JP4872704B2 - Valve operating device for internal combustion engine - Google Patents

Description

  The present invention relates to a valve operating apparatus for an internal combustion engine that continuously controls valve characteristics of an intake valve or an exhaust valve.

  In a valve operating device of a multi-cylinder reciprocating engine (internal combustion engine) mounted on an automobile, an intake valve (or exhaust gas) is provided on the upper surface of the cylinder head in order to reduce fuel consumption by measures against engine exhaust gas and improving pumping loss. Incorporating a variable valve system that continuously and variably controls the characteristics of the valve. Many of the variable valve operating apparatuses have a structure in which the characteristics of the intake valve, such as the opening / closing timing of the intake valve and the valve lift amount, are continuously changed by receiving the cam of the camshaft as disclosed in Patent Document 1. .

  In many of the assembly of such variable valve operating devices, after mounting the cylinder head on the cylinder block on the main line for assembling the engine, the components of the variable valve operating device are assembled to each part of the cylinder head. The method of assembling the whole is used. Recently, in order to increase the production efficiency of the main line, as in the structure shown in Patent Document 2, the work of assembling the camshaft and the valve to the cylinder head is performed on the main line. Attempts have been made to modularize a variable valve operating device arranged between a camshaft of a cylinder head and a valve by using a subline. Specifically, each mechanism of the variable valve operating apparatus is held by a holding member arranged after the cylinder. In other words, modularize only the variable valve system that is difficult to assemble in the sub-line, and return the modularized variable valve system to the main line and assemble it into the cylinder head (with the camshaft and valves assembled) By doing so, measures were taken from the main line to suppress time-consuming work processes.

  By the way, the variable valve operating apparatus is required to continuously control the valves of the respective cylinders with the same valve characteristics so that the set performance is exhibited in any engine operating state. For this purpose, the variable valve operating apparatus is required to adjust the valve drive output in accordance with the cam profile of each cam for each cylinder to eliminate the variation between cylinders.

  However, adjustment of the variation between cylinders is troublesome in that the positional relationship between the cam and the component that receives the cam of the variable valve operating device is aligned for each cylinder so that the continuously variable valve characteristics are properly exhibited. The fine adjustment work which spends considerable time is forced.

  In particular, Patent Document 2 is effective in that it eliminates the labor of assembling the variable valve operating system from the main line. However, with regard to the adjustment work, the variable motion in which the cylinder head with the camshaft has a component that receives the cam is provided. Since it can only be carried out after the valve device has been assembled, adjustment work (adjustment of variation between cylinders) that still requires considerable time is still necessary on the main line for assembling the engine, and there has been a problem inducing main line stagnation. .

Therefore, as in Patent Document 3, attempts have been made to modularize the camshaft and the variable valve operating device.
JP 2005-299536 A JP 2005-299538 A JP-A-2005-240617

  By the way, the variable valve operating device is normally fixed to the upper surface portion of a peripheral wall (wall formed so as to surround four sides of the cylinder head) formed on the outer peripheral portion of the cylinder head.

  However, the upper surface of the peripheral wall of the cylinder is the highest portion of the cylinder head, that is, the uppermost portion. In addition, since the height of the holding member is increased by including the camshaft, when the modularized structure is assembled to the cylinder head, the overall height of the cylinder head is considerably increased. For this reason, it is easy to increase the size of the engine (total engine height: large).

  SUMMARY OF THE INVENTION An object of the present invention is to provide a valve operating apparatus for an internal combustion engine in which a variable valve operating apparatus modularized including a camshaft can be installed in a compact cylinder head.

In order to achieve the above object, an invention according to claim 1 is an internal combustion engine having a plurality of cylinders, in which a variable valve gear is installed on the surface of the cylinder head opposite to the cylinder side. In the valve operating apparatus, the variable valve operating apparatus is provided with a plurality of holding members extending in the width direction of the cylinder head on the cylinder head, at least in the foremost part and the rearmost part of the plurality of cylinders according to the arrangement of the cylinders, The holding member is composed of a holder member and a cap member assembled to the lower end portion of the holder member, and a camshaft having a cam for each cylinder is held between the holder member and the cap member and is camped above the holder member. In response, the intake valve variable valve mechanism is provided to continuously and variably control the valve characteristics, and the intake valve variable valve mechanism is formed on the installation seat formed on the upper part of each holding member. A frame-shaped frame is formed by inserting a control shaft and an exhaust rocker shaft that constitute a variable valve mechanism for intake into a holding hole formed along the support shaft and formed below the installation seat of the holding member. The holder member, the rocker shaft, and the cap member are pierced perpendicularly to the upper surface of the cylinder head by the fixing bolt member, and the control shaft, the holder member, and the cap member are separated from the fixing bolt member. The fixing valve member is modularized by projecting obliquely with respect to the upper surface of the cylinder head, and the modular variable valve operating device is disposed in a recess that is recessed toward the cylinder side of the cylinder head. A valve operating device for an internal combustion engine was configured as a configuration.

  In the invention described in claim 2, the variable valve operating apparatus is further installed such that the camshaft is located on the cylinder head side and located in the recess.

According to the first aspect of the present invention, since the variable valve operating device is modularized, the assembly becomes easy. The variable valve operating device can be installed in a recessed portion recessed on the cylinder side of the cylinder head. In addition, since the holding member is provided only at a position necessary for modularization, the weight of the frame-shaped frame can be minimized without increasing the size of the frame-shaped frame.

The variable valve operating apparatus modularized including the camshaft can be installed on the cylinder head while suppressing the height dimension. That is, it can be compactly installed on the cylinder head, and the internal combustion engine can be made compact.
Due to the structure in which the camshaft is sandwiched between the holder member and the cap member, the journal bearing portion of the camshaft needs to have a smaller diameter than the outer diameter of the cam, so the height of the holding member can be suppressed and the camshaft can be further included. The variable valve device can be compactly installed on the cylinder head.
Each holding member can be fixed easily and reliably using a support shaft.

  According to the second aspect of the present invention, the camshaft having a narrower width than the variable valve mechanism is disposed on the cylinder head side, so that it can be easily accommodated in the recess formed in the cylinder head, and the variable valve mechanism Is located outside the recess, the variable valve mechanism can be easily adjusted even after the variable valve device is installed in the cylinder head.

  Hereinafter, the present invention will be described based on an embodiment shown in FIGS.

  FIG. 1 is a perspective view of the head of an engine body of a multi-cylinder internal combustion engine, for example, an in-line four-cylinder reciprocating gasoline engine, FIG. 2 is an exploded perspective view of the head, and FIG. 3 is mounted on the head. FIG. 4 to FIG. 8 are sectional views of respective parts of the head (A to B in FIG. 1, DD and EE in FIG. 2). Respectively.

  In FIG. 1, 1 is a cylinder head mounted on the head of a cylinder block 2 (shown in FIG. 5 by a two-dot chain line), 3 is a rocker cover that covers the top of the cylinder head 1, and 4 is a cylinder head 2 and a rocker cover 3. The variable valve operating apparatus comprised by the SOHC type valve operating apparatus accommodated between these is shown.

  As shown in FIGS. 1, 2 and 5 to 8, the cylinder head 1 is surrounded by a peripheral wall 1a which is narrow and surrounded by a peripheral wall 1a formed on the outer periphery on the four sides on the opposite side to the cylinder side. The head main body 1x is used with the uppermost portion (the point farthest from the lower surface of the cylinder head). That is, the upper surface 1y of the cylinder head body 1x becomes the bottom surface of the recess 1z surrounded by the peripheral wall 1a. The upper end surface of the peripheral wall 1a is a rocker cover mounting seat 1b. Combustion chambers 7 (illustrated in FIGS. 5 and 8) are formed on the lower surface of the head body 1x, following the four cylinders 6 (illustrated by a two-dot chain line in FIG. 5) formed in the cylinder block 2. ing. A pair of intake ports 8 and a pair of exhaust ports 9 (both shown in part of FIGS. 5 and 8) extending from the combustion chamber 7 are formed on both sides (width direction) of the head body 1x. A pair of normally closed intake valves 8 a is assembled to the intake port 8, and a pair of normally closed exhaust valves 9 a is assembled to the exhaust port 9. The stem ends of the valves 8a and 9a protrude upward from both sides of the upper surface 1y of the head body 1x. For example, an ignition plug is attached to each combustion chamber 7 or an injector is attached to each cylinder (none of them are shown). However, in the figure, 10 (only FIG. 5 is shown) indicates a piston housed in the cylinder 6 so as to be able to reciprocate.

  For example, as shown in FIG. 2, the variable valve device 4 is assembled with a camshaft 15 on the lower side (cylinder head side) of the frame-shaped frame 11 and is controlled by a control shaft 14 on the camshaft 15. A swing cam type variable valve mechanism 13 for intake and a rocker arm mechanism 17 on the exhaust side (only a part of which is shown in FIG. 5) are assembled into a modular structure.

  The structure of each part will be described. 11 a to 11 c are a plurality of (four) holding members that constitute the frame-shaped frame 11. As shown in FIGS. 1 and 2, the holding members 11a to 11c are divided in accordance with the arrangement of the cylinders 6 (four), and are arranged in parallel at the positions of the frontmost part, the cylinders, and the rearmost part of the cylinder row. The That is, the holding members 11a to 11c are divided into a plurality of parts so as to support at least both ends of the camshaft 15. As shown in FIG. 3, the holding members 11a to 11c each have a wall-shaped holder member 18a extending in the width direction of the cylinder head 1 (a direction perpendicular to the cylinder row direction), and a lower end of the holder member 18a. A structure is used in which a two-piece structure with a cap member 18b combined with a portion and a plurality of fixing bolt members 18c assembled so as to penetrate through the holder member 18a and the cap member 18b are used. The same structure is used for the holder member 18a. Specifically, as shown in FIGS. 3 and 6, the holder member 18a is formed with suction / exhaust rocker shaft holding holes 20a and 20b that are arranged in parallel in a lateral direction (parallel) on both sides of the middle stage. Yes. An arc-shaped installation seat 21 is formed on the upper surface of the holder member 18a between the suction / exhaust rocker shaft holding holes 20a, 20b at a point near the exhaust side hole 20b. On the lower surface of the holder member 18a, a semicircular journal bearing surface 22 is formed between the suction / exhaust rocker shaft holding holes 20a, 20b and at a point near the exhaust side hole 20b. The entire lower surface of the holder member 18 a excluding the bearing surface 22 is used as a cap mounting seat 23. As the cap member 18b, for example, a plate-like member whose center is recessed in an arc shape is used, a semicircular journal bearing surface 25 is formed at the center of the upper surface, and the entire upper surface excluding the bearing surface 22 is the cap mounting surface. 26. The flat lower surface portions on both sides of the lower surface of the cap member 18b across the journal bearing surface 22 are used as a module installation seat surface 27. Unlike the other members, the foremost holder member 18a and the cap member 18b are separately formed with a pair of leg portions 29 protruding on both sides. The pair of legs 29 are also formed with a journal bearing surface 22, a cap mounting seat 23, a journal bearing surface 25, a cap mounting surface 26, and a seating surface 27. Each leg 29 has a through hole 28 through which a head bolt (not shown) is inserted. A sensor mounting portion 30 is formed on the holder member 18a arranged at the rearmost portion. As shown in FIG. 4, the sensor mounting portion 30 is formed with a cylindrical portion 31a extending from the intake rocker shaft holding hole 20a toward the rearmost portion, and a fan-shaped sensor mounting portion is provided at the tip of the cylindrical portion 31a. A structure for forming the boss portion 31b is used.

  As shown in FIGS. 2 and 3, each intake rocker shaft holding hole 20a has a control shaft constituting the intake variable valve mechanism 13 extending from the frontmost holding member 11a to the rearmost holding member 11c. 14 (made of a hollow member) is rotatably inserted. A rocker shaft 34 (consisting of a hollow member) constituting the rocker arm mechanism 17 on the exhaust side is inserted into each exhaust rocker shaft holding hole 20b from the foremost holding member 11a to the rearmost holding member 11c. A support shaft 35 (consisting of a hollow member) constituting the intake variable valve mechanism 13 extends along the uppermost installation seat 21 from the frontmost holding member 11a to the rearmost holding member 11c. It is. Thus, the frame-shaped frame 11 is configured in which the holding members 11a to 11c are legs, and the control shaft 14, the rocker shaft 34, and the support shaft 35 are fixed arms that pass between the legs. A camshaft 15 is inserted between the journal bearing surface 22 and the journal bearing surface 25 from the foremost holding member 11a to the rearmost holding member 11c. A plurality of journal portions 37 (shown in FIGS. 3 and 6) formed on the shaft portion of the camshaft 15 are received between the journal bearing surface 22 and the journal bearing surface 25, and the camshaft 15 is rotatably supported. It is. Thus, the camshaft 34 is assembled to the frame-shaped member 11. As shown in FIGS. 3 and 4, the cam shaft 15 between the journal portions 37 (between the holding members) has an intake cam 38a at the center, and exhaust cams 38b (two) on both sides thereof. The cam group which has is formed.

  The variable valve mechanism 13 (intake side) is assembled to the support shaft 35 portion and the control shaft 14 portion between the holder members 18a, and the rocker arm mechanism 17 (exhaust side) is also assembled to the exhaust rocker shaft 34 portion. For each cylinder).

  Here, each mechanism will be described. As the variable valve mechanism 13, as shown in FIGS. 3, 5, and 8, for example, a mechanism in which a rocker arm 40, a swing cam 50, and a center rocker arm 60 are combined is used. Yes.

  To describe these, the rocker arm 40 has a bifurcated arm shape. Specifically, the rocker arm 40 includes a pair of L-shaped rocker arm pieces 43 in which a needle roller 41 is rotatably interposed between one end portions and an adjust screw portion 42 serving as a valve driving portion is provided at the other end portion. It is formed. Then, a pair of support holes 44 formed in the middle part of each rocker arm piece 43 is slidably inserted into the control shaft 14 portion between the holder members 18a, and the needle roller 41 is disposed on the support shaft 35 side. The adjusting screw portion 42 is arranged on the side opposite to the support shaft 35.

  As shown in FIGS. 3, 5, and 8, the swing cam 50 has a cylindrical support boss 52 at one end of the arm 51, and a cam surface 53 that extends in the vertical direction at the other end. And a structure in which a sliding roller 54 is rotatably embedded in the lower portion of the arm portion 51 so that the outer peripheral surface is exposed from the lower side is used. Reference numeral 54 a denotes a shaft member that supports the sliding roller 54. The support boss 52 is fitted into the support shaft 35 portion between the holder members 18a, and the swing cam 35 is swingably supported by the support shaft 34 as a fulcrum. With this support, the cam surface 53 at the tip of the arm portion 51 is brought into rolling contact with the needle roller 41. A pusher receiving rib 56 projects from the upper portion of the supporting boss portion 52. Under the rib 56, for example, a pusher 57 having a piston structure is combined in an oblique direction. The pusher 57 is supported by fitting a C-shaped leg portion 58 formed on the side portion to the exhaust side rocker shaft 34 portion. An installation seat 59 is formed below the pusher 57.

  The center rocker arm 60 is composed of an L-shaped component disposed at a portion surrounded by the intake cam 38a, the sliding roller 54, and the control shaft 14 as shown in FIGS. The center rocker arm 60 includes a relay arm portion 61 that extends toward the upper sliding roller 54 and a fulcrum arm portion 62 that extends directly below the side control shaft 14 portion. An inclined surface for controlling the movement of the swing cam 50, specifically, a flat inclined surface 65 having a low control shaft side and a high support shaft side is formed on the distal end surface of the relay arm member 61. ing. A sliding roller 63 is rotatably supported in the same direction as the intake cam 38a at an intermediate portion where both arm portions 61 and 62 intersect. Of the relay arm portion 61 interposed between the intake cam 38a and the swing cam 50, the sliding roller 63 is in rolling contact with the cam surface of the intake cam 38a, and the tip of the relay arm portion 61 is inclined. The surface 65 abuts against the outer peripheral surface of the sliding roller 54 of the swing cam 50. Thus, the cam displacement of the intake cam 38a is transmitted to the swing arm 50 through the relay arm portion 61. Further, a support pin portion 66 is supported on the fulcrum arm portion 62 by a pin 67 so as to be freely bent. The distal end portion of the support pin portion 66 is rotatably inserted into a through hole 68 formed on the lower side of the control shaft 14 in a direction orthogonal to the axial direction, and the center rocker arm 60 is supported by the control shaft 14. When the control shaft 14 is rotationally displaced by this support, the rocker arm 60 that swings around the pin 67 (end of the support pin portion 66) changes the rolling contact position with the center intake cam 38a, and the camshaft 15 It can be displaced in the direction (advancing direction and retarding direction) intersecting with. By this displacement, the opening / closing timing of the intake valve 8a and the valve lift amount are continuously varied at the same time. That is, the cam surface 53 has a base circle section (for example, formed by an arc surface centered on the axis of the support shaft 35) on the upper side and a lift section (for example, a lift area of the intake cam 38a) on the lower side that is continuous with the base circle section. When the sliding roller 63 of the center rocker arm 60 is displaced in the advance direction or the retard direction of the intake cam 38a, the posture of the swing cam 50 changes, and the needle The region of the cam surface 53 where the rollers 41 come and go changes. That is, the ratio between the base section and the lift section where the needle roller 41 goes and changes. From the change in the ratio of the base section and the lift section with the phase change in the advance angle direction and the phase change in the retard angle direction, the opening / closing timing of the intake valve 8a is changed at the same time while making the valve closing timing more variable than the valve opening timing. The valve lift amount of the intake valve 8a is continuously varied. This is output from the rocker arm 40 as a valve drive output. At this time, in order to prevent the alignment between the sliding roller 54 and the inclined surface 65 from shifting, the wall portions 51a on both sides surrounding both sides (width direction) of the sliding roller 54 as shown in FIGS. A pair of guide wall portions 51b extending from 51a to both sides of the front end portion of the relay arm portion 61 that abuts are formed. Specifically, the guide wall portion 51 b is provided so as to cover the contact point between the sliding roller 54 of the swing cam 50 that is swinging and the inclined surface 65 of the center rocker arm 60, and the center rocker arm 60 supports the support pin portion 66. It prevents the fulcrum from shaking.

  As shown in FIGS. 3, 5, and 8, an adjusting mechanism 70 is assembled to the control shaft 14 portion into which the support pin portion 33 is inserted. In the adjustment mechanism 70, for example, a screw hole 71 is formed in the control shaft 14 portion so as to open to the upper part continuously with the through hole 68. A structure is used in which a screw member 73 having a screw is screwed so as to be able to advance and retreat. That is, the adjustment mechanism 70 has a structure in which the protruding amount of the support pin portion 66 is changed by rotating the screw member 73, and the rolling contact position of the sliding roller 63 is changed based on the change. Then, by changing the rolling contact position of the sliding roller 63, the posture of the center rocker arm 60 and the posture of the swing cam 50 are changed to adjust the valve opening / closing timing and the valve lift amount (both valve characteristics). The screw member 73 is locked by a lock nut 74. Reference numeral 75 denotes a notch forming a seating surface of the lock nut 74.

  At the end of the control shaft 14 protruding from the foremost holder member 18a, as shown in FIGS. 2 and 3, an arm member 78 projecting upward in the diametrical direction of the control shaft 14, here, for example, is a screw member 79. It is fixed (screwed), and a rotational displacement required for continuous control of valve characteristics is inputted from the end of the arm member 78. Reference numeral 77 denotes a screw member for fixing the base portion of the arm member 78.

  As shown in FIGS. 3 and 5, the rocker arm mechanism 17 (exhaust side) has a structure in which a pair of rocker arms 80 are rotatably assembled to the rocker shafts 34 on both sides of the legs 58 of the pusher 57. Specifically, each of the rocker arms 80 has a support hole 81 at an intermediate portion, a roller member 82 as an abutment member at one end portion, and an adjustment screw portion 83 as a valve drive portion at the other end portion. Have. The support hole 81 of the rocker arm 80 is inserted into the rocker shaft 34 portion between the holder member 18a and the leg portion 58 (the pusher 57), and supports the rocker arm 80 in a swingable manner. With this support, the roller member 82 is disposed on the exhaust cam 38b side, and the adjusting screw 83 is disposed on the opposite side. That is, each rocker arm 80 can be combined with the exhaust valve 9a.

  As shown in FIGS. 3, 6, and 7, a fixing bolt member 18 c is inserted from a seat surface 90 formed on an upper surface portion directly above the rocker shaft 34 that is an upper portion of each holder member 18 a. With this fixing bolt member 18c, the central portion in the diameter direction of the rocker shaft 34, the wall portion on the side of the support shaft 35 adjacent to the camshaft 15 (one side across the camshaft 15), and the rocker shaft 34 side of the cap member 18b. The cap part is pierced in a straight line (skewer). In addition, from the support shaft 35 disposed at the highest point, from each seating surface 21a (uppermost part) formed on the upper outer peripheral portion of the support shaft portion, FIG. 3, FIG. 4, FIG. 6 and FIG. As shown, the fixing bolt 18c is inserted obliquely. With the diagonally inserted fixing bolt 18c, the diametrically central portion of the support shaft 35, the wall portion between the rocker shaft 34 and the control shaft 14, the wall portion between the camshaft 15 and the control shaft 14, and the cap member 18b. The cap portion on the control shaft 14 side is pierced in a straight line (skewing). Reference numerals 92 and 93 denote straight and oblique straight bolt insertion holes formed in the holder member 18a and the cap member 18b. Note that the fixing bolt member 18c that is inserted obliquely is one for the holder member 18a and the cap member 18b arranged at the foremost part and the rearmost part, and is arranged between the cylinders where the load acts more than that part. There are two holder members 18a and cap members 18b (because a load associated with the variable valve operates from both sides). Of course, two or more may be used.

  Further, a shaft displacement detection sensor 16 for detecting the rotational displacement of the control shaft 14 is detachably attached to the sensor mounting boss 31b of the last holder member 18a, for example, by screwing. As shown in FIG. 4, the shaft displacement detection sensor 16 has a structure in which the entire sensor is exposed to the outside when the variable valve device 4 is fitted between the cylinder head 1 and the rocker cover 3.

  By such modularization, the variable valve operating device 4 becomes a structure that can adjust the variation among cylinders independently. In other words, the variable valve device 4 can adjust the variation between cylinders before being assembled to the cylinder head 1. Thus, the variable valve device 4 is adjusted to the variation between cylinders before being assembled to the cylinder head 1 and then assembled to the cylinder head 1 as shown in FIGS. 2, 7 and 8. ing.

  Specifically, the modular variable valve device 4 before being assembled to the cylinder head 1 is a sub-line different from the main line for assembling the engine, and a simulation system that simulates the cylinder head of the engine. It may be used to adjust the variation between cylinders. For example, the modular variable valve device 4 is assembled to the simulated cylinder head, and the arm member 78 and the camshaft 15 are assembled to the simulated drive device (not shown) so that the signal of the shaft displacement detection sensor 16 can be detected. Then, according to the rotational position detected by the shaft displacement detection sensor 16, the operation of advancing and retracting the screw member 73 of the adjustment mechanism 70 for each cylinder so that the opening / closing timing and valve lift amount between the cylinders are aligned. Just do it.

  The adjusted variable valve operating device 4 is conveyed by a jig or a conveying device (both not shown) while keeping the state unchanged, and the actual cylinder head 1 on the main line for assembling the engine. Module installation seats 94 and 95 (seat surface for receiving the seat surface 27) already formed at a fixed position in the recess 1Z (the cylinder block has already been assembled), for example, the upper surface 1y (the bottom surface of the recess): FIG. (Shown in FIG. 8). Specifically, both side portions (including the leg portions 29) of the cap member 18b are placed on the module installation seats 94 and 95, and the screw portions 18d (tips) of the fixing bolt members 18c on both sides protruding from near both sides of the camshaft 15 are mounted. Is screwed into a screw hole 18e (only shown in FIG. 7) formed in the module mounting seats 94 and 95. As a result, the adjusted variable valve device 4 is fixed to the upper surface 1y (bottom surface of the recess) of the cylinder head 1 on the main line. Each adjustment screw portion 42 of the intake side rocker arm 40 is disposed at the stem end of the intake valve 8a, and the adjustment screw portion 83 of the exhaust side rocker arm 80 is disposed at the stem end of the exhaust valve 9a. The installation seat 59 abuts against an installation seat 1c (shown in FIGS. 1 and 5) formed on the inner surface of the peripheral wall 1a of the cylinder block 1, displaces the entire pusher 57 with the leg portion 58 as a fulcrum, and pushes down the tip of the swing cam 50. Energize in the direction.

  On the other hand, as shown in FIGS. 1 to 3, a drive source device that drives the variable valve mechanism 13, for example, an electric actuator device 95 is installed at the forefront of the cylinder head 1. The electric actuator device 95 includes a laterally-oriented motor unit 96 disposed outside the peripheral wall 1a of the cylinder head 1, a reduction gear unit 97 (deceleration of the motor output) connected to the front portion of the motor unit 96, and the same reduction gear. A drive unit having a screw shaft 99 connected to the output portion of the portion 97 via a universal joint 98 (universal joint) is used as one component. The electric actuator device 95 is configured such that the leg 97b formed on the casing 97a of the speed reducer portion 97 is bolted to the upper surface 1y of the cylinder head 1 so that the shaft center is in the direction intersecting the variable valve operating device 4. 1 assembled. As a result, the motor unit 96 is projected out of the cylinder head 1 and the screw shaft 99 is extended to the end of the arm member 78 on the opposite side. In addition, the part which penetrates the surrounding wall 1a is made into a fan shape. The nut member 100 is screwed into the screw shaft 99 so as to be able to advance and retract. The nut member 100 is formed of a pin-shaped member having a flange portion 100c at one end portion and having a screw hole 100a penetrating in a diametrical direction at a shaft portion. Screwed. The nut member 100 is attached to the tip of the arm member 78 so that the electric actuator device 95 can drive the control shaft 14. That is, the nut member 100 is rotatably inserted into a support cylinder 78a formed at the distal end portion of the arm member 78 (variable valve operating apparatus 4), and the distal end portion is prevented from coming off by, for example, a C-shaped clip member 100b. As a result, the arm member 78 is incorporated. The screw shaft portions around the nut member 100 pass through a pair of elongated through holes 78b formed on both sides of the peripheral wall of the support cylinder 78a and extending in the circumferential direction. When the motor unit 96 is operated, the screw shaft 99 is rotated. The nut member 100 moves on the swingable screw shaft 99 and pushes and pulls the arm member 78 forward and backward to rotate the control shaft 14. In other words, the opening / closing timing of the intake valve 8a and the valve lift amount are continuously controlled by driving the electric actuator device 95.

  The rocker cover 3 is formed in a box shape following the shape of the cylinder head 1 as shown in FIG. In addition, a fan-shaped notch 3a (for sensor only shown in FIG. 4) is formed in the peripheral portion corresponding to the penetrating portion of the shaft displacement detection sensor 16 and the motor portion 96a while allowing the penetrating portion to be sealed. It is. As shown in FIGS. 1 and 4, the rocker cover 3 is installed on a rocker cover mounting seat 1 b at the periphery of the cylinder head 1, and among the devices mounted on the cylinder head 1, a shaft displacement detection sensor 16 and a motor unit. The variable valve device 4 and the electric actuator device 95 are accommodated in a sealed space between the cylinder head 1 and the rocker cover 3 while exposing the 96 a to the outside of the rocker cover 3.

  Thus, when the variable valve device 4 is configured to be installed in the concave portion 1z that is concave toward the cylinder side of the cylinder head 1 via the holding members 11a to 11c, the variable valve device that includes the cam shaft 15 and is modularized. Since the device 4 enters the recess 1z, even if the height dimension tends to be increased by the camshaft 15, it can be installed in the cylinder head 1 while suppressing the height dimension.

  Therefore, the overall height of the engine is suppressed, and the engine can be made compact.

  In particular, the modular variable valve operating apparatus 4 uses a configuration in which the camshaft 15 and the variable valve mechanism 13 are arranged in this order from the cylinder head 1 side, and the camshaft 15 is positioned in the recess 1z of the cylinder head 1. Since it installed in this way, it becomes easy to accommodate in the recessed part 1z (part enclosed by the surrounding wall 1a). That is, the modularized structure is formed in the cylinder head 1 by a structure in which a camshaft 15 having a narrower width than the variable valve mechanism 13 is disposed on the cylinder head 1 side as shown in FIG. It can be easily stored in the recess 1z. In addition, since the variable valve mechanism 13 is located outside the recess 1z (the portion surrounded by the peripheral wall 1a), the variable valve mechanism 13 is adjusted even after the variable valve device 15 is installed in the cylinder head 1. Can be easily done.

  In addition, since the holding members 11a to 11c have a structure in which the camshaft 15 is sandwiched between the holder member 18a and the cap member 18b, the journal portion 37 of the camshaft 15 has a smaller diameter than the cam outer shape. Therefore, the height of the holding members 11a to 11c can be suppressed, so that the variable valve apparatus 4 including the camshaft 15 can be installed low. That is, the variable valve apparatus 4 including the camshaft 15 can be more compactly installed on the cylinder head 1.

  In addition, if the holding members 11a to 11c are divided into a plurality of parts so as to pivotally support at least both ends of the camshaft 15, and each is connected by the camshaft 15, the variable valve operating apparatus 4 is modularized. Therefore, since the holding member is provided only at a necessary location, the holding members 11a to 11c can be prevented from being enlarged and the weight can be minimized.

  In addition, even if the variable valve mechanism 14 is modularized together with the rocker arm mechanism 17 on the exhaust side, the width dimension on the lower side does not vary greatly as shown in FIG. It is effective for a structure in which the variable valve device 14 including the camshaft 15 and the rocker arm mechanism 17 is modularized in the cylinder head 1 of the SOHC engine.

Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit of the present invention.

1 is a partially cutaway perspective view showing a cylinder head of an internal combustion engine according to an embodiment of the present invention together with a valve gear mounted on the cylinder head. The disassembled perspective view which shows the variable valve operating apparatus modularized with the periphery apparatus. The disassembled perspective view for demonstrating the structure of each part of the variable valve operating apparatus. Sectional drawing which follows the arrow A in FIG. Sectional drawing which follows the arrow B in FIG. Sectional drawing which follows the arrow C in FIG. Sectional drawing which follows the DD line | wire in FIG. Sectional drawing which follows the EE line | wire in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Cylinder head, 1a ... Circumferential wall, 1y ... Upper surface, 1z ... Recessed part, 3 ... Rocker cover, 4 ... Variable valve apparatus, 8a ... Intake valve, 11a-11c ... Holding member, 13 ... Variable valve mechanism, 14 ... Control shaft, 15 ... cam shaft, 17 ... Rocker arm mechanism for exhaust, 18a ... Holder member, 18b ... Cap member, 18c ... Fixing bolt member, 34 ... Rocker shaft for exhaust, 35 ... Support shaft, 38a ... For intake Cam ... 40 ... Rocker arm, 50 ... Swing cam, 60 ... Center rocker arm, 70 ... Adjustment mechanism, 80 ... Exhaust rocker arm, 94, 95 ... Module installation seat.

Claims (2)

In an internal combustion engine having a plurality of cylinders, a valve operating device for an internal combustion engine configured by installing a variable valve operating device on a surface of the cylinder head opposite to the cylinder side,
The variable valve operating device is:
A plurality of holding members extending in the width direction of the cylinder head are installed on the cylinder head at least at the foremost part and the rearmost part of the plurality of cylinders in accordance with the arrangement of the cylinders,
The holding member is composed of a holder member and a cap member assembled to a lower end portion of the holder member, and a camshaft having a cam for each cylinder is held between the holder member and the cap member and the holder A variable valve mechanism for intake is provided on the upper side of the member to receive the cam and continuously and variably control the valve characteristics,
The installation seat formed at the upper part of each holding member is provided with a support shaft that constitutes the variable valve mechanism for intake and is fixed to each holding member, and is formed below the installation seat of the holding member. The control shaft and the exhaust rocker shaft constituting the variable valve mechanism for intake are inserted into the holding hole to form a frame-shaped frame,
The holder member, the rocker shaft, and the cap member are pierced perpendicularly to the upper surface of the cylinder head by a fixing bolt member, and the control shaft, the holder member, and the cap member are connected to the fixing bolt. A bolt member for fixing different from the member, and is modularized by projecting obliquely with respect to the upper surface of the cylinder head,
Further, the valve operating apparatus for an internal combustion engine, wherein the modular variable valve operating apparatus is disposed in a recess that is recessed toward the cylinder of the cylinder head.   The variable valve operating device is arranged in the order of the camshaft and the variable valve operating mechanism from the cylinder head side, and is configured so that the camshaft is positioned in the recess. Item 8. A valve operating apparatus for an internal combustion engine according to Item 1.

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