JP3482809B2 - Control device for internal combustion engine with variable valve mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a variable valve mechanism for controlling opening and closing of intake valves and exhaust valves of an internal combustion engine at timings according to the operating state of the engine, and controls a control element for combustion control of the internal combustion engine. Regarding the control device for the internal combustion engine,
In particular, the present invention relates to a control device for an internal combustion engine with a variable valve mechanism, which is suitable for controlling the ignition timing and volumetric efficiency of the engine.

[0002]

2. Description of the Related Art A reciprocating internal combustion engine (hereinafter referred to as an engine) is provided with an intake valve and an exhaust valve (hereinafter collectively referred to as an engine valve or simply a valve). Since the valve is driven in a valve lift state according to the shape and rotational phase of the cam, the valve opening / closing timing and the valve opening period (the period during which the valve is open is shown in units of crank rotation angle) It depends on the shape and rotation phase.

By the way, in the case of an intake valve and an exhaust valve provided for an engine, the optimum opening / closing timing and valve opening period differ depending on the load condition and speed condition of the engine. Therefore, various so-called variable valve actuation mechanisms have been proposed, which are capable of changing the valve opening / closing timing and the valve opening period. One of the variable valve mechanisms has a high speed cam and a low speed cam with different cam profiles, and when the engine speed is below a predetermined value (low speed rotation), the valve is operated by the low speed cam. When the engine is opened / closed and the engine speed is higher than a certain value (high speed rotation), the valve is opened / closed by the high speed cam so that the optimal opening / closing timing and opening period can be achieved at both low speed and high speed. Technology for driving valves such as intake valves and exhaust valves has been developed.

However, such a variable valve mechanism has an optimum opening / closing timing in the vicinity of two rotation speeds, that is, in the vicinity of a certain rotation speed in the low speed rotation range of the engine and in the vicinity of a certain rotation speed in the high speed rotation range. Although the valve opening period can be obtained, the optimum opening / closing timing and the valve opening period are not necessarily obtained in the engine rotation range other than this. Therefore, between the cam and the cam shaft, a non-constant velocity joint that increases / decreases or changes the phase of the cam with respect to the rotational speed of the cam shaft during one revolution of the cam shaft is provided. A technique has been developed in which the valve opening / closing timing and the valve opening period can be adjusted continuously or in multiple stages by adjusting the characteristics of speed or phase change. Such techniques are disclosed, for example, in Japanese Examined Patent Publication No. 47-20654 and Japanese Patent Laid-Open No. 3-16830.
9, JP-A-4-183905, JP-A-6-1063.
No. 9-41923 and JP-A-9-41924.

[0005]

By the way, engine control elements include ignition timing, volume efficiency, fuel injection timing, and the like. These control elements include engine speed, intake pressure (engine load), and the like. It is desirable to control the value to be an optimum value according to the operating state of the engine. Therefore, when electronically controlling such control elements, the operating state of the engine (engine speed, intake pressure, etc.) is detected using a map that stores data of optimum control elements for engine speed, intake pressure, etc. However, the control element is controlled by calculating the optimum control element data according to the map.

However, the control elements such as the ignition timing and the volumetric efficiency depend not only on the operating state of the engine but also on the opening and closing timing of the valves such as the intake valve and the exhaust valve and the valve opening period (these are collectively referred to as the valve opening characteristics). Also changes the optimum value. Therefore, when the valve opening characteristic can be controlled, it is more appropriate to set control elements such as ignition timing and volume efficiency according to the valve opening characteristic as well as the operating state of the engine.

For example, in the case of a low-speed / high-speed two-stage switching type variable valve mechanism that selects a high-speed cam and a low-speed cam to open / close the valve, as shown in FIGS. 9 (A) and 9 (B). , Low speed valve timing map (low speed map),
2 with high speed valve timing map (high speed map)
It is considered that one map is provided and the map is used properly according to the selected state of the valve timing to calculate the optimum control element data for the engine operating state and the valve timing state. In addition, in FIG.
The engine speed Ne and the intake pressure Pb are parameters indicating the operating state of the engine.

[0008] As described above, in the method in which the map is selectively used according to the valve opening characteristic of the valve, the valve opening characteristic (opening / closing timing and opening period) of the valve can be adjusted continuously or in multiple stages. In the case of the variable valve mechanism, as shown in FIG. 10, for example, if the valve opening characteristic of the valve is switched to n stages according to the engine speed, n number of maps are required. It is necessary to prepare a large number of maps according to

As described above, when the number of maps to be stored becomes large, the storage means such as the ROM also needs to have a large capacity, which causes a problem that the cost of the storage means increases, and a large number of maps are prepared. In order to do so, there is a problem in that it takes a lot of man-hours and is very time-consuming even when performing map matching or the like, which results in cost and time.

The present invention was devised in view of the above-mentioned problems, and prepares a large number of maps in an internal combustion engine having a variable valve mechanism capable of adjusting the valve opening characteristic of the valve continuously or in multiple stages. An object of the present invention is to provide a control device for an internal combustion engine with a variable valve mechanism, which is capable of controlling a control element related to combustion control of the engine without using it.

[0011]

Therefore, the control device for an internal combustion engine with a variable valve mechanism according to the present invention according to claim 1 determines the valve opening characteristics of the intake valve or the exhaust valve according to the operating state of the internal combustion engine. In an internal combustion engine having a variable valve mechanism that continuously or stepwise changes from the first valve opening characteristic to the second valve opening characteristic so as to obtain the optimum valve opening characteristic, the operating state of the internal combustion engine is changed. Correspondingly, map storage means for storing a plurality of maps in which data relating to control elements relating to combustion control of the internal combustion engine are stored, and an operating state of the internal combustion engine based on the maps stored in the map storage means And a plurality of maps corresponding to the operating state of the internal combustion engine when the variable valve mechanism is set to the first valve opening characteristic. Optimal control element data When the variable valve mechanism is set to the second valve-opening characteristic, the optimum control element corresponding to the operating state of the internal combustion engine. A second valve opening characteristic time map to which data is mapped, and corresponds to the operating state of the internal combustion engine when the variable valve mechanism is set to the optimum valve opening characteristic corresponding to the operating state of the internal combustion engine And an optimal valve opening characteristic time map in which the optimal control element data is mapped,
The actual valve opening characteristic detection means for detecting the actual setting state of the variable valve mechanism or the actual setting state of the valve opening characteristic is provided, and the control means detects the actual setting state detected by the actual valve opening characteristic detection means. If the valve opening characteristic is the optimum valve opening characteristic according to the operating condition of the internal combustion engine, the control element is controlled based on the optimum valve opening characteristic time map, and the actual valve opening characteristic detection means detects the actual valve opening characteristic. Is not the optimum valve opening characteristic according to the operating state of the internal combustion engine but is closer to the first valve opening characteristic than the valve opening characteristic, the optimum valve opening characteristic time map and the first valve opening characteristic map The control element is controlled on the basis of the interpolated value obtained from the valve opening characteristic time map and the actual valve opening characteristic detected by the actual valve opening characteristic detecting means is optimally opened according to the operating state of the internal combustion engine. If it is not the valve characteristic but the second valve opening characteristic side of the optimum valve opening characteristic, the optimum valve opening characteristic time map It is characterized by being configured to control the control element based on the interpolation value obtained from the valve opening characteristic time map of the second.

According to a second aspect of the present invention, there is provided a control device for an internal combustion engine with a variable valve mechanism, comprising:
At least the first valve opening characteristic time map is for the minimum valve opening period in which the optimum control element data is mapped corresponding to the operating state of the internal combustion engine in the minimum valve opening period of the variable valve mechanism. It is characterized by being a map. In this case, the second valve opening characteristic time map shows that the variable valve operating mechanism maps the optimum valve element data corresponding to the operating state of the internal combustion engine during the maximum valve opening period. It is preferably a time period map.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 illustrate a control device for an internal combustion engine with a variable valve mechanism as one embodiment of the present invention, and FIGS. 3 to 7 illustrate a variable valve mechanism according to the present embodiment. is there.

The internal combustion engine according to this embodiment is
A reciprocating internal combustion engine, and a variable valve mechanism according to this embodiment drives an intake valve or an exhaust valve (collectively referred to as an engine valve or simply a valve) installed above a cylinder. It is equipped with 3 to 5 are a perspective view, a cross-sectional view, and a schematic layout view (schematic view as seen from the end face in the axial direction) showing the main part of the present variable valve mechanism.
As shown in FIG. 1, the cylinder head 1 has a valve (valve member) 2 for opening and closing an intake port or an exhaust port (not shown).
The stem 2A of the valve 2 is equipped with a valve spring 3 for urging the valve 2 toward the closing side.
(See FIG. 5) is installed.

Further, at the stem end 2A of the valve 2,
The rocker arm 8 is in contact, and the cam 6 is in contact with this rocker arm 8. Then, the valve 2 is driven in the opening direction against the biasing force of the valve spring 3 by the convex portion (cam crest portion) 6A of the cam 6. The variable valve mechanism is provided for rotating the cam 6 as described above.

As shown in FIGS. 3 and 4, this variable valve mechanism is rotationally driven in conjunction with a crank shaft (not shown) of the engine via a belt (timing belt) 41 and a pulley 42. A cam shaft (first rotating shaft member) 11;
The cam (cam portion) 6 is provided with a cam lobe (second rotating shaft member) 12 provided on the outer periphery of the cam shaft 11.
Is provided so as to project on the outer periphery of the cam lobe 12. In addition,
The outer periphery of the cam lobe 12 is rotatably supported by the bearing portion 7 on the cylinder head 1 side.

The camshaft 11 is supported by the bearing portion 7 via the cam lobe 12, but the camshaft 1
The end portion 1 is axially supported by the bearing portion 1A of the cylinder head 1 via the end portion member 43 that is coupled on the same axis. Since the pulley 42 described above is mounted on such an end member 43, the end member 43 equipped with this pulley 42 can be referred to as an input portion.

As shown in FIGS. 4 and 5, the bearing portion 7 has a two-split structure and includes a lower bearing half portion 7A formed in the cylinder head 1 and a lower bearing half portion 7A. It comprises a bearing cap 7B joined from above and a bolt 7C for connecting the bearing cap 7B to the lower bearing half 7A. Further, as shown in FIG. 5, a joint surface 7D between the lower bearing half portion 7A and the bearing cap 7B is set to be substantially horizontal so as to be orthogonal to the axial center line of the cylinder (not shown). The bearing lower half portion 7A and the bearing cap 7B are firmly coupled in the substantially vertical direction by bolts 7C that are fastened in the substantially vertical direction (up and down direction).

Then, the cam shaft 11 and the cam lobe 1
A non-constant velocity joint 13 is provided between the two. The variable valve mechanism is suitable for a multi-cylinder engine, and when applied to a multi-cylinder engine, the cam lobe 12 and the non-uniform speed are provided on both or one of the intake side and the exhaust side of each cylinder. The joint 13 is provided. Here, as an example, a case where the present variable valve mechanism is applied only to the intake side of an in-line four-cylinder engine will be described.

The non-constant velocity joint 13 includes a control disc (shaft support member) 14 rotatably supported on the outer circumference of the intake-side camshaft 11, and an eccentric portion integrally provided on the control disc 14. (Spindle part) 15, engagement disk (intermediate rotation member) 16 provided on the outer periphery of the eccentric part 15, first slider member (first connection member) 17 and second slider member 16 connected to the engagement disk 16. It has a slider member (second connecting member) 18. The engagement disc 16 is also called a harmonic ring.

As shown in FIG. 4 , the eccentric portion 15 has a rotation center O ₂ at a position eccentric from the rotation center (first rotation center axis) O ₁ of the camshaft 11, and the engagement disk 16 is Center of this eccentric portion 15 (second rotation center axis) O ₂
It is designed to rotate around. As shown in FIG. 3, the first slider member 17 and the second slider member 18 are
The slider body portions 21 and 22 are provided at the tips thereof, and the drive pin portions 23 and 24 are provided at the other end sides.

As shown in FIG. 4, the slider body groove 21 of the first slider member 17 is slidably fitted in one surface of the engagement disk 16 in the radial direction (radial direction). 16A and the slider body 22 of the second slider member 18 are slidably fitted in the slider groove 1
6A and 6A are formed. Here, the two slider grooves 16A and 16B are arranged on the same diameter so as to shift the rotational phases by 180 ° from each other.

The camshaft 11 is provided with a drive arm 19, the cam lobe 12 is provided with an arm portion 20, and the drive pin portion 23 of the first slider member 17 is rotatably fitted in the drive arm 19. Hole 1
9A is provided, and the arm portion 20 has a hole portion 2 into which the drive pin portion 24 of the second slider member 18 is rotatably fitted.
0A is provided.

The drive arm 19 includes an arm portion 20 between the cam lobe 12 and the control disk 14.
Is provided in a space other than the above so as to project from the camshaft 11 in the radial direction (radial direction), and is coupled by a lock pin 25 so as to rotate integrally with the camshaft 11. On the other hand, the arm portion 20 connects the end portion of the cam lobe 12 to
The engaging disk 16 is integrally formed so as to project in the radial direction and the axial direction to a position close to one side surface of the engaging disk 16.

By the way, the slider body 21 and the groove 16A
5, between the outer flat surfaces 21B and 21C of the slider body 21 and the inner wall flat surfaces 28A and 28A of the groove 16A, as shown in FIG.
28B, between the groove 16B and the slider body 22, the rotational force is transmitted between the inner wall planes 28C and 28D of the groove 16B and the outer planes 22B and 22C of the slider body 22. .

Since the engaging disc 16 is eccentric when transmitting the rotation in this way, the engaging disc 16 is
Repeats leading and delaying with respect to the cam shaft 11, and the cam lobe 12 repeats leading and delaying with respect to the engaging disk 16 while the cam lobe 12 is separated from the cam shaft 11. It is designed to rotate at a non-uniform speed.

For example, FIG. 6 is a diagram for explaining that the cam lobe 12 rotates at a non-constant speed with respect to the cam shaft 11.
(A1) to (A3) are diagrams illustrating changes in the rotational angular velocity of the engagement disc 16 with respect to the camshaft 11, and (B1) to (B3) are diagrams illustrating changes in the rotational angular velocity of the cam lobe 12 with respect to the engagement disc 16. As shown in FIG. 6 (A1), the rotation center (second rotation center axis) O ₂ of the engagement disk 16 is eccentric upward with respect to the rotation center (first rotation center axis) O _{1 of} the camshaft 11. The slider groove 16A and the first slider member 17 in the eccentric direction.
The camshaft 1 with the state of being positioned at the reference position of rotation.
It is assumed that 1 rotates clockwise.

In FIGS. 6A1 and 6A2,
S1 indicates the position of the reference point on the camshaft 11 side (for example, the center point of the first slider member 17) at the rotation reference position,
H1 indicates the position of the reference point on the engagement disk 16 side (for example, the reference point of the slider groove 16A) at the rotation reference position. In S2 to S12, the reference point (center point of the first slider member 17) on the camshaft 11 side is the rotation reference position S1.
Shows the respective positions when rotated by a predetermined angle (here, 30 °) from each other, and H2 to H12 are these camshafts 11.
Each position of the reference point (reference point of the slider groove 16A) on the side of the engaging disk 16 that rotates according to the reference point positions S2 to S12 on the side is shown.

Here, the rotation of the reference point on the camshaft 11 side is about the first rotation center axis O ₁ as the center of the engagement disc 1.
The rotation of the reference point on the 6 side is performed around the second rotation center axis O ₂ . As shown in FIG. 6 (A2),
The reference point on the camshaft 11 side (the center point of the first slider member 17) is 30 ° from S1 to S2 (∠S1 · O ₁ · S).
When rotated only 2), the reference point on the engagement disk 16 side (the reference point of the slider groove 16A) changes from H1 to H2 ∠H1 · O
_{Since it} rotates by ₂ · H2, the rotation angle is larger than the camshaft 11 side (∠H1 · O ₂ · H2> ∠S1 · O
Rotate only ₁・ S2). That is, the engagement disk 16 side rotates at a faster speed than the camshaft 11 side.

Next, the camshaft 11 side is S2 → S3.
_{30 ° (∠S2 · O 1 ·} S3) If only rotated to, the engagement disc 16 side to the _{H2 → H3, ∠H2 · O 2} · H
Since it rotates by the angle of 3, the rotation angle is slightly larger than the camshaft 11 side (∠H2 ・ O ₂・ H3> ∠S
2 ・ O ₁・ S3) rotate. That is, during this period, the engagement disk 16 side rotates at a speed slightly higher than the camshaft 11 side.

Next, the camshaft 11 side is S3 → S4.
_{30 ° (∠S3 · O 1 ·} S4) If only rotated to, the engagement disc 16 side to the _{H3 → H4, ∠H3 · O 2} · H
Since it rotates by the angle of 4, the rotation angle is almost the same as the camshaft 11 side (∠H3 ・ O ₂・ H4≈∠S3 ・
Rotate only O ₁ · S4). That is, during this period, the engagement disk 16 side rotates at a speed substantially equal to that of the camshaft 11 side.

Next, the camshaft 11 side is S4 → S5.
When rotated by 30 ° (∠S4 ・ O ₁・ S5), the engagement disc 16 side changes from H4 to H5, ∠H4 ・ O ₂・ H
Since it rotates by the angle of 5, the rotation angle (∠H4 ・ O ₂・ H5≈∠S4 ・
Rotate only O ₁ · S 5). That is, during this period, the engagement disk 16 side rotates at a speed substantially equal to that of the camshaft 11 side.

Further, the camshaft 11 side is S5 → S6.
30 ° rotates only (∠S5 · O ₁ · S6) to, side engagement disc 16 to _{H5 → H6, ∠H5 · O 2} · H
Since it rotates by the angle of 6, the rotation angle is slightly smaller than the camshaft 11 side (∠H5 ・ O ₂・ H6 <∠S
Rotate 5 ・ O ₁・ S6) only. That is, during this period, the engagement disk 16 side rotates at a speed slightly slower than the camshaft 11 side.

Further, the camshaft 11 side is S6 → S7.
_{30 ° (∠S6 · O 1 ·} S7) If only rotated to, the engagement disc 16 side to the _{H6 → H7, ∠H6 · O 2} · H
Since it rotates by the angle of 7, the rotation angle is smaller than that on the camshaft 11 side (∠H6 ・ O ₂・ H7 <∠S6 ・
Rotate only O ₁ · S7). That is, during this period, the engagement disk 16 side rotates at a slower speed than the camshaft 11 side.

Thus, the position H is on the side of the engaging disc 16.
1, the camshaft 11 side rotates the fastest, and then the camshaft 11 side is S1 → S2 → S3 →
During the rotation from S4 → S5 → S6 → S7, the engaging disc 16 side is H1 → H2 → H3 → H4 → H5 → H6 → H.
7, the speed with respect to the camshaft 11 side is gradually reduced, and during this time, the speed of the engagement disk 16 side becomes almost equal to that of the camshaft 11 side between positions H3 and H5, and thereafter, the engagement disk 16 side Camshaft 11
Slower than the side, and at position H7, camshaft 11
It will rotate the slowest to the side.

After this, the camshaft 11 side is S7 → S8.
During the rotation of S9 → S10 → S11 → S12 → S1, the engagement disk 16 side is H7 → H8 → H9 → H10.
→ H11 → H12 → H1
Increase the speed to the side, during this time from positions H9 to H1
The speed of the engagement disc 16 side becomes almost equal to that of the camshaft 11 side near 0, and thereafter the engagement disc 16 side
The side becomes faster than the camshaft 11 side, and at the position H1, the side rotates the fastest with respect to the camshaft 11 side.

The rotation speed on the side of the engagement disk 16 relative to the rotation speed on the side of the camshaft 11 is such that the rotation angle of the camshaft 11 (the position S1 is 0 ° or 360 ° and rotates clockwise as described above). (A3). This FIG. 6 (A
In 3), the rotation speed of the camshaft 11 is constant (on the horizontal axis), and the rotation speed on the engagement disk 16 side changes with a characteristic like a cosine curve.

The change in the rotational angular velocity on the cam lobe 12 side with respect to the rotation on the engaging disk 16 side is shown in FIG.
1) to (B3). 6 (A1) to (A
3) corresponds to FIGS. 6B1 to 6B3, respectively. Further, as shown in FIG. 6 (B1), the engagement disk 16 side and the cam lobe 12 side are provided with the slider groove 16B and the second slider member 18 located at a position rotated by 180 ° with respect to the first slider member 17. Rotation is transmitted via. Therefore, in the direction in which the rotation center (second rotation center axis) O _{2 of} the engagement disk 16 is eccentric to the rotation center (first rotation center axis) O _{1 of} the camshaft 11, the slider groove 16A is formed.
And the reference state located on the first slider member 17 [FIG.
In (A1)], as shown in FIG. 6 (B1), the slider groove 16B and the second slider member 18 are rotated by 180 ° from the slider groove 16A and the first slider member 17 (downward in the figure). And this is the reference position.

Further, in FIGS. 6B1 and 6B2,
H'1 indicates the position at the rotation reference position of the reference point on the side of the engaging disk 16 (for example, the reference point of the slider groove 16B), and R '
Reference numeral 1 indicates the position of the reference point on the cam lobe 12 side (for example, the center point of the second slider member 18) at the rotation reference position. Further, H'2 to H'12 are first reference points on the side of the engaging disk 16 (reference points of the slider groove 16A) H2 to H12.
Shows a second reference point (reference point of the slider groove 16B) on the side of the engaging disk 16 and R2 to R12 are second reference points (reference point of the slider groove 16B) H'on these engaging disk 16 sides. 2 to H'12, each position of a reference point (center point of the second slider member 18) on the cam lobe 12 side that rotates in accordance with 2 to H'12 is shown.

Here, the rotation of the reference point on the side of the engagement disk 16 is about the second rotation center axis O ₂ and the cam lobe 12 is rotated.
The rotation of the side reference point is about the first rotation center axis O ₁ .
Each is done. As shown in FIGS. 6 (B2) and (B3), the cam lobe 12 side rotates with a characteristic in which the speed characteristic of the engagement disc 16 side with respect to the cam shaft 11 side is further strengthened, and is moved to the engagement disc 16 side at the position R1. On the other hand, it rotates the fastest, and then the engaging disk 16 side is H'1.
→ H'2 → H'3 → H'4 → H'5 → H'6 → H'7, the cam lobe 12 side is R1 → R2 → R
The speed with respect to the engaging disc 16 side is gradually decreased in the order of 3 → R4 → R5 → R6 → R7. During this period, the cam lobe 12 side becomes approximately equal to the engaging disc 16 side in the vicinity of the positions R3 to R4, and thereafter. Is slower on the cam lobe 12 side than on the engagement disc 16 side and rotates at the slowest speed with respect to the engagement disc 16 side at position R7.

After this, H'7 →
H'8 → H'9 → H'10 → H'11 → H'12 → H '
While rotating to 1, the cam lobe 12 side is R7 → R8
→ R9 → R10 → R11 → R12 → R1 The speed with respect to the engaging disc 16 side is gradually increased, and during this period, the cam lobe 12 side becomes approximately equal to the engaging disc 16 side in the vicinity of positions R9 to R10. After that, the cam lobe 12 side becomes faster than the engaging disc 16 side, and at the position R1, the cam lobe 12 side rotates the fastest with respect to the engaging disc 16 side.

FIG. 6B3 shows such a cam lobe 1
The rotation speed characteristic on the side of the engagement disk 16 is shown in correspondence with the rotation speed characteristic on the side of the engagement disk 16 (characteristic similar to that shown in FIG. 6A3). The characteristic changes on the side of the rotational speed on the side such as a cosine curve, and the characteristic on the side of the engaging disk 16 is further increased (that is, the amplitude is increased). That is, the rotation speed on the cam lobe 12 side changes with respect to the rotation speed on the cam shaft 11 side with a characteristic like a cosine curve.

In contrast to the rotational speed characteristic on the cam lobe 12 side, the rotational phase characteristic on the cam lobe 12 side (that is,
The characteristics (whether the cam lobe 12 side advances or lags behind the cam shaft 11 side) are shown by curves PA1 and PA2 in the graph shown in the middle part of FIG. That is, as shown in FIGS. 6 (A1), (B1) and FIG. 7 (a1), the rotation center (second rotation center axis) O ₂ of the engagement disk 16 is the rotation center of the cam shaft 11 and the cam lobe 12 ( The first eccentric center of rotation (O ₁ ) is eccentric upward (high-speed upward eccentricity). And the center of rotation O
A state in which the slider groove 16A and the first slider member 17 are located above ₁ , ₁ and O ₂ and the slider groove 16B and the second slider member 18 are located below the rotation centers O ₁ and O ₂ , respectively,
When the reference (camshaft rotation angle is 0), the phase characteristic on the cam lobe 12 side is as shown by the curve PA1 in FIG.

As shown by the curve PA1 in FIG. 7, as shown in FIG.
1) and the symbols S1, H1, in FIGS. 6A2 and 6B2.
When the camshaft rotation angle is 0 as indicated by H'1 and R1, the cam lobe 12 side has the same phase angle as the camshaft 11 side. The rotation phase characteristic of the cam lobe 12 side according to the rotation angle of the cam shaft 11 thereafter, that is,
The cam lobe 12 with respect to the rotation phase on the cam shaft 11 side
The characteristics of the advance and the delay of the rotation phase on the side of
It corresponds to an integral value obtained by integrating the rotation speed on the cam lobe 12 side (see FIG. 6B3) with respect to the rotation speed on the side.

Therefore, as shown by the curve PA1 in FIG. 7, when the camshaft 11 rotates from 0 ° to 90 °, the cam lobe 12 side precedes the camshaft 11 side and the advance angle thereof gradually increases. Yes, but camshaft 11
At 90 °, the cam lobe 12 side precedes the cam shaft 11 side most (see FIG. 7 (a2)), and thereafter, when the cam shaft 11 rotates from 90 ° to 180 °. Indicates that although the cam lobe 12 side precedes the cam shaft 11 side, the advance angle thereof gradually decreases, and when the cam shaft 11 reaches 180 °, the cam lobe 1 side
The side 2 has the same phase angle as the side of the camshaft 11 [see FIG. 7 (a3)].

Further, when the cam shaft 11 is rotated from 180 ° to 270 °, the cam lobe 12 side is delayed from the cam shaft 11 side and the delay angle is gradually increased, but the cam shaft 11 becomes 270 °. The cam lobe 12 side is delayed most than the cam shaft 11 side [see FIG. 7 (a4)].
When rotating from 70 ° to 360 °, the cam lobe 1
Although the second side is behind the camshaft 11 side, the delay angle gradually decreases, and when the camshaft 11 reaches 360 °, the cam lobe 12 side has the same phase angle as the camshaft 11 side [Fig. (See (a5)].

Here, when the position of the valve 2 with respect to the cam 6 is set so that the valve lift is maximized when the camshaft 11 is at a position of 180 °, the lift curve of the valve is as shown by a curve VL1 in FIG. become. The curve VL0 in FIG. 7 shows that the cam lobe 12 side has the camshaft 11
3 shows the lift curve characteristic (lift curve base) of the valve when the cam lobe 12 side is not eccentric to the side and the cam shaft 11 side always has the same phase angle.

In the lift curve characteristic shown by the curve VL1,
The valve opening timing (opening start timing) ST1 is earlier than the lift curve base opening timing ST0, and the valve closing timing (opening end timing) ET1 is later than the lift curve base closing timing ET0. The opening timing ST1 of the valve is earlier than that of the lift curve base because the rotation phase angle of the cam lobe 12 side is ahead of the cam shaft 11 side in the region where the valve starts to open, and the valve closing timing ET1. Is slower than the lift curve base,
This is because the rotational phase angle on the cam lobe 12 side lags behind the cam shaft 11 side in the region where the valve finishes opening.

On the other hand, as shown in FIG. 7 (b1), the rotation center (second rotation center axis) O ₂ of the engagement disk 16 is the rotation center (first rotation center axis) O of the camshaft 11 and the cam lobe 12. _It is eccentric downward with respect to ₁ (low speed downward eccentricity), and the slider groove 16A is provided above the rotation centers O ₁ and O _2.
And the first slider member 17 is located, and the rotation centers O ₁ , O
₂ below the slider groove 16B and the second slider member 18
Is the reference (camshaft rotation angle is 0)
Then, the phase characteristic on the cam lobe 12 side becomes as shown by the curve PA2 in FIG.

That is, as shown by the curve PA2 in FIG.
When the camshaft rotation angle is 0 as shown in FIG. 7 (a1), the cam lobe 12 side has the same phase angle as the camshaft 11 side.
When rotating from 90 ° to 90 °, the cam lobe 12 side lags behind the cam shaft 11 side and the delay angle gradually increases. However, when the cam shaft 11 reaches 90 °, the cam lobe 12 side moves toward the cam shaft 11 side. 7 (b2), the camshaft 11 moves 9
When rotating from 0 ° to 180 °, the cam lobe 12
Side is delayed from the camshaft 11 side, but the delay angle gradually decreases, and when the camshaft 11 reaches 180 °, the cam lobe 12 side has the same phase angle as the camshaft 11 side [Fig. b3)].

Further, when the camshaft 11 rotates from 180 ° to 270 °, the cam lobe 12 side precedes the camshaft 11 side and the advance angle thereof gradually increases, but the camshaft 11 becomes 270 °. At this point, the cam lobe 12 side is the most advanced than the cam shaft 11 side [see FIG. 7 (b4)], and then
When rotating from 70 ° to 360 °, the cam lobe 1
Although the 2 side is ahead of the camshaft 11 side, the advance angle is gradually reduced and the camshaft 11 is 360 °.
The cam lobe 12 side, the cam shaft 11
The phase angle is the same as that on the side [see FIG. 7 (b5)].

In this way, when the cam lobe 12 rotates with the rotation phase characteristic shown by the curve PA2 in FIG.
The lift curve of the valve is as shown by the curve VL2 in FIG. With the lift curve characteristic shown by the curve VL2,
The valve opening timing (opening start timing) ST2 is later than the lift curve base opening timing ST0, and the valve closing timing (opening end timing) ET2 is earlier than the lift curve base closing timing ET0.

In this way, the valve opening timing ST2
Is slower than the lift curve base because the rotational phase angle of the cam lobe 12 side is behind that of the cam shaft 11 side in the region where the valve starts to open.
Further, the valve closing timing ET2 is earlier than the lift curve base because the rotational phase angle of the cam lobe 12 side is ahead of the cam shaft 11 side in the region where the valve finishes opening.

As described above, the lift curve characteristic of the valve can be changed according to the rotation center (second rotation center axis) O ₂ of the engagement disk 16, that is, the eccentric position of the engagement disk 16. . If the opening timing of the valve is early and the closing timing is late, the valve opening period becomes long, which is suitable for high-speed engine rotation.If the valve opening timing is slow and the closing timing is fast, the valve opening period becomes short, Suitable for low speed rotation.

[0055] Therefore, as shown in FIG. 7 (a1), the center of rotation of the engagement disc 16 (second rotation center axis line) the rotational center of the O ₂ camshaft 11 (first rotating center axis) O ₁
On the other hand, if it is above (in the direction opposite to the rotation phase direction that gives the valve lift top), the valve opening period becomes the longest, so that eccentricity for high speed occurs, and as shown in FIG.
Rotation center of engagement disc 16 (second rotation center axis) O ₂
Is the rotation center of the camshaft 11 (first rotation center axis)
If it is below O ₁ (in the direction of the rotation phase that gives the valve lift top), the valve opening period is the shortest, so that eccentricity for low speed is achieved.

Then, the rotation center (second rotation center axis line) O _{2 of} the engaging disk 16 is at the position shown in FIG.
When the position is intermediate to the position shown in (b1),
The valve 2 is driven with the valve characteristics (valve opening timing and closing timing) according to the position.
That is, when the second rotation center axis O ₂ is shifted from the upper eccentric position shown in FIG. 7 (a1) to the lower position, the valve characteristic is the lift curve characteristic (high-speed characteristic) shown by the curve VL1.
To approach the lift curve base characteristic shown by the curve VL0, the second rotation center axis O ₂ becomes almost the same height as the first rotation center axis O ₁ (the vertical deviation disappears).
Then, the valve characteristic becomes close to the lift curve base characteristic. Furthermore, the second rotation center axis O ₂ is shown in FIG.
When shifting to the downward eccentric position shown in 1), the valve characteristic approaches from the lift curve base characteristic shown by the curve VL0 to the lift curve characteristic (low speed characteristic) shown by the curve VL2.

Therefore, depending on the operating state of the engine such as the engine speed (rotation speed), the second rotation center axis O
_If the position of ₂ is adjusted continuously or stepwise, the valve 2 can be driven with a characteristic that is always suitable for the operating state of the engine. In order to adjust the position of the rotation center (second rotation center axis line) O ₂ of the engagement disk 16, it is sufficient to rotate the eccentric portion 15 that supports the engagement disk 16 in an eccentric state. An eccentric position adjusting mechanism (controlling member) 30 for adjusting the eccentric position of the eccentric portion 15 by rotating the control disk 14 having the eccentric portion 15 is provided. A sliding bearing 47 is provided on a sliding contact surface of the eccentric portion 15 with the camshaft 11, and a sliding contact surface of the eccentric portion 15 with an engaging disk 16 is a bearing (here, a needle bearing) 37. Can be provided.

[0058] The eccentric position adjusting mechanism 30, FIG. 3, FIG. 4
As shown in FIG. 3, the camshaft 11 includes an eccentricity control gear 31 formed on the outer periphery of the control disk 14 and a control gear 35 that meshes with the eccentricity control gear 31.
Gear shaft (control shaft) 3 installed in parallel with
2 and an actuator 33 for rotationally driving the control shaft 32.
The operation is controlled through an ECU (control means) 34.

The actuator 33 is constructed so as to rotate the gear shaft 32 so that the eccentric portion 15 becomes eccentric for low speed when the actuator 33 fails. That is, as shown in FIG. 3, the ECU 34 is provided with an engine speed sensor (not shown).
From the throttle position sensor (TPS information), the detection information (AFS information) from the air flow sensor (not shown), and the like. Adjustment mechanism 30
The control of the motor is performed according to the rotational speed and the load state of the engine based on these pieces of information.

Then, for example, when the engine is operating at high speed or under high load, the rotational phase of the control disk 14 is adjusted so that the valve lift characteristic shown by the curve VL1 in FIG. Control to do. Further, when the engine is operating at low speed or under low load, the rotational phase of the control disk 14 is adjusted so that the valve lift characteristic is as shown by the curve VL2 in FIG. 7, and the valve opening period is controlled to be short. To do. In general, the rotational phase of the control disk 14 is adjusted so that the valve lift characteristic is an intermediate value between the curve VL1 and the curve VL2 in FIG. 7, depending on the engine speed and load.

The rotational phase of the control disk 14 is controlled by the ECU (control means) 34 according to the engine speed. That is,
As for the valve lift characteristics (valve opening characteristics) such as valve opening / closing timing and opening period, there is an optimum state according to the engine speed, and by controlling the rotational phase of the control disk 14 based on the engine speed, The optimum valve lift characteristic (valve opening characteristic) for the rotational speed can be obtained.

Now, the control device of the internal combustion engine with the variable valve mechanism will be described. The control device for an internal combustion engine according to the present invention uses the variable valve mechanism described above, that is, the valve opening characteristics (valve opening / closing timing and opening period) of the intake valve and the exhaust valve, which are the optimum valve opening characteristics according to the operating state of the internal combustion engine. Therefore, the internal combustion engine is provided with a variable valve mechanism that can be continuously or stepwise changed from the minimum valve opening period to the maximum valve opening period.

The present apparatus, as shown in FIG. 1, has a control element 101 for controlling combustion of an internal combustion engine (engine) 100.
Is provided with a control means (the above-mentioned ECU) 34 for controlling the engine according to the operating state of the internal combustion engine 100. The control means 34 relates to the control element 101 using a plurality of maps stored in the map storage means 102. It is designed to control. Here, the control element 101 is specifically ignition timing, fuel injection, or the like.

That is, the ignition timing, the fuel injection, etc. are set according to the operating state of the engine, but in this embodiment, the engine operating speed Ne is mainly used as the operating state of the engine.
Further, an engine speed sensor 103 and a pressure sensor (intake pressure sensor) 104 for detecting the intake pressure (intake pipe pressure) Pb are used, and the ignition timing or the fuel injection amount is determined based on the detection result of these detecting means. Volume efficiency is set.

On the other hand, the rotation phase of the control disk 14 of the variable valve mechanism 105 is based on the engine speed Ne detected by the engine speed sensor 103.
The control means 34 controls to an optimum state. However, control elements such as ignition timing and fuel injection are optimal values not only depending on the engine operating condition, but also depending on the opening / closing timing of valves such as intake valves and exhaust valves and the valve opening period (collectively referred to as valve opening characteristics). Changes. Therefore, when the valve opening characteristic can be controlled, control elements such as ignition timing and fuel injection are set according to the valve opening characteristic as well as the engine operating state (engine speed Ne and intake pressure Pb). Is more appropriate.

During the steady operation of the engine, the rotation phase of the control disk 14 of the variable valve mechanism [ie, the valve lift characteristic (valve opening characteristic)] is optimum according to the operating state of the engine (engine speed Ne). In this case, the actual valve opening characteristic agrees with the optimum valve opening characteristic for the engine operating state (engine speed Ne).

Control elements such as ignition timing and fuel injection are set to control the operating state of the engine (engine speed Ne and intake pressure Pb).
Etc.) and the valve opening characteristic, if the valve opening characteristic is the optimum valve opening characteristic with respect to the engine speed Ne, the valve opening characteristic is unique with respect to the engine speed Ne. If the engine speed Ne and the intake pressure Pb are known, the valve opening characteristic is determined corresponding to this operating state, and the ignition timing, fuel injection, etc., which are optimal for this operating state and valve opening characteristic, are determined. The control element is also determined.

Therefore, in the present device, the actual valve opening for detecting the actual setting state of the variable valve mechanism (for example, the rotational phase angle of the control disk 14) or the actual setting state of other valve opening characteristics (valve opening period). An actual valve opening angle detecting means 106 is provided as a characteristic detecting means (actual valve opening period detecting means).
The rotational phase angle or the valve opening characteristic of the control disc 14 detected by the actual valve opening angle detecting means 106 (valve opening period)
Is in the optimum state, that is, in a state according to the operating state of the engine (engine speed Ne), FIG.
Using the optimal valve opening time map (optimal valve opening angle map, optimal map for short) with the optimal valve opening characteristics as shown in
Control elements such as ignition timing and fuel injection (volumetric efficiency) are set.

The valve opening angle is the phase angle of the control disk 14 that realizes the optimum valve opening characteristic or the optimum valve opening period. In the present embodiment, the minimum phase angle 0 ° is the minimum valve opening characteristic or Corresponds to the minimum valve opening period, maximum phase angle 18
0 ° corresponds to the maximum valve opening characteristic or the maximum valve opening period, and the optimum valve opening angle is these minimum valve opening angle 0 ° to maximum valve opening angle 18
Within the range of 0 °.

Further, the optimum valve opening angle map shown in FIG. 2B, the minimum valve opening angle map and the maximum valve opening angle map shown in FIGS. Engine operating conditions (that is, engine speed Ne, intake pressure P
b) and the valve opening characteristic) are associated with the optimum values (control element data) of control elements such as ignition timing and fuel injection.

The optimum valve opening time map gives control elements such as ignition timing and fuel injection to the engine speed Ne and the intake pressure Pb. The condition that the characteristics are optimum is also included, and the control elements such as the ignition timing and the fuel injection (volume efficiency) are optimum not only for the engine speed Ne and the intake pressure Pb but also for the valve opening characteristics. It is set to a value.

However, during transient operation of the engine, such as during acceleration or deceleration, the engine speed N is not always due to a delay in response to the rotation adjustment of the control disk 14.
There are situations in which the valve opening characteristics are not optimal according to e. In such a case, if the ignition timing and fuel injection (volume efficiency) are set in the optimal valve opening angle map, the actual valve opening characteristic and the optimal valve opening characteristic are different, so the optimal valve opening characteristic is optimized. It is not possible to provide control elements such as ignition timing or fuel injection.

Therefore, when the rotational phase angle or the valve opening characteristic of the control disk 14 detected by the actual valve opening angle detecting means 106 is not in the optimum state according to the operating state of the engine (engine speed Ne). The control elements such as ignition timing and fuel injection (volumetric efficiency) are set as follows. That is, the map storage means 10
In addition to the optimum valve opening angle time map [Fig. 2 (B)] as the above-mentioned optimum valve opening time map, a second valve opening time map as shown in Fig. 2 (A) is shown. A map for minimum valve opening period (map for minimum valve opening angle, abbreviated as minimum map) and a map for maximum valve opening period (maximum valve opening map as a second valve opening characteristic time map as shown in FIG. 2C). The corner time map (abbreviated maximum map) is stored and stored.

The minimum valve opening angle map means that when the valve has the minimum valve opening angle (the first valve opening characteristic or the minimum valve opening period) by adjusting the control disk 14, this valve opening valve is opened. Characteristic and detected engine speed N
The control elements such as the optimal ignition timing and fuel injection are associated with e and the intake pressure Pb. Further, the maximum valve opening angle map means that when the valve has the maximum valve opening angle (the second valve opening characteristic or the maximum valve opening period) by adjusting the control disk 14, The control elements such as the optimum ignition timing and fuel injection correspond to the detected engine speed Ne and the detected intake pressure Pb.

Depending on whether or not the valve opening characteristic is in the optimum state, control elements such as ignition timing and fuel injection are appropriately used by using the three maps shown in FIGS. 2 (A) to 2 (C). Is set. That is, if the actual valve opening characteristic is the optimum valve opening characteristic according to the engine operating state (engine speed Ne), the control element is simply calculated from the optimum valve opening angle map [FIG. 2 (B)] as described above. (Ignition timing and fuel injection) can be set, and if the actual valve opening characteristic is not the optimum valve opening characteristic, the actual valve opening characteristic is smaller than the optimum valve opening characteristic [that is, the first valve opening characteristic (first valve opening characteristic (first valve opening characteristic)). Of the valve opening period)) or a large value (that is, whether the valve opening characteristic is close to the second valve opening characteristic (second valve opening period) side).

That is, when the actual valve opening characteristic is smaller than the optimum valve opening characteristic [close to the first valve opening characteristic (first valve opening period) side], the minimum value as shown in FIG. The valve opening time map (first valve opening characteristic time map or minimum valve opening time map) and the optimum valve opening time map (optimal valve opening characteristic time map or optimum valve opening period) as shown in FIG. 2B. Control element (ignition timing and fuel injection) by interpolation method using
Is configured to set.

For example, at a certain engine speed Ne _i and a certain intake pressure Pb _j , the actual valve opening angle θ is the optimum valve opening angle θ _i.
Is smaller than that (that is, the actual valve opening characteristic is closer to the first valve opening characteristic (first valve opening period) side than the optimal valve opening characteristic)), the minimum valve opening angle map and the optimal valve opening angle Based on the corresponding values of the map (optimal values of the control element according to the engine speed Ne _i , the intake pressure Pb _j, etc.) α _ij and β _ij , and the actual valve opening angle θ and the optimum valve opening angle θ _i , The optimum value (target value) X of the control element (ignition timing or fuel injection) is set by the function f (i) such as

X = f (i) = [(θ _i −θ) · α _ij + θ
_i · beta _ij] / theta _i example and is the intake pressure Pb at a certain engine speed Ne _{i
When j} , the actual valve opening angle θ is 50 ° and the optimum valve opening angle θ _i is 60
And the optimum value of the ignition timing obtained from the minimum valve opening angle map is α _ij = 2 ° A (CA), and the optimum value of the ignition timing obtained from the optimum valve opening angle map is β _ij = 14 °. A (C
A), the optimum value of ignition timing at this time (target value)
X can be calculated as follows.

X = [(60-50) · 2 + 50 · 14]
/ 60 = 12 [° A (CA)] Further, when the actual valve opening characteristic is larger than the optimum valve opening characteristic [close to the second valve opening characteristic (second valve opening period) side], The maximum valve opening time map (second valve opening characteristic time map or maximum valve opening time map) as shown in (C) and FIG. 2 (B)
It is configured to set control elements (ignition timing and fuel injection) by an interpolation method using an optimal valve opening angle map (optimal valve opening characteristic time map or optimal valve opening period time map) as shown in FIG. There is.

For example, at a certain engine speed Ne _i and a certain intake pressure Pb _j , the actual valve opening angle θ is the optimum valve opening angle θ _i.
Is larger than that (that is, the actual valve opening characteristic is closer to the second valve opening characteristic (second valve opening period) side than the optimal valve opening characteristic)), the maximum valve opening angle map and the optimal valve opening angle Based on the corresponding values of the map (optimal values of the control element according to the engine speed Ne _i , the intake pressure Pb, etc. _j ) γ _ij and β _ij , and the actual valve opening angle θ and the optimum valve opening angle θ _i , By a function ff (i) such as
The optimum value (target value) X of the control element [ignition timing and fuel injection (volume efficiency)] is set.

X = ff (i) = [(θ−θ _i ) · γ _ij + (180−θ _i ) · β _ij ] /
(180−θ _i ) Here, the two points are linearly interpolated, but the interpolation method is not limited to linear, and for example, the β _ij side is weighted so that the optimum valve opening angle map is emphasized. A weighted averaging method, for example, or a method of connecting two points with an appropriate curve and interpolating along this curve is also conceivable.

Since the control device for an internal combustion engine with a variable valve mechanism according to an embodiment of the present invention is configured as described above, it is possible to control the internal combustion engine as shown in FIG. 8, for example. it can. That is, as shown in FIG. 8, first, the operating state is read (step S10). That is, the engine speed sensor 103 and the intake pressure sensor 10
4, engine speed Ne _i and intake pressure Pb _j
Read.

Then, the target valve opening angle is set according to this operating state (step S20). That is, the optimum valve opening angle θ _i according to the engine speed Ne _i is set as the target valve opening angle. Next, the actual valve opening angle θ detected by the actual valve opening angle detection means 106 is equal to the target valve opening angle (optimal valve opening angle) θ _i , or the actual valve opening angle θ is equal to the target valve opening angle (optimal valve opening angle). It is determined whether it is smaller than the opening angle θ _i (θ <θ _i ) or the actual valve opening angle θ is larger than the target valve opening angle (optimal valve opening angle) θ _i (θ> θ _i ) (step). S30).

The actual valve opening angle θ is the target valve opening angle (optimal valve opening angle) θ
_{If i} is equal to _i , the control elements (ignition timing and fuel injection) are simply calculated from the optimum valve opening angle map [FIG. 2 (B)] as described above.
The optimum value (target value) X of is set (step S50).
If the actual valve opening angle θ is smaller than the target valve opening angle (optimal valve opening angle) θ _i (θ <θ _i ), the minimum valve opening angle map (first opening angle) as shown in FIG. Valve characteristic time map or minimum valve opening time map) and optimal valve opening angle map as shown in FIG. 2B (optimal valve opening characteristic time map or optimal valve opening time map)
The control elements (ignition timing and fuel injection) are set by the interpolation method using and (step S40).

For example, at a certain engine speed Ne _i and a certain intake pressure Pb _j , the actual valve opening angle θ is the optimum valve opening angle θ _i.
If it is smaller than the above, corresponding values of the minimum valve opening angle map and the optimum valve opening angle map (engine speed Ne _i , intake pressure Pb, etc.)
_{Based on} the optimum values α _ij and β _{ij of} the control element according to _j ), the actual valve opening angle θ, and the optimum valve opening angle θ _i , the control element (ignition timing or ignition timing or The optimum value (target value) X of fuel injection) is set.

The actual valve opening angle θ is the target valve opening angle (optimal valve opening angle) θ
_If it is smaller than _i (θ <θ _i ), the map for the minimum valve opening angle (the map for the first valve opening characteristic or the map for the minimum valve opening period) as shown in FIG. ), The control element (ignition timing or fuel injection) is set by an interpolation method using an optimal valve opening angle map (optimal valve opening characteristic map or optimal valve opening period map) (step S60). .

For example, at a certain engine speed Ne _i and a certain intake pressure Pb _j , the actual valve opening angle θ is the optimum valve opening angle θ _i.
If it is larger than the above, the corresponding values of the maximum valve opening angle map and the optimum valve opening angle map (engine speed Ne _i , intake pressure Pb, etc.)
_{Based on} the optimum values γ _ij and β _{ij of} the control element according to _j ) and the actual valve opening angle θ and the optimum valve opening angle θ _i , the control element (ignition timing or ignition timing or Fuel injection)
The optimum value (target value) X of is set.

Thus, each step S50, S40, S
When the optimum value (target value) X of the control element (ignition timing and fuel injection) is set at 60, engine control (control of ignition timing and fuel injection) is performed based on this set value (target value) (step S70). In this way, in the present control device, the optimum value (target value) X of the control element (ignition timing or fuel injection) X is appropriately used by using the interpolation method only by providing three maps.
Since it is difficult to achieve the target valve opening characteristic, even during transient operation of the engine during acceleration or deceleration, it is possible to use only three maps from the operating conditions of the engine (for example, engine speed Ne _i , intake pressure Pb, etc.). _j ) and the valve opening characteristics of the intake valve and the exhaust valve, the engine control elements (ignition timing and fuel injection) can always be controlled to the optimum state.

That is, in an internal combustion engine having a variable valve mechanism capable of adjusting the valve opening characteristic continuously or in multiple stages, generally, the control of a control element for combustion control of the engine is changed to the operating state of the engine. It was necessary to prepare a large number of maps in order to be applicable to the valve opening characteristic, but with this device, only three maps were prepared.
The control element for combustion control of the engine can be appropriately controlled so that it can be applied to both the operating condition and the valve opening characteristic of the engine, and the map storage means 102 having a relatively small storage capacity is adopted. Therefore, appropriate control of the control element can be performed at low cost.

Further, combustion of the engine can be appropriately controlled during a transition of the operating state of the engine such as the engine speed such as acceleration or deceleration, which can greatly contribute to improvement of the output of the engine and improvement of fuel consumption. Further, even when the valve opening characteristic of the valve cannot be controlled to the optimum state due to the failure of the variable valve mechanism, the combustion of the engine can be appropriately controlled, and the effect under such a situation is high.

As in the present embodiment, the actuator 33
In the valve operating mechanism in which the eccentric portion 15 is driven to be the eccentricity for low speed at the time of the failure, the first valve opening characteristic time map is set to the minimum valve opening period time map as in the present embodiment. Advantages of setting the valve opening characteristics more appropriately (optimally) and ensuring performance in case of failure compared to when the map of valve opening characteristics of is calculated by interpolation between the minimum valve opening characteristics and the optimum valve opening characteristics There is.

In this embodiment, the variable valve mechanism controls the valve opening characteristic of the intake valve. However, in the present control device, the variable valve mechanism is provided in both the intake valve and the exhaust valve. It can be applied even if it controls the valve opening characteristic of the valve.

[0093]

As described in detail above, according to the control device for an internal combustion engine with a variable valve mechanism of the present invention as set forth in claim 1,
If the actual valve opening characteristic detected by the actual valve opening characteristic detecting means is the optimal valve opening characteristic according to the operating state of the internal combustion engine, the control means controls the control element based on the optimal valve opening characteristic time map. However, if the actual valve opening characteristic detected by the actual valve opening characteristic detecting means is not the optimum valve opening characteristic according to the operating state of the internal combustion engine, but on the first valve opening characteristic side of the optimum valve opening characteristic. For example, the control element is controlled based on the interpolated value obtained from the optimum valve opening characteristic time map and the first valve opening characteristic time map, and the actual valve opening characteristic detected by the actual valve opening characteristic detecting means. Is not the optimum valve opening characteristic according to the operating state of the internal combustion engine but is on the second valve opening characteristic side of the optimum valve opening characteristic, the optimum valve opening characteristic time map and the second valve opening characteristic time map Since the control element is controlled based on the interpolation value obtained from the By storing three maps, a map, a second valve opening characteristic time map, and an optimum valve opening characteristic time map, the control elements related to the combustion control of the internal combustion engine can be set to the operating state of the internal combustion engine and the actual valve opening characteristic state. There is an advantage that it can be controlled appropriately according to.

That is, in an internal combustion engine having a variable valve mechanism capable of adjusting the valve opening characteristic continuously or in multiple stages, it is possible to control the control elements for combustion control of the engine without preparing many maps. It can be performed appropriately, and it can be applied even if the storage capacity of the map storage means is relatively small, and appropriate control of the control element can be performed at low cost.

In particular, the combustion of the engine can be appropriately controlled even during a transition of the engine operating state such as the engine speed such as acceleration or deceleration, which can greatly contribute to the improvement of the output of the engine and the improvement of the fuel consumption. . Further, even if the valve opening characteristic of the valve cannot be controlled to the optimum state due to the failure of the variable valve mechanism, the combustion of the engine can be appropriately controlled.

According to the control device for an internal combustion engine with a variable valve mechanism of the present invention as defined in claim 2, further, even when the valve opening period of the valve has a valve opening characteristic for low speed due to actuator failure or the like, There is also an advantage that the valve operating characteristics at the time of this failure can be controlled appropriately.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a control device for an internal combustion engine with a variable valve mechanism according to an embodiment of the present invention.

FIG. 2 is a diagram showing a map relating to a control device for an internal combustion engine with a variable valve mechanism according to an embodiment of the present invention, (A) showing a map at a minimum valve opening angle, and (B) showing an optimum valve opening. An angular time map is shown, and (C) shows a maximum valve opening time map.

FIG. 3 is a perspective view of a variable valve mechanism according to an embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a main part of the variable valve mechanism according to the embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view showing an arrangement of main parts of a non-uniform velocity joint in the variable valve mechanism according to the embodiment of the present invention.

FIG. 6 is a view showing the operating principle of the non-uniform speed mechanism in the variable valve mechanism according to the first embodiment of the present invention, (A1)
~ (A3) shows the relationship of the rotational phase between the first rotating shaft member (camshaft) and the intermediate rotating member (engaging disk), and (B1) to (B3) shows the intermediate rotating member (engaging disk). The relationship of the rotation phase between the second rotation shaft member (cam lobe) is shown.

FIG. 7 is a characteristic diagram illustrating operating characteristics of the variable valve mechanism according to the first embodiment of the present invention regarding the non-constant speed mechanism, in which (a1) to (a5) show operating states at a low speed,
(B1) to (b5) show operating states at low speed.

FIG. 8 is a flowchart illustrating control of the internal combustion engine according to the first embodiment of the present invention.

FIG. 9 is a diagram showing a map relating to a conventional control device for an internal combustion engine with a variable valve mechanism, where (A) shows a low speed map and (B) shows a high speed map.

FIG. 10 is a diagram showing a map relating to a control device for a conventional internal combustion engine with a variable valve mechanism.

[Explanation of symbols]

2 Valves (valve members) as intake valves or exhaust valves 34 ECU as control means 100 Internal combustion engine 101 Control element [Ignition timing, fuel injection (volumetric efficiency)] 102 map storage means 103 engine speed sensor 104 Pressure sensor (intake pressure sensor) 105 Variable valve mechanism 106 Actual valve opening angle detection means

Continuation of front page (56) Reference JP-A-5-231211 (JP, A) JP-A-6-74081 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02D 13 / 00 F02D 41/00-45/00

Claims (2)

(57) [Claims] 1. A first valve opening characteristic to a second valve opening characteristic continuously or so that the valve opening characteristic of the intake valve or the exhaust valve becomes the optimum valve opening characteristic according to the operating state of the internal combustion engine. In an internal combustion engine having a variable valve mechanism that changes stepwise, a map storage that stores a plurality of maps in which data relating to control elements related to combustion control of the internal combustion engine are mapped corresponding to operating states of the internal combustion engine Means and a control means for controlling the control element according to the operating state of the internal combustion engine based on the map stored in the map storage means, wherein the plurality of maps are the variable valve mechanism When the first valve opening characteristic is set, the first valve opening characteristic time map in which the optimum control element data is mapped corresponding to the operating state of the internal combustion engine, and the variable valve mechanism are Set to the second valve opening characteristic The second valve opening characteristic time map in which the optimum control element data is mapped corresponding to the operating state of the internal combustion engine, and the variable valve mechanism corresponds to the operating state of the internal combustion engine. The optimum valve opening characteristic is set, the optimum valve opening characteristic time map in which the optimum control element data is mapped corresponding to the operating state of the internal combustion engine is included. The control means includes an actual valve opening characteristic detecting means for detecting an actual setting state or an actual setting state of the valve opening characteristic, and the control means controls the actual valve opening characteristic detected by the actual valve opening characteristic detecting means. If it is the optimum valve opening characteristic according to the operating state of the engine, the control element is controlled based on the optimum valve opening characteristic time map, and the actual valve opening characteristic detected by the actual valve opening characteristic detecting means is Optimum valve opening characteristics depending on the operating state of the internal combustion engine On the side of the first valve opening characteristic rather than the valve opening characteristic, the control element is controlled based on an interpolation value obtained from the optimum valve opening characteristic time map and the first valve opening characteristic time map, If the actual valve opening characteristic detected by the actual valve opening characteristic detecting means is not the optimum valve opening characteristic corresponding to the operating state of the internal combustion engine but is on the second valve opening characteristic side of the optimum valve opening characteristic. A variable valve mechanism, characterized in that it is configured to control the control element based on an interpolated value obtained from the optimum valve opening characteristic time map and the second valve opening characteristic time map. Control device for internal combustion engine. 2. At least the first valve opening characteristic time map is mapped with the optimum control element data corresponding to the operating state of the internal combustion engine in the minimum valve opening period of the variable valve mechanism. 2. The control device for an internal combustion engine with a variable valve mechanism according to claim 1, wherein the map is a minimum valve opening time map.