JP2002096627A - Driving source switching device of hybrid compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving source switching device of hybrid compressor enable to switch the driving source smoothly to an electric motor when stopping of a driving engine with maintaining of an air conditioning level. SOLUTION: When the driving source of hybrid compressor is switched from the driving engine to the electric motor, a torque of a compressor driving is calculated from a high pressure of a refrigerating cycle and a speed of a compressor revolving, the high pressure of a refrigeration is getting lower gradually till the torque of the compressor will be lower than the torque of the maximum driving of the electric motor, the electric motor will be driven for the first time when the torque of the compressor driving will be lower than the torque of the maximum driving of the electric motor, and when the revolving speed of the electric motor and the engine for driving will reach to the same, a generating power of the electric motor will be to the maximum by cutting off an electromagnetic clutch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid compressor having at least a condenser, an expansion valve, and an evaporator, which constitutes a part of a refrigeration cycle of an air conditioner mounted on a vehicle, and has a driving engine and an electric motor as driving sources. The present invention relates to a drive source switching device for a hybrid compressor that performs control for switching a drive source from a traveling engine to an electric motor.

[0002]

2. Description of the Related Art Conventionally, an operation control device for an on-vehicle compressor disclosed in Japanese Patent Application Laid-Open No. 9-324668 does not require stopping or accelerating due to a signal waiting or the like, unlike an idle stop vehicle or a hybrid vehicle. In such cases, the rotating machine provided for power generation is switched to an electric motor by an inverter so that the cooling performance can be sufficiently exhibited even in a system in which the traveling engine is stopped.
When the engine is stopped, the compressor is driven by the electric motor.

[0003]

However, since the driving torque of the motor is smaller than the driving torque of the internal combustion engine, even if the driving engine is simply switched to the driving by the electric motor, the driving force of the electric motor is insufficient. A problem arises in that the source cannot be smoothly shifted, and the cooling capacity of the refrigeration cycle is reduced due to a sudden decrease in the compressor capacity.

[0004] Therefore, the present invention provides a drive source switching device for a hybrid compressor capable of smoothly switching a drive source to an electric motor when a traveling engine stops while maintaining an air conditioning level. It is in.

[0005]

Therefore, the present invention constitutes at least a part of a refrigeration cycle of an air conditioner mounted on a vehicle together with a condenser, an expansion valve and an evaporator,
In a hybrid compressor having a driving engine and an electric motor as driving sources, a pressure detecting means for detecting a high pressure of the refrigeration cycle, a compressor rotational speed detecting means for detecting a rotational speed of the hybrid compressor, Engine rotation speed detection means for detecting a rotation speed; a compressor drive torque calculation for calculating a current compressor drive torque from a high pressure detected by the pressure detection means and a compressor rotation speed detected by the compressor rotation speed detection means. Means, an engine rotational speed determining means for determining that the rotational speed of the traveling engine detected by the engine rotational speed detecting means has reached an idle state, and a rotational speed of the traveling engine determined by the engine rotational speed determining means. When it is determined that the idle state has been reached, the compressor drive torque calculated by the compressor drive torque calculation means is compared with the maximum drive torque of the electric motor, and the compressor drive torque is set to the maximum drive torque of the electric motor. A high-pressure pressure reducing means for reducing the high-pressure pressure of the refrigeration cycle until the pressure decreases, and a high-pressure pressure of the refrigeration cycle is reduced by the high-pressure pressure reducing means, so that the capacitor driving torque falls below the maximum driving torque of the electric motor. A motor rotation speed increasing unit that starts driving the electric motor and gradually increases a rotation speed of the electric motor; and a rotation speed of the electric motor increases by the motor rotation speed increasing unit. If the engine speed matches the engine speed detected by Serial is to and a drive source switching means to maximize the rotation speed at the same time the electric motor when blocking the electromagnetic clutch.

Therefore, according to the present invention, when the drive source of the hybrid compressor is switched from the traveling engine to the electric motor, the compressor drive torque is calculated from the high pressure of the refrigeration cycle and the compressor rotation speed, and the compressor drive torque is calculated. The high-pressure pressure of the refrigeration cycle is gradually reduced until the driving torque becomes smaller than the maximum driving torque of the electric motor, and the electric motor is driven only when the calculated compressor driving torque becomes smaller than the maximum driving torque of the electric motor. When the rotational speed of the engine matches the rotational speed of the traveling engine, the electromagnetic clutch is shut off to maximize the output of the electric motor, so that the drive source can be smoothly transferred from the traveling engine to the electric motor. Can be done and even without stopping the compressor In, in which the air conditioning level can be maintained.

Further, in the above invention, it is preferable that the high pressure lowering means lowers the high pressure by gradually increasing a rotation speed of a condenser fan for sending cooling air to the condenser. By increasing the capacity of the condenser fan, the condensation rate in the condenser is increased and the high pressure is reduced, so that the load on the compressor can be reduced while maintaining the heat exchange capacity of the refrigeration cycle.

[0008] Further, the drive source switching means, when the motor input current to the electric motor is close to the allowable current of the electric motor, the rotation speed of the electric motor and the rotation speed of the traveling engine. Does not match,
It is desirable to shut off the electromagnetic clutch to maximize the rotation speed of the motor.

[0009]

FIG. 1 shows a schematic configuration of an embodiment of the present invention. In this schematic configuration diagram,
The traveling engine (hereinafter, engine) 1 is a direct-injection engine mounted on a hybrid vehicle or an idle stop vehicle. When the idle state has continued for a predetermined time, the supply of fuel is stopped and the engine 1 is automatically stopped.

A hybrid compressor (hereinafter referred to as a compressor) 2 having the engine 1 and the electric motor 3 as driving sources is provided. The connection with the engine 1 is opened and closed by an electromagnetic clutch 4.

Further, the compressor 2 includes at least a condenser 6, an expansion valve 8, and an evaporator 10,
The refrigeration cycle 5 absorbs the heat of the air passing through the air conditioning duct 9 and releases the heat to the air sent to the condenser 6 by the condenser fan 7. Further, the compressor 2 includes a variable displacement mechanism 16 that changes the discharge displacement Cc.

The control unit (C / U) 15 is
For example, central processing unit (CPU), read-only memory (ROM), random access memory (RAM), input / output port (I / O), A / D converter, multiplexer (MPX), D / A converter, etc. The high pressure Pd detected by the high pressure sensor 11 of the refrigeration cycle 5, the low pressure Ps detected by the low pressure sensor 12, the engine speed Ne, the compressor speed Nc, and the like are input. After being processed by a predetermined program, the duty ratio Dm of the control signal for driving the electric motor 3, the voltage Vcf of the control signal for controlling the rotation speed of the condenser fan 7, the electromagnetic clutch (Mg
cl) It outputs at least a control signal or the like for controlling 4.

The drive source switching control according to the embodiment of the present invention, which is executed in the control unit 15,
In particular, the control for switching the drive source of the compressor 2 from the engine 1 to the electric motor 3 is, for example, as shown in the flowchart of FIG. It is. Hereinafter, the drive source switching control of the compressor 2 from the engine 1 to the electric motor 3 will be described with reference to the flowchart of FIG.

In the drive source switching control started from step 100, the engine speed Ne in step 110 is changed.
It is determined whether or not is within a range near the idle rotation speed Na. In this determination, α1 is Na−λ (for example, λ = 100 rpm), and α2 is Na + λ. Accordingly, if the engine speed Ne is within the range of λ before and after the idle speed Na (Y), the process proceeds to step 120, and if not (N), the process proceeds to step 210 to perform the electromagnetic clutch (Mgcl). 4, the compressor 2 is driven by the engine 1.

If it is determined in step 110 that the engine rotation speed Ne is within a predetermined range before and after the idle rotation speed Na (Y), the routine proceeds to step 120, where the current refrigeration cycle 5 is set. High pressure P
d and the compressor rotation speed Nc to calculate the compressor drive torque τc (τc = A · F (Pd, Nc) +
B). Then, in step 130, the calculated compressor driving torque τc is compared with the maximum driving torque τm of the motor. If the compressor driving torque τc is larger than the maximum driving torque τm of the motor, the routine proceeds to step 140, where the condenser fan 7, the drive voltage Vcf is increased by β (for example, 1 V), and the process returns from step 220 to the main control routine. Then, the process proceeds to steps 110 and 120 again to calculate the compressor drive torque τc, and the determination is made again at step 130. At this time, since the amount of air blown by the condenser fan 7 increases and the condensing capacity of the compressor 6 improves, the high pressure Pd of the refrigeration cycle 5 decreases, so that the value of the compressor drive torque τc decreases. This behavior is
The determination is continued at step 110 except that the engine speed Ne deviates from the above range.

If the compressor drive torque τc is equal to or less than the maximum drive torque τm of the motor in the determination at step 130 (Y), the routine proceeds to step 150, where the motor drive is started. And step 160
, Dm + γ (for example, 5%) is set to the duty ratio Dm of the control signal supplied to the electric motor 3.
Then, the routine proceeds to step 170, where it is determined whether or not the current (effective value of current) Il supplied to the electric motor 3 is close to the rated current (maximum input current) Imax of the electric motor 3. In this determination, θ is, for example, 90%
If the supplied current Il is lower than Imax * 0.9 (Y), the routine proceeds to step 180, and if the engine rotational speed Ne is not equal to the virtual compressor rotational speed Nc by the motor, the routine proceeds to step 160. The duty ratio Dm is further increased by γ, and the virtual compressor rotation speed Nm by the electric motor 3 is increased.

By repeating this operation, in step 180, when the engine rotation speed Ne and the virtual compressor rotation speed Nc by the motor become equal, the routine proceeds to step 190, where the electromagnetic clutch (Mgcl) 4 is disconnected ( OFF) at the same time, the routine proceeds to step 200, where the duty ratio Dm is set to 100% and the output of the electric motor 3 is maximized.

In the determination in step 180, even if the engine speed Ne is not equal to the virtual compressor speed Nc, if the current value Il is 90% or more of the rated current Imax, Step 1
The routine proceeds to 90, in which the electromagnetic clutch 4 is disconnected, and at the same time, the output of the electric motor 3 is maximized. Thereby, it is possible to prevent a current higher than the rated current from flowing through the electric motor 3.

As described above, according to the present invention, as shown in FIG. 3, the engine speed Ne ranges from the rotation speed corresponding to the running speed to the rotation speed Na ± within a predetermined range around the idling rotation speed Na.
When it has decreased to λ (t1 to t2), the rotation speed Ncf of the condenser fan is increased, and accordingly, the high pressure Pd and the compressor drive torque τc decrease to become equal to or less than the maximum drive torque τm of the motor. (T3), the electric motor 3 is driven, the duty ratio Dm is gradually increased (the supply current Il is also increased accordingly), and the engine rotation speed Ne and the compressor rotation speed Nc assumed by the electric motor 3 are reduced. When they are equal (t4),
The electromagnetic clutch (Mgcl) 4 is disconnected (OFF) to release the connection with the engine 1, and the duty ratio Dm is set to 100%.
And the compressor 2 is driven with the electric motor 3 at the maximum output.

During the period from t1 to t2, as the engine speed Ne decreases, the high pressure Pd of the compressor 2 decreases.
And compressor load (compressor drive torque τc)
Does not change because the capacity variable mechanism 16 operates in a direction to maintain the high pressure Pd.

[0021]

As described above, according to the present invention, when the driving source is switched from the traveling engine to the electric motor, the capacity of the condenser fan is increased to reduce the high pressure of the refrigeration cycle. Therefore, since the load on the compressor can be reduced below the maximum output of the motor, switching from the traveling engine to the electric motor can be smoothly performed.

In switching, the output of the electric motor is gradually increased, and when the output of the electric motor increases to the output of the engine, the electromagnetic clutch is disconnected and the electric motor is set to the maximum output. This allows a smooth transition of the driving source from the engine for use to the electric motor.

Further, by increasing the capacity of the condenser fan to increase the condensation capacity of the condenser, the high pressure of the refrigeration cycle is reduced, so that the capacity of the refrigeration cycle can be maintained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram according to the present invention.

FIG. 2 is a flowchart illustrating a drive source switching control according to the present invention.

FIG. 3 is a timing chart of each signal.

[Explanation of symbols]

 Reference Signs List 1 driving engine 2 hybrid compressor 3 electric motor 4 electromagnetic clutch 5 refrigeration cycle 6 condenser 7 condenser fan 8 expansion valve 9 air conditioning duct 10 evaporator 11 high pressure sensor 12 low pressure sensor 15 control unit 16 variable capacity mechanism

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazuhiro Irie 39, Higashihara, Chiyo-ji, Oga-gun, Osato-gun, Saitama Prefecture F-term (reference) 3G093 AA07 AA12 BA22 CA04 DA01 DB25 EC02

Claims (3)

[Claims] 1. A hybrid compressor having at least a condenser, an expansion valve, and an evaporator, which constitutes a part of a refrigeration cycle of an air conditioner mounted on a vehicle, and has a driving engine and an electric motor as driving sources. Pressure detection means for detecting pressure; compressor rotation speed detection means for detecting the rotation speed of the hybrid compressor; engine rotation speed detection means for detecting the rotation speed of the traveling engine; A compressor driving torque calculating means for calculating a current compressor driving torque from the high pressure and the compressor rotation speed detected by the compressor rotation speed detecting means; and a rotational speed of the traveling engine detected by the engine rotational speed detecting means. Eye An engine rotational speed determining means for determining that led to Le state, when the rotational speed of the running engine is determined to have reached the idle state by the engine rotational speed determining means,
The compressor drive torque calculated by the compressor drive torque calculation means is compared with the maximum drive torque of the electric motor, and the high pressure of the refrigeration cycle is reduced until the compressor drive torque falls below the maximum drive torque of the electric motor. When the high pressure of the refrigeration cycle is reduced by the high pressure reducing means and the capacitor driving torque falls below the maximum driving torque of the electric motor, the driving of the electric motor is started. A motor rotation speed increasing means for gradually increasing the rotation speed of the electric motor; and a case where the rotation speed of the electric motor is increased by the motor rotation speed increasing means and coincides with the engine rotation speed detected by the engine rotation speed detection means. At the same time, the electromagnetic clutch is disconnected Drive source switching apparatus for a hybrid compressor which is characterized by comprising a drive source switching means for the rotational speed of the dynamic motor maximum. 2. The drive of a hybrid compressor according to claim 1, wherein said high-pressure reducing means gradually reduces the high-pressure by increasing the rotation speed of a condenser fan for sending cooling air to said condenser. Source switching device. 3. The drive source switching unit further includes: a motor input current to the electric motor, when the motor input current is close to an allowable current of the electric motor, the rotation speed of the electric motor and the driving engine. 3. The drive source switching device for a hybrid compressor according to claim 1, wherein even when the rotational speeds do not match, the electromagnetic clutch is disconnected to maximize the rotational speed of the motor. 4.