JP4163679B2 - Engine valve gear - Google Patents

Description

  The present invention relates to a valve operating apparatus for an engine in which a lift amount of an engine valve that is an intake valve or an exhaust valve is changed steplessly.

  In order to change the lift amount of the engine valve steplessly, one end of the push rod is fitted to the other end portion of the rocker arm having a valve contact portion that contacts the engine valve on one end side, and the other end of the push rod and A valve operating apparatus in which a link mechanism is provided between valve cams is already known from Patent Document 1.

  However, in the one disclosed in Patent Document 1, it is necessary to secure a relatively large space for arranging the link mechanism and the push rod between the valve cam and the rocker arm, and the valve gear becomes large. In addition, since the driving force from the valve cam is transmitted to the rocker arm via the link mechanism and the push rod, it is difficult to say that the follower of the rocker arm with respect to the valve cam, ie, the open / close operation followability of the engine valve is excellent.

Therefore, the applicant of the present invention has one end portion of the first and second link arms rotatably connected to the rocker arm, and the other end portion of the first link arm is rotatably supported by the engine body. An engine valve device in which the other end portion is displaced by driving means has already been proposed in Patent Document 2, and according to this valve device, the valve device can be made compact, It is possible to ensure excellent followability to the valve cam by transmitting power from the valve cam directly to the rocker arm.
JP-A-8-74534 JP 2004-36560 A

  By the way, in the proposed valve gear (Japanese Patent Laid-Open No. 2004-36560), the other end of the second link arm is rotatably supported by a movable support shaft, and is connected to the movable support shaft. The movable support shaft is displaced by driving the control shaft to be angularly displaced about an axis parallel to the axis of the movable support shaft. To precisely control the lift amount of the engine valve It is necessary to increase the support rigidity of the control shaft.

  The present invention has been made in view of such circumstances, and is designed to be compact while ensuring the followability of the opening / closing operation while continuously changing the lift amount of the engine valve, and moreover, the control shaft. It is an object of the present invention to provide an engine valve operating device with increased support rigidity.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a rocker arm that has a cam abutting portion that abuts on a valve cam and is linked to and coupled to an engine valve, and one end portion of the rocker arm is rotatable. And a second link whose one end is pivotally connected to the rocker arm and whose other end is pivotally supported at a fixed position of the engine body via a fixed support shaft. An arm, a movable support shaft that rotatably supports the other end of the second link arm, and a crank shape that is connected to the movable support shaft and is parallel to the axis of the movable support shaft. A valve operating apparatus for an engine , comprising: a control shaft that is supported by an engine body so as to be capable of rotating; and a driving means that is coupled to the control shaft to angularly displace the movable support shaft , Conte The shaft of the pair of webs arranged on both sides of the rocker arm, a journal part that is connected to the outer surface of the base end of each of the webs at a right angle and is rotatably supported by the engine body, and the journal part A connecting portion that connects the two webs at an offset position, and is configured in a crank shape, and the movable support shaft is provided between the two webs on one side of the connecting portion so as to connect between the webs. A second link between the webs on one side of the connecting portion so that the second link arm and the rocker arm overlap a part of the webs when viewed from the direction along the rotation axis of the control shaft. A part of each of the arm and the rocker arm is arranged .

The invention according to claim 2, in addition to the configuration of the invention according to claim 1, before Symbol control shaft, characterized in that it is supported on the engine body at opposite sides of the rocker arm.

According to a third aspect of the invention, in addition to the configuration of the first or second aspect of the invention, a single control shaft commonly connected to the movable support shafts of a plurality of cylinders arranged in a row is supported on the engine body. It is characterized by being.

According to a fourth aspect of the invention, in addition to the configuration of the first aspect of the invention, the journal portion of the control shaft is coupled to the upper holder coupled to the cylinder head of the engine body and the upper holder from below. It is supported so as to be rotatable with respect to the lower holder.

According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect of the present invention, the camshaft having the valve cam is rotatable by the upper holder and a cap fastened to the upper holder from above. A cam holder that is supported by the head is configured.

According to a sixth aspect of the invention, in addition to the configuration of the fifth aspect of the invention, the upper holder separate from the cylinder head is fastened to the cylinder head.

According to a seventh aspect of the invention, in addition to the configuration of the invention according to any one of the fourth to sixth aspects, a roller bearing that can be divided in half is interposed between the upper and lower holders and the journal portion. It is characterized by being.

The invention of claim 8, wherein, in addition to the configuration of the invention according to any one of claims 4-7, the upper and lower holders joined to each other, the support boss portion for the control shaft which projects into the web-side The journal portion formed and penetrating the control shaft support boss portion is rotatably supported between the upper and lower holders.

According to a ninth aspect of the present invention, in addition to the configuration of the fifth aspect of the present invention, a camshaft support boss projecting toward the rocker arm is formed on the cap, and the camshaft is used for the camshaft. It is characterized in that it is rotatably supported between the upper holder and the cap through the support boss part.

According to a tenth aspect of the present invention, in addition to the configuration of the ninth aspect of the invention, a rib connecting the control shaft support boss portion and the camshaft support boss portion protrudes from the upper holder. It is characterized by.

According to an eleventh aspect of the invention, in addition to the configuration of the invention of the first aspect , the control shaft has an outer surface of the connecting portion between the engine valve and a plug cylinder provided in a cylinder head. It is arranged so as to face the plug cylinder, and an escape groove for avoiding interference with the plug cylinder is formed on the outer surface of the connecting portion.

According to the present invention, it is possible to change the lift amount of the engine valve steplessly by driving the control shaft angularly and displacing the movable support shaft steplessly, and the first and second link arms. One end of the valve is directly connected to the rocker arm so that it can be rotated, so that the space for arranging both link arms can be reduced and the valve operating device can be made compact. Since it is directly transmitted to the cam contact portion, it is possible to ensure excellent followability to the valve cam. In particular, the control shaft includes a pair of webs arranged on both sides of the rocker arm, a journal part that is connected to the outer surface of the base end of each of the webs at a right angle and is rotatably supported by the engine body, and the journal part. Since it has a connecting portion connecting the two webs at an offset position and is configured in a crank shape, a movable support shaft is provided so as to connect between the two webs on one side of the connecting portion. The connection strength of the movable support shaft to the control shaft can be increased, and the support rigidity of the compact control shaft can be increased, thereby making it possible to precisely control the lift amount of the engine valve . Moreover, each of the second link arm and the rocker arm is arranged between the two webs on one side of the connecting portion so that the second link arm and the rocker arm overlap with a part of the both webs when viewed from the direction along the rotation axis of the control shaft. Since a part is arranged, the mechanism for making the lift amount of the engine valve variable can be made compact.

According to the second aspect of the present invention, the support rigidity of the control shaft can be further enhanced by supporting the control shaft on both sides by supporting the control shaft on both sides of the rocker arm.

According to the invention of claim 3 , by using a single control shaft common to a plurality of cylinders, an increase in the number of parts can be avoided and the engine can be made compact.

According to the invention of claim 4 , it is possible to improve the assembling property of the engine body to the cylinder head.

According to the fifth aspect of the present invention, it is possible to improve the assemblability of the camshaft to the cylinder head while minimizing the number of parts for supporting the camshaft.

According to the invention of claim 6, the degree of freedom in designing the cylinder head when supporting the control shaft can be increased.

According to the seventh aspect of the present invention, it is possible to improve the assembly of the control shaft while reducing the friction loss at the support portion of the control shaft.

According to the invention of claim 8 , the support rigidity of the control shaft can be further increased.

According to invention of Claim 9 , the support rigidity of a cam shaft can be improved.

According to the invention of claim 10 , the support rigidity of the control shaft and the camshaft can be further increased.

Furthermore, according to the eleventh aspect of the present invention, the plug cylinder can be disposed closer to the valve operating device side, and the engine can be made compact.

  Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 10 show an embodiment of the present invention. FIG. 1 is a partial longitudinal sectional view of an engine, taken along line 1-1 of FIG. 2, and FIG. 2 is taken along line 2-2 of FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2, FIG. 4 is an enlarged view of the main part of FIG. 1, FIG. 5 is a bottom view of the intake side rocker arm as viewed from the direction of arrow 5 in FIG. 6 is a perspective view of the lift variable mechanism, FIG. 8 is a sectional view taken along line 8-8 in FIG. 4, FIG. 9 is a sectional view taken along line 9-9 in FIG. 2, and FIG. It is the perspective view seen from the 10 arrow 10 direction.

  First, in FIG. 1, an engine body 11 of an in-line multi-cylinder engine E includes a cylinder block 13 having cylinder bores 12 provided therein, a cylinder head 14 coupled to the top surface of the cylinder block 13, and a cylinder head 14 And a head cover 15 coupled to the top surface of each of the cylinders. A piston 16 is slidably fitted to each cylinder bore 12 and a combustion chamber 17 facing the top of each piston 16 is a cylinder block 13 and a cylinder. It is formed between the heads 14.

  The cylinder head 14 is provided with intake ports 18 and exhaust ports 19 that can communicate with the combustion chambers 17. The intake ports 18 are opened and closed by intake valves 20 that are a pair of engine valves. Each exhaust port 19 is opened and closed by a pair of exhaust valves 21. Between the spring seat 22 and the cylinder head 14 provided at the upper end portion of the stem 20a provided in the intake valve 20, a valve spring 23 for urging each intake valve 20 in the valve closing direction is provided. Further, between the spring seat 24 and the cylinder head 14 provided at the upper end portion of the stem 21 a provided in the exhaust valve 21, a valve spring 25 that urges each exhaust valve 21 in the valve closing direction is provided.

  The intake side valve operating device 28 that opens and closes each intake valve 20 is configured according to the present invention, and includes an intake side camshaft 30 having an intake side valve cam 29 for each cylinder, and an intake side valve control. Each cylinder is provided with an intake-side rocker arm 31 and a lift variable mechanism 32 that are linked to and coupled to a pair of intake valves 20... The exhaust side valve operating device 33 that opens and closes 21... Is driven by an exhaust side camshaft 35 having an exhaust side valve cam 34 for each cylinder and the exhaust side valve cam 34 and swings for each cylinder. And an exhaust-side rocker arm 36 that is linked and connected in common to the pair of exhaust valves 21.

  2 and 3 together, upper holders 38 are fastened to the cylinder head 14 so as to be arranged on both sides of each cylinder, and the intake side cam holder is attached to each upper holder 38. 41 ... and the exhaust side cam holder 42 ... are joined together, and caps 39 ..., 40 ..., which are configured together, are fastened from above. Thus, the intake side camshaft 30 is rotatably supported between the upper holders 38 constituting the intake side cam holders 39 and the cap 39, and the upper holders 38 constituting the exhaust side cam holders 42 in cooperation with each other. An exhaust camshaft 35 is rotatably supported between the caps 40.

  One end of the exhaust side rocker arm 36 is supported so as to be swingable by an exhaust side rocker shaft 43 having an axis parallel to the exhaust side camshaft 35 and supported by the upper holder 38. A pair of tappet screws 44, 44 that abut on the upper ends of the stems 21a of the pair of exhaust valves 21 are screwed to the other end so that the forward and backward positions can be adjusted. In addition, a shaft 45 parallel to the exhaust side rocker shaft 36 is provided at an intermediate portion of the exhaust side rocker arm 36, and a roller 47 that is in rolling contact with the exhaust side valve cam 34 is in contact with the shaft 45. Is pivotally supported by the exhaust-side rocker arm 36.

  Such an exhaust side valve operating device 33 is configured such that the rocking support portion of the exhaust side rocker arm 36, that is, the exhaust side rocker shaft 43 is linked to the exhaust valve 21 of the exhaust side rocker arm 36, and the connecting portion, that is, the tappet screw 44. Are also arranged on the cylinder head 14 so as to be arranged outside.

  4 and 5, tappet screws 49, 49 that are in contact with the upper ends of the stems 20a of the pair of intake valves 20 from above are screwed into one end of the intake side rocker arm 31 so that the forward and backward positions can be adjusted. A valve connection part 31a is provided. The other end portion of the intake side rocker arm 31 is provided with a first support portion 31b and a second support portion 31c disposed below the first support portion 31b so as to be connected to each other. The portions 31b and 31c are formed in a substantially U shape that opens on the opposite side to the intake valves 20.

  The first support portion 31 b of the intake side rocker arm 31 is provided with a roller 50 as a cam contact portion that is in rolling contact with the intake side valve cam 29 of the intake side camshaft 30 via a first connecting shaft 51 and a roller bearing 52. The roller 50 is pivotally supported, and is disposed so as to be sandwiched between first U-shaped first support portions 31b.

  Referring also to FIG. 6, the intake side rocker arm 31 is molded by light alloy casting or the like, and has, for example, a substantially triangular hollow portion 53 at the center of the upper surface of the valve connecting portion 31 a. A pair of lightening portions 54, 54 are formed on both sides of the lower surface of the valve coupling portion 31a, which is the surface opposite to the upper surface, so as to be arranged alternately with the lightening portions 53. The

  By the way, the said thinning part 53,54,54 is shape | molded simultaneously with the shaping | molding of the intake side rocker arm 31, and a thinning part is formed as the draft of the upper thinning part 53 goes to the upper surface of the valve connection part 31a. 53 is a direction to widen the opening area, whereas the draft angle of the lower lightening portions 54, 54 is a direction to increase the opening area of the lightening portions 54, 54 toward the lower surface of the valve connecting portion 31a. The inclination direction of the inner surface of the lightening portion 53 is the same as the inclination direction of the inner surface of the lightening portions 54, 54, and the valve connecting portion 31 a is between the lightening portions 53, 54; 53, 54 adjacent to each other. The thicknesses of the wall portions 31d and 31d formed in are substantially uniform.

  Referring to FIGS. 7 and 8 together, the variable lift mechanism 32 has one end rotatably connected to the first support portion 31 b of the intake side rocker arm 31 and the other end fixed to the engine body 11. One end of the first link arm 58 is pivotally supported at a position via a suction side rocker shaft 57 as a fixed support shaft, and the second support portion 31c of the suction side rocker arm 31 is pivotally connected. The second link arm 59, the movable support shaft 60 that rotatably supports the other end of the second link arm 59, and the movable support shaft 60 can be angularly displaced about an axis parallel to the axis. The control shaft 61 is connected to the movable support shaft 60, and the actuator motor 62 is connected to the control shaft 61 so as to angularly displace the movable support shaft 60.

  One end portion of the first link arm 58 is formed in a substantially U shape so as to sandwich the first support portion 31b of the intake side rocker arm 31 from both sides, and a first connection that pivotally supports the roller 50 on the intake side rocker arm 31. The shaft 51 is rotatably connected to the first support portion 31b. The intake side rocker shaft 57 that rotatably supports the other end of the first link arm 58 is supported by upper holders 38 that are fastened to the cylinder head 14.

  One end portion of the second link arm 59 disposed below the first link arm 58 is disposed so as to be sandwiched between the second support portions 31 c of the intake side rocker arm 31, and is second supported via the second connecting shaft 63. The part 31c is pivotally connected.

  Support bosses 64, 64 are integrally projected on the upper holders 38, 38 on both sides of the other end portion of the first link arm 58 so as to support the intake side rocker shaft 57. The movement of the other end of the first link arm 58 in the direction along the axis of the intake rocker shaft 57 is restricted.

  The two intake valves 20 are spring-biased by the valve springs 23 in the valve closing direction, and the two intake valves 20 that are spring-biased in the valve closing direction are opened by the intake side rocker arm 31 in the valve opening direction. The roller 50 of the intake-side rocker arm 31 is in contact with the intake-side valve cam 29 by the action of the valve springs 23 when the intake valve 20 is closed. The spring force of... Does not act on the intake side rocker arm 31, and the roller 50 moves away from the intake side valve cam 29, and the control accuracy of the valve lift amount when the intake valve 20. There is a possibility that. Accordingly, the intake side rocker arm 31 is biased in a direction in which the roller 50 is brought into contact with the intake side valve cam 29 by a rocker arm biasing spring 65 different from the valve springs 23.

  The rocker arm urging springs 65 are coiled torsion springs surrounding the support bosses 64, and are provided between the engine body 11 and the intake side rocker arm 31. That is, one end of the rocker arm urging spring 65 is engaged with the support boss 64, and the other end of the rocker arm urging spring 65 is inserted into the hollow first connecting shaft 51 that operates integrally with the intake side rocker arm 31. Engaged.

  The other end portion of the first link arm 58 is formed in a cylindrical shape so that the outer periphery is arranged inwardly in a side view rather than the outer periphery of the rocker arm biasing spring 65 wound in a coil shape. A plurality of, for example, a pair of protrusions 66 and 67 for preventing the rocker arm urging springs 65 from falling to the first link arm 58 side are provided at both ends in the axial direction at the other end of the first link arm 58. Projections are provided at intervals in the direction. Therefore, while preventing the other end portion of the first link arm 58 from increasing in size, the rocker arm biasing springs 65 can be prevented from falling and the support rigidity of the other end portion of the first link arm 58 can be increased. .

  Moreover, the protrusions 66 and 67 are arranged so as to avoid the operating range of the second link arm 59, and the protrusions 66, 67... Are provided at the other end of the first link arm 58. The operating range of the second link arm 59 can be sufficiently secured.

  Oil jets 68 for supplying oil toward the upper portion on the other end side of the intake side rocker arm 31 are attached to caps 39 in intake cam holders 41 provided on the engine body 11.

  Incidentally, one of the plurality of upper holders 38 is provided with a passage 69 for guiding oil from an oil pump (not shown). Further, arc-shaped recesses 70 are provided on the upper portions of the upper holders 38 so as to face the lower half of the intake side camshaft 30, and the passage 69 communicates with one of the recesses 70. . On the other hand, the intake-side camshaft 30 is provided with an oil passage 71 coaxially, and the intake-side camshaft 30 is connected to the intake-side camshaft 30 at the portion corresponding to each intake-side cam holder 41. The holes 72 are provided so that the outer ends thereof open to the outer surface of the intake side camshaft 30. The intake side cam holders 41 and the intake side camshaft 30 are connected to each other via the communication holes 72. Lubricating oil is supplied.

  In addition, the lower surface of the cap 39 that constitutes the intake side cam holder 41 with the upper holder 38 is provided with a recess 73 that forms a passage leading to the recess 70 with the upper surface of the upper holder 38. The oil jets 68 are attached to the caps 39 so as to communicate with the passages 74 provided in the caps 39 through the passages 73.

  The oil jets 68 are attached to the caps 39 of the intake cam holders 46 provided on the engine body 11 so as to rotatably support the intake side camshaft 30 in this way, so that the intake side camshaft 30 and the intake side cam holder 41... Can be supplied from the oil jet 68 with a sufficiently high pressure and a sufficient amount of oil by utilizing an oil passage for lubricating the space 41.

  Further, the oil jet 68 supplies oil to the upper first connecting shaft 51 side of the first and second connecting shafts 51 and 63 that connect one end portions of the first and second link arms 58 and 59 to the intake side rocker arm 31. Therefore, the oil lubricated between the first link arm 58 and the intake side rocker arm 31 flows down to the second link arm 59 side below.

  In addition, the oil introduction holes 75 and 76 that allow a part of the movable support shaft 60 and the second connection shaft 63 to face the intermediate portion are second in the direction orthogonal to the straight line connecting the axes of the movable support shaft 60 and the second connection shaft 63. Provided in the link arm 59, one end of each oil introduction hole 75, 76 opens toward the first connecting shaft 51 side. Accordingly, the oil that has flowed downward from the first link arm 58 is effectively guided between the second link arm 59 and the movable support shaft 60 and the second connecting shaft 63, which is simple and reduces the number of parts. With the lubrication structure, the connecting portion between the intake side rocker arm 31 and the first and second link arms 58 and 59 and the space between the second link arm 59 and the movable support shaft 60 are both lubricated to ensure smooth valve operation. can do.

  The control shaft 61 is a single shaft that is supported by the engine body 11 in common for a plurality of cylinders arranged in a row, and includes webs 61 a and 61 a disposed on both sides of the intake-side rocker arm 31, and bases of both webs 61 a and 61 a. Each cylinder has a journal portion 61b, 61b that is connected to the outer surface of the end portion at a right angle and is rotatably supported by the engine body 11, and a connecting portion 61c that connects the webs 61a, 61a. Is done.

The control shaft 61 is at least partially when viewed from a direction along its rotational axis i.e. the journal portion 61b ... axis of the arrangement as web 61a ... part of overlap between the second link arm 5 9 In this example The movable support shaft 60 is connected to the control shaft 61 so as to connect the webs 61a and 61a.

  Each journal portion 61b of the control shaft 61 is rotatably supported between an upper holder 38 that is coupled to the cylinder head 14 of the engine body 11 and a lower holder 77 that is coupled to the upper holder 38 from below. Is done. The lower holders 77 ... are formed separately from the cylinder head 14 so as to be fastened to the upper holders 38 ..., and on the upper surface of the cylinder head 14, the recesses 78 for arranging the lower holders 77 ... Is provided.

  In addition, roller bearings 79 are interposed between the upper and lower holders 38, 77, and the journal portions 61b, and the roller bearings 79 are connected to a plurality of webs 61a, 61a, and the connection. ... Are arranged between the journal portions 61 b of the control shaft 61 common to the plurality of cylinders and the upper and lower holders 38, 77.

  By the way, the upper and lower holders 38, 77,... Are formed with control shaft support boss portions 80 projecting toward the web 61a of the control shaft 61 so as to penetrate the journal portion 61a. On the other hand, the upper holders 38 and the caps 39, which are coupled to each other to form the intake side cam holders 41 in cooperation, have camshaft support boss portions 81 that allow the intake side camshaft 30 to pass therethrough. The upper holders 38 are integrally formed with ribs 82 connecting the control shaft support boss portions 80 and the camshaft support boss portions 81. Established.

  In the ribs 82, passages 83 for guiding oil to the roller bearings 79 are provided so as to communicate with the recesses 70 on the upper surface of the upper holder 38.

  By the way, the exhaust side valve operating device 33 is arranged in the cylinder head 14 so that the swing support portion of the exhaust side rocker arm 36 is arranged outside the interlocking and connecting portion to the exhaust valve 21 of the exhaust side rocker arm 36. On the other hand, in the intake side valve operating device 28, the intake side rocker shaft 57 and the movable support shaft 60 are arranged on the inner side of the interlocking and connecting portion of the intake side rocker arm 31 to the intake valve 20. In this manner, the cylinder head 14 is disposed.

  In addition, a plug cylinder 87 into which a spark plug 86 attached to the cylinder head 14 is inserted so as to face the combustion chamber 17 is attached to the cylinder head 14 between the intake side and exhaust side valve devices 28, 33. The cylinder 87 is arranged so as to be inclined so as to approach the exhaust side valve operating apparatus 33 as it goes upward.

  Thus, the control shaft 61 in the intake side valve operating device 28 is arranged between the intake valves 20 and the plug cylinders 87 so that the connecting portions 61c are opposed to the plug cylinders 87. However, relief grooves 88 for avoiding interference with the plug cylinders 87 are formed on the outer surface of the connecting portions 61c.

  By the way, the second connecting shaft 63 that connects the second link arm 59 to the intake side rocker arm 31 when the intake valves 20 are closed is coaxial with the journal portion 61b of the control shaft 61. Oscillates around the axis of the journal portion 61b..., The movable support shaft 60 moves on an arc centered on the axis of the journal portion 61b.

  9 and 10, one of the journal portions 61b... Provided in the control shaft 61 protrudes from a support hole 89 provided in the head cover 15. A control arm 91 is fixed to the tip of the journal portion 61b. The control arm 91 is driven by an actuator motor 62 attached to the outer wall of the cylinder head 14. That is, the nut member 93 meshes with the screw shaft 92 rotated by the actuator motor 62, and the other end of the connection link 95 pivotally supported at one end by the pin 94 on the nut member 93 is connected to the control arm 91 via the pins 96 and 96. Connected to Therefore, when the actuator motor 62 is actuated, the nut member 93 moves along the rotating screw shaft 92, and the control shaft 61 is moved around the journal portion 61b by the control arm 91 connected to the nut member 93 via the connection link 95. The movable support shaft 60 is displaced by swinging.

  A rotation angle sensor 97 such as a rotary encoder is provided on the outer wall surface of the head cover 15, and one end of a sensor arm 98 is fixed to the tip of the sensor shaft 97a. A guide groove 99 extending linearly along the longitudinal direction is formed in the control arm 91, and a connecting shaft 100 provided at the other end of the sensor arm 98 is slidably fitted in the guide groove 99. .

  The screw shaft 92, the nut member 93, the pin 94, the connection link 95, the pins 96 and 96, the control arm 91, the rotation angle sensor 97, the sensor arm 98 and the connection shaft 100 are bolts 102 on the side surfaces of the cylinder head 14 and the head cover 15. And a cover 103 that covers the open end surface of the case 101 is attached to the case 101 with screw members 104.

  In the variable lift mechanism 32, when the control arm 91 is rotated counterclockwise from the position shown in FIG. 9 by the actuator motor 62, the control shaft 61 connected to the control arm 91 is also rotated counterclockwise to move the movable support. The shaft 60 is lowered. When the roller 50 is pressed by the intake side valve cam 29 of the intake side camshaft 30 in this state, the four nodes connecting the intake side rocker shaft 57, the first connecting shaft 51, the second connecting shaft 63, and the movable support shaft 60 are connected. The link is deformed and the intake side rocker arm 31 swings downward, the tappet screws 49 and 49 press the stem 20a of the intake valve 20, and the intake valve 20 is opened with a low lift.

  When the control arm 91 is rotated to the solid line position in FIG. 9 by the actuator motor 62, the control shaft 61 connected to the control arm 91 is rotated clockwise, and the movable support shaft 60 is raised. In this state, when the roller 50 is pressed by the intake side valve cam 29 of the intake camshaft 30, the four-bar link is deformed, the intake side rocker arm 31 swings downward, and the tappet screws 49, 49 are connected to the intake valve. 20 ... stems 20a are pressed and intake valves 20 ... are opened with high lift.

  Next, the operation of this embodiment will be described. In the variable lift mechanism 32 for continuously changing the opening lift amount of the intake valves 20..., One end of the first and second link arms 58 and 59 is a pair. The other end of the first link arm 58 is supported by the engine body 11 in parallel with the intake side rocker arm 31 having a valve connecting portion 31a linked and connected to the intake valves 20. The second link arm 59 is rotatably supported by a movable movable shaft 60 that is displaceable by the intake side rocker shaft 57.

  Therefore, the lift amount of the intake valves 20 can be changed steplessly by displacing the movable support shaft 60 steplessly, and the intake amount can be controlled without using a throttle valve. In addition, one end portions of the first and second link arms 58 and 59 are directly connected to the intake side rocker arm 31 so as to be rotatable, so that the space for disposing both the link arms 58 and 59 is reduced and the valve operating device is made compact. Since the power from the intake side valve cam 29 is directly transmitted to the roller 50 of the intake side rocker arm 31, excellent followability to the intake side valve cam 29 can be secured. Further, the positions of the intake side rocker arm 31 and the first and second link arms 58 and 59 in the direction along the axis of the intake side camshaft 30 can be arranged at substantially the same position, and the axis of the intake side camshaft 31 is aligned. The intake side valve operating device 28 in the direction can be made compact.

  One end of the first link arm 58 is rotatably connected to the intake side rocker arm 31 via the first connection shaft 51, and the roller 50 is pivotally supported on the intake side rocker arm 31 via the first connection shaft 51. Therefore, it is possible to achieve the pivotable connection of the one end portion of the first link arm 58 to the intake side rocker arm 31 and the pivotal support of the roller 50 to the intake side rocker arm 31 with the common first connection shaft 51. Thus, the number of parts can be reduced and the intake side valve operating device 28 can be made more compact.

  In the intake side valve operating device 28 including the link variable mechanism 32 among the intake side and exhaust side valve operating devices 28 and 33, the intake side rocker shaft 57 and the movable support shaft 60 are connected to the intake valves 20 of the intake side rocker arm 31. The swinging support portion of the exhaust side rocker arm 36 provided in the exhaust side valve operating device 33 is disposed inside the interlocking and connecting portion, and is disposed outside the interlocking and connecting portion of the exhaust side rocker arm 36 and the exhaust valve 21. Therefore, even if the sandwiching angle α (see FIG. 1) of the intake valves 20... And the exhaust valves 21. However, mutual interference between the intake side and exhaust side valve operating devices 28 and 33 can be avoided.

  The exhaust side valve operating device 33 is connected to the engine body 11 via an exhaust side camshaft 35 having an exhaust side valve cam 34 and an exhaust side rocker shaft 43 so as to be swung by being driven by the exhaust side valve cam 35. A plug cylinder 68 provided between the intake side and the exhaust side valve operating devices 28 and 33 is provided with an exhaust side rocker arm 36 which is supported so as to be swingable and is linked to and connected to the exhaust valves 21. Accordingly, the plug cylinder 68 is disposed so as to avoid interference with the intake side and exhaust side valve operating devices 28 and 33 because it is attached to the cylinder head 14 so as to be closer to the exhaust side valve operating device 33. Thus, it is possible to contribute to further downsizing of the entire cylinder head 14.

  By the way, in the link variable mechanism 32 of the intake side valve operating apparatus 28, the control shaft 61 to which the movable support shaft 60 is connected is configured in a crank shape. The control shaft 61 is made compact after the control shaft 61 is made compact. This makes it possible to precisely control the lift amount of the intake valves 20. In addition, the control shaft 61 includes webs 61a, 61a disposed on both sides of the intake side rocker arm 31, and a journal portion that is rotatably supported by the engine body 11 in a manner perpendicular to the outer surfaces of the base ends of the webs 61a, 61a. 61b, 61b and a connecting portion 61c connecting both webs 61a, 61a are formed in a crank shape, and the movable support shaft 60 is connected to the control shaft 61 so as to connect both webs 61a, 61a. Therefore, the connection strength of the movable support shaft 60 to the control shaft 61 can be increased. The control shaft 61 is supported by the engine body 11 on both sides of the intake side rocker arm 31, and the support rigidity of the control shaft 61 is further enhanced by supporting both ends, and the lift amount variable control of the intake valves 20 is more precise. Can be performed.

  In addition, since the single control shaft 61 is supported by the engine body 11 in common for a plurality of cylinders arranged in a row, an increase in the number of parts can be avoided and the engine E can be made compact. In addition, since the second link arm 59 and the control shaft 61 are arranged so that at least a part of the second link arm 59 and the control shaft 61 are overlapped when viewed from the direction along the rotation axis of the control shaft 61, the lift amount of the intake valves 20 is variable. The lift variable mechanism 32 can be made compact.

  The journal portion 61b of the control shaft 61 is rotatable between an upper holder 38 that is coupled to the cylinder head 14 of the engine body 11 and a lower holder 77 that is coupled to the upper holder 38 from below. The lower holder 77, which is supported and can be assembled to the engine body 11 of the control shaft 61 and is separate from the cylinder head 14, is fastened to the upper holder 38. Therefore, the degree of freedom in designing the cylinder head 14 for supporting the control shaft 61 can be increased.

  Further, since the roller bearings 79 that can be divided in half are interposed between the upper and lower holders 38, 77, and the journal portion 61b, the friction loss at the support portion of the control shaft 61 is reduced. Assembling property of the control shaft 61 can be improved.

  The upper and lower holders 38, 77, which are coupled to each other are formed with control shaft support boss portions 80 projecting toward the web 61a of the control shaft 61. Since the penetrating journal portions 61b are rotatably supported between the upper and lower holders 38, 77, etc., the support rigidity of the control shaft 61 can be further increased.

  Also, camshaft support bosses 81 projecting toward the intake side rocker arm 31 are formed on the upper holders 38 and caps 39 that are coupled to the upper holders 38 from above, and the intake side camshaft 30. However, since it is rotatably supported between the upper holders 38 and the caps 39 through the camshaft support boss portions 81, the number of parts for supporting the intake camshaft 30 is minimized. Thus, it is possible to improve the assembling property of the intake side camshaft 30 to the cylinder head 14 and increase the support rigidity of the intake side camshaft 30.

  Further, ribs 82 connecting between the control shaft support boss portions 80 and the camshaft support boss portions 81 project from the upper holder 38, so that the support shaft 61 and the intake side camshaft 30 have a supporting rigidity. It can be further increased.

  By the way, the control shaft 61 is arranged between the intake valves 20... And the plug cylinder 87 provided in the cylinder head 14 so that the outer surface of the connecting portion 61c faces the plug cylinder 87. Since an escape groove 88 for avoiding interference with the plug cylinder 87 is formed on the outer surface of 61c, the plug cylinder 87 can be disposed closer to the intake side valve device 28 side, and the engine E Compactness is possible.

  In the intake side rocker arm 31 of the intake side valve operating device 28, the lightening portions 53, 54 and 54 which are alternately arranged are formed on opposite surfaces of the valve connecting portion 61a. Can be achieved.

  Moreover, when the intake side rocker arm 31 is molded, the thinned portions 53, 54, 54 are also formed, but the draft angles of the adjacent thinned portions 53, 54; 53, 54 are opposite to each other. Therefore, the inner side surfaces of the thinned portions 53, 54; 53, 54 adjacent to each other are inclined in the same direction, and therefore the intake side rocker arm 31 is interposed between the thinned portions 53, 54; 53, 54 adjacent to each other. The wall portions 31d and 31d formed in the above are substantially equal in thickness, and the rigidity of the intake rocker arm 31 can be maintained by the wall portions 31d and 31d having substantially the same thickness.

  Further, since the intake side valve device 28 includes the variable lift mechanism 32 that allows the lift amount of the intake valves 20 to be steplessly variable, the number of parts is relatively large, and the weight of the intake side valve device 28 is increased. Even in the intake side valve operating device 28 having the lift variable mechanism 32 that tends to be associated, the intake side valve operating device 28 can be reduced in weight by reducing the weight of the intake side rocker arm 31, and the limit rotational speed can be increased. Can be achieved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

FIG. 3 is a partial longitudinal sectional view of the engine, taken along line 1-1 of FIG. FIG. 2 is a sectional view taken along line 2-2 of FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. It is a principal part enlarged view of FIG. It is the bottom view which looked at the intake side rocker arm from the 5th arrow direction of FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG. It is a perspective view of a lift variable mechanism. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 4. It is a 9-9 line arrow directional view of FIG. It is the perspective view seen from the 10 arrow direction of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Engine main body 14 ... Cylinder head 20 ... Intake valve 29 as an engine valve ... Valve cam 30 ... Cam shaft 31 ... Rocker arm 38 ... Upper holder 39 ... Cap 50... Roller 57 as cam contact portion... Intake side rocker shaft 58 as fixed support shaft... First link arm 59. ..Control shaft 61a ... Web 61b ... Journal portion 61c ... Connection portion 62 ... Actuator motor 77 as drive means ... Lower holder 79 ... Roller bearing 80 ... For control shaft Support boss 81 ... Camshaft support boss 82 ... Rib 87 ... Plug cylinder 88 ... Escape groove

Claims (11)

A rocker arm (31) that has a cam contact portion (50) that contacts the valve cam (29) and is linked to and connected to the engine valve (20), and one end portion of the rocker arm (31) is rotatable. A first link arm (58) connected to the engine main body (11) at a fixed position and rotatably supported via a fixed support shaft (57) and one end of the rocker arm (31). The second link arm (59) is rotatably connected, the movable support shaft (60) is rotatably supported on the other end of the second link arm (59), and is configured in a crank shape. A control shaft (61) coupled to the movable support shaft (60) and supported on the engine body (11) so as to be rotatable about an axis parallel to the axis of the movable support shaft (60); Previous to angularly move the movable spindle (60) A valve operating system for an engine and a drive means coupled to the control shaft (61) (62),
The control shaft (61) is connected to a pair of webs (61a) disposed on both sides of the rocker arm (31) and to the engine body (11) at right angles to the outer surfaces of the base ends of both webs (61a). A journal portion (61b) rotatably supported and a connecting portion (61c) connecting the two webs (61a) at a position offset with respect to the journal portion (61b) are configured in a crank shape. And the movable support shaft (60) is provided between the two webs (61a) on one side of the connecting portion (61c),
The connecting portion (61c) is arranged such that the second link arm (59) and the rocker arm (31) overlap with a part of both webs (61a) when viewed from the direction along the rotation axis of the control shaft (61). ), A part of each of the second link arm (59) and the rocker arm (31) is disposed between the two webs (61a) . Before SL control shaft (61) is a valve operating device for an engine according to claim 1, characterized in that it is supported on the engine body (11) on both sides of said rocker arm (31). Claim 1 or 2 single said control shaft connected in common to the movable support shaft of the plurality cylinders arranged in a row (60) (61), characterized in that it is supported on the engine body (11) The valve operating device for an engine according to 1. Lower holder before Symbol control shaft journal portion of (61) (61b) is coupled from the lower and upper holders (38) coupled to the cylinder head of the engine body (11) (14), the upper holder (38) The valve operating apparatus for an engine according to claim 1 , wherein the valve operating apparatus is rotatably supported between the engine and the engine. The previous SL upper holder (38), out with the cap (39) which is fastened from above to the upper holder (38), rotatably supporting the camshaft (30) having the valve operating cam (29) cam holder ( 41) The engine valve operating apparatus according to claim 4, wherein 41) is configured. Before SL said upper holder separately from the cylinder head (14) (38), a valve operating device for an engine according to claim 5, characterized in that it is fastened to the cylinder head (14). Before and SL upper and lower holder (38,77), between the journal portion (61b), one of the claims 4 to 6 half can roller bearing (79) is characterized in that it is interposed The engine valve operating device according to claim 1. The mutually coupled upper and lower holder (38,77), said web control shaft supporting boss portion protruding (61a) side (80) is formed, the control shaft supporting boss portions (80) The valve operating apparatus for an engine according to any one of claims 4 to 7 , wherein the penetrating journal portion (61b) is rotatably supported between the upper and lower holders (38, 77). Through prior Symbol cap (39), said rocker arm (31) supporting boss camshaft projecting side (81) is formed, said camshaft (30), the camshaft support boss portion (81) 6. The valve gear for an engine according to claim 5 , wherein the valve is rotatably supported between the upper holder (38) and the cap (39). Said control shaft supporting boss portions (80) and the camshaft support boss portion (81) rib connecting the (82) according to claim 9, characterized in that it is protruded to the upper holder (38) Engine valve gear. Before SL control shaft (61) is, the engine valve (20), between the plug cylinder provided in the cylinder head (14) and (87), the plug tube and the outer surface of the connecting portion (61c) (87) to be arranged so as to be opposed to the outer surface of the connecting portion (61c), according to claim 1, wherein a clearance groove for avoiding interference with the plug cylinder (87) (88) is formed Engine valve gear.

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