JP3939905B2 - Engine starter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine starter that starts an engine, and more particularly, to an engine start controller that starts an engine without using a starter.
[0002]
[Prior art]
Conventionally, when an automobile travels in an urban area, when the vehicle is stopped due to traffic light or traffic jams, the engine continues to rotate in an idling state, resulting in a deterioration in fuel consumption rate, an increase in exhaust gas, and a ride comfort. Worsened and increased noise. Therefore, for example, as described in Japanese Patent Application Laid-Open No. 58-18557, it is known that the engine is stopped when it is determined that the automobile is surely stopped. At the time of restart, when a predetermined restart condition is satisfied, the engine is restarted using a starter motor. However, since starter motors were originally developed on the premise that they should be used only when starting the engine, an engine that is frequently stopped and restarted will cause an extreme increase in the number of starter uses. In addition, the life of the peripheral parts may be shortened, and the engine may not be restarted due to damage or wear. In addition, as the starter usage increases, the charging / discharging load of the battery also increases. Therefore, when the discharge current is high, such as during the rain or at night, the battery discharge increases and restarts. There is a possibility that the charge amount of the alternator, in other words, the driving load increases, resulting in deterioration of fuel consumption.
[0003]
Therefore, for example, as described in Japanese Patent Application Laid-Open No. 11-125136, when the engine is stopped, the piston is stopped in a range of 5 ° to 110 ° after the top dead center. It is known to self-start an engine by injecting a fuel corresponding to an amount and then igniting. As a result, the power consumed by the starter motor at the time of conventional start-up can be reduced, and the starter motor and accessories can be reduced in weight, or the starter can be completely abolished to reduce the size and weight of the engine system and reduce costs. Can be achieved.
[0004]
[Problems to be solved by the invention]
However, when the present inventors conducted an experiment on the method described in JP-A-11-125136, it was found that self-starting was impossible. That is, taking a multi-cylinder engine, for example, a 4-cylinder engine that ignites in order of each cylinder of 1-3-4-2 as an example, if the cylinder used for self-starting is the first cylinder, during the expansion stroke of the first cylinder, The compression of the third cylinder has begun. For this reason, it has been found that with the torque generated by the first combustion of the first cylinder, the compression of the third cylinder cannot be performed, the engine stops as it is, and self-starting fails.
[0005]
An object of the present invention is to provide an engine starter capable of self-start without using a starter.
[0006]
[Means for Solving the Problems]
(1) In order to achieve the above object, the present invention ignites a fuel injection means for directly injecting fuel into a cylinder, a crank angle detection means for detecting a crank angle when the engine is stopped, and an air-fuel mixture in the cylinder. An engine starting device for detecting a cylinder in an expansion stroke after the engine is temporarily stopped and injecting and igniting fuel to restart the engine. Swell Detect the cylinder in the tension stroke, inject fuel into the cylinder in the expansion stroke and ignite the engine Starterless Low pressure compression control means for reducing the compression force of the cylinder in the compression stroke when restarting is provided.
With this configuration, the compression force that consumes the torque generated in the expansion stroke can be reduced, and self-starting can be performed without using a starter.
[0007]
(2) In the above (1), preferably, the low pressure compression control means includes a valve timing phase varying means for controlling an opening / closing timing of an intake valve of the cylinder in the compression stroke, and a fuel injection in the cylinder in the expansion stroke. And a control means for controlling the closing timing of the intake valve by the valve timing phase varying means so that the intake valve of the cylinder in the compression stroke is opened at the time of ignition.
[0008]
(3) In the above (1), preferably, the low pressure compression control means includes an auxiliary exhaust valve provided on an exhaust side of the cylinder in the compression stroke and a fuel injection / ignition of the cylinder in the expansion stroke. The auxiliary exhaust valve of the cylinder in the compression stroke is configured to include control means for controlling the auxiliary exhaust valve.
[0009]
(4) In order to achieve the above object, the present invention provides a fuel injection means for directly injecting fuel into a cylinder, a crank angle detection means for detecting a crank angle when the engine is stopped, and an air-fuel mixture in the cylinder. In an engine starting device for detecting a cylinder in an expansion stroke and restarting the engine by injecting and igniting fuel after the engine is temporarily stopped after the engine is temporarily stopped. Swell Detect the cylinder in the tension stroke, inject fuel into the cylinder in the expansion stroke and ignite the engine Starterless A high-pressure expansion control means for increasing the expansion force when restarting is provided.
With this configuration, the torque generated in the expansion stroke can be increased and self-starting can be performed without using a starter.
[0010]
(5) In the above (4), preferably, the high-pressure expansion control means includes variable valve timing means for varying the opening / closing timings of the intake valve and the exhaust valve of the cylinder in the intake stroke at the time of restart, and the expansion stroke in the expansion stroke. Control of the variable valve timing means so as to close the intake valve and exhaust valve of the cylinder in the intake stroke at the time of fuel injection / ignition of a cylinder, and control to inject and ignite fuel into the cylinder of the cylinder It consists of means.
[0011]
(6) In the above (5), preferably, the control means provides an air intake and air exhaust stroke after an expansion / exhaust stroke of the cylinder in the air intake stroke.
[0012]
(7) In the above (4), preferably, the high-pressure expansion control means includes a high-pressure air supply means for supplying high-pressure air to the cylinder in the expansion stroke and a fuel injection / It comprises control means for controlling to supply high-pressure air from the high-pressure air supply means at the time of ignition.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of the engine starter according to the first embodiment of the present invention will be described with reference to FIGS.
First, the overall configuration of the engine starter according to the present embodiment will be described with reference to FIG. In the following description, the multi-cylinder engine according to the present embodiment is, for example, a four-cylinder engine that ignites in order of each cylinder of 1-3-4-2, and a cylinder used for self-starting is a first cylinder.
FIG. 1 is a block diagram showing an overall configuration of an engine starter according to a first embodiment of the present invention.
[0014]
The fuel injection valve 10 is attached so as to inject fuel directly into the cylinder 20. The control unit 30 controls the amount of fuel injected from the fuel injection valve 10 and the injection timing. An intake valve 40 and an exhaust valve 50 are provided above the cylinder 20. A spark plug 60 is provided at the top of the cylinder 20. The ignition timing by the spark plug 60 is controlled by the control unit 30.
[0015]
The reciprocating motion of the piston 70 that moves up and down in the cylinder 20 is transmitted to the crankshaft 74 via the connecting rod 72 to rotate the crankshaft 74. When the crankshaft 74 rotates, the ring gear 76 rotates in the same manner.
[0016]
The crank angle sensor 80 uses the ring gear 76 to detect the rotational speed of the engine, that is, the rotational angle of the crankshaft 74. The detected signal is taken into the control unit 30. The stopper 90 engages with the ring gear 76 to stop the rotation of the crankshaft 74.
[0017]
A valve timing phase varying mechanism 44 is attached to a cam 42 that moves the intake valve 40. The valve timing phase varying mechanism 44 can open and close the intake valve 40 with respect to a predetermined crank angle, and is controlled by the control unit 30. The valve timing phase varying mechanism 44 is provided only in the third cylinder of the four-cylinder engine. That is, when the first cylinder used for self-starting is in the expansion stroke, the third cylinder is in the compression stroke, and the valve timing phase variable mechanism 44 is provided in the cylinder in the compression stroke.
[0018]
When the engine is stopped, the control unit 30 uses the detection signal of the crank angle sensor 80 to control the stopper 90 so that the crank angle is stopped at a position where a starterless start is possible. Further, the control unit 30 stops the fuel injection from the fuel injection valve 10 and further stops the supply of the ignition signal to the spark plug 60. Details of the control when the engine is stopped by the control unit 30 will be described later with reference to FIG.
[0019]
When the engine is started, the control unit 30 uses the detection signal of the crank angle sensor 80 to close the intake valve 40 and the exhaust valve 50, and the piston 70 starts to push down the connecting rod 72, that is, the expansion stroke. Cylinders at are detected. Then, fuel is injected from the fuel injection valve 10 into the cylinder 20 of the cylinder in the expansion stroke, an ignition signal is supplied to the spark plug 60, and the fuel spray in the cylinder 20 is ignited. Details of control at the time of engine start by the control unit 30 will be described later with reference to FIG.
[0020]
Next, the contents of control when the engine is automatically stopped by the control unit of the engine starter according to the present embodiment will be described with reference to FIG.
FIG. 2 is a flowchart showing the contents of control when the engine is automatically stopped by the control unit of the engine starter according to the first embodiment of the present invention.
[0021]
In steps s100 to s120, the control unit 30 executes a process for confirming that the automobile is in a state of being surely stopped. That is, in step s100, the control unit 30 determines whether or not the vehicle speed is zero. If the vehicle speed is zero, the process proceeds to step s105. If the vehicle speed is not zero, the automobile has not stopped reliably, and the process returns to step s100.
[0022]
Next, in step s105, the control unit 30 determines whether or not the brake is being depressed. If the brake is depressed, the process proceeds to step s110. If the brake is not depressed, the vehicle has not stopped reliably, and the process returns to step s100.
[0023]
Next, in step s110, the control unit 30 checks the navigation system. Here, if the navigation system has not instructed a right turn, the process proceeds to step s115. If the navigation system has instructed a right turn, there is a possibility of a right turn immediately thereafter. Since the operation has not stopped, the process returns to step s100.
[0024]
Next, in step s115, the control unit 30 checks the turn signal. Here, if the turn signal does not indicate a right turn, the process proceeds to step s120, and if the turn signal indicates a right turn, there is a possibility of making a right turn immediately thereafter or for starting. Since the turn signal is lit, the vehicle is not surely stopped, and the process returns to step s100.
[0025]
Next, in step s120, the control unit 30 determines whether or not a certain period of time has passed since the control unit 30 is stopped (after satisfying the requirements of steps s100 to s115). If the fixed time has elapsed, the process proceeds to step s125. If the fixed time has not elapsed, the vehicle has not stopped reliably, and the process returns to step s100.
[0026]
When it is determined that the requirements of steps s100 to s120 are satisfied and the automobile is stopped reliably, the control unit 30 stops the fuel injection from the fuel injection valve 10 in step s125. Furthermore, in step s130, the control unit 30 cuts off the ignition by the spark plug 30.
[0027]
Next, in step s135, the control unit 30 determines whether or not the engine speed is equal to or lower than the engine speed Nmin just before engine stop. Here, the rotation speed Nmin just before the engine stop is, for example, 300 rpm. If the engine speed is higher than the engine speed Nmin just before the engine stop, the process returns to step s135 to monitor the engine speed Nmin or less just before the engine stop, and if the engine speed is less than the engine speed Nmin just before the engine stop, the process proceeds to step s140.
[0028]
Next, in step s140, the control unit 30 determines whether or not the first cylinder used for self-starting is in the middle of the expansion stroke (10 ° to 140 ° after top dead center). When the first cylinder is not in the middle stage of the expansion stroke (10 ° to 140 ° after the top dead center), the process returns to step s140.
[0029]
If it is determined that the first cylinder is in the middle of the expansion stroke, in step s145, the control unit 30 operates the stopper 90 to forcibly stop the engine.
[0030]
Next, in step s145, the control unit 30 determines the number of the cylinder (first cylinder in the present embodiment) that injects fuel first and the crank angle when the engine is stopped so that it can be referred to at the time of subsequent starterless start. Remember.
[0031]
As described above, in the present embodiment, the cylinder used for self-starting (in the above example, the first cylinder) is forcibly stopped at the middle of the expansion stroke (10 ° to 140 ° after top dead center). I try to do it.
[0032]
Here, the reason why the crank angle for stopping the cylinder used for self-starting (the first cylinder in the above example) is set in the range of 10 ° to 140 ° after top dead center will be described with reference to FIG.
FIG. 3 is an explanatory diagram of the crank angle when the engine is automatically stopped by the control unit of the engine starter according to the first embodiment of the present invention.
[0033]
Even if the cylinder to be used for the starterless start is in the expansion stroke, it cannot be started in the areas A and C indicated by hatching. That is, when the piston position is near the compression top dead center (area A), the amount of air in the cylinder is small, so the amount of air-fuel mixture is also reduced. This is because it cannot be accelerated. Also, when the piston position is near bottom dead center (area C), unlike the case of top dead center, a large amount of air-fuel mixture can be obtained, but sufficient torque cannot be obtained due to the structure of the crank, and exhaust This is because the number of rotations of the crankshaft cannot be sufficiently increased because the valve starts to open. Therefore, in the starterless start according to the present embodiment, the region B that is larger than about 10 ° to 25 ° and smaller than about 120 ° to 140 ° is used on the basis of the compression top dead center.
[0034]
Next, the control contents at the time of engine start by the control unit of the engine start device according to the present embodiment will be described with reference to FIGS.
FIG. 4 is a flowchart showing the contents of control when the engine is started by the control unit of the engine starter according to the first embodiment of the present invention.
[0035]
In steps s200 to s220 in FIG. 4, the control unit 30 ensures safety when the engine is restarted. That is, in step s200, the control unit 30 determines whether or not the vehicle speed is zero. If the vehicle speed is zero, the process proceeds to step s205, and if not, the process returns to step s200.
[0036]
Next, in step s205, the control unit 30 determines whether or not the brake is being depressed. If the brake is depressed, the process proceeds to step s210. If the brake is not depressed, the process returns to step s200.
[0037]
Next, in the case of a manual transmission (MT) vehicle, in step s210, the control unit 30 determines whether or not the clutch pedal is depressed. If the clutch pedal is depressed, the process proceeds to step s215, and if the clutch pedal is not depressed, the process returns to step s200.
[0038]
In the case of an automatic transmission (AT) vehicle, in step s215, the control unit 30 determines whether or not the shift lever is in the drive (D) range. If it is in the D range, the process proceeds to step s218. If it is not in the D range, it is considered that the driver does not intend to start, and the process returns to step s200.
[0039]
Next, in the case of an AT car as well, in step s218, if the shift lever is in the D range and the brake pedal is released or the pedal effort is weakened to a predetermined value or less, the driver intends to start. Since it is determined that there is, the process proceeds to step s220. If the brake pedal maintains a depressing force equal to or greater than a predetermined value, the driver does not intend to start, and the process returns to step s200.
[0040]
Next, in step s220, the control unit 30 determines whether or not the water temperature is equal to or higher than Tmin. If the engine water temperature is low, starterless start cannot be performed due to increased friction, so the water temperature signal is checked. When the water temperature is equal to or higher than Tmin, the process proceeds to step s230, and when the water temperature is lower than Tmin, the process proceeds to step s225.
[0041]
If the water temperature is lower than Tmin, the control unit 30 stops the starterless start and switches to the starter start in step s225.
[0042]
On the other hand, when the water temperature is equal to or higher than Tmin, in step s230, the control unit 30 refers to information on the crank angle at the time of start stored when the engine is stopped (information stored in step s150 in FIG. 2).
[0043]
Next, in step s235, the control unit 30 controls the valve timing phase varying mechanism 44 to delay the phase of the intake side cam 42, so that the closing timing of the intake valve 40 is 10 ° before TDC (TDC-10). Set to °). As described above, the valve timing phase varying mechanism 44 is provided only in the third cylinder of the four-cylinder engine. When the first cylinder used for self-starting is in the expansion stroke, the third cylinder is in the compression stroke. It is in. The closing timing of the intake valve 40 in the compression stroke of the third cylinder is set to 10 ° before top dead center.
Here, the content of the intake valve lift control of the third cylinder at the time of engine start by the engine starter according to the present embodiment will be described with reference to FIG.
FIG. 5 is an explanatory diagram of intake valve lift control at the time of engine start by the engine start device according to the first embodiment of the present invention.
[0044]
In FIG. 5, the horizontal axis indicates time, and each stroke (exhaust stroke, intake stroke, compression stroke, expansion stroke) of the third cylinder is shown. The vertical axis indicates the valve lift amount of each of the intake valve 40 and the exhaust valve 50.
[0045]
In the figure, a solid line E indicates the valve lift amount of the normal exhaust valve 50. In the exhaust stroke of the third cylinder, the exhaust valve 50 begins to lift up slightly before BDC, and the exhaust valve 50 closes after TDC. A solid line A indicates the valve lift amount of the normal intake valve 40. In the intake stroke of the third cylinder, the intake valve 40 starts to lift up slightly before TDC, and the intake valve 40 closes after BDC. As described above, in the normal operation, the intake valve 40 of the third cylinder is controlled so that the intake valve 40 is closed after BDC.
[0046]
On the other hand, in step s235, the control unit 30 controls the valve timing phase varying mechanism 44 to delay the phase of the intake side cam 42 and set the closing timing of the intake valve 40 to 10 ° before TDC (TDC− 10 °). That is, as indicated by a broken line B in the figure, the closing timing of the intake valve 40 is 10 ° before top dead center (TDC−10 °). As a result, the third cylinder is in a state where the intake valve 50 is open even in the compression stroke.
[0047]
In the above description, the closing timing of the intake valve 40 that is set is, for example, a fixed value of 10 degrees before top dead center (TDC-10 °), but it depends on the starting crank angle of the first cylinder. Can be a value. For example, when a large amount of torque can be generated by the first cylinder, the closing timing of the intake valve 40 of the third cylinder is as early as 30 ° before top dead center (TDC−30 °), for example, as indicated by the alternate long and short dash line D. Thus, the compression pressure can be increased. Further, when the generated torque is small, the closing timing of the intake valve 40 is set to be delayed by 2 ° before top dead center (TDC-2 °), for example, as indicated by a two-dot chain line C, so as to lower the compression pressure. You can also That is, it can be varied in the range from 30 ° before top dead center (TDC-30 °) to 2 ° before top dead center (TDC-2 °) according to the crank angle at the start of the first cylinder.
[0048]
Next, in step s240 of FIG. 4, the control unit 30 calculates the volume of the first cylinder, that is, the amount of air in the first cylinder, based on the crank angle referred to in step s230, and the calculated air A fuel injection amount that provides a predetermined air-fuel ratio (A / F) with respect to the amount is determined. That is, when the piston is close to the top dead center, the amount of air is small, so the fuel injection is also reduced. Conversely, when the piston is close to the bottom dead center, the amount of air is large and the fuel injection amount is also increased.
[0049]
Next, in step s245, the control unit 30 controls the fuel injection valve to inject the fuel of the injection amount determined in step s240 into the cylinder of the first cylinder.
[0050]
Next, in step s250, after the fuel injection in step s245, the control unit 30 sends an ignition signal to the first cylinder after a lapse of a predetermined time (a time during which the fuel vaporization sufficiently proceeds), and the ignition plug 60 generates an ignition spark. I ignite by skipping. When the fuel spray is ignited, the fuel is combusted to generate an expansion force, and an expansion stroke for pushing down the piston is generated in the first cylinder.
[0051]
At this time, since the compression pressure of the third cylinder in the compression stroke is reduced because the intake valve 40 is open, the work required for compression is reduced, and the rotational torque generated by the combustion of the first cylinder is more than necessary. The compression top dead center of the third cylinder is exceeded without dropping.
[0052]
Next, in step s255, the control unit 30 determines whether the start is successful. Successful start is determined by whether or not the engine speed has reached a predetermined speed (for example, 300 rpm) or more. At this point, since the engine has not reached full rotation, the determination is made based on whether or not the rotational speed (angular speed) of the ring gear 76 is equal to or higher than the rotational speed at 300 rpm. If the start is successful, the process proceeds to step s280. If the start is not successful, the process proceeds to step s260.
[0053]
If the engine has been successfully started, in step s280, the control unit 30 has set the closing timing of the intake valve 40 to 10 ° before top dead center (TDC-10 °) by the valve timing phase varying mechanism 44. Return things to normal settings. That is, the valve lift amount of the intake valve 40 is returned from the characteristic of the broken line C shown in FIG. 5 to the characteristic of the solid line A.
In step s285, the control unit 30 switches to normal engine operation control.
[0054]
On the other hand, if it is determined in step s255 that the start is not successful, in step s260, the control unit 30 determines whether there is a cylinder with an appropriate crank angle in the middle of the expansion stroke that is not used for the start. To do. If there is a cylinder with an appropriate crank angle in the middle of the expansion stroke that is not used for starting, the process proceeds to step s270, and the control unit 30 stops starterless start and switches to starter start. If there is a cylinder with an appropriate crank angle in the middle of the expansion stroke that is not used for starting, the routine proceeds to step s275.
[0055]
When there is an expansion stroke cylinder that is not used for starting, in step s275, the control unit 30 refers to the No. and crank angle of another cylinder currently in the expansion stroke. When a 4-cylinder engine that ignites in order of each cylinder of 1-3-3-4-2 and the cylinder used for self-starting is the first cylinder, the third cylinder is the expansion stroke next to the first cylinder. Therefore, reference is made to the crank angle of the third cylinder. Then, returning to step s240, by executing steps s240 to s250, fuel injection and ignition of the third cylinder are performed, and the next combustion is performed.
[0056]
Here, when the third cylinder is in the expansion stroke, it is the fourth cylinder that is in the compression stroke. Since the fourth cylinder is not provided with the valve timing phase varying mechanism 44, when the third cylinder is in the expansion stroke, the compression force of the fourth cylinder is the normal compression force, but the first cylinder in the previous stroke is the compression force. Since the crankshaft starts to rotate due to the combustion of the cylinder, the rotational driving force due to the expansion of the third cylinder is added to the inertial force, and the compression force of the fourth cylinder can be overcome, leading to a successful start. When the start is successful, the operation is switched to the normal operation through the processing of steps s280 and s285.
[0057]
Here, the correlation of each process of the starterless start according to the present embodiment will be described with reference to FIG.
FIG. 6 is an explanatory diagram of each stroke at the time of engine start by the engine start device according to the first embodiment of the present invention. In FIG. 6, the horizontal axis represents time (stroke). The vertical axis indicates the first, third, fourth, and second cylinders.
[0058]
In the first stroke, the first cylinder is in the expansion stroke and the third cylinder is in the compression stroke. Therefore, the fuel spray is burned in the first cylinder by the processing of steps s245 and s250 in FIG. At this time, the timing of closing the intake valve of the third cylinder is delayed by the processing of step s235, and the intake valve is open, so the compression stroke is low pressure compression (in FIG. In order to distinguish from the normal compression process, (compression) is shown). If the start is successful in the first stroke, the normal four-cycle stroke is repeated for each cylinder in the second stroke and thereafter, and a normal operation state is obtained.
[0059]
Even if the start is not successful in the first stroke, the third cylinder is in the expansion stroke in the second stroke, and the fuel spray is burned in the third cylinder by the processing in steps s245 and s250 in FIG. To do. At this time, the fourth cylinder is in a normal compression stroke, but the crankshaft starts to rotate due to the combustion of the first cylinder in the previous stroke, so the rotational driving force due to the expansion of the third cylinder is added to the inertial force. In addition, it is possible to overcome the compression force of the fourth cylinder and lead to a successful start. When the start is successful, it switches to normal operation.
[0060]
In the above description, the valve timing phase varying mechanism 44 is provided only in the third cylinder, but may be provided also in the fourth cylinder. Thereby, the compression stroke of the fourth cylinder in the second stroke can be a low-pressure compression stroke, so that the starting can be made more reliable. In this case, after the process of step s275 in FIG. 4, as shown by a broken line, the process returns to step s235, and the intake valve closing timing of the fourth cylinder is set to 10 ° before top dead center (TDC−10 °), for example. Then, the processing after step s240 is executed.
[0061]
Here, transition of the engine speed and torque at the time of engine start by the engine start device according to the present embodiment will be described with reference to FIG.
FIG. 7 is an explanatory diagram of changes in engine speed and torque when the engine is started by the engine starter according to the first embodiment of the present invention. In FIG. 7A, the horizontal axis indicates time, and the vertical axis indicates engine speed. In FIG. 7B, the horizontal axis indicates time, and the vertical axis indicates the torque rotation number generated. The solid line indicates the state according to the present embodiment, and the broken line indicates the state according to the conventional example.
[0062]
In FIG. 7B, a solid line G1 indicates the torque generated by the combustion of the first cylinder that is the starting cylinder. On the other hand, in FIG. 7B, the broken line G3old indicates the torque consumed by the third cylinder in the compression stroke. Therefore, the torque G1 generated by the combustion of the first cylinder is consumed as the torque G3old by the third cylinder in the compression stroke. In FIG. 7A, the broken line Fold indicates the transition of the engine speed of the first cylinder, which is the start cylinder. As shown in the drawing, the engine speed does not increase and the engine fails to start. It becomes.
[0063]
On the other hand, in FIG. 7B, a solid line G3new indicates the torque consumed by the third cylinder when the compression stroke is set to constant pressure compression by using the valve timing phase variable mechanism 44 according to the present embodiment. Since the compression torque G3new consumed by this embodiment is smaller than the conventional compression torque G3old, the torque G1 generated by the combustion of the first cylinder is not completely consumed by the torque G3new by the third cylinder in the compression stroke. Is. In FIG. 7A, the solid line Fnew shows the transition of the engine speed of the first cylinder, which is the starting cylinder, but as shown in the figure, the engine speed does not decrease completely, and the next third Since the engine speed increases again due to the generated torque of the cylinder (solid line G3new in FIG. 7B), the engine can be successfully started.
[0064]
As described above, according to the present embodiment, since the compression force in the compression stroke can be reduced, self-starting can be enabled without using a starter. Some recent engines include a variable valve timing phase mechanism, and such an engine can be self-started only by controlling the engine without adding a new mechanism.
[0065]
Next, the configuration of the engine starter according to the second embodiment of the present invention will be described with reference to FIGS. As in the first embodiment, the multi-cylinder engine according to the present embodiment is, for example, a four-cylinder engine that ignites in order of each cylinder of 1-3-4-2, and the cylinder used for self-starting is the first cylinder. To do.
First, the overall configuration of the engine starter according to the present embodiment will be described.
FIG. 8 is a block diagram showing the overall configuration of the engine starter according to the second embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.
[0066]
In the first embodiment, the intake valve 40 is provided with the valve timing phase varying mechanism 44, whereas in the present embodiment, such a valve timing phase varying mechanism 44 is not provided. Instead, the exhaust valve The auxiliary exhaust valve 100 and the decompression mechanism 102 are provided on the 50 side. When the cylinder used for self-starting is the first cylinder, the auxiliary exhaust valve 100 and the decompression mechanism 102 are provided in the third cylinder in the compression stroke. The auxiliary exhaust valve 100 is an exhaust valve that is smaller than the exhaust valve 50. The decompression mechanism 102 is an actuator that opens and closes the auxiliary exhaust valve 100.
[0067]
In this embodiment, when performing combustion for self-starting in the first cylinder in the expansion stroke, the control unit 30A operates the decompression mechanism 102 of the third cylinder in the compression stroke to open the auxiliary exhaust valve 100. The compression force of the third cylinder is reduced to achieve low pressure compression as in the embodiment shown in FIG.
[0068]
Next, the control contents at the time of engine start by the control unit of the engine starter according to the present embodiment will be described with reference to FIG.
FIG. 9 is a flowchart showing the contents of control when the engine is started by the control unit of the engine starter according to the second embodiment of the present invention. The same reference numerals as those in the flowchart shown in FIG. 4 indicate the same processing contents.
[0069]
In steps s200 to s220 in FIG. 9, the control unit 30A secures the start condition when the engine is restarted and detects the driver's intention to start. Then, the process proceeds to step s230 and subsequent steps. In step s230, the control unit 30A refers to information on the crank angle at the time of start stored when the engine is stopped (information stored in step s150 in FIG. 2).
[0070]
Next, in step s235A, the control unit 30A operates the decompression mechanism 102 to open the auxiliary exhaust valve 100 until the set crank angle, for example, 10 degrees before top dead center (TDC-10 °), Release the compression pressure of the third cylinder. As a result, as in the first embodiment, the compression force of the third cylinder in the compression stroke can be reduced and a low pressure compression state can be achieved at the starterless start.
[0071]
The closing timing of the auxiliary exhaust valve 100 is, for example, a fixed value of 10 degrees before top dead center (TDC-10 °), but may be a value corresponding to the crank angle at the start of the first cylinder. For example, when a large amount of torque can be generated by the first cylinder, the closing time of the auxiliary exhaust valve 100 of the third cylinder is advanced to, for example, 30 ° before top dead center (TDC-30 °) to increase the compression pressure. Can be. Further, when the generated torque is small, the closing timing of the auxiliary exhaust valve 100 can be set, for example, so as to delay the closing pressure by 2 ° (TDC-2 °) before the top dead center to lower the compression pressure. That is, it can be varied in the range from 30 ° before top dead center (TDC-30 °) to 2 ° before top dead center (TDC-2 °) according to the crank angle at the start of the first cylinder.
[0072]
Hereinafter, the control unit 30A generates the expansion force by burning the fuel in the first cylinder by executing the processing of steps s240 to 285 in FIG. At this time, the compression pressure of the third cylinder in the compression stroke is reduced because the auxiliary exhaust valve 100 is open, so the work required for compression is reduced and the rotational torque generated by the combustion of the first cylinder is required. Without exceeding the above, the engine is successfully started by exceeding the compression top dead center of the third cylinder. When the start is successful, the operation is switched to the normal operation through the processing of steps s280 and s285.
[0073]
In the above description, the auxiliary exhaust valve 100 and the decompression mechanism 102 are provided only in the third cylinder, but may be provided in the fourth cylinder or all cylinders. Thereby, the compression stroke of the fourth cylinder in the second stroke can be a low-pressure compression stroke, so that the starting can be made more reliable.
[0074]
As described above, according to the present embodiment, since the compression force in the compression stroke can be reduced, self-starting can be enabled without using a starter. Further, since the exhaust valve is opened and the already burned gas is sucked into the cylinder, the fuel spray is easily vaporized and the ignition can be reliably performed by injecting the fuel into this high temperature already burned gas.
[0075]
Next, the configuration of the engine starter according to the third embodiment of the present invention will be described with reference to FIGS. As in the first embodiment, the multi-cylinder engine according to the present embodiment is, for example, a four-cylinder engine that ignites in order of each cylinder of 1-3-4-2, and the cylinder used for self-starting is the first cylinder. To do.
Initially, the whole structure of the engine starting apparatus by this embodiment is demonstrated using FIG.
FIG. 10 is a block diagram showing the overall configuration of the engine starter according to the third embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.
[0076]
In the first and second embodiments, the low pressure compression is used to reduce the compression force, whereas in the present embodiment, high pressure expansion is performed to increase the expansion force. Therefore, in the present embodiment, the intake valve 40 includes a variable valve timing mechanism 46, and the exhaust valve 50 includes a variable valve timing mechanism 56. In the case of a four-cylinder engine, the variable valve timing mechanisms 46 and 56 are provided in all the cylinders. The variable valve timing mechanisms 46 and 56 can control the opening and closing of the intake valve 40 and the exhaust valve 50 using, for example, electromagnetic force, and the opening and closing timing is controlled by a control signal from the control unit 30B. .
[0077]
In this embodiment, two or more cylinders that are originally different in stroke are simultaneously used as an expansion stroke for starterless start, thereby generating a torque of an expansion stroke higher than conventional and enabling starterless start. Yes.
[0078]
Next, the control contents at the time of engine start by the control unit of the engine starter according to the present embodiment will be described with reference to FIGS.
FIG. 11 is a flowchart showing the control contents at the time of engine start by the control unit of the engine start device according to the third embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same processing contents. This embodiment is particularly characterized in the processing contents of steps s235B, s245B, s250B, s252, and s275B.
[0079]
Moreover, FIG. 12 is explanatory drawing of each process at the time of engine starting by the engine starting apparatus by the 3rd Embodiment of this invention. In FIG. 12, the horizontal axis represents time (stroke). The vertical axis indicates the first, third, fourth, and second cylinders.
[0080]
In steps s200 to s220 in FIG. 11, the control unit 30B ensures a start condition when the engine is restarted, and detects the driver's intention to start. Thereafter, in step s220, the control unit 30B determines whether or not the water temperature is equal to or higher than Tmin. If the engine water temperature is low, in step s225, the control unit 30B stops the starterless start and starts the starter. Switch.
[0081]
On the other hand, when the water temperature is equal to or higher than Tmin, in step s230B, the control unit 30B refers to information on the crank angle at the time of start stored when the engine is stopped (information stored in step s150 in FIG. 2).
[0082]
Next, in step s235B, when the first cylinder is used for starting, the control unit 30B further controls the variable bubble timing mechanisms 46 and 56 of the fourth cylinder, which is originally the intake stroke, so that the intake valve 40 And the exhaust valve 50 is closed.
[0083]
Next, in step s240, the control unit 30B calculates the volume of the first cylinder, that is, the air amount in the first cylinder, based on the crank angle referred to in step s230B, and with respect to the calculated air amount, The fuel injection amount at which the predetermined air-fuel ratio (A / F) is obtained is determined. That is, when the piston is close to the top dead center, the amount of air is small, so the fuel injection is also reduced. Conversely, when the piston is close to the bottom dead center, the amount of air is large and the fuel injection amount is also increased. This fuel injection amount is not only the fuel injection amount for the first cylinder but also the fuel injection amount for the fourth cylinder.
[0084]
Next, in step s245B, the control unit 30B controls the fuel injection valve to simultaneously inject the fuel of the injection amount determined in step s240 into the first and fourth cylinders.
[0085]
Next, in step s250B, after the fuel injection in step s245B, the control unit 30B sends an ignition signal to each of the first cylinder and the fourth cylinder after a predetermined time (time when fuel vaporization sufficiently proceeds), The plug 60 ignites by igniting the spark. When the fuel spray is ignited, the fuel is combusted to generate an expansion force, and an expansion stroke for pushing down the piston is simultaneously generated in the first cylinder and the fourth cylinder.
[0086]
Here, as shown in FIG. 12, in the first stroke, the first cylinder and the fourth cylinder are simultaneously in the expansion stroke. Therefore, compared with the example shown in FIG. 6, the expansion force can be doubled and the generated torque can be increased. At this time, since the third cylinder is in a normal compression stroke, torque is consumed, but since the generated torque is large, self-starting can be successful.
[0087]
Next, in step s252, the control unit 30B determines whether or not the second stroke has ended. If not completed, the process proceeds to step s275B. If completed, the process proceeds to step s255.
[0088]
At the time when the first stroke is completed, the second stroke is not yet completed, and therefore, in step s275B, the control unit 30B refers to the No. and crank angle of another cylinder currently in the expansion stroke. In the case of a 4-cylinder engine that ignites in the order of the cylinders 1-3-3-2, and the cylinders used for self-starting are the first cylinder and the fourth cylinder, the next expansion strokes are the third cylinder and the second cylinder. Since there are two cylinders, for example, the crank angle of the third cylinder is referred to. Then, returning to step s235B, by executing steps s235B to s250B, fuel injection and ignition of the third cylinder and the second cylinder are performed, and the next combustion is performed. As a result, as shown in FIG. 12, in the second stroke, the third cylinder and the second cylinder are simultaneously in the expansion stroke. Therefore, compared with the example shown in FIG. 6, the expansion force can be doubled and the generated torque can be increased. At this time, since the first cylinder and the fourth cylinder are in the exhaust stroke, the torque is hardly consumed and the generated torque is large, so that the self-start can be successful.
[0089]
When the second stroke is finished, in step s255, the control unit 30B determines whether the start is successful. If the start is successful, the process proceeds to step s285. If the start is not successful, the process proceeds to step s270.
[0090]
If the engine has been successfully started, the control unit 30B switches to normal engine operation control in step s285.
[0091]
On the other hand, if it is determined in step s255 that the start was not successful, in step s270, the control unit 30B stops the starterless start and switches to the starter start.
[0092]
In the example shown in FIG. 12, the crankshaft makes one revolution in the first stroke to the fourth stroke, but in the third stroke, the fourth cylinder is referred to as an intake stroke that does not contribute to combustion (hereinafter referred to as “air intake”). In the fourth stroke, the fourth cylinder is set to an exhaust stroke that does not contribute to combustion (hereinafter referred to as “air exhaust”). Similarly, in the fourth stroke, the second cylinder is air intake, and in the fifth stroke, the second cylinder is air exhaust. Thereby, scavenging in a cylinder can be performed together and the combustion efficiency of the next stroke can be improved.
[0093]
In the above description, as shown in FIG. 12, the first stroke of the third cylinder is the compression stroke, but the control unit 30B controls the variable valve timing mechanism 46 to close the intake valve 40. By delaying the timing to, for example, 10 degrees before the top dead center, the engine speed can be increased smoothly at the starterless start, except for the resistance caused by the compression work of the third cylinder, as in the first embodiment. it can. Alternatively, instead of closing the intake valve 40 late, the variable valve timing mechanism 56 may be controlled to open the exhaust valve 50 and release the compression pressure.
[0094]
As described above, according to the present embodiment, since the expansion force in the expansion stroke can be improved, self-starting can be performed without using a starter. An engine having a variable valve timing mechanism can be self-started only by controlling the engine without adding a new mechanism.
[0095]
Next, the configuration of the engine starter according to the fourth embodiment of the present invention will be described with reference to FIGS. As in the first embodiment, the multi-cylinder engine according to the present embodiment is, for example, a four-cylinder engine that ignites in order of each cylinder of 1-3-4-2, and the cylinder used for self-starting is the first cylinder. To do.
Initially, the whole structure of the engine starting apparatus by this embodiment is demonstrated using FIG.
FIG. 13 is a block diagram showing the overall configuration of the engine starter according to the fourth embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.
[0096]
In the third embodiment, high pressure expansion is performed to increase the expansion force by simultaneously setting two cylinders in the expansion stroke, whereas in this embodiment, high pressure air is forced into the cylinder. At the same time, high-pressure expansion is performed by injecting fuel corresponding to the amount of air. By this high-pressure expansion, a torque of an expansion stroke higher than the conventional one is generated to enable starterless start.
[0097]
Therefore, in this embodiment, the auxiliary intake valve 110 and the air tank 120 are provided. The auxiliary intake valve 110 is provided at the outlet side of the air tank 120 on the intake side of the cylinder in the expansion stroke during starterless start. The auxiliary intake valve 110 is opened and closed by an actuator 112. The actuator 112 is controlled by the control unit 30C.
[0098]
In the air tank 120, air pressurized by the air pump 122 is accumulated. The pressure inside the air tank 120 is detected by the pressure sensor 124 and taken into the control unit 30C. The pressure sensor 142 may be substituted if a pressure sensor for grasping the combustion state is attached in the cylinder 20. For example, the air pump 122 is connected to the drive shaft and operated when the vehicle is decelerated. By comprising in this way, the deceleration energy of a vehicle can be used effectively. The air pump 122 may be driven by a motor. Further, in an engine with a supercharger, an air pump is not particularly provided, and the intake pipe pressure at the time of positive pressure may be accumulated in the air tank 120 by a one-way valve or the like. Further, the actuator 112 can be operated to introduce the compression pressure of the cylinder at the time of engine braking of the vehicle. In this case, the air pump 122 need not be operated. The volume of the air tank 120 may be, for example, about the combustion chamber volume at the top dead center of the engine, and the pressure is about 2 to 10 atm.
[0099]
Next, the control contents at the time of engine start by the control unit of the engine start device according to the present embodiment will be described with reference to FIGS.
FIG. 14 is a flowchart showing the contents of control when the engine is started by the control unit of the engine starter according to the fourth embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same processing contents. This embodiment is particularly characterized in the processing contents of steps s232, 234, 240C, s277, and s279.
[0100]
FIG. 15 is an explanatory diagram of each stroke when the engine is started by the engine starter according to the fourth embodiment of the present invention. In FIG. 15, the horizontal axis indicates time (stroke). The vertical axis indicates the first, third, fourth, and second cylinders.
[0101]
In steps s200 to s220 in FIG. 14, the control unit 30C secures the start condition when the engine is restarted, and detects the driver's intention to start. Thereafter, in step s220, the control unit 30C determines whether or not the water temperature is equal to or higher than Tmin. If the engine water temperature is low, in step s225, the control unit 30C stops the starterless start and starts the starter. Switch.
[0102]
On the other hand, when the water temperature is equal to or higher than Tmin, in step s230, the control unit 30 refers to information on the crank angle at the time of start stored when the engine is stopped (information stored in step s150 in FIG. 2).
[0103]
Next, in step s232, the control unit 30C detects the internal pressure of the air tank 120 with the pressure sensor 124, and the control unit 30C stores it. Note that the internal pressure of the air tank 120 is increased to 2 to 10 atm in advance before starting the starterless operation.
[0104]
Next, in step s232, the control unit 30C operates the actuator 112, opens the auxiliary intake valve 110, and introduces compressed air into the cylinder 20.
[0105]
Next, in step s240C, the control unit 30C calculates the amount of air in the first cylinder based on the crank angle referred to in step s230 and the internal pressure of the air tank 120 detected and stored in step s232, and this calculation is performed. A fuel injection amount that is a predetermined air-fuel ratio (A / F) with respect to the air amount is determined.
[0106]
Next, in step s245, the control unit 30C controls the fuel injection valve to inject the fuel of the injection amount determined in step s240C into the cylinder of the first cylinder.
[0107]
Next, in step s250, after the fuel injection in step s245, the control unit 30C sends an ignition signal to the first cylinder after a lapse of a predetermined time (a time during which fuel vaporization sufficiently proceeds), and an ignition spark is generated by the spark plug 60. I ignite by skipping. When the fuel spray is ignited, the fuel is combusted and an expansion force is generated to push down the piston.
[0108]
Here, as shown in FIG. 15, in the first stroke, the first cylinder is in the expansion stroke. Since the expansion stroke at this time is injecting fuel to the high-pressure air, the normal expansion stroke is performed. High-pressure expansion (shown as [expansion] in FIG. 15) having a larger expansion force than that can increase the generated torque. At this time, since the third cylinder is in the normal compression stroke, torque is consumed, but since the torque generated in the first cylinder is large, self-starting can be successful.
[0109]
Next, in step s255, the control unit 30C determines whether the start is successful. If the start is successful, the process proceeds to step s285. If the start is not successful, the process proceeds to step s260.
[0110]
If the engine has been successfully started, in step s285, the control unit 30 switches to normal engine operation control.
[0111]
On the other hand, if it is determined in step s255 that the start is not successful, in step s260, the control unit 30C determines whether there is a cylinder with an appropriate crank angle in the middle of the expansion stroke that is not used for the start. To do. If there is no cylinder with an appropriate crank angle in the middle of the expansion stroke that is not used for starting, the process proceeds to step s270, and the control unit 30C stops the starterless start and switches to the starter start. If there is a cylinder with an appropriate crank angle in the middle of the expansion stroke that is not used for starting, the routine proceeds to step s275.
[0112]
When there is an expansion stroke cylinder that is not used for starting, in step s275, the control unit 30 refers to the No. and crank angle of another cylinder currently in the expansion stroke. When a 4-cylinder engine that ignites in order of each cylinder of 1-3-3-4-2 and the cylinder used for self-starting is the first cylinder, the third cylinder is the expansion stroke next to the first cylinder. Therefore, reference is made to the crank angle of the third cylinder.
[0113]
Next, in step s277, the control unit 30C determines whether or not the internal pressure of the air tank 120 is equal to or higher than a reference value (for example, 2 atm). If it is equal to or greater than the reference value, the process returns to step s240C and steps s240C to s250 are executed to inject and ignite the third cylinder to perform the next combustion and obtain an expansion force by high-pressure expansion. Note that the air tank 120 and the auxiliary intake valve 110 are also provided in the third cylinder.
[0114]
If the internal pressure of the air tank is less than the reference value, the control unit 30C operates the air pump 122 to fill the air tank 120 with compressed air in step s279. Thereafter, the process returns to step s240C, and steps s240C to s250 are executed to inject and ignite the third cylinder to perform the next combustion and obtain an expansion force by high-pressure expansion.
[0115]
As described above, since air is rapidly introduced into the cylinder 20 from the auxiliary intake valve 110, turbulence in the cylinder 20 can be promoted, and mixing of fuel and air is promoted to improve combustion efficiency. The amount of fuel used can also be reduced.
[0116]
The auxiliary intake valve 110 may be provided only in the third cylinder when the first cylinder to be used at the starterless start is determined, for example, when it is the first cylinder, or when the first cylinder to be used is arbitrary. It is necessary to provide all cylinders. Even in that case, the number of the air tank 120, the air pump 122, and the pressure sensor 124 may be one, and it is only necessary to provide piping to each cylinder.
[0117]
As described above, according to the present embodiment, since the expansion force in the expansion stroke can be improved, self-starting can be performed without using a starter.
[0118]
In each of the above-described embodiments, the case of a four-cylinder engine has been mainly described. However, if a mechanism for injecting fuel into a cylinder is provided, the same means is mainly used in an engine having two or more cylinders to obtain an effect. be able to. Further, for the purpose of explanation, the first cylinder is initially injected and ignited, but it is of course possible to inject and ignite other cylinders first by the crank angle.
[0119]
In each of the embodiments, the engine is mechanically stopped by the stopper 90. However, if the cylinder to be used for combustion first is not limited as described above, the crank angle is near the top dead center or the bottom dead center. Except in certain cases, it is not always necessary to use a stopper mechanism. Further, in the second embodiment, the crank angle is roughly desired by controlling and using the decompression mechanism 102, and in the third embodiment, by controlling the opening and closing of the intake and exhaust valves 40, 50. It is also possible to stop at the position.
[0120]
As described above, according to each embodiment of the present invention, the engine can be restarted without using a starter. Therefore, the starter motor can be used less frequently while providing an automatic engine stop / start function. Can be improved.
Further, the power consumption of the starter can be saved and the fuel consumption can be improved.
Furthermore, by stopping the engine during idling, unnecessary idling can be prevented, the amount of exhaust gas, noise and vibration can be suppressed, and fuel consumption can be improved.
In addition, due to the compression work of another cylinder in the compression stroke at the time of combustion of the first cylinder, there is no possibility that the engine speed decreases and the start fails, and a smooth start can be performed.
[0121]
【The invention's effect】
According to the present invention, the engine can be self-started without using a starter.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall configuration of an engine starter according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing the contents of control when the engine is automatically stopped by the control unit of the engine starter according to the first embodiment of the present invention.
FIG. 3 is an explanatory diagram of a crank angle when the engine is automatically stopped by the control unit of the engine starter according to the first embodiment of the present invention.
FIG. 4 is a flowchart showing the contents of control when the engine is started by the control unit of the engine starter according to the first embodiment of the present invention.
FIG. 5 is an explanatory diagram of intake valve lift control at the time of engine start by the engine start device according to the first embodiment of the present invention.
FIG. 6 is an explanatory diagram of each stroke at the time of engine start by the engine start device according to the first embodiment of the present invention.
FIG. 7 is an explanatory diagram of changes in engine speed and torque when the engine is started by the engine starter according to the first embodiment of the present invention.
FIG. 8 is a block diagram showing an overall configuration of an engine starter according to a second embodiment of the present invention.
FIG. 9 is a flowchart showing control contents at the time of engine start by a control unit of an engine start device according to a second embodiment of the present invention.
FIG. 10 is a block diagram showing an overall configuration of an engine starter according to a third embodiment of the present invention.
FIG. 11 is a flowchart showing control contents at the time of engine start by a control unit of an engine start device according to a third embodiment of the present invention.
FIG. 12 is an explanatory diagram of each stroke at the time of engine start by an engine start device according to a third embodiment of the present invention.
FIG. 13 is a block diagram showing an overall configuration of an engine starter according to a fourth embodiment of the present invention.
FIG. 14 is a flowchart showing control contents at the time of engine start by a control unit of an engine start device according to a fourth embodiment of the present invention.
FIG. 15 is an explanatory diagram of each stroke at the time of engine start by an engine start device according to a fourth embodiment of the present invention.
[Explanation of symbols]
10 ... Fuel injection valve
20 ... Cylinder
30 ... Control unit
40 ... Intake valve
42 ... Camshaft
44 ... Valve timing phase variable mechanism
46, 56 ... Variable valve timing mechanism
50 ... Exhaust valve
60 ... Spark plug
70 ... Piston
72 ... Connecting rod
74 ... Crankshaft
76 ... Ring gear
80 ... Crank angle sensor
90 ... Stopper
100 ... Auxiliary exhaust valve
102 ... Decompression mechanism
110 ... Auxiliary intake valve
112 ... Actuator
120 ... Air tank
122 ... Air pump
124 ... Pressure sensor

Claims (7)

The fuel injection means for directly injecting fuel into the cylinder, the crank angle detection means for detecting the crank angle when the engine is stopped, and the ignition means for igniting the air-fuel mixture in the cylinder are expanded after the engine is temporarily stopped. In an engine starter that detects cylinders in the stroke, injects and ignites fuel and restarts the engine,
After suspension of the engine, Rise to detect cylinder in Zhang stroke, when injecting fuel and ignition to restart the engine in the starter-less in a certain cylinder in the expansion stroke, lower the compressive force of the cylinder in the compression stroke An engine starter characterized by comprising low pressure compression control means. The engine starter according to claim 1, wherein
The low pressure compression control means includes a valve timing phase varying means for controlling the opening and closing timing of the intake valve of the cylinder in the compression stroke;
And control means for controlling the closing timing of the intake valve by the valve timing phase varying means so that the intake valve of the cylinder in the compression stroke is opened at the time of fuel injection / ignition of the cylinder in the expansion stroke. Engine starting device. The engine starter according to claim 1, wherein
The low-pressure compression control means includes an auxiliary exhaust valve provided on the exhaust side of the cylinder in the compression stroke,
An engine starter comprising: control means for controlling the auxiliary exhaust valve so that the auxiliary exhaust valve of the cylinder in the compression stroke is opened during fuel injection / ignition of the cylinder in the expansion stroke. A fuel injection means for directly injecting fuel into a cylinder, comprising: a crank angle detection means for detecting a crank angle when the engine is stopped, and ignition means for igniting air-fuel mixture in the cylinder, after suspension of the engine, Rise In an engine starter that detects a cylinder in a tension stroke and injects and ignites fuel to restart the engine,
High pressure expansion control means that detects the cylinder in the expansion stroke after the engine is temporarily stopped and injects and ignites fuel in the cylinder in the expansion stroke and restarts the engine without a starter, thereby increasing the expansion force An engine starter characterized by that. The engine starting device according to claim 4,
The high-pressure expansion control means includes
Variable valve timing means for varying the opening and closing timing of the intake valve and the exhaust valve of the cylinder in the intake stroke at the time of restart;
At the time of fuel injection / ignition of the cylinder in the expansion stroke, the variable valve timing means is controlled so as to close the intake valve and exhaust valve of the cylinder in the intake stroke, and fuel is injected into the cylinder of this cylinder. And an engine starting device comprising ignition control means. The engine starter according to claim 5, wherein
An engine starter characterized in that the control means provides an air intake and air exhaust stroke after an expansion / exhaust stroke of a cylinder in the air intake stroke. The engine starting device according to claim 4,
The high-pressure expansion control means includes
High-pressure air supply means for supplying high-pressure air to the cylinder in the expansion stroke at the time of restart;
An engine starter comprising: control means for controlling to supply high-pressure air from the high-pressure air supply means at the time of fuel injection / ignition of the cylinder in the expansion stroke.

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