JPH0730890Y2 - Oil supply device for cylinder head of OHC type internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to an oil supply device for a cylinder head of an OHC type internal combustion engine, and more particularly to an oil supply device for smoothly supplying oil to a camshaft bearing device and a rocker arm support device. Regarding the device.

<Prior Art> As a conventional cylinder head of an OHC type internal combustion engine, there is, for example, one shown in FIGS.
60-79141 gazette etc.).

That is, two intake valves 1a and 1b and two exhaust valves 2a and 2b are provided for each cylinder, and a pair of camshafts 3 and 4 above them are provided with intake cams 5 and exhaust valves, respectively. And a cam 6 are provided.

Further, above the cylinder head H, a plug insertion cylinder 8 of the ignition plug 7 and suction and absorption members formed on both sides of the plug insertion cylinder 8 are provided.
Support devices 11 and 12, such as hydraulic lifters, which serve as swing fulcrums of the exhaust rocker arms 9 and 10, and both sides of the plug insertion cylinder 8 are bored along the camshafts 3 and 4 to form the pair of cams. Bearing devices 13 and 14 of the shafts 3 and 4 and oil supply passages 15 and 16 for supplying oil to the support devices 11 and 12 are provided.

Thus, the spark plug 7, the supporting devices 11 and 12, and the oil supply passages 15 and 16 are centrally equipped, and the valve operating mechanism including the supporting devices 11 and 12 is interposed between the pair of camshafts 3 and 4. is doing.

<Problems to be Solved by the Invention> However, in such a conventional cylinder head oil supply device for an OHC type internal combustion engine, the oil supply passages 15 and 16 simultaneously supply oil to the bearing devices 13 and 14 and the support devices 11 and 12. Since it is bored so that the passage has a large inner diameter, it is necessary to secure a sufficient amount of oil. Therefore, it takes time for the passage to be completely filled with oil, and even if sufficient oil pressure is applied from the oil pump, it takes time for oil to be sufficiently supplied. Will impair the lubricity of.

Further, in the above configuration, since the oil supply passages 15 and 16 are provided at the uppermost portion of the cylinder head, when the V-type internal combustion engine or the internal combustion engine is mounted on an automobile or the like with a large inclination, the internal combustion engine is stopped. Then, the oil is no longer supplied from the oil pump, and when restarting from a state where the oil has fallen out, a shortage of oil will occur.

That is, it takes a long time for the oil to be supplied to the oil supply passage which is obliquely located and is consequently positioned upward. Here, the bearing devices 13 and 14 of the camshafts 3 and 4, which are the oil supply points, are kept lubricated by the oil adhering to the bearing devices 13 and 14 even if the oil supply is insufficient. However, with respect to the support devices 11 and 12 such as the hydraulic lifters that serve as the rocking fulcrum of the rocker arm, if the oil is not supplied, the oil supply may be insufficient and an abnormal noise may occur.

In particular, at the time of starting the cold machine, the viscosity of the oil increases and it takes a long time to refuel, so that the tendency is remarkable.

The present invention has been made in view of such a problem, and an object thereof is to make it possible to sufficiently supply oil to a supporting device such as a hydraulic lifter that serves as a rocking fulcrum of the rocker arm. is there.

<Means for Solving the Problems> Therefore, the present invention provides a lubrication passage for the bearing device of the camshaft and a first lubrication passage connected to the lubrication pump, and an lubrication passage for the support device of the rocker arm. A first oil supply passage and a second oil supply passage, the second oil supply device extending in a camshaft direction to form a rib structure, and a communication passage that connects the first and second oil supply passages to each other. , And the communication passage are arranged so as to become lower in this order.

<Operation> In the above-described configuration, the second oil supply passage is provided separately from the first oil supply passage, and the first lubrication passage located above is the first oil supply passage for the oil supply to the supporting device such as the hydraulic lifter. After passing through a communication passage provided below the first oil supply passage, and above the communication passage, and
It is performed through a second oil supply passage below the first oil supply passage.

Therefore, when the oil pump is stopped, even if the oil in the first oil supply passage flows down, the oil in the second oil supply passage does not flow down.

Furthermore, since the second oil supply passage has the rib structure, the section modulus of the cylinder head in the camshaft direction increases.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings. still,
2 and 8 show the structure of a single cylinder head.

In this embodiment, the present invention is applied to an in-line 4-cylinder engine. As shown in FIGS. 1 to 3, one cylinder has two intake valves.
In an OHC type internal combustion engine equipped with one exhaust valve and two exhaust valves,
In the cylinder head 21, the first and second intake passages 23a and 23b and the first and second exhaust passages 24 are provided for each combustion chamber 22 of each cylinder.
a and 24b (the second exhaust passage 24b is not shown) are formed by branching. And each passage 23a / 24b or 24
The a and 24b face the combustion chamber 22 via the first and second intake valves 25a and 25b and the first and second exhaust valves 26a and 26b.
The intake / exhaust valves 25a, 25b, 26a, 26b are urged to close by corresponding valve springs 27a, 27b, 28a, 28b.

Next, the valve train will be described. However, since the valve operating system on the side of the intake valves 25a and 25b and the valve operating system on the side of the exhaust valves 26a and 26b have the same configuration, the corresponding parts are designated by the same reference numerals, and the intake valves 25a and 25b will be described below. Only the valve operating system on the side will be described.

A cam shaft 31 common to all cylinders is provided above the first and second intake valves 25a and 25b, and a cam 32 is formed on each of the cylinders on the cam shaft 31.

The cam shaft 31 is located between the cylinders on the cylinder head 21, and is provided by a cam bracket 43 as a bearing device.
It is rotatably supported.

Further, above the cylinder head 21, at the center of each cylinder, an ignition plug insertion cylinder 40 is provided so as to protrude upward. A plug insertion hole 41 having an open upper surface is formed in the plug insertion cylinder 40, and the bottom surface of the plug insertion hole 41 is inserted into the combustion chamber 22 via a screw hole 42 formed in the upper wall of the combustion chamber 22. To be done.

Around the plug insertion tube 40, a hydraulic lifter hole 33a is provided, which serves as a rocking fulcrum of the rocker arm 34 and into which a hydraulic lifter 33 as a support device is inserted. The hydraulic lifter 33 is provided so as to absorb the expansion due to the temperature of the valve operating system and always maintain the valve clearance of the valve operating system at zero. Hydraulic lifter 33
A concave spherical seat 35 formed at one end of the rocker arm 34 is capped on the spherical tip of the rocker arm 34 to support the rocker arm 34 in a swingable manner. The passage is provided.

The rocker arm 34 is in contact with the upper ends of the valve shafts of the intake valves 25a and 25b on the lower surface of the other end. Further, a cam follower portion 37 is formed on the upper surface of the intermediate portion of the rocker arm 34, and the cam 32 freely abuts on the rocker arm 34.

If each camshaft 31 is rotated by the drive of the engine, each rocker arm 34 swings up and down, and the intake valves 25a
5b is opened and closed at a predetermined timing.

The valve trains on the exhaust valves 26a and 26b side have the same configuration.

Next, the refueling system will be described.

As shown in FIGS. 2 to 8, in order to lubricate the bearing device 43 of each camshaft with lubrication, the first oil supply passage A20a extending in the camshaft direction is provided on both outer side walls of the cylinder head 21.
As shown in FIG. 3, the holes are drilled from the left side in the drawing so as to extend over the # 2 cylinder and the # 4 cylinder. Similarly, # 1
The first oil supply passage B20b for the cylinder is provided from the right side in the figure. The first oil supply passage A20a and the first oil supply passage
Blind plugs are applied to the openings at both ends of B20b.

Each of the first oil supply passages A20a is located below them, that is, in the combustion chamber.
Connecting passage A4 located on the 22 side and crossing the central parts thereof
Communicated with each other by 7.

The communication passage A47 extends in the vertical direction of the cylinder head 21 and communicates with an oil supply passage A48a which is connected to an oil pump (not shown) (see FIG. 5).

Further, as shown in FIG. 4, a plurality of branch oil passages 52, 53 are respectively branched from the respective first oil supply passages A20a, and one of the branch oil passages 52 is provided in the intake side bearing device 43, respectively. The branch oil passage 53 is opened in the bearing surface, and the other branch oil passage 53 is opened in the bearing surface of the exhaust side bearing device 43.

Similarly, as for oil supply to the intake side and exhaust side bearing devices 43 of the # 1 cylinder, first, as shown in FIG. 7, the first oil supply passage B2 on the intake side is supplied from an oil pump (not shown) through the oil supply passage B48b.
After passing through 0b, a part of the communication passage B (not shown) branches to the first oil supply passage B on the exhaust side, which is performed from the branch oil passages 52, 53 provided in the respective first oil supply passages B20b.

On the other hand, as the oil supply passages to the respective hydraulic lifters 33, as shown in FIG. 6, second oil supply passages are provided respectively. Each of the second oil supply passages 60 is located in a rib 70 that is raised above the upper deck 19 of the cylinder head 21, and is formed so as to extend from the # 1 cylinder to the # 4 cylinder in the camshaft direction. It is a passage of structure. Both ends of the cylinder head of the second oil supply passage 60 are also closed by blind plugs (not shown). These second oil supply passages 60 are the first oil supply passages A2
It is provided at a position lower than 0a. Further, at least one of the first fuel supply passages A20a and the second fuel supply passages 60 are communicated with each other via a communication passage 62. Here passage
The middle portion 62a of the 62 has a lower portion than both the first oil supply passage A20a and the second oil supply passage 60.

Each second oil supply passage 60 is connected to each intake side hydraulic lifter 33.
The branch passage 54 that is led to the
And a branch passage 55 led to 33 (see FIG. 1).

In the oil supply system having such a configuration, the lubricating oil from the oil pump is distributed and supplied to each first oil supply passage A20a through the oil supply passage A48a and the communication passage A47. And
Oil is supplied to the bearing devices 43, 43 of the # 2 cylinder and the # 4 cylinder of each camshaft 31 from the respective first oil supply passages A20a through the branch passages 52, 53.

Next, the oil is sent to each of the second oil supply passages 60 through the communication passages 62, and further through the branch passages 54 and 55 to the # 1 cylinder and the # 4 cylinder.
Oil is supplied to the hydraulic lifter 33 of the cylinder.

Here, the first oil supply passage A2 to each camshaft bearing device
0a, the first oil supply passage B20b, and the second oil supply passage 60 to each hydraulic lifter 33 are separate passages.
It is possible to reduce the diameter of 60 appropriately. Therefore,
The oil pressure corresponding to the oil discharge pressure of the oil pump can be applied to the hydraulic lifter 33, and it is possible to prevent the lubrication of the contact surface and the swing surface from being impaired by supplying the oil from the spherical projection end.

On the other hand, when the oil pump is stopped due to engine stop,
Although oil flows down through the oil passage A48a, the communication passage 62
Are located below each first oil supply passage A20a,
Even if the oil in the first oil supply passages A, B20a, b flows down, the oil in the communication passage 62 and the second oil supply passage 60 does not fall out. Therefore, the second oil supply passages 60 to the hydraulic lifter 33 are always filled with oil, and the lubricity of the contact surface and the swing surface of the hydraulic lifter 33 is not impaired when the recooling machine is started. . In other words, it is possible to avoid the inconvenience of the position where the oil is not conveyed to the respective oil supply points until the oil is filled in the second oil supply passages 60, and the insufficient oil supply is prevented.

Especially when the oil pump is installed in a V-cylinder array internal combustion engine or an automobile in a state of being greatly inclined, even when the oil pump is stopped due to the engine stop, even if the oil supply position that is positionally above is completely removed from the oil pump. After the oil is conveyed through the oil supply passage, the oil is not supplied and the oil remains in the communication passage 62 and the second oil supply passage 60. Therefore, the oil is supplied to the oil supply position located above at the time of cold start. The time can be shortened and the present invention is effective.

On the other hand, by providing each of the second oil supply passages 60 in the shape of a rib above the upper deck 19 of the cylinder head, the section modulus in the direction of the camshaft 31 is increased, and the strength against bending load and twisting load is increased.

Therefore, in the heat treatment process for obtaining the strength of the cylinder head, even if bending stress or torsional stress at the time of rapid cooling occurs, the cylinder head can be prevented from warping.

In addition, in the drawings showing the structure of the cylinder head alone shown in FIGS. 2 to 8, the drilling hole and the sand removing hole are actually provided with blind plugs before the valve operating system device is assembled to the cylinder head. To be done.

Also, as shown in FIG. 2 and FIG.
Oil is returned to the oil pan through oil holes formed in the cylinder block (not shown) and 80.

Further, 90 is a blow-by gas passage.

<Effect of the Invention> As described above, according to the present invention, the second oil supply passage to the support device, which serves as the rocking fulcrum of each rocker arm, is separated from the first oil supply passage to the camshaft bearing device. Therefore, when the second oil supply passage has a small diameter, and the oil supply passage is sufficiently filled with oil and pressure is applied from the oil pump, the hydraulic pressure according to the discharge pressure can be applied to the support device, It is possible to prevent the lubrication of the contact surface and the oscillating surface from being impaired by supplying the oil from the protruding end.

Further, since the communication passage that connects the first and second oil supply passages is provided below the first and second oil supply passages, the oil does not fall out from the second oil supply passage when the internal combustion engine is stopped.

Therefore, when the recooling machine is started, lubrication is sufficiently performed without impairing the lubricity of the contact surface and the swing surface of the supporting device. As a result, the lubrication performance is significantly improved, and it is possible to reduce friction and improve wear resistance.

The above-mentioned effects are effectively exerted even when the internal combustion engine is attached to an automobile or the like in a tilted state.

Further, the second oil supply passage having the rib structure increases the section modulus of the cylinder head with respect to the camshaft direction, thereby improving the strength of the cylinder head.

[Brief description of drawings]

FIG. 1 is a sectional view of a cylinder head of a valve operating system showing an embodiment of the present invention (corresponding to CC section in FIG. 2), FIG. 2 is a plan view of a single cylinder head, and FIG. A side view of the cylinder head alone, FIG. 4 is a sectional view taken along the line DD in FIG. 2, and FIG. 5 is a view in FIG. 2 showing a first oil supply passage A.
-A sectional view, FIG. 6 is a KK sectional view in FIG. 2 showing the second oil supply passage, and FIG. 7 is a BB sectional view in FIG. 2 showing the first oil supply passage B. FIG. 8 is a sectional view taken along line EE in FIG. 2 showing an oil drop hole, FIG. 9 is a conceptual diagram showing an oil supply system, and FIG. 10 is a sectional view of a cylinder head of a valve system showing a conventional example. FIG. 11 is a sectional view of a cylinder head including a cam bracket showing a conventional example. 19 ... upper deck, 20a ... first oil supply passage A, 20b ...
… First oil supply passage B, 21 …… Cylinder head, 25a ……
Intake valve, 26a …… Exhaust valve, 31 …… Camshaft, 32 ……
Cam, 33 …… hydraulic lifter, 34 …… rocker arm, 43 ……
Camshaft bearing device, 60 ... Second oil supply passage, 62 ...
Communication passage, 70 ... rib

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area F02F 1/24 G 7710-3G

Claims (1)

[Scope of utility model registration request] 1. A cylinder head of an OHC type internal combustion engine, comprising: a bearing device for a cam shaft that drives the intake valve and the exhaust valve to open and close, and a support device that serves as a rocking fulcrum of a rocker arm that follows the cam of the cam shaft. A first oil supply passage which is an oil supply passage of the bearing device of the camshaft and which is connected to an oil supply pump, and a first oil supply passage which is connected to a support device of the rocker arm and which extends in a rib structure in the camshaft direction. A second oil supply passage, and a communication passage that connects the first and second oil supply passages to each other. The first oil supply passage, the second oil supply passage, and the communication passage are arranged in this order in a lower order. OHC characterized by being arranged so that
Refueling device for cylinder head of internal combustion engine.