JP2012117494A - Oil passage structure for engine with variable valve timing mechanism - Google Patents

Abstract

In an oil passage structure of an engine with a variable valve timing mechanism, oil is stably supplied to a hydraulic actuator, and maintenance workability of a throttle portion of the oil passage is improved.
Both ends are joined to the chain case (8) and the cylinder head (3) between the inner wall (26) of the chain case (8) and the end wall (35) of the cylinder head (3). A block (36) is arranged, and a supply oil passage (39) and a part (45) of the lubricating oil passage (43) are formed in the block (36), and one part of the lubricating oil passage (43) is formed. The part (45) is formed so as to pass through the block (36) linearly, and the throttle part (46) is provided in the middle part of a part (45) of the lubricating oil passage (43).
[Selection] Figure 1

Description

  The present invention relates to an oil passage structure of an engine with a variable valve timing mechanism, and more particularly to an oil passage structure of an engine with a variable valve timing mechanism that supplies oil to a bearing portion of a camshaft and a hydraulic actuator.

  Some engines mounted on vehicles are equipped with a variable valve timing mechanism that changes the valve timing. In this variable valve timing mechanism, a hydraulic actuator is attached to the end of a cam shaft that is pivotally supported by a cylinder head, a hydraulic control valve is attached to a chain case that covers the timing chain, and the oil supply state from this hydraulic control valve The hydraulic actuator is operated to change the valve timing, and the bearing portion of the camshaft is lubricated with oil.

JP 2000-110532 A

  An oil passage structure of an engine with a hydraulic control device according to Patent Document 1 includes an oil passage for a valve operating system that supplies oil from an oil filter disposed at a lower end of the engine to the camshaft through the inside of the engine. A control oil passage that branches from the middle of the valve system oil passage and supplies oil to the hydraulic control valve is provided, and a throttle member is provided on the valve system oil passage and at the upper end of the cylinder head It is.

However, in the above-mentioned patent document 1, since the distance from the oil filter to the throttle member is increased and the distance from the throttle member to the hydraulic control valve is also increased, the valve is moved by the throttle member immediately after the engine is started. It takes time until the oil pressure in the system oil passage is increased and oil flows to the hydraulic control valve side. For this reason, there is a concern that the stability and responsiveness of the oil to the hydraulic actuator may be reduced.
Further, in such a structure, when foreign matter such as impurities or metal fragments enter the oil passage, the foreign matter is clogged at a portion facing the upstream side of the throttle member, so that the throttle member is not removed from above the engine. It was difficult to remove foreign matter.
In addition, since the throttle member is provided near the boundary between the cylinder head cover and the cylinder head, many parts such as mounted parts (parts such as an air cleaner) and cylinder head cover arranged on the upper part of the cylinder head cover are used for maintenance of the throttle member. It is necessary to remove these parts from the engine, which causes a disadvantage that the maintainability of the operator is lowered.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an oil passage structure for an engine with a variable valve timing mechanism that stably supplies oil to a hydraulic actuator and improves the maintenance workability of a throttle portion of the oil passage.

  According to the present invention, a hydraulic actuator for changing valve timing is attached to an end of a camshaft supported by a cylinder head of an engine, a hydraulic control valve is attached to a chain case that covers the timing chain, and an oil pump is attached to the chain case. A communicating oil passage is formed, the oil passage and the hydraulic control valve are connected by a supply oil passage, and a lubricating oil passage for supplying oil to the bearing portion of the camshaft formed in the cylinder head is provided. In an oil passage structure of an engine with a variable valve timing mechanism that communicates with a supply oil passage and has a throttle portion in the lubricating oil passage, both end portions between an inner wall of the chain case and an end wall of the cylinder head A block that is joined to the chain case and the cylinder head. Forming a supply oil passage and a part of the lubrication oil passage in a rack, forming a part of the lubrication oil passage so as to penetrate the block linearly, The diaphragm portion is provided in a part of the intermediate portion.

  The oil passage structure of the engine with a variable valve timing mechanism according to the present invention can stably supply oil to the hydraulic actuator and improve the maintenance workability of the throttle portion of the oil passage.

FIG. 1 is an enlarged view of a main part of the oil passage structure of the engine of FIG. (Example) 2 is a cross-sectional view of the engine taken along line II-II in FIG. (Example) FIG. 3 is a front view of the engine. (Example) FIG. 4 is a side view of the engine. (Example) FIG. 5 is a perspective view of the engine. (Example) FIG. 6 is an exploded perspective view of the engine. (Example) FIG. 7 is a cross-sectional view of the inner wall of the chain case as viewed from the end wall of the cylinder head along the line VII-VII in FIG. (Example) 8 is a cross-sectional view of the end wall of the cylinder head viewed from the inner wall of the chain case along the line VIII-VIII in FIG. (Example) FIG. 9 is a cross-sectional view of the engine. (Modification)

  The present invention provides a stable supply of oil to a hydraulic actuator and improves the maintenance workability of the throttle part of the oil passage. The throttle part is arranged close to the oil pump, or the throttle part is provided with a lubricating oil passage. It is realized by providing it.

1 to 8 show an embodiment of the present invention.
3 to 6, reference numeral 1 denotes a multi-cylinder (3-cylinder) engine mounted on a vehicle, 2 a cylinder block, 3 a cylinder head, 4 a cylinder head cover, and 5 an oil pan. The engine 1 includes a crankshaft 6 in a cylinder block 2, and the crankshaft 6 is disposed horizontally in a vehicle width direction Y that is a direction orthogonal to the vehicle longitudinal direction X. A crank sprocket 7 is attached to the end of the crankshaft 6 as shown in FIGS.
A chain case 8 is attached to the right part of the cylinder block 2 and the cylinder head 3. A transmission 9 is connected to the left part of the cylinder block 2.
An air cleaner 11, a resonator 12, and an intake manifold 13 are arranged on the upper portion of the engine 1 so as to constitute an intake device 10. The intake manifold 13 is disposed on the rear side of the engine 1.
An exhaust manifold 15 is disposed at the front of the engine 1 so as to constitute an exhaust device 14. A catalytic converter 16 is attached to the exhaust manifold 15.

As shown in FIG. 6, the cylinder head 3 is provided with first to third spark plug cylinders 17A to 17C sequentially from the right side corresponding to each cylinder.
As shown in FIGS. 6 to 8, the cylinder head 3 has an intake cam shaft 18 and an exhaust cam shaft 19 arranged as a cam shaft at a predetermined distance and arranged in the direction of the crankshaft. The intake camshaft 18 is pivotally supported by first to fourth intake bearing portions 20A to 20D that are sequentially formed on the cylinder head 3 from the right side. The exhaust cam shaft 19 is pivotally supported by first to fourth exhaust bearing portions 21 </ b> A to 21 </ b> D that are sequentially formed on the cylinder head 4 from the right side. The first intake bearing portion 19A and the first exhaust bearing portion 21A at the right end are connected by a central bearing portion 22 extending in the vehicle width direction Y.
An intake cam sprocket 23 and an exhaust cam sprocket 24 are attached to the intake cam shaft 18 and the exhaust cam shaft 19. A timing chain 25 covered with a chain case 8 is wound around the intake cam sprocket 23, the exhaust cam sprocket 24, and the crank sprocket 7 of the crankshaft 6.

  As shown in FIG. 7, an oil pump 27 that is driven by rotation of the crankshaft 6 is provided below the inner wall 26 of the chain case 8. An oil filter 28 for filtering oil from the oil pump 27 is attached to the lower part of the cylinder block 2.

The engine 1 includes a variable valve timing mechanism 29.
As shown in FIGS. 6 to 8, in the variable valve timing mechanism 29, an intake hydraulic actuator 30 and an exhaust hydraulic actuator 31 that change the valve timing are attached to end portions of the intake cam shaft 18 and the exhaust cam shaft 19. ing.
As shown in FIGS. 3 and 8, the chain case 8 includes an intake hydraulic control valve 32 that communicates with the intake hydraulic actuator 30 as a hydraulic control valve at the position of the upper cylinder head 3, and an exhaust hydraulic type. An exhaust hydraulic control valve 33 communicating with the actuator 31 is attached.
Further, an oil passage 34 communicating with the oil pump 27 is formed in the chain case 8 as shown in FIG. The oil passage 34 is formed in the chain case 8 so as to extend upward from the lower oil pump 27 through the oil filter 28.

As shown in FIGS. 6 to 8, between the inner wall 26 of the chain case 8 and the end wall 35 of the cylinder head 3, a block 36 whose both ends are joined to the chain case 8 and the cylinder head 3 is disposed. Is done. Therefore, as shown in FIGS. 7 and 8, the block 36 includes a cylinder head side joint surface 37 that is a joint surface to the cylinder head 3 side and a chain case side joint surface that is a joint surface to the chain case 8 side. 38.
As shown in FIG. 1, a supply oil passage 39 that connects the oil passage 34 to the intake hydraulic control valve 32 and the exhaust hydraulic control valve 33 is formed in the block 36. The supply oil passage 39 includes a central supply oil passage 40, an intake-side supply oil passage 41 that branches off from the central supply oil passage 40 and communicates with the intake hydraulic control valve 32 and an exhaust hydraulic control valve 33. And an exhaust side supply oil passage 42 communicating with the exhaust side.

A lubricating oil passage 43 for supplying oil to the bearing portions of the intake camshaft 18 and the exhaust camshaft 19 is provided in the central bearing portion 22 and the block 36 as the bearing portion of the camshaft formed in the cylinder head 3. . The lubricating oil passage 43 communicates with the main lubricating oil passage 44 formed in the central bearing portion 22 in the vertical direction, and as a part of the lubricating oil passage 43. It comprises a block-side lubricating oil passage 45 formed in the block 36.
As shown in FIG. 2, the block-side lubricating oil passage 45 is linearly formed so as to penetrate the block 36 and communicates with a supply oil passage 39 formed in the block 36.
As shown in FIG. 2, a throttle portion 46 is provided at an intermediate portion of the block-side lubricating oil passage 45. A throttle valve 47 is disposed in the throttle unit 46.
Further, as shown in FIG. 1, the central bearing portion 22 as the bearing portion of the camshaft formed in the cylinder head 3 is connected to the intake side hydraulic actuator 30 adjacent to the main lubricating oil passage 44. A first oil passage 48 and an exhaust-side first oil passage 49 communicating with the exhaust hydraulic actuator 31 are formed. An intake-side second oil passage 50 communicating with the intake hydraulic actuator 30 is formed in the first intake bearing portion 20A of the intake camshaft 18 formed in the cylinder head 3. Further, an exhaust-side second oil passage 51 communicating with the exhaust hydraulic actuator 31 is formed in the first exhaust bearing portion 21 </ b> A of the exhaust camshaft 19 formed in the cylinder head 3.
The block 36 includes a block intake side first oil passage 52 that communicates with the intake side first oil passage 48, a block exhaust side first oil passage 53 that communicates with the exhaust side first oil passage 49, and an intake side first oil passage 52. A block intake side second oil passage 54 communicating with the two oil passages 50 and a block exhaust side second oil passage 55 communicating with the exhaust side second oil passage 51 are formed.

With this structure, the throttle portion 46 can be disposed closer to the oil pump 27 than when the throttle portion 46 is provided in the cylinder head 3. Further, a supply oil passage 39 and a block-side lubrication oil passage 45 which is a part of the lubrication oil passage 43 are provided in the small block 36, and a throttle portion is provided in the block-side lubrication oil passage 45 in the block 36. By providing 46, the intake hydraulic control valve 32 / exhaust hydraulic control valve 33 and the throttle 46 can be arranged close to each other, and the intake hydraulic control valve 32 / exhaust hydraulic control valve 33 and the throttle 46 can be placed between them. The length of the oil passage 45 for block side lubrication to the supply oil passage 39 and the throttle 46 formed can be shortened.
As a result, after the oil reaches the throttle 46 immediately after the engine 1 is started, the oil pressure in the supply oil passage 39 located upstream from the throttle 46 is instantaneously increased, and the oil is supplied to the intake hydraulic control valve 32. The oil can be supplied to the exhaust hydraulic control valve 33, and oil can flow stably to the intake hydraulic actuator 30 and the exhaust hydraulic actuator 31 even immediately after the engine 1 is started.
Further, by providing the throttle portion 46 in the middle portion of the block lubrication oil passage 45 formed in the block 36, the oil flowing in from the chain case 8 side contains foreign matters such as impurities and metal fragments, and the chain case Even if a foreign object is clogged in the narrowed portion 46 facing the 8 side, the foreign material can be easily removed from the narrowed portion 46 simply by removing the block 36 from the chain case 8.
Furthermore, since the block-side lubricating oil passage 45 is linearly formed so as to penetrate the block 36, foreign substances and the like can be easily removed from the throttle portion 46, and the block-side lubricating oil in the block 36 can be removed. Maintenance such as cleaning of the passage 45 can be improved.
Furthermore, tapping for attaching the throttle valve 46 is not necessary, and the block side lubricating oil passage 45 can be easily processed.

As shown in FIG. 2, the throttle portion 46 is integrally formed in the block-side lubricating oil passage 45 and is disposed at a position close to the chain case-side joining surface 38 of the block 36. Further, a tapered portion 56 is formed in the block-side lubricating oil passage 45 so that the cross-sectional area of the block-side lubricating oil passage 45 gradually increases from the throttle portion 46 toward the end wall 35 of the cylinder head 3.
With such a structure, the drawn portion 46 can be formed by die cutting without providing a new part, and the workability can be improved. Further, since the throttle portion 46 is disposed at a position close to the chain case side joining surface 38 of the block 36, the distance from the throttle portion 46 to the end wall 35 of the cylinder head 3 can be extended.
Therefore, the passage cross-sectional area of the block-side lubricating oil passage 45 can be gradually increased so that a sudden change in the passage cross-sectional area from the throttle portion 46 to the end wall 35 of the cylinder head 3 does not occur. The part 56 can be formed.
As a result, the oil that has passed through the throttle portion 46 can stably supply the oil to the cylinder head 3 without causing abrupt hydraulic pressure fluctuation, and can prevent the generation of noise due to the hydraulic pressure fluctuation.

FIG. 9 shows a modification of the present invention.
In this modified example, the throttle valve 47 constituting the throttle portion 46 is provided separately from the block 36.
With such a structure, the throttle valve 47 can be easily replaced only by removing the chain case 8 without removing the in-vehicle components (for example, the air cleaner 11) and the cylinder head cover 4 disposed on the upper portion of the engine 1, thereby The operator's replacement workability and maintainability can be improved.

  The oil passage structure of the engine with a variable valve timing mechanism according to the present invention can be applied to various engines.

DESCRIPTION OF SYMBOLS 1 Engine 2 Cylinder block 3 Cylinder head 4 Cylinder head cover 6 Crankshaft 8 Chain case 18 Intake camshaft 19 Exhaust camshaft 22 Center bearing part 25 Timing chain 26 Chain case inner wall 27 Oil pump 28 Oil filter 29 Variable valve timing mechanism 30 Intake hydraulic actuator 31 Exhaust hydraulic actuator 32 Intake hydraulic control valve 33 Exhaust hydraulic control valve 34 Oil passage 35 End wall of cylinder head 36 Block 37 Cylinder head side joint surface of block 38 Chain case side joint surface of block 39 Supply Oil passage 43 Oil passage for lubrication 44 Oil passage for main lubrication 45 Oil passage for lubrication on the block side 46 Throttle part 47 Throttle valve 56 Taper part

Claims (3)

  A hydraulic actuator that changes the valve timing is attached to the end of the camshaft supported by the cylinder head of the engine, a hydraulic control valve is attached to the chain case that covers the timing chain, and an oil passage that communicates with the oil pump in the chain case The oil passage and the hydraulic control valve are connected by a supply oil passage, and a lubricating oil passage for supplying oil to a bearing portion of the camshaft formed in the cylinder head is provided as the supply oil passage. An oil passage structure of an engine with a variable valve timing mechanism, wherein both ends of the chain case are between the inner wall of the chain case and the end wall of the cylinder head. And a block to be joined to the cylinder head, and the block includes the block A supply oil passage and a part of the lubricating oil passage are formed, a part of the lubricating oil passage is formed so as to pass through the block linearly, and an intermediate part of the part of the lubricating oil passage An oil passage structure for an engine with a variable valve timing mechanism, wherein the throttle part is provided in a part.   The throttle portion is integrally provided in the lubricating oil passage and is disposed at a position close to a joint surface of the block to the chain case side, and the lubricating oil passage extends from the throttle portion to the end of the cylinder head. 2. The oil passage structure for an engine with a variable valve timing mechanism according to claim 1, wherein a taper portion in which a passage cross-sectional area of the lubricating oil passage gradually increases toward a wall is formed.   The oil passage structure for an engine with a variable valve timing mechanism according to claim 1, wherein the throttle portion is provided separately from the block.

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