JP2011185100A - Valve timing changing device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve timing changing device of an internal combustion engine which can fix valve timing at an intermediate angle through a lock mechanism at engine start after the engine stop even when engine operation is stopped without fixing the valve timing while suppressing adverse effects on valve timing changing performance. <P>SOLUTION: The valve timing changing device comprises a variable mechanism 40 for changing valve timing of an intake valve, and an advance angle and retard angle discharge passages 46A, 47A which allow hydraulic fluid to be discharged toward a center bolt 44 from an advance chamber 46 and retard chamber 47. If rotation of the variable mechanism 40 is stopped at an arbitrary phase at least one of oil pressure chambers 46, 47 for communicating to respective discharge passages 46A, 47A in a position vertically higher than the center bolt 44 is always brought into an atmosphere releasing state through an atmosphere releasing mechanism regardless of a stop phase of the variable mechanism 40. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention includes a variable mechanism that changes the valve timing of the intake valve and the exhaust valve, a lock mechanism that fixes the valve timing to an intermediate angle between the most retarded angle and the most advanced angle, and an advance chamber and a retard chamber. The present invention relates to a valve timing changing device for an internal combustion engine that includes a discharge passage that extends to the rotating shaft side of a camshaft and can discharge hydraulic oil from each chamber.

  As a valve timing changing device for an internal combustion engine, a first rotating body that is drivingly connected to a crankshaft and a second rotating body that is drivingly connected to a camshaft are utilized using the hydraulic pressure of hydraulic oil supplied from an oil pump. A valve in which the valve timing of the intake and exhaust valves that are opened and closed by the camshaft is changed by changing the relative rotation phase of the camshaft relative to the crankshaft has been put into practical use.

  Hereinafter, a configuration example of a valve timing changing device including a conventional one will be described with reference to FIG. In FIG. 11, “R” indicates the rotational direction of the camshaft (not shown), and “C” indicates the rotational axis of the camshaft.

  The first rotating body 300 is provided with a plurality of recesses 301 so as to surround the rotating shaft of the camshaft, while the second rotating body 400 is radially extended in the radial direction of the rotating shaft and each recessed portion 301 is extended. A plurality of vanes 401 disposed therein are provided. The inside of the recess 301 is partitioned by the plurality of vanes 401, and the advance chamber 510 and the retard chamber 520 are formed in such a manner as to sandwich the vane 401, respectively.

  Further, the advance oil passage 610 and the retard oil passage 620 that communicate with the advance chamber 510 and the retard chamber 520 to supply and discharge hydraulic fluid to the hydraulic chambers 510 and 520, respectively, are largely camshafts. An axial passage (not shown) extending in the axial direction inside, and an axial passage 510 and a retarding chamber 520 connected to the axial passage at the end of the camshaft and extending radially in the radial direction. It is comprised by the diameter channel | path 611,621 connected to. For example, when the valve timing is advanced, the hydraulic oil is supplied from the oil pump to the advance chamber 510 through the axial passage and the radial passage of the advance oil passage 610 and the hydraulic oil in the retard chamber 520 is delayed. The oil is returned to the oil pan through the diameter passage and the shaft passage of the square oil passage 620.

  On the other hand, when retarding the valve timing, hydraulic oil is supplied from the oil pump to the retard chamber 520 through the axial passage and the radial passage of the retard oil passage 620 and the hydraulic oil in the advance chamber 510 is advanced oil. The oil is returned to the oil pan through the diameter passage and the shaft passage of the passage 610. Further, the supply / discharge state of the hydraulic oil to / from each of the hydraulic chambers 510 and 520 is controlled through a flow control valve 700 provided in the middle of the advance oil passage 610 and the retard oil passage 620.

  Further, the relative rotational phase of both the rotators 300 and 400 is fixed to an intermediate phase excluding the most retarded angle phase and the most advanced angle phase in the region where the both rotators 300 and 400 are relatively rotatable, and the valve timing is set to a predetermined intermediate angle. There is also known a valve timing changing device including a lock mechanism 800 that is fixed to the valve. This intermediate angle is set to the most suitable angle when starting the engine, for example. As a result, good engine startability can be ensured.

  In addition, as shown in FIG. 11, the lock mechanism 800 has a lock pin 801 protruding from one of the rotating bodies 300 and 400 toward the other rotating body, and the lock pin 801 is connected to the other rotating body. As a representative example, a member that mechanically restricts the relative rotation of the two rotating bodies by being fitted in a lock hole 802 formed in the rotating body of FIG.

  More specifically, an accommodation space (not shown) is formed in one of the rotating bodies, and a lock pin 801 biased by the elastic force of a spring (not shown) is accommodated in this accommodation space. . In addition, hydraulic oil is supplied to a part of the housing space, and a release chamber that urges the lock pin 801 in a direction opposite to the urging direction of the spring against the urging force of the spring by a force based on the hydraulic pressure. (Not shown) is formed. In addition, a lock hole 802 into which the lock pin 801 is fitted is formed in a portion of the other rotating body facing the lock pin 801 when the valve timing becomes an intermediate angle. When the valve timing is fixed at an intermediate angle, the supply of hydraulic oil to the release chamber is stopped, and the lock pin 801 is projected from the accommodation space by the urging force of the spring and fitted into the lock hole 802. Then, by fitting the lock pin 801 into the lock hole 802 in this way, the relative rotation of both the rotary bodies 300 and 400 is restricted, and the valve timing is fixed at the intermediate angle.

  By the way, in the valve timing changing device having such a lock mechanism 800, the lock is achieved by adjusting the hydraulic pressures of the advance chamber 510 and the retard chamber 520 and rotating both the rotating bodies 300 and 400 relatively before stopping the engine operation. The rotary members 300 and 400 are rotated relative to each other so that the pin 801 and the lock hole 802 can be fitted to each other, and the hydraulic oil is discharged from the release chamber, so that the lock pin 801 protrudes by the biasing force of the spring. It is made to fit in the lock hole 802. In this way, the engine operation is stopped in a state where the relative rotation of both rotating bodies 300 and 400 is restricted through the lock mechanism 800. However, depending on the situation when the engine is stopped, the relative rotation of the rotating bodies 300 and 400 is not restricted through the lock mechanism 800, that is, the engine operation is stopped without fixing the valve timing to an intermediate angle. There is a possibility. However, even in such a case, the vane 401 of the second rotating body 400 swings due to the fluctuation of the cam torque when the engine is started, and the second rotating body 400 rotates to the advance side or the retard side. Utilizing these, when the positions of the lock pin 801 and the lock hole 802 coincide with each other, the valve timing can be fixed at an intermediate angle although it is slightly delayed from the start of engine start. Incidentally, in recent years, a stepped hole is adopted as the lock hole 802 in order to secure the valve timing using the swing of the vane 401, that is, the rotation of the second rotating body 400. Various improvements have been made (see, for example, Patent Document 1).

  When a large amount of hydraulic oil remains in the advance chamber and retard chamber of the variable mechanism when the engine is started after the engine operation is stopped without fixing the valve timing, the second Since the swing of the vane of the rotating body is hindered by the hydraulic pressure of the hydraulic oil, it is difficult to fix the valve timing by the swing of the vane using the cam torque fluctuation as described above. In particular, when the temperature of the hydraulic oil is low and the viscosity thereof is high, such as during a cold start, this tendency becomes more prominent.

  Here, for example, in the valve timing changing device described in Patent Document 2, a communication hole communicating with the atmosphere is formed in some retarded chambers, and hydraulic oil is not supplied to or discharged from the retarded chambers. By doing so, the resistance when rotating the second rotating body toward the advance side, that is, when the valve timing is advanced, is made smaller than when the resistance is retarded. Thus, the responsiveness when the valve timing is advanced is improved.

  Furthermore, if the engine operation is stopped without fixing the valve timing, cam torque fluctuations act on the camshaft, so in many cases, the rotational phase of the second rotating body is the most retarded phase, and the valve timing is also the latest. It becomes a corner. For this reason, in the above-described valve timing changing device, when the engine is started after the engine operation is stopped without fixing the valve timing, the second timing is improved as well as the response when the valve timing is advanced. The amount of rotation when the rotating body advances can be increased, and the valve timing can be fixed at an intermediate angle.

JP 2009-24659 A JP 11-159308 A

  As described above, in the valve timing changing device described in Patent Document 2, a part of the retarded angle chamber is substantially prevented from functioning as a hydraulic pressure chamber, so that a large amount of hydraulic oil enters the retarded angle chamber when the engine is started. It is possible to ease the situation of remaining. However, when such a configuration is adopted, responsiveness deterioration when the valve timing is quickly retarded to the target angle is unavoidable. In other words, in order to ensure good engine startability in such a conventional device, the valve timing changing performance during normal engine operation must be sacrificed to some extent, and there is still room for improvement in this respect. It was.

  The present invention has been made in view of such conventional circumstances, and the purpose thereof is to suppress the adverse effect on the valve timing changing performance, even when the engine operation is stopped without fixing the valve timing. It is an object of the present invention to provide a valve timing changing device for an internal combustion engine capable of reliably fixing the valve timing to an intermediate angle through a lock mechanism when the engine is subsequently started.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, there is provided a variable mechanism that changes the valve timing of at least one of the intake valve and the exhaust valve by changing the relative rotation phase of the camshaft with respect to the crankshaft, and sets the valve timing to the most advanced angle and the maximum angle. The variable mechanism is a rotating body that rotates about the same rotating shaft and is drivingly connected to the crankshaft and surrounds the rotating shaft. And a plurality of vanes that are drive-coupled to the first rotating body having the plurality of storage chambers and the camshaft and that extend radially in the radial direction of the rotation shaft and are respectively disposed in the storage chambers. A plurality of advance chambers as hydraulic chambers that are partitioned and formed in a manner sandwiching the vanes in the housing chamber and supplied with hydraulic oil from an oil pump And a plurality of retarding chambers, and a discharge timing passage extending from the hydraulic chambers toward the rotary shaft and capable of discharging hydraulic oil from the hydraulic chambers. When the rotation of the rotary body is stopped, an air release mechanism is provided that communicates the hydraulic chamber and the atmospheric space so that the hydraulic chamber is open to the atmosphere. At least one of the hydraulic chambers that communicates with the discharge passage at a position vertically above the rotating shaft and from which hydraulic oil can be discharged to the discharge passage is set to the stop phase of the two rotating bodies. Regardless of the gist, it is always open to the atmosphere.

  In the configuration in which the hydraulic oil in the hydraulic chamber is discharged through the discharge passage extending from the hydraulic chamber to the rotating shaft side of each rotating body, when both rotating bodies stop when the engine is stopped, With respect to the hydraulic chamber communicated with the discharge passage at a position vertically below the rotation shaft center, the hydraulic oil cannot be discharged into the discharge passage. On the other hand, for the hydraulic chamber that communicates with the discharge passage at a position vertically above the rotational axis center of both rotating bodies, it is possible to discharge hydraulic oil to the discharge passage, but due to the oil tightness of the hydraulic chamber, Although it is affected, its emissions are small.

  Therefore, in the present invention, when the rotation of both the rotating bodies stops at an arbitrary phase as the engine operation is stopped, the discharge passage is at a position vertically above the rotational axis center of both rotating bodies regardless of the stopping phase. At least one of the hydraulic chambers that can communicate with the hydraulic fluid and can discharge the hydraulic oil through the same discharge passage is in an atmospheric release state that is communicated with the atmospheric space by the atmospheric release mechanism. Accordingly, the atmosphere is introduced into the hydraulic chamber thus opened to the atmosphere, and the hydraulic oil in the hydraulic chamber is discharged through the discharge passage according to the amount of the introduced atmosphere. Since the hydraulic oil is discharged from the hydraulic chamber in this way, the hydraulic pressure of the hydraulic chamber acting on the vane is reduced and the swinging of the hydraulic chamber is likely to occur, so the rotation amount of the second rotating body is also increased. Will come to do. In addition, since this atmospheric release mechanism communicates the hydraulic chamber and the atmospheric space at least when the rotation of both rotating bodies is stopped, in other words, there is some other control request during engine operation. Unless this is the case, the hydraulic chamber is kept in an oil-tight state, so that hydraulic oil is not discharged. As described above, according to the present invention, the valve timing can be reliably fixed to the intermediate angle through the lock mechanism when starting the engine while suppressing adverse effects on the valve timing changing performance.

  The gist of a second aspect of the present invention is that, in the valve timing changing device for an internal combustion engine according to the first aspect, the atmosphere release mechanism opens the retardation chamber as the hydraulic chamber to the atmosphere release state.

  When engine operation stops without the valve timing being fixed by the lock mechanism, cam torque fluctuations act on the camshaft, so in many cases, the rotational phase of the second rotating body is at or near the most retarded phase. The valve timing becomes the most retarded angle or an angle close thereto. That is, the amount of hydraulic oil remaining in the retard chamber is greater than the amount of hydraulic oil remaining in the advance chamber. For this reason, when the valve timing is fixed at an intermediate angle by rotating the second rotating body by swinging the vane, the hydraulic oil remaining in the retard chamber is compared with the advance chamber. It is likely to become the main factor to prevent. In this regard, according to the second aspect of the present invention, since at least the retard chamber is opened to the atmosphere through the atmosphere opening mechanism, the valve timing can be fixed to the intermediate angle more quickly at the time of engine start. Become.

  A third aspect of the present invention is the valve timing changing device for an internal combustion engine according to the first or second aspect, wherein the atmosphere release mechanism sets the advance chamber as an air release state as the hydraulic chamber. It is said.

  Further, as described above, when the engine operation is stopped without the valve timing being fixed by the lock mechanism, the hydraulic oil remaining in the retarded chamber at the time of subsequent engine start is the main factor that prevents the vane from swinging. Become. On the other hand, there is no hydraulic oil remaining in the advance chamber, or even if it remains, the amount of oil is less than that in the retard chamber, so the hydraulic oil remaining in the advance chamber affects the vane oscillation. The impact is small. However, when the vane swings toward the retard chamber, a negative pressure is generated in the advance chamber, and the swing is regulated by a force based on this negative pressure. In this regard, according to the third aspect of the invention, at least the advance chamber is opened to the atmosphere through the atmosphere release mechanism, so that the advance chamber can be maintained at substantially atmospheric pressure when the engine is started. Thus, it is possible to suppress the swing of the vane from being restricted by the negative pressure generated in the advance chamber, and to quickly fix the valve timing to the intermediate angle through the lock mechanism.

  According to a fourth aspect of the present invention, in the valve timing changing device for an internal combustion engine according to any one of the first to third aspects, the atmosphere opening mechanism is a retard angle positioned on both sides of the specific vane. The gist is that the chamber and the advance chamber are opened to the atmosphere as the hydraulic chamber.

  According to the present invention, both the retarded angle chamber and the advanced angle chamber in one recess defined by the specific vane are opened to the atmosphere, so that the hydraulic oil remaining in the retarded angle chamber can be quickly discharged through the discharge passage. On the other hand, the internal pressure of the advance chamber can be maintained at substantially atmospheric pressure, and the generation of negative pressure when the vane is swung can be suppressed. As a result, it is possible to preferably suppress the swinging of the vane by the hydraulic pressure or air pressure of the hydraulic chamber, and to increase the amount of rotation of the second rotating body to quickly fix the valve timing to the intermediate angle. Will be able to.

  According to the invention described in claim 5, the atmosphere release mechanism is provided with an atmosphere communication path that connects the hydraulic chamber and the atmosphere space, and an opening / closing that is provided in the atmosphere communication path and opens / closes the atmosphere communication path. A valve body that displaces the valve body of the on-off valve to a position that blocks the atmosphere communication path during engine operation, and that displaces the valve body to a position that opens the atmosphere communication path when the engine is stopped It can be embodied in such a manner.

  Further, for example, an electromagnetic valve or the like can be adopted as an on-off valve provided in such an air release mechanism. However, according to the invention described in claim 6, the on-off valve is supplied from the oil pump during engine operation. Displacement to a position where the atmospheric communication passage is blocked based on hydraulic pressure of the hydraulic oil, and displacement to a position where the atmospheric communication passage is opened when the supply of hydraulic oil by the oil pump is stopped when the engine is stopped. It is desirable to adopt a configuration that includes the valve body. According to this, since it is not necessary to separately provide a drive source for displacing the valve body, the configuration of the atmosphere release mechanism can be simplified.

  According to a seventh aspect of the present invention, in the valve timing changing device for an internal combustion engine according to the sixth aspect, the supply and discharge states of the hydraulic oil to the lock mechanism are controlled so that the lock mechanism is locked and unlocked. A flow control valve for switching, and the atmospheric release mechanism is configured to connect the hydraulic chamber and the atmospheric space based on the hydraulic pressure of hydraulic oil directly supplied to and discharged from the oil pump regardless of the control state of the flow control valve. The gist is to switch the communication state.

  For example, when the valve timing is fixed at an intermediate angle by operating the lock mechanism during engine operation and restricting the relative rotation of both rotating bodies during idle operation, hydraulic oil is supplied from the oil pump to the atmosphere release mechanism. Therefore, the valve body is in a state where communication between the hydraulic chamber and the atmospheric space is blocked. Therefore, the hydraulic oil in the hydraulic chamber is not discharged through the discharge passage, and the hydraulic chamber is kept in an oil-tight state. As a result, in addition to the lock mechanism, the relative rotation of both rotating bodies is restricted by the hydraulic pressure in the hydraulic chamber, so that the valve timing can be more reliably fixed at the intermediate angle.

  According to an eighth aspect of the present invention, in the flow rate control valve according to the sixth aspect, the flow rate control valve is configured to control a supply / discharge state of hydraulic fluid to the lock mechanism to switch between a lock state and an unlock state of the lock mechanism. The atmospheric release mechanism is characterized in that hydraulic oil supply / discharge control is performed through the flow rate control valve.

According to the present invention, the hydraulic chamber and the atmospheric space can be communicated / blocked through hydraulic oil supply / discharge control by the flow rate control valve.
According to a ninth aspect of the present invention, in the valve timing changing device for an internal combustion engine according to the fifth aspect, the on-off valve causes the atmospheric communication path to pass through the atmospheric communication path by a centrifugal force generated by the rotation of the two rotating bodies during engine operation. The gist includes the valve body that is displaced to a position to be shut off, and that is displaced to a position to open the atmosphere communication path by a biasing force of a spring when the rotation of both the rotating bodies is stopped when the engine is stopped. .

  As described above, for example, an electromagnetic valve or the like can be adopted as the opening / closing valve provided in the atmosphere release mechanism. However, according to the invention described in claim 9, the opening / closing valve is configured so that the both rotating bodies are not operated during engine operation. A position at which the atmospheric communication passage is opened by the urging force of a spring when the rotation of both the rotating bodies stops when the engine is stopped while the atmospheric communication passage is displaced by a centrifugal force generated by rotation. It is desirable to employ a configuration that includes the valve body that is displaced to the right. According to this, since it is not necessary to separately provide a drive source for displacing the valve body, the configuration of the atmosphere release mechanism can be simplified.

The schematic diagram which shows typically the relationship between the variable mechanism and hydraulic fluid supply mechanism about 1st Embodiment which actualized the valve timing change apparatus of the internal combustion engine of this invention. The route diagram which shows the supply-and-discharge route of hydraulic fluid about the variable mechanism of the embodiment. FIG. 3 is a cross-sectional view of the variable mechanism of the same embodiment, in which a cross-sectional structure taken along line DB-DB in FIG. 2 is developed on a plane, (a) is a cross-sectional view showing a state in which hydraulic oil is supplied to the lock mechanism; (B) is sectional drawing which shows the state from which hydraulic fluid was discharged | emitted from the lock mechanism. FIG. 3 is a cross-sectional view of the variable mechanism of the same embodiment, in which a cross-sectional structure taken along line DC-DC in FIG. (B) is sectional drawing which shows the state from which hydraulic fluid was discharged | emitted from the air release mechanism. About the variable mechanism of the embodiment, the cross-sectional structure which followed the DB-DB line | wire of FIG. 2 is expand | deployed on a plane, and the schematic diagram which shows this typically. About the variable mechanism of the embodiment, the operating state of the internal combustion engine, the operating mode of the first and second lock pins, the open / closed state of the first and second atmospheric communication paths, and the operating mode of the open pin The table which shows the relationship between the supply-and-discharge state of the hydraulic fluid with respect to a 3rd cancellation | release chamber, and the open / cut-off state of a 3rd air | atmosphere communication path. The variable mechanism in the second embodiment embodying the valve timing changing device for an internal combustion engine of the present invention, the operating state of the internal combustion engine, the operation modes of the first and second lock pins, and the first and second atmospheres The table which shows the relationship between the open / close state of an open mechanism, the operation | movement aspect of an open pin, the supply / exhaust state of the hydraulic fluid with respect to a 3rd cancellation | release chamber, and the open / close state of a 3rd atmosphere communicating path. Regarding the variable mechanism in the first embodiment, the variable mechanism in the second embodiment, and the variable mechanism in the conventional valve timing changing device according to the valve timing changing device for an internal combustion engine of the present invention, A table that summarizes the self-advancing function and lock transferability. Sectional drawing which expanded the cross-section in the variable mechanism on the plane about other embodiment of this invention. The top view which shows the planar structure about a part of variable mechanism both (a) and (b) about other embodiment of this invention. FIG. 6 is a route diagram illustrating a hydraulic oil supply / discharge route in a variable mechanism of a conventional valve timing changing device.

(First embodiment)
1 to 6, a first embodiment in which the valve timing changing device for an internal combustion engine of the present invention is embodied as a valve timing changing device for changing the valve timing of an intake valve will be described. In the following description, unless otherwise specified, simply “valve timing” means the valve timing of the intake valve.

  As shown in FIG. 1, an oil pan 101 for storing hydraulic oil for driving various hydraulically driven auxiliary machines is attached to the lower part of the internal combustion engine 10. On the other hand, a camshaft 31 for opening and closing an intake valve (not shown) is provided at the upper part of the internal combustion engine 10, and a valve timing changing device 20 for changing the valve timing is provided on the camshaft 31. It has been. The rotational force of the crankshaft 11 is transmitted from the chain 12 through the valve timing changing device 20 to the camshaft 31 of the intake valve. In this way, when the camshaft 31 is rotated by the rotational force of the crankshaft 11, the intake valve is driven to open and close by a cam (not shown) formed on the camshaft 31. The hydraulic oil stored in the oil pan 101 has a function as a lubricating oil for lubricating each part of the internal combustion engine 10 in addition to a function of generating a hydraulic pressure for driving the valve timing changing device 20. ing.

  The valve timing changing device 20 includes a variable mechanism 40 that changes the valve timing of the intake valve, and a lock mechanism 50 for fixing the valve timing at a specific angle. Further, the variable mechanism 40 and the lock mechanism 50 have hydraulic oil. And an electronic control unit 120 that controls the operating state of the variable mechanism 40, that is, valve timing, through the hydraulic oil supply mechanism 100.

  The hydraulic oil supply mechanism 100 includes a plurality of oil passages that supply the hydraulic oil of the oil pan 101 to the variable mechanism 40 and the lock mechanism 50 while returning the hydraulic oil from the variable mechanism 40 and the lock mechanism 50 to the oil pan 101. A hydraulic oil circuit 110 and an oil pump 102 that pumps up the hydraulic oil of the oil pan 101 and supplies the hydraulic oil to the hydraulic oil circuit 110 are included. In the middle of the hydraulic oil circuit 110, hydraulic oil is supplied to and discharged from the first flow rate control valve 103, the lock mechanism 50, and the atmosphere release mechanism 90 (see FIG. 2) that controls the supply and discharge state of the hydraulic oil to the variable mechanism 40. A second flow control valve 104 for controlling the state is provided. As the oil pump 102, an engine drive type driven by the crankshaft 11 is employed.

  Further, the electronic control unit 120 takes in detection signals of various sensors including the crank angle sensor 121 and the cam angle sensor 122, sets a target angle for valve timing suitable for the engine operating state based on the detection signals, and The valve timing changing device 20 is controlled so that the target angle matches the actual valve timing.

  Next, the configuration of the variable mechanism 40 will be described with reference to FIGS. Note that the variable mechanism 40 of FIG. 1 shows a cross-sectional structure along the DA-DA line of FIG. FIG. 2 shows a planar structure of the variable mechanism 40 with the cover 42 shown in FIG. 1 removed from the variable mechanism 40. It is assumed that the camshaft 31 and the sprocket 41C rotate in the rotation direction RA shown in FIG.

  The variable mechanism 40 includes a first rotating body 41 that rotates in synchronization with the crankshaft 11 via the chain 12 and a second rotation that rotates in synchronization with the camshaft 31 of the intake valve. The body 43 is constituted.

  The first rotating body 41 is connected to the crankshaft 11 and rotates in synchronization therewith, a housing 41B assembled to the sprocket 41C and rotated integrally therewith, and a cover 42 attached to the housing 41B. It is comprised by. In the housing 41B, three partition walls 41A projecting radially inward are formed at substantially equal angular intervals in the circumferential direction.

  In the second rotating body 43, a boss 43 </ b> B assembled to the center bolt 44 is fixed to the end of the camshaft 31. The boss 43B is formed with three vanes 43A projecting radially outward from the outer circumferential surface thereof at substantially equal angular intervals in the circumferential direction. Then, the inner circumferential surface of the partition wall 41 </ b> A in the first rotating body 41 and the outer circumferential surface of the boss 43 </ b> B in the second rotating body 43 are slidably contacted, so that the three storage chambers 45 are formed on the camshaft 31. The vanes 43 </ b> A are swingably disposed with respect to the storage chambers 45 while being formed so as to surround the rotation shaft. Accordingly, each storage chamber 45 is divided into an advance chamber 46 and a retard chamber 47 by the vane 43A.

  By controlling the supply / discharge state of the hydraulic oil to and from the advance chamber 46 and the retard chamber 47 through the first flow control valve 103, the first rotating body 41 and the second rotating body 43 of the variable mechanism 40 Relative rotation phase, in other words, the valve timing is changed.

Next, a method for changing the valve timing by the variable mechanism 40 will be described.
When the second rotating body 43 rotates in the rotation direction RA with respect to the first rotating body 41 by supplying the operating oil to the advance chamber 46 while discharging the operating oil in the retard chamber 47. The valve timing is advanced. Then, the second rotating body 43 further rotates in the rotation direction RA with respect to the first rotating body 41, and at least one of the vanes 43A is in contact with the partition wall 41A and cannot rotate any more (the most advanced angle phase). Then, the valve timing is set to the most advanced angle.

  On the other hand, the second rotating body 43 is opposite to the rotation direction RA with respect to the first rotating body 41 by supplying the operating oil to the retarding chamber 47 while discharging the operating oil in the advance chamber 46. When rotating in the direction, the valve timing is retarded. Then, the second rotating body 43 further rotates in the direction opposite to the rotation direction RA with respect to the first rotating body 41, and at least one of the vanes 43A is in contact with the partition wall 41A and cannot rotate any more (the latest). (Angular phase), the valve timing is set to the most retarded angle.

  Further, the variable mechanism 40 determines the relative rotational phase of the first and second rotating bodies 41 and 43 between the most advanced angle phase and the most retarded angle phase regardless of the hydraulic pressure of the advance angle chamber 46 and the retard angle chamber 47. A locking mechanism 50 is provided to fix the intermediate phase between them. Thus, the relative rotational phase of the first and second rotating bodies 41 and 43 is fixed to the intermediate phase through the lock mechanism 50, so that the valve timing is fixed to the intermediate angle between the most advanced angle and the most retarded angle. Is done. The intermediate angle is set so that the valve timing and the valve overlap of the intake valve and the exhaust valve are suitable at the time of engine start and idling.

Next, the configuration of the lock mechanism 50 will be described.
The lock mechanism 50 includes a first lock mechanism 60 that restricts the relative rotational phase of the first and second rotating bodies 41 and 43 from changing to an advance side from the intermediate phase, and the relative rotational phase from the intermediate phase. Is also constituted by a pair of mechanisms having different functions such as a second lock mechanism 70 (see FIG. 2) that restricts the change to the retard side. Since the first lock mechanism 60 and the second lock mechanism 70 have substantially the same structure, the description of the configuration of the second lock mechanism 70 is omitted here.

  The first lock mechanism 60 is provided in one of the three vanes 43 </ b> A formed in the second rotating body 43 to form a first accommodation space 62 in which the first lock pin 61 is accommodated. In addition, a first spring 63 that biases the first lock pin 61 toward the first rotating body 41 so that the end of the first lock pin 61 protrudes from the storage space 62 is provided in the storage space 62. It is accommodated (see FIG. 1). A first release chamber 62 </ b> A to which hydraulic oil is supplied is formed in a portion of the first accommodation space 62 located on the opposite side of the first spring 63 with the first lock pin 61 interposed therebetween. Based on the hydraulic pressure in the first release chamber 62 </ b> A, the first lock pin 61 is biased in the direction opposite to the biasing force of the first spring 63. On the other hand, when the relative rotational phase of the first and second rotating bodies 41 and 43 becomes an intermediate phase, in other words, when the valve timing becomes an intermediate angle, A first lock hole 64 into which the lock pin 61 can be fitted and removed is formed.

  In such a first lock mechanism 60, when the relative rotational phase of the first and second rotating bodies 41 and 43 is an intermediate phase, hydraulic fluid is discharged from the first release chamber 62A. When the hydraulic pressure decreases, the first lock pin 61 protrudes from the first accommodation space 62 by the urging force of the first spring 63, and its end is fitted into the first lock hole 64. That is, the first lock mechanism 60 is in a locked state. As described above, when the first lock mechanism 60 is in the locked state, the advance side of the first lock pin 61 even if the torque to the advance side acts on the second rotating body 43. By engaging the wall surface and the advance side wall surface of the first lock hole 64, the valve timing is restricted from being advanced from the intermediate angle. On the other hand, when the hydraulic oil is supplied to the first release chamber 62A and the hydraulic pressure is increased in this locked state, the first lock pin 61 is urged by the hydraulic pressure, and the first lock It is removed from the hole 64 and accommodated in the first accommodation space 62. That is, the first lock mechanism 60 is unlocked. As described above, when the first lock mechanism 60 is in the unlocked state, the valve timing can be changed to an arbitrary angle based on the supply / discharge state of the hydraulic oil with respect to the advance chamber 46 and the retard chamber 47. It becomes like this.

  The second lock mechanism 70 is provided in one of the two vanes 43A excluding the vane 43A provided with the first lock mechanism 60 among the three vanes 43A. As in the valve timing regulation or change mode in the first lock mechanism 60, in the second lock mechanism 70, when the second lock mechanism 70 is in the locked state, the second rotating body Even when a torque toward the retarded angle acts on 43, the retarded sidewall surface of the second lock pin 71 and the retarded sidewall surface of the second lock hole 74 are engaged, The valve timing is regulated to be retarded from the intermediate angle. On the other hand, when the second lock mechanism 70 is in the unlocked state, the valve timing can be changed to an arbitrary angle based on the supply / discharge state of the hydraulic oil with respect to the advance chamber 46 and the retard chamber 47. become.

  As shown in FIG. 2, among the three vanes 43A, the remaining one vane 43A in which the first lock mechanism 60 and the second lock mechanism 70 are not provided is provided with an air release mechanism 90. ing. The atmosphere release mechanism 90 will be described in detail with reference to FIG.

  Next, with reference to FIG. 2, the flow mode of the hydraulic oil between the variable mechanism 40 including the lock mechanism 50 and the air release mechanism 90 and the hydraulic oil supply mechanism 100 will be described. As will be described later, in addition to the function of restricting the relative rotation of the first and second rotating bodies 41 and 43, the lock mechanism 50 quickly supplies the hydraulic oil in the hydraulic chambers 46 and 47 in the same manner as the air release mechanism 90. In addition, it has an air release function for introducing the atmosphere into the interior.

  The hydraulic oil circuit 110 includes a plurality of oil passages, that is, a first supply oil passage 111, a first discharge oil passage 112, an advance oil passage 113, a retard oil passage 114, a second supply oil passage 115, and a second supply oil passage 115. The discharge oil passage 116, the first release oil passage 117, the second release oil passage 118, and the third release oil passage 119 are configured. Here, the first supply oil path 111 supplies the hydraulic oil discharged from the oil pump 102 to the first flow control valve 103. On the other hand, the first discharged oil passage 112 returns the hydraulic oil discharged from the variable mechanism 40 to the first flow control valve 103 to the oil pan 101. The first exhaust oil passage 112 does not actually have a fixed shape such as a pipe or a hole, but is an inner wall of the internal combustion engine 10 having a shape suitable for guiding hydraulic oil to the oil pan 101 ( For example, the inner wall of the chain case). Further, the advance oil passage 113 circulates hydraulic oil between the first flow control valve 103 and each advance chamber 46. The retard oil passage 114 circulates hydraulic oil between the first flow control valve 103 and each retard chamber 47.

  Further, the second supply oil passage 115 supplies the hydraulic oil discharged from the oil pump 102 to the second flow control valve 104. On the other hand, the second discharge oil passage 116 returns the hydraulic oil discharged from the lock mechanism 50 and the atmosphere release mechanism 90 to the second flow control valve 104 to the oil pan 101. The second exhaust oil passage 116 is constituted by the inner wall of the internal combustion engine 10 and the like, like the first exhaust oil passage 112. Further, the first release oil passage 117 circulates hydraulic oil between the second flow control valve 104 and the first release chamber 62A. The second release oil passage 118 circulates hydraulic oil between the second flow control valve 104 and the second release chamber 72A. The third release oil passage 119 circulates the hydraulic oil between the second flow control valve 104 and the third release chamber 92 </ b> A to which the hydraulic oil is supplied in the atmosphere release mechanism 90.

  The advance oil passage 113 and the retard oil passage 114 are independently connected to the advance chamber 46 and the retard chamber 47, respectively. The first release oil passage 117, the second release oil passage 118, and the third release oil passage 119 are respectively a first release chamber 62A, a second release chamber 72A, and a third release chamber. Each is connected to 92A independently. That is, the first flow control valve 103 is configured as a valve that can independently control the supply and discharge state of the hydraulic oil to and from the advance chamber 46 and the retard chamber 47, while the second flow control valve 104 is The hydraulic oil supply / discharge state with respect to the first release chamber 62A, the second release chamber 72A, and the third release chamber 92A can be independently controlled.

  The boss 43B extends in the radial direction from the respective advance chambers 46, the respective retard chambers 47, the first release chamber 62A, the second release chamber 72A, and the third release chamber 92A toward the center bolt 44. The advance discharge passage 46A, the retard discharge passage 47A, the first discharge passage 62B, the second discharge passage 72B, and the third discharge passage 92B are provided. The advance discharge passage 46A communicates with the first discharge oil passage 112 via the first flow control valve 103. The hydraulic oil in each advance chamber 46 is discharged to the first exhaust oil passage 112 through the advance discharge passage 46A. The retarded discharge passage 47 </ b> A communicates with the first discharged oil passage 112 through the first flow control valve 103. The hydraulic oil in each retard chamber 47 is discharged to the first exhaust oil passage 112 through the retard discharge passage 47A. The first discharge passage 62 </ b> B is communicated with the second discharge oil passage 116 via the second flow control valve 104. The hydraulic fluid in the first release chamber 62A is discharged to the second discharge oil passage 116 through the first discharge passage 62B. The second discharge passage 72 </ b> B is communicated with the second discharge oil passage 116 via the second flow control valve 104. The hydraulic oil in the second release chamber 72A is discharged to the second discharge oil passage 116 through the second discharge passage 72B. The third discharge passage 92 </ b> B communicates with the second discharge oil passage 116 via the second flow control valve 104. The hydraulic oil in the third release chamber 92A is discharged to the second discharge oil passage 116 through the third discharge passage 92B.

  Here, the relationship between the supply / discharge states of the first flow control valve 103 and the second flow control valve 104 and the supply / discharge state of the hydraulic fluid for the variable mechanism 40 when the valve timing is fixed at an intermediate angle will be described. .

  The first flow control valve 103 sets the supply / discharge state of the hydraulic oil by changing the position of a spool (not shown) accommodated in the first flow control valve 103 to a specific position, whereby the first supply oil passage 111 is set. And the connection state of the 1st discharge | emission oil path 112, the advance oil path 113, and the retard oil path 114 is switched. Further, the second flow control valve 104 sets the supply / discharge state of the hydraulic oil by changing the position of a spool (not shown) accommodated therein to a specific position, whereby the second supply oil is set. The connection state of the path 115 and the second discharge oil path 116, the first release oil path 117, the second release oil path 118, and the third release oil path 119 is switched.

  When a request for fixing the valve timing at an intermediate angle is made, the supply / discharge state of the first flow control valve 103 is set to, for example, “mode A”, and the supply / discharge state of the second flow control valve 104 is set to “mode B”. Is set to a state in which the relative rotational phases of the first and second rotating bodies 41 and 43 are fixed, that is, a state in which the variable mechanism 40 is fixed (hereinafter, referred to as “fixed mode”).

  In mode A, the advance oil passage 113 and the first supply oil passage 111 are connected, and the retard oil passage 114 and the first discharge oil passage 112 are connected. In mode B, the first to third release oil passages 117 to 119 and the second discharge oil passage 116 are connected. That is, the hydraulic oil is supplied to the advance chamber 46, the hydraulic oil is discharged from the retard chamber 47, and the hydraulic oil is discharged from the release chambers 62A, 72A, and 92A.

  When the first flow control valve 103 is set to mode A and the second flow control valve 104 is set to mode B, the rotation phase of the second rotating body 43 is to be changed to the advance side. Yes, since the lock pins 61 and 71 are in a state of being displaced to the locked state, the valve timing is reached when the rotation phase reaches the intermediate phase as the second rotating body 43 rotates to the advance side. Is fixed at the middle angle.

  The supply / discharge states of the first and second flow control valves 103 and 104 are basically selected in response to a valve timing change request set based on the engine operation state. For example, when there is a request for fixing the intermediate timing of the valve timing in an extremely low load state including when the engine is stopped or idling, the above-described fixing mode is selected.

  By the way, when the engine is stopped without the relative rotational phase of the first and second rotating bodies 41 and 43 being fixed at the intermediate phase as described above (hereinafter referred to as “when the engine is abnormally stopped”), the next engine The relative rotation phase is fixed to the intermediate phase by utilizing the fact that the vane 43A swings due to the fluctuation of the cam torque at the start and the second rotating body 43 rotates accordingly. In this case, in a situation where a large amount of hydraulic oil remains in the advance chamber 46 and the retard chamber 47, the swing of the vane 43A is hindered by the hydraulic pressure of the hydraulic oil. Fixing the valve timing to the intermediate angle may not be performed quickly.

  Therefore, in the present embodiment, each advance chamber 46 and each retard chamber 47 and the atmospheric space are communicated with the first lock mechanism 60 and the second lock mechanism 70 described above, and the hydraulic chambers 46 and 47 are connected to the atmosphere. A first atmospheric communication path 81 and a second atmospheric communication path 82 are provided to be opened.

  With reference to FIG. 3, details of the first and second atmospheric communication paths 81 and 82 provided in the first lock mechanism 60 and the second lock mechanism 70 will be described. 3 is a cross-sectional view in which a cross-sectional structure taken along the line DB-DB in FIG. 2 is developed on a plane.

  The first lock mechanism 60 has a first lock hole 64 and a first lock hole 64 extending from the first lock hole 64 toward the retard side in the circumferential direction on the sprocket 41C of the first rotating body 41. A groove 65 is formed. The depth of the first lock groove 65 is set to be shallower than the first lock hole 64. The vane 43 </ b> A has a first advance communication passage 66 that communicates the advance chamber 46 and the first accommodation space 62, and a first advance passage that communicates the retard chamber 47 and the first accommodation space 62. A retard communication passage 67 is formed. Further, the vane 43A is formed with a first open passage 68 that communicates the first accommodation space 62 and the atmospheric space. The opening in the first accommodation space 62 of the first advance communication passage 66, the first retard communication passage 67, and the first opening passage 68 is such that the first lock pin 61 is located in the first release chamber 62A. It is formed at a position where it is blocked by the pin 61 when urged to a position where it abuts against the cover 42 by hydraulic pressure. Further, each of the passages 66, 67, and 68 is fitted into the first lock hole 64 and the first lock groove 65 when the first lock pin 61 is biased by the first spring 63. Even when they are not joined, they are formed at positions that are not blocked by the pins 61. The first advance communication path 66 and the first retard communication path 67 are formed at the same position in the biasing direction of the first spring 63. The first atmospheric communication path 81 includes a first advance communication path 66, a first retard communication path 67, and a first open path 68.

  In the first lock mechanism 60 having such a structure, as shown in FIG. 3A, the hydraulic oil is supplied to the first release chamber 62A as the internal combustion engine 10 is operated. Thus, when the first lock pin 61 is urged in the direction opposite to the urging force of the first spring 63, the first advance communication passage 66, the first retard communication passage 67, and the first release passage. 68 is blocked by the pin 61. That is, when the first lock pin 61 is displaced to a position where the first atmospheric communication passage 81 is blocked, the hydraulic oil in the hydraulic chambers 46 and 47 is not discharged through the first atmospheric communication passage 81. .

  Further, as shown in FIG. 3B, for example, when the supply / discharge state of the second flow rate control valve 104 is set to mode B, the hydraulic pressure in the first release chamber 62A decreases. When the first lock pin 61 is urged by the first spring 63 and when the relative rotational phase of the first and second rotating bodies 41 and 43 becomes an intermediate phase, the pin 61 is The lock hole 64 is fitted. At this time, the first advance communication passage 66, the first retard communication passage 67, and the first open passage 68 are communicated. That is, the first lock pin 61 is displaced to a position where the first atmospheric communication passage 81 is opened. Thus, when the vane 43A provided with the first atmospheric communication passage 81 stops vertically above the center bolt 44 when the internal combustion engine 10 is stopped, the advance chamber 46 and the retard chamber 47 have Air is introduced through the first air communication passage 81. The hydraulic oil remaining in the hydraulic chambers 46 and 47 is discharged through the advance discharge passage 46A and the retard discharge passage 47A, respectively, according to the amount of air introduced.

  Similarly, in the second lock mechanism 70, the first rotating body 41 is formed with a second lock groove 75 extending from the second lock hole 74 to the retard side along the circumferential direction. The vane 43 </ b> A has a second advance communication path 76 that communicates the advance chamber 46 and the second accommodation space 72, and a second retard communication passage that communicates the retard chamber 47 and the second accommodation space 72. A second open passage 78 that connects the corner communication passage 77 and the second accommodation space 72 to the atmospheric space is formed. The second advance communication passage 76, the second retard communication passage 77, and the second release passage 78 are positions where the second lock pin 71 is brought into contact with the cover 42 by the hydraulic pressure of the second release chamber 72A. It is formed at a position where it is blocked by the pin 71 when it is urged by. Further, the passages 76, 77, 78 are fitted into the second lock hole 74 and the second lock groove 75 when the second lock pin 71 is urged by the second spring 73. Even when they are not joined, they are formed at positions that are not blocked by the pins 71. Further, the second advance communication path 76 and the second retard communication path 77 are formed at the same position in the biasing direction of the second spring 73. The second atmospheric communication passage 82 includes a second advance communication passage 76, a second retard communication passage 77, and a second open passage 78.

  In the second lock mechanism 70 having such a structure, as shown in FIG. 3A, hydraulic oil is supplied to the second release chamber 72 </ b> A as the internal combustion engine 10 is operated. When the second lock pin 71 is urged in the direction opposite to the urging force of the second spring 73, the second advance communication passage 76, the second retard communication passage 77, and the second release passage. 78 is blocked by the pin 71. That is, when the second lock pin 71 is displaced to a position where the second atmospheric communication passage 82 is blocked, the hydraulic oil in the hydraulic chambers 46 and 47 is not discharged through the second atmospheric communication passage 82. .

  Further, as shown in FIG. 3B, for example, when the supply / discharge state of the second flow rate control valve 104 is set to mode B, the hydraulic pressure in the second release chamber 72A decreases. When the second lock pin 71 is urged by the second spring 73 and when the relative rotational phase of the first and second rotating bodies 41 and 43 becomes an intermediate phase, the pin 71 is It comes to fit into the lock hole 74. At this time, the second advance communication passage 76, the second retard communication passage 77, and the second open passage 78 are communicated. That is, the second lock pin 71 is displaced to a position where the second atmospheric communication path 82 is opened. As a result, when the vane 43A provided with the second atmospheric communication passage 82 stops vertically above the center bolt 44 as the internal combustion engine 10 stops, the advance chamber 46 and the retard chamber 47 have Air is introduced through the second air communication passage 82. The hydraulic oil remaining in the hydraulic chambers 46 and 47 is discharged through the advance discharge passage 46A and the retard discharge passage 47A, respectively, according to the amount of air introduced.

  Here, when the variable mechanism 40 stops in a state where the vane 43A in which the first and second atmospheric communication passages 81 and 82 are not provided is positioned above the center bolt 44 at the time of abnormal engine stop, From the advance angle chamber 46 and the retard angle chamber 47 on both sides of the vane 43A, the valve timing is changed to the intermediate angle by utilizing the swing of the vane 43A of the second rotating body 43 at the time of starting the engine, as described above. It may be difficult to fix to.

  Therefore, in the present embodiment, an air release mechanism that opens the advance chamber 46 and the retard chamber 47 on both sides of the vane 43A in which the first lock mechanism 60 and the second lock mechanism 70 are not provided. 90 is provided.

The details of the atmosphere release mechanism 90 will be described with reference to FIG. 4 is a cross-sectional view in which a cross-sectional structure taken along the line DC-DC in FIG. 2 is developed on a plane.
In the atmosphere release mechanism 90, a third accommodation space 92 in which the release pin 91 is accommodated is formed, and in the accommodation space 92, the release pin 91 is urged toward the first rotating body 41 side. The spring 93 is accommodated. A third release chamber 92A to which hydraulic oil is supplied is formed in a portion of the third accommodation space 92 that is located on the opposite side of the third spring 93 with the release pin 91 interposed therebetween. Based on the hydraulic pressure in the release chamber 92 </ b> A, the release pin 91 is biased in the direction opposite to the biasing force of the third spring 93. The vane 43 </ b> A of the mechanism 90 is provided with a third advance communication path 94 that communicates the advance chamber 46 and the third accommodation space 92. Furthermore, the third accommodation space 92 and the retarded angle chamber 47 and the third accommodation space 92 that communicate with the third accommodation space 92, and the third retarded passage 95 and the third open passage that communicates the third accommodation space 92 and the atmospheric space. 96 is formed. The third advance communication passage 94, the third retard communication passage 95, and the third release passage 96 are urged to a position where the release pin 91 contacts the cover 42 by the hydraulic pressure of the third release chamber 92A. When formed, it is formed at a position where it is blocked by the pin 91. Further, the passages 94, 95, and 96 are formed at positions that are not blocked by the pin 91 even when the release pin 91 is biased by the third spring 93. Further, the third advance communication path 94 and the third retard communication path 95 are formed at the same position in the biasing direction of the third spring 93. The third advance communication passage 94, the third retard communication passage 95, and the third open passage 96 constitute a third atmospheric communication passage 83.

  In the atmosphere opening mechanism 90 having such a structure, as shown in FIG. 4A, the hydraulic oil is supplied to the third release chamber 92A as the internal combustion engine 10 is operated. When the release pin 91 is biased in the direction opposite to the biasing force of the third spring 93, the third advance communication passage 94, the third retard communication passage 95, and the third release passage 96 are connected to the same pin. Blocked by 91. That is, when the release pin 91 is displaced to a position where the third atmospheric communication path 83 is blocked, the hydraulic oil in the hydraulic chambers 46 and 47 is not discharged through the third atmospheric communication path 83.

  Further, as shown in FIG. 4B, for example, when the supply / discharge state of the second flow control valve 104 is set to mode B, the hydraulic pressure in the third release chamber 92A decreases. When the release pin 91 is biased by the third spring 93, the third advance communication path 94, the third retard communication path 95, and the third release path 96 are communicated. That is, the release pin 91 is displaced to a position where the third atmosphere communication path 83 is opened. As a result, when the vane 43A provided with the third atmospheric communication path 83 stops vertically above the center bolt 44 when the internal combustion engine 10 stops, the advance chamber 46 and the retard chamber 47 have Air is introduced through the third air communication passage 83. The hydraulic oil remaining in the hydraulic chambers 46 and 47 is discharged through the advance discharge passage 46A and the retard discharge passage 47A, respectively, according to the amount of air introduced.

  With reference to FIG. 5, the manner in which the valve timing is fixed to the intermediate angle by the lock mechanism 50 when the engine abnormally stops will be described. FIG. 5 schematically shows the cross-sectional structure along the DB-DB line in FIG. 2 developed on a plane.

  In order to ensure good engine startability through the control of the variable mechanism 40, it is required that the valve timing is already held at the intermediate angle when the start operation of the internal combustion engine 10 is started. Therefore, in the internal combustion engine 10, when an engine stop request accompanying an ignition switch switching operation is generated during engine operation, the valve timing is fixed at an intermediate angle by the lock mechanism 50 in preparation for the next engine start. That is, when the engine is normally stopped, the valve timing is fixed at an intermediate angle by the lock mechanism 50 before the operation of the internal combustion engine 10 is stopped based on the engine stop request, and then the operation of the internal combustion engine 10 is performed based on the engine stop request. Stop. On the other hand, when an abnormal engine stop occurs, the above-described valve timing is not fixed before the engine is normally stopped, which causes a problem of a decrease in startability at the next engine start.

In this regard, according to the lock mechanism 50 of the variable mechanism 40, the valve timing is fixed to the intermediate angle as follows when the engine is started after the abnormal engine stop.
Here, it is assumed that the start operation of the internal combustion engine 10 is started in a state where the relative rotational phases of the first and second rotating bodies 41 and 43 are on the retard side with respect to the intermediate phase due to the abnormal engine stop. To do.

  In this case, when the first lock pin 61 is displaced to a position corresponding to the first lock groove 65 due to the rotation of the second rotating body 43 to the advance side accompanying the fluctuation of the cam torque, FIG. As shown in FIG. 5A, the first lock pin 61 protrudes from the vane 43 </ b> A and the tip end portion is inserted into the first lock groove 65.

  Then, with the tip of the first lock pin 61 being in the first lock groove 65, the first lock pin 61 is The first lock groove 65 is moved to the advance side.

  In this state, when the second lock pin 71 is displaced to a position corresponding to the second lock groove 75, the second lock pin 71 is moved from the vane 43A as shown in FIG. It protrudes and its tip is inserted into the second lock groove 75.

  Further, when the first lock pin 61 is displaced to a position corresponding to the first lock hole 64 as the second rotating body 43 is displaced to the advance side, as shown in FIG. In addition, the first lock pin 61 protrudes from the vane 43 </ b> A, and the tip portion thereof is inserted into the first lock hole 64.

  Then, under this state, when the second lock pin 71 is displaced to a position corresponding to the second lock hole 74, as shown in FIG. 71 protrudes and the tip part is inserted into the second lock hole 74.

  In this way, the rotation of the second rotating body 43 to the advance side due to the cam torque variation is the relationship between the advance side wall surface of the first lock pin 61 and the advance side wall surface of the first lock hole 64. And the rotation to the retard side is regulated by the engagement between the retard side wall surface of the second lock pin 71 and the retard side wall surface of the second lock hole 74, thereby The relative rotational phase between the first rotating body 41 and the second rotating body 43 is regulated by the intermediate phase.

  Here, when the starting operation of the internal combustion engine 10 is started, under the situation where a large amount of hydraulic oil remains in each advance chamber 46 and retard chamber 47, as described above, the lock mechanism 50 performs the operation. The valve timing may not be fixed to the intermediate angle.

  In this regard, according to the variable mechanism 40 of the present embodiment, the hydraulic pressure in the release chambers 62A, 72A, and 92A decreases, regardless of the position at which the variable mechanism 40 stops when the engine abnormally stops. Through at least one of the second and third atmospheric communication passages 81, 82, 83, the advance chamber 46 and the retard chamber 47 positioned vertically above the center bolt 44 are opened to the atmosphere. As a result, since the hydraulic oil is discharged from the hydraulic chambers 46 and 47 through the discharge passages 46A and 47A while the engine is stopped, many operations are performed in all the advance chambers 46 and the retard chambers 47 at the next engine start. The frequency with which the oil residue situation occurs will be reduced. Therefore, the valve timing can be quickly fixed to the intermediate angle through the lock mechanism 50 when the engine is started after the abnormal engine stop.

  FIG. 6 shows the operating state of the internal combustion engine 10, the operation modes of the first and second lock pins 61, 71, the open / close state of the first and second atmospheric communication passages 81, 82, and the open pin 91. The following summarizes the relationship between the operation mode, the hydraulic oil supply / discharge state with respect to the third release chamber 92A, and the open / cut-off state of the third atmospheric communication passage 83.

  When hydraulic oil is discharged from the release chambers 62A, 72A, and 92A based on the fact that the supply / discharge state of the second flow control valve 104 is set to mode B as the internal combustion engine 10 is stopped, The first and second lock pins 61, 71 and the release pin 91 are displaced toward the urging direction of the springs 63, 73, 93 (denoted as “projection” in the drawing). As a result, the advance communication passages 66, 76, 94, the retard communication passages 67, 77, 95 and the open passages 68, 78, 96 are communicated with each other, and the first, second, and third air communication channels are communicated. The passages 81, 82 and 83 are opened. In this case, the hydraulic oil remaining in the advance chamber 46 and the retard chamber 47 located vertically above the center bolt 44 is discharged through the discharge passages 46A and 47A.

  On the other hand, when the hydraulic oil is supplied to the release chambers 62A, 72A, and 92A as the internal combustion engine 10 is operated, the first and second lock pins 61 and 71 and the release pin 91 are connected to the springs 63 and 73, respectively. , 93 are displaced in the direction opposite to the urging force (denoted as “accommodating” in the figure). As a result, the advance communication passages 66, 76, 94, the retard communication passages 67, 77, 95, and the open passages 68, 78, 96 are blocked by the pins 61, 71, 91, and the first and The second and third atmospheric communication passages 81, 82, and 83 are cut off. In this case, the hydraulic oil is not discharged through the discharge passages 46A and 47A even in the advance chamber 46 and the retard chamber 47 that are positioned vertically above the center bolt 44.

  When a request to fix the valve timing at an intermediate angle occurs during engine operation, the supply / discharge state of the second flow control valve 104 is set to mode B, so that each release is possible even during engine operation. The first, second, and third atmospheric communication passages 81, 82, 83 are opened based on the discharge of the hydraulic oil from the chambers 62 A, 72 A, 92 A, and are positioned above the center bolt 44 in the vertical direction. The hydraulic oil remaining in the advance chamber 46 and the retard chamber 47 is discharged through the discharge passages 46A and 47A.

According to the valve timing changing device for an internal combustion engine of the present embodiment, the following effects can be obtained.
(1) When the rotation of the first and second rotating bodies 41 and 43 stops at an arbitrary phase as the engine operation stops, the vertical direction is higher than the rotation axis center of the camshaft 31 regardless of the stop phase. The advance angle chamber 46 and the retard angle chamber 47 located in the position are communicated with the atmospheric space by at least one of the first and second lock mechanisms 60 and 70 and the atmospheric release mechanism 90 to be in an atmospheric release state. Accordingly, the atmosphere is introduced into the hydraulic chambers 46 and 47 thus opened to the atmosphere, and the hydraulic oil in the hydraulic chambers 46 and 47 is discharged through the discharge passages 46A and 47A according to the amount of the introduced atmosphere. Will come to be. Since the hydraulic oil is discharged from the hydraulic chambers 46 and 47 in this way, the hydraulic pressure of the hydraulic chambers 46 and 47 acting on the vane 43A is reduced and the swinging is likely to occur. Since the rotation amount of the body 43 also increases, the valve timing can be reliably fixed to the intermediate angle through the lock mechanism 50 when the engine is started.

  (2) The atmospheric communication passages 81, 82, 83 communicate the hydraulic chambers 46, 47 with the atmospheric space when the engine is stopped and when the engine is idle. In other words, during the engine operation, the hydraulic chambers 46 and 47 are kept in an oil-tight state unless the engine is idle during an engine stop, so that hydraulic fluid is not discharged. As described above, the valve timing can be reliably fixed to the intermediate angle through the lock mechanism when starting the engine while suppressing adverse effects on the valve timing changing performance.

  (3) The retarded angle chamber 47 positioned vertically above the rotational axis center of the camshaft 31 can be opened to the atmosphere through any of the atmospheric communication passages 81, 82, 83. As a result, the valve timing can be more quickly fixed to the intermediate angle at the next engine start at the time of abnormal engine stop.

  (4) The advance chamber 46 positioned vertically above the rotational axis center of the camshaft 31 can be opened to the atmosphere through any of the atmospheric communication passages 81, 82, 83. As a result, the advance chamber 46 can be maintained at substantially atmospheric pressure at the next engine start when the engine abnormally stops, and the swing of the vane 43A is restricted by the negative pressure generated in the advance chamber 46. The valve timing can be quickly fixed to the intermediate angle through the lock mechanism 50.

  (5) The retarding chamber 47 and the advance chamber 46 partitioned by one vane 43A are both open to the atmosphere. As a result, the hydraulic oil remaining in the retard chamber 47 positioned vertically above the rotational axis center of the camshaft 31 can be quickly discharged through the retard discharge passage 47A. On the other hand, the internal pressure of the advance chamber 46 can be maintained at substantially atmospheric pressure to suppress the generation of negative pressure when the vane 43A swings. As a result, it is possible to suitably suppress the swing of the vane 43A from being restricted by the hydraulic pressure or air pressure of the hydraulic chambers 46 and 47. As a result, the amount of rotation of the second rotating body 43 can be increased to quickly fix the valve timing to the intermediate angle.

  (6) The lock mechanism 50 allows the retard chamber 47 and the advance chamber 46 to be opened to the atmospheric space, thereby discharging the hydraulic oil in the hydraulic chambers 46 and 47 through the discharge passages 46A and 47A, and a valve. It also has a function of fixing the timing to an intermediate angle. Thereby, it is not necessary to newly provide a mechanism (atmospheric release mechanism) having a function only for opening the hydraulic chambers 46 and 47 to the atmospheric space. That is, using the existing mechanism (lock mechanism), the hydraulic oil can be suitably discharged from the retard chamber 47 and the advance chamber 46 when the engine is stopped.

  (7) The first lock groove 65 and the second lock groove 75 are grooves having a depth smaller than that of the first lock hole 64 and the second lock hole 74, respectively. 2 from the second lock hole 74 to a predetermined position on the retard side. As a result, when the relative rotation phase between the first rotating body 41 and the second rotating body 43 is on the retard side with respect to the first locking groove 65, the lock pins 61, 71 are moved to the springs 63, 73, respectively. When the vane 43A swings due to the cam torque variation, the lock pins 61 and 71 are regulated by the first lock groove 65 and the second lock groove 75, respectively, in that order. Thereafter, the first lock hole 64 and the second lock hole 74 are fitted in this order. Therefore, since the lock pins 61 and 71 and the lock holes 64 and 74 are engaged with each other without being regulated, the valve timing is intermediated quickly. It can be fixed to the corner.

  (8) The intermediate angle of the lock mechanism 50 is set to a value suitable for an extremely low load state including when the engine is stopped or idle, and the lock mechanism 50 is shifted to the locked state before the engine is stopped. Thereby, the operation of the internal combustion engine 10 can be restarted at a valve timing suitable for engine start. As a result, good engine startability can be ensured, and stable idle operation can be performed after engine start.

(Second Embodiment)
With reference to FIGS. 1, 2, and 7, a second embodiment of the present invention will be described focusing on the differences from the first embodiment. Note that the description of the configuration common to the first embodiment is omitted.

  In the air release mechanism 90 according to the first embodiment, the second flow rate control valve 104 controls the supply / discharge state of the hydraulic oil to the third release chamber 92A. On the other hand, in the present embodiment, hydraulic oil is supplied to and discharged from the third release chamber 92 </ b> A in conjunction with the engine hydraulic pressure that is the hydraulic pressure supplied to the internal combustion engine 10.

  The third release chamber 92A in this embodiment is located between the oil pan 101 and the oil pump 102 without passing through the second flow rate control valve 104, as indicated by a two-dot chain line in FIGS. In this configuration, the hydraulic oil is directly distributed. That is, since the engine-driven oil pump 102 is in a driving state as the internal combustion engine 10 is operated, hydraulic oil having a predetermined pressure discharged from the pump 102 is supplied to the third release chamber 92A. Thus, when the release pin 91 is urged in the direction opposite to the urging force of the third spring 93, the third advance communication passage 94, the third retard communication passage 95, and the third release passage 96, Is blocked by the pin 91. That is, when the release pin 91 is displaced to a position where the third atmospheric communication path 83 is blocked, the hydraulic oil in the hydraulic chambers 46 and 47 is not discharged through the third atmospheric communication path 83.

  Therefore, even when a request for fixing the valve timing to an intermediate angle occurs during engine operation, when the vane 43A provided with the atmospheric release mechanism 90 stops in the vertical direction, the hydraulic pressure from the oil pump 102 is increased. Accordingly, since the hydraulic oil is always supplied to the third release chamber 92A, the hydraulic oil in the hydraulic chambers 46 and 47 is discharged through the third atmospheric communication passage 83 as described above. There is nothing. Therefore, the hydraulic pressure in each of the hydraulic chambers 46 and 47 makes it possible to maintain the phase of the second rotating body 43 at an intermediate phase, and the characteristic that the lock mechanism 50 quickly shifts to the locked state (hereinafter referred to as “lock”). Transferability ”).

  When the engine is stopped, the hydraulic oil is discharged from the advance chamber 46 and the retard chamber 47 as in the first embodiment. Therefore, the cam torque variation is fully utilized at the next engine start when the engine abnormally stops. Thus, the function of advancing the rotational phase of the second rotating body 43 to the intermediate phase (hereinafter referred to as “self-advancing function”) can be exhibited. As a result, the valve timing can be quickly fixed at the intermediate angle.

  FIG. 7 shows an operating state of the internal combustion engine 10, operation modes of the first and second lock pins 61 and 71, open / close states of the first and second atmospheric communication passages 81 and 82, and an open pin 91. A summary of these operation modes, the relation between the hydraulic oil supply / discharge state with respect to the third release chamber 92A, and the open / cut-off state of the third atmospheric communication passage 83 will be described.

  As the internal combustion engine 10 stops, hydraulic oil is discharged from the release chambers 62A and 72A and the engine oil pressure is set based on the fact that the supply / discharge state of the second flow control valve 104 is set to mode B. When the hydraulic oil is discharged from the third release chamber 92A by disappearing, the first and second lock pins 61, 71 and the release pin 91 are displaced toward the urging direction of the springs 63, 73, 93. (Indicated as “protrusion” in the figure). As a result, the advance communication passages 66, 76, 94, the retard communication passages 67, 77, 95 and the open passages 68, 78, 96 are communicated with each other, and the first, second, and third air communication channels are communicated. The passages 81, 82 and 83 are opened. In this case, the hydraulic oil remaining in the advance chamber 46 and the retard chamber 47 located vertically above the center bolt 44 is discharged through the discharge passages 46A and 47A.

  On the other hand, when the hydraulic oil is supplied to the release chambers 62A, 72A, and 92A as the internal combustion engine 10 is operated, the first and second lock pins 61 and 71 and the release pin 91 are connected to the springs 63 and 73, respectively. , 93 are displaced in the direction opposite to the urging force (denoted as “accommodating” in the figure). As a result, the advance communication passages 66, 76, 94, the retard communication passages 67, 77, 95, and the open passages 68, 78, 96 are blocked by the pins 61, 71, 91, and the first and The second and third atmospheric communication passages 81, 82, and 83 are cut off. In this case, the hydraulic oil is not discharged through the discharge passages 46A and 47A even in the advance chamber 46 and the retard chamber 47 that are positioned vertically above the center bolt 44.

  When a request to fix the valve timing at an intermediate angle occurs during engine operation, the supply / discharge state of the second flow control valve 104 is set to mode B, so that each release is possible even during engine operation. Based on the hydraulic oil being discharged from the chambers 62A and 72A, the first and second atmospheric communication passages 81 and 82 are opened. As a result, when the vane 43A provided with the first lock mechanism 60 and the second lock mechanism 70 is positioned above the center bolt 44 in the vertical direction, the advance angle chamber 46 and the retard angle located on both sides of the vane 43A. The hydraulic oil in the chamber 47 is discharged through the discharge passages 46A and 47A.

  On the other hand, when the engine is in operation, the third release chamber 92A is always supplied with hydraulic oil when the oil pump 102 is driven, so that the atmosphere release mechanism 90 is cut off. That is, when the vane 43A provided with the atmospheric release mechanism 90 stops vertically above the center bolt 44, the advance chamber 46 and the retard chamber 47 located on both sides of the vane 43A are opened to the atmospheric space. Accordingly, the hydraulic pressures of the hydraulic chambers 46 and 47 are maintained.

  In FIG. 8, the control state of the hydraulic oil with respect to the atmosphere release mechanism 90, and the self-advance function that the variable mechanism 40 of the first embodiment, the variable mechanism 40 of the second embodiment, and the variable mechanism that does not include the atmosphere release mechanism 90 are provided. And the summary about lock transferability is shown.

  In the first embodiment (see FIG. 6), the second flow rate control valve 104 controls the supply / discharge state of the hydraulic oil to / from the third release chamber 92A of the atmosphere release mechanism 90. That is, when there is a request for fixing the valve timing to an intermediate angle during engine operation of the internal combustion engine 10, etc., when the supply / discharge state of the second flow control valve 104 is set to mode B, each release is performed. The hydraulic oil in the chambers 62A, 72A, and 92A is returned to the oil pan 101 through the release oil passages 117, 118, and 119. As a result, the hydraulic oil in the advance chamber 46 and the retard chamber 47 located vertically above the center bolt 44 is discharged. Even when the engine is stopped, the hydraulic oil in the advance chamber 46 and the retard chamber 47 that are positioned vertically above the center bolt 44 is discharged. Therefore, while the self-advance function at the time of starting the engine can be exhibited, it is not possible to sufficiently expect the lock transferability by the hydraulic pressure of each hydraulic chamber 46, 47.

  In the second embodiment (see FIG. 7), the supply / discharge state of the hydraulic oil with respect to the third release chamber 92A of the atmosphere release mechanism 90 is controlled in conjunction with the engine oil pressure. That is, even when a request for fixing the valve timing to an intermediate angle occurs during engine operation of the internal combustion engine 10, even when the supply / discharge state of the second flow control valve 104 is set to mode B The hydraulic oil in the third release chamber 92A is not discharged. As a result, when the vane 43A provided with the air release mechanism 90 is positioned vertically above the center bolt 44, the hydraulic oil is discharged from the advance chamber 46 and the retard chamber 47 located on both sides of the vane 43A. It will never be done. When the engine is stopped, the hydraulic oil is discharged from the advance chamber 46 and the retard chamber 47 located vertically above the center bolt 44 through the first, second, and third atmospheric communication passages 81, 82, 83. The Accordingly, the self-advance function at the time of starting the engine can be exhibited, and when the vane 43A provided with the air release mechanism 90 stops vertically above the center bolt 44, the vane 43A is adjacent to the vane 43A. Since the hydraulic oil is not discharged from the advance chamber 46 and the retard chamber 47 located at the position, the lock transferability by the hydraulic pressure of the hydraulic chambers 46 and 47 is increased.

  In the variable mechanism that is not provided with the atmospheric release mechanism 90, the vane 43A that is not provided with the first lock mechanism 60 and the second lock mechanism 70 when the engine is stopped is located above the center bolt 44 in the vertical direction. When stopped, the hydraulic oil cannot be sufficiently discharged from the advance chambers 46 and the retard chambers 47 located on both sides of the vane 43A, and therefore a self-advance function at the time of starting the engine cannot be expected. . On the other hand, even when the supply / discharge state of the second flow control valve 104 is set to mode B during engine operation, the remaining 1 in which the first lock mechanism 60 and the second lock mechanism 70 are not provided. When the two vanes 43A are positioned above the center bolt 44 in the vertical direction, the hydraulic oil is not discharged from the advance angle chamber 46 and the retard angle chamber 47 adjacent to the vane 43A. The lock transferability by the hydraulic pressures 46 and 47 is increased.

According to this embodiment described above, in addition to the effects (1) to (8) of the first embodiment, the following effects can be achieved.
(9) The release pin 91 is displaced to a position where the third atmospheric communication path 83 is blocked based on the hydraulic pressure of the hydraulic oil supplied from the oil pump 102 during engine operation, while the oil pump 102 is activated when the engine is stopped. Based on the fact that the supply of hydraulic oil was stopped, the third atmospheric communication passage 83 was displaced to a position where it was opened. Thereby, it is not necessary to separately provide a drive source for displacing the release pin 91, so that the configuration of the atmosphere release mechanism 90 can be simplified.

  (10) When the valve timing is fixed at an intermediate angle by operating the lock mechanism 50 during engine operation and restricting the relative rotation of the rotating bodies 41 and 43, such as during idle operation, Since the hydraulic oil is supplied from the pump 102, the communication between the hydraulic chambers 46 and 47 and the atmospheric space is blocked by the release pin 91. Therefore, even when the lock mechanism 50 is in a locked state during engine operation, the air release mechanism 90 operates in the hydraulic chambers 46 and 47 positioned vertically above the rotational axis center of the camshaft 31. Oil is not discharged through the discharge passages 46A and 47A, and the hydraulic chambers 46 and 47 are kept in an oil-tight state. As a result, in addition to the lock mechanism 50, the relative rotation of the rotating bodies 41 and 43 is regulated by the hydraulic pressures of the hydraulic chambers 46 and 47 adjacent to both sides of the vane 43A in which the air release mechanism 90 is provided. The timing can be more reliably fixed at the intermediate angle.

(Other embodiments)
In addition, the embodiment of the present invention is not limited to the above-described embodiments, and can be carried out, for example, in the following manner. The following modifications are not applied only to the above-described embodiments, and different modifications can be combined with each other.

  In the first embodiment, the first flow control valve 103 controls the supply / discharge state of the hydraulic fluid to the advance chamber 46 and the retard chamber 47, and the second flow control valve 104 controls the first release chamber. 62A, the second release chamber 72A, and the third release chamber 92A are configured to control the supply / discharge state of the hydraulic oil, but the configuration of the flow control valve for controlling the supply / discharge state of the hydraulic oil to each chamber is as follows. It is not limited to this. In other words, a single flow rate control valve is provided for controlling the supply / discharge state of hydraulic fluid to the advance chamber 46, the retard chamber 47, the first release chamber 62A, the second release chamber 72A, and the third release chamber 92A. It can also be configured. Further, the first flow control valve for controlling the supply / discharge state of the hydraulic fluid to the advance chamber 46, the retard chamber 47, the first release chamber 62A, and the second release chamber 72A and the operation to the third release chamber 92A. It can also be set as the 2nd flow control valve which controls the supply and discharge state of oil. Even if it is such a structure, there can exist the effect of (1)-(8) mentioned above.

  In each of the above embodiments, the advance communication passages 66, 76, 94 and the retard communication passages 67, 77, 95 are formed at the same position in the urging direction of the springs 63, 73, 93, respectively. However, the positions where the advance communication paths 66, 76, 94 and the retard communication paths 67, 77, 95 are formed are not limited to this. That is, the advance communication paths 66, 76, 94 may be formed closer to the first rotating body 41 than the retard communication paths 67, 77, 95. Moreover, it can also be set as the reverse structure. For example, the case where this modification is applied to the atmosphere release mechanism 90 will be described with reference to FIG.

  As shown in FIG. 9A, when the release pin 91 is urged to the position where it abuts against the cover 42 by the hydraulic pressure of the third release chamber 92A, the third advance communication path 94 and the third The retard communication passage 95 and the third open passage 96 are blocked by the pin 91. As a result, even when the vane 43A provided with the atmosphere release mechanism 90 stops vertically above the center bolt 44, the advance chamber 46 and the retard chamber 47 located on both sides of the vane 43A. The hydraulic oil is not discharged through the discharge passages 46A and 47A.

  Next, when the hydraulic pressure in the third release chamber 92A decreases and the release pin 91 is displaced to a position as shown in FIG. 9B, the third retard communication passage 95 and the third release passage. As a result of communication with 96, only the retarded angle chamber 47 is opened to the atmosphere. At this time, when the vane 43A provided with the air release mechanism 90 stops vertically above the center bolt 44, the hydraulic oil in the retard chamber 47 located next to the vane 43A is transferred to the retard discharge passage. It will be discharged through 47A. On the other hand, since the third advance communication path 94 is blocked by the opening pin 91, the hydraulic oil in the advance chamber 46 is not discharged. As described above, when only the hydraulic oil in the retard chamber 47 is discharged, even if the rotational phase of the second rotating body 43 is displaced to the most retarded phase at the time of abnormal engine stop, the retard angle is increased. Since the hydraulic oil is suitably discharged from the chamber 47, the valve timing can be quickly fixed to the intermediate angle by utilizing the cam torque variation at the next engine start.

  Then, when the hydraulic pressure in the third release chamber 92A further decreases and the release pin 91 is displaced to a position as shown in FIG. 9C, the third advance communication path 94 and the third retard angle. When the communication passage 95 and the third open passage 96 communicate with each other, the hydraulic chambers 46 and 47 are opened to the atmosphere. At this time, when the vane 43A provided with the air release mechanism 90 stops vertically above the center bolt 44, the hydraulic oil in the hydraulic chambers 46 and 47 located on both sides of the vane 43A is discharged. The gas is discharged through the passages 46A and 47A. Even if it is such a structure, there can exist the effect of (1)-(10) mentioned above.

  In each of the above embodiments, each of the first, second, and third atmospheric communication passages 81, 82, and 83 is provided in the vane 43A. However, the place where these are provided is not limited thereto. For example, the first rotating body 41 can be provided. Such a configuration will be described with reference to FIG. In the following, it is assumed that the atmospheric release mechanism 200 is positioned above the center bolt 44 in the vertical direction when the relative rotation of the first and second rotating bodies 41 and 43 stops.

  As shown in FIG. 10A, the atmosphere release mechanism 200 includes a storage chamber 201 in which a spring 202 and a valve body 203 biased toward the center bolt 44 by the spring 202 are stored, and the storage chamber. Respective advance communication paths 204 and retard communication paths 205 communicating with 201 and the advance chamber 46 and the retard chamber 47 are formed in the partition wall 41A. The storage chamber 201 is formed so as to be open to the atmospheric space. That is, when the first rotating body 41 rotates in the rotational direction RA as the internal combustion engine 10 is operated, the valve body 203 is urged in the direction opposite to the center bolt 44 by centrifugal force. Thereby, the communication with the storage chamber 201, the advance communication path 204, and the retard communication path 205 is blocked by the valve body 203.

  On the other hand, when the rotation of the first rotating body 41 is stopped as the internal combustion engine 10 stops, the valve body 203 is urged by the spring 202 and displaced to the position shown in FIG. At this time, the accommodation chamber 201 communicated with the atmospheric space, the advance communication path 204, and the retard communication path 205 communicate with each other. That is, the atmosphere release mechanism 200 is in an open state. As a result, the atmosphere is introduced into the advance chamber 46 and the retard chamber 47 through the atmosphere release mechanism 200. The hydraulic oil remaining in the hydraulic chambers 46 and 47 is discharged through the advance discharge passage 46A and the retard discharge passage 47A, respectively, according to the amount of air introduced.

  In each of the above embodiments, the advance chambers 46, 76, 94, the retard communication passages 67, 77, 95, and the open passages 68, 78, 96 are provided, so Although the corner chamber 47 is configured to be open to the atmosphere, the hydraulic chamber that is open to the atmosphere is not limited thereto. That is, only the advance chamber 46 may be opened to the atmosphere by providing only the advance communication passages 66, 76, 94 and the open passages 68, 78, 96. Even if it is such a structure, there can exist the effect of (1), (2), (4), (6)-(10) mentioned above. In this case, the advance chamber 46 can be maintained at substantially atmospheric pressure, and it is possible to suppress the swing of the vane 43 </ b> A from being restricted by the negative pressure generated in the advance chamber 46. Through this, the valve timing can be quickly fixed at the intermediate angle.

  In each of the above embodiments, the advance chambers 46, 76, 94, the retard communication passages 67, 77, 95, and the open passages 68, 78, 96 are provided, so Although the corner chamber 47 is configured to be open to the atmosphere, the hydraulic chamber that is open to the atmosphere is not limited thereto. That is, only the retard chamber 47 may be opened to the atmosphere by providing only the retard communication passages 67, 77, 95 and the open passages 68, 78, 96. Even if it is such a structure, there can exist the effect of (1), (2), (3), (6)-(10) mentioned above. In this case, even when the rotational phase of the second rotating body 43 is displaced to the most retarded angle phase when the engine abnormally stops, the hydraulic oil is suitably discharged from the retarded angle chamber 47. When the engine is next started, it is possible to quickly fix the valve timing to the intermediate angle by using the fluctuation of the cam torque.

  In each of the above embodiments, in the vane 43A, the open passages 68, 78, and 96 are formed on the retarded chamber 47 side with the storage spaces 62, 72, and 92 interposed therebetween. , 96 is not limited to this. That is, you may make it form in the advance angle chamber 46 side on both sides of each accommodation space 62,72,92. Even if it is such a structure, there can exist the effect of (1)-(10) mentioned above.

  In each of the above embodiments, the variable mechanism 40 includes the three vanes 43A. However, the number of the vanes 43A may be two or less, or four or more. When the number of vanes 43A is two or less or four, any one of the air communication paths 81, 82, and 83 may be provided for each vane 43A. Further, when the number of the vanes 43A is five or more, each of the atmospheric communication paths 81, 82, 83 may be provided so as to be substantially uniform in the circumferential direction of the second rotating body 43. Even if it is such a structure, there can exist the effect of (1)-(10) mentioned above.

  In each of the above embodiments, the lock mechanism for regulating the valve timing to the intermediate angle, that is, the first lock mechanism 60 and the second lock mechanism 70 can open the advance chamber 46 and the retard chamber 47 to the atmosphere. However, the mechanism capable of opening the hydraulic chambers 46 and 47 to the atmosphere is not limited thereto. For example, any one of the lock mechanisms 60 and 70 may be omitted. In this case, the air release mechanism 90 may be provided on the remaining vane 43A. Even if it is such a structure, there can exist the effect of (1)-(5), (9) mentioned above.

  In each of the above-described embodiments, when the lock pins 61 and 71 are operated by the hydraulic pressure of the release chambers 62A and 72A, the advance chamber 46 and the retard chamber 47 located on both sides of the vane 43A where the pin 61 is provided. However, the configuration in which the advance chamber 46 and the retard chamber 47 can be opened or shut off to the atmospheric space is not limited to this. That is, any one of the lock pins 61 and 71 can be a restriction pin for restricting the valve timing from being changed to the retard side or the advance side from the intermediate angle. Even if it is such a structure, there can exist the effect of (1)-(10) mentioned above.

  In each of the above-described embodiments, the lock mechanism 60, 70 includes the lock pins 61, 71, the release chambers 62A, 72A, and the springs 63, 73 on the second rotating body 43. Although the configuration in which the lock holes 64 and 74 and the lock grooves 65 and 75 are provided in the rotating body 41 is employed, the configuration of the lock mechanisms 60 and 70 is not limited thereto. For example, each lock pin 61, 71 and each release chamber 62A, 72A and each spring 63, 73 are provided in the first rotary body 41, and each lock hole 64, 74 and each lock groove 65, 73 are provided in the second rotary body 43. 75 can also be provided. In this case, the first and second atmospheric communication passages 81 and 82 may be provided in the first rotating body 41. Even if it is such a structure, there can exist the effect of (1)-(10) mentioned above.

  In each of the lock mechanisms 60 and 70 and the air release mechanism 90 of the above embodiments, the pins 61, 71, and 91 provided on the second rotating body 43 are driven by the urging force of the springs 63, 73, and 93. Although it was set as the structure displaced toward the rotary body 41 side of this, this can also be changed as follows. That is, each pin 61, 71, 91 is provided in the first rotating body 41 in the radial direction, and is displaced toward the second rotating body 43 side by the urging force of each spring 63, 73, 93. You can also Even if it is such a structure, there can exist the effect of (1)-(10) mentioned above.

  In each of the above embodiments, an engine-driven oil pump is used as the oil pump 102. However, an electric pump driven by a motor may be employed. Even if it is such a structure, there can exist the effect of (1)-(8) mentioned above.

  In each of the above embodiments, the variable mechanism 40 includes the first and second lock mechanisms 60 and 70 that fix the valve timing to an intermediate angle. However, the valve timing fixed by the lock mechanisms 60 and 70 is used. Is not limited to the intermediate angle. That is, it can be changed to the most advanced angle. In short, any valve timing other than the most retarded angle can be adopted as the specific angle of the valve timing fixed by the lock mechanisms 60 and 70.

  The configuration of the valve timing changing device to which the present invention is applied including the configuration of the variable mechanism 40 is not limited to the contents exemplified in the above embodiments. That is, the present invention can be applied not only to the intake valve but also to any valve timing changing device of the exhaust valve or the intake valve and the exhaust valve as long as it has a variable mechanism that changes the valve timing. In this case as well, it is possible to achieve operational effects according to the operational effects of the above embodiments.

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Crankshaft, 12 ... Chain, 20 ... Valve timing change device, 31 ... Camshaft (rotary shaft), 40 ... Variable mechanism, 41 ... First rotating body, 41A ... Partition wall, 41B ... Housing 41C ... Sprocket 42 ... Cover 43 ... Second rotating body 43A ... Vane 43B ... Boss 44 ... Center bolt 45 ... Accommodating chamber 46 ... Advance chamber 46A ... Advance discharge passage 47 ... retardation chamber, 47A ... retardation discharge passage, 50 ... lock mechanism, 60 ... first lock mechanism, 61 ... first lock pin, 62 ... first accommodation space, 62A ... first release chamber, 62B ... first discharge passage, 63 ... first spring, 64 ... first lock hole, 65 ... first lock groove, 66 ... first advance communication passage, 67 ... first retard communication passage, 68 ... 1st open passage, 70 ... 2nd Lock mechanism, 71 ... second lock pin, 72 ... second storage space, 72A ... second release chamber, 72B ... second discharge passage, 73 ... second spring, 74 ... second lock hole, 75 ... second locking groove, 76 ... second advance communication passage, 77 ... second retard communication passage, 78 ... second open passage, 81 ... first atmospheric communication passage, 82 ... second Atmospheric communication path, 83 ... third atmospheric communication path, 90 ... atmospheric release mechanism (open / close valve), 91 ... opening pin (valve element), 92 ... third accommodation space, 92A ... third release chamber, 92B ... Third discharge passage, 93 ... third spring, 94 ... third advance communication passage, 95 ... third retard communication passage, 96 ... third open passage, 100 ... hydraulic oil supply mechanism, 101 ... Oil pan 102 ... oil pump 103 ... first flow control valve 104 ... second flow control valve 110 ... hydraulic oil , 111... First supply oil passage, 112... First discharge oil passage, 113... Advanced oil passage, 114 .. retard oil passage, 115 .. second supply oil passage, 116. 117: First release oil passage, 118: Second release oil passage, 119: Third release oil passage, 120: Electronic control device, 121: Crank angle sensor, 122: Cam angle sensor, 200 DESCRIPTION OF SYMBOLS ... Air release mechanism, 201 ... Accommodating chamber, 202 ... Spring, 203 ... Valve body, 204 ... Advance communication path, 205 ... Delay communication path

Claims (9)

A variable mechanism that changes the valve timing of at least one of the intake valve and the exhaust valve by changing the relative rotation phase of the camshaft with respect to the crankshaft, and the valve timing is set to an intermediate angle between the most advanced angle and the most retarded angle. A lock mechanism for fixing, and the variable mechanism is a rotating body that rotates around the same rotation shaft, and is connected to the crankshaft and has a plurality of storage chambers in a manner surrounding the rotation shaft. A second rotating body that is drivingly connected to the first rotating body and the camshaft and that extends radially in the radial direction of the rotating shaft and has a plurality of vanes disposed in each of the housing chambers; A plurality of advance chambers and a plurality of retard chambers as hydraulic chambers that are partitioned and configured to sandwich the vane in the room and are supplied with hydraulic oil from an oil pump; In the valve timing apparatus for an internal combustion engine having an exhaust passage capable of discharging the respective hydraulic fluid from said hydraulic chamber to extend in the rotation axis side from the hydraulic chamber,
At least when the rotation of both rotating bodies is stopped, the hydraulic chamber and the atmospheric space are communicated with each other so that the hydraulic chamber is opened to the atmosphere. When the rotation of the body stops at an arbitrary phase, at least one of the hydraulic chambers that communicates with the discharge passage at a position vertically above the rotation shaft and from which hydraulic oil can be discharged into the discharge passage is rotated in both directions. An apparatus for changing a valve timing of an internal combustion engine, wherein the valve is always open to the atmosphere regardless of the stop phase of the body. The valve timing changing device for an internal combustion engine according to claim 1, wherein the atmosphere release mechanism is configured to open the retard chamber to the atmosphere as the hydraulic chamber. The valve timing change device for an internal combustion engine according to claim 1 or 2, wherein the air release mechanism sets the advance chamber as an air release state as the hydraulic chamber. The internal combustion engine according to any one of claims 1 to 3, wherein the air release mechanism is in an air release state with a retard chamber and an advance chamber located on both sides of the specific vane as the hydraulic chamber. Valve timing change device. The atmospheric release mechanism is
An air communication passage communicating the hydraulic chamber and the air space; and an opening / closing valve provided in the air communication passage for opening / closing the air communication passage, and opening and closing the air communication passage at a position where the air communication passage is shut off during engine operation. The valve timing of the internal combustion engine according to any one of claims 1 to 4, wherein the valve body is displaced to a position where the atmosphere communication path is opened when the engine is stopped while the valve body of the valve is displaced. Change device. The on-off valve is displaced to a position for blocking the atmospheric communication path based on the hydraulic pressure of hydraulic oil supplied from the oil pump during engine operation, while supply of hydraulic oil by the oil pump is stopped when the engine is stopped. The valve timing changing device for an internal combustion engine according to claim 5, including the valve body that is displaced to a position for opening the atmosphere communication path based on the fact. The apparatus further comprises a flow control valve that controls a supply / discharge state of the hydraulic fluid to the lock mechanism to switch between a lock state and an unlock state of the lock mechanism, and the atmosphere release mechanism is independent of the control state of the flow control valve. The valve timing changing device for an internal combustion engine according to claim 6, wherein the communication state between the hydraulic chamber and the atmospheric space is switched based on the hydraulic pressure of hydraulic oil directly supplied to and discharged from an oil pump. The system further comprises a flow control valve that controls a supply / discharge state of the hydraulic oil to the lock mechanism to switch between a lock state and an unlock state of the lock mechanism, and the atmosphere release mechanism controls the supply / discharge of the hydraulic oil through the flow control valve. The valve timing changing device for an internal combustion engine according to claim 6. The on-off valve is displaced to a position where the atmospheric communication path is blocked by the centrifugal force generated with the rotation of the both rotating bodies during engine operation, while the rotation of the both rotating bodies stops with the engine stopped. The valve timing changing device for an internal combustion engine according to claim 5, including the valve body that is displaced to a position where the atmospheric communication path is opened by a biasing force of a spring.

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