JP2005201149A - Variable valve system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To point varying directions of valve timing following the operating angle variation to the same direction between both cylinder trains. <P>SOLUTION: In the variable valve mechanism of an engine having two cylinder trains of which camshafts 10, 10A and 10B rotate in the same direction, power transmission mechanisms 14A and 14B are disposed in each cylinder train. The power transmission mechanisms 14A and 14B have input members 22A and 22B that contact with cams 12A and 12B and shift in interlock with their rotation, transmit the variation of the positions to open or close valves 2A and 2B, and vary the abutting positions of the input members 22A and 22B on the cams 12A and 12B. Thus, the interlocking state of the rotation of the cams 12A and 12B with opening or closing of the valves 2A and 2B is varied, and the operating angles of the valves 2A and 2B can be varied. The power transmission mechanisms 14A and 14B are arranged so that the varying directions of the abutting positions of the input members 22A and 22B on the cams 12A and 12B when the operating angles are varied are the same with respect to the rotation direction of the cams 12A and 12B between both cylinder trains. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a variable valve operating apparatus in which a valve operating angle can be changed by a mechanical mechanism, and in particular, an engine having two cylinder rows in which the rotational direction of a camshaft is the same between cylinder rows, such as a V-type engine. The present invention relates to a variable valve gear.

2. Description of the Related Art Conventionally, as disclosed in, for example, Patent Document 1, there is known a variable valve operating apparatus that changes a valve operating angle in accordance with an engine operating condition. In the variable valve operating apparatus described in Patent Document 1, a power transmission mechanism is disposed between a rocker arm that supports a valve and a cam provided on a cam shaft. The power transmission mechanism is provided with a protrusion on a control shaft arranged parallel to the camshaft, rotatably supporting the first intervening arm that contacts the rocker arm by the control shaft, and a second intervening arm that contacts the cam. It is configured to be rotatably attached to the protrusion. The tip of the second intervening arm is in contact with the first intervening arm, and the swinging motion of the second intervening arm accompanying the rotation of the cam is transmitted to the rocker arm via the first intervening arm. In this variable valve operating apparatus, the swing start angle of the first intervening arm driven by the second intervening arm by changing the contact position of the control shaft with the cam of the second intervening arm by rotating the control shaft by a small angle. It is possible to change the operating angle of the valve.
JP 2002-371816 A JP 2001-123810 A JP-A-10-169421

  By the way, there is an engine having two cylinder rows such as a V-type engine. In the V-type engine, normally, the valve operating mechanisms provided in both cylinder rows are arranged symmetrically between the cylinder rows. For this reason, when the variable valve operating apparatus as in the prior art is applied to a V-type engine, the power transmission mechanism may be simply arranged symmetrically between the cylinder rows.

  However, in a general V-type engine, cam shafts are arranged symmetrically between the cylinder rows, but the rotation direction is set not in the left-right symmetry between the cylinder rows but in the same direction. For this reason, when the power transmission mechanism is arranged symmetrically between the cylinder rows, the relationship between the change direction of the contact position of the second intervening arm with the cam and the rotation direction of the cam is reversed between the left and right variable valve gears. turn into. That is, for example, when the control shaft is rotated to change the valve operating angle to the small operating angle side, in the power transmission mechanism of one of the cylinder rows, the contact position of the second intervening arm with the cam rotates the cam. In contrast, in the power transmission mechanism of the other cylinder row, the contact position of the second intervening arm with the cam changes to the retard side with respect to the cam rotation direction. End up. As a result, the valve operation timing (valve timing) is advanced on one cylinder row side as the operating angle is changed, but the valve timing is retarded on the other cylinder row side.

  In an engine having a variable valve timing mechanism, the valve timing can be adjusted by variably controlling the phase of the camshaft relative to the crankshaft. As described above, even if the valve timing change direction due to the change in the operating angle is the reverse direction between the two cylinder rows, the valve timing phase difference between the two cylinder rows can be eliminated by controlling the valve timing variable mechanism. Is possible. However, for this purpose, it is necessary to perform different control using the left and right valve timing variable mechanisms. Moreover, since the phase difference of the valve timing between the cylinder rows changes in accordance with the change amount of the operating angle, it is necessary to change the control amount each time. For this reason, the control of the variable valve timing mechanism becomes complicated.

  From the above, when a variable valve gear is mounted on an engine having two cylinder rows, such as a V-type engine, the power transmission mechanism is not simply arranged symmetrically between the cylinder rows. Some contrivance is required to make the change direction of the valve timing accompanying the angle change the same direction between the two cylinder rows.

  The present invention has been made in order to solve the above-described problems, and provides a variable valve apparatus that can change the valve timing change direction in accordance with the change in the working angle between the two cylinder rows. For the purpose.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a variable valve operating apparatus for an engine including two cylinder rows in which the rotation direction of the camshaft is the same between the cylinder rows.
A power transmission mechanism that has an input member that contacts a cam provided on the cam shaft and displaces in conjunction with rotation of the cam, and transmits a change in the position of the input member to the valve to open and close the valve;
Changing the contact position of the input member with the cam to change the interlocking state between the rotation of the cam and the opening and closing movement of the valve, and changing the operating angle of the valve; In preparation for each cylinder row,
In the power transmission mechanism, the change direction of the contact position of the input member with the cam when the operating angle of the valve is changed is the same direction between the two cylinder rows with respect to the rotation direction of the cam. It is characterized by being arranged.

  In addition, according to a second aspect, in the first aspect, the power transmission mechanism changes a contact position of the input member with the cam when the operating angle of the valve is changed to a small operating angle side. Is arranged to be on the advance side with respect to the rotational direction of the cam.

  In a third aspect based on the first aspect, a part of the power transmission mechanism is substantially an axis between the two cylinder rows with respect to a virtual axis parallel to the cam shaft passing through the middle of the two cylinder rows. It is characterized by being arranged symmetrically.

  According to the present invention, the change direction of the contact position of the input member with the cam when the valve operating angle is changed is the same direction between the two cylinder rows with respect to the cam rotating direction. The change direction of the valve timing accompanying the change can be made the same direction between the two cylinder rows. Thereby, the controllability of valve timing control can be improved.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
The variable valve operating apparatus of this embodiment is a variable valve operating apparatus mounted on a V-type engine. Variable valve units are arranged in the left and right cylinder rows, respectively. Here, first, the configuration of the variable valve unit arranged in one cylinder row will be described.

  FIG. 1 is a side view showing the configuration of the variable valve unit 1 according to the first embodiment of the present invention. The variable valve operating unit 1 is arranged in the right cylinder row (cylinder row located on the right side when viewed from the side in which the rotation direction of the crankshaft is clockwise) of the V-type engine. The variable valve unit 1 has a rocker arm type mechanical valve mechanism, and the rotational motion of the camshaft 10 is converted into the rocking motion of the rocker arm 4 by the cam 12 provided on the camshaft 10. Is converted into a reciprocating motion in the vertical direction of the valve 2 supported by the valve. In the variable valve operating unit 1, the rocker arm 4 is not directly driven by the cam 12, but the rocking motion of the rocker arm 4 is interlocked with the profile change of the cam 12 between the cam 12 and the rocker arm 4. An interlocking mechanism (power transmission mechanism) 14 is interposed. The variable valve unit 1 can continuously change the interlocking state between the profile change of the cam 12 and the swinging motion of the rocker arm 4 by variably controlling the interlocking mechanism 14. The operating angle and lift amount of the valve 2 can be continuously changed by changing the swing amount and swing timing of the valve 2.

  The interlocking mechanism 14 includes three arms, a first arm 18, a second arm 20, and a third arm 22 as an input member, and a control shaft 16. The first arm 18 is rotatably connected to one end of the second arm 20 by a control shaft 16. The control shaft 16 is a stationary shaft arranged in parallel with the cam shaft 10, and the second arm 20 is integrally fixed to the control shaft 16 by press-fitting a pin 32 and is protruded upward from the control shaft 16. The position inside is fixed. The third arm 22 is rotatably connected to the other end of the second arm 20 by a pin 24, and hangs down from a connection point with the second arm 20 with its tip directed obliquely downward. A selection roller 28 is rotatably attached to the tip of the third arm 22, and the third arm 22 is in contact with the first arm 18 via the selection roller 28.

  The first arm 18 includes a passive arm 181 disposed so as to be orthogonal to the control shaft 16 at a position away from the control shaft 16, and a driven cam disposed so as to be shifted in the axial direction of the control shaft 16 with respect to the passive arm 181. 182. The passive arm 181 and the driven cam 182 are integrated, and the driven cam 182 is rotatably supported by the control shaft 16 so that it can rotate integrally around the control shaft 16. Although omitted in FIG. 1, a pair of driven cams 182 are provided on both sides of the passive arm 181 (in FIG. 1, only the rear driven cam 182 is shown, and the front driven cam is omitted). The first arm 18 is constituted by one passive arm 181 and driven cams 182 and 182 on both sides thereof.

  The passive arm 181 includes an arm portion 181a extending to the side where the third arm 22 is disposed with respect to the control shaft 16, and an arm portion 181b extending to the opposite side. A passive surface 181 c is formed on the arm portion 181 a so as to face the selection roller 28 located at the tip of the third arm 22. The other arm portion 181b is hung with the other end of the lost motion spring 30 having one end fixed in the space. The lost motion spring 30 is a compression spring, and the passive arm 181 is urged to rotate in the direction of pressing the passive surface 181c against the selection roller 28 around the control shaft 16. The passive arm 181 and the third arm 22 are in contact between the passive surface 181 c and the selection roller 28.

  The driven cam 182 has two surfaces 182a and 182b having different profiles. The non-operation surface 182a, which is one of the surfaces, is formed with a constant distance from the axis of the control shaft 16. The other working surface 182b is provided in the direction of rotation of the first arm 18 by the urging force of the lost motion spring 30 as viewed from the non-working surface 182a (in FIG. 1, the clockwise direction about the control shaft 16). It has been. The working surface 182b is connected so as to be continuous with the non-working surface 182a, and is formed such that the distance from the axis of the control shaft 16 gradually increases in the rotational direction.

  The interlocking mechanism 14 is arranged so that the driven cam 182 of the first arm 18 contacts the rocker roller 6 of the rocker arm 4 and the third arm 22 contacts the cam 12. A cam roller 26 is rotatably attached to an intermediate portion of the third arm 22, that is, between the pin 24 and the selection roller 28, and the cam 12 is in contact with the cam roller 26. The rocker roller 6 is rotatably attached to an intermediate portion of the rocker arm 4. A valve 2 is attached to the end of the rocker arm 4 on the camshaft 10 side with the rocker roller 6 interposed therebetween, and the other end is rotatably supported by a hydraulic lash adjuster 8. The valve 2 is urged in a closing direction, that is, a direction in which the rocker arm 4 is pushed up by a valve spring (not shown), and the rocker roller 6 is pressed against the driven cam 182 of the first arm 18 by this urging force. The variable valve unit 1 is provided with a rocker arm 4 and a valve 2 corresponding to each of the two driven cams 182 and 182, and the variable valve unit 1 simultaneously connects the two valves 2 and 2. It is configured to drive.

  With the configuration described above, the profile change of the cam 12 accompanying the rotation of the cam shaft 10 is first input to the third arm 22 via the cam roller 26 that contacts the cam 12. Since the third arm 22 is pin-coupled to the second arm 20 whose position in the space is fixed, the third arm 22 swings around the pin 24 in accordance with the profile change of the cam 12 inputted. The swinging motion of the third arm 22 is input to the passive arm 181 of the first arm 18 via the selection roller 28. Since the passive surface 181c of the passive arm 181 is always pressed against the selection roller 28 by the biasing force of the lost motion spring 30, the passive arm 181 is centered on the control shaft 16 according to the swinging motion of the third arm 22. Swing. As a result, the driven cam 182 integrated with the passive arm 181 also rotates about the control shaft 16.

  Specifically, first, when the camshaft 10 rotates clockwise from the state shown in FIG. 1, the contact position of the cam roller 26 on the cam 12 moves from the non-operation surface 12a to the operation surface 12b. The third arm 22 is relatively pushed down by the cam 12, and the passive arm 181 is pushed down by the selection roller 28. As a result, the driven cam 182 integrated with the passive arm 181 rotates counterclockwise about the control shaft 16. When the cam shaft 10 further rotates and the contact position of the cam roller 26 on the cam 12 passes the top of the working surface 12b, the passive arm 181 is pushed upward by the urging force of the lost motion spring 30 this time. As a result, the driven cam 182 rotates clockwise about the control shaft 16.

  As the driven cam 182 rotates about the control shaft 16 in this way, the contact position of the driven cam 182 with the rocker roller 6 changes. When the rocker roller 6 is in contact with the non-working surface 182a, the distance from the axis of the control shaft 16 to the surface of the non-working surface 182a is constant. The position within does not change. Therefore, the rocker arm 4 does not swing and the valve 2 is held at a fixed position. In the variable valve operating unit 1, the positional relationship of each part is adjusted so that the valve 2 is closed when the rocker roller 6 is in contact with the non-operation surface 182a.

  When the position of contact with the rocker roller 6 is switched from the non-working surface 182a to the working surface 182b by the rotation of the driven cam 182 in the counterclockwise direction, the rocker arm 4 responds to the profile change of the working surface 182b. It is pushed down and swings counterclockwise around the support point by the hydraulic lash adjuster 8. As a result, the valve 2 is pushed down by the rocker arm 4 and opened. Conversely, when the driven cam 182 rotates in the clockwise direction and the contact position with the rocker roller 6 is switched from the working surface 182b to the non-working surface 182a, the valve 2 is pushed back by the urging force of the valve spring and closed. I speak. Hereinafter, the position where the non-operating surface 182a on the driven cam 182 is switched to the operating surface 182b is referred to as a lift start position.

  The lift of the valve 2 becomes maximum when the cam roller 26 comes into contact with the top of the working surface 12b of the cam 12, and the lift amount depends on the contact position of the driven cam 182 with the rocker roller 6 (hereinafter referred to as the final contact position). Determined. Further, a period during which the contact position of the driven cam 182 with the rocker roller 6 exceeds the lift start position (hereinafter referred to as a lift period) corresponds to the operating angle of the valve 2. The final contact position and the lift period vary depending on the contact position (hereinafter referred to as the initial contact position) of the driven cam 182 with the rocker roller 6 when the cam roller 26 is in contact with the non-working surface 12a of the cam 12. This initial contact position is geometrically determined by the positional relationship of the cam 12, the rocker arm, the first arm 18, the second arm 20, and the third arm 22. Therefore, if this positional relationship can be changed, it becomes possible to change the rocking amount and rocking timing of the rocker arm 4 and to change the operating angle and the lift amount of the valve 2.

  In the variable valve unit 1, the operating angle of the valve 2 and the lift amount are continuously changed by adjusting the rotation angle of the control shaft 16 and making the installation angle of the second arm 20 variable. . That is, when the control shaft 16 rotates, the second arm 20 fixed to the control shaft 16 also tilts about the axis of the control shaft 16, and the tip 24 and the cam shaft 10 are in accordance with the tilt angle. The distance changes. As the distance between the pin 24 and the cam shaft 10 changes, the cam roller 26 of the third arm 22 moves along the circumferential surface of the cam 12 in the circumferential direction of the cam shaft 10. In the case shown in FIG. 1, when the control shaft 16 rotates in the clockwise direction and the distance between the pin 24 and the cam shaft 10 increases, the cam roller 26 rotates around the cam 12 in the counterclockwise direction, that is, in the cam 12. Move forward with respect to the direction of rotation. On the contrary, when the control shaft 16 rotates counterclockwise and the distance between the pin 24 and the cam shaft 10 becomes short, the cam roller 26 rotates around the cam 12 in the clockwise direction, that is, with respect to the rotation direction of the cam 12. Move to the retarded angle side.

  By changing the positions of the pin 24 and the cam roller 26, the position and the inclination angle of the third arm 22 also change, and the position of the selection roller 28 at the tip also changes. As a result, the inclination angle of the passive arm 181 that presses the passive surface 181c against the selection roller 28 changes, and as a result, the rotation angle of the driven cam 182 around the control shaft 16 changes and the rocker of the driven cam 182 changes. The initial contact position with the roller 6 changes. In the case shown in FIG. 1, when the control shaft 16 rotates in the clockwise direction, the third arm 22 tilts in the clockwise direction, and the selection roller 28 moves around the control shaft 16 in the counterclockwise direction. As a result, the driven cam 182 rotates counterclockwise around the control shaft 16 as the inclination angle of the passive arm 181 changes, and the initial contact position of the driven cam 182 with the rocker roller 6 moves away from the working surface 182b. Change direction. Conversely, when the control shaft 16 rotates counterclockwise, the third arm 22 tilts counterclockwise, and the selection roller 28 moves around the control shaft 16 in the clockwise direction. As a result, the driven cam 182 rotates clockwise around the control shaft 16, and the initial contact position changes in a direction approaching the action surface 182b.

  As described above, the final contact position on the working surface 182b that the rocker roller 6 can reach and the lift period during which the rocker roller 6 exceeds the lift start position are determined by the initial contact position of the driven cam 182 with the rocker roller 6. . When the initial contact position is far from the working surface 182b, the final contact position is close to the non-working surface 182b and the lift period is shortened. As a result, the valve opening characteristic of the valve 2 changes to the small operating angle / small lift side. Conversely, when the initial contact position is close to the working surface 182b, the final contact position is far from the non-working surface 182b, and the lift period becomes longer. As a result, the valve opening characteristic of the valve 2 changes to the large working angle / large lift side.

  Therefore, in the variable valve operating unit 1, the valve opening characteristic of the valve 2 is changed to the small operating angle / small lift side by rotating the control shaft 16 in the clockwise direction. At the same time, when the contact position of the cam roller 26 with the cam 12 moves to the advance side with respect to the rotation direction of the cam 12, the valve timing is advanced. Further, when the control shaft 16 rotates counterclockwise, the valve opening characteristic of the valve 2 is changed to the large working angle / large lift side. At the same time, the contact position of the cam roller 26 with the cam 12 moves to the retard side with respect to the rotation direction of the cam 12, whereby the valve timing is retarded.

  Next, the characteristics of the variable valve unit arranged in the other cylinder row (left cylinder row) will be described with reference to FIGS. FIG. 2 is a side view of the variable valve device according to the present embodiment as viewed in the axial direction of the crankshaft. FIG. 3 is a side view of the variable valve device as a comparative example as viewed in the axial direction of the crankshaft. FIG. 4 is a diagram showing the relationship between the valve timing, the operating angle, and the lift amount of the variable valve unit arranged in the other cylinder row in the variable valve device of the present embodiment, and FIG. It is a figure which shows the relationship between the valve timing of a variable valve unit arrange | positioned at a cylinder row | line | column, a working angle, and a lift amount.

  First, in the comparative example, as shown in FIG. 3, the left and right variable valve units 1A and 1C are arranged symmetrically. The variable valve unit 1A on the right side is the variable valve unit 1 shown in FIG. 1 described above, and the variable valve unit 1C on the left side is simply the left and right side of the variable valve unit 1A on the right side. In the variable valve unit 1C on the left side, the valve opening characteristic of the valve 2 is changed to the small working angle / small lift side by rotating the control shaft 16C counterclockwise symmetrically with the variable valve unit 1A. When the control shaft 16C rotates in the clockwise direction, the valve opening characteristic of the valve 2C is changed to the large working angle / large lift side.

  However, the rotational directions of the left and right camshafts 10A and 10C are not symmetrical and are the same direction. For this reason, in the left variable valve unit 1C, the relationship between the moving direction of the cam roller 26C in contact with the cam 12C and the rotation direction of the cam 12C in accordance with the operation of the control shaft 16C is as follows. The relationship in the valve unit 1A is different. In the variable valve unit 1A on the right side, as described with reference to FIG. 1, when the control shaft 16A is rotated clockwise to change the valve opening characteristic of the valve 2A to the small operating angle / small lift side, The contact position of 26A with the cam 12A moves to the advance side with respect to the rotation direction of the cam 12A, and the valve timing is advanced. On the other hand, in the variable valve unit 1C on the left side, when the control shaft 16C is rotated counterclockwise to change the valve opening characteristic of the valve 2C to the small working angle / small lift side, the cam 12C of the cam roller 26C Is moved to the retard side with respect to the rotational direction of the cam 12C, and the valve timing is retarded. The same applies to the case where the valve opening characteristics of the valves 2A and 2C are changed to the large working angle / large lift side, while the valve timing is retarded in the right variable valve unit 1A, whereas the left variable valve unit. In 1C, the valve timing is advanced. That is, in the variable valve device of the comparative example, as shown in FIG. 5, when the valve opening characteristic of the valve 2C is changed to the small operating angle / small lift side, the valve timing is retarded, and the valve opening characteristic of the valve 2C is The valve timing is advanced when it is changed to the large operating angle / large lift side.

  As described above, when the left and right variable valve units 1A and 1C are configured to be bilaterally symmetric, the change direction of the valve timing accompanying the change in the operating angle is reversed between the cylinder rows. On the other hand, in the variable valve operating apparatus according to the present embodiment, the variable valve unit 1B having the configuration as shown in FIG. It is possible to make the same direction between rows. Below, it demonstrates centering on the difference in the structure of left and right variable valve unit 1A, 1B.

  When the left and right variable valve units 1A and 1B are compared, the valve system comprising the valves 2A and 2B, the rocker arms 4A and 4B, and the hydraulic lash adjusters 8A and 8B and the camshafts 10A and 10B The variable valve units 1A and 1B are arranged symmetrically. However, the rotation directions of the camshafts 10A and 10B are not symmetrical and set in the same direction. Further, the interlocking mechanisms (power transmission mechanisms) 14A and 14B are not symmetrically arranged between the left and right variable valve units 1A and 1B, and are cam shafts that pass between the left and right variable valve units 1A and 1B. They are arranged almost symmetrically about an imaginary axis L parallel to 10A and 10B.

  Similarly to the interlocking mechanism 14A of the right variable valve unit 1A, the interlocking mechanism 14B of the left variable valve unit 1B includes three arms, a first arm 18B, a second arm 20B, and a third arm 22B, and a control shaft 16B. It is composed of Among these, the second arm 20B, the third arm 22B, and the control shaft 16B have the same structure as that of the right variable valve unit 1A. However, the positional relationship between the second arm 20B and the third arm 22B with respect to the control shaft 16B is different from that of the right variable valve unit 1A and is substantially symmetric about the virtual axis L as described above. That is, the position of the second arm 20B in the space is fixed while protruding downward from the control shaft 16B, the third arm 22B is rotatably connected to the second arm 20B by the pin 24B, and the tip is raised obliquely upward. In this state, it is disposed between the control shaft 16B and the cam 12B. Further, a cam roller 26B is rotatably attached to an intermediate portion of the third arm 22B, and the cam 12B is in contact with the cam roller 26B.

  The interlocking mechanism 14B of the left variable valve unit 1B is largely different from that of the right variable valve unit 1A in the structure of the first arm 18B. The first arm 18B includes a passive arm 181B and a driven cam 182B. The driven cam 182B is in contact with the rocker roller 6B of the rocker arm 4B while being rotatably supported by the control shaft 16B. The cam profile of the driven cam 182B is different from that of the right side variable valve unit 1A. In the driven cam 182A of the right side variable valve unit 1A, the working surface 182Ab is formed on the inner side (engine center side) with respect to the non-working surface 182Aa. On the other hand, in the driven cam 182B, the action surface 182Bb is formed outside the non-action surface 182Ba. Also, the fixed angle of the passive arm 181B with respect to the driven cam 182B is different from that of the right variable valve operating unit 1A, and the passive arm 181B is fixed to the driven cam 182B with its passive surface 181Bc oriented vertically. The passive arm 181B presses the passive surface 181Bc against the selection roller 28B of the third arm 22B by a biasing force of a lost motion spring (not shown).

  With the configuration as described above, in the variable valve unit 1B, the profile change of the cam 12B accompanying the rotation of the cam shaft 10B is first input to the third arm 22B via the cam roller 26B contacting the cam 12B. The third arm 22B swings about the pin 24B according to the input profile change of the cam 12B, and the swinging motion of the third arm 22B is the passive arm 181B of the first arm 18B via the selection roller 28B. Is input. Since the passive surface 181Bc of the passive arm 181B is always pressed against the selection roller 28B by the biasing force of the lost motion spring, the passive arm 181B swings around the control shaft 16B according to the swinging motion of the third arm 22B. Move. As a result, the driven cam 182B integrated with the passive arm 181B also rotates about the control shaft 16B, and the rocker arm 4B swings according to the change in the contact position of the rocker roller 6B on the driven cam 182B. The valve 4B opens and closes.

  In the variable valve unit 1B, similarly to the variable valve unit 1A, the operating angle and the lift amount of the valve 2B can be changed by changing the rotation angle of the control shaft 16B. In the case shown in FIG. 2, when the control shaft 16 </ b> B rotates in the clockwise direction, the cam roller 26 </ b> B moves around the cam 12 </ b> B counterclockwise, that is, toward the advance side with respect to the rotation direction of the cam 12. Conversely, when the control shaft 16B rotates in the counterclockwise direction, the cam roller 26B moves around the cam 12B in the clockwise direction, that is, toward the retard side with respect to the rotation direction of the cam 12.

  In the case shown in FIG. 2, when the control shaft 16B rotates clockwise, the selection roller 28B also moves clockwise around the control shaft 16B, and the passive arm 181B pressed against the selection roller 28B is also controlled. It rotates around the shaft 16B in the clockwise direction. As a result, the driven cam 182B rotates clockwise around the control shaft 16B together with the passive arm 181B, and the initial contact position of the driven cam 182B with the rocker roller 6 changes in a direction away from the working surface 182Bb. As a result, the valve opening characteristic of the valve 2B changes to the small operating angle / small lift side. Conversely, when the control shaft 16B rotates counterclockwise, the selection roller 28B also moves counterclockwise around the control shaft 16B, and the passive arm 181B pressed against the selection roller 28B also moves around the control shaft 16B. It rotates counterclockwise. As a result, the driven cam 182B rotates counterclockwise around the control shaft 16B, and the initial contact position changes in a direction approaching the action surface 182Bb. Thereby, the valve opening characteristic of the valve 2B changes to the large working angle / large lift side.

  Therefore, in the variable valve unit 1B, the valve opening characteristic of the valve 2B is changed to the small operating angle / small lift side by rotating the control shaft 16B in the clockwise direction. At the same time, the valve timing is advanced by moving the contact position of the cam roller 26B with the cam 12B toward the advance side with respect to the rotational direction of the cam 12B. When the control shaft 16B rotates counterclockwise, the valve opening characteristic of the valve 2B is changed to the large operating angle / large lift side. At the same time, the contact position of the cam roller 26B with the cam 12B moves to the retard side with respect to the rotation direction of the cam 12B, so that the valve timing is retarded. That is, according to the variable valve unit 1B, as shown in FIG. 4, when the valve opening characteristic of the valve 2B is changed to the small operating angle / small lift side, the valve timing can be advanced. When the valve opening characteristic is changed to the large operating angle / large lift side, the valve timing can be retarded.

  Thus, according to the variable valve operating apparatus of the present embodiment, the change direction of the valve timing accompanying the change in the operating angle can be the same in the left variable valve unit 1B and the right variable valve unit 1A. it can. Thereby, the phase difference of the valve timing between the left and right cylinders can be eliminated, and the controllability when the valve timing is variably controlled by the valve timing variable mechanism (not shown) can be improved. The variable valve timing mechanism is a device that adjusts the valve timing by variably controlling the phases of the camshafts 10A and 10B with respect to the crankshaft (not shown), and is provided in each of the left and right cylinders. When the variable valve device of the present embodiment is applied to a V-type engine in which a valve timing variable mechanism is mounted on the engine, a common control logic can be used for the left and right valve timing variable mechanisms.

  In the intake valve, when changing the valve operating angle, it is preferable to change the valve closing timing without changing the valve opening timing. According to the variable valve operating apparatus of the present embodiment, as shown in FIG. 4, when the valve operating angle is changed to the small operating angle side, the valve timing is advanced. A change in the valve opening timing can be reduced. Therefore, the amount of adjustment when adjusting the valve timing (valve opening timing) by the variable valve timing mechanism can be small, and control delay can be prevented.

Others.
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the variable valve device of the present invention is mounted on a V-type engine. However, the engine has two cylinder rows in which the rotation direction of the camshaft is the same between the cylinder rows. For example, it can be applied to other types of engines.

It is a side view which shows the structure of the variable valve operating unit concerning embodiment of this invention. It is the side view which looked at the variable valve apparatus concerning embodiment of this invention in the axial direction of the crankshaft. It is the side view which looked at the variable valve apparatus as a comparative example in the axial direction of the crankshaft. FIG. 3 is a diagram showing the relationship between the valve timing, the operating angle, and the lift amount of the left variable valve unit in the variable valve apparatus shown in FIG. 2. FIG. 4 is a diagram showing the relationship between the valve timing, the operating angle, and the lift amount of the left variable valve unit in the variable valve apparatus shown in FIG. 3.

Explanation of symbols

1,1A, variable valve unit (right side)
1B, 1C Variable valve unit (left side)
2, 2A, 2B Valve 4, 4A, 4B Rocker arm 6, 6A, 6B Rocker roller 8, 8A, 8B Hydraulic lash adjuster 10, 10A, 10B Cam shaft 12, 12A, 12B Cam 12a Non-operating surface 12b Working surface 14, 14A, 14B Interlocking mechanism 16, 16A, 16B Control shaft 18, 18A, 18B First arm 181, 181A, 181B Passive arm 181a Arm part 181b Arm part 181c, 181Ac, 181Bc Passive surface 182, 182A, 182B Driven cam 182a, 182Aa , 182Ba Non-working surfaces 182b, 182Ab, 182Bb Working surfaces 20, 20A, 20B Second arms 22, 22A, 22B Third arms 24, 24A, 24B Pins 26, 26A, 26B Cam rollers 28, 28A, 28B Selection roller 30 Lost Mosi Down spring

Claims (3)

In a variable valve operating system for an engine having two cylinder rows in which the rotation direction of the camshaft is the same between the cylinder rows
A power transmission mechanism that has an input member that contacts a cam provided on the cam shaft and displaces in conjunction with rotation of the cam, and transmits a change in the position of the input member to the valve to open and close the valve;
Changing the contact position of the input member with the cam to change the interlocking state between the rotation of the cam and the opening and closing movement of the valve, and changing the operating angle of the valve; In preparation for each cylinder row,
In the power transmission mechanism, the change direction of the contact position of the input member with the cam when the operating angle of the valve is changed is the same direction between the two cylinder rows with respect to the rotation direction of the cam. It is arranged so that it may become. Variable valve operating device characterized by things.   In the power transmission mechanism, the change direction of the contact position of the input member with the cam when the operation angle of the valve is changed to the small operation angle side is an advance side with respect to the rotation direction of the cam. The variable valve operating apparatus according to claim 1, wherein the variable valve operating apparatus is arranged as described above.   The part of the power transmission mechanism is arranged substantially symmetrically between the two cylinder rows with respect to a virtual axis parallel to the camshaft passing through the middle of the two cylinder rows. The variable valve operating device described.

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