JP2001182563A - Method and device for controlling amount of intake air for ignition type internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce pumping loss by controlling an amount of intake air into a cylinder using a variable valve system with a simple structure, and to improve fuel consumption and stabilize idling operation by combining the variable valve system and a throttle valve for increasing lean limit. SOLUTION: A solid cam 27 for driving an intake valve is provided with continuously changing at least a lifting amount of a cam profile in the axial direction from idling operation to full load operation through light load operation and high load rotation range. The solid cam 27 is displaced in the axial direction with being connected with a pedaling amount of an accelerator pedal to change at least the lifting amount of the intake valve 21 with being connected with the pedaling amount of the accelerator pedal and also change the opening of the throttle valve 8 with being connected with the pedaling amount of the accelerator pedal, and by combining these changes, the amount of the intake air into the cylinder is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to gasoline, alcohol, natural gas, LPG,
The present invention relates to a method and an apparatus for controlling an intake air amount into a cylinder in an ignition type internal combustion engine using CNG or the like as a fuel.

[0002]

2. Description of the Related Art In a current ignition type internal combustion engine, the amount of intake air into a cylinder is changed only by changing the opening of a throttle valve (butterfly valve) provided on a throttle body in conjunction with the depression amount of an accelerator pedal. Is controlled to the required amount in each of the idle operation, the light load operation range, the high load operation range, and the full load operation. However, in the light load operation range, in order to close the throttle valve, the pressure in the intake pipe downstream of the throttle valve becomes a negative pressure with respect to the atmospheric pressure, and this negative pressure causes pumping loss and the fuel in the light load range The consumption rate (fuel consumption) is worsening. In the fuel burn improvement measures that are currently in practical use, such as lean burn systems (in-port injection) and direct injection systems,
Since the pressure in the intake pipe is negative, there is a problem that the fuel efficiency improvement rate reaches a plateau due to pumping loss.

Therefore, in recent years, the amount of intake air into the cylinder is controlled by changing the lift amount and valve opening duration of the intake valve in conjunction with the depression amount of the accelerator pedal by a variable valve mechanism. A so-called non-throttle engine that eliminates a throttle valve and reduces pumping loss has been proposed. The following are being studied as the variable valve mechanism. A variable valve mechanism including two or more cams, one or more rocker arms, and a mechanism for switching a cam acting on the rocker arms. A variable valve mechanism with a hydraulic mechanism between the cam and the intake valve that changes the lift of the intake valve. A variable valve mechanism that drives the intake valve with an arbitrary lift and valve opening angle using an electromagnetic actuator without using a cam.

[0004]

However, the non-throttle engines proposed so far have the following problems, so that they are still far from being put to practical use. (1) The above-described variable valve mechanism has problems such as a complicated structure, a large number of parts, a large space, and a high cost. There are issues with responsiveness, cooling, reliability, etc. (2) In the case where idle operation is performed only by reducing the lift amount and the valve opening operation angle of the intake valve, the idle operation is likely to be unstable unless the accuracy of the valve operating mechanism is significantly increased. Further, if the pumping loss is reduced by eliminating the throttle valve, the fuel efficiency is improved, but on the other hand, there arises a problem that the engine brake is weakened and the exhaust gas recirculation device cannot be used.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and reduce the pumping loss by controlling the amount of air taken into the cylinder by a variable valve mechanism having a simple structure, a small number of parts, and taking up no space. It is in. In addition, by combining this variable valve mechanism with a throttle valve, not only can the pumping loss be reduced to improve fuel economy, but also the lean limit can be extended to improve fuel economy,
The object is to stabilize the idling operation or to generate a negative pressure on the downstream side of the throttle valve when necessary so that the throttle valve can be used.

[0006]

In order to solve the above problems, the following intake air amount control method (1) and intake air amount control device (2) for an ignition type internal combustion engine are employed.

(1) At least the lift amount of the cam profile (preferably as described later) from the cam profile for the idling operation to the cam profile for the full load operation through the cam profile for the light load operation region and the cam profile for the high load rotation region. The three-dimensional cam for driving the intake valve, which is provided with both the lift amount and the valve opening operation angle continuously changed in the axial direction, is displaced in the axial direction in conjunction with the depression amount of the accelerator pedal, thereby obtaining the intake valve. By changing at least the lift amount (preferably, both the lift amount and the valve opening operating angle as described later) in conjunction with the depression amount of the accelerator pedal, at least a part of the intake air amount into the cylinder is controlled. (In other words, it is responsible for at least part of the control of the amount of intake air into the cylinder) Intake air amount control method. In this specification, for convenience, the terms “lift amount” and “valve opening angle” are used in common for both the cam profile and the intake valve. Also, the “valve opening duration”
It refers to the angle range in which the valve is open from the valve opening time to the valve closing time.

[0008] Regarding the displacement of the three-dimensional cam, "in conjunction with the depression amount of the accelerator pedal" means that the depression amount of the accelerator pedal and the displacement amount of the three-dimensional cam are linearly linked (proportional relationship).
It is not particularly limited to, for example, may be linked in a curve,
The stepping amount may be interlocked stepwise, or the stepping amount and the displacement amount of the three-dimensional cam may start to interlock after the accelerator pedal depression amount reaches a predetermined amount (the same applies hereinafter).

The control method according to the following aspect (1-1) depends on whether or not control by a throttle valve is used.
(1-2).

(1-1) A combination of changing at least the lift amount of the intake valve in conjunction with the depression amount of the accelerator pedal and changing the opening of the throttle valve in conjunction with the depression amount of the accelerator pedal are combined. Control the amount of intake air. The following modes (1-1-1) and (1-1-2) can be exemplified as this combination method.

(1-1-1) In an idling operation or a light load operation region, a turbulent flow is generated in the cylinder by keeping at least the lift amount of the intake valve small or increasing it in a small range. The intake air amount is controlled by changing the opening of the throttle valve. Further, in the high load operation range or the full load operation, the following aspects can be exemplified. The negative pressure on the downstream side of the throttle valve is reduced by keeping the opening of the throttle valve substantially at the maximum, and the intake air amount is controlled mainly by changing at least the lift amount of the intake valve. The intake air amount is controlled by using a combination of continuously changing the opening degree of the throttle valve and changing at least the lift amount of the intake valve.

The "light load driving range" refers to a driving range at a low speed (approximately a specified speed in an urban area) at a constant speed or at a moderate acceleration, and the "high load driving range" refers to a high speed (highway). (About the specified speed) at the time of constant speed running, sudden acceleration, or uphill (hereinafter the same).

(1-1-2) Immediately after shifting from the idling operation to the light load operation range, the opening degree of the throttle valve is substantially maximized so as to reduce the negative pressure on the downstream side of the throttle valve, and substantially the entire operation is performed. In the range, the intake air amount is controlled mainly by changing at least the lift amount of the intake valve.

(1-2) Eliminating the throttle valve or keeping its opening substantially at its maximum, and controlling at least the amount of intake air by changing at least the lift amount of the intake valve.

Further, in the present control method, the three-dimensional cam is provided with both the lift amount and the valve opening operation angle with the above change, so that both the lift amount and the valve opening operation angle of the intake valve are determined by the depression amount of the accelerator pedal. It is preferable to change them in conjunction with each other. It is also possible to use a small rotation of the three-dimensional cam in the direction around the axis in conjunction with the depression amount of the accelerator pedal, thereby changing the opening / closing timing of the intake valve.

(2) At least the lift amount (preferably the lift amount and valve opening) of the cam profile from the cam profile for the idling operation to the cam profile for the full load operation through the cam profile for the light load operation region and the cam profile for the high load rotation region. The three-dimensional cam is provided by continuously changing both the operating angle in the axial direction, a cam displacement device for displacing the three-dimensional cam in the axial direction in conjunction with the depression amount of the accelerator pedal, and driven by the three-dimensional cam. With an intake valve,
A structure in which at least a part of the intake air amount into the cylinder is controlled by changing at least the lift amount (preferably both the lift amount and the valve opening operation angle) of the intake valve based on the axial displacement of the three-dimensional cam. Intake air amount control device for an ignition type internal combustion engine.

The control device may include an intervening member interposed between the three-dimensional cam and the intake valve, and pressing the intake valve by slidingly contacting a predetermined cam profile determined by the axial displacement of the three-dimensional cam. it can. As an intervening member,
Although not particularly limited, a rocker arm (including a swing arm), a direct-hit valve lifter, and the like can be exemplified.

Preferably, the intervening member is provided with a follow-up contact portion that contacts the three-dimensional cam while following a change in the contact line angle accompanying the rotation of the three-dimensional cam. Examples of the follow-up contact portion include a follow-up contact portion swingably fitted to a seat provided on the intervening member, and a roller rotatably mounted on a spherical bearing.

The maximum displacement of the three-dimensional cam in the axial direction is 20 mm
Or more, more preferably 25 mm or more, and 30 mm or more.
mm or more is most preferable. When two or more intake valves are provided for one cylinder, each intake valve can be driven by the same number of the three-dimensional cams as the intake valves, but all the intake valves are driven by one three-dimensional cam. It is preferable to configure so that

Further, in the present control device, the three-dimensional cam is provided with both the lift amount and the valve opening operation angle with the above change, so that both the lift amount and the valve opening operation angle of the intake valve are determined by the depression amount of the accelerator pedal. It is preferable to configure so as to change in conjunction. It is also possible to provide a small cam rotation device that rotates the three-dimensional cam slightly around the axis in conjunction with the depression amount of the accelerator pedal, thereby changing the opening / closing timing of the intake valve.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a control device and a control method for an intake air amount of an ignition type internal combustion engine embodying the present invention;

First, the intake air amount control device will be described. As shown in FIG. 1, a cylinder head 2 is joined on a cylinder block 1 of an ignition type internal combustion engine to form a combustion chamber 3 in a cylinder. The head 2 is formed with a left exhaust port 4 and a right intake port 5 in FIG. An intake manifold 6 is connected to the intake port 5, and a throttle valve 8 is provided on a throttle body 7 formed upstream of the intake manifold 6. In the illustrated example, the fuel injection valve 9 is moved toward the intake port 5.
Is installed, but in the case of direct injection, the combustion chamber 3
The fuel injection valve 9 is attached toward the. An ignition plug 10 is attached to the cylinder head 2 toward the combustion chamber 3. The shape of the combustion chamber 3 and the mounting position of the spark plug 10 can be appropriately selected and changed.

An exhaust valve 11 is provided on the exhaust port 4 side of the cylinder head 2, and its stem portion 11b is slidably inserted into a valve guide 12 fixed to the cylinder head 2, and its umbrella portion 11a is The exhaust port 4 is closed by contacting a valve seat 13 provided on the opening edge of the exhaust port 4, or the exhaust port 4 is opened by being separated downward. Valve retainer 14 attached to the upper end of exhaust valve 11 and cylinder head 2
A valve spring 15 is interposed between the two and biases the exhaust valve 11 upward (in a direction in which the umbrella portion 11a closes the exhaust port 4).

A cam 17 for driving the exhaust valve 11 is formed on the exhaust side camshaft 16 provided above the exhaust valve 11, and the cam 17 has a constant cam profile. Between the cam 17 and the exhaust valve 11, a direct-hit valve lifter 18 as an example of an intervening member that presses the exhaust valve 11 by slidingly contacting the cam 17 is interposed. The valve lifter 18 is a known valve lifter having a cylindrical side wall and a disk-shaped end wall.

An intake valve 21 is provided on the intake port 5 side of the cylinder head 2, and its stem 21 b is slidably inserted into a valve guide 22 fixed to the cylinder head 2, and its head 21 a The intake port 5 is closed by contacting a valve seat 23 provided on an opening edge of the intake port 5, or the intake port 5 is opened by being separated downward. Valve retainer 24 attached to the upper end of intake valve 21 and cylinder head 2
A valve spring 25 is interposed between the two and biases the intake valve 21 upward (in a direction in which the umbrella portion 21a closes the intake port 5).

A three-dimensional cam 27 for driving the intake valve 21 is formed on a camshaft 26 on the intake side provided above the intake valve 21. The lift of the cam profile of the three-dimensional cam 27 and the valve opening operating angle are provided. The cam profile for the light load operation in which the lift amount and the valve opening operation angle gradually increase from the idle operation cam profile in which the lift amount and the valve opening operation angle are minimum (close to the base circle portion), Through a high-load operation cam profile in which the valve-opening operation angle further gradually increases, until a full-load operation cam profile in which the lift amount and the valve-opening operation angle are maximum.
It is provided with a continuous change in the axial direction. The three-dimensional cam 27 includes a base circular portion 27a and a nose portion 27b, as shown in FIGS.
Is a cylindrical surface having no inclination because the radius is the same in any of the cam profiles. However, the nose part 2
7b is inclined like a conical surface due to the change in the lift amount and the valve opening action angle.

The camshaft 26 includes a camshaft 26
In addition, there is provided a cam displacement device 28 for displacing the three-dimensional cam 27 in the axial direction in conjunction with the depression amount of the accelerator pedal. The cam displacement device 28 includes a sensor that detects the amount of depression of an accelerator pedal, a control device such as a microcomputer that determines the amount of displacement of the three-dimensional cam 27 based on the detected value,
And a drive unit using hydraulic pressure, electromagnetic force, or the like controlled by the control device.

A direct hit between the three-dimensional cam 27 and the intake valve 21 as an example of an intervening member that presses the intake valve 21 by receiving a sliding contact of a predetermined cam profile determined by the axial displacement of the three-dimensional cam 27. A valve lifter 30 is interposed. As shown in FIGS. 3 to 6, the valve lifter 30 includes a cylindrical side wall 31, a disk-shaped end wall 32 provided at an upper end of the side wall 31, and an upper surface of the end wall 32. The seat 33 includes, for example, a seat 33 that forms an inner surface of a semi-cylinder, and a follow-up contact portion 40 that is fitted to the seat 33 so as to swing (roll). The side wall 31 is vertically slidably and non-rotatably guided by a lifter guide hole 29 (FIGS. 5 and 6) formed in the cylinder head 2. A shim 39 (FIGS. 5 and 6) for adjusting the valve clearance is interposed between the pressing portion at the center of the lower surface of the end wall portion 32 and the end of the intake valve 21.

The seat 33 and the follow-up contact portion 40 which constitute the follow-up contact mechanism will be described in detail. In the center of the upper surface of the end wall portion 32, a raised portion 34 which is long in a direction perpendicular to the axis of the three-dimensional cam 27 is provided.
Are integrally formed, and the raised portion 34 is provided with a seat 33 extending in the same direction. Both ends of the seat 33 are open so as to penetrate and there are no obstacles, so that the precision machining of the seat 33 can be performed easily and accurately. In addition, seat 3
An engaging concave portion 35 is provided at a substantially central portion in the longitudinal direction of 3. Since the inner bottom surface of the engagement recess 35 is, for example, a flat or gentle curved concave surface, the engagement recess 35 can be easily processed, and both inner surfaces of the engagement recess 35 can be polished easily and accurately. It can be carried out.

The follow-up contact portion 40 is a half-split cylindrical shape including a semi-cylindrical surface 41 that swingably contacts the seat 33 and a flat contact surface 42 that contacts the three-dimensional cam 27. For example, a fan-shaped engaging projection 4 is provided at a halfway portion of the semi-cylindrical surface 41 in the longitudinal direction.
3 are integrally provided, and the engaging projection 43 is
And swingably sandwiched therebetween. By this engagement,
With the longitudinal end surface of the follow-up contact portion 40 appearing, the longitudinal movement of the follow-up contact portion 40 is restricted. The position of the engaging projection 43 may be at the central portion in the longitudinal direction of the semi-cylindrical surface 41, but it is preferable that the engaging convex portion 43 be offset to the side where the three-dimensional cam 27 starts to contact, rather than the central portion in the longitudinal direction.

The follow-up contact portion 40 is configured such that the contact surface 42 comes into contact with the three-dimensional cam 27 while swinging at a small angle while following the change in the contact line angle accompanying the rotation of the three-dimensional cam 27. At this time, the three-dimensional cam 27 is
The contact surface 42 is slid in the longitudinal direction, but the engaging convex portion 43 is engaged with the engaging concave portion 35 to restrict the longitudinal movement of the following contact portion 40. 40 does not come off seat 33.

Further, since the longitudinal movement of the follow-up contact section 40 is regulated in a state where the longitudinal end face of the follow-up contact section 40 appears, there is no need to provide a regulating wall on the end face, and the follow-up contact section is not required. It is possible to maximize the surface length of the cam 40 (the length of the contact surface 42 in the longitudinal direction). Therefore, even in an internal combustion engine having a small cylinder bore diameter, the height of the nose portion 27b in the high-load operation cam profile or the full-load operation cam profile of the three-dimensional cam 27 is increased,
A large lift amount of the intake valve 21 can be obtained.

In order to keep the longitudinal direction of the follow-up contact portion 40 always in the sliding contact direction of the three-dimensional cam 27, a rotation preventing mechanism (not shown) for holding the valve lifter 30 so as not to rotate around its axis. Is provided. The rotation preventing mechanism is not limited to a specific structure, but includes a structure (not shown) in which a protrusion and a groove (or hole) provided relatively to the valve lifter 30 and the lifter guide hole 29 are slidably engaged. Can be exemplified.

In the three-dimensional cam 27, as shown in FIG. 5, the cam profile for idling operation slides on the follow-up contact portion 40, and the cam profile for full load operation slides on the follow-up contact portion 40 as shown in FIG. The position is axially displaced by the cam displacement device 28 between the positions,
max is 25 mm or more. This maximum displacement Dma
When x is small, the rate of change of the cam profile becomes large, and the cam profile is largely changed by a slight displacement, so that the accuracy of control tends to be low. On the other hand, as the maximum displacement Dmax increases, the rate of change of the cam profile can be reduced, and the cam profile can be changed with a sufficient displacement, thereby increasing the control accuracy. However, if the maximum displacement Dmax is too large, the three-dimensional cam 2
When the cylinder 7 is displaced, the cylinder 7 abuts (interferes) with the cam support 36 (FIG. 2) supporting the camshaft 26 between the cylinders. Therefore, the upper limit of the maximum displacement Dmax is a limit amount at which such interference does not occur. Will be.

In order to increase the maximum displacement Dmax, it is preferable to provide one three-dimensional cam 27 per cylinder as shown in FIG. This is because if there is one three-dimensional cam 27 with respect to the interval between the cam supports 36, a sufficient margin can be obtained. However, the cam support 36
2B, the maximum displacement Dmax can be increased without causing the interference even if the three-dimensional cams 27 are provided for each cylinder, as shown in FIG. 2B.

During idling operation of the internal combustion engine,
The camshaft 26 is displaced rearward in FIG. 1 by the cam displacing device 28 in conjunction with the depression amount (none) of the accelerator pedal, and as shown in FIG. It comes into sliding contact with the contact surface 42. As shown in FIG. 5A, when the base circle portion 27a comes into contact with the contact surface 42, the angle of the contact line is three-dimensional cam 2
The follow-up contact portion 40 is not inclined with respect to the end wall portion 32 because it is parallel to the axis 7. As shown in FIG. 5B, when the nose portion 27b contacts the contact surface 42, the contact line angle is inclined, for example, by about several degrees to 30 degrees with respect to the axis of the three-dimensional cam 27. Follows by tilting (swinging) by the angle. In this way, the three-dimensional cam 27 presses the valve lifter 30 at the follow-up contact portion 40, and the three-dimensional cam 27 shown in FIG.
9A and 9B, the intake valve 21 is opened and closed with the minimum lift amount Lidle and the valve opening operating angle.

In the full load operation range of the internal combustion engine, the camshaft 2 is operated in conjunction with the depression amount (maximum) of the accelerator pedal.
The cam profile 6 is displaced forward in FIG. 1 by the cam displacement device 28, and the full-load operation area cam profile of the three-dimensional cam 27 slides on the contact surface 42 of the follow contact portion 40 as shown in FIG. The three-dimensional cam 27 pushes the valve lifter 30 at the following contact portion 40 which swings and follows in the same manner as in the above idle operation, and is shown by a line Imax in FIG. 6 (b) and FIG. 9 (a) or (b). Thus, the intake valve 21 is opened and closed with the maximum lift amount Lmax and the valve opening operation angle.

Also, between the idle operation and the full load operation, that is, in the light load operation range and the high load operation range, the camshaft 26 is displaced in conjunction with the intermediate depression amount of the accelerator pedal. The three-dimensional cam 27 is continuously displaced by the device 28 so that the cam profile for the light load operation range or the cam profile for the high load operation range of the three-dimensional cam 27 follows the contact portion 40.
In sliding contact with Therefore, the three-dimensional cam 27 is connected to the intake valve 2 as shown by the lines Ilow and Ihigh in FIG. 9A or 9B.
1 is opened and closed with a small lift amount Llow and a valve opening operation angle or a large lift amount Lhigh and a valve opening operation angle.

FIG. 9A shows an example in which the fully open timing is made substantially constant. By changing the valve opening angle (angle range), the overlap between the exhaust valve 11 and the intake valve 21 is reduced. It can be reduced in the idling rotation or light load operation range, and can be increased in the high load operation range or full load operation. FIG. 9B shows an example in which the opening / closing timing and the full opening timing are delayed toward the idling rotation side, and the overlap between the exhaust valve 11 and the intake valve 21 is further reduced in the idling rotation or light load operation range ( Or eliminate it). Such a change in timing can be realized by designing the three-dimensional cam 27, or by providing a small cam rotation device (not shown) on the cam shaft 26, and interlocking the three-dimensional cam 27 with the amount of depression of the accelerator pedal. It can also be realized by making a small rotation around the axis.

As described above, the three-dimensional cam 27 is displaced in the axial direction in conjunction with the depression amount of the accelerator pedal, so that the lift amount and the valve opening operating angle of the intake valve 21 (ie, the time integral value of the opening area of the intake valve 21) are obtained. ), The amount of intake air to the combustion chamber 3 in the cylinder is at least partially controlled.

As shown in FIG. 7, the throttle valve 8 is also linked with the throttle pedal 8 in the same manner as in the prior art (however, the control method may be different as described later). Of the intake air to the combustion chamber 3 in the cylinder by changing the opening S of the cylinder from the fully closed opening S0 to the fully opened opening Smax through the opening Sidle during idling operation. Is at least partially controlled.

Now, a method of controlling the intake air amount by the intake air amount control device configured as described above will be described.
This control method is divided into the following modes (1-1) and (1-2) depending on whether or not control by the throttle valve 8 is used.

(1-1) The lift amount and valve opening duration of the intake valve 21 are changed in accordance with the depression amount of the accelerator pedal, and the opening of the throttle valve 8 is changed in association with the depression amount of the accelerator pedal. Controlling the amount of intake air by combining this with changing. The following modes (1-1-1) and (1-1-2) can be exemplified as this combination method.

The modes (1-1-1) and (1-1-2) will be described with reference to FIG. 8, and therefore each graph line in FIG. 8 will be described first. In FIG. 8, a line A indicates that the lift amount and the valve opening duration of the intake valve 21 are kept small in an idle operation or a light load operation range, and increase linearly or in a curve in a high load operation range or a full load operation. (For convenience, only a linear increase is illustrated.
Same for all other lines. ). The line B linearly or curvilinearly increases the lift amount and the valve opening duration of the intake valve 21 with a small change rate in the idle operation or the light load operation range, and increases in the high load operation range or the full load operation. This is an example in which the rate of change increases linearly or in a curve. A line C is an example in which the lift amount and the valve opening duration of the intake valve 21 are increased linearly or curvedly at a continuous rate of change in the idling operation or the full load operation. Line α
Is an example in which the opening degree of the throttle valve 8 is increased linearly or curvedly at a continuous rate of change in idle operation or full load operation. The line β increases the opening of the throttle valve 8 linearly or curvilinearly with a small change rate in the idling operation or light load operation range, and linearly increases with a large change rate in the high load operation range or full load operation. Or it is an example of increasing in a curve. The line γ linearly or curvedly increases the opening of the throttle valve 8 until it reaches a substantially full opening in an idling operation or a light load operation range,
This is an example in which it is kept almost fully open in a high load operation range or a full load operation. The line δ is an example in which the opening degree of the throttle valve 8 is increased until the throttle valve 8 is almost fully opened immediately after the shift from the idling operation to the light load operation range, and is kept almost fully open in the light load operation range or the full load operation. In FIG. 8, the line γ and the line δ are slightly separated in a high load operation range or a full load operation, but this is merely for the sake of clarity, and there is no particular difference. are doing.

(1-1-1) In the idling operation or the light load operation region, the lift amount and the valve opening operation angle of the intake valve 21 are kept small or small as shown by the line A, B or C in FIG. By increasing the range, the turbulent flow is generated in the combustion chamber 3 in the cylinder, and as shown by the line α, β or γ in FIG. Control. In this case, turbulence / swirl is generated, whereby stable combustion is obtained, the feeling is improved, the lean limit can be extended, and the combustibility is improved. Also, as mentioned above,
When the idling operation is performed only by reducing the lift amount and the valve opening angle of the intake valve, the idling operation is likely to be unstable unless the accuracy of the valve operating mechanism is significantly increased. , It is easy to stabilize idle operation. Further, since the opening of the throttle valve 8 can be made larger than before, the pumping loss is reduced and the fuel efficiency is improved. further,
It also works with engine brakes and can use an exhaust gas recirculation system.

The high load operation range or full load operation following this mode can be classified into the following two modes. The negative pressure on the downstream side of the throttle valve 8 is reduced by keeping the opening of the throttle valve 8 almost fully open as shown by the line γ, and the lift amount of the intake valve 21 is mainly reduced by the line A, B or C The intake air amount is controlled by changing the valve opening operation angle. In this case, pumping loss is reduced and fuel economy is improved. As shown by the line α or β, the opening of the throttle valve 8 is continuously changed, and as shown by the line A, B or C,
The intake air amount is controlled by using both the lift amount of the intake valve 21 and changing the valve opening operation angle. Also in this case, since the opening degree of the throttle valve 8 can be made larger than before, the pumping loss is reduced and the fuel efficiency is improved.

(1-1-2) As shown by the line δ in FIG. 8, immediately after shifting from the idling operation to the light load operation range, the opening of the throttle valve 8 is almost fully opened to thereby reduce the negative pressure on the downstream side of the throttle valve. The pressure is reduced, and the intake air amount is controlled by changing mainly the lift amount and the valve opening operation angle of the intake valve 21 in substantially the entire operation range. In this case, the idling operation is easily stabilized. In addition, since the opening of the throttle valve 8 is substantially fully opened in almost the entire operation range except the idling operation, the pumping loss is reduced most and the fuel efficiency is improved. Furthermore, the engine brake is also effective, and an exhaust gas recirculation device can be used.

In each of the above embodiments, the lift amount and the valve opening operating angle of the intake valve 21 are, for example, as shown in FIG.
It can be changed as shown in (a) or (b).

(1-2) Either the throttle valve 8 is eliminated or its opening is kept almost fully open as shown by the line ε in FIG. 10, and the accelerator pedal depression amount is shown by the line D or E in FIG. In response to this, the lift amount and the valve opening operation angle of the intake valve 21 are increased linearly or curvedly, thereby controlling the entire intake air amount. In this case, pumping loss is reduced and fuel economy is improved.

As described above, according to the intake air amount control device and control method of the present embodiment, the following effects can be obtained. (1) The amount of intake air into the cylinder can be controlled by a variable valve mechanism that has a simple structure, a small number of parts, and requires no space. (2) By reducing the pumping loss, fuel efficiency in a practical operation range (particularly, under a light load operation range and a high load operation range) is improved. (3) Due to the generation of the turbulence and swirl, stable combustion is obtained, the feeling is improved, and the lean limit can be extended, so that the combustibility is improved. (4) In a practical operation range (particularly, under a light load operation range and a high load operation range), the intake valve 21 can be lifted by a necessary amount of intake air, so that it operates when the spring load of the valve spring 25 is small. I do. Therefore, the surface pressure between the three-dimensional cam 27 and the follow-up contact portion 40 is reduced, and the friction therebetween is reduced, so that fuel efficiency is improved.

Next, FIGS. 11 to 15 show modified examples in which the valve lifter 30 is changed to another intervening member. The intervening member shown in FIG.
The valve lifter 50 includes an end wall 52 having an elliptical plate shape and provided at an upper end of the side wall 51. By providing the longitudinal direction of the following contact portion 40 in the long diameter direction of the end wall portion 52,
The cam contact surface length of the following contact portion 40 can be increased. In addition, because it is an ellipse, even without providing a special rotation prevention mechanism,
The rotation of the valve lifter 50 can be prevented.

The intervening member in FIG. 12 is a valve lifter in which one valve lifter 60 can drive two intake valves 21. As described above, there is an advantage that two intake valves 21 can be employed even if one three-dimensional cam 27 is provided for one cylinder. The follow-up contact member 40 has a seat 33 around its periphery.
The difference from the above-described embodiment t is that the holding structure is held by being surrounded by the above. However, the holding structure (the engaging convex portion 43 and the engaging concave portion 35 in FIG. 3) of the above-described embodiment may be adopted.

The intervening member shown in FIG. The point that the follow-up contact member 40 is held by being surrounded by the seat 33 is different from the above-described embodiment, but the holding structure of the embodiment (the engagement protrusion 43 shown in FIG. 3).
And the engagement recess 35).

The interposed member in FIG. 14 is a rocker arm 80 in which one rocker arm 80 can drive two intake valves 21. As described above, there is an advantage that two intake valves 21 can be employed even if one three-dimensional cam 27 is provided for one cylinder. The point that the follow-up contact member 40 is held by being surrounded by the seat 33 is different from the above-described embodiment, but the holding structure of the embodiment (FIG. 3)
May be the engagement projection 43 and the engagement recess 35).

The intervening member shown in FIG. 15 is also a rocker arm 90 in which one rocker arm 90 can drive two intake valves 21. As described above, there is an advantage that two intake valves 21 can be employed even if one three-dimensional cam 27 is provided for one cylinder. The tracking contact member 100 is a spherical bearing 1
The present embodiment is also different from the above-described embodiment in that the roller is rotatably mounted on the outside of the roller. This follow-up contact member 100 can be adopted in the above-described embodiment and other modified examples.

It should be noted that the present invention is not limited to the configuration of the embodiment, and can be embodied with modifications without departing from the spirit of the invention.

[0057]

As described in detail above, according to the method and apparatus for controlling the intake air amount of an ignition type internal combustion engine according to the present invention,
The structure is simple, the number of parts is small, and the amount of air taken into the cylinder can be controlled by the variable valve mechanism that does not take up space, thereby reducing pumping loss. In addition, by combining this variable valve mechanism and the throttle valve, it is possible not only to reduce pumping loss and improve fuel efficiency, but also to increase the lean limit to improve fuel efficiency, stabilize idle operation, When necessary, a negative pressure can be generated downstream of the throttle valve so that it can be used.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an intake air amount control device according to an embodiment of the present invention.

FIG. 2 is a plan view of the same device.

FIG. 3 is a perspective view of a variable valve mechanism in the device.

FIG. 4 is an exploded perspective view of the variable valve mechanism.

FIG. 5 is a sectional view of the variable valve mechanism during idling operation.

FIG. 6 is a cross-sectional view of the variable valve mechanism during full load operation.

FIG. 7 is a cross-sectional view around a throttle valve of the same device.

FIG. 8 is a graph illustrating a method of controlling the amount of intake air by the device.

FIG. 9 is a graph showing a valve lift amount and a timing by a variable valve mechanism of the apparatus.

FIG. 10 is a graph illustrating another method of controlling the amount of intake air by the same device.

FIG. 11 is a cross-sectional view showing a modification of the embodiment.

FIG. 12 is a cross-sectional view showing a modification of the embodiment.

FIG. 13 is a cross-sectional view showing a modification of the embodiment.

FIG. 14 is a cross-sectional view showing a modification of the embodiment.

FIG. 15 is a cross-sectional view showing a modification of the embodiment.

[Explanation of symbols]

 Reference Signs List 3 Combustion chamber 5 Intake port 6 Intake manifold 8 Throttle valve 21 Intake valve 21a Head 21b Stem 26 Camshaft 27 Solid cam 27a Base circle 27b Nose 28 Cam displacement device 30 Valve lifter 31 Side wall 32 End wall 33 Seat 36 Cam support 40 Follower contact part 50 Valve lifter 60 Valve lifter 70 Rocker arm 80 Rocker arm 90 Rocker arm 100 Follower contact member

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F01L 13/00 301 F01L 13/00 301C F02D 9/02 F02D 9/02 D 351 351M 11/10 11/10 F 41/02 310 41/02 310A 320 320 41/04 301 41/04 301B 310 310B 320 320 320/10/10 310 41/10 310 320 320 F term (reference) 3G016 AA06 AA19 BA28 BA36 BB05 BB18 BB22 CA04 CA06 CA13 CA14 CA47 CA48 CA52 CA56 CA57 DA01 DA22 DA23 GA00 3G065 CA00 DA04 EA03 EA07 GA46 JA04 JA09 JA11 KA02 3G092 AA01 AA11 BA01 DA01 DA04 DA09 DA14 DC03 DG05 DG09 EA01 EA02 EA12 EA22 EA25 FA24 FA25 FA01 GA01 GA05 GA06 KA07 KA08 KA09 KA14 LA03 LA07 LB02 LC02 LC08 PA01Z PA11Z PE10Z PF03Z

Claims (16)

[Claims] An at least lift amount of the cam profile is continuously changed in the axial direction from an idle operation cam profile to a full load operation cam profile through a light load operation range cam profile and a high load rotation range cam profile. By displacing the attached three-dimensional cam for driving the intake valve in the axial direction in conjunction with the depression amount of the accelerator pedal, and thereby changing at least the lift amount of the intake valve in conjunction with the depression amount of the accelerator pedal, A method for controlling an intake air amount of an ignition type internal combustion engine, comprising controlling at least a part of an intake air amount into a cylinder. 2. changing at least a lift amount of the intake valve in conjunction with a depression amount of an accelerator pedal;
2. The intake air amount control method for an ignition-type internal combustion engine according to claim 1, wherein the intake air amount is controlled by a combination of changing an opening degree of a throttle valve in conjunction with a depression amount of an accelerator pedal. 3. In an idling operation or a light load operation region, a turbulent flow is generated in a cylinder by keeping at least a lift amount of the intake valve small or increasing it in a small range. 3. The intake air amount control method for an ignition type internal combustion engine according to claim 2, wherein the intake air amount is controlled by changing an opening degree. 4. In a high-load operation range or a full-load operation, the negative pressure on the downstream side of the throttle valve is reduced by keeping the opening of the throttle valve substantially at a maximum, and at least the lift amount of the intake valve is reduced. 3. The amount of intake air is controlled by changing the amount of intake air.
4. A method for controlling an intake air amount of an ignition type internal combustion engine according to claim 3. 5. In a high-load operation range or a full-load operation, the intake air flow rate is controlled by simultaneously changing the opening degree of the throttle valve and changing at least the lift amount of the intake valve. 4. The method according to claim 3, wherein the intake air amount is controlled. 6. The system of claim 6, wherein the negative pressure on the downstream side of the throttle valve is reduced by making the opening of the throttle valve substantially maximum immediately upon shifting from the idling operation to the light load operation range. 3. The intake air amount control method for an ignition type internal combustion engine according to claim 2, wherein the intake air amount is controlled mainly by changing at least a lift amount of the intake valve in a range. 7. The ignition according to claim 1, wherein the throttle valve is eliminated or its opening is maintained at a substantially maximum level, and the intake air amount is entirely controlled by changing at least the lift amount of the intake valve. A method for controlling the amount of intake air of a type internal combustion engine. 8. The three-dimensional cam is provided with both the lift amount and the valve opening operation angle with the change, so that both the lift amount and the valve opening operation angle of the intake valve change in conjunction with the depression amount of the accelerator pedal. The method for controlling the intake air amount of an ignition type internal combustion engine according to any one of claims 1 to 7, wherein the method is performed. 9. The intake air amount is controlled by simultaneously rotating the three-dimensional cam in a direction around an axis in conjunction with the amount of depression of an accelerator pedal and changing the opening / closing timing of the intake valve. A method for controlling the amount of intake air of an ignition type internal combustion engine according to claim 1. 10. At least the lift amount of the cam profile is continuously changed in the axial direction from the idling operation cam profile to the full load operation cam profile through the light load operation range cam profile and the high load rotation range cam profile. A three-dimensional cam provided with the three-dimensional cam, a cam displacement device for displacing the three-dimensional cam in the axial direction in conjunction with the depression amount of an accelerator pedal, and an intake valve driven by the three-dimensional cam; The intake of an ignition type internal combustion engine configured to control at least partially the amount of intake air into a cylinder by changing at least the lift amount of the intake valve in accordance with the depression amount of an accelerator pedal based on the displacement of the intake valve Air flow control device. 11. An intervening member interposed between the three-dimensional cam and the intake valve, the intervening member pressing the intake valve by sliding contact of a cam profile determined by an axial displacement of the three-dimensional cam. 11. The intake air amount control device for an ignition type internal combustion engine according to claim 10. 12. The intake air amount control device for an ignition type internal combustion engine according to claim 10, wherein the maximum displacement of the three-dimensional cam in the axial direction is set to 20 mm or more. 13. When each cylinder has two or more intake valves, each intake valve is driven by the same number of the three-dimensional cams as the intake valves.
13. The intake air amount control device for an ignition type internal combustion engine according to any one of claims 12 to 12. 14. The ignition type internal combustion engine according to claim 10, wherein, when two or more intake valves are provided for one cylinder, all the intake valves are driven by one three-dimensional cam. Engine air intake control device. 15. The three-dimensional cam is provided with both the lift amount and the valve opening operation angle with the change, so that both the lift amount and the valve opening operation angle of the intake valve change in conjunction with the depression amount of the accelerator pedal. Claims 10 to 1 configured to cause
5. The intake air amount control device for an ignition type internal combustion engine according to claim 4. 16. A small cam rotation device for slightly rotating the three-dimensional cam around an axis in conjunction with the depression amount of an accelerator pedal, thereby changing the opening / closing timing of the intake valve. The intake air amount control device for an ignition type internal combustion engine according to any one of claims 1 to 4.