JP4179101B2 - Variable valve gear for engine - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an engine, and more particularly to a variable valve operating apparatus for an engine in which a valve lift amount is varied by a three-dimensional cam.

  The vehicle is provided with a camshaft provided with a three-dimensional cam having a cam profile changed in the axial direction in the cylinder head of the engine, and a rocker shaft is arranged in parallel with the camshaft, and according to engine operating conditions. A rocker shaft driving means for displacing (sliding) the rocker shaft in the axial direction; a valve lift amount changing means for changing the valve lift amount according to the amount of displacement of the rocker shaft in the axial direction; and a three-dimensional cam; Some have a variable valve operating system for an engine that continuously slides the valve lift curve by sliding relative to the valve shaft (center of the valve stem). In other words, in a variable valve gear for an engine that improves the engine performance by varying the valve lift, a three-dimensional cam in which the valve lift is gradually changed in the axial direction of the camshaft is used. The valve lift curve is continuously variable by sliding relative to the valve shaft (center of the valve stem).

In a variable valve gear for an engine, a roller is rotatably supported on a shaft provided on a rocker arm, and this roller is brought into contact with a three-dimensional cam whose cam profile changes in the cam shaft direction. The camshaft is fixed in the axial direction, and the rocker arm is moved by the oil pressure of the ball bearing and the hydraulic biasing means.
Further, in the variable valve operating apparatus of the engine, a plurality of cams having different cam profiles are arranged side by side on the camshaft, and the abutting portion of the swing member is arranged in the camshaft in the axial direction of the camshaft. There is provided a drive means for changing the cam that is movably supported and fixed, the camshaft is fixed in the axial direction, and the rocker arm is moved by the oil pressure of the ball bearing and the hydraulic biasing means.
Further, the variable valve device of the engine includes a camshaft having a three-dimensional cam (a three-dimensional cam) whose cam profile is continuously changed in the axial direction, and a displacement that continuously displaces the camshaft in the axial direction. And a swing arm or rocker arm that swings based on the cam profile of the 3D cam and opens and closes two adjacent valves simultaneously. This arm follows the change in the contact line angle as the 3D cam rotates. However, there is a roller mechanism with a follow-up contact portion that comes into contact with a three-dimensional cam and a pin with a male screw that presses the end portions of two valves.
Furthermore, the variable valve device of the engine includes a camshaft having a three-dimensional cam (a three-dimensional cam) in which the cam profile is changed in the axial direction, and the camshaft in the axial direction according to the operating condition (state) of the engine. A rocker arm having a portion that comes into contact with a plurality of valves is provided to be swingable with respect to the engine body, and a sub-rocker is provided to rotatably support a roller follower that is in contact with the solid cam. In some cases, a means for swingably supporting the sub rocker is provided, and friction is reduced while preventing uneven wear of a three-dimensional cam or the like via a roller follower.
Japanese Utility Model Publication No. 60-65307 Japanese Utility Model Publication No. 3-122208 Japanese Patent Laid-Open No. 10-18823 Japanese Patent Laid-Open No. 5-18221

  However, conventionally, in a variable valve system for an engine, as in Patent Documents 1 and 2, the camshaft is fixed in the axial direction, and the rocker arm is moved by the oil pressure of a ball bearing or a hydraulic biasing means. In this case, a hydraulic circuit and a spring are required, and there is a disadvantage that the structure becomes complicated. Also, as in Patent Documents 3 and 4 above, when the three-dimensional cam is moved in the axial direction and the two valves are simultaneously driven by the integrated rocker arm, the camshaft is moved in the axial direction, but the camshaft is rotated. In addition, controlling the amount of movement in the axial direction increases the driving force when changing the valve lift amount, increases unnecessary energy loss, improper control, and lowers fuel consumption. was there.

According to the present invention, a camshaft provided with a three-dimensional cam in which a cam profile is changed in the axial direction is provided in a cylinder head of an engine, a rocker shaft is provided in parallel with the camshaft, and according to the engine operating conditions. An engine variable valve operating system provided with a rocker shaft driving means for displacing the rocker shaft in the axial direction and provided with a valve lift amount changing means for changing the valve lift amount in accordance with the amount of displacement of the rocker shaft in the axial direction. The valve lift amount changing means includes a first rocker arm rotatably supported on the rocker shaft and always in contact with a plurality of valves, and a roller fixed to the rocker shaft and in contact with the three-dimensional cam. is composed of a second rocker arm which is rotatably supported rotating, C-shaped said first rocker arm And the second rocker arm is disposed in a space surrounded by the C-shaped first rocker arm and the rocker shaft, and the first rocker arm includes a first support portion and a second support portion. And the valve support part, the width of the first support part is smaller than the width of the second support part, and the valve lift of the three-dimensional cam is not performed on the first support part Formed on the side having the shape, and the second support portion is formed on the side having the shape that can maximize the valve lift of the three-dimensional cam, and the amount of movement of the roller in the rocker shaft axial direction The amount of movement from the axial center of the cam profile of the three-dimensional cam to the shape side where no valve lift is performed is the largest valve lift amount from the axial center of the cam profile of the three-dimensional cam. Doo is characterized in that it is set larger than the movement amount of the possible shapes side.

In the variable valve device for an engine of this invention, in order to change the valve lift, instead of moving the camshaft axially, a second which supports the rocker shaft, only the contact portion between the three-dimensional cam Since it is configured to move with the rocker arm, it is possible to simplify the configuration and reduce the driving force when changing the valve lift, reduce unnecessary energy loss, and perform appropriate control. A rocker to which the second rocker arm is fixed in order to improve fuel efficiency, improve the reliability of the valve system, and move the second rocker arm with a roller in contact with the three-dimensional cam. The position of contact with the 3D cam can be changed by simply moving the shaft, eliminating the need for a dedicated mechanism for moving each cylinder separately, simplifying the configuration, and reducing costs. Rukoto can.

In the present invention, the rocker arm is simply configured to reduce the driving force when changing the valve lift amount.
Hereinafter, embodiments of the present invention will be described in detail and specifically with reference to the drawings.

  1 to 20 show a first embodiment of the present invention. 11 to 16, reference numeral 2 denotes a multi-cylinder engine (4 cylinders: # 1, # 2, # 3, # 4) mounted on a vehicle (not shown), 4 denotes a cylinder block, 6 denotes a cylinder head, 8 is a cylinder head cover, and 10 is a variable valve operating device. The engine 2 has a four-valve configuration in which two valves are provided on the intake side and two valves are provided on the exhaust side per cylinder.

  As shown in FIGS. 11, 12, and 16, in the cylinder head 6, an intake side port 14-1 is formed on the intake side wall 12-1 for each cylinder, and an exhaust side exhaust is provided. Exhaust-side ports 14-2 are formed on the side walls 12-2, and combustion chambers 16 are formed on the lower surface so as to communicate with the intake-side ports 14-1 and the exhaust-side ports 14-2. -1 and the exhaust side wall 12-2 are provided with a front side wall 12F and a rear side wall 12R. Further, fuel injection valves 18 corresponding to the intake side ports 14-1 are attached to the intake side wall 12-1 of the cylinder head 6 for each cylinder. Each fuel injection valve 18 is provided with a fuel delivery pipe 20 oriented in the longitudinal direction of the engine (longitudinal direction) on the intake side. Further, as shown in FIGS. 12 and 13, an ignition plug 22 facing the combustion chamber 6 and an ignition plug pipe 24 covering the ignition plug 22 are attached to the upper part of the cylinder head 6 for each cylinder. ing.

  Further, at the upper part of the cylinder head 6, as shown in FIG. 16, an intake side port supported by a plurality of (five) shaft support mechanisms 26 oriented in the width direction and arranged at predetermined intervals between the cylinders. The intake side camshaft 28-1 on the 14-1 side and the exhaust side camshaft 28-2 on the exhaust side port 14-2 side are arranged side by side in the engine longitudinal direction (longitudinal direction). As shown in FIGS. 11 and 12, the shaft support mechanism 26 has a first camshaft housing 30 erected on the upper surface of the cylinder head 6, an intake side camshaft 28-1, and an exhaust side camshaft 28-2. The first camshaft housing 30 includes a second camshaft housing 32, which is fixed on the cylinder head 6 with a plurality of housing fixing bolts 34 from above. The intake-side camshaft 28-1 and the exhaust-side camshaft 28-2 is supported so that it cannot move in the axial direction (fixed in the axial direction) and is rotatable. As shown in FIG. 16, the first camshaft housing 30 of the shaft support mechanism 26 on the engine rear R side includes an intake side extending portion 36-1 and an exhaust side extending portion 36-2 extending to the engine rear R side. Is integrated with a rear housing 38.

  Each camshaft 28 is provided with a three-dimensional cam 42 in which the cam profile is changed in the axial direction.

  That is, as shown in FIGS. 11, 13, 15, and 16, the intake side camshaft 28-1 has an intake side sprocket 40-1 attached to an end portion on the engine front F side, and each cylinder. Corresponding to these positions, four intake side three-dimensional cams 42-1 are integrally provided. Similarly to the intake side camshaft 28-1, the exhaust side camshaft 28-2 has an exhaust side sprocket 40-2 attached to an end portion on the F front side of the engine and corresponds to the position of each cylinder. The four exhaust side three-dimensional cams 42-2 are integrally provided. A timing chain (not shown) is wound around the intake side sprocket 40-1 and the exhaust side sprocket 40-2.

  As shown in FIG. 1, the intake-side three-dimensional cam 42-1 has a cam profile changed in the axial direction, and the intake-side camshaft 28-1 cannot be displaced in the axial direction (cannot slide). 6 is not displaced in the axial direction (sliding), and only the rotational motion accompanying the rotation of the intake camshaft 28-1 is performed. That is, as shown in FIG. 1, the intake camshaft 28-1 includes a flat surface 42A and an inclined surface 42B as cam surfaces, so that the valve lift amount of the intake side three-dimensional cam 42-1 can be maximized. The possible cam profile side, that is, the maximum cam lift part 42-1F is arranged on the engine front F side, and the minimum cam lift part 42-1R where the valve lift amount becomes zero is arranged on the engine rear R side. The shaft is not axially displaceable and is rotatably supported.

  Since the exhaust side three-dimensional cam 42-2 is configured in the same manner as the intake side three-dimensional cam 42-1, the description thereof is omitted here.

  As shown in FIGS. 9 and 10, the cylinder head 6 includes two intake side valves 44-1 and 44-1 that communicate / disconnect the intake side port 14-1 and the combustion chamber 16 for each cylinder. In addition to being provided, two exhaust-side valves 44-2 and 44-2 are provided to communicate / disconnect the exhaust-side port 14-2 and the combustion chamber 16.

  As shown in FIG. 11, the intake side valve 44-1 is held by an intake side valve guide 46-1 fixed to the cylinder head 6 so as to be movable in the axial direction. The intake side valve 44-1 is fitted with an intake side spring 52-1 which is elastically pressed between the intake side retainer 48-1 attached to the tip side and the intake side spring seat portion 50 of the cylinder head 6. Is provided. Further, the exhaust side valve 44-2 is held by an exhaust side valve guide 46-2 fixed to the cylinder head 6 so as to be movable in the axial direction. The exhaust side valve 44-2 is fitted with an exhaust side spring 52-2 which is elastically pressed between the exhaust side retainer 48-2 attached to the tip side and the exhaust side spring seat portion 50-2 of the cylinder head 6. Is provided.

  Further, the first camshaft housing 30 of each shaft support mechanism 26 is parallel to the intake side camshaft 28-1 and the exhaust side camshaft 28-2 and is connected to the intake side camshaft 28, as shown in FIGS. -1 and the exhaust side camshaft 28-2 on the inner side (cylinder center side), the intake side rocker shaft 54-1 and the exhaust side rocker shaft 54-2 are axially displaceable (slidable) and non-rotatably supported. Has been.

  An intake side valve lift amount changing means 56-1 is provided between the intake side three-dimensional cam 42-1 of the intake side camshaft 28-1 and the tip of the intake side valve 44-1. Further, an exhaust side valve lift amount changing means 56-2 is provided between the exhaust side three-dimensional cam 42-2 of the exhaust side camshaft 28-2 and the tip of the exhaust side valve 44-2.

  As shown in FIGS. 5 to 8, the intake side valve lift amount changing means 56-1 includes a first intake side rocker arm 60-1 and a second intake side rocker arm 62-1 obtained by dividing the intake side rocker arm 58-1 into two parts. The valve lift amount is changed in accordance with the amount of displacement of the intake side rocker shaft 54-1 in the axial movement (slide). The first intake side rocker arm 60-1 is rotatably supported by the intake side rocker shaft 54-1, and is always in contact with a plurality of (two) intake side valves 44-1 and 44-2. The second intake-side rocker arm 62-1 rotatably supports an intake-side roller 64-1 fixed to the intake-side rocker shaft 54-1 and in contact with the intake-side three-dimensional cam 42-1.

  The first intake side rocker arm 60-1 includes an intake side one support portion 66-1 whose base end side is a first support portion, an intake side other support portion 68-1 which is a second support portion, and the intake side. On the other hand, the front ends of the support portion 66-1 and the intake side other support portion 68-1 are connected to each other, and an intake side valve support portion 70-1 parallel to the intake side rocker shaft 54-1 is formed in a C shape. In addition, it is sandwiched between the adjacent shaft support mechanisms 26 on both ends, and is held so as not to be axially displaced (slid) even if the intake-side rocker shaft 54-1 is axially displaced (slided). Only the rocking motion is performed around the intake side rocker shaft 54-1. As shown in FIG. 1, the second intake-side rocker arm 62-1 has an intake-side arm space 72 formed between the C-shaped first intake-side rocker arm 60-1 and the intake-side rocker shaft 54-1. -1.

  Further, as shown in FIG. 1, in the first intake side rocker arm 60-1, the intake side one support portion 66-1 that is the first support portion does not perform the valve lift of the intake side cam 42-1. The intake side other support portion 68-1 which is disposed on the side having the shape, that is, on the minimum cam lift portion 42-1R side of the intake side three-dimensional cam 42-1 and is the second support portion, The side cam 42-1 is disposed on the side having the shape that can maximize the valve lift, that is, on the side of the maximum cam lift 42-1F of the intake side three-dimensional cam 42-1. In this case, the width W1 of the intake side one support portion 66-1 is formed smaller than the width W2 of the intake side other support portion 68-1.

  As shown in FIG. 2 to FIG. 4, in the rocker shaft axial movement amount of the intake side roller 64-1, the axial center of the cam profile of the intake side three-dimensional cam 42-1 at the center 64C of the intake side roller 64-1. (Neutral shaft) The amount of movement L1 from 42C to the shape side where the valve lift is not performed is the shape in which the valve lift amount can be maximized from the axial center 42C of the cam profile of the intake side three-dimensional cam 42-1. It is set larger than the movement amount L2 to the side.

  Thus, the width W1 of the intake side one support portion 66-1 that is the first support portion of the first intake side rocker arm 60-1 is set to the width of the intake side other support portion 68-1 that is the second support portion. The amount of movement L1 from the axial center (neutral shaft) 42C of the intake side three-dimensional cam 42-1 of the intake side roller 64-1 to the shape side where valve lift is not performed is made smaller than W2. The reason why the larger amount of movement L2 from the axial center 42C of the cam profile of the intake side three-dimensional cam 42-1 to the shape side where the valve lift amount can be maximized is set is as follows.

  That is, as shown in FIGS. 18 and 20, when the valve lift is near zero and the valve lift is near the maximum, when the load between the intake side roller 64-1 and the intake side three-dimensional cam 42-1 is compared, When Fa <Fb and the distances a and b from the center (neutral axis) 64C of the intake side roller 64-1 are set to a = b, the moment received by the first intake side rocker arm 60-1 is Ma = Fa. * A, Mb = Fb * b, and Ma <Mb. Therefore, at the time of the maximum lift, a relatively large moment Mb is generated, which may cause a malfunction.

  Therefore, in this embodiment, in order to eliminate the above problem, in the first intake side rocker arm 60-1, the width W1 of the intake side one support portion 66-1 <the width of the intake side other support portion 68-1. W2 is set, and in the intake side roller 64-1, the movement amount L1 from the axial center (neutral axis) 42C of the cam profile of the intake side three-dimensional cam 42-1 to the shape side where valve lift is not performed. > By setting the moving amount L2 from the axial center 42C of the cam profile of the intake side three-dimensional cam 42-1 to the shape side where the valve lift amount can be maximized, the moment Ma <Mb is obtained. The required rigidity amount of the first intake side rocker arm 60-1 is lowered (decreasing the deformation amount due to the load) close to Ma = Mb, that is, the rigidity of the intake side rocker arm 58-1 is small. However, the amount of deformation is reduced, and the load on the intake side other support portion 68-1R as the second support portion is improved, so that the intake side other support portion of the first intake side rocker arm 60-1 is improved. It is possible to improve the lubrication performance of 68-1.

  As shown in FIGS. The intake-side valve support 70-1 has an intake-side adjuster 74 whose lower end is in contact with the tips of the intake-side valves 44-1 and 44-1, so as to communicate with the two intake-side valves 44-1 and 44-1. -1,74-1 are provided, and intake side nuts 76-1, 76-1 are screwed to the upper end side of the intake side adjustment task screws 74-1, 74-1. The intake side adjustment screw 74-1 and the intake side nut 76-1 can adjust the valve clearance of the intake side valve 44-1.

  A second rocker arm 62-1 is fixed to the intake side rocker shaft 54-1 as shown in FIGS. The second rocker arm 62-1 is connected to the intake boss 78-1 fixed to the intake rocker shaft 54-1, and is connected to the intake boss 78-1 and orthogonal to the intake rocker shaft 54-1. It consists of an intake side one holding part 80-1 and an intake side other holding part 82-1, which are oriented in the direction. The intake side boss portion 78-1 is fixed to the intake side rocker shaft 54-1 by the intake side movement restricting means 84-1. The intake side movement restricting means 84-1 is fitted into intake side grooves 86-1 and 86-1 formed on the outer peripheral surface of the intake side rocker shaft 54-1, and a pair of intake side boss portions 78-1 on both sides. It consists of intake side washers 88-1 and 88-1 and intake side E-rings 90-1 and 90-1. The front end sides of the intake side one holding part 80-1 and the intake side other holding part 82-1 are provided on the intake side roller shaft 92 so as to be rotatable and slidable. The intake side roller shaft 92 rotates and slides an intake side roller 64-1 sandwiched between an intake side one holding portion 80-1 and an intake side other holding portion 82-1 that are slidable in the axial direction. The intake side formed in the intake side one hole 94-1 formed in the intake side one support part 66-1 of the first intake side rocker arm 60-1 and the intake side other support part 68-1 at both ends. The other hole 96-1 is inserted and fixed. Therefore, the intake-side three-dimensional cam 42-1 integral with the intake-side camshaft 28-1 cannot be moved (slid) in the axial direction, is fixed in the axial direction, and the intake-side three-dimensional cam 42-1 , The intake-side roller 64-1 contacts the intake-side three-dimensional cam 42-1 and rotates on the intake-side roller shaft 92 while moving in the axial direction on the intake-side roller shaft 92 together with the intake-side rocker shaft 54-1. When moved, the first intake side rocker arm 60-1 swings about the intake side roller shaft 92, so that the reliability of the operation can be improved as a system in which the valve lift is varied steplessly. Is.

  That is, the contact position between the intake side three-dimensional cam 42-1 and the intake side roller 64-1 changes due to the axial displacement (slide) of the second intake side rocker arm 62-1 and the intake side roller 64-1. The valve lift amount of the intake side valve 44-1 changes continuously. At this time, since the intake side roller 64-1 is interposed on the contact surface between the intake side three-dimensional cam 42-1 and the second intake side rocker arm 62-1, the friction with respect to the intake side three-dimensional cam 42-1 is reduced. Is possible.

  Since the exhaust side valve lift amount changing means 56-2 is configured in the same manner as the intake side valve lift amount changing means 56-1, only the corresponding members in FIGS. A description thereof will be omitted.

  As shown in FIG. 14, the intake-side rocker shaft 54-1 is displaced (slid) in the axial direction in accordance with the operating conditions of the engine 2 at the end portion on the engine rear R side. Intake side rocker shaft drive means 98-1 is provided. Further, the exhaust side rocker shaft 54-2 has an exhaust side rocker shaft that is displaced (slid) in the axial direction at an end portion on the R rear side of the engine according to the operating conditions of the engine 2. Driving means 98-2 is provided.

  As shown in FIGS. 14 to 16, the intake-side rocker shaft driving means 94-1 includes an intake-side outer peripheral male screw 100-1 at an end portion on the engine rear R side and an intake air screwed into the intake-side outer peripheral male screw 100-1. An intake side pinion gear 108-1 that meshes with an intake side rotating body 104-1 provided with a side inner peripheral female screw 102-1 and an intake side communication gear 106-1 protruding from the outer peripheral surface of the intake side rotating body 104-1 is provided. And an intake side motor 110-1. Then, when the intake side motor 110-1 is driven, the intake side rotating body 104-1 is rotated via the intake side pinion gear 108-1 and the intake side connection gear 106-1, whereby the intake side rocker shaft 54-. 1 is displaced (slid) in the axial direction.

  Since the exhaust side rocker shaft driving means 98-2 is configured in the same manner as the intake side rocker shaft driving means 98-1, only the corresponding members in FIGS. The description is omitted.

  Further, as shown in FIG. 16, the rear end surface of the rear housing 38 connected to the second camshaft housing 32 of the shaft support mechanism 26 on the rear R side of the engine has an intake side motor 110-1 and an exhaust side motor on the rear end surface. A motor case 112 to which 110-2 is attached is provided by being rigidly coupled by a predetermined fixing means (not shown). The motor case 112 houses a part of the intake side rocker shaft driving means 98-1 and the exhaust side rocker shaft driving means 98-2. An intake side cam angle sensor 114-1 and an exhaust side cam angle sensor 114-2 are fixedly provided on the upper portion of the outer peripheral surface of the motor case 112.

  Next, the operation of the first embodiment will be described by taking only the intake side of the engine 2 as an example.

  In the variable valve operating apparatus 10, when the intake side rocker shaft 54-1 is displaced (slid) in the axial direction in accordance with the engine 2 operating state, the intake side rocker shaft 54-1 is displaced in the axial direction. The intake side roller 64-1 and the second intake side rocker arm 62-1 fixed to the intake side rocker shaft 54-1 follow and are displaced in the axial direction, but are integrated with the intake side camshaft 28-1. The first intake side rocker arm 60-1 slidably provided on the intake side three-dimensional cam 42-1 and the intake side rocker shaft 54-1 is not displaced in the axial direction, and a continuously variable lift is realized. .

  The operation of the intake side valve lift changing means 56-1 will be described with reference to FIGS. 2 to 4. In FIG. 2, the center 64C of the intake side roller 64-1 is the cam profile of the intake side three-dimensional cam 42-1. In FIG. 3, the center 64C of the intake side roller 64-1 is inhaled from the axial center 42C of the cam profile of the intake side three-dimensional cam 42-1. On the side of the side camshaft 54-1 that has a shape where the valve lift is not performed, the valve lift is zero with a large movement amount L1, whereas in FIG. 4, the center 64C of the intake side roller 64-1 is located. Is a movement amount L2 smaller than the movement amount M1 from the axial center 42C of the cam profile of the intake side three-dimensional cam 42-1 to the shape side where the valve lift amount can be maximized. Location to valve lift is at a maximum.

  That is, as shown in FIGS. 17 and 18, when the intake side valve 44-1 is not lifted, the intake side three-dimensional cam 42-1 is rotated together with the rotation of the intake side camshaft 28-1. In the intake-side rocker shaft driving means 94-1, the intake-side rotating body 104-1 rotates through the intake-side pinion gear 108-1 and the intake-side connecting gear 106-1 by the intake-side motor 110-1 being driven. The intake-side outer peripheral male screw 100-1 of the intake-side rocker shaft 54-1 screwed to the intake-side inner peripheral female screw 102-1 of the side-side rotating body 104-1 moves toward the engine rear R side by the rotation of the intake-side rotating body 104-1. By moving, the intake-side rocker shaft 54-1 is axially displaced toward the engine rear R side, and the axial change of the intake-side rocker shaft 54-1 toward the engine rear R side is achieved. As a result, the second intake side rocker arm 62-1 and the intake side roller 64-1 are positioned on the rightmost side, so that the minimum cam lift portion of the intake side three-dimensional cam 42-1 at a location where the intake side valve 44-1 does not lift. The intake side roller 64-1 is in contact with 42-1R, and the intake side valve 44-1 is not operating.

  19 and 20, when the intake side valve 44-1 is in the full lift state, the intake side three-dimensional cam 42-1 is rotated together with the rotation of the intake side camshaft 28-1, In the intake-side rocker shaft driving means 98-1, the intake-side rotating body 104-1 rotates through the intake-side pinion gear 108-1 and the intake-side connecting gear 106-1 by the intake-side motor 110-1 being driven. The intake-side outer peripheral male screw 100-1 of the intake-side rocker shaft 54-1 screwed into the intake-side inner peripheral female screw 102-1 of the side rotating body 104-1 moves toward the engine front F side by the rotation of the intake-side rotating body 104-1. By moving, the intake side rocker shaft 54-1 is axially displaced toward the front F side of the engine, and the axial change of the intake side rocker shaft 54-1 toward the front F side of the engine is achieved. As a result, the second intake-side rocker arm 62-1 and the intake-side roller 64-1 are positioned on the leftmost side, and thereby the intake-side three-dimensional cam 42-1 at the location where the intake-side valve 44-1 is fully lifted (maximum lift). The intake side roller 64-1 contacts the maximum cam lift part 42-1F, and the intake side valve 44-1 enters the maximum lift state.

  On the other hand, when the second intake side rocker arm 62-1 is positioned at the intermediate portion of the intake side three-dimensional cam 42-1, due to the axial displacement (slide) of the intake side rocker shaft 54-1 as in FIG. The intermediate lift state of the intake side valve 44-1 is realized.

  At this time, in the first intake side rocker arm 60-1, the width W1 of the intake side one support portion 66-1 is set to be smaller than the width W2 of the intake side other support portion 68-1, and the intake side roller 64-1 is set. , The movement amount L1 from the axial center (neutral axis) 42C of the cam profile of the intake side three-dimensional cam 42-1 to the shape side where valve lift is not performed> the cam profile of the intake side three-dimensional cam 42-1 By setting the movement amount L2 to the shape side where the valve lift amount can be maximized from the axial center 42C, the moment where Ma <Mb is brought close to Ma = Mb, the first The required amount of rigidity of the intake side rocker arm 60-1 is reduced (the amount of deformation due to the load is reduced), that is, the amount of deformation is reduced even if the rigidity of the intake side rocker arm 58-1 is small. And better balance of the load to a certain intake side the other supporting portion 68-1, it is possible to improve the lubrication performance on the intake side the other supporting portion 68-1 of the first intake-side rocker arm 60-1.

  Note that the exhaust side of the engine 2 operates in the same manner as the intake side, and therefore the description thereof is omitted here.

  As a result, only the intake side of the engine 2 will be described. The intake side valve lift amount changing means 56-1 is rotatably supported by the intake side rocker shaft 54-1 and is always in contact with the plurality of intake side valves 44-1. The first intake side rocker arm 60-1 and the intake side roller 64-1 fixed to the intake side rocker shaft 54-1 and in contact with the intake side three-dimensional cam 42-1 are rotatably supported. Since the second intake-side rocker arm 62-1 is used, the intake-side rocker shaft 54-1 is used instead of moving the intake-side camshaft 28-1 in the axial direction in order to change the valve lift amount. And the second intake-side rocker arm 62-1 that supports only the contact portion with the intake-side three-dimensional cam 42-1 are configured to move in the axial direction. In addition, a complicated structure such as a gear is not required and a special mechanism is not required, and the existing intake side rocker shaft 54-1 is moved (slid) in the axial direction to simplify the structure and change the valve lift amount. It is possible to reduce the driving force at the time, reduce unnecessary energy loss, improve the fuel efficiency by performing appropriate control, improve the reliability of the valve operating system, and improve the intake side three-dimensional cam 42. Intake side rocker shaft 62-1 to which the second intake side rocker arm 62-1 is fixed in order to move the second intake side rocker arm 62-1 provided with the intake side roller 64-1 in contact with -1 in the axial direction. Since the position of contact with the intake side three-dimensional cam 42-1 can be changed simply by moving the axis 54-1 in the axial direction, a dedicated mechanism for moving each cylinder is not required separately, and the configuration is simplified. Inexpensive and Also, it is possible to reduce the friction between the intake-side three-dimensional cam 42-1 by the intake side roller 64-1.

  Further, the intake side valve lift amount changing means 56-1 forms a first intake side rocker arm 60-1 in a C-shape, and the C-shaped first intake side rocker arm 60-1 and the intake side rocker shaft. Since the second intake-side rocker arm 62-1 is arranged in the intake-side arm space 72-1 surrounded by 54-1, only one intake-side cam 42-1 is provided per cylinder. The configuration can be simplified, and the rigidity can be increased and the size can be reduced compared to the case where the first intake side rocker arm 60-1 is Y-shaped.

  Furthermore, since the second intake side rocker arm 62-1 is fixed to the intake side rocker shaft 54-1 by the intake side movement restricting means 84-1, it is not a special movement restricting structure, but a separate member. The movement can be restricted and the configuration can be simplified.

  Furthermore, the first intake side rocker arm 60-1 has an intake side one support part 66-1 and an intake side other support part 68-1, and the width W1 of the intake side one support part 66-1 is the other side on the intake side. The intake side one support part 66-1 is formed on the side of the intake side cam 42-1 that has a shape that does not perform valve lift, and the intake side other support part is formed smaller than the width W2 of the support part 68-1. 68-1 is formed on the side of the intake side three-dimensional cam 42-1 having a shape that can maximize the valve lift, and the intake side roller 64- that moves in the axial direction together with the intake side rocker shaft 54-1. 1, the movement amount L1 from the axial center 42C of the cam profile of the intake side three-dimensional cam 42-1 to the shape side where the valve lift is not performed is the axial direction of the cam profile of the intake side three-dimensional cam 42-1. From the center 42C Since the valve lift amount is set to be larger than the moving amount L2 to the shape side that can be increased, the required rigidity of the intake side rocker arm 58-1 can be set low, and the weight and shape can be reduced. -The degree of freedom of design can be increased with materials and the like, and the load balance to the intake side other support portion 68-1 of the second intake side rocker arm 62-1 can be balanced, and the intake side other support portion The lubricating performance of 68-1 can be improved.

  21 to 23 show a second embodiment of the present invention.

  The features of the second embodiment are as follows. That is, in the first embodiment, the intake side rocker shaft 54-1 is displaced (slid) in the axial direction to adjust the valve lift, but the intake side rocker shaft 54-1 and the second intake side rocker arm 62 are adjusted. -1 is provided with an arm slide means 154 such as a screw mechanism 152 or a ball, and the intake rocker shaft 54-1 is rotated to move the second intake rocker arm 62-1 in the axial direction. It was set as the structure which displaces (slides).

  According to the configuration of the second embodiment, the second intake-side rocker arm 62-1 is axially displaced by the rotation amount of the intake-side rocker shaft 54-1, and an appropriate valve lift amount can be determined. Further, since the intake-side rocker shaft 54-1 is rotated, the space may be smaller than when the intake-side rocker shaft 54-1 is moved in the axial direction, which is advantageous in terms of space and simplifies the configuration. be able to.

  FIG. 24 shows a special configuration of the present invention and shows a third embodiment.

  The features of the third embodiment are as follows. That is, an inclined portion 64S that is in contact with the inclined surface 42B of the intake side three-dimensional cam 42-1 is formed on the outer peripheral surface of the intake side roller 64-1.

  According to the configuration of the third embodiment, since the inclined portion 64S of the intake side roller 64-1 is in surface contact with the inclined surface 42B of the intake side cam 42-1, the intake side cam 42-1 and the intake side roller The contact state with 64-1 can be ensured, and the power transmission from the intake side cam 42-1 side can be improved.

  The structure in which the lift amount of the valve is changed by the movement of the three-dimensional cam can be applied to other variable valve operating devices.

It is a top view of the intake side valve lift amount changing means in the first embodiment. It is a top view of the intake side valve lift amount changing means when the intake side roller is in a neutral position in the first embodiment. It is a top view of the intake side valve lift amount changing means when the intake side roller is in the zero lift position in the first embodiment. It is a top view of the intake side valve lift amount changing means when the intake side roller is at the maximum lift position in the first embodiment. It is a perspective view of the intake side valve lift amount changing means in the first embodiment. FIG. 6 is a plan view of intake side valve lift amount changing means indicated by an arrow VI in FIG. 5 in the first embodiment. It is a side view of the intake side valve lift amount changing means in the first embodiment. FIG. 8 is a right side view of intake side valve lift amount changing means according to an arrow VIII in FIG. 7 in the first embodiment. It is a top view of the intake side valve lift amount changing means and the exhaust side valve lift amount changing means in the first embodiment. FIG. 10 is a right side view of the intake side valve lift amount changing means and the exhaust side valve lift amount changing means according to the arrow X in FIG. 9 in the first embodiment. It is sectional drawing of the engine by the XI-XI line of FIG. 13 in 1st Example. It is sectional drawing of the engine by the XII-XII line of FIG. 13 in 1st Example. It is a top view of the engine in the 1st example. It is sectional drawing of the engine by the XIV-XIV line | wire of FIG. 11 in 1st Example. It is a perspective view of the variable valve apparatus in 1st Example. It is a perspective view of the engine in the 1st example. In the first embodiment, the valve lift amount is zero and the intake side roller is in contact with the flat surface of the intake side three-dimensional cam. FIG. 6 is a configuration diagram when the valve lift amount is zero and the intake side roller is in contact with the minimum lift portion of the inclined surface of the intake side three-dimensional cam in the first embodiment. FIG. 6 is a configuration diagram when the valve lift amount is maximum and the intake side roller is in contact with the flat surface of the intake side three-dimensional cam in the first embodiment. FIG. 6 is a configuration diagram when the valve lift amount is maximum and the intake side roller is in contact with the maximum lift portion of the inclined surface of the intake side three-dimensional cam in the first embodiment. It is a top view of the intake side valve lift amount changing means in the second embodiment. FIG. 22 is a right side view of intake side valve lift amount changing means according to an arrow XXII in FIG. 21 in the second embodiment. It is sectional drawing of the intake side valve lift amount change means of FIG. 21 in 2nd Example. It is a partial top view of the intake side valve lift amount changing means in the third embodiment.

Explanation of symbols

2 Engine 4 Cylinder block 6 Cylinder head 8 Cylinder head cover 10 Variable valve operating device 26 Shaft support mechanism 28-1 Intake side camshaft 42-1 Intake side three-dimensional cam 44-1 Intake side valve 54-1 Intake side rocker shaft 56- 1 intake side valve lift amount changing means 58-1 intake side rocker arm 60-1 first intake side rocker arm 62-1 second intake side rocker arm 64-1 intake side roller 98-1 intake side rocker shaft driving means 110-1 Intake motor

Claims (1)

A camshaft provided with a three-dimensional cam in which the cam profile is changed in the axial direction is provided in a cylinder head of the engine, a rocker shaft is arranged in parallel with the camshaft, and the rocker shaft is arranged according to the operating condition of the engine. In the variable valve operating system for an engine, provided with a rocker shaft driving means for displacing the shaft in the axial direction, and provided with valve lift amount changing means for changing the valve lift amount in accordance with the amount of displacement of the rocker shaft in the axial direction. The lift amount changing means rotatably supports a first rocker arm that is rotatably supported by the rocker shaft and is always in contact with a plurality of valves, and a roller that is fixed to the rocker shaft and is in contact with the three-dimensional cam. is composed of a second rocker arm that is supported by, and forming said first rocker arm in a C-shape, The second rocker arm is disposed in a space surrounded by the C-shaped first rocker arm and the rocker shaft, and the first rocker arm includes a first support portion, a second support portion, and a valve support portion. The width of the first support portion is smaller than the width of the second support portion, and the first support portion has a shape that does not perform the valve lift of the three-dimensional cam. And the second support portion is formed on the side of the three-dimensional cam having a shape that can maximize the valve lift amount. The amount of movement from the axial center of the cam profile of the original cam to the shape side where the valve lift is not performed can be maximized from the axial center of the cam profile of the three-dimensional cam. Variable valve device for an engine, characterized in that it is set larger than the movement amount to Jo side.

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