JP3832231B2 - Internal combustion engine rotation start device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an internal combustion engine rotation start device that starts rotation of a crankshaft of an internal combustion engine that has stopped rotating.
[0002]
[Prior art]
When starting the internal combustion engine, the crankshaft of the internal combustion engine is rotated by driving a rotation output means such as a starter. At this time, together with the friction of the internal combustion engine, the compression pressure of the cylinder particularly in the compression stroke acts as a rotational resistance force. If this rotational resistance is excessive, the rotation of the internal combustion engine stops immediately before the top dead center of the cylinder in the compression stroke, which may cause a start failure. In particular, when the temperature is warm, the increase in the compression pressure is large, so that a starting failure is likely to occur.
[0003]
In order to eliminate such a starting failure, when the rotation of the internal combustion engine stops at the time of starting, a technique for executing intermittent torque in the forward direction or forward / reverse rotation by the rotation output means (Japanese Patent Laid-Open No. 3-3969) Publication). In this technology, by executing intermittent torque in the forward direction or forward / reverse rotation, the pressure in the cylinder is released when the torque is interrupted, the frictional force is reduced by changing from static friction to dynamic friction, and inertia torque is generated. Thus, starting can be facilitated.
[0004]
In addition to this, a technology that expects the effects as described above by reversely rotating the internal combustion engine by driving the rotation output means from the start and then performing forward rotation (JP-A-7-71350). Is disclosed.
[0005]
[Problems to be solved by the invention]
However, the former prior art merely performs intermittent torque in the forward direction or forward / reverse rotation, and does not consider the arrival phase of the crankshaft due to the reverse rotation. For this reason, the phase of the crankshaft may return too much, opening the intake valve of the cylinder in the compression stroke at the start of rotation, and the inside of the cylinder may become atmospheric pressure. When the next forward rotation is performed in such a state, conversely, the compression pressure is increased and the rotational resistance is further increased compared to the first forward rotation. For this reason, the possibility of stopping during rotation again increases. Further, if the crankshaft phase is not sufficiently returned by the reverse rotation, the effect of the inertia torque by the flywheel or the like becomes insufficient when the forward rotation is performed again. For this reason, even if the pressure in the cylinder is slightly reduced, the rotation resistance during compression cannot be opposed and the rotation may be stopped.
[0006]
In the latter prior art, the reverse is executed from the beginning. However, in this reverse rotation from the beginning, since the pressure in the cylinder is atmospheric pressure, there is no effect of releasing the pressure from the inside of the cylinder to the outside. In addition, when switching from the first reverse rotation to the normal rotation, the piston ring floats in the piston ring groove, so that the atmospheric pressure is introduced into the cylinder that is at a lower pressure than the atmospheric pressure. Conversely, the pressure in the cylinder will be excessive. Therefore, the compression pressure is higher than that in the case of normal rotation from the beginning, and the possibility that the rotation resistance force becomes excessive and the rotation stops is increased.
[0007]
In the latter prior art, the reverse rotation angle width is set to a very small value of π / 4 (45 °). However, since the phase of the crankshaft is unknown at the time of the first reversal, the intake valve may be opened even with such a small reversal of the angular width. On the other hand, if the intake valve is not opened, sufficient inertia torque cannot be obtained by such a small reverse rotation of the angular width, and there is a risk that the rotation will stop.
[0008]
Thus, in both prior arts, there is a high possibility that the start of rotation of the internal combustion engine will be difficult, and it is difficult to say that the startability has been sufficiently improved.
An object of the present invention is to provide an internal combustion engine rotation start device that can easily start rotation of an internal combustion engine that has stopped rotating.
[0009]
[Means for Solving the Problems]
In the following, means for achieving the above object and its effects are described.
The internal combustion engine rotation start device according to claim 1 is an internal combustion engine rotation start device that starts rotation of the crankshaft of the internal combustion engine by driving the rotation output means, and at the start of rotation of the crankshaft, When the forward rotation driving means for rotating the crankshaft to the forward rotation side by driving and the rotation of the crankshaft to the forward rotation side by the forward rotation driving means are stopped, the compression stroke is just before the top dead center at the compression stroke. Immediately before the intake valve in the cylinder is opened, the reverse rotation drive means for rotating the crankshaft to the reverse rotation side, and after the crankshaft is rotated to the reverse rotation side by the reverse rotation drive means, the rotation output means is driven to normalize the crankshaft. Re-forward rotation drive means for re-rotating on the rotation side is provided.
[0010]
The forward rotation drive means rotates the crankshaft to the forward rotation side by driving the rotation output means at the beginning of rotation of the crankshaft. If the rotation is started by this first normal rotation, the rotation is quickly achieved.
[0011]
On the other hand, when the rotation of the crankshaft to the forward rotation side by the normal rotation driving means stops, the reverse rotation driving means until just before the intake valve in the cylinder just before the compression stroke top dead center at the time of stop is opened. Rotate the crankshaft to the reverse side. By this reverse rotation, the piston ring can be lifted in the piston ring groove at the start of the reverse rotation, so that the pressure in the cylinder immediately before the top dead center of the compression stroke at the time of stop can be reduced to the outside.
[0012]
By the way, when the rotation of the crankshaft is first stopped by the forward rotation performed by the forward rotation driving means, this stop phase is a phase that has been stopped due to the rotational resistance by the compression pressure, and a certain cylinder has a compression stroke. This indicates that the phase exists in the state immediately before the top dead center. For this reason, in the cylinder immediately before the top dead center of the compression stroke, the reverse rotation angle width from this stop phase to immediately before the intake valve is opened is naturally determined. Therefore, the reverse rotation drive means can perform reverse rotation until just before the intake valve in the corresponding cylinder opens, only by performing reverse rotation corresponding to the reverse rotation angle width from the stop phase. That is, the crankshaft can be reversed to the maximum, and atmospheric pressure is not introduced from the intake valve to the corresponding cylinder.
[0013]
In this way, when the re-forward rotation driving means next rotates the crankshaft again to the normal rotation side by driving the rotation output means, the pressure in the corresponding cylinder is again just before the top dead center of the compression stroke. Lower than last time. In addition, since it is re-forward rotation after the reverse rotation until just before the intake valve opens, sufficient inertia torque is generated. Moreover, the frictional force is small due to the dynamic friction.
[0014]
This makes it easy to start the rotation of the internal combustion engine that has stopped rotating.
According to a second aspect of the present invention, in the internal combustion engine rotation starting device according to the first aspect, the reverse rotation driving means stops the rotation of the crankshaft to the normal rotation side by the normal rotation driving means and the renormal rotation driving means. In this case, the crankshaft is rotated in the reverse direction until the intake valve in the cylinder immediately before the compression stroke top dead center is opened at the time of the stop.
[0015]
The reverse drive means is used not only when the rotation of the crankshaft to the forward rotation side by the forward rotation drive means but also when the rotation of the crankshaft to the forward rotation side by the re-forward drive means is stopped. At the time of stop, the crankshaft is rotated in the reverse direction until just before the intake valve in the cylinder just before the compression stroke top dead center is opened.
[0016]
As a result, even if the rotation cannot be started even by the re-forward rotation driving means, the rotation can be started more reliably by the reverse rotation again by the action described in the first aspect.
[0017]
In the internal combustion engine rotation starting device according to claim 3, in addition to the configuration according to claim 2, the rotation of the crankshaft to the reverse rotation side by the reverse rotation driving means and the forward rotation side of the crankshaft by the renormal rotation driving means If the rotation of the internal combustion engine does not start after the re-rotation to the reference number of times is repeated, the rotation of the crankshaft by the rotation of the rotation output means and the drive of the second rotation output means or the second rotation Rotation output switching means for switching the rotation of the crankshaft only by driving the rotation output means and executing rotation of the internal combustion engine is provided.
[0018]
In this way, after the forward rotation by the forward rotation driving means, the rotation of the crankshaft to the reverse rotation side by the reverse rotation driving means and the re-rotation of the crankshaft to the forward rotation side by the re-forward rotation driving means are executed a reference number of times. After that, if the rotation of the internal combustion engine has not started, the rotation output switching means rotates the crankshaft or the second rotation output by driving the rotation output means and the second rotation output means. The crankshaft is rotated only by driving the means. Thus, even if the rotation is stopped by the normal rotation driving means, the reverse rotation driving means, and the re-normal rotation driving means, the internal combustion engine can be reliably started to rotate.
[0019]
According to a fourth aspect of the present invention, there is provided the internal combustion engine rotation start device according to the third aspect, wherein the rotation output means is a motor generator disposed in or outside a driving force transmission system from the internal combustion engine to the wheels. The rotation output means 2 is a starter.
[0020]
Thus, using the motor generator as the rotation output means, the forward rotation drive means, the reverse rotation drive means, and the re-forward rotation drive means rotate the internal combustion engine. In this motor generator drive control, when the internal combustion engine does not start rotation, the rotation output switching means switches to rotation by the motor generator and the starter as the second rotation output means, or rotation by only the starter.
[0021]
As a result, even if the rotation of the internal combustion engine does not start even when the motor generator is driven, the rotation of the internal combustion engine can be reliably started.
[0022]
The internal combustion engine rotation start device according to claim 5 is activated for automatic start of the internal combustion engine when the automatic start condition is satisfied after the automatic stop of the internal combustion engine in the configuration according to any one of claims 1 to 4. It is characterized by that.
[0023]
The internal combustion engine rotation start device may be activated for automatic start of the internal combustion engine. The automatic start is a start not intended by the driver. Therefore, as described above, since the rotation of the internal combustion engine can be easily started, the startability can be sufficiently improved, and the driver does not feel uncomfortable at the time of automatic start.
[0024]
According to a sixth aspect of the present invention, in the internal combustion engine rotation starting device according to any one of the first to fifth aspects, the reverse drive means is predetermined from a crank angle phase at which the rotation of the crankshaft to the forward rotation side is stopped. By reversing the crankshaft by the angular width, the crankshaft is rotated in the reverse direction until immediately before the intake valve in the cylinder just before the compression stroke top dead center is opened at the time of the stop.
[0025]
As described in the first aspect, since the stop phase immediately before the compression stroke top dead center is in a substantially constant range in the cylinder immediately before the compression stroke top dead center at the time of stop, the intake valve opens from this stop phase. The reverse rotation angle width until just before is determined automatically. Therefore, the reverse drive means can perform reverse rotation just before the intake valve in the corresponding cylinder is opened by only performing reverse rotation by a predetermined angular width from the stop phase.
[0026]
In the internal combustion engine rotation start device according to claim 7, in the configuration according to any one of claims 1 to 5, the reverse drive means is predetermined from a crank angle phase at which the rotation of the crankshaft to the forward rotation side is stopped. By rotating the crankshaft in reverse for a time, the crankshaft is rotated in the reverse direction until immediately before the intake valve in the cylinder just before the compression stroke top dead center at the time of stop is opened.
[0027]
In addition to directly reversing the crankshaft until just before the intake valve is opened by directly detecting the reverse rotation angle width, it is possible to perform reverse rotation by a necessary angular width depending on the rotation time to the reverse rotation side.
[0028]
In the internal combustion engine rotation start device according to claim 8, in the configuration according to any one of claims 1 to 7, the reverse drive means performs rotation of the crankshaft to the reverse side by driving the rotation output means. Features.
[0029]
The rotation of the crankshaft to the reverse side of the crankshaft by the reverse drive means opens the intake valve of the corresponding cylinder using the torque in the reverse direction due to the compression pressure generated by the forward rotation executed by the forward drive means immediately before this. Although it may be reversed until just before the valve is operated, the rotation output means may be driven in this way.
[0030]
Thus, by positively using the driving force of the rotation output means, it is possible to reverse the rotation immediately and reliably until just before the intake valve of the corresponding cylinder is opened. Thus, since the reverse rotation is positively reversed by the driving force of the rotation output means, the piston ring can be surely lifted in the piston ring groove at the start of the reverse rotation, and the pressure in the corresponding cylinder can be sufficiently released. Can do.
[0031]
Further, as described in the seventh aspect, when the reverse rotation for the required angular width is performed on the crankshaft by the rotation time to the reverse rotation side, the reverse rotation speed is stabilized, so that the crankshaft is reversed to a more accurate phase position. Will be able to.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
[Embodiment 1]
FIG. 1 is a system configuration diagram of a vehicle internal combustion engine to which the above-described invention is applied and a control device therefor. Here, a gasoline engine (hereinafter referred to as “engine”) 2 is used as the internal combustion engine.
[0033]
The output of the engine 2 is output from the crankshaft 2a of the engine 2 to the output shaft 6a side via a torque converter 4 and an automatic transmission (hereinafter referred to as “A / T”) 6, and finally the wheels Is transmitted to. In addition to the driving force transmission system from the engine 2 to the wheels, the output of the engine 2 is transmitted to the belt 14 via the pulley 10 connected to the crankshaft 2a. The other pulleys 16 and 18 are rotated by the output transmitted by the belt 14. The pulley 10 is provided with an electromagnetic clutch 10a, which is turned on (connected) and turned off (cut off) as necessary, so that transmission / non-transmission of output can be switched between the pulley 10 and the crankshaft 2a. Is.
[0034]
Of the pulleys 16 and 18, the pulley 16 is connected to the rotating shaft of the auxiliary machinery 22 so that it can be driven by the rotational force transmitted from the belt 14. Examples of the auxiliary machinery 22 include an air conditioner compressor, a power steering pump, an engine cooling water pump, and the like. Although shown as one auxiliary machine 22 in FIG. 1, in reality, one or more of an air conditioner compressor, a power steering pump, an engine cooling water pump, and the like exist, and each has a pulley to provide a belt. 14 is configured to rotate in conjunction with 14. In the first embodiment, it is assumed that an air conditioner compressor, a power steering pump, and an engine cooling water pump are provided as the auxiliary machinery 22.
[0035]
Further, a motor generator (hereinafter referred to as “M / G”) 26 is interlocked with the belt 14 by the pulley 18. The M / G 26 functions as a generator as required (hereinafter referred to as “power generation mode” or “regeneration mode”), thereby converting the rotational force transmitted from the crankshaft 2a via the pulley 18 into electrical energy. Convert. Further, the M / G 26 functions as a motor as needed (hereinafter referred to as “driving mode”) so that one or both of the crankshaft 2a of the engine 2 and the auxiliary machinery 22 are operated by the belt 14 via the pulley 18. Rotate.
[0036]
Here, the M / G 26 is electrically connected to the inverter 28. When the M / G 26 is set to the power generation mode or the regenerative mode, the inverter 28 is switched to switch the low-voltage power supply from the M / G 26 to the high-voltage power supply (here, 36 V) battery 30 and via the DC / DC converter 32. The battery 34 is switched to be a power source for the ignition system, meters, ECUs and others so that the battery 34 (here 12V) is charged with electric energy.
[0037]
When the M / G 26 is set to the “driving mode”, the inverter 28 supplies power to the M / G 26 from the high-voltage power supply battery 30 that is a power source, thereby driving the M / G 26 and the pulley 18 and the belt. 14, the crankshaft 2 a is rotated when the engine is stopped, when the auxiliary machinery 22 is rotated, or when the engine is automatically started, automatically stopped, or started. The inverter 28 can adjust the rotational speed of the M / G 26 by adjusting the supply of electric energy from the high-voltage power supply battery 30.
[0038]
A starter 36 is provided to start the engine when it is cold. The starter 36 is supplied with electric power from the low-voltage power supply battery 34 and rotates the ring gear to start the engine 2.
[0039]
The A / T 6 is provided with an electric hydraulic pump 38 to which electric power is supplied from the low-voltage power supply battery 34, and supplies hydraulic oil to the hydraulic control unit inside the A / T 6. This hydraulic oil adjusts the operating states of the clutch, brake, and one-way clutch inside the A / T 6 by a control valve in the hydraulic pressure control unit, and switches the shift state as necessary.
[0040]
The eco-run ECU 40 executes on / off switching of the electromagnetic clutch 10a, mode control of the M / G 26, the inverter 28, control of the starter 36, and other control of the storage amount for the batteries 30 and 34 (not shown). Further, driving on / off of the auxiliary machinery 22 excluding the water pump, driving control of the electric hydraulic pump 38, shift control of A / T6, fuel injection control by the fuel injection valve (intake port injection type or in-cylinder injection type) 42, electric motor The opening degree control of the throttle valve 46 by 44 and other engine control are executed by the engine ECU 48. In addition, by providing a VSC (Vehicle Stability Control) -ECU 50, automatic control of the brakes of each wheel is also executed.
[0041]
The eco-run ECU 40 detects the rotation speed of the rotation shaft of the M / G 26 from the rotation speed sensor built in the M / G 26, whether the driver has started the eco-run system, and other data from the eco-run switch. Further, the engine ECU 48 detects the engine cooling water temperature THW from the water temperature sensor, whether the accelerator pedal is depressed from the idle switch, the accelerator opening ACCP from the accelerator opening sensor, the steering angle θ of the steering from the steering angle sensor, the vehicle speed SPD from the vehicle speed sensor, A throttle position TA to a throttle position TA, a shift position SHFT from a shift position sensor, a cylinder discrimination sensor to an intake top dead center of a specific cylinder, an engine speed sensor to an engine speed NE, a cylinder discrimination sensor and an engine speed sensor, The crank angle, the air conditioner switch ON / OFF operation, and other data are detected for engine control and the like. The VSC-ECU 50 also detects whether or not the brake pedal is depressed and other data from the brake switch for braking control and the like.
[0042]
Each of these ECUs 40, 48, and 50 is configured with a microcomputer as a center, and the CPU executes necessary arithmetic processing in accordance with a program written in the internal ROM, and various types of ECUs 40, 48, and 50 are performed based on the calculation results. Control is being executed. These arithmetic processing results and the data detected as described above can be communicated with each other between the ECUs 40, 48, 50, and the data is exchanged as necessary to execute the control in conjunction with each other. It is possible to do.
[0043]
Next, a control process executed by the eco-run ECU 40 will be described. Among the controls described below, the automatic stop process and the automatic start process are executed when the driver turns on the eco-run switch.
[0044]
The automatic stop process is shown in the flowchart of FIG. This process is a process that is repeatedly executed in a short cycle. The steps in the flowchart corresponding to the individual processing contents are represented by “S˜”.
[0045]
When this automatic stop process is started, first, an operation state for determining execution of automatic stop is read (S110). For example, the engine coolant temperature THW detected from the water temperature sensor, the accelerator pedal depression / non-existence detected from the idle switch, the amount of power stored in the batteries 30, 34, the brake pedal depression / non-depression detected from the brake switch, and the vehicle speed sensor The vehicle speed SPD and the like are read into the RAM work area inside the eco-run ECU 40.
[0046]
Next, it is determined whether or not an automatic stop condition is satisfied from these operating states (S120). For example, (1) the engine 2 is warmed up and not overheated (the engine cooling water temperature THW is lower than the water temperature upper limit and higher than the water temperature lower limit), and (2) the accelerator pedal is not depressed. State (idle switch is on), (3) state where the stored amount of the battery 30, 34 is at a required level, (4) state where the brake pedal is depressed (brake switch is on), and (5) When the conditions (1) to (5) that the vehicle is stopped (vehicle speed SPD is 0 km / h) are all satisfied, it is determined that the automatic stop condition is satisfied.
[0047]
If any one of the above conditions (1) to (5) is not satisfied, the automatic stop condition is not satisfied (“NO” in S120), and the process is temporarily terminated.
On the other hand, when the driver stops the vehicle at, for example, an intersection or the like and the automatic stop condition is satisfied (“YES” in S120), the traveling M / G control process is stopped (S130). This running M / G control process is a process that is started in an automatic start process (FIG. 3) described later. Specifically, the traveling M / G control process sets the M / G 26 in the power generation mode during normal traveling, and recovers the traveling energy by setting the M / G 26 in the regeneration mode when the vehicle is decelerated during fuel deceleration. This is a process of assisting the rotation of the engine 2 immediately after returning from the cut.
[0048]
Next, an engine stop process is performed (S140). That is, when the fuel cut instruction is issued from the eco-run ECU 40 to the engine ECU 48, the fuel injection of the fuel injection valve 42 is stopped, and the throttle valve 46 is fully closed. As a result, the combustion in the engine combustion chamber is stopped, and the operation of the engine 2 is stopped.
[0049]
Next, execution of the M / G drive process when the engine is stopped is set (S150). The engine stop M / G drive process is a process for securing the vibration of the engine 2 and the vehicle and the brake booster pressure by controlling the rotation of the crankshaft 2a with the M / G 26 after the operation of the engine 2 is stopped. In this way, this process is once ended.
[0050]
Next, the automatic start process is shown in the flowchart of FIG. This process is a process that is repeatedly executed in a short cycle.
When the automatic start process is started, first, an operation state for determining execution of automatic start is read (S410). Here, for example, the engine cooling water temperature THW, the idle switch state, the charged amount of the batteries 30 and 34, the brake switch state, the vehicle speed SPD, etc. are the same as the data read in step S110 of the automatic stop process (FIG. 2). Read into the RAM work area.
[0051]
Next, it is determined whether or not the automatic start condition is satisfied from these operating states (S420). For example, under the condition that the engine is stopped by the automatic stop process, (1) the engine 2 is warmed up and not overheated (the engine cooling water temperature THW is lower than the water temperature upper limit and the water temperature lower limit Higher than the value), (2) the accelerator pedal is not depressed (idle switch is on), (3) the charged amount of the batteries 30, 34 is at a required level, and (4) the brake pedal is depressed. Is not satisfied even in one of the conditions (1) to (5) that the vehicle is stopped (the brake switch is on) and (5) the vehicle is stopped (the vehicle speed SPD is 0 km / h) It is determined that the automatic start condition is satisfied.
[0052]
If the engine is not stopped by the automatic stop process, or if all of the above conditions (1) to (5) are satisfied even in the engine stop state by the automatic stop process, the automatic start condition is not satisfied (S420). "NO"), the process is temporarily terminated.
[0053]
If any one of the above conditions (1) to (5) is not satisfied in the engine stop state by the automatic stop process, it is assumed that the automatic start condition is satisfied (“YES” in S420), and the above-mentioned engine stop M / The G drive process is stopped (S430). Then, execution of an M / G drive start start process (FIG. 4) to be described later and the above-described running M / G control process is set (S440), and this process is temporarily terminated.
[0054]
Next, the M / G drive start start process is shown in the flowchart of FIG. This process is a process that is started by executing step S440 and is repeatedly executed in a short cycle.
[0055]
When the M / G drive start start process is started, an instruction to prohibit the air-conditioner on is first given to the engine ECU 48 (S510). Thus, if the air conditioner is turned on, the engine ECU 48 stops driving the air conditioner. Accordingly, it is possible to reduce the load generated in the M / G 26 at the start of starting.
[0056]
Next, the electromagnetic clutch 10a is turned on (S520), and the M / G 26 is set to the drive mode (S530). Then, it is determined whether engine rotation has started (S540). At this time, since the M / G 26 is only set to the drive mode immediately before, the engine 2 is not rotating (“NO” in S540), and then engine rotation start processing is executed (S550).
[0057]
The details of the engine rotation start process are shown in the flowchart of FIG. When this process is started, it is first determined whether or not this is the first engine rotation start process at the time of the current engine start (S610). Since this is the first process (“YES” in S610), mode A is set as the rotational drive mode of the M / G 26 (S620).
[0058]
Then, it is determined whether or not the rotational drive mode is set to mode A (S630). Here, since it is set to mode A as initially set in step S620 (“YES” in S630), drive control is performed so that the M / G 26 rotates forward (S640). Next, it is determined whether or not the reference time Ta has elapsed since the start of forward rotation driving of the M / G 26 (S650). If the reference time Ta has not elapsed (“NO” in S650), the process is temporarily terminated.
[0059]
In the next control cycle, since it is not the first engine rotation start process at the time of the current engine start (“NO” in S610), the determination in step S630 is then performed. Here, since the mode is A (“YES” in S630), the forward rotation driving of the M / G 26 (S640) is repeated as long as the reference time Ta does not elapse (“NO” in S650).
[0060]
When the reference time Ta has elapsed (“YES” in S650), it is determined whether or not the engine 2 is currently rotating (S660). Here, the reference time Ta is set to a time sufficient to overcome the resistance due to the compression pressure of the cylinder into which the atmospheric pressure is introduced at the time of automatic stop and to determine that the engine 2 is rotating by the M / G 26. ing. Therefore, the rotation of the engine 2 at the time when the reference time Ta has elapsed is determined from the output state of the engine speed sensor, and if there is no output from the engine speed sensor, the engine 2 has stopped rotating due to the compression pressure. I can judge. If there is an output from the engine speed sensor, it can be determined that the engine 2 has overcome the compression pressure and has started rotating.
[0061]
If the engine is rotating ("YES" in S660), it is determined that the engine starts (S670). Therefore, in the next control cycle, “YES” is determined in step S540 of the M / G drive start start process (FIG. 4), and processes in steps S560 to S590 are performed as described later.
[0062]
On the other hand, if the engine is not rotating (“NO” in S660), that is, if the engine 2 is stopped, the mode B is set to the rotational drive mode (S680). Therefore, in the next control cycle, “NO” is determined in step S610, “NO” is determined in S630, and it is then determined whether or not the mode is B (S690). Since it is mode B (“YES” in S690), reverse / forward rotation processing is executed (S700).
[0063]
Details of the reverse rotation / forward rotation processing are shown in the flowchart of FIG. When this process is started, it is first determined whether or not the first reverse / forward rotation process at the time of the current engine start (S810). Since this is the first process (“YES” in S810), the reverse rotation mode is set as the rotation direction mode of the engine 2 (S820). Then, the counter C is cleared (S830).
[0064]
Next, it is determined whether or not the rotation direction mode is the reverse rotation mode (S840). Since the reverse rotation mode is initially set (“YES” in S840), the M / G 26 is driven in reverse rotation (S850). As a result, the crankshaft 2a of the engine 2 reverses. The phase of the crankshaft 2a at the start of the reverse rotation is from the phase that stopped without overcoming the resistance of the compression pressure during the forward rotation driving of the M / G 26 in step S640. This stop phase exists in the crank angle region of −10 to −20 ° with respect to the top dead center of the compression stroke.
[0065]
Then, it is determined from this reverse rotation start phase whether or not the angular width has been reversed by 80 ° (S860). If the rotation is not reversed by 80 ° (“NO” in S860), the process is temporarily terminated as it is. Thereafter, “NO” is determined in step S810, “YES” is determined in step S840, and the reverse rotation driving of the M / G 26 is continued until the reverse rotation of the 80 ° width is performed (S850). In the first embodiment, the rotation angle width of the crankshaft 2a is not directly detected, but the determination is made based on the elapse of a reference time (for example, 150 msec) corresponding to the reverse rotation of the 80 ° width.
[0066]
When the reference time corresponding to the reverse rotation of 80 ° width, that is, the reverse rotation of 80 ° width has elapsed (“YES” in S860), the rotation direction mode is set to the normal rotation mode (S870). As a result, in the next control cycle, “NO” is determined in step S810, and “NO” is determined in step S840, and then M / G 26 is driven forward (S880). Then, it is determined whether or not the reference time Tb has elapsed since the start of the forward rotation driving of the current M / G 26 (S890). If the reference time Tb has not elapsed (“NO” in S890), the process is temporarily terminated. Thereafter, the forward drive of the M / G 26 continues until the reference time Tb elapses from the start of the forward drive (S880). The length of the reference time Tb may be changed according to the value of the counter C described later. For example, the reference time Tb in the forward rotation drive of the M / G 26 at the end (C = 2) in the mode B may be longer than before (C = 0, 1).
[0067]
When the reference time Tb has elapsed from the start of forward rotation driving (“YES” in S890), it is determined whether or not the engine 2 is currently rotating (S900). Here, the reference time Tb is set to a time sufficient to overcome the resistance due to the compression pressure of the cylinder after the reverse rotation of the engine 2 and to determine that the engine 2 is rotating by the M / G 26. Accordingly, the rotation of the engine 2 at the time when the reference time Tb has elapsed is determined from the output state of the engine speed sensor, and if there is no output from the engine speed sensor, the engine 2 has stopped rotating due to the compression pressure. I can judge. If there is an output from the engine speed sensor, it can be determined that the engine 2 has overcome the compression pressure and has started rotating.
[0068]
If the engine is rotating ("YES" in S900), it is determined that the engine starts (S910). Therefore, in the next control cycle, “YES” is determined in step S540 of the M / G drive start start processing (FIG. 4), and processing in steps S560 to S590 is performed as described later.
[0069]
On the other hand, if the engine is not rotating (“NO” in S900), that is, if the engine 2 is stopped, the counter C is incremented (S920). Next, it is determined whether or not the counter C is equal to or less than the counter determination value n (S930). The counter determination value n is a value that defines the number of repetitions of reverse rotation / forward rotation of the engine 2 by driving the M / G 26. For example, the counter determination value n = 1 to 3 is set. Here, it is assumed that the counter determination value n = 3 because the number of repetitions of reverse rotation / forward rotation is defined as three.
[0070]
If C <n (“YES” in S930), the reverse rotation mode is set as the rotation direction mode (S940). As a result, in the next control cycle, “NO” in step S810, “YES” in step S840, and then the M / G 26 reverse rotation drive (S850) is started. Again, the engine 2 has a width of 80 ° from the stop phase. Is reversed. Then, when the reverse rotation of the 80 ° width is completed (“YES” in S860), the normal rotation is executed again (“NO” in S840 by S870).
[0071]
If the engine rotation is thus started by repeating the second reverse rotation and the normal rotation (“YES” in S900), “YES” is determined in step S540 of the M / G drive start start process (FIG. 4) in the next control cycle. ”And processing of steps S560 to S590 is performed as described later.
[0072]
On the other hand, when the engine rotation has not started (“NO” in S900), the counter C is incremented (S920), and it is determined whether the counter C is equal to or smaller than the counter determination value n (S930). Here, since counter C = 2 and C <n (“YES” in S930), the reverse rotation mode is set as the rotation direction mode (S940). As a result, the third reversal and forward rotation is repeated.
[0073]
Then, after the reference time Tb has elapsed (“YES” in S890), if engine rotation starts (“YES” in S900), the M / G drive start start process (FIG. 4) is performed in the next control cycle. In step S540, “YES” is determined, and steps S560 to S590 are performed as described later.
[0074]
On the other hand, when the engine rotation has not started (“NO” in S900), the counter C is incremented (S920), and it is determined whether the counter C is equal to or smaller than the counter determination value n (S930). Here, since counter C = 3 and C ≧ n (“NO” in S930), next, mode C is set to the rotational drive mode (S950). Thus, in the next control cycle, in the engine rotation start process (FIG. 5), “NO” is determined in steps S610, S630, and S690, respectively, and the engine 2 is driven by driving both the M / G 26 and the starter 36. The engine 2 is normally rotated to start the rotation of the engine 2 (S710). When driving the starter 36, considering the meshing with the ring gear, the M / G 26 is temporarily stopped, and after the engine speed NE is increased by driving the starter 36, it is increased to, for example, 100 rpm. Therefore, the M / G 26 may be driven.
[0075]
Next, it is determined whether or not the engine is rotating (S720). If the engine is not rotating yet ("NO" in S720), the present process is temporarily terminated. On the other hand, if the engine starts rotating (“YES” in S720), it is determined that the engine starts (S730). Although not shown, in this case, if the engine 2 does not start rotating even after the reference time has elapsed, it is determined that a failure has occurred.
[0076]
If the engine 2 starts to rotate in this way, it is determined as “YES” in the determination of whether or not to start the engine rotation (S540) in the next control cycle. Then, output control of the M / G 26 is executed (S560), and control for gradually increasing the engine speed NE to the level of the idle target speed NEidl, for example, 600 rpm, is started by the output of the M / G 26.
[0077]
Then, after the start of the M / G drive start process, it is determined whether or not the accelerator pedal has been depressed (S570). If the accelerator pedal is not depressed (“YES” in S570), it is next determined whether the engine speed NE has not yet reached the idle target speed NEidl (S580). If the engine speed NE has not yet reached the idle target speed NEidl at the initial rotation of the M / G 26 (“YES” in S580), the present process is temporarily terminated.
[0078]
If the engine speed NE reaches the idle target speed NEidl by the output of M / G 26 while repeating step S560 ("NO" in S580), the eco-run ECU 40 instructs the engine ECU 48 to start fuel injection. (S590). As a result, fuel is injected from the fuel injection valve 42, and the engine 2 starts and starts operation.
[0079]
Further, when the accelerator pedal is depressed before the engine speed NE reaches the idle target speed NEidl (“NO” in S570), the eco-run ECU 40 immediately instructs the engine ECU 48 to start fuel injection. (S590).
[0080]
Next, the traveling M / G control process is shown in the flowchart of FIG. This process is a process that is started by executing step S440 and is repeatedly executed in a short cycle. First, it is determined whether or not the engine 2 has been started by the above-described M / G drive start start process (FIG. 4) (S1010). If it is before the start is completed (“NO” in S1010), this process is temporarily terminated as it is.
[0081]
When the start of the engine 2 is completed by the M / G drive start start process (FIG. 4) (“YES” in S1010), the M / G drive start start process (FIG. 4) is stopped (S1020).
[0082]
Then, it is determined whether or not the rotational drive mode is a start in mode C (S1030). If it is a start in mode A or mode B (“NO” in S1030), the process proceeds to the next step S1050. If it is a start in mode C (“YES” in S1030), the starter 36 is stopped. (S1040).
[0083]
Then, the engine ECU 48 is instructed to permit the air conditioner-on prohibited in step S510 (S1050). Thus, in the engine ECU 48, if the air conditioner switch is turned on, the air conditioner compressor can be switched to interlock with the rotation of the pulley 16 to drive the air conditioner.
[0084]
Next, it is determined whether or not the vehicle is decelerated (S1060). Here, when the vehicle is decelerating, for example, the vehicle is decelerating when the accelerator pedal is completely returned during traveling, that is, when the idle switch is on during traveling. Therefore, if the vehicle is not decelerating (idle switch off) (“YES” in S1060), the electromagnetic clutch 10a is turned on or kept on (S1070), and the M / G 26 is set to the power generation mode (S1080). Once this process is finished. Thus, during normal travel, the M / G 26 stores the batteries 30 and 34 by power generation and serves as a power source for various electric systems.
[0085]
If it is determined that the vehicle is decelerating (“NO” in S1060), the deceleration M / G control process is executed (S1090). This deceleration M / G control process is a process in which the M / G 26 is set to the regeneration mode and the traveling energy of the vehicle is recovered as electric energy when the fuel is cut when the vehicle is decelerated.
[0086]
An example of the processing according to the first embodiment described above is shown in the timing chart of FIG. In FIG. 8, when the automatic start condition is satisfied at time t0, the mode A is set in the rotational drive mode, the M / G 26 rotates forward, and the crankshaft 2a of the engine 2 rotates in the forward rotation direction. start. However, the engine cannot be rotated against the compression pressure, and the engine rotation is stopped (time t1).
[0087]
Then, at the time t2 after the reference time Ta from the start of forward rotation of the M / G 26, it is determined that the engine rotation has stopped and the mode B is set. In mode B, the crankshaft 2a is rotated to the reverse side by the M / G 26 until immediately before the intake valve in the cylinder just before the compression stroke top dead center at the time of stop (time t3). Next, the crankshaft 2a is rotated forward by the M / G 26 to determine the rotation after the reference time Tb (time t4). At this time, if the crankshaft 2a of the engine 2 has stopped rotating, the M / G 26 further rotates the crankshaft 2a for the second time (time t4 to t5) and forward (time t5 to t6). To determine the rotation after the reference time Tb (time t6). At this time, if the crankshaft 2a of the engine 2 has stopped rotating, the third reverse rotation (time t6 to t7) and forward rotation (time t7 to t8) of the crankshaft 2a are executed, and the reference time The rotation after Tb is determined (time t8). If the crankshaft 2a does not start rotating even after the third reverse rotation and forward rotation, the starter 36 is driven. In the example of FIG. 8, at the initial driving of the starter 36, the M / G 26 is temporarily stopped until the engine speed increases (for example, increases to 100 rpm) in order to ensure the meshing between the starter 36 and the ring gear. The example which provided the period (time t8-t9) to perform is shown. As a result, the rotation of the crankshaft 2a is reliably started, and thereafter the engine 2 is started by fuel injection.
[0088]
In the configuration of the first embodiment described above, M / G 26 is the rotation output means, starter 36 is the second rotation output means, steps S610 to S640 are the forward rotation drive means, and steps S650, S660, S680. , S690, S810, S820, S840 to S860, S890, S900, S940 are processing as the reverse rotation driving means, Steps S870, S880 are processing as the renormal rotation driving means, Steps S710, S830, S920, S930, S950. Corresponds to the processing as the rotation output switching means.
[0089]
According to the first embodiment described above, the following effects can be obtained.
(I). At the beginning of rotation of the crankshaft 2a during automatic start, the crankshaft 2a is rotated to the normal rotation side by driving the M / G 26. If the rotation can be started by the first normal rotation, the rotation is quickly achieved. However, when the rotation of the crankshaft 2a to the forward rotation side stops, the crankshaft 2a is moved by the M / G 26 until immediately before the intake valve in the cylinder immediately before the top dead center of the compression stroke at the time of stoppage. Rotate to reverse side. By this reverse rotation, the piston ring can be lifted in the piston ring groove at the start of the reverse rotation, so that the pressure in the cylinder just before the top dead center of the compression stroke at the time of stop can be reduced.
[0090]
By the way, when the rotation of the crankshaft 2a is stopped at the first forward rotation, this stop phase is a phase stopped due to the rotational resistance due to the compression pressure, and a certain cylinder is in a state immediately before the top dead center of the compression stroke. This indicates that the phase is at a certain phase. This phase exists between −10 ° and −20 ° when the top dead center of the compression stroke is 0 °. Therefore, for this cylinder, the reverse rotation angle width until immediately before the intake valve opens is automatically determined.
[0091]
For example, if the opening timing of the intake valve is -120 °, the intake valve will not open even if the intake valve is reversed to just before -120 °. However, in consideration of the reverse rotation of the crankshaft 2a due to the inertial force after stopping the reverse rotation drive by the M / G 26, in the first embodiment, the rotation angle width by the reverse drive of the M / G 26 is set to 80 °. As a result, the crankshaft 2a is actually reversed until just before the intake valve opening timing (−120 °).
[0092]
Therefore, it is possible to reverse the crankshaft 2a until just before the intake valve of the corresponding cylinder is opened by only performing the reverse rotation drive for the reverse rotation angle width (80 °). That is, the crankshaft 2a can be reversely rotated to the maximum, and atmospheric pressure is not introduced from the intake valve to the corresponding cylinder.
[0093]
Therefore, when the crankshaft 2a is re-rotated to the normal rotation side by forward rotation of the M / G 26, the pressure in the corresponding cylinder is lower than the previous time even immediately before the top dead center of the compression stroke. ing. In addition, since it is re-forward rotation after the reverse rotation until just before the intake valve opens, sufficient inertia torque is generated. Moreover, the frictional force is small due to the dynamic friction. As a result, the rotation of the engine 2 that has stopped rotating can be easily started, and the startability of the engine 2 can be improved during automatic start.
[0094]
(B). Note that if the rotation of the engine 2 does not start even after normal rotation is performed again, reverse rotation and re-forward rotation are further repeated. As a result, even when the engine rotation cannot be started once by the reverse rotation and re-forward rotation processing, the reverse rotation and the normal rotation can be repeated again, and the start of the engine rotation can be further ensured.
[0095]
(C). If engine rotation does not start even after reverse rotation and re-forward rotation are performed n times, here three times, the crankshaft 2a is rotated using the M / G 26 and the starter 36. . Accordingly, even if the engine 2 does not rotate even if reverse rotation and re-forward rotation are repeated, the engine 2 can be reliably started to rotate.
[0096]
(D). The engine rotation start process (FIGS. 5 and 6) described above is started when the engine 2 is automatically started. The automatic start is a start not intended by the driver. Therefore, as described above, the engine rotation can be easily started and sufficient startability can be achieved, so that the driver does not feel uncomfortable at the time of automatic start.
[0097]
(E). The rotation of the crankshaft 2a to the reverse side is performed by driving the M / G 26. As described above, by actively using the driving force of the M / G 26 at the time of reverse rotation, the reverse rotation can be performed immediately and immediately before the intake valve of the corresponding cylinder is opened. As described above, since the reverse rotation is positively performed by the driving force of the M / G 26, the piston ring can be surely lifted in the piston ring groove at the start of the reverse rotation, and the pressure in the corresponding cylinder can be sufficiently released. Can do.
[0098]
Furthermore, when the reverse rotation for the angular width (80 °) required for the crankshaft 2a is determined by the rotation time to the reverse rotation side as in the first embodiment, the reverse rotation speed is stabilized, so that the crankshaft 2a can be accurately It becomes possible to reverse the phase position.
[0099]
[Other embodiments]
In the first embodiment, in the mode C, both the M / G 26 and the starter 36 are driven. However, only the starter 36 may be driven.
[0100]
In the first embodiment, the reverse rotation and the re-forward rotation in the mode B are performed three times when the engine 2 does not start rotating, but may be once or twice, or four times or more. But it ’s okay.
[0101]
In the first embodiment, the reverse rotation angle width (80 ° in this case) of the M / G 26 is determined based on the passage of the reference time corresponding to the reverse rotation angle width. ° Judgment may be made by directly detecting the reverse rotation.
[0102]
In the first embodiment, the reverse rotation of the crankshaft 2a is performed by driving the M / G 26. In addition, the M / G 26 is stopped and the compression pressure generated by the forward rotation performed immediately before is stopped. By using the torque in the reverse rotation direction, the reverse rotation may be performed until just before the intake valve of the corresponding cylinder is opened.
[0103]
In the first embodiment, the M / G 26 is arranged outside the driving force transmission system from the engine 2 to the wheels, but is arranged outside the driving force transmission system from the engine 2 to the wheels. The engine 2 may be configured to start rotating using the motor that is used, and the engine rotation starting process (FIGS. 5 and 6) of the first embodiment can be applied.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a vehicle internal combustion engine and a control device thereof according to a first embodiment.
FIG. 2 is a flowchart of automatic stop processing executed by the eco-run ECU according to the first embodiment.
FIG. 3 is a flowchart of automatic start processing executed by the eco-run ECU according to the first embodiment.
FIG. 4 is a flowchart of an M / G drive start start process executed by the eco-run ECU according to the first embodiment.
FIG. 5 is a flowchart of an engine rotation start process executed by the eco-run ECU according to the first embodiment.
FIG. 6 is a flowchart of reverse rotation / forward rotation processing executed by the eco-run ECU according to the first embodiment;
FIG. 7 is a flowchart of a running M / G control process executed by the eco-run ECU according to the first embodiment.
FIG. 8 is a timing chart showing an example of processing according to the first embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 2 ... Engine, 2a ... Crankshaft, 4 ... Torque converter, 6 ... A / T, 6a ... Output shaft, 10 ... Pulley, 10a ... Electromagnetic clutch, 14 ... Belt, 16, 18 ... Pulley, 22 ... Auxiliaries, 26 ... M / G, 28 ... Inverter, 30 ... Battery for high-voltage power supply, 32 ... DC / DC converter, 34 ... Battery for low-voltage power supply, 36 ... Starter, 38 ... Electric hydraulic pump, 40 ... Eco-run ECU, 42 ... Fuel injection Valve, 44 ... Electric motor, 46 ... Throttle valve, 48 ... Engine ECU, 50 ... VSC-ECU.

Claims (8)

An internal combustion engine rotation start device for starting rotation of a crankshaft of an internal combustion engine by driving a rotation output means,
Forward rotation drive means for rotating the crankshaft to the forward rotation side by driving the rotation output means at the start of rotation of the crankshaft;
When rotation of the crankshaft to the forward rotation side by the forward rotation drive means stops, the crankshaft is moved to the reverse rotation side until just before the intake valve in the cylinder just before the top dead center of the compression stroke at the time of stoppage. A reverse drive means for rotating;
After the crankshaft rotates to the reverse side by the reverse drive means, re-forward drive means for re-rotating the crankshaft to the normal side by driving the rotation output means;
An internal combustion engine rotation start device comprising: 2. The structure according to claim 1, wherein when the rotation of the crankshaft to the normal rotation side by the normal rotation driving unit and the renormal rotation driving unit is stopped, the reverse rotation driving unit is dead on the compression stroke at the time of the stop. An internal combustion engine rotation starting device that rotates a crankshaft in a reverse direction until immediately before an intake valve in a cylinder immediately before a point is opened. In addition to the configuration of claim 2, the rotation of the crankshaft to the reverse rotation side by the reverse rotation driving means and the rerotation of the crankshaft to the normal rotation side by the renormal rotation driving means are repeated a reference number of times. Later, when the rotation of the internal combustion engine does not start, the crankshaft is rotated by driving the rotation output means and the second rotation output means or only by driving the second rotation output means. An internal combustion engine rotation start device comprising rotation output switching means for switching to rotation and executing rotation of the internal combustion engine. 4. The configuration according to claim 3, wherein the rotation output means is a motor generator disposed in or outside a driving force transmission system from an internal combustion engine to a wheel, and the second rotation output means is a starter. An internal combustion engine rotation start device. 5. The internal combustion engine rotation start device according to claim 1, wherein the internal combustion engine rotation start device is started for automatic start of the internal combustion engine when an automatic start condition is satisfied after the internal combustion engine is automatically stopped. In the configuration according to any one of claims 1 to 5, the reverse drive means reversely rotates the crankshaft by a predetermined angular width from a crank angle phase at which the rotation of the crankshaft to the forward rotation side is stopped. An internal combustion engine rotation starting device that rotates the crankshaft in the reverse direction until immediately before the intake valve opens in a cylinder just before the top dead center of the compression stroke at the time of stopping. 6. The structure according to claim 1, wherein the reverse rotation driving means reverses the crankshaft for a predetermined time from a crank angle phase at which the rotation of the crankshaft to the forward rotation side is stopped. An internal combustion engine rotation starting device that rotates the crankshaft in the reverse direction until immediately before the intake valve of the cylinder just before the compression stroke top dead center opens. 8. The internal combustion engine rotation start device according to claim 1, wherein the reverse rotation driving means rotates the crankshaft to the reverse rotation side by driving the rotation output means.

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