JP2013155709A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine capable of realizing a cylinder deactivation system without increasing sliding resistance in reduced-cylinder operation.SOLUTION: In an internal combustion engine includes a camshaft capable of switching between a state where the whole of the camshaft revolves and valves of all cylinders are driven and the state where a part of the camshaft is separated, the part is not revolved, and some valves of the cylinders associated with the part are not driven. The camshaft is equipped with a drive-side shaft 43, a driven-side shaft 45, a driven piece 47, a claw clutch 50, and a sleeve 49.

Description

  The present invention relates to an internal combustion engine having a cylinder deactivation system.

  A so-called cylinder deactivation system that improves fuel efficiency by temporarily stopping the combustion cycle of some cylinders during low-load operation with a small torque required for traveling, that is, temporarily reducing the number of cylinders to be operated Is known (see, for example, Patent Document 1). As an example of the cylinder deactivation system, a clutch mechanism that switches connection and disconnection between the camshaft and the cam is built in the camshaft, and the connection state between the camshaft and the cam is switched by controlling this clutch mechanism. What is considered. That is, the operation of the valve is stopped while the cam of the cylinder to be deactivated is not connected to the camshaft, and fuel injection (and intake and combustion associated therewith) is stopped.

  However, in such a case, the camshaft diameter increases, the sliding area between the camshaft and the cam increases, and there arises a problem that the sliding resistance during the reduced-cylinder operation increases.

Japanese Utility Model Sho 60-173645

  An object of the present invention is to provide an internal combustion engine that can realize a cylinder deactivation system with a relatively simple structure without increasing the sliding resistance between the camshaft and the cam during reduced-cylinder operation.

  The present invention employs the following configuration in order to solve the above-described problems. That is, the internal combustion engine according to the present invention has a state in which the whole is rotated to drive the valves of all cylinders, and a part of the valves of some cylinders that are partly disconnected and that part of the cylinders do not rotate and are engaged with the part. The camshaft includes a camshaft that can be switched between a non-driven state, the camshaft receiving a rotational driving force from the crankshaft and a rotational driving force from the drive shaft. A driven side shaft, a driven piece that rotates integrally with the driven side shaft and that is displaceable along the axial direction relative to the drive side shaft and the driven side shaft, and a shaft end of the drive side shaft And the shaft end of the driven piece facing the shaft end, and the shaft end of the driven piece is A claw clutch that engages with the shaft end of the live-side shaft to eliminate the relative angular difference between the driven piece and the drive-side shaft, and rotates integrally with the driven-side shaft and the driven piece. In addition, the drive side can be displaced along the axial direction relative to the drive side shaft, the driven side shaft and the driven piece, and after the relative angular difference between the driven piece and the drive side shaft is eliminated, the drive side The sleeve includes a key coupling or a spline coupling to the shaft, and a sleeve capable of interrupting the transmission of the rotational driving force by separating the key coupling or the spline coupling from the drive side shaft.

  In such a case, the cam corresponding to the cylinder to be stopped can be completely stopped by separating the camshaft. Therefore, the sliding resistance between the cam and the camshaft during the reduced cylinder operation can be reduced as compared with the conventional one. A cylinder deactivation system can be realized with a relatively simple structure, and fuel consumption can be improved.

  On the outer peripheral surface of the sleeve, a groove is formed that extends along the circumferential direction and gradually displaces in the axial direction as the sleeve rotates, and a protrusion protruding from the actuator is formed in the groove. By engaging the sleeve, the sleeve is displaced along the axial direction to the side away from the drive-side shaft, and the groove is formed from the cam nose of a cam mounted on the driven-side shaft. Is preferably extended along the direction of rotation in response to the transmission of the rotational driving force over a range of angles between the cam lobe and the bottom of the cam lobe that contacts the valve next.

  Here, the “cam nose” refers to the highest point (vertex) of the cam lobe (cam crest), and is the part that comes into contact with the tappet or rocker arm and becomes the maximum valve lift when the cam drives the valve.

  Since the present invention is configured as described above, a cylinder deactivation system can be realized with a relatively simple structure without increasing the sliding resistance between the camshaft and the cam during reduced-cylinder operation.

The figure which shows the outline | summary of the internal combustion engine for vehicles used as the application object of this invention. The figure which shows the principal part of the internal combustion engine. The figure explaining the stroke of each cylinder of the internal combustion engine. The figure which shows the hardware resource structure of the control part which manages control of the internal combustion engine. The figure explaining the action | operation of the intake camshaft of the internal combustion engine. The figure explaining the action | operation of the intake camshaft of the internal combustion engine. The figure explaining the action | operation of the intake camshaft of the internal combustion engine. FIG. 6 is a view corresponding to FIG. 5 for explaining the operation of the sleeve of the internal combustion engine. FIG. 6 is a view corresponding to FIG. 6 for explaining the operation of the sleeve of the internal combustion engine. The figure explaining the action | operation of the intake camshaft of the internal combustion engine.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of a vehicle internal combustion engine 1 to which the present embodiment is applied. The internal combustion engine 1 in the present embodiment is, for example, an in-line four-cylinder double overhead camshaft (DOHC) type gasoline engine, and FIG. 1 shows a schematic configuration of an arbitrary one of the four cylinders.

  The internal combustion engine 1 includes a cylinder block and a cylinder head 5. The cylinder block includes a cylinder bore 9 in which a piston 7 reciprocates. The cylinder head 5 includes a combustion chamber 11. An intake port 13 and an exhaust port 15 are formed in the cylinder head 5, and the intake port 13 and the exhaust port 15 are arranged to oppose each other with a spark plug 17 attached at substantially the center of the ceiling portion of the combustion chamber 11 as a center. In addition, two openings per cylinder are provided so as to communicate with the combustion chamber 11.

  The intake port 13 is closed by the intake valve 19, and the intake valve 19 is operated and opened by the rotation of the intake camshaft 21. On the other hand, the exhaust port 15 is closed by the exhaust valve 23, and the exhaust valve 23 is operated and opened by the rotation of the exhaust camshaft 25. In other words, each cylinder 27 includes a pair of intake valves 19 and a pair of exhaust valves 23 that are arranged with the position where the spark plug 17 is provided as a boundary. These intake valves 19 are in sliding contact with intake cams 29 provided on the intake camshaft 21, and are opened and closed at a predetermined timing according to the rotation of the intake cams 29 by the rotation of the intake camshaft 21. These exhaust valves 23 are in sliding contact with the exhaust cams 31 provided on the exhaust camshaft 25, and open and close at a predetermined timing according to the rotation of the exhaust cams 31 by the rotation of the exhaust camshaft 25. . In the internal combustion engine 1 in the present embodiment, a timing chain 39 is wound around the crank sprocket 33, the intake side sprocket 35, and the exhaust side sprocket 37, and the rotational driving force provided from the crankshaft 41 by the timing chain 39 is used as the intake side sprocket. The rotational driving force is transmitted to the exhaust camshaft 25 via the exhaust side sprocket 37 while being transmitted to the intake camshaft 21 via the exhaust 35.

  As shown in FIG. 2, the intake camshaft 21 includes a drive-side shaft 43 that receives a rotational driving force from the crankshaft 41, a driven-side shaft 45 that receives a rotational driving force from the drive-side shaft 43, A driven piece 47 that is displaceable along the axial direction relative to the drive side shaft 43 and the driven side shaft 45, and an axis end of the drive side shaft 43 and an axis of the driven piece 47 facing the end of the shaft. The pawl clutch 50 provided across the end portion, the driven side shaft 45 and the driven piece 47 rotate integrally with each other, and the axis line is relative to the drive side shaft 43, the driven side shaft 45 and the driven piece 47. And a sleeve 49 that is displaceable along the direction. The intake camshaft 21 includes a connection state in which the drive side shaft 43 and the driven side shaft 45 are mechanically connected via the driven piece 47 and the sleeve 49, and the drive side shaft 43 and the driven side shaft 45. It can be separated from the mechanically separated state.

  The drive side shaft 43 has an axial shape, and one end side is attached and fixed to the intake side sprocket 35. On the other end side of the drive side shaft 43, a cam surface 51 is provided that forms a pawl clutch 50 for coupling with the driven piece 47. Further, a projection 53 for connecting to the sleeve 49 is provided on the outer peripheral surface of the drive side shaft 43. The protrusion 53 suppresses the rotational operation while allowing the sleeve 49 to move in the axial direction with respect to the drive-side shaft 43. Specifically, the protrusion 53 is closer to one end than the base end portion of the cam surface 51. The key is provided and has a rectangular shape in a cross-sectional view extending in the axial direction of the drive-side shaft 43. The drive side shaft 43 is provided with an intake cam 29a of the first cylinder 27a and an intake cam 29b of the second cylinder 27b.

  The driven side shaft 45 has an axial shape having the same diameter as that of the drive side shaft 43, and one end side is attached to the cylinder head 5 and fixed. A driven piece 47 is disposed on the other end side of the driven shaft 45 via an elastic body. More specifically, the other end side of the driven side shaft 45 receives one end side of the compression coil spring 55 that is the elastic body disposed between the driven side shaft 45 and the driven piece 47. . Further, a projection 57 for connecting to the sleeve 49 is provided on the outer peripheral surface of the driven side shaft 45. The protrusion 57 is for suppressing the rotation operation while allowing the sleeve 49 to move in the axial direction with respect to the driven side shaft 45. Specifically, the protrusion 57 is provided on the other end side of the driven side shaft 45. This is a key having a rectangular shape in a cross-sectional view extending in the axial direction of the driven side shaft 45. The driven shaft 45 is provided with an intake cam 29c of the third cylinder 27c and an intake cam 29c of the fourth cylinder 27c.

  The driven piece 47 rotates integrally with the driven side shaft 45, and is disposed between the drive side shaft 43 and the driven side shaft 45. The driven piece 47 has an axial shape having the same diameter as that of the drive side shaft 43 and the driven side shaft 45, and is disposed inside the sleeve 49 so as to be movable in the axial direction. One end side of the driven piece 47 receives the other end side of the compression coil spring 55. On the other hand, the other end of the driven piece 47 is provided with a cam surface 59 that constitutes a pawl clutch 50 for connection to the drive side shaft 43. Further, a projection 61 for connecting to the sleeve 49 is provided on the outer peripheral surface of the driven piece 47. The protrusion 61 suppresses the rotational movement while allowing the relative movement of the driven piece 47 and the sleeve 49 in the axial direction. Specifically, the protrusion 61 has a rectangular cross-sectional view extending in the axial direction of the driven piece 47. It is a key that makes a shape. A positioning projection 63 is provided on the outer peripheral surface of the driven piece 47 so as not to protrude from the sleeve 49 in the axial direction by a predetermined amount or more. The positioning projection 63 defines a relative position of the driven piece 47 and the sleeve 49 in the axial direction. Specifically, the positioning projection 63 is provided on the opposite side across the projection 61 and the axial center. It protrudes in a direction perpendicular to this axis.

  The pawl clutch 50 is provided across the shaft end of the drive-side shaft 43 and the shaft end of the driven piece 47 facing the shaft end, and the shaft end of the driven piece 47 is connected to the drive-side shaft 43. In this case, the relative angle difference around the axis of the driven piece 47 with respect to the drive-side shaft 43 is eliminated when approaching the shaft end. This claw clutch 50 is called, for example, a spiral claw, and transmits only rotation in a predetermined position direction to the driven shaft 45 side. It can be turned into a rotation.

  The sleeve 49 is provided so as to cover part or all of the outer periphery of the drive side shaft 43, the driven side shaft 45, and the driven piece 47, and a relative angular difference around the axis of the driven piece 47 with respect to the drive side shaft 43. After the key is removed, the drive side shaft 43 is key-coupled, and separated from the drive-side shaft 43 to release the key coupling, thereby interrupting the transmission of the rotational driving force. The sleeve 49 has a cylindrical shape including a space 65 in which the other end side of the drive side shaft 43, the other end side of the driven side shaft 45, and the driven piece 47 can be accommodated. Is disposed on the cylinder head 5 to which one end thereof is attached via an elastic body. More specifically, one end side of the sleeve 49 receives one end side of the compression coil spring 67 that is the elastic body disposed between the sleeve 49 and the cylinder head 5.

  On the inner periphery of the sleeve 49, there is provided a groove 69 in which protrusions 53, 57, 61 provided on the drive side shaft 43, the driven side shaft 45 and the driven piece 47 can be engaged. The groove 69 is a key groove having a rectangular shape in a cross-sectional view extending in the axial direction of the sleeve 49. In addition, a positioning recess 71 capable of engaging with the positioning projection 63 of the driven piece 47 is provided on the inner periphery of the sleeve 49. The positioning recess 71 is in the shape of a long hole extending in the axial direction. The first wall 73 is engaged with one end of the positioning projection 63 of the driven piece 47 and the other end of the positioning projection 63 is engaged. A matching second wall 75.

  Further, as shown in FIGS. 8 and 9, a concave groove 77 is formed on the outer peripheral surface of the sleeve 49. The groove 77 extends along the circumferential direction and gradually displaces in the axial direction as the sleeve 49 rotates. The protrusion protruding from the actuator is engaged with the concave groove 77, so that the sleeve 49 is displaced along the axial direction to the side away from the drive side shaft 43. As shown in FIG. 10, the recessed groove 77 rotates when the driven shaft 45 receives a rotational driving force from the cam nose 28c of the intake cam 29c of the third cylinder 27c assembled to the driven shaft 45. It extends along the direction of the angle over a range of angles between the cam lobe 30d of the intake cam 29d of the fourth cylinder 27d that contacts the intake valve 19 next. The concave groove 77 is provided so as to be inclined with respect to the sleeve 49 from one end side to the base end side. Specifically, the concave groove 77 extends over a range of 225 ° in the circumferential direction and is axial. Is formed over a predetermined distance required to move the sleeve 49. Note that the amount of displacement of the sleeve 49 in the axial direction in the predetermined distance, in other words, in the disconnected state and the connected state, is set larger than the amount of displacement of the driven piece 47 in the axial direction.

  The actuator includes a control rod 79 that is the protrusion that can protrude and retract in the concave groove 77, and includes an engagement position that engages with the concave groove 77 and a non-engagement position that does not engage with the concave groove 77. It can be operated between. In this embodiment, a pull-type solenoid 81 having a plunger that is attracted by energizing an electromagnetic coil and pulled back to its original position by de-energizing is used as an actuator. This plunger functions as the protrusion (control rod 79) of the present invention.

  The exhaust camshaft 25 is arranged in parallel to the intake camshaft 21, and one end side is attached to the exhaust side sprocket 37 and the other end side is attached to the cylinder head 5 and fixed. . The exhaust camshaft 25 is provided with an exhaust cam 31a of the first cylinder 27a, an exhaust cam 31b of the second cylinder 27b, an exhaust cam 31c of the third cylinder 27c, and an exhaust cam 31d of the fourth cylinder 27d. Is the usual one.

  The internal combustion engine 1 includes a cylinder 27, an injector 85 for injecting fuel, an intake system path 87 for supplying intake air to each cylinder 27, and an exhaust system path 89 for exhausting exhaust from each cylinder 27. It comprises.

  The intake system path 87 takes in air from the outside and guides it to the intake port 13 of the cylinder 27. On the intake system path 87, an air cleaner 91, a throttle valve 93, and a surge tank 95 are arranged in this order from the upstream side. Further, there is a bypass passage 97 that bypasses the throttle valve 93, and an idle speed control valve 99 is provided in the bypass passage 97.

  The exhaust system path 89 guides exhaust generated as a result of burning fuel in the cylinder 27 from the exhaust port 15 of the cylinder 27 to the outside. A three-way catalyst 101 is disposed on the exhaust system path 89.

  In the four-cylinder internal combustion engine 1, as shown in FIG. 3, the expansion stroke of the first cylinder 27a and the expansion stroke of the fourth cylinder 27d, and the expansion stroke of the second cylinder 27b and the expansion stroke of the third cylinder 27c are respectively performed. Visited at equal intervals with a phase difference of 360 ° CA (crank angle), the piston 7 of the first cylinder 27a and the piston 7 of the fourth cylinder 27d, and the piston 7 of the second cylinder 27b and the piston 7 of the third cylinder 27c And move forward and backward completely in sync.

  As shown in FIG. 4, the ECU 103, which is a control unit that controls the internal combustion engine 1, is a microcomputer system having a processor 105, a memory 107, an input interface 109, an output interface 111, and the like.

The input interface 109 includes an intake pressure signal a output from the intake pressure sensor 113 for detecting the pressure in the surge tank 95, that is, an intake pipe pressure, an intake air temperature signal b output from the intake air temperature sensor 115, and the internal combustion engine 1. The water temperature signal c output from the water temperature sensor 117 for detecting the cooling water temperature of the water, the current signal d output from the O ₂ sensor 119, and the throttle position sensor 121 for detecting the open / closed state of the throttle valve 93. The throttle opening signal e, the engine speed signal f output from the crank angle sensor 123 for detecting the engine speed, and the cam angle signal g output from the cam angle sensor 125 for detecting the compression top dead center of the cylinder 27 Etc. are input.

  The crank angle sensor 123 and the cam angle sensor 125 will be supplemented. The crank angle sensor 123 outputs a rotation speed signal at intervals of 10 ° CA, for example. Specifically, external teeth are provided on the outer periphery of a rotating body fixed to the shaft end of the crankshaft 41, and an electromagnetic pickup is installed so as to face the external teeth. It arrange | positions intermittently at intervals of 10 degree CA along. When the external teeth pass in the vicinity of the electromagnetic pickup as the crankshaft 41 rotates, the electromagnetic pickup outputs a pulse signal that becomes the engine speed signal f. The engine speed can be calculated from the interval between the pulse signals. Incidentally, the crank angle sensor 123 is configured to output no signal at a predetermined timing. This is because a part of the outer teeth of the rotating body is missing. Therefore, it is also possible to detect the current rotation angle of the crankshaft 41 with reference to the missing position.

  The cam angle sensor 125 is disposed in the vicinity of the intake camshaft 21 and outputs a cam angle signal g which is a pulse signal corresponding to the compression top dead center of each cylinder 27, for example. Specifically, a projection is provided from a rotating body fixed to the shaft end of the intake camshaft 21, and is disposed so as to pass through the vicinity of the electromagnetic pickup so as to face the projection. When the projection passes near the electromagnetic pickup as the intake camshaft 21 rotates, the electromagnetic pickup outputs a pulse signal that becomes the cam angle signal g. (In this embodiment, a pulse signal is output at the timing of the compression top dead center of the first cylinder 27a, and then the second cylinder 27b and the second cylinder visited at intervals of 180 ° CA, 360 ° CA, and 540 ° CA, respectively. The pulse signal is output again at the timing of the compression top dead center of the fourth cylinder 27d and the third cylinder 27c, and after the timing of the compression top dead center of the third cylinder 27c, the compression top dead center of the first cylinder 27a is again output. The phase difference until the timing comes is 180 ° CA.

  From the output interface 111, the fuel injection signal h is output to the injector 85, the ignition signal i is output to the spark plug 17, the opening operation signal j of the idle speed control valve 99, the sleeve operation signal k to the solenoid 81, and the like. To do.

  The processor 105 interprets and executes a program stored in advance in the memory 107 to control the operation of the internal combustion engine 1. The processor 105 acquires various information necessary for operation control of the internal combustion engine 1 via the input interface 109, and calculates a fuel injection timing, an ignition timing, and the like based on the information. Then, various control signals corresponding to the calculation result are applied to the injector 85 and the spark plug 17 via the output interface 111.

  Next, the operation between the disconnected state and the connected state of the intake camshaft 21 will be described.

  First, at the time of high load operation or the like, as shown in FIGS. 5 and 8, the intake camshaft 21 is kept in a connected state. That is, by energizing the solenoid 81 and causing the plunger, which is the control rod 79, to be attracted to the solenoid 81 main body side, the engagement between the control rod 79 and the concave groove 77 of the sleeve 49 is released. In this state, the compression state of the compression coil spring 67 disposed between the cylinder head 5 and the sleeve 49 is released and repels, and the compression coil disposed between the driven shaft 45 and the driven piece 47. The compressed state of the spring 55 is released and repels. Thus, the drive-side shaft 43 and the driven-side shaft 45 of the intake camshaft 21 are connected via the sleeve 49 and the driven piece 47 urged by the compression coil springs 67 and 55.

  When it is desired to improve the fuel consumption by executing the cylinder deactivation system during low load operation or the like from this connected state, the intake camshaft 21 is disconnected. In other words, the driven side shaft 45 to which the intake cam 29c of the third cylinder 27c and the intake cam 29d of the fourth cylinder 27d are attached, and the drive side to which the intake cam 29a of the first cylinder 27a and the intake cam 29b of the second cylinder 27b are attached. By disconnecting the connection state with the shaft 43, the operation of the intake cam 29c of the third cylinder 27c and the intake cam 29d of the fourth cylinder 27d is stopped, and the intake valve 19 of the third cylinder 27c and the intake valve of the fourth cylinder 27d are stopped. The operation of 19 is temporarily stopped. Specifically, the solenoid 81 is de-energized to release the suction state of the plunger, which is the control rod 79, thereby engaging the control rod 79 with the concave groove 77 of the sleeve 49. The control rod 79 engaged on one end side of the concave groove 77 moves relative to the other end side along the concave groove 77. As shown in FIGS. Move to the cylinder head 5 side. At that time, the compression coil spring 67 disposed between the cylinder head 5 and the sleeve 49 contracts against the urging force. Further, since the driven piece 47 is moved to the driven side shaft 45 side, the compression coil spring 55 disposed between the driven side shaft 45 and the driven piece 47 is contracted against the urging force. As described above, the driven piece 47 and the drive side shaft 43 are disengaged as the sleeve 49 is pulled out from the drive side shaft 43 by the control rod 79 which is a moving means.

  When it is desired to stop the cylinder deactivation system from this disconnected state during a high load operation or the like, the intake camshaft 21 is brought into a connected state. In other words, the driven side shaft 45 to which the intake cam 29c of the third cylinder 27c and the intake cam 29d of the fourth cylinder 27d are attached, and the drive side to which the intake cam 29a of the first cylinder 27a and the intake cam 29b of the second cylinder 27b are attached. By connecting the shaft 43, all the intake cams 29a, 29b, 29c, 29d of the first to fourth cylinders 27a, 27b, 27c, 27d are operated, and the first to fourth cylinders 27a, 27b, 27c are operated. , 27d are operated. Specifically, the solenoid 81 is energized and the plunger, which is the control rod 79, is attracted, whereby the engagement between the control rod 79 and the concave groove 77 of the sleeve 49 is disengaged. Then, the sleeve 49 moves away from the cylinder head 5 due to the repulsive force of the compression coil spring 67 disposed between the cylinder head 5 and the sleeve 49 and is disposed between the driven side shaft 45 and the driven piece 47. The driven piece 47 moves in a direction away from the driven shaft 45 by the repulsive force of the compressed coil spring 55. At this time, the driven piece 47 is moved to the drive side shaft 43 side while the positioning projection 63 hits the first wall portion 73. Then, as shown in FIG. 7, after the claw clutch 50 formed across the drive side shaft 43 and the driven piece 47 is connected and the phases of the drive side shaft 43 and the driven piece 47 are matched, as shown in FIG. 5. Further, the projection 53 of the drive side shaft 43 is engaged with the groove 69 of the driven piece 47. In this way, after the phases of the shafts to be coupled are matched, the coupling operation of the projection 53 and the groove 69 that disables the rotational movement with respect to the sleeve 49 is performed, so that the drive side shaft 43 and the driven side shaft 45 Can be connected smoothly. Then, after the protrusion 53 of the drive side shaft 43 is engaged with the groove 69 of the driven piece 47, the driving force of the drive side shaft 43 is transmitted to the driven side shaft 45 via the sleeve 49. The driven side shaft 45 rotates in synchronization. That is, power transmission in the positive direction from the drive side shaft 43 to the driven side shaft 45 is performed mainly via the sleeve 49, and a part of the claw clutch provided straddling the drive side shaft 43 and the driven piece 47. 50.

  Thus, the ECU 103, which is the control device of the present embodiment, detects the operating state, and when it is desired to activate / deactivate the cylinder deactivation system, the ECU 103 sleeves the solenoid 81 so that the intake camshaft 21 is disconnected / connected. An operation signal k is applied.

  In the four-cylinder internal combustion engine 1 that explodes in the order of the first, second, fourth, and third cylinders, the third and fourth cylinders 27c, 27d are used when the intake camshaft 21 is disconnected from the connected state. The sleeve 49 is moved when no driving force is required for the intake valve 19. Specifically, as shown in FIG. 3, control is performed so that the control rod 79 of the solenoid 81 starts to engage with the concave groove 77 of the sleeve 49 during the intake stroke of the third cylinder 27 c. At that time, in the third cylinder 27c, the piston 7 is positioned at an intermediate point where the piston 7 moves from the top dead center to the bottom dead center, and the intake valve 19 is fully opened. The resulting valve spring is compressed. On the other hand, in the fourth cylinder 27d, the piston 7 is located at an intermediate point where the piston 7 moves from the bottom dead center to the top dead center, and the intake valve 19 is closed. If the control rod 79 is protruded for a certain time from this state, the fixed control rod 79 is guided in the concave groove 77, and the sleeve 49 moves to the driven shaft 45 side. At this time, as shown in FIG. 10, since the concave groove 77 of the sleeve 49 is formed over 225 ° in the circumferential direction, the sleeve 49 is fixed when moved by 450 ° CA as shown in FIG. The

  On the other hand, when the intake camshaft 21 is switched from the disconnected state to the connected state, the engagement between the control rod 79 of the solenoid 81 and the concave groove 77 of the sleeve 49 is released in any operating state of each cylinder 27. Thus, the control rod 79 may be immersed.

  As described above, the internal combustion engine 1 of the present embodiment is in a state in which the whole is rotated to drive the intake valves 19 of all the cylinders 27, and a part of the internal combustion engine 1 is disconnected and the part does not rotate and is associated with the part. Provided with an intake camshaft 21 that can be switched between a state in which the intake valve 19 of the cylinder 27 is not driven, and the intake camshaft 21 receives a rotational driving force from a crankshaft 41. 43, a driven-side shaft 45 that receives transmission of rotational driving force from the drive-side shaft 43, and rotates integrally with the driven-side shaft 45, and relatively to the drive-side shaft 43 and the driven-side shaft 45. A driven piece 47 that is displaceable along the axial direction, the shaft end of the drive side shaft 43 and the shaft end It is provided across the shaft end portion of the driven piece 47 facing each other. The claw clutch 50 that eliminates the relative angular difference, and the driven side shaft 45 and the driven piece 47 rotate integrally with each other, and the drive side shaft 43, the driven side shaft 45 and the driven piece 47 are relative to each other. Can be displaced along the axial direction, and after the relative angular difference between the driven piece 47 and the drive-side shaft 43 is eliminated, the drive-side shaft 43 is key-coupled and separated from the drive-side shaft 43. Then, the transmission of rotational driving force is cut off by canceling the key combination. Since it comprises a sleeve 49 which can Rukoto, the intake camshaft 21 and the intake cam 29 corresponding to the cylinder 27 to pause can be stopped completely. That is, since the intake camshaft 21 connected to the intake valve 19 to be paused can be partially disconnected, the sliding resistance between the cam and the camshaft during the reduced cylinder operation is reduced compared to the conventional one, It is possible to improve fuel efficiency by stopping the combustion cycle of some cylinders 27 in a situation where the torque required for traveling is small. In the present embodiment, such a cylinder deactivation system does not operate when the operation pattern becomes uneven, such as during high-load operation where the accelerator pedal is depressed or when passing through an intersection. When a high load operation or a non-uniform operation is detected while the cylinder deactivation system is operating, the intake valves 19 of the deactivated third and FIG. 4 cylinders 27c and 27d start to move.

  In particular, in this embodiment, when the driven piece 47 and the sleeve 49 are shifted from the disconnected state from the drive-side shaft 43 to the connected state, the drive is performed after the pawl clutch 50 that is an engaging portion for phase alignment is engaged. The protrusion 53 of the side shaft 43 and the groove 69 of the sleeve 49 are engaged, so that the drive side shaft 43 and the driven side shaft 45 are completely connected. This is because when the intake valve 19 of the third cylinder 27c moves in the closing direction at the time of connection, the intake cam 29c of the third cylinder 27c receives driving force from the valve springs of these intake valves 19, and the driven side shaft 45 moves in the reverse direction. This is to prevent the occurrence of a problem that the driven portion 47 and the drive-side shaft 43 are separated from each other by being driven by each other.

  In the present embodiment, the intake camshaft 21 is configured so as to be disconnected and connected, and the exhaust camshaft 25 has a normal configuration, and is thus stopped during the reduced-cylinder operation. It is possible to prevent the unburned gas from being accumulated in the cylinders of the third and fourth cylinders 27c and 27d.

  Further, a concave groove 77 that can be engaged with the control rod 79 is provided on the outer periphery of the sleeve 49, and the control rod 79 and the concave groove 77 of the sleeve 49 are engaged with each other from the connected state. Since the transition is made to the disconnected state, the connection state and the disconnected state of the intake camshaft 21 can be switched with a relatively simple structure.

  In particular, in the present embodiment, since the concave groove 77 provided in the sleeve 49 is formed over 225 ° in the circumferential direction, it is difficult for the control rod 79 to be burdened. That is, in the four-cylinder internal combustion engine 1 that explodes in the order of the first, second, fourth, and third cylinders, the intake valves 19 of the third and fourth cylinders 27c and 27d that are separated need to have driving force. The exhaust stroke of the fourth cylinder starts from the time when there is not, specifically, from the lower side of the intake cam 29c of the third cylinder 27c to the upper side of the fourth cylinder 27d, in other words, from the middle of the intake stroke of the third cylinder 27c. A concave groove 77 is formed so as to correspond to immediately before. That is, the concave groove 77 provided in the sleeve 49 is the fourth intake cam 29d next to the driven shaft 45 from a position corresponding to the top of the cam lobe 30c (cam nose 28c) of the third intake cam 29c of the driven shaft 45. The cam lobe 30d is provided up to a position corresponding to the bottom of the cam lobe 30d. Therefore, the concave groove 77 can be set in a range in which a load is not easily applied to the control rod 79, and durability can be improved. Further, since the sleeve 49 is moved by using the control rod 79 and the intake cam 29 to rotate, the cylinder deactivation system can be realized with a simple mechanism. The concave groove 77 provided in the sleeve 49 may be smaller than 225 ° in the circumferential direction. However, by increasing the overall length of the concave groove 77 as much as possible, the degree of inclination of the concave groove 77 is increased. The control rod 79 can be loosened, and the load can hardly be applied.

  The present invention is not limited to the above embodiment.

  The internal combustion engine of the present invention may be anything as long as it can employ a cylinder deactivation system, and is not limited to the inline four-cylinder described above.

  The camshaft of the present invention is not limited to that applied to the intake camshaft described above, and may be applied to an exhaust camshaft.

  Further, the pawl clutch may be any clutch as long as the phases of the drive-side shaft and the driven piece can be matched, and is not limited to the above-described mode.

  The control rod may be anything as long as it can project and retract with an electric or hydraulic actuator, and is not limited to a solenoid plunger. Further, the moving means of the sleeve is not limited to the control rod and the groove, and the sleeve without the groove may be moved by an actuator such as a solenoid.

  The protrusion provided on the drive side shaft, the driven side shaft, and the driven piece and engaging with the groove provided on the inner periphery of the sleeve is not limited to the above-described aspect. For example, a groove may be provided on the drive side shaft, driven side shaft, and driven piece side, and a protrusion may be provided on the inner periphery of the sleeve. It is also possible to adopt a spline that has been cut out. If this is the case, the shaft (drive side shaft, driven side shaft and driven piece) and the boss (sleeve) can be moved relative to each other in the axial direction, and more than the engagement between one groove and the projection. The transmission torque can be increased.

  The sleeve may be any sleeve as long as it can connect the drive side shaft, the driven side shaft and the driven piece in a non-rotatable state in the connected state, and the drive side shaft and the driven side as described above. It is not limited to the cylindrical shape that covers the shaft and the driven piece from the outer periphery, but the drive side shaft, the driven side shaft and the channel shape that connects the driven piece from the side, the drive side shaft, the driven side shaft, and the driven piece. It may be in the form of a block connected inside (end faces to be connected).

  The concave groove is a third cylinder that comes into contact with the intake valve next to the cam nose of the intake cam of the fourth cylinder assembled to the driven shaft along the direction in which the driven shaft receives the rotational driving force and rotates. It may extend over a range of angles between the cam lobes of the cylinder intake cams, specifically, a range of 45 °.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  The present invention can be applied to an internal combustion engine mounted on a vehicle or the like.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 28 ... Cam nose 30 ... Cam lobe 41 ... Crankshaft 43 ... Drive side shaft 45 ... Driven side shaft 47 ... Driven piece 49 ... Sleeve 50 ... Claw clutch 77 ... Concave groove 79 ... Control rod (protrusion)

Claims (2)

A cam that can switch between a state in which the whole rotates to drive the valves of all cylinders and a state in which some of the cylinders are disconnected and the parts do not rotate and engage the valves of some of the cylinders An internal combustion engine comprising a shaft,
The camshaft is
A drive-side shaft that receives the rotational driving force from the crankshaft;
A driven shaft that receives a rotational driving force from the drive shaft;
A driven piece that rotates integrally with the driven side shaft and that is displaceable along the axial direction relative to the drive side shaft and the driven side shaft;
Provided across the shaft end of the drive-side shaft and the shaft end of the driven piece facing the shaft end, and engaged when the shaft end of the driven piece approaches the shaft end of the drive-side shaft. A claw clutch that eliminates the relative angular difference around the axis with respect to the drive side shaft of the driven piece;
The driven side shaft and the driven piece rotate integrally with each other and can be displaced along the axial direction relative to the drive side shaft, the driven side shaft and the driven piece, and the axis of the driven piece with respect to the drive side shaft After eliminating the relative angular difference of the surroundings, key coupling or spline coupling to the drive side shaft is performed, and transmission of rotational driving force is cut off by separating the key coupling or spline coupling away from the drive side shaft. An internal combustion engine comprising a sleeve capable of The outer circumferential surface of the sleeve is formed with a groove that extends along the circumferential direction and gradually displaces in the axial direction as the sleeve rotates.
The protrusion protruding from the actuator is engaged with the concave groove so that the sleeve is displaced along the axial direction to the side away from the drive side shaft,
The concave groove extends from the cam nose of a cam assembled to the driven shaft to the hem of the cam lobe that contacts the valve next along the direction in which the driven shaft rotates by receiving the rotational driving force. The internal combustion engine according to claim 1, wherein the internal combustion engine extends over a range of angles.

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