JP5526791B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device that automatically stops an engine when a predetermined automatic stop condition is satisfied, and then automatically restarts the engine.

  2. Description of the Related Art Conventionally, an engine control device that performs so-called idle stop control for automatically stopping and restarting an engine has been developed.

  For example, Patent Document 1 discloses a device that restarts an engine by injecting fuel into a cylinder that was in an expansion stroke when the engine was stopped and burning it.

  Conventionally, a master back using negative pressure has been used as a brake device that applies braking force to wheels. This brake master back has two negative pressure chambers separated by a diaphragm. One of the negative pressure chambers is normally maintained at a negative pressure, while the amount of operation is reduced when the brake pedal is operated. In response, the atmosphere is introduced. The brake master back boosts the operating force of the brake pedal by introducing the atmosphere into the one negative pressure chamber according to the operation of the brake pedal and pressing the diaphragm toward the other negative pressure chamber. Then, braking force is applied to the wheels.

JP 2007-2111710 A

  In the intake passage or the exhaust passage of the engine, a control valve that changes the flow state of the gas in the passage by changing the flow passage area of these passages, and a negative pressure control valve driving means for opening and closing the control valve May be provided. In this case, if the means for supplying the negative pressure to the negative pressure type control valve driving means and the means for supplying the negative pressure to the brake master back are common, the negative pressure type control valve driving means causes Is consumed, there is a possibility that a sufficient negative pressure cannot be supplied to the brake master back side. On the other hand, when the engine is restarted after being automatically stopped as described above, it is desired to drive the control valve promptly with a predetermined opening so that the engine is driven in a suitable state.

  In view of such circumstances, the present invention controls an engine capable of supplying a sufficient negative pressure to the brake master back and controlling the control valve provided in the intake / exhaust passage to a predetermined opening degree. The purpose is to provide a device.

In order to solve the above-mentioned problem, the present invention automatically stops the engine when a preset engine automatic stop condition is satisfied, and when the preset engine restart condition is satisfied, In an engine control apparatus that burns in an engine cylinder and restarts the engine, it is provided in at least one of an intake passage and an exhaust passage connected to the engine and can change a gas flow state in the passage. A control valve, a control valve driving means for driving the control valve by receiving negative pressure, a brake master back for applying braking force to the wheels by receiving negative pressure, and a negative pressure associated with the operation of the engine to generate a pressure, a negative pressure supply means for supplying in common to the control valve drive unit and the master back brake, the negative pressure supply to the control valve driving means It is provided in a negative pressure passage connected to the stage, and when the electric power is supplied, the negative pressure passage is opened to allow air to flow between the negative pressure supply means and the control valve driving means. On the other hand, when the power supply is stopped, the negative pressure passage is closed, and a solenoid valve that shuts off the air flow between the negative pressure supply means and the control valve drive means is provided. The negative pressure to the control valve driving means is supplied to the master back for rake while the engine is restarted after the engine is automatically stopped until the engine speed reaches a predetermined value or more. by stopping the supply of, as the restart of the engine is completed, and starts the supply of negative pressure to the control valve drive means while supplying a negative pressure to the master back brake, said control valve drive Stop supplying negative pressure to the means before The power supply to the solenoid valve is stopped and the negative pressure passage is closed, and the supply of the negative pressure to the control valve driving means is started by restarting the power supply to the solenoid valve. An engine control device is provided which is performed by opening a negative pressure passage (Claim 1).

  According to this apparatus, the engine restart is completed after the engine is automatically stopped until the engine restart is completed, that is, after the engine is stopped and the generation of the negative pressure is stopped by the negative pressure supply means. Thus, the supply of negative pressure to the control valve driving means is stopped until the generation of negative pressure by the negative pressure supply means is started with the operation of the engine, and the negative pressure on the control valve driving means side is stopped. Since pressure consumption is suppressed and the negative pressure drop of the brake master back is suppressed, a sufficient braking force can be applied to the wheels by the brake master back. In addition, during the operation of the engine after completion of the restart of the engine, negative pressure is supplied to the control valve driving means, and the control valve sets the gas flow state in at least one of the intake passage and the exhaust passage to a predetermined state. Therefore, the engine can be driven in a suitable state.

  In the present invention, a brake pressure applying means that is interposed between the brake master back and the wheel, receives a braking force output from the brake master back, and applies a brake pressure to the wheel, and the brake pressure Hill holder means capable of holding the brake pressure applied to the wheel by the applying means, and the negative pressure supply means completes restart of the engine, and holds the brake pressure by the hill holder means. After the release, it is preferable to start supplying negative pressure to the control valve driving means (claim 2).

  In this way, the brake pressure applied to the wheels by the brake pressure applying means is held by the hill holder means, so that the vehicle can be stopped more reliably during the automatic stop of the engine, and the hill holder The supply of negative pressure to the control valve driving means is started when the holding of the means is released and the vehicle is ready to start, and control is performed when the vehicle starts while maintaining the negative pressure of the master back for braking. The valve can be controlled to a suitable state.

  In the present invention, the control valve further includes biasing means for biasing the control valve, the control valve being provided in the exhaust passage and capable of changing a flow area of the exhaust passage, and supplying the negative pressure In a state where no negative pressure is supplied to the control valve driving means by the means, the flow passage area is maximized by the biasing force of the biasing means, and negative pressure is supplied to the control valve driving means. In this state, it is preferable that the control valve driving means is driven in a direction to reduce the flow passage area against the urging force of the urging means as the negative pressure is supplied (Claim 3).

  The control valve provided in the exhaust passage requires a relatively large negative pressure when driven than the control valve provided in the intake passage. For this reason, in particular, by stopping the negative pressure supply to the control valve provided in the exhaust passage until the completion of the restart after the automatic stop of the engine, the negative pressure consumption during this period can be further reduced and the negative pressure of the master back for braking can be reduced. The decrease in pressure can be further suppressed.

  Further, the control valve provided in the exhaust passage is configured to be disposed at a position where the flow passage area of the exhaust passage is maximized by the biasing force of the biasing means in a state where negative pressure is not supplied. When the control valve is restarted, the exhaust resistance is prevented from increasing as the flow passage area of the exhaust passage is reduced, and the engine can be started easily.

  In the present invention, the turbine provided in the exhaust passage and driven by the exhaust passing through the exhaust passage, and the intake air provided in the intake passage and passing through the intake passage by the driving force of the turbine are boosted. A turbocharger having a compressor, wherein the exhaust passage has a bypass passage communicating with the upstream and downstream of the turbine to bypass the turbine, and the control valve is provided in the bypass passage. The flow passage area of the bypass passage is preferably changed (claim 4).

  In this way, when the engine is restarted, the control valve maximizes the flow passage area of the bypass passage, and the exhaust resistance is kept small. On the other hand, after the engine is restarted, the control valve is driven and the flow passage of the bypass passage is reduced. By changing the area and driving the turbocharger to a suitable state, the state after restarting the engine can be made a suitable state.

  In the present invention, the turbine provided in the exhaust passage and driven by the exhaust passing through the exhaust passage, and the intake air provided in the intake passage and passing through the intake passage by the driving force of the turbine are boosted. Preferably, a turbocharger having a compressor is provided, and the control valve is provided upstream of the turbine in the exhaust passage and changes a flow passage area of the exhaust passage upstream of the turbine. ).

  In this way, when the engine is restarted, the control valve maximizes the flow passage area of the exhaust passage and the exhaust resistance is kept small. On the other hand, after the engine is restarted, the control valve is driven to reduce the exhaust to the turbine. By making the distribution state suitable, the state after restarting the engine can be made suitable.

  As described above, according to the present invention, it is possible to control the control valve to a suitable state when the engine is operating while maintaining the negative pressure applied to the brake master back and ensuring the braking force to the wheels.

It is a schematic block diagram of the control apparatus of the engine which concerns on embodiment of this invention. It is a flowchart which shows the control procedure of the control apparatus of the engine which concerns on embodiment of this invention. It is a timing chart which shows the control procedure of the control apparatus of the engine which concerns on embodiment of this invention. It is a schematic block diagram of the control apparatus of the engine which concerns on other embodiment of this invention.

  A preferred embodiment of an engine control apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of the engine control apparatus 100. The engine control device 100 includes an engine 1, a first turbocharger (turbocharger) 30, a second turbocharger (turbocharger) 40, and a hydraulic brake device (brake pressure applying means). ) 50, a brake master back 60, a suction pump 70 (negative pressure supply means), an ECU 90, and various control valves 22a, 24a, 26a.

  The engine 1 includes a cylinder block 2a and a cylinder head 2b mounted thereon. A plurality of cylinders 3 into which pistons 4 are fitted are formed in the cylinder block 2a and the cylinder head 2b. A crankshaft 6 connected to the piston 4 is supported on the cylinder block 2a. A combustion chamber 5 is defined above each piston 4 with the cylinder head 2b. An intake port 9 and an exhaust port 10 communicating with each combustion chamber 5 are formed in the cylinder head 2b. The cylinder head 2b is provided with an intake valve 11 and an exhaust valve 12 for blocking the intake port 9 and the exhaust port 10 from the combustion chamber 5, respectively, and an injector 7 for injecting fuel into the combustion chamber 5. It has been. In this embodiment, the engine 1 is a diesel engine, and the fuel injected from the injector 7 is ignited in the combustion chamber 5 to drive the engine 1.

  An intake passage 15 is connected to the intake port 9, and intake air is introduced into the combustion chamber 5 through the intake passage 15 and the intake port 9. An exhaust passage 16 is connected to the exhaust port 10, and exhaust gas is led out from the combustion chamber 5 to the atmosphere through the exhaust passage 16 and the exhaust port 10.

  The first turbocharger 30 has a first compressor 32 provided in the intake passage 15 and a first turbine 34 provided in the exhaust passage 16, and the first turbine 34 receives the exhaust and rotates. As a result, the first compressor 32 rotates, thereby pressurizing the intake air.

  Similarly, the second turbocharger 40 has a second compressor 42 provided in the intake passage 15 and a second turbine 44 provided in the exhaust passage 16, and the second turbine 44 exhausts the exhaust. By receiving and rotating, the second compressor 42 rotates, thereby pressurizing the intake air. The second compressor 42 is provided on the downstream side of the first compressor 32, and the second turbine 44 is provided on the upstream side of the first turbine 34.

  The intake passage 15 is provided with an intake bypass passage 15 a that connects the upstream portion and the downstream portion of the second compressor 42 and bypasses the second compressor 42. The exhaust passage 16 is connected to an upstream portion and a downstream portion of the second turbine 44 to bypass the second turbine 44, and the second exhaust bypass passage 16a. On the downstream side, a first exhaust bypass passage (bypass passage) 16b that connects the upstream portion and the downstream portion of the first turbine 34 and bypasses the first turbine 34 is provided.

  The intake bypass passage 15a is provided with a bypass valve 22a which is one of the control valves. The bypass valve 22a opens and closes the intake bypass passage 15a to change the flow passage area of the intake bypass passage 15a, whereby the intake air amount that passes through the intake bypass passage 15a and hence the intake air amount that flows into the first compressor 32. To change.

  The second exhaust bypass passage 16a is provided with a regulating valve 24a which is one of the control valves. The regulating valve 24a changes the amount of exhaust passing through the second exhaust bypass passage 16a by opening and closing the second exhaust bypass passage 16a and changing the flow passage area of the second exhaust bypass passage 16a. Along with the change in the exhaust amount, the exhaust amount flowing into the second turbine 44, that is, the rotational force of the second turbine 44 and thus the rotational force of the second compressor 42 is changed, and the supercharging pressure of the intake air is changed.

  The second exhaust bypass passage 16b is provided with a waste gate valve 26a which is one of the control valves. The waste gate valve 26a changes the amount of exhaust gas passing through the second exhaust bypass passage 16b by opening and closing the second exhaust bypass passage 16b and changing the flow passage area of the second exhaust bypass passage 16b. . Along with the change in the exhaust amount, the exhaust amount flowing into the first turbine 34, that is, the rotational force of the first turbine 34 and hence the rotational force of the first compressor 32 is changed, and the supercharging pressure of the intake air is changed.

  The bypass valve 22a, the regulating valve 24a, and the waste gate valve 26a are all driven by negative pressure valve actuators (control valve driving means) 22b, 24b, and 26b. Each of these negative pressure type valve actuators 22b, 24b, and 26b has a negative pressure chamber, and when these negative pressure chambers are set to a negative pressure, the bypass valve 22a, the regulating valve 24a, and the waste gate valve 26a are respectively provided. To drive.

  The bypass valve 22a, the regulating valve 24a, and the waste gate valve 26a are each biased to the open side by a spring (not shown), and the negative pressure valve actuators 22b, 24b, and 26b are biased by the spring. Against this, the valves 22a, 24a, 26a are driven to the closed side. That is, the valves 22a, 24a, and 26a are in the fully opened position, that is, the bypass passages 15a, 16a, and 16b, by the biasing force of the springs when the negative pressure chambers of the negative pressure type valve actuators 22b, 24b, and 26b are set to atmospheric pressure. Is disposed at a position where the flow path area of the negative pressure valve actuators 22b, 24b, and 26b decreases, that is, as the negative pressure in the negative pressure chamber increases, Driven in the direction of decreasing the road area. The opening degree of these valves 22a, 24a, 26a is changed according to the operating conditions. As described above, the valves 22a, 24a, and 26a are so-called normally open type valves that are fully opened when not driven by the negative pressure type valve actuators 22b, 24b, and 26b.

  The hydraulic brake device 50 applies a brake pressure to the wheel 80 in accordance with the operation of the brake pedal 54. The hydraulic brake device 50 has a predetermined hydraulic pressure, that is, a brake, applied to a brake shoe or the like pressed against the wheel 80 by driving a piston in a hydraulic cylinder included in the hydraulic brake device 50 according to an operation amount of the brake pedal 54. A pressure is applied, and a braking force is applied to the wheel 80 through the brake shoe or the like. A hill holder (hill holder means) 88 is provided between the hydraulic brake device 50 and the wheel 80 for blocking the hydraulic pressure supply passage 52 from the hydraulic brake device 50 to the wheel 80 and holding the brake pressure applied to the wheel 80. Is provided. The hill holder 88 is driven by an electric actuator such as a solenoid valve and shuts off the hydraulic pressure supply passage 52 so that the brake pressure toward the wheel 80 is maintained even when the hydraulic pressure in the hydraulic cylinder is reduced. To maintain the braking force of the vehicle.

  The brake master back 60 is a so-called booster, and boosts the operating force of the brake pedal 54 and transmits it to the hydraulic brake device 50. The brake master back 60 has two negative pressure chambers separated by a diaphragm, and air is introduced into one of the pedal side negative pressure chambers according to the operation of the brake pedal, and the diaphragm is moved to the other wheel side. It is comprised so that it may press to the negative pressure chamber side, The piston of the said hydraulic brake device 50 is pressed by this pressing force. Thus, the brake master back 60 transmits the operating force of the brake pedal to the hydraulic brake device 50 and applies a braking force to the wheels 80 via the hydraulic brake device 50 and the like.

  The suction pump 70 sucks air in the negative pressure chambers of the negative pressure type valve actuators 22b, 24b, 26b and the pedal side negative pressure chamber of the brake master back 60 and supplies negative pressure to the negative pressure chambers. Is to do. Negative pressure passages 22c, 24c, 26c connected to the negative pressure chambers of the negative pressure valve actuators 22b, 24b, 26b, and a negative pressure passage 61 connected to the pedal side negative pressure chamber of the brake master back 60, Are connected to the suction pump 70 in communication with each other. The suction pump 70 is connected to the crankshaft 6 of the engine 1 and rotates with the rotation of the engine 1 to generate a suction force, that is, a negative pressure.

  The ECU 90 is a controller based on a well-known microcomputer, and includes a CPU for executing a program, a memory including a RAM and a ROM for storing a program and data, and an I / O for inputting and outputting various signals. It has a bus. The ECU 90 receives detection signals from various sensors via the I / O bus, performs various calculations based on the detection signals, and performs the negative pressure valve actuators 22b, 24b, 26b, the hill holder 88, and the This is for controlling each actuator such as the injector 7.

  The control procedure of the engine control apparatus 100 by the ECU 90 will be described with reference to the flowchart of FIG. 2 and the timing chart of FIG.

  First, in step S1, it is determined whether or not an automatic engine stop condition for automatically stopping the engine 1 is satisfied regardless of the operation of the ignition key. The automatic stop condition is, for example, a condition that the vehicle speed is a predetermined value (for example, 0) or less and the brake pedal is operated.

  If the determination in step S1 is NO, that is, if the automatic stop condition is not satisfied, step S1 is repeated. On the other hand, if the determination in step S1 is YES, that is, if the automatic stop condition is satisfied, in step S2, idle stop control for automatically stopping the engine 1 is performed. Specifically, the fuel injection by the injector 7 is stopped, and the engine 1 is automatically stopped. When the fuel injection is stopped, the engine 1 stops after a while. In addition to stopping fuel injection by the injector 7, the stop position of the engine 1 is controlled to a predetermined position in preparation for the next restart. In the present embodiment, the load on the engine 1 is changed so that the piston 4 in the compression stroke stops at a position close to bottom dead center.

  Next, in step S3, it is determined whether the engine 1 is stopped. Specifically, it is determined whether the rotational speed of the engine 1 is 0 or less. If the determination in step S3 is YES, that is, if it is determined that the engine 1 has stopped, the process proceeds to step S4. If this determination is NO, step S3 is repeated.

  In step S4, the hill holder 88 is driven to maintain the brake pressure toward the wheel 80 side. Specifically, the hydraulic actuator that drives the hill holder 88 is energized to block the hydraulic pressure supply passage 52 by the hill holder 88.

  Next, in step S5, the supply of negative pressure to the negative pressure type valve actuators 22b, 24b, 26b is stopped. That is, the negative pressure chamber of each negative pressure type valve actuator 22b, 24b, 26b is made atmospheric pressure. In this embodiment, solenoid valves 22d, 24d, and 26d are provided between the negative pressure valve actuators 22b, 24b, and 26b and the suction pump 70. These solenoid valves 22d, 24d and 26d are connected to the suction pump 70 side and the atmosphere side with respect to the communication destinations of the negative pressure passages 22c, 24c and 26c connected to the negative pressure chambers of the respective negative pressure type valve actuators 22b, 24b and 26b. In the state where electric power is supplied, the negative pressure passages 22c, 24c, 26c communicate with the suction pump 70, and the supply of electric power is stopped to stop the negative pressure passages 22c, 24c, 26c and the atmosphere. Communicate with the side. In step S5, power supply to the solenoid valves 22d, 24d, and 26d is stopped, and the negative pressure passages 22c, 24c, and 26c are switched to the atmosphere side, so that the negative pressure chambers of the negative pressure valve actuators 22b, 24b, and 26b are obtained. Is atmospheric pressure. In addition, this step S5 is implemented in the state in which the engine 1 is automatically stopped. In this automatic stop state of the engine 1, unlike the case where the ignition key is turned off and the engine 1 is stopped, the solenoid valve can be energized. In this step S5, the solenoid can be energized. Shut off power to the valve. By setting the negative pressure chambers of the negative pressure valve actuators 22b, 24b, and 26b to atmospheric pressure, the bypass valve 22a, the regulating valve 24a, and the waste gate valve 26a are respectively negative pressure valve actuators 22b, 24b, and 26b. The driving force is lost and the spring is fully opened by the biasing force of the spring.

  Here, as the engine 1 stops, the suction pump 70 stops, and the suction pump 70 stops the negative pressure supply to the brake master back 60 and the negative pressure valve actuators 22b, 24b, and 26b. Therefore, when the engine 1 is stopped, the negative pressure passages 22c, 24c, 26c connected to the negative pressure valve actuators 22b, 24b, 26b, respectively, and the suction pump 70 communicate with each other, and the negative pressure valve actuators 22b, 24b, When the negative pressure chamber 26b is maintained at a negative pressure, air is supplied from the valves 22a, 24a, and 26a into the negative pressure chambers of the negative pressure valve actuators 22b, 24b, and 26b, as indicated by chain lines in FIG. Leakage may cause air to leak into the negative pressure passage 61 on the brake master back 60 side, and the negative pressure in the negative pressure chamber of the brake master back 60 may decrease.

  On the other hand, in the engine control apparatus 100, as described above, the negative pressure supply to the negative pressure valve actuators 22b, 24b, and 26b is stopped and the negative pressure valve actuators 22b, 24b, and 26b are stopped. The connected negative pressure passages 22c, 24c, 26c and the suction pump 70 are shut off. Therefore, air leakage into the brake master back 60 is suppressed, and the negative pressure in the negative pressure chamber of the brake master back 60 is maintained as shown by the solid line in FIG.

  Next, in step S6, it is determined whether an engine restart condition is satisfied. For example, if the amount of depression of the accelerator pedal is equal to or greater than a predetermined value, it is determined that this engine restart condition is satisfied. If this determination is NO, step S6 is repeated, and if this determination is YES, the process proceeds to step S7.

  In step S7, restart control for restarting the engine 1 is performed (time t1 in FIG. 3). Specifically, the starter motor is driven to forcibly rotate the crankshaft 6 and fuel injection by the injector 7 is started. In the present embodiment, fuel is injected into the cylinder 3 stopped in the compression stroke when the engine 1 is automatically stopped. As described above, the piston 4 in the cylinder 3 stopped in this compression stroke is located near the bottom dead center. Therefore, the air in the cylinder 3 is sufficiently compressed with the forced rotation of the crankshaft 6 by the starter motor, the fuel is surely self-ignited in the cylinder 3, and the engine 1 is restarted.

  At this time, the intake bypass valve 22a is disposed at the fully open position and the intake bypass passage 15a is opened by the control in step S5. Therefore, the intake air can flow into the cylinder 3 through the intake bypass passage 15a without passing through the first compressor 32 having a large resistance, and the intake air amount in the cylinder 3 is ensured. The regulator valve 24a is disposed at the fully open position, and the first exhaust bypass passage 16a is opened. Further, the waste gate valve 26a is also in the fully open position, and the first exhaust bypass passage 16b is opened. Therefore, the exhaust discharged from the cylinder 3 passes through the exhaust bypass passages 16a and 16b without passing through the first turbine 34 and the second turbine 44 having high resistance. Thereby, exhaust resistance is suppressed small and the engine 1 restarts easily.

  Next, the hill holder 88 is released in step S8 as the restart condition of the engine 1 is satisfied and the vehicle enters a start state. Specifically, the energization of the electric actuator that drives the hill holder 88 is released, and the holding of the brake pressure by the hill holder 88 is released.

  Next, in step S9, it is determined whether or not the restart of the engine 1 is completed. Specifically, it is determined that the restart is completed when the rotational speed of the engine 1 is equal to or greater than a predetermined value N1. The predetermined value is set to 500 rpm, for example. The rotational speed of the engine 1 is detected by a crank angle sensor or the like attached to the engine 1. When the determination in step S9 is YES and the restart of the engine 1 is completed, the process proceeds to step S10. On the other hand, if this determination is NO, step S9 is repeated.

  In step S10, it is determined whether or not the hill holder 88 is released. If this determination is YES, the process proceeds to step S11. On the other hand, if this determination is NO, step S10 is repeated.

  When the engine 1 is restarted and the crankshaft 6 resumes rotation (time t2 in FIG. 3), the suction pump 70 operates as the crankshaft 6 rotates. The suction pump 70 generates sufficient negative pressure against air leakage from the negative pressure valve actuators 22b, 24b, and 26b. Therefore, in step S11 after the restart of the engine 1 is completed, supply of negative pressure to the negative pressure valve actuators 22b, 24b, and 26b is started. That is, the solenoid valves 22d, 24d, and 26d provided upstream of the negative pressure type valve actuators 22b, 24b, and 26b are energized to communicate the negative pressure chambers of the negative pressure type valve actuators 22b, 24b, and 26b with the suction pump 70. Then, the supply of negative pressure to these negative pressure chambers is resumed. Here, as shown in FIG. 3, since the supply of the negative pressure to the brake master back 60 is resumed with the operation of the suction pump 70, the negative pressure of the brake master back 60 increases after time t1.

  The negative pressure type valve actuators 22b, 24b, and 26b are supplied with negative pressure, and drive the bypass valve 22a, the regulating valve 24a, and the waste gate valve 26a to a predetermined opening degree. In the present embodiment, as shown in FIG. 3, all of the bypass turbocharger 30 and the second turbocharger 40 are set with the bypass valve 22a, the regulating valve 24a, and the wastegate valve 26a fully closed. To sufficiently boost the intake air and supply sufficient air into the cylinder 3 to improve the acceleration performance after restart.

  As described above, according to the control apparatus 100 of the present engine, the negative pressure supply to the negative pressure valve actuators 22b, 24b, and 26b is stopped until the restart of the engine 1 is completed after the engine 1 is automatically stopped. Thus, negative pressure is supplied only to the master back 60 for braking. Therefore, negative pressure consumption in the negative pressure type valve actuators 22b, 24b, 26b, that is, air from the bypass valve 22a, the regulating valve 24a, the wastegate valve 26a side to the negative pressure chambers of the negative pressure type valve actuators 22b, 24b, 26b. The negative pressure of the brake master back 60 is prevented from lowering due to the leakage of air and the leakage of air from damaged parts such as pipes constituting the negative pressure passages 22c, 24c, 26c extending from the negative pressure chambers, A sufficient braking force can be applied to the wheel 80 by the brake master back 60. Then, the supply of negative pressure to the negative pressure type valve actuators 22b, 24b, and 26b is started after the restart of the engine 1 is completed, so that the bypass valve 22a and the regulator are controlled when the vehicle starts after the restart of the engine 1 is completed. The rate valve 24a and the waste gate valve 26a can be controlled to a suitable state.

  In particular, until the restart of the engine 1 is completed, the bypass valve 22a, the regulating valve 24a, and the wastegate valve 26a are fully opened to reduce the intake resistance and the exhaust resistance, and the startability of the engine 1 can be ensured. After the start of the engine 1 is completed, the bypass valve 22a, the regulating valve 24a, and the wastegate valve 26a are controlled to be closed to drive the first turbocharger 30 and the second turbocharger 40 to a suitable state. Acceleration can be improved.

  The control valve driven by the negative pressure type valve actuator to which negative pressure is supplied by the suction pump 70 is not limited to the bypass valve 22a, the regulating valve 24a, and the waste gate valve 26a. For example, as shown in FIG. 4, instead of the first turbine 34 and the second turbine 44, a so-called VGT (Variable Geometry Turbo) provided with a valve 134 a capable of changing the exhaust amount introduced into the blades of the turbine 134. The valve 134a for changing the exhaust amount may be driven by a negative pressure valve actuator 134b to which a negative pressure is supplied by the suction pump 70.

  In this case, the negative pressure supply to the negative pressure valve actuator 134b is stopped after the engine 1 is automatically stopped until the restart of the engine 1 is completed. After the restart of the engine 1 is completed, the negative pressure valve actuator 134b is stopped. Supply negative pressure to The negative pressure type valve actuator 134b controls the valve 134a to the closed side so that the exhaust gas flowing into the turbine 134 is throttled to increase the flow velocity, thereby increasing the supercharging efficiency of the turbine 134 and improving the acceleration performance.

  The control valve may be an SCV (Swirl Control Valve) or the like for providing a swirl to the intake air that is provided in the intake port 11 and flows into the cylinder 3.

  Further, the control for driving the hill holder 88 when the engine 1 is automatically stopped may be omitted. However, if the hill holder 88 is driven when the engine 1 is automatically stopped to hold the brake pressure to the wheel 80, the wheel 80 can be stopped more reliably.

  The engine 1 is not limited to a diesel engine, but may be a spark ignition engine. In this case, since the negative pressure is generated in the intake passage 15 as the engine 1 is driven, the suction pump 60 is omitted, and the intake passage 15, the brake master back 60, and each negative pressure type valve actuator 22b are omitted. , 24b, 26b are connected to each other, and the negative pressure generated in the intake passage 15 is preferably supplied to the brake master back 60, the negative pressure type valve actuators 22b, 24b, 26b and the like. In addition, when the engine 1 is restarted, it is preferable to start combustion from within the cylinder 3 that was in the expansion stroke when the engine 1 was automatically stopped.

1 Engine 15 Intake passage 16 Exhaust passage 22a Intake bypass valve (control valve)
22b Negative pressure type valve actuator (control valve drive means)
24a Regulating valve (control valve)
24b Negative pressure type valve actuator (control valve drive means)
26a Wastegate valve (control valve)
26b Negative pressure type valve actuator (control valve driving means)
30 1st turbocharger (turbocharger)
32 First compressor (compressor)
34 First turbine (turbine)
40 Second turbocharger (turbocharger)
42 Second compressor (compressor)
44 Second turbine (turbine)
50 Hydraulic brake device (brake pressure applying means)
60 Brake master back 70 Suction pump (negative pressure supply means)
88 Hill holder (hill holder means)
90 ECU
100 Engine control device

Claims (5)

When the preset engine automatic stop condition is satisfied, the engine is automatically stopped. When the preset engine restart condition is satisfied, the engine is combusted in the cylinder of the engine and restarted. In the engine control device
A control valve provided in at least one of an intake passage and an exhaust passage connected to the engine and capable of changing a flow state of a gas in the passage;
Control valve driving means for driving the control valve in response to supply of negative pressure;
A master back for braking that applies braking force to the wheels by receiving negative pressure,
Negative pressure supply means for generating negative pressure as the engine operates and supplying the negative pressure in common to the control valve drive means and the brake master back ;
Provided in a negative pressure passage connected to the control valve driving means and the negative pressure supply means, and when the power is supplied, the negative pressure passage is opened and the negative pressure supply means and the control valve drive means A solenoid valve that closes the negative pressure passage and shuts off the air flow between the negative pressure supply means and the control valve drive means when power supply is stopped And
The negative pressure supply means supplies the negative pressure to the brake master back while the engine is restarted after the engine is automatically stopped until the engine speed reaches a predetermined value or more. Supply of negative pressure to the drive means is stopped, and supply of negative pressure to the control valve drive means is started while supplying negative pressure to the brake master back as the engine restart is completed. And
The supply of negative pressure to the control valve driving means is stopped by stopping the supply of power to the solenoid valve and closing the negative pressure passage.
The engine control device according to claim 1, wherein the supply of the negative pressure to the control valve driving means is started by restarting the power supply to the solenoid valve and opening the negative pressure passage . The engine control device according to claim 1,
Brake pressure applying means that is interposed between the brake master back and the wheel, receives a braking force output from the brake master back, and applies a brake pressure to the wheel;
Hill holder means capable of holding the brake pressure applied to the wheel by the brake pressure applying means,
The hill holder means holds the brake pressure for a period from the automatic engine stop to the engine restart,
The negative pressure supply means starts supplying negative pressure to the control valve drive means after the restart of the engine is completed and the holding of the brake pressure by the hill holder means is released. Engine control device. The engine control apparatus according to claim 1 or 2,
Biasing means for biasing the control valve;
The control valve is provided in the exhaust passage so that the flow passage area of the exhaust passage can be changed, and the urging is performed in a state where no negative pressure is supplied to the control valve driving means by the negative pressure supply means. When the negative pressure is supplied to the control valve driving means, the biasing force is supplied by the control valve driving means along with the supply of the negative pressure. An engine control device that is driven in a direction to reduce the flow path area against the urging force of the urging means. The engine control device according to claim 3,
A turbo engine having a turbine provided in the exhaust passage and driven by exhaust passing through the exhaust passage, and a compressor provided in the intake passage and boosting the intake air passing through the intake passage by the driving force of the turbine. Equipped with a feeder,
The exhaust passage has a bypass passage that communicates the upstream and downstream of the turbine and bypasses the turbine;
The engine control device, wherein the control valve is provided in the bypass passage and changes a flow passage area of the bypass passage. The engine control device according to claim 3,
A turbo engine having a turbine provided in the exhaust passage and driven by exhaust passing through the exhaust passage, and a compressor provided in the intake passage and boosting the intake air passing through the intake passage by the driving force of the turbine. Equipped with a feeder,
The control valve is provided on the upstream side of the turbine in the exhaust passage, and changes the flow passage area of the exhaust passage upstream of the turbine.

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