JPH10169419A - Variable valve system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drive a valve with good accuracy through a cam by properly supporting a rotating system while considering transfer load exerted on the rotating system in a variale valve system using a non-uniform speed joint. SOLUTION: In an intermediate rotating member 16 forming a non-uniform speed joint, the connecting position of a first connecting member 17 and a second connecting member 18 is set in the intermediate rotating member 16 so that the maximum load of the intermediate rotating member 16 generated during opening or closing of a valve member 2 is exerted on the direction substantially perpendicular to the connecting surface 7D of a bearing component member for indirectly supporting the intermediate rotating member 16 to the main body of an internal combustion engine, and/or on the direction of a member 7A with high rigidity in the bearing component member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve mechanism for controlling the opening and closing of an intake valve and an exhaust valve of an internal combustion engine at a timing according to the operating state of the engine. The present invention relates to a variable valve mechanism using a non-constant velocity joint capable of outputting while increasing and decreasing the pressure.

[0002]

2. Description of the Related Art As a reciprocating valve which is driven to be opened and closed by a cam, for example, an intake valve and an exhaust valve provided in a reciprocating internal combustion engine (hereinafter, referred to as an engine) (hereinafter, these are collectively referred to as an engine valve). There is. Since such a valve is driven in a valve lift state according to the shape and rotation phase of the cam, the valve opening / closing timing and the opening period (a period in which the valve is opened in units of the crank rotation angle are shown. ) Also depends on the shape and rotation phase of the cam.

[0003] In the case of an intake valve or an exhaust valve provided in an engine, the optimum opening / closing timing and opening period differ depending on the load state and speed state of the engine. Therefore, various so-called variable valve timing devices have been proposed in which the opening / closing timing and the opening period of such a valve can be changed. In particular, a non-constant velocity joint using an eccentric mechanism is interposed between the cam and the camshaft, and the cam is rotated more or less than the rotation speed of the camshaft during one rotation of the camshaft. Or change the phase,
Techniques have also been developed that allow the opening and closing timing and opening period of a valve to be adjusted.

[0004] Techniques using this non-constant velocity joint have been proposed in, for example, Japanese Patent Publication No. 47-20654, Japanese Patent Application Laid-Open Nos. 3-168309 and 4-183905.

[0005]

By the way, in the variable valve mechanism of the internal combustion engine using the above-described variable speed joint,
In each case, the rotational force is transmitted to the cam via the non-constant velocity joint. Since the non-constant-velocity joint transmitting torque as described above has a structure in which torque is transmitted through a member eccentric with respect to the rotation axis of the cam, a connection member that transmits torque while sliding in the radial direction. The torque is transmitted through a complicated transmission path via several types of members, including a pin member.

Accordingly, it is natural that this non-constant-velocity joint is configured with high accuracy. However, in consideration of the force acting on the non-constant-velocity joint, it is particularly necessary to set the pin members for transmitting the rotational force and the like. However, this is a very important condition for smoothly transmitting the rotational force to the cam and obtaining highly accurate valve operating characteristics. Also,
This greatly contributes to the durability and miniaturization of the valve train. However, each of the above-mentioned prior arts does not particularly refer to a technique regarding how to set a pin member as a connection member in consideration of a force acting on a non-constant velocity joint, and has a high precision valve train. It is difficult to obtain characteristics and to achieve durability and miniaturization of the valve train.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has an object to appropriately support a rotary system in consideration of a transmission load acting on the rotary system in a variable valve mechanism using a variable speed joint. It is an object of the present invention to provide a variable valve mechanism in which a valve can be accurately driven through a cam.

[0008]

According to a first aspect of the present invention, there is provided a variable valve mechanism according to the present invention, wherein a first rotary shaft member is driven to rotate about a first rotation center axis by a crankshaft of an internal combustion engine; A shaft support for guiding rotation about a second rotation center axis different from the first rotation center axis and parallel to the first rotation center axis; and rotatable or swingable relative to the outer periphery of the first rotation shaft member; A shaft support member provided so as to be able to move, an intermediate rotation member supported by the shaft support member, and the intermediate rotation member connected to the first rotation shaft member, and the intermediate rotation member is connected to the first rotation shaft. A first connecting member rotatable in conjunction with the member, a second rotating shaft member rotating around the first rotation center axis and having a cam portion, and connecting the second rotating shaft member to the intermediate rotating member. A second contact that enables the second rotating shaft member to rotate in conjunction with the intermediate rotating member. A member that is provided integrally with or separate from the second rotating shaft member and that is driven through the cam portion, and that flows into the combustion chamber of the internal combustion engine in accordance with the rotation phase of the second rotating shaft member. Or a valve member for setting an exhaust emission period, a control member for engaging with the shaft support member, and displacing the second rotation center axis which is the center of rotation of the shaft support portion in accordance with the operation state of the internal combustion engine. And a bearing component for indirectly supporting the intermediate rotating member with respect to the main body of the internal combustion engine, wherein the bearing component is provided on the cylinder head side of the internal combustion engine. A first bearing member provided on the first bearing member and a second bearing member provided facing the first bearing member are formed by joining with each other, and the first bearing member and the second bearing member are connected to each other. Are formed on a plane substantially parallel to the first rotation center axis. The two maximum load directions of the intermediate rotating member generated when the valve member opens and closes act in a direction substantially orthogonal to the joint surface and / or in a direction of a member having higher rigidity around the bearing component. As described above, the connection position of the first connection member and the second connection member in the intermediate rotation member is set.

The variable valve mechanism of the present invention according to claim 2 is
2. The mechanism according to claim 1, wherein the connection position of the first connection member is at a phase angle position closer to the cam ridge portion of the cam portion than the connection position of the second connection member around the first rotation center axis. It is characterized by being set. According to a third aspect of the present invention, in the mechanism according to the first or second aspect, the center lines of the first connection member and the second connection member at the time of maximum lift of the valve member are connected. The flat surface is set so as to be substantially orthogonal to the joining surface.

According to a fourth aspect of the present invention, there is provided the variable valve mechanism of the present invention.
2. The mechanism according to claim 1, further comprising: an input portion for receiving a rotational force of a crankshaft of the internal combustion engine, the first rotary shaft member being driven to rotate around a first rotational center axis by the rotational force of the crankshaft; A shaft support for guiding rotation about a second rotation center axis different from the rotation center axis and parallel to the first rotation center axis, and supported rotatably or swingably on the outer periphery of the first rotation shaft member; A shaft support member provided for a cylinder of the internal combustion engine, an intermediate rotation member supported by the cylinder for the cylinder, and the intermediate rotation member for the first rotation shaft member. A first connecting member that is coupled to rotate the intermediate rotating member in conjunction with the first rotating shaft member, a second rotating shaft member that rotates around the first rotation center axis and has a cam portion, The second rotating shaft member is connected to the intermediate rotating member, and the second rotating shaft member is connected to the second rotating shaft member. A second connecting member that enables the rotating shaft member to rotate in conjunction with the intermediate rotating member; and a second connecting shaft that is provided integrally with or separate from the second rotating shaft member and that is driven through the cam portion to form the second rotating shaft. A valve member for setting an intake flow period or an exhaust release period into the combustion chamber of the cylinder in accordance with the rotation phase of the member, and engaging with the bearing member, and supporting the bearing member according to an operation state of the internal combustion engine. And a control member for displacing the second rotation center axis, which is the center of rotation of the variable rotation valve mechanism, wherein a maximum load direction of the intermediate rotation member generated when the valve member opens and closes is the first rotation direction. The connection position of the first connection member and the second connection member in the intermediate rotation member is set so as to be in a direction not overlapping with the direction of the input load applied to the input portion of the rotation shaft member.

According to a fifth aspect of the present invention, there is provided a variable valve mechanism,
5. The mechanism according to claim 4, wherein the connection position of the second connection member is at a phase angle position closer to the cam ridge portion of the cam portion than the connection position of the first connection member around the first rotation center axis. It is characterized by being set. According to a sixth aspect of the present invention, there is provided the variable valve mechanism according to the fourth or fifth aspect, wherein the shaft support member, the intermediate rotating member, the first rotating member,
The connection member, the second connection member, and the valve member are all provided for each cylinder of the internal combustion engine.

According to a seventh aspect of the present invention, there is provided a variable valve mechanism,
A first rotating shaft member having an input portion for receiving a rotating force of a crankshaft of the internal combustion engine, the first rotating shaft member being rotated around the first rotating center axis by the rotating force of the crankshaft; A shaft support for guiding rotation about a second rotation center axis parallel to the first rotation center axis is provided, and is rotatably or swingably supported on the outer periphery of the first rotation shaft member with respect to a cylinder of the internal combustion engine. A shaft support member provided with
An intermediate rotating member which is supported by the shaft supporting member and is provided for the cylinder; and an intermediate rotating member which is connected to the first rotating shaft member so that the intermediate rotating member is interlocked with the first rotating shaft member. A first connection member that is rotatable and rotatable, a second rotation shaft member that rotates about the first rotation center axis and has a cam portion, and the second rotation shaft member is connected to the intermediate rotation member. A second connection member that enables the second rotation shaft member to rotate in conjunction with the intermediate rotation member; and a second connection member that is provided integrally with or separate from the second rotation shaft member, and is driven through the cam portion to form the second rotation shaft member. A valve member for setting an intake inflow period or an exhaust release period into the combustion chamber of the cylinder in accordance with the rotation phase of the rotary shaft member, and engaging with the shaft support member, in accordance with an operation state of the internal combustion engine. A variable valve mechanism having a control member for displacing the second rotation center axis, which is the rotation center of the shaft support, In the variable valve operating mechanism of a cylinder that is provided in each cylinder and is not adjacent to the input section, the direction of the maximum load of the intermediate rotating member is substantially opposite to the direction of the driving reaction force that the support shaft of the cam section receives from the valve member. The connection position of the first connection member and the second connection member in the intermediate rotation member is set so as to be in the direction.

The variable valve mechanism of the present invention according to claim 8 is
The mechanism according to any one of claims 1 to 7, wherein a connection position of the first connection member and the second connection member is provided at a position substantially opposed to each other across the first rotation center axis. Features.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 18 show a variable valve mechanism as one embodiment of the present invention. The internal combustion engine according to this embodiment is a reciprocating internal combustion engine, and the variable valve mechanism is an intake valve or an exhaust valve installed above the cylinder (these are collectively referred to as valves hereinafter).
It is provided to drive.

FIG. 2 is a cross-sectional view showing a main part of a cylinder head 1 of an engine (internal combustion engine) having the variable valve mechanism. As shown in FIG. Alternatively, a valve (valve member) 2 is provided to open and close the exhaust port, and a valve spring 3 (see FIG. 5) for urging the valve 2 toward the closing side is provided at a stem end 2A of the valve 2. ing.

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 the rocker arm 8. Then, the valve 2 is driven in the opening direction by resisting the urging force of the valve spring 3 by the convex portion (cam peak portion) 6A of the cam 6. The variable valve mechanism is provided to rotate the cam 6.

As shown in FIG. 2, the present variable valve mechanism includes a camshaft (not shown) that is driven to rotate in conjunction with a crankshaft (not shown) of an engine via a belt (timing belt) 41 and a pulley 42. A first rotary shaft member) 11 and a cam lobe (second
A cam (cam portion) 6 is provided on the outer periphery of the cam lobe 12. The outer periphery of the cam lobe 12 is rotatably supported by a bearing (bearing component) 7 on the cylinder head 1 side.

The camshaft 11 is supported by the bearing 7 via the cam lobe 12, but the camshaft 1
The end of the cylinder head 1 is axially supported by a bearing 1A of the cylinder head 1 via an end member 43 connected to the same axis. Since the above-described pulley 42 is provided on such an end member 43, the end member 43 provided with the pulley 42 can be referred to as an input unit.

As shown in FIGS. 2 and 5, the bearing portion 7 has a split structure, and includes a lower bearing half (first bearing member) 7A formed on the cylinder head 1 and It comprises a bearing cap (second bearing member) 7B joined to the lower bearing half 7A from above, and a bolt 7C for connecting the bearing cap 7B to the lower bearing half 7A. The joint surface 7D between the lower bearing half 7A and the bearing cap 7B is set to be substantially horizontal so as to be orthogonal to the axis of the cylinder (not shown), and the vertical direction (vertical direction) in FIGS. The lower half 7A of the bearing is secured by bolts 7C fastened toward
And the bearing cap 7B are firmly connected in the vertical direction.

Then, the camshaft 11 and the cam lobe 1
2 is provided with a non-constant velocity joint 13. The non-constant velocity joint 13 includes a control disk (shaft support member) 14 as a control member rotatably supported on the outer periphery of the camshaft 11, and an eccentric portion (integrally provided on the control disk 14). Shaft support portion) 15 and this eccentric portion 1
Engaging disk (intermediate rotating member) 1 provided on the outer periphery of
6 and a first slider member (first connection member) 17 and a second slider member (second connection member) 18 connected to the engagement disk 16.

The eccentric portion 15 is, as shown in FIG. 2, a rotation center of the camshaft 11 (rotation axis, first rotation center axis).
It has a rotation center O ₂ at a position eccentric from O _1, and the engagement disk 16 rotates around the rotation center (second rotation center axis) O ₂ of the eccentric portion 15. In addition, as shown in FIG.
A slider groove 16A as a first groove and a slider groove 16B as a second groove are formed in a radial direction (radial direction). Here, two slider grooves 16 are used.
A and 16B are arranged on the same diameter so that the rotation phases are shifted from each other by 180 °. The camshaft 11 has a first slider member 1 constituting a first pin member.
7 is provided with a drive arm 19 as an arm member to be connected and engaged, and the cam lobe 12 is connected to a second slider member 18 constituting a second pin member, and is an arm portion as an attachment portion to be engaged. 20 are provided.

The drive arm 19 is provided in a space except the arm portion 20 between the cam lobe 12 and the control disk 14 so as to protrude from the camshaft 11 in a radial direction (radial direction).
5 so as to rotate integrally with the camshaft 11. On the other hand, the arm portion 20 is integrally formed so that the end of the cam lobe 12 protrudes in a radial direction (radial direction) to a position near one side surface of the engaging disc 16.

The first slider member 17 and the second slider member 18 are provided at one end thereof so as to be slidable in the slider grooves 16A and 16B of the engaging disk 16 in the radial direction (radial direction). Slider body 21, 22
On the other end side, a drive arm 19 and drive pin portions 23 and 24 provided in holes 19A and 20A of the arm portion 20 are provided. These drive pin portions 23 and 24 are provided with a drive arm 19 and an arm portion 20.
The holes 19A and 20A are connected so as to be able to rotate.

Therefore, in the non-constant velocity joint 13, the rotation of the camshaft 11 is transmitted from the drive arm 19 to the hole 1.
9A, the drive pin portion 23, the hole portion 21A, the slider body portion 21, and the groove 16A to transmit to the engaging disk 16,
Further, the groove 16B, the slider body 22, the hole 22A,
Through the drive pin 24 and the hole 20A, the arm 20
To the cam lobe 12.

The outer flat surfaces 21B and 21C of the slider body 21 are provided between the slider body 21 and the groove 16A.
Between the inner wall planes 28A and 28B of the groove 16A.
B between the slider body 22 and the inner wall planes 28C and 28D of the groove 16B and the outer plane 22 of the slider body 22.
Transmission of rotational force is performed between B and 22C.

When the rotation is transmitted in this manner, the engagement disk 16 is eccentric, so that the engagement disk 16
Repeatedly leads and delays with respect to the camshaft 11, and the cam lobe 12 repeats leading and delaying with respect to the engaging disc 16, while the cam lobe 12 It rotates at irregular speed.

The principle of this rotation is described with reference to FIGS.
Based on (D), the description will be made while focusing on the rotation phases of the engagement disc 16 and the cam lobe 12 so as to correspond to each rotation phase (camshaft angle) of the camshaft. That is, as shown in FIG. 7 (A), the first slider member upwardly on the rotating center O ₁ and the straight line connecting the rotational center O ₂ of the engagement disc 16 (in practice plane) BL of the camshaft 11 Reference is made to a state where the axis of the drive pin portion 17 of the second slider member 18 is located below the straight line (plane) BL and the axis of the drive pin portion 24 of the second slider member 18 (camshaft angle = 0 deg). 7), a case where the camshaft 11 rotates clockwise from this state as shown by an arrow in FIG. 7A.

As described above, the rotation of the camshaft 11 is performed by the drive arm 19 from the hole 19A, the drive pin 23, the hole 21A, the slider body 21, and the groove 16A.
Since going to transmit to the engagement disk 16 via, for example, the camshaft 11 is 90deg around its rotational center O ₁
(= Right angle) and the camshaft angle is 90 °
(Hereinafter, "deg" indicating an angle is indicated using "°")
Then, the drive pin portion 23 is at a position as shown in FIG.

The engagement rotational center O ₂ of the disk 16 is a cam shaft 11 is eccentric with respect to the rotation center O ₁ (where is eccentric downward in the drawing), so the drive pin 23 and the slider main body The center of 21 rotates by 90 ° with respect to the rotation center O ₁ of the camshaft 11, but rotates by 90 ° with respect to the rotation center O ₂ of the engagement disc 16.
Rotation angle θ ₁ (= 90 ° −θ) smaller by angle θ ₂ than
₂ )

At the same time, the rotation of the engaging disk 16 is further increased by the groove 16B, the slider body 22, and the hole 22.
A, the drive pin portion 24, and the hole portion 20A, the power is transmitted from the arm portion 20 to the cam lobe 12. Since the amount of rotation of the drive pin 24 and the slider main body 22 with respect to the rotation center O ₂ of the engagement disk 16 is equal to the amount of rotation of the drive pin 23 and the slider main body 21 with respect to the rotation center O ₂ , the drive pin 24 and the slider Main unit 22
Of the engagement disk 16 with respect to the rotation center O ₂ is θ
It becomes ₁ . Moreover, given the amount of rotation theta ₃ with respect to the rotation center O ₁ of the drive pin 24 and the cam lobe 12 of the slider body 22, the rotation amount theta ₃ can be represented as follows, the engagement disc 16 Becomes smaller than the rotation amount θ _{1 with} respect to the rotation center O ₂ .

Θ_Three= 90 ° -θ_Four, Where θ_Four≒ 2θ
_Two Therefore, the camshaft 11 has its rotation center O₁Times
In addition, the camshaft angle is 90 ° from 0 ° to 90 °
During rotation, the cam lobe 12 is rotated about the rotation center O. ₁Around
Less than 90 °_ThreeWill only rotate
During this time, the cam lobe 12 is
Will also rotate at low speed.

That is, when the camshaft angle is 0 °, the cam lobe 12 has the same rotation phase as the camshaft 11, but as the camshaft angle increases, the cam lobe 12 delays the rotation phase with respect to the camshaft 11. And the rotational phase is most delayed at a camshaft angle of 90 °. Then, further, around the cam shaft 11 is rotated around O _1, from the camshaft angle 90 ° to 180 °, when rotated by 90 °, the drive pin portion 23 is in the position as shown in FIG. 7 (C) .

When the drive pin portion 23 reaches the position shown in FIG. 7C, the axis of the drive pin portion 24 is located above the straight line BL, and the drive pin portion 2 is located below the straight line BL.
3, the rotation phase of the camshaft 11 and the rotation phase of the cam lobe 12 match. Therefore, during this time, that is, from the state of the camshaft angle of 90 ° shown in FIG. 7B to the camshaft angle of 180 ° shown in FIG. 7C, the camshaft 11 rotates by 90 °. the cam lobe 12 will be rotated by the rotation amount theta ₅ represented by the following formula, during this time, the cam lobe 12 will be rotated at a high speed than the camshaft 11.

Θ ₅ = 180 ° −θ ₃ = 90 ° + θ ₄ That is, the cam lobe 12 has a camshaft angle of 90 °.
, The rotational phase was delayed the most with respect to the camshaft 11, but as the camshaft angle increased from 90 ° to 180 °, the rotational phase delay gradually decreased. It is equal to 11.

Then, the camshaft 11 rotates further.
Center O₁Around the camshaft angle 180 ° to 27
When rotated by 90 ° to 0 °, the drive pin 23
Is located as shown in FIG. 7 (D). Drive pin
When the part 23 comes to the position shown in FIG.
In contrast to the case shown, the drive pin portion 23 and the slider
The main body 21 is provided with a rotation center O of the camshaft 11.₁Against
Is rotated 90 °, but the center of rotation of the engagement disc 16
O _TwoFor angles θ greater than 90 °_TwoMore rotation amount
θ₆(= 90 ° + θ_Two), And the drive pin portion 24 and
And the rotation center O of the engagement disk 16 of the slider body 22.
_TwoIs the amount of rotation with respect to₆, And this drive pin part
24 and during rotation of the cam lobe 12 of the slider body 22
Heart O₁Is the amount of rotation with respect to₇Becomes This rotation amount θ
₇Can be expressed as:
Center of rotation O_TwoRotation amount θ₆Even bigger than
Become.

Θ ₇ = 90 ° + θ ₄ = θ ₅ Therefore, during this time, that is, during the period from FIG. 7 (C) to FIG. 7 (D), while the cam shaft 11 rotates by 90 °, the cam lobe 12 It will be rotated by the rotation amount theta ₇ represented by the above formula, during which, the cam lobe 12 will be rotated at a high speed than the camshaft 11.

That is, at a camshaft angle of 180 °, the cam lobe 12 has the same rotational phase as the camshaft 11, but as the camshaft angle increases, the cam lobe 12 advances the rotational phase with respect to the camshaft 11. That is, the rotation phase is advanced most at the camshaft angle of 270 °. And then,
Around the cam shaft 11 is the rotation center O _1, 360 ° from the camshaft angle 270 ° (= 0 °) until, when rotated by 90 °, the drive pin 23, again to FIG. 7 (A)
The position is as shown in

When the drive pin portion 23 reaches the position shown in FIG. 7A, the axis of the drive pin portion 23 is located above the straight line BL, and the drive pin portion 2 is located below the straight line BL.
Thus, the rotational phase of the camshaft 11 and the rotational phase of the cam lobe 12 match. Therefore, during this period, that is, from FIG.
(A), the camshaft 11 rotates by 90 °, while the cam lobe 12 rotates by a rotation amount θ ₈ (not shown) expressed by the following equation.
The cam lobe 12 rotates at a lower speed than the camshaft 11.

Θ ₈ = 180 ° −θ ₇ = 90 ° −θ ₄ = θ ₃ That is, the cam lobe 12 has a camshaft angle of 270.
Although the rotation phase advanced the camshaft 11 at the highest angle, the advance of the rotation phase gradually decreased as the camshaft angle increased from 270 ° to 360 °, and the rotation phase at the camshaft angle 360 ° Camshaft 1
It is equal to 1.

As described above, the cam lobe 12 moves ahead of or behind the camshaft 11 and rotates at an uneven speed with respect to the rotation speed of the camshaft 11. Changes in
For example, as shown in FIG. 8, the waveform becomes similar to a sine wave. In FIG. 8, the horizontal axis is the camshaft angle corresponding to the description of FIGS. 7A to 7D, and the vertical axis is the cam lobe 12.
Is a phase difference with respect to the camshaft 11, and the case where the phase is ahead of the camshaft 11 is set in the positive direction.

The opening and closing timing of the valve can be adjusted by utilizing the characteristic of the cam lobe 12 leading or lagging behind the camshaft 11 as described above. For example, in the vicinity of the opening timing of the valve 2, the opening timing of the valve 2 can be advanced if the cam lobe 12 precedes the camshaft 11, and if the cam lobe 12 is delayed with respect to the camshaft 11, the valve 2 can be opened. Release timing can be delayed. Also,
If the cam lobe 12 precedes the camshaft 11 near the closing timing of the valve 2, the closing timing can be accelerated, and the cam lobe 12 is moved to the camshaft 1.
If it is delayed for 1, the closing timing of the valve 2 can be delayed.

The manner in which the phase of the cam lobe 12 shifts with respect to the camshaft 11 is determined by the control disk 1.
4 can be adjusted by changing the position of the eccentric center O ₂ of the eccentric portion 15 integrally provided on the. In order to adjust the phase of the eccentric part 15, the control disk (eccentric member) 14 shown in FIG.
An eccentric position adjusting mechanism (controlling member) 30 that adjusts the eccentric position by rotating is provided.

The eccentric position adjusting mechanism 30 includes a gear mechanism 32 for rotating the control disk 14 through a first gear 31 formed on the outer periphery of the control disk 14.
And an electric motor (not shown) as driving means for driving the gear mechanism 32. The gear mechanism 32
A gear shaft 32A installed in parallel with the camshaft 11,
A control gear 32B is provided on the gear shaft 32A and meshes with the first gear 31. The gear shaft 32A is driven to rotate by a motor (not shown).

The motor (not shown) is controlled by an electronic control unit (ECU) (not shown) as control means. That is, the ECU controls the operation of the motor based on the detection signal of the position sensor (not shown) so that the rotation phase of the control disk 14 is in a required state. As described above, when the rotational phase (position) of the control disk 14 is changed, the state of the phase difference of the cam lobe with respect to the camshaft angle changes.

The characteristic diagram of the cam lobe phase difference shown in FIG.
This corresponds to the eccentric state that changes as shown in FIGS. 7A to 7D with respect to the camshaft angle. At this time, the rotational phase of the control disk 14 is set to a reference value (that is, the control disk 14). Rotation phase = 0 °)
If the rotational phase of the control disk 14 is, for example, 45 °, 90 °, 135 °, or 180 °, the value of the cam lobe phase difference with respect to the camshaft angle shifts.

In the upper part of FIG. 8, 0 °, 45 °, 90 °,
Although 135 ° and 180 ° are shown, these are for reading the horizontal axis of the figure according to the position (rotational phase) of the control disk 14, and the position where each angle of the control disk 14 is described is And the camshaft angle of 180 ° in the control disk angle.

That is, if the position of the control disk 14 is 0 °, the horizontal axis scale at a camshaft angle of 180 ° is as shown in FIG. 8, but if the position of the control disk 14 is 45 °, the camshaft angle The horizontal axis scale of 180 ° indicates a position indicating this “45 °” (“22” in FIG. 8).
5 ° position). When the position of the control disk 14 is 90 °, the camshaft angle 18
The horizontal axis scale of 0 ° is displaced to a position indicating this “90 °” (a position of “270 °” in FIG. 8).

Further, when the position of the control disk 14 becomes 135 °, the horizontal axis scale at a camshaft angle of 180 ° indicates a position indicating this “135 °” (“315” in FIG. 8).
°)), the position of the control disk 14 is 1
At 80 °, the horizontal axis scale of the camshaft angle of 180 ° indicates the position indicating this “180 °” (“360 °” in FIG. 8).
Position).

As described above, when the position of the control disk 14 is adjusted, the lift state of the valve also changes. That is, the camshaft angle as shown in FIG.
At this time, the top of the convex portion 6A of the cam 6 is set so as to act on the valve 2, and as shown in FIGS. 7 (A) to 7 (D) and FIG. When the characteristic is set, the valve lift state has a characteristic as shown by a curve L1 in FIG.

That is, when the rotational phase of the control disk 14 is 0 ° and the cam lobe 12 is operated as shown in FIGS. 7A to 7D, the phase delay is the longest when the camshaft angle is 90 °. When the camshaft angle is between 0 ° and 180 °, the cam lobe 12 has a phase delay with respect to the camshaft 11. When the camshaft angle is 270 °, the phase is the most advanced. When the camshaft angle is from 180 ° to 360 °, the cam lobe 12 leads the phase of the camshaft 11.

That is, when the rotational phase of the control disk 14 is adjusted to 0 °, the cam lobe 12 becomes centered around the camshaft angle 0 ° at which the valve lift becomes maximum, and before this (the camshaft angle is negative). The phase advances,
After this (the camshaft angle is positive), the phase of the cam lobe 12 is delayed, so that the valve lift state has a characteristic as shown by the curve L5 in FIG.

When the rotation phase of the control disk 14 is adjusted to 45 °, the characteristic of the cam lobe phase difference changes, and the phase is delayed the most when the camshaft angle is 45 °. Compared with the case where the phase is 0 °, the phase advance of the cam lobe 12 before the camshaft angle is 0 ° (the camshaft angle is negative) decreases, and after that (the camshaft angle is positive). The phase delay of the cam lobe 12 is also reduced. Therefore,
The valve lift state has a characteristic as shown by a curve L4 in FIG.

Further, when the rotation phase of the control disk 14 is adjusted to 90 °, the characteristic of the cam lobe phase difference further changes, and the phase is delayed most when the camshaft angle is 0 °. Compared with the case where the rotation phase is 45 °, the phase advance of the cam lobe 12 before the camshaft angle is 0 ° (the camshaft angle is negative) decreases, and after that (the camshaft angle is positive). The phase delay of the cam lobe 12 is also reduced. Therefore, the lift state of the valve has a characteristic as shown by a curve L3 in FIG.

Similarly, when the rotational phase of the control disk 14 is adjusted to 135 ° or 180 °, the lift state of the valve has characteristics as shown by the curves L2 and L1 in FIG. Here, the valve lift is described as being maximized in the state of FIG. 7A, but depending on the setting of the relationship of the cam position with respect to the control disk, the valve maximum may be changed in a state other than FIG. 7A. Become a lift,
The change of the valve opening / closing characteristic with respect to the rotation phase of the control disk 14 is different from the above.

In particular, in this variable valve mechanism, ECU (not shown) detects information (engine speed information) from an engine speed sensor (not shown) and detection information (AFS) from an air flow sensor (not shown). ) And the like, and the control of the motor in the eccentric position adjusting mechanism 30 is performed based on the information and according to the rotational speed of the engine and the load state.

That is, when the engine is running at a high speed or under a high load, the rotation phase of the control disk 14 is adjusted so as to have a valve lift characteristic such as the curves L4 and L5 in FIG. Control so that Further, when the engine is running at a low speed or a low load, the rotation phase of the control disk 14 is adjusted so that the valve lift characteristics such as the curves L1 and L2 in FIG. To control.

In this mechanism, as shown in FIG. 2, one side surface 16C of the engagement disc (intermediate rotating member) 16 is provided.
Face the arm portion (mounting portion) 20 of the cam lobe 12, and in particular, the end face (flange portion) 20 A of the arm portion 20 of the cam lobe 12 abuts one side surface of the engaging disc (intermediate rotating member) 16. In contact. As shown in FIG. 3, the end face 20A of the arm portion 20 extends to a slider groove (second groove portion) 16B provided in the arm portion 20 to a portion having a phase difference of about 90 ° or more. . Especially,
This extension is disposed as far outward as possible from the axis. One side surface of the engaging disk 16 also comes into contact with the extended arm portion end surface (flange portion) 20A.

Thus, in particular, the two slider grooves (the first grooves) positioned so as to sandwich the axis of the engagement disk 16 at the position of the arm end face 20A corresponding to the hatched portion in FIG. Abutment portions (arm end surfaces) 20A provided at locations P1 on both sides of the axis of the engagement disk 16 which are substantially perpendicular to the straight line connecting the 16A and 16B.
The engaging disc 16 comes into contact with the cam lobe 12 side, so that the engaging disc 16 is prevented from tilting (falling) in the axial runout direction.

In this embodiment, the slider member 1
Reference numerals 7 and 18 denote first members integrally with the pin members 23 and 24, respectively.
It is formed as a pin member and a second pin member. Also,
In this mechanism, one side surface of the engaging disc 16 is in contact with the end surface (flange portion) 20A of the arm portion, and in particular, in the arm end surface 20A, at a position substantially perpendicular to the pin members 23 and 24 and at the axis. Since it is in contact with an extended portion (see a shaded portion in FIG. 3) arranged as far outward as possible, the inclination (falling) of the engaging disc 16 is prevented.

Further, a waved washer 36 is provided at the rear end of the cam lobe 12, and the arm end face 2 is provided.
The contact force of the 0A on one side surface of the engaging disk 16 is increased so that the load for preventing the engaging disk 16 from falling down can be sufficiently secured. The main part of the arm end face 20A (FIG. 3) which works particularly effectively to prevent the engagement disc 16 from falling down.
(See shaded portion P1) is disposed as far outward from the axis as possible, so that the load for preventing the waved washer 36 from falling down can be extremely effectively exerted. Accordingly, the waved washer 36 can be of a relatively low elasticity, that is, a small one.

The engagement disk 16 and the cam lobe 12
As described above, since the rotor rotates while generating a slight phase shift according to the eccentricity, the contact portion between the engagement disc 16 and the arm end face 20A slightly slides.
Since lubricating oil (engine oil) is supplied to this portion, such sliding is performed smoothly.

In this embodiment, the camshaft 11
Load point M _{1 of} the first pin member (first slider member) 17 for transmitting the rotation of the
The load point M _{2 of} the second pin member (second slider member) 18 for transmitting the rotation of the motor 6 to the cam lobe 12 is
Is set inside the engaging disk 16, and the effect of preventing the engaging disk 16 from falling due to the contact of the arm portion end surface 20 </ b> A with one side surface of the engaging disk 16 is prevented. Become added, engaging disk 1
Although the fall prevention effect of No. 6 has been made even greater,
It is possible to prevent the engaging disc 16 from falling down only by a configuration in which the arm end face 20A is brought into contact with one side surface of the engaging disc 16 to support it.

Further, in the present embodiment, the engagement disc 16
The bearing 37 is interposed between the sliding portion between the eccentric portion 15 and the eccentric portion 15, that is, between the outer periphery of the eccentric portion 15 and the inner periphery of the engagement disk 16. Here, a needle bearing that can be interposed more compactly is used.
Is not limited to this needle bearing, and various bearings can be used.

The engagement disk 16 and the eccentric portion 15
In particular, when the sliding part with is "mere sliding bearing",
The friction between the engaging disc 16 and the eccentric portion 15 increases due to the viscosity of the lubricating oil and the like at the time of starting the engine.
By providing the bearing 37, the friction between the engaging disk 16 and the eccentric portion 15 is greatly reduced, and the transmission of the rotational force and the phase adjustment through the engaging disk 16 can be performed more smoothly. The engine's startability can be improved. Conversely, since the load on the starter and the actuator for starting and adjusting the eccentric position can be reduced, a smaller capacity and smaller one can be adopted as the starter or the actuator.

A bearing such as a needle bearing may be installed between the sliding portion between the eccentric portion 15 and the camshaft 11, or the sliding portion between the engaging disk 16 and the eccentric portion 15 and the eccentric portion 15 may be provided. It may be installed both between the camshaft 11 and the sliding part. However, if the bearings of both sliding parts are interposed, the system becomes large and the mountability decreases. If there is a problem, a bearing for one of the sliding parts is interposed. In this case, the bearing can be more effectively exhibited when it is installed between the engaging disc 16 and the eccentric portion 15 having a larger diameter than the diameter between the camshaft 11 and the eccentric portion 15. Is preferred.

Note that reference numerals 7A, 11A,
An oil hole 11B supplies lubricating oil (engine oil) to each sliding portion. In this mechanism, the engaging disk (intermediate rotating member) 16, a control disk (shaft support member) 14 for supporting the engaging disk 16, a cam lobe (second rotating shaft member) 12, and a camshaft (first rotating shaft) are provided. In consideration of not applying an excessive load to the bearing (bearing component) 7 and the bearing 1A for supporting the cam lobe 12 on the cylinder head 1 with the cam lobe 12, each member is as follows. You have set the placement.

First, the camshaft 11 and the cam lobe 1
2 and the force applied to the engagement disc 16 through the camshaft 11 and the cam lobe 12 will be described. A rotational force (that is, cam drive torque) corresponding to the rotation of the crankshaft of the engine is applied to the camshaft 11.

Considering the force applied to the cam lobe 12, the cam lobe 12 receives a spring reaction force from the valve spring 3 and an inertia force due to reciprocating motion of the valve and the like as the valve 2 is lifted (opened) through the cam 6. . Therefore, as shown in FIG. 10, the cam rotation driving torque with respect to the valve lift amount VL of the engine mainly acts to oppose the valve spring force in the low speed range, so that the curve T
Becomes properties such as _L, a characteristic as the curve T _H to work primarily to counteract the inertia load of the valve in the high speed range.

As shown in FIG. 10, since the direction of the torque acting on the cam is reversed at the maximum point of the valve lift, the cam driving torque is changed from positive to negative or negative at the maximum point of the valve lift. Reverse from positive to positive. Considering the force applied to the engaging disc 16, this engaging disc 16
The cam drive force T1 from the camshaft side slider 17 applied as the rotational force of the camshaft 11 and the reaction force F with respect to the cam drive force T1 from the cam lobe side slider 18
1 is applied, and the resultant force FF of the cam driving force T1 and the reaction force F1 becomes the force applied to the engagement disk 16.

Here, assuming that the engaging disc 16 is rotating counterclockwise, when the valve is moving in the opening direction, as shown in FIG.
And the reaction force F1 act in opposite directions to each other, so that the resultant force FF of the cam driving force T1 and the reaction force F1 is equal to a straight line connecting the center of the camshaft side slider 17 and the center of the cam lobe side slider 18. It acts in the vertical direction and in the anti-rotation direction for the cam lobe side slider 18.

When the valve is moving in the closing direction, the resultant force FF is in a direction perpendicular to a straight line connecting the center of the camshaft-side slider 17 and the center of the camlobe-side slider 18 as shown in FIG. Contrary to 11, the cam lobe-side slider 18 acts in the rotational direction. The direction of the resultant force FF is reversed at the time of the maximum valve lift.

The force supporting the engaging disk 16 is the resultant force FF
The resultant force FF is generated by the cam driving torque. Therefore, the cam drive torque is
That is, when the valve lift is rising, it acts on the cam lobe side slider 18 in the anti-rotation direction, and when the valve is closed, it acts on the cam lobe side slider 18 in the rotation direction.

FIG. 1 shows the vector of the resultant force FF applied to the engagement disk 16 in accordance with the phase of the cam 6.
As shown in FIG. FIG. 12 shows the position of the cam lobe-side slider 18 with a C in a circle indicating a pin, and the camshaft-side slider 17 with an S in the circle. Reference numeral 16 rotates counterclockwise.

Further, the upward direction of the vertical axis in FIG. 12 indicates the rotation center (first rotation center axis) O ₁ at the time of maximum valve lift.
And the position of the cam lobe slider 18 to the right (in the clockwise direction) from the upper side of the vertical axis, to the left (in the counterclockwise direction) from the upper side of the vertical axis. The positions of the cam lobe slider 18 after the maximum valve lift are shown.

In FIG. 12, FL1 indicates the magnitude and direction of the resultant force FF applied to the engagement disc 16 when the valve is opened, and FL2 indicates the magnitude and direction of the resultant force FF applied to the engagement disc 16 when the valve is closed. ing. As FL1 shown in FIG. 12, when the valve opening motion, the cam driving force T ₁ is a maximum was reached from the open beginning of the valve to the upstream cam driving torque maximum point, the resultant force FF also maximized applied to the engagement disc 16. The resultant force FF at this time is determined by the camshaft side slider 17 and the cam lobe side slider 18.
Is perpendicular to the line connecting the two, and is directed in the anti-rotation direction for the cam lobe side slider 18. That is, the camshaft-side slider 17
Of the cam lobe-side slider 18 and 90 ° behind the phase of the cam lobe-side slider 18 in the rotational direction.

Further, as indicated by FL2 in FIG. 12, when the valve is closed, the cam driving force T ₁ reaches a maximum when the down cam driving torque reaches a maximum point just before the valve starts to close. The resultant force FF applied also becomes maximum. The resultant force FF at this time is the camshaft-side slider 17.
Is perpendicular to the line connecting the cam lobe side slider 18 and the cam lobe side slider 18 and faces in the rotation direction for the cam lobe side slider 18.

That is, the phase shifts 90 degrees behind the phase of the camshaft-side slider 17 in the rotational direction, and shifts 90 degrees forward of the phase of the camlobe-side slider 18 in the rotational direction. As described above, the directions of the two maximum loads applied to the engagement disc 16 are directed to the V-shape opposite to the direction of the cam lobe side slider 18 at the time of the maximum valve lift.

In the variable valve operating mechanism, the valve lift period is adjusted in accordance with the rotation speed of the engine and the like. The valve lift period is adjusted to be short at a low speed and long at a high speed. When a characteristic diagram (vector diagram) of the resultant force FF applied to the engagement disk 16 is estimated and shown for each engine speed region, the result is as shown in FIG.

In FIG. 13, (A) shows when the engine is rotating at low speed, and (B) shows when the engine is rotating at high speed. As shown in FIG. 13A, when the engine is running at low speed, the valve lift period is adjusted to be short, and the cam drive torque _TL is mainly composed of the valve spring force. Each of the cam drive torque maximum points approaches the valve maximum lift point.

Accordingly, the maximum load direction of the resultant force FL1 at the time of opening the valve is accordingly set to the right direction on the horizontal axis (the phase angle of the cam lobe-side slider 18 at the time of maximum valve lift is more than 9 degrees).
Approaching in the clockwise direction by 0 °), and the maximum load direction of the resultant force FL2 when the valve is closed is accordingly 90 ° more than the phase angle to the left on the horizontal axis (the cam lobe slider 18 phase angle at the time of maximum valve lift). Approach only in the counterclockwise direction).

Therefore, 2
The directions of the two maximum loads are also directed to a V-shape opposite to the direction of the cam lobe slider 18 at the time of the valve maximum lift, but the angle θ _L formed by the two maximum load directions is
It spreads as the valve lift period (valve opening period) is shortened and the engine speed is reduced. Further, as shown in FIG. 13 (B), at the time of high speed rotation of the engine, after which the valve lift period is adjusted longer, the cam driving torque T _H because the inertia force of the valve is proactive, upstream cam driving torque maximum point In addition, both the down cam drive torque maximum point and the valve maximum lift point move away from each other. Accordingly, the maximum load direction of the resultant force FL1 when the valve is opened moves away from the rightward direction on the abscissa (clockwise direction by 90 ° from the phase angle of the cam lobe side slider 18 at the time of maximum valve lift), and the valve closes. The maximum load direction of the resultant force FL2 at the time of movement is accordingly leftward on the horizontal axis (a direction counterclockwise by 90 ° from the phase angle of the cam lobe slider 18 at the time of maximum valve lift).
Keep away from

Therefore, 2
The directions of the two maximum loads are also directed to a V shape opposite to the direction of the cam lobe slider 18 at the time of the valve maximum lift, but the angle between the two maximum load directions is the valve lift period (valve opening period). As the engine speed increases and the engine speed increases. 14 and FIG.
The torque required for the cam drive, that is, the cam drive torque to be applied to the engagement disc 16 through the camshaft 11,
FIG. 14 shows a case where the engine is running at a low speed, and FIG. 15 shows a case where the engine is running at a high speed. As shown in the figure, it can be seen that as the engine speed increases, the torque required for driving the cam increases and the maximum torque point moves away from the maximum lift.

As described above, considering the force applied to the engaging disk 16, there is a certain characteristic in that direction as shown in FIGS. 12 and 13, and as shown in FIGS. It can be seen that the higher the speed, the greater the force applied. In the present variable valve mechanism, the pulley 42 of a part of the cylinders [namely, the camshaft (first rotary shaft member) 11]
Except for the engagement disks 16 of the cylinder closest to the mounting end (see FIG. 2).
In such a configuration, the maximum load having two maximum load directions applied to the engagement disk 16 is set so as not to cause a large support load on the camshaft 11 and the bearing portion 7 which indirectly support the engagement disk 16. Have been.

That is, as shown in FIGS. 1 and 5, the phase position of the cam lobe side slider 18 with respect to the cam 6 so that the cam lobe side slider 18 is located vertically above the cylinder head 1 at the time of maximum valve lift. Is set. As a result, a large force applied to the engagement disc 16 is directed downward in all the rotation regions of the engine as shown in FIGS. 13 (A) and 13 (B).

When a large force applied to the engagement disc 16 is directed downward in this manner, the force is applied to the camshaft 11.
Through this, it is supported by the lower part of the bearing part 7, that is, the lower half part (first bearing member) 7A of the bearing formed on the cylinder head 1. In the bearing portion 7, this lower bearing half portion 7A
Is formed on the cylinder head 1 and is much higher in rigidity than the bearing cap (second bearing member) 7B joined from above, so that a large force is applied to the engagement disk 16 at the lower bearing half 7A. Can be reliably supported without causing a large deformation.

Generally, the camshaft 11 is provided above the valve 2.
In consideration of the fact that the cam lobe side slider 18 is positioned vertically above the cylinder head 1 at the time of maximum valve lift, as shown in FIG. At the time of the maximum lift, the camshaft-side slider 17 is set on the side closer to the valve 2 and the cam lobe-side slider 18 is set on the side farther from the valve 2.

The lower bearing half 7A and the bearing cap 7B
Considering that the joint surface 7D is set horizontally in the cylinder head 1, the setting is such that the cam lobe side slider 18 is located vertically above the cylinder head 1 at the time of maximum valve lift. Is
As shown in FIG. 1, at the time of the valve maximum lift, a straight line connecting the camshaft side slider 17 and the cam lobe side slider 18 is set in a direction orthogonal to the joint surface 7D.

In addition, if the maximum load direction applied to the engaging disk 16 is expressed by using the direction of the maximum load applied to the engaging disk 16, the direction of the maximum load applied to the engaging disk 16 is directed to the lower half portion 7A of the bearing.
It can also be described that the setting is made so as to face a direction (directly downward in FIG. 1) orthogonal to the joint surface 7D between the lower bearing half 7A and the bearing cap 7B. Of course, bearing cap 7
If the stiffness of the bolts and the like connecting the bearing B and the bearing cap 7B to the lower half 7A of the bearing is sufficiently high, a setting in which the phase is shifted from that of FIG. In other words, when expressed using the maximum load direction applied to the engagement disk 16, the maximum load direction applied to the engagement disk 16 is directed toward the upper half portion 7B of the bearing. 7
Direction perpendicular to the joining surface 7D with B (directly below in FIG. 1)
May be set to face.

As a result, the maximum load applied to the engaging disk 16 does not act largely on one of the left and right bolted portions of the bearing cap 7B, and is shared between the left and right bolted portions of the bearing cap 7B. Then, it becomes possible to resist this maximum load. Therefore, the load on each bolt connecting the bearing cap 7B to the lower bearing half 7A is reduced, and the strength and rigidity of the bearing 7 can be ensured.

In this case, at the time of maximum valve lift,
The cam lobe side slider 18 may be set vertically below the cylinder head 1, and the camshaft side slider 17 may be set at the maximum valve lift.
Is the cam lobe slider 18 on the side remote from the valve 2.
May be set on the side closer to the valve 2, and in any case, at the time of maximum valve lift, a straight line connecting the camshaft-side slider 17 and the camlobe-side slider 18 is defined as a joint surface 7D. It will be set in the direction perpendicular to the direction.

Further, the above-mentioned cylinders [that is, the end of the camshaft (first rotary shaft member) 11 on the pulley 42 mounting side (FIG. 2)
Cylinders other than the cylinder closest to the engagement disc 16), the engagement disc 16 can be seen from the axis of the camshaft 11 as seen from FIGS.
The maximum load FF applied to the valve spring is the valve spring reaction force F2 which is received by the support shaft of the cam portion 6 (the axis of the camshaft 11).
In the opposite direction.

Thus, the valve spring reaction force F2 applied to the axis of the camshaft 11 and the engagement disk 16
Will act in a direction to cancel each other. That is, as shown in FIG. 16 (B), the valve spring reaction force F2 acts almost upward on the axis of the camshaft 11, while the engagement disc 1
The maximum load FF applied to 6 acts substantially downward on the axis of the camshaft 11.

Due to the valve spring reaction force F2 and the maximum load FF applied to the engaging disk 16, a moment acts on the bearing (the bearing 7 or the bearing 1A at the end of the cylinder head) of the camshaft 11 or the cam lobe 12. That is, the moment MM can be expressed as in the following equation (1) with the counterclockwise direction being the positive direction in the bearing in FIG.

MM = FF × LL2−F2 × LL1 (1) As described above, the bearing due to the valve spring reaction force F2 and the bearing due to the maximum load FF applied to the engagement disc 16 cancel each other out. The magnitude (| MM |) of the moment MM acting on the bearing becomes small, and the load on the bearing portion is reduced.

On the other hand, if the maximum load FF applied to the engagement disk 16 is in the same direction as the valve spring reaction force F2, the state becomes as shown in FIG.
1 and the moment MM acting on the bearing of the cam lobe 12
Is large as shown in the following equation (2). | MM | = | −FF × LL2-F2 × LL1 | (2) As described above, the valve spring reaction force F2 and the maximum load FF applied to the engagement disc 16 cancel each other. With this configuration, the moment MM around the bearing portion becomes small, and the load on the bearing portion is reduced.

In the present variable valve mechanism, the cylinder closest to the end of the camshaft (first rotary shaft member) 11 on which the pulley 42 is mounted (see FIG. 2) has the maximum load FF applied to the engagement disk 16. Is set so that it does not overlap with the direction of the input load applied to the input portion of the camshaft (first rotary shaft member) 11, that is, the end member 43 equipped with the pulley 42.

The input load is a load F3 that the end member (input portion) 43 receives from the timing belt 41 through the pulley 42 as shown in FIG. That is, since tension is applied to the timing belt 41, the pulley 42 receives a force in a direction substantially perpendicular to the joint surface from the joint with the belt 41, and such a force is applied to the pulley 42 as a whole, for example. It acts in the direction indicated by arrow F3 in FIG.

On the other hand, in the present mechanism, as shown in FIG. 6, the direction of the cam lobe side slider 18 with respect to the axis of the cam shaft 11 at the time of the maximum valve lift by the cam 6 is in the direction of the input load F3. It is set to almost match. Since the direction of the maximum load FF applied to the engagement disk 16 is in the opposite direction to the position of the cam lobe side slider 18 at the time of the maximum valve lift, as shown in FIGS. Of the maximum load FF applied to the end member (input portion) 43 is substantially opposite to the direction of the input load F3 applied to the end member (input portion) 43, and does not overlap with the input load direction F3.

With such a setting, in the bearing portion 1A of the cylinder head 1 that supports the end member (input portion) 43,
The input load direction F3 and the maximum load FF applied to the engagement disk 16 cancel each other, so that no excessive force acts on the bearing 1A. Since the variable valve mechanism as one embodiment of the present invention is configured as described above, the valve opening degree characteristic is controlled while adjusting the rotational phase of the control disk 14 through the eccentric position adjusting mechanism 30. You.

That is, the ECU (not shown) sets the rotation phase of the control disk 14 according to the engine speed and the load condition based on the engine speed information and AFS information and the like, and the position sensor (not shown) The control disk 14 is driven through operation control of a motor (not shown) so that the actual rotational phase of the control disk 14 is set based on the detection signal of the control disk 14.

Through the control of the operation of the motor by the ECU, for example, the center of the curve L3 shown in FIG.
, The valve opening period is lengthened as indicated by the curves L4 and L5, and conversely, as the engine speed and the load on the engine decrease, the valve opening period is shortened as indicated by the curves L2 and L1 in FIG. .

In this way, while controlling the rotational phase (position) of the control disk 14 according to the operating state of the engine, it is possible to drive the valve suitable for the operating state of the engine. In particular, since the lift characteristics of the valve can be continuously adjusted, the valve can always be driven with characteristics optimal for the operating state of the engine.

In this mechanism, the engaging disk (intermediate rotating member) 16, the control disk (shaft supporting member) 14 supporting the engaging disk 16, and the cam lobe (second
Rotating shaft member) 12 and camshaft (first rotating shaft member)
The bearing 11 (bearing component) for supporting the cam lobe 12 on the cylinder head 1 and the bearing 1A are considered so as not to apply an excessive load, so that the valve can be driven with high accuracy. There is an advantage that the durability and reliability of the device can be improved, and an advantage that the shaft members 11 and 12 and the bearing portions 7 and 1A can be reduced in size.

That is, in this mechanism, the engaging disc 16
Considering the characteristics of the force applied to the surface (see FIGS. 12 and 13),
The engaging disks 16 of all the cylinders except the engaging disks 16 of the cylinder closest to the end of the camshaft (first rotary shaft member) 11 on the pulley 42 mounting side (see FIG. 2) are connected to the engaging disks 16. The maximum load having the two maximum load directions to be applied is set so as not to be a large supporting load on the camshaft 11 and the bearing 7 that indirectly support the engagement disk 16.

As a result, as shown in FIGS. 13A and 13B, a large force applied to the engagement disk 16 is directed downward in all the rotation regions of the engine. The lower bearing (first bearing member) 7A formed on the cylinder head 1 having high rigidity is supported through the shaft 11 so that a large force applied to the engagement disk 16 by the lower bearing 7A causes a large deformation. Will be surely supported.

At the same time, in the engaging discs 16 of the cylinders other than the cylinder closest to the end of the camshaft (first rotating shaft member) 11 on the pulley 42 mounting side (see FIG. 2), the axis of the camshaft 11 is In consideration of the above, the maximum load FF applied to the engagement disk 16 is substantially in the direction opposite to the direction of the valve spring reaction force F2 which is received by the support shaft of the cam portion 6 (the axis of the camshaft 11). The magnitude of the moment MM acting on the part becomes smaller,
The burden on the bearing part is reduced.

The camshaft (first rotating shaft member) 1
For the cylinder closest to the end of the first pulley 42 mounting side (see FIG. 2), the maximum load F
Since the direction of F is set so that it does not overlap with the direction of the input load applied to the input portion of the camshaft (first rotary shaft member) 11, that is, the end member 43 equipped with the pulley 42, the input load is The direction F3 and the maximum load FF applied to the engagement disk 16 can be offset, and the bearing 1A
No excessive force is applied.

In this manner, the deformation of the shaft members such as the camshaft (first rotary shaft member) 11 and the cam lobe 12 and the bearings 7 and 1A can be suppressed, and the valve can be driven with high precision. It becomes. Shaft member 1
Since the load on the bearings 1, 12 and the bearings 7, 1A is reduced, the durability and reliability of the device are also improved, and conversely, the shaft members 11, 12 and the bearings 7, 1A are reduced in size. You can also do things.

In the variable valve mechanism of this embodiment, only the cylinder (see FIG. 2) at the end on the pulley 42 side is engaged in a direction opposite to the direction of the belt load (input load) F3 as shown in FIG. Although the positions of the first pin member 23 (first slider member 17) and the second pin member 24 (second slider member 18) are set so that the maximum load FF of the combined disk 16 acts, productivity is taken into consideration. Then, the position of the first pin member and the position of the second pin member may be set for the cylinder at the end on the pulley 42 side similarly to the other cylinders.

In the variable valve mechanism of this embodiment, the axis of the first pin member and the axis of the second pin member are shifted by about 180 ° about the first rotation center axis O _1. ,
Although the axis of the first pin member, the first rotation center axis O ₁ , and the axis of the second pin member are arranged substantially linearly, the axis of the first pin member and the axis of the second pin member are arranged. the relative positional relationship between the axis is not limited thereto, the axis and the first rotation center axis of the first pin member O ₁ and the axis of the second pin member, other than the 180 ° angle (e.g. obtuse Or an acute angle).

Further, since the non-constant velocity joint 13 can be installed for each cylinder, the invention is not limited to the shape and form of the engine, but includes various in-line multi-cylinder engines such as a four-cylinder engine. This mechanism can be applied to all types of engines. Also,
In this variable valve mechanism, the valve drive mode between the valve stem and the cam is not limited to the one shown in the embodiment,
For example, the present invention can be applied to various valve driving modes described in the related art.

[0112]

As described above in detail, according to the variable valve mechanism according to the first to third aspects of the present invention, the two maximum load directions of the intermediate rotary member generated when the valve member is opened and closed are determined by the bearing component member. The connection position of the first connection member and the second connection member on the intermediate rotating member is set so as to act in a direction substantially orthogonal to the joint surface between the first bearing member and the second bearing member. As a result, the maximum load on the intermediate rotating member that occurs when the valve member opens and closes mainly acts on the joining direction of the first bearing member and the second bearing member of the bearing constituent member, so that the first bearing member The rotating system including the intermediate rotating member is securely supported while effectively utilizing the joining force between the valve member and the second bearing member, and the valve member is accurately operated with desired operating characteristics. There is an advantage that can be.

Further, since the maximum load direction does not act in a direction along the joining force, an excessive force is hardly applied to the joint between the first bearing member and the second bearing member.
The load on the joint portion is reduced, and the durability of the bearing portion is improved, as well as the miniaturization of the bearing portion can be promoted, which can contribute to the reduction in size and weight of the variable valve mechanism.

Further, the first connection member and the second connection member are so arranged that the two maximum load directions of the intermediate rotary member generated when the valve member opens and closes act in the direction of the member having higher rigidity around the bearing constituting member. By setting the connection position of the member in the intermediate rotating member, the maximum load of the intermediate rotating member generated when the valve member opens and closes mainly acts on a member having higher rigidity. There is an advantage that the valve member can be pivotally supported and the valve member can be operated accurately with desired operating characteristics. Of course, the load on the joint is reduced, and the durability of the bearing portion is improved, as well as the miniaturization of the bearing portion can be promoted, which can contribute to the miniaturization and weight reduction of the variable valve mechanism. There are advantages too.

According to the variable valve mechanism of the present invention, the connecting position of the first connecting member is set to a phase angle position closer to the cam portion than the connecting position of the second connecting member. Only by doing so, the load on the bearing portion as described above can be easily and surely reduced, and the effects and advantages as described above can be easily obtained based on a simple design concept.

According to the third aspect of the present invention, when the valve member is fully lifted, the plane connecting the first connecting member and the second connecting member is substantially equal to the connecting surface. Since it is configured so as to be orthogonal, it is compatible with a general existing engine arrangement, it is possible to easily and surely reduce the burden on the bearing portion, and the above-described effects and advantages are easily obtained. be able to.

According to the variable valve mechanism of the present invention, the maximum load direction of the intermediate rotary member generated when the valve member opens and closes is determined by the load applied to the input portion of the first rotary shaft member. Since the connection position of the first connection member and the second connection member in the intermediate rotation member is set so as not to overlap with the direction, the maximum load direction of the intermediate rotation member and the first rotation shaft member Advantageously, the direction of the input load applied to the input portion does not overlap, and the deformation of the bearing portion, the first rotating shaft member, and the like is suppressed, and the valve member can be operated accurately with desired operating characteristics. There is. Of course, the burden on the bearing portion and the first rotating shaft member is reduced, and the durability of these rotating systems is improved, and the first rotating shaft member and its bearing portion can be further miniaturized. Also, there is an advantage that can contribute to miniaturization and weight reduction of the variable valve mechanism.

In particular, according to the variable valve mechanism of the present invention, the connecting position of the second connecting member is closer to the cam ridge of the cam portion than the connecting position of the first connecting member. Just by setting the phase angle position, the load on the bearing portion can be easily and reliably reduced, and the above-described effects and advantages can be easily obtained based on a simple design concept.

According to the variable valve mechanism of the present invention, the shaft support member, the intermediate rotating member, the first connecting member, the second connecting member, and the valve member are all provided in the internal combustion engine. Since the valve is provided for each cylinder of the engine, the valve can always be driven with optimal characteristics for the engine through each cylinder, and there is an advantage that the degree of freedom in setting various configurations of the variable valve mechanism is increased. .

According to the variable valve mechanism of the present invention, in the variable valve mechanism of a cylinder that is not adjacent to the input portion, the maximum load direction of the intermediate rotating member is adjusted by the support shaft of the cam portion. Since the connecting position of the first connecting member and the second connecting member in the intermediate rotating member is set so that the direction is substantially opposite to the direction of the driving reaction force received from the valve member,
The maximum load of the intermediate rotary member and the driving reaction force received by the support shaft of the cam portion cancel each other, so that the deformation of the bearing portion and the first rotary shaft member is suppressed, and the valve member has a desired operating characteristic. There is an advantage that it can be operated accurately.

Needless to say, the burden on the bearing portion and the first rotating shaft member is reduced, and the durability of these rotating systems is improved. In addition, the miniaturization of the first rotating shaft member and its bearing portion is promoted. Therefore, there is also an advantage that it can contribute to downsizing and weight reduction of the variable valve mechanism, and further downsizing and weight reduction of the internal combustion engine.

According to the variable valve mechanism of the present invention, the connecting position of the first connecting member and the second connecting member is provided at a position substantially opposed to the first rotation center axis. As a result, the burden on the bearing portion can be easily and reliably reduced, and the above-described effects and advantages can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an arrangement of a main part of a variable velocity joint in a variable valve mechanism according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a main part of a variable valve mechanism according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a non-constant velocity joint in the variable valve mechanism according to one embodiment of the present invention, and is a cross-sectional view taken along line AA of FIG. 2;

FIG. 4 is a cross-sectional view showing a non-constant velocity joint in the variable valve mechanism according to the embodiment of the present invention, and is a cross-sectional view taken along line BB of FIG. 2;

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

FIG. 6 is a schematic cross-sectional view showing an arrangement of a main part of a variable velocity joint in the variable valve mechanism according to one embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing an operation of a variable speed mechanism in the variable valve mechanism according to the embodiment of the present invention;
(A) to (D) show the phase states of the respective parts when the mechanism is operated in this order.

FIG. 8 is a characteristic diagram illustrating an unequal-speed mechanism of the variable valve mechanism according to the embodiment of the present invention.

FIG. 9 is a diagram illustrating valve lift characteristics according to eccentric position adjustment by the variable valve mechanism according to one embodiment of the present invention.

FIG. 10 is a diagram illustrating the setting of the unequal speed mechanism of the variable valve mechanism according to the embodiment of the present invention, and is a diagram illustrating an example of a valve lift amount of an engine and a change in cam driving torque by a valve.

FIG. 11 is a view for explaining the setting of the unequal speed mechanism of the variable valve mechanism according to the embodiment of the present invention, and is a view for explaining a force applied to an intermediate rotating member (engaging disc).

FIG. 12 is a diagram illustrating the setting of the unequal-speed mechanism of the variable valve mechanism according to the embodiment of the present invention, and shows a vector of a force applied to the intermediate rotating member (engaging disk) according to the phase of the cam. FIG.

FIG. 13 is a view for explaining setting of the unequal speed mechanism of the variable valve mechanism according to the embodiment of the present invention, and shows a vector of a force applied to the intermediate rotating member (engaging disc) according to the phase of the cam. FIG. 7A shows a low-speed rotation region, and FIG. 7B shows a high-speed rotation region.

FIG. 14 is a diagram illustrating the setting of the unequal speed mechanism of the variable valve mechanism according to one embodiment of the present invention, and is a diagram illustrating torque required for cam driving with respect to the angle of a cam shaft; This shows a case in a low-speed rotation region.

FIG. 15 is a diagram illustrating the setting of the unequal-speed mechanism of the variable valve mechanism according to the embodiment of the present invention, and is a diagram illustrating torque required for cam driving with respect to an angle of a cam shaft; This shows a case in a high-speed rotation region.

FIG. 16 is a view for explaining the setting of the unequal speed mechanism of the variable valve mechanism according to one embodiment of the present invention, and is a view for explaining the moment applied around the axis; FIG. FIG. 3B is a diagram showing a case of the present mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cylinder head of engine (internal combustion engine) 1A Bearing part 2 Valve (valve member) 2A Stem end part of valve 2 3 Valve spring 6 Cam 6A Convex part (cam peak part) of cam 6 7 Bearing part (bearing constituent member) 7A Lower bearing half (first bearing member) 7B Bearing cap (second bearing member) 7C Bolt 7D Joint surface between bearing lower half 7A and bearing cap 7B 8 Rocker arm 11 Camshaft (first rotary shaft member) 11A, 11B Oil hole 12 Cam lobe (second rotary shaft member) 13 Variable velocity joint 14 Control disk (shaft support member) as control member 15 Eccentric portion (shaft support portion) 16 Engagement disk (intermediate rotary member) 16A As first groove portion The slider groove 16B of the slider 16C as the second groove portion 16C One side surface of the engagement disk 17 The first slider member (first connection member) Reference Signs List 8 second slider member (second connection member) 19 drive arm 19A, 20A, 21A, 22A hole portion 20 arm portion 21, 22 slider body portion 22B, 22C outer flat surface 23, 24 drive pin portion (pin member) 25 lock pin 28A, 28B Inner wall plane 30 Transmission mechanism 31 First gear 32 Gear mechanism 32A Gear shaft 32B Second gear (control gear) 32C Third gear 36 Waved washer 37 Bearing 41 Belt (timing belt) 42 Pulley 43 End member (input) part) 0 ₁ first rotation center axis line 0 ₂ second rotation center axis line

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hideo Nakai 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation

Claims (8)

[Claims] 1. A first rotating shaft member that is driven to rotate around a first rotation center axis by a crankshaft of an internal combustion engine, and a second rotation member that is different from the first rotation center axis and parallel to the first rotation center axis. A shaft support member provided with a shaft support for guiding rotation about a rotation center axis, and rotatably or swingably provided on the outer periphery of the first rotary shaft member; and intermediate rotation supported by the shaft support member. A member, a first connection member connecting the intermediate rotation member to the first rotation shaft member, and enabling the intermediate rotation member to rotate in conjunction with the first rotation shaft member; and a first rotation center axis. A second rotating shaft member that rotates around and has a cam portion, the second rotating shaft member being connected to the intermediate rotating member,
A second connecting member that enables the rotating shaft member to rotate in conjunction with the intermediate rotating member; and a second connecting shaft that is provided integrally with or separate from the second rotating shaft member and that is driven through the cam portion to rotate the rotating shaft member. A valve member for setting an intake inflow period or an exhaust release period to the combustion chamber of the internal combustion engine in accordance with the rotational phase of the member; A variable valve mechanism having a control member for displacing the second rotation center axis which is a rotation center of a support, wherein the bearing indirectly supports the intermediate rotation member with respect to a main body of the internal combustion engine. A first bearing member provided on the cylinder head side of the internal combustion engine, and a second bearing member provided opposite to the first bearing member are joined to each other. And the first bearing member and the second shaft The junction surface of the member, the first
The two maximum load directions of the intermediate rotary member, which are formed by a plane substantially parallel to the rotation center axis and are generated when the valve member opens and closes, are substantially orthogonal to the joint surface and / or around the bearing component member. Wherein the connection position of the first connection member and the second connection member in the intermediate rotation member is set so as to act in the direction of a member having higher rigidity. 2. The connecting position of the first connecting member is set to a phase angle position closer to the cam ridge portion of the cam portion around the first rotation center axis than the connecting position of the second connecting member. The variable valve mechanism according to claim 1, wherein 3. The first valve at the time of maximum lift of the valve member.
3. The variable valve mechanism according to claim 1, wherein a plane connecting the center lines of the connecting member and the second connecting member is set so as to be substantially orthogonal to the joining surface. 4. A first rotating shaft member having an input portion for receiving a rotating force of a crankshaft of an internal combustion engine, the first rotating shaft member being driven to rotate around a first rotating center axis by the rotating force of the crankshaft, and the first rotating center axis. A shaft support for guiding rotation about a second axis of rotation that is different from the first axis of rotation and parallel to the first axis of rotation, and is rotatably or oscillatably supported on the outer periphery of the first axis of rotation. A shaft support member provided for a cylinder of the engine, an intermediate rotation member supported by the cylinder for the support member, and an intermediate rotation member connected to the first rotation shaft member. A first connection member that enables the intermediate rotation member to rotate in conjunction with the first rotation shaft member; a second rotation shaft member that rotates about the first rotation center axis and has a cam portion; Connecting the second rotating shaft member to the member,
A second connecting member that enables the rotating shaft member to rotate in conjunction with the intermediate rotating member; and a second connecting shaft that is provided integrally with or separate from the second rotating shaft member and that is driven through the cam portion to rotate the rotating shaft member. A valve member for setting an intake period or an exhaust release period of the cylinder into the combustion chamber in accordance with the rotation phase of the member; and a valve member engaged with the shaft support member, and the shaft support portion depending on an operation state of the internal combustion engine. And a control member for displacing the second rotation center axis, which is the rotation center of the variable rotation valve mechanism, wherein the maximum load direction of the intermediate rotation member generated when the valve member opens and closes is the first rotation direction. The connection position of the first connection member and the second connection member in the intermediate rotation member is set so as to be in a direction not overlapping the input load direction applied to the input portion of the rotation shaft member. Variable valve mechanism. 5. The connecting position of the second connecting member is set at a phase angle position closer to the cam ridge of the cam portion around the first rotation center axis than the connecting position of the first connecting member. The variable valve mechanism according to claim 4, wherein 6. The vehicle according to claim 1, wherein the shaft support member, the intermediate rotating member, the first connecting member, the second connecting member, and the valve member are all provided for each cylinder of the internal combustion engine. The variable valve mechanism according to claim 4 or 5. 7. A first rotating shaft member having an input portion for receiving a rotating force of a crankshaft of the internal combustion engine, the first rotating shaft member being driven to rotate around a first rotating center axis by the rotating force of the crankshaft, and the first rotating center axis. A shaft support for guiding rotation about a second axis of rotation that is different from the first axis of rotation and parallel to the first axis of rotation, and is rotatably or oscillatably supported on the outer periphery of the first axis of rotation. A shaft support member provided for a cylinder of the engine, an intermediate rotation member supported by the cylinder for the support member, and an intermediate rotation member connected to the first rotation shaft member. A first connection member that enables the intermediate rotation member to rotate in conjunction with the first rotation shaft member; a second rotation shaft member that rotates about the first rotation center axis and has a cam portion; Connecting the second rotating shaft member to the member,
A second connecting member that enables the rotating shaft member to rotate in conjunction with the intermediate rotating member; and a second connecting shaft that is provided integrally with or separate from the second rotating shaft member and that is driven through the cam portion to rotate the rotating shaft member. A valve member for setting an intake period or an exhaust release period of the cylinder into the combustion chamber in accordance with the rotation phase of the member; and a valve member engaged with the shaft support member, and the shaft support portion depending on an operation state of the internal combustion engine. A variable valve mechanism having a control member for displacing the second axis of rotation which is the center of rotation of each cylinder; and in the variable valve mechanism of a cylinder not adjacent to the input section, The intermediate rotating member of the first connecting member and the second connecting member such that the maximum load direction of the rotating member is substantially opposite to the direction of the driving reaction force received from the valve member by the support shaft of the cam portion. A variable valve train, wherein a connection position is set. 8. The connection position of the first connection member and the second connection member is provided at a position substantially opposed to the first rotation center axis. The variable valve mechanism according to any one of the above.