JP2009030551A - Start control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a start control device for an internal combustion engine, capable of preventing rotation in the reverse direction of the armature of a starting device without enlargement of a one-way clutch. <P>SOLUTION: A CPU of an engine ECU estimates a cylinder internal pressure Pt (step S4) upon judgment that the engine has stopped (YES in step S1) and, if the cylinder internal pressure Pt is greater than a prescribed value of Px (YES in step S5), turns on a start prohibition flag (step S6) to prohibit starting of a starter. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal combustion engine start control device, and in particular, transmits a driving force generated in an armature by a starter motor to a crankshaft of the internal combustion engine via a one-way clutch and prevents reverse rotation of the armature. The present invention relates to a start control device for an internal combustion engine that controls a constantly meshing start device having a function of

  In general, as an always-meshing type starting device, one in which a ring gear on the internal combustion engine side and a pinion gear on the starting device side are always meshed directly or via an intermediate gear or the like is known.

  Such a starter is provided with a one-way clutch between the crankshaft of the internal combustion engine and the ring gear. When the internal combustion engine is started, this one-way clutch is engaged and transmits the driving force generated by the starter motor to the crankshaft, so that the internal combustion engine completes explosion and can rotate independently. In this state, the driving force of the internal combustion engine is not transmitted to the starter side because of the disengaged state.

  Specifically, the one-way clutch is composed of an inner ring fixed to the ring gear, an outer ring fixed to the crankshaft, and a transmission element provided between the inner and outer rings, and is normally rotated from the inner ring to the outer ring. Is input, the transmission element meshes with the inner and outer rings, and rotation can be transmitted.When normal rotation is input from the outer ring to the inner ring, the transmission element is disengaged from either the inner ring or the outer ring. Thus, the rotation transmission is disabled, so that rotation in only one direction is transmitted.

  In the above-described starting device, immediately after the internal combustion engine is stopped, the piston in the compression stroke is pushed back by the pressure in the cylinder increased in pressure near the top dead center, that is, the compression reaction force, and cannot exceed the top dead center. Therefore, the crankshaft rotates in the reverse direction. In this case, since the one-way clutch is engaged when the transmission element meshes with the inner and outer rings, reverse rotation is transmitted to the starter side. As a result, the armature of the starting device rotates in reverse at a rotational speed corresponding to the gear ratio between the ring gear and the pinion gear, and there is a problem that a large centrifugal force is applied to the armature.

As a starting device that solves such a problem, a starting device that includes a reverse rotation preventing clutch that prevents the armature from rotating in the direction opposite to that during driving of the internal combustion engine is known (for example, Patent Document 1). reference).
JP 2006-226146 A

  However, in the starter described in Patent Document 1, as described above, when the crankshaft rotates in the reverse direction, the one-way clutch is engaged, so that the reverse rotation is transmitted to the starter side. However, since the armature cannot reversely rotate due to the reverse rotation prevention clutch, torque due to reverse rotation is applied to the one-way clutch.

  At this time, when the starting device is driven, the driving torque of the starting motor is input to the one-way clutch via the pinion gear and the ring gear. That is, when an attempt is made to start the starter immediately after the internal combustion engine is stopped, torque due to reverse rotation and drive torque of the starter act on the one-way clutch.

  Therefore, in the starting device for an internal combustion engine described in Patent Document 1, in order that the one-way clutch can withstand the torque caused by the reverse rotation and the driving torque of the starting device, the number of transmission elements is increased. There was a problem that the direction clutch had to be enlarged.

  The present invention has been made to solve the above-described conventional problems, and can start an internal combustion engine that can prevent the armature of the starting device from rotating in the reverse direction without increasing the size of the one-way clutch. An object is to provide a control device.

  In order to achieve the above object, a start control device for an internal combustion engine according to the present invention transmits (1) a driving force generated in an armature by a starter motor to a crankshaft of the internal combustion engine via a one-way clutch. An internal combustion engine start control device for controlling a constantly meshing start device having a function of preventing reverse rotation of the armature, and estimating means for estimating a pressure in a cylinder after the internal combustion engine is stopped; Determining means for determining whether or not the pressure in the cylinder estimated by the estimating means is greater than a predetermined value; and determining by the determination means that the pressure in the cylinder is greater than a predetermined value. In this case, there is provided a configuration including prohibiting means for prohibiting starting of the internal combustion engine by the starting device.

  With this configuration, when the pressure in the cylinder after the stop of the internal combustion engine is large, the starter does not start the internal combustion engine, so that the torque due to the compression reaction force that increases in proportion to the pressure in the cylinder and the starter It is possible to prevent excessive torque from acting on the one-way clutch due to overlap with the drive torque. Therefore, it is possible to prevent the armature of the starter from rotating in the reverse direction without increasing the size of the one-way clutch.

  An internal combustion engine start control apparatus according to the present invention is the internal combustion engine start control apparatus according to the above (1), wherein (2) the estimating means includes the pressure in the cylinder immediately after the internal combustion engine is stopped and the Based on the elapsed time since the internal combustion engine stopped, the pressure in the cylinder after the internal combustion engine stopped is estimated.

  With this configuration, the pressure in the cylinder after the internal combustion engine is stopped can be estimated by a simple method.

  In addition, the internal combustion engine start control device according to the present invention is the internal combustion engine start control device according to (2), wherein (3) the estimating means is configured such that the temperature of air sucked into the cylinder, the cylinder Estimating the amount of air charged in the cylinder based on the negative pressure in the intake passage for sucking air into and the working angle of the intake valve that opens and closes between the cylinder and the intake passage, Based on the estimated amount of air and the volume ratio of air charged in the cylinder when the intake valve is closed and immediately after the internal combustion engine is stopped, the pressure in the cylinder immediately after the internal combustion engine is stopped is estimated. It has the composition to do.

  With this configuration, the cylinder pressure after the internal combustion engine is stopped can be estimated without providing a sensor for detecting the pressure in the cylinder.

  According to the present invention, it is possible to provide a start control device for an internal combustion engine that can prevent the armature of the start device from rotating in the reverse direction without increasing the size of the one-way clutch.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an engine and a control device thereof according to an embodiment of the present invention.

  First, the configuration will be described.

  As shown in FIG. 1, the start control device for an internal combustion engine according to the present embodiment controls an internal combustion engine constituted by, for example, a 4-cylinder engine 1 mounted on an automobile or the like. A combustion chamber 3 partitioned by a piston 2 is formed in the cylinder 1a of the engine 1 constituting a part of the four cylinders, and air is sucked into the combustion chamber 3 through the intake passage 4 and from the fuel injection valve 5 Fuel is supplied. When ignition is performed on the air-fuel mixture composed of the sucked air and the supplied fuel by the spark plug 6, the air-fuel mixture burns, the piston 2 reciprocates, and the crankshaft 7 of the engine 1 rotates. In addition, the air-fuel mixture after combustion is sent out from the combustion chamber 3 to the exhaust passage 8 as exhaust.

  The engine 1 is also provided with an intake valve 9 that opens and closes between the combustion chamber 3 and the intake passage 4 and an exhaust valve 10 that opens and closes between the combustion chamber 3 and the exhaust passage 8.

  Further, the engine 1 is provided with a starter 11 for starting the engine 1. The starter 11 transmits a driving force generated by a starter motor 34 (described later) to the crankshaft 7 via the pinion gear 12 and the ring gear 13 when starting the engine 1. The pinion gear 12 and the ring gear 13 are always meshed with each other. That is, the starter 11 constitutes a constant-mesh starter according to the present invention because the gears in the transmission path to the crankshaft 7 are always meshed.

  Here, the starter 11 will be described in detail.

  FIG. 2 is a partial cross-sectional view showing the drive force transmission mechanism of the starter according to the embodiment of the present invention. FIG. 3 is a partial cross-sectional view showing the main part of the starter according to the embodiment of the present invention.

  As shown in FIG. 2, the pinion gear 12 is attached to the output shaft 26 of the starter 11. The pinion gear 12 is always meshed with a ring-shaped gear portion 13 a formed at the peripheral portion of the ring gear 13, and rotates the ring gear 13 by receiving a driving force from the starter 11.

  The ring gear 13 is provided on the outer peripheral portion of the rear end of the crankshaft 7 and is attached to the crankshaft 7 via an inner race 28 a of the one-way clutch 27 and a bearing 30. The one-way clutch 27 includes an inner race 28a, a transmission element 29, and an outer race 28b, and transmits a driving force from the starter 11 that rotates the ring gear 13 to the crankshaft 7 side. Note that the one-way clutch 27 is constituted by, for example, a one-way clutch such as a sprag type or a roller type.

  An outer race support plate 31 is attached to the outer race 28 b of the one-way clutch 27, and the outer race support plate 31 is attached to the rear end of the crankshaft 7.

  The flywheel 32 is formed in a disk shape, is fastened and fixed by a bolt at the rear end of the crankshaft 7 together with the outer race support plate 31, and rotates together with the crankshaft 7. Thereby, the flywheel 32 absorbs the rotational speed difference of each stroke of the engine 1 and ensures a stable rotational operation of the engine 1.

  That is, the one-way clutch 27, the bearing 30, the outer race support plate 31, the ring gear 13, and the pinion gear 12 constitute a driving force transmission mechanism that transmits the driving force of the starter 11 to the crankshaft 7. The reduction ratio of the driving force transmission mechanism is determined by the number of teeth of the pinion gear 12 and the number of teeth of the ring gear 13.

  When the engine 1 is started, if the ring gear 13 is rotated by the driving force of the starter 11 via the pinion gear 12, the one-way clutch 27 is engaged, and the driving force of the starter 11 is transmitted to the outer race support plate 31. Is done. As a result, the crankshaft 7 is rotated by the driving force of the starter 11, that is, cranking is performed.

  When the engine 1 completes explosion, that is, when the engine 1 rotates independently without borrowing the force of the starter 11, the rotational speed of the outer race support plate 31 interlocked with the crankshaft 7 is higher than the rotational speed of the ring gear 13. The speed is increased and the one-way clutch 27 is disengaged. As a result, the one-way clutch 27 is idled, and the driving force of the crankshaft 7 is not transmitted to the starter 11 side.

  As shown in FIG. 3, the starter 11 includes a starter motor 34 that receives energization and generates a rotational force on the armature 33, and an electromagnetic relay 35 that opens and closes a main contact (not shown) provided in the energization circuit of the starter motor 34. The speed reduction device 36 that decelerates the rotation of the armature 33 and transmits it to the output shaft 26, the pinion gear 12 supported by the output shaft 26, and the armature 33 that rotates in the direction opposite to that when the engine 1 is driven. It is constituted by a reverse rotation preventing clutch 37 or the like for preventing.

  The starter motor 34 is disposed in the inner circumference of a yoke 38 forming a magnetic circuit, and a field magnet configured by arranging a plurality of permanent magnets 39 at equal intervals in the circumferential direction, and is rotatably arranged on the inner circumference of the field magnet. The armature 33 is configured by a brush 41 and the like that are in sliding contact with the commutator 40 provided on the armature 33. When the main contact of the starter motor 34 is controlled to be closed by the electromagnetic relay 35, the starter motor 34 receives power from an in-vehicle battery (not shown) and generates a rotational force in the armature 33. The field magnet may be a field coil instead of the permanent magnet 39.

  The electromagnetic relay 35 incorporates a solenoid (not shown) that is energized from the battery via a starter relay (not shown), and opens and closes the main contact using an electromagnetic force generated by energizing the solenoid.

  The output shaft 26 is arranged coaxially with the armature shaft 42, and one end side is rotatably supported by the front housing 44 via the bearing 43, and the other end side is connected to the armature shaft 42 via the speed reduction device 36. ing.

  The pinion gear 12 is spline-coupled to the outer periphery of the output shaft 26 so as to be rotatable integrally with the output shaft 26.

  The reverse rotation prevention clutch 37 includes a clutch inner 45, a clutch outer 46, a clutch roller 47, and the like. When the engine 1 is driven, the clutch roller 47 is idled and the clutch inner 45 is allowed to rotate. That is, when the engine 1 is driven, the rotation of the clutch inner 45 is allowed, so that the rotation of the armature 33 is transmitted to the output shaft 26 via the reduction gear 36.

  On the other hand, when the rotational force in the direction opposite to that during driving of the engine 1 is transmitted to the armature 33, the clutch roller 47 is locked between the clutch inner 45 and the clutch outer 46, and the rotation of the clutch inner 45 is restricted. Will be. In this way, the reverse rotation prevention clutch 37 prevents the armature 33 from rotating in the direction opposite to that when the engine 1 is driven.

  As shown in FIG. 1, the engine ECU 14 is configured as a microcomputer centered on a CPU 15. In addition to the CPU 15, a ROM 16 for storing processing programs, a RAM 17 for temporarily storing data, and A / D conversion. An input interface circuit 18 and an output interface circuit 19 including a vessel and the like are provided, and the fuel injection valve 5, the spark plug 6, the intake valve 9, the exhaust valve 10, the starter 11, and the like are controlled.

  The engine ECU 14 is connected with an intake air temperature sensor 20, a negative pressure sensor 21, a valve operating angle sensor 22, and a crank angle sensor 23.

  The intake air temperature sensor 20 is provided in the intake passage 4, detects the temperature of intake air in the intake passage 4 (hereinafter referred to as “intake air temperature”) T, and outputs a signal corresponding to the detected temperature T. It outputs to engine ECU14.

  The negative pressure sensor 21 is provided in the intake passage 4, detects the negative pressure Pn in the intake passage 4, and outputs a signal corresponding to the detected negative pressure Pn to the engine ECU 14.

  The valve operating angle sensor 22 is provided in the vicinity of a camshaft (not shown) of the intake valve 9, detects the operating angle (hereinafter referred to as “valve operating angle”) VL of the intake valve 9, and detects the detected valve operating angle. A signal corresponding to VL is output to the engine ECU 14.

  The crank angle sensor 23 is provided in the vicinity of the crankshaft 7 and detects the actual crank angle CR of the crankshaft 7 and the rotational speed of the engine 1 (hereinafter referred to as “engine rotational speed”) NE. A signal corresponding to the crank angle CR and the engine speed NE is output to the engine ECU 14.

  The ROM 16 is filled in the cylinder 1a with the intake air temperature T detected by the intake air temperature sensor 20, the negative pressure Pn detected by the negative pressure sensor 21, the valve operating angle VL detected by the valve operating angle sensor 22, and the cylinder 1a. An air quantity characteristic map associated with the air quantity is stored. Note that the relationship among the intake air temperature T, the negative pressure Pn, the valve operating angle VL, and the amount of air is obtained, for example, by conducting experiments in advance. When the negative pressure Pn is large, the amount of air charged in the cylinder 1a is reduced. Further, when the timing at which the intake valve 9 closes in the compression stroke is delayed, a part of the sucked air returns from the intake valve 9 to the intake passage 4, so that the amount of air charged in the cylinder 1a decreases. Further, since the air density decreases when the intake air temperature T is high, the amount of air charged in the cylinder 1a decreases. These characteristics are reflected in the air quantity characteristic map.

  Further, the ROM 16 associates the cylinder pressure P0 immediately after the engine 1 is stopped and the counter value t of a timer indicating the elapsed time since the engine 1 is stopped with the cylinder pressure Pt after the engine 1 is stopped. A pressure characteristic map is stored. The relationship between the cylinder pressure P0 and the counter value t of the timer and the cylinder pressure Pt is obtained, for example, by conducting experiments in advance.

  The RAM 17 stores information indicating on or off of a start prohibition flag indicating whether starter 11 is prohibited from starting. Further, the RAM 17 stores information indicating whether an engine state flag indicating whether the engine 1 is operating or not, and engine state history information indicating a history of the engine state flag. Further, the RAM 17 stores a predetermined value Px for determining whether the start prohibition flag is on or off.

  Hereinafter, a characteristic configuration of the CPU 15 according to the embodiment of the present invention will be described.

  The CPU 15 estimates the cylinder pressure Pt after the engine 1 is stopped. Specifically, the CPU 15 refers to the air amount characteristic map stored in the ROM 16, the intake air temperature T detected by the intake air temperature sensor 20, the negative pressure Pn detected by the negative pressure sensor 21, and the valve action. Based on the valve operating angle VL detected by the angle sensor 22, the amount of air charged in the cylinder 1a is estimated. The CPU 15 outputs a signal for closing the intake valve 9 based on the actual crank angle CR detected by the crank angle sensor 23 when the signal for closing the intake valve 9 is output and immediately after the engine 1 is stopped. The volume ratio of the air filled in the cylinder 1a at the time and immediately after the engine 1 is stopped is calculated. The CPU 15 estimates the in-cylinder pressure P0 immediately after the engine 1 is stopped based on the estimated air amount and the calculated volume ratio. The CPU 15 refers to the pressure characteristic map stored in the ROM 16 and estimates the cylinder pressure Pt after the engine 1 is stopped based on the estimated cylinder pressure P0 and the counter value t of the timer. Yes. That is, the CPU 15 constitutes the estimation means of the present invention.

  Further, the CPU 15 determines whether or not the estimated in-cylinder pressure Pt is larger than a predetermined value Px. That is, the CPU 15 constitutes a determination unit of the present invention.

  Further, when the CPU 15 determines that the in-cylinder pressure Pt is larger than a predetermined value Px, the starter 11 prohibits the start of the engine 1. That is, the CPU 15 constitutes prohibiting means of the present invention.

  Next, the operation will be described.

  FIG. 4 is a flowchart showing the operation of the CPU according to the embodiment of the present invention. The process described below is realized by a program stored in advance in the ROM 16.

  As shown in FIG. 4, first, the CPU 15 determines whether or not the engine 1 has been stopped (step S1). For example, the CPU 15 determines whether or not the engine speed NE detected by the crank angle sensor 23 is 0 or less. The CPU 15 determines that the engine 1 has stopped when the engine speed NE is 0 or less, and determines that the engine 1 has not stopped when the engine speed NE is not 0 or less. If the CPU 15 determines that the engine 1 has not stopped (NO in step S1), the CPU 15 turns on the engine state flag and proceeds to step S8.

  On the other hand, if the CPU 15 determines that the engine 1 has been stopped (YES in step S1), the CPU 15 turns off the engine state flag and determines whether or not the engine 1 has stopped since rotating (step S2). ). For example, the CPU 15 refers to the engine state history information and determines whether or not the previous engine state flag is on and the current engine state flag is off. If the CPU 15 determines that the previous engine state flag is on and the current engine state flag is off, the CPU 15 determines that the engine 1 has stopped from rotating, and otherwise. It is determined that the engine 1 is not stopped since it is rotating.

  Here, if the CPU 15 determines that the engine 1 is not stopped since it is rotating (NO in step S2), the CPU 15 proceeds to step S4.

  On the other hand, if the CPU 15 determines that the engine 1 has been stopped since it is rotating (YES in step S2), the CPU 15 starts a timer and estimates the cylinder pressure P0 immediately after the engine 1 is stopped (step S3). ).

  For example, the CPU 15 refers to the air amount characteristic map stored in the ROM 16, the intake air temperature T detected by the intake air temperature sensor 20, the negative pressure Pn in the intake passage 4 detected by the negative pressure sensor 21, and Based on the valve operating angle VL detected by the valve operating angle sensor 22, the amount of air charged in the cylinder 1a is estimated. The CPU 15 calculates the volume ratio of the air filled in the cylinder 1a when the signal for closing the intake valve 9 is output and immediately after the engine 1 is stopped. Then, the CPU 15 estimates the cylinder pressure P0 when the engine 1 is stopped based on the estimated air amount and the calculated volume ratio.

  Next, the CPU 15 estimates the in-cylinder pressure Pt (step S4). For example, the CPU 15 refers to the pressure characteristic map stored in the ROM 16 and estimates the cylinder pressure Pt based on the cylinder pressure P0 estimated in step S3 and the counter value t of the timer.

  Next, the CPU 15 determines whether or not the in-cylinder pressure Pt estimated in step S4 is larger than a predetermined value Px (step S5). If the CPU 15 determines that the in-cylinder pressure Pt is greater than Px (YES in step S5), the CPU 15 turns on the start prohibition flag (step S6) and proceeds to step S8.

  On the other hand, if the CPU 15 determines that the in-cylinder pressure Pt is equal to or less than Px (NO in step S5), that is, the pressure escapes between the piston 2 and the cylinder, the intake valve 9, the exhaust valve 10, or the like. If the in-cylinder pressure Pt decreases as a result, the start prohibition flag is turned off (step S7), and the process proceeds to step S8.

  Next, the CPU 15 determines whether or not there is a request for starting the engine 1 (step S8). For example, the CPU 15 determines whether or not there is a request for starting the engine 1 by determining whether or not the ignition key is turned to a predetermined start position. If the CPU 15 determines that there is no request for starting the engine 1 (NO in step S8), the CPU 15 stops the starter 11 (step S9) and ends the process. For example, the CPU 15 outputs a stop signal for stopping the drive of the starter 11 to the starter 11.

  On the other hand, if it is determined that there is a request for starting the engine 1 (YES in step S8), the CPU 15 determines whether or not the start prohibition flag is off (step S10). If the CPU 15 determines that the start prohibition flag is on (NO in step S10), the process proceeds to step S9.

  On the other hand, if the CPU 15 determines that the start prohibition flag is OFF (YES in step S10), the CPU 15 drives the starter 11 (step S11) and ends the process. For example, the CPU 15 outputs a drive signal for driving the starter 11 to the starter 11.

  Next, the change with time of the torque input to the one-way clutch 27 will be described.

  FIG. 5 is a diagram showing a change with time of torque input to the conventional one-way clutch. FIG. 6 is a diagram showing a change with time of torque input to the one-way clutch according to the embodiment of the present invention.

  In the conventional internal combustion engine start control device, as shown in FIG. 5, since there is no limit on the starter start, the starter can be started even when the compression reaction force is large. Therefore, if the starter is started immediately after the engine is stopped, the torque of the large compression reaction force and the drive torque of the starter are input to the one-way clutch redundantly, so that excessive torque is applied to the one-way clutch. There was a possibility of being input.

  On the other hand, in the CPU 15 of the present embodiment, as shown in FIG. 6, the starter 11 is prohibited from starting until the compression reaction force proportional to the cylinder pressure Pt becomes small. Accordingly, it is possible to prevent a large compression reaction torque and a starter driving torque from being input to the one-way clutch 27 in an overlapping manner and an excessive torque from being input to the one-way clutch 27. Since the time from when the engine 1 is stopped until the compression reaction force is reduced is about 100 to 200 ms, there is no feeling of startiness due to prohibiting the starter 11 from starting.

  As described above, the CPU 15 according to the present embodiment is proportional to the in-cylinder pressure Pt in order to prohibit the starter 11 from starting the engine 1 when the in-cylinder pressure Pt after the engine 1 is stopped is large. Thus, it is possible to prevent an excessive torque from acting on the one-way clutch 27 due to an overlap between the torque due to the compression reaction force that increases and the drive torque of the starter 11. Therefore, the armature 33 of the starter 11 can be prevented from rotating in the reverse direction without increasing the size of the one-way clutch 27.

  Further, the CPU 15 according to the present embodiment can estimate the in-cylinder pressure Pt after the engine 1 is stopped by a simple method.

  Furthermore, the CPU 15 according to the present embodiment can estimate the in-cylinder pressure Pt after the engine 1 is stopped without providing a sensor for detecting the pressure in the cylinder 1a.

  In the present embodiment, in step S5, the CPU 15 determines whether or not the in-cylinder pressure Pt estimated in step S4 is larger than a predetermined value Px, but this is not limitative. Instead, it may be determined whether or not the in-cylinder pressure detected by a pressure sensor (not shown) is larger than a predetermined value Px.

  In the present embodiment, the CPU 15 turns on the start prohibition flag when the in-cylinder pressure Pt is larger than a predetermined value Px, and turns off the start prohibition flag otherwise. However, the present invention is not limited to this. When the torque of the compression reaction force acting on the one-way clutch 27 is larger than a predetermined value, the start prohibition flag is turned on. Otherwise, the start prohibition flag is turned off. May be.

  In this case, the compression reaction torque acting on the one-way clutch 27 is estimated by the CPU 15 based on the pressure P in the cylinder 1a directly detected by a pressure sensor (not shown) provided in the combustion chamber 3. Alternatively, the estimation may be performed based on the torque of the crankshaft 7 detected by a torque sensor (not shown) provided in the vicinity of the crankshaft 7.

  As described above, the present invention has the effect of preventing the armature of the starting device from rotating in the reverse direction without increasing the size of the one-way clutch. This is useful for a start control device for an internal combustion engine that controls a constant-mesh start device that transmits to the crankshaft of the internal combustion engine via a one-way clutch.

It is a schematic block diagram which shows the engine which concerns on embodiment of this invention, and its control apparatus. It is a fragmentary sectional view which shows the drive force transmission mechanism of the starter which concerns on embodiment of this invention. It is a fragmentary sectional view which shows the principal part of the starter concerning embodiment of this invention. It is a flowchart which shows operation | movement of CPU which concerns on embodiment of this invention. It is a figure which shows the time-dependent change of the torque input into the conventional one-way clutch. It is a figure which shows the time-dependent change of the torque input into the one-way clutch which concerns on embodiment of this invention.

Explanation of symbols

1 Engine 11 Starter 14 Engine ECU
15 CPU (estimating means, judging means, prohibiting means)
20 Intake air temperature sensor 21 Negative pressure sensor 22 Valve operating angle sensor 23 Crank angle sensor 27 One-way clutch

Claims (3)

A driving force generated in the armature by the starting motor is transmitted to the crankshaft of the internal combustion engine via a one-way clutch, and a constantly meshing starting device having a function of preventing reverse rotation of the armature is controlled. An internal combustion engine start control device,
Estimating means for estimating the pressure in the cylinder after the internal combustion engine is stopped;
Determining means for determining whether or not the pressure in the cylinder estimated by the estimating means is greater than a predetermined value;
Start of the internal combustion engine, comprising: prohibiting means for prohibiting start of the internal combustion engine by the starter when the determination means determines that the pressure in the cylinder is greater than a predetermined value Control device.   The estimating means estimates the pressure in the cylinder after the stop of the internal combustion engine based on the pressure in the cylinder immediately after the stop of the internal combustion engine and the elapsed time since the stop of the internal combustion engine. The start control device for an internal combustion engine according to claim 1.   The estimation means has a temperature of air sucked into the cylinder, a negative pressure in the intake passage for sucking air into the cylinder, and an action of an intake valve for opening and closing between the cylinder and the intake passage. Based on the angle, the amount of air charged in the cylinder is estimated, and the estimated amount of air and the volume of air charged in the cylinder when the intake valve is closed and immediately after the internal combustion engine is stopped The start control device for an internal combustion engine according to claim 2, wherein a pressure in the cylinder immediately after the internal combustion engine is stopped is estimated based on the ratio.

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