JP2005264840A - Variable valve system for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable valve system capable of continuously changing a great deal of the driving phase of a valve and the lift quantity of the valve while securing strength with relatively simple constitution. <P>SOLUTION: In this variable valve system 1, an eccentric shaft 15 is formed at a rocker shaft 12, and a first arm 21 supported in a swingable manner to the rocker shaft 12 and capable of driving the valve 2, a second arm 22 driven by a cam 13 and swinging around the eccentric shaft 15 as a rotating shaft, and a third arm 23 supported in a swingable manner to a support shaft 16 and displaced by the swing of the second arm 22 to drive the first arm 21, are provided as a rocker arm mechanism. The rocker shaft 12 is turned in a direction R2 to displace a center axis C4 of the eccentric shaft 15 and to displace an abutting point 46 on the cam 13, thus displacing the opening timing and lift quantity of the valve 2 continuously. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine capable of changing a drive phase and a valve lift amount of an intake valve and an exhaust valve.

  2. Description of the Related Art A technique for changing the phase and lift amount of an intake / exhaust valve in accordance with the operating state of an internal combustion engine is known for measures against exhaust gas from an internal combustion engine, for example, an automobile engine, and fuel consumption reduction. As a variable valve apparatus for that purpose, a vane variable phase valve apparatus that continuously changes the cam phase by oil pressure is known.

  There is also known a cam-switching type valve operating apparatus that switches a plurality of types of cams according to the operating state of the internal combustion engine to adapt the drive phase and lift amount of the valve to the operating state.

  Alternatively, there is also known a mechanical continuous variable valve device that uses a gear driven by a stepping motor, an intermediate lever, a return spring, and the like so that the drive phase and lift amount of the valve can be changed (for example, , See Patent Document 1 below).

Japanese Patent No. 3245492

  The vane type variable phase valve device can shift the drive phase of the valve by changing the position of the vane, but cannot change the lift amount of the valve.

  On the other hand, the cam-switching valve system and the mechanical continuously variable valve system can shift the lift amount and phase, but the cam-switching valve system requires multiple types of cams. The number is complicated and the structure is complicated. In addition, the mechanical continuous variable valve device requires a mechanism for changing the lift amount and a mechanism for shifting the phase separately, which complicates the structure and increases the size.

  Further, in the case of the conventional general continuous phase variable valve operating device, if the closing timing of the intake valve is retarded, the valve opening start timing is also retarded. For this reason, there is a problem that intake and exhaust valve overlaps are reduced or eliminated, and fuel consumption is deteriorated due to pumping loss.

  Furthermore, in some continuous phase variable valve operating devices, there is a rocker arm that supports opening and closing of the valve by a pivot structure such as a universal joint. Depending on the support structure, depending on the magnitude and direction of the driving force, There was a risk that the rocker arm would come off due to insufficient support. Further, in the above-described continuous phase variable valve operating apparatus, the pivot structure portion is rotated for controlling the drive phase of the valve, the rotation angle is limited due to the support structure, and the drive phase of the valve is also limited. There was a limit.

  The present invention has been made in view of the above-mentioned problems, and provides a variable valve operating device that can secure a support strength and can continuously change a valve driving phase and a valve lift amount with a relatively simple configuration. The purpose is to do.

The variable valve operating apparatus according to claim 1 of the present invention that solves the above problems is
A cam provided in the internal combustion engine and driven to rotate by a camshaft;
A rocker shaft provided in the internal combustion engine so as to be rotatable and having an eccentric shaft eccentrically;
Rotating means for rotating the rocker shaft;
Opening and closing means that is driven by the cam and opens and closes an intake valve or an exhaust valve;
The opening / closing means includes
A first arm that is swingably supported by the rocker shaft and that can drive the intake valve or the exhaust valve;
A second arm supported swingably on the eccentric shaft and driven by the cam;
And a third arm that is swingably supported by a support shaft disposed in the vicinity of the rocker shaft and is displaced by the swing of the second arm to drive the first arm.

A variable valve operating apparatus according to claim 2 of the present invention for solving the above-described problems is provided.
In the above variable valve gear,
The eccentric shaft is displaced in the circumferential direction of the rocker shaft by the rotation of the rocker shaft by the rotating means.
In the variable valve operating apparatus, when the rocker shaft is rotated by the rotating means, the position of the eccentric shaft is displaced in the circumferential direction of the rocker shaft. The displacement of the position of the eccentric shaft is the displacement of the swing center position of the second arm, and the contact point of the second arm with respect to the cam is also displaced in the outer peripheral direction of the cam. Thereby, the rotational phase of the second arm relative to the cam is advanced or retarded according to the position of the eccentric shaft, and finally the first arm driven via the second arm and the third arm. The driving phase is advanced or retarded.

A variable valve operating apparatus according to claim 3 of the present invention for solving the above-described problems is provided.
In the above variable valve gear,
The third arm has a contact surface portion that contacts the first arm,
The contact surface portion includes a conversion surface portion whose distance from the center of the support shaft changes in a swinging direction of the third arm.
Accordingly, when the first arm comes into contact with the conversion surface portion of the contact surface portion of the third arm when the third arm swings, the third arm converts the swing amount of the second arm to the first arm. By transmitting, the first arm is driven.

A variable valve operating apparatus according to claim 4 of the present invention for solving the above-described problems is provided.
In the above variable valve gear,
The contact surface portion includes a non-converting surface portion whose distance from the center of the support shaft does not change in the swing direction of the third arm.
Therefore, when the first arm comes into contact with the non-conversion surface portion of the contact surface portion of the third arm when the third arm swings, the third arm does not convert the swing amount of the second arm, and the first arm Transmission to the arm is lost, and the first arm is not driven.

A variable valve operating apparatus according to claim 5 of the present invention for solving the above-described problems is provided.
In the above variable valve gear,
The eccentric shaft is provided on both sides of a support portion where the rocker shaft supports the first arm,
A bifurcated shaft support portion is provided on the second arm so as to straddle the first arm,
The eccentric shaft is inserted into the bifurcated shaft support portion.

A variable valve operating apparatus according to claim 6 of the present invention for solving the above-described problems is provided.
In the above variable valve gear,
The rocker shaft is provided with the eccentric shaft on one side of a support portion for supporting the first arm, and
The second arm is provided with one shaft support so as not to directly interfere with the first arm,
The eccentric shaft is fitted into the shaft support portion.

  According to the first and second aspects of the present invention, when the rocker shaft is rotated by the rotating means, the position of the eccentric shaft of the rocker shaft is displaced, so that the rocker shaft is swingably supported by the eccentric shaft. The swing center position of the second arm is also displaced around the rocker shaft axis, and the drive phases of the intake valve and the exhaust valve can be continuously changed according to the displacement position of the swing center. Further, since the rocker shaft and the second arm can be provided as one component (assembly), the assembly at the time of manufacture can be facilitated and the assemblability can be improved. Furthermore, since the second arm is attached to the eccentric shaft of the rocker shaft, the support strength can be maintained regardless of the magnitude and direction of the load applied to the second arm, and the reliability of the variable valve system is maintained. Can do.

  According to the third aspect of the present invention, since the conversion surface portion that changes the distance from the center of the support shaft is provided on the contact surface portion of the third arm, the swing amount of the second arm is controlled by the third arm. It can be converted and transmitted to the first arm. In addition to this configuration, the lift amount of the intake valve and the exhaust valve can be changed by displacing the swing center position of the second arm by the rotating means.

  According to the fourth aspect of the present invention, since the non-converting surface portion that does not change the distance from the center of the support shaft is provided on the contact surface portion of the third arm, the second arm of the second arm with respect to the cam is rotated by the rotating means. Even if the rotational phase is advanced by a predetermined angle, the swing amount corresponding to the substantially predetermined angle from the start of swinging of the second arm can be canceled by the non-converting surface portion, and the valve opening start timing is substantially set regardless of the valve lift amount. Can be the same.

  According to the invention of claim 5 of the present invention, since the second arm is supported on the eccentric shaft at two locations so as to straddle the first arm, the contact portion between the second arm and the cam, Even if an unbalanced load is generated at the contact portion between the second arm and the third arm, the second arm can be prevented from being displaced in the axial direction of the rocker shaft, and the reliability of the variable valve system can be maintained.

  According to the sixth aspect of the present invention, since the second arm is supported on the eccentric shaft at one location so as not to directly interfere with the first arm, the rocker arm mechanism serving as the displacement means has a compact configuration. It can be.

  Hereinafter, an embodiment of a variable valve apparatus according to the present invention will be described with reference to FIGS.

1 to 5 show an example of an embodiment of a variable valve operating apparatus according to the present invention.
FIG. 1 is a side view of a variable valve operating apparatus according to the present invention, and FIG. 2 is a top view thereof (viewed from direction A in FIG. 1).
FIG. 1 shows the state of the variable valve device when the valve is closed when the phase of the cam angle is retarded, and FIG. 3 shows the state of the variable valve device when the valve is opened when the phase of the cam angle is retarded. Indicates the state. FIG. 4 shows the state of the variable valve apparatus when the valve is closed when the phase of the cam angle is advanced, and FIG. 5 shows the state of the variable valve apparatus when the valve is opened when the phase of the cam angle is advanced. Show.

  A variable valve operating apparatus 1 according to the present embodiment is disposed, for example, in a cylinder head (not shown) portion of an internal combustion engine such as an automobile engine. As shown in FIG. The intake valve 2 and the like constituting the valve are driven to open and close. The intake valve 2 is urged in a direction to close the intake passage 4 by a valve spring 3, and the variable valve apparatus 1 is used to resist the valve spring 3 at a predetermined timing and a predetermined lift amount. The intake valve 4 is depressed to open the intake passage 4. Note that a similar variable valve operating device 1 may be provided on the exhaust valve side, and the opening / closing control of the exhaust valve may be similarly performed.

  The variable valve operating apparatus 1 includes a camshaft 11 that is rotatably provided, a rocker shaft 12 that is rotatably provided, a cam 13 that is formed on the camshaft 11, and a camshaft 11. It has a rocker arm mechanism 14 (opening / closing means) driven by a cam 13 that is rotationally driven, and the valve 2 is driven to open and close by driving the rocker arm mechanism 14.

  The camshaft 11 and the rocker shaft 12 are disposed so as to be parallel to each other. Further, the camshaft 11 rotates in the direction indicated by the arrow R1 with the rotation center C2 of the camshaft 11 in FIG. 1 as the rotation center in accordance with the rotation of the crankshaft (not shown) of the internal combustion engine. Yes.

  The rocker shaft 12 can be rotated in the direction indicated by the arrow R2 in FIG. The rocker shaft 12 is provided with a plurality of eccentric shafts 15 having a smaller diameter than the rocker shaft 12 and having a swing center C4 that is eccentric from the rotation center C1 of the rocker shaft 12. Thus, the rocker shaft 12 is formed in a so-called crank structure by providing the rocker shaft 12 with a plurality of eccentric shafts 15. In the case of a multi-cylinder engine, one or a plurality of eccentric shafts 13 are provided for each of a plurality of cylinders arranged in the same row. For example, when the variable valve device of the present embodiment is used for an intake valve of an in-line four-cylinder engine, if one intake valve is provided per cylinder, four eccentric shafts 15 are provided on one rocker shaft 12. If the configuration has two intake valves per cylinder, eight eccentric shafts 15 are provided on one rocker shaft 12.

  When the rocker shaft 12 is rotated in the direction of the arrow R2 by the rotating means 24, the eccentric shaft 15 on which the second arm 22 is supported is displaced in the circumferential direction of the rocker shaft 12, and the contact point 46 is accordingly moved. The cam 13 is displaced in the circumferential direction. By this displacement, the rotational phase of the second arm 22 with respect to the cam 13 can be greatly changed to the retard side or the advance side. The rocker shaft 12 has no limitation on the rotation angle, and can set a large change in rotation phase.

  The rocker arm mechanism 14 includes a first arm 21, a second arm 22, and a third arm 23 as main components.

  The first arm 21 has an end portion 31 provided with an adjusting screw 32 and a shaft fitting insertion portion 34 through which the rocker shaft 12 is inserted, and is supported so as to be rotatable relative to the rocker shaft 12. Has been. The adjustment screw 32 provided at the end 31 of the first arm 21 can be adjusted so that there is no play between the first arm 21 and the head portion 5 of the valve 2. A roller 33 is provided in the vicinity of the adjustment screw 32 and functions as a force transmission unit that transmits the force from the third arm 23 to the first arm 21. Therefore, when the camshaft 11 rotates in the direction indicated by the arrow R1, the second arm 22, the third arm 23, and the first arm 21 swing in conjunction with this rotation, and the tip of the adjustment screw 32 is connected to the valve. The second head 5 is pressed down to drive the valve 2 in the valve opening direction. The adjustment screw 32 and the roller 33 are appropriately arranged with respect to the position of the rotation center C1 of the rocker shaft 12 according to the force acting on the first arm 21 and its swing distance.

  The second arm 22 has sandwiching portions 41 and 42 having recesses with a semicircular cross section, and is arranged so that the eccentric shaft 15 is sandwiched between these recesses and fixed between the sandwiching portions 41 and 42 by a plurality of bolts 44. By doing so, the eccentric shaft 15 is supported so as to be swingable. The second arm 22 has a roller support portion 47 and an operation portion 43. The roller support portion 47 is provided with a roller 45 that is rotatably supported. The roller 45 is brought into rolling contact with the cam 13 at a contact point 46, so that the eccentricity is caused by the displacement of the outer peripheral shape of the cam 13 as the cam 13 rotates. The second arm 22 is swung around the swing center C4 of the shaft 15. The operating portion 43 abuts the relay portion 53 of the third arm 23 at the end thereof, and relays the operation of the second arm 22 swung by the cam 13 to the third arm 23. In the case of the present embodiment, the second arm 22 is substantially L-shaped in a side view, has the clamping portions 41 and 42 at one end portion, and has the operation portion 43 at the other end portion. The roller support portion 47 is provided at the bent portion of the L shape.

  The eccentric shaft 15 is not necessarily limited to the arrangement shown in FIG. 1 as long as the oscillation center C4 is arranged in an offset (eccentricity) state with respect to the rotation center C1 of the rocker shaft 12. However, when it is desired to make the configuration of the variable valve operating apparatus 1 compact, it is desirable that the diameter be smaller than that of the rocker shaft 12 and that the cross section be inscribed in the outer diameter of the rocker shaft 12 as in this embodiment. In that case, the diameter of the eccentric shaft 15 is set in consideration of the rigidity of the entire rocker shaft 12 having the eccentric shaft 15. In the case of the present embodiment, as an example, the diameter of the eccentric shaft 15 is set to approximately half of the outer diameter of the rocker shaft 12.

  In the case of the present embodiment, as shown in FIG. 2, the eccentric shaft 15 is provided on one side of the support portion where the rocker shaft 12 supports the first arm 21, so that the rocker shaft 12 does not directly interfere with the first arm 21. One shaft support portion 48 is provided on the two arms 22, and the eccentric shaft 15 is fitted and inserted into the clamping portions 41 and 42 on the shaft support portion 48 side. In the case where the load received by the second arm is not excessive, a configuration in which the single shaft support portion 48 is attached to the eccentric shaft 15 side is sufficient. Even if an eccentric load is generated at the contact portion between the second arm 22 and the cam 13, the contact portion between the second arm 22 and the third arm 23, etc. by appropriately setting the axial length of the eccentric shaft 15. Further, the second arm 22 may be prevented from being displaced in the axial direction of the rocker shaft 12, problems such as uneven wear may be prevented, and the reliability of the variable valve operating apparatus 1 may be maintained.

  The third arm 23 is provided in the vicinity of the rocker shaft 12 in a swingable manner on the support shaft 16 disposed in parallel with the rocker shaft 12, and the roller 33 of the first arm 21 and the operating portion 43 of the second arm 22. It functions as a transmission cam of the 1st arm 21 and the 2nd arm 22 by being arranged between. The third arm 23 is provided with a contact surface portion 51 that contacts the roller 33 of the first arm 21 and a relay portion 53 that contacts the operation portion 43 of the second arm 22. A spring (not shown) urges the central position C3 of the support shaft 16 in the counterclockwise direction, that is, the direction in which the second arm 22 is brought into contact with the cam 13.

  As the second arm 22 swings, the contact surface portion 51 that functions as a cam surface is displaced in the swing direction of the third arm 23, that is, in the circumferential direction of the support shaft 16. Specifically, the contact surface portion 51 has a distance from the center position C3 of the support shaft 16 from the non-converting surface portion 51a that does not change even when the third arm 23 swings, and the center position C3 of the support shaft 16. The distance has a conversion surface portion 51 b that increases toward the tip end portion 52 of the third arm 23 as the third arm 23 swings.

  That is, the conversion surface portion 51b of the contact surface portion 51 converts the swing amount of the second arm 22 to drive the first arm 21, so that the center position C3 of the support shaft 16 is moved along with the swing of the third arm 23. The surface shape is such that the distance from the surface changes. On the other hand, the non-converting surface portion 51 a of the contact surface portion 51 swings the second arm 22 even when the rotation phase of the contact point 46 of the second arm 22 with respect to the cam 13 is advanced by a predetermined angle by the rotation means 24. It is formed in a surface shape that can cancel the swing amount from the start to a substantially predetermined angle. This is because the non-converting surface portion 51a is formed so that the distance from the center position C3 of the support shaft 16 does not change even if the third arm 23 swings. This is because the third arm 23 is not converted, and transmission to the first arm 21 is lost.

  Accordingly, when the second arm 22 is swung toward the third arm 23 around the eccentric shaft 15 by the convex portion 13a of the cam 13, and when the third arm 23 rotates clockwise via the relay portion 53, When the first arm 21 is rotated in the arrow S3 direction by the contact surface portion 51, the valve 2 is opened. At this time, the contact point 35 between the roller 33 of the first arm 21 and the abutment surface portion 51 of the third arm 23 is displaced in the circumferential direction of the support shaft 16 as the second arm 22 swings, and the contact point 35. If the position of the contact point 35 is on the conversion surface 51b, the valve 2 is not opened and the drive phase of the valve opening can be controlled. Accordingly, the valve lift amount of the valve opening can be controlled.

Next, with reference to FIG. 1 and FIG. 3, operation | movement of the variable valve apparatus 1 of a present Example is demonstrated.
In FIG. 1, the rocker shaft 12 is turned by the turning means 24 toward the angle θ ₁ retarded side from the neutral position N. In this case, the contact point 46 of the second arm 22 is displaced to contact with the cam 13 on the retard side (left side in FIG. 1) from the neutral point P _N. Further, the operating portion 43 of the second arm 22 is displaced to the left in FIG.

  In this state, the camshaft 13 rotates in the direction of arrow R1, and as shown in FIG. 3, when the convex portion 13a of the cam 13 pushes up the roller 45 of the second arm 22, the second arm 22 rotates the eccentric shaft 15. It swings counterclockwise as an axis (arrow S1 in FIG. 1). For this reason, the operation part 43 of the second arm 22 pushes the relay part 53, and the third arm 23 swings clockwise (arrow S2 in FIG. 1). Thereby, since the conversion surface portion 51b of the contact surface portion 51 presses the roller 33, the first arm 21 swings counterclockwise (arrow S3 in FIG. 1), and the position of the tip portion of the adjustment screw 32 in FIG. The valve 2 is opened by moving from P1 to the position P2 of the tip of the adjustment screw 32 in FIG.

  In this case, as shown in FIG. 1, since the contact point 35 of the roller 33 is located near the conversion surface portion 51b before the valve is opened, the roller 33 comes into contact with the third arm 23 when it swings clockwise. In the contact surface portion 51 of the third arm 23, the non-conversion surface portion 51a is short and the conversion surface portion 51b is long.

For this reason, the first arm 21 starts to be driven in the direction in which the valve 2 is opened while the cam angle is small, and the first arm 31 is moved to the arrow R3 while the roller 33 contacts the conversion surface 51b over a long range. Thus, a large valve opening angle, that is, a large valve lift amount H1 is obtained (see FIG. 3). In this case, as shown in FIG. 6 (see curve θ ₁ ), the valve lift amount is large and the valve lift peak is retarded. This is a valve drive suitable for a large intake amount with a high rotation and a high load. A curve θ ₁ in FIG. 6 shows a cam angle-valve lift amount curve when the rocker shaft 12 is retarded by θ ₁ from the neutral position N.

Next, with reference to FIGS. 4 and 5, the operation of the variable valve operating apparatus 1 of the present embodiment in a state different from the above will be described.
4 and 5 show a state in which the rocker shaft 12 is rotated by the rotation means 24 to the angle θ ₂ advance side from the neutral position N. In this case, the contact point 46 of the second arm 22 is displaced from the neutral point P _N to the advance side (right side in FIG. 4) with respect to the cam 22. Further, the operating portion 43 of the second arm 22 is displaced to the right in FIG. 4, and the third arm 23 is displaced counterclockwise. In the state in FIG. 4, the contact point 35 of the roller 33 before the valve opening is located closer to the non-converting surface portion 51 a as compared with the state in FIG. 1, so that when the third arm 23 swings, In the contact surface portion 51 of the third arm 23 that is in contact with the roller 33, the non-conversion surface portion 51a becomes longer and the conversion surface portion 51b becomes shorter.

  In this state, the camshaft 13 rotates in the direction of the arrow R1, and as shown in FIG. 5, when the convex portion 13a of the cam 13 pushes up the roller 45 of the second arm 22, the second arm 22 rotates the eccentric shaft 15. The shaft swings counterclockwise (see S1 in FIG. 4). For this reason, the operation part 43 of the second arm 22 pushes the relay part 53, and the third arm 23 swings clockwise (see S2 in FIG. 4). Thereby, since the conversion surface portion 51b of the contact surface portion 51 presses the roller 33, the first arm 21 swings (see S3 in FIG. 4), and the position P3 of the tip portion of the adjustment screw 32 in FIG. Then, the valve 2 is opened by moving to the position P4 of the tip of the adjusting screw 32.

In this case, the roller 33 of the first arm 21 has a long period (distance) in contact with the non-converting surface portion 51a in the contact surface portion 51 of the third arm 23 that functions as a transmission cam. Accordingly, when the third arm 23 rotates clockwise, the distance that the roller 33 moves on the conversion surface portion 51b is shortened, and the rotation amount of the first arm 21 is a slight valve lift as shown in FIG. The amount is H2. In this case, as shown in FIG. 6 (see curve θ ₂ ), the valve drive phase is advanced and the small valve opening angle, that is, the valve lift amount is reduced, so that the small intake amount with low rotation and load is small. The valve is suitable for driving. A curve θ ₂ in FIG. 6 shows a cam angle-valve lift amount curve when the rocker shaft 12 is advanced by θ ₂ from the neutral position N.

Further, when the rocker shaft 12 is rotated by the rotating means 24 to the advance side of the angle θ ₂ larger than the neutral position N, as shown by the dotted line in FIG. A state where the valve 2 is not opened, that is, a cylinder resting state is also possible.

  If the variable valve operating apparatus 1 having the above configuration is applied to the intake system, the opening side of the valve 2 can be fixed and the closing side can be continuously changed, so that a high expansion ratio cycle can be achieved.

  In addition, fuel efficiency can be reduced by synergistic action with inertial intake. Inertial intake means that the pressure pulsation generated by the intake action of the piston causes inertia in the intake air in the intake pipe. Utilizing this inertial intake, the valve 2 starts to close at the peak time of the intake pulsation, so that fresh air continues to flow into the cylinder even when the piston passes the bottom dead center, and the volumetric efficiency can be improved. Since the peak time of pulsation varies depending on the engine speed, the intake air amount can be increased by starting to close the valve 2 in accordance with the peak time.

In the variable valve operating apparatus 1 of the present embodiment, when the rocker shaft 12 is rotated by the rotating means 24 on the basis of the phase from the start to the end of the curve θ ₁ and the valve lift amount of the curve θ _{1 in} FIG. In FIG. 6, the period in which the second arm 22 is advanced with respect to the cam 13 can be canceled by increasing the period in which the non-converting surface portion 51b of the third arm 23 contacts the roller 33. As a result, FIG. curve N in (cam angle in the neutral position N of the rocker shaft 12 - valve lift curve), as shown in curve theta _2, can be a valve opening start timing substantially constant.

  Therefore, according to this variable valve operating apparatus 1, since the valve closing timing can be changed while the valve opening start timing is fixed, the amount of intake air is changed by changing the valve closing timing in accordance with the pulsation of the inertial intake air. Increase of the fuel consumption, and the effect of reducing fuel consumption can be obtained. Moreover, by controlling the amount of air optimally, a good combustion state is obtained, and unburned matters and the like are reduced to improve the exhaust gas component.

  In the case of a conventional continuous variable phase valve device, if the intake valve closing timing is retarded, the valve opening start timing is also retarded, and the valve overlap of intake and exhaust is reduced or eliminated, resulting in a pumping loss. Had occurred. On the other hand, according to the variable valve operating apparatus 1 of the present embodiment, the valve closing timing can be retarded with the valve opening start timing fixed, so that the valve closing timing is delayed while maintaining valve overlap. By making the angle, the amount of intake air can be increased, and the effect of reducing fuel consumption can be obtained.

  In general, when the air is excessive and the load is low, the exhaust temperature is lowered. However, according to the variable valve operating apparatus 1 of the present embodiment, the intake air amount can be controlled according to the operating state of the engine. By reducing it, the exhaust temperature can be increased. For this reason, when the catalyst for exhaust gas purification is provided, the catalyst can be activated to function effectively. In this case, since the exhaust gas can be purified by the catalyst, the engine body can be set in a state where the fuel consumption is good even if the exhaust gas component deteriorates a little. Thereby, while improving the fuel consumption of an engine main body and purifying exhaust gas with a catalyst, both high fuel consumption and purification of exhaust gas can be achieved. Further, according to the variable valve operating apparatus 1 of the present embodiment, it is not necessary to provide an intake or exhaust throttle for controlling the intake air amount by reducing the intake air amount at low load, and the cost can be reduced. is there.

FIG. 7 is a top view showing another example of the embodiment of the variable valve operating apparatus according to the present invention.
In the variable valve gear 1A, the configurations of the rocker shaft 12A and the second arm 22A are mainly different from those of the second arm 22 of the first embodiment described above (see FIG. 2). This is configured in consideration of the case where an excessive load is applied to the second arm 22. In addition, since it is the same as that of the variable valve apparatus 1 of Example 1 about a structure other than the above, an effect | action, and an effect, it attaches | subjects a common code | symbol to the overlapping structure, and abbreviate | omits detailed description.

  As shown in FIG. 7, in the variable valve gear 1A, the second arm 22A is bifurcated from the roller support portion 47 to form two shaft support portions 48a and 48b. In the rocker shaft 12A, The eccentric shaft 15 is formed on both sides of the support portion where the rocker shaft 12A supports the first arm 21, and these eccentric shafts 15 are fitted to the fitting portions 41a and 42a of the two shaft support portions 48a and 48b. It is the structure inserted by the joint parts 41b and 42b. That is, the bifurcated shaft support portions 48a and 48b of the second arm 22A are arranged so as to straddle a part of the first arm 21.

  As in the present embodiment, the support portion on the side of the eccentric shaft 15 in the second arm 22A is branched and supported by the two shaft support portions 48a and 48b, and the second arm 22A is supported between the two shaft support portions 48a and 48b. Since a part of one arm 21 is sandwiched, even when an unbalanced load is generated at a contact portion between the second arm 22A and the cam 13, a contact portion between the second arm 22A and the third arm 23, etc. The second arm 22A can be prevented from displacing in the axial direction of the rocker shaft 12, and problems such as uneven wear can be prevented, and the reliability of the variable valve gear 1A can be maintained.

  Contrary to the present embodiment, a bifurcated shaft fitting portion 34 for fitting the rocker shaft 12 to the first arm 21 is provided on the first arm 21 side, so that the first arm 21 is supported by the rocker shaft 12. The eccentric shaft 15 is provided between the insertion portions 34, the bifurcated shaft fitting insertion portion 34 of the first arm 21 is disposed so as to straddle a part of the second arm 22, and the eccentric shaft 15 is attached to the shaft support portion 48. You may make it insert between the fitting parts 41 and 42. FIG.

It is a figure which shows an example of embodiment of the variable valve apparatus which concerns on this invention, and is a figure at the time of valve closing in the state which the phase of cam angle retarded. It is a top view of the variable valve apparatus shown in FIG. FIG. 2 is a view when the valve is opened in a state in which the phase of the cam angle of the variable valve apparatus shown in FIG. 1 is retarded. FIG. 2 is a view when the valve is closed in a state where a phase of a cam angle of the variable valve operating apparatus shown in FIG. 1 is advanced. FIG. 2 is a view when the valve is opened in a state where the phase of the cam angle of the variable valve operating apparatus shown in FIG. 1 is advanced. It is a graph which shows the relationship between the cam angle and valve lift of the variable valve apparatus shown by FIG. It is a figure which shows another example of embodiment of the variable valve apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A Variable valve gear 2 Valve 11 Cam shaft 12 Rocker shaft 13 Cam 14 Rocker arm mechanism 15 Eccentric shaft 21 First arm 22 Second arm 23 Third arm 24 Rotating means

Claims (6)

A cam provided in the internal combustion engine and driven to rotate by a camshaft;
A rocker shaft provided in the internal combustion engine so as to be rotatable and having an eccentric shaft eccentrically;
Rotating means for rotating the rocker shaft;
Opening and closing means that is driven by the cam and opens and closes an intake valve or an exhaust valve;
The opening / closing means includes
A first arm that is swingably supported by the rocker shaft and that can drive the intake valve or the exhaust valve;
A second arm supported swingably on the eccentric shaft and driven by the cam;
An internal combustion engine comprising: a third arm that is swingably supported by a support shaft disposed in the vicinity of the rocker shaft, and that is displaced by the swing of the second arm to drive the first arm. Variable valve gear for engine.   2. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the eccentric shaft is displaced in a circumferential direction of the rocker shaft by the rotation of the rocker shaft by the rotating means. The third arm has a contact surface portion that contacts the first arm,
The variable valve operating apparatus for an internal combustion engine according to claim 2, wherein the contact surface portion includes a conversion surface portion whose distance from the center of the support shaft changes in a swinging direction of the third arm.   4. The variable valve operating apparatus for an internal combustion engine according to claim 3, wherein the contact surface portion has a non-converting surface portion whose distance from the center of the support shaft does not change in the swing direction of the third arm. The eccentric shaft is provided on both sides of a support portion where the rocker shaft supports the first arm, and
A bifurcated shaft support portion is provided on the second arm so as to straddle the first arm,
The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein the eccentric shaft is fitted into the bifurcated shaft support portion. The rocker shaft is provided with the eccentric shaft on one side of a support portion for supporting the first arm, and
The second arm is provided with one shaft support so as not to directly interfere with the first arm,
The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein the eccentric shaft is fitted into the shaft support portion.

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