JP3355356B2 - Oil passage structure of internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil passage structure for an internal combustion engine that supplies oil discharged from an oil pump to a variable valve timing device via an oil control valve.

[0002]

2. Description of the Related Art In a four-stroke engine, for example, a technique of changing the opening / closing timing of a valve according to the engine speed in order to increase the middle / low speed torque is known. VVT) has been proposed and is already in practical use.

[0003] By the way, there is a VVT whose operation is controlled by hydraulic pressure. In this type of VVT,
The oil discharged from the oil pump passes through an oil control valve (hereinafter abbreviated as OCV) to the VVT.
The oil is supplied from the OCV to the VVT through two oil passages for advance and retard.

[0004]

By the way, conventionally, OC
Oil from the V is transferred from the cam journal to the V via the cam shaft.
The configuration for supplying to the VT has been adopted, but in this configuration, it is necessary to form two oil passages for advance and retard by avoiding the cam cap bolt hole, and realize a compact oil passage structure. In addition to the above, there is a problem that at least one cam cap bolt has to be disposed outside and the size of the cam cap bolt needs to be functionally increased, so that the cam cap bolt cannot be shared.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a compact layout of an oil passage in a small space without changing the position or size of a cam cap bolt. An object of the present invention is to provide an oil passage structure for an internal combustion engine.

[0006]

To achieve the above object, the present invention provides an oil passage structure for an internal combustion engine that supplies oil discharged from an oil pump to a variable valve timing device via an oil control valve.
At least a part of a portion formed in a cylinder head of an oil passage from the oil control valve to the variable valve timing device is arranged outside a cam cap bolt, and the cylinder head is provided with
First oil grooves communicating with the oil passage on the second head side
To avoid the cam cap bolt, and
Connected to the first oil groove
A second oil groove is formed to communicate with each second oil groove.
Oil passage formed in the camshaft and passed through the oil passage
The oil is supplied to the variable valve timing device.
It is characterized in that form.

[0007]

Therefore, according to the present invention, at least a part of a portion (cylinder head side oil passage) formed in the cylinder head of the oil passage from the oil control valve to the variable valve timing device is arranged outside the cam cap bolt. Therefore, the oil passage can be compactly laid out in a small space without changing the position and size of the cam cap bolt.

According to the present invention, the oil from the oil control valve passes through the first and second oil grooves formed in the cam cap via the oil passage on the cylinder head side and the oil passage formed on the cam shaft. Although the oil is supplied to the variable valve timing device, the oil is guided from the first oil groove formed on the mating surface of the cylinder head of the cam cap to the cam journal portion (that is, the second oil groove) of the cam cap. The oil passage from the oil control valve to the cam journal can be compactly laid out in a small space without changing the position or size of the oil control valve.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a plan view of a cylinder head of an internal combustion engine having an oil passage structure according to the present invention, FIG. 2 is a side view of the cylinder head (a view in the direction of arrow A in FIG. 1), and FIG.
Is a front side front view of the cylinder head (viewed from arrow B in FIG. 1).
4 is a front view of the cylinder head on the rear side (a view in the direction of arrow C in FIG. 1), FIG. 5 is a cross-sectional view taken along the line DD of FIG. 1, FIG. 6 is a front view of the cam cap, 7 is a bottom view of the cam cap, FIG. 8 is a sectional view taken along line EE of FIG. 6, and FIG.
FIG. 10 is a block diagram schematically showing an oil passage structure according to the present invention.

The internal combustion engine according to the present embodiment is a four-stroke in-line four-cylinder engine, and its cylinder head 1 has an intake port 2 and an exhaust port 3 for each cylinder as shown in FIG. Each of the intake ports 2 and the exhaust ports 3 is open to a combustion recess 4 formed on the bottom surface of the cylinder head 1 (joining surface with a cylinder block (not shown)). The valve is opened and closed at an appropriate timing by a valve and an exhaust valve (both not shown). As shown in FIGS. 2 and 5,
An injector mounting hole 5 communicating with the intake port 2 of each cylinder is formed in an upper portion on the intake side of the cylinder head 1, and an injector (not shown) for fuel injection is screwed into the injector mounting hole 5.

Also, as shown in FIG.
On the upper surface of the cylinder, four lifter holes 6 and 7 into which the respective valve lifters of the intake valve and the exhaust valve are fitted are formed for each cylinder, that is, four in total.

Further, as shown in FIGS. 1 and 5, in the center of the cylinder head 1 in the width direction, a plug hole 8 opening to the combustion recess 4 is formed for each cylinder. Is screwed with a spark plug (not shown). In FIG. 1, reference numeral 9 denotes a sand hole formed in the upper surface of the cylinder head 1, and 10 denotes a bolt hole through which a head bolt for attaching the cylinder head 1 to a cylinder block (not shown) is inserted.

By the way, the intake valve and the exhaust valve are arranged on the intake side and the exhaust side of the upper part of the cylinder head 1 so as to be rotatable in the length direction (left and right direction in FIG. 1) (FIG. 6 and FIG. 10), and are driven by an exhaust cam shaft (not shown).

Thus, in the engine according to the present embodiment, a VVT (variable valve timing device) 12 (see FIG. 10) is provided at the front end of the intake camshaft 11, as shown in FIG. Sprocket 1 attached to the VVT 12 and the front end of the exhaust camshaft.
An endless chain 15 is wound between the sprocket 3 and an end of a crankshaft (not shown).

Therefore, when the engine is driven, the crankshaft rotates through the sprocket 14, the chain 15, the cam sprocket 13, and the VVT 12 to rotate the intake camshaft 1
1 and the exhaust camshaft are respectively driven and driven to rotate. The intake valve and the exhaust valve are respectively opened and closed at appropriate timing to perform required gas exchange in the cylinder of each cylinder. Thus, the VVT 12 is controlled by hydraulic pressure to advance or retard the opening / closing timing of the intake valve, thereby increasing, for example, low / medium speed torque.

The intake camshaft 11 has a total of four cam journals 16 (see FIGS. 1 and 5) formed on the upper surface of the cylinder head 1 for each cylinder and a front end (left side in FIG. 1). It is rotatably supported by one wide cam journal part 17 formed in the part. Each of the cam journal portions 16 and 17 has a cam cap bolt hole 18 formed on both sides thereof.
6, a cam cap (not shown) is attached, and the other cam journal portion 17 is similarly attached with a cam cap 20 shown in FIGS. As shown in FIG. 1, the cam journal 17 has two oil grooves 21 and
2 are formed.

Similarly, an exhaust camshaft (not shown) is formed on the upper surface of the cylinder head 1 at a total of four cam journals 23 (see FIGS. 1 to 5) formed for each cylinder and at the front end. A single wide cam journal portion 24 is rotatably supported. A cam cap (not shown) is connected to each of the cam journal portions 23 and 24 by a cam cap bolt (not shown) screwed into a cam cap bolt hole 25. Have been.

Next, the oil passage structure according to the present invention will be described.

In the engine according to the present embodiment,
As shown in FIG. 2, oil collected in an oil pan 26 provided at the lower part of the engine is pressurized by an oil pump 27 and supplied to various parts.
The VT 12 is driven and controlled, and each sliding portion is lubricated.

That is, the engine according to this embodiment includes:
A control oil passage 30 for supplying oil discharged from the oil pump 27 and passing through the oil filter 28 to the VVT 12 through an OCV (oil control valve) 29 shown in FIG. 3 and a cam journal section of the cylinder head 1 A lubricating oil passage 31 is provided to supply the lubricating oil passage 31 to the lubricating oil passages 16, 17, 23, and 24. As shown in FIG. ).

Here, the structure of the control oil passage 30 and the lubrication oil passage 31 will be described.

As shown in FIG. 2, oil passages 33 and 34 are branched from a main oil gallery 32 formed in a cylinder block (not shown).
Numeral 34 denotes an oil passage that rises upward in the cylinder block and is formed vertically below the cylinder head 1.
36 respectively. The oil passage 37 derived from the oil filter 28 is connected to the oil passage 3.
The main oil gallery 32 is connected to the main oil gallery 32 at points 3 to a (points from the oil passages 34 to b), and a <b in the present embodiment as shown in the figure.

Incidentally, in the cylinder head 1,
The oil passage 35 is connected to an oil passage 38 formed horizontally toward the front side.
Reference numeral 8 is connected to an oil filter 39 which is removably mounted on the front end of the cylinder head 1. As shown in FIGS. 1 and 3, the oil filter 39 is connected to an oil passage 40 that is formed horizontally outward (toward the front in FIG. 1).
The oil passage 41 is formed so as to rise vertically upward (see FIGS. 2 and 3).

On the other hand, as shown in FIG. 3, the mounting seat 42 protrudes from the front end face of the cylinder head 1 on the intake side.
The OCV 29 is mounted on the cylinder head 1 (see FIG. 1), and an oil passage 43 connected to the OCV 29 is formed horizontally above the cylinder head 1.
The oil passage 41 is connected to 3. And
From this oil passage 43, an advance oil passage 44 and a retard oil passage 45 are erected obliquely upward (see FIGS. 2 and 3).
As shown in FIG. 1, the cam journal portion 17 is open to the mating surface with the cam cap 20 and outside the outer cam cap bolt hole 18 (on the front side in FIG. 1). still,
As shown in FIG. 1, the oil passages 41, 44, 45 are formed outside the outer cam cap bolt holes 18.

On the other hand, as shown in FIGS. 6 to 9, the cam cap 20 is formed with journal portions 46 for receiving the upper half of the intake camshaft 11, and cam cap bolt holes are formed on both sides thereof. 47 penetrates in the vertical direction.
Further, two oil grooves 48 and 49 for advance and retard are formed along the journal portion 46.

The cam cap bolt hole 47 is formed on the bottom surface of the cam cap 20 (the mating surface with the cylinder head 1).
The two oil grooves 50 and 51 for advance and retard are formed to avoid the oil groove.
8 and 49 respectively. In the present embodiment, since the cam cap 20 is formed by die casting, the oil grooves 48 to 51 are formed at the same time as the forming, and it is not necessary to form them by post-processing (machining). Costs can be reduced.

As shown in FIG. 6, the intake camshaft 11 has two oil passages 52, 53 for advance and retard.
Are formed in parallel to each other in the axial direction, and the oil passages 52 and 53 are formed in oil passages 54 and 55 formed in the radial direction.
And communicates with the oil grooves 21, 22 and 48, 49 via the VVT 12 and is connected to advance and retard oil chambers S1, S2 of the VVT 12 shown in FIG.

The configuration of the control oil passage 30 described above is schematically shown in a block diagram shown in FIG.

Next, the structure of the lubricating oil passage 31 in the cylinder head 1 will be described.

As shown in FIGS. 1 and 2, the oil passage 36 formed vertically below the cylinder head 1 is formed horizontally toward the rear side (to the right in FIGS. 1 and 2). The oil passage 56 is connected to an oil passage 58 formed perpendicularly to an oil passage seat 57 projecting from the rear end surface of the cylinder head 1.
It is connected to the.

On the other hand, as shown in FIGS. 1 and 4, an oil passage 59 is formed horizontally above the oil passage seat 57, and the oil passage 58 is connected to the oil passage 59. From the oil passage 59, two oil passages 60, 61 are formed toward the front side (left side in FIG. 1) toward the rear side (rightmost end in FIG. 1) of the cam journal portions 16, 2, respectively.
3 extends horizontally to the side. As shown in FIG. 5, small-diameter oil passages 62 and 63 are formed diagonally upward from the oil passages 60 and 61 toward the outside.
6 and 23 respectively.

Incidentally, the four-cycle engine according to the present embodiment is a water-cooled engine, and as shown in FIG.
A water jacket 64 is formed in the cylinder head 1, and cooling water supplied from the cylinder block side through the cooling water passage 65 and other cooling water passages cools the cylinder head 1 in a process of flowing through the water jacket 64. As shown in FIG. 4, the cooling water is discharged from a cooling water outlet 66 which is opened at the rear side (the side where the lubricating oil passage 31 is provided) of the cylinder head 1 and guided to a radiator (not shown).

When the engine is driven and the oil pump 27 is driven by a part of the engine power, the oil discharged from the oil pump 27 passes through the oil filter 28 and is purified. The oil is supplied to the VVT 12 through a control oil passage 30 to be used for drive control of the VVT 12, and is guided to the cam journals 16 and 23 through a lubrication oil passage 31, and the intake camshaft 11 and an exhaust cam (not shown) Used for shaft lubrication.

That is, the oil flowing through the control oil passage 30 is supplied to the oil passages 35 and 3 in the cylinder head 1.
8. The oil is guided to the OCV 29 through the oil filter 39 and the oil passages 40 and 41, and flows from the OCV 29 through the oil passages 44 and 45 for advancing and retarding to the cam cap 20. In the cam cap 20, FIG.
As shown by arrows in FIG. 7, oil flows through oil grooves 50 and 51 for advancing and retarding, and oil flows from oil grooves 48 and 49 formed in the journal 46 to the intake camshaft 1.
The oil is guided to oil passages 52 and 53 for advance and retard through oil passages 54 and 55 formed in the VVT 1 and supplied to oil chambers S1 and S2 of the VVT 12 through the oil passages 52 and 53, respectively. You.

The OCV 29 controls oil in accordance with, for example, the engine speed, so that the oil chambers S1, S
2, the opening and closing timing of the intake valve is advanced or retarded, respectively, and thereby, for example, middle and low speed torques are increased.

On the other hand, Oite oil passage 36 and 56 into the oil cylinder head 1 through the lubricating oil passage 31,
A part of the oil is guided to an oil passage 59 through an oil passage 60, a part of which is guided to a cam journal portion 16 on the intake side through an oil passage 60, and is used for lubrication of the intake camshaft 11. It is guided to the cam journal portion 23 on the side to be used for lubrication of the exhaust camshaft. An oil passage (not shown) is formed in each of the intake camshaft 11 and the exhaust camshaft in the axial direction.
The oil supplied to 23 is supplied to the other cam journals 16 and 23 through those oil passages.

As described above, in the present embodiment, a part (oil passages 41, 44, 45) formed in the cylinder head 1 of the control oil passage 30 is replaced with the cam cap bolt 18
The oil passage 4 in a small space without changing the position and size of the cam cap bolt.
1, 44 and 45 can be laid out compactly.

The oil from the OCV 29 is supplied to the VVT 12 through oil passages 44 and 45, oil grooves 48 to 51 formed in the cam cap 20 and oil passages 52 and 53 formed in the intake camshaft 11. However, the oil flows from the oil grooves 50, 51 formed on the bottom surface of the cam cap 20 (the mating surface with the cylinder head 1) to the cam journal portion 46 of the cam cap 20 (that is, the oil grooves 48,
49), the oil passages (oil passages 44 and 45 and oil grooves 48 to 5) from the OCV 29 to the cam journal 46 without changing the position and size of the cam cap bolt for mounting the cam cap 20.
1) can be laid out compactly in a small space. Further, since the position and size of the cam cap bolt for attaching the cam cap 20 can be made the same as those of the other cam cap bolts (not shown), all the cam cap bolts can be shared, and the cost can be reduced. Down can be planned.

Incidentally, the above is particularly a water-cooled four-cycle series
Although the case where the present invention is applied to a cylinder engine has been described, the present invention is applicable to any other type of four-stroke engine.

[0042]

As is apparent from the above description, according to the present invention, at least one of the portions (cylinder head side oil passages) formed in the cylinder head of the oil passage extending from the oil control valve to the variable valve timing device. Since the portion is arranged outside the cam cap bolt, an effect that the oil passage can be compactly laid out in a small space without changing the position and size of the cam cap bolt is obtained.

According to the present invention, the oil from the oil control valve passes through the first and second oil grooves formed in the cam cap via the oil passage on the cylinder head side and the oil passage formed on the cam shaft. Although the oil is supplied to the variable valve timing device, the oil is guided from the first oil groove formed on the mating surface of the cylinder head of the cam cap to the cam journal portion (that is, the second oil groove) of the cam cap. The oil passage from the oil control valve to the cam journal can be compactly laid out in a small space without changing the position and size of the oil control valve.

[Brief description of the drawings]

FIG. 1 is a plan view of a cylinder head of an internal combustion engine having an oil passage structure according to the present invention.

FIG. 2 is a side view of the cylinder head of the internal combustion engine having the oil passage structure according to the present invention (a view in the direction of arrow A in FIG. 1).

FIG. 3 is a front side front view (a view in the direction of arrow B in FIG. 1) of a cylinder head of the internal combustion engine having the oil passage structure according to the present invention.

4 is a rear side front view (a view in the direction of arrow C in FIG. 1) of a cylinder head of the internal combustion engine having the oil passage structure according to the present invention.

FIG. 5 is a sectional view taken along line DD of FIG. 1;

FIG. 6 is a front view of the cam cap.

FIG. 7 is a bottom view of the cam cap.

FIG. 8 is a sectional view taken along line EE of FIG. 6;

FIG. 9 is a sectional view taken along line FF of FIG. 6;

FIG. 10 is a block diagram schematically showing an oil passage structure according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 cylinder head 11 camshaft 12 variable valve timing device (VVT) 20 cam cap 27 oil pump 29 oil control valve (OCV) 35, 38, 40, 41, 43 to 45 oil passages 48, 49 oil grooves (second oil grooves) ) 50,51 Oil groove (first oil groove) 52,53 Oil passage

Claims (1)

(57) [Claims] In an oil passage structure of an internal combustion engine for supplying oil discharged from an oil pump to a variable valve timing device via an oil control valve, a cylinder head of an oil passage from the oil control valve to the variable valve timing device is provided. At least a part of the portion to be formed is disposed outside the cam cap bolt, and the cylinder cap mating surface of the cam cap is provided with the above-mentioned series.
First oil grooves communicating with the oil passage on the second head side
To avoid the cam cap bolt, and
Connected to the first oil groove
A second oil groove is formed to communicate with each second oil groove.
Oil passage formed in the camshaft and passed through the oil passage
The oil is supplied to the variable valve timing device.
An oil passage structure for an internal combustion engine, characterized in that it is formed .