JP5484987B2 - Variable valve gear for engine - Google Patents

Description

  The present invention relates to a variable valve gear for an engine.

  Some variable valve gears vary the valve opening lift amount and valve closing timing in the low load operation region and the high load operation region by connecting or disconnecting two adjacent rocker arms with a pin member. (See Patent Document 1).

  In the variable valve operating apparatus according to Patent Document 1, a so-called slipper type rocker arm is used in which a camshaft cam is brought into direct contact with a rocker arm to swing.

Japanese Patent No. 3029486

  By the way, in the variable valve operating apparatus as described in Patent Document 1, when the rocker arm is switched from the slipper type to the roller type in order to improve fuel efficiency, a pin member and a roller for connecting or cutting two adjacent rocker arms are provided. Since it is necessary to provide in a rocker arm, a rocker arm will enlarge.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a variable valve operating apparatus for an engine that can reduce the size and weight of a roller-type rocker arm.

As a means for solving the above problems, the invention described in claim 1 is a cam (for example, the first intake cam 39 and the second intake cam 40 in the embodiment) provided on the cam shaft (for example, the intake side camshaft 41 in the embodiment). ) Rocks the rocker arms (for example, the first intake side rocker arm 33 and the second intake side rocker arm 34 in the embodiment) to open and close the valves (for example, the first intake valve 13 and the second intake valve 14 in the embodiment). Then, by connecting or disconnecting two adjacent rocker arms with a pin member (for example, the connection pin 49 in the embodiment), the valve opening / closing timing is made variable, and the pin member is advanced and retracted by pressing the pin member. Actuator (e.g. implementation) having a push rod (e.g. push rod 65 in the embodiment) The engine (for example, connecting or disconnecting the two rocker arms (33, 34) by advancing and retracting the pin member (49) between the two adjacent rocker arms (33, 34) by the actuator 63) In the variable valve operating device of the engine 1) in the embodiment, the rocker arm rotatably supports a roller (for example, the rollers 45 and 51 in the embodiment) that contacts the cam (for example, the roller in the embodiment). Support holes 47, 53), pin support portions (for example, pin support holes 50, 55 in the embodiment) for slidably holding the pin member, and the rocker arm as a cylinder head (for example, the cylinder head 3 in the embodiment). Rocker arm shaft (for example, the intake side rocker arm in the embodiment) A shaft support portion (for example, shaft support holes 48 and 54 in the embodiment) that is swingably supported by the shaft 37), and the roller support portion, the pin support portion, and the shaft support portion are formed in parallel to each other. a support hole that is, the push rod, to slide the pin member by parallel reciprocating in the axis of the pin support portion, in the end face for pressing the pin member (e.g., the embodiment of the push rod The end surface 65a) is set so as to be able to press the pin member over the swinging range of the pin member accompanying the swinging of the rocker arm, and a spring (for example, the spring 58 in the embodiment) is provided on the pin support portion. One of the rocker arms (for example, the second intake side rocker arm 34 in the embodiment) is biased toward the plunger (for example, In the embodiment, a plunger 59) is provided, and the pin member is provided on the plunger side and is in contact with the plunger (for example, the pressing portion 61 in the embodiment), and extends from the pressing portion and contacts the push rod. It is comprised by the rod side contact part (for example, rod side contact part 62 of embodiment) contacted and the diameter smaller than the said press part .
According to the second aspect of the present invention, the pin support portion (for example, the pin support hole 55 of the embodiment) has a small diameter at a side portion of the one rocker arm (for example, the second intake side rocker arm 34 of the embodiment). Forming a fine pore (for example, the fine pore 60 in the embodiment) and penetrating the side portion of the one rocker arm, and the rod-side contact portion of the pin member extends from the pressing portion to extend the pore. It is comprised so that it may penetrate.

The invention according to claim 3 is characterized in that a distance between centers of the rocker arm shaft and the pin member is set shorter than a distance between centers of the rocker arm shaft and the roller. .

According to a fourth aspect of the present invention, the pin support portion is disposed closer to the umbrella portion of the valve (for example, the umbrella portions 17 and 17 in the embodiment) than the line connecting the centers of the rocker arm shaft and the roller. And the center of the pin support portion is disposed between a straight line that passes through the center of the rocker arm shaft and extends along the axial direction of the valve, and a straight line that passes through the center of the roller and extends along the axial direction of the valve. It is characterized by being.

According to a fifth aspect of the present invention, the pin support portion is a contact portion of the rocker arm (for example, the embodiment) in which the rocker arm and a valve stem (for example, the valve stem 18, 18 in the embodiment) of the valve abut. The abutment portions 56, 57) are arranged closer to the umbrella portion of the valve (for example, the umbrella portions 17, 17 in the embodiment).

The invention according to claim 6 is characterized in that the pin support portion is disposed outside the valve.
The invention according to claim 7 is characterized in that the pin support portion is arranged inside the valve.

According to the first and second aspects of the invention, since the support holes are formed in parallel, the support holes can be arranged close to each other. Weight reduction can be achieved. Furthermore, since the push rod pushes the pin member within the width of the rocker arm in a side view, the cylinder head can be prevented from being enlarged. Further, the pin member can be switched by an actuator installed outside the cylinder head.

According to invention of Claim 3 , the rigidity at the time of the connection by a pin member is securable by shortening the distance of a rocker arm shaft and a pin member. In addition, since the distance between the center of the rocker arm shaft and the pin member is shorter than the distance between the center of the rocker arm shaft and the roller, a space for the valve spring provided in the valve can be secured, and the rocker arm becomes smaller and the reciprocating part Equivalent weight can be reduced.

According to the fourth aspect of the present invention, when the cam shaft is arranged above the rocker arm, the pin support portion is installed on the side opposite to the cam, thereby improving the degree of freedom in arranging the cam shaft. it can. In addition, the center of the pin support portion is disposed between the straight line that passes through the center of the rocker arm shaft and extends along the axial direction of the valve and the straight line that passes through the center of the roller and extends along the axial direction of the valve. Interference with the provided valve spring can be easily avoided, the rocker arm can be made smaller, and the cylinder head can be made smaller.

According to the invention described in claim 5, when it is configured to arrange the cams axis above the rocker arm, the rocker arm and the valve stem and the pin supporting portion than the contact portion abutting the rocker arm of the valve Is arranged on the umbrella side of the valve, so that an actuator for moving the pin member without being restricted by the cam shaft can be arranged in the cylinder head.

According to the sixth aspect of the present invention, the invention can be applied to a valve operating system using an outer pivot type rocker arm.
According to the seventh aspect of the present invention, the invention can be applied to a valve operating system using an inner pivot type rocker arm.

1 is a longitudinal sectional view of an engine according to a first embodiment of the present invention. It is a top view of the engine principal part seen from the AA line of FIG. It is a cross-sectional view of the engine seen from the BB line of FIG. It is an enlarged view of the rocker arm in 1st Embodiment. It is an enlarged view of the rocker arm in 1st Embodiment. It is a longitudinal cross-sectional view of the engine which concerns on the 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the engine which concerns on the 3rd Embodiment of this invention. It is a top view of the engine principal part which concerns on the 4th Embodiment of this invention. It is sectional drawing of the rocker arm in 4th Embodiment, (A) is sectional drawing which follows the XX line and ZZ line of FIG. 8, (B) follows the YY line of FIG. It is sectional drawing. It is sectional drawing which follows the VV line | wire of FIG. 9 of the rocker arm in 4th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 shows a cross section of an engine 1 having a structure according to a first embodiment of the present invention. Reference numeral 2 indicates a cylinder block of the engine 1, and reference numeral 3 indicates a cylinder head. The upper part of the cylinder head 3 is covered with a head cover 3B. A piston 4 is fitted in the cylinder block 2 so as to be able to reciprocate. One end of a connecting rod 5 is connected to the piston 4 and the other end of the connecting rod 5 is connected to a crankshaft (not shown). The cylinder head 3 is formed with a combustion chamber 6 that faces the top of the piston 4.

  The engine 1 is an engine having two intake valves and two exhaust valves, and the cylinder head 3 communicates with the combustion chamber 6 through the intake ports 7 and 8 and opens to one side surface of the cylinder head 3. An intake port 12 communicating with the combustion chamber 6 and the exhaust ports 10 and 11 and opening on the other side of the cylinder head 3 is formed. Although the intake port 7 and the exhaust port 10 are not shown, the intake port 7 is located on the front side of the intake port 8 in the direction perpendicular to the paper surface, and the exhaust port 10 is located on the near side of the intake port 11 in the direction perpendicular to the paper surface. It is shown in parentheses in the figure.

  The cylinder head 3 includes a first intake valve 13 and a second intake valve 14 that communicate or block communication between the intake port 9 and the combustion chamber 6, and a first communication valve that communicates or blocks communication between the exhaust port 12 and the combustion chamber 6. The 1 exhaust valve 15 and the 2nd exhaust valve 16 are provided so that opening and closing operation is possible. The second intake valve 14 opens and closes the intake port 8, and the second exhaust valve 16 opens and closes the exhaust port 10. Although only the second intake valve 14 and the second exhaust valve 16 are shown in FIG. 1, the first intake valve 13 and the first exhaust valve 15 are located on the front side in the vertical direction of the paper, and are shown in parentheses in the drawing. It is shown in

  The first intake valve 13 and the second intake valve 14 include umbrella portions 17 and 17 for opening and closing the intake ports 7 and 8, and valve stems 18 and 18 protruding from the umbrella portions 17 and 17, respectively. Is inserted into guide holes 19, 19 formed in the cylinder head 3, and the upper ends of the valve stems 18, 18 are biased in the direction in which the umbrella portions 17, 17 are closed via the inner springs 20, 20 and the outer springs 21, 21. To do.

  One end of each of the inner springs 20 and 20 and the outer springs 21 and 21 is brought into contact with a seating surface 23 and 23 formed around the guide holes 19 and 19 of the cylinder head 3 via the spring seats 22 and 22, and the other end thereof. It is connected to the upper part of the valve stems 18 and 18 via spring retainers 24 and 24. The inner springs 20, 20 are arranged on the inner peripheral side of the outer springs 21, 21.

  The first exhaust valve 15 and the second exhaust valve 16 include umbrella portions 25 and 25 for opening and closing the exhaust ports 10 and 11 and valve stems 26 and 26 protruding from the umbrella portions 25 and 25, respectively. Is inserted into guide holes 27, 27 formed in the cylinder head 3, and the upper ends of the valve stems 26, 26 are urged in the closing direction of the umbrella portions 25, 25 via the inner springs 28, 28 and the outer springs 29, 29. To do.

  The inner springs 28, 28 and the outer springs 29, 29 are brought into contact with seating surfaces 31, 31 formed around the guide holes 27, 27 of the cylinder head 3 via spring seats 30, 30, and the other ends thereof. The valve stems 26, 26 are connected to the upper portions of the valve stems 26, 26 via spring retainers 32, 32. The inner springs 28 and 28 are arranged on the inner peripheral side of the outer springs 29 and 29.

  Referring also to FIG. 2, the first intake valve 13 is opened and closed by a first intake side rocker arm 33, and the second intake valve 14 is opened and closed by a second intake side rocker arm 34. The first exhaust valve 15 is opened and closed by a first exhaust side rocker arm 35, and the second exhaust valve 16 is opened and closed by a second exhaust side rocker arm 36. The first intake side rocker arm 33 and the second intake side rocker arm 34 are swingably supported by an intake side rocker arm shaft 37 supported by the cylinder head 3, and the first exhaust side rocker arm 35 and the second exhaust side rocker are supported. The rocker arm 36 is swingably supported by an exhaust-side rocker arm shaft 38 supported by the cylinder head 3.

  In FIG. 1, only the second intake-side rocker arm 34 and the second exhaust-side rocker arm 36 are shown, but the first intake-side rocker arm 33 and the first exhaust-side rocker arm 35 are close to each other in the direction perpendicular to the paper surface. It is located on the side and is shown in parentheses in the figure.

  Above the first intake-side rocker arm 33 and the second intake-side rocker arm 34, a first intake cam 39 and a second intake cam that swing the first intake-side rocker arm 33 and the second intake-side rocker arm 34, respectively. An intake side camshaft 41 in which 40 are arranged in the axial direction is provided. The cam crest 39A of the first intake cam 39 is set lower than the cam crest 40A of the second intake cam 40. A driven sprocket 41A is provided at one end of the intake side camshaft 41 (FIG. 2, left side of the drawing).

  Above the first exhaust side rocker arm 35 and the second exhaust side rocker arm 36, an exhaust side camshaft 44 having an exhaust cam 42 that swings the first exhaust side rocker arm 35 and the second exhaust side rocker arm 36, respectively. Is provided. A driven sprocket 44A is provided at one end of the exhaust side camshaft 44 (FIG. 2, the left side of the drawing).

  A cam chain 44B is hung on the driven sprocket 41A and the driven sprocket 44A, and the cam chain 44B is hung on a drive sprocket of a crankshaft (not shown). The rotation of the intake camshaft 41 and the exhaust camshaft 44 is transmitted via the cam chain 44B.

  Referring also to FIG. 3, the first intake-side rocker arm 33 includes a roller support hole 47 that rotatably supports a roller 45 that contacts the first intake cam 39 of the intake-side camshaft 41 via the shaft 46, and an intake-side Pin support for slidably holding a shaft support hole 48 through which the rocker arm shaft 37 is inserted and a connecting pin 49 that connects or disconnects the adjacent second intake side rocker arm 34 and the first intake side rocker arm 33. Hole 50.

  The roller support hole 47, the shaft support hole 48, and the pin support hole 50 extend along the axial direction of the intake camshaft 41, and are formed in parallel to each other.

  The second intake side rocker arm 34 is inserted through the intake side rocker arm shaft 37 and a roller support hole 53 that rotatably supports the roller 51 that contacts the second intake cam 40 of the intake side camshaft 41 via the shaft 52. And a pin support hole 55 for slidably holding a connection pin 49 that connects or disconnects the adjacent first intake side rocker arm 33 and second intake side rocker arm 34. ing.

  Similarly to the above, the roller support hole 53, the shaft support hole 54, and the pin support hole 55 extend along the axial direction of the intake side camshaft 41 and are formed in parallel to each other. 1 shows a longitudinal section of the second intake-side rocker arm 34. In the drawing, only the roller 51, the shaft 52, and the like of the second intake-side rocker arm 34 are shown. In FIG. 1, the roller 45 and the shaft 46 of the first intake side rocker arm 33 are shown in parentheses.

  The first intake-side rocker arm 33 and the second intake-side rocker arm 34 have the same shape, and the shaft support hole 48 and the shaft support hole 54 are connected to the first intake valve 13 and the second intake valve 14, respectively. This is a so-called outer pivot type rocker arm arranged outside.

  In the first intake side rocker arm 33 and the second intake side rocker arm 34, as shown in FIG. 1, the roller support hole 47 and the roller support hole 53 are obliquely above the shaft support hole 48 and the shaft support hole 54. The pin support hole 50 and the pin support hole 55 are disposed below the roller support hole 47 and the roller support hole 53, and the shaft support hole 48 and the shaft support hole 54.

  Arm-shaped abutment portions 56 and abutment portions 57 that extend to the upper ends of the valve stems 18 and 18 and abut against the valve stems 18 and 18 are provided in the inner portions of the peripheral portions of the roller support hole 47 and the roller support hole 53, respectively. It has been. The contact portion 56 is shown in parentheses in FIG. When the first intake cam 39 in contact with the roller 45 rotates, the first intake side rocker arm 33 swings, and the contact portion 56 presses the upper end of the valve stem 18. Thereby, the umbrella part 17 opens. Further, when the second intake cam 40 in contact with the roller 51 rotates, the second intake-side rocker arm 34 swings, and the contact portion 57 presses the upper end of the valve stem 18. Thereby, the umbrella part 17 opens.

  FIG. 3 shows a cross section viewed from the line B-B in FIG. 1, and shows cross sections of the pin support hole 50 and the pin support hole 55. As shown in the figure, the pin support hole 50 is provided with a plunger 59 that is biased toward the second intake side rocker arm 34 by a spring 58. The pin support hole 55 forms a small hole 60 having a reduced diameter at the side portion of the second intake side rocker arm 34, and penetrates the side portion of the second intake side rocker arm 34.

  A connecting pin 49 is accommodated in the pin support hole 55, and the connecting pin 49 is provided on the plunger 59 side, a pressing portion 61 that comes into contact with the plunger 59, and a rod that extends from the pressing portion 61 and penetrates the pore 60. It is comprised by the side contact part 62. FIG.

  The connecting pin 49 is attached to the side wall 3 </ b> A of the cylinder head 3, is adjacent to the second intake-side rocker arm 34, and includes a switching mechanism 64 having an actuator 63 disposed on the outer peripheral side of the intake-side camshaft 41. It is pressed by. The actuator 63 includes a push rod 65 that can advance and retreat in the axial direction of the intake camshaft 41, and an end surface 65 a of the push rod 65 abuts on the rod side abutting portion 62 of the connecting pin 49. Thus, the connecting pin 49 can be pushed into the pin support hole 50 of the first intake side rocker arm 33. The push rod 65 extends and contracts in parallel on the axis of the pin support holes 50 and 55 to slide the connecting pin 49 in the pin support holes 50 and 55. Further, the length in the longitudinal direction of the pressing portion 61 is set to be substantially the same as the length (depth) in the longitudinal direction of the pin support hole 55, and in a state where the connecting pin 49 is not pressed by the actuator 63, The actuator 63 side of the pressing portion 61 is in contact with the end surface (the fine hole 60 side) of the pin support hole 55 so that the movement in the axial direction is restricted.

  Here, referring to FIG. 4, a view of the second intake side rocker arm 34 side from the line CC in FIG. 2 is shown. In the figure, “L1” indicates a straight line passing through the center point of the shaft support hole 48 and the shaft support hole 54 and the center point of the roller support hole 47 and the roller support hole 53, and “L2” indicates the shaft support hole 48. And a straight line passing through the center point of the shaft support hole 54 and along the opening / closing direction of the first intake valve 13 and the second intake valve 14 (the axial direction of the valve stem 18). “L3” indicates the roller support hole 47 and the roller A straight line passing through the center point of the support hole 53 and along the opening / closing direction of the first intake valve 13 and the second intake valve 14 (the axial direction of the valve stem 18) is shown. “L4” indicates a straight line passing through the center point of the shaft support hole 48 and the shaft support hole 54 (intake side rocker arm shaft 37) and the center point of the pin support hole 50 and the pin support hole 55 (connection pin 49). ing.

  The arrangement positions of the pin support hole 50 and the pin support hole 55 will be described with reference to these straight lines and FIG. 2. The pin support hole 50 and the pin support hole 55 are located at the center points of the shaft support hole 48 and the shaft support hole 54. It is arranged closer to the umbrella portions 17 and 17 of the valve than the straight line “L1” passing through the center points of the roller support hole 47 and the roller support hole 53.

  Further, the pin support hole 50 and the pin support hole 55 have straight center points along the opening / closing directions of the first intake valve 13 and the second intake valve 14 through the center points of the shaft support hole 48 and the shaft support hole 54. L2 ”and a straight line“ L3 ”passing through the center points of the roller support hole 47 and the roller support hole 53 and extending along the opening and closing directions of the first intake valve 13 and the second intake valve 14 are arranged. .

  Further, the pin support hole 50 and the pin support hole 55 are compared with the contact portion 56 of the first intake side rocker arm 33 and the contact portion 56 of the second intake side rocker arm 34, as shown in FIG. As shown by a straight line L extending orthogonally to the contact portion 56 and the contact portion 57, they are disposed closer to the umbrella portions 17 and 17 of the valve. That is, the pin support hole 50 and the pin support hole 55 are disposed at positions closer to the contact portion 56 and the contact portion 57 at a linear distance from the umbrella portions 17 and 17. Further, the pin support hole 50 and the pin support hole 55 are disposed outside the axial extension line S <b> 1 of the valve stem 18 in comparison with the valve stem 18.

  Further, referring to the straight lines “L1” and “L4”, the distance D2 between the centers of the intake side rocker arm shaft 37 and the connecting pin 49 is between the centers of the intake side rocker arm shaft 37 and the rollers 45 and 51. It is set shorter than the distance D1. 5 is a view showing a state in which the second intake-side rocker arm 34 swings from the state shown in FIG. 4. In this figure, the second intake-side rocker arm 34 is located on the front side of the drawing. The end surface 65a of the push rod 65 that is positioned is indicated by a virtual line (one-dot chain line). In FIG. 5, the end surface 65a of the push rod 65 can be pressed over the swing range of the rod side contact portion 62 of the connection pin 49 accompanying the swing of the second intake side rocker arm 34. The setting is shown. When the second intake-side rocker arm 34 swings, the rod-side contact portion 62 slides on the end surface 65a.

  When the engine 1 is in the low load operation region, as shown in FIG. 3, the pressing portion 61 of the connecting pin 49 is located on the split surface between the first intake side rocker arm 33 and the second intake side rocker arm 34. The push rod 65 of the actuator 63 holds the position of the connecting pin 49 so that the tip is positioned. When the engine 1 is in a high load operating range, the push rod 65 is operated to resist the urging force of the plunger 59 (spring 58) provided on the first intake side rocker arm 33 by operating the push rod 65. Then push it into the pin support hole 50.

  Accordingly, in the engine 1, the first intake side rocker arm 33 and the second intake side rocker arm 34 are interlocked in the high load operation region, and the first intake valve 13 is connected to the first intake valve 13 via the first intake side rocker arm 33. 2 Opening and closing drive is performed by the valve opening characteristics of the intake cam 40. Here, since the cam crest 40A of the second intake cam 40 is set higher than the cam crest 39A of the first intake cam 39, the first intake valve 13 opens in a higher load operation region than in a low load operation region. The valve lift and valve closing timing can be switched large and long.

  On the other hand, the first exhaust side rocker arm 35 and the second exhaust side rocker arm 36 always swing together. The configuration of the first exhaust side rocker arm 35 and the second exhaust side rocker arm 36 will be described. As shown in FIG. 3, the first exhaust side rocker arm 35 and the second exhaust side rocker arm 36 have an exhaust side camshaft 44. The third rocker arms 66 are arranged between them and are connected to each other via a connecting shaft 67 provided on the third rocker arm 66.

  The connecting shaft 67 extends in the axial direction of the exhaust camshaft 44. The third rocker arm 66 has a roller support hole 70 that rotatably supports a roller 68 that contacts the exhaust cam 42 shown in FIG. 2 via a shaft 69, and a shaft support hole 71 that allows the exhaust-side rocker arm shaft 38 to be inserted therethrough. And the connection shaft support hole 72 which penetrates the said connection shaft 67 shown in FIG. 3 is formed. Here, the roller support hole 70, the shaft support hole 71, and the connecting shaft support hole 72 are formed in parallel along the axial direction of the exhaust side camshaft 44. In FIG. 1, a longitudinal section of the third rocker arm 66 is shown, and a roller 68, a shaft 69, and a roller support hole 70 are shown.

  The first exhaust-side rocker arm 35 and the second exhaust-side rocker arm 36 are respectively provided with shaft support holes 73 and 73 through which the exhaust-side rocker arm shaft 38 shown in FIG. 2 is inserted, and the connecting shaft 67 shown in FIG. The connecting shaft support holes 74, 74 through which are inserted are formed. Further, the first exhaust-side rocker arm 35 and the second exhaust-side rocker arm 36 extend to the upper ends of the valve stems 26, 26, respectively, and are arm-shaped contact portions 75 and contact portions that contact the valve stems 26, 26. 76 (see also FIG. 1).

  In this exhaust side valve operating system, the exhaust cam 42 in contact with the roller 68 provided on the third rocker arm 66 rotates, so that the first exhaust side rocker arm 35 and the second exhaust side rocker arm 36 move. Swings together. Thereby, the abutting part 75 and the abutting part 76 press the upper ends of the valve stems 26 and 26, so that the umbrella parts 25 and 25 are opened at the same timing.

  As described above, in the engine 1 according to the present embodiment, the first intake-side rocker arm 33 includes the roller support hole 47 that rotatably supports the roller 45 that contacts the first intake cam 39, and the connecting pin 49. A pin support hole 50 for slidably holding, and a shaft support hole 48 for swinging the first intake side rocker arm 33 to the cylinder head 3 by an intake side rocker arm shaft 37 are provided. The pin support hole 50 and the shaft support hole 48 are formed in parallel to each other along the axial direction of the intake camshaft 41.

  The second intake-side rocker arm 34 has a roller support hole 53 that rotatably supports the roller 51 that contacts the second intake cam 40, a pin support hole 55 that holds the connecting pin 49 slidably, The second intake-side rocker arm 34 is provided with a shaft support hole 54 for swingably supporting the cylinder head 3 by the intake-side rocker arm shaft 37. The roller support hole 53, the pin support hole 55, and the shaft support hole 54 are inhaled. They are formed parallel to each other along the axial direction of the side camshaft 41.

  According to this, since each support hole can be arranged close to each other, the first intake-side rocker arm 33 including the roller 45 and the second intake-side rocker arm 34 including the roller 51 are reduced in size and weight. Can be achieved.

The push rod 65 of the actuator 63 that advances and retracts the connecting pin 49 expands and contracts in parallel on the axis of the pin support holes 50 and 55 to slide the connecting pin 49.
1 and 3 together, the push rod 65 pushes the connecting pin 49 within the width of the first intake side rocker arm 33 and the second intake side rocker arm 34 in a side view. The enlargement of the head 3 can be prevented.

  4, the distance D2 between the centers of the intake-side rocker arm shaft 37 and the connecting pin 49 is shorter than the distances D1 between the centers of the intake-side rocker arm shaft 37 and the rollers 45 and 51. Is set.

  According to this, by making the distance between the intake side rocker arm shaft 37 and the connection pin 49 closer, it is possible to ensure rigidity when the first intake side rocker arm 33 and the second intake side rocker arm 34 are connected by the connection pin 49. Further, since the distance between the centers of the intake-side rocker arm shaft 37 and the connecting pin 49 is shorter than the distances between the centers of the intake-side rocker arm shaft 37 and the rollers 45 and 51, the inner springs 28 and 28 and the outer spring 29 29, and the first intake-side rocker arm 33 and the second intake-side rocker arm 34 become smaller, and the equivalent weight of the reciprocating part can be reduced.

  In addition, the pin support hole 50 and the pin support hole 55 are more than the straight line “L1” passing through the center point of the shaft support hole 48 and the shaft support hole 54 and the center point of the roller support hole 47 and the roller support hole 53. 17 and 17 side. The center points of the pin support hole 50 and the pin support hole 55 pass through the center points of the shaft support hole 48 and the shaft support hole 54, and are straight lines along the opening and closing directions of the first intake valve 13 and the second intake valve 14. L2 ”and a straight line“ L3 ”passing through the center points of the roller support hole 47 and the roller support hole 53 and extending along the opening and closing directions of the first intake valve 13 and the second intake valve 14 are arranged. .

  According to this, when it is the structure which arrange | positions a cam shaft like the engine 1 above a rocker arm, a pin support part will be installed on the opposite side to a cam, and the arrangement | positioning freedom degree of a cam shaft can be improved. . Further, the center of the pin support hole 50 and the pin support hole 55 passes through the center point of the shaft support hole 48 and the shaft support hole 54 and a straight line “L2” along the opening / closing direction of the first intake valve 13 and the second intake valve 14. The first intake-side rocker arm 33 and the first intake-side rocker arm 33 are disposed between the first intake valve 13 and the straight line along the opening / closing direction of the second intake valve 14 through the center points of the roller support hole 47 and the roller support hole 53. (2) The interference between the intake side rocker arm 34 and the inner springs 28, 28 and the outer springs 29, 29 can be easily avoided, and the size of the first intake side rocker arm 33 and the second intake side rocker arm 34 is reduced. The cylinder head 3 can be downsized.

  Further, the pin support hole 50 and the pin support hole 55 are compared with the contact portion 56 of the first intake side rocker arm 33 and the contact portion 56 of the second intake side rocker arm 34. It is arranged closer to the umbrella parts 17 and 17 than the contact part 57.

  According to this, the actuator 63 that moves the connecting pin 49 without being restricted by the intake side camshaft 41 can be arranged in the cylinder head 3. As shown in FIG. 3, the end surface 65a of the push rod 65 on the tip side (the side that presses the connecting pin 49) contacts the rod side of the connecting pin 49 that accompanies the swinging of the second intake side rocker arm 34. The connecting pin 49 is set to be able to be pressed over the swing range of the portion 62. According to this, the connection pin 49 can be switched by the actuator 63 installed outside the cylinder head 3.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. Components similar to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  An engine 80 according to this embodiment shown in FIG. 6 is an intake side two-valve and exhaust side two-valve engine as in the first embodiment. The first intake side rocker arm 81 and the second intake side are arranged on the left side of the drawing. A rocker arm 82 is disposed, and a first exhaust side rocker arm 83 and a second exhaust side rocker arm 84 are disposed on the right side of the drawing. FIG. 6 shows only the second intake-side rocker arm 82 and the second exhaust-side rocker arm 84, but the first intake-side rocker arm 81 and the first exhaust-side rocker arm 83 are on the front side in the direction perpendicular to the paper surface. Located in parentheses in the figure.

  Above the first intake-side rocker arm 81 and the second intake-side rocker arm 82, a first intake cam 85 and a second intake cam that swing the first intake-side rocker arm 81 and the second intake-side rocker arm 82, respectively. An intake side camshaft 87 in which 86 are arranged in the axial direction is provided. In the drawing, only the second intake cam 86 is shown, but the first intake cam 85 is located on the front side in the vertical direction of the drawing and is shown in parentheses in the drawing.

  Above the first exhaust side rocker arm 83 and the second exhaust side rocker arm 84, an exhaust side camshaft 89 having an exhaust cam 88 that swings the first exhaust side rocker arm 83 and the second exhaust side rocker arm 84, respectively. Is provided.

  The second intake-side rocker arm 82 is supported by the cylinder head 3 and a roller support hole 92 that rotatably supports a roller 90 that contacts the second intake cam 86 of the intake-side camshaft 87 via the roller shaft 91. (2) A shaft support hole 94 through which an intake side rocker arm shaft 93 for swingably supporting the intake side rocker arm 82 is inserted, and the adjacent first intake side rocker arm 81 and second intake side rocker arm 82 are connected or disconnected. And a pin support hole 95 for slidably holding the connecting pin 49 to be slidable. The roller support hole 92, the shaft support hole 94, and the pin support hole 95 are formed in parallel along the axial direction of the intake side camshaft 87.

  The second intake side rocker arm 82 is a so-called inner pivot type rocker arm in which the shaft support hole 94 is disposed inside the engine 80 with respect to the second intake valve 14, and the roller support hole 92 is formed in the shaft support hole 94. On the other hand, it is located outside the engine 1. An arm-shaped contact portion 96 that extends to the upper end of the valve stem 18 and contacts the valve stem 18 is provided on the outer peripheral portion of the shaft support hole 94. The first intake side rocker arm 81 has the same shape as the second intake side rocker arm 82, and has the same roller support hole, shaft support hole and pin support hole as the second intake side rocker arm 82. However, the description is omitted because of the same configuration.

  In FIG. 6, “L5” indicates a straight line passing through the center point of the shaft support hole 94 and the center point of the roller support hole 92, and “L6” passes through the center point of the shaft support hole 94 and passes through the second intake valve 14. Represents a straight line along the opening / closing direction (the axial direction of the valve stem 18), and “L7” passes through the center point of the roller support hole 92 and extends along the opening / closing direction of the second intake valve 14 (the axial direction of the valve stem 18). A straight line is shown.

  The arrangement position of the pin support hole 95 of the second intake side rocker arm 82 will be described with reference to these straight lines. The pin support hole 95 is a straight line passing through the center point of the shaft support hole 94 and the center point of the roller support hole 92. It is arrange | positioned rather than "L5" at the umbrella parts 17 and 17 side of a valve | bulb. The pin support hole 95 has a center point passing through the center point of the shaft support hole 94 and a straight line “L6” along the opening / closing direction of the second intake valve 14, and the center point of the roller support hole 92. It arrange | positions so that it may be located between the straight line "L7" along the opening / closing direction of the valve | bulb 14. FIG. Further, in comparison with the contact portion 96 of the first intake-side rocker arm 81, the pin support hole 95 is formed by the contact portion 96 as shown by a straight line L extending perpendicular to the upper end of the valve stem 18 in the figure. Is also arranged on the umbrella portion 17 side of the valve. That is, the pin support hole 95 is disposed at a position closer to the abutting portion 96 by a linear distance from the umbrella portion 17. Further, the pin support hole 95 is disposed inside the axial extension line S <b> 2 of the valve stem 18 in comparison with the valve stem 18.

  Since the connection pin 49 is accommodated in the pin support hole 95 and the connection pin 49 is pressed by an actuator (not shown) to connect the first intake side rocker arm 81, the configuration is the same as in the first embodiment. Detailed description of the part is omitted. In FIG. 6, “L8” indicates a straight line passing through the center point of the shaft support hole 94 (intake side rocker arm shaft 93) and the center point of the pin support hole 95 (connecting pin 49).

  Referring to the straight lines “L5” and “L8”, the distance D4 between the centers of the intake side rocker arm shaft 93 and the connecting pin 49 is shorter than the distance D3 between the centers of the intake side rocker arm shaft 93 and the roller 90. Is set. The roller support hole, shaft support hole, and pin support hole of the first intake side rocker arm 81 are arranged in the same manner as the second intake side rocker arm 82, but detailed description thereof is omitted.

  Also in the engine 80, in the high load operation region, the first intake side rocker arm 81 and the second intake side rocker arm 81 are interlocked so that the first intake valve 13 is caused by the valve opening characteristic of the second intake cam 40. Open / close drive.

  In addition to the effects described in the first embodiment, the engine 80 according to the present embodiment described above is suitable for a pivot type engine, and the first intake cam 85 and the second intake cam 86 are exhausted from the exhaust. The cylinder head 3 can be reduced in size as much as the space between the cam 88 and the cam 88 can be used effectively.

<Third Embodiment>
Next, a third embodiment of the present invention will be described.

  FIG. 7 shows an engine 100 according to this embodiment. In the engine 100, a combustion chamber 103 is formed in which the top of the piston 102 faces the cylinder head 101. The cylinder head 101 communicates with the combustion chamber 103 through the exhaust port 104 and opens to one side of the cylinder head 101. The cylinder port 101 communicates with the combustion chamber 103 through the two intake ports 106 and 107. And an intake port 108 that is open to the outside. In addition, although not shown in figure, the inlet 107 is located in the paper surface perpendicular | vertical back side of the inlet 106, and is shown in the parenthesis in the figure.

  The cylinder head 101 includes an exhaust valve 109 for communicating or blocking between the exhaust port 105 and the combustion chamber 103, and a first intake valve 110 and a second intake valve for communicating or blocking between the intake port 108 and the combustion chamber 103. A valve 111 is provided so that it can be opened and closed. Although not shown, the second intake valve 111 is located on the back side of the first intake valve 110 in the direction perpendicular to the paper surface and is shown in parentheses in the figure.

  A camshaft 112 that is rotatably supported by the cylinder head 101 is disposed between the exhaust valve 109 and the first intake valve 110 and the second intake valve 111. On the camshaft 112, an exhaust cam 113, a first intake cam 114, and a second intake cam 115 are provided side by side in the direction perpendicular to the paper surface.

  The exhaust valve 109 is opened and closed by an exhaust-side rocker arm 116 that swings in conjunction with the rotation of the exhaust cam 113 of the camshaft 112, and the first intake valve 110 and the second intake valve 111 are connected to the first intake cam 114 and the first intake valve 114. 2 Opened and closed by the first intake-side rocker arm 117 and the second intake-side rocker arm 118 that swing in conjunction with the rotation of the intake cam 115. Although not shown, the second intake-side rocker arm 118 is located on the back side in the direction perpendicular to the paper surface of the first intake-side rocker arm 117 and is shown in parentheses in the figure.

  The first intake-side rocker arm 117 is swingably supported by inserting an intake-side rocker arm shaft 120 extending along the axial direction into the camshaft 112 through a shaft support hole 119 formed in the substantially longitudinal center of the first intake-side rocker arm 117. ing. The intake side rocker arm shaft 120 is supported by the cylinder head 101. One end of the first intake-side rocker arm 117 is provided with a roller 121 that contacts the first intake cam 114 formed on the camshaft 112, and the other end is a tappet screw that contacts the stem end 122 of the first intake valve 110. 123 is provided.

  The roller 121 is rotatably supported by a shaft 125 inserted through a roller support hole 124 formed on one end side of the first intake side rocker arm 117. The axial direction of the shaft 125 extends along the axial direction of the camshaft 112.

  In the present embodiment, the first intake-side rocker arm 117 and the adjacent second intake-side rocker arm 118 are connected or disconnected by a pin member so that both can be interlocked. A pin support hole 127 is formed in the upper part of the rocker arm 117 and accommodates a connecting pin 126 (shown by a one-dot chain line) provided in the second intake side rocker arm 118. The pin support hole 127 is formed so as to extend along the axial direction of the camshaft 112.

  The engine 100 is provided with an actuator 63 (see FIG. 3) similar to that of the first embodiment. When the actuator 63 presses the connecting pin 126, the connecting pin 126 is pushed into the pin support hole 127. Thus, the first intake side rocker arm 117 and the second intake side rocker arm 118 are connected.

  The second intake-side rocker arm 118 has the same shape as the first intake-side rocker arm 117, and the manner in which the connecting pin 126 is slidably accommodated is the same as in the first and second embodiments. Therefore, the description is omitted.

  In FIG. 5, “L9” indicates a straight line passing through the center point of the shaft support hole 119 and the center point of the roller support hole 124, and “L10” passes through the center point of the shaft support hole 119 and passes through the first intake valve 110. A straight line along the opening / closing direction of the first intake valve 110 passing through the center point of the roller support hole 124 is indicated by “L11”. “L12” indicates a straight line passing through the center point of the shaft support hole 119 (intake-side rocker arm shaft 120) and the center point of the pin support hole 127 (connection pin 126).

  The arrangement position of the pin support hole 127 will be described with reference to these straight lines. The pin support hole 127 has a center point passing through the center point of the shaft support hole 119 and a straight line along the opening / closing direction of the first intake valve 110. It is arranged so as to be positioned between “L10” and a straight line “L11” that passes through the center point of the roller support hole 124 and extends in the opening / closing direction of the first intake valve 110. Further, referring to the straight lines “L9” and “L12”, the distance D5 between the centers of the intake-side rocker arm shaft 120 and the connecting pin 126 is greater than the distance D6 between the centers of the intake-side rocker arm shaft 120 and the roller 117. Is also set short.

  Also in the embodiment described above, since the shaft support hole 119, the roller support hole 124, and the pin support hole 127 are formed in parallel in the first intake side rocker arm 117, the support holes are brought close to each other. Therefore, the rocker arm including the roller can be reduced in size and weight. The same effect can be obtained with the second intake side rocker arm 118.

<Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described. An engine 130 according to the present embodiment shown in FIG. 8 is an exhaust side two-valve engine and an intake side two-valve engine as in the first embodiment, but includes an intake-side camshaft and an intake-side rocker arm. Is different from the first embodiment. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In FIG. 8, the intake side camshaft 131 is configured by sequentially arranging a first intake cam 132, a second intake cam 133, and a third intake cam 134 in the axial direction thereof. The first intake cam 132 and the third intake cam 134 have a cam crest having the same height, and the second intake cam 133 has a cam crest set higher than the first intake cam 132 and the third intake cam 134. ing. A first intake side rocker arm 135 is provided below the first intake cam 132, a second intake side rocker arm 136 is provided below the second intake cam 133, and a third intake side is provided below the third intake cam 134. A rocker arm 137 is provided.

  The first intake side rocker arm 135, the second intake side rocker arm 136, and the third intake side rocker arm 137 have a first shaft support hole 138 and a second shaft support hole, respectively, on the outer portion of the engine 130 (upper side in the drawing). 139 and a third shaft support hole 140 are formed. An intake side rocker arm shaft 141 supported by the cylinder head 3 is inserted into the first shaft support hole 138, the second shaft support hole 139, and the third shaft support hole 140, and the first intake side rocker arm 135, The intake side rocker arm 136 and the third intake side rocker arm 137 are swingably supported. The intake side rocker arm shaft 141 extends along the axial direction of the intake side camshaft 131.

  A first roller support hole 142 and a second roller support hole are formed in the engine 1 of the first intake side rocker arm 135, the second intake side rocker arm 136, and the third intake side rocker arm 137, respectively, on the inner side of the engine 1 (the lower side in the drawing). 143 and a third roller support hole 144 are formed. The first roller support hole 142, the second roller support hole 143, and the third roller support hole 144 are inserted with shafts 145, 146, and 147 that extend along the axial direction of the intake camshaft 131, respectively. , 149, 150 are rotatably supported. The roller 148 supported by the first roller support hole 142 contacts the first intake cam 132, the roller 149 supported by the second roller support hole 143 contacts the second intake cam 133, and the third roller support hole 144 supports The roller 150 that makes contact with the third intake cam 134.

  FIG. 9A shows a cross section of the first intake side rocker arm 135 viewed from the XX line of FIG. 8 and a cross section of the third intake side rocker arm 137 viewed from the ZZ line of FIG. FIG. 9B shows a cross section of the second intake-side rocker arm 136 as viewed from the Y-Y line of FIG. As shown in FIG. 9A, the first intake side rocker arm 136 and the third intake side rocker arm 137 have the same shape.

  As shown in FIG. 9A, a first pin support hole 151 is formed between the first shaft support hole 138 and the first roller support hole 142 in the first intake side rocker arm 135 and below. ing. FIG. 10 shows a cross section viewed from the line VV in FIG. 9A, and the first pin support hole 151 accommodates a plunger 153 biased by the spring 152 toward the second intake side rocker arm 136 side. Has been. In FIG. 9A, the cross sections of the spring 152 and the plunger 153 are omitted for convenience of explanation.

  Referring to FIG. 9B, a second pin support hole 154 is formed between the second shaft support hole 139 and the second roller support hole 143 in the second intake side rocker arm 136. Similarly to the above, FIG. 10 shows a cross section viewed from the line VV in FIG. 9B. The second pin support hole 154 accommodates a connecting intermediate pin 155 that can slide along the axial direction of the intake camshaft 131. One end of the connecting intermediate pin 155 is in contact with the plunger 153.

  Then, referring to FIG. 9A again, a third pin support hole 156 is formed between the third shaft support hole 140 and the third roller support hole 144 in the third intake-side rocker arm 137. . Referring to FIG. 10, the third pin support hole 156 accommodates the same connection pin 157 as in the first embodiment. One end of the connecting pin 157 is in contact with the connecting intermediate pin 155. The length in the longitudinal direction of the portion accommodated in the third pin support hole 156 of the connecting pin 157 is set to be substantially the same as the length (depth) of the third pin support hole 156 in the longitudinal direction.

  Here, referring to FIG. 4 used in the first embodiment, the shape of the first intake-side rocker arm 135 is the same as that of the first intake-side rocker arm 33 of the first embodiment. The arrangement relationship among the shaft support hole 138, the first roller support hole 142, and the first pin support hole 151 is such that the shaft support hole 48 and the roller of the first embodiment are compared from the straight lines “L1” to “L4”. The arrangement relationship between the support hole 47 and the pin support hole 50 is the same.

  Similarly, the positional relationship among the second shaft support hole 139, the second roller support hole 143, and the second pin support hole 154 is similar to the shaft support hole 48 and the roller support hole 47 of the first embodiment. The arrangement relationship with the pin support hole 50 is the same. Similarly, the positional relationship among the third shaft support hole 140, the third roller support hole 144, and the third pin support hole 156 is similar to the shaft support hole 48 and the roller support hole 47 of the first embodiment. It is the same as the arrangement relationship with the pin support hole 50,

  In this embodiment, referring to FIGS. 8 and 10, an actuator 63 for moving the push rod 65 similar to that in the first embodiment is provided, and an actuator 63 provided with a connecting pin 157 in the cylinder head 3. The structure pressed by the push rod 65 is the same as that of the first embodiment.

  Referring to FIG. 10, in this engine 130, when the high load operation region is reached, the push rod 65 presses the connection pin 157, so that the connection pin 157 is connected to the third pin support hole 156 and the second pin support hole 154. Between the second pin support hole 154 and the first pin support hole 151, and the connecting intermediate pin 155 is pressed against the plunger 153.

  As a result, the first intake side rocker arm 135, the second intake side rocker arm 136, and the third intake side rocker arm 137 are connected, so that the first intake side rocker arm 135 and The third intake side rocker arm 137 is driven to open and close. Here, since the cam peaks of the second intake cam 133 are set higher than the cam peaks of the first intake cam 132 and the second intake cam 134, the first intake side rocker arm 135 and the third intake side rocker arm 137 are set. The valve that is opened / closed by is switched in a larger and longer valve opening lift amount and valve closing timing in the high load operation region than in the low load operation region.

  Also in the embodiment described above, the support holes in the first intake side rocker arm 135, the second intake side rocker arm 136, and the third intake side rocker arm 137 are formed in parallel, and the support holes are brought close to each other. Therefore, it is possible to reduce the size and weight of the rocker arm including the roller. Since each support hole has the same arrangement relationship as in the first embodiment, the other effects described in the first embodiment can also be obtained.

  The present invention has been described so far with the first to fourth embodiments. However, the configuration in the above embodiment is an example of the present invention, and the present invention is not limited to the above embodiment. For example, in each of the above-described embodiments, the configuration has been described in which the intake-side valve opening / closing timing is variable by connecting or disconnecting the adjacent intake-side rocker arm, but the exhaust-side rocker arm is connected or disconnected. Therefore, it may be configured such that the opening / closing timing of the valve on the exhaust side is variable, and it is assumed that the present invention is implemented in this manner.

1 Engine 3 Cylinder Head 13 First Intake Valve (Valve)
14 Second intake valve (valve)
17 Umbrella part 18 Valve stem 33 First intake side rocker arm (rocker arm)
34 Second intake side rocker arm (rocker arm)
37 Intake side rocker arm shaft (Rocker arm shaft)
39 First intake cam (cam)
40 Second intake cam (cam)
41 Intake camshaft (camshaft)
47, 53 Roller support hole (roller support part)
48, 54 Shaft support hole (shaft support)
49 Connecting pin (pin member)
50, 55 Pin support hole (pin support part)
63 Actuator 65 Push rod

Claims (7)

The rocker arms (33, 34) are swung by the cams (39, 40) provided on the cam shaft (41) to open and close the valves (13, 14), and the two adjacent rocker arms (33, 34). By connecting or disconnecting with a pin member (49), the opening and closing timing of the valve (13, 14) can be made variable, and the push member (49) is advanced and retracted by pressing the pin member (49). 65), the two rocker arms (33, 34) are connected or disconnected by advancing and retracting the pin member (49) between the two adjacent rocker arms (33, 34). In the variable valve gear of the engine (1),
The rocker arm (33, 34) slides between the roller member (47, 53) for rotatably supporting the roller (45, 51) contacting the cam (39, 40) and the pin member (49). A pin support part (50, 55) for holding the movable part and a shaft support part (48, 54) for supporting the rocker arm (33, 34) on the cylinder head (3) by a rocker arm shaft (37). ) And
The roller support portions (47, 53), the pin support portions (50, 55), and the shaft support portions (48, 54) are support holes formed in parallel to each other;
The push rod (65) slides the pin member (49) by moving back and forth in parallel on the axis of the pin support portion (50, 55) ,
An end surface (65a) for pressing the pin member (49) of the push rod (65) extends over the swing range of the pin member (49) accompanying the swing of the rocker arm (33, 34), and the pin The member (49) is set to be pressable,
The pin support portion (50) is provided with a plunger (59) biased toward one of the rocker arms (34) by a spring (58),
The pin member (49) is provided on the plunger (59) side and is in contact with the plunger (59). The pin member (49) extends from the pressing portion (61) and contacts the push rod (65). A variable valve operating apparatus for an engine comprising: a rod side contact portion (62) having a diameter smaller than that of the pressing portion (61) .   The pin support portion (55) forms a pore (60) having a reduced diameter in the side portion of the one rocker arm (34) and penetrates the side portion of the one rocker arm (34). ,
  The rod side contact portion (62) of the pin member (49) is configured to extend from the pressing portion (61) and pass through the pore (60). The variable valve operating device for the engine described. The distance (D2) between the centers of the rocker arm shaft (37) and the pin member (49) is greater than the distance (D1) between the centers of the rocker arm shaft (37) and the rollers (45, 51). The variable valve operating apparatus for an engine according to claim 1 , wherein the variable valve operating apparatus is set to be shorter. The pin support portion (50, 55) has an umbrella portion (17) of the valve (13, 14) rather than a line (L1) connecting the centers of the rocker arm shaft (37) and the rollers (45, 51). , 17) and a straight line (L2) along the axial direction of the valve (13, 14) passing through the center of the rocker arm shaft (37) and the center of the pin support portion (50, 55) When engine according to claim 3, characterized in that said roller (45, 51) straight (L3) as along the axial direction of the valve (13, 14) the center of, and is disposed between the Variable valve gear. The pin support portion (50, 55) contacts the rocker arm (33, 34) where the rocker arm (33, 34) contacts the valve stem (18, 18) of the valve (13, 14). The variable valve operating apparatus for an engine according to claim 4 , wherein the variable valve operating apparatus for the engine according to claim 4 , wherein the variable valve operating apparatus is disposed closer to the umbrella portion of the valve (13, 14) than the portion (56, 57). The variable valve gear for an engine according to any one of claims 1 to 5 , wherein the pin support portion (50, 55) is disposed outside the valve (13, 14). The variable valve operating apparatus for an engine according to any one of claims 1 to 5 , wherein the pin support portion (95) is disposed inside the valve (13, 14).

Images