process proceeds to step S2. If it is determined as No, the process proceeds to step S3.

Step S2 is a step of setting the integrated value SS to SS = 0 following the determination that the air conditioner switch 13 is switched from OFF to ON in step S1 for the first time.
After the processing in step S2, the process returns to step S1.

In step S3, following the determination that it is not the first time to switch the air conditioner switch 13 from OFF to ON in step S1, an air conditioner (A / C) that switches the air conditioner switch 13 from ON to OFF and then ON again. This is a step of determining whether or not it is at the start of restart.
If it is determined as Yes in step S3, the process proceeds to step S8. If it is determined as No, the process proceeds to step S4.

Step S4 is a step of calculating the target output duty D by PI control (proportional control + integral control) following the determination that the A / C restart is not started in step S3 (in the flowchart of FIG. 5 described later). See description).
After the process in step S4, the process proceeds to step S5.

Step S5 is a step of storing the integrated value following the calculation of the integrated value in the PI control in Step S4, clearing the integrated value in Step S13, or setting the initial integrated value in Step S15. .
After the processing in step S5, the process proceeds to step S6.

In step S6, following the target output duty D calculated in the PI control in step S4, the duty output set in step S12, or the duty output set in step S14, a duty signal by each duty ratio is output. This is a step of outputting to the high pressure valve 9 (actuator).
After the processing in step S6, the process proceeds to step S7.

Step S7 is a step of storing the duty value output to the high-pressure valve 9 (actuator) following the output to the actuator in step S6 (output value storage means).
After the processing in step S7, the process returns to step S1.

Step S8 is a step of reading the stored duty memory value following the determination that the A / C restart is started in step S3.
This duty memory value is the duty value output to the high pressure valve 9 when the variable capacity compressor 1 is started and then stopped. After the processing in step S8, the process proceeds to step S9.

Step S9 is a proportional initial value proportional to the temperature difference (Teva-TMeva) between the actual evaporator outlet temperature Teva and the target evaporator outlet temperature TMeva at the start of restart of the variable displacement compressor 1 following the reading of the duty memory value in Step S8. Is calculated as a first target value (first target value calculation means).
Note that the information on the actual evaporator outlet temperature Teva is acquired based on the sensor signal from the evaporator outlet temperature sensor 8. The target evaporator outlet temperature TMeva is set based on information such as the set temperature by the blowout temperature setting device 14. After the processing in step S9, the process proceeds to step S10.

Step S10 is a step of setting the duty memory value (output storage value) read in step S8 as the second target value following the calculation of target 1 = P (proportional) in step S9 (second target value setting). means).
After the processing in step S10, the process proceeds to step S11.

Step S11 is a step of determining whether or not the first target value exceeds the second target value following the target 2 = DUTY memory in step S10.
If it is determined as Yes in step S11, the process proceeds to step S12. If it is determined as No, the process proceeds to step S14.

Step S12 is a step of setting the duty output to the first target value (proportional initial value) following the determination that target 1> target 2 in step S11.
After the processing in step S12, the process proceeds to step S13.

Step S13 is a step of clearing the integrated value, that is, the integrated initial value at the start of A / C restart, following the setting of DUTY output = target 1 in step S12.
After the processing in step S13, the process proceeds to step S5.

Step S14 is a step for setting the duty output to the second target value (duty memory value) following the determination that target 1 ≦ target 2 in step S11.
After the processing in step S14, the process proceeds to step S15.

In step S15, following the setting of DUTY output = target 2 in step S14, the integrated initial value at the start of A / C restart is set to a value obtained by subtracting the proportional initial value from the duty memory value.
After the processing in step S15, the process proceeds to step S5.

  FIG. 5 is a flowchart showing a flow of target output duty calculation processing by PI control executed in step S4 of the flowchart of FIG. 4, and each step will be described below. Note that this process is repeatedly executed, for example, at a cycle of 100 msec.

Step S401 is a step of calculating the proportionality constant Kh based on the difference temperature (Teva−TMeva) between the actual evaporator outlet temperature Teva and the target evaporator outlet temperature TMeva.
Here, as shown in the frame of step S401, the proportionality constant Kh has a range of ± 1 ° C. as a dead zone, and as the temperature difference (Teva−TMeva) increases to the plus side, the temperature difference (Teva−TMeva) increases. It is given as a value that increases in proportion to the negative side. For example, in a region exceeding ± 5 ° C., the proportionality constant Kh is given as an upper limit value (for example, Kh = 7).
After the processing in step S401, the process proceeds to step S402.

Step S402 is a step of calculating an integral constant Ks based on the difference temperature (Teva-TMeva) between the actual evaporator outlet temperature Teva and the target evaporator outlet temperature TMeva.
Here, as shown in the frame of step S402, the integration constant Ks has a range of ± 1 ° C. as a dead zone, and when the temperature difference (Teva−TMeva) is larger on the plus side, the temperature difference (Teva−TMeva) When the value is large on the minus side, the value is given at a constant value (for example, Ks = 0.01) in any case.
After the processing in step S402, the process proceeds to step S403.

Step S403 is a step of calculating the integrated value SS following the calculation of the integration constant Ks in step S402.
The formula for calculating the integrated value SS is:
SS = S + Ks × (Teva−TMeva)
It is. However, S is an integrated value up to the previous time.
After the processing in step S403, the process proceeds to step S404.

Step S404 is a step of determining whether or not the integrated value SS calculated in step S403 is equal to or greater than the integrated value upper limit Smax following the calculation of the integrated value SS in step S403.
If it is determined as Yes in step S404, the process proceeds to step S408, and if it is determined as No, the process proceeds to step S405.

Step S405 is a step of determining whether or not the integrated value SS calculated in step S403 is equal to or less than the integrated value lower limit Smin following the determination that SS <Smax in step S404.
If it is determined as Yes in step S405, the process proceeds to step S407. If it is determined as No, the process proceeds to step S406.

Step S406 is a step of setting the integrated value SS calculated in step S403 as the integrated value S up to the previous time following the determination that Smin <SS <Smax in steps S404 and S405.
After the processing in step S406, the process proceeds to step S409.

Step S407 is a step of setting the integrated value lower limit Smin as the integrated value S up to the previous time following the determination that SS ≦ Smin in step S405.
After the processing in step S407, the process proceeds to step S409.

Step S408 is a step of setting the integrated value upper limit Smax as the integrated value S up to the previous time following the determination that SS ≧ Smax in step S404.
After the processing in step S408, the process proceeds to step S409.

In step S409, the ECV duty P is calculated following the update of the integrated value S up to the previous time in any of step S406, step S407, and step S408.
The formula for calculating this ECV duty P is:
P = Kh × (Teva−TMeva) + SS
It is.
After the processing in step S409, the process proceeds to step S410.

Step S410 is a step of determining whether or not the ECV duty P is equal to or greater than the duty calculation value upper limit Dmax following the calculation of the ECV duty P in step S409.
If it is determined as Yes in step S410, the process proceeds to step S414. If it is determined as No, the process proceeds to step S411.

Step S411 is a step of determining whether or not the ECV duty P is equal to or less than the duty calculation value lower limit Dmin following the determination of P <Dmax in step S410.
If it is determined as Yes in step S411, the process proceeds to step S413. If it is determined as No, the process proceeds to step S412.

Step S412 is a step of setting the ECV duty P calculated in step S409 as the target output duty D following the determination that Dmin <P <Dmax in steps S410 and S411.
After the processing in step S412, the process proceeds to DUTY operation END.

Step S413 is a step of setting the duty calculation value lower limit Dmin as the target output duty D following the determination that P ≦ Dmin in Step S411.
After the processing in step S413, the process proceeds to DUTY operation END.

Step S414 is a step of setting the duty calculation value upper limit Dmax as the target output duty D following the determination that D ≧ Dmax in Step S410.
After the processing in step S414, the process proceeds to DUTY calculation END.

  Next, the operation will be described.

[At the first start of A / C]
When the air conditioner switch 13 is turned ON while riding in the vehicle, at the start of the OFF → ON operation of the air conditioner switch 13, the process proceeds from step S1 to step S2 in the flowchart of FIG. = 0 is set.
And it returns to step S1 from step S2, and the flow which progresses to step S1-> step S3-> step S4-> step S5-> step S6-> step S7 is repeated in the flowchart of FIG.

  For example, when the integral value SS is Smin <SS <Smax and the ECV duty P is Dmin <P <Dmax, in the flowchart of FIG. 5, step S401 → step S402 → step S403 → step S404 → step S405 → The process proceeds from step S406 to step S409 to step S410 to step S411 to step S412. In step S409, the proportional value {Kh × (Teva−TMeva)} and the integrated value SS {= S + Ks × (Teva−TMeva) with respect to the difference temperature (Teva−TMeva) between the actual evaporator outlet temperature Teva and the target evaporator outlet temperature TMeva. }, The ECV duty P is determined. In step S412, this ECV duty P is set as the target output duty D.

  In step S5, the integrated value SS calculated in the PI control in step S4 is stored. In step S6, the duty signal based on the target output duty D calculated in the PI control in step S4 is stored in the high-pressure valve 9. Compressor control for outputting to the coil 94 is performed. In step S7, the duty value output to the coil 94 of the high-pressure valve 9 is stored for each control cycle.

Therefore, when the temperature difference (Teva−TMeva) between the actual evaporator outlet temperature Teva and the target evaporator outlet temperature TMeva is large at the time when the air conditioner switch 13 is turned on, the actual evaporator outlet temperature Teva matches the target evaporator outlet temperature TMeva. Thus, the capacity control of the variable capacity compressor 1 is performed with the target output duty D gradually increasing.
Note that, in setting the integrated value S and determining the target output duty D up to the previous time, as shown in FIG. 5, since both are limited by the upper limit value and the lower limit value, the rising gradient of the integrated value SS is also the target output duty. The rising gradient of D (= duty output) becomes smooth (see the characteristics from time t1 to time t2 in FIG. 7).

[When A / C is restarted and target 1> target 2]
For example, when the air conditioner switch 13 is operated (ON → OFF) in the morning in the morning, and then the car is used during the hot daytime and the air conditioner switch 13 is turned ON, in step S3 of the flowchart of FIG. While the A / C restart start condition is satisfied, the condition of target 1> target 2 in step S11 is satisfied.

  The reason why the condition of target 1> target 2 is satisfied is that the duty memory value (= target 2) output at the time of the OFF operation is low when the air conditioner switch 13 is turned ON → OFF in the morning time when the outside air temperature is low. It becomes. On the other hand, when the air conditioner switch 13 is turned ON during the daytime when the outside air temperature is high, the actual evaporator outlet temperature Teva is high at the time of the ON operation, and the difference temperature (Teva−TMeva) from the target evaporator outlet temperature TMeva is large. This is because the proportional duty value (= target 1) becomes a high value.

  Therefore, at the time of the first control activation by the ON operation of the air conditioner switch 13, in the flowchart of FIG. 4, step S1, step S3, step S8, step S9, step S10, step S11, step S12, step S13, step S5, step The flow proceeds from S6 to step S7. Then, from the next control cycle, in the flowchart of FIG. 4, the flow of step S1 → step S3 → step S4 → step S5 → step S6 → step S7 is repeated.

  Therefore, as in the case of the initial activation of A / C, the integrated value is cleared in step S13, so that only the proportional amount is initially controlled, and the integrated value is gradually increased while maintaining the integrated time. As a result, the displacement control of the variable displacement compressor 1 with the gradually increasing target output duty D is performed so that the actual evaporator outlet temperature Teva matches the target evaporator outlet temperature TMeva.

  That is, when the condition of target 1> target 2 is satisfied, if the compressor capacity control is started with the duty memory value, the duty memory value is a low value, so the initial cooling capacity may be insufficient. On the other hand, if the maximum duty is always output at the time of restart, there is a possibility of overcooling, which consumes more power than necessary, causing deterioration of fuel consumption performance and the like. Therefore, a state determination is made based on the condition of target 1> target 2, and when the condition of target 1> target 2 is satisfied, a method of starting compressor capacity control by proportional control is adopted, so that there is no excess or deficiency. Can ensure a good cooling capacity.

[When A / C is restarted and target 1 ≤ target 2]
When the air conditioner switch 13 is operated in a short time (ON → OFF → ON), the A / C restart start condition in step S3 in the flowchart of FIG. 4 is satisfied, but the condition of target 1> target 2 in step S11 is satisfied. Is not established.

  The reason that the condition of target 1> target 2 is not satisfied is that a short time has elapsed since the air conditioner switch 13 was turned off, and the actual temperature by the evaporator outlet temperature sensor 8 is still recognized as low. When the air conditioner switch 13 is turned on, it is determined that the evaporator 3 is already cooled, the temperature difference (Teva-TMeva) becomes a small value, and the proportional duty value (= target 1) is the output that is originally required. The value is lower than the duty. On the other hand, the duty memory value (= target 2) output when the air conditioner switch 13 is turned OFF outputs a high target output duty D in order to make the actual evaporator outlet temperature Teva coincide with the target evaporator outlet temperature TMeva. It is because it becomes a high value.

  Therefore, at the time of the first control activation by the ON operation of the air conditioner switch 13, in the flowchart of FIG. 4, step S1, step S3, step S8, step S9, step S10, step S11, step S14, step S15, step S5, step The flow proceeds from S6 to step S7. Then, from the next control cycle, in the flowchart of FIG. 4, the flow of step S1 → step S3 → step S4 → step S5 → step S6 → step S7 is repeated.

  Therefore, unlike the case where the condition of target 1> target 2 is satisfied, the first duty output is set as the duty memory value in step S14, and the integrated initial value is given by the difference between the duty memory value and the proportional component in step S15. Thus, similarly to the case where the ON operation of the air conditioner switch 13 is maintained as it is, the displacement control of the variable displacement compressor 1 by the proportional control and the integral control is performed from the start of the restart.

  That is, when the condition of target 1> target 2 is not satisfied, if the compressor capacity control is performed to clear the integrated value at the start of restart, the initial cooling capacity is insufficient. Therefore, the state is determined based on the condition of target 1> target 2, and if the condition of target 1> target 2 is not satisfied, the air conditioner switch 13 is turned off to compensate for the lack of cooling capacity due to the integrated value at the initial stage of restart. The duty memory value that was sometimes output was used as the initial output value for restart, and the integrated initial value was calculated from the duty memory value to maintain the PI control.

As a result, when the air conditioner switch 13 is operated in a short time, the output duty can be increased quickly, and the lack of cooling capacity at the time of restart can be covered.
In particular, this is effective when an incorrect air conditioner switch 13 that is turned ON → OFF → ON in a short time is operated.

[Comparison of compressor control action when A / C is restarted]
Conventionally, the displacement control of a variable displacement compressor is performed by calculating the control duty by PI control based on the expression {proportional coefficient × differential temperature + (integral coefficient × differential temperature + integrated value up to the previous time)}, and the duty output to the actuator As shown in the flowchart of FIG. 6, when the A / C activation is started, the control is always performed to clear the accumulated value accumulated so far.

Therefore, for example, as shown in FIG. 7, after turning on the air conditioner switch at time t1, turning off the air conditioner switch at time t2, and turning on the air conditioner switch at time t3 when a short time has passed, The case of starting will be described.
In this case, from the time point t3 to the time point t4, only the proportional control amount of (proportional coefficient × difference temperature) is started. Therefore, the duty output characteristic and the integrated value characteristic are shown by the one-dot chain line characteristic in FIG. As shown, the characteristic gradually increases from 0.
As a result, in the case of the conventional technology that does not have an initial integration value, a calculation delay occurs due to the integration time (time required from t3 to t4) until the integral control is output, and this calculation delay restarts the variable displacement compressor. It causes a lack of cooling capacity at times.

  On the other hand, in the control device for the variable displacement compressor 1 according to the first embodiment, when the air conditioner switch is turned on at time t3 in FIG. Since the duty memory value according to the cooling capacity request at the time point t2 when stopping is output at the start of the restart, when the condition of target 1> target 2 is not satisfied, the start initial response of the restart of the cooling capacity is secured. The

  In addition, when the air conditioner switch is turned on at time t3 in FIG. 7 and restarted, a value obtained by subtracting the proportional amount from the duty memory value is set as the integrated initial value. That is, when the restart is started by the duty memory value, the integration control by the integrated initial value is started together with the proportional control from the next control cycle. For this reason, the duty output characteristic and the integrated value characteristic show a step-like characteristic that rises from a value of 0 at the time of t3, as shown by the solid line characteristic in FIG. Is represented by A in FIG. 7, and the effect margin of the integrated value characteristic with the prior art is represented by B in FIG. 7. As a result, the lack of cooling capacity at the beginning of the restart, which has been a problem in the past, is solved.

  Incidentally, the output value for driving and controlling the variable capacity compressor 1 is determined by the proportional control amount + the integral control amount, and the integral control amount is added to the proportional control amount to + α minutes, and the cooling capacity is insufficient due to this integral control amount. It is for covering.

Next, the effect will be described.
In the control device for the variable displacement compressor 1 of the first embodiment, the effects listed below can be obtained.

  (1) When the variable displacement compressor 1 is in operation, the compressor control means is provided for determining the output value based on the proportional value and the integrated value with respect to the difference between the actual temperature and the target temperature, and outputting the determined output value to the variable displacement actuator. In the control apparatus for a variable displacement compressor, there is provided an output value storage means (step S7) for storing, as an output storage value, an output value for the variable displacement actuator when the variable displacement compressor 1 is started and then stopped. (FIG. 4) shows that when the restart of the variable displacement compressor 1 is started, the restart start output value for the variable displacement actuator is set as the output stored value, and the value obtained by subtracting the proportional initial value from the output stored value is the integrated initial value. Since the variable capacity compressor start control unit (steps S8 to S15) is When restarting after stopping the compressor 1, it is possible to resolve the initial lack of cooling capacity at high temperatures.

  (2) first target value calculating means (step S9) for calculating a proportional initial value proportional to the difference between the actual temperature and the target temperature at the start of restart of the variable displacement compressor 1 as the first target value; Second target value setting means (step S10) for setting the output storage value by the value storage means (step S7) as a second target value, and the variable capacity compressor start control unit (steps S8 to S15), When the restart of the variable displacement compressor 1 is started (when determined as Yes in step S3), and when the first target value is equal to or less than the second target value (when determined as No in step S11), The restart start output value for the variable capacity actuator is set as the output storage value (step S14), and the value obtained by subtracting the proportional initial value from the output storage value is set as the integrated initial value (step S15). Therefore, only when the condition that the first target value for which the cooling capacity is insufficient at the time of restart is less than the second target value is satisfied, such as when the variable displacement compressor 1 is restarted in a short time after the stop. Can cover the lack of cooling capacity.

  (3) The variable capacity compressor start control unit (steps S8 to S15) is at the start of restart of the variable capacity compressor 1 (when it is determined Yes in step S3), and the first target value is the first value. When larger than the two target values (when it is determined Yes in step S11), the restart start output value for the variable capacity actuator is set as a proportional initial value (step S12), and the integrated initial value is cleared (step S13). Therefore, only when the condition that the first target value is larger than the second target value is satisfied, such as when the variable displacement compressor 1 is restarted after a long time has elapsed since the stop, appropriate cooling without excess or deficiency is performed. Capability can be secured.

  (4) The variable capacity compressor 1 is provided as a component of a refrigeration cycle including an evaporator 3 disposed in an air conditioning unit 2 of a vehicle, and detects an evaporator outlet temperature at a position immediately after the evaporator 3 on the downstream side. An evaporator outlet temperature sensor 8 is provided, and the first target value calculation means (step S9) is a temperature difference (Teva-TMeva) between the actual evaporator outlet temperature Teva and the target evaporator outlet temperature TMeva at the start of restart of the variable capacity compressor 1. ) Is calculated as the first target value, the lack of cooling capacity in the passenger compartment can be resolved when the air conditioning unit 2 including the variable capacity compressor 1 is stopped and then restarted.

  (5) The variable displacement compressor 1 includes a high-pressure valve 9 that controls the flow rate of refrigerant discharged by the valve lift amount determined by the pressure load F (Ps), the spring load F (K), and the magnetic force F (I) acting on the diaphragm 91. The variable capacity actuator is a coil 94 that electrically changes the magnetic force F (I) acting on the diaphragm 91 of the high-pressure valve 9 by applying an effective current based on a duty control signal. Compressor capacity change control can be performed with simple current control.

  As described above, the control device for the variable displacement compressor of the present invention has been described based on the first embodiment. However, the specific configuration is not limited to the first embodiment, and the claims relate to each claim. Design changes and additions are allowed without departing from the scope of the invention.

  In the first embodiment, a high-pressure valve is used as a variable displacement actuator as the variable displacement compressor. However, in the case of a variable displacement compressor whose capacity is changed by external electrical control, for example, a swash plate that makes the compression stroke variable It may be a variable displacement compressor that changes the inclination angle, an electric variable displacement compressor that is controlled by an inverter, or the like.

  In the first embodiment, in order to efficiently control the compressor, the state determination is performed based on the magnitude relationship between the target 1 and the target 2. However, for example, when the restart of the variable capacity compressor is started without performing the state determination. Alternatively, the variable displacement compressor activation control may be performed in which the restart start output value for the variable capacity actuator is always set as the output storage value, and the value obtained by subtracting the proportional initial value from the output storage value is set as the integrated initial value.

  In the first embodiment, an example of application to a variable displacement compressor provided as a constituent element of a refrigeration cycle including an evaporator disposed in an air conditioning unit of a vehicle is shown. The present invention can also be applied to air conditioners and the like used in offices and factories.

FIG. 1 is an overall view showing an externally controlled compressor system to which a control device for a variable displacement compressor according to a first embodiment is applied. FIG. 3 is a cross-sectional view illustrating an example of a high pressure valve that controls the capacity of the variable displacement compressor according to the first embodiment. It is a time chart which shows an example of the current waveform and voltage waveform of the control duty signal applied to the coil of the high pressure valve shown in FIG. 3 is a flowchart illustrating a flow of compressor control processing executed by the ECV controller 12 according to the first embodiment. It is a flowchart which shows the flow of the target output duty calculation process by PI control performed in step S4 of the flowchart of FIG. It is a flowchart which shows the flow of the compressor control processing performed with the conventional controller. It is a time chart which shows each contrast characteristic of an air-conditioner switch signal characteristic, a duty output characteristic, and an integrated value characteristic at the time of ON-> OFF-> ON operation of an air-conditioner switch in a short time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Variable capacity compressor 2 Air conditioning unit 3 Evaporator 4 Condenser 5 Liquid receiver 6 Expansion valve 7 Blower 8 Evaporator outlet temperature sensor (evaporator outlet temperature detection means)
9 High pressure valve 90 Ball valve 91 Diaphragm 92 Valve control body 93 Set spring 94 Coil 10 Radiator 11 Capacitor fan 12 ECV controller 13 Air conditioner switch 14 Blowing temperature setting device

Claims (6)

When operating a variable displacement compressor, an output value is determined by a proportional value and an integrated value with respect to the difference between the actual temperature and the target temperature, and a variable displacement compressor equipped with a compressor control means for outputting the determined output value to the variable displacement actuator. In the control device,
An output value storage means for storing an output value for the variable displacement actuator when the variable displacement compressor is started and then stopped as an output storage value;
When the restart of the variable displacement compressor is started, the compressor control means sets the restart start output value for the variable displacement actuator to the output stored value, and sets the value obtained by subtracting the proportional initial value from the output stored value as the integrated initial value. A control apparatus for a variable displacement compressor, comprising: a variable displacement compressor start control unit that performs the operation. In the control apparatus of the variable displacement compressor according to claim 1,
First target value calculation means for calculating, as a first target value, a proportional initial value proportional to the difference between the actual temperature and the target temperature at the start of restart of the variable capacity compressor;
A second target value setting means for setting an output storage value by the output value storage means as a second target value;
The variable capacity compressor start control unit is a start time of restart of the variable capacity compressor, and when the first target value is equal to or less than the second target value, the restart start output value for the variable capacity actuator is set as an output storage value. In addition, a control apparatus for a variable displacement compressor, characterized in that a value obtained by subtracting a proportional initial value from an output storage value is used as an integrated initial value. In the control apparatus for the variable displacement compressor according to claim 2,
The variable displacement compressor start control unit sets the restart start output value for the variable displacement actuator to a proportional initial value when the restart of the variable displacement compressor is started and the first target value is larger than the second target value. And a control device for the variable displacement compressor, wherein the initial integrated value is cleared. In the control device for the variable displacement compressor according to claim 2 or 3,
The variable capacity compressor is provided as a component of a refrigeration cycle including an evaporator disposed in an air conditioning unit of a vehicle,
Evaporator outlet temperature detection means for detecting the evaporator outlet temperature is provided immediately after the evaporator on the downstream side,
The first target value calculating means calculates, as the first target value, a proportional initial value that is proportional to a temperature difference between an evaporator outlet temperature detection value and a target evaporator outlet temperature at the start of restart of the variable capacity compressor. Control device for variable displacement compressor. The control apparatus for a variable displacement compressor according to any one of claims 1 to 4,
The variable capacity compressor has a high-pressure valve that controls a refrigerant flow rate that is discharged by a valve lift amount determined by a pressure load acting on the diaphragm, a spring load, and a magnetic force,
The variable capacity actuator is a coil that electrically changes the magnetic force acting on the diaphragm of the high-pressure valve by applying an effective current based on a duty control signal. In the operation of the variable displacement compressor, the output value is determined by the proportional value and the integrated value with respect to the difference between the actual temperature and the target temperature, and the determined output value is output to the variable displacement actuator.
After starting the variable displacement compressor, store the output value for the variable displacement actuator when stopping as an output storage value,
At the start of restart of the variable capacity compressor, the restart start output value for the variable capacity actuator is set as an output stored value, and a value obtained by subtracting a proportional initial value from the output stored value is set as an integrated initial value. Control device for variable displacement compressor.

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