JP2012002095A - Variable valve system of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively lubricate synchro pins and pistons even when lubricating the synchro pins and the pistons by an actuator, in a variable valve system of an internal combustion engine in which the synchro pins movable between coupling positions coupling rocker arms and coupling releasing positions releasing the coupling are slidably fitted into parts of guide holes arranged in a plurality of rocker arms, respectively, and the piston is slidably fitted into the residual one guide hole so as to regulate the moving ends of the synchro pins at the coupling positions.SOLUTION: Oil feeding holes 56, 57, 58 whose inner ends open to the inner surface of the guide holes 45, 46, 47 and whose outer ends open to the upper parts of the rocker arms 29, 30, 31 are arranged in the plurality of rocker arms 29, 30, 31, respectively.

Description

  In the present invention, a plurality of rocker arms adjacent to each other are provided with guide holes that are coaxially connected at a timing when the engine valves that are driven to open and close by the rocker arms are in a closed state, and part of the guide holes, A sync pin that enables movement between a connection position for connecting adjacent rocker arms and a connection release position for releasing the connection is slidably fitted, and the remaining one guide hole among the guide holes, The present invention relates to a variable valve operating apparatus for an internal combustion engine in which a piston connected to the synchro pin is slidably fitted so as to restrict a moving end of the synchro pin at the connecting position.

  A plurality of rocker arms are connected by sliding the synchro pins and pistons, which are slidably fitted in contact with the guide holes of the plurality of rocker arms, by applying an operating hydraulic pressure from a hydraulic pressure source to the synchro pins. A variable valve operating apparatus for an internal combustion engine in which the connection of a plurality of rocker arms is released by lowering the hydraulic pressure acting on the synchro pin is already known from Patent Document 1 and the like.

Japanese Patent Publication No. 6-29525

  In the variable valve operating device disclosed in Patent Document 1, the synchro pin and the piston are lubricated using the hydraulic pressure. However, in order to drive the synchro pin and the piston with the working oil pressure, a high oil pressure different from the oil pressure used for lubricating the internal combustion engine and valves for switching the oil pressure are necessary. In an internal combustion engine or a small internal combustion engine having a rolling bearing type crankshaft that is not required, a high operating hydraulic pressure for driving the synchro pin and the piston and a control means for controlling the operating hydraulic pressure are equipped. That is difficult due to cost and space constraints. Therefore, if the connection and disconnection of a plurality of rocker arms are switched by pushing the synchro pin and piston with an actuator such as a solenoid or an electric motor, the high hydraulic pressure and the control means are not required. Instead, it is necessary to lubricate the synchro pin and the piston.

  The present invention has been made in view of such circumstances, and a variable valve for an internal combustion engine capable of effectively performing synchronization of the synchro pin and the piston even when the synchro pin and the piston are lubricated by the actuator. An object is to provide an apparatus.

  In order to achieve the above object, according to the present invention, a plurality of adjacent rocker arms are provided with guide holes that are coaxially connected to each other at a timing when an engine valve driven to open and close by the rocker arms is in a closed state. A synchro pin that allows movement between a connection position for connecting adjacent rocker arms and a connection release position for releasing the connection is slidably fitted in a part of the guide hole of the guide holes. In the variable valve operating apparatus for an internal combustion engine, a piston connected to the synchro pin is slidably fitted into the remaining one guide hole so as to restrict a moving end of the synchro pin at the connecting position. The plurality of rocker arms are each provided with an oil supply hole having an inner end opened on the inner surface of the guide hole and an outer end opened on the top of the rocker arm. The first feature to be.

  According to the present invention, in addition to the configuration of the first feature, the plurality of rocker arms are provided with oil discharge holes each having an inner end opened on the inner surface of the guide hole and an outer end opened on the lower portion of the rocker arm. This is the second feature.

  According to the third aspect of the present invention, in addition to the configuration of the first or second feature, the oil supply hole is disposed at a position where the inner end thereof is always opposed to the outer periphery of the synchro pin having a circular cross section. Features.

  According to the present invention, in addition to any one of the first to third features, the guide hole for slidably fitting the piston has an end wall on the side opposite to the synchro pin and has a bottom. The return spring is formed in such a manner that a coil-like return spring is contracted between the piston and the end wall, and the oil supply hole provided in the rocker arm having the bottomed guide hole is in a disconnected state of the plurality of rocker arms. The fourth feature is that the inner end faces the outer periphery of the lens.

  In the present invention, in addition to the configuration of the fourth feature, a slit extending in the axial direction is provided at the end wall side end of the piston formed in a bottomed cylindrical shape that is closed on the opposite side to the end wall. It is a fifth feature that it is provided.

  According to the present invention, in addition to any of the first to fifth features, a head cover that covers each of the rocker arms from above is coupled to a cylinder head in which the engine valve is disposed to be openable and closable. According to a sixth aspect of the present invention, a rib that drops oil toward the oil supply hole of each rocker arm protrudes from the inner surface.

  In addition to any of the configurations of the sixth feature, the present invention provides the synchro pin slidably fitted in a guide hole of a specific rocker arm disposed on one end side along the arrangement direction of the plurality of rocker arms. Further, a projecting portion projecting outward from the specific rocker arm is provided coaxially, and an actuator attached to the cylinder head or the head cover and projecting at least partially outward from the cylinder head or the head cover includes the synchro A seventh feature is that the pin is connected to the protrusion so as to exert a pressing force on the pin.

  The intake valve 21 of the embodiment corresponds to the engine valve of the present invention, and the intake side rocker arms 29, 30, 31, 66, 67 of the embodiment correspond to the rocker arm of the present invention.

  According to the first feature of the present invention, since the oil supply hole is provided between the upper portion of the rocker arm and the inner surface of the guide hole, it is possible to guide oil from the outside into the guide hole from the oil supply hole, Even if the synchro pin and the piston are driven without using the hydraulic pressure, the synchro pin and the piston can be effectively lubricated.

  According to the second feature of the present invention, since the oil discharge hole is provided between the lower part of the rocker arm and the inner surface of the guide hole, the oil introduced into the guide hole can be appropriately discharged from the guide hole. It is possible to improve the oil circulation by preventing the pumping by the pin and the piston.

  According to the third feature of the present invention, since the inner end of the oil supply hole always faces the outer periphery of the synchro pin having a circular cross section, the oil is moved to the entire inner periphery of the guide hole as the synchro pin slides. Can be supplied effectively.

  According to the fourth feature of the present invention, a coil-like return spring is contracted between the piston slidably fitted into the bottomed guide hole and the end wall of the guide hole, and the oil supply hole has a plurality of oil supply holes. When the rocker arm is not connected, it is arranged at a position where the inner end faces the outer periphery of the return spring, so that wear due to sliding contact with the inner surface of the guide hole of the return spring is suppressed, and oil changes due to the volume change between the piston and the end wall. Oil can be effectively supplied from the supply hole into the guide hole.

  According to the fifth feature of the present invention, since the slit extending in the axial direction is provided at the end wall side end of the bottomed cylindrical piston, the piston is prevented from being in close contact with the inner surface of the guide hole. In addition, it is possible to prevent a delay in operation due to close contact.

  According to the sixth aspect of the present invention, the rib for dropping the oil toward the oil supply hole of each rocker arm is provided on the inner surface of the head cover that covers each rocker arm from above, so that it is scattered between the cylinder head and the head cover. The oil thus introduced can be effectively guided to the oil supply holes of the respective rocker arms to smoothly lubricate the respective guide holes.

  Furthermore, according to the seventh feature of the present invention, the protrusion that is coaxially provided on the synchro pin that is slidably fitted in the guide hole of the specific rocker arm on one end side in the arrangement direction and protrudes outside from the specific rocker arm In addition, since the actuator having at least a part protruding outward from the cylinder head or the head cover is connected, it is possible to prevent the temperature of the actuator from rising and maintain the operation of the actuator satisfactorily.

It is a principal part longitudinal cross-sectional view of the internal combustion engine of 1st Embodiment. 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. 1. It is sectional drawing corresponding to FIG. 3 in the state in which the several rocker arm was connected. It is sectional drawing corresponding to FIG. 2 of 2nd Embodiment. It is sectional drawing corresponding to FIG. 3 of 2nd Embodiment.

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

  The first embodiment of the present invention will be described with reference to FIGS. 1 to 4. First, in FIG. 1, a piston 13 is slidably fitted into a cylinder bore 12 provided in a cylinder block 11 of an internal combustion engine. A cylinder head 15 that forms a combustion chamber 14 facing the top of the piston 13 with the cylinder block 11 is coupled to the cylinder block 11. The cylinder head 15 is provided with an intake port 16 and an exhaust port 17 that can communicate with the combustion chamber 14. An intake device 19 having a fuel injection valve 18 is connected to the intake port 16, and the exhaust port 17 is not shown. An exhaust device is connected.

  The cylinder head 15 has a pair of intake valves 21 for switching communication / blocking of the intake port 16 to the combustion chamber 14 and a pair of exhaust valves for switching communication / blocking of the exhaust port 17 to the combustion chamber 14. The intake valves 21 are energized in the valve closing direction by the valve springs 23, and the exhaust valves 22 are energized in the valve closing direction by the valve springs 24.

  A head cover 26 that forms a valve operating chamber 25 is coupled to the cylinder head 15. The intake valve 21... And the exhaust valve 22. The valve operating device 27 is accommodated.

  Referring to FIGS. 2 and 3 together, the valve operating device 27 is a single cam disposed between the intake valves 21... And the exhaust valves 22. The shaft 28, the pair of intake valves 21, and the first, second, and third intake side rocker arms 29, 30, and 31 interposed between the camshaft 28, the pair of exhaust valves 22, and the camshaft 28. And a pair of exhaust-side rocker arms 32 interposed therebetween.

  An intermediate portion of the pair of exhaust-side rocker arms 32 is supported so as to be swingable by an exhaust-side rocker shaft 33 having an axis parallel to the camshaft 28. Rollers 35 that are in rolling contact with exhaust side cams 34 provided on the shaft 28 are pivotally supported, and tappet screws 36 that abut the stem end 22a of the exhaust valve 22 at the other end of the exhaust side rocker arm 32. ... are screwed together so that the forward / backward position can be adjusted.

  The first, second, and third intake side rocker arms 29, 30, and 31 are arranged in parallel in the direction along the axis of the camshaft 28 so that the second intake side rocker arm 30 is sandwiched between the first and third intake side rocker arms 29, 31. It is disposed and is supported so as to be swingable by an intake side rocker shaft 37 having an axis parallel to the exhaust side rocker shaft 33.

  Tappet screws 38, 38 abutting on the stem ends 21a of the intake valves 21 are screwed into one end portions of the first and third intake side rocker arms 29, 31 so that the forward and backward positions can be adjusted. Rollers 39, 39 that are in rolling contact with a pair of intake side low-speed cams 40, 40 provided on the camshaft 28 are pivotally supported at the other ends of the three intake side rocker arms 29, 31, respectively. The intake-side rocker shaft 37 supports an intermediate portion of the first and third intake-side rocker arms 29 and 31 and one end of the second intake-side rocker arm 30 so as to be swingable. A roller 42 that is in rolling contact with an intake-side high-speed cam 41 provided on the camshaft 28 between the intake-side low-speed cams 40 is supported on the other end. Also, a lost motion spring (not shown) is contracted between the arm portion 30a integrally connected to one end of the second intake side rocker arm 30 and the cylinder head 15, and the second intake side rocker arm 30 is The roller 42 is urged by the lost motion spring so that the roller 42 is always in rolling contact with the intake side high-speed cam 41.

  The intake-side low-speed cam 40 and the intake-side high-speed cam 41 have arc base circles 40a, 41a centered on the axis of the camshaft 28, and camshafts more than the base circles 40a, 41a. 28 are formed so as to have cam crests 40b, 41b connected to both ends in the circumferential direction of the base circles 40a,. Thus, the base circle portions 40a..., 41a of the intake side low speed cam 40 and the intake side high speed cam 41 are formed along virtual circles of the same radius centered on the axis of the camshaft 28, The amount of protrusion and angle range of the cam nose 41b of the side high speed cam 41 from the base circle 41a is the amount of protrusion and angle range of the cam nose 40b of the intake side low speed cam 40 ... from the base circle 40a. Set as above.

  The first to third intake-side rocker arms 29 to 31 are oscillated by following the intake-side high-speed cam 41 with the first and third intake-side rocker arms 29 and 31 linked to and connected to the intake valves 21. Regardless of the second intake-side rocker arm 30, the intake-side low-speed cam 40 is driven and swung to respond to the cam profile of the intake-side low-speed cam 40 during low-speed operation of the internal combustion engine. The state in which the opening / closing operation is performed in the operation mode and the first and second intake side rocker arms 29 and 31 are connected to the second intake side rocker arm 30 to connect the intake valve 21 to the intake side high speed cam 41 during high speed operation of the internal combustion engine. A valve operating characteristic changing mechanism 43 is provided for switching between a state in which the opening / closing operation is performed in an operation mode corresponding to the cam profile.

  The valve operating characteristic changing mechanism 43 is provided above the first to third intake-side rocker arms 29 to 31 between the intake-side rocker shaft 37 and the camshaft 28, and is adjacent to the first to first intake-side rocker arms 29 to 31. The first sync pin 48, the second sync pin 49, and the piston 50 are slidably fitted in first, second, and third guide holes 45, 46, 47 provided in the three intake side rocker arms 29-31, respectively. Prepare.

  The first to third guide holes 45 to 47 have an axis parallel to the intake side rocker shaft 37 and the camshaft 28, and the first guide hole 45 has an end wall 51 on the opposite side to the second intake side rocker arm 30. A second guide hole 46, which is a through hole that is open at both ends, is provided in the second intake side rocker arm 30. The second intake side rocker arm 30 has a bottomed shape and is provided in the first intake side rocker arm 29. A third guide hole 47 having an end wall 52 on the opposite side to 30 and having a bottomed shape is provided in the third intake side rocker arm 31. Moreover, the first to third guide holes 45 to 47 are formed to have the same diameter, and the intake valves 21 that are opened and closed by the first to third intake-side rocker arms 29 to 31 are closed. That is, the rollers 39 of the first and second intake side rocker arms 29, 31 are in rolling contact with the base circle portion 40a of the intake side low speed cam 40, and the roller 42 of the second intake side rocker arm 30 is in contact with the intake side high speed cam. The first to third guide holes 45 to 47 are arranged so as to be coaxially connected at the timing of rolling contact with the base circle portion 41 a of 41.

  The first sync pin 48 is formed to have an axial length substantially corresponding to the entire length of the first guide hole 45 and to have an outer periphery with a circular cross section. As shown in FIGS. The first and second intake side rocker arms 29, 30 abut on the end wall 51 of the first guide hole 45 and the end surface on the second intake side rocker arm 30 side is disposed between the first and second intake side rocker arms 29, 30. 30 between the connection release position for releasing the connection of 30 and the connection position for connecting the first and second intake side rocker arms 29 and 30 by partially fitting them into the second guide hole 46 as shown in FIG. It is possible to slide with.

  Moreover, a first slidably fitted into the first guide hole 45 of the first intake-side rocker arm 29 which is a specific rocker arm arranged on one end side along the arrangement direction of the first to third intake-side rocker arms 29 to 30. The one sync pin 48 is provided with a shaft-like protruding portion 48a that movably passes through the end wall 51 of the first guide hole 45 and protrudes outward from the first intake side rocker arm 29, coaxially and integrally. An annular gap 64 is formed between the end wall 51 and the protrusion 48a. On the other hand, the cylinder head 15 or the head cover 26, in this embodiment, the cylinder head 15, has an actuator, for example, a solenoid 53, at least a part (most in this embodiment) protruding outward from the cylinder head 15. The solenoid 53 is connected to the protrusion 48 a so as to exert a pressing force on the first sync pin 48.

  Thus, the solenoid 53 has an output shaft 54 extending toward the projecting portion 48 a, and the tip of the projecting portion 48 a is slidably contacted with a disc portion 54 a provided at the tip of the output shaft 54. Thus, the disk portion 54a is formed to have a size that allows the protruding portion 48a that swings together with the first intake side rocker arm 29 to always slide.

  The second sync pin 49 is formed to have an axial length substantially corresponding to the entire length of the second guide hole 46 and to have an outer periphery with a circular cross section. One end of the second sync pin 49 is in sliding contact with the first sync pin 48. As shown in FIGS. 2 and 3, the second sync pin 49 has one end disposed between the first and second intake-side rocker arms 29 and 30 and the other end on the third intake-side rocker arm 31 side being second and third. A connection release position for releasing the connection between the second and third intake side rocker arms 30 and 31 between the intake side rocker arms 30 and 31 and a part on the other end side as shown in FIG. To the connecting position where the second and third intake-side rocker arms 30 and 31 are connected.

  The first and second sync pins 48 and 49 are slidably fitted in the first to third guide holes 45 to 47 with the first to third intake side rocker arms 29 to 31 being disconnected. In the third guide hole 50, which is the remaining guide hole excluding the second guide holes 45 and 46, the piston 50 that regulates the moving end at the connecting position of the first and second sync pins 48 and 49 is slidable. Mated. The piston 50 is formed in a bottomed cylindrical shape with one end on the side opposite to the end wall 52 of the third guide hole 47, that is, on the second synchro pin 49 side. One end of the piston 50 is slidably contacted. Thus, as shown in FIGS. 2 and 3, one end of the piston 50 is located between the second and third intake side rocker arms 30 and 31 when the first to third intake side rocker arms 29 to 31 are in the disconnected state. As shown in FIG. 4, when the first to third intake side rocker arms 29 to 31 are connected, the other end of the piston 50 comes into contact with the end wall 52 of the third guide hole 50. A coiled return spring 55 is contracted between the piston 50 and the end wall 52.

  Moreover, a plurality of slits 63 (see FIG. 3) extending in the axial direction are provided at the end of the piston 50 on the end wall 52 side.

  Thus, when the pressing force from the solenoid 53 acts on the protruding portion 48 a of the first sync pin 48, the first sync pin 48 and the second sync pin 49 resist the spring force of the return spring 55. The piston 50 moves to the connecting position while being pushed in, and the moving end at the connecting position of the first and second sync pins 48 and 49 is restricted by the piston 50 coming into contact with the end wall 52. When the pressing force action from the solenoid 53 to the projecting portion 48a is released, the first and second sync pins 48 and 49 are pushed by the piston 50 to which the spring force of the return spring 55 acts, so that the first and second sync pins 48 and 49 are on the connection release position side. Will return.

  In such a valve operating characteristic changing mechanism 43, the first to third intake side rocker arms 29 to 31 have inner ends opened to the inner surfaces of the first to third guide holes 45 to 47 and outer ends of the first to third intake side rocker arms 29 to 31. Oil supply holes 56, 57, and 58 are provided in the upper portions of the third intake side rocker arms 29 to 31, respectively.

  Thus, the first and second sync pins 48 and 49 having a circular outer peripheral surface are slidably fitted in the non-connected state of the first to third intake side rocker arms 29 to 31, respectively. The first and second intake-side rocker arms 29 and 30 provided with the second guide holes 45 and 46 are arranged at positions where the inner ends are always opposed to the outer peripheries of the first and second sync pins 48 and 49, respectively. Oil supply holes 56 and 57 are provided.

  In addition, the oil supply hole 58 provided in the third intake side rocker arm 31 provided with the third guide hole 47 into which the piston 50 is slidably fitted is not connected to the first to third intake side rocker arms 29 to 31 ( In the state shown in FIGS. 2 and 3, the return spring 55 is disposed at a position where the inner end faces the outer periphery.

  Further, the first to third intake-side rocker arms 29 to 31 have inner ends that open to the inner surfaces of the first to third guide holes 45 to 47 and outer ends that are lower portions of the first to third intake-side rocker arms 29 to 31. In this embodiment, the oil discharge holes 59 to 61 are provided at first to third intake side rocker arms at positions facing the rollers 39. It opens in the lower part of 29-31.

  Further, ribs for dropping oil toward the oil supply holes 56 to 58 of the first to third intake side rocker arms 29 to 31 are formed on the inner surface of the head cover 26 that covers the first to third intake side rocker arms 29 to 31 from above. 62 extends in a direction along the axis of the camshaft 28 and projects.

  Next, the operation of the first embodiment will be described. The first to third intake-side rocker arms 29 to 31 have intake valves 21 that are opened and closed by the intake-side rocker arms 29 to 31 in a closed state. First to third guide holes 45 to 47 that are coaxially connected at a certain timing are provided, respectively, and the first and second guide holes 45 and 46 that are a part of the first to third guide holes 45 to 47 are provided. It is possible to move between a connection position for connecting the adjacent first and second intake side rocker arms 29, 30 and the adjacent second and third intake side rocker arms 30, 31 and a connection release position for releasing the connection. The first and second sync pins 48 and 49 are slidably fitted, and the first and third guide holes 47, which are the remaining ones of the first to third guide holes 45 to 47, are inserted into the first and second guide holes 47. 2 synchro pins The piston 50 connected to the 8, 49 is slidably fitted so as to restrict the moving ends of the first and second sync pins 48, 49 at the connecting position. An oil supply hole 56 having an inner end opened to the inner surfaces of the first to third guide holes 45 to 47 and an outer end opened to the upper portions of the first to third intake side rocker arms 29 to 31 in the intake side rocker arms 29 to 31. , 57 and 58 are provided, respectively, so that oil from the outside can be guided into the first to third guide holes 45 to 47 from the oil supply holes 56 to 58, and the first oil pressure without using high operating hydraulic pressure. Even in the structure in which the first sync pin 48, the second sync pin 49, and the piston 50 are driven, the first sync pin 48, the second sync pin 49, and the piston 50 can be effectively lubricated.

  The first to third intake side rocker arms 29 to 31 have an inner end opened to the inner surface of the guide holes 56 to 58 and an outer end opened to the lower portions of the first to third intake side rocker arms 29 to 31. Since the holes 59, 60, 61 are respectively provided, the oil introduced into the guide holes 56 to 58 can be appropriately discharged from the guide holes 56 to 58, and the first sync pin 48, the second sync pin 49, and the piston. The pumping by 50 can be prevented from occurring and the oil circulation can be improved.

  Further, the first and second intake side rocker arms 29 in which the first and second synchro pins 48 and 49 having a circular outer cross section are fitted in a state where the first to third intake side rocker arms 29 to 31 are not connected. , 30 is provided at a position where the inner ends of the oil supply holes 56, 57 are always opposed to the outer circumferences of the first and second sync pins 48, 49, the first and second sync pins 48, With the sliding of 49, oil can be effectively supplied to the entire inner circumference of the first and second guide holes 45, 46.

  In addition, an oil supply hole 58 provided in the third intake side rocker arm 31 having a bottomed third guide hole 47 into which the piston 50 is slidably fitted is not provided in the first to third intake side rocker arms 29 to 31. Since the inner end faces the outer periphery of the coiled return spring 55 contracted between the end wall 52 of the third guide hole 47 and the piston 50 in the connected state, the third guide of the return spring 55 is arranged. The wear due to the sliding contact of the inner surface of the hole 47 can be suppressed, and the oil supply from the oil supply hole 58 into the third guide hole 47 can be effectively performed by the volume change between the piston 50 and the end wall 52.

  Further, since the end portion on the end wall 52 side of the piston 55 formed in a bottomed cylindrical shape closed on the side opposite to the end wall 52 is provided with a slit 63 extending in the axial direction, the piston 55 is It is possible to prevent the three guide holes 47 from being in close contact with the inner surface, and to prevent an operation delay due to the close contact.

  Incidentally, in the connected state of the first to third intake side rocker arms 29 to 31, as shown in FIG. 4, the oil supply hole 58 and the oil discharge hole 61 provided in the third intake side rocker arm 31 are formed in the slits 63 of the piston 50. When in the corresponding position, oil does not accumulate in the space between the piston 50 and the third intake side rocker arm 31, but the oil supply hole 58 and the oil discharge hole 61 are closed on the outer periphery of the piston 50. May accumulate oil in a slightly pressurized state in the space between the piston 50 and the third intake side rocker arm 31, and in this case, the first to third intake side rocker arms 29 to 31 are disconnected from the connected state. When the piston 50 moves to switch to the state, the oil pressure due to the accumulated oil is added to the spring force of the return spring 55 in addition to the piston force. Will be acting on the emissions 50, transition operation to the non-connected state is improved from the first to the connected state of the third intake-side rocker arms 29 to 31.

  Ribs 62 for dropping oil toward the oil supply holes 56 to 58 of the first to third intake side rocker arms 29 to 31 are formed on the inner surface of the head cover 26 that covers the first to third intake side rocker arms 29 to 31 from above. Since the protrusions are provided, the oil scattered between the cylinder head 15 and the head cover 26 is effectively guided to the oil supply holes 56 to 58 of the first to third intake side rocker arms 29 to 31, thereby first to third guide holes 45. -47 can be smoothly lubricated.

  Further, the first sync pin 48 slidably fitted in the first guide hole 45 of the first intake side rocker arm 29 arranged on one end side along the arrangement direction of the first to third intake side rocker arms 29 to 31. A projecting portion 48a projecting outward from the first intake side rocker arm 29 is coaxially provided, and a solenoid 53 attached to the cylinder head 15 and projecting outward from the cylinder head 15 at least partially includes a first sync. Since the pin 48 is connected to the protruding portion 48a so as to exert a pressing force, the temperature of the solenoid 53 can be prevented from rising and the operation of the solenoid 53 can be maintained well.

  Further, when the first to third intake side rocker arms 29 to 31 are shifted from the connected state to the non-connected state, the first sync pin 48 removes oil accumulated between the end wall 51 of the first guide hole 45 and the annular gap. The oil is moved to the end wall 51 side while being discharged from 64, but the amount of oil discharged from the annular gap 64 is regulated by the throttling effect by the annular gap 64, whereby an oil film is formed on the inner surface of the end wall 51. Since the 1st synchro pin 48 contact | abuts to the end wall 51 via an oil film, a contact sound can be suppressed.

  A second embodiment of the present invention will be described with reference to FIG. 5 and FIG. 6, but the parts corresponding to the first embodiment are only given the same reference numerals and shown in detail. The detailed explanation is omitted.

  Between the pair of intake valves 21 and the camshaft 65, a pair of intake-side rocker arms 66, 67 arranged in a direction parallel to the axis of the camshaft 65 are interposed. It is supported by an intake rocker shaft 68 having an axis parallel to the shaft 65 so as to be swingable.

  Tappet screws 69 and 69 abutting on the intake valves 21 are screwed into one end portions of both intake side rocker arms 66 and 67 so that the forward and backward positions can be adjusted, and the other end portion of one intake side rocker arm 66 is A roller 72 that is in rolling contact with the sliding contact projection 70 provided on the camshaft 65 is pivotally supported, and the other end of the other intake side rocker arm 67 is in sliding contact with the intake side cam 71 provided on the camshaft 65. A roller 73 is pivotally supported.

  The sliding contact projection 70 is formed to have a circular outer periphery centering on the axis of the camshaft 65 corresponding to the base circle portion of the intake side cam 71. Therefore, in a state where the intake side rocker arms 66 and 67 are not connected, one intake side rocker arm 66 does not swing, and the other intake side rocker arm 67 swings by following the intake side cam 71. While one of the intake valves 21 remains closed, the other intake valve 21 opens and closes with an operating characteristic corresponding to the cam profile of the intake side cam 71. Further, in a state where the both intake side rocker arms 66 and 67 are connected, one intake side rocker arm 66 swings together with the other intake side rocker arm 67 that swings by following the intake side cam 71, and both intake valves 21. Are opened and closed with operating characteristics corresponding to the cam profile of the intake side cam 71.

  A pair of intake-side rocker arms 66 and 67 adjacent to each other are opened and closed by the intake-side rocker arms 66 and 67 with guide holes 74 and 75 having the same diameter and parallel to the intake-side rocker shaft 68 and the camshaft 65. When the intake valves 21 are closed, the guide holes 66 provided in one intake side rocker arm 66 have a bottomed shape in which the opposite side to the other intake side rocker arm 67 is closed by an end wall 76. The guide hole 75 provided in the other intake side rocker arm 67 is formed in a bottomed shape in which the opposite side to the one intake side rocker arm 66 is closed by an end wall 77.

  A sync pin 78 is fitted into one guide hole 74 in a state where both intake side rocker arms 66 and 67 are not connected. A part of the sync pin 78 is fitted into the other guide hole 75. The connection position for connecting the intake side rocker arms 66 and 67 and the end face on the other intake side rocker arm 67 side are disposed between the intake side rocker arms 66 and 67 to release the connection between the intake side rocker arms 66 and 67. It can slide between the release positions.

  Moreover, the guide hole 74 is provided in the synchro pin 78 slidably fitted in the guide hole 74 of the intake side rocker arm 66 which is a specific rocker arm arranged on one end side along the arrangement direction of the both intake side rocker arms 66 and 67. A shaft-like projecting portion 78a that movably passes through the end wall 76 and projects outwardly from the intake side rocker arm 66 is provided coaxially and integrally. On the other hand, a solenoid 53 is attached to the cylinder head 15 so that at least a part (most part in this embodiment) protrudes outward from the cylinder head 15. The solenoid 53 applies a pressing force to the sync pin 78. In this manner, the projection 78a is connected to the projection 78a.

  Thus, the solenoid 53 has an output shaft 54 extending toward the projecting portion 48a, and the tip of the projecting portion 78a is slidably contacted with a disc portion 54a provided at the tip of the output shaft 54. The plate portion 54a is formed to have a size that allows the protruding portion 78a that swings together with the intake-side rocker arm 66 to always slide.

  Of the guide holes 74, 75, the remaining guide holes 75 except for the guide holes 74 slidably fitted in the state where the intake side rocker arms 66, 67 are not connected are connected to the connection positions of the sync pins 78. A piston 79 that restricts the moving end is fitted to be slidable. The piston 79 is formed in a cylindrical shape with a bottom that is opposite to the end wall 77 of the guide hole 75, that is, the synchro pin 78 side, and a coiled return spring 80 is compressed between the piston 79 and the end wall 77. Established. Moreover, a plurality of slits 81 (see FIG. 5) extending in the axial direction are provided at the end of the piston 80 on the end wall 77 side.

  Thus, when the pressing force from the solenoid 53 acts on the protrusion 78a of the synchro pin 78, the synchro pin 78 moves to the connecting position while pushing the piston 79 against the spring force of the return spring 80. When the piston 79 abuts against the end wall 77, the moving end at the connecting position of the sync pin 78 is regulated. Further, when the pressing force action from the solenoid 53 to the projecting portion 78a is released, the sync pin 78 is returned to the connection release position side by being pushed by the piston 79 to which the spring force of the return spring 80 acts.

  Both intake side rocker arms 66 and 67 are provided with oil supply holes 82 and 83 having inner ends opened in the inner surfaces of the guide holes 74 and 75 and outer ends opened above the intake side rocker arms 66 and 67, respectively.

  Thus, the intake-side rocker arm 66 provided with the guide hole 74 in which the synchro pin 78 having a circular outer peripheral surface is slidably fitted in the non-connected state of the two intake-side rocker arms 66 and 67 is provided on the intake-side rocker arm 66. An oil supply hole 82 is provided so that the inner end is always opposed to the outer periphery of the synchro pin 78 having a circular outer periphery.

  In addition, an oil supply hole 83 provided in the intake side rocker arm 67 provided with a guide hole 75 in which the piston 79 is slidably fitted is provided on the outer periphery of the return spring 80 in an unconnected state with the intake side rocker arms 66 and 67. It is arranged at the position where you can face.

  The intake rocker arms 66 and 67 are provided with oil discharge holes 84 and 85 whose inner ends are opened in the inner surfaces of the guide holes 74 and 75 and whose outer ends are opened below the intake rocker arms 66 and 67, respectively.

  Further, on the inner surface of the head cover 26 that covers the intake side rocker arms 66 and 67 from above, ribs 86 for dropping oil toward the oil supply holes 82 and 83 of the intake side rocker arms 66 and 67 are projected.

  The same effect as that of the first embodiment can be obtained also by the second embodiment.

  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. Is possible.

  For example, in the above embodiment, the intake valve 21 has been described as an engine valve. However, the present invention can also be applied using the exhaust valve 22 as an engine valve.

15 ... Cylinder head 21 ... Intake valve 26 as engine valve ... Head cover 29, 30, 31, 66, 67 ... Intake side rocker arm 45, 46, 47, 74, 75 ... as rocker arm Guide holes 48, 49, 78 ... Sync pins 48a, 78a ... Projections 50, 79 ... Pistons 52, 77 ... End walls 53 ... Solenoids 55, 80 as actuators ... Return springs 56, 57, 58, 82, 83 ... oil supply holes 59, 60, 61, 84, 85 ... oil discharge holes 62, 86 ... ribs 63, 81 ... slits

Claims (7)

  A plurality of rocker arms (29, 30, 31; 66, 67) adjacent to each other are in a closed state of the engine valve (21) that is opened and closed by the rocker arms (29, 30, 31; 66, 67). Guide holes (45, 46, 47; 74, 75) that are coaxially connected to each other at timing are provided, and adjacent rocker arms (29, 30) are provided in a part of the guide holes (45, 46, 47; 74, 75). , 30, 31; 66, 67), and a synchro pin (48, 49; 78) that allows movement between the connection position for releasing the connection and the connection release position for releasing the connection. Of the guide holes (45, 46, 47; 74, 75), the remaining one guide hole (47, 75) has a piston (50; 79) connected to the synchro pin (48, 49; 78). The ream In a variable valve operating apparatus for an internal combustion engine that is slidably fitted so as to restrict the moving end of the synchro pin (48, 49; 78) at a position, a plurality of the rocker arms (29, 30, 31; 66, 67), an inner end is opened in the inner surface of the guide hole (45, 46, 47; 74, 75), and an outer end is opened in the upper part of the rocker arm (29, 30, 31; 66, 67). A variable valve operating apparatus for an internal combustion engine, wherein oil supply holes (56, 57, 58; 82, 83) are respectively provided.   Inner ends of the plurality of rocker arms (29, 30, 31; 66, 67) are opened in the inner surfaces of the guide holes (45, 46, 47; 74, 75), and outer ends of the rocker arms (29, 30, 31. The variable valve operating system for an internal combustion engine according to claim 1, further comprising an oil discharge hole (59, 60, 61; 84, 85) opened at a lower portion of 31; 66, 67).   2. The oil supply hole (56, 57; 82) is arranged at a position where the inner end thereof is always opposed to the outer periphery of the synchro pin (48, 49; 78) having a circular cross section. Or the variable valve operating apparatus of the internal combustion engine of 2.   A guide hole (47; 75) into which the piston (50; 79) is slidably fitted has an end wall (52; 77) opposite to the synchro pin (48, 49; 78). The bottomed guide hole (47; 75) is formed with a bottom, and a coiled return spring (55; 80) is contracted between the piston (50; 79) and the end wall (52; 77). The oil supply hole (58; 83) provided in the position where the inner end faces the outer periphery of the return spring (55; 80) when the plurality of rocker arms (29, 30, 31; 66, 67) are not connected. The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 3, wherein   A slit extending in the axial direction at an end of the piston (50; 79) on the end wall (52; 77) side of the piston (50; 79) formed in a bottomed cylindrical shape closed on the opposite side to the end wall (52; 77). (63; 81) is provided, The variable valve operating apparatus of the internal combustion engine of Claim 4 characterized by the above-mentioned.   A head cover (26) that covers each of the rocker arms (28 to 31; 66, 67) from above is coupled to a cylinder head (15) in which the engine valve (21) is disposed to be openable and closable. Ribs (62; 86) for dropping oil toward the oil supply holes (56-58; 82, 83) of the respective rocker arms (28-31; 66, 67) are projected on the inner surface of the rocker arms. The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 5.   The slidably fitted into a guide hole (45; 74) of a specific rocker arm (28; 66) arranged on one end side along the arrangement direction of the plurality of rocker arms (28 to 31; 66, 67). A protrusion (48a; 78a) protruding outward from the specific rocker arm (28; 66) is coaxially provided on the synchro pin (48; 78), and is attached to the cylinder head (15) or the head cover (26). The protrusion (53) is such that an actuator (53) protruding at least partially outward from the cylinder head (15) or the head cover (26) exerts a pressing force on the synchro pin (48; 78). The variable valve operating apparatus for an internal combustion engine according to claim 6, wherein the variable valve operating apparatus is connected to 48a; 78a).

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