JP2638952B2 - Electromagnetic clutch control device for variable displacement compressor - Google Patents

Description

The present invention relates to an electromagnetic clutch control device for a variable displacement compressor for a vehicle.

(Prior Art) Conventionally, in this type of electromagnetic clutch control device for a variable displacement compressor for a vehicle, for example, a Japanese Utility Model Application No.
As disclosed in Japanese Patent Publication No. 31 (1995), the minimum current to the electromagnetic clutch is determined so that torque required for driving the compressor is generated from the electromagnetic clutch according to the discharge pressure of the compressor, the number of revolutions, and the like. There is something that I did.

(Problems to be Solved by the Invention) However, in such a configuration, the followability of the torque of the electromagnetic clutch to a load change due to a change in the capacity of the compressor is poor. For example, when the capacity of the compressor is reduced during acceleration of the vehicle and the capacity of the compressor is suddenly increased and restored at the end of acceleration, there is a problem that the electromagnetic clutch is likely to slip due to insufficient torque.

In view of the above, the present invention provides an electromagnetic clutch control device for a variable displacement compressor for a vehicle, in which the compressor capacity at the end of the acceleration is maintained while maintaining good acceleration performance when the vehicle is accelerated. It is intended to perform the return without causing the electromagnetic clutch to slip.

(Means for Solving the Problems) In order to solve the above-described problems, the present invention provides an electromagnetic clutch 1 that is engaged in accordance with supply power, and a variable power that is operated by being transmitted from an engine by the engagement of the electromagnetic clutch 1. A displacement type compressor 2; a displacement control means 4 for controlling the capacity of the variable displacement type compressor 2; and a power control means 5 for controlling supply power to the electromagnetic clutch 1 in accordance with the displacement of the variable displacement type compressor 2. A detecting means 3 for detecting when the vehicle is accelerating, and for a predetermined time after the detecting means 3 detects the acceleration of the vehicle, the capacity control means 4 is provided with the variable capacity type The power control means 5 reduces the capacity of the compressor 2 and at least during this predetermined time, the power control means 5 detects the supply power immediately after the detection means 3 detects the acceleration of the vehicle. Adopting technical means that substantially maintain the value.

(Operation and Effect) With the configuration of the present invention, the power supply to the electromagnetic clutch is varied according to the variable capacity of the variable displacement compressor 2 during normal operation of the vehicle (during non-acceleration), and at the time of acceleration. During a predetermined time after the detection means 3 detects the acceleration of the vehicle, the capacity control means 4 controls the capacity of the compressor 2 to be reduced, and the power control means 5 detects the power supplied to the electromagnetic clutch 1. Means 3
Is controlled so that it does not substantially change before and after the detection of. Therefore, the acceleration of the vehicle can be ensured satisfactorily in accordance with the torque decrease accompanying the decrease in the capacity of the compressor 2, and the torque of the electromagnetic clutch 1 is reduced even when the capacity of the compressor 2 is increased and returned at the end of the acceleration. Is always kept larger than the torque of As a result, the capacity of the compressor 2 can be restored without causing the electromagnetic clutch 1 to slip.

(Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 shows an example in which the present invention is applied to a vehicle air conditioner. Air conditioner is air duct
The air duct 10 has a blower 11,
An evaporator 20 of the refrigeration cycle Rc, an air mix damper (not shown), and the like are sequentially provided. Refrigerating cycle Rc has a variable displacement compressor 30, the compressor 30, depending on its capacity, pipe as a refrigerant is compressed compressed refrigerant from the evaporator 20 through the pipe P ₁
It is discharged into the P _2. In such a case, the capacity of the compressor 30 changes in proportion to the opening of the solenoid valve 31 attached to the compressor 30. The operation of the compressor 30 is effected by the transmission of torque from the engine of the vehicle to the compressor 30 due to the selective engagement of the electromagnetic clutch 32 attached to the compressor 30. However, in the present embodiment, a dry single-plate electromagnetic clutch is employed as the electromagnetic clutch 32.

Further, the refrigerating cycle Rc has a capacitor 40, the capacitor 40 is applied through a pipe P ₃ to the gas-liquid separator 50 as a condenser to condense the refrigerant compressed refrigerant from the pipe P _2. Gas-liquid separator 50, the pipe P ₃ pipes of the liquid phase component in the refrigerant as the refrigerant P from _4, applied to the expansion valve 60 and the pipe P ₅ is passed through the evaporator 20. The evaporator 20 cools the airflow from the blower 11 to be blown into the vehicle compartment of the vehicle through the air mix damper and the like.

Next, an electric control circuit for the solenoid valve 31 and the electromagnetic clutch 32 of the compressor 30 will be described.
The operation switch SW is operated when operating the air conditioner and generates an operation signal. The temperature setting device 70a
A desired temperature in the vehicle interior is set and generated as a set temperature signal. The internal temperature sensor 70b detects the actual temperature in the vehicle interior and generates an internal temperature detection signal. Outlet temperature sensor 70c
Detects the actual temperature of the airflow blown from the evaporator 20 and generates the detected temperature as a blowout temperature detection signal. The throttle switch 80 detects a rapid change in the opening of the throttle valve of the engine of the vehicle and generates an acceleration detection signal.

A / D converter 90 is a set temperature signal from temperature setter 70a,
The internal air temperature detection signal from the internal air temperature sensor 70b and the air temperature detection signal from the outlet air temperature sensor 70c are digitally converted into a set temperature digital signal, an internal air temperature digital signal, and an outlet air temperature digital signal, respectively. Microcomputer 10
0 executes the computer program in cooperation with the accelerator switch 80 and the A / D converter 90 according to the flowchart shown in FIG. 3, and during this execution, each computer connected to the solenoid valve 31 and the electromagnetic clutch 32, respectively. The arithmetic processing for controlling the driving circuits 110 and 120 is performed. However, the above-described computer program is stored in the ROM of the microcomputer 100 in advance. The microcomputer 100 is put into an operating state by power supply from the battery B via the ignition switch IG of the vehicle, and starts executing a computer program in response to an operation signal from the operation switch SW.

In the present embodiment configured as described above, by closing the ignition switch IG, the vehicle is started with the start of the engine and the microcomputer is started.
Put 100 in operation. Then, when an operation signal is generated from the operation switch SW, the microcomputer 100 starts execution of the computer program in step 200 according to the flowchart of FIG. 3, initializes in step 210, and sets A in step 220. The set temperature digital signal, the internal temperature digital signal, and the outlet temperature digital signal from the D converter 90 are represented by Tset, the internal temperature Tin, and the outlet temperature T.
Entered as e. Unless the acceleration detection signal from the throttle switch 80 has been generated at this stage. The microcomputer 100 determines “NO” with the switch 230,
In step 231, the set temperature Tset, the internal temperature Tin, and the outlet temperature Te
Based on the above, the required blowing temperature Teo of the airflow into the vehicle speed compartment is determined, in step 232, the target capacity Cvo of the compressor 30 is determined based on the blowing temperature Te and the like, and in step 233,
Duty ratio DT indicating target opening of solenoid valve 31
And the target applied voltage Vclo to the electromagnetic clutch 32 is set to the target capacity Cv.
Determined based on o.

Thereafter, in step 240, the microcomputer 100 changes the applied voltage to the electromagnetic clutch 32 according to the change state from the actual capacity of the compressor 30 (that is, the preceding target capacity) to the current target capacity Cvo. Is determined. In such a case, compared to the change in compressor torque Tcom due to the change in the capacity of the compressor 30, the clutch torque Tcl due to the engagement of the electromagnetic clutch 32 is always higher than the target applied voltage Vclo so that the electromagnetic clutch 32 does not always slip. The phase is made different from that of the duty ratio DT.

At this stage, the electromagnetic clutch 32 is in the disengaged state (assuming that Vclo = 0 has been initialized in step 210).
If so, the microcomputer 100 advances the computer program from step 240 to step 241. That is, in step 241, when the electromagnetic clutch 32 is started from Vclo = 0, taking into consideration that both the capacity of the compressor 30 and the operation of the electromagnetic clutch 32 become unstable, as shown in FIG. The applied voltage Vclo is initially set to 100 (%) as specified by the curve Laa, and then
The duty ratio DT is increased linearly as specified by the curve Naa, and after reaching the desired value of DT, a certain time delay
Arithmetic processing is performed to reduce Vclo to a desired value.

During the repetition of the execution of the computer program passing through the steps 220 to 240, 241 and 250, the target capacity Cvo, the duty ratio DT and the target applied voltage Vclo
Is repeatedly determined, and in step 250, the duty ratio DT and the target applied voltage Vclo are repeatedly generated as a duty output signal and a voltage output signal, respectively. Therefore, the target applied voltage Vclo to the electromagnetic clutch 32 is equal to the curve Laa
Is controlled by the drive circuit 120 based on the voltage output signal from the microcomputer 100,
The driving degree of the opening of the solenoid valve 31, that is, the duty ratio DT is controlled by the drive circuit 110 based on the duty output signal from the microcomputer 100 along the curve Naa.

Therefore, when the electromagnetic clutch 32 is activated, the clutch torque Tcl of the electromagnetic clutch 32 is controlled so as to be specified by the curve Lab shown in FIG. 4, while the compressor torque Tcom of the compressor 30 is controlled by the curve Lab shown in FIG. Controlled as specified by Nab. Therefore, even when the operation of the electromagnetic clutch 32 and the capacity of the compressor 30 are unstable when the electromagnetic clutch 32 is activated, the electromagnetic clutch 32
Non-slip clutch torque Tcl and compressor 30
The compressor torque Tcom can be accurately and smoothly realized with a phase difference as shown in FIG.
The cooling capacity of the refrigeration cycle Rc when starting the electromagnetic clutch 32 can be smoothly ensured.

When the computer program proceeds to step 240 in such a state, if the microcomputer 100 proceeds to step 242 based on the determination that the electromagnetic clutch 32 and the compressor 30 are in a steady state, For example, as shown in FIG. 5, when the compressor torque Tcom and the clutch torque Tcl are decreased along the curves Nbb and Lbb, respectively, the duty ratio DT is linearly increased while being advanced by a predetermined phase with respect to the target applied voltage Vclo. When the compressor torque Tcom and the clutch torque Tcl are increased along each of the curves Nbb and Nba, the duty ratio DT is increased linearly while being delayed by a predetermined phase with respect to the target applied voltage Vclo. The arithmetic processing is performed. For this reason, the clutch torque Tcl is controlled so as to always exceed the compressor torque Tcom.As a result, the displacement control of the compressor 30 without the slippage of the electromagnetic clutch 32, that is, the steady state of the refrigeration cycle Rc is performed. Cooling capacity control can be realized.

Thereafter, when an acceleration detection signal is generated from the throttle switch 80, the microcomputer 100 determines “YES” in step 230, and performs acceleration processing of the vehicle in step 260. In this acceleration process, in response to the determination of "YES" in step 230, the duty ratio DT is set to 0 (see the curve Nca) as shown in FIG. Set the voltage Vclo to “YES” in step 230
Is performed so as to continuously maintain the value at the time of steady state immediately before the determination. In such a case, the processing is performed for the following reasons. That is, the time during which the capacity of the compressor 30 is reduced so as not to deteriorate the accelerating performance when the vehicle is accelerated is usually extremely short, and during this time, the rotation of the compressor 30 due to the rotation fluctuation of the engine is performed. Fluctuations are severe, and fluctuations in the discharge pressure and torque of the compressor 30 are remarkable. When the compressor torque is restored immediately before acceleration at the end of the acceleration of the vehicle, the voltage applied to the electromagnetic clutch 32 is decreased at the same time as the acceleration, and is restored immediately before the end of the acceleration. And causes the electromagnetic clutch 32 to slip at the end of acceleration. In order to prevent this, the above-described acceleration processing is performed.

Thus, in the process of repeating the calculations passing through the steps 230, 260, and 250, the target applied voltage Vclo to the electromagnetic clutch 32 under the minimum capacity of the compressor 30 due to DT = 0 is set to a value immediately before the start of acceleration of the vehicle. Is also maintained. Therefore, even if the compressor torque Tcom decreases along the curve Ncb in FIG. 6, the clutch torque Tcl is maintained at the value immediately before acceleration along the curve Lcb in FIG. Even if Tcom increases along the curve Ncb, the clutch torque Tcl always exceeds the compressor torque Tcom, and as a result, without the slippage of the electromagnetic clutch 32, the good acceleration of the vehicle and at the end of acceleration. Of the compressor torque Tcom can be accurately and accurately followed.

At the end of such acceleration, if the determination in step 230 becomes “NO” again, the computer program proceeds to step 240. If it is determined that the capacity of the compressor 30 is to be rapidly changed from the small capacity to the large capacity based on the target capacity Cvo in step 232, the microcomputer 100 advances the computer program to step 243, and executes the capacity increase processing. I do. In this capacity increasing process, as shown in FIG.
The arithmetic processing is performed so that the duty ratio (see the curve Nda) increases stepwise with a predetermined phase advance with respect to the duty ratio (see the curve Nda). Therefore, in the process of repeating the operation passing through each of the steps 230, 240, 243, and 250, Vclo as described above is used.
Based on the phase difference from DT, the clutch torque Tcl (see curve Ldb) is controlled so as to always exceed the compressor torque Tcom (curve Ndb). Therefore, the capacity of the compressor 30 can be increased to a desired large capacity without causing the electromagnetic clutch 32 to slip.

When the computer program proceeds to step 240 as described above, the target capacity Cvo
If it is determined that the capacity of the compressor 30 is changed from the large capacity to the small capacity based on the
0 advances the computer program to step 244 to perform capacity reduction processing. In this capacity reduction processing, the eighth
As shown in the figure, the target applied voltage Vclo (see the curve Lea) decreases with a predetermined phase behind the duty ratio DT (see the curve Nea), and the target applied voltage Vclo decreases linearly, while the duty ratio DT decreases. Is calculated so as to decrease step by step. Therefore, each step 230, 2
In the process of repeating the calculation passing through 40, 244, and 250, the clutch torque Tc is determined based on the above-described phase difference between Vclo and DT.
l (see curve Leb)) is the compressor torque Tcom (curve Ne)
b) is controlled so that it always exceeds. Therefore, the capacity of the compressor 30 can be reduced to a required small capacity without causing the electromagnetic clutch 32 to slip.

In implementing the present invention, the control of the electromagnetic clutch 32 is not limited to the applied voltage, but may be performed by the applied current.

In practicing the present invention, the present invention is not limited to an air conditioner, but may be applied to various refrigeration cycles such as a refrigerator for a vehicle. The electromagnetic clutch 32 is not limited to a dry single-plate electromagnetic clutch, but may be a dry multi-plate electromagnetic clutch, a wet multi-plate electromagnetic clutch, an electromagnetic particle-type electromagnetic clutch, or the like.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to the description of the claims, FIG. 2 is a block diagram showing an embodiment of the present invention, FIG. 3 is a flowchart showing the operation of the microcomputer of FIG.
4 to 8 show the duty ratio DT and the target applied voltage Vc.
6 is a graph showing temporal changes of lo, compressor torque Tcom, and clutch torque Tcl. Explanation of reference numerals 30 …… Compressor, 31… Solenoid valve, 32 ……
Electromagnetic clutch, 80 ... throttle switch, 100 ... microcomputer.

Claims (1)

(57) [Claims] 1. An electromagnetic clutch that is engaged in accordance with a supply power, a variable displacement compressor that is operated by transmitting power from an engine by the engagement of the electromagnetic clutch, and a displacement control that controls a displacement of the variable displacement compressor. Means, and power control means for controlling power supplied to the electromagnetic clutch in accordance with the capacity of the variable displacement compressor, comprising: detection means for detecting when the vehicle is accelerating; For a predetermined time after detecting the acceleration of the vehicle, the capacity control means reduces the capacity of the variable displacement compressor, and at least during the predetermined time, the power control means reduces the supply power to An electromagnetic clutch of a variable displacement compressor, wherein the detection means keeps the value almost immediately before detecting the acceleration of the vehicle. Chi controller.