JP2005098341A - Control device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of a vehicle including an air conditioner for lengthening the fuel cut time during deceleration. <P>SOLUTION: An air conditioner is needed for keeping the amenity, and it may be switched off in some case and not be switched off depending on the condition. In the case where the air condition may be switched off judging from the operating condition of the air conditioner, the vehicle speed for operating the deceleration lock-up control or the rotational frequency of an input shaft of an automatic transmission is lowered than that in the case where the air conditioner can not be switched off. In the case where the air condition may be switched off judging from the operating condition of the air conditioner, the air conditioner is switched off to set lower the fuel cut permissible rotational frequency, and the deceleration lockup control is operated to keep the engine rotational frequency comparatively high to lengthen the fuel cut time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention generally relates to a vehicle control device, and more particularly to a control device capable of switching a vehicle speed of a lockup operation during deceleration of a vehicle equipped with an air conditioner.

  In general, an air conditioner mounted on an automobile operates using an engine as a drive source. For example, an air conditioner having a cooling function has a refrigeration cycle system to create a low temperature state. The refrigeration cycle system includes a compressor that operates using an engine as a drive source.

  When the compressor is driven by the engine and the refrigerant circulates in the refrigeration cycle system, the air sent to the passenger compartment is cooled and the passenger compartment is cooled. Here, the electromagnetic clutch provided between the engine and the compressor can be disconnected from each other.

  The control device for controlling the air conditioner monitors the degree of cooling request and the operating state of the engine from time to time, and turns on and off the electromagnetic clutch based on the monitoring result, thereby improving the cooling effect obtained by the air conditioner. Control.

  On the other hand, in order to improve the fuel consumption of the engine, a technique of stopping fuel supply when the engine is decelerated, that is, a fuel cut is generally employed. In general, this type of fuel cut technique is stopped when the engine speed drops to a predetermined reference value after the fuel cut is performed, and the control is returned to the normal control for fuel supply.

  This return to normal control prevents the occurrence of engine stall after deceleration. And the reduction effect of the fuel consumption by a fuel cut can be heightened by setting the rotation speed after this return as low as possible.

  By the way, in what drives a compressor by an engine like the said air conditioner, the load resulting from a compressor will be added to an engine during the action | operation of an air conditioner. Therefore, when the engine is decelerated and the fuel is cut and the compressor load is applied to the engine, the engine speed decreases more rapidly by the amount of the compressor load. The engine stall tends to occur due to inertia.

  Therefore, when the fuel cut is performed during the operation of the air conditioner, it is necessary to set the return rotational speed from the fuel cut to a higher value than that when the air conditioner is stopped. Therefore, the fuel cut reduction effect of the fuel cut is reduced as much as the return rotational speed is set higher. In order to avoid this, it is necessary to appropriately control the operation of the air conditioner in accordance with the fuel cut during deceleration of the engine.

  Japanese Utility Model Laid-Open No. 2-50038 discloses a deceleration control device that stops the operation of an air conditioner when the fuel is cut. In this deceleration control device, the control unit disconnects the compressor of the air conditioner from the engine by turning off the electromagnetic clutch simultaneously with the fuel cut.

  Thereby, the load of the compressor is not applied to the engine at the time of deceleration, and the decrease in the rotational speed of the engine becomes slow. As a result, it is possible to set the return rotational speed from the fuel cut to a low value to some extent, and the effect of reducing fuel consumption by the fuel cut can be improved.

  Japanese Patent No. 3214800 discloses an air conditioner control device that performs an air conditioning cut once when a fuel cut is performed during engine deceleration, and prohibits the execution of the air conditioning cut for a predetermined period after the air conditioning cut. Has been.

According to this control device, when the fuel cut is executed during deceleration, the load on the air conditioner applied to the engine is reduced. Since the air conditioning cut is prohibited for a predetermined period after the air conditioning cut is performed once, the air conditioner is not stopped for a long time. As a result, when the engine is decelerated, it is possible to prevent deterioration of the fuel consumption of the engine and maintain the air conditioning effect by the air conditioner well.
On the other hand, the conventional deceleration lockup control of the lockup mechanism of the torque converter is permitted when the vehicle speed and the input shaft rotation speed of the automatic transmission are equal to or higher than a predetermined value. In addition, when the compressor of the air conditioner is in operation, the fuel cut permission rotational speed is high, and thus there is a case where the fuel cannot be cut even if the deceleration lockup control is operated.

For this reason, in the conventional deceleration lockup control, the deceleration lockup control is operated only when the compressor is operating and at a higher vehicle speed and at the input shaft rotation speed of the automatic transmission.
Japanese Utility Model Publication No. 2-50038 Japanese Patent No. 3214800

  In the conventional deceleration lock-up control, the deceleration lock-up control is activated only when the compressor of the air conditioner is operating and at a higher vehicle speed and the input shaft rotation speed of the automatic transmission. Even if the cut is made, the lock-up control does not operate, so the engine rotation tends to decrease and the fuel cut time is shortened.

  That is, whether or not the fuel cut is entered or whether or not the fuel cut is continued is regulated by the rotational speed of the engine. Therefore, even if the input shaft of the automatic transmission is relatively high, the deceleration lock is performed as before. If the up control is not activated, there is a problem that the engine speed decreases and the fuel cut time is shortened.

  Therefore, an object of the present invention is to provide a vehicle control device equipped with an air conditioner that can lengthen the fuel cut time during deceleration traveling.

  FIG. 1 shows a principle block diagram of the present invention. The vehicle targeted by the control device of the present invention is driven by the engine 2, the torque converter 4 with the lock-up mechanism 6 connected to the engine 2, the automatic transmission 8 connected to the torque converter 4, and the engine 2. The air conditioner 10 and the control device 12 of the lockup mechanism 6 are provided.

  The vehicle control device according to claim 1 includes a deceleration determination means 13 for determining when the vehicle is decelerating and a lockup control device when the first determination condition is met when the air conditioner 10 is operating and the vehicle is decelerating. 12 includes first determination means 14 for operating the lockup mechanism 6 to lockup the lockup mechanism 6 to the fastening side. The deceleration determination means 13 determines that the vehicle is decelerating when the throttle valve is off, for example.

  The vehicle control device further includes a forced inoperability determining means 18 for determining whether the air conditioner 10 can be switched from the operating state to the inactive state based on the operating state of the air conditioner 10, and the forced inoperability determining means 18. When it is determined that the air conditioner 10 can be switched from the operating state to the non-operating state, the lockup control device 12 is operated and the lockup mechanism 6 is engaged when the vehicle satisfies the second determination condition when the vehicle is decelerating. The second determination means 16 for performing the lock-up control is included.

  The compulsory non-operable determination means 18 not only completely turns off the air conditioner but also in an operation state currently required for the air conditioner (for example, a state where the air conditioner is operating at a set temperature of 25 ° C.). On the other hand, in other words, it includes determining whether it is possible to reduce the output of the air conditioner and thereby reduce the load on the engine with respect to the load on the engine in the operating state.

  According to the second aspect of the present invention, when the forced inoperability determining means 18 determines that the air conditioner 10 can be switched from the operating state to the inactive state, the fuel cut to the engine is executed when the vehicle decelerates. The permitted engine speed is set to a predetermined value smaller than the speed when the air conditioner 10 is operated.

  According to a third aspect of the present invention, when the air conditioner is not operated and the vehicle is decelerated, the lockup control device is operated to lock up the lockup mechanism to the fastening side when the third determination condition is met. Third control means for controlling is further provided, and the first, second and third determination means 14, 16 and 20 are each composed of the vehicle speed and the input shaft speed of the automatic transmission. A vehicle control device that satisfies the relationship of third determination condition ≦ second determination condition <first determination condition is provided.

  According to the first aspect of the present invention, when it is determined by the forced inoperability determination means that the air conditioner can be switched from the operating state to the inactive state, the lockup is performed when the second determination condition is met when the vehicle is decelerated. Since the mechanism is locked up to the fastening side, the engine speed can be kept relatively high, and the fuel cut time can be extended to improve fuel efficiency.

  According to the second aspect of the present invention, when it is determined by the forced inoperability determining means that the air conditioner can be switched from the operating state to the inactive state, the fuel cut to the engine is permitted when the vehicle decelerates. Since the engine speed is set to a value smaller than the engine speed when the air conditioner is in operation, the fuel cut time can be lengthened and fuel efficiency can be improved.

  According to the third aspect of the present invention, the first, second, and third determination conditions are each configured by the vehicle speed and the input shaft rotational speed of the automatic transmission. Since the relationship between the vehicle speed and the input shaft rotational speed is set to satisfy the relationship of the third determination condition ≦ the second determination condition <the first determination condition, the lockup control can be performed optimally, Since the cut time can be controlled, fuel consumption can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 is a diagram showing a configuration of an automatic transmission mounted on a vehicle according to an embodiment of the present invention and a control device for the automatic transmission, and an automatic transmission 26 is connected to a crankshaft 24 of the internal combustion engine 22.

  The automatic transmission 26 is connected to the crankshaft 24, and includes a torque converter 28 having a pump impeller 28a and a turbine runner 28b, a lockup clutch 30 for connecting the pump impeller 28a and the turbine runner 28b, and an output of the torque converter 28. A multi-stage transmission gear mechanism 32 connected to the side, and a hydraulic control mechanism 34 for controlling the operation of the lock-up clutch 30 and the multi-stage transmission gear mechanism 32.

  The hydraulic control mechanism 34 includes an on / off type solenoid valve (hereinafter referred to as “A solenoid valve”) 34 a that switches between engagement and disengagement of the lockup clutch 30, and an A solenoid valve 34 a that is on. A duty control type solenoid valve (hereinafter referred to as “B solenoid valve”) 34b for controlling the engagement pressure when in the combined state, and a speed change actuator 34c for controlling the shift position (gear ratio) of the gear mechanism 32. Yes.

  The A solenoid valve 34a, the B solenoid 34b, and the speed change actuator 34c are connected to an electronic control unit (hereinafter referred to as “ECU”) 36 for automatic transmission control. The ECU 36 is connected via the A solenoid valve 34a and the B solenoid valve 34b. The engagement state of the lockup clutch 30 is controlled, and the shift position of the multi-stage transmission gear mechanism 32 is controlled via the transmission actuator 34c.

  The automatic transmission 26 is provided with a shift position sensor 38 for detecting the shift position SRTDG of the multi-stage transmission gear 32, and the detection signal is supplied to the ECU 36.

  The output of the engine 22 is transmitted from the crankshaft 24 to the left and right drive wheels 42 and 44 through the torque converter 28, the gear mechanism 32, and the differential device 40 in order, and drives them. A vehicle speed sensor 46 that detects the vehicle speed VP of the vehicle is provided on the output side of the automatic transmission 26, and the detection signal is supplied to the ECU 36.

  The engine 22 includes a throttle valve opening sensor 52 that detects an opening θTH of a throttle valve 50 provided in the middle of the intake pipe 48, an engine water temperature sensor 54 that detects an engine cooling water temperature TW, and an engine speed NE. An engine speed sensor 56 for detection is provided, and detection signals from these sensors are supplied to the ECU 36. The engine speed sensor 56 outputs a TDC signal pulse at a predetermined crank angle position every 180 degrees rotation of the crankshaft 24 and supplies it to the ECU 36.

  Further, a throttle actuator 58 made of, for example, an electric motor is connected to the throttle valve 50, and this throttle actuator 58 is connected to the ECU 36. The ECU 36 is connected to an accelerator opening sensor 60 for detecting the amount of depression of the accelerator pedal of the vehicle (hereinafter referred to as “accelerator opening”) APFZ, and the detection signal is supplied to the ECU 36.

  The ECU 36 controls the throttle valve opening θTH in accordance with the accelerator opening APFZ and the like. That is, in this embodiment, the accelerator pedal and the throttle valve 50 are not mechanically connected, and the throttle valve opening θTH is controlled according to the accelerator opening AP and other operating conditions.

  The ECU 36 is further connected to a selection lever position sensor 62 for detecting a selection lever position for selecting an operation mode of the automatic transmission 26 and a brake switch 64 for detecting depression of a brake pedal. It is supplied to the ECU 36.

  The ECU 36 is connected to an engine control electronic control unit (not shown) that controls the amount of fuel supplied to the engine 22 (opening time of the fuel injection valve), ignition timing, and the like, and transmits control parameter information to each other. It is configured as follows.

  The ECU 36 shapes an input signal from the various sensors described above, corrects the voltage level to a predetermined level, and converts an analog signal value into a digital signal value, and a central processing circuit (CPU). Drive signals to a storage circuit including a ROM and a RAM for storing various calculation programs executed by the CPU, a shift map and calculation results described later, and the A solenoid valve 34a, the B solenoid valve 34b, and the speed change actuator 34c. And an output circuit.

  The ECU 36 controls the engagement state, the shift position, and the throttle valve opening θTH of the lockup clutch 30 based on detection signals from various sensors. In addition, the process demonstrated with reference to a flowchart below is performed by CPU of ECU36.

  Hereinafter, the forced air conditioner (hereinafter abbreviated as “air conditioner”) off process will be described in detail with reference to the flowchart of FIG. 3. First, in step 10 (abbreviated as S10 in the drawing), it is determined whether or not the throttle is on. When the throttle is on, the vehicle is in an accelerated traveling state, and when the throttle is off, the vehicle is in a decelerating traveling state.

  If it is determined in step 10 that the throttle is on, the process proceeds to step 11 to determine whether the air conditioner is operating. If the air conditioner is in operation, the routine proceeds to step 12 where it is determined whether or not the vehicle speed V is greater than V1. Here, V1 is, for example, 50 to 55 km / h.

  When the vehicle speed V is higher than V1, the routine proceeds to step 13, where it is determined whether or not the input shaft speed of the automatic transmission is higher than NM1, NM1 is 1800-1900 rpm, for example. If it is determined in step 13 that the input shaft rotational speed is greater than NM1, the routine proceeds to step 14 where a deceleration lockup permission flag is set.

  If it is determined in step 11 that the air conditioner is not operating, the process proceeds to step 15 to determine whether or not the vehicle speed V is greater than V2. Here, V2 is 35-40 km / h, for example. When the vehicle speed is higher than V2, the routine proceeds to step 16, where it is determined whether or not the input shaft speed of the automatic transmission is higher than NM2.

  NM2 is 1300-1400 km / h, for example. If it is determined in step 16 that the input shaft speed is greater than NM2, the routine proceeds to step 14 where a deceleration lockup permission flag is set.

  On the other hand, if it is determined in step 12 that the vehicle speed V is V1 or less, if it is determined in step 13 that the input shaft speed is NM1 or less, if it is determined in step 15 that the vehicle speed V is V2 or less, and if in step 16 If it is determined that the input shaft speed is NM2 or less, the routine proceeds to step 17 where 0 is substituted for the deceleration lockup permission flag. That is, the deceleration lockup is not permitted.

  If it is determined in step 10 that the throttle is off, that is, if it is determined that the vehicle is in a decelerating running state, the process proceeds to step 18 to determine whether the air conditioner is operating. If the air conditioner is operating, the process proceeds to step 19 to determine whether or not the air conditioner can be turned off.

  When it is possible to turn off the air conditioner, it is determined from a combination of the following parameters, for example.

  a) The temperature of the evaporator of the air conditioner is sufficiently low.

  b) The passenger compartment is close to the temperature required by the driver.

  c) When it can be determined that the comfort can be maintained even when the air conditioner is turned off for several seconds in consideration of the outside air temperature.

  d) There is almost no temperature change in the wind from the air conditioner for several seconds.

  Further, in addition to turning off the air conditioner according to the operating state of the air conditioner, it is possible to perform control to weaken the operating state of the air conditioner, that is, to reduce the output. In this case, conditions can be appropriately set for the determination of the above parameters, and the degree of reduction in the output of the air conditioner can be determined in advance within a range in which comfort can be maintained with respect to the parameter conditions.

  Depending on the strength of the operating state of the air conditioner, that is, the degree of reduction of the output, the lockup rotation speed at the time of deceleration and the fuel cut rotation speed of the engine can be changed. In this case, the greater the degree of reduction in the output of the air conditioner, the higher the lock-up rotation speed at the time of deceleration and the fuel cut rotation speed of the engine are preferably set, and appropriate control can be performed according to the operating state. .

  If it is determined in step 19 that the air conditioner cannot be turned off, the process proceeds to step 20 to determine whether the vehicle speed V is greater than V3. Here, V3 is, for example, 40 to 45 km / h.

  If it is determined that the vehicle speed V is greater than V3, the routine proceeds to step 21, where it is determined whether or not the engine speed Ne is greater than Ne4. Here, Ne4 is 1500-1600 rpm.

  If it is determined at step 21 that the engine speed Ne is greater than Ne4, the routine proceeds to step 22 where it is determined whether or not a deceleration lockup flag is set. If it is determined that the flag is set, the routine proceeds to step 23 where deceleration lockup control is executed.

  If it is determined in step 18 that the air conditioner is off and if it is determined in step 19 that the air conditioner can be turned off, the routine proceeds to step 24, where it is determined whether or not the vehicle speed V is greater than V4. Here, V4 is, for example, 25 to 30 km / h.

  If it is determined at step 24 that the vehicle speed V is greater than V4, the routine proceeds to step 25, where it is determined whether or not the engine speed Ne is greater than Ne5. Here, Ne5 is, for example, 1000 to 1100 rpm.

  If it is determined in step 25 that the engine speed Ne is greater than Ne5, the routine proceeds to step 26, where it is determined whether or not a deceleration lockup flag is set. If it is determined that the flag is set, the process proceeds to step 27 to determine whether the air conditioner is operating.

  If the air conditioner is in operation, the process proceeds to step 28 to set a forced air conditioner off flag and forcibly turns off the air conditioner. Next, the routine proceeds to step 23 where deceleration lockup control is executed. Even when it is determined at step 27 that the air conditioner is off, the routine proceeds to step 23 where deceleration lockup control is executed.

  On the other hand, if step 20, step 21, step 22, step 24, step 25, or step 26 is negative, the process proceeds to step 29 and this process is performed without performing deceleration lockup control.

  Next, the fuel cut process during deceleration will be described with reference to the flowchart of FIG. First, in step 40, it is determined whether or not the throttle is off. If it is determined that the throttle is off, the routine proceeds to step 41 to determine whether or not the air conditioner is operating.

  If it is determined that the air conditioner is in operation, the routine proceeds to step 42, where it is determined whether or not the forced air conditioner off flag is set. If it is determined that the forced air conditioner off flag is set, the routine proceeds to step 43, where it is determined whether or not the engine speed Ne is greater than Ne1. Here, Ne1 is, for example, 1310 to 1410 rpm. If it is determined that the engine speed Ne is greater than Ne1, the routine proceeds to step 44 where fuel cut is executed.

  If it is determined at step 42 that the forced air conditioner off flag is not set, the routine proceeds to step 45, where it is determined whether or not the engine speed Ne is greater than Ne2. Here, Ne2 is 1800-1900 rpm, for example. If it is determined that the engine speed Ne is greater than Ne2, the routine proceeds to step 44 where fuel cut is executed.

  If it is determined in step 41 that the air conditioner is off, the process proceeds to step 46 to determine whether or not the engine speed Ne is greater than Ne3. Here, Ne3 is 1300-1400 rpm. If it is determined that the engine speed Ne is greater than Ne3, the routine proceeds to step 44 where fuel cut is executed.

  If step 40, step 43, step 45 or step 46 is negative, the process is terminated without executing fuel cut.

  FIG. 5 shows a timing chart when the forced air-conditioner is off as described in the flowchart of FIG. First, a deceleration lockup permission flag is set, and deceleration lockup control is started when the throttle is off. That is, the lockup clutch is controlled to the engagement side.

  When the lockup clutch is engaged, the engine crankshaft and the input shaft of the automatic transmission are directly connected, so the engine speed becomes the same as the input shaft speed and gradually decreases with time.

  Conventionally, since the deceleration lockup control is not activated, there is a problem that the engine speed is lowered and the fuel cut time is short. In the present invention, since the deceleration lockup control is entered and the lockup clutch is engaged, the engine speed is kept high and the fuel cut time is longer than before.

It is a block diagram which shows the principle of this invention. It is a figure which shows the structure of the automatic transmission mounted in the vehicle which concerns on this invention, and its control apparatus. It is a flowchart of a forced air-conditioner OFF process. It is a flowchart of the fuel cut at the time of deceleration. It is a timing chart at the time of forced air-conditioner OFF.

Explanation of symbols

22 Engine 26 Automatic transmission 28 Torque converter 30 Lock-up clutch 32 Multi-speed gear mechanism 34 Hydraulic control mechanism 36 Electronic control unit (ECU)
46 Vehicle speed sensor 48 Intake pipe 52 Throttle valve opening sensor 56 Engine speed sensor

Claims (3)

A vehicle control device comprising a lockup control device for a torque converter with a lockup mechanism connected to an engine, an automatic transmission connected to the torque converter, and an air conditioner driven by the engine,
Deceleration determination means for determining when the vehicle is decelerated,
A first determination means for operating the lock-up control device to lock-up the lock-up mechanism to the fastening side when the air conditioner is operating and the vehicle is traveling at a reduced speed when the first determination condition is met;
Based on the operating state of the air conditioner, forced non-operable determination means for determining whether the air conditioner can be switched from the operating state to the non-operating state;
When it is determined by the forced inoperability determining means that the air conditioner can be switched from the operating state to the inactive state, the lockup control device is operated when the second determination condition is met when the vehicle decelerates. Second determination means for performing lock-up control of the lock-up mechanism to the fastening side;
A vehicle control device comprising:   When it is determined by the forced non-operation determining means that the air conditioner can be switched from the operating state to the non-operating state, the engine speed that permits execution of a fuel cut to the engine when the vehicle is decelerating is set to the air conditioning. 2. The vehicle control device according to claim 1, wherein the vehicle control device is set to a predetermined value smaller than an engine speed when the device is operated. When the air conditioner is not operated and the vehicle is decelerating, the vehicle further includes third determining means for operating the lockup control device and controlling the lockup mechanism to the fastening side when the third determination condition is met. And
Each of the first, second, and third determination conditions includes a vehicle speed and an input shaft rotation speed of the automatic transmission, and the vehicle speed and the input shaft rotation speed are determined by third determination condition ≦ second determination condition <first determination. The vehicle control device according to claim 1, wherein a condition relationship is satisfied.

Images