WO2012077220A1 - Variable valve gear for internal combustion engine - Google Patents

Abstract

A variable valve gear (20) is provided with a varying mechanism (25) for varying the valve timing, a holding mechanism (26) for holding the valve timing at a specific time, and an oil pressure mechanism (80) for controlling the oil pressures of respective oil chambers of the variable valve gear (20). In the oil pressure mechanism (80), a communication oil path (98) through which a first supply oil path (93) and a release oil path (97) communicate with each other is provided. The first supply oil path (93) is provided on the upstream side from an oil control valve (91) and selectively supplies operating oil to either an advance chamber (37) or a retard chamber (38). The release oil path (97) is provided on the downstream side from the oil control valve (91) and supplies the operating oil to a first release chamber (57), a second release chamber (77), and a third release chamber (44). The communication oil path (98) supplies oil pressure that generates biasing force smaller than that of the release oil pressure (P1) of the first release chamber (57) to the release chamber (57), and supplies oil pressure that generates biasing force smaller than that of the release oil pressure (P2) of the second release chamber (77) to the release chamber (77).

Description

Variable valve operating device for internal combustion engine

The present invention includes a variable mechanism that changes the valve timing, a holding mechanism that holds the valve timing at a specific time, and an oil passage control unit that controls the supply and discharge states of hydraulic oil to and from the oil chambers of the variable mechanism and the holding mechanism. The present invention relates to a variable valve operating apparatus for an internal combustion engine including a hydraulic mechanism.

As a device mounted on an internal combustion engine, there is known a variable valve operating device provided with a variable mechanism that changes the valve timing of a valve that is driven to open and close by a camshaft according to an operating state (see, for example, Patent Document 1).

FIG. 11A shows the configuration of a conventional general variable mechanism including the variable mechanism described in Patent Document 1. FIG. 11A shows the internal structure of the variable mechanism 100 when the sprocket 101 side is viewed from the cover side with the cover of the variable mechanism 100 removed. In FIG. 11A, the rotation direction of the cam shaft (not shown) is indicated by an arrow RA.

A variable mechanism 100 shown in FIG. 11 includes, as two rotating bodies rotating around the same rotating shaft, a sprocket 101 drivingly connected to a crankshaft (not shown), a housing 102 fixed thereto, and a camshaft. And a vane rotor 103 that is drivingly connected. Each vane 103 </ b> A of the vane rotor 103 is disposed in a storage chamber 105 formed inside the housing 102. The storage chamber 105 is divided into an advance chamber 106 and a retard chamber 107 by a vane 103A. Then, the vane 103A is displaced in the storage chamber 105 by the hydraulic pressure supplied to the advance chamber 106 and the retard chamber 107, and the housing 102 and the vane rotor 103 described above rotate relative to each other, whereby the cam shaft relative to the crankshaft rotates. The phase, in other words, the valve timing is changed.

Also, the variable mechanism 100 is provided with a holding mechanism 110 that holds the valve timing at a specific time. As shown in FIG. 11B, the holding mechanism 110 includes a pin 111 provided on the vane 103A and a recess 112 formed on the sprocket 101 so that the pin 111 is inserted or removed. The pin 111 is urged in a direction to be fitted into the recess 112 by the spring 113, and is urged in a direction to be removed from the recess 112 by the pressure of the hydraulic oil supplied to the release chamber 114.

Then, when a holding condition for holding the valve timing at a specific time is satisfied, such as when an engine stop is requested, the hydraulic oil is discharged from the release chamber 114. Along with this, when the hydraulic pressure in the release chamber 114 decreases and the pin 111 is fitted into the recess 112 by the biasing force of the spring 113, the relative rotation between the vane rotor 103 and the housing 102 is restricted, and the valve timing is maintained at a specific time ( Hereinafter, this state is referred to as “lock state”). On the other hand, when a release condition for releasing the valve timing from a specific time is satisfied, such as when the valve timing is changed, hydraulic oil is supplied to the release chamber 114. Along with this, the hydraulic pressure in the release chamber 114 rises and the pin 111 is pulled out from the recess 112 by the biasing force based on this hydraulic pressure, and the restriction on the relative rotation between the vane rotor 103 and the housing 102 is released (hereinafter, this state is referred to as “ "Release state"). Thereafter, the hydraulic oil is supplied to and discharged from the advance chamber 106 and the retard chamber 107, so that the valve timing held at the specific timing is controlled to a desired timing suitable for the engine operating state. In addition, the supply / discharge state of the hydraulic fluid with respect to each hydraulic pressure in the advance chamber 106 and the retard chamber 107 of the variable mechanism 100 and the release chamber 114 of the holding mechanism 110 is controlled by the oil passage control unit.

JP 2008-286209 A

By the way, in the variable valve operating apparatus as described above, when the holding mechanism is in the locked state, the release chamber is opened through the release oil passage, so that hydraulic oil is discharged from the release chamber and the release oil passage. In some cases, there is almost no hydraulic oil. And when there is almost no hydraulic oil in the release chamber and the release oil passage in this way, even if supply of hydraulic oil to the release chamber is started to switch the holding mechanism from the locked state to the release state, the release chamber and the release oil The biasing force based on the pressure of the hydraulic oil does not act on the pin until the path is in an oil tight state filled with the hydraulic oil. And since there is a time during which the urging force based on such hydraulic pressure does not act, the time required for the pin to be removed from the recess becomes long, and the holding mechanism cannot be quickly shifted from the locked state to the released state. It becomes. That is, in the conventional variable valve apparatus, there is still room for improvement in improving the responsiveness when the holding mechanism is switched from the locked state to the released state when the release condition is satisfied. It was.

The present invention has been made in view of such circumstances, and an object of the present invention is an internal combustion engine capable of improving responsiveness when a holding mechanism that holds a valve timing at a specific time is switched from a locked state to a released state. The object is to provide a variable valve gear.

In order to achieve the above object, a variable valve operating apparatus for an internal combustion engine according to the present invention includes a first rotating body drivingly connected to a crankshaft, a driving shaft connected to a camshaft, and the same as the first rotating body. A second rotating body that rotates around the rotation axis of the first rotating body, and an advance chamber and a retard chamber that are defined by the first rotating body and the second rotating body, A variable mechanism that changes the valve timing of the valve that is driven to open and close by the camshaft by relatively rotating each rotating body by hydraulic pressure that is selectively supplied to the retard chamber; A pin provided on one side, a recess provided on the other of the rotating bodies and into which the pin fits, a biasing member for biasing the pin in a direction to fit into the recess, and the pin serving as the recess For urging the pin in the direction of withdrawal from A release chamber to which dynamic oil is supplied, and lowering the hydraulic pressure of the release chamber and fitting the pin into the recess to release the lock timing and the hydraulic pressure of the release chamber to hold the valve timing at a specific time A holding mechanism capable of switching the valve timing to a release state that can be changed to a time different from a specific time by raising the pressure to a hydraulic pressure and removing the pin from the recess; and the advance chamber, the retard chamber, and the A variable valve operating apparatus for an internal combustion engine comprising a hydraulic mechanism having an oil passage control unit that controls a supply / discharge state of the hydraulic oil with respect to the release chamber, wherein the hydraulic mechanism supplies hydraulic oil from a hydraulic oil supply source to the oil passage. A supply oil passage that supplies the control oil to the advance chamber and the retard chamber from the oil passage control portion and the oil passage control portion; From the road controller to the release chamber Comprising a release oil passage for supplying hydraulic oil, and a communicating oil passage for supplying the oil supply passage and said release oil passage and a small hydraulic pressure of the hydraulic fluid from the release oil pressure communicates with the release chamber.

According to the above configuration, even when the holding mechanism is in the locked state and the oil passage control unit is in a discharge state in which the hydraulic oil is discharged from the release chamber and the release oil passage, The release chamber is supplied with hydraulic oil having a lower hydraulic pressure than the release hydraulic pressure from the supply oil passage through the communication oil passage. For this reason, it is possible to increase the amount of hydraulic oil remaining in the release oil passage and the release chamber while maintaining the holding mechanism in the locked state. Therefore, when the release condition for switching the holding mechanism from the locked state to the released state is satisfied and hydraulic oil starts to be supplied from the oil passage control unit to the release chamber via the release oil passage, the release chamber quickly becomes oil-tight. The hydraulic pressure in the release chamber rises quickly. When the release condition of the holding mechanism is satisfied in this way, the hydraulic pressure in the release chamber can be quickly increased, so that the responsiveness when switching the holding mechanism from the locked state to the released state can be improved. .

-It is preferable that the said communicating oil path connects the part from the said hydraulic oil supply source to the said oil path control part in the said supply oil path, and the said cancellation | release oil path.
The hydraulic pressure of the hydraulic oil in the part of the supply oil path from the oil path control unit to the advance chamber or retard chamber is advanced, retarded, or kept at the current timing. It depends on the valve timing control request such as whether or not. On the other hand, the hydraulic pressure of the hydraulic oil in the part from the hydraulic oil supply source to the oil path control unit in the supply oil path does not depend on the control timing of such valve timing, The hydraulic oil can be stably supplied to the release oil passage and the release chamber. For this reason, according to the structure mentioned above, hydraulic fluid can remain suitably in the inside of a cancellation | release oil path or a cancellation | release chamber, and the responsiveness of a holding mechanism can be improved further.

The holding mechanism includes a first holding mechanism that restricts the valve timing from changing to the advance side with respect to the specific time, and a first holding mechanism that restricts the valve timing from changing to the retard side from the specific time. 2 holding mechanism, and the first holding mechanism and the second holding mechanism cooperate to set the valve timing to the specific time which is an intermediate time between the most advanced timing and the most retarded timing. The release oil passage is a first release chamber provided in the first holding mechanism as the release chamber and a second release provided in the second holding mechanism as the release chamber. It is preferable to supply hydraulic oil to both the chamber.

As described above, the first holding mechanism and the second holding mechanism cooperate to hold the valve timing at a specific timing which is an intermediate timing between the most advanced timing and the most retarded timing. In the configuration provided, the pin can be easily pulled out of the recess when the holding mechanism is switched from the locked state to the released state as compared with a configuration in which the valve timing is held at a specific time by a single holding mechanism. That is, when the valve timing is about to change to the retard side due to the alternating torque acting on the camshaft, the pin of the first holding mechanism is easily pulled out of the recess. On the other hand, when the valve timing is about to change to the advance side due to the alternating torque acting on the camshaft, the pin of the second holding mechanism is easily pulled out of the recess. However, in the configuration having a plurality of release chambers such as the first release chamber and the second release chamber in this way, the total volume of these release chambers is increased and the first release chamber and the second release chamber are released from the release oil passage. Since it is necessary to supply hydraulic oil to both the release chamber, the volume of the release oil path is also increased. For this reason, when the release conditions as described above are satisfied, the responsiveness of the holding mechanism tends to be further reduced due to the small amount of hydraulic oil remaining in the release chamber and the release oil passage. However, according to the above-described configuration, even when the variable valve operating apparatus has such a tendency, it is possible to improve the responsiveness when the holding mechanism is switched from the locked state to the released state.

The holding mechanism is a ratchet that advances the valve timing stepwise from a timing retarded from the specific timing to the specific timing by relatively rotating the rotating bodies with an alternating torque acting on the camshaft. The holding mechanism further includes an atmospheric communication path that communicates the advance chamber and the retard chamber with the atmospheric space, and the pin opens the atmospheric communication path or It also serves as an on-off valve that shuts off, and it is preferable that the pin opens the atmosphere communication path as the hydraulic pressure in the release chamber decreases.

If the valve timing is not maintained at a specific time that is an intermediate time when the engine is stopped, the first rotating body and the second rotating body are stopped in a state where the valve timing is at the most retarded time. At the next engine start, an alternating torque acts on the camshaft, so the valve timing is advanced to a specific time through a ratchet type autonomous advance mechanism that uses the relative rotation of each rotating body. Is possible. However, in this way, in order to relatively rotate the first rotating body and the second rotating body when the engine is started, the hydraulic oil is discharged from the advance chamber and the retard chamber after the engine is stopped, and the oil pressure of each oil chamber is It is desirable that is sufficiently lowered.

In the above configuration, the holding mechanism further includes an atmospheric communication path that communicates the advance chamber and the retard chamber with the atmospheric space, and the pin opens the atmospheric communication path as the hydraulic pressure in the release chamber decreases. Accordingly, when the supply of hydraulic oil to the release chamber is stopped after the engine is stopped and each hydraulic pressure is reduced, the atmosphere is introduced into the advance chamber and the retard chamber through the atmosphere communication path. As a result, when the hydraulic oil is quickly discharged from the advance chamber and the retard chamber, the first rotating body and the second rotating body easily rotate relative to each other due to the alternating torque acting on the camshaft when the engine is started. The valve timing can be rapidly advanced to a specific time.

In one aspect of the present invention, an atmospheric communication passage that communicates the advance chamber and the retard chamber with the atmospheric space, an on-off valve that opens or closes the atmospheric communication passage, and a direction that blocks the atmospheric communication passage An on-off valve oil chamber to which hydraulic oil for energizing the on-off valve is supplied, and an atmosphere release mechanism provided at a position different from the holding mechanism in the circumferential direction of the rotating shaft. The release oil passage supplies hydraulic oil to the on-off valve oil chamber in addition to the release chamber.

If the valve timing is not maintained at a specific time that is an intermediate time when the engine is stopped, the first rotating body and the second rotating body are stopped in a state where the valve timing is at the most retarded time. At the next engine start, an alternating torque acts on the camshaft, so the valve timing is advanced to a specific time through a ratchet type autonomous advance mechanism that uses the relative rotation of each rotating body. Is possible. However, in this way, in order to relatively rotate the first rotating body and the second rotating body when the engine is started, the hydraulic oil is discharged from the advance chamber and the retard chamber after the engine is stopped, and the oil pressure of each oil chamber is It is desirable that is sufficiently lowered.

In the above configuration, the atmospheric communication passage that communicates the advance chamber and the retard chamber with the atmospheric space, the open / close valve that opens or closes the atmospheric communication passage, and the open / close valve that biases the open / close valve in a direction that blocks the atmospheric communication passage. And an open / close valve oil chamber to which hydraulic oil is supplied. Further, the air release mechanism is provided at a position different from the holding mechanism in the circumferential direction of the rotation shaft. Therefore, when the supply of the hydraulic oil to the on-off valve oil chamber is stopped after the engine is stopped and the hydraulic pressure is lowered, the atmosphere is introduced into the advance chamber and the retard chamber through the atmosphere communication passage. As a result, when the hydraulic oil is discharged from the advance chamber and the retard chamber, the first rotating body and the second rotating body easily rotate relative to each other due to the alternating torque acting on the camshaft when the engine is started. You can quickly advance to a specific time.

However, in the configuration provided with the air release mechanism as described above, since the release chamber of the air release mechanism is provided in addition to the release chamber of the holding mechanism described above, the total volume of the release chamber and the oil chamber for the open / close valve is In addition to the increase, since it is necessary to supply hydraulic oil from the release oil passage to the on-off valve oil chamber in addition to the release chamber, the volume of the release oil passage also increases. For this reason, when the release condition as described above is satisfied, a decrease in the responsiveness of the holding mechanism due to a small amount of hydraulic oil remaining in the release chamber and the release oil passage tends to become even more apparent. However, according to the above-described configuration, even when the variable valve operating apparatus has such a tendency, it is possible to improve the responsiveness when the holding mechanism is switched from the locked state to the released state.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which shows the variable valve operating apparatus of the internal combustion engine concerning embodiment of this invention, and an internal combustion engine provided with the same. The end view which shows the internal structure which looked at the cover side from the sprocket side in the state which removed the sprocket about the variable mechanism of the variable valve apparatus. FIG. 3 is a cross-sectional view showing a cross-sectional structure along the line AA in FIG. 2. FIG. 3 is a cross-sectional view showing a cross-sectional structure along the line BB in FIG. 2. Schematic shown about the structure of the hydraulic-fluid channel | path of a hydraulic mechanism. The figure explaining the relationship between the quantity of the hydraulic fluid each supplied to a variable mechanism, a holding mechanism, and an air release mechanism through an oil control valve, and the stroke of an oil control valve. It is sectional drawing explaining the state of an advance angle holding | maintenance mechanism and an atmospheric release mechanism when an oil control valve is set to the 3rd mode, the 4th mode, and the 5th mode, (a) is an advance angle Sectional drawing of a holding mechanism, (b) is sectional drawing of an air release mechanism. It is sectional drawing explaining the state of an advance angle holding mechanism and an air release mechanism when an engine is stopped or a holding mechanism is locked, (a) is an advance angle holding mechanism when the holding mechanism is in a locked state. A sectional view showing a sectional structure, (b) is a sectional view showing a sectional structure of the advance holding mechanism when the holding mechanism is not locked and the engine is stopped, and (c) is a sectional view showing when the holding mechanism is in the locked state and the engine. Sectional drawing which shows the cross-section of the air release mechanism during a stop. FIG. 3 schematically shows a cross-sectional structure taken along line BB in FIG. 2 on a plane, in which (a) to (d) show a valve timing from a most retarded timing to a specific timing when the engine is started. Sectional drawing which shows the process of advancing to the order. The figure which shows the relationship between the supply / exhaust state of the hydraulic fluid in a variable valve operating apparatus, and each mode of an oil control valve, and the relationship between the state of a variable mechanism, a holding mechanism, and an air release mechanism, and each mode of an oil control valve. (A) is an end view showing the internal structure of the variable mechanism of the prior art, (b) is a cross-sectional view showing a cross-sectional structure taken along line CC of (a).

Hereinafter, an embodiment in which the present invention is embodied as a variable valve operating apparatus that changes the valve timing of an intake valve of an internal combustion engine will be described with reference to FIGS. 1 to 10.
As shown in FIG. 1, a crankshaft 12 that converts a reciprocating motion into a rotational motion is connected to a piston 11 that is accommodated in a cylinder of the internal combustion engine 10 so as to be able to reciprocate. Further, an intake camshaft 22 that opens and closes the intake valve 21 and an exhaust camshaft 24 that opens and closes the exhaust valve 23 are provided in the upper part of the internal combustion engine 10.

On the other hand, an oil pan 14 that stores hydraulic oil is attached to the lower part of the internal combustion engine 10, and an oil pump 13 that is driven by the rotational force of the crankshaft 12 to assemble the hydraulic oil of the oil pan 14 is provided. This oil pump 13 functions as a hydraulic oil supply source.

The variable valve operating device 20 is provided at the tip of the camshaft 22 to change the valve timing of the intake valve 21 and a specific intermediate timing (hereinafter referred to as the most advanced timing). And a hydraulic mechanism 90 that controls the hydraulic pressure of each oil chamber provided in the variable valve operating apparatus 20. The sprocket 31 of the variable mechanism 25 is drivingly connected to the crankshaft 12 through a timing chain (not shown). The sprocket 31 is attached to the housing 32 so as to block one opening of the flat cylindrical housing 32 of the variable mechanism 25. The cover 30 of the variable mechanism 25 is opposite to the side on which the sprocket 31 is provided. The side housing 32 is provided so as to close the opening.

The hydraulic mechanism 90 includes an oil control valve (hereinafter referred to as “OCV”) 91 and a hydraulic oil passage 90A. The OCV 91 controls the supply / discharge state of the hydraulic oil to / from each oil chamber provided in the variable valve operating apparatus 20. The hydraulic oil passage 90 </ b> A includes a plurality of oil passages that supply the hydraulic oil of the oil pan 14 to the oil chambers, and a plurality of oil passages that return the hydraulic oil from the oil chambers to the oil pan 14.

The internal combustion engine 10 is provided with various sensors for detecting the operating state of the internal combustion engine 10. For example, as such various sensors, a crank angle sensor 15 provided in the vicinity of the crankshaft 12 for detecting the crank angle and the engine rotational speed, and a cam angle provided in the vicinity of the camshaft 22 for detecting the position of the camshaft 22. There are sensors 16 and the like. Signals output from these various sensors are taken into the ECU 17 that comprehensively controls various devices of the internal combustion engine 10.

ECU17 is provided with the memory | storage device etc. which memorize | store the arithmetic result of various controls, the function map used for the calculation, etc. other than an arithmetic unit and a drive circuit. The ECU 17 detects the operating state of the internal combustion engine 10 based on output signals from various sensors and executes various controls. In such variable valve timing control, the valve timing of the intake valve 21 is controlled at a timing according to the engine operating state by appropriately changing the spool position (OCV stroke) of the OCV 91 based on the engine operating state. To do.

Next, the configuration of the variable mechanism 25 will be described with reference to FIG. FIG. 2 shows the internal structure of the variable mechanism 25 when the cover 30 is viewed from the sprocket 31 side with the sprocket 31 removed. The sprocket 31, the housing 32, and the cover 30 described above are fixed to each other by bolts (not shown) and rotate integrally around the rotation axis of the cam shaft 22. The cover 30, the sprocket 31, and the housing 32 function as a first rotating body that is drivingly connected to the crankshaft 12. The cam shaft 22 and the housing 32 are assumed to rotate in the rotation direction RA shown in FIG.

The housing 32 is provided with three partition portions 35 extending radially inward. The housing 32 accommodates a vane rotor 33 that rotates about the same rotation axis as the housing 32 so as to be rotatable relative to the housing 32. The vane rotor 33 includes a boss 33A coupled to the camshaft 22 so as to be integrally rotatable, and three vanes 33B projecting radially outward from the boss 33A. The boss 33 </ b> A is fixed to the end of the cam shaft 22 by a center bolt 34. Three compartments 36 are defined by the compartments 35 of the housing 32 and the bosses 33A of the vane rotor 33, and each compartment 36 is partitioned into an advance chamber 37 and a retard chamber 38 by the vanes 33B. ing. The vane rotor 33 functions as a second rotating body that is drivingly connected to the cam shaft 22.

The variable mechanism 25 is provided with a holding mechanism 26 that holds the valve timing at a specific time. This specific time is set so that the valve timing is suitable for starting the engine.

The holding mechanism 26 is provided in the advance angle holding mechanism 50 provided in one certain vane 33B (lower vane 33B in FIG. 2) and in another vane 33B (upper left vane 33B in FIG. 2). And a retard holding mechanism 70. The advance angle holding mechanism 50 has a function of restricting relative rotation of the housing 32 and the vane rotor 33 in the direction in which the valve timing changes to the advance side with respect to the specific time. On the other hand, the retard holding mechanism 70 has a function of restricting relative rotation of the housing 32 and the vane rotor 33 in a direction in which the valve timing is retarded from a specific timing. Further, the advance angle holding mechanism 50 and the retard angle holding mechanism 70 also function as a ratchet type autonomous advance angle mechanism that advances the valve timing stepwise from a timing that is behind the specific timing to a specific timing. The valve timing is held at a specific time by the cooperation of the advance angle holding mechanism 50 and the retard angle holding mechanism 70. Further, the advance angle holding mechanism 50 is provided with an atmosphere release mechanism 60 that allows the advance chamber 37 and the retard chamber 38 to communicate with the atmospheric space. The retard holding mechanism 70 is provided with an atmosphere release mechanism 80 that allows the advance chamber 37 and the retard chamber 38 to communicate with the atmospheric space.

Further, among the three vanes 33B, the remaining one vane 33B (the upper right vane 33B in FIG. 2) where the advance angle holding mechanism 50 and the retard angle holding mechanism 70 are not provided is included in the advance angle chamber 37 and the retard angle chamber. An air release mechanism 40 is provided for communicating the air with the air space.

The center bolt 34 incorporates the OCV 91 described above. The variable mechanism 25 is provided with a plurality of oil passages extending in the radial direction of the vane rotor 33 from the OCV 91 to the oil chambers of the advance chamber 37, the retard chamber 38, the holding mechanism 26, and the atmosphere release mechanism 40. ing. Specifically, the advance oil passage 95 communicates the OCV 91 and the advance chamber 37. The retard oil path 96 communicates the OCV 91 and the retard chamber 38. Further, the first release oil passage 97 </ b> A communicates the OCV 91 and the first release chamber 57 of the advance angle holding mechanism 50. The second release oil passage 97 </ b> B communicates the OCV 91 and the second release chamber 77 of the retard holding mechanism 70. The third release oil passage 97C communicates the OCV 91 and the third release chamber 44 of the atmosphere release mechanism 40. The OCV 91 functions as an oil passage control unit that controls the supply / discharge state of hydraulic oil to the advance chamber 37, the retard chamber 38, and the release chambers 57, 77, and 44.

Next, the configuration of the atmosphere release mechanism 40 will be described with reference to FIG. Hereinafter, the side where the cover 30 of the variable mechanism 25 is disposed in the axial direction of the cam shaft 22 is referred to as “front end side ZA”, and the side where the sprocket 31 is disposed is referred to as “base end side ZB”.

The air release mechanism 40 is opened or closed by a bottomed cylindrical open / close pin 41 accommodated in a vane hole 33C formed in the vane 33B so as to extend in the axial direction of the cam shaft 22 and a open / close pin 41. And a third release chamber 44 into which hydraulic oil is supplied or discharged.

The open / close pin 41 reciprocates in the vane hole 33C to the distal end side ZA and the proximal end side ZB. The opening / closing pin 41 divides the vane hole 33 </ b> C into a third release chamber 44 on the cover 30 side and a third spring chamber 45 on the sprocket 31 side. The atmosphere communication path 42 includes a third spring chamber 45, an advance communication path 46, a retard communication path 47, and an atmosphere release path 48. The third spring chamber 45 accommodates a third spring 43 that biases the open / close pin 41 toward the distal end side ZA. The advance communication passage 46 communicates the third spring chamber 45 and the advance chamber 37. The retard communication passage 47 communicates the third spring chamber 45 and the retard chamber 38. The air release passage 48 communicates the third spring chamber 45 and the air space.

The hydraulic oil is supplied to or discharged from the third release chamber 44 through the third release oil passage 97C. The opening / closing pin 41 is urged toward the base end side ZB by the urging force based on the hydraulic pressure in the third release chamber 44. The outer peripheral surface of the open / close pin 41 in a state adjacent to the sprocket 31 closes the advance communication passage 46, the retard communication passage 47, and the air release passage 48, so that these passages are blocked from the third spring chamber 45. To do. On the other hand, the outer peripheral surface of the open / close pin 41 in a state adjacent to the cover 30 opens the advance communication passage 46, the retard communication passage 47, and the air release passage 48, so that these passages communicate with the third spring chamber 45. Let Thus, the open / close pin 41 functions as an open / close valve that opens or closes the atmosphere communication path 42, and the third release chamber 44 operates to urge the open / close pin 41 in a direction to close the atmosphere communication path 42. It functions as an oil chamber for an on-off valve to which oil is supplied.

Next, the configuration of the holding mechanism 26 will be described with reference to FIG. FIG. 4 shows the advance angle holding mechanism 50 on the left side and the retard angle holding mechanism 70 on the right side.
The advance holding mechanism 50 includes a first pin 51, a first recess 53 into which the first pin 51 is inserted or removed, and an urging member that urges the first pin 51 toward the distal end ZA. A first spring 52 and a first release chamber 57 into which hydraulic oil is supplied or discharged are provided. The first pin 51, the first spring 52, and the first release chamber 57 are all provided in the vane 33B. On the other hand, the first recess 53 is formed in the cover 30.

The first pin 51 includes an outer pin 51A formed in a bottomed cylindrical shape, and a columnar inner pin 51B disposed inside the outer pin 51A while penetrating the bottom plate 51C of the outer pin 51A. . The outer pin 51A reciprocates to the distal end side ZA and the proximal end side ZB in a vane hole 56 as a space formed in the vane 33B so as to extend in the axial direction of the cam shaft 22. That is, the outer pin 51A partitions the vane hole 56 into a first release chamber 57 on the cover 30 side and a first spring chamber 58 on the sprocket 31 side. Similarly, the inner pin 51B reciprocates in the vane hole 56 to the distal end side ZA and the proximal end side ZB, and further, the inner pin 51B protrudes outside the vane 33B in a state adjacent to the cover 30 and enters the first recess 53. Insert. Further, a flange-like stopper 51D is formed on the outer periphery of the inner pin 51B so as to protrude so as to abut or separate from the bottom plate 51C of the outer pin 51A.

The first recess 53 has an arc shape extending along the circumferential direction of the cover 30. Specifically, the bottom surface of the first recess 53 is stepped in the circumferential direction of the cover 30, that is, the first recess 53 includes a first upper step portion 54 formed with a relatively shallow depth, The first lower step portion 55 is formed with a relatively deep depth. The first upper stage portion 54 is located on the retard side with respect to the first lower stage portion 55.

The first spring chamber 58 accommodates a first spring 52 that biases the first pin 51 toward the distal end side ZA. The first spring 52 is a general term for an outer spring 52A that biases the outer pin 51A toward the distal end ZA and an inner spring 52B that biases the inner pin 51B toward the distal end ZA. The outer spring 52A and the inner spring 52B are arrange | positioned mutually independently. On the other hand, hydraulic oil is supplied to the first release chamber 57 through the first release oil passage 97A (see FIG. 2). The first pin 51 is urged toward the base end side ZB by a force based on the pressure of the hydraulic oil supplied to the first release chamber 57. When the hydraulic pressure in the first release chamber 57 reaches the first release hydraulic pressure P1, the first pin 51 is removed from the first recess 53.

The advance angle holding mechanism 50 further includes an atmosphere release mechanism 60 having an atmosphere communication path 62 that communicates the advance chamber 37 and the retard chamber 38 with the atmosphere space. The atmosphere communication passage 62 includes the first spring chamber 58, the advance communication passage 66 that communicates the first spring chamber 58 and the advance chamber 37, the first spring chamber 58, and the retard chamber 38. Are formed by a retard communication passage 67 that communicates with each other, and an air release passage 68 that communicates the first spring chamber 58 with the atmospheric space.

The first pin 51 described above has a function of fitting or removing from the first recess 53, and also functions as an on-off valve that opens or shuts off the air communication path 62. That is, the first pin 51 is configured to close the advance communication passage 66, the retard communication passage 67, and the air release passage 68 at the outer peripheral surface when adjacent to the proximal end side ZB. Yes.

As shown on the right side of FIG. 4, the retard holding mechanism 70 includes a second pin 71, a second recess 73 in which the second pin 71 is inserted or removed, and the second pin 71 on the distal side ZA. A second spring 72 as a biasing member that biases the hydraulic oil and a second release chamber 77 into which hydraulic oil is supplied or discharged. The second pin 71, the second spring 72, and the second release chamber 77 are all provided in the vane 33B. On the other hand, the second recess 73 is formed in the cover 30.

The second pin 71 includes an outer pin 71A formed in a bottomed cylindrical shape, and a columnar inner pin 71B disposed inside the outer pin 71A while penetrating the bottom plate 71C of the outer pin 71A. . The outer pin 71A reciprocates to the distal end side ZA and the proximal end side ZB in a vane hole 76 as a space formed in the vane 33B so as to extend in the axial direction of the cam shaft 22. That is, the outer pin 71A partitions the vane hole 76 into a second release chamber 77 on the cover 30 side and a second spring chamber 78 on the sprocket 31 side. Similarly, the inner pin 71B reciprocates in the vane hole 76 to the distal end side ZA and the proximal end side ZB, and the inner pin 71B protrudes outside the vane 33B in a state adjacent to the cover 30 to form a second recess. 73. Further, a flange-like stopper 71D is formed on the outer periphery of the inner pin 71B so as to protrude so as to abut against or separate from the bottom plate 71C of the outer pin 71A.

The second recess 73 has an arc shape extending along the circumferential direction of the cover 30. Specifically, the bottom surface of the second recess 73 forms a step in the circumferential direction of the cover 30, that is, the second recess 73 is formed with a second upper step portion 74 formed with a relatively shallow depth. The second lower step 75 is formed with a relatively deep depth. The second upper stage portion 74 is located on the retard side with respect to the second lower stage portion 75.

The second spring chamber 78 accommodates a second spring 72 that biases the second pin 71 toward the distal end side ZA. The second spring 72 is a generic term for an outer spring 72A that biases the outer pin 71A toward the distal end ZA and an inner spring 72B that biases the inner pin 71B toward the distal end ZA. The outer spring 72A and the inner spring 72B are arranged independently of each other. On the other hand, hydraulic oil is supplied to the second release chamber 77 through the second release oil passage 97B (see FIG. 2). Due to the force based on the pressure of the hydraulic oil supplied to the second release chamber 77, the second pin 71 is urged toward the base end side ZB. Specifically, when the hydraulic pressure in the second release chamber 77 reaches the second release hydraulic pressure P <b> 2, the second pin 71 is removed from the second recess 73.

The retard holding mechanism 70 further includes an atmosphere release mechanism 80 having an atmosphere communication passage 82 that communicates the advance chamber 37 and the retard chamber 38 with the atmosphere space. The air communication passage 82 includes the second spring chamber 78, the advance communication passage 86 that communicates the second spring chamber 78 and the advance chamber 37, the second spring chamber 78, and the retard chamber 38. Are formed by a retarded angle communication passage 87 that communicates with the second spring chamber 78 and an air release passage 88 that communicates between the second spring chamber 78 and the atmospheric space.

The above-described second pin 71 has a function of fitting or removing from the second recess 73, and also functions as an on-off valve that opens or shuts off the air communication path 82. That is, the second pin 71 is configured to close the advance communication passage 86, the retard communication passage 87, and the air release passage 88 at the outer peripheral surface when adjacent to the base end side ZB. Yes.

The first pin 51, the second pin 72, the first upper step 54 and the first lower step 55 of the first recess 53, and the second upper step 74 and the second lower step of the second recess 73 The unit 75 functions as a ratchet type autonomous advance mechanism. That is, the first upper step portion 54 and the first lower step portion 55 of the first recess 53 are moved toward the retard side of the pin 51 when the first pin 51 is fitted into the step portions 54 and 55, respectively. Each displacement is regulated. On the other hand, the second upper step portion 74 and the second lower step portion 75 of the second recess 73 are moved toward the retard side of the pin 71 when the second pin 71 is fitted into the step portions 74 and 75, respectively. Each displacement is regulated. When the first pin 51 is fitted into the first lower step portion 55 and the second pin 71 is fitted into the second lower step portion 75, the first lower step portion 55 is moved by the end of the advance side. The displacement of the first pin 51 toward the advance side is restricted, and at the same time, the displacement of the second pin 71 toward the retard side is restricted by the end of the second lower step 75 on the retard side. Thereby, the valve timing is held at a specific time. FIG. 4 shows a state where the holding mechanism 26 is in a locked state and the valve timing is held at a specific time.

Next, the configuration of the hydraulic oil passage 90A of the hydraulic mechanism 90 will be described with reference to FIG. The hydraulic oil passage 90 </ b> A includes a supply oil passage 92, an advance oil passage 95, a retard oil passage 96, a release oil passage 97, a communication oil passage 98, and a discharge oil passage 99. In the following description, each oil passage through which the hydraulic oil supplied from the oil pump 13 is supplied to the OCV 91 is referred to as “upstream side” of the OCV 91, and the hydraulic oil through the OCV 91 is supplied from the OCV 91 to each oil. Each oil passage that circulates until it is supplied to the chamber is referred to as the “downstream side” of the OCV 91.

The supply oil path 92 is provided on the upstream side of the OCV 91 and communicates with the oil pump 13 and the OCV 91. In addition, the supply oil passage 92 has a first supply oil passage 93 connected to the advance / retard angle supply port 93P of the OCV 91 and a second supply connected to the release supply port 94P of the OCV 91 at the branch point 92D. Branches to an oil passage 94.

The advance oil passage 95 is provided on the downstream side of the OCV 91, and communicates the advance port 95 </ b> P of the OCV 91 and the advance chamber 37. The retard oil passage 96 is provided on the downstream side of the OCV 91, and communicates the retard port 96 </ b> P of the OCV 91 with the retard chamber 38. The first supply oil passage 93, the advance oil passage 95, and the retard oil passage 96 described above supply hydraulic oil from the oil pump 13 to the OCV 91, and the advance chamber 37 and the retard chamber 38 from the OCV 91. It functions as a supply oil passage which supplies hydraulic oil selectively to.

The release oil passage 97 is provided on the downstream side of the OCV 91 independently of the first supply oil passage 93, the advance oil passage 95, and the retard oil passage 96 described above, and the first release chamber 57, the second The release chamber 77 and the third release chamber 44 communicate with the release port 97P of the OCV 91, respectively. The release oil passage 97 includes a first release oil passage 97A connected to the first release chamber 57, a second release oil passage 97B connected to the second release chamber 77, and a third release chamber. Branching to a third release oil passage 97C connected to 44 at a branch point 97D.

The communication oil path 98 communicates the upstream side of the branch point 97 </ b> D in the release oil path 97 and the first supply oil path 93. The flow path resistance of the communication oil path 98 is such that the hydraulic oil having a hydraulic pressure smaller than the first release hydraulic pressure P1 is supplied to the first release chamber 57 and the hydraulic pressure smaller than the second release hydraulic pressure P2 is operated. It is preset to allow oil to be supplied to the second release chamber 77. Specifically, when the holding mechanism 26 is in the locked state, the amount of hydraulic oil discharged from each release chamber 57, 77, the urging force of each spring 52, 72, the volume of each release chamber 57, 77, and the first The flow resistance of the communication oil path 98 is set so that an appropriate amount of hydraulic oil is supplied to the release chambers 57 and 77 in consideration of the pressure of the hydraulic oil flowing through the supply oil path 93 and the like. .

The discharge oil passage 99 is connected to the discharge port 99P of the OCV 91 and extends to the oil pan 14.
Next, the relationship between the amount of hydraulic oil supplied to the variable mechanism 25, the holding mechanism 26, and the atmosphere release mechanism 40 through the OCV 91 and the OCV stroke will be described with reference to FIG. The vertical axis in FIG. 6 indicates the flow rate of the hydraulic oil, and the horizontal axis in FIG. 6 indicates the OCV stroke.

When the OCV 91 is switched between the first mode to the fifth mode through the control of the OCV stroke, and the opening area between the ports of the OCV 91 changes, the hydraulic oil supply / discharge state in the hydraulic oil passage 90A. Is changed.

In the first mode, the advance port 95P and the advance / retard supply port 93P are communicated. As a result, hydraulic fluid is supplied from the first supply oil passage 93 to the advance oil passage 95 (shown as “93 → 95”). On the other hand, the retard port 96P and the discharge port 99P are communicated. As a result, the hydraulic oil is discharged from the retard oil passage 96 to the discharge oil passage 99 (“96 → 99”). Further, the release port 97P and the discharge port 99P communicate with each other. As a result, the hydraulic oil is discharged from the release oil passage 97 to the discharge oil passage 99 (“97 → 99”). This first mode is set when the engine is started.

In the second mode, the advance port 95P communicates with the advance / retard supply port 93P. As a result, hydraulic fluid is supplied from the first supply oil passage 93 to the advance oil passage 95 (“93 → 95”). In addition, since the opening area of these advance port 95P and advance / retard supply port 93P is set to a smaller area as compared with the first mode described above, a smaller amount of hydraulic oil than in the first mode is used. The first supply oil passage 93 is supplied to the advance oil passage 95. On the other hand, the retard port 96P and the discharge port 99P are communicated. As a result, the hydraulic oil is discharged from the retard oil passage 96 to the discharge oil passage 99 (“96 → 99”). Further, the release port 97P and the discharge port 99P communicate with each other. As a result, the hydraulic oil is discharged from the release oil passage 97 to the discharge oil passage 99 (“97 → 99”). The second mode is set when engine operation is stopped and during idle operation.

In the third mode, the advance port 95P and the advance / retard supply port 93P are communicated with each other. As a result, hydraulic fluid is supplied from the first supply oil passage 93 to the advance oil passage 95 (“93 → 95”). On the other hand, the retard port 96P and the discharge port 99P are communicated. As a result, the hydraulic oil is discharged from the retard oil passage 96 to the discharge oil passage 99 (“96 → 99”). Further, the release port 97P and the release supply port 94P communicate with each other. As a result, the hydraulic oil is supplied from the second supply oil passage 94 to the release oil passage 97 (“94 → 97”). This third mode is set when the valve timing is advanced.

In the fourth mode, the advance port 95P and the retard port 96P are maintained in the closed state. As a result, the supply and discharge of hydraulic oil to and from the advance oil passage 95 and the retard oil passage 96 are stopped. On the other hand, the release port 97P communicates with the release supply port 94P. As a result, the hydraulic oil is supplied from the second supply oil passage 94 to the release oil passage 97 (“94 → 97”). The fourth mode is set when the valve timing is held at the target time and when the holding mechanism 26 is switched from the locked state to the released state.

In the fifth mode, the advance port 95P and the discharge port 99P are communicated. As a result, the hydraulic oil is discharged from the advance oil passage 95 to the discharge oil passage 99 (“95 → 99”). Further, the retard port 96P and the advance / retard supply port 93P are communicated with each other. As a result, hydraulic fluid is supplied from the first supply oil passage 93 to the retarded oil passage 96 (“93 → 96”). Further, the release port 97P and the release supply port 94P communicate with each other. As a result, the hydraulic oil is supplied from the second supply oil passage 94 to the release oil passage 97 (“94 → 97”). This fifth mode is set when the valve timing is retarded.

Next, the operation of the variable valve apparatus 20 including the variable mechanism 25, the holding mechanism 26, and the hydraulic mechanism 90 described above will be described.
When the crankshaft 12 rotates as the engine operates, the driving force is transmitted to the variable mechanism 25 via a timing chain (not shown), and the camshaft 22 rotates together with the variable mechanism 25. Thus, the intake valve 21 is opened and closed by a cam (not shown) provided on the cam shaft 22.

Further, when the supply or discharge of the hydraulic oil to or from the advance chamber 37 and the retard chamber 38 of the variable mechanism 25 is controlled through the OCV 91, the vane 33 </ b> B is formed in the storage chamber 36 based on the hydraulic pressure of the advance chamber 37 and the retard chamber 38. Displace. Thereby, the relative rotational position of the vane rotor 33 with respect to the sprocket 31 and the housing 32, that is, the relative rotational position of the cam shaft 22 with respect to the crankshaft 12 is changed, and the valve timing of the intake valve 21 is changed.

That is, as shown in FIG. 6, when the OCV 91 is set to the third mode, the working oil is supplied to the advance chamber 37 of the variable mechanism 25 while the retard chamber 38 is discharged. The Thus, when the vane rotor 33 rotates relative to the housing 32 in the advance direction, the valve timing is advanced. When the vane 33B comes into contact with the inner wall on the advance side of the retard chamber 38, the valve timing becomes the most advanced timing.

On the other hand, when the OCV 91 is set to the fifth mode, the working oil is supplied to the retarding chamber 38 while the working oil in the advance chamber 37 is discharged. Thereby, when the vane rotor 33 rotates relative to the housing 32 in the retarding direction, the valve timing is retarded. When the vane 33B comes into contact with the inner wall on the retard side of the advance chamber 37, the valve timing becomes the most retarded timing.

Further, when the OCV 91 is set to the fourth mode, the supply and discharge of the hydraulic oil from the advance chamber 37 and the retard chamber 38 are stopped. As a result, the relative rotation between the vane rotor 33 and the housing 32 stops, and the valve timing is maintained at a predetermined target time.

When the OCV 91 is in the third mode, the fourth mode, or the fifth mode, the valve timing is set to the most retarded angle timing and the most advanced angle timing by controlling the hydraulic pressure in the advance chamber 37 and the retard chamber 38. The first pin 51 and the second pin 71 are maintained in the state of being accommodated in the vane 33B (released state).

Next, referring to FIG. 7, the advance angle holding mechanism 50, the retard angle holding mechanism 70, and the atmosphere release mechanism when the OCV 91 is set to the third mode, the fourth mode, or the fifth mode. 40 states will be described. Since the retard holding mechanism 70 has the same structure as the advance holding mechanism 50, the illustration is omitted and the description is simplified (the same applies hereinafter).

As shown in FIG. 7A, in the advance angle holding mechanism 50, hydraulic oil is supplied to the first release chamber 57 through the first release oil passage 97A. Thereby, the biasing force based on the hydraulic pressure of the first release chamber 57 is maintained to be larger than the biasing force of the first spring 52 (the resultant force of the biasing force of the outer spring 52A and the biasing force of the inner spring 52A). ing. That is, the hydraulic pressure in the first release chamber 57 is maintained so as to be larger than the first release hydraulic pressure P1. At this time, the bottom plate 51C of the outer pin 51A is in contact with the stopper 51D of the inner pin 51B, and the inner pin 51B is moved to the base end side ZB together with the outer pin 51A. It has been pulled out. Further, the advance communication passage 66, the retard communication passage 67, and the atmosphere release passage 68 are closed by the outer pin 51A, and the atmosphere communication passage 62 is blocked. Therefore, the flow of air between the first spring chamber 58 and the advance chamber 37, between the first spring chamber 58 and the retard chamber 38, and between the first spring chamber 58 and the atmospheric space is as follows. Blocked.

On the other hand, in the retard holding mechanism 70, hydraulic oil is supplied to the second release chamber 77 through the second release oil passage 97B, whereby the hydraulic pressure in the second release chamber 77 is changed to the second release hydraulic pressure P2. Is maintained to be larger. As a result, the inner pin 71 </ b> B is removed from the second recess 73. Further, the advance communication path 86, the retard communication path 87, and the atmosphere release path 88 are closed by the outer pin 71A, and the atmosphere communication path 82 is blocked. Therefore, the flow of air between the second spring chamber 78 and the advance chamber 37, between the second spring chamber 78 and the retard chamber 38, and between the second spring chamber 78 and the atmospheric space is reduced. Blocked.

Further, as shown in FIG. 7B, in the atmosphere release mechanism 40, the working oil is supplied to the third release chamber 44 through the third release oil passage 97 </ b> C, whereby the third release chamber 44. The urging force based on the hydraulic pressure is maintained to be larger than the urging force of the third spring 43. As a result, the open / close pin 41 has moved to the base end side ZB, so that the advance communication path 46, the retard communication path 47, and the atmosphere release path 48 are closed by the open / close pin 41, and the atmosphere communication path 42 is blocked. ing. Therefore, the flow of air between the third spring chamber 45 and the advance chamber 37, between the third spring chamber 45 and the retard chamber 38, and between the third spring chamber 45 and the atmospheric space is reduced. Blocked.

Next, referring to FIG. 4 and FIG. 8A, the advance angle holding mechanism 50 and the retard angle holding when the holding mechanism 26 is switched to the locked state and when the holding mechanism 26 is in the locked state. The state of the mechanism 70 will be described.

When the internal combustion engine 10 shifts to idle operation, the OCV 91 is controlled so that the holding mechanism 26 is switched to the locked state. That is, when the valve timing is on the retard side with respect to the specific timing, the OCV 91 is set to the second mode. On the other hand, when the valve timing is more advanced than the specific timing, the OCV 91 is once set to the fifth mode, and the valve timing is retarded. Thereafter, the OCV 91 is set to the second mode. As a result, the valve timing is gradually advanced, and hydraulic oil is discharged from the first release chamber 57, the second release chamber 77, and the third release chamber 44, respectively. As a result, when the valve timing reaches a specific time, the first pin 51 is fitted into the first recess 53, the second pin 71 is fitted into the second recess 73, and the holding mechanism 26 is locked. Become.

Specifically, as shown in FIGS. 4 and 8A, the hydraulic oil is discharged from the first release chamber 57 of the advance holding mechanism 50 through the first release oil passage 97A, and the first release is performed. When the hydraulic pressure in the chamber 57 is lower than the first release hydraulic pressure P1, the first pin 51 biased by the first spring 52 is fitted into the first recess 53 (first lower step portion 55). At the same time, when hydraulic oil is discharged from the second release chamber 77 of the retard holding mechanism 70 and the hydraulic pressure in the second release chamber 77 is lower than the second release hydraulic pressure P2, as shown in FIG. In addition, the second pin 71 urged by the second spring 72 is fitted into the second recess 73 (second lower step 75). Thereby, the displacement of the first pin 51 toward the advance side is restricted by the end portion of the first lower step 55 on the advance side, and the displacement of the second pin 71 toward the retard side is the second. The valve timing is held at a specific time by being regulated at the retarded end of the lower step 75.

Further, as shown in FIG. 8A, when the holding mechanism 26 is in the locked state, in the advance holding mechanism 50, both the outer pin 51A and the inner pin 51B, which are the first pins 51, are on the distal end side ZA. Has moved. Therefore, the advance communication path 66, the retard communication path 67, and the atmosphere release path 68 are not closed by the outer pin 51A, and the atmosphere communication path 62 is opened. Therefore, in the atmosphere release mechanism 60, the first spring chamber 58 and the advance chamber 37, the first spring chamber 58 and the retard chamber 38, and the first spring chamber 58 and the atmosphere space are separated. Air flow between them is allowed (open to the atmosphere). On the other hand, also in the retard holding mechanism 70, the advance communication path 86, the retard communication path 87, and the atmosphere release path 88 are not closed by the outer pin 71A, and the atmosphere communication path 82 is opened. Accordingly, in the atmosphere release mechanism 80, the second spring chamber 78 and the advance chamber 37, the second spring chamber 78 and the retard chamber 38, and the second spring chamber 78 and the atmosphere space are separated. Air flow between them is allowed (open to the atmosphere).

Next, referring to FIG. 8B, the advance angle holding mechanism when the engine stop is executed in a state where the holding mechanism 26 has not been switched to the locked state (hereinafter referred to as “when the engine is abnormally stopped”). 50 and the state of the retard holding mechanism 70 will be described. After the engine is stopped, when the hydraulic oil supply to the first release chamber 57 of the advance angle holding mechanism 50 is stopped and the hydraulic pressure in the first release chamber 57 decreases, the outer pin 51A is attached to the distal end ZA by the outer spring 52A. Moved with force. Thereby, in the atmospheric release mechanism 60, the first spring chamber 58 and the advance chamber 37, the first spring chamber 58 and the retard chamber 38, and the first spring chamber 58 and the atmospheric space are provided. The air flow between the two is allowed (open to the atmosphere). On the other hand, also in the retard holding mechanism 70, the second spring chamber 78 is interposed between the second spring chamber 78 and the advance chamber 37 in the atmosphere release mechanism 80 as the hydraulic pressure in the second release chamber 77 decreases. And the retardation chamber 38 and between the second spring chamber 78 and the atmospheric space are allowed to flow (atmospheric release state).

Next, the state of the atmosphere release mechanism 40 when the holding mechanism 26 is in a locked state and when the engine is stopped will be described with reference to FIG.
When the holding mechanism 26 is switched to the locked state, the OCV 91 is set to the second mode and the release port 97P and the discharge port 99P communicate with each other, so that the hydraulic oil is discharged from the third release chamber 44. Therefore, when the holding mechanism 26 is in the locked state, the open / close pin 41 is moved to the distal end side ZA in the air release mechanism 40. As a result, the advance communication path 46, the retard communication path 47, and the atmosphere release path 48 are not closed by the open / close pin 41, and the atmosphere communication path 42 is opened. Therefore, in the atmosphere release mechanism 40, the third spring chamber 45 and the advance chamber 37, the third spring chamber 45 and the retard chamber 38, and the third spring chamber 45 and the atmosphere space are separated. Air flow between them is allowed (open to the atmosphere).

In addition, when the engine is stopped, the supply of hydraulic oil to the third release chamber 44 is stopped and the hydraulic pressure is lowered with the stop of the engine, so that the open / close pin 41 is moved to the tip side ZA. Thereby, the atmosphere release mechanism 40 will be in an atmosphere release state.

As described above, since the holding mechanism 26 is switched to the locked state during the idle operation, the valve timing is held at a specific time when the engine is stopped once the engine operation is temporarily stopped via the idle operation. The engine operation is stopped in a state where the holding mechanism 26 is in a locked state. And if the cancellation | release condition which cancels | releases valve timing from specific time is satisfied during engine operation, the holding mechanism 26 will be switched to a cancellation | release state. Specifically, when the OCV 91 is set to the fourth mode, the hydraulic oil is supplied to the first release chamber 57, the second release chamber 77, and the third release chamber 44 through the release oil passage 97. Are supplied respectively. Thereby, the 1st pin 51 and the 2nd pin 71 are extracted from the 1st recessed part 53 and the 2nd recessed part 73, respectively. Thereafter, as described above, the control of the OCV 91 is executed so that the valve timing becomes a desired time suitable for the engine operating state.

On the other hand, at the time of the abnormal engine stop described above, the valve timing changes to the most retarded timing due to the relative rotation of the vane rotor 33 and the housing 32 until the stop of the internal combustion engine 10 is completed. This is because the crankshaft 12 and the camshaft 22 rotate relative to each other in the direction in which the valve timing is retarded as the supply of hydraulic oil to the advance chamber 37 and the retard chamber 38 is stopped. Then, when the engine is subsequently started, the relative rotation of the vane rotor 33 and the housing 32 changes their directions so that the valve timing is changed to the retard side and the advance side by the alternating torque acting on the camshaft 22. Will come to do. Specifically, a negative torque acting in the direction in which the valve timing is advanced and a positive torque acting in the direction in which the valve timing is retarded alternately act on the cam shaft 22.

Here, in order to ensure the startability of the internal combustion engine 10, it is desirable that the holding mechanism 26 is in a locked state at the time of cranking and the valve timing is at a specific time. Therefore, in the present embodiment, the ratchet type autonomous advance angle mechanism described above is provided. As a result, the housing 32 and the vane rotor 33 are rotated relative to each other based on the alternating torque acting on the camshaft 22 to gradually advance the valve timing step by step from the state where the valve timing is at the most retarded timing to the specific timing. The holding mechanism 26 is quickly switched to the locked state.

Next, the process in which the valve timing is advanced from the most retarded timing to the specific timing when the engine is started will be described with reference to FIG. FIGS. 9A to 9D sequentially show the process in which the valve timing is advanced from the most retarded timing to the specific timing. 9A to 9D, the first pin 51 and the second pin are shown so that the relationship between the operating state of the advance holding mechanism 50 and the operating state of the retard holding mechanism 70 can be easily grasped. 71 is shown to protrude from the same vane 33B in opposite directions, and the first concave portion 53 and the second concave portion 73 are shown to face each other in the axial direction.

When cranking is started in the internal combustion engine 10, the vane rotor 33 and the housing 32 rotate relative to each other based on the negative torque acting on the cam shaft 22. Then, the first pin 51 is fitted into the first upper step portion 54 in a period in which the first pin 51 can protrude toward the first upper step portion 54 (FIG. 9A). In this state, based on the negative torque further acting on the camshaft 22, the second pin 71 is fitted into the second upper stage portion 74 (FIG. 9B), and the first pin 51 is the first The second pin 71 is fitted into the second lower step 75 (FIG. 9D). As a result, the holding mechanism 26 is switched to the locked state and the valve timing is held at a specific time, so that the internal combustion engine 10 is started well.

However, when a large amount of hydraulic oil remains in all the advance chambers 37 and retard chambers 38 when the engine is started after an abnormal engine stop, there is an alternating torque acting on the camshaft 22. Even in this case, the relative rotation between the vane rotor 33 and the housing 32 is suppressed by the hydraulic pressure of the advance chamber 37 and the retard chamber 38. For this reason, as described above, it may be difficult to quickly switch the holding mechanism 26 to the locked state.

In this regard, in the present embodiment, since the air release mechanisms 60, 80, 40 are provided in any of the three vanes 33B of the variable mechanism 25, the air release mechanisms 60, 80, 40, after the engine is stopped. At least one of 40 stops at a position above the center bolt 34 in the vertical direction. Further, these atmospheric release mechanisms 60, 80, 40 are in an open atmosphere state while the engine is stopped. Therefore, the atmosphere is introduced into the advance chamber 37 and the retard chamber 38 through the atmosphere communication passages 62, 82, 42 in the atmosphere release mechanisms 60, 80, 40 stopped above the center bolt 34 in the vertical direction. As a result, when the hydraulic oil is discharged from the advance chamber 37 and the retard chamber 38 through the advance oil passage 95 and the retard oil passage 96, a large amount of oil is supplied to all the advance chambers 37 and the retard chambers 38 when the engine is started. The frequency of occurrence of the situation in which the hydraulic oil remains is reduced. Therefore, when the engine is started after an abnormal engine stop, the hydraulic pressure in the advance chamber 37 and the retard chamber 38 that suppresses the relative rotation between the vane rotor 33 and the housing 32 is reduced, and the holding mechanism 26 is quickly switched to the locked state and the valve It can be held at a specific timing.

Incidentally, as described above, when the internal combustion engine 10 is in the idle state and the holding mechanism 26 is maintained in the locked state, the OCV 91 is set to the second mode. At this time, since the release port 97P and the discharge port 99P are communicated with each other, the first release chamber 57, the second release chamber 77, and the third release chamber 44 are opened through the release oil passage 97. . Accordingly, the hydraulic oil is discharged from the release chambers 57, 77, 44 and the release oil passages 97A, 97B, 97C, respectively, so that the inside of the hydraulic oil is not filled, so that there is almost no hydraulic oil. It may become a state that does not.

Here, when the release condition is satisfied when the holding mechanism 26 is in the locked state, the OCV 91 is set to the fourth mode in order to switch the holding mechanism 26 to the released state. As a result, the release port 97P and the release supply port 94P communicate with each other, and the supply of hydraulic oil from the second supply oil passage 94 to the release oil passage 97 is started.

However, even if the first supply chamber 57 and the first release oil passage 97A are not filled with the hydraulic oil under the above-described situation, the supply of the hydraulic oil through the second supply oil passage 94 is started. The urging force based on the pressure of the hydraulic oil does not act on the first pin 51 until the first release chamber 57 and the first release oil passage 97A are in an oil-tight state filled with the hydraulic oil. Similarly, in a situation where the second release chamber 77 and the second release oil passage 97B are not filled with the hydraulic oil, even if the supply of hydraulic oil through the second supply oil passage 94 is started, the second The urging force based on the pressure of the hydraulic oil does not act on the second pin 71 until the release chamber 77 and the second release oil passage 97B are in an oil-tight state filled with the hydraulic oil. Since there is a time during which the urging force based on such hydraulic pressure does not act, the time required for the pins 51 and 71 to be removed from the recesses 53 and 73 becomes longer, and the holding mechanism 26 is changed from the locked state to the released state. The problem arises that it cannot be migrated quickly.

Therefore, the hydraulic mechanism 90 of the present embodiment is provided with a communication oil passage 98 that communicates the upstream side of the branch point 97D in the release oil passage 97 and the first supply oil passage 93. Thereby, even when the OCV 91 is set to the first mode or the second mode and the holding mechanism 26 is switched to the locked state, the OCV 91 is always supplied to the release oil passage 97 through the communication oil passage 98. .

Next, the relationship between each mode of the OCV 91 and the supply of hydraulic oil in the communication oil passage 98 will be described with reference to FIG. When the holding mechanism 26 is in the locked state and the OCV 91 is set to the first mode or the second mode, the hydraulic oil is advanced through the first supply oil passage 93, the OCV 91, and the advance oil passage 95. Therefore, the hydraulic oil flowing through the first supply oil passage 93 is supplied to the release oil passage 97 through the communication oil passage 98. Since this communication oil path 98 is connected to the upstream side of the branch point 97D of the release oil path 97, the hydraulic oil supplied to the release oil path 97 is the first release oil path 97A, the second release oil. The oil is supplied to the passage 97B and the third release oil passage 97C. The hydraulic oil supplied to the first release oil passage 97A, the second release oil passage 97B, and the third release oil passage 97C is supplied to the first release chamber 57, the second release chamber 77, and Each is supplied to the third release chamber 44.

Note that, as described above, the flow resistance of the communication oil passage 98 is such that hydraulic fluid having a hydraulic pressure smaller than the first release hydraulic pressure P1 described above is supplied to the first release chamber 57 and from the second release hydraulic pressure P2. The hydraulic oil is set in advance so that a small hydraulic fluid is supplied to the second release chamber 77. For this reason, the first pin 51 is prevented from being detached from the first recess 53 based on the hydraulic pressure of the hydraulic oil supplied through the communication oil passage 98. Further, the second pin 71 is prevented from being pulled out from the second recess 73 based on the hydraulic pressure of the hydraulic oil supplied through the communication oil passage 98. Accordingly, when the OCV 91 is set to the first mode or the second mode, the holding mechanism 26 is maintained in the locked state and remains in the release chambers 57 and 77 and the release oil passages 97A and 97B. The amount of hydraulic oil can be increased. Therefore, when the release condition is satisfied, if the OCV 91 is set to the fourth mode and hydraulic fluid is supplied from the second supply oil passage 94 to the release oil passage 97, the first release chamber 57 is quickly The hydraulic pressure in the release chamber 57 quickly rises in an oil-tight state. Thereby, the urging force based on the hydraulic pressure of the first release chamber 57 immediately acts on the first pin 51, and the first pin 51 quickly moves to the proximal side ZB. In addition, the urging force based on the hydraulic pressure in the second release chamber 77 immediately acts on the second pin 71, and the second pin 71 quickly moves to the proximal side ZB. Note that the hydraulic oil supplied through the communication oil passage 98 is also supplied to the third release chamber 44 through the third release oil passage 97C, and thus the third release chamber 44 and the third release oil passage. The amount of hydraulic oil remaining inside 97C also increases.

Further, when the OCV 91 is set to the third mode or the fifth mode, the hydraulic oil is being supplied to the advance chamber 37 or the retard chamber 38 through the first supply oil passage 93. Accordingly, the hydraulic oil flowing through the first supply oil passage 93 is supplied to the release oil passage 97 through the communication oil passage 98. Furthermore, since hydraulic oil is supplied to the release oil passage 97 through the second supply oil passage 94, the first release chamber 57, the second release chamber 77, and the third release chamber 44 are all hydraulic oil. It is kept in an oil-tight state filled with.

Further, when the OCV 91 is set to the fourth mode, the supply of hydraulic oil to the advance chamber 37 and the retard chamber 38 through the first supply oil passage 93 is stopped, so that the communication oil passage 98 is provided. The supply of the hydraulic oil to the release oil passage 97 through is also stopped. However, at this time, since hydraulic oil is supplied to the release oil passage 97 through the second supply oil passage 94, the first release chamber 57, the second release chamber 77, and the third release chamber 44 are Is also kept in an oil-tight state filled with hydraulic oil.

According to the embodiment described above, the following operational effects can be achieved.
(1) Since the communication oil path 98 that connects the first supply oil path 93 and the release oil path 97 is provided, the holding mechanism 26 is in a locked state, and the release chambers 57, 77, 44 and the release oil path Even when the hydraulic oil is discharged from 97A, 97B, and 97C, the hydraulic oil is supplied to the release chambers 57, 77, and 44 and the release oil passages 97A, 97B, and 97C through the communication oil passage 98. Is supplied. For this reason, it is possible to increase the amount of hydraulic oil remaining in the release chambers 57, 77, 44 and the release oil passages 97A, 97B, 97C while maintaining the holding mechanism 26 in the locked state. Accordingly, a release condition for switching the holding mechanism 26 from the locked state to the released state is established, and when the hydraulic oil starts to be supplied from the OCV 91 to the release chambers 57 and 77 through the release oil passage 97, the release chambers 57 and 77 are quickly As a result, the hydraulic pressure in the release chambers 57 and 77 rises quickly. That is, the hydraulic pressure in the first release chamber 57 can be quickly raised to the first release hydraulic pressure P1, and the hydraulic pressure in the second release chamber 77 can be quickly raised to the second release hydraulic pressure P2. Can do. Therefore, it is possible to improve the responsiveness when the holding mechanism is switched from the locked state to the released state.

(2) The oil pressure in the advance oil passage 95 and the retard oil passage 96 varies depending on the valve timing control request. That is, the oil pressure in the advance oil passage 95 and the retard oil passage 96 varies depending on each mode of the OCV 91. For example, when the OCV 91 is set to the first mode, the amount of hydraulic oil flowing through the advance oil passage 95 is larger than when the OCV 91 is set to the second mode. When the OCV 91 is set to the fifth mode and the valve timing is retarded, the supply of hydraulic oil to the advance oil passage 95 is stopped, while the hydraulic oil is supplied to the retard oil passage 96. Supplied. On the other hand, the hydraulic pressure in the first supply oil passage 93 does not depend on the valve timing control request described above, that is, in each mode of the OCV 91, so that the release oil passages 97A and 97B and the release chambers 57 and 77 Thus, the hydraulic oil can be stably supplied through the communication oil passage 98. Accordingly, the hydraulic oil can be suitably left inside the release oil passages 97A and 97B and the release chambers 57 and 77, and the responsiveness of the holding mechanism 26 can be further improved.

(3) The holding mechanism 26 includes an advance angle holding mechanism 50 and a retard angle holding mechanism 70, respectively. Therefore, when the holding mechanism 26 is switched from the locked state to the released state, the first pin 51 has the first recess 53 during the period in which the valve timing is about to change to the retard side due to the alternating torque acting on the cam shaft 22. It becomes easy to pull out from. On the other hand, the second pin 71 is easily pulled out from the second recess 73 during the period when the valve timing is about to change to the advance side by the alternating torque acting on the cam shaft 22. Therefore, when starting the engine, these pins 51 and 71 can be quickly removed from the recesses 53 and 73, respectively.

(4) The advance holding mechanism 50 and the retard holding mechanism 70 are provided in different vanes 33B. Further, the advance angle holding mechanism 50 is provided with an atmosphere release mechanism 60, while the retard angle hold mechanism 70 is provided with an atmosphere release mechanism 80. For this reason, when any one of the atmosphere release mechanism 60 and the atmosphere release mechanism 80 stops at the upper position in the vertical direction of the center bolt when the engine is stopped, the atmosphere release mechanisms 60 and 80 stopped at the upper position in the vertical direction. The atmosphere is introduced into the advance chamber 37 and the retard chamber 38 through the atmosphere communication passages 62 and 82, respectively. As a result, when the hydraulic oil is quickly discharged from the advance chamber 37 and the retard chamber 38, the housing 32 and the vane rotor 33 easily rotate relative to each other due to the alternating torque acting on the cam shaft 22 when the engine is started. Can be quickly advanced to a specific time.

(5) Since the release oil passage 97 supplies hydraulic oil to both the first release chamber 57 and the second release chamber 77, the release oil passage 97 is compared with a configuration having a single holding mechanism as the holding mechanism 26. Thus, the total volume of the release chambers 57 and 77 and the release oil passage 97 increases. Therefore, compared with the configuration having a single holding mechanism as the holding mechanism 26, the responsiveness of the holding mechanism 26 is reduced due to the small amount of hydraulic oil remaining in the release chambers 57 and 77 and the release oil passage 97. It tends to become more apparent. In this respect, since the hydraulic oil is supplied to the release oil passage 97 from the first supply oil passage 93 through the communication oil passage 98, the responsiveness when the holding mechanism 26 is switched from the locked state to the released state is improved. Can do.

(6) The air release mechanism 40 is provided in the remaining one vane 33B where the advance angle holding mechanism 50 and the retard angle holding mechanism 70 are not provided. In other words, all three vanes 33B of the vane rotor 33 are provided with atmospheric release mechanisms 60, 80, 40. Therefore, when the engine is stopped, at least one of the atmospheric release mechanisms 60, 80, 40 stops at the upper part of the center bolt 34 in the vertical direction. Further, these atmospheric release mechanisms 60, 80, 40 are opened to the atmosphere after the engine is stopped. Therefore, after the engine is stopped, the atmosphere is introduced into the advance chamber 37 and the retard chamber 38 through the atmosphere communication passages 62, 82, 42 of the atmosphere release mechanisms 60, 80, 40 stopped above the center bolt 34 in the vertical direction. The As a result, when the hydraulic oil is quickly discharged from the advance chamber 37 and the retard chamber 38, the housing 32 and the vane rotor 33 easily rotate relative to each other due to the alternating torque acting on the cam shaft 22 when the engine is started. Can be quickly advanced to a specific time.

(7) The release oil passage 97 has a third release chamber 44 (atmospheric release mechanism) in addition to the first release chamber 57 (advance angle holding mechanism 50) and the second release chamber 77 (retard angle holding mechanism 70). 40) is supplied with hydraulic oil. Therefore, the total volume of the release chambers 57, 77, and 44 and the release oil passage 97 is increased as compared with the configuration in which the atmosphere release mechanism 40 is not provided. Therefore, compared with a configuration in which the atmosphere release mechanism 40 is not provided, the responsiveness deterioration when the holding mechanism 26 is switched from the locked state to the released state tends to become even more apparent. In this regard, hydraulic oil is supplied to the release oil passage 97 through the communication oil passage 98, and the inside of the first release chamber 57, the second release chamber 77, the third release chamber 44, and the release oil passage 97. Therefore, it is possible to improve the responsiveness when switching the holding mechanism 26 from the locked state to the released state.

(8) The variable valve operating apparatus 20 is provided with a single OCV 91, and the oil pressure of each oil chamber of the variable mechanism 25, the holding mechanism 26, and the atmosphere opening mechanism 40 is controlled by this OCV 91. Therefore, the number of parts can be reduced and the production cost of the variable valve apparatus 20 can be reduced as compared with a configuration in which a plurality of OCVs are provided.

(Other embodiments)
Note that the variable valve operating apparatus for an internal combustion engine according to the present invention is not limited to the configuration exemplified in the above-described embodiment, and can be implemented as, for example, the following forms appropriately modified.

In the above embodiment, an example in which the communication oil path 98 that connects the first supply oil path 93 and the release oil path 97 provided on the upstream side of the OCV 91 is provided is shown. On the other hand, a communication oil passage 198 that connects the advance oil passage 95 and the release oil passage 97 may be provided as shown by a one-dot chain line in FIG. The hydraulic oil is supplied to the advance oil passage 95 when the OCV 91 is set to the first mode or the second mode and the holding mechanism 26 is in the locked state. Therefore, the hydraulic oil flowing through the advance oil passage 95 is supplied to the release oil passage 97 through the communication oil passage 98. Therefore, the effects shown in the above (1) and (3) to (8) can be achieved. Furthermore, you may make it provide both the communication oil path 98 shown by the said embodiment, and the communication oil path 198 shown by the one point difference line of FIG.

The relationship between each mode of the OCV 91 shown in the above embodiment and the supply / discharge state of the hydraulic oil in the hydraulic oil passage 90A is an example, and can be changed as appropriate. Even in this case, by providing the communication oil path 98 that communicates the first supply oil path 93 and the release oil path 97 provided on the upstream side of the OCV 91, the above-described functions and effects can be achieved. . Further, in the case of providing a communication oil path that communicates the supply oil path and the release oil path provided on the downstream side of the OCV 91, the supply oil path is supplied with hydraulic oil when the holding mechanism 26 is in the locked state. And the release oil passage may be communicated with each other. In other words, when the OCV 91 is set so that the hydraulic oil is discharged from the first release chamber 57 and the second release chamber 77, the supply oil passage to which the hydraulic oil is supplied and the release oil passage are communicated with each other. You just have to do it. For example, if the OCV 91 is controlled so that hydraulic oil is supplied to the retard chamber 38 when the holding mechanism 26 is in the locked state, the retard oil passage 96 and the release oil passage 97 What is necessary is just to provide a communication oil path so that it may communicate. Even in this case, the effects shown in the above (1) and (3) to (8) can be achieved.

In the above-described embodiment, the OCV 91 is set to the fourth mode when the holding mechanism 26 is switched from the locked state to the released state. However, the holding mechanism 26 may be switched to the release state while the valve timing is advanced by controlling the OCV 91 in the third mode. Alternatively, the OCV 91 may be set to the fifth mode so that the holding mechanism 26 is switched to the released state while the valve timing is retarded.

In the above embodiment, the example in which the communication oil path 98 is connected to the upstream side of the branch point 97D of the release oil path 97 is shown. However, if the hydraulic oil can be supplied to the first release chamber 57 and the second release chamber 77, the connection location of the communication oil passage 98 can be changed. For example, it is branched in the middle of the communication oil passage 98, and one of the branched oil passages is connected to the first release oil passage 97A, and the other oil passage is connected to the second release oil passage 97B. Also good. Even in this case, the amount of hydraulic oil remaining in the first release chamber 57, the second release chamber 77, the first release oil passage 97A, and the second release oil passage 97B can be increased. Therefore, each effect mentioned above can be produced.

In the above-described embodiment, hydraulic fluid having a flow path resistance of the communication oil passage 98 smaller than the first release hydraulic pressure P1 is supplied to the first release chamber 57, and from the second release hydraulic pressure P2. An example is shown in which a small hydraulic fluid is supplied to the second release chamber 77. However, the flow resistance of the communication oil passage can be changed as appropriate. For example, in addition to setting the entire length of the communication oil path to the same flow path cross-sectional area, the hydraulic oil that flows through the communication oil path by providing a throttle in the middle of the communication oil path to form a portion having a small flow path cross-sectional area It is also possible to adjust the amount.

In the above embodiment, the hydraulic oil having a hydraulic pressure smaller than the first release hydraulic pressure P1 described above is supplied to the first release chamber 57 and the flow resistance of the communication oil path 98 from the second release hydraulic pressure P2. An example is shown in which a small hydraulic fluid is supplied to the second release chamber 77. This is because the hydraulic pressure of the release chamber involved when the holding mechanism 26 switches from the locked state to the released state is the hydraulic pressure of the first release chamber 57 and the hydraulic pressure of the second release chamber 77. On the other hand, the hydraulic pressure of the third release chamber 44 when the opening / closing pin 41 is urged to the base end side ZB is set as the third release hydraulic pressure P3, and the third release hydraulic pressure P3 is also considered and described above. The flow resistance of the communication oil path 98 may be set.

In the above-described embodiment, the example in which the hydraulic oil is always supplied to the release oil path 97 through the communication oil path 98 while the hydraulic oil is flowing through the first supply oil path 93 has been described. It is not necessary to be supplied to the release oil passage 97. That is, it is only necessary that the hydraulic oil be supplied to the release oil passage 97 when the engine is operating and the holding mechanism 26 is in the locked state. As a result, the release chambers 57 and 77 and the release oil passage 97 are always filled with the hydraulic oil, and thus the above-described effects can be achieved. For example, a valve that opens or shuts off the communication oil passage may be provided, and the valve may be appropriately opened and closed so that the hydraulic oil flows through the communication oil passage as appropriate.

In the above embodiment, the example is shown in which the OCV 91 is set to the second mode and the holding mechanism 26 is switched to the locked state during the idling operation of the internal combustion engine 10. On the other hand, in the idle state, it is possible to adopt a mode in which the valve timing is held at a target time suitable for the idle operation and the holding mechanism 26 is held in the released state. Even in this case, when the engine is stopped, the holding mechanism 26 is switched to the locked state as the supply of hydraulic oil to each oil chamber is stopped. Therefore, when the holding mechanism 26 is in the locked state at the next engine start. Cranking is started. Therefore, the hydraulic oil can be supplied to the release oil passage 97 through the communication oil passage 98 from the period in which the holding mechanism 26 is in the locked state before the release mechanism is switched to the release state. Can be dense. Therefore, it is possible to improve the responsiveness when the holding mechanism 26 is switched from the locked state to the released state when the release condition is satisfied after the engine is started.

In the above embodiment, the example in which the atmosphere release mechanism 60 is provided in the advance angle holding mechanism 50 and the atmosphere release mechanism 80 is provided in the retard angle holding mechanism 70 has been described. On the other hand, a mode in which neither of the atmosphere release mechanism 60 and the atmosphere release mechanism 80 is provided, or a mode in which only one of them is provided can be adopted. Even in this case, at least the effects shown in the above (1) to (3), (5), and (8) can be achieved. As described above, after stopping the engine, the vane 33B having the air release mechanism is stopped above the center bolt 34 in the vertical direction so that the hydraulic oil stored in the advance chamber 37 and the retard chamber 38 can be quickly discharged. Then, it is desirable to provide more atmospheric release mechanisms.

In the above embodiment, an example in which the atmosphere release mechanism 40 is provided in the vane 33B that is not provided with the advance angle holding mechanism 50 or the retard angle holding mechanism 70 has been described, but the atmosphere release mechanism 40 may be omitted. Even in this case, the effects shown in the above (1) to (5) and (8) can be achieved.

In the above embodiment, the vane rotor 33 has the three vanes 33B, and the air release mechanism 60, the air release mechanism 80, and the air release mechanism 40 are provided in each of the three vanes 33B. However, the number of vanes 33B included in the vane rotor 33 is not limited to three. For example, when providing a vane rotor having four vanes, the advance angle holding mechanism 50 and the atmosphere release mechanism 60, the retard angle hold mechanism 70 and the atmosphere release mechanism 80 are provided in different vanes, respectively, and the remaining two vanes include: What is necessary is just to provide the atmospheric release mechanism 40 provided separately from the holding mechanism 26, respectively. As a result, any one of the vanes 33B having the air release mechanism stops after the engine is stopped in the vertical direction above the center bolt 34, so that the hydraulic oil stored in the advance chamber 37 and the retard chamber 38 can be quickly discharged. Can do. Further, by applying the present invention, it is possible to improve the responsiveness when the holding mechanism 26 is switched from the locked state to the released state.

In the above embodiment, the example in which the advance angle holding mechanism 50 and the retard angle holding mechanism 70 are provided in the different vanes 33B has been described. On the other hand, a configuration in which the advance angle holding mechanism 50 and the retard angle holding mechanism 70 are provided in the same vane 33B may be employed. However, as described above, after stopping the engine, the vane 33B having the air release mechanism is stopped above the center bolt 34 in the vertical direction so that the hydraulic oil stored in the advance chamber 37 and the retard chamber 38 can be quickly discharged. Then, it is desirable to provide more atmospheric release mechanisms. Therefore, when the advance angle holding mechanism 50 and the retard angle holding mechanism 70 are provided in the same vane 33B, it is desirable that the remaining vane 33B is provided with an air release mechanism 40 provided separately from the holding mechanism. And by applying this invention, the responsiveness at the time of switching a holding | maintenance mechanism from a locked state to a cancellation | release state can be improved.

In the above embodiment, an example in which the first concave portion 53 is configured by the plurality of step portions 54 and 55 and the second concave portion 73 is configured by the plurality of step portions 74 and 75 has been described. On the other hand, the recessed part in which such a some step part is not formed is also employable. Even in this case, at least the actions and effects shown in (1) and (2) above can be achieved. However, when the engine is started after an abnormal engine stop, in order to quickly switch the holding mechanism 26 to the locked state, a plurality of step portions 54, 55, 74, and 75 are formed in the holding mechanism 26 as shown in the above embodiment. It is desirable that

In the above embodiment, the holding mechanism 26 includes the advance angle holding mechanism 50 and the retard angle holding mechanism 70. On the other hand, the holding mechanism may be configured by a single holding mechanism that holds the valve timing at a specific time with a single pin and a single recess. Even in this case, by applying the present invention, the responsiveness when the holding mechanism 26 is switched from the locked state to the released state can be improved.

In addition, a holding mechanism is configured by a single holding mechanism, and an air release mechanism 40 provided separately from the holding mechanism is provided in each vane 33B different from the vane 33B provided with the holding mechanism. Also good. Even in this case, by applying the present invention, the responsiveness when the holding mechanism is switched from the locked state to the released state can be improved.

In the above embodiment, an example is shown in which the specific time when the holding mechanism 26 holds the valve timing is an intermediate time, but the specific time can be changed. For example, the present invention can also be applied to a variable valve apparatus having a holding mechanism that holds the valve timing at the most retarded timing. Even in this case, there may be a problem that when the holding mechanism is locked, the hydraulic oil flows out from the release chamber and the release oil passage, and the release chamber is not filled with the hydraulic oil. Therefore, by applying the present invention, it is possible to improve the responsiveness when the holding mechanism 26 is switched from the locked state to the released state.

In the above embodiment, an example in which a single OCV 91 is provided has been described, but a plurality of oil control valves may be provided. Even in this case, by providing a communication oil passage that communicates the release oil passage and the supply oil passage provided on the downstream side of the oil control valve, the functions and effects described in the above (1) to (7) are provided. Can be played.

In the above embodiment, the concave portions 53 and 73 are formed on the cover 30, but the concave portions 53 and 73 may be formed on the sprocket 31.
In the above embodiment, the sprocket 31 is drivingly connected to the crankshaft 12 and the vane rotor 33 is drivingly connected to the camshaft 22. However, the variable mechanism 25 may be configured such that the sprocket 31 is drivingly connected to the camshaft 22 and the vane rotor 33 is drivingly connected to the crankshaft 12. Even in this case, the above-described effects can be achieved.

In the above embodiment, an example in which the variable valve device of the present invention is embodied as the variable valve device 20 that changes the valve timing of the intake valve 21 is shown. However, the variable valve valve that changes the valve timing of the exhaust valve 23 is shown. It is also possible to embody the present invention as a mechanism. The present invention can also be applied to each of a variable valve mechanism that changes the valve timing of the intake valve 21 and a variable valve mechanism that changes the valve timing of the exhaust valve 23.

DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Piston, 12 ... Crankshaft, 13 ... Oil pump (hydraulic oil supply source), 14 ... Oil pan, 15 ... Crank angle sensor, 16 ... Cam angle sensor, 17 ... ECU, 20 ... Variable motion Valve device, 21 ... intake valve, 22 ... intake camshaft, 23 ... exhaust valve, 24 ... exhaust camshaft, 25, 100 ... variable mechanism, 26, 110 ... holding mechanism, 30 ... cover (first rotating body) ), 31, 101... Sprocket (first rotating body), 32, 102... Housing (first rotating body), 33, 103 .. vane rotor (second rotating body), 33A... Boss, 33B, 103A. 34, center bolt, 35, compartment, 36, 105, accommodating chamber, 37, 106, advance chamber, 38, 107, retard chamber, 40, 60, 80 ... atmosphere release mechanism, 41 ... open / close pin (open / close) valve) 42, 62, 82 ... atmosphere communication passage, 43 ... third spring, 44 ... third release chamber (oil chamber for on-off valve), 45 ... third spring chamber, 46, 66, 86 ... advance communication passage , 47, 67, 87 ... retard communication passage, 48, 68, 88 ... atmosphere release passage, 50 ... advance holding mechanism (first holding mechanism), 51 ... first pin (pin, on-off valve), 51A , 71A ... outer pin, 51B, 71B ... inner pin, 51C, 71C ... bottom plate, 51D, 71D ... stopper, 52 ... first spring (biasing member), 52A, 72A ... outer spring, 52B, 72B ... inner spring 53... First recess (recess) 54. First upper step 55. First lower step 56, 76, 33 C. Vane hole 57. First release chamber 58. First spring Chamber, 70 ... retard holding mechanism (second holding mechanism), 71 ... second pin (pin, on-off valve), 72 ... 2 springs (biasing members), 73 ... second recesses (recesses), 74 ... second upper stage parts, 75 ... second lower stage parts, 77 ... second release chambers, 78 ... second spring chambers , 90 ... Hydraulic mechanism, 90A ... Hydraulic oil passage, 91 ... Oil control valve (OCV, oil passage control unit), 92 ... Supply oil passage, 92D ... Branch point, 93 ... First supply oil passage, 93P ... Advance / Delay Angle supply port, 94 ... second supply oil passage, 94P ... release supply port, 95 ... advance oil passage, 95P ... advance port, 96 ... retard oil passage, 96P ... retard port, 97 ... release oil , 97A ... first release oil passage, 97B ... second release oil passage, 97C ... third release oil passage, 97D ... branch point, 97P ... release port, 98, 198 ... communication oil passage, 99 ... Drain oil passage, 99P ... discharge port, 111 ... pin, 112 ... recess, 113 ... spring, 114 ... release chamber.

Claims (5)

1. A first rotating body that is drivingly connected to the crankshaft; a second rotating body that is drivingly connected to the camshaft and rotates about the same rotation axis as the first rotating body; and the first rotating body And an advance chamber and a retard chamber formed by the second rotor and each of the rotors by hydraulic pressure selectively supplied to the advance chamber and the retard chamber. A variable mechanism that changes the valve timing of a valve that is driven to open and close by the camshaft by relative rotation;
   A pin provided on one side of each of the rotating bodies; a recess provided on the other side of each of the rotating bodies; and a biasing member that biases the pins in a direction in which the pins are fitted into the recesses; A release chamber that is supplied with hydraulic oil for urging the pin in a direction in which the pin is pulled out of the recess, and the pin is inserted into the recess by reducing the hydraulic pressure of the release chamber. In a locked state in which the valve timing is held at a specific time, and a release state in which the valve timing can be changed to a time different from the specific time by raising the hydraulic pressure in the release chamber to the release hydraulic pressure and removing the pin from the recess. A holding mechanism that can be switched to
   A variable valve operating apparatus for an internal combustion engine, comprising: a hydraulic mechanism having an oil passage control unit that controls a supply and discharge state of hydraulic oil to and from the advance chamber, the retard chamber, and the release chamber;
   The hydraulic mechanism is
   A supply oil passage that supplies hydraulic oil from a hydraulic oil supply source to the oil passage control unit and selectively supplies the hydraulic oil from the oil passage control unit to the advance chamber and the retard chamber;
   A release oil path that is provided independently of the supply oil path and supplies hydraulic oil from the oil path control unit to the release chamber;
   A variable valve operating apparatus for an internal combustion engine, comprising: a communication oil passage that communicates the supply oil passage with the release oil passage and supplies hydraulic oil having a hydraulic pressure smaller than the release oil pressure to the release chamber.
2. 2. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the communication oil passage communicates a portion of the supply oil passage from the hydraulic oil supply source to the oil passage control unit and the release oil passage.
3. The holding mechanism restricts the valve timing from changing to the advance side with respect to the specific time, and the second holding mechanism restricts the valve timing from changing to the retard side from the specific time. And the first holding mechanism and the second holding mechanism cooperate to hold the valve timing at the specific timing which is an intermediate timing between the most advanced timing and the most retarded timing. Is what
   The release oil passage operates in both a first release chamber provided in the first holding mechanism as the release chamber and a second release chamber provided in the second holding mechanism as the release chamber. The variable valve operating apparatus for an internal combustion engine according to claim 1 or 2, wherein oil is supplied.
4. The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 3,
   The holding mechanism is a ratchet-type autonomous system that advances the valve timing stepwise from a timing retarded from the specific timing to the specific timing by relatively rotating the rotating bodies with an alternating torque acting on the camshaft. Including an advance mechanism,
   The holding mechanism further includes an atmospheric communication path that communicates the advance chamber and the retard chamber with the atmospheric space;
   The pin serves as an on-off valve that opens or shuts off the atmosphere communication path, and the pin opens the atmosphere communication path as the hydraulic pressure in the release chamber decreases. Variable valve gear for engine.
5. The variable valve operating apparatus for an internal combustion engine according to claim 4,
   An atmospheric communication passage that communicates the advance chamber and the retard chamber with the atmospheric space, an open / close valve that opens or closes the atmospheric communication passage, and the open / close valve that biases the open / close valve in a direction that blocks the atmospheric communication passage An on-off valve oil chamber to which hydraulic oil is supplied, and further includes an air release mechanism provided at a position different from the holding mechanism in the circumferential direction of the rotating shaft,
   The release oil passage supplies hydraulic fluid to the on-off valve oil chamber in addition to the release chamber.

Images