JP3865021B2 - Engine oil passage structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine oil passage structure applied to an automobile engine equipped with a VVT mechanism.
[0002]
[Prior art]
A VVT (variable valve timing) mechanism is known as one that changes the valve timing and valve lift amount in accordance with the state of the engine load and improves the output and stability of the engine. Since this mechanism is driven by an actuator that operates with oil pressure, an oil control valve (hereinafter referred to as OCV) that switches the flow of oil to the actuator is required. Oil supply to the OCV is performed by an oil supply passage (hereinafter simply referred to as an oil passage) connected to an oil pump that sucks oil from an oil pan.
[0003]
A three-cylinder engine having a VVT mechanism will be described with reference to FIGS. In the engine 1, pistons (not shown) are fitted into three cylinder bores 3 provided in the cylinder block 2, and a crankshaft 4 (only a part of which is shown) is rotated by a connecting rod. The front part of the cylinder block 2 is covered with a chain cover 5. An oil pan 6 is provided at the lower part of the cylinder block 2, and a cylinder head 7 and a cylinder head cover 8 are provided at the upper part.
[0004]
Two camshafts 9 (only one is shown) for intake and exhaust are rotatably provided in the cylinder head 7, and cams 10 arranged at predetermined intervals abut against the valve lifter 11. The valve 12 is driven to open and close. An actuator 13 is provided in the vicinity of the end of the camshaft 9, and the opening / closing timing of the valve 12 is changed by the pressure of oil supplied from the OCV 14 provided below the actuator 13.
[0005]
An oil pump 15 is provided in front of the crankshaft 4 and is driven by the crankshaft 4. A suction pipe 17 having an oil strainer 16 at the tip is connected to the suction side of the oil pump 15 toward the inside of the oil pan 6 so that the oil in the oil pan 6 is sucked.
[0006]
The discharge side of the oil pump 15 is divided into a normal lubrication system and one that goes to the OCV 14, but the system that goes to the OCV 14 is connected to a connection 19 at the end of the cylinder block 2 by an oil passage 18, The lower end of the passage 20 is connected. The oil passage 20 extends upward along the cylinder block 2 and is connected to a connection portion 21 provided in the cylinder block 2. The connection portion 21 and the OCV 14 are connected by an oil passage 22 provided in the cylinder block 2.
[0007]
In the conventional engine 1 having such a configuration, when the crankshaft 4 rotates and the oil pump 15 operates, a part of the oil flows in a normal route and a part flows in the OCV 14. When receiving a signal from a control circuit (not shown), the OCV 14 opens the valve to drive the actuator 13, changes the rotational direction position of the cam 9 relative to the camshaft 8, and changes the opening / closing timing of the valve 12.
[0008]
[Problems to be solved by the invention]
In the structure as described above, a pipe is often used as the oil passage 20. However, when the oil passage 20 is installed outside the engine 1, a large layout is required to avoid interference with auxiliary equipment. It becomes a restriction. Further, when oil leaks from the oil passage 20 formed of a pipe or a portion where the oil passage 20 is connected, there is a possibility that the oil flows out to the outside of the engine. In the case of the above structure, there is a problem that the number of parts such as pipes constituting the oil passage 20 increases.
[0009]
On the other hand, as another problem, since the chain cover 5 has a plate shape, the vibration is large and is one of the causes of engine noise. For this reason, ribs are provided on the rear surface (inner surface when assembled to the cylinder block 2) to increase rigidity and suppress vibration. However, if the ribs are provided in this way, it naturally increases the weight, the cost, and the cost for manufacturing the mold.
[0010]
The present invention has been made in view of this point, and even if there is a problem such as the above-mentioned cost increase, a rib is provided to improve the strength, and an oil passage is formed integrally therewith, like the conventional one. It is an object of the present invention to provide a structure that does not require an oil passage to be routed outside the engine. As a prior art in which an oil passage is provided in the chain cover, there is one disclosed in Japanese Utility Model Publication No. 5-6112. However, the present invention is an oil passage structure for an engine having a configuration totally different from that of the present invention. Is to provide.
[0011]
[Means for Solving the Problems]
As a means for solving the above-mentioned problems, the invention described in claim 1 is characterized in that the camshaft is disposed in the cylinder head, and the actuator operated by the oil pressure is connected to the end of the cylinder head in the longitudinal direction . and disposed at an end of the cam shaft so as to protrude from the parts, in the engine for a motor vehicle was to change the valve timing by said actuator, a cylinder block disposed on the lower surface of the cylinder head, said cylinder head the one attaching the chain cover for covering the lower portion of the actuator and the cylinder block, said cylinder head cover covering an upper portion of the actuator attached to the upper end of the upper surface and the chain cover of the cylinder head, said in response to the actuator cylinder the bulging portion that bulges in the longitudinal direction of the head, the silicon An oil that is formed on the head cover and the chain cover and switches the flow of oil to the actuator below the bulging portion of the chain cover disposed below the joint surface between the cylinder head cover and the chain cover. It arranged a control valve, an oil passage for communicating the downstream side of the oil control valve and the oil filter, characterized in that formed on the chain cover integrally on the inside of the chain cover.
[0012]
The invention described in claim 2 is characterized in that, in the invention described in claim 1 , the oil flowing out from the oil control valve flows into the actuator via an oil passage formed in the cylinder head. To do.
[0013]
The invention described in claim 3 is the invention described in claim 1 or 2 , wherein the chain cover is formed by casting, and an oil passage connecting the oil control valve and a downstream side of the oil filter is provided, It is characterized in that both ends of the pipe placed on the inner surface of the chain cover are fixed by welding.
[0014]
The invention described in claim 4 is the invention described in claim 1 or 2 , wherein the chain cover is formed by casting, and an oil passage connecting the oil control valve and the downstream side of the oil filter is provided. It is characterized by the fact that it is formed of a partially cast pipe.
[0015]
If it is set as the structure of Claims 1-4 , some oil discharged from the oil pump will flow to an oil control valve (OCV) through the oil path provided in the inside of a chain cover. Further, in this case, if the configuration described in claims 3 and 4 is adopted, the oil that has passed through the oil filter is supplied to the cylinder head and the oil control valve, so that the oil is sent to the cylinder head without passing through the oil filter. Unlike what is described in the above-mentioned publication, there is no influence of foreign matter contained in the oil.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIG. 1 shows the inner surface of the chain cover 5, which is a surface provided with ribs 23 for reinforcement and vibration prevention. As shown in the drawing, a plurality of ribs 23 are provided vertically and horizontally and obliquely, and a sufficient strength can be obtained even when the thickness of the chain cover 5 is reduced, and vibration is not generated.
[0017]
The oil passage 24 according to the present invention is formed by welding both ends of a pipe placed on the inner surface of the chain cover 5, the lower end is connected to the sub gallery 25, and the upper end is the OCV 14 (see FIG. 5). Connected to the inner surface.
[0018]
FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 and shows the positional relationship between the main gallery 26 and the sub gallery 25. As shown in the figure, the main gallery 26 and the sub gallery 25 are both bent in an L shape, the right end of the main gallery 26 communicates with the oil pump 15 (see FIG. 5), and the right end of the sub gallery 25 is the oil passage. 24 to be connected to the OCV 14. The left end of the main gallery 26 is connected to an oil filter 28 (see FIG. 3), and the oil cooler 27 (see FIG. 3) is connected to the left end of the sub gallery 25.
[0019]
FIG. 3 is a system diagram illustrating the flow of oil according to the present invention. The oil pump 15 sucks the oil in the oil pan 6 through the strainer 16 and flows it from the oil cooler 27 to the oil filter 28 by the main gallery 26. The oil that has exited the oil filter 28 flows again to the OCV 14 through the oil passage 24 via the oil cooler 27 by the sub gallery 25.
[0020]
The outlet of the sub gallery 25 is branched into a second oil passage 29 different from the oil passage 24 so that oil is sent to each journal of the cylinder head 7 and the cylinder block 2. The circuit configuration may be provided without providing the oil cooler 27.
[0021]
In the embodiment described above, the oil passage 24 is formed by fixing both ends of the pipe placed on the inner surface of the chain cover 5 by welding, but instead, it is formed by casting the pipe into the chain cover 5. May be.
[0022]
【The invention's effect】
According to the first and second aspects of the present invention, an oil passage that communicates between the oil control valve and the downstream side of the oil filter is provided in the engine (inside the chain cover). The degree of freedom in layout of auxiliary equipment arranged around is improved. Even if oil leaks from the oil passage, only the VVT mechanism needs to be disturbed.
In addition, the oil control valve is installed in the chain cover instead of the cam housing and cylinder head cover by making effective use of the space below the bulging part of the chain cover located below the joint surface between the cylinder head cover and the chain cover. The oil passage that communicates with the oil control valve disposed on the chain cover can be formed integrally with the chain cover inside the chain cover independently of the oil passage that supplies oil to the valve operating mechanism. It becomes possible.
Furthermore, since oil that has passed through an oil filter is supplied to the oil control valve, the oil control valve can be used even if foreign matter is mixed into the oil, as compared to the one described in the above-mentioned publication that does not pass through the oil filter. Does not affect.
[0023]
Furthermore, the number of parts and the number of assembling steps can be greatly reduced as compared with the case where an oil passage connecting the oil control valve and the downstream side of the oil filter is provided outside the cylinder block. And since the oil passage toward the OCV also has the function of a rib, the reinforcement effect of the chain cover is enhanced, vibration and noise generation can be suppressed, and the number of ribs for reinforcement can be reduced. And cost reduction.
[0024]
According to the invention described in claim 3 , since the oil passage is formed only by welding both ends of the pipe placed on the inner surface of the chain cover, the number of manufacturing steps can be significantly reduced. According to the invention described in claim 4 , since the pipe is only cast when the chain cover is manufactured by casting, a non-linear shape can be freely obtained as the shape of the oil passage. .
[Brief description of the drawings]
FIG. 1 is a rear view of a chain cover showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a portion along the line AA in FIG.
FIG. 3 is a system diagram illustrating the flow of oil in the engine according to the present invention.
FIG. 4 is a longitudinal sectional view showing a main part of the internal structure of the engine.
5 is a front view of FIG. 4 as viewed from the left. FIG.
[Explanation of symbols]
1 Engine 5 Chain cover 7 Cylinder head 13 Actuator 14 OCV
24 Oil passage 28 Oil filter 29 Second oil passage

Claims (4)

A cam shaft disposed in the cylinder head, an actuator for operating with oil pressure, and disposed at an end of the cam shaft so as to protrude from the longitudinal ends of the cylinder head, changing the valve timing by said actuator In the automotive engine
A cylinder block is disposed on the lower surface of the cylinder head, and a chain cover that covers a lower portion of the actuator is attached to the cylinder head and the cylinder block, while an upper surface of the cylinder head and an upper end of the chain cover are attached to the actuator. Install the cylinder head cover covering an upper portion, a bulging portion that bulges in the longitudinal direction of the cylinder head in response to the actuator, the formed in the cylinder head cover and said chain cover, and the cylinder head cover and the chain cover An oil control valve for switching the flow of oil to the actuator is disposed below the bulging portion of the chain cover disposed below the joint surface of the oil pipe, and the oil control valve and the downstream side of the oil filter are connected to each other. Oil communication to contact The oil passage structure of which is characterized in that formed in the chain cover and integrally in the interior of the chain cover. 2. The oil passage structure for an engine according to claim 1 , wherein the oil flowing out from the oil control valve flows into the actuator through an oil passage formed in the cylinder head. The chain cover is formed by casting, and an oil passage connecting the oil control valve and the downstream side of the oil filter is formed by fixing both ends of a pipe placed on the inner surface of the chain cover by welding. An oil passage structure for an engine according to claim 1 or 2 . The said chain cover is formed by casting, The oil passage which connects the said oil control valve and the downstream of an oil filter was formed with the pipe cast in the part, The Claim 1 or 2 characterized by the above-mentioned. Engine oil passage structure.

Images