JP2011032945A - Hydraulic fluid passage structure of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the tension applying function and vibration damping function of a tensioner and to improve the operational performance of a variable valve timing mechanism, by suppressing supply of hydraulic fluid containing air to the tensioner and a variable valve timing mechanism operating mechanism in such a manner that the structure of a hydraulic fluid passage allowing the flowing of hydraulic fluid supplied to the hydraulic tensioner and hydraulic variable valve timing mechanism of an internal combustion engine is devised. <P>SOLUTION: This hydraulic fluid passage structure includes: a tensioner oil passage 63 branched downwardly from a common oil passage 62 allowing the flowing of the hydraulic fluid introduced to the tensioner 31 and variable valve timing mechanism 50, and introducing the hydraulic fluid to the tensioner 31; a control oil passage 70 branched upwardly from the common oil passage 62, and introducing the hydraulic fluid to the variable valve timing mechanism 50; and a hydraulic control valve 100 controlling the hydraulic pressure of the hydraulic fluid in the variable valve timing mechanism 50. The hydraulic control valve 100 allows leakage of the hydraulic fluid from the upstream oil passages 71, 72 of the control oil passage 70. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an operation supplied to the tensioner and the operating mechanism in an internal combustion engine including a hydraulic tensioner that applies tension to the endless transmission band of the winding transmission mechanism and a hydraulic operation mechanism that operates an actuated member. The present invention relates to a hydraulic oil passage structure through which oil flows. The operating mechanism is, for example, a valve characteristic variable mechanism that is provided in a valve operating device and can change the valve operating characteristic of the engine valve.

In an internal combustion engine, a tensioner oil passage that guides hydraulic oil to a hydraulic tensioner that applies tension to an endless transmission band of a winding transmission mechanism extends in a vertical direction, and oil supplied from an oil pump is supplied to the tensioner oil passage. A hydraulic oil passage structure supplied to the lower end is known (see, for example, Patent Document 1).
Further, as a valve characteristic variable mechanism provided in a valve operating apparatus for an internal combustion engine, a variable valve timing mechanism capable of changing the opening / closing timing of an intake valve is known (see, for example, Patent Document 2).

JP 2006-144999 A Japanese Patent No. 3497462

The hydraulic oil passage structure of an internal combustion engine usually has an oil passage formed over a plurality of members, and a hydraulic control valve (for example, a spool valve) having a valve body that slides to control the hydraulic pressure is used. In addition, since hydraulic oil is supplied from a hydraulic oil supply source (for example, an oil pump) that is operated and stopped in response to the operation and stop of the internal combustion engine, The hydraulic oil in the hydraulic oil supply source may leak from a minute clearance and air may enter.
Then, the air that has entered the oil passage is mixed into the hydraulic oil after the internal combustion engine is started and flows through the oil passage. For this reason, when the tensioner oil passage extends in the vertical direction and hydraulic oil flows in from the lower end thereof and is supplied to the tensioner through the upper end, air mixed in the hydraulic oil (hereinafter referred to as “mixed air”). ) Also flows into the tensioner, so that the tensioner is easily moved by the presence of mixed air in the oil chamber of the tensioner, leading to a decrease in the tension imparting function and the damping function that suppresses endless transmission band vibration. To do.

  The present invention has been made in view of such circumstances, and in an internal combustion engine including a hydraulic tensioner and a hydraulic operation mechanism, a hydraulic oil passage structure through which hydraulic oil supplied to the tensioner and the operation mechanism flows. By devising, the supply of hydraulic fluid containing air to the tensioner and the operating mechanism is suppressed, thereby improving the tensioning function and damping function of the tensioner and improving the operating performance of the operating mechanism. For the purpose.

The invention described in claim 1 includes a hydraulic tensioner (31) that applies tension to the endless transmission band (28) of the winding transmission mechanism (25) that rotationally drives the driven members (21i, 21e), and a driven member ( A hydraulic oil passage structure of an internal combustion engine provided in an internal combustion engine including a hydraulic actuation mechanism (50) for actuating 21i) and through which hydraulic oil supplied to the tensioner (31) and the actuation mechanism (50) flows. , The base oil passage (62) through which the working oil guided to the tensioner (31) and the operating mechanism (50) flows, and the base oil passage (62) branches downward to operate the tensioner (31). A tensioner oil passage (63) for guiding oil, a control oil passage (70) for branching upward from the base oil passage (62) to guide the working oil to the operating mechanism (50), and the control oil passage (70) Placed in A hydraulic control valve (100) for controlling the hydraulic pressure of the hydraulic oil in the operating mechanism (50), and the control oil passage (70) extends from the base oil passage (62) to the hydraulic control valve (100). The hydraulic control valve (100) has an upstream oil passage (71, 72) that extends only upward, and allows the hydraulic oil to leak from the upstream oil passage (71, 72). It is an oil passage structure.
According to the first aspect of the present invention, since the tensioner oil passage is branched downward from the base oil passage, when air is mixed in the hydraulic oil flowing through the base oil passage, the mixed air ( In other words, the mixed air) is less likely to flow from the base oil passage into the tensioner oil passage, so that the supply of hydraulic fluid containing mixed air to the tensioner is suppressed, and the tensioner tensioning function for the endless transmission band and Damping function is improved. In addition, since the control oil passage branches upward from the base oil passage, mixed air easily flows into the control oil passage from the base oil passage, but the upstream oil passage of the control oil passage extends only upward. In addition, since the hydraulic control valve has a structure in which hydraulic oil in the upstream oil passage leaks, the mixed air in the upstream oil passage smoothly flows from the base oil passage toward the hydraulic control valve and reaches the hydraulic control valve. Since the hydraulic oil that is leaking in the hydraulic control valve is discharged from the control oil path to the external space, the mixed air can easily escape from the control oil path. As a result, supply of operating oil containing mixed air to the operating mechanism is suppressed, and the operating performance of the operating mechanism with respect to the operated member is improved.
The invention according to claim 2 is the hydraulic oil passage structure of the internal combustion engine according to claim 1, wherein the tensioner oil passage (63) and the control oil passage (70) are downstream end portions of the base oil passage (62). (62b).
According to the second aspect of the present invention, the mixed air in the base oil passage flows into the control oil passage that branches upward at the downstream end of the base oil passage, and easily flows out of the base oil passage. The mixed air remaining in the oil passage can be quickly reduced. As a result, mixed air in the tensioner oil passage and the control oil passage branched from the base oil passage can be quickly reduced.
According to a third aspect of the present invention, in the hydraulic oil passage structure of the internal combustion engine according to the first or second aspect, the lower end portion (71a) communicating with the base oil passage (62) and the hydraulic control valve (100) are communicated. The upstream oil passage (71, 72) having an upper end (72b) is a passage (73) extending substantially straight upward from the lower end (71a) to the upper end (72b), Alternatively, the first lower end portion does not move away from the upper end portion (72b) of the upstream oil passage (71, 72) in the horizontal direction as it approaches the upper end portion (71b) from the first lower end portion (71a) in the vertical direction. The first straight oil passage (71) extending substantially straight upward from (71a) and the upper end portion (72b) of the upstream oil passage (71, 72) from the lower end portion (72a) in the vertical direction. As the first straight oil passage ( 1) from the upper end (71b) of the upstream oil passage (71, 72) to the upper end (72b) of the upstream oil passage (71, 72) in the horizontal direction without moving away from the upper end (72b) of the upstream oil passage (71, 72). The second straight oil passage (72) extends substantially straight upward.
According to the third aspect of the present invention, since the upstream oil passage is substantially straight or nearly straight, mixed air stays in the control oil passage as compared with the case where the upstream oil passage is bent in a complicated manner. Is suppressed. In addition, when the upstream oil passage is formed by machining, the removal of generated chips becomes easy, the remaining chips are reduced, and the filter provided in the oil passage or the hydraulic control valve is clogged. The pressure loss due to the pressure can be reduced, and further, the cost can be reduced by reducing or eliminating the number of filters.
According to a fourth aspect of the present invention, in the hydraulic oil passage structure of the internal combustion engine according to any one of the first to third aspects, the control oil passage (70) is bordered by the hydraulic control valve (100). Between the upstream oil passage (71, 72) positioned between the base oil passage (62) and the hydraulic control valve (100), and between the hydraulic control valve (100) and the operating mechanism (50). The hydraulic control valve (100) is slidably fitted to the valve body (101) and is parallel to the operation axis (La). A movable valve body (102) is provided, and the downstream oil passage (80, 90) is arranged such that the upstream oil passage (71, 72) communicates with the hydraulic control valve (100) with respect to the operating axis. The hydraulic control valve (100) communicates with the position offset in the direction.
According to the fourth aspect of the present invention, when the valve body of the hydraulic control valve moves in the operation axis direction, mixed air is discharged together with the hydraulic oil through a slight clearance between the valve body and the sliding valve body. As a result, the mixed air easily escapes from the control oil passage, and the operating oil containing the mixed air is suppressed from being supplied to the operating mechanism.
According to a fifth aspect of the present invention, in the hydraulic oil passage structure for an internal combustion engine according to any one of the first to fourth aspects, the control oil passage (70) is located downstream of the hydraulic control valve (100). A sliding contact between the sliding member (21i) and the supporting member (41) is formed between the sliding member (21i) and a supporting member (41) that slidably supports the sliding member (21i). A lubricating oil passage (84) for lubricating the surface (Pb) with hydraulic oil is provided, and the control oil passage (70) extends upward from the hydraulic control valve (100) to the lubricating oil passage (84). And an oil passage (81) extending in a straight line.
According to the fifth aspect of the present invention, when the mixed air flows into the oil passage through the hydraulic control valve, the oil passage extends in a straight line and communicates with the lubricating oil passage. Easy to flow into the road. Since the mixed air that has flowed into the lubricating oil passage is slidable and can easily escape from the sliding contact surface where a slight clearance is formed, the working oil containing the mixed air is supplied to the operating mechanism. Is suppressed.
According to a sixth aspect of the present invention, in the hydraulic oil passage structure for an internal combustion engine according to any one of the first to fifth aspects, the operating mechanism (50) is a valve-operated camshaft (21i) that is the operated member. Is a variable valve timing mechanism (50) for controlling the opening / closing timing of the engine valve (12) by controlling
According to the sixth aspect of the present invention, even when the mixed oil is contained in the hydraulic oil from the base oil passage supplied to the tensioner and the variable valve timing mechanism, similarly to the tensioner, the variable valve timing mechanism Is prevented from being supplied with hydraulic oil containing mixed air. As a result, the operation performance of the variable valve timing mechanism with respect to the valve camshaft is improved, and the control responsiveness and control accuracy of the opening / closing timing of the engine valve are improved.

  In a hydraulic oil passage structure of an internal combustion engine provided with a hydraulic tensioner and a hydraulic operation mechanism, supply of hydraulic oil containing air to the tensioner and the operation mechanism is suppressed. The operating performance of the operating mechanism can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure of the principal part when the internal combustion engine provided with the hydraulic-fluid structure to which this invention was provided is seen from the axial direction of a cam shaft, and one part is shown by the cross section. It is a figure of the principal part when the internal combustion engine of FIG. 1 is seen from a cylinder axial direction. It is principal part sectional drawing in the schematic III-III line | wire of FIG. 2, About a cylinder block, it is sectional drawing in the plane which orthogonally crosses the rotation center line of a cam shaft and contains a cylinder axis line. It is sectional drawing of the principal part in the general IV-IV line of FIG.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
Referring to FIGS. 1 and 3, an internal combustion engine E to which the present invention is applied includes a cylinder block 1 in which a plurality of cylinders 1 a into which pistons 5 are reciprocally fitted are arranged in series and provided integrally. An engine head comprising a lower block 2 coupled to the lower end of the cylinder block 1, a cylinder head 3 coupled to the upper end of the cylinder block 1, and a head cover 4 coupled to the upper end of the cylinder head 3; The multi-cylinder four-stroke internal combustion engine includes an engine body including an oil pan in which lubricating oil is stored, and further includes a crankshaft 7 connected to each piston 5 via a connecting rod 6.
The crankshaft 7 is rotatably supported by the lower part 1b of the cylinder block 1 and the lower block 2. The lower portion 1b of the cylinder block 1, the lower block 2, and the oil pan constitute a crankcase that forms a crank chamber in which the crankshaft 7 is accommodated. The cylinder block 1, the lower block 2, and the oil pan constitute an engine block.
Further, in this embodiment, the internal combustion engine E is mounted such that the cylinder axis Lc (and hence the cylinder axis direction parallel to the cylinder axis Lc) is inclined at a predetermined inclination angle with respect to the vertical direction (see FIG. 1). It is mounted on the target vehicle at an angle.

  In this specification and claims, the vertical direction is the vertical direction, and the upper direction is vertically upward (that is, upward in a direction parallel to the vertical direction) and diagonally upward (that is, intersects the vertical direction). Similarly, the lower part includes the vertically lower part (that is, the lower part in the direction parallel to the vertical direction) and the oblique lower part (that is, the lower part in the direction intersecting the vertical direction). And

Referring to FIGS. 1 to 3, the cylinder head 3 opens and closes an intake port 10 and an exhaust port 11 that open to a combustion chamber 8 formed between the piston 5 and the cylinder head 3 for each cylinder 1 a. An intake valve 12 and an exhaust valve 13 are provided as engine valves.
The internal combustion engine E is disposed in a valve operating chamber 9 formed by the cylinder head 3 and the head cover 4, and operates a valve operating device 20 that opens and closes the intake valve 12 and the exhaust valve 13, and intake air via the intake port 10. An intake device 14 that guides the fuel to the combustion chamber 8, a fuel injection valve (not shown) that injects fuel that mixes with the intake air to form an air-fuel mixture, and combustion generated by combustion of the air-fuel mixture in the combustion chamber And an exhaust device 15 that guides gas to the outside of the internal combustion engine E through the exhaust port 11 as exhaust gas.
The piston 5 is driven by the pressure of the combustion gas generated when the air-fuel mixture in the combustion chamber 8 is ignited and burned by the spark plug 16, and reciprocates to drive the crankshaft 7 via the connecting rod 6. . The spark plug 16 is housed in a cylindrical housing tube 17 held by a holding portion 18 provided in the cylinder head 3.

  The valve gear 20 includes an intake cam shaft 21i as a first cam shaft having an intake cam 22i as a valve cam and an exhaust cam shaft 21e as a second cam shaft having an exhaust cam 22e as a valve cam. An intake rocker arm 23i that is a cam follower that contacts and contacts the intake valve 12 and the exhaust valve 13 and that is driven by the intake cam 22i and the exhaust cam 22e to open and close the intake valve 12 and the exhaust valve 13, respectively. It includes a rocker arm 23e and a variable valve timing mechanism 50 as a hydraulic operating mechanism that is a hydraulic actuator controlled by a control device 120 (see FIG. 1). The variable valve timing mechanism 50 is a valve characteristic variable mechanism that controls the opening / closing timing of the intake valve 12 so as to be changeable.

The internal combustion engine E further includes a wrapping transmission mechanism 25 for valve timing that rotates the camshafts 21i and 21e (and therefore the cams 22i and 22e) as driven members in synchronization with the rotation of the crankshaft 7. And a tensioner device 30 that applies tension to the chain 28 of the winding transmission mechanism 25.
The winding transmission mechanism 25 includes a driving sprocket 26 that is a driving rotating body provided on the crankshaft 7 as a driving shaft, and a driven rotating body that is provided on the intake camshaft 21i via a variable valve timing mechanism 50. Each camshaft is provided with a sprocket 27i, a driven sprocket 27e as a driven rotating body provided on the exhaust camshaft 21e, and an endless chain 28 as an endless transmission belt stretched over these sprockets 26, 27i, 27e. 21i and 21e are rotationally driven at a rotational speed half that of the crankshaft 7.

  The winding transmission mechanism 25 includes sidewalls 1w and 3w of the cylinder head 3 and the cylinder block 1 on one side in the axial direction that is parallel to the rotation center lines Li and Le of the cam shafts 21i and 21e, It is arranged in a chain chamber 29 as a transmission chamber formed by the cover 19 coupled to the side walls 1 w and 3 w and the head cover 4.

  Referring to FIG. 1, the tensioner device 30 includes a hydraulic tensioner 31 as a hydraulic actuator attached with a bolt screwed into a screw hole 33b of a mounting seat 33 provided integrally with the side wall 1w, and a swing on the side wall 3w. A tensioner shoe 32 is provided as a guide member that is movably supported and is urged by the tensioner 31 and pressed against the chain 28. The tensioner 31 is disposed below a later-described branching portion 64, and the fulcrum portion 32 a of the tensioner shoe 32 pivotally attached to the mounting seat 34 provided on the side wall 3 w is disposed above the tensioner 31.

  The tensioner 31 known per se includes a body 31a fixed to the mounting seat 33 with bolts, and a plunger 31b as a pressing member that is accommodated in the body 31a and can be advanced and retracted in the urging direction. The plunger 31b is urged by a tensioner spring that applies tension, and applies tension to the chain 28 via the tensioner shoe 32 by the pressure of hydraulic oil in the oil chamber formed by the cooperation of the body 31a and the plunger 31b. To do.

1 to 3, the cam shafts 21 i and 21 e are rotatably supported by a cam holder that is fixed to the cylinder head 3 and provided integrally therewith. The cam holder includes a plurality of bearing members 40 serving as support members arranged at intervals in the axial direction.
Each bearing member 40 that rotatably supports each cam shaft 21i, 21e by its journal 24i, 24e includes a lower bearing portion 42 as a first bearing portion that is integrally formed with the cylinder head 3, and a lower bearing. The upper bearing portion 43 as a second bearing portion coupled to the portion 42 by a bolt 49 as a coupling means. The lower bearing portion 42 is provided with a screw hole 42c into which the bolt 49 is screwed.

Of the plurality of bearing members 40 that support the intake camshaft 21i, an end portion as a specific bearing member that is located at an end portion on the one-direction side in the axial direction and is adjacent to the variable valve timing mechanism 50 in the axial direction The bearing member 41 is provided with oil passages 81, 84, 91, 94 through which hydraulic oil for operating the variable valve timing mechanism 50 flows. The bearing member 41 includes a lower bearing portion 44 and an upper bearing portion 45.
In addition, an oil groove (illustrated) through which oil that lubricates between the journals 24i and 24e that are in sliding contact is guided to the remaining bearing members 40 that support the intake camshaft 21i and all the bearing members 40 that support the exhaust camshaft 21e. Not provided).

  The lower bearing portion 42 and the upper bearing portion 43 having bearing surfaces 42a and 43a, which are in sliding contact with the outer peripheral surfaces 24a of the journals 24i and 24e, are fastened by bolts 49 in a state where the mating surfaces 42b and 43b are in contact with each other. Integrated. Therefore, each of the cam shafts 21 i and 21 e is a sliding member that is slidably supported by the bearing member 40. The bearing member 40 is divided into two parts, a lower bearing part 42 and an upper bearing part 43, by a dividing surface Pa formed by the mating surfaces 42b and 43b.

  A variable valve timing mechanism 50 capable of continuously changing the opening / closing timing of the intake valve 12 between the most retarded angle timing and the most advanced angle timing is provided between the winding transmission mechanism 25 and the intake camshaft 21i. This is a known device that causes relative rotation, and is provided between the driven sprocket 27i and the camshaft 21i on the transmission path of the rotational driving force from the winding transmission mechanism 25 to the camshaft 21i, and is a cam for the crankshaft 7. The phase of the shaft 21i and therefore the cam 22i is controlled according to the engine operating state. Therefore, the cam shaft 21 i is an operated member whose operation is controlled by the variable valve timing mechanism 50.

  The variable valve timing mechanism 50 provided at the shaft end 21i1 protruding in the axial direction from the bearing member 41 in the camshaft 21i includes a driving side rotating body 51 and a driven side rotating body 52 that can rotate relative to each other. Prepare. The driving-side rotator 51 rotates integrally with the driven sprocket 27i, and the driven-side rotator 52 is coupled by a bolt 55 and rotates integrally with the cam shaft 21i. Between the rotating bodies 51, 52 in the circumferential direction of the camshaft 21i, the rotating bodies 51, 52 respectively provide one or more advance oil chambers 53 and second oils as a plurality of first oil chambers here. A retard oil chamber 54 as a chamber is formed at intervals in the circumferential direction.

Next, with reference to FIG. 1, FIG. 2 and FIG. 4, the hydraulic oil path structure provided in the internal combustion engine E and through which the hydraulic oil for operating the variable valve timing mechanism 50 will be described.
Referring to FIG. 1, an oil pump 60 that constitutes a lubrication system provided in the internal combustion engine E and is driven by the power of the crankshaft 7 lubricates the crankshaft 7 and the piston 5 (see FIG. 3) of the internal combustion engine E. This is a hydraulic oil supply source that supplies part of the discharged oil as hydraulic oil for the tensioner 31 and the variable valve timing mechanism 50 while supplying oil to a location.

  The hydraulic oil passage structure includes an oil pump 60 that supplies hydraulic oil during operation of the internal combustion engine E and stops supply of hydraulic oil when the internal combustion engine E is stopped, a main gallery 61 that is supplied with oil from the oil pump 60, and a main gallery. Oil supply path for supplying oil 61 to the tensioner 31 and the variable valve timing mechanism 50 as hydraulic oil, and hydraulic control for controlling the hydraulic pressure of the hydraulic oil in the advance oil chamber 53 and the retard oil chamber 54 of the variable valve timing mechanism 50 And a valve 100.

  The oil pump 60 disposed in the crank chamber is composed of, for example, a trochoid pump, and discharges oil pumped up from the oil pan, which is an oil reservoir, to the main gallery 61. The main gallery 61 constituting the lubrication system is provided in the cylinder block 1 and extends in a straight line in the axial direction. From the main gallery 61, a number of branch oil passages for supplying oil to a number of lubrication points of the internal combustion engine E are branched.

  The oil supply passage is divided into a common oil passage 62 as a base oil passage through which hydraulic oil guided to the tensioner 31 and the variable valve timing mechanism 50 flows together, and the hydraulic oil is branched downward from the common oil passage 62 to the tensioner 31. And a control oil passage 70 that branches upward from the common oil passage 62 and guides hydraulic oil to the variable valve timing mechanism 50.

The common oil passage 62 provided in the cylinder block 1 extends in a straight line from the main gallery 61 in an orthogonal direction substantially orthogonal to the cylinder axial direction when viewed from the axial direction (hereinafter referred to as “axial view”). (See FIG. 1), the upstream end 62a opens to the main gallery 61, and the downstream end 62b is a dead end. The downstream end portion 62 b is one branch portion 64 where the tensioner oil passage 63 and the control oil passage 70 branch. The hydraulic oil flowing from the upstream end portion 62 a through the common oil passage 62 is tensioner oil in the branch portion 64. The flow is divided into a path 63 and a control oil path 70.
Note that the expression “almost” includes the case where there is no modifier “almost” and does not exactly match the case where there is no modifier “almost”, but the modifier “almost”. It means a range in which there is no significant difference with respect to the effect as compared with the case where there is no.

  A tensioner oil passage 63 provided in the cylinder block 1 and opened to the branching portion 64 at the upstream end portion 63a extends in a straight line obliquely downward with respect to the vertical direction, and a downstream end portion 63b provided in the mounting seat 33. The mounting seat 33 opens to the mounting surface 33a to which the body 31a is mounted. The hydraulic oil in the tensioner oil passage 63 is guided to the oil chamber of the tensioner 31 through the oil passage provided in the body 31a from the outlet 63c at the downstream end of the mounting seat 33. As another example, the tensioner oil passage 63 may extend linearly downward from the branch portion 64.

  Referring to FIGS. 1, 2, and 4, the control oil passage 70 in which the hydraulic control valve 100 is disposed is located between the common oil passage 62 and the hydraulic control valve 100 with the hydraulic control valve 100 as a boundary. The upstream oil passages 71 and 72 extending only upward from the common oil passage 62 to the hydraulic control valve 100, and the advance oil chamber 53 and the retard oil chamber 54 of the hydraulic control valve 100 and the variable valve timing mechanism 50 (FIG. 2). And an advanced oil passage 80 serving as a first downstream oil passage and a retard oil passage 90 serving as a second downstream oil passage, respectively.

The upstream oil passages 71, 72 extend from the lower end portion 71 a that is the upstream end portion that opens to the branch portion 64 in the axial direction, substantially parallel to the cylinder axial direction as the specific direction, and the upper end portion that is the downstream end portion In 71b, the first upstream oil passage 71 that opens to the mating surface 1c of the cylinder block 1 with the cylinder head 3 and the lower end 72a that is the upstream end of the cylinder head 3 that opens to the mating surface 3c of the cylinder block 1 are shown. And a second upstream oil passage 72 having an upper end portion 72b that is a downstream end portion that opens to the inlet port 110 of the hydraulic control valve 100.
The upstream oil passages 71 and 72 having a lower end portion 71a communicating with the common oil passage 62 and an upper end portion 72b communicating with the hydraulic control valve 100 are configured such that the upper end portion 71b and the lower end portion 72a are connected by mating surfaces 1c and 3c. It is bent at the formed bent portion.

As the first upstream oil passage 71 approaches the second upper end 71b from the first lower end 71a in the vertical direction, the first upstream oil passage 71 extends substantially straight upward from the lower end 71a without moving away from the upper end 72b in the horizontal direction. One straight oil passage. The tensioner oil passage 63 and the first upstream oil passage 71 constitute a substantially straight passage and are substantially orthogonal to the common oil passage 62 (see FIG. 1).
Further, as the second upstream oil passage 72 approaches the upper end portion 72b from the lower end portion 72a in the up-down direction, the upper end portion 71b and the lower end portion 72a to the upper end portion 72b in the horizontal direction do not move away from the upper end portion 72b in the horizontal direction. It is the 2nd straight oil path extended in the shape of a straight line.

As another example, the upstream oil passages 71 and 72 include a passage 73 (in FIG. 1) in which both the first and second upstream oil passages 71 and 72 extend substantially linearly from the lower end portion 71a to the upper end portion 72b. It is indicated by a thick two-dot chain line.) In other words, it may be a passage in which one straight line intersecting the entire upstream oil passages 71, 72 exists.
Furthermore, as another example, the first upstream oil passage 71 may be formed with respect to the common oil passage 62 so that its inferior angle is obtuse (for example, like the passage 73). This makes it easier for the mixed air in the common oil passage 62 to flow into the control oil passage 70, and further suppresses the hydraulic oil containing the mixed air from being supplied to the tensioner oil passage 63.

Each of the advance oil passage 80 and the retard oil passage 90 communicating with the second upstream oil passage 72 via the hydraulic control valve 100 is a first oil passage communicating with the hydraulic control valve 100 at the upstream end. Connection oil passages 81, 91, journal oil passages 84, 94 as second oil passages communicating with the connection oil passages 81, 91, and in-shaft oil passages as third oil passages communicating with the journal oil passages 84, 94 85, 95. The journal oil passages 84 and 94 are lubrication oil passages for lubricating a sliding contact surface Pb constituted by a bearing surface 44a of the lower bearing portion 44, a bearing surface 45a of the upper bearing portion 45, and an outer peripheral surface 24a (see also FIG. 2). Doubles as
The first and second upstream oil passages 71 and 72, the connection oil passage 81, and an upstream connection oil passage 92 described later are formed by machining such as cutting with a drill, for example.

Referring to FIG. 4, the hydraulic control valve 100 is detachably attached to the cylinder head 3 with a bolt 109 via a bracket 108 while being accommodated in an accommodation hole 3d provided in the side wall 3w. A hydraulic control valve 100 including a spool valve includes a cylindrical valve body 101 inserted into the accommodation hole 3d, and a columnar spool 102 that is a valve body slidably fitted into the valve body 101. A solenoid 103 as a drive unit that is fixed to the valve body 101 and drives the spool 102, and a return spring 104 that urges the spool 102 to occupy the initial position when the solenoid 103 is demagnetized when the internal combustion engine E is stopped. With.
Here, in the hydraulic control valve 100, the valve body 101 and the spool 102 constitute a valve portion in which the upper end portion 72b of the second upstream oil passage 72 and the upstream end portions 81a and 92a of the connection oil passages 81 and 91 communicate with each other. .

The control device 120 (see FIG. 1) includes an engine state detection unit that detects an engine state (for example, engine speed) of the internal combustion engine E, and an electronic control unit that receives a detection signal from the engine state detection unit. The hydraulic control valve 100 is controlled according to the engine operating state determined based on the engine state detected by the engine state detecting means.
The solenoid 103, which is controlled and operated by the control device 120 provided in the internal combustion engine E, drives the drive member 103a that abuts the end of the spool 102, causing the spool 102 to resist the urging force of the return spring 104. It is steplessly moved in the direction of the operating axis that is parallel to the operating axis La (also the central axis of the hydraulic control valve 100). The hydraulic control valve 100 is disposed so that the operation axis La is substantially located on a cam orthogonal plane orthogonal to the rotation center line Li of the cam shaft 21i (see FIG. 2).

  The valve body 101 has an inlet port 110 where the upper end portion 72b of the second upstream oil passage 72 opens, and an advance port as a first outlet port which opens to the first connection oil passage 81 and the second connection oil passage 91, respectively. 111 and a retardation port 112 as a second outlet port and a pair of drain ports 113 and 114 are provided. On the other hand, the spool 102 has a central groove 115, a pair of lands 118, 119 located on both sides of the central groove 115 in the operation axis direction, and a pair of end grooves 116 located on both sides of both lands 118, 119. , 117 are provided.

  The hydraulic control valve 100 occupies the initial position shown in FIG. 4 when the engine is stopped. In this initial position, the urging force of the solenoid 103 that urges the spool 102 disappears, so that the spool 102 is urged by the return spring 104 and the advance port 111 is blocked from the inlet port 110. The port 113 communicates with the inlet port 110 in a state where the retard port 112 is blocked from the drain port 114.

  A small clearance in the radial direction about the operation axis La is formed between the valve body 101 and the spool 102 in order to allow the spool 102 to slide. Therefore, the hydraulic control valve 100 affects the operation of the variable valve timing mechanism 50 between the ports 110, 111; 110, 112; 111, 113; 112, 114 adjacent in the operation axis direction through the clearance. Allowing the hydraulic oil to leak with a small amount of leakage.

  Referring also to FIGS. 1 and 2, the tip end portion 101 a as an exposed portion of the valve body 101 protrudes through the accommodation hole 3 d and exposed in the valve operating chamber 915. The drain port 113 provided at the tip 101a opens directly to the valve operating chamber 9 without passing through the drain oil passage, and allows the hydraulic oil discharged from the advance oil chamber 53 to enter the valve operating chamber 9 and the side wall 3w. It flows out into the chain chamber 29 through the provided opening 3h. On the other hand, the drain port 114 allows the hydraulic oil discharged from the retarded oil chamber 54 to flow into the chain chamber 29 through the drain oil passage 3k provided on the side wall 3w and opening to the chain chamber 29Ca.

  In the advance oil passage 80 through which the hydraulic oil flows between the hydraulic control valve 100 and the advance oil chamber 53 of the variable valve timing mechanism 50, the connection oil passage 81 extends upward from the advance port 111 and the operation axis La. Extends in a straight line in a direction orthogonal to the journal oil passage 84 and opens into the journal oil passage 84. The journal oil passage 84 is constituted by an annular groove formed by a semicircular annular groove provided on each of the bearing surfaces 44a and 45a and the outer peripheral surface 24a, and the in-shaft oil passage 85 is formed on the cam shaft 21i. It communicates with the advance oil chamber 53.

  Similarly, in the retarded oil passage 90 through which hydraulic oil flows between the hydraulic control valve 100 and the retarded oil chamber 54 of the variable valve timing mechanism 50, the hydraulic oil is connected between the journal oil passage 94 and the hydraulic control valve 100. The connection oil passage 91 through which the oil flows is extended from the retard port 112 and opens into the journal oil passage 94. The journal oil passage 94 is formed by an annular groove formed by a semi-annular groove provided on each of the bearing surfaces 44 a and 45 a and the outer peripheral surface 24 a, and between the journal oil passage 94 and the retard oil chamber 54. An in-shaft oil passage 95 through which the hydraulic oil flows is formed in the camshaft 21 i and communicates with the retard oil chamber 54.

The connection oil passage 91 is formed by a groove provided in each of the mating surfaces 44 b and 45 b, and is formed between the downstream connection oil passage 93 that opens to the journal oil passage 94, and between the downstream connection oil passage 93 and the hydraulic control valve 100. And an upstream connecting oil passage 92 through which hydraulic oil is circulated. The upstream connection oil passage 92 is provided over the lower bearing portion 44 and the side wall 3w, extends upward from the retard port 112, and extends in a straight line in a direction perpendicular to the operation axis La when viewed in the axial direction. The surface 44b is bent at a substantially right angle with respect to the upstream connection oil passage 92 and opens to a downstream connection oil passage 93 extending in a direction substantially perpendicular to the cylinder axial direction.
The passage length of the first connection oil passage 81 is shorter than the passage length of the connection oil passage 91, which is the sum of the passage length of the upstream connection oil passage 92 and the passage length of the downstream connection oil passage 93, and further upstream. It is shorter than the passage length of the side connection oil passage 92.

  The advance oil passage 80 and the retard oil passage 90 are positions that are offset in the operation axis direction with respect to the position of the inlet port 110 where the upstream oil passages 71 and 72 communicate with the hydraulic control valve 100, and more specifically. Corresponding to the advance port 111 and the retard port 112, the hydraulic control valve 100 communicates with the position of the inlet port 110 at positions offset on both sides in the operation axis direction.

When the internal combustion engine E starts operation, the oil pump 60 driven by the crankshaft 7 supplies oil to the main gallery 61. A part of the oil in the main gallery 61 flows into the common oil passage 62 as hydraulic oil, and then splits up and down into the tensioner oil passage 63 and the control oil passage 70 at the branching portion 64 respectively, and the tensioner 31 and the variable valve timing mechanism. 50 respectively.
In the control oil passage 70, the advance oil passage 90 and the retard oil passage with respect to the advance oil chamber 53 and the retard oil chamber 54 according to the engine operating state by the hydraulic control valve 100 controlled by the control device 120. The hydraulic oil is supplied and discharged through 90, and the rotating bodies 51 and 52 rotate relative to each other, whereby the phase of the camshaft 21i with respect to the crankshaft 7 and thus the opening / closing timing of the intake valve 12 is changed to the advance side or the retard side. The
Further, the hydraulic oil is confined in the oil chambers 53 and 54 without the hydraulic oil being supplied to and discharged from the oil chambers 53 and 54 by the hydraulic control valve 100, so that both the rotating bodies 51 and 52 are relatively rotated. Without rotating, the phase of the camshaft 21i with respect to the crankshaft 7 and thus the opening / closing timing of the intake valve 12 are maintained.

  Further, the minute clearance formed between the bearing surfaces 42a and 43a (44a and 45a) and the outer peripheral surface 24a is necessary to support the cam shafts 21i and 21e in a rotatable manner, and therefore the lower bearing portion 42 and the upper bearing. The portion 43 is larger than the minute clearance at the dividing surface Pa (that is, the mating surfaces 42b, 43b (44b, 45b)) of the bearing member 40 that is fastened by the bolt 49. Therefore, the oil pump 60 is inserted into the oil pump 60 when the engine is stopped. The intruded air and the air that has entered the upstream oil passages 71 and 72 due to the minute clearance between the members forming the upstream oil passages 71 and 72 are connected to the downstream connecting oil passage when the oil pump 60 starts supplying hydraulic oil. It is easy to be discharged from the journal oil passages 84 and 94 as compared to 93. The air that has entered the first journal oil passage 84 is caused by the connection oil passage 81 being in the jar. The hydraulic oil 84 is directly connected to the hydraulic oil passage 84, so that it is more easily discharged by the hydraulic oil whose pressure loss is smaller than that of the connection oil passage 91. Therefore, the advance oil passage 80 is connected to the retard oil passage 90. In comparison, since hydraulic fluid with less air mixing is supplied, the response of the variable valve timing mechanism 50 to the advance side is improved.

  When the engine is stopped, the oil pump 60 is stopped, the supply of oil to the main gallery 61 is stopped, and the hydraulic control valve 100 occupies the initial position shown in FIG. For this reason, the hydraulic oil in the advance oil chamber 53 and the advance oil passage 80 passes through the advance port 111 and the drain port 113 as time passes, and the valve operates as a drain space that is an external space with respect to the hydraulic oil passage structure. It flows out into the chamber 9. On the other hand, the hydraulic oil in the retarding oil chamber 54 and the retarding oil passage 90 is in a state where the retarding oil passage 90 communicates with the upstream oil passages 71 and 72 connected to the main gallery 61 through the retarding port 112 and the inlet port 110. Then, the oil gradually flows out from a slight clearance between the members forming the retarded oil passage 90 and the upstream oil passages 71 and 72.

Next, operations and effects of the embodiment configured as described above will be described.
The hydraulic oil passage structure of the internal combustion engine E through which the hydraulic oil supplied to the tensioner 31 and the variable valve timing mechanism 50 circulates includes a common oil passage 62 through which the hydraulic oil guided to the tensioner 31 and the variable valve timing mechanism 50 flows. A tensioner oil passage 63 that branches downward from the common oil passage 62 and guides hydraulic oil to the tensioner 31; a control oil passage 70 that branches upward from the common oil passage 62 and guides hydraulic oil to the variable valve timing mechanism 50; A hydraulic control valve 100 that is disposed in the oil passage 70 and controls the hydraulic pressure of the hydraulic oil in the variable valve timing mechanism 50, and the control oil passage 70 extends only upward from the common oil passage 62 to the hydraulic control valve 100. The hydraulic control valve 100 allows leakage of hydraulic oil from the upstream oil passages 71, 72.
With this hydraulic oil path structure, the tensioner oil path 63 is branched downward from the common oil path 62. Therefore, when air is mixed in the hydraulic oil flowing through the common oil path 62, the mixed air (that is, , Mixed air) is less likely to flow from the common oil passage 62 into the tensioner oil passage 63, so that supply of hydraulic oil containing mixed air to the tensioner 31 is suppressed, and tension is applied to the chain 28 by the tensioner 31. Function and vibration suppression function are improved. Further, since the control oil passage 70 branches upward from the common oil passage 62, mixed air easily flows into the control oil passage 70 from the common oil passage 62, but upstream oil passages 71 and 72 of the control oil passage 70. Since the hydraulic control valve 100 has a structure in which the hydraulic oil in the upstream oil passages 71 and 72 leaks, the mixed air in the upstream oil passages 71 and 72 flows from the common oil passage 62. The oil flows smoothly toward the hydraulic control valve 100, reaches the hydraulic control valve 100, and is discharged from the control oil path 70 to the valve chamber 9 as an external space together with the hydraulic oil leaking in the hydraulic control valve 100. The mixed air easily escapes from the path 70. As a result, supply of hydraulic oil containing mixed air to the variable valve timing mechanism 50 is suppressed, and the operation performance of the variable valve timing mechanism 50 with respect to the cam shafts 21i and 21e is improved. Control responsiveness and control accuracy of opening / closing timing are improved.

  Since the tensioner oil passage 63 and the control oil passage 70 are branched from the downstream end portion 62 b of the common oil passage 62, the mixed air in the common oil passage 62 is branched upward at the downstream end portion 62 b of the common oil passage 62. Therefore, the mixed air remaining in the common oil passage 62 can be quickly reduced. As a result, mixed air in the tensioner oil passage 63 and the control oil passage 70 branched from the common oil passage 62 can be quickly reduced.

  The upstream oil passages 71, 72 having a lower end portion 71 a communicating with the common oil passage 62 and an upper end portion 72 b communicating with the hydraulic control valve 100 have upper ends in the horizontal direction as they approach the upper end portion 72 b from the lower end portion 71 a in the vertical direction. The first upstream oil passage 71 extending substantially straight upward from the lower end 71a without moving away from the portion 72b, and the upper end 71b and lower end as the upper end 71b and the lower end 72a approach the upper end 72b in the vertical direction. A second upstream oil passage 72 extending in a straight line upward in a horizontal direction from the portion 72a to the upper end portion 72b without being separated from the upper end portion 72b, or the upstream oil passages 71, 72 are located at the lower end portion The upstream oil passages 71 and 72 have a shape or a shape that is almost in a straight line because the passage 73 extends in a straight line upward from 71a to the upper end portion 72b. Since in a straight line, as compared with the case of oil passage 71 and 72 is complicatedly bent, that the contaminated air is staying in the control oil passage 70 is suppressed. Further, when the upstream oil passages 71 and 72 are formed by machining, the removal operation of the generated chips becomes easy, and the remaining chips are reduced and provided in the oil passage and the hydraulic control valve 100. Pressure loss due to filter clogging can be reduced, and cost can be reduced by reducing or eliminating the number of filters.

The control oil passage 70 includes upstream oil passages 71 and 72 located between the common oil passage 62 and the hydraulic control valve 100 with the hydraulic control valve 100 as a boundary, and between the hydraulic control valve 100 and the variable valve timing mechanism 50. The hydraulic control valve 100 has an advance oil passage 80 and a retard oil passage 90 positioned therebetween, and is slidably fitted to the valve body 101 so as to be movable in the operation axis direction parallel to the operation axis La. The advance oil passage 80 and the retard oil passage 90 are provided with a spool 102, and the hydraulic control valve 100 is offset from the position where the upstream oil passages 71 and 72 communicate with the hydraulic control valve 100 in the operation axis direction. Communicate with.
With this structure, when the valve body of the hydraulic control valve 100 moves in the operation axis direction, mixed air is discharged together with the hydraulic oil through a slight clearance between the valve body 101 and the sliding spool 102. The mixed air easily escapes from the path 70, and the variable valve timing mechanism 50 is prevented from being supplied with hydraulic oil containing mixed air.

The control oil passage 70 is formed downstream of the hydraulic control valve 100 between the cam shaft 21i and the bearing member 41 that slidably supports the journal 24i of the cam shaft 21i. The outer peripheral surface 24a that is the sliding contact surface Pb and the journal oil passage 84 that is a lubricating oil passage for lubricating the bearing surfaces 44b and 45b with the working oil are provided, and the control oil passage 70 is connected from the hydraulic control valve 100 to the journal oil. A connecting oil passage 81 that is an oil passage extending straight up to the passage 84 is provided.
With this structure, when mixed air flows into the connecting oil passage 81 through the hydraulic control valve 100, the connecting oil passage 81 extends in a straight line and communicates with the journal oil passage 84. Easy to flow in. Since the mixed air that has flowed into the journal oil passage 84 is slidable and easily escapes from the sliding contact surface Pb in which a slight clearance is formed, the variable valve timing mechanism 50 includes mixed air. Supply of oil is suppressed.

Hereinafter, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
The lower bearing portion of the bearing member of the cam holder may be a member separate from the cylinder head, and may be integrally provided by being fixed to the cylinder head by a coupling means (for example, a bolt).
The variable valve timing mechanism 50 may be provided only on the intake cam shaft, the exhaust cam shaft, or the exhaust cam shaft.
The valve cam shaft of the valve gear may be a single cam shaft having an intake cam and an exhaust cam.
The first upstream oil passage 71 of the tensioner oil passage 63 and the control oil passage 70 may be branched in the common oil passage 62 at a position where the distance from the main gallery 61 along the common oil passage 62 is different. The branch part 64 may not be the downstream end part 62b, and may be between the upstream end part 62a and the downstream end part 62b.
The variable valve characteristic mechanism may be a connection switching mechanism that controls the lift amount of the intake valve by using a connection member that connects and releases a plurality of rocker arms as cam followers included in the valve operating apparatus as an actuated member.
The hydraulic operation mechanism may be a hydraulic mechanism other than the variable valve characteristic mechanism, and there may be one downstream oil passage.
The base oil passage may be the main gallery 61. Therefore, the tensioner oil passage 63 and the control oil passage 70 may branch directly from the main gallery 61 without providing the common oil passage 62.
The winding transmission mechanism may include an endless belt as an endless transmission band.
The internal combustion engine may be a compression ignition engine, and may be a V-type engine or a single cylinder engine having one cylinder.
The target on which the internal combustion engine is mounted may be a machine other than the vehicle, for example, a ship propulsion device such as an outboard motor having a crankshaft oriented in the vertical direction, or a power generation device.

DESCRIPTION OF SYMBOLS 1 Cylinder block 3 Cylinder head 20 Valve mechanism 21i Cam shaft 25 Winding transmission mechanism 31 Tensioner 50 Variable valve timing mechanism 61 Main gallery 62 Common oil path 63 Tensioner oil path,
70 control oil passage 71, 72 upstream oil passage 80 advance oil passage 90 retard oil passage 100 hydraulic control valve

Claims (6)

The tensioner and the operating mechanism are provided in an internal combustion engine including a hydraulic tensioner that applies tension to an endless transmission band of a winding transmission mechanism that rotationally drives the driven member, and a hydraulic operating mechanism that operates the driven member. In the hydraulic oil passage structure of the internal combustion engine through which the hydraulic oil supplied to the refrigerant flows,
A base oil passage through which hydraulic oil guided to the tensioner and the operating mechanism flows; a tensioner oil passage that branches downward from the base oil passage and guides the hydraulic oil to the tensioner; and branches upward from the base oil passage. A control oil path that guides hydraulic oil to the operating mechanism, and a hydraulic control valve that is disposed in the control oil path and controls the hydraulic pressure of the hydraulic oil in the operating mechanism,
The control oil passage has an upstream oil passage extending only upward from the base oil passage to the hydraulic control valve,
The hydraulic control valve according to claim 1, wherein the hydraulic control valve allows leakage of hydraulic oil from the upstream oil passage. The hydraulic oil passage structure for an internal combustion engine according to claim 1,
The hydraulic oil passage structure for an internal combustion engine, wherein the tensioner oil passage and the control oil passage are branched from a downstream end portion of the base oil passage. The hydraulic oil passage structure for an internal combustion engine according to claim 1 or 2,
The upstream oil passage having a lower end communicating with the base oil passage and an upper end communicating with the hydraulic control valve is a passage extending substantially straight upward from the lower end to the upper end. Alternatively, the first straight oil that extends in a substantially straight line upward from the first lower end without moving away from the upper end of the upstream oil passage in the horizontal direction as it approaches the upper end from the first lower end in the vertical direction. And the upper oil passage in the horizontal direction from the upper end portion of the first straight oil passage to the upper end portion of the upstream oil passage as it approaches the upper end portion of the upstream oil passage from the lower end portion in the vertical direction. A hydraulic oil passage structure for an internal combustion engine, comprising: a second straight oil passage that extends substantially straight upward without moving away from the upper end portion. The hydraulic oil passage structure for an internal combustion engine according to any one of claims 1 to 3,
The control oil passage is located between the base oil passage and the hydraulic control valve, and between the hydraulic control valve and the operating mechanism, with the hydraulic control valve as a boundary. A downstream oil passage,
The hydraulic control valve includes a valve body that is slidably fitted to the valve body and is movable in the direction of the operation axis parallel to the operation axis.
The downstream oil passage communicates with the hydraulic control valve at a position offset in the operation axis direction with respect to a position where the upstream oil passage communicates with the hydraulic control valve. Construction. The hydraulic oil passage structure for an internal combustion engine according to any one of claims 1 to 4,
The control oil passage is formed downstream of the hydraulic control valve and between a sliding member and a support member that slidably supports the sliding member, and the sliding contact between the sliding member and the support member It has a lubricating oil passage for lubricating the surface with hydraulic oil,
The operating oil passage structure for an internal combustion engine, wherein the control oil passage has an oil passage that extends straight upward from the hydraulic control valve to the lubricating oil passage. The hydraulic oil passage structure for an internal combustion engine according to any one of claims 1 to 5,
An operating oil passage structure for an internal combustion engine, wherein the operating mechanism is a variable valve timing mechanism for controlling a valve timing of an engine valve by controlling a valve camshaft as the operated member.

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