JP4291742B2 - Idling stop judgment device - Google Patents

Description

  The present invention relates to an idling stop determination device, and more particularly to resetting an engine stop condition when idling is stopped.

  From the viewpoint of global warming prevention and resource saving, when the vehicle stops at a red light at an intersection, etc., the engine is automatically stopped and the driver operates to start again (for example, by depressing the accelerator pedal) Also, it is also called an idling stop system (economy running system, engine automatic stop and start system) that restarts the engine when the brake pedal is depressed or the shift lever is switched to the forward travel position. It is also described as eco-run).

  In a vehicle equipped with such an idling stop system, control for stopping the engine is performed when a predetermined stop condition is satisfied. The predetermined stop condition includes a condition regarding a braking force acting on the vehicle. The condition regarding the braking force acting on the vehicle is the condition regarding the operating pressure of the brake booster or the brake master cylinder. That is, when the operating pressure of the brake booster or the brake master cylinder satisfies a predetermined condition, control for stopping the engine is performed.

  For example, the following publications are disclosed as techniques for setting engine stop conditions at the operating pressure of a brake booster.

  Patent Document 1 (Japanese Patent Laid-Open No. 2002-195068) discloses a control device for an on-vehicle internal combustion engine that can sufficiently obtain an effect of improving fuel consumption by automatically stopping the internal combustion engine while traveling. This control device is mounted on a vehicle including a brake booster that accumulates a negative pressure generated in an intake system of an internal combustion engine as an operating pressure and is operated based on the operating pressure. A control device for an in-vehicle internal combustion engine that permits the automatic stop of the internal combustion engine while the vehicle is running on condition that the operating pressure has reached a required level includes variable means for making the required level variable according to the braking situation of the vehicle. Prepare.

According to Patent Document 1, when the brake pedal is depressed to brake the vehicle while the vehicle is running, the brake booster is activated and the operating pressure is changed to the atmospheric side. According to the above configuration, the required level used as the automatic stop condition of the internal combustion engine is changed to an appropriate one by the variable means according to the braking situation of the vehicle that affects the change of the operating pressure to the atmosphere side. be able to. And, by making the required level of the operating pressure variable in this way, the internal combustion engine during running of the vehicle is suppressed while the operating pressure is insufficient to operate the brake booster normally after the automatic stop of the internal combustion engine. It is possible to appropriately improve the fuel consumption by appropriately executing the automatic stop.
JP 2002-195068 A

  However, if the stop condition for the operating pressure of the brake booster or the brake master cylinder is set so as to require a high braking force, for example, it is necessary to sufficiently secure the braking force for maintaining the vehicle stop state. Therefore, there is a problem that the engine is not automatically stopped unless the driver depresses the brake pedal strongly. That is, when the vehicle is stopped, unnecessary idling is performed, resulting in deterioration of fuel consumption.

  On the other hand, if the stop condition is set so as to require a braking force lower than the required braking force, the engine may be restarted in a state where the braking force for maintaining the stopped state of the vehicle is not sufficiently secured. There is. In particular, when control for stopping the engine is performed in a state in which an auxiliary machine such as an air conditioner is operating, the engine is controlled so that the idle rotation speed at the time of restarting is increased. Therefore, when the engine is restarted in a state where sufficient braking force is not ensured in the vehicle and the shift position in the transmission is the travel position, the driver is forced by the engine torque generated at the time of restart. There is a problem that you may feel uncomfortable.

  In Patent Document 1, the torque generated in the vehicle when the engine is restarted as described above is not taken into consideration.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an idling stop determination device that appropriately sets an engine stop condition for braking force.

  An idling stop determination device according to a first aspect of the present invention is a determination device that determines whether or not the idling stop is possible in a vehicle equipped with an idling stop system that temporarily stops the engine when the vehicle condition satisfies a predetermined stop condition. It is. When the determination device satisfies the stop condition, the determination device calculates the idle speed when the engine is restarted based on a predetermined condition, and sets the stop condition based on the calculated idle speed. Setting means for resetting the condition regarding the braking force acting on the included vehicle and determination means for determining whether or not idling stop is possible based on the reset stop condition.

  According to the first aspect of the present invention, when the engine stop condition is satisfied, the idling stop determination device determines whether the engine is restarted based on a predetermined condition (for example, a condition based on an operating state of an auxiliary machine such as an air conditioner). The calculation means for calculating the idle rotation speed of the vehicle and the condition regarding the braking force acting on the vehicle included in the stop condition based on the calculated idle rotation speed (for example, the stop condition for the operating pressure of the brake master cylinder) Or setting means for resetting the stop condition for the operating pressure of the brake booster, and determination means for determining whether or not idling stop is possible based on the reset stop condition. When the engine stop condition is satisfied, the idling speed at the time of engine restart is calculated high when an auxiliary machine such as an air conditioner is operating. This is because it is necessary to operate an A / C (Air Conditioning) compressor or the like when the engine is restarted. Therefore, a high braking force is set as a stop condition for the operating pressure of the brake master cylinder or the operating pressure of the brake booster in accordance with the calculated idle speed at the time of restart. That is, the hydraulic pressure on the high pressure side is required for the operating pressure of the brake master cylinder. Or if it is the operating pressure of a brake booster, the negative pressure on the vacuum side is required. Thus, when the engine is restarted, a braking force for maintaining the vehicle stop state is ensured, so that the driver can be prevented from feeling uncomfortable based on the engine torque. Further, when the auxiliary machine is not operating, the idle speed at the time of engine restart is calculated to be low. Therefore, a low braking force is set as a stop condition for the operating pressure of the brake master cylinder or the operating pressure of the brake booster. As a result, the engine can be easily stopped automatically, and the engine can be automatically stopped earlier. That is, fuel consumption can be improved. Therefore, it is possible to provide an idling stop determination device that appropriately sets the engine stop condition for the braking force.

  In the idling stop determination device according to the second aspect of the invention, in addition to the configuration of the first aspect of the invention, the setting means sets the stop condition so that the braking force increases as the calculated idle rotational speed increases. Means for setting.

  According to the second aspect of the invention, the braking force acting on the vehicle included in the stop condition (for example, the brake master cylinder or By resetting the stop condition for the brake booster operating pressure), the driver will feel uncomfortable based on the torque of the engine because the braking force to maintain the vehicle's stopped state is sufficiently secured when the engine is restarted. You can avoid feeling.

  In the idling stop determination device according to the third invention, in addition to the configuration of the first or second invention, the setting means is means for setting a stop condition for the operating pressure of the brake master cylinder that generates the braking force. including.

  According to the third invention, the stop condition for the operating pressure of the brake master cylinder that generates the braking force is set. That is, in accordance with the increase in the calculated idle speed, a high braking force is set as a stop condition for the operating pressure of the brake master cylinder. By requesting the high-pressure side hydraulic pressure as the operating pressure of the brake master cylinder, when the engine is restarted, a sufficient braking force is maintained to keep the vehicle stopped, so that the driver feels uncomfortable based on the engine torque. You can avoid feeling.

  In the idling stop determination device according to the fourth invention, in addition to the configuration of the first or second invention, the braking force setting means sets a stop condition for the operating pressure of the brake booster that generates the braking force. Including means.

  According to the fourth invention, the stop condition for the operating pressure of the brake master cylinder that generates the braking force is set. That is, in accordance with the increase in the calculated idle rotation speed, a high braking force is set as a stop condition for the operating pressure of the brake booster. By requiring negative pressure on the vacuum side as the operating pressure of the brake booster, when the engine is restarted, a sufficient braking force is maintained to keep the vehicle stopped, so the driver feels uncomfortable based on the engine torque. You can avoid feeling.

  In the idling stop determination device according to the fifth invention, in addition to the configuration of any one of the first to fourth inventions, the predetermined condition is a condition based on the operating state of the auxiliary machine operated by the engine. .

  According to the fifth invention, the predetermined condition is a condition based on the operating state of the auxiliary machine operated by the engine. Thus, when the engine stop condition is satisfied, the idle speed at the time of restart is calculated to be high in a state where an auxiliary machine such as an air conditioner is operating.

  Hereinafter, an idling stop determination device according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  As shown in FIG. 1, a vehicle 100 having an idling stop determination device according to an embodiment of the present invention will be described.

  The vehicle 100 includes an ECU (Electronic Control Unit) 102, an A / C compressor 104, an engine 106, a starter 108, a belt 110, an intake passage 112, a negative pressure passage 114, a transmission 116, a crankshaft. 118, a brake pedal 120, a brake booster 124, a brake master cylinder 126, a negative pressure sensor 128, a hydraulic pressure sensor 130, a hydraulic pressure circuit 132, tires 134 and 138, and a brake mechanism 136.

  The pulley of the A / C compressor 104 is connected to the pulley of the engine 106 via the belt 110. Therefore, as the pulley of the engine 106 rotates, the pulley of the A / C compressor 104 rotates and the A / C compressor 104 operates.

  The engine 106 is connected to the transmission 116 via a crankshaft 118.

  The shift 116 is not particularly limited as long as it is an automatic transmission, but may be a stepped automatic transmission or a continuously variable automatic transmission, for example. When the driving position is switched by the driver in the transmission 116, a driving position signal is transmitted to the ECU 102. The output side of the transmission 116 is connected to tires 134 and 138 via a propeller shaft, a differential mechanism, and a drive shaft. That is, the tires 134 and 138 are driven by the rotational drive on the output side of the transmission 116.

  A brake disc is provided on the drive shaft. A brake mechanism 136 is provided so as to sandwich the brake disk.

  On the other hand, the engine 106 is provided with an intake passage 112. The intake passage 112 is connected to the brake booster 124 via the negative pressure passage 114. Both ends of the brake booster 124 are connected to the brake pedal 120 and the brake master cylinder 126, respectively.

  A negative pressure is generated in the brake booster 124 using the force of sucking air from the intake passage 112 when the engine 106 is operating. The brake booster 124 boosts the pedal force input to the brake pedal 120 based on the generated negative pressure, and transmits the boosted force to the master cylinder 126. Note that the structure and operation of the brake booster 124 are well-known techniques and will not be described in detail here.

  The brake master cylinder 126 is connected to the brake mechanism 136 via the hydraulic circuit 132. The brake master cylinder 126 is provided with a piston (not shown) inside. And according to the input from the brake booster 124, the hydraulic pressure in the brake master cylinder 126 is increased by operating the piston. Thereby, the hydraulic pressure in the hydraulic circuit 132 is increased.

  When the hydraulic pressure in the hydraulic circuit 132 increases, the hydraulic pressure in the brake mechanism 136 increases. As a result, a piston (not shown) inside the brake mechanism 136 is operated, and the brake disc is sandwiched via a brake pad (not shown). Thereby, the rotational drive of the tire 134 is restricted. That is, as the hydraulic pressure of the brake mechanism 136 increases, a braking force corresponding to the hydraulic pressure is generated in the vehicle 100.

  The brake booster 124 is provided with a negative pressure sensor 128. The negative pressure signal detected by the negative pressure sensor 128 is transmitted to the ECU 102. The brake master cylinder 126 is provided with a hydraulic pressure sensor 130. A hydraulic signal detected by the hydraulic sensor 130 is transmitted to the ECU 102.

  The ECU 102 includes a memory (not shown) that stores various data and programs, and a CPU (Central Processing Unit) that executes the programs stored in the memory.

  In addition, an idling stop system is mounted on vehicle 100 having the idling stop determination device according to the present embodiment.

  When vehicle 100 satisfies a predetermined stop condition, ECU 102 executes an idling stop system. The idling stop system is a system that controls the engine 106 to stop when a condition input to the ECU 102 satisfies a predetermined stop condition. When the stop condition of the engine 106 is not satisfied, the ECU 102 supplies power from the secondary battery to the starter 108. Then, the starter 108 is driven to rotate the crankshaft 118 of the engine 106. Thereby, the engine 106 is restarted (cranking).

  The predetermined stop condition for stopping the engine includes a condition for the hydraulic pressure that is the operating pressure of the brake master cylinder 126. That is, when the vehicle depresses the brake pedal 120 and the operating pressure of the brake master cylinder 126 based on the hydraulic signal transmitted from the hydraulic sensor 130 becomes a predetermined operating pressure in a state where the vehicle is stopped at an extremely low speed, the ECU 102 Then, control for stopping the engine 106 is performed.

  When the engine stop condition is satisfied, ECU 102 calculates a target idle speed when engine 106 is restarted according to a condition based on the operating state of the auxiliary machine. That is, if it is detected that an auxiliary machine such as an air conditioner is operating before the engine is stopped, the ECU 102 calculates a high target idle speed when the engine is restarted. This is for operating the A / C compressor 104 when the engine is restarted. When the target idle speed is calculated, the ECU 102 performs so-called idle up control for performing control so that the calculated target idle speed is obtained after the engine is restarted.

  Here, when the idle speed of the engine 106 at the time of restart is high, when the shift position in the transmission 116 is the travel position, the braking force for maintaining the stop state of the vehicle cannot be sufficiently ensured. There is a possibility that the driver may feel uncomfortable due to the rotational torque of the engine 106 generated at the time of starting. On the other hand, if the stop condition for the operating pressure of the brake master cylinder 126 is set so as to require a high braking force, the engine will not be automatically stopped unless the driver fully depresses the brake pedal.

  Therefore, the ECU 102 that is the idling stop determination device according to the present embodiment resets the stop condition for the operating pressure of the brake master cylinder 126 based on the calculated target idle speed when the engine stop condition is satisfied. To do.

  Specifically, the ECU 102 resets the stop condition for the operating pressure of the brake master cylinder 126 based on the map as shown in FIG. 2 from the calculated target idle rotation. As shown in FIG. 2, in the present embodiment, the idle speed N (1) to N (2) and the brake master cylinder operating pressure P (1) to P (2) are in a proportional relationship, but are not particularly limited. . For example, the relationship between the idle speed and the operating pressure of the brake master cylinder 126 may be a relationship based on a predetermined function or a relationship based on a non-linear graph.

  A control structure of a program executed by ECU 102 that is the idling stop determination device according to the present embodiment will be described with reference to FIG.

  In step (hereinafter, step is abbreviated as S) 1000, ECU 102 determines whether or not a stop condition for engine 106 is satisfied. At this time, for example, the ECU 102 determines whether or not a stop condition for the engine 106 is satisfied based on the traveling state of the vehicle, the operating state of the auxiliary machine, the operating state of the brake, the shift position switching state, and the like. If the stop condition of engine 106 is satisfied (YES in S1000), the process proceeds to S1100. If not, the process is repeated.

  In S1100, ECU 102 determines whether or not a condition for starting the idle-up control when the engine is restarted is satisfied. The condition for starting the idle up control is not particularly limited, but in the present embodiment, the condition is based on the operating state of an auxiliary machine such as an air conditioner. That is, ECU 102 determines whether or not to perform idle-up control at the time of restart according to the operating state of an auxiliary machine such as an air conditioner. If the conditions for starting the idle up control are satisfied (YES in S1100), the process proceeds to S1200. If not (NO in S1100), the process proceeds to S1300.

  In S1200, ECU 102 calculates a target idle speed based on a condition for starting the idle up control. In the present embodiment, for example, ECU 102 calculates a target idle speed in accordance with the operating state of an auxiliary machine such as an air conditioner. At this time, the method for calculating the target idle speed is not particularly limited, and for example, it is calculated based on the load on the engine 106 by the auxiliary machine.

  In S1300, ECU 102 sets the target idle speed to a normal value. The normal value is a predetermined rotational speed that is lower than the target idle rotational speed when the idle-up control is performed.

  In step S1400, the ECU 102 determines the stop condition (the hydraulic pressure necessary to permit the engine 106 to stop) for the operating pressure of the brake master cylinder 126 based on the calculated target idle speed and a map as shown in FIG. ) Is reset.

  In S1500, ECU 102 determines whether or not the reset engine stop condition is satisfied. This determination is the same processing as in S1000. Therefore, detailed description will not be repeated. If the reset engine stop condition is satisfied (YES in S1500), the process proceeds to S1600. If not, the process ends.

  In S1600, ECU 102 stops idling of engine 106. That is, ECU 102 controls to stop the operation of engine 106.

  An operation of ECU 102 that is the idling stop device according to the present embodiment based on the above-described structure and flowchart will be described.

  If the brake pedal 120 is depressed by the driver and the stop condition of the engine 106 is satisfied when the shift position in the transmission 116 is the traveling position (YES in S1000), auxiliary equipment such as an air conditioner is operating. If present (YES in S1100), the target idle speed at the time of restart is calculated (S1200). If the auxiliary machine is not operating (NO in S1100), the target idle speed at the time of restart is set to a normal value (S1300). Based on the target idle speed, the stop condition for the operating pressure of the brake master cylinder 126 is reset from the map (S1400). If the reset engine stop condition is satisfied (YES in S1500), the engine is stopped.

  As described above, when the idling stop determination device according to the present embodiment satisfies the engine stop condition, the idle speed at the time of engine restart is determined based on the condition regarding the operating state of the auxiliary machine such as an air conditioner. In order to reset the stop condition for the operating pressure of the brake master cylinder, which is a condition for the braking force acting on the vehicle included in the stop condition, based on the calculation means for calculating And setting means for determining whether or not idling stop is possible based on the reset stop condition. When the engine stop condition is satisfied, the idling speed at the time of engine restart is calculated high when an auxiliary machine such as an air conditioner is operating. This is for operating the A / C compressor or the like when the engine is restarted. For this reason, a high braking force is set as a stop condition for the operating pressure of the brake master cylinder in accordance with the calculated idle speed at restart. That is, the hydraulic pressure on the high pressure side is required for the operating pressure of the brake master cylinder. Thus, when the engine is restarted, a braking force for maintaining the vehicle stop state is ensured, so that the driver can be prevented from feeling uncomfortable based on the engine torque. Further, when the auxiliary machine is not operating, the idle speed at the time of engine restart is calculated to be low. Therefore, a low braking force is set as a stop condition for the operating pressure of the brake master cylinder. As a result, the engine can be easily stopped automatically, and the engine can be automatically stopped earlier. That is, fuel consumption can be improved.

  Therefore, it is possible to provide an idling stop determination device that appropriately sets the engine stop condition for the braking force.

  Note that the idle stop determination device according to the present embodiment resets the stop condition for the operating pressure of the brake master cylinder based on the calculated target idle speed, but based on the calculated target idle speed. Thus, the stop condition for the operating pressure of the brake booster may be reset. At this time, if the calculated target idle speed is high, a vacuum-side negative pressure is required as a stop condition for the operating pressure of the brake booster.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the vehicle which has the idling stop determination apparatus which concerns on this Embodiment. It is a figure which shows the relationship between idle rotation speed and the operating pressure of a brake master cylinder. It is a flowchart which shows the control structure of the program performed by ECU which is an idling stop determination apparatus which concerns on this Embodiment.

Explanation of symbols

  100 vehicle, 102 ECU, 104 A / C compressor, 106 engine, 108 starter, 110 belt, 112 intake passage, 114 negative pressure passage, 116 transmission, 118 crankshaft, 120 brake pedal, 124 brake booster, 126 brake master cylinder 128, negative pressure sensor, 130 hydraulic sensor, 132 hydraulic circuit, 134,138 tires.

Claims (4)

A determination device for determining whether or not the idling stop is possible in a vehicle equipped with an idling stop system that temporarily stops the engine when the vehicle state satisfies a predetermined stop condition,
When the stop condition is satisfied, based on a predetermined condition, a calculation means for calculating an idle speed when the engine is restarted;
Setting means for resetting a condition for a braking force acting on the vehicle included in the stop condition, based on the calculated idle speed;
Determination means for determining whether or not idling stop is possible based on the reset stop condition;
The setting means includes means for resetting a condition for the braking force included in the stop condition so as to correspond to the increased braking force in response to an increase in the calculated idle speed. Including idling stop determination device. The idling stop determination device according to claim 1 , wherein the setting means includes means for setting a stop condition for an operating pressure of a brake master cylinder that generates the braking force. The idling stop determination device according to claim 1 , wherein the setting means includes means for setting a stop condition for an operating pressure of a brake booster that generates the braking force. The idling stop determination device according to any one of claims 1 to 3 , wherein the predetermined condition is a condition based on an operating state of an auxiliary machine operated by the engine.

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