JPH06115346A - Freezing cycle controller for automobile - Google Patents

Abstract

PURPOSE:To provide a device to prevent an engine stop by making the capacity of a refrigerant compressor small and drive torque small at the time of vehicle sudden deceleration having been detected. CONSTITUTION:An engine controller 10 detects the sudden deceleration of a vehicle from a vehicular speed; an engine rotary speed; a throttle opening; and brake ON-OFF. When the engine controller 10 detects sudden deceleration, an air-conditioning controller 9 controls a capacity variable control valve 8 and makes the capacity of a refrigerant compressor 2 the minimum capacity. Then, the drive torque of the refrigerant compressor 2 does not become larger than the last previous idling, so an engine stalling at the time of idling after vehicle sudden stoppage can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to capacity control of an external variable refrigerant compressor driven by an engine for running a vehicle.

[0002]

2. Description of the Related Art An example of engine idling control will be described. When the vehicle is stopped and the engine starts idling, the engine control device that controls idling is
Memory learning the last intake air amount of the last idling,
The final intake air amount is used as a reference to adjust the load (auxiliary machinery load) that has changed during traveling to determine the intake air amount at the start of idling.

[0003]

On the other hand, the refrigerant compressor is usually driven by an engine for running the vehicle. Also,
Among the refrigerant compressors, the external variable refrigerant compressor has a larger fluctuation in driving torque of the refrigerant compressor than that of the fixed capacity refrigerant compressor. Therefore, when the capacity of the external variable refrigerant compressor changes from a small capacity to a large capacity during traveling, as the capacity of the refrigerant compressor increases (increases the drive load of the compressor) during traveling at the start of idling. Unless the intake air amount of the engine during idling (engine generated torque) is increased, engine stall may occur. Therefore, it is possible to constantly detect or estimate the drive torque of the refrigerant compressor and compensate for the increase or decrease of the drive torque to determine the intake air amount of the idling of the engine, but in order to detect or estimate the drive torque, It requires a dedicated sensor, and has the disadvantage of high cost.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. An object of the present invention is to provide a refrigeration cycle control device for an automobile capable of preventing engine stalling without detecting or estimating the driving torque of a refrigerant compressor. Is provided.

[0005]

A refrigeration cycle control device for an automobile according to the present invention includes a refrigeration cycle equipped with an external variable refrigerant compressor which is driven by an engine for driving a vehicle and whose capacity is varied by a signal from the outside. The technical means includes a sudden deceleration detecting means for detecting a sudden deceleration of the vehicle, and a control device for controlling the refrigerant compressor to have a small capacity when the sudden deceleration of the vehicle is detected.

[0006]

When the control device detects the sudden deceleration of the vehicle using the sudden deceleration detecting means, the control device reduces the capacity of the refrigerant compressor. Then, since the drive load of the refrigerant compressor is reduced when the vehicle is rapidly decelerated, even if idling is started when the vehicle is stopped, the engine load is not generated due to the drive load of the refrigerant compressor.

[0007]

As described above, the vehicle refrigeration cycle controller of the present invention determines the capacity of the refrigerant compressor during a sudden deceleration of the vehicle without detecting or estimating the driving torque of the refrigerant compressor. By making it small, engine stall can be prevented. Further, as the vehicle rapid deceleration detecting means, existing vehicle detecting means such as vehicle speed, engine rotation speed, throttle opening, and brake ON / OFF can be used, which can be realized at low cost.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a refrigeration cycle control device for an automobile of the present invention will be described based on an embodiment shown in the drawings. [Structure of Embodiment] FIGS. 1 and 3 show an embodiment of the present invention, and FIG. 1 is a schematic structure diagram of a refrigeration cycle controller for an automobile. The refrigeration cycle 1 shown in this embodiment has a well-known configuration including a refrigerant compressor 2, a refrigerant condenser 3, a receiver 4, a pressure reducing device 5, and a refrigerant evaporator 6, and the refrigerant compressor 2
Is driven by an engine 7 for running the vehicle.

The evaporator 6 is installed in the duct 11 of the air conditioner shown in FIG. The duct 11 sends air toward the passenger compartment, and the inside / outside air switching means 12 switches the inside air and the outside air to the inside of the duct 11 at the upstream end.
Equipped with. A blower 13, a refrigerant evaporator 6, and a heating unit 14 are sequentially arranged in the duct 11 from upstream to downstream. The heating means 14 includes a heater core 15 that radiates engine cooling water (warm water), an air mix damper 17 that adjusts a ratio of air flowing through a bypass passage 16 that bypasses the heater core 15 and air passing through the heater core 15. Become. At the downstream end of the duct 11, there are a face outlet 18 that blows air toward the passenger's chest, a defroster outlet 19 that blows air toward the windshield, and a foot outlet 20 that blows air toward the occupant's feet. A face damper 2 that adjusts the amount of air to each outlet is formed in the passage that leads to each outlet.
1, a defroster damper 22, and a foot damper 23 are provided.

The refrigerant compressor 2 is an external variable refrigerant compressor in which the compression capacity of the refrigerant is continuously or stepwise changed by the variable capacity control valve 8. The variable capacity control valve 8 for changing the compression capacity is an air conditioner. It is controlled by the control device 9.
The air-conditioning control device 9 determines that the temperature detected by the post-evaporation sensor 24 installed downstream of the air flow of the refrigerant evaporator 6 is
The capacity of the refrigerant compressor 2 is automatically controlled by the capacity variable control valve 8 so as to be within a predetermined range.

On the other hand, the engine 7 detects an NE sensor for detecting the rotational speed of the engine 7, a throttle sensor for detecting the throttle opening, a brake switch provided on the brake pedal for detecting the depression state of the brake pedal, and a vehicle speed. Therefore, the operating condition is controlled by the engine control device 10 based on the respective input signals of the vehicle speed sensor for detecting the rotation speed of the propeller shaft, the shift sensor for detecting the shift state of the transmission, and the like. The idling control by the engine control device 10 of the present embodiment is, as shown in the related art, when the vehicle stops and the engine 7 starts idling, the last intake air amount of the previous idling is stored in the internal storage device. The final intake air amount is used as a reference to adjust the load (auxiliary machinery load) that has changed during traveling to determine the intake air amount at the start of this idle. The start of idling is, for example, when the vehicle speed becomes zero, or when the rotation speed of the engine 7 enters a predetermined idle region.

The air conditioning controller 9 increases the capacity of the refrigerant compressor 2 when the vehicle is running, and the refrigerant compressor 2 is started at the time of idling.
An engine stall prevention function is provided to prevent engine stall due to an increase in drive torque of the. This engine stall prevention function
The engine control device 10 detects a sudden deceleration of the vehicle from the NE sensor, the throttle sensor, the brake switch, the vehicle speed sensor, and the shift sensor (above deceleration detection means of the present invention), and the engine control device 10 outputs a rapid deceleration signal. Is output to the air conditioning control device 9, the air conditioning control device 9 controls the refrigerant compressor 2 to the minimum capacity for a predetermined time (for example, 5 seconds) by the variable capacity control valve 8.

The operation of the engine stall prevention function will be described with reference to the flowchart of FIG. Engine control device 1
For 0, first, the vehicle speed is input (step S1), and the deceleration of the vehicle speed is calculated from the vehicle speed (step S2). Then, it is judged whether or not the calculated deceleration is equal to or more than a predetermined value (step S3). If the result of this determination is NO, the routine returns, and if YES, the rotation speed of the engine 7 is input (step S4), and the deceleration of the engine rotation is calculated from this rotation speed (step S5). Then, it is judged whether or not the calculated deceleration is equal to or more than a predetermined value (step S6). If the result of this determination is NO, the process returns, and if YES, a brake signal is input (step S7), and it is determined whether or not the brake is depressed (step S8). If the result of this judgment is NO, the routine returns. If it is YES, the throttle opening is input (step S9), and it is judged whether or not the throttle opening is below a predetermined value (step S10). If the result of this determination is NO, the process returns, and if YES, the position of the shift gear is input (step S11), and it is determined whether or not the gears are connected, that is, whether or not gear shifting is in progress (step S12). . If the result of this judgment is NO, return and YE
In the case of S, it is judged as "rapid deceleration" (step S13), and a "rapid deceleration signal" is output to the air conditioning controller 9 (step S13).
14).

When receiving the "rapid deceleration signal" from the engine control device 10, the air conditioning control device 9 activates a timer for counting a predetermined time (for example, 5 seconds) (step S1).
5) An interrupt signal for forcibly reducing the capacity of the refrigerant compressor 2 to the capacity variable control valve 8 is output (step S).
16). Then, it is judged whether or not the operation time of the timer has passed a predetermined time (step S17). This judgment result is NO
If YES, the process returns to step S16, and if YES, the small capacity control of the refrigerant compressor 2 is terminated (step S18), and then the process returns. It should be noted that the determination in step S12 as to whether or not the gear change is in progress is to determine whether or not the engine rotation speed has decreased due to an upshift, and is for eliminating malfunction.

[Operation of Embodiment] Next, the operation of the above embodiment will be briefly described. When the driving vehicle suddenly stops while the vehicle is traveling, the brake is depressed and the vehicle speed, the engine rotation speed, and the throttle opening are reduced. When the engine control unit 10 detects that the brake is stepped on, the vehicle speed, the engine speed, and the throttle opening have become small, and the transmission gear is not in the shift state, a "rapid deceleration signal" is output to the air conditioning control unit 9. . When receiving the "rapid deceleration signal", the air conditioning controller 9 forcibly sets the capacity of the refrigerant compressor 2 to the minimum capacity by the capacity variable control valve 8 for a predetermined time. Then, the drive torque of the refrigerant compressor 2 becomes the minimum torque. For this reason,
When the vehicle stops and starts the idling operation, the engine control unit 10 adjusts the load (auxiliary equipment load) changed during traveling, based on the last intake air amount of the previous idling. Even if the intake air amount at the time of starting the idling this time is determined, the drive torque of the refrigerant compressor 2 does not become larger than that at the previous time, so that the engine stall during idling can be prevented.

[Effects of the Embodiment] In the present embodiment, as shown by the above-described operation, the drive torque of the refrigerant compressor 2 is detected or estimated, and the load changed while the drive torque is running is taken into consideration. The engine stall can be prevented only by reducing the capacity of the refrigerant compressor 2 at the time of sudden deceleration of the vehicle without performing control for determining the intake air amount at the start of idling. Also, when the vehicle suddenly decelerates, the NE sensor, the throttle sensor,
Since existing detection means such as a brake switch, a vehicle speed sensor, and a shift sensor can be used, it is not necessary to newly provide a sensor, and the present invention can be realized at low cost.

[Modification] In the above embodiment, when the rapid deceleration is determined, the capacity of the refrigerant compressor is reduced, but the cooling load (outside air temperature, blower air volume, suction air temperature, target cooling temperature). Is not greatly increased from the end of the previous idling, it is determined that the drive torque of the refrigerant compressor at the last idling last time is not greatly increased, and in that case, control is performed to reduce the capacity of the refrigerant compressor. It may be provided so as not to exist. In the above embodiment, five judgment criteria of vehicle speed, engine speed, brake signal, throttle opening, and transmission gear position are provided for judgment of sudden deceleration, but sudden deceleration is performed by combining one or more of these criteria. May be determined. Further, although the cost is increased, a sensor for detecting a sudden deceleration may be provided. In the above embodiment, when the rapid deceleration is determined, the capacity of the refrigerant compressor is reduced for a predetermined time, but the capacity of the refrigerant compressor may be reduced for a predetermined time after the vehicle stops. . In addition, the small capacity control of the refrigerant compressor is canceled when either one of the first predetermined time after the rapid deceleration is determined and the second predetermined time after the vehicle is stopped has elapsed. It may be provided in. When the vehicle speed is equal to or higher than a predetermined speed, it may be provided so as not to perform the small capacity control even if the rapid deceleration is determined. If the rotation speed of the engine is equal to or higher than a predetermined speed, the small capacity control may not be performed even if the rapid deceleration is determined. This is because if the vehicle does not come to a stop, engine stall does not occur, so if the vehicle does not stop even after deceleration, the capacity of the refrigerant compressor is reduced and the capacity of the refrigeration cycle is reduced. It is to prevent it. Although the capacity of the refrigerant compressor is controlled to the minimum capacity during sudden deceleration, it may be controlled to a small capacity such that engine stall does not occur. Although an example in which the sudden deceleration is determined by the engine control device is shown, the sudden deceleration may be determined by the air conditioning control device. In the idling control of the above-mentioned embodiment, an example in which the last engine load at the last idling is learned and the first data at the start of the idling this time is shown is shown. The application of the present invention is also useful for idling control by other methods, such as detecting an audio signal, a brake lamp, etc., and performing idling control from the load amount thereof.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a refrigeration cycle control device for an automobile.

FIG. 2 is a schematic configuration diagram of a duct of the air conditioner.

FIG. 3 is a flowchart showing an operation of an engine stall prevention function.

[Explanation of symbols]

 1 Refrigeration cycle 2 Refrigerant compressor 7 Engine 9 Air-conditioning controller 10 Engine controller

Claims (1)

[Claims] 1. A refrigeration cycle provided with an external variable refrigerant compressor driven by a vehicle running engine and having a variable capacity according to a signal from the outside, and a rapid deceleration detection means for detecting a rapid deceleration of the vehicle, A refrigeration cycle control device for an automobile, comprising: a control device for controlling the refrigerant compressor to a small capacity when a rapid deceleration of the vehicle is detected.