JP2005048882A - Oil passage structure of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil passage structure of an engine capable of suppressing the reduction of amount of oil in an oil storage chamber while an engine stops. <P>SOLUTION: A chain tensioner operated by non-compression oil is tightened in a protruding part 27 on a front face of a cylinder head 13. The oil passage 34 for leading the oil discharged from an oil pump into the chain tensioner is provided in each part of the engine, and the oil storage chamber 35 is provided on the halfway of the oil passage 34. The oil storage chamber 35 is composed of a recessed part 36 provided in the protruding part 27 and a space surrounded by the chain tensioner closing the recessed part 36 while it is tightened in the protruding part 27. A branched passage 43 which is branched from the oil passage 34 to supply oil to a valve timing variable mechanism VVT which is oil supply destination different from the chain tensioner is provided. The branched passage 43 is connected with the oil storage chamber 35 while the engine is mounted on a vehicle by forming an elevation angle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine oil in which a hydraulic device such as a chain tensioner that is operated by incompressible oil is one of the oil supply destinations, and the oil is supplied to the oil supply destination through an oil passage provided in a cylinder head or the like. It relates to a passage structure.

  The engine is equipped with a winding transmission that transmits rotation of a crankshaft as an output shaft to an intake / exhaust camshaft or the like. In this winding transmission, for example, a crank sprocket is attached to the crankshaft, and cam sprockets are attached to the intake and exhaust camshafts, respectively. A timing chain is wound around the crank sprocket and the cam sprocket. Therefore, when the crankshaft and the crank sprocket rotate, the timing chain circulates along with the rotation, and the intake / exhaust camshaft is driven to rotate together with the cam sprocket. Further, the engine is provided with a chain tensioner for adjusting the tension of the timing chain.

  As one form of such a chain tensioner, a type that operates by incompressible oil is common. According to this chain tensioner, when the engine is operated, a part of the oil discharged from the oil pump and passing through the oil passage in the cylinder block, the cylinder head or the like is supplied to the chain tensioner. When the timing chain is loosened, in the chain tensioner, the plunger biased by the spring protrudes from the cylinder and presses the chain. As the plunger moves, the check valve opens and oil flows into the cylinder. On the other hand, when a force for immersing the plunger into the cylinder is applied, the check valve is closed and the oil is gradually returned from the orifice to the oil passage. The tension of the timing chain is adjusted to be constant by such protrusions and depressions of the plunger.

  By the way, when the engine stops, the oil pump also stops operating, so oil is not supplied to each part of the engine. Due to its own weight, the oil in the oil passage flows in a direction opposite to the direction in which it has flown, and the oil in the oil passage is reduced. When the engine is started in this state, the oil pump is driven, and the amount of oil necessary for operation is required for the chain tensioner until the oil discharged from the oil pump reaches the chain tensioner through the oil passage. Oil is not supplied. Also, air may be taken into the chain tensioner. The chain tensioner cannot perform its original operation due to oil shortage or air mixing, and the tension of the timing chain cannot be adjusted appropriately. As a result, the timing chain vibrates and hits against other parts such as a tension lever of the tensioner device, and a hitting sound is generated, or a hitting sound is generated when the timing chain is wound around the sprocket.

  Therefore, it is considered to provide an oil storage chamber upstream of the chain tensioner in the oil passage. For example, the oil storage chamber described in Patent Document 1 is provided at the attachment portion between the chain tensioner and the cylinder head. In other words, the chain tensioner is provided with a recess that is open on its mounting surface. The chain tensioner is attached to the cylinder head via a gasket, and the open portion is blocked by the wall surface of the cylinder head to form an oil storage chamber.

  According to this technology, the oil in the oil storage chamber continues to be stored without backflow even when the engine is stopped. When the engine is started, the oil in the oil storage chamber is sucked into the cylinder by the self-suction action of the chain tensioner. That is, when the engine is started, the tension of the timing chain is likely to fluctuate due to fluctuations in the rotation of the crankshaft. When the tension decreases, the plunger biased by the spring protrudes from the cylinder. Along with this protrusion, the check valve opens, and the oil stored in the oil storage chamber is sucked into the cylinder. Therefore, even during the period from when the engine is started until the oil discharged from the oil pump reaches the chain tensioner, the amount of oil necessary for operation is taken into the chain tensioner and the above-mentioned oil shortage and air mixing It is possible to eliminate problems caused by the above.

In addition, as a prior art document concerning this invention, the patent document 2 shown below other than the patent document 1 mentioned above is mentioned.
Japanese Utility Model Publication No. 3-33251 Japanese Utility Model Publication No. 4-52644

  By the way, the oil in the oil storage chamber leaks from the gap between the cylinder head and the chain tensioner, or oozes out of the oil storage chamber through the gasket. For this reason, there is no particular problem when the engine is constantly supplied with oil, but the amount of oil in the oil storage chamber decreases while the engine is stopped. However, in the above-described chain tensioner, no consideration is given to such oil reduction. Therefore, if the amount of oil remaining in the oil storage chamber is small, it may be difficult to ensure the amount of oil necessary for operation in the oil tensioner at the next engine start.

These problems are not limited to the chain tensioner, and may similarly occur in various hydraulic devices that operate with incompressible oil.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an oil passage structure for an engine that can suppress a decrease in oil in an oil storage chamber while the engine is stopped. is there.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, a hydraulic device that operates with incompressible oil is one of the oil supply destinations, and an oil passage for supplying oil to the hydraulic device is provided in the engine. In the middle, an oil storage chamber is provided for storing oil sucked by the hydraulic device when the engine is started, and a branch for supplying oil to an oil supply destination different from the hydraulic device by branching from the oil passage The passage is connected so as to form an elevation angle with respect to the oil storage chamber when the engine is mounted.

  According to the above configuration, oil discharged from an oil supply source such as an oil pump flows through the oil passage and the oil storage chamber during operation of the engine. Part of the oil that flows into the oil storage chamber flows out of the oil storage chamber and is supplied to the hydraulic equipment that is one of the oil supply destinations, and another part flows out of the oil storage chamber and passes through the branch passage. The oil is supplied to a different oil supply destination from the hydraulic equipment. The hydraulic equipment that receives the oil supply and other oil supply destinations are operated by the oil.

  Since the oil supply from the oil supply source is stopped while the engine is stopped, the oil in the oil passage tends to flow in the direction opposite to that during engine operation due to its own weight. On the other hand, in the oil storage chamber, of the stored oil, the portion below the oil inlet remains stored, and does not flow backward to the upstream side of the oil storage chamber. Therefore, an amount of oil necessary for the operation of the hydraulic device can be secured in the oil storage chamber. Since the secured oil is sucked into the hydraulic equipment when the engine is started, the hydraulic equipment is operated by the sucked oil even during the period until the oil from the oil supply source reaches the hydraulic equipment. It is possible.

  Also, since the branch passage is connected to the oil storage chamber at an elevation angle with the engine mounted, the oil in the branch passage flows in the opposite direction to the engine operation due to its own weight when the engine is stopped. Returned to the room. Therefore, even if part of the oil originally stored in the oil storage chamber leaks to the outside, the leakage is replenished by the inflow from the branch passage. As a result, it is possible to suppress a decrease in the amount of oil stored in the oil storage chamber while the engine is stopped, and to ensure the amount of oil necessary for the operation of the hydraulic equipment in the oil storage chamber at the next engine start. .

According to a second aspect of the present invention, in the first aspect of the present invention, the oil inflow port in the oil storage chamber is opened at an upper portion of the oil storage chamber.
While the engine is stopped, as described above, the portion of the oil in the oil storage chamber below the inflow port remains stored in the oil storage chamber. In this respect, in the invention described in claim 2, the inflow port is provided in the upper part of the oil storage chamber. As a result, the lower edge of the oil inlet, that is, the upper limit of the oil level that can be taken in the oil storage chamber when the engine is stopped increases, and as a result, a large amount of oil can be stored in the oil storage chamber while the engine is stopped. Become.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the oil storage chamber is provided at a location where the hydraulic device is mounted in the engine, and the open portion thereof is the mounted hydraulic pressure. Suppose that it is comprised by the recessed part closed with an apparatus.

  According to the above configuration, the hydraulic device closes the opening of the recess and forms an oil storage chamber only by performing a simple operation of attaching the hydraulic device to the engine. Further, a dedicated member for closing the recess is not necessary, and the structure of the oil storage chamber can be simplified.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the engine is mounted in an inclined state so as to become higher toward the open portion side in the depth direction of the concave portion, and the oil storage chamber It is assumed that the oil inlet is opened at a location closer to the opening than the deepest portion of the recess.

  While the engine is stopped, as described above, the portion of the oil in the oil storage chamber below the inflow port remains stored in the oil storage chamber. In this regard, in the invention described in claim 4, in the engine mounted in an inclined state so as to be higher toward the opening portion side of the recess, the inlet is opened at a position closer to the opening portion than the deepest portion of the recess. Yes. Therefore, in the state where the engine is mounted, the inflow port opens at a position higher than that at the deepest part of the oil storage chamber. Accordingly, the maximum amount of oil that can be stored in the oil storage chamber while the engine is stopped increases.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, an oil outlet to the hydraulic device in the oil reservoir is opened at a lower portion of the oil reservoir. Suppose that

  According to the above configuration, since the oil outlet to the hydraulic equipment is opened at the lower part of the oil storage chamber, even if the oil in the oil storage chamber decreases due to leakage to the outside while the engine is stopped, The oil level is less likely to be lower than the upper edge of the outlet. Therefore, unless the oil in the oil storage chamber is extremely reduced due to the engine being stopped for a long period of time, the air that adversely affects the operation of the hydraulic device is not taken into the hydraulic device at the next engine start. Oil that is not mixed with air can be reliably supplied to the hydraulic equipment.

  According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the oil supply port in the hydraulic device in the attached state is an oil supply to the hydraulic device in the oil storage chamber. It is assumed that the engine is provided with a guide passage that connects the supply port and the outflow port.

  According to the above configuration, even when the supply port is positioned higher than the outflow port, air is mixed from the outflow port opened in the lower part of the oil storage chamber through the guide passage and the supply port. No oil can be supplied to the hydraulic equipment.

  According to a seventh aspect of the present invention, in the invention according to any one of the first to sixth aspects, the engine is rotated by transmitting the rotation of the crankshaft via a crankshaft and a winding transmission member. It is assumed that the hydraulic device is a tensioner that is actuated by the oil and applies tension to the winding transmission member.

  According to said structure, rotation of a crankshaft is transmitted to a driven member via a winding transmission member at the time of engine operation, and the driven member is rotationally driven. Even if the winding transmission member tries to vibrate during this rotation transmission, the tension of the winding transmission member is adjusted by applying tension to the tensioner. By using this tensioner as the hydraulic equipment described above and an oil passage structure that connects the branch passage that makes an elevation to the oil storage chamber, the amount of oil required for operation is secured in the oil storage chamber, and oil is supplied when the engine is started. Even during the period until the oil from the source reaches the tensioner, the hydraulic device can be reliably operated. As a result, troubles caused by inadequate adjustment of the tension of the winding transmission member, for example, when the winding transmission member hits another part and a hitting sound is generated, or when the winding transmission member is wound around the driven member It is possible to suppress a phenomenon that a hitting sound is generated.

Hereinafter, an embodiment in which the present invention is embodied in an in-vehicle engine will be described with reference to the drawings.
As shown in FIG. 1, the engine 11 includes a cylinder block 12 having a plurality of cylinders arranged in the front-rear direction of the vehicle (a direction orthogonal to the paper surface in FIG. 1), and a cylinder head mounted on the cylinder block 12. 13. The engine 11 is mounted on the vehicle in an inclined state so as to be higher toward the front side and higher toward one side (the right side in FIG. 1) due to restrictions on mounting (see FIGS. 3 and 4). ).

  A crankshaft 14 that is an output shaft of the engine 11 and is disposed so as to extend in the front-rear direction of the vehicle is rotatably supported by the cylinder block 12. The cylinder head 13 includes an intake valve that opens and closes a connection portion (intake port) of the intake passage to the combustion chamber of each cylinder, and an exhaust valve that opens and closes a connection portion (exhaust port) of the exhaust passage to the combustion chamber of each cylinder. Are also not shown). Further, an intake camshaft 15 for opening and closing the intake valve and an exhaust camshaft 16 for opening and closing the exhaust valve are disposed in the cylinder head 13 substantially in parallel with the crankshaft 14. These intake / exhaust camshafts 15 and 16 are rotatably supported on the cylinder head 13 by bearings.

  In order to transmit the rotation of the crankshaft 14 to the intake / exhaust camshafts 15 and 16, a crank sprocket 17 is attached to the front end portion of the crankshaft 14 so as to be integrally rotatable. Cam sprockets 18 and 19 are attached to the front end portions of the intake and exhaust camshafts 15 and 16 so as to be integrally rotatable. A timing chain 21 as a winding transmission member is wound around the crank sprocket 17 and the cam sprockets 18 and 19. Here, the intake / exhaust camshafts 15 and 16 correspond to driven members that are driven to rotate by the rotation of the crankshaft 14 being transmitted via the timing chain 21.

  Further, the engine 11 is operated by oil, thereby changing the rotational phase of the camshaft (here, the intake camshaft 15) with respect to the crankshaft 14, and thereby adjusting the opening / closing timing of the intake valve driven by the camshaft 15. A variable valve timing mechanism (VVT) 22 for changing is provided.

  A chain damper 23 is provided between the crank sprocket 17 and the cam sprocket 18 and in the vicinity of the outer side of the timing chain 21 to restrict and attenuate the swing of the timing chain 21.

  The engine 11 is provided with a tensioner device 24 for adjusting the tension applied to the timing chain 21 to be constant. The tensioner device 24 includes a tension lever (also called slipper) 25 disposed between the crank sprocket 17 and the cam sprocket 19 and in the vicinity of the outer side of the timing chain 21. The tension lever 25 is supported at its lower end by a shaft 26 so as to be swingable in the vehicle width direction (left-right direction in FIG. 1) with respect to the cylinder head 13.

  A protrusion 27 is integrally provided in a lower portion of the front surface of the cylinder head 13 at a location corresponding to the upper portion of the tension lever 25, that is, in the vicinity of one side surface (left side in FIG. 1) of the cylinder head 13 (FIG. 2). reference). A chain tensioner 28 as a hydraulic device that is operated by incompressible oil is fixed to the protrusion 27. As the chain tensioner 28, a chain tensioner 28 having a general structure including a cylinder 31, a plunger 32, a spring, a check valve, an orifice and the like is used. The cylinder 31 is fastened to the protrusion 27 by a fastening member such as a bolt in a horizontally placed state. 2 is a hole into which a bolt is screwed. The plunger 32 is accommodated in the cylinder 31 so as to be able to project and retract in a substantially horizontal direction, and its tip is engaged with the upper portion of the tension lever 25. The spring always urges the plunger 32 toward the timing chain 21 (right side in FIG. 1).

  In the chain tensioner 28, when the timing chain 21 is loosened, the plunger 32 biased by the spring projects from the cylinder 31 to the right. With this protrusion, the tension lever 25 swings to the right in FIG. 1 with the shaft 26 as a fulcrum, and presses the timing chain 21. With the movement (protrusion) of the plunger 32, the check valve opens, and the oil flows into the cylinder 31.

  Contrary to the above, when the timing chain 21 is tensioned, the tension lever 25 swings to the left in FIG. 1 with the shaft 26 as a fulcrum, and a force for immersing the plunger 32 into the cylinder 31 is applied. The check valve is closed and oil is gradually returned from the orifice to the oil passage 34. Thus, the plunger 32 cannot immediately immerse and responds only to forces that persist for a period of time. Thus, in the chain tensioner 28, the plunger 32 is easy to move in the direction protruding from the cylinder 31, and is difficult to move in the immersive direction. Then, the tension of the timing chain 21 is adjusted by the movement of the plunger 32.

  During operation, the engine 11 uses the above-described chain tensioner 28, variable valve timing mechanism 22, support portions (bearings) of the intake and exhaust camshafts 15 and 16 as oil supply destinations, and supplies oil to those oil supply destinations. A mechanism for supplying is provided. A part of the mechanism is constituted by a mechanical oil pump (not shown) that is driven by the crankshaft 14 and sucks and discharges oil stored in the oil pan. Further, as shown in FIGS. 3 and 5, an oil passage 34 for guiding oil discharged from the oil pump to various oil supply destinations is provided in the cylinder block 12 and the cylinder head 13. Yes. A part of the oil passage 34 extends substantially in the vertical direction at a position near the side surface of one side (left side in FIG. 4) of the cylinder head 13. The oil passage 34 is branched halfway and extends forward, and is connected to the chain tensioner 28 via the protrusion 27 described above.

  As shown in FIGS. 5 and 6, an oil storage chamber 35 for temporarily storing oil flowing through the oil passage 34 is provided in the middle of the oil passage 34 and in the vicinity of the upstream of the chain tensioner 28. . In the present embodiment, the oil storage chamber 35 is provided on the protrusion 27 which is a place where the chain tensioner 28 is attached on the front surface of the cylinder head 13. The protrusion 27 is provided with a recess 36 opened at the front surface thereof. The oil passage 34 described above is opened in the recess 36, and oil flowing through the oil passage 34 can flow into the recess 36 using the opening as an inlet 37. The opening 36 a of the recess 36 is closed when the chain tensioner 28 is fastened to the protrusion 27. In this way, the space surrounded by the recess 36 and the mounting surface 28a of the chain tensioner 28 on the protrusion 27 is an oil storage chamber 35.

  As described above, the engine 11 is mounted on the vehicle in an inclined state so as to be higher toward the front side. By this mounting, the concave portion 36 is inclined so as to become higher toward the open portion 36a side in the depth direction (vehicle longitudinal direction). A stepped portion 33 that is shallower than the deepest portion 36 b of the recessed portion 36 is provided in the upper portion of the recessed portion 36. An inflow port 37 is opened at the front surface of the stepped portion 33. In this way, the inflow port 37 is an upper part of the oil storage chamber 35 and is located closer to the open part 36a than the deepest part 36b of the concave part 36 (a place between the deepest part 36b of the concave part 36 and the open part 36a). ).

  As shown in FIGS. 4 and 5, the oil outlet (hereinafter referred to as the first outlet 38) of the oil to the chain tensioner 28 in the oil reservoir 35 is opened at the lower part of the wall surface of the recess 36. In the state where the chain tensioner 28 is fastened to the protrusion 27, the oil supply port 39 (see FIG. 3) of the chain tensioner 28 is positioned higher than the first outlet 38. The protrusion 27 is provided with a groove 41 extending substantially upward from the first outlet 38 of the recess 36 and connected to the supply port 39. The groove 41 is closed when the chain tensioner 28 is fastened to the protrusion 27. A guide passage for guiding the oil in the oil storage chamber 35 to the chain tensioner 28 through the first outlet 38, the supply port 39 and the like by the space thus surrounded by the groove 41 and the mounting surface 28a of the chain tensioner 28. 42 is configured.

  Further, the cylinder head 13 is provided with a branch passage 43 for guiding a part of the oil flowing through the oil passage 34 described above to the valve timing variable mechanism 22 which is an oil supply destination different from the chain tensioner 28. One end (left side in FIGS. 4 and 5) of the branch passage 43 is connected to the lower portion of the recess 36. The opening part in the recessed part 36 of the branch channel | path 43 comprises the 2nd outflow port 44, and the oil in the oil storage chamber 35 can flow out into the branch channel | path 43 through the 2nd outflow port 44. FIG. A part of the branch passage 43 extends linearly from the recess 36 toward the other side (intake side) side wall of the cylinder head 13. Thus, the branch passage 43 connected to the oil storage chamber 35 forms an elevation angle with respect to the oil storage chamber 35 in a state where the engine 11 is mounted on the vehicle. In the present embodiment, as described above, the engine 11 is mounted on the vehicle so that the upper surface or the lower surface of the cylinder head 13 becomes higher as it approaches the intake side wall surface from the exhaust side wall surface. It is inclined at an angle α.

  The oil passage structure of this embodiment is configured as described above. According to this structure, when the engine 11 is operated, the oil basically flows from the bottom to the top by the operation of the oil pump. A part of this oil flows from the inlet 37 into the oil storage chamber 35 in the process of passing through the oil passage 34 as shown by the arrows in FIG. A part of the inflowed oil flows out from the first outlet 38 at the lower part of the oil storage chamber 35, is then guided to the guide passage 42, and is supplied to the chain tensioner 28 from the supply port 39. A part of the oil in the oil storage chamber 35 flows out from the second outlet 44 opened at the lower part of the oil storage chamber 35. This oil passes through the branch passage 43 and is supplied to the variable valve timing mechanism 22. The chain tensioner 28 and the variable valve timing mechanism 22 that are supplied with oil are operated by the oil.

  When the engine 11 is stopped, the oil pump also stops operating, so that oil is not supplied to each part of the engine 11. For this reason, when the oil inside the chain tensioner 28 leaks to the outside through the gaps between the components, the oil inside the chain tensioner 28 gradually decreases. The oil in the oil passage 34 tends to flow in the opposite direction (from top to bottom) when the engine 11 is operating due to its own weight.

  On the other hand, in the present embodiment, of the oil stored in the oil storage chamber 35, the portion above the lower edge of the inlet 37 may flow back through the oil passage 34 through the inlet 37. The portion below the inflow port 37 remains accumulated, and does not flow backward to the upstream side (oil pump side) of the oil storage chamber 35. Here, if the inflow port 37 is opened at an intermediate portion or a lower portion in the height direction of the concave portion 36, most of the oil stored in the oil storage chamber 35 during engine operation is in the inflow port 37 while the engine is stopped. The oil flow back to the upstream side of the oil passage 34 (outflow), and the merit of the oil storage chamber 35 for storing the oil is halved.

  On the other hand, in this embodiment, since the inlet 37 is opened at the upper part of the recess 36, the lower edge of the inlet 37, that is, the upper limit of the oil level 45 that can be taken in the oil storage chamber 35 when the engine is stopped is set. Get higher.

  Further, as described above, the engine 11 is mounted on the vehicle in a state of being inclined so as to be higher toward the front side, and in the oil storage chamber 35, it is higher toward the open portion 36 a side of the recess 36. In such an engine 11, the inflow port 37 is opened at a position closer to the open portion 36 a (front side) than the deepest portion 36 b of the recess 36. Therefore, in the state where the engine 11 is mounted, the inflow port 37 is opened at a position higher than that opened at the deepest part 36 b of the oil storage chamber 35. Due to this increase, the amount of oil that can be stored in the oil storage chamber 35 to the maximum while the engine is stopped increases. Also in this point, the lower limit of the oil inlet 37, that is, the upper limit of the oil level 45 that can be taken in the oil storage chamber 35 while the engine is stopped is high.

  Further, if the first outlet 38 is opened at an intermediate portion or an upper portion in the height direction of the oil storage chamber 35 (recess 36), the oil storage chamber 35 is in the middle of a decrease in oil in the oil storage chamber 35. Even when a relatively large amount of oil remains therein, the oil level 45 is lower than the upper edge of the first outlet 38. In this case, air enters from the first outlet 38 opened to the atmosphere, and the oil in a state where the air is mixed is supplied to the chain tensioner 28, thereby preventing normal operation. In this regard, in the present embodiment, the first outlet 38 is opened at the lower portion of the oil storage chamber 35 (recess 36). For this reason, even if the oil in the oil storage chamber 35 decreases due to leakage or the like while the engine 11 is stopped, the oil level 45 is unlikely to be lower than the upper edge of the first outlet 38. Unless a phenomenon occurs in which a large amount of oil leaks to the outside and only a small amount of oil remains in the oil storage chamber 35, such as when the engine 11 is stopped for a long time, the oil level 45 remains at the first outlet 38. The first outlet 38 is not easily opened to the atmosphere.

  Further, the supply port 39 in the chain tensioner 28 is located at a place higher than the first outlet 38. However, since the supply port 39 is connected to the first outlet 38 opened at the lower portion of the above-described recess 36 by the guide passage 42, the oil level 45 becomes extremely low as described above, and the first flow As long as the outlet 38 is not opened to the atmosphere, air does not enter the guide passage 42.

  Further, since the branch passage 43 is at an elevation angle with respect to the oil storage chamber 35 with the engine 11 mounted, when the engine 11 is stopped, the oil in the branch passage 43 is in the opposite direction to that during operation of the engine 11 due to its own weight. The flow is returned to the oil storage chamber 35. Therefore, even if the oil in the oil storage chamber 35 leaks from the gap between the attachment portions of the protrusions 27 and the chain tensioners 28, the leakage is replenished by the inflow from the branch passage 43.

  As described above, when the engine is started in a state where a sufficient amount of oil is stored in the oil storage chamber 35, a part of the stored oil is first flowed as follows. It is taken into the chain tensioner 28 from the supply port 39 through the outlet 38 and the guide passage 42. When the engine is started, the rotation fluctuation of the engine 11 is larger than that during normal operation, and the tension of the timing chain 21 is likely to fluctuate. As described above, when the tension fluctuation occurs under the condition that the oil in the chain tensioner 28 is decreasing, the plunger 32 repeatedly moves in and out of the cylinder 31. When the tension decreases, the plunger 32 biased by the spring protrudes from the cylinder 31. Along with this protrusion, the check valve is opened, and the oil stored in the oil storage chamber 35 is sucked into the cylinder 31. At this time, as described above, since a sufficient amount of oil is stored in the oil storage chamber 35, air is not sucked into the cylinder 31 together with the oil. On the other hand, when the tension becomes high, the plunger 32 is pushed into the cylinder 31, but the check valve is closed, so that the oil sucked in as described above is difficult to escape from the cylinder 31. Therefore, even before the oil is pumped from the oil pump side, the oil is sucked into the cylinder 31 every time the plunger 32 moves in and out, and the oil leakage is replenished. As a result, when the engine 11 is started, the chain tensioner 28 can be normally operated from an early stage.

  Further, since the oil pump is driven as the engine 11 is started, the oil discharged from the oil pump is pumped to the oil storage chamber 35 through the oil passage 34 and is supplied to the chain tensioner 28 together with the oil in the oil storage chamber 35. Supplied.

According to the embodiment described in detail above, the following effects can be obtained.
(1) Since the oil storage chamber 35 is provided in the middle of the oil passage 34 for supplying oil to the chain tensioner 28, an amount necessary for the operation of the chain tensioner 28 is obtained even when the engine 11 is stopped. Oil can be secured in the oil storage chamber 35. Since this oil is sucked into the chain tensioner 28 by the self-suction action when the engine is started, the chain tensioner 28 can be operated normally even during the period until the oil from the oil pump reaches the chain tensioner 28. . Then, troubles due to inadequate adjustment of the tension of the timing chain 21, for example, the timing chain 21 hits other parts such as the tension lever 25, and noise is generated, or the timing chain 21 is wound around the cam sprocket 19. It is possible to suppress a phenomenon in which a hitting sound is sometimes generated.

  (2) A branch passage 43 for supplying oil to the variable valve timing mechanism 22 is connected to the oil storage chamber 35 at an elevation angle when the engine 11 is mounted. For this reason, even if a part of the oil originally stored in the oil storage chamber 35 leaks to the outside, the leakage is replenished by the inflow from the branch passage 43. As a result, the oil storage amount in the oil storage chamber 35 is suppressed from decreasing while the engine 11 is stopped, and the amount of oil necessary for the operation of the chain tensioner 28 is supplied to the oil storage chamber 35 when the engine 11 is started next time. It is possible to secure with certainty. Therefore, the effect (1) is further ensured.

  (3) By opening the inlet 37 at the upper part of the oil storage chamber 35, the upper limit of the oil level 45 that can be taken in the oil storage chamber 35 while the engine is stopped is increased. For this reason, more oil can be stored in the oil storage chamber 35.

  (4) The oil storage chamber 35 is comprised by the recessed part 36 formed in the protrusion 27, and the attachment surface 28a of the chain tensioner 28 fastened to the protrusion 27 (FIG. 6). For this reason, the oil storage chamber 35 can be formed only by performing a simple operation of fastening the chain tensioner 28 to the protrusion 27. Further, a dedicated member for closing the recess 36 is not required, and the structure of the oil storage chamber 35 can be simplified.

  (5) Further, the guide passage 42 is constituted by the groove 41 formed in the protrusion 27 and the mounting surface 28 a of the chain tensioner 28 fastened to the protrusion 27. For this reason, the guide passage 42 can be formed only by performing a simple operation of fastening the chain tensioner 28 to the protrusion 27. Further, a dedicated member for closing the groove 41 is not required, and the structure of the guide passage 42 can be simplified.

  (6) In the engine 11 mounted in an inclined state so as to be higher toward the front side (as far as the open portion 36a side in the depth direction of the concave portion 36), the inlet 37 is provided with the open portion 36a than the deepest portion 36b of the concave portion 36. An opening is made at a close position (FIG. 6). For this reason, the inlet 37 can be made high and the maximum amount of oil that can be stored in the oil storage chamber 35 while the engine 11 is stopped can be increased.

  (7) When the oil level 45 becomes lower than the first outlet 38, oil containing air is supplied to the chain tensioner 28 through the first outlet 38 opened to the atmosphere. If such pneumatic oil is supplied, the chain tensioner 28 may not operate normally, and the tension of the timing chain 21 may not be adjusted to the intended value.

  In this regard, in the present embodiment, the first outlet 38 is opened at the lower portion of the oil storage chamber 35. For this reason, unless the oil in the oil storage chamber 35 is extremely reduced due to the engine 11 being stopped for a long period of time, the oil that does not contain air is reliably supplied to the chain tensioner 28 at the next start of the engine 11, The chain tensioner 28 can be normally operated.

  (8) In relation to the above (7), the first outlet 38 and the supply port 39 provided in the lower part of the oil storage chamber 35 are communicated with each other by the guide passage 42. Therefore, oil that does not contain air can be reliably supplied to the chain tensioner 28 through the guide passage 42 and the supply port 39 from the first outlet 38 that opens at the lower portion of the oil reservoir 35. In addition, this configuration can cope with the case where the supply port 39 is positioned higher than the first outlet 38. It is not necessary to change the position of the supply port 39 on the chain tensioner 28 side.

Note that the present invention can be embodied in another embodiment described below.
The oil passage structure of the present invention can be applied to hydraulic equipment other than the chain tensioner 28 as long as it operates with non-compressible oil and more precisely exhibits a self-suction action when starting the engine. . An example of such a hydraulic device is a lash adjuster. A lash adjuster is a hydraulic device used in a valve operating mechanism that swings the rocker arm with the rotation of the intake / exhaust camshaft to open and close the intake / exhaust valve, and operates with incompressible oil. The rocker arm is brought into contact with the intake and exhaust valves.

-You may connect the branch channel | path 43 to parts other than the lower part of the recessed part 36, for example, the intermediate part in a height direction.
-You may change the position of the inflow port 37 in the recessed part 36, or the 1st outflow port 38 to the position different from the said embodiment.

  -This invention is applicable also to the engine mounted in the state which is not inclined about the front-back direction of a vehicle. In this case, the step portion 33 in the oil storage chamber 35 may be omitted, and the inflow port 37 may be opened at the deepest portion 36 b of the recess 36.

The schematic front view of the tensioner apparatus in one Embodiment which actualized this invention. The perspective view of a cylinder head front part. The side view of a cylinder head front part. The front view of a cylinder head. The perspective view of the oil storage chamber in a cylinder head. AA line sectional view of Drawing 4.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Engine, 14 ... Crankshaft, 15 ... Intake camshaft (driven member), 16 ... Exhaust camshaft (driven member), 21 ... Timing chain (wound transmission member), 28 ... Chain tensioner (hydraulic equipment), 34 ... Oil passage, 35 ... Oil storage chamber, 36 ... Recess, 36a ... Opening part, 36b ... Deepest part, 37 ... Inlet, 38 ... First outlet, 39 ... Supply port, 42 ... Guide passage, 43 ... Branch passage 44 ... Second outlet.

Claims (7)

A hydraulic device that is operated by incompressible oil is one of the oil supply destinations, and an oil passage for supplying oil to the hydraulic device is provided in the engine. An oil storage chamber is provided for storing oil sucked by the equipment, and a branch passage for supplying oil to an oil supply destination that is branched from the oil passage and is different from the hydraulic equipment is provided with the oil in an engine-mounted state. An oil passage structure for an engine, wherein the oil passage structure is connected so as to form an elevation angle with respect to a storage chamber. The oil passage structure for an engine according to claim 1, wherein an oil inflow port in the oil storage chamber is opened at an upper portion of the oil storage chamber. 3. The engine according to claim 1, wherein the oil storage chamber is provided at a location where the hydraulic device is attached in the engine, and an open portion thereof is configured by a recess that is closed by the hydraulic device in an attached state. Oil passage structure. The engine is mounted in an inclined state so as to be higher toward the open portion side in the depth direction of the recess,
4. The oil passage structure for an engine according to claim 3, wherein the oil inlet in the oil reservoir chamber is opened at a location closer to the opening than the deepest portion of the recess. The engine oil passage structure according to any one of claims 1 to 4, wherein an oil outlet to the hydraulic device in the oil storage chamber is opened at a lower portion of the oil storage chamber. The oil supply port in the hydraulic device in the mounted state is located at a position higher than the oil outlet to the hydraulic device in the oil storage chamber,
The engine oil passage structure according to any one of claims 1 to 5, wherein the engine is provided with a guide passage that connects the supply port and the outflow port. The engine includes a crankshaft and a driven member that is driven to rotate by transmitting rotation of the crankshaft through a winding transmission member,
The engine oil passage structure according to any one of claims 1 to 6, wherein the hydraulic device is a tensioner that is actuated by the oil to apply tension to the winding transmission member.

Images