JP2005239065A - Air-conditioning control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-conditioning control device for a vehicle capable of smoothly maintaining constant speed traveling control even if external vehicle speed variation factor exists. <P>SOLUTION: The air-conditioning control device for the vehicle is provided with an internal combustion engine 2 mounted on the vehicle 1; a vehicle speed detection means 3 for detecting the vehicle speed of the vehicle 1; constant speed traveling means 15, 17 for maintaining predetermined speed and traveling the vehicle utilizing the detection result of the vehicle speed detection means 3; an air conditioner 5 for driving a variable displacement compressor 6 using an output of the internal combustion engine 2; and a control means 16 for controlling driving of the compressor 6. The vehicle speed variation during traveling that a predetermined speed by the constant speed traveling means 15, 17 is maintained is detected using the vehicle speed detection means 3. The compressor 6 is controlled by the control means 16 so as to suppress the vehicle speed variation. Thereby, an air-conditioning load of the internal combustion engine is adjusted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air conditioning control device for a vehicle that performs constant speed traveling control and air conditioner control for traveling the vehicle while maintaining a predetermined speed.

A technology (cruise control system) for driving a vehicle while keeping the vehicle speed constant, such as on a highway, has already been put into practical use. This technology makes it possible for the driver to travel while maintaining the set vehicle speed without stepping on the accelerator, which is useful for reducing fatigue during driving. Note that if the brake is depressed during the constant speed traveling control, the constant speed traveling control is cancelled. Recently, not only keeping the vehicle speed constant, but also detecting the inter-vehicle distance from the vehicle in front using a laser sensor, etc. during constant-speed driving control, and reducing the engine output or hydraulic brake when the inter-vehicle distance decreases. Some have been put into practical use that operate or brake the driver (laser cruise control system). In such a case, after the inter-vehicle distance is ensured, control for increasing the vehicle speed to the preset vehicle speed can be performed.
JP 2003-139440 A

  During such constant speed traveling control, the vehicle speed may fluctuate due to road gradients or wind effects. If the road gradient is uphill, the vehicle speed will slow down, and even if the headwind becomes strong, the vehicle speed will slow down. In the constant speed running control, the output of the engine 2 is adjusted to absorb such fluctuations in the vehicle speed so that the vehicle speed becomes constant. Specifically, the throttle valve is of an electronic control type, and the throttle opening is controlled (in addition, fuel injection amount control can be performed in coordination) to absorb vehicle speed fluctuations. The invention described in [Patent Document 1] described above is also intended to absorb vehicle speed fluctuation during constant speed traveling control by adjusting the throttle opening.

  However, the sensitivity of the engine output fluctuation to the throttle opening change is sensitive, and overshoot and undershoot are likely to occur. Depending on the situation, in the case of an automatic transmission vehicle or the like, there is a concern that a gear change may occur due to an overshoot or undershoot, resulting in smooth running. Therefore, there has been a demand for an improvement that improves such a problem. Therefore, an object of the present invention is to provide a vehicle air conditioning control device that can maintain constant speed traveling control smoothly even if there is an external vehicle speed fluctuation factor.

  The vehicle air conditioning control device according to claim 1 is a vehicle in which an internal combustion engine mounted on a vehicle, vehicle speed detection means for detecting a vehicle speed of the vehicle, and a predetermined speed is maintained using a detection result of the vehicle speed detection means. A constant speed traveling means for traveling the vehicle, an air conditioner for driving the variable displacement compressor using the output of the internal combustion engine, and a control means for controlling the driving of the compressor, and maintaining a predetermined speed by the constant speed traveling means. The vehicle speed variation during traveling is detected using vehicle speed detection means, and the compressor is controlled by the control means so as to suppress the vehicle speed fluctuation, thereby adjusting the air conditioner load of the internal combustion engine.

  According to a second aspect of the present invention, in the air conditioning control device for a vehicle according to the first aspect, the air conditioner includes a cold storage unit that stores the generated cold heat, and the vehicle interior is provided by the cold heat stored in the cold storage unit. It is characterized by cooling.

  According to the air conditioning control device for a vehicle according to claim 1, the air conditioner load on the internal combustion engine is changed by changing the capacity (refrigerant discharge capacity) of the variable displacement compressor of the air conditioner to change the vehicle speed during the constant speed traveling control. Fluctuate and absorb. The vehicle driving force adjustment due to air conditioner load change is not too sensitive and does not cause overshoot or undershoot in vehicle speed control. Further, the compressor capacity control has good responsiveness and good controllability. For this reason, constant speed traveling control can be smoothly maintained even when there are external vehicle speed fluctuation factors (changes in road gradient, changes in the influence of wind, etc.).

  Further, according to the vehicle air conditioning control device of the second aspect, the cold energy stored in the cold heat portion can be used even if the compressor is variably controlled to absorb the vehicle speed fluctuation during the constant speed traveling control. Therefore, the air conditioner performance is not sacrificed.

  An embodiment of the control device of the present invention will be described below. The main components of a vehicle having the control device of this embodiment are shown in FIG. The driving force that drives the vehicle 1 is generated by the engine 2 that is an internal combustion engine. The engine 2 itself is a known general engine. The output of the engine 2 is transmitted to driving wheels via a transmission and a differential gear (not shown) to drive the vehicle 1. Further, an alternator (generator) 4 that is driven by utilizing a part of the output of the engine 2 and a compressor 6 of the air conditioner 5 are attached to the engine 2. The alternator 4 and the compressor 6 are auxiliary machines that generate energy using the output of the engine 2.

  The alternator 4 is an AC generator, and includes a rectifier that rectifies the generated AC current into a DC current and an IC regulator that adjusts the voltage to obtain a constant output, and outputs DC power. The electric power generated by the alternator 4 is used as it is by the engine 2 and other auxiliary machines as well as for charging the battery 7. The battery 7 stores the electric energy generated by the alternator 4. The alternator 4 can control the power generation amount by controlling the excitation current.

  The air conditioner 5 introduces air cooled by a heat exchanger 8 serving as a cooling heat source for cooling the vehicle interior or air heated by a heater core (not shown) serving as a heat source into the vehicle interior by a blower fan 9. Car air conditioning (or dehumidification) in the passenger compartment. In the air conditioner 5, the compressor 6, the condenser 10, the cool storage unit 12, and the compressor 6 form one refrigerant circulation system. Further, another circulation system is formed between the cold storage unit 12 and the heat exchanger 8. That is, the cold generated by the air conditioner 5 is temporarily stored in the cold storage unit 12, and the cold heat of the cold storage unit 12 is introduced into the vehicle via the heat exchanger 8. The cold storage unit 12 and the battery 7 described above function as a storage device (energy storage unit) 11 that stores energy.

  The generation of cold heat in the air conditioner 5 will be briefly described. The refrigerant is compressed by the compressor 6, the heat is taken away by the condenser 10, and the refrigerant is liquefied, and the refrigerant is easily vaporized by an expansion valve built in the cool storage unit 12. The regenerator material in the regenerator 12 is cooled by the heat of vaporization at this time. The cold storage unit 12 accumulates cold heat by keeping the temperature of the internal cold storage material low. The refrigerant discharged from the cold storage unit 12 is compressed again by the compressor 6 and circulates repeatedly through the compressor 6 -the condenser 10 -the cold storage unit 12 described above.

  Further, the inside of the circulation pipe between the cold storage unit 12 and the heat exchanger 8 is also filled with the refrigerant, and the cold heat stored in the cold storage unit 12 is transmitted to the heat exchanger 8 in the passenger compartment by the circulation of the refrigerant. It is done. The cold heat of the heat exchanger 8 is introduced into the vehicle interior by the blower fan 9 described above. As the refrigerant filled in the circulation pipe between the cold storage section 12 and the heat exchanger 8 described above, liquid such as water, brine (brine), ethylene glycol solution, or gas such as carbon dioxide is used. The cold storage unit 12 includes a temperature sensor that detects an internal cold storage material temperature and a refrigerant temperature. The heat exchanger 8 also has a built-in temperature sensor.

  The above-described compressor 6 of the present embodiment is of an externally controlled variable capacity type, and can continuously and variably control the refrigerant discharge amount by a signal (DUTY signal) from the outside. The structure is of a known general swash plate type, and the capacity is changed by changing the inclination of the swash plate. The inclination of the swash plate is controlled by the DUTY signal described above. The compressor 6 can have a capacity of zero so that the refrigerant is not discharged, and does not require a clutch or the like.

  The alternator 4 described above is connected to an electronic control unit (ECU) 15 that controls the engine 2, and its power generation amount is variably controlled. A wheel speed sensor (vehicle speed detection means) 3 attached to each wheel is also connected to the engine ECU 15. The wheel speed sensor 3 detects the rotational speed of the wheel, and the speed of the vehicle 1 can be detected from the detection result. The above-described compressor 6 is connected to an air conditioner ECU (control means) 16 that controls the air conditioner 5, and its refrigerant protrusion amount (compressor capacity) is variably controlled. The air conditioner ECU 16 is also connected with a vehicle interior temperature sensor 20 for detecting the temperature in the vehicle interior and an operation panel 21. The operation panel 21 sets the set temperature, the air blowing mode, the air volume, and the like. The above-described control DUTY signal for the compressor 6 is also generated by the air conditioner ECU 16 and sent to the compressor 6. The engine ECU 15 and the air conditioner ECU 16 are connected to an integrated ECU 17 that comprehensively controls various controls of the entire vehicle 1.

  The integrated ECU 17 also functions as a control unit that performs constant speed traveling control in which the vehicle 1 travels while maintaining a set predetermined vehicle speed. The integrated ECU 17 controls the output of the engine 2 in cooperation with the engine ECU 15 or the like during constant speed running control (also performs transmission gear change and brake control if necessary), and keeps the speed of the vehicle 1 constant. . At this time, the vehicle speed detected by the wheel speed sensor 3 described above is used for constant speed traveling control. In the constant speed travel control, control may be performed in consideration of the inter-vehicle distance from the preceding vehicle. In this case, means (for example, a radar sensor, a millimeter wave sensor, etc.) for detecting the inter-vehicle distance from the preceding vehicle is also connected to the integrated ECU 17. These ECUs 15 to 17 coordinate the control of the engine 2 and the air conditioning control by the air conditioner 5. The battery 7 is also connected to the integrated ECU 17, and the voltage of the battery 7 is monitored by the integrated ECU 17.

Next, control using the above-described apparatus will be described. A control flowchart according to the present embodiment is shown in FIG. The control of the flowchart of FIG. 2 is repeatedly executed at predetermined time intervals. First, as shown in FIG. 2, it is determined whether or not the constant speed traveling control is being executed, which is whether or not the target vehicle speed (set vehicle speed) in the constant speed traveling control is set (step 200). . In a cruise control system or the like, the procedure is usually performed by pressing a set button during 80 km running to set the target vehicle speed for constant speed running control to 80 km.
When the target vehicle speed is not set, that is, when the constant speed traveling control is not performed and Step 200 is negative, the control of the flowchart of FIG. 2 is temporarily ended.

  On the other hand, when the target vehicle speed is set, that is, when the constant speed traveling control is performed and step 200 is affirmed, the actual vehicle speed of the vehicle 1 is obtained from the detection result of the wheel speed sensor 3 next. (Step 210). Since the constant speed traveling control is being performed, the actual vehicle speed is naturally detected in this control. Next, the detected actual vehicle speed is compared with the target vehicle speed. Specifically, it is determined whether or not the actual vehicle speed exceeds the target vehicle speed (step 220). If step 220 is positive, the actual vehicle speed is higher than the target vehicle speed. In this case, the control DUTY ratio of the compressor 6 is changed so that the load (compressor load) applied to the engine 2 by the compressor 6 is increased (step 230).

  Here, when the control DUTY ratio is increased, the capacity of the compressor 6 is increased, the refrigerant discharge amount is increased, and the compressor load is increased. When the compressor load is changed in step 230, the control DUTY ratio is increased by a predetermined amount. If the control of the flowchart of FIG. 2 is repeatedly executed and step 220 is affirmed again, the control DUTY ratio of the compressor 6 is increased by the same amount. Thus, the control DUTY ratio (compressor load) is gradually increased. When the compressor load is increased, the load on the engine 2 is increased, the amount of engine output used for driving the vehicle 1 is reduced, and the vehicle speed is reduced. As a result, the actual vehicle speed of the vehicle 1 approaches the target vehicle speed.

  On the other hand, when step 220 is denied, the actual vehicle speed is slower than the target vehicle speed. In this case, the control DUTY ratio of the compressor 6 is changed so that the load (compressor load) applied to the engine 2 by the compressor 6 is reduced (step 240). Here, when the control DUTY ratio is reduced, the capacity of the compressor 6 is reduced, the refrigerant discharge amount is reduced, and the compressor load is reduced. When the compressor load is changed in step 240, the control DUTY ratio is decreased by a predetermined amount. If the control of the flowchart of FIG. 2 is repeatedly executed and step 220 is negative again, the control DUTY ratio of the compressor 6 is decreased by the same amount. Thus, the control DUTY ratio (compressor load) is gradually reduced. By reducing the compressor load, the engine output reduced for the air conditioner is reduced, the amount used for driving the vehicle 1 can be increased, and the vehicle speed is increased. As a result, the actual vehicle speed of the vehicle 1 approaches the target vehicle speed.

  The engine output fluctuation due to the compressor load fluctuation is not as sensitive as the engine output fluctuation caused by the intake air amount adjustment by the throttle valve. For this reason, as described above, when the load of the compressor 6 of the air conditioner 5 is variably controlled so as to absorb the fluctuation in the vehicle speed during the constant speed traveling control, this is converged to the target vehicle speed when there is a fluctuation in the vehicle speed. It is difficult to cause overshoot and undershoot. As a result, the constant speed traveling control can be maintained smoothly.

  Moreover, in this embodiment, since the cold storage part 12 which stores the cold heat which the air conditioner 5 produced | generated is provided, even if it changes the capacity | capacitance of the compressor 6 at the time of constant speed driving control, the cold heat stored in the cold storage part 12 Can be used, and it can be avoided that the cooling effect is deteriorated or the cooling cannot be performed. In addition, the control apparatus of this invention is not limited to embodiment mentioned above. In the above-described embodiment, the integrated ECU 17, the engine ECU 15, and the air conditioner ECU 16 share the control, but the way of sharing is not limited to the above-described embodiment. Moreover, when using ECU for the control apparatus of this invention, it does not mean that the number must be three.

It is a block diagram which shows the structure of the vehicle which has one Embodiment of the control apparatus of this invention. It is a control flowchart by one Embodiment of the control apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine (internal combustion engine), 3 ... Wheel speed sensor (vehicle speed detection means), 5 ... Air conditioner, 6 ... Compressor, 8 ... Heat exchanger, 9 ... Blower fan, 10 ... Condenser, 12 ... Cold storage 15, engine ECU (constant speed traveling means), 16 air conditioner ECU (control means), 17 integrated ECU (constant speed traveling means).

Claims (2)

An internal combustion engine mounted on the vehicle, vehicle speed detection means for detecting the vehicle speed of the vehicle, constant speed running means for running the vehicle while maintaining a predetermined speed using a detection result of the vehicle speed detection means, An air conditioner for driving the variable displacement compressor using the output of the internal combustion engine, and a control means for controlling the driving of the compressor;
An air conditioner for the internal combustion engine is detected by using the vehicle speed detecting means to detect vehicle speed fluctuations during running while maintaining a predetermined speed by the constant speed running means, and controlling the compressor by the control means so as to suppress the vehicle speed fluctuations. A vehicle air conditioning control device characterized by adjusting a load.   2. The vehicle air conditioning control device according to claim 1, wherein the air conditioner includes a cold storage unit that stores the generated cold heat, and performs cooling of the vehicle interior by the cold heat stored in the cold storage unit.

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