JP4340908B2 - Engine oil passage structure - Google Patents

Description

  The present invention relates to an oil passage structure of an engine having a variable valve timing mechanism, and more particularly to an oil passage structure of an engine having an oil filter between an oil control valve and an actuator.

  2. Description of the Related Art Conventionally, a variable valve timing mechanism that changes the opening / closing timing of an intake / exhaust valve by shifting the rotational phase of a camshaft relative to the rotation of a crankshaft has been employed in an engine. In general, in an engine equipped with a variable valve timing mechanism, as shown in FIGS. 10 to 12, the actuator 3 that shifts the rotational phase of the camshaft 2 with respect to the rotation of the crankshaft 1 and the supply and discharge of the hydraulic pressure of the actuator 3 are controlled. An oil control valve 4 to be controlled is equipped. As shown in FIG. 3, the actuator 3 and the oil control valve 4 communicate with each other through an advance angle side oil passage 5 and a retard angle side oil passage 6, and the oil control valve 4 is switched to advance the advance angle side. When the hydraulic pressure is applied to the oil passage 5, the actuator 3 is actuated to the advance side, and when the hydraulic pressure is applied to the retard angle side oil passage 6, the actuator 3 is actuated to the retard side. Further, as shown in FIGS. 4 and 5, the oil control valve 4 is provided with a solenoid 8 that operates based on a control signal of an ECU (electronic control unit) 7, and the oil control valve 4 is connected to the solenoid control valve 4. 8, the spool 4 b housed in the housing 4 a is slid to control the supply and discharge of the hydraulic pressure in the actuator 3, thereby shifting the rotational phase of the camshaft 2 relative to the rotation of the crankshaft 1 to change the valve timing. .

  Further, in the actuator 3 of such a variable valve timing mechanism, as shown in FIGS. 4, 5, and 11, a housing 10 that rotates integrally with the camshaft timing sprocket 9, and a camshaft timing sprocket with respect to the housing 10. There are some which have a vane 11 that can rotate within a predetermined range around 9 rotation axes. In order to operate the actuator 3 to the advance side, the spool 4b of the oil control valve 4 is moved to the right side from the intermediate position shown in FIG. 6, and the operating oil pressure of the oil control valve 4 is shown in FIG. The supply port 12 and the advance angle side port 13 are communicated with each other, and the drain port 15 and the retard angle side port 14 are communicated with each other. As a result, as shown in FIGS. 4 and 5, the hydraulic pressure is applied to the advance side hydraulic chamber 16 of the actuator 3 and the oil filled in the retard side hydraulic chamber 17 returns to the oil control valve 4. Then, the valve is discharged from the drain port 15, and the vane 11 is rotated to the advance side with respect to the housing 10, that is, the camshaft timing sprocket 9, so that the valve timing is shifted to the advance side. As shown in FIGS. 4 and 5, the hydraulic oil for the variable valve timing mechanism is obtained by sucking the oil stored in the oil pan 18 by the oil pump 19 and passing it through the oil filter 22, and then the lubricating oil oil. The oil is supplied to the oil control valve 4 through a hydraulic oil passage 21 provided by branching the passage 20.

  In such an oil control valve 4, the spool 4b and the spool hole 4c into which the spool 4b is slidably fitted are precision-machined parts. And the spool hole 4c may interfere with the operation of the oil control valve 4. Therefore, Patent Document 1 discloses an invention in which a hydraulic oil oil passage 21 upstream of the oil control valve 4 is provided with an oil filter detachable from an opening provided outside the engine.

However, in the invention disclosed in Patent Document 1, when foreign matter exists in the hydraulic oil returned from the actuator 3 to the oil control valve 4, the foreign matter cannot be removed, and the foreign matter cannot be removed from the spool 4 b and the spool. There is a possibility that the oil control valve 4 may be hindered by being caught between the holes 4c. Further, this oil filter is arranged at the intersection of the oil passages orthogonal to each other, and the hydraulic oil flows from the opening of the cylindrical filter and flows out from the side surface, so that the hydraulic oil pressure loss is large and the variable valve timing mechanism There was a problem that the performance (responsiveness) of the system deteriorated.
Japanese Utility Model Publication No. 7-42402 (paragraph numbers 0024 and 0025, FIG. 7)

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide an oil passage structure for an engine that can stabilize the operation of a variable valve timing mechanism.

In order to achieve the above object, the invention according to claim 1 of the present invention is an engine that rotates a camshaft in synchronization with a crankshaft by winding a timing chain around the cranksprocket and the camshaft timing sprocket. is attached to the variable valve timing mechanism to shift the valve timing to the advance side or retard side by an actuator is operated to change the rotational phase of the camshaft relative to the crankshaft Bei example, the timing chain case The actuator is provided with an oil control valve for controlling the hydraulic pressure to the actuator, and the oil from the oil pan passes through the oil filter and then passes through the oil passage for hydraulic oil branched from the oil passage for lubrication. Feed as hydraulic oil No other hand, in the oil passage structure of the middle engine installed another oil filter to further even the working oil for the oil passage, the mounting surface of the oil control valve when viewed through the engine in the axial direction of the crankshaft The hole for installing the other oil filter is positioned below the camshaft timing sprocket in the cylinder head and surrounded by the timing chain, and the other oil filter is disposed in the middle of the oil passage for hydraulic oil. A hole for installing an oil filter is extended to the engine body side so as to open to the timing chain case, and the other oil filter is positioned in the hydraulic oil passage between the oil control valve and the actuator. The other oil fill is placed in the hole. Actuating the variable valve timing mechanism in the hydraulic fluid passing through a motor and said Rukoto.

According to a second aspect of the present invention, in the oil passage structure of the engine according to the first aspect , when the engine is seen through from the axial direction of the crankshaft , the mounting surface of the oil control valve and the hole for installing another oil filter Is provided below the camshaft timing sprocket and within a range surrounded by three points of the axial center of the two camshafts and the axial center of the crankshaft.
According to a third aspect of the present invention, in the engine oil passage structure according to the first or second aspect, the other oil filter is formed in a bottomed cylindrical shape.

  According to the present invention, foreign matter present in the hydraulic oil between the actuator of the variable valve timing mechanism and the oil control valve that controls the supply and discharge of the hydraulic pressure to the actuator enters the oil control valve, and the sliding portion of the spool It is possible to prevent the operation of the variable valve timing mechanism from being hindered. Further, since the oil filter is installed so as to extend in the axial direction of the oil passage, the diameter of the filter can be reduced.

  An oil passage structure according to an embodiment of the present invention will be described with reference to FIGS. First, the outline of the oil passage structure of the present embodiment will be described. In the oil passage structure of the present embodiment, as shown in FIGS. 1 to 3, an oil filter 23 is installed downstream of an oil control valve 4 that controls the supply and discharge of hydraulic pressure to and from the actuator 3 of the variable valve timing mechanism. As a result, the foreign matter existing in the hydraulic oil between the actuator 3 and the oil control valve 4 is removed. Further, in the oil passage structure of the present embodiment, as shown in FIG. 3, the advance side oil is provided between the actuator 3 of the variable valve timing mechanism and the oil control valve 4 for controlling the hydraulic pressure to the actuator 3. A passage 5 and a retarded-side oil passage 6 are disposed, and an oil filter 23 (see FIG. 9) is installed in each of the oil passages 5 and 6. The hydraulic oil for operating the actuator 3 of the variable valve timing mechanism is pumped to the oil control valve 4 by an oil pump 19 (see FIG. 3).

  Next, the variable valve timing mechanism will be described. As shown in FIG. 3, a timing chain 26 (see FIG. 11) is wound around the crank sprocket 24 and the camshaft timing sprocket 9, and the camshaft 2 is rotated in synchronization with the crankshaft 1. The valve timing is shifted to the advance side or the retard side by operating the actuator 3 to change the rotational phase of the camshaft 2 with respect to the crankshaft 1.

  In the actuator 3 of such a variable valve timing mechanism, as shown in FIGS. 4 and 5, a housing 10 that rotates integrally with the camshaft timing sprocket 9, and a rotation around the rotation axis of the camshaft 2 with respect to the housing 10. And a vane 11 that shifts the rotational phase of the camshaft 2 relative to the crankshaft 1 by moving. When the valve timing is shifted to the advance side, the oil control valve 4 is switched to apply the operating hydraulic pressure to the advance side hydraulic chamber 16 formed in the actuator 3 as shown in FIG. The hydraulic oil in the retard side hydraulic chamber 17 is discharged from the retard side oil passage 6. As a result, the vane 11 rotates relative to the housing 10 in the clockwise direction in FIG. 4 to shift the rotational phase of the camshaft 2 relative to the crankshaft 1 to the advance side as shown in FIG. ing. When the valve timing is shifted to the retard side, the oil control valve 4 is switched so that the operating hydraulic pressure is applied to the retard side hydraulic chamber 17 formed in the actuator 3 and the advance side hydraulic chamber 16 By discharging the hydraulic oil from the advance side oil passage 5, the vane 11 rotates relative to the housing 10 counterclockwise in FIG. 4, and the rotational phase of the camshaft 2 relative to the crankshaft 1 is retarded. It has a structure to move to.

  Next, the structure of the oil control valve 4 that controls the supply and discharge of the hydraulic pressure to the actuator 3 will be described. As shown in FIGS. 6 to 8, the oil control valve 4 includes a housing 4a, a spool 4b that is slidably mounted in a spool hole 4c of the housing 4a, and an ECU (electronic control unit) 7 (see FIGS. 4 and 8). 5), a three-position solenoid 8 for sliding the spool 4b is provided. The housing 4a has a supply port 12 to which hydraulic oil pumped by an oil pump 19 (see FIG. 3) is supplied, an advance side port 13 connected to the advance side oil passage 5, and a retard side oil passage. 6 is provided with a retard port 14 connected to 6, a drain port 15 for returning hydraulic oil discharged from the advance hydraulic chamber 16 or the retard hydraulic chamber 17 to the timing chain case 25 (see FIG. 3). Each port communicates with the spool hole 4c. Then, from the state of the intermediate position of the solenoid 8 (see FIG. 6), the spool 4b is moved in the right direction in FIG. 6 with respect to the housing 4a, and as shown in FIG. 12, the retard port 14 and the drain port 15 are in communication with each other. Further, by moving the spool 4b from the intermediate position of the solenoid 8 (see FIG. 6) to the left in FIG. 6 with respect to the housing 4a, as shown in FIG. The port 12 communicates with the advance port 13 and the drain port 15. As shown in FIG. 6, when the solenoid 8 is positioned at the intermediate position, the advance port 13, the retard port 14 and the supply port 12 are shut off.

  Next, the oil passage structure in the working hydraulic circuit will be described. First, the hydraulic oil passage 21 for supplying hydraulic pressure to the oil control valve 4 will be described. As shown in FIGS. 4 and 5, the hydraulic oil passage 21 is provided by branching the lubricating oil passage 20 into the timing chain case 25, and is installed at a predetermined position of the timing chain case 25. The oil control valve 4 communicates with the supply port 12. Further, downstream of the oil control valve 4, as shown in FIGS. 1 and 3, one opening is communicated with the timing chain case 25 to an advance side oil passage 5 a formed in the cylinder head 27. An advance side oil passage 5 b is provided in which the other opening communicates with the advance port 13 of the oil control valve 4. Further, as shown in FIGS. 2 and 3, the timing chain case 25 has one opening communicating with a retarded-side oil passage 6a formed in the cylinder head 27 and the other opening serving as an oil control valve. A retarding-side oil passage 6b communicated with the four retarding-side ports 14 is provided.

  Next, the structure of the advance side oil passage 5b and the retard side oil passage 6b will be described in detail. First, the advance side oil passage 5b will be described. As shown in FIG. 1, the advance side oil passage 5b includes a hole 28a formed substantially parallel to the camshaft 2 from the mounting surface 25a side of the timing chain case 25 toward the oil control valve mounting surface 25b, and a timing chain case. 25, the hole 28b extended in the axial direction of the hole 28a from the oil control valve mounting surface 25b side of the 25 is crossed. Further, as shown in FIG. 1, the hole 28b is formed upward with an inclination of a predetermined angle from the oil control valve mounting surface 25b, and the diameter of the opening 28d is larger than the diameter of other portions. Is also formed large. As shown in FIG. 1, an oil filter 23 is installed in the hole 28b. As shown in FIG. 9, the oil filter 23 has a side surface 23a formed in a bottomed cylindrical shape with a mesh 23c. By fitting the sleeve 23b formed in the opening into the hole 28b, the side surface 23a is installed in the advance side oil passage 5b so as to face the intersection 28c between the hole 28a and the hole 28b.

  Next, the retard side oil passage 6b will be described. As shown in FIG. 2, the retard side oil passage 6b includes a hole 29a formed substantially in parallel with the camshaft 2 from the mounting surface 25a side of the timing chain case 25 toward the oil control valve mounting surface 25b, and a timing chain case. 25 has a structure in which a hole 29b extending in the axial direction of the hole 29a intersects from the oil control valve mounting surface 25b side. Further, as shown in FIG. 2, the hole 29b is formed upward from the oil control valve mounting surface 25b so as to be inclined at a predetermined angle, and the diameter of the opening 29d is larger than the diameter of other portions. Is also formed large. And the oil filter 23 is installed in the hole 29b, as shown in FIG. This oil filter 23 is the same oil filter 23 as the oil filter 23 (see FIG. 1) installed in the hole 28b of the advance side oil passage 5b, and the sleeve 23b formed in the opening is fitted into the hole 29b. Thus, the side surface 23a is installed in the retarded-side oil passage 6b so as to face the intersection 29c between the hole 29a and the hole 29b.

  In such a configuration, the operation of the oil passage structure of the present embodiment will be described. First, the operation when the valve timing is shifted to the advance side will be described. When the valve timing is shifted to the advance side, the solenoid 8 is driven by the control signal of the ECU (electronic control unit) 7 (see FIGS. 4 and 5), and the spool 4b of the oil control valve 4 is shown in FIG. By moving from the intermediate position to the right side in FIG. 6, as shown in FIG. 7, the supply port 12 and the advance port 13 of the oil control valve 4 are communicated with each other, and the drain port 15 and the retard side are connected. The port 14 is communicated. As a result, the hydraulic oil in the advance side oil passage 5 flows into the advance side hydraulic chamber 16 formed in the actuator 3 of the variable valve timing mechanism, and the hydraulic oil in the retard side hydraulic chamber 17 becomes the retard side oil. After flowing down the passage 6 and passing through the side surface 23a of the oil filter 23 installed in the hole 29b, it flows into the oil control valve 4 and is discharged from the drain port 15 to the inside of the timing chain case 25.

  When the valve timing is shifted to the retard side, the solenoid 8 is driven by a control signal from the ECU (electronic control unit) 7 (see FIGS. 4 and 5), and the spool 4b of the oil control valve 4 is shown in FIG. 6, the supply port 12 of the oil control valve 4 and the retard side port 14 are communicated with each other and the drain port 15 is moved to the left side in FIG. The advance port 13 communicates with the advance port 13. As a result, the hydraulic oil in the retard side oil passage 6 flows into the retard side hydraulic chamber 17 formed in the actuator 3 of the variable valve timing mechanism, and the hydraulic oil in the advance side hydraulic chamber 16 becomes the advance side oil. After flowing down the passage 5 and passing through the side surface 23a of the oil filter 23 installed in the hole 28b, it flows into the oil control valve 4 and is discharged from the drain port 15 to the inside of the timing chain case 25.

  Accordingly, the hydraulic oil that is returned from the actuator 3 of the variable valve timing mechanism to the oil control valve 4 flows into the oil control valve 4 after passing through the oil filter 23, and therefore between the actuator 3 and the oil control valve 4. It is possible to prevent the existing foreign matter from being caught in the sliding portion of the spool 4b of the oil control valve 4 and hindering the operation of the variable valve timing mechanism.

  In addition, the oil filter 23 has a simple structure and can be installed by fitting the sleeve 23b into the holes 28b and 29b, so that the filter diameter can be reduced and the occupied volume can be reduced. Oil filters 23 can be installed in both the angle side oil passage 5 and the retard angle side oil passage 6.

  Furthermore, since the oil filter 23 is installed so that the side surface 23a faces the intersecting portions 28c and 29c of the advance side oil passage 5 and the retard angle side oil passage 6, the effective area of the filter can be increased, The pressure loss can be reduced as much as possible, and the maintenance cycle of the oil filter 23 can be extended by preventing the filter from being clogged. In addition, since the oil filter 23 is installed with an inclination so as to face upward, it is possible to easily remove foreign matters that have been collected or collected in the hole in which the oil filter is installed during maintenance of the filter.

It is a figure which shows the oil structure of this Embodiment, and is an axial sectional view of a part of the advance side oil passage of a timing chain case in particular. It is a figure which shows the oil structure of this Embodiment, and is an axial sectional view of the retard side oil passage of a part of timing chain case especially. It is explanatory drawing of the oil path of the hydraulic fluid of the engine provided with the variable valve timing mechanism. It is explanatory drawing which shows the outline of the working hydraulic circuit of a variable valve timing mechanism. It is explanatory drawing which shows the outline of the working hydraulic circuit of a variable valve timing mechanism. It is function explanatory drawing of an oil control valve, and is a figure especially when a solenoid is located in an intermediate position. It is a function explanatory view of an oil control valve, and is a figure showing a state where a supply port and an advance side port were especially connected. It is a function explanatory view of an oil control valve, and is a figure showing a state where a supply port and a retard side port were especially connected. It is explanatory drawing of the oil filter provided in the working hydraulic circuit of the variable valve timing mechanism. It is a front view of the engine provided with the variable valve timing mechanism, and a part is shown with a section. It is a side view of the engine provided with the variable valve timing mechanism, and a part is shown in cross section. It is a top view of the engine provided with the variable valve timing mechanism, and a part is shown by the cross section.

Explanation of symbols

1 crankshaft, 2 camshaft, 3 actuator, 4 oil control valve, 5 advance oil passage, 6 retard oil passage, 23 oil filter, 25 timing chain case, 25b oil control valve mounting surface, 26 timing chain, 27 Cylinder head

Claims (3)

A timing chain is wound around the crank sprocket and the camshaft timing sprocket so that the camshaft is mounted on an engine that rotates in synchronization with the crankshaft , and the actuator is operated to change the rotation phase of the camshaft relative to the crankshaft. Bei give a variable valve timing mechanism to shift the valve timing to the advance side or retard side by changing, disposed the oil control valve for controlling the hydraulic fluid pressure to the actuator to a timing chain case, from the oil pan another oil, while feeding a working fluid into the actuator via the hydraulic oil for the oil passage branched from the lubricating oil passage after passing through the oil filter once in the middle to further even the working oil for the oil passage Oirufi of In the oil passage structure of the installed engine data,
When the engine is seen through from the axial direction of the crankshaft, the mounting surface of the oil control valve and the hole for installing the other oil filter are located below the camshaft timing sprocket in the cylinder head and in the timing chain. A hole for installing the other oil filter disposed in the middle of the oil passage for the hydraulic oil is extended to the engine body side to open to the timing chain case, and the other oil filter Rukoto the arranged bore to actuate the variable valve timing mechanism in the hydraulic fluid passed through said another oil filter so as to be positioned on the hydraulic oil for the oil passage between the oil control valve and the actuator The oil passage structure of the engine characterized by When the engine is seen through from the axial direction of the crankshaft, the mounting surface of the oil control valve and the hole for installing the other oil filter are below the camshaft timing sprocket, and the two camshafts 2. The engine oil passage structure according to claim 1, wherein the engine oil passage structure is provided within a range surrounded by three points of an axis center of the crankshaft and an axis center of the crankshaft. The engine oil passage structure according to claim 1 or 2 , wherein the another oil filter is formed in a bottomed cylindrical shape.

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