JP5239789B2 - Internal combustion engine - Google Patents

Description

  The present invention includes a variable valve lift mechanism that makes the maximum lift amount of the intake valve variable and a valve timing variable mechanism that makes the valve timing of the intake valve variable so that the maximum lift amount and the valve opening period of the intake valve are correct. It is related with the internal combustion engine which has the following correlation.

  Conventionally, an Atkinson cycle has been proposed as a system for improving fuel consumption in an internal combustion engine. The Atkinson cycle is a system that reduces pumping loss and effectively uses thermal energy. Specifically, in order to make the expansion ratio larger than the compression ratio, the variable valve timing mechanism delays the intake valve closing timing to the compression stroke, thereby sucking the air-fuel mixture that is smaller than the actual exhaust amount. (See Patent Document 1).

By the way, in the variable valve timing mechanism, since the oil pump cannot supply sufficient hydraulic oil when the engine is started, the internal rotor may rotate and collide with the housing to generate abnormal noise. Therefore, in order to prevent such abnormal noise, a lock mechanism is provided that restricts the relative rotation of the internal rotor when the hydraulic pressure drops. The lock mechanism is provided to fix the inner rotor at a position corresponding to the most retarded angle.
JP 09-166030 A

  However, an internal combustion engine having a variable valve lift mechanism and a variable valve timing mechanism and having a positive correlation between the maximum lift amount and the intake valve opening period as shown in FIG. In the case of applying the Atkinson cycle, the following problems have arisen. For the sake of explanation, an internal combustion engine having an intake valve opening period of 200 ° CA when the medium is set to a medium value as the maximum lift applied when the engine is started as an internal combustion engine having no phase coupling. Give up.

  As shown in FIG. 5B, when an Atkinson cycle is performed in an internal combustion engine without phase coupling during an engine load, the intake valve is configured to be closed later than in a conventional internal combustion engine. For example, the maximum lift amount and the valve timing are set so that the intake valve is closed at a position of 100 ° CA from the bottom dead center BDC. Specifically, as shown in FIG. 5B, when the valve timing is set to the most retarded angle locked state by the variable valve timing mechanism, the intermediate value of the valve opening period of the intake valve is 140 ° CA from the top dead center TDC. The maximum lift amount is set to a value at which the valve opening period of the intake valve is 280 ° CA. When the engine is started in the most retarded angle locked state, the maximum lift amount is set to a medium level. Specifically, the valve opening period of the intake valve is set to 200 ° CA. At this time, as shown in FIG. 5C, the opening timing IVO of the intake valve is 40 ° CA from the top dead center TDC, and the closing timing IVC is 60 ° CA from the bottom dead center BDC. However, the valve closing timing IVC is later than the conventional internal combustion engine without phase coupling that does not apply the Atkinson cycle, as shown below.

  Next, a case where the Atkinson cycle is not applied in the same internal combustion engine will be described. In this case, as shown in FIG. 8A, the maximum lift amount and the valve timing are set so that the intake valve is closed at a position of 70 ° CA from the bottom dead center BDC. Specifically, when the valve timing is set to the most retarded angle locked state by the variable valve timing mechanism, the intermediate value of the intake valve opening period is set to a value that becomes 120 ° CA, and the maximum lift amount is The valve opening period is set to a value of 260 ° CA. When the engine is started in the most retarded angle locked state, the maximum lift amount is set to a medium level when the engine is started. Specifically, the valve opening period of the intake valve is set to 200 ° CA. At this time, the intake valve closing timing IVC is 40 ° CA from the bottom dead center BDC, as shown in FIG.

  That is, when the Atkinson cycle is applied to an internal combustion engine without phase coupling, the fuel consumption is improved by reducing pump loss, but the closing timing IVC of the intake valve is delayed compared to an internal combustion engine not using the Atkinson cycle. . Therefore, there is a problem that exhaust at the time of starting the engine deteriorates.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an internal combustion engine capable of improving fuel consumption by the Atkinson cycle and suppressing deterioration of exhaust at the time of engine start. It is in.

In the following, means for achieving the above object and its effects are described .

(1) The present invention varies the valve timing of the intake valve by changing the rotational phase of the internal rotor connected to the intake camshaft with respect to the crankshaft and the variable valve lift mechanism that makes the maximum lift amount of the intake valve variable. In the internal combustion engine having a positive correlation between the maximum lift amount and the valve opening period of the intake valve, the internal rotor is moved from the most retarded state to the most advanced angle state when the engine is stopped. An intermediate lock mechanism that fixes at an intermediate lock position between them is provided, and when the engine is in an intermediate load, intake is achieved by increasing the maximum lift amount by the variable valve lift mechanism while setting the valve timing to the most retarded state by the variable valve timing mechanism. the valve from the bottom dead center and closed configurations from the point of exceeding from 90 ° CA, the inside a time of engine start When the rotor is fixed at the intermediate lock position, the maximum lift amount is set to a predetermined amount smaller than the maximum lift amount set at the intermediate load by the variable valve lift mechanism so that the valve timing is appropriate for engine start. The gist is to do.

  According to the present invention, the intake valve can be closed by a configuration in which the intake valve is closed from the time when it exceeds 90 ° CA from the bottom dead center at the time of engine load, so that the fuel consumption of the internal combustion engine can be improved and Since the lock mechanism is provided, the intake valve closing timing can be set to an appropriate position even when the maximum lift amount is ensured to a predetermined amount at the time of engine start, and deterioration of exhaust can be suppressed.

(2) In the invention according to claim 2, the intermediate lock mechanism regulates a change in rotational phase of the internal rotor with respect to the crankshaft by fitting the lock pin protruding from the internal rotor and the lock pin. The intermediate lock hole is provided with a step for enlarging the opening to the advance side.

  According to the present invention, the lock pin is disposed on the advance side with respect to the intermediate lock hole, and when the lock pin is fitted into the intermediate lock hole by changing the phase of the internal rotor to the retard side, Since the lock pin can be inserted from the opening of the stepped portion, the lock pin can be accurately fitted into the intermediate lock hole.

A preferred embodiment of an internal combustion engine 1 according to the present invention will be described with reference to FIGS.
As shown in FIG. 1, the engine body 10 of the internal combustion engine 1 includes a cylinder block 12 having a plurality of cylinders, and a piston 13 is provided in each cylinder for reciprocal movement. The piston 13 is connected to a crankshaft 18 provided at the lower portion of the engine body 10 via a connecting rod 19, and the reciprocating motion of the piston 13 is converted to a rotational motion of the crankshaft 18 via the connecting rod 19.

  A cylinder head 11 is provided above the cylinder block 12. A combustion chamber 14 is formed by a space surrounded by the bottom surface of the cylinder head 11 and the upper end surface of the piston 13. An intake passage 16 and an exhaust passage 17 are formed in the cylinder head 11 so as to communicate with the combustion chamber 14. Air outside the engine body 10 is sucked into the combustion chamber 14 through the intake passage 16. The amount of intake air flowing through the intake passage 16 is adjusted according to the opening of the throttle valve. Exhaust gas generated in the combustion chamber 14 passes through the exhaust passage 17 and is discharged to the outside of the engine body 10.

  A fuel injection valve 20 is disposed in the cylinder head 11. The fuel injection valve 20 is opened in response to a command from the electronic control unit 90 to inject and supply fuel. The fuel injected from the fuel injection valve 20 is mixed with the air sucked into the combustion chamber 14 to form an air-fuel mixture. The cylinder head 11 is provided with a spark plug 15 that ignites the air-fuel mixture in the combustion chamber 14. Further, the cylinder head 11 is provided with an intake valve 40 and an exhaust valve 46 that can open and close the intake port and the exhaust port, respectively. An intake camshaft 41 and an exhaust camshaft 47 for opening and closing each of the intake valve 40 and the exhaust valve 46 are provided above the cylinder head 11. The intake camshaft 41 and the exhaust camshaft 47 are connected to the crankshaft 18 by a timing chain (not shown). That is, the intake valve 40 and the exhaust valve 46 are driven to open and close by the rotation of the intake camshaft 41 and the exhaust camshaft 47, and the intake port, the exhaust port, and the combustion chamber 14 are communicated or blocked.

  The intake camshaft 41 is provided with a variable valve timing mechanism 50. The variable valve timing mechanism 50 adjusts the relative rotation phase of the intake camshaft 41 with respect to the rotation phase of the crankshaft 18 to change and set the valve timing of the intake valve 40. Specifically, the valve opening timing and the valve closing timing are changed to the advance side or the retard side by the variable valve timing mechanism 50. The variable valve timing mechanism 50 is driven by controlling the hydraulic pressure acting on the mechanism through the hydraulic control valve 85. The configuration of the variable valve timing mechanism 50 will be described later.

  A variable valve lift mechanism 30 is provided between the intake camshaft 41 and the intake valve 40. The variable valve lift mechanism 30 changes and sets the valve operating angle and the maximum lift amount of the intake valve 40. The variable valve lift mechanism 30 is provided between an intake rocker arm 44 that abuts the upper end of the intake valve 40 and the intake camshaft 41, and is configured by an arm assembly 31 that is swingably supported with respect to the cylinder head 11. . One end of the intake rocker arm 44 is supported by a lash adjuster 43, and the other end of the intake rocker arm 44 is in contact with the intake valve 40. The arm assembly 31 includes an input arm 33 to which the rotation of the intake camshaft 41 is input, an output arm 32 that swings the intake rocker arm 44, and a control shaft 34 that is movably provided along the axial direction of the arm assembly 31. I have. The arm assembly 31 is configured such that the relative position of the input arm 33 and the output arm 32 in the swing direction can be changed by driving the control shaft 34 in the axial direction. The control shaft 34 is driven by an actuator 35 that operates according to a command from the electronic control unit 90. Then, the valve lift angle of the intake valve 40 is continuously changed between the maximum operating angle and the minimum operating angle by driving the variable valve lift mechanism 30 so that the maximum lift amount of the intake valve 40 is continuously changed. Is done. That is, the maximum lift amount is the upper limit lift amount at the maximum operating angle, and the maximum lift amount is the lower limit lift amount at the minimum operating angle.

  The engine body 10 is provided with various sensors for detecting the engine operating state. For example, the crank position sensor 91 detects the rotational phase of the crankshaft 18, that is, the crank angle. The cam position sensor 93 detects the rotational phase of the intake camshaft 41, that is, the valve timing of the intake valve 40. The valve operating angle of the intake valve 40 is detected by the operating angle sensor 92.

  Various controls of the internal combustion engine 1 are performed by an electronic control unit 90. The electronic control device 90 receives the detection signals of the sensors. Then, calculation processing is performed based on these detection signals, and various controls are performed based on the calculation results. For example, the driving of the spark plug 15 and the fuel injection valve 20 is controlled based on the engine operating state detected by the sensors and the like. Further, the variable valve timing mechanism 50 and the variable valve lift mechanism 30 are controlled so as to obtain desired characteristics according to the engine operating state, and the valve timing and valve operating angle of the intake valve 40 are set.

  Next, the configuration of the variable valve timing mechanism 50 will be described with reference to FIGS. FIG. 2A shows a cross-sectional structure of the variable valve timing mechanism 50, and FIG. 2B is a cross-sectional view cut along a plane along line II in FIG. FIG. 3C is a cross-sectional view cut along a plane along line II-II in FIG. FIG. 3 is a schematic diagram of a hydraulic control system of the variable valve timing mechanism 50.

  As shown in FIG. 2A, the variable valve timing mechanism 50 is provided coaxially with the sprocket 60 that rotates in synchronization with the crankshaft 18 and the intake camshaft 41 and is rotatable relative to the sprocket 60. An internal rotor 61 is provided, and a housing 51 that houses the internal rotor 61 is provided.

The sprocket 60 is drivingly connected to the crankshaft 18 via a timing chain, and rotates in synchronization with the crankshaft 18.
The internal rotor 61 is composed of a rotor body 63 and three vanes 62 formed to project from the rotor body 63 in the radial direction. Further, the inner rotor 61 is fixed to the tip of the intake camshaft 41 with a center bolt so that the rotation axis of the rotor body 63 and the intake camshaft 41 is coaxial, and is configured to rotate integrally with the intake camshaft 41. ing. Further, the rotation axes of the intake camshaft 41 and the inner rotor 61 are coaxial with the axis of the sprocket 60, rotate relative to the sprocket 60, and are held at a predetermined angle with respect to the sprocket 60. It is comprised so that it may rotate with 60. That is, the rotation phase of the intake camshaft 41 is relatively advanced or retarded by rotating the internal rotor 61 relative to the sprocket 60 based on a command from the electronic control unit 90.

  In addition, a lock pin 69 for fixing the internal rotor 61 to the lock position is provided on one of the vanes 62 of the internal rotor 61 so as to protrude. The configuration of the lock pin 69 will be described later.

  The housing 51 includes a housing main body 52 and a cover 53. The housing main body 52 is fixed to the sprocket 60 with a plurality of mounting bolts, and is configured to rotate integrally with the sprocket 60.

  Three compartments 54 in which the vanes 62 of the internal rotor 61 are accommodated are provided on the inner peripheral surface of the housing body 52. These compartments 54 are separated by a partition wall 55. Each compartment 54 is divided into a retard hydraulic chamber 64 and an advanced hydraulic chamber 65 by a vane 62. Specifically, the end surface 62 a of the vane 62 is in sliding contact with the inner peripheral surface 54 c of the partition chamber 54, while the end surface 55 a of the partition wall 55 is in sliding contact with the outer peripheral surface 63 a of the rotor body 63. Further, when the inner rotor 61 rotates to a position corresponding to the most retarded angle, the most retarded side surface 62r of the vane 62 comes into contact with the most retarded side surface 54r of the compartment 54, and the inner rotor 61 is most advanced. When rotated to a position corresponding to a corner, the side surface 62f on the most advanced angle side of the vane 62 comes into contact with the side surface 54f on the most advanced angle side of the compartment 54. The retard hydraulic chamber 64 is a space that is expanded when the internal rotor 61 is rotated to the retard side, and the advance hydraulic chamber 65 is expanded when the internal rotor 61 is rotated to the advance side. It is space.

  In the variable valve timing mechanism 50 having such a configuration, the most retarded angle is such that the intermediate value of the valve opening period of the intake valve 40 is 140 ° CA when the phase of the internal rotor 61 is the most retarded angle. Set to position.

  Next, the lock pin 69 will be described with reference to FIGS. The lock pin 69 is a pin that is driven when the internal rotor 61 moves to the intermediate lock position (intermediate lock phase) when the engine is stopped and the like, and fixes the internal rotor 61 at that position. The lock pin 69 is provided on a predetermined vane 62 so as to protrude in a direction along the rotation axis of the internal rotor 61, and is always urged in a direction protruding from the vane 62 by an urging spring (not shown). In addition, a lock pin working chamber (not shown) for releasing the lock by pulling the lock pin 69 by applying the hydraulic pressure of the hydraulic oil is formed at the tip of the lock pin 69. The lock pin working chamber communicates with the advance hydraulic chamber 65, and the hydraulic pressure of the advance hydraulic chamber 65 is supplied.

  On the other hand, the sprocket 60 is formed with an intermediate lock hole 70 into which the lock pin 69 is inserted at a portion facing the position of the lock pin 69 when the internal rotor 61 is rotated to the intermediate lock position. Further, as shown in FIG. 3C, the intermediate lock hole 70 is provided with a step 72 for expanding the opening 71 to the advance side.

  With such a configuration, the lock pin 69 operates as follows. That is, when the oil pump 87 is stopped in the engine operation stop state or the like and the hydraulic pressure in the advance hydraulic chamber 65 is lowered, the hydraulic pressure in the lock pin working chamber is also lowered. Therefore, the lock pin 69 is moved to the vane 62 by the urging force of the urging spring. Protrude from. When the internal rotor 61 reaches the intermediate lock position, the lock pin 69 is fitted into the intermediate lock hole 70, and the internal rotor 61 is fixed. In particular, when the lock pin 69 is inserted into the intermediate lock hole 70 from the advance side, the lock pin 69 is inserted into the intermediate lock hole 70 after fitting into the opening of the stepped portion.

  When the engine operation is started and the hydraulic pressure in the advance hydraulic chamber 65 becomes equal to or higher than a predetermined pressure, the lock pin 69 is pushed back against the biasing force of the biasing spring by the hydraulic pressure, and the lock pin 69 and the intermediate lock hole 70 The engagement is released.

  Further, in the intermediate lock mechanism having such a configuration, the intermediate lock position is provided between the most retarded angle and the most advanced angle, and the intake valve 40 is provided when the internal rotor 61 is rotated to a position corresponding to the intermediate lock position. Is set at a position where the intermediate value of the valve opening period becomes 120 ° CA.

FIG. 3 shows a hydraulic control system of the variable valve timing mechanism 50. The hydraulic control system controls driving of the internal rotor 61 and the lock pin 69.
The hydraulic control system includes a retard oil passage 81 that supplies or discharges hydraulic oil to the retard hydraulic chamber 64, an advance oil passage 82 that supplies or discharges hydraulic oil from the advance hydraulic chamber 65 and the lock pin operating chamber, A supply oil passage 83 for supplying hydraulic oil from the oil pan 86 to these oil passages by an oil pump 87, a discharge oil passage 84 for discharging the hydraulic oil from these oil passages, and supply, discharge and holding of the hydraulic oil are controlled. And a hydraulic control valve (OCV) 85. When the internal rotor 61 is turned to the retard side, the retard oil passage 81 is connected to the supply oil passage 83 and the advance oil passage 82 is connected to the discharge oil passage 84 by the control of the hydraulic control valve 85. Connected. When the internal rotor 61 is rotated to the advance side, the retard oil passage 81 is connected to the discharge oil passage 84 and the advance oil passage 82 is connected to the supply oil passage 83.

Next, an example of setting the valve operating angle and the valve operating angle will be described with reference to FIGS.
As shown in FIG. 4, the engine is conventionally set in the area A at the time of engine load, but is set in the area B in the present embodiment. More specifically, the phase of the internal rotor 61 is set to the most retarded angle when the engine is loaded, and the maximum lift amount of the variable valve lift mechanism 30 is set to a value at which the valve opening period of the intake valve is 280 ° CA. Is done. With this setting, according to the example of the present embodiment, the intermediate value of the valve opening period of the intake valve 40 is 140 ° CA from the top dead center TDC by setting the phase of the internal rotor 61 to the most retarded angle. Since the opening period of the intake valve 40 is 280 ° CA according to the above setting, the opening timing IVO of the intake valve 40 is 0 ° CA and the closing timing IVC is lower as shown in FIG. 100 ° CA from dead center BDC. Therefore, according to the above setting, the closing timing IVC of the intake valve 40 can be delayed to a position exceeding 90 ° CA from the bottom dead center BDC.

  Further, as shown in FIG. 4, the region C is set when the engine is started. Specifically, when the engine is started, the phase of the internal rotor 61 is a phase corresponding to the intermediate lock position, and the maximum lift amount of the variable valve lift mechanism 30 is 200 ° CA during the valve opening period of the intake valve 40. Is set to the value With such a setting, by setting the phase of the internal rotor to a phase corresponding to the intermediate lock position, the intermediate value of the valve opening period of the intake valve 40 becomes 120 ° CA. Since the period is 200 ° CA, as shown in FIG. 5B, the closing timing of the intake valve 40 is 40 ° CA from the bottom dead center. Therefore, according to the above setting, when the engine is started, the phase of the internal rotor 61 is set to the intermediate lock position instead of the most retarded angle, so that the intake valve 40 can be closed even if the maximum lift amount is secured as in the prior art. The valve timing IVC can be set to the same timing as that of a conventional internal combustion engine.

  In the present embodiment, as shown in FIG. 6, the opening timing IVO and the closing timing IVC of the intake valve 40 are substantially the same as the lift portion in which the intake valve is substantially open, It is defined by the boundary with the buffer part in the closed state.

According to the internal engine of the present embodiment, the following effects can be achieved.
(1) The internal combustion engine 1 includes an intermediate lock mechanism that fixes the internal rotor 61 at an intermediate lock position between the most retarded state and the most advanced angle state when the engine is stopped. When the engine is in an intermediate load, the valve timing variable mechanism 50 is controlled to the maximum lift or near the maximum lift while the variable valve timing mechanism 50 is controlled to be retarded from the intermediate lock phase, thereby delaying the closing timing of the intake valve 40. ing. Further, when the engine is started and the internal rotor 61 is fixed at the intermediate lock position, the maximum lift amount is adjusted by the variable valve lift mechanism 30 so that the valve timing is appropriate for starting the engine.

  Therefore, when the engine is in a middle load, the intake valve 40 can be compressed based on the Atkinson cycle by delaying the closing timing of the intake valve 40, and the fuel consumption of the internal combustion engine 1 can be improved. In addition, the internal lock mechanism can fix the internal rotor 61 at a position deviated from the most retarded angle when the engine is started, so that the intake valve 40 can be closed even if the maximum lift amount is secured to a predetermined amount. The valve timing IVC can be set to an appropriate position, and exhaust deterioration can be suppressed.

  (2) Further, when the engine is under a load, the intake valve 40 is closed by controlling the variable valve lift mechanism 30 to the maximum lift or near the maximum lift while controlling the variable valve timing mechanism 50 to the retard side from the intermediate lock phase. The timing may be delayed.

  According to this configuration, the compression / expansion ratio of the intake air can be further increased at the time of engine load, and therefore the fuel consumption of the internal combustion engine 1 can be further improved by the intake air compression based on the Atkinson cycle.

  (3) The internal combustion engine 1 includes an intermediate locking mechanism similar to the above. When the engine is in an intermediate load, the intake valve 40 exceeds 90 ° CA from the bottom dead center by increasing the maximum lift amount by the variable valve lift mechanism 30 while setting the valve timing to the most retarded state by the variable valve timing mechanism 50. It is configured to close at the time. Further, when the engine is started and the internal rotor 61 is fixed at the intermediate lock position, the maximum lift amount is adjusted by the variable valve lift mechanism 30 so that the valve timing is appropriate for the engine start.

  Therefore, when the engine is in a middle load, the intake valve 40 is closed from the time when it exceeds 90 ° CA from the bottom dead center, and the intake air compression is performed. Therefore, the fuel efficiency of the internal combustion engine 1 can be improved. In addition, the internal lock mechanism can fix the internal rotor 61 at a position deviated from the most retarded angle when the engine is started, so that the intake valve 40 can be closed even if the maximum lift amount is secured to a predetermined amount. The valve timing IVC can be set to an appropriate position, and exhaust deterioration can be suppressed.

  (4) Further, the intermediate lock mechanism includes a lock pin 69 protruding from the internal rotor 61 and an intermediate lock hole for restricting the rotational phase change of the internal rotor 61 relative to the crankshaft 18 by fitting with the lock pin 69. 70. Further, the intermediate lock hole 70 is provided with a step 72 for expanding the opening 71 to the advance side.

  Therefore, when the lock pin 69 is disposed on the advance side with respect to the intermediate lock hole 70 and the lock pin 69 is fitted into the intermediate lock hole 70 by changing the phase of the internal rotor 61 to the retard side, the advance side The lock pin 69 can be inserted from the opening 71 of the step portion, and the lock pin 69 can be accurately fitted into the intermediate lock hole 70.

(Other embodiments)
In addition, the embodiment of the present invention is not limited to the embodiment exemplified in each of the above-described embodiments, and can be implemented by changing it as shown below, for example.

  In the above embodiment, an example of setting the valve operating angle and the valve operating angle of the intake valve 40 that makes the closing timing IVC of the intake valve 40 suitable for execution of the Atkinson cycle at an engine load and at the time of engine startup is given. However, the present invention is not limited to the above settings in order to achieve the effects of the present invention. That is, in the setting of the engine middle load, any setting may be used as long as the closing timing IVC of the intake valve 40 can be delayed as compared with the conventional internal combustion engine. Further, the setting at the time of starting the engine may be a setting that allows the closing timing IVC of the intake valve 40 to be the same as that of the conventional internal combustion engine.

  In the above embodiment, the closing valve timing of the intake valve 40 is delayed by enlarging the maximum lift amount by setting the phase of the internal rotor 61 to the most retarded angle during engine load, but the present invention is limited to this. Not. That is, any setting may be used as long as the intake valve 40 can be closed at a later timing.

  For example, at the time of engine load, the intake valve 40 is closed by controlling the variable valve lift mechanism 30 to the maximum lift or near the maximum lift while controlling the variable valve timing mechanism 50 to the retard side from the intermediate lock phase. The timing may be delayed.

The schematic diagram which shows an internal combustion engine about 1st Embodiment which actualized the internal combustion engine of this invention. (A) Sectional drawing which shows the cross-section of a valve timing variable mechanism about the internal combustion engine of the embodiment. (B) Sectional drawing which follows II of the figure (a) about the internal combustion engine. (C) Sectional drawing which follows II-II of the figure (a) about the internal combustion engine. The schematic diagram which shows the hydraulic control system of a valve timing variable mechanism about the internal combustion engine of the embodiment. The graph which showed the example of a setting of a valve working angle and a valve working angle about the internal combustion engine of the embodiment. (A) The diagram which showed the timing of the intake valve in engine load about the internal combustion engine of the embodiment. (B) A diagram showing the timing of the intake valve when starting the engine for the internal combustion engine. The cam lift graph of an intake valve about the internal combustion engine of the embodiment. Diagram showing intake valve timing for an internal combustion engine equipped with an Atkinson cycle and a most retarded angle locking mechanism. The diagram which showed the timing of the intake valve about the conventional internal combustion engine provided with the most retarded angle locking mechanism.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 10 ... Engine main body, 11 ... Cylinder head, 12 ... Cylinder block, 13 ... Piston, 14 ... Combustion chamber, 15 ... Spark plug, 16 ... Intake passage, 17 ... Exhaust passage, 18 ... Crankshaft, 19 DESCRIPTION OF SYMBOLS ... Connecting rod, 20 ... Fuel injection valve, 30 ... Valve lift variable mechanism, 31 ... Arm assembly, 32 ... Output arm, 33 ... Input arm, 34 ... Control shaft, 35 ... Actuator, 40 ... Intake valve, 41 ... Intake camshaft 43 ... Rush adjuster 44 ... Intake rocker arm 46 ... Exhaust valve 47 ... Exhaust camshaft 50 ... Valve timing variable mechanism 51 ... Housing 52 ... Housing body 53 ... Cover 54 ... Compartment chamber 54r ... Side surface on the retarded angle side, 54 f... Side surface on the most advanced angle side, 54 c. Partition wall, 55a ... end face, 60 ... sprocket, 61 ... internal rotor, 62 ... vane, 62r ... most retarded side face, 62f ... most advanced side face, 62a ... end face, 63 ... rotor body, 63a ... outer peripheral face , 64 ... retarded hydraulic chamber, 65 ... advanced hydraulic chamber, 69 ... lock pin, 70 ... intermediate lock hole, 71 ... opening, 72 ... step, 85 ... hydraulic control valve, 81 ... retarded oil passage, 82 ... Advance oil passage, 83 ... Supply oil passage, 84 ... Drain oil passage, 86 ... Oil pan, 87 ... Oil pump, 90 ... Electronic control device, 91 ... Crank position sensor, 92 ... Working angle sensor, 93 ... Cam position sensor .

Claims (2)

A variable valve lift mechanism that varies the maximum lift amount of the intake valve, and a variable valve timing mechanism that varies the valve timing of the intake valve by changing the rotational phase of the internal rotor connected to the intake camshaft with respect to the crankshaft. In an internal combustion engine in which the maximum lift amount and the valve opening period of the intake valve have a positive correlation,
An intermediate lock mechanism for fixing the internal rotor at an intermediate lock position between the most retarded angle state and the most advanced angle state when the engine is stopped;
A configuration in which the intake valve is closed from 90 degrees above the bottom dead center by increasing the maximum lift amount by the variable valve lift mechanism while setting the valve timing to the most retarded state by the variable valve timing mechanism at the time of engine load. age,
When the engine is started and the internal rotor is fixed at the intermediate lock position, the maximum lift amount is set by the variable valve lift mechanism at the time of intermediate load so that the valve timing is appropriate for starting the engine. An internal combustion engine having a predetermined amount smaller than a lift amount . The internal combustion engine according to claim 1 ,
The intermediate lock mechanism includes a lock pin protruding from the internal rotor, and an intermediate lock hole for restricting a rotational phase change of the internal rotor with respect to the crankshaft by fitting with the lock pin. Is provided with a step for enlarging the opening to the advance side.

Images