JP6403974B2 - Engine lubricant supply mechanism - Google Patents

Description

  The present invention relates to a technology of an engine lubricating oil supply mechanism that supplies lubricating oil stored in an oil pan to each part of the engine.

  2. Description of the Related Art Conventionally, a technology of an engine lubricating oil supply mechanism that supplies lubricating oil stored in an oil pan to each part of the engine is known. For example, as described in Patent Document 1.

  Patent Document 1 describes an engine lubricating oil supply mechanism that feeds lubricating oil stored in an oil pan with an oil pump and supplies the lubricating oil to each part of the engine (for example, a lash adjuster). The lash adjuster can suppress the valve clearance by the hydraulic pressure of the supplied lubricating oil.

  In the technique described in Patent Document 1, a relief path (oil path) is connected to the upstream side of the lash adjuster, and a pressure adjusting valve (relief valve) is provided in the relief path. When the lubricating oil supplied to the lash adjuster becomes high pressure, the pressure adjusting valve is opened, and the lubricating oil is returned to the oil pan through the relief path. As a result, the flow rate of the lubricating oil supplied to the lash adjuster is limited (that is, the pressure rise of the lubricating oil is limited), and the occurrence of the pump-up phenomenon can be suppressed. At the same time, excessive lubricating oil can be prevented from being supplied to the lash adjuster.

  However, the technique described in Patent Document 1 has room for improvement in that the drive torque of the oil pump itself cannot be reduced even though the flow rate of the lubricating oil supplied to the lash adjuster can be limited. .

JP 2012-219725 A

  The present invention has been made in view of the above situation, and a problem to be solved is to provide a lubricating oil supply mechanism for an engine capable of reducing the driving torque of an oil pump.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

That is, according to the first aspect of the present invention, there is provided a lubricating oil supply mechanism for an engine that supplies the lubricating oil stored in the oil pan to each part of the engine, and is a variable displacement type that pumps the lubricating oil stored in the oil pan. An oil pump, a flow rate control valve that adjusts the flow rate of the lubricating oil by restricting the flow path of the lubricating oil as the hydraulic pressure on the downstream side increases, and a flow rate control valve that is disposed on the downstream side of the flow rate control valve, A lash adjuster that operates by the hydraulic pressure of the lubricating oil flowing through the valve and suppresses the occurrence of valve clearance, and a valve timing change device that is operated by the hydraulic pressure of the lubricating oil supplied from the oil pump without passing through the flow rate control valve; , comprising a, the lash adjuster includes a lash adjuster on the exhaust side and the intake side of the lash adjuster, the flow control valve, said intake Are those respectively provided to the side of the lash adjuster and the exhaust-side lash adjuster.

  As effects of the present invention, the following effects can be obtained.

The present invention can reduce the driving torque of the oil pump while preventing the excessive supply of lubricating oil to the lash adjuster, thereby improving the fuel consumption.

The schematic diagram which showed the structure of the lubricating oil supply mechanism which concerns on one Embodiment of this invention. Sectional drawing which showed the structure of the flow control valve. (A) The figure which showed a mode that the flow volume (downstream hydraulic pressure) of lubricating oil was restrict | limited by the flow control valve. (B) The figure which showed the characteristic of the oil pump single-piece | unit. (A) The figure which showed the change of the hydraulic pressure in the downstream of an oil pump when the flow volume of lubricating oil is restrict | limited by the flow control valve. (B) The figure which showed a mode that the flow volume of lubricating oil was restrict | limited by the flow control valve. (C) The figure which showed the change of the oil_pressure | hydraulic of the downstream of an oil pump at the time of changing the characteristic of an oil pump. The schematic diagram which showed the structure of the lubricating oil supply mechanism which concerns on other embodiment of this invention.

  In the following description, the left-right direction is defined according to the arrows shown in the figure.

  Below, the structure of the lubricating oil supply mechanism 1 of the engine which concerns on one Embodiment of this invention is demonstrated using FIG. The lubricating oil supply mechanism 1 supplies lubricating oil stored in the oil pan 2 to each part of the engine.

  The lubricating oil stored in the oil pan 2 is sucked by the oil pump 6 through the oil strainer 4. The oil pump 6 is formed in a variable displacement type that can change the discharge amount of lubricating oil per one rotation (details will be described later). The oil pump 6 is driven by the engine and at a rotational speed corresponding to the rotational speed of the engine. In the oil pump 6, there is provided a relief valve 6 a that returns the lubricating oil from the discharge side of the oil pump 6 to the suction side according to the discharge pressure of the oil pump 6.

  The lubricating oil sucked into the oil pump 6 is pumped by the oil pump 6 and supplied to the main oil hole 12 through the sub oil hole 8 and the oil filter 10. The oil filter 10 is provided with a relief valve 10a for circulating lubricating oil when the oil filter 10 is clogged.

  The lubricating oil supplied to the main oil hole 12 is further branched and supplied to the cylinder head 14, the chain tensioner 28, the oil jet 30, the piston jet 34, and the crank journal 38, respectively.

  The lubricating oil supplied to the cylinder head 14 is further branched and supplied to the OCV 16, the intake side lash adjuster 20, and the exhaust side lash adjuster 24, respectively.

  Here, a flow rate control valve 50 is provided in the middle of the oil passage for supplying lubricating oil from the cylinder head 14 to the lash adjuster 20 on the intake side and the lash adjuster 24 on the exhaust side. The configuration of the flow control valve 50 will be described later.

  The OCV (oil control valve) 16 controls the supply of the lubricating oil to the valve timing changing device 18 and the discharge of the lubricating oil from the valve timing changing device 18. The lubricating oil supplied from the cylinder head 14 is appropriately supplied to the valve timing changing device 18 by the OCV 16 and is discharged from the valve timing changing device 18. Further, the lubricating oil discharged from the OCV 16 is returned to the oil pan 2 again.

  Here, the valve timing changing device 18 is a hydraulic device that is operated by the hydraulic pressure of the supplied lubricating oil and changes the opening / closing timing of an intake valve (not shown). The valve timing changing device 18 is provided at one end of an intake side camshaft (intake camshaft (not shown)) on which a cam for opening and closing the intake valve is formed. When lubricating oil is supplied to the advance chamber of the valve timing changing device 18, the phase of the intake camshaft with respect to a crankshaft (not shown) is advanced, and the opening / closing timing of the intake valve can be advanced. On the other hand, when lubricating oil is supplied to the retard chamber of the valve timing changing device 18, the phase of the intake camshaft relative to the crankshaft (not shown) can be retarded, and the opening / closing timing of the intake valve can be delayed.

  In the present embodiment, the valve timing changing device 18 is provided only on the intake camshaft. However, the exhaust camshaft (exhaust camshaft (exhaust camshaft)) is provided with a cam that opens and closes an exhaust valve (not shown). (Not shown)) (provided on at least one of the intake camshaft and the exhaust camshaft).

  Further, the lubricating oil branched in the cylinder head 14 operates the intake side lash adjuster 20, lubricates the intake camshaft journal 22, and is returned to the oil pan 2 again.

  Here, the lash adjuster 20 is a hydraulic device that suppresses the occurrence of intake-side valve clearance (for example, clearance between the intake valve and the cam of the intake camshaft). The lash adjuster 20 can suppress the occurrence of a clearance between the intake valve and the intake camshaft cam by the hydraulic pressure of the supplied lubricating oil and the urging force of the spring provided therein.

  Further, the lubricating oil branched in the cylinder head 14 operates the exhaust side lash adjuster 24 and lubricates the exhaust camshaft journal 26 and is returned to the oil pan 2 again.

  Here, the lash adjuster 24 is a hydraulic device that suppresses the occurrence of an exhaust valve clearance (for example, a clearance between the exhaust valve and the cam of the exhaust camshaft). The lash adjuster 24 can suppress the occurrence of a clearance between the exhaust valve and the cam of the exhaust camshaft by the hydraulic pressure of the supplied lubricating oil and the urging force of the spring provided therein.

  Further, the lubricating oil branched in the main oil hole 12 is returned again to the oil pan 2 through the chain tensioner 28.

  Here, the chain tensioner 28 is a hydraulic device that applies tension to the timing chain 32 for transmitting driving force to the intake camshaft and the exhaust camshaft. The chain tensioner 28 can apply a predetermined tension to the timing chain 32 by the hydraulic pressure of the supplied lubricating oil, and can suppress vibration and slack of the timing chain 32.

  Further, the lubricating oil branched off in the main oil hole 12 is injected into the timing chain 32 by the oil jet 30. The lubricating oil lubricates the timing chain 32 and then returns to the oil pan 2 again.

  Further, the lubricating oil branched in the main oil hole 12 is injected to the piston 36 by the piston jet 34. The lubricating oil lubricates the piston 36 and then returns to the oil pan 2 again.

  Further, the lubricating oil branched in the main oil hole 12 lubricates the crank journal 38 and the crank pin 40 in order, and then returns to the oil pan 2 again.

  Below, the structure of the flow control valve 50 is demonstrated using FIG.

  The flow control valve 50 mainly includes a valve body 51, a spool 52, a spring 53, and a pressure adjusting screw 54.

  The valve body 51 is a substantially cylindrical member. The valve body 51 is formed with a sliding portion 51a, a first port 51b, a second port 51c, a communication oil passage 51d, and a female screw portion 51e.

  The sliding part 51a is a hole formed so as to penetrate the inside of the valve body 51 in the longitudinal direction. The sliding part 51a is formed to have a circular cross section. One end portion (right end portion) of the sliding portion 51a is appropriately closed by a closing member.

  The first port 51 b is a hole formed so as to communicate the sliding portion 51 a and the outside of the valve body 51. The first port 51b is formed at a position facing the upstream oil passage of the flow control valve 50 and communicates with the upstream oil passage.

  The second port 51 c is a hole formed so as to communicate the sliding portion 51 a and the outside of the valve body 51. The second port 51c is formed at a position facing the downstream oil passage of the flow control valve 50 and communicates with the downstream oil passage.

  The communication oil passage 51d is formed so as to communicate the vicinity of the right end portion of the sliding portion 51a and the oil passage on the downstream side of the flow control valve 50.

  The female thread 51e is formed in the vicinity of the other end (left end) of the valve body 51. The female thread portion 51e is formed by cutting a screw inside a hole on the same axis as the sliding portion 51a.

  The spool 52 is for restricting the flow path of the lubricating oil flowing through the flow control valve 50 as appropriate. The spool 52 is a substantially cylindrical member. The spool 52 is disposed inside the sliding portion 51 a of the valve body 51. More specifically, the spool 52 is disposed from the vicinity of the right end of the sliding portion 51a of the valve body 51 to the vicinity of the left end. The spool 52 is formed with a first enlarged diameter portion 52a and a second enlarged diameter portion 52b.

  The first enlarged diameter portion 52a is a portion formed so that its diameter is larger than that of other portions. The first enlarged diameter portion 52 a is formed near the left end portion of the spool 52. The diameter (outer diameter) of the first enlarged diameter portion 52 a is formed to be substantially the same as the diameter (inner diameter) of the sliding portion 51 a of the valve body 51.

  The 2nd enlarged diameter part 52b is a part formed so that the diameter may become larger than another part. The second enlarged diameter portion 52b is formed in the vicinity of the right end portion of the spool 52 and separated from the first enlarged diameter portion 52a by a predetermined distance. The diameter (outer diameter) of the second enlarged diameter portion 52 b is formed to be substantially the same as the diameter (inner diameter) of the sliding portion 51 a of the valve body 51.

  The second enlarged diameter portion 52 b is formed at a position facing a part of the first port 51 b of the valve body 51. That is, a part of the first port 51b is closed (squeezed) by the second enlarged diameter portion 52b.

  The first enlarged diameter portion 52a and the second enlarged diameter portion 52b of the spool 52 configured as described above are in contact with the sliding portion 51a of the valve body 51 so as to be slidable in the left-right direction. It arrange | positions so that it can slide to the left-right direction in the inside of the sliding part 51a of the main body 51. FIG. Further, as the spool 52 slides in the left-right direction, the closing condition (throttle condition) by the second enlarged diameter portion 52b of the first port 51b of the valve body 51 changes. That is, the opening area of the first port 51b is changed.

  The spring 53 is disposed on the left side of the spool 52 (between the spool 52 and a pressure adjusting screw 54 described later), and biases the spool 52 toward the right side with a predetermined force.

  The pressure adjusting screw 54 supports the spring 53 from the left and adjusts the urging force applied to the spool 52 by the spring 53. The pressure adjusting screw 54 is fixed to the female thread portion 51 e of the valve body 51.

  In the flow control valve 50 configured as described above, a portion surrounded by the first enlarged diameter portion 52a, the second enlarged diameter portion 52b of the spool 52, and the sliding portion 51a of the valve body 51 is filled with lubricating oil. One oil chamber R1 is formed. A second oil chamber R <b> 2 filled with lubricating oil is formed in a portion surrounded by the second enlarged diameter portion 52 b of the spool 52 and the sliding portion 51 a of the valve body 51.

  The first oil chamber R1 and the second oil chamber R2 are partitioned by the second enlarged diameter portion 52b of the spool 52, and are connected by the communication oil passage 51d and the second port 51c.

  Hereinafter, a state in which the flow rate of the lubricating oil flowing through the flow rate control valve 50 is adjusted by the flow rate control valve 50 will be described with reference to FIGS. 2 and 3A.

  The flow rate of the lubricating oil flowing through the flow rate control valve 50 (the second port 51c of the flow rate control valve 50) is after the portion (throttle) in which the first port 51b is throttled by the second enlarged diameter portion 52b and the hydraulic equipment (see FIG. 2, the pressure resistance (differential pressure) after (atmospheric pressure), that is, the differential pressure between the downstream side of the flow control valve 50 and the atmospheric pressure. It changes according to. When the hydraulic pressure on the downstream side of the flow control valve 50 reaches a predetermined pressure, the flow control valve 50 adjusts the throttle so that the differential pressure becomes substantially constant. This will be specifically described below.

  When the engine starts and its rotational speed (engine rotational speed) increases, the rotational speed of the oil pump 6 increases and the amount of lubricating oil supplied to the flow control valve 50 also increases. When the engine speed is low, the spool 52 is pushed rightward by the spring 53, and the opening area of the first port 51b is secured widely. For this reason, the hydraulic pressure on the downstream side of the flow control valve 50 also increases as the engine speed increases.

  Here, the hydraulic pressure downstream of the flow control valve 50 is also applied to the second oil chamber R2 via the communication oil passage 51d. Therefore, when the engine speed further increases and the hydraulic pressure on the downstream side of the flow control valve 50 (that is, the hydraulic pressure in the second oil chamber R2) increases, the spool 52 moves to the left against the biasing force of the spring 53. Will be slid. As a result, the opening area of the first port 51b is reduced.

  Thus, the engine speed has increased to a predetermined value (N1 in FIG. 3A), and the hydraulic pressure on the downstream side of the flow control valve 50 has reached a predetermined value (P1 in FIG. 3A). Thereafter, since the flow rate of the lubricating oil flowing through the flow control valve 50 is limited, the increase amount of the hydraulic pressure on the downstream side of the flow control valve 50 is remarkably reduced (very small amount). Thereby, the flow rate of the lubricating oil supplied to the downstream side of the flow rate control valve 50 can be adjusted (restricted).

  In this way, the downstream hydraulic pressure value (predetermined value P1) at which the flow rate of the lubricating oil is limited may change the position of the pressure adjusting screw 54 or change the spring 53 to one having different characteristics. This can be set arbitrarily.

  In FIG. 3A, the hydraulic pressure on the downstream side of the flow rate control valve 50 when it is assumed that the flow rate of the lubricating oil as described above is not performed is indicated by a broken line.

  Hereinafter, as in the present embodiment, the flow control valve 50 is provided in the middle of an oil passage for supplying lubricating oil from the cylinder head 14 to the lash adjuster 20 on the intake side and the lash adjuster 24 on the exhaust side. The effect will be described.

  As described above, the flow rate of the lubricating oil flowing through the flow rate control valve 50 is limited by the flow rate control valve 50. For this reason, the flow rate of the lubricating oil supplied from the cylinder head 14 to the lash adjuster 20 on the intake side and the lash adjuster 24 on the exhaust side is limited. Accordingly, it is possible to prevent excessive lubricating oil from being supplied to the lash adjuster 20 on the intake side and the lash adjuster 24 on the exhaust side.

  In particular, the intake side lash adjuster 20 and the exhaust side lash adjuster 24 are appropriately operated with the downstream hydraulic pressure value (predetermined value P1) at which the flow rate of the lubricating oil is limited by the flow control valve 50. Therefore, it is equivalent to the oil pressure required for the operation (more specifically, a value higher than and close to the oil pressure required for properly operating the intake side lash adjuster 20 and the exhaust side lash adjuster 24). By setting so that the intake side lash adjuster 20 and the exhaust side lash adjuster 24 are appropriately operated, excessive lubricating oil is supplied to the intake side lash adjuster 20 and the exhaust side lash adjuster 24. Can be prevented.

  It is also possible to prevent excessive lubricating oil from being supplied to the intake camshaft journal 22 and the exhaust camshaft journal 26 disposed further downstream than the intake lash adjuster 20 and the exhaust lash adjuster 24. it can. As a result, friction loss in the intake camshaft journal 22 and the exhaust camshaft journal 26 can be reduced, and as a result, fuel consumption can be improved.

  Further, by providing the flow control valve 50 in the middle of the oil passage for supplying the lubricating oil from the cylinder head 14 to the lash adjuster 20 on the intake side and the lash adjuster 24 on the exhaust side, the drive torque of the oil pump 6 can be reduced. Reduction can be achieved. This will be specifically described below.

  First, the characteristics of the oil pump 6 alone will be described. As shown in FIG. 3B, the oil pump 6 is formed in a variable displacement type that can change the discharge amount of the lubricating oil per one rotation.

  Specifically, the oil pump 6 has a hydraulic pressure (discharge pressure) on the downstream side of the oil pump 6 with respect to the engine speed (that is, the rotation speed of the oil pump 6) in a region where the engine speed is low (low rotation range L). Is set to be relatively high.

  Further, in the oil pump 6, in the first half (middle rotation range first half M1) of the medium engine speed range (middle rotation range), the amount of increase in the discharge pressure of the oil pump 6 with respect to the engine rotation speed is remarkably reduced (extremely). It is set to be small).

  Further, the oil pump 6 has an increase in the discharge pressure of the oil pump 6 with respect to the engine speed in the latter half of the region where the engine speed is medium (the second half of the middle speed region M2) (the engine speed is N2 to N3) It is set to be relatively high.

  Further, the oil pump 6 is set so that the increase amount of the discharge pressure of the oil pump 6 with respect to the engine speed is significantly reduced (very small) in a region where the engine speed is high (high rotation range H). .

  In this way, particularly by suppressing the discharge pressure of the oil pump 6 in the middle rotation range (middle rotation range first half M1 and middle rotation range second half M2), excessive supply of lubricating oil is suppressed and energy loss is reduced. be able to. The characteristics of the oil pump 6 described above (the point at which the discharge amount of the lubricating oil changes (discharge pressure)) can be changed arbitrarily by changing the design of control valves, springs and the like provided in the oil pump 6. it can.

  When such an oil pump 6 is used in the lubricating oil supply mechanism 1 according to this embodiment, the flow rate control valve 50 is circulated by the flow rate control valve 50 as shown in FIGS. 4 (a) and 4 (b). When the flow rate of the lubricating oil is limited, the amount of increase in hydraulic pressure (discharge pressure) on the downstream side of the oil pump 6 increases. That is, the discharge pressure of the oil pump 6 is earlier (at a relatively low engine speed) than when the flow rate of the lubricating oil is not limited by the flow rate control valve 50 (see the broken line in FIG. 4A). Becomes higher. For example, in the second half of the middle rotation range M2 (from N2 'to N3'), the engine speed changes to a lower speed than when the flow rate of the lubricating oil is not limited by the flow control valve 50 (from N2 to N3).

  On the other hand, in the region where the engine speed is medium (for example, the first half of the middle rotation region M1 and the second half of the middle rotation region), the supply amount of the lubricating oil to each part of the engine is sufficiently secured. Therefore, an increase in the discharge pressure of the oil pump 6 at an early stage in a region where the engine speed is relatively high is not preferable because the lubricating oil is excessively supplied to each part of the engine. Further, the driving torque of the oil pump 6 is also increased, and as a result, fuel consumption is deteriorated.

  Therefore, the drive torque of the oil pump 6 can be reduced (reduced) by changing the characteristics of the oil pump 6. Specifically, the second half of the middle rotation range M2 is changed so as to be in the same engine speed range (from N1 to N2) as when the flow rate of the lubricating oil is not limited by the flow control valve 50 (see FIG. 4 (c) solid line reference). As a result, the driving torque of the oil pump 6 corresponding to the region indicated by the broken line in FIG. 4C can be reduced, and as a result, fuel efficiency can be improved.

As described above, the engine lubricating oil supply mechanism 1 according to this embodiment is an engine lubricating oil supply mechanism 1 that supplies the lubricating oil stored in the oil pan 2 to each part of the engine. A variable displacement oil pump 6 that pumps the stored lubricating oil, a flow control valve 50 that adjusts the flow rate of the lubricating oil by narrowing the flow path of the lubricating oil as the hydraulic pressure on the downstream side increases, The lash adjuster 20 and the lash adjuster 24 are disposed downstream of the flow control valve 50 and are operated by the hydraulic pressure of the lubricating oil flowing through the flow control valve 50 to suppress the occurrence of valve clearance.
With this configuration, it is possible to reduce the driving torque of the oil pump 6 while preventing excessive lubrication oil from being supplied to the lash adjuster 20 and the lash adjuster 24, thereby improving fuel efficiency. be able to.

Further, the downstream hydraulic pressure when the flow rate control valve 50 restricts the flow path of the lubricating oil is set to be higher than the hydraulic pressure necessary for operating the lash adjuster 20 and the lash adjuster 24. It is.
With this configuration, it is possible to reduce the drive torque of the oil pump 6 while ensuring the hydraulic pressure necessary to operate the lash adjuster 20 and the lash adjuster 24.

  The configuration of the lubricating oil supply mechanism described in the present embodiment (that is, the route of the lubricating oil supplied to each part of the engine, the equipment to which the lubricating oil is supplied, etc.) is an example, and the present invention is not limited thereto. It is not limited. That is, the route of the lubricating oil and the equipment to which the lubricating oil is supplied can be arbitrarily changed.

  Moreover, in this embodiment, although the oil pump 6 was illustrated, the structure of the variable capacity | capacitance type oil pump which concerns on this invention is not restricted to this. For example, as the oil pump according to the present invention, an electric oil pump capable of changing the discharge amount of the lubricating oil may be used. Further, in the present embodiment, the amount of lubricating oil discharged can be changed in stages (low rotation range L, medium rotation range (three stages of medium rotation range first half M1 and medium rotation range second half M2) and high rotation range H). Although the oil pump 6 has been described as an example, the present invention is not limited to this. For example, it is possible to use a variable displacement oil pump capable of continuously changing the discharge amount of the lubricating oil.

  Further, in the present embodiment, the configuration in which one flow rate control valve 50 is provided on the upstream side of the intake side lash adjuster 20 and the exhaust side lash adjuster 24 (see FIG. 1) is exemplified, but the present invention is not limited thereto. It is not a thing. That is, as shown in FIG. 5, it is also possible to employ a configuration in which one flow control valve 50 is provided on each of the upstream side of the intake side lash adjuster 20 and the upstream side of the exhaust side lash adjuster 24.

1 Lubricating oil supply mechanism 2 Oil pan 6 Oil pump 16 OCV
18 Valve timing changing device 20 Rush adjuster 24 Rush adjuster 28 Chain tensioner 32 Timing chain 50 Flow control valve

Claims (1)

A lubricating oil supply mechanism for an engine that supplies lubricating oil stored in an oil pan to various parts of the engine,
A variable displacement oil pump that pumps the lubricating oil stored in the oil pan;
A flow rate control valve that adjusts the flow rate of the lubricating oil by restricting the flow path of the lubricating oil as the hydraulic pressure on the downstream side increases,
A lash adjuster disposed downstream of the flow control valve, actuated by the hydraulic pressure of the lubricating oil flowing through the flow control valve, and suppresses the occurrence of valve clearance;
A valve timing changing device that is actuated by the hydraulic pressure of lubricating oil supplied from the oil pump without going through the flow rate control valve;
Equipped with,
The lash adjuster is
Including the lash adjuster on the intake side and the lash adjuster on the exhaust side,
The flow control valve is
Provided for the intake side lash adjuster and the exhaust side lash adjuster, respectively.
Engine oil supply mechanism.

Images