JP2006002687A - Valve gear, internal combustion engine, and valve-rest unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve operation performance of a switching piece for switching between a valve-rest state and a valve-operation state. <P>SOLUTION: The valve train comprises a switching piece 317, and a coil spring 324 for imparting an urging force to the switching piece 317. The switching piece 317 has a center 317a of rotation eccentric with reference to the axial center of a valve stem 202. The switching piece 317 is rotatably mounted in the manner so that an end face 317b on the rotation center side and a tip face 317c slide along the inside periphery of a housing 302 to section the inside of the housing 302 into a pressure chamber 319 and a gas chamber 320. In the state in which the volume of the pressure chamber 319 is reduced by the urge of the coil spring 324, the switching piece 317 is positioned off the upper part of the valve stem 202 (valve-rest state). In the state in which the switching piece 317 is rotated against the urge of the coil spring 324 by the fluid pressure of the pressure chamber 319, the switching piece 317 is positioned in the upper part of the valve stem 202 (valve-operation state). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a valve operating apparatus suitable for switching between a valve deactivation state and a valve operation state, an internal combustion engine including the same, and a valve deactivation unit.

  As this type of technology, for example, Patent Document 1 discloses a variable cylinder system in which a frame 502 is rotatably provided in a lifter body 501 as shown in FIG. In this variable cylinder system, when all cylinders are operated, the top 502 is returned to the state by the bias of the spring 503 as shown in FIG. On the other hand, during the reduced cylinder operation, as shown in FIG. 12B, the hydraulic pressure is guided to the oil chamber 504 to rotate the piece 502 around the pin 505, and the first penetration formed in the piece 502. The hole 506 is aligned with the second through hole 507 so that the cam lift is not transmitted to the valve.

Japanese Patent Laid-Open No. 5-71323

  However, in the variable cylinder system disclosed in Patent Document 1, it is necessary to increase the size of the top 502 because the through hole 506 is formed in the top 502. For this reason, the weight of the top 502 is increased, and it is necessary to increase the hydraulic pressure for rotating the top 502 or increase the urging force of the spring 503, which may impair the operability of the top 502.

  In addition, since the area on which the hydraulic pressure acts is small compared to the overall size of the top 502, the hydraulic pressure must be increased, and the operability of the top 502 may be impaired.

  Furthermore, it is necessary to assemble parts such as the frame 502, the frame support 508, the pin 505, and the spring 503 one by one in the lifter body 501, and the assembling work takes time.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to improve the operability of a switch for switching between a valve resting state and a valve operating state, and further to improve the assembling property.

The valve operating apparatus of the present invention includes a tappet that advances and retreats along a tappet guide by rotation of a cam, a valve that opens and closes as the tappet advances and retreats, an annular housing that is provided in the tappet, The housing has a rotation center that is eccentric from the axial center of the valve stem, and is rotatably assembled in the housing such that the end surface and the front end surface of the rotation center slide along the inner peripheral surface of the housing. A switching element that divides the inside into a pressure chamber and a gas chamber, and an urging unit that applies an urging force to the switching element in a direction to reduce the volume of the pressure chamber, the urging force of the urging unit When the volume of the pressure chamber is reduced, the switching element is in a valve resting state in which the switch is displaced from above the valve stem, and the switching is performed by the fluid pressure in the pressure chamber. There in a state of being rotated against the biasing force of the biasing means, characterized in that the Kirikaeko has a configuration in which the valve operating state positioned above the valve stem.
The internal combustion engine of the present invention is an internal combustion engine in which intake and exhaust are controlled by an intake valve and an exhaust valve, and is characterized in that the valve operating device of the present invention is provided on at least one of the intake side and the exhaust side. Have
A valve pausing unit according to the present invention is a valve pausing unit used in a valve operating apparatus including a tappet that advances and retreats along a tappet guide by rotation of a cam and a valve that opens and closes as the tappet advances and retreats. A plate-shaped upper cover, an annular housing, a disk-shaped lower cover in which an insertion hole through which the valve stem is inserted is formed at the center, and a rotation center that is eccentric from the axial center of the valve stem of the valve And a switching element that is rotatably assembled in the housing so that the rotation center side end surface and the tip end surface slide along the inner peripheral surface of the housing, and divides the inside of the housing into a pressure chamber and a gas chamber. And an urging means for applying an urging force to the switching element in a direction to reduce the volume of the pressure chamber, and the upper cover and the lower cover are connected to the housing. In the state where the valve stem is stacked in the axial direction of the valve stem and is unitized in the tappet, and the volume of the pressure chamber is reduced by the biasing force of the biasing means, the switch is In a state in which the valve is deviated from above the stem and the switch is rotated against the urging force of the urging means by the fluid pressure in the pressure chamber, the switch is located above the valve stem. It is characterized in that it is configured so as to be in a valve operating state located at.

  According to the present invention, the switching element rotates so that the rotation center side end surface and the distal end surface slide along the inner peripheral surface of the housing. The entire one side surface (surface on the pressure chamber side) can be a pressure receiving surface, and the operability of the switching element can be improved. In addition, since the switch is positioned so as to deviate from the top of the valve stem in the valve rest state, it is not necessary to form a through hole in the switch, so that the switch can be operated with a large size by avoiding an increase in the size of the switch. Can be prevented from being damaged.

  In addition, the upper cover and lower cover are stacked in the axial direction of the valve stem across the housing with the switch and urging means built in, and the assembly into the tappet is greatly improved. Can do.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a four-cycle water-cooled parallel four-cylinder internal combustion engine (engine) mounted on a motorcycle will be described as an example. First, a schematic configuration of a motorcycle will be described with reference to FIG. 1. A motorcycle 100 has a body frame 101, and a head pipe 102 is provided in front thereof. The head pipe 102 is provided with a suspension mechanism (not shown) and a steering mechanism including a pair of left and right front forks 104 that rotatably support the front wheel 103.

  The body frame 101 is of a twin tube type, for example, and is expanded in the left-right direction immediately after the head pipe 102 and then a pair of left and right tank rails 105 extending rearward and obliquely downward. A pair of left and right center frames 106 connected to the end portions and extending substantially in the vertical direction, and a pair of left and right seat rails 107 extending rearward from the rear upper end of the center frame 106 are included.

  A fuel tank 108 is disposed above the tank rail 105, and an operation seat 109 is disposed behind the fuel tank 108 and above the seat rail 107. A pivot shaft 110 is installed at the center lower portion of the center frame 106, and a swing arm 111 is pivotally mounted around the pivot shaft 110 so as to be swingable. A rear wheel 112 is pivotally supported at the rear end of the swing arm 111 so as to be rotatable.

  In the motorcycle 100, the front portion of the vehicle body is covered with a streamlined cowling 113 to reduce the air resistance during traveling and protect the occupant from traveling wind pressure. A seat cowl 114 is attached around the driving seat 109 at the rear of the vehicle body so as to cover the upper part of the rear wheel 112, and a rear fender 115 is provided at the rear thereof.

  A four-cycle water-cooled parallel four-cylinder engine unit 1 is disposed below the fuel tank 108 at the lower center of the vehicle body of the motorcycle 100. In the engine unit 1, as shown in FIG. 2, a cylinder assembly 2 that is integrally provided with a plurality of cylinders (cylinders) is mounted on the upper part of the crankcase 3 with a slight forward tilt.

  The engine unit 1 is supplied with clean air from an air cleaner 116 (see FIG. 2) disposed above and housed in the inner part of the fuel tank 108. The amount of air supplied from the air cleaner 116 is a throttle. Controlled by valves 124 and 125. Further, fuel is injected and supplied by the injectors 122 and 123.

  Four exhaust pipes 117 are connected to the front side of the cylinder assembly 2 of the engine unit 1, and a muffler 118 is connected after being assembled in the collecting pipe. Each exhaust pipe 117 once extends downward from the front surface of the engine unit 1, then bends in a generally L shape at the front lower part of the crankcase 3 of the engine unit 1, and further turns around the lower part of the engine unit 1 to the rear. Extend to.

  A radiator 119 constituting a cooling device is disposed below the head pipe 102 and in front of the engine unit 1. The radiator 119 is connected to a water pump 42 described later via a cooling water pipe 120, and supplies cooled cooling water to the water pump 42.

  Next, the structure around the engine unit 1 and the engine unit 1 will be described. 2 is a diagram showing the left side of the engine unit 1, FIG. 3 is a diagram showing the back of the engine unit 1, and FIG. 4 is a diagram showing the right side of the engine unit 1. In each figure, arrows Fr and Rr indicate the vehicle longitudinal direction, and arrows L and R indicate the vehicle lateral direction, respectively.

  In the engine unit 1 of the present embodiment, as shown in FIG. 2, a cylinder assembly 2 that is integrally provided with a plurality of cylinders (cylinders) is disposed on the upper part of the crankcase 3 with a slight forward tilt. The crankcase 3 has a structure in which a cylinder block integrated upper crankcase 4 integrally formed with the cylinder assembly 2 and a lower crankcase 5 are coupled in an upper and lower half, and the lower crankcase 5 is further coupled in an upper and lower half. Is done.

  In the cylinder assembly 2, as shown in FIG. 3, four cylinders 6 are juxtaposed in the left-right (vehicle width) direction, and pistons 7 are slidably fitted into the cylinder bores of the respective cylinders 6. The cylinders are numbered 1, 2, 3, and 4 in order from the left.

  In the crankcase 3, a crankshaft 9 is pivotally supported by a mating surface 8 between the upper crankcase 4 and the lower crankcase 5.

  The piston 7 and the crankshaft 9 of each cylinder are connected via a connecting rod 10. As a result, the reciprocating motion of the piston 7 is converted into the rotational motion of the crankshaft 9 via the connecting rod 10, and engine output is obtained.

  A water jacket 11 is formed around each cylinder 6 of the cylinder assembly 2, and cooling water supplied from the water pump 42 flows through the water jacket 11.

  A cylinder head 12 and a cylinder head cover 13 are provided on the upper part of the cylinder assembly 2, and a combustion chamber 14 is formed on the lower surface of the cylinder head 12 so as to be aligned with the cylinder bore of the cylinder 6.

Inside the cylinder head 12, an intake valve 200 _IN that controls the opening and closing of the intake port 15 a of the combustion chamber 14 and an exhaust valve 200 _EX that controls the opening and closing of the exhaust port 16 a are disposed with the spark plug 17 interposed therebetween. In the engine unit 1 of the present embodiment, each cylinder has two valves (4 valves) on the intake side and the exhaust side, respectively, and as will be described in detail later, one intake valve 200 _IN of the two intake valves 200 _IN. Includes a valve deactivation unit 300.

  In each cylinder, a bifurcated intake passage 15 connected to two intake ports 15a and a bifurcated exhaust passage 16 connected to two exhaust ports 16a are formed in the cylinder head 12.

An air-fuel mixture of air supplied from the air cleaner 116 and fuel supplied from the injectors 122 and 123 is supplied to the intake passage 15 of each cylinder via the throttle body 121. As shown in FIG. 2, in a side view, the intake passage 15 is disposed inclined at an angle to the vertical close to form an intake valve 200 _IN and sharp V-shape. The air cleaner 116 and the intake passage 15 are connected via a straight throttle body 121, and a downdraft type (downward type) intake system is configured.

  In the engine unit 1 of the present embodiment, a so-called dual throttle valve type is employed, and a primary valve 124 is disposed on the downstream side in the throttle body 121 and a secondary valve 125 is disposed on the upstream side. The downstream primary valve 124 is artificially rotated by the occupant's accelerator operation, and the upstream secondary valve 125 is driven by a not-shown engine controller via a motor actuator. The pulley of the primary valve 124 and the motor actuator of the secondary valve 125 are separated from each other and are provided at the end portions of the respective throttle shafts. By adopting this dual throttle valve, for example, when the throttle is opened at a stroke at the corner outlet, the air flow rate is controlled by the secondary valve 125, so that sudden torque fluctuations are alleviated and smooth power characteristics are achieved. Realized.

  Further, the first injector 122 is disposed in the vicinity of the primary valve 124, specifically, downstream of the fully closed position. The first injector 122 is disposed in a nearly horizontal state and injects fuel toward the downstream side in the throttle body 121. In this case, the wall surface position in the injection direction is upstream from the bifurcated branch portion of the intake passage 15. The first injector 122 is controlled in its injection amount and injection timing by an engine controller (not shown), and is mainly used in a transition period such as a high rotation, high load region or intermediate acceleration of the engine unit 1.

Further, a second injector 123 is disposed upstream of the secondary valve 125, specifically, inside the air cleaner 116 so as to face the funnel opening 121 a of the throttle body 121. The second injector 123 is controlled in its injection amount and injection timing by an engine controller (not shown), and is mainly used in a low rotation / low load region of the engine unit 1. It is also used in a state where the intake valve 200 _IN is deactivated.

  On the other hand, the exhaust pipe 117 is connected to the exhaust passage 16 of each cylinder as described above.

The intake valve 200 _IN and the exhaust valve 200 _EX are driven by an intake cam 18a and an exhaust cam 19a provided on the intake side camshaft 18 and the exhaust side camshaft 19, respectively. The intake side camshaft 18 and the exhaust side camshaft 19 extend in the cylinder parallel direction (left-right direction) and are pivotally supported by the mating surfaces 20 of the cylinder head 12 and the cylinder head cover 13. The camshafts 18 and 19 have a hollow structure, and the hollow interior is oil passages 18b and 19b (the oil passage 19b does not appear in the figure).

  As shown in FIG. 4, at the right end of the engine unit 1, a cam chain 24 is attached to sprockets 21, 22, and 23 attached to the shaft ends of the crankshaft 9, the intake side camshaft 18, and the exhaust side camshaft 19, respectively. The intake side camshaft 18 and the exhaust side camshaft 19 are rotated and driven by the power of the crankshaft 9 via the cam chain 24. As shown in FIG. 3, a sensing rotor 25 is attached to the right shaft end of the crankshaft 9 and a crank angle sensor 26 is arranged near the side to detect the crank angle. A crank cover 27 is attached to these outsides.

  The crankshaft 9 is arranged in the vehicle width direction in the crankcase 3, but a plurality of bulkheads 28 rise at positions where the cylinders 6 are sandwiched at the bottom of the front portion of the lower crankcase 5. The crankshaft 9 is pivotally supported by a journal bearing 29 set on the mating surface 8 of the upper crankcase 4 and the lower crankcase 5 in each bulk head 28. A generator 32 including a generator coil 30 and a generator rotor 31 is arranged at the left shaft end of the crankshaft 9, and the generator coil 30 is attached and supported inside the cover 33.

  The rear half of the crankcase 3 also serves as a mission case 34, and a counter shaft 35 and a drive shaft 36 are arranged in parallel with the crankshaft 9. The counter shaft 35 and the drive shaft 36 are supported by the mating surface 37 of the lower crankcase 5. In the transmission case 34, a transmission device is arranged between the counter shaft 35 and the drive shaft 36, and the rotation of the counter shaft 35 is transmitted to the drive shaft 36 through the transmission device. A drive sprocket 38 is attached to the shaft end of the drive shaft 36, thereby forming a power transmission path from the engine unit 1 to the rear wheel 112.

  An oil pan 39 is coupled to the lower portion of the lower crankcase 5, and the lower crankcase 5 has an open bottom surface corresponding to the inner second and third cylinders so as to communicate with the oil pan 39. . On the other hand, the lower bottom surface of the lower crankcase 5 corresponding to the first and fourth cylinders at the left and right ends is curved (substantially semicircular) along a substantially crank locus. A boss 41 forming the main gallery 40 of the oil passage is integrally provided at the lowermost part of the semicircular shape.

  A water pump 42 is disposed on the side wall of the crankcase 3 (lower crankcase 5) located behind the crankshaft 9. As described above, the water pump 42 is connected to the cooling water pipe 120 to which the cooling water is supplied from the radiator 119, and the cooling water pipe 126 to supply the cooling water to the water jacket 11 is connected.

  An oil pump is disposed in the lower crankcase 5, and an oil strainer is mounted in the oil pan 39 below the oil pump. The oil accumulated in the oil pan 39 is pumped from the deep part of the oil pan 39 by an oil pump through an oil strainer. Oil discharged from the oil pump is filtered through the oil filter 43 and flows into the main gallery 40.

  From the main gallery 40, oil is supplied to each part of the engine that requires lubrication. That is, each bulkhead 28 is formed with a journal oil passage 44 that rises upward from the main gallery 40 and communicates with the journal bearing 29, whereby lubricating oil is supplied to the journal bearing 29 and the piston 7.

  As shown in FIG. 4, an oil passage 45 extending in the vertical direction is formed on the right end side of the crankcase 3, and lubricating oil is supplied to the chain guide 46 of the cam chain 24 in the middle thereof.

Further, the oil passage 45 extends to the cylinder head 12 and branches to communicate with the oil passages 18b and 19b of the camshafts 18 and 19. Lubricating oil supplied to the oil passages 18b and 19b is supported from the oil passages 18c and 19c formed in the radial direction of the camshafts 17 and 18 (the oil passage 19c does not appear in the drawing) to the shaft support portions of the camshafts 18 and 19. is supplied to, even staying in its periphery is provided with sliding portion (tappet shim 211) and the exhaust cam 19a of the intake cam 18a and the intake valve 200 _iN into sliding contact portion between the exhaust valve 200 _EX.

Next, an intake valve 200 _IN (referred to as “one intake valve”) including the valve deactivation unit 300 among the two intake valves 200 _IN of each cylinder will be described with reference to FIGS. As shown in FIG. 5, a cylindrical valve guide 201 is held inside the cylinder head 12, and the valve stem 202 is guided by the valve guide 201. When the valve face 203 is separated from the valve seat 204 via the valve stem 202, the intake port 15 a is opened, and a mixture of air supplied from the air cleaner 116 and fuel injected and supplied from the injectors 122, 123 is generated in the combustion chamber 14. Introduced into

  A spring seat 205 is provided on the deck surface 47 (see FIG. 3) around the valve guide 201 and serving as the ceiling of the water jacket. A valve retainer 207 is provided near the upper end of the valve stem 202 via a collet 206. An inner spring 208 is disposed between the spring seat 205 and the valve retainer 207, and applies an urging force in a direction in which the valve face 203 is brought into contact with the valve seat 204, that is, in a direction in which the intake port 15a is closed.

  Further, a tappet guide 209 is formed inside the cylinder head 12, and the tappet 210 is slidably assembled. The tappet 210 is formed in a closed and bottomless cylindrical shape having a peripheral wall portion 210a and a ceiling portion 210b, and a tappet shim 211 to which the intake cam 18a is slidably contacted is mounted in a recess on the outer surface of the ceiling portion 210b.

  Here, the valve rest unit 300 is fitted in the tappet 210 so as to be rotatable and detachable. The valve resting unit 300 will be described in detail below. A disk-shaped upper cover 301, a housing 302, and a disk-shaped lower cover 303 are stacked in the axial direction of the valve stem 202, and two pins ( Rivet) 304 is penetrated and the tip of these rivets 304 is crushed to form a unit. In this case, the rivet 304 is loosely fitted with the lower cover 303 and is press-fitted with the upper cover 301, and the tip is crushed after press-fitting into the upper cover 301 to improve durability.

  Hereinafter, the valve pause unit 300 will be described in detail. In the upper cover 301, as shown in FIG. 8, a protrusion 305 is formed at the center of the upper surface, and this protrusion 305 contacts the inner surface of the ceiling 210b of the tappet 210. Touch. For example, if several types of upper covers 301 with different heights of the protrusions 305 are prepared and the upper cover 301 can be selected as appropriate, the height position of the tappet 210 can be adjusted without the tappet shim 211. It is possible to adjust the tappet gap.

  A through hole 306 is formed at the center of the upper cover 301, and a bar member 307 is provided at the through hole 306 and a hole 210 c formed at the center of the ceiling portion 210 b of the tappet 210. As shown in FIG. 5, the lower end surface of the bar member 307 is substantially flush with the inner surface (bottom surface) of the upper cover 301.

  As shown in FIG. 9, in the lower cover 303, an insertion hole 308 penetrating vertically is formed in the center thereof, and the valve stem 202 is inserted into the insertion hole 308. As shown in FIG. 5, the upper end surface of the valve stem 202 is substantially flush with the inner surface (upper surface) of the lower cover 303 when the valve is closed.

  In the housing 302, as shown in FIG. 10, the housing 302 has an annular shape as a whole, and the outer shape thereof is an arc surface 309, an arc surface 310 having a diameter different from the arc surface 309, and the center of the arc surface 310. It has a rivet hole forming portion 311 in which the formed rivet hole 311a is formed, and has a symmetric shell shape.

  The maximum outer diameter of the housing 302 is smaller than the outer diameters of the upper cover 301 and the lower cover 302, and the valve resting unit 300 is housed in the tappet 210, and the housing 302 is combined with the peripheral wall portion 210 a of the tappet 210 to form oil. A path 312 is formed (see FIGS. 6 and 7). The oil passage 312 communicates with an oil passage 214 formed in the tappet guide 209 through a communication hole 213 formed in the peripheral wall portion 210 a of the tappet 210. In this case, the oil passage 312 swells in the arcuate surface 310 and an oil pool is formed, so that the amount of oil stored in the oil passage 312 can be secured and deterioration when staying for a period of time can be prevented.

  The inner shape of the housing 302 is substantially the same as the outer shape except for the rivet hole forming portion 311, and the housing 302 has a substantially uniform thickness. That is, it has an arc surface 313 corresponding to the outer arc surface 309 and an arc surface 314 corresponding to the outer arc surface 310 and having a diameter different from that of the arc surface 313. However, the thickness is increased at two places, and a protrusion forming portion 316 provided with the protrusion 315 and a vane support portion 318 for supporting a vane 317 described later are formed.

  As shown in FIGS. 6 and 7, a wing-like switch 317 (referred to as a “vane”) having the same thickness (height) as the housing 302 is rotatably assembled in the housing 302 thus configured. The housing 302 is partitioned into a pressure chamber 319 and a gas chamber 320. In this case, the upper cover 301 and the lower cover 303 are formed with through holes 321 and 322 in the gas chamber 320, and the gas chamber 320 is always outside (the space in the tappet 210, the spring, regardless of the rotation position of the vane 317). 208, 212). These through holes 321 and 322 are used for the intake and discharge of air when the vane 317 rotates to change the volume of the gas chamber 320, the discharge of oil leaking from the pressure chamber 319 side to the gas chamber 320, and the valve pause unit 300. It performs functions such as weight reduction.

  The vane 317 has a rotation center 317a that is eccentric from the axial center O of the valve stem 202. In this example, one rivet 304 is used as the rotation axis. In this case, it is desirable that the rotation center 317a of the vane be positioned outside a virtual circle having a radius from the center of the tappet 210 to half of the radius of the tappet, so that the effective length of the vane 317 can be increased.

  The base end surface 317b (end surface on the rotation center 317a side) of the vane 317 is formed as an arc surface centered on the rotation center 317a, and the vane support portion 318 is formed on the inner peripheral surface (arc surface) 313 of the housing 302. It can slide along. Further, the front end surface 317c of the vane 317 is also formed in an arc surface having a diameter different from that of the base end surface 317b with the rotation center 317a as the center, and is slidable along the inner peripheral surface (arc surface) 314 of the housing 302. The In other words, the portion of the inner peripheral surface 313 of the housing 302 where the vane support portion 318 is formed and the inner peripheral surface 314 of the housing 302 are also arcuate surfaces centered on the rotation center 317 a of the vane 317.

  In this case, a rod-shaped seal member 323 is attached to a sliding portion between the vane 317 and the housing 302. These seal members 323 preferably have a low friction and a lower elasticity than metal. The seal member 323 may be provided on either the vane 317 side or the housing 302 side.

  The vane 317 is formed in an arc shape that protrudes toward the pressure chamber 319 and has a width that is the same as or slightly larger than the diameter of the valve stem 202. A valve stem relief portion 317d is formed on the side surface of the vane 317 on the gas chamber 320 side, and the vane 317 is positioned so as to be displaced from above the valve stem 202 in the state shown in FIG. A part of the vane 317 has a concave shape whose cross section is open to the lower cover 303 side in order to reduce the weight.

  In the vicinity of the tip of the vane 317, a protrusion 317e that contacts the protrusion 315 in the state shown in FIG. The rotation restricting position of the vane 317 is determined by the protrusions 315 and 317e. A coil spring 324 is disposed between the inner peripheral surface of the housing 302 and the vicinity of the tip of the vane 317 using the protrusions 315 and 317e as spring guides, and applies a biasing force in the direction of reducing the volume of the pressure chamber 319. To do. In this case, by arranging the coil spring 324 in an arc shape along the arc surface 314 of the housing 302, the length of the coil spring 324 necessary for taking a sufficient load and keeping the stress low can be secured even in a small space. can do.

  Further, in the vicinity of the tip of the vane 317, a protrusion 317f is provided on the side surface on the pressure chamber 319 side. The protrusion 317f can determine the rotation restriction position of the vane 317 and can secure the minimum volume of the pressure chamber 319. Further, even in the state shown in FIG. 6, since a gap is secured between the side surface of the vane 317 on the pressure chamber 319 side and the inner peripheral surface of the housing 302, the pressure receiving area is not reduced. The protrusion 317f may be provided on the housing 302 side.

  The housing 302 is formed with a communication path for communicating the pressure chamber 319 and the oil passage 312 around the housing 302. In this example, as shown in FIG. 10, a semicircular cutout 325 opened on the upper cover 301 side and a semicircular cutout 326 opened on the lower cover 303 side are formed in the housing 302, and the upper cover is formed on the housing 302. The communication path is configured with the 301 and the lower cover 303 assembled. Although the hole itself forming the communication path may be formed in the housing 302, in that case, it is difficult to maintain the strength around the hole if the diameter of the hole is increased. On the other hand, if notches 325 and 326 having a semicircular shape or other shapes are formed as in this example, and the communication path is configured with the upper cover 301 and the lower cover 303, the strength of the housing 302 is increased. Can be maintained. Further, by forming a plurality of notches 325 and 326 along the housing 302, not only stress concentration is avoided, but also a necessary cross-sectional area is secured as a communication path, and fine foreign matters such as worn metal powder are not easily clogged. It becomes easy to discharge.

  An outer spring 212 is disposed between the bottom surface of the valve deactivation unit 300 (that is, the bottom surface of the lower cover 303) and the spring seat 205 in a state where the valve deactivation unit 300 having the above-described configuration is housed in the tappet 210. The In this way, the valve deactivation unit 300 also functions as a retainer, and in the valve deactivation state shown in FIG. 6, the valve deactivation unit 300 receives only the urging force of the outer spring 302 and abuts against the tappet 210 to integrally reciprocate. I do. Since the load acting on the lower cover 303 of the valve deactivation unit 300 is relatively low in this way, the material can be selected with a high degree of freedom, and a light material with high thermal conductivity can be selected. The bottom of the lower cover 303 is formed with a recess in which the rivet head of the rivet 304 is accommodated, so that the outer spring 212 is in direct contact with the lower cover 303 and is not hooked on the rivet 304.

  Next, the operation of the valve deactivation unit 300 will be described. As shown in FIG. 6, when the protrusion 317 f is in contact with the inner peripheral surface of the housing 302 by the urging force of the coil spring 324, the vane 317 is moved to the valve stem 202. Deviation from above. Therefore, for example, the upper end of the valve stem 202 remains in the housing 302 even if the tappet 210 and further the valve pausing unit 300 in the tappet 210 descends against the urging force of the outer spring 212 following the rotation of the intake cam 18a. Since it can move, only the tappet 210 and the valve deactivation unit 300 are lowered, and the valve stem 202 is not lowered.

  On the other hand, when the hydraulic pressure in the pressure chamber 319 becomes equal to or higher than the set pressure, the vane 317 rotates against the urging force of the coil spring 324 and the protrusions 315 and 317e come into contact with each other as shown in FIG. In this state, the vane 317 is positioned above the valve stem 202. Therefore, for example, when the tappet 210 and further the valve pausing unit 300 in the tappet 210 are lowered against the urging force of the outer spring 212 following the rotation of the intake cam 18a, the valve stem 202 is also moved by the inner spring via the vane 317. The intake port 15a is opened against the urging force 208 (valve operating state).

Here, the hydraulic pressure introduction path to the valve deactivation unit 300 will be described. As shown in FIG. 2, as shown in FIG. 2, in the cylinder head 12, the cylinder is arranged in parallel between the intake valve 200 _IN and the intake passage 15. An oil passage 48 extending in the direction (left-right direction) is formed. The oil passage 48 communicates with the oil passage 45 shown in FIG. 4 via a hydraulic control valve OCV (not shown) that switches supply / holding / discharge of oil. The oil passage 48 communicates with the oil passage 214 opened by the tappet guide 209 in which one intake valve 200 _IN of each cylinder is arranged as described above. Thereby, the pressure of the pressure chamber 319 in the valve deactivation unit 300 can be controlled by switching the hydraulic control valve OCV. The oil introduced from the oil passage 214 also functions as lubricating oil for the tappet 210 and the tappet guide 209, and also exhibits a cooling action for each part when it is distributed.

The basic configuration of the intake valve 200 _IN (referred to as “the other intake valve”) and the exhaust valve 200 _{EX not including} the valve deactivation unit 300 has been described so far, except for the valve deactivation unit 300. one of the intake valve 200 _iN and are substantially similar, the intake when the tappet in accordance with the rotation of the cam 18a (the exhaust cam 19a) is vertically, the intake port 15a abuts the valve stem on the inner surface of the upper wall portion of the tappet is vertically (Exhaust port 16a) opens and closes. However, as shown in FIG. 3, in one intake valve 200 _IN (right side in the figure) and the other intake valve 200 _IN , the height of the valve retainer is set to one intake valve 200 _IN (right side in the figure). The other intake valve 200 _IN becomes higher by the amount of intervening valve deactivation unit 300. Therefore, on the other intake valve 200 _IN side, a heat radiation boss 49 having a predetermined height is provided on the deck surface 47 which becomes the ceiling of the water jacket, and various inner springs are provided between the one intake valve 200 _IN and the other intake valve 200 _IN. The elements (spring constant, natural length, number of turns, initial load, etc.) are made uniform.

In the engine unit 1 described above, in the low-speed rotation region, the pressure in the pressure chamber 319 of the valve deactivation unit 300 is kept low, and the valve deactivation state in which the vane 317 is shifted from the upper side of the valve stem 202 is set (FIG. 6). Only the other intake valve _200IN is lifted. As a result, the intake flow is promoted to generate an intake swirl flow in the combustion chamber, and so-called lean burn can be achieved. In this case, the output can be increased by increasing the fuel injection speed.

When the rotation range of the engine unit 1 exceeds the low-speed rotation range, the hydraulic control valve is switched so that the pressure in the pressure chamber 319 of the valve deactivation unit 300 exceeds the set pressure, and the vane 317 is positioned above the valve stem 202. a valve operation state (FIG. 7), thereby lifting the two intake valves 200 _iN of each cylinder.

  As described above, the vane 317 rotates so that the rotation center side end surface 317b and the tip end surface 317c slide along the inner peripheral surface of the housing 302, so that the effective length of the vane 317 is secured. The entire surface of the vane 317 on the pressure chamber 319 side can be a pressure receiving surface, and the operability of the vane 317 can be improved. Further, since the vane 317 is positioned so as to be displaced from the upper side of the valve stem 202 in the valve resting state, the vane 317 can be prevented from becoming large and the operability of the vane 317 can be prevented from being impaired.

  Further, by stacking the upper cover 301 and the lower cover 303 with the housing 302 in which the vane 317 and the coil spring 324 are incorporated so as to be unitized, it is possible to significantly improve the assembling property in the tappet 210. . Moreover, even if it is a simple shape individually, a complicated shape can be formed by combining, post-processing and post-processing are easy, and productivity can be improved. In consideration of the thermal expansion coefficient, load fatigue strength, vibration wear, etc., it is also possible to use different materials for each part or to perform different surface treatments.

  As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention.

It is a side view showing a motorcycle according to an application example of the present invention. It is a figure which shows the left side surface of an engine unit. It is a figure which shows the back surface of an engine unit. It is a figure which shows the right side surface of an engine unit. It is a figure which shows the intake valve containing a valve deactivation unit. It is a top view of the state which removed the upper cover which shows the valve stop state of a valve stop unit. It is a top view of the state which removed the upper cover which shows the valve operation state of a valve pause unit. It is a figure which shows an upper cover, (a) is a top view, (b) is side sectional drawing, (c) is a bottom view. It is a figure which shows a lower cover, (a) is a top view, (b) is side sectional drawing, (c) is a bottom view. It is a top view which shows a housing. It is a figure which shows a vane, (a) is a side view, (b) is a top view. It is a figure for demonstrating the conventional variable cylinder system, (a) is a figure which shows the state at the time of all cylinder driving | operation, (b) is a figure which shows the state at the time of reduced cylinder driving | operation.

Explanation of symbols

1 Engine Unit 200 _IN Intake Valve 202 Valve Stem 210 Tappet 300 Valve Resting Unit 301 Upper Cover 302 Housing 303 Lower Cover 304 Rivet 305 Projecting Part 306 Through Hole 307 Bar Member 308 Insertion Hole 309 Arc Surface 310 Arc Surface 311 Rivet Hole Forming Section 312 Oil path 313 Arc surface 314 Arc surface 315 Projection 316 Projection formation part 317 Vane 317a Center of rotation 317b Base end surface 317c Tip surface 317d Valve stem relief 317e Projection 317f Projection 318 Vane support part 319 Pressure chamber 320 Gas chamber 320 Hole 322 Through hole 323 Seal member 324 Coil spring 325 Notch 326 Notch

Claims (17)

A tappet that advances and retreats along the tappet guide as the cam rotates,
A valve that opens and closes as the tappet advances and retreats;
An annular housing provided in the tappet;
The rotation center is eccentric from the axial center of the valve stem of the valve, and the rotation center side end surface and the tip surface are rotatably assembled in the housing so as to slide along the inner peripheral surface of the housing. A switching member for partitioning the inside of the housing into a pressure chamber and a gas chamber;
Urging means for applying an urging force in a direction to reduce the volume of the pressure chamber with respect to the switching element,
In a state where the volume of the pressure chamber is reduced by the urging force of the urging means, the switching element is in a valve resting state in which the switching element is displaced from above the valve stem, and the switching element is moved by the fluid pressure in the pressure chamber. A valve operating apparatus characterized in that in a state of rotating against the urging force of the urging means, the switching element is in a valve operating state located above the valve stem.   2. The valve operating apparatus according to claim 1, wherein the rotation center side end surface and the tip surface of the switching element are arc surfaces having different diameters from each other about the rotation center.   3. The valve operating device according to claim 1, wherein a relief portion of the valve stem is formed on a side surface of the switching element on the gas chamber side.   4. The valve gear according to claim 1, wherein the rotation center of the switching element is located outside a virtual circle having a radius from the center of the tappet to half the radius of the tappet. .   5. The switch according to claim 1, wherein the switch has a width equal to or larger than a diameter of the valve stem at least at a position located above the valve stem in the valve operating state. Valve operating device.   The protrusion for ensuring the minimum volume of a pressure chamber in the said valve | bulb resting state is provided in at least any one of the said switch and the internal peripheral surface of the said housing, The any one of Claims 1-5 characterized by the above-mentioned. 2. The valve gear according to item 1.   Protrusions that contact each other in the valve operating state are provided on the inner peripheral surface of the switch and the housing, respectively, and a coil spring that is the urging means is provided using the protrusions as spring guides. The valve gear according to any one of claims 1 to 6.   A seal member provided on a rotation center side end surface of the switching element or an inner peripheral surface of the housing, and a seal member provided on a front end surface of the switching element or an inner peripheral surface of the housing. The valve gear according to any one of 1 to 7.   A disc-shaped upper cover and a disc-shaped lower cover in which an insertion hole through which the valve stem is inserted is formed in the center, and is laminated in the axial direction of the valve stem with the housing interposed therebetween to form a unit. The valve operating device according to any one of claims 1 to 8, wherein the tappet is configured to be installed in the tappet.   The valve operating apparatus according to claim 9, wherein a plurality of pins are passed through the upper cover, the housing, and the lower cover stacked in the axial direction of the valve stem to form a unit.   11. The valve operating apparatus according to claim 10, wherein one pin of the plurality of pins is used as a rotation shaft of the switching element.   The maximum outer diameter of the housing is smaller than the outer diameters of the upper cover and the lower cover, and a fluid path is formed around the housing together with the tappet in a state where the unitized one is installed in the tappet. The valve operating apparatus according to any one of claims 9 to 11, wherein the valve operating apparatus is characterized in that:   The housing is formed with a notch that opens to the upper cover side or the lower cover side, and a communication passage for introducing a fluid into the pressure chamber is formed together with the upper cover or the lower cover. The valve gear according to any one of claims 9 to 12.   14. The valve operating valve according to claim 9, wherein a through hole is formed in the gas chamber of the switching element in at least one of the upper cover and the lower cover. apparatus. An internal combustion engine configured to control intake and exhaust by an intake valve and an exhaust valve,
An internal combustion engine comprising the valve gear according to any one of claims 1 to 14 on at least one of an intake side and an exhaust side.   A plurality of intake valves and a plurality of exhaust valves are provided in one cylinder, and the valve operating device according to any one of claims 1 to 14 is provided on a part of the intake valves of the plurality of intake valves. The internal combustion engine according to claim 15, characterized in that: A valve resting unit used in a valve operating apparatus comprising a tappet that advances and retreats along a tappet guide by rotation of a cam, and a valve that opens and closes as the tappet advances and retreats,
A disc-shaped upper cover;
An annular housing;
A disc-shaped lower cover in which an insertion hole through which the valve stem is inserted is formed in the center;
The rotation center is eccentric from the axial center of the valve stem of the valve, and the rotation center side end surface and the tip surface are rotatably assembled in the housing so as to slide along the inner peripheral surface of the housing. A switching member for partitioning the inside of the housing into a pressure chamber and a gas chamber;
Urging means for applying an urging force in a direction to reduce the volume of the pressure chamber with respect to the switching element,
The upper cover and the lower cover are laminated in the axial direction of the valve stem with the housing interposed therebetween, and a unitized one is mounted on the tappet,
In a state where the volume of the pressure chamber is reduced by the urging force of the urging means, the switching element is in a valve resting state in which the switching element is displaced from above the valve stem, and the switching element is moved by the fluid pressure in the pressure chamber. A valve resting unit characterized in that, in a state of rotating against the urging force of the urging means, the switching element is in a valve operating state located above the valve stem.

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