KR20090121692A - Continuously variable valve lift system for engines and controlling method thereof - Google Patents

Abstract

PURPOSE: A continuously variable valve lifting device of an engine and a control method thereof are provided to prevent degradation of fuel rate by friction. CONSTITUTION: A continuously variable valve lifting device comprises an eccentric cam(20), a locker arm(30), a fluctuation cam(40), a fluctuation cam link(50), a variable lever and a linking unit. The eccentric cam is installed in an eccentric cam shaft(10). The locker arm is installed in the eccentric cam. The fluctuation cam link links the locker arm and the fluctuation cam. The variable lever is installed in the eccentric cam shaft.

Description

Continuously variable valve lift system for engines and controlling method

The present invention relates to a continuous variable valve lift apparatus of an engine and a control method thereof.

In general, the function of the intake / exhaust valve of the engine is to control the flow of intake and exhaust in the cylinder, and to maintain airtightness in the cylinder.

That is, during the compression stroke and the explosion stroke, both the intake / exhaust valves are closed to maintain airtightness in the cylinder, and during the intake stroke and the exhaust stroke, only the intake valve or the exhaust valve is opened, respectively, to intake fuel gas and discharge the combustion gas.

Opening and closing of the valve is made by pressing the end of the valve through the rocker arm (swing arm) formed on the cam shaft, the cam shaft is rotated by receiving the rotational force of the crankshaft through the timing chain or the timing belt.

On the other hand, an important factor that determines the airtightness of the valve, the amount of intake / exhaust gas, etc. is a valve lift, which means the distance that the valve face is away from the valve seat.

In general, the larger the valve lift in the case of the intake valve, the larger the amount of outside air or fuel gas is introduced into the cylinder during inhalation. .

On the other hand, it is a continuous variable valve lift apparatus which can continuously change the said valve lift through the motor and the mechanism of a predetermined structure.

Continuously variable valve lift devices (CVVLs) are developed in various forms for each automobile manufacturer, and although they may be named differently, they are all operated with high valve lift and low valve lift. It aims to improve the effectiveness of the continuously variable valve lift system (improving engine power and improving fuel economy) through smooth transition of states and control of high / low valve lift and lost motion angle.

However, when the low lift swing angle is larger than the high lift swing angle in the CVVL, the friction loss caused by the return spring increases during the low lift operation, thereby lowering fuel economy.

In addition, the conventional CVVL has a problem that it is difficult to actually implement a continuous variable valve lift device having an advance function because the lost motion angle is excessively increased even when there is no advance function of the valve timing or the advance function.

Accordingly, the present invention has been made in view of the above matters, and the high lift swing angle is larger than the low swing swing angle through friction control of the high / low valve lift operation state and precise control of the valve lift and lost motion angle. The purpose is to prevent fuel loss from loss, reduce the lost motion angle to the optimum condition, facilitate the implementation of CVVL, and ensure that the progressive effect can be generated despite the loss of the lost motion angle.

The present invention for achieving the above object, the rocker arm rotatably installed with respect to the eccentric cam; An eccentric cam shaft fixed in an eccentric position with respect to the eccentric cam; A rocking cam rotatably installed with respect to the eccentric cam shaft to provide an actuation force to the intake / valve valves; A rocking cam link connecting between one end of the rocker arm and one end of the rocking cam; A variable lever installed with the eccentric cam shaft as a fixed point to form a variable pivot point for variably adjusting the position of the contact point with the drive cam installed on the cam shaft according to the rotation angle of the eccentric cam shaft; And a two-section link mechanism for connecting between the other end of the rocker arm and the variable pivot point of the variable lever at the contact point.

One end of the rocker arm and one end of the rocking cam link is axially coupled to a position spaced apart from each other in the axial direction on the connecting axis.

The two-stage link mechanism is characterized by consisting of a swinging roller link, one end of which is hinged to the other end of the rocker arm, and a variable lever link of which one end is hinged to the variable pivot point of the variable lever.

The variable pivot point is formed on the pivot end of the variable lever, the variable pivot point is formed on the axis of the variable lever link shaft for axially connecting the pivot point of the variable lever and the pivot point of the variable lever link. It is done.

The contact point is set at the coupling portion between the other end of the swing roller link and the swing end of the variable lever link, the contact point is characterized in that the rocking roller in rolling contact with the drive cam is installed.

In addition, the present invention is a rocker arm rotatably installed with respect to the eccentric cam and having a top / bottom connection; An eccentric cam shaft fixed in an eccentric position with respect to the eccentric cam; A rocking cam rotatably installed with respect to the eccentric cam shaft to provide an actuation force to the intake / valve valves; An oscillating cam link having one end hinged to an upper end connecting portion of the oscillating cam and the other end being axially connected to the upper connecting portion of the rocker arm via a connecting shaft; A variable lever installed with the eccentric cam shaft as a fixed point to form a variable pivot point for variably adjusting the position of the contact point with the drive cam installed on the cam shaft according to the rotation angle of the eccentric cam shaft; A rocking roller link having one end hinged to a bottom connection portion of the rocker arm; And a variable lever link for mounting a swing roller in contact with the drive cam so that one end is hinged to the variable pivot point of the variable lever and the other end is hinged to the other end of the swing roller link to form the contact point. Characterized in that.

The present invention also provides a rocker arm rotatably mounted to the eccentric cam and having a left / right connection; An eccentric cam shaft fixed in an eccentric position with respect to the eccentric cam; A swinging cam pivotally mounted to the eccentric camshaft to provide an actuation force to the intake / valve valve; A rocking cam link connecting the left connection of the rocker arm and one end of the rocking cam; A variable lever installed with the eccentric cam shaft as a fixed point to form a variable pivot point for variably adjusting the position of the contact point with the drive cam installed on the cam shaft according to the rotation angle of the eccentric cam shaft; A rocking roller link having one end hinged to a right connection portion of the rocker arm; And a variable lever link for mounting a swing roller in contact with the drive cam so that one end is hinged to the variable pivot point of the variable lever and the other end is hinged to the other end of the swing roller link to form the contact point. Characterized in that.

In addition, the present invention is a rocker arm rotatably installed with respect to the eccentric cam and having an upper / lower connection at one side; An eccentric cam shaft fixed in an eccentric position with respect to the eccentric cam; A rocking cam rotatably installed with respect to the eccentric cam shaft to provide an actuation force to the intake / valve valves; A rocking cam link connecting the bottom connection portion of the rocker arm and one end of the rocking cam; A variable lever installed with the eccentric cam shaft as a fixed point to form a variable pivot point for variably adjusting the position of the contact point with the drive cam installed on the cam shaft according to the rotation angle of the eccentric cam shaft; One end of the rocker arm is hingedly coupled to one end of the rocker arm, and the other end is equipped with a rocking roller in rolling contact with the drive cam so as to form the contact point. And a variable lever link that is hinged to the variable pivot point of the variable lever therebetween.

In addition, the present invention is characterized in that it further comprises a return spring for maintaining the contact state between the rocking roller and the drive cam by supporting the rocking cam in the installation direction of the drive cam.

According to the present invention having the configuration described above, the high lift swing angle can be made larger than the low lift swing angle, thereby preventing the fuel consumption from being lost due to the friction loss caused by the return spring in the low lift operation state, and making the lost motion angle the optimum condition. Since it can be reduced, CVVL can be easily implemented, and the progressive effect can be reliably generated despite the loss of lost motion angle.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

1 to 12 respectively show a continuous variable valve lift apparatus of an engine according to an embodiment of the present invention.

The eccentric cam shaft 10 is connected to a CVVL motor (hereinafter referred to as a motor) capable of continuously controlling the rotation angle like a step motor, and variably adjusting the rotation angle, and the eccentric cam 20 in the middle portion. ) Is integrally mounted. The outer circumferential surface shape of the eccentric cam 20 is circular. The eccentric cam 20 is accommodated in the inner circumferential surface of the rocker arm 30, the hole forming the inner circumferential surface is of course formed in the same size and shape as the eccentric cam 20. (There is a clearance gap for rotating the eccentric cam) For this purpose, the eccentric cam 20 is fitted and coupled to the eccentric cam shaft 10, and the rocker arm 30 is rotatably installed on the eccentric cam 20.

At this time, the axial center (X-1) of the eccentric cam 20 and the axial center (X-2) of the eccentric cam shaft 10 is set to be spaced apart from each other. That is, the rocker arm 30 is pivotally installed on the basis of the axial center X-1 of the eccentric cam 20, and the eccentric cam shaft 10 has the axial center X-2 of the rocker arm 30. It is set to a position eccentrically by a predetermined amount from the axial center X-1 of the eccentric cam 20, and the oscillation cam 40 is pivotable about the axial center X-2 of the eccentric cam shaft 10. It is installed so as to receive the pressing force provided from the rotation of the drive cam (1) to provide the operating force required when opening and closing the intake / valve valve.

The rocker arm 30 has a hinge pin connecting portion that can be connected to the hinge pin at both ends of the body. In this embodiment, the hinge pin connecting portions of both ends of the body of the rocker arm 30 are installed so as to be positioned above and below the eccentric camshaft 10, respectively. The eccentric cam shaft 10 is rotatably mounted to the rocking cam 40 at the side of the rocker arm 30.

The swing cam 40 has a circular mounting portion in which a hole through which the eccentric cam shaft 10 penetrates is formed, and is formed in a substantially triangular shape at the lower portion of the swing cam roller 10 to the swing arm roller 2 of the swing arm 3. The valve operation portion is in contact with the valve operation portion is formed on the lower surface of the cam profile for high lift and low lift operation.

In addition, the rear surface of the valve operation part (the opposite direction of the driving cam 1) is supported by the return spring 110, and more particularly, the return spring 110 may move the swing cam 40 to the driving cam. (1) is elastically supported toward the installation direction of (1) to maintain the contact between the swinging roller 100 and the drive cam (1) at all times. (See Fig. 2, the return spring of the swinging cam is shown only in Fig. Not shown in the rest of the drawing.)

In addition, the swing cam 40 has a hinge pin connecting portion protruding upwardly to connect a hinge pin to an upper end of the mounting portion, and the hinge pin connecting portion and one side hinge pin connecting portion of the rocker arm 30 are eccentric. The upper portion of the cam shaft 10 is connected to the swing cam link 50 in the shape of a tracer. That is, the rocking cam link 50 is connected between one end of the rocker arm 30 and one end of the rocking cam 40, more specifically, both ends of the rocking cam link 50 The hinge pin is rotatably connected to the hinge pin connecting portion of the rocker arm 30 and the swinging cam 40. In particular, one end of the rocker arm 30 and one end of the rocking cam link 50 is axially connected via a connecting shaft (S), one end of the rocker arm 30 and the rocking cam link ( One end of 50) is axially coupled to a position spaced apart from each other in the axial direction on the connection axis (S) line.

On the other hand, the eccentric cam shaft 10 is integrally mounted to one side end of the variable lever 60 to the side of the swing cam 40. Therefore, when the eccentric cam shaft 10 is rotated by a motor, the eccentric cam 20 and the variable lever 60 are rotated at the same time. The other end of the variable lever 60, that is, the free end not mounted to the eccentric cam shaft 10 is installed in a substantially horizontal direction so that the variable lever link 80 is rotatably mounted via the variable lever link shaft 70. do.

In other words, one end of the variable lever 60 is installed with the shaft center (X-2) of the eccentric cam shaft 10 as a fixed point, and according to the rotation angle of the eccentric cam shaft 10, the cam shaft 1a. A variable pivot point (X-3) for variably adjusting the position of the contact point (X-4) with the drive cam (1) installed in the) is formed at the other end side free end. That is, the variable pivot point X-3 is formed at the pivot end of the variable lever 60, and the variable pivot point X-3 is the pivot end of the variable lever 60 and the variable lever link 80. Is formed on the axis of the variable lever link shaft 70 for axially connecting the pivot points of the shaft, and the contact point (X-4) is the other end of the swinging roller link 90 to be described later and the variable lever link (80). Is set at the joint between the pivot ends.

The two-section link mechanism connects the other end of the rocker arm 30 and the variable pivot point X-3 of the variable lever 60 at the contact point X-4. The link mechanism includes a variable lever link 80 having one end hinged to the variable pivot point X-3 of the variable lever 60 and a swing roller link having one end hinged to the other end of the rocker arm 30. It consists of 90.

That is, the lower end of the variable lever link 80 and the lower hinge pin connecting portion of the rocker arm 30 are connected to the swing roller link 90. In addition, both ends of the rocking roller link 90, the lower hinge pin connecting portion of the rocker arm 30 and the lower end of the variable lever link 90 are connected to each other through a hinge pin.

On the other hand, the end of the swinging roller link 90 is connected to the variable lever link 80 is provided with a swinging roller 100 in contact with the drive cam (1) receives the operating force. That is, the rocking roller 100 is installed so as to make a rolling contact with the drive cam 1 in a state capable of idling at the contact point (X-4). One end of the swing arm 3 is in contact with the top of the stem of the valve 4, and the other end is connected to a hydraulic lash adjuster 5.

The structure of the continuous variable valve lift apparatus of the engine according to an embodiment of the present invention is provided with a rocker arm 30 rotatably installed about the axial center X-1 of the eccentric cam 20 and having upper and lower connections. And an eccentric cam shaft 10 fixed at an eccentric position with respect to the axial center X-1 of the eccentric cam 20 and pivotable about the axial center X-2 of the eccentric cam shaft 10. Oscillating cam 40, which is installed so as to provide an actuation force to the intake / valve valve, one end is hinged to the upper connection portion of the swing cam 40, the other end is connected to the upper connection and the connecting shaft (S) of the rocker arm 30 (S) Rotation cam link 50 which is axially connected via a), the shaft center (X-2) of the eccentric cam shaft 10 is installed as a fixed point cam shaft according to the rotation angle of the eccentric cam shaft 10 Variable lever 60 for forming a variable turning point (X-3) for variably adjusting the position of the contact point (X-4) with the drive cam (1) installed in (1a), the Oscillating roller link 90, one end of which is hinged to the lower connection portion of the rocker arm 30, and one end hinged to the variable pivot point (X-3) of the variable lever 60 and the other end of the rocking roller link A variable lever link (80) is mounted to the other end of the hinge (90) to mount the swinging roller (100) in rolling contact with the drive cam (1) to form the contact point (X-4).

Embodiments of the above configuration operate as follows. (A) and (b) of FIG. 7 are operation state diagrams of the high lift state, FIG. 8 (a) and (b) are the inner side views thereof, and FIG. 9 (a) and (b) of the low lift state Fig. 10 (a) and Fig. 10 (b) are inner side views thereof.

As shown in FIG. 7A, the variable lever 60 and the swinging roller link 90 are approximately horizontal in the high lift state, and the variable lever link 80 connecting them is approximately vertical, and the swinging roller link is substantially vertical. The rocking roller 100 provided at the end of the 90 is located at the same height as the center of the drive cam 1.

In the state of (a) before the operating force is applied to the rocking roller 100 by the drive cam 1, the rocking cam 40 has a high inclined slope formed at the bottom of the high lift operation (a; rocking cam). In the middle of the ascending slope in the groove), if the swinging roller 100 is pushed by the cam nose while the drive cam (1) rotates, the swinging roller link (90) pushes the lower end of the rocker arm (30), The rocker arm 30 is rotated in the clockwise direction with respect to the axial center (X-1) of the eccentric cam 20, the rocking cam link 50 by pushing the top of the rocking cam 40 rocking cam 40 The swing arm roller 2 is pressed against the shaft center X-2 of the eccentric camshaft 10 while being rotated clockwise to open the swing arm 3 by pressing the valve (Fig. 12 (a). ))

At this time, since the swing roller 100 is positioned at the center height of the drive cam 1 and the swing roller link 90 is disposed in a horizontal state, the amount of movement of the swing roller link 90 by the drive cam 1 is increased. Large, and the amount of rotation of the rocking cam 40 by the rocker arm 30 and the rocking cam link 50 is large, as shown in Figure 7 (b) while the rocking cam 40 is rotated to the end (b) of the lower side The swing arm roller (2) is pressed until this occurs and high lift occurs.

The transition from the high lift operation state to the low lift operation state by the motor operation is performed as follows.

When the variable lever 60 rotates clockwise integrally with the eccentric cam shaft 10 as shown in FIG. 9 (a), the swing roller 100 descends together with the variable lever link 80. Accordingly, the rocking arm 40 is rotated counterclockwise by the rocking roller link 90 being pulled downward in the inclined state and the rocking cam 40 rotates through the rocking cam link 50. Pull the top of the pivoting cam 40 to rotate in the counterclockwise direction. That is, when the variable lever 60 is rotated clockwise as the eccentric cam shaft 10 rotates, the turning point X-3 of the variable lever 60 is lowered compared to the high lift operating state. At this time, the installation state of the rocker arm 30 is also linked by the change of the position of the axial center X-1 of the eccentric cam 20 with respect to the axial center X-2 of the eccentric cam shaft 10. Will change. That is, when the rocker arm 30 is rotated counterclockwise based on the axis center X-1, the lower end of the rocker arm 30 pushes the rocking roller link 90, thereby The position of the contact point X-4 between the variable lever link 80 and the swinging roller link 90 is closer to the operation cam 1 in the lowered state compared to the high lift operation state. b))

Accordingly, the swing cam 40 moves to the low loft operation start position (c; the start position of the rising slope in the groove of the gentle slope formed on the bottom of the swing cam), and the movement angle is the lost motion angle. angle).

In the low loft operation state as described above, since the swing roller 100 is lowered than the center of the drive cam 1 and the swing roller link 90 is inclined, the swing roller link 90 by the drive cam 1 is inclined. The amount of horizontal sliding is not large.

Therefore, when the rocker arm 30 is pushed by the swinging roller link 90, the amount of rotation is not large, and thus the amount of clockwise rotation of the swinging cam 40 via the swinging cam link 50 is not large. . In addition, the swing cam 40 reciprocates in a narrow range from the swing arm roller 2 in contact with its lower surface to the intermediate position d of the descending slope in a groove of a gentle slope formed on the lower side. Therefore, the amount of pressing of the swing arm roller 2 by the swinging cam 40 is reduced, so that the amount of pressing of the valve 4 by the swing arm 3 is also reduced, thereby reducing the lift of the valve 4.

In addition, in the above low loft operation state, as described above, since the swing roller 100 descends and moves in a direction opposite to the rotational direction of the drive cam 1, the valve opening point by the drive cam 1 is advanced. A progressive state is implemented.

On the contrary, when the forward lever 60 is rotated counterclockwise as in the high lift state and the swinging roller 100 is moved toward the rotational direction of the drive cam 1, the perceptual state in which the valve opening point by the drive cam 1 is slowed down. Is implemented.

FIG. 13 is a graph illustrating a valve lift according to a variable lever operating angle when eccentric cams having various eccentric directions and eccentric amounts are applied.

As shown in the graph, various variable valve control characteristic curves can be obtained by adjusting the direction and the amount of eccentricity of the eccentric cam, and in particular, the present invention provides a variable valve control as in (B) compared to the conventional case in which the eccentric cam is fixed. We can find a case where the characteristic curve has linearity. Thus, design and manufacturability can be improved and valve lift control performance can be improved.

In addition, according to the present invention, as shown in Figures 14 and 15, according to the eccentric amount and the eccentric direction of the eccentric cam 20, the high lift swing angle is larger than the low swing swing angle, and at the same time can find a design region having an optimal lost motion angle Will be. In FIG. 14, it can be seen that a section in which the high lift swing angle is larger than the low swing swing angle exists in the range in which the lost motion angle is the lowest according to the eccentric amount of the eccentric cam, and the lost motion angle is optimal according to the eccentric direction in FIG. 15. It can be seen that there is a section in which the high lift swing angle is larger than the low lift swing angle.

That is, according to the application of the eccentric cam 20, the high lift swing angle of the swing cam 40 is made larger than the low swing swing angle, and the lost motion angle is smaller than the low swing swing angle so as to realize a state as shown in FIG. do. Since the return spring of the oscillation cam 40 is installed in accordance with the high lift swing angle, if the low swing swing angle is larger than the high lift swing angle, the reaction force of the return spring is strongly acted in the low lift operation state to increase the friction, thereby reducing fuel economy. .

However, when the high lift swing angle can be implemented to be larger than the low swing swing angle as in the present invention, the reaction force of the return spring is not increased in the low lift operation state, thereby preventing the fuel economy from being lowered due to the friction increase.

On the other hand, if the lost motion angle is larger than the low swing angle, the CVVL implementation is impossible (when the lost motion angle is greater than the low angle, the swing swing of the swing cam starts in the air). The optimum range smaller than this low swing swing angle can be found, making it easy to implement CVVL and apply it to a real engine.

That is, the present invention can precisely control the valve lift operation angle (also referred to as the high lift swing angle and the low swing swing angle) and the lost motion angle by adjusting the eccentric amount and the eccentric direction of the eccentric cam as described above.

In addition, since the position of the swinging roller 100 can be moved to the opposite side of the rotational direction of the drive cam 1 by the variable lever 60 and the variable lever link 80, it is possible to reliably implement the advance function in the loft operation state. It becomes possible.

That is, in the present invention in which the eccentric cam 20 and the progressive lever 60 are interlocked, the valve lift operation angle and the lost motion angle can be precisely controlled to maximize the advance effect, thereby improving the CVVL effect.

FIG. 17 illustrates another embodiment of the present invention, in which an eccentric cam 21 is integrally mounted to the eccentric cam shaft 11, and the locker is mounted in a rotatable state by receiving the eccentric cam 21 on an inner circumferential surface thereof. Hinge pin connecting portions 31a and 31b protrude from both sides of the body of the arm 31, and the hinge pin connecting portions 31a and 31b are disposed in the left and right directions. That is, the hinge pin connecting portions 31a and 31b form the left / right connecting portions at both sides of the rocker arm 31. The rocker arm 31 is pivotally mounted with respect to the axial center X-1 of the eccentric cam 21. The eccentric camshaft 11 is fixed at an eccentric position with respect to the axial center X-1 of the eccentric cam 21.

The oscillation cam 41 is rotatably installed on the eccentric cam shaft 11, and a protruding end for pressing the swing arm roller 2 during the high lift operation is formed in a direction opposite to the driving cam 1, and the protrusion An end portion and a hinge pin connecting portion 31a formed in a direction opposite to the drive cam 1 of the rocker arm 31 are connected via the swing cam link 51. That is, the swing cam 41 is pivotally installed with respect to the axial center X-2 of the eccentric cam shaft 11 to provide operation power to the intake / valve valve. The rocking cam link 51 connects between the left connection portion of the rocker arm 31 and one end of the rocking cam 41.

In addition, the variable lever 61 is integrally disposed on the eccentric cam shaft 11 so as to face vertically upward, and the variable lever link 81 is connected to the variable lever 61 via the variable lever link shaft 71. Is rotatably connected, and the variable lever link 81 extends to an upper portion of the drive cam 1, and a hinge pin connecting portion toward the drive cam 1 of the rocker arm 31 via the rocking roller link 91; 31b). That is, the variable lever 61 is installed with the shaft center (X-2) of the eccentric cam shaft 11 as a fixed point and is installed on the cam shaft 1a according to the rotation angle of the eccentric cam shaft 11. A variable pivot point X-3 for variably adjusting the position of the contact point X-4 with the drive cam 1 is formed.

A rocking roller 101 is provided at an end of the variable lever link 81 of the rocking roller link 91, and the rocking roller 101 is in contact with an upper portion of the drive cam 1. That is, the swinging roller link 91 is hinged at one end to the right connection portion of the rocker arm 31. The variable lever link 81 is hinged to one end of the variable pivot point (X-3) of the variable lever 61 and the other end is hinged to the other end of the swinging roller link 91 to the contact point ( X-4) is mounted with a swing roller 101 in rolling contact with the drive cam (1).

In the above embodiment, the swing arm roller 2 is in contact with the high lift operation start position of the lower side of the swing cam 41 in the arrangement state as described above.

When the driving cam 1 is rotated in this state, as the swinging roller 101 is raised, the swinging roller link 91 pulls the hinge pin connecting portion 31b upward toward the driving cam 1 so that the rocker arm 31 ) Is rotated counterclockwise, and the hinge pin connecting portion 31b opposite the driving cam 1 rotates the swinging cam 41 via the swinging cam link 51 to achieve a high lift swing.

In this state, when the eccentric cam shaft 11 is rotated counterclockwise by the motor, the rocking roller 101 is moved downward in the indicated forward direction so that the rocker arm 31 rotates clockwise to swing rocking cam link 51. Pulls the swinging cam 41 to rotate clockwise. Therefore, the contact of the swing arm roller 2 on the lower surface of the swing cam 41 is moved from the high lift operation start position toward the drive cam 1 to move to the low lift operation start position.

In this state, since the swinging roller 101 is lowered than in the high lift operation state, the amount of swinging the roller 101 is small when the driving cam 1 rotates, and thus the rocker arm 31 by the swinging roller link 91 is formed. The counterclockwise rotation of the also decreases and eventually the swing angle of the swinging cam 41 is reduced to perform a low lift operation. That is, a state in which the high lift swing angle is larger than the low lift swing angle may be implemented.

The structure of the continuous variable valve lift apparatus of the engine according to another embodiment of the present invention is provided with a rocker arm 31 rotatably installed with respect to the axial center X-1 of the eccentric cam 21 and having left and right connections. And an eccentric cam shaft 11 fixed at an eccentric position with respect to the axial center X-1 of the eccentric cam 21 and pivotable about the axial center X-2 of the eccentric cam shaft 11. Rocking cam 41 which is installed so as to provide an actuation force to the intake / valve valve, rocking cam link 51 for connecting between the left connection of the rocker arm 31 and one end of the rocking cam 41, the eccentricity The contact point X with the drive cam 1 installed on the cam shaft 1a according to the rotational angle of the eccentric cam shaft 11 is installed with the shaft center X-2 of the cam shaft 11 as a fixed point. A variable lever 61 forming a variable pivot point X-3 for variably adjusting the position of -4), and one end of the rocker arm 31 is hinged at one end thereof. One end is hinged to the swinging roller link 91 and the variable pivot point X-3 of the variable lever 61 and the other end is hinged to the other end of the swinging roller link 91 so that the contact point ( And a variable lever link (81) for mounting the swing roller (101) in rolling contact with the drive cam (1) to form X-4).

18 is another embodiment of the present invention. The eccentric cam 22 is integrally mounted to the eccentric cam shaft 12, and the rocker arm 32 is mounted in a state in which the eccentric cam 22 is accommodated on the inner circumferential surface and is rotatable. The rocker arm 32 has two hinge pin connecting portions 32a and 32b formed at predetermined angles on the opposite side of the drive cam 1, and the length of the upper hinge pin connecting portion 32b is higher than the lower hinge pin connecting portion 32a. Is formed long. That is, the rocker arm 32 is pivotally installed with respect to the axial center (X-1) of the eccentric cam 22 and has an upper / lower connection part at one side, and the upper / lower connection part is a hinge pin connection part ( 32a, 32b).

The swing cam 42 is rotatably mounted to the eccentric cam shaft 12, and the swing cam 42 also has a protruding end for pressing the swing arm roller 2 in a high lift operation state of the drive cam 1. It is formed in the opposite direction and is connected to the lower hinge pin connecting portion (32a) via a rocking cam link (52). Of course, the relative rotation between the parts connected by the hinge pin is possible. That is, the eccentric camshaft 12 is fixed to the eccentric position with respect to the axial center X-1 of the eccentric cam 22. The swing cam 42 is pivotally installed with respect to the axial center X-2 of the eccentric cam shaft 12 to provide an actuation force to the intake / valve valve. The rocking cam link 52 connects between the lower end connecting portion of the rocker arm 32 and one end of the rocking cam 42.

The variable lever 62 is installed to be integrally rotated to the eccentric cam shaft 12 in a vertically upright state, and the variable lever link 82 of an oblique angle bent at an end of the variable lever 62 is formed. The variable lever link shaft 72 is rotatably mounted, and the hinge pivot point by the variable lever link shaft 72 becomes a bent portion. That is, the variable lever 62 is installed with the shaft center (X-2) of the eccentric cam shaft 12 as a fixed point and is installed on the cam shaft 1a according to the rotation angle of the eccentric cam shaft 12. A variable pivot point X-3 for variably adjusting the position of the contact point X-4 with the drive cam 1 is formed.

The drive cam 1 side portion of the variable lever link 82 is formed to have a relatively longer length than the opposite portion and extends toward the upper side of the drive cam 1, and the swing roller 102 is rotatable at the end thereof. It is mounted and in contact with the top of the drive cam (1).

The opposite side of the drive cam 1 of the variable lever link 82 is formed to have a relatively shorter length than the portion provided with the swinging roller 102, and the upper hinge pin connecting portion 32b of the rocker arm 32 is formed. The hinge pins are connected to each other in a rotatable manner. That is, the variable lever link 82 is hinged to an upper end connecting portion of the rocker arm 32 and is in contact with the driving cam 1 so as to form the contact point X-4 at the other end. The swinging roller (102) is mounted, and the variable pivot point (X-3) and the hinge of the variable lever (62) between the upper connection point of the rocker arm (32) and the installation point of the swinging roller (102). Combined.

In the above embodiment, the swing arm roller 2 is in contact with the high lift operation start position of the lower side of the swing cam 41 in the arrangement state as described above.

In this state, when the driving cam 1 is rotated (clockwise), the swinging roller 102 is raised so that the variable lever link 82 rotates counterclockwise around the variable lever link shaft 72, and thus the variable lever. The rocker arm 32 is rotated in the same counterclockwise direction as the opposite end of the link 82 presses the upper hinge pin connecting portion 32b, so that the lower hinge pin connecting portion 32b of the rocker arm 32 moves to the rocking cam link. The high lift operation is achieved by rotating the swing cam 42 through a counterclockwise direction 52.

In this state, when the eccentric cam shaft 12 is rotated by a motor and the variable lever 62 is rotated counterclockwise by a predetermined angle (about 11 o'clock), the swinging roller 102 moves downward of the drive cam 1. A true state is realized, and at the same time, the variable lever link 82 is rotated clockwise in response to the downward movement of the rocking roller 102 so that the upper hinge pin connecting portion 32b is pulled so that the rocker arm 32 is in the same direction. The swing cam 42 is pulled by the swing cam link 52 and rotates clockwise so that the contact point of the swing arm roller 2 at the lower surface of the swing cam 42 is at the high lift start position. It will move to the starting position of the low lift operation.

In the state where the swinging roller 102 is lowered along the driving cam 1 surface as described above, the rocker arm 32 by the variable lever link 82 because the amount of rising of the swinging roller 102 is small when the driving cam 1 rotates. ), The amount of rotation of the swing cam 42 by the swing cam link 52 is also reduced, so that the size of the low swing swing angle is smaller than that of the high lift swing angle.

The structure of the continuous variable valve lift apparatus of the engine according to another embodiment of the present invention is provided with a rocker arm rotatably installed with respect to the axial center (X-1) of the eccentric cam 22 and having an upper / lower connection at one side. And an eccentric cam shaft 12 fixed to a position eccentric with respect to the axial center X-1 of the eccentric cam 22, and an axial center X-2 of the eccentric cam shaft 12. Oscillating cam 42 that is pivotally mounted to provide an actuation force to the intake / valve valve, oscillating cam link 52 connecting between the lower connection of the rocker arm 32 and one end of the oscillating cam 42 And a contact point with the drive cam 1 installed on the cam shaft 1a according to the rotation angle of the eccentric cam shaft 12, which is installed with the shaft center X-2 of the eccentric cam shaft 12 as a fixed point. One end of the variable lever 62 forming the variable turning point X-3 for variably adjusting the position of the point X-4, and the upper connection portion of the rocker arm 32. It is hinged and mounted to the other end of the rocking roller 102 in rolling contact with the drive cam 1 to form the contact point (X-4), the upper connection point of the rocker arm 32 and the swing And a variable lever link 82 hinged with the variable pivot point X-3 of the variable lever 62 between the installation point of the roller 102.

Hereinafter, a control method of a continuous variable valve lift apparatus of an engine according to the present invention will be described in detail.

As shown in Fig. 19, changes in the engine speed, the throttle opening degree, and the intake pressure are respectively detected in the start-up state. (S10 to S13)

Subsequently, the current load condition of the vehicle corresponding to the engine speed, the throttle opening degree, and the intake air pressure detected in the process is determined.

Subsequently, an opening / closing timing and a valve lift of the intake / valve valve corresponding to the load condition determined in the above process are calculated.

Subsequently, the opening / closing timing of the intake / valve valve and the valve lift are adjusted according to the opening / closing timing of the intake / valve valve and the valve lift calculated in the above process (S16). It is implemented by the operation signal output to the driver (CVVL motor).

Next, the opening and closing timing of the intake / valve valve and the change in the valve lift performed in the above process are detected.

Subsequently, the opening / closing timing of the intake / valve valve and the valve lift value detected in the above process are compared with the opening / closing timing of the intake / valve valve calculated in the above step and the calculated value of the valve lift. If it is in the range of, control is terminated, and if it is out of the setting error, the following process of calculating the opening / closing timing and valve lift of the intake / valve valve corresponding to the load condition is repeated.

On the other hand, the process of determining the load condition is made by reading from the map data that is stored in advance by presetting and storing the change in the engine speed, the throttle opening degree and the intake pressure during driving.

1 is a front view of the present invention,

2 is a rear view of FIG. 1;

3 is a perspective view of the present invention,

Figure 4 is a perspective view of the variable lever removed in Figure 3,

5 is a perspective view of the variable lever link and its connecting shaft in Figure 4 removed,

FIG. 6 is a perspective view of a state in which one rocking cam and a rocking cam link are removed from FIG. 5; FIG.

(A), (b) is an operating state of the high lift state,

(A), (b) is an inner side view of it,

9 (a) and 9 (b) are diagrams illustrating an operating state of a low lift state,

(A), (b) is an inner side view of it,

11 is a schematic diagram illustrating a coupling relationship for components of the present invention;

FIG. 12 is a schematic diagram showing a change in installation state for each component during the high / low lift shown in FIGS. 7 and 9, respectively.

13 is a variable lever operating angle-valve lift characteristic curve graph according to the eccentric cam,

14 is an eccentric amount of the eccentric cam-swing cam swing angle graph,

15 is a swing angle graph of the eccentric direction-swing cam of the eccentric cam,

16 is a schematic diagram showing the relationship between a high lift swing angle, a low swing swing angle, and a lost motion angle;

17 and 18 are diagrams showing a high lift state as other embodiments of the present invention,

19 is a flowchart illustrating a control logic according to the present invention.

       * Description of the symbols for the main parts of the drawings *

10: eccentric cam shaft 20: eccentric cam

30: rocker arm 40: rocking cam

50: rocking cam link 60: variable lever

70: variable lever link shaft 80: variable lever link

90: rocking roller link 100: rocking roller

110: return spring

Claims (16)

An eccentric cam installed eccentrically on the eccentric cam shaft; A rocker arm pivotally mounted to the eccentric cam; A swinging cam pivotally mounted to the eccentric camshaft; A rocking cam link interlocking between the rocker arm and the rocking cam; A variable lever pivotally mounted to the eccentric camshaft; A continuously variable valve lift apparatus for an engine having a two-section link mechanism for connecting between the rocker arm and the variable lever. The method according to claim 1, The rocker arm and the rocking cam link is a continuous variable valve lift apparatus of the engine, characterized in that connected via a connecting shaft. The method according to claim 2, The rocker arm and the rocking cam link is hinged coupled to the position spaced apart from each other in the axial direction on the axis of the connecting shaft. The method according to claim 2, The variable lever is a continuous variable valve lift device of the engine, characterized in that connected via the two-section link mechanism and the variable lever link shaft. The method according to claim 4, The two-stage link mechanism comprises a variable lever link hinged to the variable lever link shaft and a swinging roller link hinged to the rocker arm. The method according to claim 5, Continuous variable valve lift apparatus of the engine, characterized in that the rocking roller is installed on the connection portion between the variable lever link and the rocking roller link. An eccentric cam installed eccentrically on the eccentric cam shaft; A rocker arm rotatably mounted to the eccentric cam and having upper and lower ends; A swinging cam rotatably installed on the eccentric camshaft; A connecting shaft connecting the upper connecting portion of the rocker arm and a swinging cam link hinged to the swinging cam; A variable lever link shaft hinged to a variable lever pivotally mounted to the eccentric cam shaft; And a swinging roller installed at a connection portion between a variable lever link hinged to the variable lever link shaft and a swing roller link hinged to a lower end connection portion of the rocker arm. An eccentric cam installed eccentrically on the eccentric cam shaft; A rocker arm pivotally mounted to the eccentric cam and having a left / right connection; A swinging cam rotatably installed on the eccentric camshaft; A connecting shaft connecting a left connecting portion of the rocker arm and a swinging cam link hinged to the swinging cam; A variable lever link shaft hinged to a variable lever pivotally mounted to the eccentric cam shaft; A rocking roller link hinged to a right connection portion of the rocker arm; A continuous variable valve lift apparatus of an engine having a swing roller installed at a connection portion between the variable lever link hinged to the variable lever link shaft and the swing roller link. An eccentric cam installed eccentrically on the eccentric cam shaft; A rocker arm rotatably installed on the eccentric cam and having an upper / lower connection portion at one side thereof; A swinging cam rotatably installed on the eccentric camshaft; A connecting shaft connecting the lower connecting portion of the rocker arm and a swinging cam link hinged to the swinging cam; A variable lever link shaft hinged to a variable lever pivotally mounted to the eccentric cam shaft; And a variable lever link hinged to the variable lever link shaft and having one end connected to an upper connection portion of the rocker arm and a rocking roller mounted at the other end thereof. The method according to any one of claims 6 to 9, And a return spring which supports the swing cam in a shot direction toward the drive cam. The method according to claim 4 or 7 to 9, And the variable lever link shaft is hingedly coupled to the pivoting end of the variable lever. The method according to claim 2 or 7 to 9, And the connecting shaft and the variable lever link shaft are installed in parallel with the eccentric cam shaft, respectively. The method according to any one of claims 6 to 8, The swinging roller is a continuous variable valve lift device of the engine, characterized in that installed in the swing end of the swinging roller link. Detecting a driving state of the vehicle; Determining a load condition corresponding to the driving state of the vehicle detected in the step; Calculating opening and closing timing and valve lift of the intake / valve valve corresponding to the load condition determined in the step; Adjusting the opening and closing timing of the intake / valve valve and the valve lift according to the opening / closing timing of the intake / valve valve and the calculated value of the valve lift calculated in the step; Detecting a change in the opening / closing timing of the intake / valve valve and the valve lift performed in the step; The opening / closing timing of the intake / valve valve detected in the above step and the change value of the valve lift and the calculated value are compared, and the control is terminated if it is within the setting error range. The control method of the continuous variable valve lift apparatus of the engine repeatedly performing the following process of calculating the opening and closing timing and the valve lift. The method according to claim 14, The detecting of the operating state is performed by detecting an engine speed, a throttle opening degree, and an intake pressure. The method according to claim 14, The determining of the load condition is a control method of a continuously variable valve lift apparatus of an engine, characterized in that the predetermined map data through the change in the engine speed, the throttle opening degree and the intake air pressure.

Images