JPH05306603A - Lubricating device of valve gear for four cycle engine - Google Patents

Abstract

PURPOSE:To provide specified engine performance even in starting an engine by constituting a lubricating device so that the movement of a lash adjuster to absorb the gaps produced between a suction and discharge valve in a valve gear and the swing end of a locker arm and the locker arm and a cam shaft may be immediately obtained even in staring the engine. CONSTITUTION:An oil passage 42 is provided to lead lubricating oil toward a lash adjuster 23 from the lower side of a cylinder head 3. This oil passage 42 is provided with an upper oil passage 44 extending to a position higher than the lash adjuster 23 and a turning oil passage 45 turning downward from this upper oil passage 44 to the lash adjuster 23. The lash adjuster 23 is arranged between both the oil passages 44 and 45 when looked arranged in parallel with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubrication device for a valve mechanism for a four-cycle engine, and more particularly, to a lash adjuster pivotally supporting a rocker arm provided with an oil passage for supplying lubricating oil. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, there is a lubricating device constructed as follows. According to this, the rocker arm is pivotally supported by the hydraulic lash adjuster attached to the cylinder head so as to be vertically swingable, and the swing end of the rocker arm is engaged with the valve. A cam shaft that cam-engages the rocker arm is provided, and the valve is interlocked with the rocking of the rocker arm due to the rotation of the cam shaft. On the other hand, an oil passage for guiding the lubricating oil from the lower side of the cylinder head to the lash adjuster is formed in the cylinder head, and the lubricating oil is passed through the oil passage by the hydraulic pump interlocked with the operation of the engine so that the lubricating oil is passed through the lash adjuster. Is supplied to. When a gap is about to be formed between the valve and the rocker arm rocking end or between the rocker arm and the cam shaft during engine operation due to thermal expansion or wear, the lash adjuster is Is extended by the oil pressure of the lubricating oil supplied to the valve, and the above gap is automatically absorbed.This allows the valve to accurately interlock with the operation of the camshaft and rocker arm, and to always give the valve a specified stroke. It is designed to be used.

[0003]

By the way, in the above-mentioned conventional structure, the oil passage extends from the lower side of the cylinder head so as to gradually rise toward the lash adjuster. Therefore, for example, when the engine stops and the hydraulic pump stops in conjunction with this, the lubricating oil in the lash adjuster falls downward through the oil passage due to its own weight, and the air in the lash adjuster drops. May accumulate. In this case, when the hydraulic pump is then started by starting the engine, the elasticity of the air accumulated in the lash adjuster at this start allows the lash adjuster to absorb the gap. Therefore, when the engine is started, the valve is not given a predetermined stroke, that is,
There is a problem that a predetermined engine performance cannot be obtained.

[0004]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the above circumstances, and is provided between the intake / exhaust valve of the transmission mechanism and the rocking end of the rocker arm, and the rocker arm and the cam shaft. The main purpose of the function of the lash adjuster is to immediately obtain the function of absorbing the gap generated between the engine and the engine even when the engine is started, so that the predetermined engine performance can be obtained even when the engine is started. To do.

[0005]

The feature of the present invention for achieving the above object is that an oil passage for guiding lubricating oil from the lower side of the cylinder head toward the lash adjuster is more than the lash adjuster. An upper oil passage extending upward and a folded oil passage folded back downward from the upper oil passage to reach the lash adjuster are provided.
When viewed in a state where the upper oil passage and the folded oil passage are arranged side by side, the lash adjuster is arranged between the two oil passages.

[0006]

[Operation] The operation of the above configuration is as follows. In particular, as shown in FIG. 1, an oil passage 42 that guides lubricating oil from the lower side of the cylinder head 3 toward the lash adjuster 23 has an upper oil passage 44 that extends above the lash adjuster 23 and an upper oil passage 44. A return oil passage 45 is provided that is folded back from the oil passage 44 and reaches the lash adjuster 23.

Therefore, for example, when the engine 1 is stopped, the pressure of the lubricating oil in the oil passage 42 decreases, and
Even if the lubricating oil in the upper oil passage 44 falls out, the lubricating oil in the return oil passage 45 remains. Therefore, since the lubricating oil of the lash adjuster 23 connected to the return oil passage 45 remains without dropping out, when the hydraulic pump is started by the start of the engine 1 thereafter, the lubricating oil is immediately supplied to each of the lash adjusters 23. Supplied.

As a result, the intake and exhaust valves 10, 14 are
And the rocking end 26 of the rocker arm 24 and the gap between the rocker arm 24 and the cam shaft 27 of the same as above are absorbed by the lash adjuster 23 immediately when the engine 1 is started. That is, the predetermined stroke is always given to each of the valves 10 and 14.

Further, in particular, as shown in FIG. 1, when the upper oil passage 44 and the folded oil passage 45 are viewed side by side, the lash adjuster 23 is provided between the two oil passages 44, 45. Is provided. Therefore, the thick portion of the cylinder head 3 between the upper oil passage 44 and the return oil passage 45 is effectively used for disposing the lash adjuster 23.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In the figure, reference numeral 1 is a 4-cycle parallel multi-cylinder engine,
This engine 1 is mounted on an automobile. For convenience of explanation, the direction of the arrow Fr in the figure is the front, and the left and right are the directions toward the front. The engine 1 has a plurality of cylinders 2 projecting upward from the crankcase, and these cylinders 2 are arranged side by side integrally on the left and right. Cylinder head 3 is on this cylinder 2.
Is detachably screwed with a bolt 4. Figure 1
As shown in FIG. 3, the cylinder head 3 has a front wall 3a, a rear wall 3b, and a bottom wall 3 that integrally connects the lower portions of the front wall 3a and the rear wall 3b in a side sectional view.
c and are formed in a substantially U shape. A cylinder head cover 5 is removably screwed onto the cylinder head 3 with bolts 6 shown in FIG.

An upper portion of the combustion chamber 8 is formed on the lower surface of the cylinder head 3. An intake passage 9 that communicates with the combustion chamber 8 from the rear surface side of the cylinder head 3 is formed in the cylinder head 3, and the downstream end of the intake passage 9 opens into the combustion chamber 8 through three intake ports. Three intake valves 10 for opening and closing these intake ports are supported by a rear wall 3b of the cylinder head 3 so as to be vertically movable, and these intake valves 10 are biased upward by springs 11 so as to close the intake ports. Has been done.

In particular, as shown in FIG. 3, an exhaust passage 13 communicating from the combustion chamber 8 to the front side of the cylinder head 3 is formed in the cylinder head 3, and the upstream end of the exhaust passage 13 has two exhaust ports. Through the opening to the combustion chamber 8. Two exhaust valves 14 for opening and closing these exhaust ports are movably supported on the front wall 3a of the cylinder head 3 in the same manner as above, and these exhaust valves 14 are springs 15 upward to close the exhaust ports. Being energized.

A valve operating mechanism 1 for opening the intake valve 10 and the exhaust valve 14 in association with driving of the engine 1.
7 is provided. The valve mechanism 17 has a cam chamber 18 formed between the cylinder head 3 and the cylinder head cover 5.

A support hole 22 having a bottom is formed in the rear wall 3b of the cylinder head 3 so as to open upward toward the cam chamber 18, and a hydraulic lash adjuster 23 is fitted and supported in the support hole 22. ing. The base end 25 of the rocker arm 24 is pivotally supported on the upper end of the lash adjuster 23, and the rocking end 26 of the rocker arm 24 extends forward and can be rocked up and down. It is joined.

The cam chamber 18 is provided with a cam shaft 27 extending leftward and rightward corresponding to the upper surfaces of the rocker arms 24 in the front-rear midway. The camshaft 27 is rotatable about its axis by a plurality of bearings 28. Is supported by. The support hole 22, the lash adjuster 23, the rocker arm 24, the cam shaft 27, and the bearing 28 are the exhaust valve 1
4 is also provided in the same manner as above. However, the one for the exhaust valve 14 is provided substantially symmetrically with respect to the one for the intake valve 10 in the front-rear direction.

The cam shafts 27 rotate in conjunction with the driving of the engine 1, and the rocker arms 24 cam-engage with the rotation of the cam shafts 27 so that the rocking ends 26 rock. Further, the intake valve 10 and the exhaust valve 14 are interlocked with the swing of the swing end 26 to appropriately open and close the intake and exhaust ports. In addition, 29 is a housing hole for housing the spark plug.

In FIG. 4, the lash adjuster 2 is shown.
3 will be explained. The lash adjuster 23 has a cylindrical body 30 fitted in the support hole 22, and a plunger 31 is fitted in the body 30 so as to be slidable in the axial direction. An oil reservoir 32 is provided inside the plunger 31.
Is formed, and the first and second communication holes 33, 34 for communicating the oil reservoir 32 with the outside of the body 30 are formed in the body 3
0 and the plunger 31 are formed in the upper and lower middle portions.

The inner bottom surface of the body 30 and the plunger 3
1. A high pressure chamber 35 is formed between the outer bottom surface of the spring 1 and a spring 36 for urging the plunger 31 upward.
Is provided. Further, a check valve 37 is provided to allow the lubricating oil in the oil reservoir chamber 32 to flow only into the high pressure chamber 35. A spherical convex surface 38 is provided on the upper end of the plunger 31.
Is formed, the spherical concave surface 39 formed on the proximal end 25 of the rocker arm 24 is fitted to the spherical convex surface 38, whereby the proximal end 25 of the rocker arm 24 is pivotally supported on the lash adjuster 23 as described above. There is. An oil passage 40 for guiding the lubricating oil in the oil reservoir 32 to the joint surface between the spherical convex surface 38 and the spherical concave surface 39 is formed at the upper end of the plunger 31.

Lubricating oil is supplied to each of the lash adjusters 23 from a hydraulic pump interlocking with the engine 1. The lubricating oil passes through the first communicating hole 33 and the second communicating hole 34 and is stored in an oil reservoir. It is sent to the chamber 32 and is sent to the high pressure chamber 35 through the check valve 37.

In all the drawings, the intake valve 10 and the exhaust valve 14 are subject to thermal expansion and wear during the operation of the engine 1.
And a rocking end 26 of the rocker arm 24 or a gap between the rocker arm 24 and the cam shaft 27 is about to be generated, the plunger 31 is pushed up by the spring 36 and the gap is automatically absorbed. To be done. Further, when the plunger 31 is about to be pushed down by the external force from the rocker arm 24, the pressure of the lubricating oil in the high pressure chamber 35 becomes high, and this tends to move to the oil sump chamber 32.
This is regulated by a check valve 37, and the plunger 31 is held at a predetermined upper and lower position. In this way, the intake valve 1 is attached to the cam shaft 27 and the rocker arm 24.
0 and the exhaust valve 14 are accurately linked so that the intake valve 10 and the exhaust valve 14 are always given a predetermined stroke.

The hydraulic pump is provided on the crankcase side of the engine 1. On the other hand, an oil passage 42 extending from the lower side of the cylinder head 3 toward the lash adjuster 23 through the cylinder 2 has an oil passage 42.
The lubricating oil from the hydraulic pump is supplied to the lash adjuster 23 through the oil passage 42. The oil passage 42 is a lower oil passage 43 extending upward from the cylinder 2 side along the rear wall 3b of the cylinder head 3.
And an upper oil passage 44 extending from the lower oil passage 43 to a position higher than the first communication hole 33 of the lash adjuster 23. The upper end of the upper oil passage 44 is open to the upper end of the rear wall 3b. . A return oil passage 45 is formed in the rear wall 3b of the upper oil passage 44. The return oil passage 45 is folded downward from the middle of the upper oil passage 44. The return end of the return oil passage 45 has a distribution oil passage 46 extending leftward and rightward on the rear wall 3b. The distribution oil passage 46 communicates with the first communication hole 33 of each lash adjuster 23 on the intake valve 10 side. .

On the other hand, the front wall 3a of the cylinder head 3 is formed with an oil passage 47 extending downward from the upper end of the front wall 3a, and the distributed oil extending left and right from the lower end of the oil passage 47. A passage 48 is formed, and the distribution oil passage 48 communicates with the first communication hole 33 of each lash adjuster 23 on the exhaust valve 14 side. The upper ends of the upper oil passage 44 and the oil passage 47 are connected by a communication pipe 49,
The communication pipe 49 is detachably screwed to the upper surfaces of the front wall 3a and the rear wall 3b by a flange 50 and a bolt 51. Further, the distribution oil passages 46, 4 described above
The left and right ends of 8 are connected to each other by a connecting oil passage 52 extending substantially horizontally. Then, the lubricating oil from the hydraulic pump that is interlocked with the engine 1 is supplied to each lash adjuster 23 through the oil passage 42.

From the above state, for example, when the engine 1 is stopped, the pressure of the lubricating oil in the oil passage 42 decreases, and the lubricating oil in the lower oil passage 43 and the upper oil passage 44 of the oil passage 42 slips out. Even in such a case, the lubricating oil in the return oil passage 45 and the oil passage 47 remains. Therefore, the return oil passage 45 and the oil passage 4
Since the lubricating oil of each lash adjuster 23 connected to No. 7 does not fall out and remains as it is, when the hydraulic pump is started by the start of the engine 1 thereafter, the lubricating oil is immediately supplied to each of the lash adjusters 23. It

As a result, the intake and exhaust valves 10 and 14 are
And the rocking end 26 of the rocker arm 24 and the gap between the rocker arm 24 and the cam shaft 27 of the same as above are absorbed by the lash adjuster 23 immediately when the engine 1 is started. That is, the predetermined stroke is always given to each of the valves 10 and 14.

In particular, when the upper oil passage 44 and the folded oil passage 45 are arranged side by side as shown in FIG. 1 (according to the drawing, they are arranged side by side). The lash adjuster 23 is provided between the oil passages 44 and 45.
Are arranged.

For this reason, in the rear wall 3b of the cylinder head 3, the thick portion between the upper oil passage 44 and the return oil passage 45 is effectively utilized for the disposition of the lash adjuster 23. As a result, the rear wall 3b of the cylinder head 3 is prevented from becoming large in shape.

In FIGS. 1 and 2, when the cylinder head 3 and the cylinder head cover 5 are assembled to the cylinder 2, first, the cylinder head 3 is screwed onto the cylinder 2 with the bolt 4. At this time, a bent portion 54 for avoiding the tool 53 is formed at an intermediate portion of the communication pipe 49 so that the tool 53 for screwing the bolt 4 does not come into contact with the communication pipe 49. Further, the cylinder 2 and the cylinder head 3 are slightly tilted forward, and the horizontal oil level of the stationary lubricating oil in this case is shown in FIG.
It is indicated by reference numeral 55 in FIG.

[0028]

According to the present invention, the oil passage for guiding the lubricating oil from the lower side of the cylinder head toward the lash adjuster extends upward from the lash adjuster, and from this upper oil passage. Since the oil passage includes a return oil passage that is folded back downward and reaches the lash adjuster, for example, the pressure of the lubricating oil in the oil passage decreases as the engine stops, and the lubricating oil in the upper oil passage of the oil passage is reduced. Even if the oil drops out, the lubricating oil remains in the return oil passage. Therefore, since the lubricating oil of the lash adjuster connected to this return oil passage remains without falling off,
After that, when the hydraulic pump is started by starting the engine, the lubricating oil is immediately supplied to each of the lash adjusters.

As a result, the function of the lash adjuster that absorbs the gaps between the valve and the rocking end of the rocker arm and between the rocker arm and the cam shaft is the same.
There is an advantage that it can be obtained immediately even when the engine is started, that is, a predetermined stroke is always given to each valve to obtain a predetermined engine performance. When the upper oil passage and the folded oil passage are arranged side by side, the lash adjuster is arranged between the two oil passages. The thick portion of the cylinder was effectively used for the arrangement of the lash adjuster.Therefore, even when the oil passage has the upper oil passage and the folded oil passage as described above, the shape of the cylinder head becomes large. Is suppressed.

[Brief description of drawings]

FIG. 1 is a partial side sectional view of an engine.

FIG. 2 is a partial plan view of the engine.

FIG. 3 is a partial side sectional view of an engine of a portion different from FIG.

FIG. 4 is a vertical sectional view of a lash adjuster.

[Explanation of symbols]

 1 Engine 2 Cylinder 3 Cylinder Head 5 Cylinder Head Cover 10 Intake Valve 14 Exhaust Valve 17 Valve Mechanism 23 Rush Adjuster 24 Rocker Arm 26 Swing End 27 Camshaft 42 Oil Path 44 Upper Oil Path 45 Folding Oil Path

Claims (1)

[Claims] 1. A cylinder head is provided with a valve for intake and exhaust, and a rocker arm is pivotally supported on a hydraulic lash adjuster mounted on the cylinder head so as to be vertically swingable. A camshaft for cam-engaging with the rocker arm is provided, and the valve is interlocked with the rocker arm swinging due to the rotation of the camshaft. The valve head moves from the lower side of the cylinder head to the lash adjuster. In a lubrication device of a valve operating mechanism for a four-cycle engine in which an oil passage for guiding lubricating oil is formed in the cylinder head, the oil passage includes an upper oil passage extending above the lash adjuster, and an upper oil passage It is provided with a return oil passage that is folded back downward and reaches the lash adjuster. When viewed in a state of being set, lubrication system for a four-cycle engine valve train which is disposed the lash adjuster between these two oil passages.