JP2005240615A - Variable valve device of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the whole structure including an electric motor for driving a control shaft to rotate, a storing box and a sensor compact in the axial direction of the control shaft in a variable valve device of an engine in which one end of the control shaft for varying the operational characteristic of an engine valve according to the rotation around the axis is projected into the storing box fitted to the outer surface of the side wall of an engine body, the electric motor is fitted to the outer surface of the storing box, and a power transmission means including a screw shaft is stored in the storing box to transmit the power of the electric motor to the control shaft. <P>SOLUTION: The electric motor 110 having an output shaft 20 whose axis is parallel to the screw shaft 114 is fitted to the outer surface of the storing box 90, the power transmission means 111 including a speed reduction gear mechanism 119 provided between the output shaft 120 and the screw shaft 114 is stored in the storing box, and the sensor disposed coaxially with the control shaft 61 to detect the rotation amount of the control shaft 61 is fitted to the wall part of the storing box 90 opposite to one end of the control shaft 61. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a variable valve operating device for an engine, and more particularly, to a control shaft capable of changing the operating characteristics of an engine valve in response to rotation around an axis, in a storage box in which one end thereof is attached to the outer side wall of the engine body. And an electric motor which is rotatably supported by the engine body and is arranged on the outer side of the storage box is attached to the outer surface of the storage box, and the axis is arranged on a plane perpendicular to the axis of the control shaft The present invention relates to a variable valve operating device for an engine which is housed in the housing box so that power transmission means including a screw shaft transmits power of an electric motor to the control shaft.

Such a variable valve operating device is already known from Patent Document 1 and the like.
JP 2003-74318 A

  In the conventional variable valve operating apparatus, an electric motor having an output shaft having an axis parallel to the control shaft is attached to the storage box, and the screw shaft whose axis is arranged on a plane perpendicular to the control shaft and the output shaft is provided. Rotational power is transmitted from the output shaft through the bevel gear mechanism, and the rotational movement of the screw shaft is converted into the rotational movement of the control shaft through the control arm, and the amount of rotation of the control shaft is detected. The sensor for doing so is attached to the storage box so as to face one end of the control shaft.

  In such a conventional variable valve device configuration, the entire structure of the electric motor, the storage box and the sensor for rotationally driving the control shaft becomes larger in the axial direction of the control shaft, which increases the size of the engine. It will be connected.

  The present invention has been made in view of such circumstances, and an engine variable valve in which an entire structure including an electric motor for rotationally driving a control shaft, a storage box, and a sensor is made compact in the axial direction of the control shaft. An object is to provide an apparatus.

  In order to achieve the above object, according to the present invention, a control shaft capable of changing the operating characteristics of an engine valve in response to rotation around an axis line enters one end of a control box into a storage box attached to the outer surface of the engine body side wall. A screw shaft that is rotatably supported by the engine body, an electric motor disposed outside the storage box is attached to the outer surface of the storage box, and an axis is disposed on a plane perpendicular to the axis of the control shaft In the variable valve operating apparatus of the engine housed in the storage box for transmitting the power of the electric motor to the control shaft, the electric motor has an output shaft having an axis parallel to the screw shaft. And the power transmission means includes a reduction gear mechanism provided between the output shaft and the screw shaft. Stored, a sensor is arranged to detect the amount of rotation of said control shaft to a control shaft coaxially, characterized in that attached to the wall of the storage box opposite to the one end of the control shaft.

  According to the above configuration of the present invention, since the electric motor is attached to the outer surface of the storage box with the axis of the output shaft parallel to the axis of the screw shaft, the electric motor and the engine of the storage box in the direction along the axis of the control shaft. The amount of protrusion from the main body can be suppressed. In addition, it is possible to detect the amount of rotation of the control shaft with high accuracy by arranging a sensor so as to be coaxially opposed to one end of the control shaft. Even if such a sensor is arranged, the electric motor and the storage box In addition, the overall structure including the sensor and the sensor can be made compact in the axial direction of the control shaft, and the engine can be prevented from being enlarged. In addition, since the rotational power output from the output shaft of the electric motor is transmitted to the screw shaft via the reduction gear mechanism, the electric motor can be reduced in size and further reduced in size.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 11 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. 4 is a sectional view of the variable lift mechanism, FIG. 8 is a sectional view taken along the line 8-8 in FIG. 4, FIG. 9 is a sectional view taken along the line 9-9 in FIG. 2, and FIG. FIG. 11 is a perspective view showing a part of the power transmission means.

  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 as a pair of engine valves, respectively. 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. The cam 29 swings in response to the cam 29 and changes the valve opening lift amount among the operating characteristics of the intake side rocker arm 31 and the intake valve 20. The exhaust variable valve mechanism 33 for opening and closing the exhaust valves 21 is provided with a variable lift mechanism 32 for each cylinder, and an exhaust side camshaft 35 having an exhaust side valve cam 34 for each cylinder; Each cylinder is provided with an exhaust-side rocker arm 36 that swings following the exhaust-side valve cam 34 and that is linked to and connected to a pair of exhaust valves 21 for each cylinder.

  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. Further, 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.

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

  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 31a is between the adjacent lightening portions 53, 54; 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. A first link arm 58 that is rotatably supported at a position via an intake side rocker shaft 57, and a second link arm whose one end portion is rotatably connected to the second support portion 31c of the intake side rocker arm 31. 59, a movable support shaft 60 that rotatably supports the other end of the second link arm 59, and a movable support shaft 60 that can angularly displace the movable support shaft 60 about an axis parallel to the axis. And a control shaft 61 coupled to the.

  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 part on the other end side of the intake side rocker arm 31 are attached to the caps 39 of the intake side 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 are opened on the outer surface of the intake side camshaft 30. As a result, lubricating oil is supplied between the intake side cam holders 41 and the intake side camshaft 30 through the communication holes 72.

  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. A journal portion 61b, 61b that is connected to the engine body 11 so as to be rotatable at right angles to the outer surface of the end portion, and a connecting portion 61c that connects the webs 61a, 61a for each cylinder. The movable support shaft 60 is connected to the control shaft 61 so as to connect both 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, needle bearings 79 are interposed between the upper and lower holders 38, 77, and the journal portions 61b, and the needle bearings 79 are connected to the 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 needle 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.

  When the control shaft 61 rotates in the direction in which the movable support shaft 60 descends and the roller 50 is pressed by the intake side valve cam 29 of the intake side camshaft 30, the intake side rocker shaft 57, the first connecting shaft 51, The four-bar link connecting the second connecting shaft 63 and the movable support shaft 60 is deformed, the intake side rocker arm 31 swings downward, the tappet screws 49, 49 press the stem 20 a of the intake valve 20, and the intake valve 20. Open the valve with a low lift.

  Further, when the control shaft 61 rotates in the direction in which the movable support shaft 60 rises and the roller 50 is pressed by the intake side valve cam 29 of the intake camshaft 30, the four-bar link is deformed and the intake side rocker arm 31 is deformed. Swings downward, the tappet screws 49, 49 press the stem 20a of the intake valves 20 ..., and the intake valves 20 ... open with high lift.

  9 and 10 together, one end portion of the control shaft 61 along the cylinder arrangement direction, that is, the journal portion 61b on one end side along the cylinder arrangement direction among the plurality of journal portions 61b provided in the control shaft 61. Is inserted into a storage box 90 attached to the outer surface of the side wall of the cylinder head 14 in the engine body 11, and is attached to the engine body 11 by supporting at least a part of the outer periphery of the journal portion 61 b. Among the plurality of upper holders 38 that are attached to the cylinder head 14 while supporting the upper half of the outer periphery of the journal portion 61b in this embodiment, the upper holder 38 on one end side in the cylinder arrangement direction is , While surrounding the journal portion 61b on one end side along the cylinder arrangement direction, Positioning portion 91 allowed to protrude a part from the side wall outer surface of the cylinder head 14 and the head cover 15 in 11 is provided integrally.

  By the way, the mating surface 92 of the cylinder head 14 to the head cover 15 is formed flat, whereas the portion of the mating surface 93 of the head cover 15 to the cylinder head 14 corresponding to the positioning portion 19 is a recess opened downward. 93a is formed, and a concave portion 94 that is recessed in an arc shape is provided on the portion of the mating surface 92 of the cylinder head 14 corresponding to the concave portion 93a so as to open to the outside. In addition, a ridge 14 a extending vertically is integrally provided on the inner surface of the side wall of the cylinder head 14, and the upper surface of the ridge 14 a is substantially U-shaped to surround the recess 94 and is flush with the mating surface 92. A continuous flat sealing surface 95 is formed.

  The positioning portion 91 includes a sandwiched portion 91a formed in a substantially trapezoidal shape so as to be sandwiched between the concave portion 93a of the mating surface 92 of the cylinder head 14 and the mating surface 93 of the head cover 15, and the sandwiched portion 91a and the upper holder. 38 is integrally provided with a connecting portion 91b that connects the two portions 38 and a cylindrical protruding portion 91c that is continuous with the lower portion of the sandwiched portion 91a so as to partially protrude from the outer surface of the side wall of the cylinder head 14 and the head cover 15.

  The positioning portion 91 is provided with a through hole 96 through which the journal portion 91b of the control shaft 91 is inserted, and a needle bearing 97 is interposed between the outer end side inner surface of the through hole 96 and the journal portion 91b. The

  A seal member 98 interposed between the mating surfaces 92 and 93 of the cylinder head 14 and the head cover 15 is attached to the mating surface 93 of the head cover 15, and the seal member 98 is formed on the recess 93 a of the mating surface 93. It is formed so as to be interposed between the inner surface and the sandwiched portion 91 a of the positioning portion 91. Further, in the positioning portion 91, the lower portion of the projection 91c is fitted into the recess 94 of the mating surface 92, but the lower surface of the portion excluding the projection 91c corresponds to the mating surface 92 and the seal surface 95 of the cylinder head 14. The seal surface 99 is formed between the mating surface 92 and the seal surface 95 of the cylinder head 14 and the seal surface 99 so as to surround the protrusion 91c. The member 100 is interposed so that both ends thereof are connected to the seal member 98.

  The storage box 90 includes a box main body 101, a bowl-shaped case 102 fastened to the box main body 101, and a lid member 103 fastened to the box main body 101.

  The box main body 101 is integrally provided with a case portion 101a that is formed in a box shape that is open on the side opposite to the cylinder head 14, and a support wall portion 101b that extends downward and continues to one side wall of the case portion 101a. A plurality of bolts 104 are attached to the outer surface of the side wall of the cylinder head 14. The case 102 is fastened to the box main body 101 with a plurality of bolts 105 so as to cover the one side wall and the support wall portion 101b of the case 101a from the outside, and the lid member 103 is separated from the cylinder head 14. The case portion 101a is fastened to the case portion 101a by tightening together a plurality of bolts 104 for fastening the case portion 101a among the plurality of bolts 104 so as to cover the case portion 101a from the opposite side.

  In the box main body 101 of the storage box 90, a fitting 91c that protrudes from the outer surface of the side wall of the cylinder head 14 and the head cover 15 of the positioning portion 91 is fitted to the end wall that contacts the outer surface of the side wall of the cylinder head 14. A hole 106 is provided, and an annular seal member 107 that elastically contacts the outer periphery of the protrusion 91 c is attached to the inner surface of the fitting hole 106.

  An electric motor 110 disposed outside the storage box 90 is attached to the storage box 90, and the rotational power of the electric motor 110 is transmitted to the journal portion 91 b that is one end of the control shaft 91 in the storage box 90. The power transmission means 111 for carrying out is accommodated.

  Referring also to FIG. 11, the power transmission means 111 includes a control arm 113 whose base end portion is solidified via a key 112 at one end portion of the journal portion 61 b that is inserted into the storage box 90, and a journal portion 61 b. A screw shaft 114 whose axis is arranged in a plane perpendicular to the axis of the screw, a nut member 115 screwed to the screw shaft 114, one end connected to the nut member 115 by a pin 116, and the other end to pins 117 and 117. , And a reduction gear mechanism 119 provided between the screw shaft 114 and the electric motor 110.

  The control arm 113 is housed in the case portion 101a of the box body 101 in the storage box 90, and most of the screw shaft 114 having an axis extending in the lateral direction is mostly in the case portion 101a below the journal portion 61b. The both ends of the screw shaft 114 are rotatably supported by the side wall of the case portion 101a. Moreover, one end of the screw shaft 114 is inserted into the case member 102.

  The electric motor 110 has an output shaft 120 parallel to the axis of the screw shaft 114, and is disposed outside the storage box 90 below the screw shaft 114. The electric motor 110 disposed below the case portion 101a includes a plurality of bolts 121 on the support wall portion 101b of the box main body 101 so that one end portion of the output shaft 120 projects into the case member 102. Mounted.

  The reduction gear mechanism 119 is provided between the output shaft 120 and the screw shaft 114 of the electric motor 110 and is housed in the case member 102. The drive gear 122 fixed to the output shaft 120, and the drive gear 122. And a driven gear 123 fixed to one end of the screw shaft 114.

  By the way, a pair of detected portions 124 and 124 are projected from the base end portion of the control arm 113 so as to be arranged on a virtual arc centered on the axis of the journal portion 61 b of the control shaft 61. In the storage box 90, the amount of rotation of the control shaft 61 is detected by detecting the detected parts 124 and 124 on the lid member 103 which is a wall part facing the one end part of the journal part 61b. A sensor 125 coaxial with the shaft 61, such as a rotary encoder, is mounted.

  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, the control shaft 61 provided in the link variable mechanism 32 of the intake side valve operating device 28 is connected to the movable support shaft 60 so that the movable support shaft 60 can be angularly displaced about an axis parallel to the axis, and is connected to the intake side. It is supported on the engine body 11 on both sides of the rocker arm 31, and the support rigidity of the control shaft 61 is enhanced by supporting both ends, and the lift amount variable control of the intake valves 20 can be precisely 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, 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, it is possible to increase the rigidity of the control shaft 61 that is angularly driven.

  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, can improve the assembly of the control shaft 61 to the engine body 11, 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. The support rigidity of the intake camshaft 30 can be increased.

  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.

  In addition, a part of the journal portion 61 b at one end of the control shaft 61 is inserted into the storage box 90 attached to the outer side wall of the engine body 11, and the electric motor 110 disposed outside the storage box 90 is connected to the storage box 90. A power transmission means 111 including a screw shaft 114 attached to the outer surface of the motor shaft and having an axis line arranged on a plane orthogonal to the axis line of the control shaft 61 is stored in the storage box 90 so as to transmit the power of the electric motor 110 to the control shaft 61. The electric motor 110 has an output shaft 120 having an axis parallel to the screw shaft 114 and is attached to the outer surface of the storage box 90, and the power transmission means 111 is a deceleration provided between the output shaft 120 and the screw shaft 114. A gear mechanism 119 is provided and stored in the storage box 90.

  Therefore, the amount of projection of the electric motor 120 and the storage box 90 from the engine body 11 in the direction along the axis of the control shaft 61 can be suppressed, and the rotational power output from the output shaft 120 of the electric motor 110 is reduced gear mechanism. Since it is transmitted to the screw shaft 114 via 119, the electric motor 110 can be reduced in size, and further downsizing can be achieved.

  Further, a sensor 125 is disposed so as to be coaxially opposed to one end portion of the control shaft 61, the amount of rotation of the control shaft 61 can be detected with high accuracy, and the electric motor 110 and the storage box 90 are controlled by the control shaft 61. Therefore, the entire structure including the electric motor 110, the storage box 90, and the sensor 125 can be made compact in the axial direction of the control shaft 61. Can be suppressed.

  Further, an upper holder 38 attached to the cylinder head 14 of the engine body 11 by rotatably supporting at least a part (upper half portion in this embodiment) of one end side outer periphery of the journal portion 61b. A positioning portion 91 that surrounds the journal portion 61b of the shaft 61 and projects a part from the side wall of the engine main body 11 is integrally provided, and a storage box 90 attached to the outer surface of the side wall of the cylinder head 14 in the engine main body 11 is provided. Since the fitting hole 106 for fitting the protrusion 91c, which is a protrusion from the side wall of the positioning portion 91, is provided, the upper portion attached to the cylinder head 14 when the storage box 90 is attached to the outer surface of the side wall of the cylinder head 14. The positioning portion 91 of the holder 38 is fitted into the fitting hole 106 of the storage box 90. As a result, it is possible to easily improve the connection accuracy between the control shaft 61 that is rotatably supported by the upper holder 38 so that at least a part of the outer periphery thereof can rotate, and the power transmission means 111 in the storage box 90. The storage box 90 is attached to the outer surface of the side wall of the cylinder head 14 in a state in which the connection accuracy of the control shaft 61 and the power transmission means 111 is improved by providing a slight allowance for the attachment position of the box 90 to the cylinder head 14. be able to.

  An upper holder 38 is attached to a cylinder head 14 that constitutes a part of the engine body 11 together with the head cover 15, and a sandwiched portion that is a part of the positioning portion 91 is provided between the mating surfaces 92 and 93 of the cylinder head 14 and the head cover 15. Since 91a is sandwiched, the variable control mechanism 32 for changing the valve opening lift amount of the intake valve 20 can be made compact by disposing the control shaft 61 at a lower position, which contributes to downsizing of the engine E. it can.

  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.

  For example, in the above-described embodiment, the case where the present invention is applied to the intake side valve operating device 28 that can change the valve opening lift amount of the intake valve 20 that is the engine valve has been described. The present invention can be widely implemented in connection with a valve gear that can be changed by turning the control shaft.

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. FIG. 9 is a sectional view taken along line 9-9 in FIG. 2. FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. It is a perspective view which shows a part of power transmission means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Engine main body 20 ... Intake valve 61 as an engine valve ... Control shaft 90 ... Storage box 103 ... Cover member 110 which is a wall part of a storage box ... Electric motor 111 ... Power transmission means 114 ... screw shaft 120 ... output shaft 119 ... reduction gear mechanism 125 ... sensor

Claims (1)

  A control shaft (61) capable of changing the operating characteristics of the engine valve (20) according to the rotation around the axis enters into a storage box (90) whose one end is attached to the outer side wall of the engine body (11). An electric motor (110) that is rotatably supported by the engine main body (11) and is disposed outside the storage box (90) is attached to the outer surface of the storage box (90), and the control shaft (61 The power transmission means (111) including a screw shaft (114) whose axis is arranged in a plane perpendicular to the axis of the storage box (in order to transmit the power of the electric motor (110) to the control shaft (61)). 90), the electric motor (110) has an output shaft (120) having an axis parallel to the screw shaft (114), and a storage box. 90), and the power transmission means (111) includes a reduction gear mechanism (119) provided between the output shaft (120) and the screw shaft (114) and is stored in the storage box (90). The sensor (125) arranged coaxially with the control shaft (61) so as to detect the amount of rotation of the control shaft (61) is connected to the storage box (90) facing one end of the control shaft (61). The variable valve operating apparatus for an engine is attached to a wall portion (103).

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