JP2012002081A - Variable valve gear of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable valve gear that can increase the frequency of fixing to a specific angle during engine start.SOLUTION: The variable valve gear of an internal combustion engine includes a hydraulic valve timing variable mechanism 30 for changing valve timing VT. The variable mechanism 30 includes: a first storage chamber 37A including a first advanced angle chamber 38A and a first retarded angle chamber 39A; a second storage chamber 37B including a second advanced angle chamber 38B and a second retarded angle chamber 39B; and a fixing mechanism 40 for fixing the valve timing VT at a middle angle VTmdl. When the engine condition is stopped, an opening mechanism 70 is provided for communicating the second advanced angle chamber 38B and the second retarded angle chamber 39B with external space and a retarded angle chamber communication passage 34A is provided for communicating the second retarded angle chamber 39B with the first retarded angle chamber 39A with each other.

Description

  The present invention includes a hydraulic variable valve mechanism that changes valve timing. The variable valve mechanism includes a first storage chamber including a first advance chamber and a first retard chamber, and a second advance angle. The present invention relates to a variable valve operating apparatus for an internal combustion engine including a second storage chamber including a chamber and a second retardation chamber, and a specific angle fixing mechanism that fixes a valve timing to a specific angle.

  The variable valve operating device described in Patent Document 1 is known.

Japanese Patent Laid-Open No. 2002-122009

  In the variable valve operating device of Patent Document 1, when the valve timing is on the retard side from the specific angle when the engine is started, the valve timing advances toward the specific angle based on the cam shaft torque fluctuation (hereinafter referred to as cam torque fluctuation). Horn. At this time, if the lubricating oil remains in the retarding chamber, the vane is prevented from swinging toward the advance side, so that the valve timing hardly reaches the specific angle. If the valve timing is on the more advanced side than the specific angle when the engine is started, the valve timing is retarded toward the specific angle based on cam torque fluctuation. At this time, if the lubricating oil remains in the advance angle chamber, the vane is prevented from swinging toward the retard angle side, so that the valve timing hardly reaches a specific angle.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a variable valve operating apparatus for an internal combustion engine that can increase the frequency at which the valve timing is fixed at a specific angle when the engine is started. It is in.

In the following, means for achieving the above object and its effects are described.
(1) The invention according to claim 1 is provided with a hydraulic variable valve mechanism for changing valve timing, and the variable valve mechanism includes a first advance chamber and a first retard chamber. In a variable valve operating apparatus for an internal combustion engine, comprising: a storage chamber; a second storage chamber including a second advance chamber and a second retard chamber; and a specific angle fixing mechanism that fixes the valve timing to a specific angle. An opening mechanism A that communicates at least one of the second advance chamber and the second retard chamber and the external space with each other in the stopped state, and the first mechanism that communicates with the external space by the open mechanism A. An engine stop state in which a communication chamber A that is at least one of a binary advance chamber and a second retard chamber and a communication passage A that communicates at least one of the first advance chamber and the first retard chamber are provided. When the second advance chamber and the second retard chamber are small, In both cases, an opening mechanism A that communicates one and the external space with each other, a communication chamber A that is a chamber communicated with the external space by the opening mechanism A, the first advance chamber, and the first retard chamber. The gist is that a communication path A that communicates at least one with each other is provided.

  In the present invention, the communication chamber A and the external space are communicated with each other when the engine is stopped, so that air is introduced into the communication chamber A. As a result, the lubricating oil in the communication chamber A is easily discharged.

  Here, in the variable valve operating apparatus in which the opening mechanism that communicates with the first advance chamber and the first retard chamber and the external space when the engine is stopped is not provided in the first storage chamber, the communication chamber A The lubricating oil in the first advance chamber and the first retard chamber is less likely to be discharged compared to

  In this regard, in the present invention, the communication chamber A and at least one of the first advance chamber and the first retard chamber are communicated with each other by the communication passage A. Therefore, the first advance chamber and the first advance chamber are connected via the communication chamber A. Air is also introduced into at least one of the retarding chambers. For this reason, the lubricating oil of at least one of the first advance chamber and the first retard chamber communicated with the communication chamber A is easily discharged. Thereby, the frequency at which the valve timing is fixed at a specific angle when the engine is started can be increased.

  It should be noted that the engine stop state is an engine stop state that is a state of the internal combustion engine from when the stop request is set to the internal combustion engine until the engine is completely stopped, and when the engine is completely stopped. Including at least one.

(2) The invention according to claim 2 is the variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the specific angle is an intermediate angle between a most advanced angle and a most retarded angle. It is said.
In variable valve gears equipped with a specific angle fixing mechanism that fixes the valve timing to an intermediate angle between the most advanced angle and the most retarded angle, if the engine stops without the valve timing being fixed to the intermediate angle, the engine stops. In the state, the valve timing is gradually retarded. Then, when the valve timing is advanced to an intermediate angle due to cam torque fluctuation at the time of subsequent engine start, the valve timing is fixed to the intermediate angle by the specific angle fixing mechanism. However, when the advance amount of the valve timing due to cam torque fluctuation is small, the frequency at which the valve timing does not advance to the intermediate angle increases. According to the present invention, since the lubricating oil that is a factor that hinders the advancement of the valve timing based on the cam torque variation is easily discharged, the frequency at which the valve timing is fixed to the intermediate angle when the engine is started can be increased.

  (3) A third aspect of the present invention is the variable valve operating apparatus for an internal combustion engine according to the first or second aspect, wherein the combination of the storage chambers including the first storage chamber and the second storage chamber is a storage chamber group. As a mechanism for introducing the air in the external space into the storage chamber set, only the opening mechanism A is provided.

  In the present invention, an opening mechanism that directly communicates the first advance chamber and the first retard chamber with the external space when the engine is stopped is not provided in the first storage chamber. Since at least one of the first advance chamber and the first retard chamber communicates with each other through the communication path A, the discharge of the lubricating oil in the same chamber is promoted.

  In the case where a storage chamber different from the first storage chamber and the second storage chamber is provided, at least one of the advance chamber and the retard chamber of the separate storage chamber is provided by an opening mechanism B different from the opening mechanism A. When communicating with an external space, air can be introduced into at least one of the advance chamber and the retard chamber of the first storage chamber via the advance chamber and the retard chamber of another storage chamber. In this case, the release mechanism that introduces air into the accommodation set including the first storage chamber and the second storage chamber is the release mechanism A, and the release mechanism that introduces air into the storage set including the first storage chamber and another storage chamber. Is an opening mechanism B.

  (4) According to a fourth aspect of the present invention, in the variable valve operating apparatus for an internal combustion engine according to the third aspect, the communication path A includes the first retard chamber and the second retard chamber as the communication chamber A. The gist is to communicate the corner chamber with each other.

  In this invention, since the first retardation chamber and the second retardation chamber are communicated with each other by the communication path A, the air introduced from the second retardation chamber is introduced into the first retardation chamber, The discharge of the lubricating oil remaining in the first retardation chamber is promoted.

  (5) The invention according to claim 5 is the variable valve operating apparatus for an internal combustion engine according to claim 3 or 4, wherein the variable valve operating mechanism includes a third advance chamber and a third retard chamber. 3 accommodation chambers, an open mechanism B that allows the third advance chamber and the external space to communicate with each other when the engine is stopped, and a communication chamber that is a chamber communicated with the external space by the open mechanism B The gist of the present invention is to include a communication passage B that communicates B with the first advance chamber.

  In this invention, since the first advance chamber and the third advance chamber are communicated with each other through the communication path B, air introduced from the third advance chamber is introduced into the first advance chamber, The discharge of the lubricating oil remaining in the first advance chamber is promoted.

  (6) The invention according to claim 6 is the variable valve operating apparatus for the internal combustion engine according to any one of claims 1 to 5, wherein the variable valve mechanism rotates in synchronization with a crankshaft. An input rotator that forms an outer peripheral wall of the variable valve mechanism, and an output rotator that rotates in synchronization with a camshaft, wherein the input rotator includes the first storage chamber and the input chamber in the axial direction. It includes a first wall and a second wall facing each other through the second storage chamber, and the communication path A is provided in the first wall or the second wall. It is a summary.

  In the present invention, since the communication path A is provided in the first wall portion or the second wall portion facing each other via the first storage chamber and the second storage chamber in the axial direction of the input rotating body, the first storage chamber And compared with the case where a communicating path is provided in the outer peripheral side and inner peripheral side of a 2nd storage chamber, it can suppress that the size of the radial direction of a variable valve mechanism increases.

  (7) The invention according to claim 7 is the variable valve operating apparatus for an internal combustion engine according to claim 6, wherein the communication path A is provided in the first wall portion, and the first wall portion is provided. Is provided between the sprocket and the first storage chamber and the second storage chamber connected to the crankshaft via a timing belt, and is provided between the first storage chamber and the second storage chamber. And a first communication hole formed in a portion of the plate corresponding to the first advance chamber or the first retard chamber communicated with the communication chamber A. A second communication hole formed in a portion of the plate corresponding to the communication chamber A, and the first communication hole and the second communication hole are formed to communicate with each other on the plate-side surface of the sprocket. The communication groove It is summarized in that those comprising.

  When the first wall portion is composed of a single member, it is necessary to form a hole as the communication path A inside the first wall portion. For this reason, there exists a possibility that the process for forming the communicating path A may become complicated. In this invention, the thing containing the sprocket and plate which were formed separately as a 1st wall part is employ | adopted, and also the communicating path A is comprised by the communicating groove formed in a sprocket, and the communicating hole formed in a plate. . For this reason, compared with the case where what consists of a single member is employ | adopted as a 1st wall part as mentioned above, the process of the 1st wall part for forming the communicating path A can be simplified. .

  (8) The invention according to claim 8 is the variable valve operating apparatus for the internal combustion engine according to claim 7, wherein the variable valve mechanism includes a third advance chamber and a third retard chamber. An open mechanism B that communicates the third advance angle chamber and the external space when the engine is stopped, a communication chamber B that communicates with the external space by the open mechanism B, and And a communication passage B that communicates with the first advance chamber, and the chambers are provided in the order of the second storage chamber, the first storage chamber, and the third storage chamber in the circumferential direction. The second advance chamber and the second retard chamber are provided as the communication chamber A, and the third advance chamber and the third retard chamber are provided as the communication chamber B. And the communication path A is connected to the first retarding chamber. A first communication hole formed in a portion of the second plate, a second communication hole formed in a portion of the plate corresponding to the second retardation chamber, and a portion of the plate facing the first advance chamber. A communication groove A formed in the sprocket so as to pass through and communicate the first communication hole and the second communication hole with each other, and the communication path B is formed in the first advance chamber. A third communication hole provided in a corresponding portion of the plate, a fourth communication hole formed in a portion of the plate corresponding to the third advance chamber, and the plate facing the first retard chamber. The gist of the invention is that it includes a communication groove B formed in the sprocket so as to pass through the portion and communicate the third communication hole and the fourth communication hole with each other.

  In the present invention, the communication groove A passes through the portion of the plate facing the first advance chamber and communicates the first communication hole and the second communication hole with each other, so the portion of the plate facing the first advance chamber. The length of the communication groove A can be shortened as compared with a configuration in which the communication holes communicate with each other without passing through the communication hole. Similarly, the communication groove B passes through the portion of the plate facing the first retardation chamber and communicates the third communication hole and the fourth communication hole with each other, so that the portion of the plate corresponding to the first retardation chamber is formed. The length of the communication groove B can be shortened as compared with a configuration in which these communication holes are connected to each other without passing through.

  (9) The invention according to claim 9 is the variable valve operating apparatus for an internal combustion engine according to any one of claims 6 to 8, wherein the specific angle fixing mechanism includes the input rotator and the output rotator. A fixing pin provided on one of the input rotating body, a fixing groove provided on the other of the input rotating body and the output rotating body, and a lubricating oil for moving the fixing pin relative to one of the input rotating body and the output rotating body. And a fixed chamber in which the valve timing is fixed to the specific angle when the fixing pin is fitted in the fixing groove, and the fixing pin is in the first position. When the operating state of the opening mechanism A becomes a closed state that blocks between the communication chamber A and the external space, and the fixing pin is in the second position, the operating state of the opening mechanism A is the communication state. Room A It is summarized as to become an open state to communicate with each other and the external space.

  In this invention, since the operating state of the opening mechanism A is changed to the open state or the closed state according to the position of the fixing pin of the specific angle fixing mechanism, the operation of the specific angle fixing mechanism for fixing the valve timing is started. In conjunction with this, the discharge of the lubricating oil is promoted promptly.

The schematic diagram which shows typically the structure of the internal combustion engine provided with the variable valve apparatus about one Embodiment of this invention. About the valve timing variable mechanism of the embodiment, (a) is a cross-sectional view showing a cross-sectional structure along the radial direction, (b) is a cross-sectional view showing a cross-sectional structure along the DA-DA line of (a). Sectional drawing which shows the cross-sectional structure which follows the DB-DB line | wire of Fig.2 (a) about the valve timing variable mechanism of the embodiment. Sectional drawing which shows the cross-sectional structure which follows the DB-DB line | wire of Fig.2 (a) about the valve timing variable mechanism of the embodiment. The schematic diagram which shows typically the hydraulic system of the valve timing variable mechanism of the embodiment. About the valve timing variable mechanism of the embodiment, (a) is a front view showing the front structure of the plate, (b) is a front view showing the front structure of the sprocket. The schematic diagram which shows typically the distribution | circulation aspect of the lubricating oil and air in the engine stop in the valve timing variable mechanism of the embodiment.

  An embodiment of the present invention will be described with reference to FIGS. In the present embodiment, an example in which the present invention is embodied as a variable valve operating apparatus for an internal combustion engine that changes the valve timing of the intake valve is shown.

  As shown in FIG. 1, the internal combustion engine 1 lubricates an engine body 10 that rotates a crankshaft 15 through combustion of an air-fuel mixture, a variable valve apparatus 20 that includes each element of a valve system, an engine body 10 and the like. It includes a lubricating device 80 that supplies oil and a control device 100 that comprehensively controls various devices including these devices.

  The engine body 10 includes a cylinder block 11 in which the air-fuel mixture is combusted, a cylinder head 12 in which the variable valve device 20 is provided, and an oil pan 13 in which lubricating oil supplied to each part of the engine body 10 stays. .

  The variable valve gear 20 includes an intake valve 21 and an exhaust valve 23 that open and close the combustion chamber 14, an intake camshaft 22 and an exhaust camshaft 24 that push down the valves, and an intake camshaft 22 with respect to the rotational phase of the crankshaft 15. And a variable valve timing mechanism 30 that changes the rotation phase (hereinafter referred to as “valve timing VT”).

  The lubricating device 80 includes an oil pump 81 that discharges the lubricating oil from the oil pan 13, a lubricating oil passage 90 that supplies the lubricating oil discharged from the oil pump 81 to each part of the internal combustion engine 1, and the variable valve timing mechanism 30. And an oil control valve 82 for controlling the supply and discharge modes of the lubricating oil.

  The control device 100 includes an electronic control device 101 that performs various arithmetic processes for controlling the internal combustion engine 1, and various sensors including a crank position sensor 102 and a cam position sensor 103.

  The crank position sensor 102 outputs a signal corresponding to the rotation angle of the crankshaft 15 (hereinafter “crank angle CA”) to the electronic control unit 101. The cam position sensor 103 outputs a signal corresponding to the rotation angle of the intake camshaft 22 (hereinafter referred to as “intake cam angle DA”) to the electronic control unit 101.

  The electronic control device 101 calculates the following parameters for use in various controls. That is, a calculation value corresponding to the crank angle CA is calculated based on the output signal of the crank position sensor 102. Further, a calculated value corresponding to the rotational speed of the crankshaft 15 (hereinafter referred to as “engine rotational speed NE”) is calculated based on the calculated value of the crank angle CA. Further, a calculation value corresponding to the cam angle DA is calculated based on the output signal of the cam position sensor 103. Further, a calculation value corresponding to the valve timing VT is calculated based on the crank angle CA and the intake cam angle DA.

  Examples of the control performed by the electronic control device 101 include an on-operation valve timing control for changing the valve timing VT during operation of the internal combustion engine 1 and a fixed control for fixing the valve timing VT based on an engine stop request or the like.

  In the valve timing control during operation, the valve timing VT is changed from the most advanced valve timing (hereinafter, “most advanced angle VTmax”) to the most retarded valve timing (hereinafter, “most delayed angle VTmin” based on the engine operating state. )).

  In the fixed control, when there is a request to fix the valve timing VT at a specific valve timing (hereinafter, “intermediate angle VTmdl”) between the most retarded angle VTmin and the most advanced angle VTmax (hereinafter, “fixed request”). The valve timing VT is fixed to the intermediate angle VTmdl. The fixed request is set when there is an engine stop request or when there is an idle operation request.

  The configuration of the variable valve timing mechanism 30 will be described with reference to FIG. 2A shows a cross section of the variable valve timing mechanism 30 along the radial direction. FIG. 2B shows a cross-sectional structure of the variable valve timing mechanism 30 along the DA-DA line in FIG.

  As shown in FIG. 2A, the variable valve timing mechanism 30 includes a housing rotor 31 that rotates in synchronization with the crankshaft 15 and a vane rotor 36 that rotates in synchronization with the intake camshaft 22. Further, a fixing mechanism 40 for fixing the valve timing VT to the intermediate angle VTmdl, an opening mechanism 70 (see FIG. 3) for supplying air to the variable mechanism 30 from a space outside the variable mechanism 30, and lubricating oil from each hydraulic chamber And a vane discharge oil passage 96 for discharging. The crankshaft 15 (sprocket 33A) and the intake camshaft 22 rotate in the direction of the arrow RA in the drawing.

  As shown in FIG. 2B, the housing rotor 31 includes a cylindrical housing body 32, a wall portion 33 attached to one end side in the axial direction of the housing body 32, and the other end in the axial direction of the housing body 32. And a cover 35 attached to the side. The wall portion 33 includes a sprocket 33A connected to the crankshaft 15 via a timing chain (not shown), and a plate 33B that is assembled to the vane rotor 36 side of the sprocket 33A and rotates integrally with the sprocket 33A.

  As shown in FIG. 2A, the housing body 32 is provided with three partition walls 32 </ b> A that project in the radial direction of the rotation shaft (the intake camshaft 22) of the housing rotor 31. The housing main body 32, the sprocket 33A, the plate 33B, and the cover 35 are fixed to each other by three bolts B inserted in the axial direction.

  The vane rotor 36 is fixed to an end portion of the intake camshaft 22 and is disposed in a space in the housing main body 32. The vane rotor 36 is provided with three vanes 36 </ b> A projecting between adjacent partition walls 32 </ b> A of the housing body 32.

  Three storage chambers 37 (a first storage chamber 37A, a second storage chamber 37B, and a third storage chamber 37C) are formed between the adjacent partition walls 32A. The storage chamber 37 is provided with an advance chamber 38 (first advance chamber 38A and second advance chamber 38B and third advance chamber 38C) and retard chamber 39 (first retard chamber 39A and The second retardation chamber 39B and the third retardation chamber 39C) are partitioned. The storage chamber 37 is surrounded by the inner periphery of the housing body 32, the outer periphery of the vane rotor 36, the plate 33B of the wall 33, and the cover 35 to form respective wall surfaces (see FIG. 3).

  The advance chamber 38 is located behind the vane 36 </ b> A in the accommodating chamber 37 in the rotational direction RA of the intake camshaft 22. The retard chamber 39 is located in the accommodation chamber 37 in front of the vane 36 </ b> A in the rotational direction RA of the intake camshaft 22. The volumes of the advance chamber 38 and the retard chamber 39 change according to the supply state of the lubricating oil to the variable valve timing mechanism 30 by the oil control valve 82.

  The vane rotor 36 is provided with a vane discharge oil passage 96 for discharging lubricating oil from the advance chamber 38 and the retard chamber 39. Since the vane discharge oil passage 96 is formed from each advance chamber 38 and each retard chamber 39 toward the center in the radial direction, the advance chamber is operated during engine operation, that is, when the valve timing variable mechanism 30 is rotating. The lubricating oil in 38 and the retarded angle chamber 39 is unlikely to flow into the vane discharge oil passage 96.

  The fixing mechanism 40 is provided in the third storage chamber 37 </ b> C and restricts the change of the valve timing VT to the advance side, and is provided in the second storage chamber 37 </ b> B and more than the first restriction mechanism 50. And a second limiting mechanism 60 that is provided on the advance side and restricts the change of the valve timing to the retard side.

The variable valve timing mechanism 30 operates as follows.
When the vane rotor 36 rotates with respect to the housing rotor 31 in the advance side, that is, in the rotation direction RA of the intake camshaft 22 by supplying the lubricant oil to the advance chamber 38 and discharging the lubricant oil from the retard chamber 39, the valve The timing VT changes to the advance side. When the vane rotor 36 is rotated to the most advanced side with respect to the housing rotor 31, that is, the rotational phase of the vane rotor 36 with respect to the housing rotor 31 (hereinafter referred to as "rotational phase P") is the frontmost phase (hereinafter referred to as rotational direction RA). When in the “most advanced angle phase PH”), the valve timing VT is set to the most advanced angle VTmax.

  By discharging the lubricating oil from the advance chamber 38 and supplying the lubricant oil to the retard chamber 39, the vane rotor 36 rotates on the retard side, that is, on the opposite side to the rotation direction RA of the intake camshaft 22 with respect to the housing rotor 31. The valve timing VT changes to the retard side. When the vane rotor 36 rotates to the most retarded side with respect to the housing rotor 31, that is, when the rotation phase P is at the most rearward phase in the rotation direction RA (hereinafter, “most retarded phase PL”), the valve timing VT is The most retarded angle VTmin is set.

  The structure of the fixing mechanism 40 and the opening mechanism 70 will be described with reference to FIGS. 3 and 4. 3 and 4 show a cross-sectional structure of the variable valve timing mechanism 30 along the line DB-DB in FIG. 2 developed on a plane.

The structure of the fixing mechanism 40 will be described.
The first limit mechanism 50 includes a first limit pin 51 that moves relative to the vane rotor 36, a first engagement groove 54 that is formed corresponding to the locus of the first limit pin 51, and the first limit pin 51. A first restriction chamber 53 for pushing in the direction and a first restriction spring 52 for pushing the first restriction pin 51 in the other direction are included.

  The first restricting pin 51 is positioned in the pin main body 51A located in the vane 36A when the tip end surface thereof is abutted against the bottom surface of the first lower groove 55, and in this time in the first engaging groove 54. And a pin tip 51B. When the hydraulic pressure in the first restriction chamber 53 is smaller than the force of the first restriction spring 52, the first restriction pin 51 operates in a direction protruding from the vane 36A (hereinafter referred to as “projection direction ZA”). When the hydraulic pressure in the first restriction chamber 53 is greater than the force of the first restriction spring 52, the first restriction pin 51 operates in the direction in which it is accommodated in the vane 36A (hereinafter referred to as “accommodating direction ZB”).

  The first engagement groove 54 is provided on the retard side with respect to two grooves having different depths, that is, the first lower groove 55 and the first lower groove 55 having a relatively large depth, and are relatively deep. The first upper groove 56 is small. The first advance angle end portion 54A that is the end portion on the advance angle side of the first lower groove 55 is provided at a position corresponding to a phase corresponding to the intermediate angle VTmdl (hereinafter referred to as “intermediate phase PM”). The first retarded end 54B, which is the retarded end of the first upper groove 56, is provided at a position corresponding to the first retarded phase PX1 located on the retarded side with respect to the intermediate phase PM. The first step end portion 54C, which is the end portion on the retard angle side of the first lower groove 55, is provided at a position corresponding to the second retard angle phase PX2 between the intermediate phase PM and the first retard angle phase PX. Yes.

  The second restriction mechanism 60 includes a second restriction pin 61 that moves relative to the vane rotor 36, a second engagement groove 64 that is formed corresponding to the locus of the second restriction pin 61, and the second restriction pin 61. A second restriction chamber 63 for pushing in the direction and a second restriction spring 62 for pushing the second restriction pin 61 in the other direction are included.

  The second restriction pin 61 has a pin body portion 61A located in the vane 36A when the tip surface thereof is abutted against the bottom surface of the second lower groove 65, and a pin tip located outside the vane 36A at this time. It is comprised by the part 61B. When the hydraulic pressure in the second restriction chamber 63 is smaller than the force of the second restriction spring 62, the second restriction pin 61 operates in the protruding direction ZA, which is the direction protruding from the vane 36A. When the hydraulic pressure in the second restriction chamber 63 is greater than the force of the second restriction spring 62, the second restriction pin 61 operates in the accommodation direction ZB, which is the direction in which the vane 36A is accommodated.

  The second engaging groove 64 has two grooves of different depths, that is, a relatively deep second lower step groove 65 and a relatively deeper depth provided on the retard side than the second lower step groove 65. A small second upper groove 66 is formed. A second advance end 64A, which is an end on the advance side of the second lower groove 65, is provided at a position corresponding to the advance phase PY on the advance side with respect to the intermediate phase PM. The third retard angle end portion 64B, which is the retard angle side end portion of the second upper groove 66, is provided at a position corresponding to the third retard angle phase PX3 on the retard angle side with respect to the first retard angle phase PX1. . A second step end portion 64C, which is an end portion of the second engagement groove 64 on the retard side of the second lower step groove 65, is provided at a position corresponding to the intermediate phase PM.

The operation of the first limiting mechanism 50 will be described.
When the lubricating oil is supplied to the first restriction chamber 53 in a state where the pin tip portion 51B of the first restriction pin 51 protrudes from the vane rotor 36, the first restriction pin 51 is accommodated in the vane rotor 36. When the lubricating oil in the first restriction chamber 53 is discharged in a state where the pin tip 51B of the first restriction pin 51 is accommodated in the vane rotor 36, the first restriction pin 51 operates in the protruding direction ZA. When the rotational phase P is between the intermediate phase PM and the first retardation phase PX1, the pin tip 51B projects into the first engagement groove 54.

The operation of the second restriction mechanism 60 will be described.
When the lubricating oil is supplied to the second restriction chamber 63 in a state where the pin tip portion 61B of the second restriction pin 61 protrudes from the vane rotor 36, the second restriction pin 61 is accommodated in the vane rotor 36. When the lubricating oil in the second restriction chamber 63 is discharged in a state where the pin tip portion 61B of the second restriction pin 61 is accommodated in the vane rotor 36, the second restriction pin 61 operates in the protruding direction ZA. When the rotational phase P is between the advance phase PY and the third retard phase PX3, the pin tip portion 61B projects into the second engagement groove 64.

  When the first limit pin 51 and the second limit pin 61 protrude into the first lower groove 55 and the second lower groove 65, respectively, the rotational phase P is fixed to the intermediate phase PM. That is, the fixing mechanism 40 fixes the rotational phase P to the intermediate phase PM by the cooperation of the first limiting mechanism 50 and the second limiting mechanism 60. That is, the valve timing VT is fixed to the intermediate angle VTmdl. Hereinafter, the operation of changing the rotational phase P toward the intermediate phase PM in order to fix the valve timing VT to the intermediate angle VTmdl is referred to as “fixed operation”.

  As the intermediate angle VTmdl, a valve timing VT suitable for starting the internal combustion engine 1 is set. That is, when comparing the case where the valve timing VT is set to the intermediate angle VTmdl at the time of engine start and the case where the valve timing VT is set to the retard angle side, the engine startability is better in the former than in the latter. high.

A specific process of the fixed control will be described.
The state of the internal combustion engine from when the stop request is set to the internal combustion engine until the internal combustion engine is completely stopped is defined as the time when the engine is stopped, and the state where the internal combustion engine is completely stopped is defined as the engine being stopped.

  When the electronic control unit 101 determines that there is a fixing request for fixing the valve timing VT to the intermediate angle VTmdl, the valve control VT controls the oil control valve 82 in a state where the valve timing VT is on the retard side with respect to the intermediate angle VTmdl. A command signal for fixing the timing VT to the intermediate angle VTmdl is transmitted. That is, the lubricant oil is supplied to the advance chamber 38 to the oil control valve 82, the lubricant oil in the retard chamber 39 is discharged, and the lubricant oil is discharged from the first restricting chamber 53 and the second restricting chamber 63. The command signal is sent.

  As a result, the lubricating oil is supplied to the advance chamber 38 and the lubricating oil in the retard chamber 39 is discharged, so that the valve timing VT is advanced. Further, since the lubricating oil is discharged from the first restricting chamber 53 and the second restricting chamber 63, the restricting pins 51 and 61 are maintained in a state of trying to protrude from the vane 36A. When the valve timing VT reaches the intermediate angle VTmdl, the limiting pins 51 and 61 are abutted against the ends of the first lower groove 55 and the second lower groove 65, and the valve timing VT is fixed to the intermediate angle VTmdl. .

  As described above, the electronic control unit 101 performs the fixing control for fixing the valve timing VT to the intermediate angle VTmdl when the engine is stopped. However, when the valve timing VT is not fixed at the intermediate angle VTmdl when the engine is stopped, the rotational phase P becomes the most retarded angle phase PL as the lubricating oil is discharged from the advance chamber 38 and the retard chamber 39 while the engine is stopped. Maintained. After the cranking starts, the vane rotor 36 rotates in the advance direction with respect to the housing rotor 31 due to cam torque fluctuation. At this time, if the lubricating oil is discharged from the first restriction chamber 53 and the second restriction chamber 63 while the engine is stopped, the first restriction pin 51 and the second restriction pin 61 are protruded by the restriction springs 52 and 62, respectively. It is maintained in a state of trying to move to ZA. For this reason, the limit pins 51 and 61 are fitted into the corresponding engagement grooves 54 and 64 in the order of the second retardation phase PX2, the third retardation phase PX3, the first retardation phase PX1 and the intermediate phase PM, and the valve timing. VT is fixed to the intermediate angle VTmdl.

  By the way, when the lubricating oil remains in the advance chamber 38 and the retard chamber 39 during cranking, the change of the valve timing VT based on cam torque fluctuation is prevented. For this reason, the variable valve timing mechanism 30 supplies external air to the advance chamber 38 and the retard chamber 39 in order to promote the discharge of the lubricating oil from the advance chamber 38 and the retard chamber 39 when the engine is stopped. An opening mechanism 70 to be introduced is provided.

The structure of the opening mechanism 70 will be described.
The opening mechanism 70 includes a part of the first restricting mechanism 50, a first opening mechanism 71 that directly communicates the third advance chamber 38 </ b> C and the third retard chamber 39 </ b> C and the external space, and a second restricting mechanism. The second opening mechanism 72 includes a part of the second advance chamber 38B and the second retard chamber 39B and directly communicates with the external space.

  The first opening mechanism 71 is provided in the vane rotor 36 to advance the restriction chamber opening passage 71A that communicates the first restriction chamber 53 and the external space with each other, and the first restriction chamber 53 and the advance chamber 38C. A corner chamber opening passage 71B, and a retard chamber opening passage 71C that allows the first restriction chamber 53 and the retard chamber 39C to communicate with each other are included.

  The second opening mechanism 72 is provided in the vane rotor 36 to advance the restriction chamber opening passage 72A that communicates the second restriction chamber 63 and the external space with each other, and the second restriction chamber 63 and the advance chamber 38B. A corner chamber opening passage 72B, and a retard chamber opening passage 72C that connects the second restriction chamber 63 and the retard chamber 39B to each other are included.

The operation of the opening mechanism 70 will be described.
As shown in FIG. 3, when the lubricating oil is sufficiently supplied to the first restriction chamber 53, the pin main body 51A moves through the restriction chamber opening passage 71A, the advance chamber opening passage 71B, and the retard chamber opening passage 71C. It is in a closed state (hereinafter referred to as “blocked state”). At this time, since the restriction chamber opening passage 71A, the advance chamber opening passage 71B, and the retard chamber opening passage 71C are closed, air flows between the external space and the advance chamber 38C and the retard chamber 39C. Is cut off. Similarly, when the lubricating oil is sufficiently supplied to the second restriction chamber 63, the pin main body 61A is in a closed state in which the restriction chamber opening passage 72A, the advance chamber opening passage 72B, and the retard chamber opening passage 72C are closed. is there. At this time, since the restriction chamber opening passage 72A, the advance chamber opening passage 72B, and the retard chamber opening passage 72C are closed, air flows between the external space and the advance chamber 38B and the retard chamber 39B. Is cut off.

  As shown in FIG. 4, when the lubricating oil is not sufficiently supplied to the first restriction chamber 53, the pin main body 51A moves through the restriction chamber opening passage 71A, the advance chamber opening passage 71B, and the retarding chamber opening passage 71C. It is in an open state (hereinafter “open state”). At this time, air is allowed to flow between the external space and the advance chamber 38C and the retard chamber 39C. Similarly, when the lubricating oil is not sufficiently supplied to the second restriction chamber 63, the pin body 61A is in an open state in which the restriction chamber opening passage 72A, the advance chamber opening passage 72B, and the retard chamber opening passage 72C are opened. is there. At this time, air is allowed to flow between the external space and the advance chamber 38B and the retard chamber 39B.

  With reference to FIG. 5, the flow mode of the lubricating oil between the lubricating device 80 and the variable valve timing mechanism 30 will be described. The figure schematically shows the configuration of the oil passage between the lubricating device 80 and the variable valve timing mechanism 30. When air is introduced into the variable valve timing mechanism 30, as indicated by broken lines in the drawing, air flows through the advance chamber communication passage 34E and the retard chamber communication passage 34A.

The structure of the lubricating oil passage 90 will be described.
The variable valve timing mechanism 30 includes three advance chambers 38A to 38C, three retard chambers 39A to 39C, a first limit chamber 53, and a second limit chamber whose oil supply and discharge states are switched by an oil control valve 82. A restriction chamber 63 is provided.

  The oil control valve 82, the advance chambers 38A to 38C, the retard chambers 39A to 39C, and the restriction chambers 53 and 63 are connected to each other through an advance oil passage 93, a retard oil passage 94, and a restriction oil passage 95, respectively. Has been. The oil control valve 82 and the oil pump 81 are connected to each other via a supply oil passage 91. The oil control valve 82 and the oil pan 13 are connected to each other via a discharge oil path 92. The advance chambers 38 </ b> A to 38 </ b> C and the retard chambers 39 </ b> A to 39 </ b> C are connected to the oil pan 13 through the vane discharge oil passage 96.

  The vane discharge oil passage 96 includes a first advance chamber discharge oil passage 97A, a first retard chamber discharge oil passage 98A, a second advance chamber discharge oil passage 97B, and a second retard chamber discharge oil passage 98B. , A third advance chamber exhaust oil passage 97C and a third retard chamber exhaust oil passage 98C.

  The first advance chamber discharge oil passage 97A connects the first advance chamber 38A and the discharge oil passage 92. The first retard chamber exhaust oil passage 98A connects the first retard chamber 39A and the exhaust oil passage 92 to each other. The second advance chamber discharge oil passage 97B connects the second advance chamber 38B and the discharge oil passage 92 to each other. The second retard chamber exhaust oil passage 98B connects the second retard chamber 39B and the exhaust oil passage 92 to each other. The third advance chamber exhaust oil passage 97C connects the third advance chamber 38C and the exhaust oil passage 92 to each other. The third retard chamber exhaust oil passage 98C connects the third retard chamber 39C and the exhaust oil passage 92 to each other.

A connection mode between the retard chambers 39 and the advance chambers 38 will be described.
The advance chamber 38 and the retard chamber 39 communicate with each other as follows. That is, the first retard chamber 39A and the second retard chamber 39B are communicated with each other via the retard chamber communication path 34A. The first advance chamber 38A and the third advance chamber 38C are communicated with each other via an advance chamber communication path 34E.

  When the engine is stopped and when the engine is stopped, the release mechanism 70 shifts from the closed state to the open state as the lubricating oil is discharged from the restriction chambers 53 and 63. Therefore, the passages 71A to 71C, 72A to 72C are opened. As a result, the air in the external space is introduced into the third advance chamber 38C and the third retard chamber 39C through the passages 71A to 71C. Further, the air in the external space is introduced into the second advance chamber 38B and the second retard chamber 39B through the passages 72A to 72C. The air introduced into the second retard chamber 39B and the third advance chamber 38C passes through the retard chamber communication passage 34A and the advance chamber communication passage 34E, respectively, and the first retard chamber 39A and the first advance angle. It is introduced into the chamber 38A.

  The structure of the wall part 33 is demonstrated with reference to FIG. FIG. 6A shows the surface of the plate 33 </ b> B on the side combined with the housing rotor 31 when assembled to the housing rotor 31. FIG. 6B shows the surface of the sprocket 33 </ b> A on the side assembled with the housing rotor 31 when assembled to the housing rotor 31.

  As shown in FIG. 6A, the plate 33B includes a first communication hole 34B, a second communication hole 34C, a third communication hole 34F, and a fourth communication hole 34G that penetrate the plate 33B in the axial direction. Three bolt holes HP for fastening the bolt B are formed.

  When the plate 33B is assembled to the housing main body 32, the positional relationship between the communication holes 34B, 34C, 34F, and 34G and each advance chamber 38 and each retard chamber 39 is as follows. That is, the first communication hole 34B is located at a site corresponding to the first retardation chamber 39A of the first storage chamber 37A. The second communication hole 34C is located at a portion corresponding to the second retardation chamber 39B of the second storage chamber 37B. The third communication hole 34F is located at a portion corresponding to the first advance chamber 38A of the first storage chamber 37A. The fourth communication hole 34G is located at a portion corresponding to the third advance chamber 38C of the third storage chamber 37C.

  As shown in FIG. 6B, a retard chamber communication groove 34D and an advance chamber communication groove 34H are formed on the surface of the sprocket 33A that is assembled to the plate 33B side. Further, three bolt holes HS for fastening the bolts B are formed.

  The retarding angle chamber communication groove 34D passes through a portion corresponding to the first advance chamber 38A and is formed from a portion corresponding to the first communication hole 34B to a portion corresponding to the second communication hole 34C. The advance chamber communication groove 34H passes through a portion corresponding to the first retard chamber 39A and is formed from a portion corresponding to the third communication hole 34F to a portion corresponding to the fourth communication hole 34G.

  The retarding chamber communicating passage 34A is formed by combining the first communicating hole 34B, the retarding chamber communicating groove 34D, and the second communicating hole 34C. Further, the advance chamber communication passage 34E is formed by combining the third communication hole 34F, the advance chamber communication groove 34H, and the fourth communication hole 34G.

With reference to FIG. 7, the relationship between the phase of each storage chamber 37 when the engine is stopped and the discharge state of the lubricant will be described. The arrow Y in the figure indicates the vertical direction.
As shown in FIG. 7, the valve timing variable mechanism 30 is arranged in a state where the first storage chamber 37A is positioned above and the second storage chamber 37B and the third storage chamber 37C are positioned below the first storage chamber 37A. When the rotation is stopped, the opening mechanism 70 introduces air into the second advance chamber 38B, the second retard chamber 39B, the third advance chamber 38C, and the third retard chamber 39C. The second advance chamber 38B, the second retard chamber 39B, the third advance chamber 38C, and the third retard chamber 39C accompanying the introduction of air into the second advance chamber 38B, the second retard chamber 39B, and the third retard chamber 39C. The lubricating oil in 39B, the third advance chamber 38C, and the third retard chamber 39C is discharged through the vane discharge oil passage 96. Thereby, the lubricating oil in the second storage chamber 37B and the third storage chamber 37C is replaced with air.

  The air introduced into the second retardation chamber 39B is introduced into the first retardation chamber 39A of the first storage chamber 37A via the retardation chamber communication path 34A. As the air is introduced into the first retarding chamber 39A, the lubricating oil in the first retarding chamber 39A passes through the first retarding chamber discharge oil passage 98A located below the first retarding chamber 39A. Discharged. Thereby, the lubricating oil in the first retarding chamber 39A is replaced with air.

  The air introduced into the third advance chamber 38C is introduced into the first advance chamber 38A of the first storage chamber 37A via the advance chamber communication path 34E. As the air is introduced into the first advance chamber 38A, the lubricating oil in the first advance chamber 38A passes through the first advance chamber discharge oil passage 97A located below the first advance chamber 38A. Discharged. Thereby, the lubricating oil in the first advance chamber 38A is replaced with air.

  When the rotation of the valve timing variable mechanism 30 is stopped while the second storage chamber 37B is positioned above, the opening mechanism 70 causes the second advance chamber 38B and the second retard chamber 39B to be moved from the external space. Air is introduced. As the air is introduced, the second advance chamber 38B and the second retard chamber 39B are provided with lubricating oil located below the second advance chamber 38B and the second retard chamber 39B. The oil is discharged through the discharge oil passage 97B and the second retard chamber discharge oil passage 98B. Thus, the lubricating oil in the second advance chamber 38B and the second retard chamber 39B is replaced with air. The same applies to the third advance chamber 38C and the third retard chamber 39C of the third storage chamber 37C including the second restriction mechanism 60.

According to this embodiment, the following effects can be obtained.
(1) In the present embodiment, the second opening mechanism 72 that communicates the second advance chamber 38B and the second retard chamber 39B with the external space when the engine is stopped, the second retard chamber 39B, A retard chamber communication passage 34A that communicates with the first retard chamber 39A is provided. In addition, when the engine is stopped, the first opening mechanism 71 that communicates the third advance chamber 38C and the third retard chamber 39C with the external space, the third advance chamber 38C, and the first advance chamber 38A. And an advance chamber communication passage 34E that communicates with each other. When the engine is stopped by the first opening mechanism 71 and the second opening mechanism 72, the second advance chamber 38B, the second retard chamber 39B, the third advance chamber 38C, and the third retard chamber 39C and the external space Are communicated with each other, air is introduced into the second advance chamber 38B, the second retard chamber 39B, the third advance chamber 38C, and the third retard chamber 39C. Accordingly, the lubricating oil in the second advance chamber 38B, the second retard chamber 39B, the third advance chamber 38C, and the third retard chamber 39C is easily discharged.

  Since the first advance chamber 38A communicates with the third advance chamber 38C through the advance chamber communication path 34E, air is also introduced into the first advance chamber 38A via the third advance chamber 38C. For this reason, the lubricating oil in the first advance chamber 38A communicating with the third advance chamber 38C is easily discharged. Further, since the first retard chamber 39A communicates with the second retard chamber 39B through the retard chamber communication path 34A, air is also introduced into the first retard chamber 39A via the second retard chamber 39B. The For this reason, the lubricating oil in the first retarding chamber 39A communicating with the second retarding chamber 39B is easily discharged. Thereby, it is possible to increase the frequency at which the valve timing VT is fixed to the intermediate angle VTmdl when starting the engine.

  Further, since the retard chambers 39 and the advance chambers 38 are connected to each other, the influence on the valve timing control during operation can be reduced as compared with the case where the retard chamber 39 and the advance chamber 38 are connected. .

  Further, since the first advance chamber 38A and the first retard chamber 39A communicate with the advance chamber 38 and the retard chamber 39 of the different storage chambers 37, the first advance chamber 38A and the first retard chamber 39A. Compared to the case of communicating with the advance chamber 38 and the retard chamber 39 of the same storage chamber 37, respectively, the efficiency of introducing air into the first advance chamber 38A and the first retard chamber 39A can be increased. it can.

  (2) In the variable valve gear 20 provided with the fixing mechanism 40 for fixing the valve timing VT to the intermediate angle VTmdl, when the engine is stopped without fixing the valve timing VT to the intermediate angle VTmdl, the valve timing is set when the engine is stopped. VT gradually retards. Then, when the valve timing VT advances to the intermediate angle VTmdl due to cam torque fluctuation at the time of subsequent engine start, the fixing mechanism 40 fixes the valve timing VT to the intermediate angle VTmdl. However, when the advance amount of the valve timing VT due to cam torque fluctuation is small, the frequency at which the valve timing VT does not advance to the intermediate angle VTmdl increases. According to the present embodiment, by providing the retard chamber communication passage 34A and the advance chamber communication passage 34E, it is possible to increase the frequency at which the valve timing VT is fixed to the intermediate angle VTmdl when the engine is started.

  (2) In the present embodiment, the first retardation chamber 39A and the second retardation chamber 39B communicate with each other through the retardation chamber communication passage 34A. The lubricating oil remaining in the retarding angle chamber 39 when the engine is started becomes a resistance when the valve timing VT is changed by cranking when the engine is started. In particular, when the advance angle is advanced from the retard angle side toward the intermediate angle VTmdl, if the lubricant oil remains in the retard angle chamber 39, the volume of the retard angle chamber 39 is unlikely to decrease, resulting in an advance resistance. The retarded angle chamber communication passage 34A is configured such that the open retarded angle chamber and the first retarded angle chamber 39A communicate with each other, so that the lubrication remaining in the first retarded angle chamber 39A by the air introduced from the second retarded angle chamber 39B. Since oil discharge is promoted, it is possible to suppress resistance when the valve timing is changed when the engine is started.

  (3) In the present embodiment, the first advance chamber 38A and the third advance chamber 38C communicate with each other through the advance chamber communication path 34E. When the valve timing VT advances at the time of starting the engine, if the volume of the advance chamber 38 increases, a negative pressure is generated in the advance chamber 38. This negative pressure becomes a resistance when the valve timing is advanced. Since the first advance chamber 38A and the third advance chamber 38C are in communication with each other, the air introduced from the third advance chamber 38C into the first advance chamber 38A is negative of the first advance chamber 38A. Since the pressure is reduced, it is possible to suppress resistance when the valve timing is changed when the engine is started.

  (4) In the present embodiment, the communication paths 34 </ b> A and 34 </ b> E are provided in the wall portion 33. For this reason, it is possible to suppress an increase in the radial size of the valve timing variable mechanism 30 as compared with the case where the communication paths 34A and 34E are provided on the outer peripheral side and the inner peripheral side of the storage chamber 37.

  (5) In the present embodiment, the communication grooves 34D and 34H constituting the communication paths 34A and 34E are provided in the sprocket 33A. Since the sprocket connected to the crankshaft 15 via the timing belt is a member conventionally included in the variable valve mechanism, by providing the communication grooves 34D and 34H using the sprocket 33A, the variable valve timing mechanism 30 is provided. Increase in size can be suppressed.

  (6) In the case of adopting a single member as the wall portion, it is necessary to form holes as the retard chamber communication passage and the advance chamber communication passage inside the wall portion. For this reason, there is a possibility that the processing for forming the advance chamber communication passage and the retard chamber communication passage may be complicated. In the present embodiment, the wall portion 33 including a sprocket 33A and a plate 33B formed separately is employed, and then the communication grooves 34D and 34H formed in the sprocket 33A and the communication holes 34B and 34C formed in the plate 33B. , 34F, and 34G constitute a retard chamber communication passage 34A and an advance chamber communication passage 34E. For this reason, compared with the case where what consists of a single member is employ | adopted as a wall part as mentioned above, the process of the wall part 33 for forming the retardation chamber communication path 34A and the advance chamber communication path 34E is simplified. Can be made.

  (8) In this embodiment, the retard chamber communication groove 34D passes through the portion of the plate 33B facing the first advance chamber 38A and communicates the first communication hole 34B and the second communication hole 34C with each other. The length of the retard chamber communication groove 34D can be shortened as compared with the configuration in which the communication holes 34B and 34C communicate with each other without passing through the portion of the plate 33B facing the first advance chamber 38A. Similarly, the advance chamber communication groove 34H passes through the portion of the plate 33B facing the first retard chamber 39A and connects the third communication hole 34F and the fourth communication hole 34G to each other. Compared to the configuration in which the communication holes 34F and 34G are connected to each other without passing through the portion of the plate 33B corresponding to 39A, the length of the advance chamber communication groove 34H can be shortened.

  (9) In this embodiment, when the limiting pins 51 and 61 are in positions where they block the passages 71A to 71C and 72A to 72C of the opening mechanism 70, the operating state of the opening mechanism 70 is the second advance chamber 38B and the second advance angle chamber 38B. The second retarded angle chamber 39B, the third advanced angle chamber 38C, the third retarded angle chamber 39C and the external space are blocked. When the limiting pins 51 and 61 are in positions where the passages 71A to 71C and 72A to 72C of the opening mechanism 70 are opened, the operating state of the opening mechanism 70 is the second advance chamber 38B and the second retard chamber 39B. The third advanced angle chamber 38C and the third retarded angle chamber 39C are in an open state in which the external space communicates with each other. That is, since the operating state of the opening mechanism 70 is changed to an open state or a closed state according to the positions of the restriction pins 51 and 61 of the fixing mechanism 40, the operation of the fixing mechanism 40 for fixing the valve timing VT is started. In conjunction with this, the discharge of the lubricating oil is promoted promptly.

(Other embodiments)
The embodiment of the present invention is not limited to the above-described embodiment, and the embodiment can be modified as shown below. The following modifications are not applied only to the above-described embodiment, and different modifications can be combined with each other.

In the above embodiment, the retard chamber communication passage 34A that communicates the first retard chamber 39A and the second retard chamber 39B, and the advance that communicates the first advance chamber 38A and the third advance chamber 38C with each other. Although the corner chamber communication path 34E is provided, the configuration of the communication path is not limited to this. That is, at least one of the retard chamber communication passage 34A, the advance chamber communication passage 34E, and the communication passages shown in the following (A) to (J) may be provided.
(A) A communication path that connects the first retardation chamber 39A and the third retardation chamber 39C to each other.
(B) A communication path that allows the first advance chamber 38A and the second retard chamber 39B to communicate with each other.
(C) A communication passage that communicates the second retardation chamber 39B and the third retardation chamber 39C with each other.
(D) A communication path that allows the second advance chamber 38B and the third advance chamber 38C to communicate with each other.
(E) A communication passage that communicates the first retard chamber 39A and the second advance chamber 38B with each other.
(F) A communication passage that communicates the first retard chamber 39A and the third advance chamber 38C with each other.
(G) A communication path that connects the first advance chamber 38A and the second retard chamber 39B to each other.
(H) A communication passage that communicates the first advance chamber 38A and the third retard chamber 39C with each other.
(I) A communication path that allows the second retard chamber 39B and the third advance chamber 38C to communicate with each other.
(J) A communication path that connects the third retard chamber 39C and the second advance chamber 38B to each other.

  In the variable valve timing mechanism 30 provided with the communication paths (C), (D), (I), and (J), one of the first opening mechanism 71 and the second opening mechanism 72 has a foreign substance in the passage. When the release mechanisms 71 and 72 do not function while the engine is stopped, for example, because air is introduced through the other release mechanism, the advance chamber 38 and the retard angle communicated with the one release mechanism. The discharge of the lubricating oil from the chamber 39 can be promoted.

  The variable valve timing mechanism 30 provided with the communication paths (E) to (J) is provided with a shut-off valve that blocks the communication path during engine operation. Thereby, the flow of the lubricating oil between the advance chamber 38 and the retard chamber 39 is blocked during engine operation. In addition, the flow amount of the lubricating oil through the communication passage between the advance chamber 38 and the retard chamber 39 during engine operation does not significantly affect the control of the valve timing VT in the normal valve timing control. By setting the amount, the shut-off valve can be omitted.

  In the above embodiment, the retard chamber communication passage 34A that communicates the second retard chamber 39B and the first retard chamber 39A is provided, but instead, the second retard chamber 39B and the first retard chamber 39A are provided. A communication path that communicates the chamber 39A and the first advance chamber 38A may be provided.

  In the above embodiment, the advance chamber communication passage 34E that communicates the third advance chamber 38C and the first advance chamber 38A is provided, but instead, the third advance chamber 38C and the first retard angle are provided. A communication path that communicates the chamber 39A and the first advance chamber 38A may be provided.

  In the above embodiment, the communication passages 34A and 34E are provided in the wall 33, but the communication passages 34A and 34E are provided in a portion on the outer peripheral side of the advance chamber 38 of the housing body 32, or in the cover 35 or the vane rotor 36. You can also.

  In the above embodiment, the communication passages 34A, 34E are formed by the communication grooves 34D, 34H formed in the sprocket 33A and the communication holes 34B, 34C, 34F, 34G formed in the plate 33B. A communication hole corresponding to the passage may be formed in the plate. Further, the plate can be omitted and a communication hole corresponding to the communication path can be formed in the sprocket.

  In the above embodiment, the retard chamber communication groove 34D is formed from the portion corresponding to the first advance hole 38B to the portion corresponding to the second communication hole 34C through the portion corresponding to the first advance chamber 38A. However, the configuration of the retard chamber communication groove is not limited to this. For example, a part corresponding to the second communication hole 34C from a part corresponding to the first communication hole 34B through a part corresponding to the second advance chamber 38B, the third retard chamber 39C, and the third advance chamber 38C. It is also possible to form the retarded angle chamber communicating groove.

  In the above embodiment, the advance chamber communication groove 34H passes through the portion corresponding to the first retardation chamber 39A and extends from the portion corresponding to the third communication hole 34F to the portion corresponding to the fourth communication hole 34G. However, the configuration of the advance chamber communication groove is not limited to this. For example, a part corresponding to the fourth communication hole 34G from a part corresponding to the third communication hole 34F through the part corresponding to the third retardation chamber 39C, the second advance chamber 38B, and the second retardation chamber 39B. An advance chamber communication groove can also be formed.

  In the above embodiment, the opening mechanism 70 using the limiting pins 51 and 61 of the limiting mechanisms 50 and 60 is included. However, a configuration in which the limiting mechanisms 50 and 60 and the opening mechanism 70 are provided separately may be employed. it can.

In the above embodiment, the opening mechanism 70 is provided in both the first limiting mechanism 50 and the second limiting mechanism 60, but the opening mechanism may be provided in only one of them.
In the above embodiment, the opening mechanism 70 that opens both the advance chamber 38 and the retard chamber 39 to the outside space is employed, but only one of the advance chamber 38 and the retard chamber 39 is opened to the outside space. An opening mechanism can also be employed.

  In the above embodiment, the configuration in which the operating state of the opening mechanism 70 and the operating state of the fixing mechanism 40 are changed based on the positions of the limiting pins 51 and 61 is adopted. It is also possible to adopt a configuration in which the 40 operating states are changed individually.

Specifically, each of the limiting pins 51 and 61 is constituted by a cylindrical first pin and a second pin provided inside the pin.
The first pin is provided to change the operating state of the opening mechanism 70, and moves in the vane in the axial direction with respect to the vane rotor based on the amount of lubricating oil in the restriction chamber. When the lubricating oil is supplied to the restriction chamber, the first pin moves to the closing position where the opening mechanism 70 is closed. Moreover, when lubricating oil is discharged | emitted from a restriction | limiting chamber, a 1st pin moves to the open position which makes the open mechanism 70 an open state.

  The second pin is provided to change the operating state of the fixing mechanism 40. When the first pin is in the closed position, the second pin is accommodated in the vane by the force in the accommodating direction applied from the first pin. Maintained in containment. Further, when the first pin is in the open position, it is maintained in a protruding state that attempts to protrude from the vane. The second pin protrudes into the engagement groove only when the first pin is in the open position and the position of the second pin with respect to the engagement groove coincides with the range of the restriction groove.

  In the above embodiment, the restricting pins 51 and 61 are provided on the vane rotor 36 and the engaging grooves 54 and 64 are provided on the housing rotor 31. However, this can be changed as follows. That is, at least one of the restricting pins 51 and 61 can be provided on the housing rotor 31, and at least one of the engaging grooves 54 and 64 can be provided on the vane rotor 36.

  In the above-described embodiment, as the structure of the fixing mechanism 40, the hydraulic pressure of each restriction chamber 53, 63 moves each restriction pin 51, 61 in the accommodation direction ZB, and each restriction spring 52, 62 corresponds to each restriction pin 51, 61. Although the structure which moves this to the protrusion direction ZA was employ | adopted, this can also be changed as follows. That is, the hydraulic pressure in each of the restriction chambers 53 and 63 is changed to a structure in which each of the restriction pins 51 and 61 is moved in the protruding direction ZA and each of the restriction springs 52 and 62 is moved in the accommodating direction ZB. You can also In this case, in order to fix the valve timing VT to the intermediate angle VTmdl when the engine is started, a structure capable of holding the hydraulic pressures of the restricting chambers 53 and 63 even when the engine is stopped is employed in the fixing mechanism 40. .

In each of the above embodiments, the first engagement groove 54 including the first lower groove 55 and the first upper groove 56 is formed in the first restriction mechanism 50. For example, the shape of the first engagement groove 54 is as follows. (A) or (B) can also be changed.
(A) Instead of the first lower groove 55, a hole into which the first limit pin 51 is fitted is formed in the intermediate phase PM. In this case, the first upper groove 56 is extended to the hole of the intermediate phase PM. At this time, the second limiting mechanism 60 can be omitted.
(B) The first upper groove 56 is omitted, and only the first lower groove 55 forms the first engagement groove 54.

In the above embodiment, the second engagement groove 64 including the second lower groove 65 and the second upper groove 66 is formed in the second restriction mechanism 60. For example, the shape of the second engagement groove 64 is as follows. It can also be changed as in (A) or (B).
(A) Instead of the second lower groove 65, a hole into which the second limit pin 61 is fitted is formed in the intermediate phase PM. At this time, the first limiting mechanism 50 can be omitted.
(B) The second upper groove 66 is omitted, and the second engagement groove 64 is configured only by the second lower groove 65.

  In the above embodiment, the variable pin timing mechanism 30 has a structure in which the limit pins 51 and 61 move in the axial direction of the vane rotor 36. However, the limit pins 51 and 61 move in the radial direction of the vane rotor 36. It is also possible to change the structure to That is, the limit pins 51 and 61 are provided on the vane 36A so that the limit pins 51 and 61 move in the radial direction of the vane rotor 36, and the engagement grooves are formed in the portions of the housing rotor 31 corresponding to the limit pins 51 and 61. 54 and 64 can also be provided.

  In the above embodiment, the single oil control valve 82 as the lubrication device 80 controls the valve timing VT and the supply / discharge state of the lubricating oil in the restriction chambers 53 and 63. However, the oil for controlling the valve timing VT A control valve and an oil control valve for controlling the supply / discharge state of the lubricating oil in the restriction chambers 53 and 63 may be provided separately.

  In the above embodiment, the valve timing variable mechanism 30 that changes the valve timing VT of the intake valve 21 is provided with the opening mechanism 70 and the communication passages 34A and 34E, but instead of or in addition to this, the valve of the exhaust valve 23 An opening mechanism and a communication path may be provided in the variable valve timing mechanism that changes the timing.

  In the above embodiment, the variable valve timing mechanism 30 including the fixing mechanism 40 for fixing to the intermediate angle VTmdl as the specific angle when the engine is stopped is employed, but instead of or in addition to this, the specific angle when the engine is stopped It is also possible to employ a variable valve timing mechanism that includes an advance angle fixing mechanism for fixing to the most advanced angle VTmax. In the variable valve mechanism having a fixing mechanism that fixes the intermediate angle and the most advanced angle, the valve timing VT is fixed to the most advanced angle VTmax when the engine is stopped, and the advanced angle fixing mechanism is released when the engine is started. Accordingly, the valve timing VT is retarded from the most advanced angle VTmax toward the intermediate angle VTmdl.

  In the above embodiment, the variable valve timing mechanism 30 including the fixing mechanism 40 for fixing to the intermediate angle VTmdl as the specific angle when the engine is stopped is employed. A variable valve timing mechanism including a retard angle fixing mechanism for fixing to the retard angle VTmin may be employed.

  In the above embodiment, the fixing control for fixing the valve timing VT to the intermediate angle VTmdl is performed when the engine is stopped, but the control for stopping the valve timing VT on the advance side from the intermediate angle VTmdl is performed when the engine is stopped. You can also.

  -The structure of the variable valve apparatus used as the application object of this invention is not restricted to the structure illustrated by the said embodiment. In other words, the present invention can be applied to any variable valve operating device as long as it includes a variable mechanism that changes the valve timing and a fixing mechanism that fixes the valve timing at a specific angle. Even in that case, the effect according to the effect of the said embodiment is obtained.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 10 ... Engine main body, 11 ... Cylinder block, 12 ... Cylinder head, 13 ... Oil pan, 14 ... Combustion chamber, 15 ... Crankshaft, 20 ... Variable valve apparatus, 21 ... Intake valve, 22 ... Intake Camshaft, 23 ... exhaust valve, 24 ... exhaust camshaft, 30 ... variable valve timing mechanism (variable valve mechanism), 31 ... housing rotor (input rotating body), 32 ... housing body, 32A ... partition wall, 33 ... wall Part (first wall), 33A ... sprocket, 33B ... plate, 34A ... retarded angle chamber communication passage (communication passage A), 34B ... first communication hole, 34C ... second communication hole, 34D ... retarded angle chamber communication groove (Communication groove A), 34E ... Advance chamber communication passage (communication passage B), 34F ... Third communication hole, 34G ... Fourth communication hole, 34H ... Advance chamber communication groove (communication groove B), 35 ... Cover ( Second wall), 6 ... vane rotor (output rotating body), 36A ... vane, 37 ... storage chamber, 37A ... first storage chamber, 37B ... second storage chamber, 37C ... third storage chamber, 38 ... advance chamber, 38A ... first advance Corner chamber, 38B ... second advance chamber, 38C ... third advance chamber (communication chamber B), 39 ... retard chamber, 39A ... first retard chamber, 39B ... second retard chamber (communication chamber A) 39C ... third retarding chamber, 40 ... fixing mechanism (specific angle fixing mechanism), 50 ... first limiting mechanism, 51 ... first limiting pin, 51A ... pin body, 51B ... pin tip, 52 ... first Restriction spring, 53 ... first restriction chamber, 54 ... first engagement groove, 54A ... first advance end, 54B ... first retard end, 54C ... first step end, 55 ... first lower groove 56 ... first upper groove, 60 ... second restriction mechanism, 61 ... second restriction pin, 61A ... pin body, 61B ... pin tip, 62 ... second restriction spring 63: Second restriction chamber, 64: Second engagement groove, 64A: Second advance end, 64B: Third retard end, 64C: Second step end, 65: Second lower groove, 66 ... Second upper groove, 70 ... Opening mechanism, 71 ... First opening mechanism (opening mechanism B), 71A ... Restricted chamber opening passage, 71B ... Advancing chamber opening passage, 71C ... Delay chamber opening passage, 72 ... Second opening Mechanism (opening mechanism A), 72A ... restricted chamber release passage, 72B ... advanced chamber release passage, 72C ... retarded chamber release passage, 80 ... lubricator, 81 ... oil pump, 82 ... oil control valve, 90 ... lubricating oil 91, supply oil passage, 92 ... discharge oil passage, 93 ... advance oil passage, 94 ... retard oil passage, 95 ... restriction oil passage, 96 ... vane discharge oil passage, 97A ... first advance chamber discharge oil , 97B ... second advance chamber discharge oil passage, 97C ... third advance chamber discharge oil passage, 98A ... first retard chamber discharge oil passage, 9 8B: Second retard chamber exhaust oil passage, 98C: Third retard chamber exhaust oil passage, 100: Control device, 101: Electronic control device, 102: Crank position sensor, 103: Cam position sensor

Claims (9)

A hydraulic variable valve mechanism that changes the valve timing is provided. The variable valve mechanism includes a first storage chamber including a first advance chamber and a first retard chamber, a second advance chamber, and a second advance chamber. In the variable valve operating apparatus for an internal combustion engine, including a second storage chamber including a retard chamber and a specific angle fixing mechanism that fixes the valve timing to a specific angle.
An opening mechanism A that communicates at least one of the second advance chamber and the second retard chamber and the external space with each other when the engine is stopped, and the open mechanism A communicates with the external space. A communication chamber A that is at least one of the second advance chamber and the second retard chamber and a communication passage A that communicates at least one of the first advance chamber and the first retard chamber with each other. A variable valve operating device for an internal combustion engine characterized by the above. The variable valve operating apparatus for an internal combustion engine according to claim 1,
The variable valve operating apparatus for an internal combustion engine, wherein the specific angle is an intermediate angle between a most advanced angle and a most retarded angle. The variable valve operating apparatus for an internal combustion engine according to claim 1 or 2,
As a storage chamber set, a set of storage chambers composed of the first storage chamber and the second storage chamber,
The variable valve operating apparatus for an internal combustion engine, wherein only the opening mechanism A is provided as a mechanism for introducing the air in the external space into the accommodation chamber set. The variable valve operating apparatus for an internal combustion engine according to claim 3,
The communication valve A communicates the first retardation chamber and the second retardation chamber as the communication chamber A with each other. The variable valve operating apparatus for an internal combustion engine according to claim 3 or 4,
The variable valve mechanism includes an opening mechanism that allows the third storage chamber including a third advance chamber and a third retard chamber to communicate with the third advance chamber and the external space when the engine is stopped. B, and a communication path B that communicates the first advance angle chamber with the communication chamber B, which is a chamber communicated with the external space by the opening mechanism B, and the variable motion of the internal combustion engine Valve device. The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 5,
The variable valve mechanism includes an input rotator that rotates in synchronization with the crankshaft and forms an outer peripheral wall of the variable valve mechanism, and an output rotator that rotates in synchronization with the camshaft.
The input rotating body includes a first wall portion and a second wall portion facing each other in the axial direction through the first storage chamber and the second storage chamber,
The communication passage A is provided in the first wall portion or the second wall portion. A variable valve operating apparatus for an internal combustion engine, characterized in that: The variable valve operating apparatus for an internal combustion engine according to claim 6,
The communication path A is provided in the first wall portion,
The first wall portion is provided between the sprocket connected to the crankshaft via a timing belt, and between the sprocket and the first storage chamber and the second storage chamber. A plate that forms a wall surface of the second storage chamber, and is formed at a portion of the plate corresponding to the first advance chamber or the first retard chamber communicated with the communication chamber A. A first communication hole, a second communication hole formed in a portion of the plate corresponding to the communication chamber A, and the first communication hole and the second communication hole on the plate-side surface of the sprocket. A variable valve operating apparatus for an internal combustion engine, comprising: a communication groove formed so as to communicate. The variable valve operating apparatus for an internal combustion engine according to claim 7,
The variable valve mechanism includes a third storage chamber including a third advance chamber and a third retard chamber, and an opening mechanism B that allows the third advance chamber and the external space to communicate with each other when the engine is stopped. The opening mechanism B includes a communication chamber B that is a chamber that communicates with the external space and a communication passage B that communicates the first advance angle chamber with each other. These chambers are provided in the order of the first storage chamber and the third storage chamber,
The second advance chamber and the second retard chamber are provided as the communication chamber A,
The third advance chamber and the third retard chamber are provided as the communication chamber B,
The communication path A includes a first communication hole formed in a portion of the plate corresponding to the first retardation chamber and a second communication hole formed in a portion of the plate corresponding to the second retardation chamber. And a communication groove A formed in the sprocket so as to pass through the portion of the plate facing the first advance chamber and to communicate the first communication hole and the second communication hole with each other. And
The communication path B includes a third communication hole provided in a portion of the plate corresponding to the first advance chamber, and a fourth communication hole formed in a portion of the plate corresponding to the third advance chamber. And a communication groove B formed in the sprocket so as to pass through the portion of the plate facing the first retarding chamber and to communicate the third communication hole and the fourth communication hole with each other. A variable valve operating apparatus for an internal combustion engine characterized by the above. The variable valve operating apparatus for an internal combustion engine according to any one of claims 6 to 8,
The specific angle fixing mechanism includes a fixing pin provided in one of the input rotator and the output rotator, a fixing groove provided in the other of the input rotator and the output rotator, and the fixing pin as the input rotator. And a fixed chamber in which lubricating oil is supplied and discharged to move with respect to one of the output rotating bodies, and the valve timing is set to the specific angle when the fixing pin is fitted in the fixing groove. Is fixed to
When the fixing pin is in the first position, the operating state of the opening mechanism A is a closed state that blocks between the communication chamber A and the external space,
When the fixing pin is in the second position, the operating state of the opening mechanism A is an open state in which the communication chamber A and the external space are in communication with each other.

Images