JPH11141362A - Starter for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the lowering of the filling efficiency of fresh air and mixture and improve the stability of an internal combustion engine by providing a starting drive means for rotating a crankshaft and a cam shaft in starting the internal combustion engine and driving the cam shaft to set the opening/ closing time of an intake valve in starting to a prescribed time. SOLUTION: An ECU 14 judges whether an engine temperature is less than a prescribed value or not in starting an internal combustion engine whose starter switch is turned on. When the judgment is YES, a relay 56 is turned on, the output current of a battery 54 is applied to an electric motor 52, and an intake side cam shaft 15 is rotationally moved via gear rows 52b, 51. Though the rotational force is inputted in a variable valve timing mechanism 32, the built-in hydraulic piston is in a floated state so that the rotational force is prevented from being transmitted to a timing pulley 15a. In this state, cranking is implemented, when the opening/closing time of the intake valve 10 is most advanced, so that the mixture filling quantity into the combustion chamber is increased and the startability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starter for an internal combustion engine mounted on an automobile or the like, and more particularly to a starter for an internal combustion engine provided with a mechanism for changing the opening and closing timing of intake and exhaust valves.

[0002]

2. Description of the Related Art In an internal combustion engine, in order to satisfy conflicting demands such as an improvement in fuel consumption rate and an increase in engine output, a variable opening / closing timing of an intake valve or an exhaust valve is changed to an optimal timing according to an engine operating state. A valve timing device is used.

As such a variable valve timing device, for example, between a timing pulley connected to a crank pulley via a belt and a camshaft, while being engaged with the timing pulley and the camshaft, an axial direction is provided. There is a device in which a meshable surface of the piston and the timing pulley or a meshing surface of the piston and the camshaft is formed by a helical helical tooth (helical spline) with a reciprocating cylindrical piston interposed therebetween.

The variable valve timing device moves the piston forward and backward using the pressure of the lubricating oil of the internal combustion engine. At this time, since the piston moves forward and backward while rotating along the helical spline, the rotation phase of the piston with respect to the timing pulley or the rotation phase of the camshaft with respect to the piston is changed. The rotation phase of the shaft is changed.

As described above, according to the variable valve timing device, the intake and exhaust valves can be opened and closed at an optimum timing according to the operating state of the internal combustion engine by moving the piston forward and backward.

[0006]

By the way, lubricating oil for an internal combustion engine is generally pumped from an oil pan by an oil pump driven by the rotational force of a crankshaft, and is pumped to the variable valve timing device and various parts of the internal combustion engine. When the internal combustion engine is started, sufficient hydraulic pressure is not applied to the variable valve timing device, and the piston is moved forward and backward so that the opening / closing timing of the intake / exhaust valve is at a desired timing. Can not.

When the internal combustion engine is started, a crankshaft is rotated by a starter motor, and this torque is transmitted to a timing pulley via a crank pulley, a belt, or the like. And transmitted to the camshaft.

At this time, a force for preventing rotation is applied to the camshaft due to friction of an intake / exhaust valve and a valve spring. When the rotation of the camshaft is thus prevented, the piston that has received the rotational force of the timing pulley advances or retreats while rotating along the helical spline.

Then, when the piston moves to the end in the advance direction or the end in the retreat direction and the movement of the piston is suppressed, the rotational force of the timing pulley is transmitted to the camshaft via the piston, The camshaft starts rotating against friction of the intake and exhaust valves, valve springs, and the like. At this time, the rotation phase of the camshaft with respect to the crankshaft is the most retarded state.

As described above, when the intake camshaft is most retarded when the internal combustion engine is started, the closing timing of the intake valve is delayed, so that fresh air or air-fuel mixture once sucked into the combustion chamber flows from the intake valve. It may flow out and the filling efficiency in the combustion chamber may decrease.

When the charge efficiency of the air-fuel mixture is reduced, the compression ratio of the air-fuel mixture in the combustion chamber is reduced in the compression stroke, so that the combustion energy of the air-fuel mixture is reduced and the startability of the internal combustion engine is deteriorated. In particular, during a cold start in which the friction of the internal combustion engine is large, there is a possibility that the internal combustion engine cannot be started against the friction.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has provided a technique capable of setting an opening / closing timing of an intake valve to a desired timing when starting an internal combustion engine. It is an object of the present invention to prevent a decrease in the charging efficiency of the air-fuel mixture or the air-fuel mixture, secure combustion energy sufficient for starting the internal combustion engine, and improve the startability of the internal combustion engine.

[0013]

The present invention employs the following means in order to solve the above-mentioned problems. That is,
The starting apparatus for an internal combustion engine according to the present invention is a starting apparatus for an internal combustion engine including a starting drive unit that rotates a crankshaft and a camshaft of the internal combustion engine when the internal combustion engine is started. Sometimes, a camshaft driving means for driving the camshaft is provided so that the opening / closing timing of the intake valve is set to a predetermined timing.

In the starting device for an internal combustion engine thus configured, when the internal combustion engine is started, so-called cranking in which the crankshaft and the camshaft are rotated by the starting drive means is performed. At this time, the camshaft driving means drives the camshaft so that the opening / closing timing of the intake valve becomes a predetermined timing. Therefore, the opening / closing timing of the intake valve during cranking is set to a desired timing.

Here, if the temperature of the internal combustion engine at the time of starting is lower than a predetermined temperature, the camshaft driving means drives the camshaft so as to advance the closing timing of the intake valve. If the temperature of the internal combustion engine is equal to or higher than the predetermined temperature, the camshaft may be driven so as to delay the closing timing of the intake valve.

That is, when the temperature of the internal combustion engine at the time of starting is lower than a predetermined temperature, a relatively large amount of combustion energy is required to start the internal combustion engine because the friction of the internal combustion engine is large. Therefore, the camshaft driving means drives the camshaft to advance the closing timing of the intake valve, so that the fresh air or the air-fuel mixture once sucked into the internal combustion engine does not flow out of the intake valve, and the fresh air or the air-fuel mixture does not flow. Since the gas filling efficiency is increased, the compression ratio of the air-fuel mixture is improved. As a result, the combustion energy of the air-fuel mixture increases, and the internal combustion engine is easily started.

On the other hand, when the temperature of the internal combustion engine at the time of starting is equal to or higher than the predetermined temperature, the friction of the internal combustion engine is small, so that a large combustion energy is not required as in the case of cold starting. Therefore, by driving the camshaft so that the camshaft drive means retards the closing timing of the intake valve,
The fresh air or the air-fuel mixture once sucked into the internal combustion engine does not flow out of the intake valve, and the efficiency of charging the fresh air or the air-fuel mixture is reduced. As a result, the combustion energy of the air-fuel mixture is reduced, and engine vibration when starting the internal combustion engine is reduced.

Next, the camshaft driving means may include a switching means for switching between transmission and interruption of the driving force to the camshaft using the driving force of the starting driving means as a driving source. Good.

In the camshaft driving means constructed as described above, the switching means transmits the driving force of the starting drive means to the camshaft when the internal combustion engine is started, and when the internal combustion engine is completely started, the starting drive means. And transmitting the driving force from the means to the camshaft. In this case, there is no need to newly provide a drive source for the camshaft drive means.

Further, the starting driving means includes pressure accumulating means for accumulating oil pressure generated during operation of the internal combustion engine, and a hydraulic motor using the oil pressure accumulated in the pressure accumulating means as a driving source. You may make it.

In this case, the pressure accumulating means of the starting drive means is
For example, energy when a vehicle on which the internal combustion engine is mounted is in a deceleration state, such as when the internal combustion engine is in an engine braking state, is accumulated as hydraulic pressure.

The starting drive means applies the hydraulic pressure accumulated in the pressure accumulating means to the hydraulic motor when the internal combustion engine is started. At this time, the hydraulic motor rotates the crankshaft and the camshaft using the hydraulic pressure.

According to such a starting driving means, the energy consumed at the time of starting is reduced as compared with the case of using an electric starter motor driven by a battery. Examples of the camshaft driving means include, for example, an electric or hydraulic motor connected to a camshaft, and a fluid pressure piston provided in a variable valve timing mechanism for changing the opening / closing timing of an intake valve or an exhaust valve. can do. When a fluid pressure piston is used as the camshaft driving means, when the internal combustion engine is started, the fluid pressure piston is driven to set the phase of the camshaft to a desired position, and then the position of the fluid pressure piston is fixed. Need to be kept.

[0024]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a starting apparatus for an internal combustion engine according to an embodiment of the present invention.

<First Embodiment> FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine to which an internal combustion engine starting device according to the present invention is applied.

The internal combustion engine 1 has a plurality of cylinders 2, each of which is provided with a piston 3 which is slidable in the axial direction. The piston 3 has a crankshaft 4 which is an engine output shaft.
And a connecting rod 5.

Above the piston 3, a combustion chamber 6 is formed. An ignition plug 7 is attached so as to face the combustion chamber 6, and an intake port 8 and an exhaust port 9 are opened to the combustion chamber 6, respectively. An intake valve 10 for opening and closing the intake port 8 and an exhaust valve 11 for opening and closing the exhaust port 9 are provided.

Subsequently, the internal combustion engine 1 comprises an intake camshaft 15 for opening and closing the intake valve 10 and an exhaust camshaft 1 for opening and closing the exhaust valve 11.
6 is provided. Timing pulleys 15a and 16a are attached to the distal ends of the intake-side camshaft 15 and the exhaust-side camshaft 16, as shown in FIG.

The timing pulleys 15a and 16a
The crankshaft 4 is connected via a timing belt 17 to a crank pulley 4 a attached to the tip of the crankshaft 4.
The transmission is transmitted to the intake side camshaft 15 and the exhaust side camshaft 16 through the a and 16a.

Here, the timing pulleys 15a, 16a
And the number of teeth of the crank pulley 4a is set such that the intake-side camshaft 15 and the exhaust-side camshaft 16 make one revolution each time the crankshaft 4 makes two revolutions, and the intake valve 10 and the exhaust valve 11 That is, each cylinder 2 opens and closes at a predetermined timing in synchronization with the intake stroke, the compression stroke, the expansion stroke, and the exhaust stroke.

Subsequently, at the base end of the crankshaft 4, a flywheel 4 having a ring gear formed around the circumference thereof
The ring gear of the flywheel 4b is engaged with a pinion gear 50b attached to the tip of a rotating shaft 50a of an electric starter motor 50.

The starter motor 50 is connected to a battery 54 via a relay 55. The relay 55
Electrically connects (on) or disconnects (off) the starter motor 50 and the battery 54.

When the relay 55 is turned on, the output current of the battery 54 is applied to the starter motor 50,
The starter motor 50 performs so-called cranking, which rotationally drives the crankshaft 4 via the pinion gear 50b and the flywheel 4b. As described above, the starter motor 50 implements the starting drive unit according to the present invention.

The intake camshaft 15
A spur gear 51 is attached to the base end of the spur gear 5.
1 meshes with a pinion gear 52b attached to the tip of a rotating shaft 52a of the electric motor 52.

The electric motor 52 is connected to a battery 54 via a relay 56. The relay 56
The electric motor 52 and the battery 54 are electrically connected (on) or disconnected (off).

When the relay 56 is turned on, the output current of the battery 54 is applied to the electric motor 52, and the electric motor 52 rotates the intake camshaft 15 via the pinion gear 52b and the spur gear 51. As described above, the electric motor 52 realizes the camshaft driving unit according to the present invention.

Returning to FIG. 1, a variable valve timing mechanism 32 for changing the rotation phase of the intake camshaft 15 with respect to the crankshaft 4 is attached to the timing pulley 15a of the intake camshaft 15. This variable valve timing mechanism 32
Is connected to an oil control valve 35 via a first hydraulic passage 33 and a second hydraulic passage 34.

The oil control valve 35 is connected to an oil pump 36 that uses the rotational force of the crankshaft 4 as a drive source, and is connected to an oil pan 37 that stores lubricating oil for the internal combustion engine 1.

The oil control valve 3
5 supplies the lubricating oil pressure-fed from the oil pump 36 to the variable valve timing mechanism 32 and leaks the lubricating oil supplied to the variable valve timing mechanism 32 and returns it to the oil pan 37. , And controls the hydraulic pressure applied to the variable valve timing mechanism 32.

Here, the configuration of the variable valve timing mechanism 32 will be described with reference to FIGS. The intake camshaft 15 has its journal portion 15b
The cylinder head 1a of the internal combustion engine 1 and a bearing cap 38 attached thereto are rotatably supported. And, on the outer periphery of the journal portion 15b,
Two annular grooves 39 and 40 extending in the circumferential direction are formed in a portion that comes into contact with the bearing cap 38 (hereinafter, the annular groove 39 near the base end is replaced with the first annular groove 39, and the annular groove 40 near the distal end is replaced with the annular groove 40). (Referred to as a second annular groove 40).

In response, the bearing cap 38 has a first hydraulic passage 38a opening at a position facing the first annular groove 39 and a second hydraulic passage 38a opening at a position facing the second annular groove 40. Two hydraulic paths 38b are formed.
These first and second hydraulic paths 38a, 38b communicate with an oil control valve 35 via first and second hydraulic paths 33, 34.

Subsequently, a first hydraulic passage 15f is formed in the axial center of the journal portion 15b, and the first hydraulic passage 15f is substantially offset from the axial center of the journal portion 15b. A parallel second hydraulic passage 15h is formed.

A communication passage 15g communicating with a part of the first annular groove 39 is provided at the base end of the first hydraulic passage 15f.
A communication passage 15i communicating with a part of the second annular groove 40 is formed at a base end of the second hydraulic passage 15h.

Next, a timing pulley 15a is attached to the tip of the journal 15b. At this time, the timing pulley 15a is
The annular projection 15d formed in the circumferential direction of the journal 5b and the camshaft sleeve 15c attached to the tip of the journal 15b are positioned relative to the journal 15b while being restricted from moving in the axial direction. It is rotatably mounted.

The camshaft sleeve 15c is
The journal portion 15 is fixed by a pin 41 and a bolt 42.
b and rotates integrally with the journal portion 15b.

A cover 43a surrounding the camshaft sleeve 15c is attached to the timing pulley 15a. The cover 43a has a bottomed cylindrical body 43d having an inner diameter larger than the outer diameter of the camshaft sleeve 15c, and an inner / outer diameter located at the base end side of the cylindrical body 43d and larger than the cylindrical body 43d. (Hereinafter referred to as a small-diameter cylindrical member 4c).
3d, the large-diameter cylindrical body is referred to as a proximal-side large-diameter portion 43c).

A flange 43b is formed at the base end of the base-side large-diameter portion 43c, and the flange 43b is fixed to one side surface of the timing pulley 15a with a bolt 44.

Here, the camshaft sleeve 15c
And the inner circumference of the tip-side small-diameter portion 43d are radially opposed to each other at a predetermined interval, and spiral grooves (helical splines) having a twist angle opposite to each other are formed on these circumferential surfaces.
15e and 43f are formed.

The helical spline 15e on the outer periphery of the camshaft sleeve 15c and the small diameter portion 43d on the distal end side
One of the inner helical splines 43f is
A spline having a straight groove parallel to the axial direction with a torsion angle of zero may be used.

Next, in the gap between the tip side small diameter portion 43d and the camshaft sleeve 15c, a journal portion 1 is provided.
5b, a cylindrical hydraulic piston 4 that can move back and forth along the axial direction
5 has been inserted.

The hydraulic piston 45 has a flange 45a formed at the base end thereof, and is inserted into a gap between the cover 43a and the camshaft sleeve 15c such that the flange 45a is located within the base end side large diameter portion 43c. Have been. At this time, the edge of the flange 45a abuts on the inner wall of the base-side large-diameter portion 43c in a liquid-tight and slidable manner.

The helical spline 1 on the outer circumference of the camshaft sleeve 15c is provided on the inner circumference of the hydraulic piston 45.
Helical spline 45b meshing with 5e is formed,
On the outer periphery of the hydraulic piston 45, the tip side small diameter portion 4 is provided.
A helical spline 45c meshing with the helical spline 43f on the inner periphery of 3d is formed, and the meshing of these helical splines causes the rotational force of the timing pulley 15a to pass through the cover 43a, the hydraulic piston 45, the camshaft sleeve 15c, and the intake camshaft. 15 is transmitted.

Here, a space surrounded by the timing pulley 15a, the cover 43a, and the journal portion 15b is defined by a base end side space portion 46 located on the base end side with respect to the flange 45a of the hydraulic piston 45. And a front end side space portion 47 located on the front end side.

The tip side space 47 is provided with the bolt 42
Through the hydraulic passage 42a passing through the
It communicates with the hydraulic passage 15f. At this time, the front end side space portion 47 is connected to the hydraulic passage 42a and the first hydraulic passage 15 described above.
f, communication path 15g, first annular groove 39, and first hydraulic path 3
The first hydraulic passage 33 is communicated with the first hydraulic passage 33 via 8a.

Next, the base end side space portion 46 is connected to the third annular groove 4 formed in the circumferential direction of the journal portion 15b through a communication passage 48 formed in the timing pulley 15a.
9 and a part of the third annular groove 49 is connected to the communication passage 15.
It communicates with the second hydraulic passage 15h via j. At this time,
The base end side space portion 46 is formed via the communication passage 48, the third annular groove 49, the communication passage 15j, the second hydraulic passage 15h, the communication passage 15i, the second annular groove 40, and the second hydraulic passage 38b. , Is communicated with the second hydraulic passage 34.

In the variable valve timing mechanism 32 configured as described above, when the hydraulic pressure is applied from the first hydraulic passage 33 and the hydraulic pressure leaks from the second hydraulic passage 34, as shown in FIG. The hydraulic pressure applied from the first hydraulic passage 33 is applied to the distal space 47 and the hydraulic pressure applied to the proximal space 46 is applied to the second hydraulic passage 34.
The hydraulic piston 45 moves from the distal end to the proximal end.

When the hydraulic piston 45 moves from the distal end to the proximal end, the hydraulic piston 45 is engaged with the helical spline 43f of the small diameter portion 43d on the distal end and the helical spline 45c on the outer periphery of the hydraulic piston 45. At the same time as the relative rotation with respect to the cover 43a, the hydraulic piston 45 relatively rotates the camshaft sleeve 15c due to the engagement between the helical spline 15e on the outer circumference of the camshaft sleeve 15c and the helical spline 45b on the inner circumference of the front hydraulic piston 45. Move.

Then, the helical splines 43f,
45c, 45b, and 15e indicate the directions in which the hydraulic piston 45 rotates relative to the cover 43a and the hydraulic piston 4
5 is formed so that the direction in which the camshaft sleeve 15c is relatively rotated coincides with the direction of rotation of the camshaft sleeve 15c.
The camshaft sleeve 15c is formed so as to advance with respect to the cover 43a, and the angle at which the hydraulic piston 45 is relatively rotated with respect to the cover 43a and the hydraulic piston 45 The angle is advanced by an angle obtained by adding the angle at which the camshaft sleeve 15c is relatively rotated.

On the other hand, in the variable valve timing mechanism 32, the hydraulic pressure leaks from the first hydraulic passage 33,
When the hydraulic pressure is applied from the hydraulic passage 34, as shown in FIG. 5, the hydraulic pressure applied from the second hydraulic passage 34 is applied to the proximal space 46, and the distal space 4
Since the hydraulic pressure applied to 7 is leaked to the first hydraulic passage 33, the hydraulic piston 45 moves from the proximal end to the distal end.

When the hydraulic piston 45 moves from the proximal end to the distal end, the hydraulic piston 45 is engaged with the helical spline 43f of the small-diameter portion 43d on the distal end and the helical spline 45c on the outer periphery of the hydraulic piston 45. At the same time as the relative rotation with respect to the cover 43a, the hydraulic piston 45 relatively rotates the camshaft sleeve 15c due to the engagement between the helical spline 15e on the outer circumference of the camshaft sleeve 15c and the helical spline 45b on the inner circumference of the front hydraulic piston 45. Move.

Then, the helical spline 43f,
45c, 45b, and 15e are formed so that the rotation phase of the camshaft sleeve 15c is delayed from the rotation phase of the cover 43a when the hydraulic piston 45 moves from the proximal end to the distal end. The angle at which the hydraulic piston 45 rotates relative to the cover 43a with respect to the cover 43a and the angle at which the hydraulic piston 45
This is an angle obtained by adding the angle of relative rotation of 5c and the angle is retarded.

Returning now to FIG. 1, the intake port 8
The intake branch pipe 19 connected to the internal combustion engine 1 is connected to a surge tank 20. The surge tank 20 is connected to an air cleaner box 22 via an intake pipe 21.

A fuel injection valve 23 is attached to the intake branch pipe 19 so that its injection hole faces the intake port 8. The intake pipe 21 is connected to an accelerator pedal (not shown) to A throttle valve 24 for opening and closing the intake passage in the pipe 21 is provided.

The exhaust port 9 communicates with an exhaust branch pipe 28 attached to the internal combustion engine 1.
8 is connected to an exhaust pipe 30 via an exhaust purification catalyst 29, and the exhaust pipe 30 is connected to a muffler (not shown).

The internal combustion engine 1 includes a crank position sensor 12 for outputting a pulse signal each time the crankshaft 4 rotates by a predetermined angle, and a water temperature sensor 13 for outputting an electric signal corresponding to the temperature of the cooling water. Is attached.

Subsequently, the intake camshaft 1
5 is provided with a cam position sensor 18 that outputs an electric signal corresponding to the displacement angle of the intake camshaft 15.

The surge tank 20 is provided with an intake pressure sensor 25 for outputting an electric signal corresponding to the intake pressure in the surge tank 20.
Is provided with a throttle position sensor 26 that outputs an electric signal according to the opening of the throttle valve 24.

Further, the exhaust branch pipe 28 is provided with the exhaust branch pipe 2.
An oxygen sensor 31 that outputs an electric signal corresponding to the oxygen concentration in the exhaust gas flowing through the inside 8 is attached. The various sensors as described above are connected to an electronic control unit ECU14 for engine control via electrical wiring, and output signals of the sensors are input to the ECU14. Further, the starter switch ST. SW53 is connected and the starter switch 53
Is input.

The ECU 14 controls the ignition plug 7, the fuel injection valve 23, the oil control valve 35, the starter motor 50, the electric motor 52 and the like based on the output signal values of various sensors.

The operation and effect of this embodiment will be described below. The ECU 14 receives the ON signal of the starter switch 53, that is, when the internal combustion engine 1 is started,
The temperature of the internal combustion engine 1 is detected, and it is determined whether the detected temperature is lower than a predetermined temperature.

Here, the ECU 14 can exemplify the temperature of the cooling water, the temperature of the lubricating oil, and the like as the parameter indicating the temperature of the internal combustion engine 1, but in the present embodiment,
The temperature of the cooling water, that is, the output signal value of the water temperature sensor 13 is used.

When the ECU 14 determines that the output signal value (temperature of the cooling water) of the water temperature sensor 13 is lower than the predetermined temperature, the friction of the internal combustion engine 1 is large, and is large for starting the internal combustion engine 1. Assuming that energy is required, only the relay 56 is turned on.

When the relay 56 is turned on, the output current of the battery 54 is applied to the electric motor 52, and the electric motor 52 rotates the intake camshaft 15 via the pinion gear 52b and the spur gear 51.

The rotational force of the intake camshaft 15 is input to the variable valve timing mechanism 32. At this time, sufficient hydraulic pressure is not applied to the variable valve timing mechanism 32, and the friction of the piston 3 and the crankshaft 4 acts on the timing pulley 15a via the crank pulley 4a and the timing belt 17, so that the friction Therefore, the hydraulic piston 45 of the variable valve timing mechanism 32 cannot be held at a desired position.

For this reason, the variable valve timing mechanism 32
When the rotational force of the intake side camshaft 15 is input to the hydraulic pump 45, the hydraulic piston 45 moves to the base end while rotating along the helical spline 43f of the cover 43a and the helical spline 15e of the camshaft sleeve 15c. The rotational force of the intake camshaft 15 cannot be transmitted to the timing pulley 15a.

However, when the hydraulic piston 45 reaches the base end (when the rotational phase of the intake camshaft 15 with respect to the timing pulley 15a is in the most advanced state), the movement of the hydraulic piston 45 is restricted. The rotational force of the side camshaft 15 is transmitted to the timing pulley 15a.

The torque transmitted to the timing pulley 15a is transmitted to the crankshaft 4 via the timing belt 17 and the crank pulley 4a, and the crankshaft 4 is rotated to start cranking.

At that time, cranking is performed in a state where the rotational phase of the intake side camshaft 15 with respect to the crankshaft 4 is the most advanced, that is, when the opening and closing timing of the intake valve 10 is the most advanced. In the stroke, the intake valve 10 is closed before the air-fuel mixture sucked into the combustion chamber 6 from the intake port 8 flows out to the intake port 8.

As a result, the amount of the air-fuel mixture charged into the combustion chamber 6 increases, and the compression ratio of the air-fuel mixture in the combustion chamber 6 increases in the subsequent compression stroke. When ignited, large combustion energy is generated, and the startability of the internal combustion engine 1 is improved.

On the other hand, if it is determined that the cooling water temperature is equal to or higher than the predetermined temperature, the ECU 14 determines that the friction of the internal combustion engine 1 is small and the internal combustion engine 1 can be started with small energy, and only the relay 55 is turned on. To

When the relay 55 is turned on, the electric power of the battery 54 is applied to the starter motor 50, and the starter motor 50 rotates the crankshaft 4 via the pinion gear 50b and the flywheel 4b.

The rotational force of the crankshaft 4 is
The power is transmitted to the timing pulleys 15a and 16a via the crank pulley 4a and the timing belt 17, and then transmitted to the intake camshaft 15 and the exhaust camshaft 16.

At this time, on the exhaust side, the rotational force of the timing pulley 16a is reduced by the camshaft 1 on the exhaust side.
6, the exhaust-side camshaft 16 rotates against the friction of the exhaust valve 11 and the like. However, on the intake side, since sufficient hydraulic pressure is not applied to the variable valve timing mechanism 32, the intake valve 10 and the like The hydraulic piston 45 cannot be held at a desired position against friction or the like.

Therefore, the variable valve timing mechanism 32
When the rotational force of the timing pulley 15a is input to
The hydraulic piston 45 moves to the distal end side while rotating along the helical spline 43f of the cover 43a and the helical spline 15e of the camshaft sleeve 15c, and transmits the rotational force of the timing pulley 15a to the intake-side camshaft 15. Can not.

However, when the hydraulic piston 45 reaches the tip (when the rotational phase of the intake camshaft 15 with respect to the timing pulley 15a is the most retarded), the movement of the hydraulic piston 45 is restricted. The torque of 15a is transmitted to the intake-side camshaft 15, and the intake-side camshaft 15 rotates to start cranking.

At this time, the cranking is performed in a state where the rotation phase of the intake side camshaft 15 with respect to the crankshaft 4 is the most retarded, that is, in a state where the opening / closing timing of the intake valve 10 is the most retarded. In the stroke, before the intake valve 10 is closed, the air-fuel mixture sucked into the combustion chamber 6 from the intake port 8 flows out to the intake port 8.

As a result, the amount of the air-fuel mixture charged into the combustion chamber 6 decreases, and in the subsequent compression stroke, the compression ratio of the air-fuel mixture in the combustion chamber 6 decreases, so that the combustion energy decreases and the engine vibration Is reduced.

According to the above-described embodiment, during the cold start in which the internal combustion engine 1 has a large friction, the intake valve 10
By advancing the opening / closing timing of the engine, the combustion energy can be increased and the startability can be improved, and at the time of a warm start in which the friction of the internal combustion engine 1 is small, the opening / closing timing of the intake valve 10 is retarded. Thus, the combustion energy can be reduced, and the engine vibration at the time of starting can be reduced.

In this embodiment, the variable valve timing mechanism 32 has been described as an example of the means for changing the rotational phase of the intake camshaft with respect to the crankshaft. However, the present invention is not limited to this. Any configuration that changes the rotation phase of the camshaft may be used.

<Second Embodiment> In the first embodiment described above, an example was described in which an electric motor for driving the intake camshaft was provided separately from the starter motor for driving the crankshaft. In the embodiment, an example in which the drive of the crankshaft and the drive of the intake-side camshaft are shared by one motor will be described.

FIG. 6 is a diagram showing a schematic configuration of a starter for an internal combustion engine according to the present embodiment.
0 pinion gear 50b and intake camshaft 1
5 between the pinion gear 50b and the flywheel 4b, a gear 58 that transmits a rotational force only when rotated in one direction is interposed between the spur gear 51 and the pinion gear 50b. A gear 59 that transmits the rotational force only when the flywheel 4b
Is configured to interpose a spur gear 60 for transmission to the motor.

The gear 58 is provided with a first gear 58b meshing with the pinion gear 50b of the starter motor 50 and a second gear 58g meshing with the spur gear 51 of the intake camshaft 15.
And a gear 58c are connected by a shaft 58a having a built-in one-way clutch.

When the first gear 58b is rotated in the direction of arrow x in the figure, the shaft 58a transmits the rotational force of the first gear 58b to the second gear 58c. When the first gear 58b is rotated in the direction opposite to the arrow x in the drawing, the rotational force of the first gear 58b is not transmitted to the second gear 58c.

On the other hand, the gear 59 is connected to the starter motor 5.
First gear 59b meshing with the 0 pinion gear 50b
And a second gear 59c meshing with the spur gear 60 are connected by a shaft 59a having a built-in one-way clutch.

When the first gear 59b is rotated in the direction of the arrow y in the figure (the direction opposite to the gear 58), the shaft 59a increases the rotational force of the first gear 59b. When the first gear 59b is rotated in the direction opposite to the arrow y in the drawing, the torque of the first gear 59b is not transmitted to the second gear 59c.

As described above, the gears 58 and 59 realize the switching means according to the present invention. Next, the starter motor 50 is connected to the battery 54 via the switch 57. The switch 57 electrically connects (ON) or disconnects (OFF) the battery 54 and the starter motor 50.
When it is connected to 0, the positive and negative of the current applied to the two terminals of the starter motor 50 can be switched.

For example, in the switch 57, when one terminal of the starter motor 50 is connected to the positive terminal of the battery 54 and the other terminal of the starter motor 50 is connected to the negative terminal of the battery 54, , The starter motor 50 rotates to one side.

On the other hand, in the switch 57, when the terminal on one side of the starter motor 50 is connected to the negative terminal of the battery 54 and the terminal on the other side of the starter motor 50 is connected to the positive terminal of the battery 54 , Starter motor 5
0 rotates to the other side (the direction opposite to one side).

When the internal combustion engine 1 is started, the ECU 14 turns on the switch 57 to rotate the starter motor 50. If the cooling water temperature at the start is lower than a predetermined temperature, the ECU 14 turns off the starter motor 50. The switch 57 is controlled so as to rotate the starter motor 50 so that the gear 58 receiving the rotational force rotates in the direction transmitting the rotational force, and the gear 59 rotates in the direction not transmitting the rotational force.

In this case, the rotational force of the starter motor 50 is transmitted to the first gear 58b of the gear 58 and the first gear 59b of the gear 59 via the pinion gear 50b. The torque of the first gear 58b is transmitted to the second gear 58c, and the shaft 59a of the gear 59 transmits the torque of the first gear 59b to the second gear 5c.
No transmission to 9c.

Then, the second gear 58c of the gear 58
Is transmitted to the intake-side camshaft 15 via the spur gear 51, and as a result, the first
As described in the embodiment, cranking is performed in a state where the rotational phase of the intake camshaft 15 with respect to the crankshaft 4 is the most advanced.

On the other hand, when the cooling water temperature at the time of starting is equal to or higher than the predetermined temperature, the ECU 14 determines that the gear 58 having received the rotational force of the starter motor 50 rotates in a direction not transmitting the rotational force, and the gear 59 has the rotational force. Switch 57 to rotate starter motor 50 to rotate in the direction in which
Control.

In this case, the rotational force of the starter motor 50 is transmitted to the first gear 58b of the gear 58 and the first gear 59b of the gear 59 via the pinion gear 50b. The torque of the first gear 58b is not transmitted to the second gear 58c, and the shaft 59a of the gear 59 transmits the torque of the first gear 59b to the second gear 59c.

The second gear 59c of the gear 59
Is transmitted to the crankshaft 4 via the spur gear 60 and the flywheel 4b, and as a result, as described in the first embodiment, the intake camshaft with respect to the crankshaft 4 The cranking is performed in a state where the rotation phases of the fifteen rotations are most retarded.

According to the above-described embodiment, the camshaft driving means and the starting driving means according to the present invention can be realized by the single starter motor 50, and the size of the starting device can be reduced. Can be.

<Embodiment 3> In the above-described first embodiment, the electric starter motor 50 has been described as an example of the starting drive means, but a hydraulic starter motor 61 as shown in FIG. You may use it.

In this case, a pinion gear 61b is attached to the tip of the rotary shaft 61a of the hydraulic starter motor 61 so that the pinion gear 61 meshes with a ring gear formed on the periphery of the flywheel 4b.

The hydraulic starter motor 61 realizes the hydraulic motor according to the present invention, and rotates the rotating shaft 61a when hydraulic pressure is applied. The hydraulic starter motor 61 is connected to a valve 63 via a first hydraulic passage 62, and the valve 63 is connected to a hydraulic accumulator 65 via a second hydraulic passage 64.

The hydraulic accumulator 65 implements the pressure accumulating means according to the present invention. When the internal combustion engine 1 is in the engine braking state, for example, when the vehicle on which the internal combustion engine 1 is decelerated, the hydraulic accumulator 65 is used. Accumulates lubricating oil using rotational force or the like.

Subsequently, the valve 63 is an electromagnetic valve composed of a solenoid coil, a moving core, and the like.
The valve opens when the drive current from the ECU 14 is applied. Then, when the cooling water temperature is lower than the predetermined temperature when the internal combustion engine 1 is started, the ECU 14 turns on the relay 56 and drives the electric motor 52 to rotate, similarly to the above-described first embodiment. Perform cranking.

On the other hand, when the cooling water temperature is equal to or higher than the predetermined temperature, the ECU 14 applies a drive current to the valve 63 to open the valve 63. At this time, the hydraulic pressure accumulated in the hydraulic accumulator 65 is applied to the hydraulic starter motor 61 via the second hydraulic passage 64, the valve 63, and the first hydraulic passage 62, and the rotation shaft of the hydraulic starter motor 61 61a is driven to rotate.

The rotational force of the hydraulic starter motor 61 is transmitted from the pinion gear 61b to the flywheel 4b.
Is transmitted to the crankshaft 4 from the flywheel 4b, and as described in the first embodiment, cranking is performed with the rotational phase of the intake-side camshaft 15 most retarded. Will be.

According to the above-described embodiment, the use of the hydraulic starter motor as the starting drive means enables the internal combustion engine 1 to be repeatedly started and stopped.
It is possible to suppress a decrease in battery voltage due to the starter motor.

[0114]

In the starting apparatus for an internal combustion engine according to the present invention, when the internal combustion engine is started, the opening and closing timing of the intake valve can be set to a predetermined timing. During a cold start that requires a large amount of combustion energy to start the engine, the opening / closing timing of the intake valve is advanced to increase the efficiency of charging fresh air or air-fuel mixture to increase the combustion energy. Can be improved.

Also, the internal combustion engine is warmed to some extent,
When the friction of the internal combustion engine is small, the opening and closing timing of the intake valve is retarded, the charging efficiency of fresh air or air-fuel mixture is reduced, the combustion energy can be reduced, and the engine vibration at startup can be reduced. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine to which an internal combustion engine starting device according to the present invention is applied.

FIG. 2 is a diagram showing a configuration of a starting device of the internal combustion engine according to the first embodiment.

FIG. 3 is a sectional view showing a configuration of a variable valve timing mechanism.

FIG. 4 is a view for explaining the operation of the variable valve timing mechanism (1).

FIG. 5 is a view for explaining the operation of the variable valve timing mechanism (2).

FIG. 6 is a diagram showing a configuration of a starting device for an internal combustion engine according to a second embodiment.

FIG. 7 is a diagram showing a configuration of an internal combustion engine starting device according to a third embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 4 ... Crankshaft (crankshaft) 10 ... Intake valve 13 ... Water temperature sensor 14 ... ECU 15 ... Intake side camshaft 15a ... Timing pulley 17 ..Timing belt 32 ... Variable valve timing mechanism 50 ... Starter motor 51 ... Spur gear 52 ... Electric motor 55 ... Relay 56 ... Relay 57 ... Switch 58 ... Gear 58a ··· shaft 58b ··· first gear 58c ··· second gear 59 ··· gear 59a ··· shaft 59b ··· first gear 59c ··· second gear 61 ··· hydraulic starter motor 63 ... Valve 65 ... Hydraulic accumulator

Claims (4)

[Claims] 1. A starting device for an internal combustion engine, comprising: starting drive means for rotating a crankshaft and a camshaft of the internal combustion engine when the internal combustion engine is started. A starting device for an internal combustion engine, comprising: camshaft driving means for driving the camshaft so that the timing is set to a predetermined timing. 2. The camshaft driving means drives the camshaft to advance the closing timing of the intake valve when the temperature of the internal combustion engine at the time of starting is lower than a predetermined temperature. 2. The apparatus according to claim 1, wherein when the temperature of the internal combustion engine is equal to or higher than the predetermined temperature, the camshaft is driven so as to retard the closing timing of the intake valve. 3. The camshaft driving means includes a switching means that uses a driving force of the starting driving means as a driving source, and switches between transmission and interruption of the driving force to the camshaft. The starting device for an internal combustion engine according to claim 1. 4. The starting drive means includes pressure accumulating means for accumulating a hydraulic pressure generated during operation of the internal combustion engine, and a hydraulic motor using a hydraulic pressure accumulated in the pressure accumulating means as a driving source. The starting device for an internal combustion engine according to claim 1, wherein