JP5859493B2 - Oil passage structure of internal combustion engine - Google Patents

Description

  The present invention relates to an oil passage structure of an internal combustion engine including a variable valve timing mechanism and a variable valve lift mechanism.

  The engine of a car is equipped with a variable valve system that changes the lift amount and valve opening timing of the intake / exhaust valve according to the operating state in order to improve output and fuel consumption, reduce harmful exhaust gas components, etc. (Valve-opening characteristic variable internal combustion engines) are increasing. As a variable valve operating device, there is a conventional variable valve lift control device (hereinafter referred to as VLC) that variably controls the valve lift stepwise or steplessly, and cam phase (valve opening timing). A valve timing control device (Variable Timing Control device: hereinafter referred to as VTC) has also appeared.

  As a VLC mechanism, there is known a mechanism in which a plurality of cams having different valve operating characteristics are formed on a camshaft, a plurality of rocker arms are provided corresponding to each cam, and a rocker arm to be connected to a valve is selectively switched. In such a switching type VLC mechanism, by driving the pin with hydraulic oil, the rocker arms adjacent to each other are connected to and disconnected from each other, and hydraulic oil is switched between hydraulic pressure by a spool valve or the like of a linear solenoid drive. It is common to switch between supplying and shutting off the hydraulic pressure to the pin using a valve.

  Further, as the VTC mechanism, an advance hydraulic chamber and a retard angle are fixed between one end of a housing driven by a crankshaft and a camshaft and accommodated in the housing so as to be capable of relative rotational displacement. A crankshaft having a rotor that defines a hydraulic chamber and relatively rotating and displacing the housing and the rotor by supplying and discharging hydraulic oil (hydraulic pressure) to and from an advance hydraulic chamber and a retard hydraulic chamber There is known one using a hydraulic cam phase variable actuator (hereinafter referred to as a VTC actuator) that changes the rotational phase of the camshaft. In this type of VTC mechanism, the supply and discharge of hydraulic fluid to and from the advance hydraulic chamber and the retard hydraulic chamber are generally controlled by a hydraulic control valve such as a linear solenoid driven spool valve.

  Both the VLC mechanism and the VTC mechanism are driven by hydraulic pressure, and as an oil passage structure of an internal combustion engine including both, a common oil passage connected to an oil pump serving as a hydraulic oil supply source is formed from the cylinder block to the cylinder head. It is known that a switching oil passage that branches from a common oil passage to a hydraulic switching valve for VLC and a phase control oil passage that reaches a hydraulic control valve for VTC are respectively formed in a cylinder head ( Patent Document 1).

Japanese Patent No. 3355165

  In the oil passage structure disclosed in Patent Document 1, since the common oil passage can be lengthened, the extension of the oil passage can be shortened to make the internal combustion engine compact. However, when the VLC hydraulic switching valve is operated, a pressure change (pressure wave) occurs in the VTC oil passage, and the pressure change may affect the operation of the VTC mechanism (VTC actuator).

  The present invention has been made in view of such a background, and an object thereof is to provide an oil passage structure of an internal combustion engine that does not affect the operation of the VTC mechanism even when the VLC mechanism is operated.

  According to one aspect of the present invention, such a problem is provided at one end of the camshaft (9, 10) and is always provided in at least one of the advance hydraulic chamber (33) and the retard hydraulic chamber (34). The variable valve timing mechanism (15, 16) that changes the relative phase of the camshaft with respect to the crankshaft (5) by applying hydraulic pressure, and the lift of the engine valve (7, 8) by switching between introduction and cutoff of hydraulic pressure An oil passage structure of an internal combustion engine (1) including a variable valve lift mechanism (19, 20) for changing an amount, a main gallery (110) provided in an engine body (6), and the main gallery (110 ) Extending from one end side of the first oil passage (118) connected to the variable valve timing mechanism (15, 16), and extending from the other end side of the main gallery (110) to the variable valve. Connect to shift mechanism (19, 20) is achieved by a configuration and a second oil passage hydraulic switching valve (26) is provided (119).

  Thus, the first oil passage (118) is formed so as to be connected to one end side of the main gallery, and the second oil passage (119) is formed so as to be connected to the other end side of the main gallery. Since the pressure change generated by the operation of the hydraulic switching valve (26) is attenuated by the main gallery (110) having a relatively large cross section, it is possible to suppress the pressure change from being transmitted to the variable valve timing mechanism (15, 16).

  Further, according to one aspect of the present invention, the structure further includes a camshaft lubricating oil passage (119C, 119D) branched from the second oil passage (119) to reach a journal bearing of the camshaft (9, 10). It can be.

  According to this configuration, the pressure change generated in the hydraulic switching valve is transmitted to the camshaft lubricating oil passage and is difficult to be transmitted to the main gallery. That is, the pressure change is variable valve timing mechanism because it escapes to the camshaft lubricating oil passage. (15, 16) can be more effectively suppressed.

  Further, according to one aspect of the present invention, an orifice (119o) is located at a position closer to the main gallery (110) than a branching portion of the second oil passage (119) to the camshaft lubricating oil passage (119C, 119D). ).

  According to this configuration, the pressure change generated by the hydraulic pressure switching valve on the downstream side of the orifice is difficult to escape from the second oil passage, and the pressure change can be hardly transmitted to the main gallery.

  Moreover, according to one aspect of the present invention, the main gallery (110) can be configured to exhibit a shape in which the oil passage cross-sectional area changes in the longitudinal direction.

  According to this structure, the pressure change generated by the operation of the hydraulic switching valve can be effectively attenuated in the main gallery.

  In addition, according to one aspect of the present invention, an oil jet oil passage (115) extending from the main gallery (110) and connected to the oil jet (105) can be provided.

  According to this configuration, since the pressure change transmitted to the main gallery escapes to the oil jet and is attenuated, it is possible to more effectively suppress the pressure change from being transmitted to the variable valve timing mechanism (15, 16).

  Further, according to one aspect of the present invention, the first oil passage (118) can be connected to only the variable valve timing mechanism (15, 16) from the main gallery (110).

  According to this configuration, since the pressure loss in the first oil passage can be suppressed, the operation of the variable valve timing mechanism can be improved.

  Further, according to one aspect of the present invention, the oil inlet (110A) to the main gallery (110) may be provided on the first oil passage (118) side.

  According to this configuration, it is possible to quickly supply hydraulic oil to a variable valve timing mechanism that requires hydraulic oil at an early stage when the engine is started compared to the variable valve lift mechanism, and to improve the operation of the variable valve timing mechanism. be able to.

  Thus, according to the present invention, it is possible to provide an oil passage structure of an internal combustion engine that does not affect the operation of the VTC mechanism even when the VLC mechanism is operated.

The perspective view which shows the principal part of the engine which concerns on embodiment Schematic diagram showing the outline of the valve timing mechanism used in the engine shown in FIG. Sectional drawing which shows two different operating states of the hydraulic control valve shown in FIG. 1 is a partially cutaway perspective view of the VLC mechanism shown in FIG. Sectional view of the VLC mechanism shown in FIG. The perspective view which shows the oil-path structure of the engine shown in FIG. Schematic diagram showing the oil passage structure of the engine shown in FIG.

  Hereinafter, an embodiment of an oil passage structure of an internal combustion engine according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the variable cam phase internal combustion engine (hereinafter referred to as engine 1) of the present embodiment is a DOHC 4-valve type 4-cycle in-line 4-cylinder gasoline engine mounted on an automobile. The engine 1 has a cylinder block 2 in which four cylinders (not shown) are formed. Each cylinder accommodates a piston 3 so as to be slidable in the vertical direction. The piston 3 is connected by a connecting rod 4 to a crankshaft 5 that is rotatably provided at the bottom of the cylinder block 2.

  A cylinder head 6 that closes the upper end of the cylinder is attached to the upper part of the cylinder block 2. The cylinder head 6 is provided with two intake valves 7 and two exhaust valves 8 for each cylinder. An intake camshaft 9 and an exhaust camshaft 10 for opening and closing the intake valve 7 and the exhaust valve 8 are rotatably attached to the upper portion of the cylinder head 6.

  A crank sprocket 11 that rotates integrally with the crankshaft 5 is attached to one end of the crankshaft 5. An intake cam sprocket 12 is attached to one end of the intake camshaft 9, and an exhaust cam sprocket 13 is attached to one end of the exhaust camshaft 10. An endless chain 14 is wound around the crank sprocket 11, the intake cam sprocket 12 and the exhaust cam sprocket 13, and the rotation of the crank sprocket 11 is transmitted to the intake cam sprocket 12 and the exhaust cam sprocket 13 by the endless chain 14. Since the sprocket diameter of the crank sprocket 11 is ½ of the sprocket diameter of the intake and exhaust cam sprockets 12 and 13, both the intake and exhaust camshafts 9 and 10 rotate at a rotational speed ½ that of the crankshaft 5. Driven.

  An intake side VTC actuator 15 is attached to one end of the intake camshaft 9, and an exhaust side VTC actuator 16 is attached to one end of the exhaust camshaft 10. An intake side cam angle sensor 17 is installed at the other end of the intake camshaft 9, and an exhaust side cam angle sensor 18 is installed at the other end of the exhaust camshaft 10. An intake side VLC mechanism 19 is interposed between the intake camshaft 9 and the intake valve 7, and an exhaust side VLC mechanism 20 is interposed between the exhaust camshaft 10 and the exhaust valve 8.

  An oil pump 21 is attached to the lower part of the cylinder block 2. The oil pump 21 is connected to the crankshaft 5 by a belt-type transmission mechanism 22 and is driven to rotate by the crankshaft 5. The oil pump 21 is a hydraulic pressure source, pumps oil from an oil pan 23 attached to the lower part of the cylinder block 2, and sends the oil to various parts of the engine 1 for lubrication and the like.

  The cylinder block 2 and the cylinder head 6 are supplied with lubricating oil to various sliding portions and also supply hydraulic oil (engine oil) from the oil pump 21 to the VTC actuators 15 and 16 and the VLC mechanisms 19 and 20. The supply oil passage 24 is formed. Further, two electromagnetic hydraulic control valves 25 are mounted on one end side of both camshafts 9 and 10 in the cylinder head 6, and the operation of flowing through the supply oil passage 24 by operating these hydraulic control valves 25. The supply mode of the oil to the VTC actuators 15 and 16 is switched. In addition, two electromagnetic hydraulic switching valves 26 are mounted on the other end side of the camshafts 9 and 10 in the cylinder head 6, and flow through the supply oil passage 24 by operating these hydraulic switching valves 26. The supply state of the hydraulic oil to the VLC mechanisms 19 and 20 is switched.

  In the vehicle compartment, various controlled devices (hydraulic control valves) attached to the engine 1 based on output information of various sensors (both cam angle sensors 17, 18, an accelerator sensor (not shown), an intake air amount sensor, a crank angle sensor, etc.). 25, an engine ECU 30 that determines a control amount of a hydraulic switching valve 26, a fuel injection valve, an ignition coil, etc. (not shown) and outputs a drive current is installed.

  Next, the configuration of both VTC actuators 15 and 16 will be described. Since both VTC actuators 15 and 16 have substantially the same configuration, the exhaust side VTC actuator 16 will be described below. As shown in FIG. 2, the VTC actuator 16 includes a substantially cylindrical housing 31 in which an exhaust cam sprocket 13 is integrally formed on the outer peripheral portion, and is accommodated in the housing 31 so as to be capable of rotational displacement and integrated with the exhaust camshaft 10. And a rotor 32 coupled to the exhaust camshaft 10 for rotation. A vane 35 protrudes from the outer peripheral surface of the rotor 32, and an advance hydraulic chamber 33 and a retard hydraulic chamber 34 are defined between the rotor 31 and the housing 31 on both sides in the rotational direction.

  When the advance hydraulic chamber 33 is set to the hydraulic pressure supply side and the retard hydraulic chamber 34 is set to the drain side, the volume of the advance hydraulic chamber 33 and the volume of the retard hydraulic chamber 34 are decreased. The rotor 32 is rotationally displaced in the clockwise direction as viewed in FIG. Thereby, the opening / closing timing of the exhaust valve 8 is shifted to the advance side. In contrast, when the retarding hydraulic chamber 34 is set to the hydraulic pressure supply side and the advance hydraulic chamber 33 is set to the drain side, the volume of the retarding hydraulic chamber 34 is increased and the volume of the advance hydraulic chamber 33 is decreased. Then, the rotor 32 is rotationally displaced in the counterclockwise direction as viewed in FIG. Thereby, the opening / closing timing of the exhaust valve 8 is shifted to the retard side. In this way, the rotational phase of the exhaust camshaft 10 relative to the crankshaft 5 is variably controlled.

  In the exhaust side VTC actuator 16, the rotor 32 is urged toward the side where the advance angle is increased by a spring (not shown) in order to reduce the pumping loss when starting the engine. Thus, the exhaust side VTC actuator 16 sets the most advanced angle position at which the volume of the advance angle hydraulic chamber 33 is maximized as the default position when the engine is stopped with the ignition switch (not shown) of the engine 1 turned off. On the other hand, in the intake side VTC actuator 15, the rotor 32 is urged toward the side that increases the delay angle by a spring (not shown) in order to reduce the pumping loss when starting the engine. Thus, the intake side VTC actuator 15 sets the most retarded angle position where the volume of the retarded hydraulic chamber 34 is maximized as the default position when the engine is stopped with the ignition switch (not shown) of the engine 1 turned off. If a more detailed description of the VTC actuators 15 and 16 is necessary, refer to Japanese Patent Application Laid-Open No. 2010-190159.

  Next, details of the hydraulic control valve 25 will be described with reference to FIG. Two valve mounting holes 36 having a circular cross-sectional shape extending inward from the outer surface of the cylinder head 6 are formed in an intermediate portion in the vertical direction of the cylinder head 6. The hydraulic control valves 25 are inserted into the valve mounting holes 36, respectively. Since the hydraulic control valve 25 has the same configuration, the exhaust side hydraulic control valve 25 will be described below. A port forming cylindrical portion 42 of the valve housing 41 is inserted into the valve mounting hole 36.

  A hydraulic oil supply port 43 and a drain port 44 are formed on the lower side of the port forming cylindrical portion 42. The hydraulic oil supply port 43 communicates with the aforementioned supply oil passage 24, and hydraulic oil pressurized by the oil pump 21 that is a hydraulic source is supplied to the hydraulic oil supply port 43. The drain port 44 communicates with a drain oil passage 29 formed in the cylinder head 6. The drain oil passage 29 is open toward the oil pump 21, and the hydraulic oil that has flowed from the drain port 44 to the drain oil passage 29 is returned to the oil pan 23 by a flow caused by gravity.

  An advance angle output port 45 and a retard angle output port 46 are formed as output ports on the upper side of the port forming cylindrical portion 42. The advance angle output port 45 communicates with an advance angle oil passage 24A formed in the cylinder head 6, and is connected to the advance angle hydraulic chamber 33 by the advance angle oil passage 24A. The retardation output port 46 communicates with a retardation oil passage 24B formed in the cylinder head 6, and is connected to the retardation hydraulic chamber 34 by the retardation oil passage 24B.

  A spool valve body 47 is provided in the port forming cylindrical portion 42 so as to be slidable in the axial direction of the port forming cylindrical portion 42 (left and right horizontal direction as viewed in FIG. 3). The spool valve body 47 has four land portions 47A to 47D spaced apart in the axial direction, and defines a hydraulic oil supply groove 43 that is always in communication with the hydraulic oil supply port 43 between the land portions 47B and 47C. doing. Further, the spool valve body 47 has a hollow structure and has an internal drain passage 50 that is always in communication with the drain port 44. The internal drain passage 50 is formed in the drain groove portions 51 and 52 defined between the land portions 47A and 47B and between the land portions 47C and 47D by holes 47E and 47F formed through the spool valve body 47 in the radial direction. Each communicates.

  A linear solenoid 55 having a general structure including an electromagnetic coil 53 and a plunger 54 is formed in a portion where the valve housing 41 protrudes to the side of the cylinder head 6 from the valve mounting hole 36. The spool valve body 47 is integrally connected to the plunger 54 by a rod 56, and is driven in the axial direction by a linear solenoid 55, whereby the axial position of the spool valve body 47 in the port forming cylindrical portion 42 is controlled. .

  In the state shown in FIG. 3A, the hydraulic oil supply groove 48 communicates with the advance angle output port 45 and the drain groove 52 communicates with the retard angle output port 46. The hydraulic oil is supplied to the advance hydraulic chamber 33 by 24A, and the hydraulic oil in the retard hydraulic chamber 34 is discharged by the retard oil passage 24B.

  On the other hand, in the state shown in FIG. 3B, the hydraulic oil supply groove 48 communicates with the retardation output port 46, and the drain groove 51 communicates with the advance output port 45. The hydraulic fluid is supplied to the retarding hydraulic chamber 34 through the oil passage 24B, and the hydraulic fluid in the advance hydraulic chamber 33 is discharged through the advanced hydraulic passage 24A.

  As described above, the exhaust-side VTC actuator 16 is a variable that changes the relative phase of the exhaust camshaft 10 with respect to the crankshaft 5 by constantly applying hydraulic pressure to at least one of the advance hydraulic chamber 33 and the retard hydraulic chamber 34. This is a valve timing mechanism.

  When the hydraulic oil supply operation by the oil pump 21 is stopped due to the engine stop, the hydraulic oil in the advance hydraulic chamber 33, the retard hydraulic chamber 34, the advance oil passage 24A, and the retard oil passage 24B of the VTC actuator 16 is provided. Falls from the drain port 44 of the hydraulic control valve 25 to the oil pan 23 due to gravity. When the engine is stopped, the VTC actuator 16 is in the most advanced angle state due to the default position. Therefore, when the engine is next started, first, hydraulic oil is supplied to the retarding hydraulic chamber 34 through the retarding oil passage 24B, and the advance angle is increased. The hydraulic oil in the advance hydraulic chamber 33 is discharged through the oil passage 24A, and control is performed to reduce the advance angle.

  Next, the configuration of both VLC mechanisms 19 and 20 will be described. Since both VLC mechanisms 19 and 20 have substantially the same corresponding configuration, the exhaust side VLC mechanism 20 will be described below. As shown in FIG. 4, the exhaust side VLC mechanism 20 is for driving two exhaust valves 8 corresponding to one cylinder, and is supported by the exhaust camshaft 10 and the cylinder head 6 so as not to rotate. It has a rocker shaft 61, a main rocker arm 62, and a pair of left and right secondary rocker arms 63 and 64. The exhaust valve 8 is supported by the cylinder head 6 so as to be linearly displaceable in the valve opening direction and the valve closing direction, and is always urged in the valve closing direction by a valve spring 65 interposed between the exhaust valve 8 and the cylinder head 6. Has been. In the following description, the extending direction of the rocker shaft 61 is defined as the left-right direction as shown in FIG.

  As shown in FIG. 5, the main rocker arm 62 and the secondary rocker arms 63 and 64 are formed with shaft insertion holes 66, 67 and 68, which are through-holes having a circular cross section, on the proximal end side, and the shaft insertion holes 66 and 67. 68, the rocker shaft 61 is inserted through the rocker shaft 61, so that the rocker shaft 61 is rotatably supported. The main rocker arm 62 is disposed between the left and right sub rocker arms 63 and 64, and is in sliding contact with each other via a washer.

  The main rocker arm 62 and the secondary rocker arms 63, 64 have tips that extend toward the exhaust valve 8 with the shaft insertion holes 66, 67, 6 as rotation centers. A tappet adjusting screw 69 that abuts on the upper end of the stem of the exhaust valve 8 is screwed to the distal ends of the secondary rocker arms 63 and 64 so as to be able to advance and retract. Pin holes 71, 72, 73 having axes parallel to the shaft insertion holes 66, 67, 68 are formed at positions that can be coaxial with each other in the intermediate portion in the longitudinal direction of the main rocker arm 62 and the secondary rocker arms 63, 64. .

  As mainly shown in FIG. 5, the pin hole 71 of the main rocker arm 62 penetrates the main rocker arm 62 in the left-right direction, the pin holes 72 and 73 of the secondary rocker arms 63 and 64 open to the main rocker arm side, and the other end is It is blocked by the bottom wall. Each of the pin holes 71, 72, 73 has a diameter increased stepwise at an intermediate portion in the axial direction, and can receive rollers 75, 76, 77 described later that are in rolling contact with the exhaust camshaft 10. . In each of the pin holes 71, 72, 73, sleeves 79, 80, 81 which are cylindrical pipes having both ends opened are press-fitted. Rollers 75, 76, and 77 are rotatably supported on the outer peripheral surface of each sleeve via bearings.

  Each of the secondary rocker arms 63 and 64 is formed with hydraulic oil passages 82 and 83 communicating with the vicinity of the bottom walls of the pin holes 72 and 73 and the shaft insertion holes 67 and 68. In addition, lubricating oil passages 84 and 85 penetrating from the shaft insertion holes 67 and 68 toward the rollers 76 and 77 are formed in the slave rocker arms 63 and 64, respectively. Open ends of the hydraulic oil passages 82 and 83 on the side of the shaft insertion holes 67 and 68 communicate with the bottoms of the hydraulic oil grooves 86 and 87 extending in the circumferential direction of the shaft insertion holes 67 and 68. Open ends of the lubricating oil passages 84 and 85 on the side of the shaft insertion holes 67 and 68 communicate with the bottoms of the lubricating oil grooves 88 and 89 extending in the circumferential direction of the shaft insertion holes 67 and 68. The main rocker arm 62 is formed with a lubricating oil passage 90 penetrating from the shaft insertion hole 66 toward the roller 75. The opening end of the lubricating oil passage 90 on the shaft insertion hole 66 side communicates with the bottom of the lubricating oil groove 91 extending in the circumferential direction of the shaft insertion hole 66.

  Inside the rocker shaft 61, an in-shaft low lift oil passage 92 and an in-shaft high lift oil passage 93 that extend in the axial direction are formed. The in-shaft low lift oil passage 92 is connected to a low lift oil passage 24 </ b> C (see FIG. 7) formed in the cylinder head 6. The high lift oil passage 93 in the shaft is connected to a high lift oil passage 24 </ b> D (see FIG. 7) formed in the cylinder head 6.

  The low lift oil passage 24 </ b> C and the high lift oil passage 24 </ b> D are connected to a hydraulic switching valve 26 (FIG. 1), and the hydraulic oil exhaust side VLC mechanism 20 that flows through the supply oil passage 24 by the operation of the hydraulic switching valve 26. The supply state for is switched. The hydraulic switching valve 26 is inserted into two valve mounting holes 37 (see FIG. 6) having a circular cross-sectional shape extending inward from the outer surface of the cylinder head 6. Since the hydraulic switching valve 26 has the same configuration as the hydraulic control valve 25 described above, detailed description thereof is omitted, but the advance output port 45 and the retard output port 46 of FIG. 3 are used as output ports. Instead of a low lift port and a high lift port, the low lift port is connected to the low lift oil passage 24C (FIG. 7), and the high lift port is connected to the high lift oil passage 24D (FIG. 7). Connected.

  Returning to FIG. 5, radial oil passages that open to the outer peripheral surface of the rocker shaft 61 are formed from the low lift oil passage 92 in the shaft and the high lift oil passage 93 in the shaft, respectively. The low lift oil passage 92 in the shaft communicates with the hydraulic oil groove 86 and the lubricating oil grooves 88, 89, 91, and the high lift oil passage 93 in the shaft communicates with the hydraulic oil groove 87 and the lubricating oil grooves 88, 89, 91. Communicating with As a result, oil is supplied from the low lift oil passage 92 in the shaft to the hydraulic oil passage 82, and oil is supplied from the high lift oil passage 93 in the shaft to the hydraulic oil passage 83. Oil is supplied from the lift oil passage 93 to the lubricating oil passages 84, 85 and 90.

  A first switching pin 94 is provided in the sleeve 80 of the right slave rocker arm 63, a second switching pin 95 is provided in the sleeve 79 of the main rocker arm 62, and a third switching pin 96 is provided in the sleeve 81 of the left slave rocker arm 64. The sleeves 80, 79, 81 are inserted so as to be slidable in the axial direction. A spring receiving hole 97 is formed in the first switching pin 94 at the end facing the bottom wall of the pin hole 73 of the right slave rocker arm 63. A compression coil spring 98 is interposed between the bottom of the spring receiving hole 97 and the bottom wall of the pin hole 73, and the first switching pin 94 is always urged to the left (side protruding from the pin hole 73). Yes.

  In a state where no oil is supplied to any of the hydraulic oil passages 82 and 83, the first switching pin 94, the second switching pin 95, and the third switching pin are driven by the biasing force of the compression coil spring 98 as shown in FIG. 96 moves to the left, and the third switching pin 96 comes into contact with the bottom wall of the pin hole 73 of the left slave rocker arm 64. In this state, the first switching pin 94 is disposed only in the right slave rocker arm 63, the second switching pin 95 is disposed only in the main rocker arm 62, and the third switching pin 96 is disposed only in the left slave rocker arm 64. The connection of the three rocker arms 62, 63, 64 is released, and each rocker arm 62, 63, 64 rotates independently. Further, in a state where oil is supplied to the hydraulic oil passage 82, in addition to the biasing force of the compression coil spring 98, the hydraulic pressure that presses the first switching pin 94 to the left is applied as an assist force, resulting in the state of FIG. . Hereinafter, a state in which no oil is supplied to any of the hydraulic oil passages 82 and 83 and a state in which oil is supplied to the hydraulic oil passage 82 are referred to as a low lift mode.

  When oil is supplied to the hydraulic oil passage 83, the oil presses the third switching pin 96 to the right as shown in FIG. 4, and the first switching pin resists the biasing force of the compression coil spring 98. 94, the second switching pin 95 and the third switching pin 96 move to the right, and the first switching pin 94 comes into contact with the bottom wall of the pin hole 72 of the right slave rocker arm 63. In this state, the second switching pin 95 is disposed at a position straddling the right slave rocker arm 63 and the main rocker arm 62, and the third switching pin 96 is disposed at a position straddling the main rocker arm 62 and the left slave rocker arm 64. The rocker arms 62, 63, 64 are connected to each other and rotate integrally. Hereinafter, a state in which oil is supplied to the hydraulic oil passage 83 is referred to as a high lift mode.

  The exhaust camshaft 10 has a high lift cam 99 that presses the roller 75 of the main rocker arm 62 and low lift cams 100 and 101 that press the rollers 76 and 77 of the secondary rocker arms 63 and 64.

  In the low lift mode, the high lift cam 99 and the low lift cams 100 and 101 press the rocker arms 62, 63 and 64 to rotate them. At this time, since the main rocker arm 62 is not connected to the sub rocker arms 63 and 64, the sub rocker arms 63 and 64 are directly driven by the low lift cams 100 and 101 to open and close the exhaust valve 8. On the other hand, in the high lift mode in which the rocker arms 62, 63 and 64 are connected to each other, the secondary rocker arms 63 and 64 are indirectly connected to the high lift cam 99 via the main rocker arm 62 and the second and third switching pins 95 and 96. To open and close the exhaust valve 8.

  As described above, the drive by the compression coil spring 98 is assisted from the low lift oil passage 92 in the shaft to the hydraulic oil passage 82. Therefore, the exhaust-side VLC mechanism 20 is basically a variable valve lift mechanism that changes the lift amount of the exhaust valve 8 by switching between introduction and shut-off of hydraulic pressure from the in-shaft high lift oil passage 93 to the hydraulic oil passage 83. .

  Next, the oil passage structure of the engine 1 configured as described above will be described with reference to FIGS. 6 and 7. FIG. 6 is a perspective view of the oil passage that is a space through the cylinder block 2 and the cylinder head 6. For convenience of explanation, the direction indicated by the arrow in FIG. 6 is used to indicate the direction. In FIG. 7, an oil path above the gasket 102 installed between the cylinder block 2 and the cylinder head 6 is formed in the cylinder head 6, and an oil path below the gasket 102 is formed in the cylinder block 2. It means that.

  As shown in FIGS. 6 and 7, a main gallery 110 is formed in the cylinder block 2 so as to extend in parallel with the crankshaft 5 (FIG. 1). The main gallery 110 is formed by casting with a core that is divided into two in the axial direction when the cylinder block 2 is cast. The main gallery 110 has the largest cross-sectional area at both ends in the axial direction and is cut at the central portion in the axial direction. The taper shape has the smallest area. The main gallery 110 is formed in such a size that the cross-sectional area is larger than that of the other oil passages in the supply oil passage 24 even in the central portion having the smallest cross-sectional area.

  The oil sent from the oil pump 21 is sent from one side surface of the cylinder block 2 to the oil filter 103 through the first block oil passage 111 formed in the cylinder block 2. The oil that has passed through the oil filter 103 is sent from the lower surface of the cylinder block 2 to the oil cooler 104 through the second block oil passage 112 formed in the cylinder head 6. The oil that has passed through the oil cooler 104 is sent from the rear surface of the cylinder block 2 to the main gallery 110 through the third block oil passage 113 formed in the cylinder head 6. A connection portion of the third block oil passage 113 with respect to the main gallery 110, that is, an oil inflow port 110 </ b> A to the main gallery 110 is positioned closer to the left end of the main gallery 110.

  Below the main gallery 110, five crankshaft lubricating oil passages 114 for supplying lubricating oil to the journals 5A to 5E (see FIG. 7) of the crankshaft 5 (FIG. 1) have a predetermined interval in the crankshaft direction. Connected after a while. When the journals 5A to 5E are designated as the first journal 5A to the fifth journal 5E in this order from the side where the VTC actuators 15 and 16 are provided, each crankshaft lubricating oil passage 114 is connected to one corresponding journal 5A to 5E. Yes. If the pins 5F to 5I of the crankshaft 5 are the first pin 5F to the fourth pin 5I in this order from the side where the VTC actuators 15 and 16 are provided, the crankshaft lubricating oil passage 114 connected to the second journal 5B is the first The crankshaft lubricating oil passage 114 formed so as to reach the second pins 5F and 5G and connected to the fourth journal 5D is formed so as to reach the third and fourth pins 5H and 5I.

  Also, at the lower part of the main gallery 110, four oil jet oil passages 115 connected to an oil jet 105 for injecting oil toward the lower surface of the piston 3 to cool the piston 3 (FIG. 1) are predetermined in the crankshaft direction. Connected at intervals. A turbocharger oil passage 116 for supplying lubricating oil to a turbocharger 106 provided so as to straddle the intake / exhaust passage is connected to a side portion of the main gallery 110 near the center in the crankshaft direction. Further, a tensioner oil passage 117 for supplying oil to the chain tensioner 107 is formed at the left end of the main gallery 110. Each crankshaft lubricating oil passage 114 is formed with an orifice 114o having an appropriate size, whereby the supply hydraulic pressure is adjusted.

  On the right wall of the cylinder block 2 and the cylinder head 6, a VTC oil passage 118 is formed with one end connected to the right end of the main gallery 110 and the other end connected to both VTC actuators 15 and 16. On the other hand, a VLC oil passage 119 having one end connected to the left end of the main gallery 110 and the other end connected to both VLC mechanisms 19 and 20 is formed on the left wall of the cylinder block 2 and the cylinder head 6. The VTC oil passage 118 and the VLC oil passage 119 are also formed with orifices 118o and 119o having appropriate sizes at the upstream end.

  The VTC oil passage 118 includes a single VTC common oil passage 118A extending upward from the main gallery 110, two intake VTC oil passages 118B and an exhaust VTC oil passage 118C branched forward and backward from the VTC common oil passage 118A. have. The intake VTC oil passage 118B and the exhaust VTC oil passage 118C pass through the hydraulic control valve 25, respectively, and then are divided into the advance oil passage 24A and the retard oil passage 24B described above. Thus, the VTC oil passage 118 is connected to only the VTC actuators 15 and 16 (only to the variable valve timing mechanism) via the hydraulic control valve 25 from the main gallery 110.

  The VLC oil passage 119 includes a single VLC common oil passage 119A extending upward from the main gallery 110, a VLC branch oil passage 119B branched from the VLC common oil passage 119A in the three directions, rearward, upward and forward, and an intake camshaft. It has a lubricating oil passage 119C and an exhaust camshaft lubricating oil passage 119D. If the cam journal bearings supporting the intake and exhaust camshafts 9 and 10 are first to fifth in order from the side where the VTC actuators 15 and 16 are provided, the intake and exhaust camshaft lubricating oil passages 119C and 119D are respectively It reaches the bearing surface of the 5-cam journal bearing.

  As shown in FIG. 7, the intake and exhaust camshafts 9 and 10 are respectively formed with in-shaft oil passages 9A and 10A. As shown in FIG. 6, the downstream ends of the intake and exhaust camshaft lubricating oil passages 119C and 119D are circumferential grooves formed in a semicircular shape on the bearing surface of the fifth cam journal bearing. Lubricating oil introduced from the bearings to the in-shaft oil passages 9A and 10A is supplied to the bearing surfaces of the second to fourth cam journals. On the other hand, in the bearing portion of the first cam journal, the downstream ends of the advance oil passage 24A and the retard oil passage 24B for supplying hydraulic oil to the VTC actuators 15 and 16 are on the bearing surface of the first cam journal bearing. Since the circumferential groove is formed in an annular shape, and this circumferential groove also serves as an oil passage for supplying lubricating oil to the first cam journal bearing, no lubricating oil is supplied from the oil passages 9A and 10A in the shaft. . The expression that the VTC oil passage 118 is connected only to the VTC actuators 15 and 16 as described above is used in a meaning that it is excluded from being used for other purposes as a result.

  As shown in FIG. 7, from the intake camshaft lubricating oil passage 119C, the negative pressure pump lubricating oil that supplies lubricating oil to the negative pressure pump 108 (FIG. 7) and the fuel pump (FIG. 7) attached to the cylinder head 6 respectively. A path 119E and a fuel pump lubricating oil path 119F are branched. The VLC branch oil passage 119B is connected to two hydraulic pressure changeover valves 26, and the low lift oil passage 24C and the high lift oil passage 24D extend from the hydraulic pressure change valves 26 toward the rocker shaft 61, respectively. ing.

  The intake camshaft lubricating oil passage 119C, the exhaust camshaft lubricating oil passage 119D, the negative pressure pump lubricating oil passage 119E, and the fuel pump lubricating oil passage 119F are respectively formed with orifices 119Co, 119Do, 119Eo, and 119Fo of appropriate sizes. The supply hydraulic pressure is adjusted.

  According to the engine 1 configured as described above, the following cam phase variable control is performed by the engine ECU 30. That is, the engine ECU 30 is based on the detection signals of the intake side cam angle sensor 17 and the exhaust side cam angle sensor 18 in addition to various operation information such as the accelerator opening, the intake air amount, and the cooling water temperature input via the input interface. Target cam phases of both camshafts 9 and 10 are set, and drive signals are output to both VTC actuators 15 and 16 via an output interface. Further, the engine ECU 30 sets the target lift amount of the intake and exhaust valves 7 and 8 based on various input information, and outputs drive signals to both the VLC mechanisms 19 and 20 via the output interface.

  As described above, the hydraulic pressure is constantly applied to at least one of the advance hydraulic chamber 33 and the retard hydraulic chamber 34 in both the VTC actuators 15 and 16, and the hydraulic oil is supplied to the VLC mechanisms 19 and 20. When the oil pressure switching valve 26 is operated for switching, a pressure change (pressure wave) occurs in the VTC oil passage 118, and this pressure change may affect the operation of the VTC actuators 15 and 16. However, in this embodiment, the VTC oil passage 118 is formed so as to be connected to one end side of the main gallery 110, and the VLC oil passage 119 is formed so as to be connected to the other end side of the main gallery 110. The pressure change is attenuated by the main gallery 110 having a large cross section, and the pressure change is suppressed from being transmitted to the VTC actuators 15 and 16. In particular, since the main gallery 110 has a shape in which the cross-sectional area changes in the longitudinal direction, the pressure change is effectively attenuated in the main gallery 110.

  Further, since the intake and exhaust camshaft lubricating oil passages 119C and 119D leading to the journal bearings of the intake and exhaust camshafts 9 and 10 branch from the VLC oil passage 119, the pressure change generated in the hydraulic switching valve 26 is changed to the intake air. And the exhaust camshaft lubricating oil passages 119C and 119D, and the transmission to the main gallery 110 is less likely to be transmitted by the VTC actuators 15 and 16.

  Further, since the orifice 119o is formed at the upstream end of the VLC oil passage 119, which is on the main gallery 110 side of the branch to the intake and exhaust camshaft lubricating oil passages 119C and 119D, the downstream side of the orifice 119o. The generated pressure change is difficult to escape from the VLC oil passage 119 and is more difficult to be transmitted by the main gallery 110.

  Further, in the present embodiment, since the oil jet oil passage 115 connected to the oil jet 105 extends from the main gallery 110, the pressure change transmitted to the main gallery 110 is attenuated by the presence of the oil jet 105, so the VTC actuator 15 , 16 is more difficult to communicate.

  In the present embodiment, since the VTC oil passage 118 is connected from the main gallery 110 only to the VTC actuators 15 and 16, the pressure loss in the VTC oil passage 118 is small, and the operation of the VTC actuators 15 and 16 is improved. In addition, since the oil inlet 110A to the main gallery 110 is provided on the VTC oil passage 118 side, the VTC actuators 15 and 16 that require hydraulic oil earlier than the VLC mechanisms 19 and 20 when starting the engine. Since the hydraulic oil is supplied immediately, the operation of the VTC actuators 15 and 16 is improved.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above-described embodiment, the internal combustion engine has been described as an onboard vehicle as an example. However, the present invention can be widely applied to ships and power generation. In addition, the specific configuration, arrangement, quantity, and the like of each member and part can be changed as appropriate without departing from the spirit of the present invention. On the other hand, not all the constituent elements shown in the above embodiment are necessarily essential, and can be selected as appropriate.

1 Engine 2 Cylinder block (Engine body)
5 Crankshaft 6 Cylinder block 7 Intake valve 8 Exhaust valve 9 Intake camshaft 10 Exhaust camshaft 15 Intake side VTC actuator 16 Exhaust side VTC actuator 19 Intake side VLC mechanism 20 Exhaust side VLC mechanism 24 Supply oil passage 25 Hydraulic control valve 26 Hydraulic pressure Switch valve 29 Drain oil passage 33 Advance angle hydraulic chamber 34 Delay angle hydraulic chamber 105 Oil jet 110 Main gallery 110A Inlet 115 Oil jet oil passage 118 VTC oil passage (first oil passage)
119 VLC oil passage (second oil passage)
119C Inlet camshaft lubricating oil passage 119Co orifice 119D Exhaust camshaft lubricating oil passage 119Do orifice

Claims (5)

Provided at one end of the camshaft, advances example on at least one hydraulic corner hydraulic chambers and retarding hydraulic chamber pressure, and the variable valve timing mechanism for changing the relative phase of the camshaft relative to the crankshaft,
An oil passage structure of an internal combustion engine comprising a variable valve lift mechanism that changes a lift amount of an engine valve by switching between introduction and cutoff of hydraulic pressure,
The main gallery provided in the engine body,
A first oil passage extending from one end of the main gallery and connected to the variable valve timing mechanism;
A second oil passage extending from the other end of the main gallery and connected to the variable valve lift mechanism, and having a hydraulic switching valve ;
A camshaft lubricating oil passage that branches off from the second oil passage and reaches a journal bearing of the camshaft ;
An oil passage structure for an internal combustion engine, wherein an orifice is formed at a position closer to the main gallery side than a branch portion to the camshaft lubricating oil passage in the second oil passage . 2. The oil passage structure for an internal combustion engine according to claim 1 , wherein the main gallery has a shape in which an oil passage cross-sectional area changes in a longitudinal direction. The oil passage structure of an internal combustion engine according to claim 1 or 2 , further comprising an oil jet oil passage extending from the main gallery and connected to an oil jet. The oil passage structure of the internal combustion engine according to any one of claims 1 to 3 , wherein the first oil passage is connected to only the variable valve timing mechanism from the main gallery. The oil passage structure of the internal combustion engine according to any one of claims 1 to 4 , wherein an oil inlet to the main gallery is provided on the first oil passage side.

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