JP6314931B2 - Engine valve gear - Google Patents

Description

  The present invention relates to a valve operating device for an engine of a vehicle or the like, and relates to a valve operating device capable of changing the lift characteristics of intake and exhaust valves.

  Conventionally, an EGR (Exhaust Gas Recirculation) technique for recirculating a part of exhaust gas to intake air is known for the purpose of reducing nitrogen oxide (NOx) in exhaust gas and improving fuel efficiency at partial load. For example, in Patent Document 1, as a technique of so-called internal EGR, a main lift part and a sub lift part are provided in an exhaust cam, and after the exhaust valve is opened by the main lift part, exhaust is performed by the sub lift while the intake valve is opened. A technology that opens a small amount of the valve to recirculate a part of the exhaust gas to the combustion chamber, and a main lift and sub-lift in the intake cam are provided, and before the intake valve is opened by the main lift, A technique is disclosed in which a minute amount of an intake valve is opened by a sub-lift portion during valve opening, and combustion gas in a combustion chamber is mixed with intake air in advance.

JP 2007-127041 A

  In recent years, research and commercialization of HCCI (Homogeneous Charge Compression Ignition) combustion as a gasoline engine combustion system have been advanced in order to achieve more advanced reduction of nitrogen oxides and improvement of fuel efficiency. The generation conditions of HCCI combustion (hereinafter referred to as CI combustion) are very strict, and it is very difficult to realize CI combustion in all operating regions. Therefore, at present, the combustion method is switched between SI combustion (Spark Ignition) by spark ignition and CI combustion in accordance with the operation region. As one means for expanding the operating range in which CI combustion is possible, it is considered effective to improve the combustion stability by increasing the degree of freedom of the internal EGR amount. That is, it is effective to increase the degree of freedom of the cam characteristics (the intake / exhaust valve lift characteristics). In this regard, although the technique of Patent Document 1 described above can implement the internal EGR, the amount thereof is almost constant, and the degree of freedom of the internal EGR amount cannot be increased. In order to solve such a problem, it is conceivable to provide a valve operating device capable of changing the cam characteristics linearly. However, this involves a significant cost increase and is not a good solution.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique capable of increasing the degree of freedom of the internal EGR amount while suppressing an increase in cost.

  In order to solve the above problem, an engine valve operating apparatus according to one aspect of the present invention is an engine valve operating apparatus having first and second exhaust valves and an intake valve in one cylinder, A shaft portion that receives the rotational force from the crankshaft, and first and second exhaust cam portions that are rotatably attached to the shaft portion so as to be integrated with the shaft portion and respectively correspond to the first and second exhaust valves. An operating state that is interposed between the exhaust-side camshaft provided, the first exhaust cam portion, and the first exhaust valve, and that transmits the pressing force accompanying the rotation of the first exhaust cam portion to the first exhaust valve, and the first exhaust A first exhaust-side variable valve lift mechanism that is switched to a stop state that interrupts transmission of the pressing force to the valve, and a second exhaust cam portion that is interposed between the second exhaust cam portion and the second exhaust valve. The operating state in which the pressing force accompanying the rotation is transmitted to the second exhaust valve and the pressing force to the second exhaust valve A second exhaust-side variable valve lift mechanism that is switched to a stop state that shuts off the first exhaust, and a control device that controls the first exhaust-side variable valve lift mechanism and the second exhaust-side variable valve lift mechanism, Each of the second exhaust cam portions includes a main lift portion that opens the exhaust valve during the exhaust stroke, and a sub-lift portion that opens the exhaust valve during the intake stroke, in addition to the valve opening by the main lift portion. The first and second exhaust-side variable valve lift mechanisms are activated, or only one of them is activated, depending on the operating region. Are controlled individually.

  According to this valve operating apparatus, when both the first and second exhaust-side variable valve lift mechanisms are in operation, both the first and second exhaust valves are opened during the intake stroke and exhaust (exhaust gas). Is returned to the combustion chamber. On the other hand, when only one of the first and second exhaust side variable valve lift mechanisms is in operation, only one of the first and second exhaust valves is opened during the intake stroke, and the exhaust gas is recirculated. . Therefore, the degree of freedom of the internal EGR amount can be increased as compared with this type of conventional valve gear in which the internal EGR amount is constant. In addition, the first and second exhaust-side variable valve lift mechanisms have a relatively simple configuration that is simply switched between a state in which the pressing force of each exhaust cam portion is transmitted to the first and second exhaust valves and a state in which they are shut off. Therefore, according to this valve gear, it is possible to increase the degree of freedom of the internal EGR amount while suppressing an increase in cost.

In this valve operating apparatus, the main lift portions of the first and second exhaust cam portions may have the same cam characteristics, and the sub lift portions may have different cam characteristics.

  According to this configuration, since the internal EGR amount when only the first exhaust-side variable valve lift mechanism is in operation is different from the internal EGR amount when only the second exhaust-side variable valve lift mechanism is in operation, the internal EGR amount is different. It becomes possible to increase the degree of freedom of quantity.

  In the valve operating apparatus, the engine includes first and second intake valves that are the intake valves. The valve operating apparatus further includes a shaft portion that receives a rotational force from a crankshaft, and the shaft. And an intake side camshaft having a first intake cam portion corresponding to the first intake valve and a second intake cam portion corresponding to the second intake valve. And an operating state that is interposed between the first intake cam portion and the first intake valve and transmits the pressing force accompanying the rotation of the first intake cam portion to the first intake valve, and the pressing force to the first intake valve A first intake side variable valve lift mechanism that switches to a stop state that interrupts transmission of the engine, and a second intake cam portion that is interposed between the second intake cam portion and the second intake cam portion. 2 Cut off the transmission state to the intake valve and the transmission of the pressing force to the second intake valve A second intake-side variable valve lift mechanism that switches to a stopped state, and the control device further includes either the first or second intake-side variable valve lift mechanism in an operating state or only one of them. The first and second intake side variable valve lift mechanisms may be individually controlled in accordance with the operation region so as to be in the operating state.

  According to this configuration, when both the first and second intake-side variable valve lift mechanisms are in operation, both the first and second intake valves are opened to perform intake, and only one of them is In the operating state, only one of the first and second intake valves is opened and intake is performed. That is, the amount of intake air varies depending on the state of the first and second intake side variable valve lift mechanisms, so that the internal EGR amount relatively changes. For this reason, it is possible to further increase the degree of freedom of the internal EGR amount. In this case as well, the first and second intake-side variable valve lift mechanisms are relatively simple by simply switching between the state in which the pressing force by each intake cam portion is transmitted to the first and second intake valves and the state in which it is shut off. Therefore, the degree of freedom of the internal EGR amount can be increased while suppressing an increase in cost.

  In this case, the first and second intake cam portions may have different cam characteristics.

  According to this configuration, there is a difference between the intake amount when only the first intake side variable valve lift mechanism is in operation and the intake amount when only the second intake side variable valve lift mechanism is in operation. it can. That is, it is possible to make a difference in the substantial internal EGR amount. For this reason, it is possible to further increase the degree of freedom of the internal EGR amount.

  In the valve operating apparatus described above, the engine may be a gasoline engine whose combustion method is switched between CI combustion by self-ignition of fuel and SI combustion by spark ignition of a spark plug. In this case, the first and second exhaust cam portions are first and second CI exhaust cam portions for CI combustion, respectively, and the exhaust camshaft is mounted on the shaft portion so as to be movable in the axial direction. And a cam element having first and second CI exhaust cam portions and first and second SI exhaust cam portions for SI combustion respectively adjacent to the first and second CI exhaust cam portions, In the valve operating apparatus, the SI arrangement corresponding to the first and second exhaust valves respectively corresponds to the first and second exhaust valves, and the first and second CI exhaust cam portions correspond to the first and second exhaust valves, respectively. An exhaust-side cam shift mechanism that switches the arrangement of the cam element portion to a CI arrangement that performs the control, and the control device further controls the exhaust-side cam shift mechanism to switch the arrangement of the cam element portion according to the operating region. Composed.

  In this case, the first and second intake cam portions are provided, and the first and second intake cam portions are first and second CI intake cam portions for CI combustion, respectively. The side camshaft is mounted on the shaft portion so as to be movable in the axial direction, and is adjacent to the first and second CI intake cam portions and the first and second CI intake cam portions, respectively. A valve element having a second SI intake cam portion, and the valve operating device includes an SI arrangement in which the first and second SI intake cam portions correspond to the first and second intake valves, respectively, The second intake valve includes an intake side cam shift mechanism that switches the arrangement of the cam element portion to the CI arrangement corresponding to the first and second CI intake cam portions, respectively, and the control device further controls the intake side cam shift mechanism. Depending on the operation area, Obtain configured as described above.

  According to these configurations, in an engine in which the combustion method is switched between SI combustion and CI combustion according to the operating region, it is possible to increase the degree of freedom of the internal EGR amount particularly during CI combustion.

  On the other hand, an engine valve operating apparatus according to another aspect of the present invention is an engine valve operating apparatus having an exhaust valve and first and second intake valves in one cylinder, and rotating from a crankshaft. An intake side cam comprising a shaft portion for receiving a force, and first and second intake cam portions mounted on the shaft portion so as to be rotatable integrally with the shaft portion and corresponding to the first and second intake valves, respectively. An operating state that is interposed between the shaft, the first intake cam portion, and the first intake valve and transmits the pressing force accompanying the rotation of the first intake cam portion to the first intake valve, and the push to the first intake valve. The first intake-side variable valve lift mechanism that is switched to a stop state that interrupts the transmission of pressure, and a pressing force that is interposed between the second intake cam portion and the second intake valve and that accompanies the rotation of the second intake cam portion The operation state for transmitting the pressure to the second intake valve and the stop for interrupting the transmission of the pressing force to the second intake valve And a control device for controlling the first intake side variable valve lift mechanism and the second intake side variable valve lift mechanism, the first and second intake cam portions. Each includes a main lift portion that opens the intake valve during the intake stroke and a sub-lift portion that opens the intake valve during the exhaust stroke separately from the valve opening by the main lift portion, and the control device includes: The first and second intake-side variable valve lift mechanisms are individually controlled in accordance with the operation region so that either of the second intake-side variable valve lift mechanisms is in an operating state or only one of them is in an operating state. Is.

  According to this valve operating apparatus, when both the first and second intake side variable valve lift mechanisms are in an operating state, both the first and second intake valves are opened during the exhaust stroke, and the combustion gas is taken into the intake air. Mixed (refluxed). On the other hand, when only one of the first and second intake side variable valve lift mechanisms is in operation, only one of the first and second intake valves is opened during the exhaust stroke, and the combustion gas recirculates to the intake air. Is done. Therefore, the degree of freedom of the internal EGR amount can be increased as compared with this type of conventional valve gear in which the internal EGR amount is constant. In addition, the first and second intake-side variable valve lift mechanisms have a relatively simple configuration in which the pressing force by each intake cam portion is switched between a state in which the pressing force is transmitted to the first and second intake valves and a state in which it is shut off. Therefore, according to this valve gear, it is possible to increase the degree of freedom of the internal EGR amount while suppressing an increase in cost.

In this valve operating apparatus, the main lift portions of the first and second intake cam portions may have the same cam characteristics, and the sub lift portions may have different cam characteristics.

  According to this configuration, the internal EGR amount when only the first intake-side variable valve lift mechanism is in operation is different from the internal EGR amount when only the second intake-side variable valve lift mechanism is in operation. It becomes possible to further increase the degree of freedom of the EGR amount.

  In the valve operating apparatus, the engine includes first and second exhaust valves that are the exhaust valves. The valve operating apparatus further includes a shaft portion that receives a rotational force from a crankshaft, and the shaft. An exhaust side camshaft having a first exhaust cam portion corresponding to the first exhaust valve and a second exhaust cam portion corresponding to the second exhaust valve mounted on the portion so as to be rotatable integrally with the shaft portion Between the first exhaust cam portion and the first exhaust valve, an operating state in which a pressing force accompanying the rotation of the first exhaust cam portion is transmitted to the first exhaust valve, and the pressing force to the first exhaust valve The first exhaust-side variable valve lift mechanism that switches to a stopped state that interrupts the transmission of the exhaust gas, and the second exhaust cam portion and the second exhaust valve are interposed between the first exhaust side variable valve lift mechanism and the second exhaust cam portion. 2 Cut off the transmission state to the exhaust valve and the transmission of the pressing force to the second exhaust valve. A second exhaust-side variable valve lift mechanism that switches to a stopped state, and the control device further includes either the first or second exhaust-side variable valve lift mechanism in an operating state or only one of them. The first and second exhaust side variable valve lift mechanisms may be individually controlled in accordance with the operation region so as to be in the operating state.

  According to this configuration, when both the first and second exhaust-side variable valve lift mechanisms are in operation, both the first and second exhaust valves are opened to perform exhaust, and only one of them is In the operating state, only one of the first and second exhaust valves is opened to perform exhaust. That is, the amount of exhaust varies depending on the state of the first and second exhaust side variable valve lift mechanisms, so that the amount of internal EGR mixed (refluxed) with intake air changes. For this reason, it is possible to further increase the degree of freedom of the internal EGR amount. In this case as well, the first and second exhaust-side variable valve lift mechanisms are relatively simple by simply switching between the state in which the pressing force by each exhaust cam portion is transmitted to the first and second exhaust valves and the state in which it is shut off. Therefore, the degree of freedom of the internal EGR amount can be increased while suppressing an increase in cost.

  In this case, the first and second exhaust cam portions may have different cam characteristics.

  According to this configuration, it is possible to cause a difference between the exhaust amount when only the first exhaust side variable valve lift mechanism is in operation and the exhaust amount when only the second exhaust side variable valve lift mechanism is in operation. it can. That is, it is possible to make a difference in the substantial internal EGR amount. For this reason, it is possible to further increase the degree of freedom of the internal EGR amount.

  In the valve operating apparatus described above, the engine may be a gasoline engine whose combustion method is switched between CI combustion by self-ignition of fuel and SI combustion by spark ignition of a spark plug. In this case, the first and second intake cam portions are first and second CI intake cam portions for CI combustion, respectively, and the intake camshaft is mounted on the shaft portion so as to be movable in the axial direction. And a cam element portion having first and second CI intake cam portions and first and second SI intake cam portions for SI combustion respectively adjacent to the first and second CI intake cam portions, In the valve operating apparatus, the SI arrangement corresponding to the first and second SI intake valves respectively corresponds to the first and second intake valves, and the first and second CI intake cam portions correspond to the first and second intake valves, respectively. An intake-side cam shift mechanism that switches the arrangement of the cam element portion to the CI arrangement to be performed, and the control device further controls the intake-side cam shift mechanism and switches the arrangement of the cam element portion according to the operation region. Composed.

  In this case, the first and second exhaust cam portions are provided, and the first and second exhaust cam portions are first and second CI exhaust cam portions for CI combustion, respectively. The side camshaft is mounted on the shaft portion so as to be movable in the axial direction, and is adjacent to the first and second CI exhaust cam portions and the first and second CI exhaust cam portions, respectively. A valve element having a second SI exhaust cam portion, and the valve operating apparatus includes an SI arrangement corresponding to the first and second SI exhaust valves respectively corresponding to the first and second exhaust valves, The second exhaust valve is provided with an exhaust side cam shift mechanism for displacing the cam element portion to the CI arrangement corresponding to the first and second CI exhaust cam portions, and the control device further controls the exhaust side cam shift mechanism. , Switching the arrangement of the cam element portion according to the operation region Sea urchin made.

  According to these configurations, in an engine in which the combustion method is switched between SI combustion and CI combustion according to the operating region, it is possible to increase the degree of freedom of the internal EGR amount particularly during CI combustion.

  As described above, according to the valve operating apparatus for an engine of the present invention, the degree of freedom of the internal EGR amount can be increased while suppressing an increase in cost.

It is sectional drawing which shows schematic structure of the gasoline engine to which this invention is applied. 1 is a side view showing a schematic configuration of a valve gear (exhaust valve gear) according to the present invention (state of CI arrangement). FIG. It is sectional drawing (A arrow line view of FIG. 2) of a valve operating apparatus. It is a principal part longitudinal cross-sectional view of a cam shaft. It is a side view which shows schematic structure of a valve operating apparatus (state of SI arrangement | positioning). It is a side view of the cam element part (first cam element part) on the exhaust side. It is a front view of a cam element part (1st cam element part). It is a plane schematic diagram which shows a 1st cylinder and its intake / exhaust valve. It is a side view of a cam element part (first cam element part) on the intake side. (A) is a front view of a cam element portion (first cam element portion) on the intake side, and (b) is a cross-sectional view showing a second operating portion of the cam element portion (a line XX in FIG. 9). FIG. It is sectional drawing of the valve operating apparatus by the side of an exhaust, (a) shows the stop state of a 1st swing arm, (b) shows the operating state of a 1st swing arm. It is a related figure which shows the relationship between a combustion system and the state of each swing arm. (A) is a characteristic diagram showing lift characteristics (exhaust side cam characteristics) of the first and second exhaust valves during SI combustion, and (b) is the first and second exhaust valves during CI combustion. It is a characteristic diagram which shows the lift characteristic. (A) is a characteristic diagram showing the lift characteristics (intake-side cam characteristics) of the first and second intake valves during SI combustion, and (b) is the lift characteristics of the first intake valve during CI combustion. (C) is a characteristic diagram showing the lift characteristic of the second intake valve during CI combustion. (A) is a characteristic line figure which shows the lift characteristic of the 1st intake / exhaust valve at the time of SI combustion, (b) is a characteristic line figure which shows the lift characteristic of the 2nd intake / exhaust valve at the time of SI combustion. (A)-(c) is a characteristic diagram which shows the lift characteristic of the 1st, 2nd intake / exhaust valve at the time of CI combustion (1st control pattern). (A)-(c) is a characteristic diagram which shows the lift characteristic of the 1st, 2nd intake / exhaust valve at the time of CI combustion (2nd control pattern). (A)-(c) is a characteristic diagram which shows the lift characteristic of the 1st, 2nd intake / exhaust valve at the time of CI combustion (3rd control pattern). (A)-(c) is a characteristic line figure which shows the lift characteristic of the 1st, 2nd intake / exhaust valve at the time of CI combustion of the valve operating apparatus which concerns on a modification.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[Schematic configuration of the engine]
FIG. 1 shows a multi-cylinder engine 1 (hereinafter simply referred to as an engine 1) to which a valve gear according to the present invention is applied. The engine 1 is mounted on a vehicle such as an automobile, and an in-line four-cylinder four-valve type in which first to fourth cylinders C1 to C4 are sequentially arranged in a direction perpendicular to the paper surface of FIG. It is a gasoline engine. Note that the valve gear according to the present invention is applicable to other multi-cylinder gasoline engines.

  The engine 1 includes a cam cap, a cylinder head 2, a cylinder block 3, a crankcase, and an oil pan that are connected vertically. In the figure, only the cylinder head 2 and the cylinder block 3 are shown.

  Four cylinder bores 4 are formed in the cylinder block 3, and pistons 5 are slidably accommodated in the respective cylinder bores 4. A combustion chamber 6 is formed for each cylinder by the piston 5, the cylinder bore 4 and the cylinder head 2. Yes.

  The cylinder head 2 is provided with an intake port 7 and an exhaust port 8 that open to the combustion chamber 6, and an intake valve 10 and an exhaust valve 11 that open and close the intake port 7 and the exhaust port 8, respectively. Equipped.

  The intake valve 10 and the exhaust valve 11 are urged in the direction of closing the ports 7 and 8 (upward in FIG. 1) by return springs 12 and 13, respectively, and are provided on the outer periphery of the camshafts 14 and 15. Each of the ports 7 and 8 is configured to be opened by being pressed by a later-described cam portion. Specifically, as the camshafts 14 and 15 rotate, the cam portions press the cam followers 42 provided at the substantially central portions of the swing arms 16 and 17, so that the swing arms 16 and 17 are moved to one end side thereof. The hydraulic lash adjusters 18 and 19 are pivoted about the pivot mechanism tops 18a and 19a, and the other ends of the swing arms 16 and 17 resist the urging force of the return springs 12 and 13 along with the pivot. Then, the intake valve 10 and the exhaust valve 11 are depressed. As a result, the ports 7 and 8 are opened. Note that a constant pressure of oil is supplied to the pivot mechanism of the hydraulic lash adjusters 18 and 19, so that the valve clearance is automatically adjusted to zero.

[Configuration of valve gear]
FIG. 2 shows a configuration on the exhaust side of the valve gear mounted on the engine 1.

  As described above, the engine 1 is an in-line four-cylinder four-valve gasoline engine, and the cylinder head 2 includes two exhaust valves 11 in total, two for each of the first to fourth cylinders C1 to C4. A total of eight return springs 13 and a total of eight swing arms 17 are provided, and one camshaft 15 (hereinafter referred to as an exhaust-side camshaft 15) extending above the swing arms 17 in the cylinder row direction. Is called). In the following description, unless otherwise stated, the valve train is described with the cylinder row direction as the front-rear direction, the first cylinder C1 side as the “front side”, and the fourth cylinder C4 side as the “rear side”. . In the figure, “F” indicates the front side, and “R” indicates the rear side.

  The exhaust-side camshaft 15 is rotatably supported by a vertical wall portion 2a provided above the center position of each of the cylinders C1 to C4 of the cylinder head 2 via a bearing portion 2b. It is driven to rotate through a chain.

  The exhaust-side camshaft 15 is first to first fitted to (attached to) the shaft portion 30 so as to be capable of relative displacement in the axial direction and to rotate integrally with the shaft portion 30. 4 cam element portions CE1 to CE4. The first to fourth cam element portions CE1 to CE4 are arranged in a line on the shaft portion 30 so as to correspond to the first to fourth cylinders C1 to C4.

  Above the exhaust-side camshaft 15, five operating devices M1 to M5 for moving the cam element portions CE1 to CE4 along the shaft portion 30 are provided. Specifically, the first operating device M1 is at the front end position of the cylinder row, the second operating device M2 is at the first and second inter-cylinder positions, and the third operating device M3 is at the second and third inter-cylinder positions. A fourth operating device M4 is disposed at the third and fourth inter-cylinder positions, and a fifth operating device M5 is disposed at the rear end position of the cylinder row.

  As shown in FIG. 3, each of the operating devices M1 to M5 includes a main body portion 21 provided with an electromagnetic actuator therein, and a substantially cylindrical shape that moves to an operating position protruding from the main body portion 21 when the electromagnetic actuator is energized. And a return spring (not shown) that urges the pin portion 22 to the retracted position on the main body portion 21 side when the energization is stopped. Each of the operating devices M1 to M5 is disposed on the opposite side of the swing arm 17 with the exhaust camshaft 15 interposed therebetween so that the pin portion 22 faces the axis of the exhaust camshaft 15 (shaft portion 30). In this example, it is attached to a pedestal portion 24 formed on a cap member fixed to the vertical wall portion 2a so as to cover the exhaust side camshaft 15.

  Each of the operation devices M1 to M5 is electrically connected to an ECU (Engine Control Unit) 50, and the ECU 50 performs a predetermined engine rotation angle timing based on a detection signal from an engine rotation angle sensor (not shown). A control signal is output so that the electromagnetic actuators of the operation devices M1 to M5 are energized.

  The exhaust camshaft 15 is provided with a detent mechanism 25 for positioning the cam element portions CE1 to CE4 at two different positions in the axial direction. FIG. 4 is a cross-sectional view of the exhaust camshaft 15 and mainly shows the detent mechanism 25 of the first cam element portion CE1 and the second cam element portion CE2.

  As shown in the figure, the detent mechanism 25 includes a hole 26 drilled in the shaft portion 30 along the radial direction from the outer peripheral surface of the shaft portion 30, a detent ball 27 accommodated in the hole 26, and A spring 28 that urges the detent ball 27 to protrude radially outward from the outer peripheral surface of the shaft portion 30 and two front and rear portions formed adjacent to each other in the axial direction on the inner peripheral surface of the cam element portion CE1 (CE2). And circumferential grooves 29a and 29b. With this configuration, when the detent ball 27 is engaged with the front circumferential groove 29a, the cam element portion CE1 (CE2) is in the rear position, and when the detent ball 27 is engaged with the rear circumferential groove 29b, The element portions CE1 (CE2) are respectively positioned at the front positions. Although not shown, the detent mechanism 25 of the third and fourth cam element portions CE3 and CE4 has the same configuration.

  In this valve operating system, the combustion system is switched between HCCI (Homogeneous Charge Compression Ignition) combustion and SI (Spark Ignition) combustion according to the operating region of the engine 1, and each cam element portion CE1 is switched along with this switching. The arrangement of .about.CE4 is switched between the CI arrangement as shown in FIGS. 2 and 4 and the SI arrangement as shown in FIG.

  Here, as shown in FIGS. 2 and 4, the CI arrangement is such that the first and third cam element portions CE1 and CE3 are in the rear position, and the second and fourth cam element portions CE2 and CE4 are in the front position. Each is positioned. Therefore, in this CI arrangement, the opposing end surfaces of the first and second cam element portions CE1 and CE2 are close to each other, and the opposing end surfaces of the second and third cam element portions CE2 and CE3 are separated from each other, and the third, The opposed end surfaces of the fourth cam element portions CE3 and CE4 are in a state of being close to each other.

  On the other hand, in the SI arrangement, as shown in FIG. 5, the first and third cam element portions CE1 and CE3 are positioned at the front position, and the second and fourth cam element portions CE2 and CE4 are positioned at the rear position, respectively. State. Therefore, in this SI arrangement, the opposing end surfaces of the first and second cam element portions CE1 and CE2 are separated from each other, the opposing end surfaces of the second and third cam element portions CE2 and CE3 are close to each other, and the third, Opposing end faces of the fourth cam element portions CE3 and CE4 are in a state of being separated from each other.

  Next, the configuration of each of the cam element portions CE1 to CE4 will be described using the first cam element portion CE1 as an example with reference to FIGS.

  The first cam element portion CE1 has a cylindrical shape, and includes a journal portion 31 supported by the bearing portion 2b at an intermediate portion in the axial direction. The two exhaust valves 11 of the first cylinder C1 are provided on both front and rear sides thereof. There are provided first and second actuating portions 32A and 32B that are actuated respectively.

  The first operating part 32A positioned on the front side operates the front exhaust valve 11 of the two exhaust valves 11, and the second operating part 32B positioned on the rear side operates the rear exhaust valve 11. It is something to be made. In this example, the first operating part 32A of each cam element part CE1 to CE4 corresponds to the first exhaust cam part of the present invention, and the second operating part 32B corresponds to the second exhaust cam part of the present invention. In the following description, as shown in FIG. 9, among the two exhaust valves 11 before and after each of the cylinders C1 to C4, the front one is the first exhaust valve 11a and the rear one is the second exhaust valve 11b. Called. Similarly, the front one of the two front and rear intake valves 10 is referred to as a first intake valve 10a, and the rear one is referred to as a second intake valve 10b.

  As shown in FIG. 6, the first operating portion 32A is provided with a first CI exhaust cam portion 33A and a first SI exhaust cam portion 34A adjacent in the front-rear direction, and the second operating portion 32B has a second CI. The exhaust cam portion 33B and the second SI exhaust cam portion 34B are provided adjacent to each other in the front-rear direction.

  As shown in FIG. 7, the first and second SI exhaust cam portions 34A and 34B are cam portions used during SI combustion, and these SI exhaust cam portions 34A and 34B include exhaust gases during the exhaust stroke. One lift part 341 having the same cam characteristics (phase and lift amount) that opens the valves 11a and 11b is provided.

  On the other hand, the first and second CI exhaust cam portions 33A and 33B are cam portions used during CI combustion. The CI exhaust cam portions 33A and 33B are provided with exhaust valves 11a and 11b during the exhaust stroke. A main lift portion 331 to be opened and a sub lift portion 332 having a smaller lift amount than the main lift portion 331 are provided. The sub-lift part 332 is a so-called internal EGR lift part that recirculates the exhaust gas of the exhaust port 8 into the combustion chamber 6 by opening the exhaust valves 11a and 11b by a minute amount during the intake stroke. The cam characteristics of the lift portions 331 and 332 of the first and second CI exhaust cam portions 33A and 33B are the same.

  FIG. 13 shows the lift characteristics of the first and second exhaust valves 11a and 11b (cam characteristics of the first and second SI exhaust cam portions 34A and 34B) based on the above-described configuration. (B) shows the lift characteristics during CI combustion during SI combustion.

  Here, as shown in FIG. 2 and FIG. 6, the CI exhaust cam portions 33A and 33B are disposed on the front side and the SI portions of the first and third cam element portions CE1 and CE3, respectively. The exhaust cam portions 34A and 34B are provided on the rear side, and the CI exhaust cam portions 33A and 33B are arranged on the rear side of the second and fourth cam element portions CE2 and CE4. The SI exhaust cam portions 34A and 34B are provided on the front side.

  With this configuration, when the cam element portions CE1 to CE4 are positioned in the SI arrangement by the detent mechanism 25, the SI exhaust cam portions 34A and 34B of the operating portions 32A and 32B of the cam element portions CE1 to CE4 are Corresponding to the cam followers 42 (see FIG. 5) of the two swing arms 17 of the corresponding cylinders C1 to C4, when positioned in the CI arrangement, the CIs of the operating parts 32A and 32B of the cam element parts CE1 to CE4 are arranged. The exhaust actuating cam portions 33A and 33B correspond to the cam followers 42 of the two swing arms 17 of the corresponding cylinders C1 and C2 (see FIG. 2), so that the two actuating portions 32A and 32B of the cam element portions CE1 to CE4 An interval is set.

  In the engine 1 of this embodiment, the order of explosion of each cylinder is set as the first cylinder C1, the third cylinder C3, the fourth cylinder C4, and the second cylinder C2, and accordingly, the cam element portions CE1 to CE4. The operating portions 32A, 32B (cam portions 33A, 33B, 34A, 34B) of the cam element portions CE1 to CE4 are slidably contacted with the cam follower 42 in the above order every 90 ° rotation of the exhaust side camshaft 15. Are provided with a phase difference between them.

  Each cam element portion CE1 to CE4 is provided with end face cams 35 at both front and rear ends. As shown in FIGS. 6 and 7, the end face cams 35 at both ends are lifted symmetrically projecting forward or backward in the axial direction from a reference surface 35a orthogonal to the axis of the cam element portion CE1 (CE2 to CE4). It has a part 35b. The lift portion 35b moves from the reference surface 35a in a direction opposite to the rotation direction X (rotation delay direction) within a predetermined angle range (for example, about 120 °) from the lift start position a to the lift end position f. The protrusion amount (lift amount) increases gradually and returns to the reference surface 35a at the lift end position f.

  And each cam element part CE1-CE4 provides a predetermined phase difference according to the explosion order of each cylinder C1-C4, respectively, and is spline-fitted to the shaft part 30, thereby each cam element part CE1-CE4. The end cams 35 that face each other also face each other with a phase difference, and as shown in FIG. 2, when the cam element portions CE1 to CE4 are positioned in the CI arrangement, the first and second cam element portions CE1. , CE2 lift portions 35b of the end face cams 35 facing each other, and lift portions 35b of the end face cams 35 of the third and fourth cam element portions CE3 and CE4 that overlap each other in the axial direction. As shown in FIG. 5, when the cam elements CE1 to CE4 are positioned in the SI arrangement, the ends of the second and third cam elements CE2 and CE3 facing each other. Lift portion 35b to each other of the cam 35 is adapted to overlap in the axial direction.

  That is, as shown in FIG. 2, the second and fourth operating devices M2 and M4 are operated in a state where the cam element portions CE1 to CE4 are positioned in the CI arrangement, and the pin portions 22 are moved to the operating positions. When the first and second cam element portions CE1 and CE2 project, the lift portion 35b of the end surface cam 35 facing each other, and the third and fourth cam element portions CE3 and CE4 lift the end surface cam 35 facing each other. The pin portion 22 engages with the portion 35b, and the first and second cam element portions CE1 and CE2 that are close to each other slide in a direction away from each other as the camshaft 15 rotates. The third and fourth cam element portions CE3 and CE4 that have been slid in a direction away from each other. Thereby, each cam element part CE1-CE4 is switched from CI arrangement | positioning shown in FIG. 2 to SI arrangement | positioning shown in FIG.

  In addition, as shown in FIG. 5, the first, third, and fifth operating devices M1, M3, and M5 are operated and the pins thereof in a state where the cam element portions CE1 to CE4 are positioned in the SI arrangement. When the portion 22 protrudes to the operating position, the lift portion 35b of the end face cam 35 at the front end of the first cam element portion CE1, the lift portion 35b of the end face cam 35 facing each other of the second and third cam element portions CE2 and CE3, And the pin part 22 engages with the lift part 35b of the end face cam 35 at the rear end of the fourth cam element part CE4, and with the rotation of the camshaft 15, the first cam element part CE1 moves rearward and the fourth cam element The portion CE4 slides forward, and the adjacent second and third cam element portions CE2 and CE3 slide in directions away from each other. Accordingly, the cam element portions CE1 to CE4 are switched from the SI arrangement shown in FIG. 5 to the CI arrangement shown in FIG. That is, in this embodiment, the exhaust side cam shift mechanism is comprised by each operation device M1-M5 and the end surface cam 35 of each cam element part CE1-CE4.

  Next, the configuration of the swing arm 17 will be described with reference to FIGS. 3 and 11. In the following description, of the two swing arms 17 before and after each of the cylinders C1 to C4, the front one is referred to as a first swing arm 17a and the rear one is referred to as a second swing arm 17b. That is, the first swing arm 17a is interposed between the first CI exhaust cam part 33A or the first SI exhaust cam part 34A and the first exhaust valve 11a, and the second swing arm 17b is used for the second CI. It is interposed between the exhaust cam portion 33B or the second SI exhaust cam portion 34B and the second exhaust valve 11b.

  The first swing arm 17a is in an operating state in which a pressing force associated with the rotation of the exhaust cam portions 33A, 34A is transmitted to the first exhaust valve 11a, and in a stopped state in which the transmission of the pressing force to the first exhaust valve 11a is interrupted. Similarly, the second swing arm 17b is connected to the second exhaust valve 11b in an operating state in which the pressing force associated with the rotation of the exhaust cam portions 33B and 34B is transmitted to the second exhaust valve 11b. It is possible to switch to a stop state in which the transmission of the pressing force is interrupted. That is, in the present embodiment, the first and second swing arms 17a and 17b correspond to the first and second exhaust-side variable valve lift mechanisms of the present invention.

  More specifically, as shown in FIG. 3, the first swing arm 17a includes an outer lever 40 supported by the top 19a of the pivot mechanism of the hydraulic lash adjuster 19 and the top of the first exhaust valve 11a. An inner lever 41 supported to be swingable via a fulcrum pin 41 a, a hydraulically operated lock pin 40 a that switches the outer lever 40 and the inner lever 41 between an engaged state and a disengaged state, and an inner lever with respect to the outer lever 40 The cam follower 42 is held by the inner lever 41.

  The inner lever 41 has a substantially crescent-like shape in front view extending from the end on the exhaust valve side of the first swing arm 17a toward the opposite end, and holds a cam follower 42 at a substantially intermediate portion thereof. Yes. The inner lever 41 is supported by the fulcrum pin 41a disposed on the extended line of the exhaust valve 11, so that the inner lever 41 is supported to be swingable in the vertical direction with respect to the outer lever 40 with one end thereof as a fulcrum. The cam follower 42 is urged by the coil spring 43 in a direction approaching the camshaft 15 (clockwise in FIG. 3).

  The lock pin 40 a is built in the outer lever 40 so as to be able to advance and retreat at a position above the top portion 19 a of the hydraulic lash adjuster 19. The outer lever 40 is connected to a hydraulic circuit 45 of the engine 1, and the lock pin 40 a is hydraulic pressure (low hydraulic pressure / high hydraulic pressure) switched in two stages by an OCV (Oil Control Valve) 47 a provided in the hydraulic circuit 45. It is comprised so that it may operate | move by. Specifically, in a stopped state of the first swing arm 17a in which the low hydraulic pressure is supplied to the outer lever 40, the lock pin 40a is disposed at a position (position shown in FIG. 3) pushed back by a return spring (not shown). When the outer lever 40 and the inner lever 41 are in a disengaged state and the first swing arm 17a is operated with a high hydraulic pressure supplied to the outer lever 40, the lock pin 40a moves against the inner lever 41 against the elastic force of the return spring. The outer lever 40 and the inner lever 41 are engaged with each other by projecting to the engaging position. Thus, when the first swing arm 17a is in a stopped state, only the inner lever 41 swings with respect to the outer lever 40, and when the second swing arm 17b is in an activated state, the inner lever 41 and the outer lever 40 are connected to the lock pin 40a. These are integrated with each other to swing together.

  That is, when the first swing arm 17a is in a stopped state, as shown in FIG. 11A, the pressing force accompanying the rotation of the exhaust camshaft 15 is transmitted only to the inner lever 41 via the cam follower 42, and the pressing force Is blocked from being transmitted to the first exhaust valve 11a. Therefore, regardless of the rotation of the exhaust camshaft 15, the first exhaust valve 11a is maintained in the closed state. On the other hand, when the first swing arm 17a is in the operating state, the pressing force accompanying the rotation of the exhaust camshaft 15 is transmitted from the inner lever 41 to the outer lever 40 as shown in FIG. Accordingly, as the exhaust camshaft 15 rotates, the entire first swing arm 17a swings with the top portion 19a of the hydraulic lash adjuster 19 as a fulcrum, whereby the first exhaust valve 11a is pushed down (opened). It becomes.

  The second swing arm 17b is switched between a stopped state and an operating state by switching the hydraulic pressure by the OCV 47b provided in the hydraulic circuit 45. That is, the first swing arm 17a and the second swing arm 17b can be switched individually.

  The exhaust side configuration of the valve gear mounted on the engine 1 has been described above. Next, the intake side configuration will be described. Since the basic configuration on the intake side of the valve operating device is substantially the same as the configuration on the exhaust side, portions common to the configuration on the exhaust side are denoted by the same reference numerals, description thereof is omitted or simplified, and differences are made. Only the point will be described in detail.

  The camshaft 14 (hereinafter referred to as the intake-side camshaft 14) includes first to fourth shaft portions 30 and first to fourth rows arranged on the shaft portion 30 so as to correspond to the first to fourth cylinders C1 to C4. Cam element portions CE11 to CE14, and the first to fourth cam element portions CE11 to CE14 can be switched between the SI arrangement and the CI arrangement by the detent mechanism 25, and the first to fifth operations. It is comprised so that it can switch by the action | operation of apparatus M1-M5.

  As shown in FIG. 9, each of the first to fourth cam element portions CE11 to CE14 includes a journal portion 51 and first and second actuating portions 52A and 52B on the front and rear sides thereof. The first operating portion 52A operates the first intake valve 10a (see FIG. 8) located on the front side of the two intake valves 10, and the second operating portion 52B is the second intake air located on the rear side. The valve 10b is operated. In this example, the first operating portion 52A of each cam element portion CE11 to CE14 corresponds to the first intake cam portion of the present invention, and the second operating portion 52B corresponds to the second intake cam portion of the present invention.

  The first operating portion 52A is provided with a first CI intake cam portion 53A and a first SI intake cam portion 54A adjacent to each other in the front-rear direction, and the second operating portion 52B includes the second CI intake cam portion 53B and the first CI intake cam portion 53B. The 2SI intake cam portion 54B is provided adjacent to the front and rear.

  The first and second SI intake cam portions 54A and 54B are cam portions used during SI combustion. These SI intake cam portions 54A and 54B are shown in FIGS. 10 (a) and 10 (b). As described above, one lift portion 541 having the same cam characteristics (phase and lift amount) that opens the intake valves 10a and 10b during the intake stroke is provided.

  On the other hand, the first and second CI intake cam portions 53A and 53B are cam portions that are used during CI combustion. These CI intake cam portions 53A and 53B are provided with intake valves 11a and 11b during the intake stroke. Lift parts 531 and 532 which are lift parts to be opened and have different characteristics (phase and lift amount) are provided. Specifically, as shown in FIG. 10A, the first CI intake cam portion 53A has a lift amount smaller than the lift portion 541 of the SI intake cam portions 54A and 54B and a phase width of the lift portion 541. As shown in FIG. 10B, the second CI intake cam portion 54B is substantially equivalent to the lift portion 541 of the SI intake cam portions 54A and 54B. A lift portion 532 having the cam characteristics is provided.

  FIG. 14 shows the lift characteristics of the first and second intake valves 10a, 10b (cam characteristics of the intake cam portions 53A, 53B, 54A, 54B) based on the above-described configuration, and (a) shows the lift characteristics during SI combustion. 1 shows the lift characteristics of the second intake valves 10a and 10b, (b) shows the lift characteristics of the first intake valve 10a during CI combustion, and (c) shows the lift characteristics of the second intake valve 10b during CI combustion. Each is shown.

  Although not shown in the drawing, the intake camshaft 14 also has the CI intake cam portions 53A and 53B on the front side of the first and third cam element portions CE11 and CE13. The SI intake cam portions 54A and 54B are provided on the rear side, and the CI intake cam portions 53A and 53B are rearward with respect to the operation portions 52A and 52B of the second and fourth cam element portions CE12 and CE14. On the side, each SI intake cam portion 54A, 54B is provided on the front side.

  Each of the cam element portions CE11 to CE14 of the intake side camshaft 14 is also provided with end face cams 55 at both front and rear ends. The end face cams 55 are configured according to the cam element portions of the exhaust side camshaft 15. This is equivalent to the end face cam 35 of CE1 to CE4.

  With this configuration, on the intake side of the valve operating mechanism, the second and fourth operating devices M2 and M4 are operated and the pin portions thereof in a state where the cam element portions CE11 to CE14 are positioned in the CI arrangement. When 22 protrudes to the operating position, each cam element portion CE11-CE14 slides and is switched to the SI arrangement, and each cam element portion CE11-CE14 is positioned in the SI arrangement, and the first, third, When the operating devices M1, M3, and M5 of No. 5 are operated and their pin portions 22 protrude to the operating position, the cam element portions CE11 to CE14 slide to be switched to the CI arrangement. That is, in the present embodiment, the intake side cam shift mechanism is configured by the intake side operation devices M1 to M5 and the end face cams 55 of the cam element portions CE11 to CE14.

  The intake-side swing arm 16 has the same configuration as the exhaust-side swing arm 17. Here, of the two swing arms 16 before and after each of the cylinders C1 to C4, the front one is referred to as a first swing arm 16a and the rear one is referred to as a second swing arm 16b. That is, the first swing arm 16a is interposed between the first CI intake cam portion 53A or the first SI intake cam portion 54A and the first intake valve 10a, and the second swing arm 16b is used for the second CI. It is interposed between the intake cam portion 53B or the second SI intake cam portion 54B and the second intake valve 10b.

  The first swing arm 16a is in an operating state in which a pressing force associated with the rotation of the intake cam portions 53A and 54A is transmitted to the first intake valve 10a, and in a stopped state in which the transmission of the pressing force to the first intake valve 10a is interrupted. Similarly, the second swing arm 16b is connected to the second intake valve 10b in an operating state in which the pressing force associated with the rotation of the exhaust cam portions 53B and 54B is transmitted to the second intake valve 10b. It is possible to switch to a stop state in which the transmission of the pressing force is interrupted. That is, in the present embodiment, the first and second swing arms 16a and 1b correspond to the first and second intake side variable valve lift mechanisms of the present invention.

  The specific configuration of the intake-side swing arms 16a and 16b is the same as that of the exhaust-side swing arms 17a and 17b. ), The second swing arm 16b is switched between the stop state and the operation state by switching the hydraulic pressure by the OCV 46b (see FIG. 3).

[Control and Effect of Intake / Exhaust Valve by ECU 50]
Next, control of the valve gear by the ECU 50 will be described. In this example, the ECU 50 corresponds to the control device of the present invention.

  As described above, the combustion mode of the engine 1 is switched between CI combustion and SI combustion in accordance with the operation region, and the ECU 50 controls the first to fifth operation devices M1 to M5 on the intake side and the exhaust side. By controlling, the arrangement of the cam element portions CE1 to CE4 of the exhaust side camshaft 15 and the cam element portions CE11 to CE14 of the intake side camshaft 14 are switched.

  Specifically, when switching from SI combustion to CI combustion, the first, third, and fifth operating devices M1, M3, and M5 on the exhaust side and the intake side are operated, whereby each cam element portion on the exhaust side is operated. By sliding CE1 to CE4 and intake side cam element portions CE11 to CE14 along the shaft portion 30, the arrangement of the cam element portions CE1 to CE4 and CE11 to CE14 is switched from the SI arrangement to the CI arrangement. Further, when switching from the CI combustion to the SI combustion, the second and fourth operating devices M2 and M4 on the exhaust side and the intake side are operated, and the arrangement of the cam element portions CE1 to CE4 and CE11 to CE14 is changed from the CI arrangement. Switch to SI placement.

  Further, the ECU 50 controls the exhaust side and intake side swing arms 16a, 16b, 17a, and 17b through the OCVs 46a, 46b, 47a, and 47b as shown in the relational diagram of FIG. “ON” in the figure indicates that the swing arm is in an operating state (see FIG. 11B), that is, a state in which the intake / exhaust valve is opened and closed as the camshaft rotates. This indicates that the swing arm is in a stopped state (see FIG. 11A), that is, the intake and exhaust valves are not opened and closed.

  During SI combustion, as shown in the figure, the ECU 50 controls the exhaust-side swing arms 17a and 17b and the intake-side swing arms 16a and 16b to be in an operating state (FIG. 11 (b)). As described above, during SI combustion, the SI exhaust cam portions 34A and 34B correspond to the exhaust valves 11a and 11b (see FIG. 5), and the SI intake cam portions 54A and 54B correspond to the intake valves 10a and 10b. Correspond. Accordingly, the lift characteristics of the exhaust valves 11a and 11b and the intake valves 10a and 10b are as shown in FIG. 15, and the SI exhaust cam portions 34A and 34B (lift portion 331) and the SI intake cam portions 54A and 54B ( The lift characteristic is based on the lift part 541).

  On the other hand, at the time of CI combustion, the ECU 50 individually controls the exhaust-side swing arms 17a and 17b and the intake-side swing arms 16a and 16b according to the operation region of the engine 1. Thus, the internal EGR amount is finely changed according to the operating state of the engine 1 by changing the lift characteristics of the exhaust valves 11a, 11b and the intake valves 10a, 10b.

  Specifically, as shown in the figure, the ECU 50 controls the lift of the exhaust valves 11a, 11b and the intake valves 10a, 10b by switching the swing arms 16a, 16b, 17a, 17b to nine states. The characteristics are changed in nine ways according to the operating state of the engine 1.

  Here, the control of each swing arm 16a, 16b, 17a, 17b is largely divided into the following first to third control patterns based on the state (operation and stop) of each swing arm 17a, 17b on the exhaust side. Separated.

<First control pattern>
The first control pattern is to control both the exhaust side swing arms 17a and 17b to be in an operating state, that is, control to open and close the two exhaust valves 11a and 11b. It includes three modes corresponding to the control states of the swing arms 16a and 16b. Specifically, a first mode in which the swing arms 16a and 16b are both controlled to be in an operating state, a second mode in which the first swing arm 16a is in a stopped state, and a second swing arm 16b is controlled to be in an operating state, It includes a total of three modes, including a third mode in which the swing arm 16a is controlled to be in an operating state and the second swing arm 16b is controlled to be in a stopped state. That is, in the first mode, the two intake valves 10a and 10b are opened and closed as the intake side camshaft 14 rotates, and in the second mode, the rear intake valve 10b (the first one of the two intake valves 10a and 10b) Only the two intake valves 10b) are opened and closed, and in the third mode, only the front intake valve 10a (first intake valve 10a) of the two intake valves 10a and 10b is opened and closed.

  Here, at the time of CI combustion, as described above, the CI exhaust cam portions 33A and 33B correspond to the exhaust valves 11a and 11b (see FIG. 2), and the CI intake cam portions 53A and 53B correspond to the intake valve 10a. 10b, the lift characteristics of the exhaust valves 11a and 11b and the intake valves 10a and 10b in the first to third aspects of the first control pattern are shown in FIGS. 16 (a) to (c), respectively. It becomes street.

<Second control pattern>
The second control pattern is the first control pattern in which the second swing arm 17b is changed from the operating state to the stopped state, that is, the front exhaust valve 11a (first exhaust valve) of the two exhaust valves 11a and 11b. In this control, only the valve 11a) is opened and closed, and the control states of the swing arms 16a and 16b on the intake side are the same as those in the first control pattern. Accordingly, the lift characteristics of the exhaust valves 11a and 11b and the intake valves 10a and 10b of the first to third aspects of the second control pattern are as shown in FIGS. 17 (a) to (c), respectively.

<Third control pattern>
The third control pattern is the first control pattern in which the first swing arm 17a is changed from the activated state to the stopped state, that is, the rear exhaust valve 11b (second one of the two exhaust valves 11a and 11b). The control is to open and close only the exhaust valve 11b), and the control of each swing arm 16a, 16b on the intake side is the same as the first control pattern. Accordingly, the lift characteristics of the exhaust valves 11a and 11b and the intake valves 10a and 10b of the first to third aspects of the second control pattern are as shown in FIGS. 18A to 18C, respectively.

  Thus, in the engine 1, during the CI combustion, the lift characteristics of the exhaust valves 11a and 11b and the intake valves 10a and 10b are changed in nine ways according to the operation region of the engine 1 under the control of the ECU 50. Become.

  As described above, according to the valve operating apparatus of the engine 1, during the CI combustion, the swing arms 16a, 16b, 17a, and 17b are switched to the operating state or the stopped state according to the operation region of the engine 1. The lift characteristics of the exhaust valves 11a and 11b and the intake valves 10a and 10b are changed to the nine lift characteristics shown in FIGS. That is, the internal EGR amount can be changed in nine ways according to the operating region of the engine 1. Therefore, the degree of freedom of the internal EGR amount can be greatly increased as compared with the conventional valve operating device for this type of engine in which the internal EGR amount is constant. Moreover, in this valve operating apparatus, each swing arm 16a, 16b, 17a, 17b is configured to be switchable between an operating state and a stopped state. Specifically, as described above, the pressing force of the CI exhaust cam portions 33A, 33B is set. The first and second exhaust valves 11a and 11b are configured to be switchable between a state of transmission and a state of being shut off, and the pressing force of the CI intake cam portions 53A and 53B is transmitted to the first and second intake valves 10a, respectively. The above-described effects can be enjoyed with a relatively simple and inexpensive configuration in which the ECU 50 can control the switching via the OCV 46a, 46b, 47a, 47b. .

  Therefore, according to the valve operating apparatus of the engine 1, it is possible to increase the degree of freedom of the internal EGR amount at the time of CI combustion while suppressing an increase in cost, and further improve the combustion stability at the time of CI combustion and perform the CI combustion. The effect that it contributes to widening a driving | operation area | region can be show | played.

[Modifications, etc.]
(1) In the above embodiment, the first and second CI exhaust cam portions 33A and 33B have the same cam characteristics, and the first and second CI intake cam portions 53A and 53B have different cams. Although having characteristics, the reverse configuration may be adopted. FIG. 19 shows an example, and the lift amount of the sub-lift portion 332 of the first CI exhaust cam portion 33A is smaller than the lift amount of the sub-lift portion 332 of the second CI exhaust cam portion 33B (the cam characteristic of the main lift portion 331 is The control patterns of the swing arms 16a, 16b, 17a, and 17b when the first and second CI intake cam portions 53A and 53B have the same cam characteristics are shown. The control pattern in FIG. 6 is a control for opening and closing the swing arms 16a and 16b on the intake side, that is, a control for opening and closing the two exhaust valves 11a and 11b, and includes three modes. Specifically, a first mode in which both swing arms 17a and 17b are in an operating state, a second mode in which the first swing arm 17a is in a stopped state, and a second swing arm 17b is in an operating state, and the first swing arm It includes a total of three modes including the third mode in which 17a is in the operating state and the second swing arm 17b is in the stopped state. Such a configuration is also applicable.

  In the above embodiment, the CI exhaust cam portions 33A and 33B of the exhaust side camshaft 15 are provided with the main lift portion 331 and the sub lift portion 332, and the exhaust valves 11a and 11b are made minute by the sub lift portion 332 during the intake stroke. The valve is opened to recirculate a part of the exhaust gas in the exhaust port 8 to the combustion chamber 6, but instead of providing the sub lift part 332 in the CI exhaust cam parts 33 A and 33 B of the exhaust side camshaft 15, Sub-lift portions may be provided on the CI intake cam portions 53A and 53B of the side camshaft 14. That is, the intake valves 10a and 10b are opened during the exhaust stroke separately from the main lift portion that opens the intake valves 10a and 10b during the intake stroke and the valve opening by the main lift portion. You may make it provide the sublift part to valve. Even with such a configuration, it is possible to increase the degree of freedom of the internal EGR amount during CI combustion, as in the above embodiment.

  In short, the specific cam characteristics of the first and second CI exhaust cam portions 33A, 33B and the first and second CI intake cam portions 53A, 53B and the swing arms 16a, 16b, 17a, 17b A specific control pattern can be selected as appropriate so that a desired lift characteristic can be obtained for the exhaust valves 11a and 11b and the intake valves 10a and 10b, that is, a desired variation can be obtained for the internal EGR amount.

  (2) In the above embodiment, in the engine 1 of the type in which the combustion method is switched between SI combustion and CI combustion according to the operation region, the exhaust valve 11a is mainly used to increase the degree of freedom of the internal EGR amount during CI combustion. 11b and the intake valves 10a and 10b, the lift characteristics are changed. Of course, the exhaust valves 11a and 11b and the intake valve 10a are used for the purpose of increasing the degree of freedom of the internal EGR amount during SI combustion. The lift characteristics of 10b may be changed. Further, with respect to an engine that only performs SI combustion (an engine that does not perform CI combustion), the lift characteristics of the exhaust valve and the intake valve may be changed for the purpose of increasing the degree of freedom of the internal EGR amount. .

  (3) In the above embodiment, the exhaust valve 11a, each swing arm 16a, 16b on the intake side and each swing arm 17a, 17b on the exhaust side can be switched between the operating state and the stopped state. 11b and the intake valves 10a and 10b can be changed in lift characteristics, but of course, only one of the lift characteristics may be changed.

  (4) In the above embodiment, as the intake side and exhaust side variable valve lift mechanism of the present invention, the outer lever 40 and the inner lever 41 are provided, and these levers 40, 41 are engaged and disengaged by hydraulic operation. Although the swing arms 16a, 16b, 17a, and 17b to be switched are provided, the specific configuration of the intake side and exhaust side variable valve lift mechanisms is not limited to this, and other configurations may be applied. . The same applies to the intake-side and exhaust-side cam shift mechanisms, and configurations other than the above-described embodiment may be applied.

  (5) In the above embodiment, an example in which the valve gear of the present invention is applied to a four-valve gasoline engine having four valves per cylinder has been described. Can be applied to an engine having two exhaust valves and one exhaust valve and a five-valve engine (for example, three intake valves and two exhaust valves).

DESCRIPTION OF SYMBOLS 10a 1st intake valve 10b 2nd intake valve 11a 1st exhaust valve 11b 2nd exhaust valve 14 Intake side camshaft 15 Exhaust side camshaft 16, 17 Swing arm 16a 1st swing arm (1st intake side variable valve lift mechanism)
16b Second swing arm (second intake side variable valve lift mechanism)
17a First swing arm (first exhaust side variable valve lift mechanism)
17b Second swing arm (second exhaust side variable valve lift mechanism)
30 Shaft portion 32A First operating portion (first cam portion)
32B 2nd operation part (2nd cam part)
33A First CI exhaust cam portion 33B Second CI exhaust cam portion 34A First SI exhaust cam portion 34B Second SI exhaust cam portion CE1 to CE5 First to fifth cam element portions M1 to M5 First to fifth operating devices ( (Intake side cam shift mechanism, exhaust side cam shift mechanism)

Claims (12)

A valve operating apparatus for an engine having first and second exhaust valves and an intake valve in one cylinder,
A shaft portion that receives the rotational force from the crankshaft, and first and second exhaust cam portions that are rotatably attached to the shaft portion so as to be integrated with the shaft portion and respectively correspond to the first and second exhaust valves. An exhaust camshaft provided,
An operating state that is interposed between the first exhaust cam portion and the first exhaust valve and transmits the pressing force accompanying the rotation of the first exhaust cam portion to the first exhaust valve, and the transmission of the pressing force to the first exhaust valve. The first exhaust-side variable valve lift mechanism that is switched to a stop state that shuts off the valve, and the second exhaust cam portion and the second exhaust valve are interposed between the second exhaust cam portion and the second exhaust cam portion so as to apply a pressing force associated with the rotation of the second exhaust cam portion. A second exhaust-side variable valve lift mechanism that is switched between an operating state that transmits to the exhaust valve and a stopped state that blocks transmission of the pressing force to the second exhaust valve;
A control device that controls the first exhaust-side variable valve lift mechanism and the second exhaust-side variable valve lift mechanism,
Each of the first and second exhaust cam portions includes a main lift portion that opens the exhaust valve during the exhaust stroke and a sub-lift portion that opens the exhaust valve during the intake stroke separately from the valve opening by the main lift portion,
The control device is configured so that the first and second exhaust-side variable valve lift mechanisms are both in an operating state or only one of them is in an operating state, depending on the operating region. A valve operating apparatus for an engine, characterized by individually controlling a valve lift mechanism. The valve gear for an engine according to claim 1,
The engine valve operating system according to claim 1, wherein the main lift portions of the first and second exhaust cam portions have the same cam characteristics, and the sub-lift portions have different cam characteristics. The valve gear for an engine according to claim 1 or 2,
The engine includes first and second intake valves that are the intake valves,
The valve gear further includes:
A shaft portion that receives rotational force from the crankshaft, and a shaft portion that is rotatably mounted integrally with the shaft portion and corresponds to the first intake cam portion and the second intake valve that correspond to the first intake valve An intake side camshaft comprising a second intake cam portion that
An operating state that is interposed between the first intake cam portion and the first intake valve and transmits the pressing force accompanying the rotation of the first intake cam portion to the first intake valve, and the transmission of the pressing force to the first intake valve. The first intake-side variable valve lift mechanism that switches to a stop state that shuts off the engine, and the second intake cam portion and the second intake valve are interposed between the second intake cam portion and the second intake cam portion to apply the pressing force associated with the rotation of the second intake cam portion. A second intake-side variable valve lift mechanism that switches between an operating state that transmits to the valve and a stopped state that blocks transmission of the pressing force to the second intake valve;
The control device further includes first and second intake air in accordance with the operating region so that both the first and second intake-side variable valve lift mechanisms are in an operating state or only one of them is in an operating state. A valve operating apparatus for an engine, wherein the side variable valve lift mechanism is individually controlled. The valve gear for an engine according to claim 3,
The valve operating apparatus for an engine, wherein the first and second intake cam portions have different cam characteristics. The valve gear for an engine according to any one of claims 1 to 4,
The engine is a gasoline engine whose combustion system is switched between CI combustion by self-ignition of fuel and SI combustion by spark ignition of a spark plug, and the first and second exhaust cam portions are each for CI combustion. 1. a second CI exhaust cam portion,
The exhaust camshaft is mounted on the shaft portion so as to be movable in the axial direction, and is for SI combustion adjacent to the first and second CI exhaust cam portions and the first and second CI exhaust cam portions, respectively. A cam element having first and second SI exhaust cams;
The valve operating apparatus includes SI arrangements in which the first and second exhaust valves respectively correspond to the first and second exhaust valves, and the first and second exhaust valves have first and second CI exhaust cam portions, respectively. An exhaust cam shift mechanism that switches the arrangement of the cam element portion to a corresponding CI arrangement;
The control device further controls the exhaust-side cam shift mechanism, and switches the arrangement of the cam element portion according to the operation region. The valve gear for an engine according to claim 5,
The first and second intake cam portions are provided, and the first and second intake cam portions are first and second CI intake cam portions for CI combustion, respectively.
The intake side camshaft is mounted on the shaft portion so as to be movable in the axial direction, and is adjacent to the first and second CI intake cam portions and the first and second CI intake cam portions. Comprising a cam element portion having first and second SI intake cam portions;
The valve operating apparatus includes an SI arrangement in which the first and second intake valves for the first and second intake valves respectively correspond to the first and second intake valves, and the first and second intake valves for the first and second CIs. An intake side cam shift mechanism that switches the arrangement of the cam element portion to a corresponding CI arrangement;
The engine control device further controls the intake-side cam shift mechanism and switches the arrangement of the cam element portion in accordance with the operation region. A valve operating apparatus for an engine having an exhaust valve and first and second intake valves in one cylinder,
A shaft portion that receives the rotational force from the crankshaft, and first and second intake cam portions that are rotatably mounted integrally with the shaft portion and corresponding to the first and second intake valves, respectively. An intake side camshaft,
An operating state that is interposed between the first intake cam portion and the first intake valve and transmits the pressing force accompanying the rotation of the first intake cam portion to the first intake valve, and the transmission of the pressing force to the first intake valve. The first intake-side variable valve lift mechanism that is switched to the stop state that shuts off the engine, and the second intake cam portion and the second intake valve are interposed between the second intake cam portion and the second intake cam portion so as to apply the pressing force associated with the rotation of the second intake cam portion. A second intake side variable valve lift mechanism that is switched between an operating state that transmits to the intake valve and a stopped state that blocks transmission of the pressing force to the second intake valve;
A control device for controlling the first intake-side variable valve lift mechanism and the second intake-side variable valve lift mechanism,
Each of the first and second intake cam portions includes a main lift portion that opens the intake valve during the intake stroke and a sub-lift portion that opens the intake valve during the exhaust stroke separately from the valve opening by the main lift portion,
The control device can change the first and second intake side variable in accordance with the operation region so that either the first or second intake side variable valve lift mechanism is in the operating state or only one of them is in the operating state. A valve operating apparatus for an engine, characterized by individually controlling a valve lift mechanism. The valve gear for an engine according to claim 7,
The engine valve operating apparatus according to claim 1, wherein the main lift portions of the first and second intake cam portions have the same cam characteristics, and the sub-lift portions have different cam characteristics. The valve gear for an engine according to claim 7 or 8,
The engine includes first and second exhaust valves that are the exhaust valves,
The valve gear further includes:
A shaft portion that receives the rotational force from the crankshaft, and is attached to the shaft portion so as to be rotatable integrally with the shaft portion, and corresponds to the first exhaust cam portion and the second exhaust valve corresponding to the first exhaust valve. An exhaust camshaft comprising a second exhaust cam portion
An operating state that is interposed between the first exhaust cam portion and the first exhaust valve and transmits the pressing force accompanying the rotation of the first exhaust cam portion to the first exhaust valve, and the transmission of the pressing force to the first exhaust valve. A first exhaust-side variable valve lift mechanism that switches to a stop state that shuts off the exhaust gas, and a second exhaust cam portion that is interposed between the second exhaust cam portion and the second exhaust valve, and that exerts a pressing force associated with the rotation of the second exhaust cam portion on the second exhaust. A second exhaust-side variable valve lift mechanism that switches between an operating state that transmits to the valve and a stopped state that blocks transmission of the pressing force to the second exhaust valve;
The control device further includes first and second exhausts depending on the operating region so that both the first and second exhaust-side variable valve lift mechanisms are in an operating state or only one of them is in an operating state. A valve operating apparatus for an engine, wherein the side variable valve lift mechanism is individually controlled. The valve gear for an engine according to claim 9,
The valve operating apparatus for an engine, wherein the first and second exhaust cam portions have different cam characteristics. The valve gear for an engine according to any one of claims 7 to 10,
The engine is a gasoline engine whose combustion system is switched between CI combustion by self-ignition of fuel and SI combustion by spark ignition of a spark plug, and the first and second intake cam portions are each for CI combustion. 1, a second CI intake cam portion,
The intake side camshaft is mounted on the shaft portion so as to be movable in the axial direction, and is adjacent to the first and second CI intake cam portions and the first and second CI intake cam portions. Comprising a cam element portion having first and second SI intake cam portions;
The valve operating apparatus includes an SI arrangement in which the first and second intake valves for the first and second intake valves respectively correspond to the first and second intake valves, and the first and second intake valves for the first and second CIs. An intake side cam shift mechanism that switches the arrangement of the cam element portion to a corresponding CI arrangement;
The engine control device further controls the intake-side cam shift mechanism and switches the arrangement of the cam element portion in accordance with the operation region. The valve gear for an engine according to claim 11,
The first and second exhaust cam portions are provided, and the first and second exhaust cam portions are first and second CI exhaust cam portions for CI combustion, respectively.
The exhaust camshaft is mounted on the shaft portion so as to be movable in the axial direction, and is for SI combustion adjacent to the first and second CI exhaust cam portions and the first and second CI exhaust cam portions, respectively. A cam element having first and second SI exhaust cams;
The valve operating apparatus includes SI arrangements in which the first and second exhaust valves respectively correspond to the first and second exhaust valves, and the first and second exhaust valves have first and second CI exhaust cam portions, respectively. An exhaust side cam shift mechanism for displacing the cam element portion in a corresponding CI arrangement;
The control device further controls the exhaust-side cam shift mechanism, and switches the arrangement of the cam element portion according to the operation region.

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