JPH10288011A - Lubricating structure of crosshead - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of abnormal abrasion between components under mutual contact by providing a lubricating structure which can excellently lubricate the contact part of a crosshead to the pressed part of a rocker arm in a four valve engine. SOLUTION: The inside of a crosshead 8 is severally drilledly provided with a lubricating oil feeding out hole 26 which longitudinally pierces a top chip 20 to block up the upper end of the guide hole 19 of a cross head and an adjust chip 13 (blocked part), and communicates with the guide hole 19 at one end, and opens toward the spherical seat 13a (a contact part) on the upper face of the above adjust chip 13 against which the semispherical part 10 (a pressed part) on the lower end of the adjust screw 11 of the rocker arm 7 at the other end, and a pair of lubricating oil introducing hole 27 which communicates with the inside of the guide hole 19 at the about just above position of the upper end of a guide pin 18 in a valve closed state (a state shown in the figure 1) at one end, and extends obliquely upward and opens toward the upper face of both arm parts 16 at the other end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosshead lubrication structure in a four-valve engine.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show an example of a four-valve engine used for a vehicle or the like.
Reference numeral 2 denotes a combustion chamber, 3 denotes a piston, 4 denotes an engine valve, and 5 denotes a port. The rocker arm 7 which is pushed up by the rotation of the cam 6 and tilts via a crosshead 8 causes the engine valve 4 to repel a spring 9. It is pushed down at an appropriate timing against the force, whereby the engine valve 4 is opened and the combustion chamber 2 and the port 5 are communicated.

Here, each of the engine valve 4, the port 5, the cam 6, and the rocker arm 7 is provided with a pair of intake and exhaust ports for each cylinder 1 in substantially the same configuration, For example, when the illustrated engine valve 4 is an intake valve, the engine valve 4 is opened by the rocker arm 7 that tilts during the intake stroke, and intake from the intake port 5 (air for a diesel engine, gasoline for a gasoline engine, When the illustrated engine valve 4 is an exhaust valve, the engine valve 4 is opened by the rocker arm 7 that tilts in the exhaust stroke when the piston 3 descends. Valved,
The exhaust gas in the combustion chamber 2 is exhausted to the exhaust port 5 by the rise of the piston 3.

At one end of the rocker arm 7, an adjusting screw 11 having a hemispherical portion 10 at the lower end is screwed and fixed with an adjusting nut 12, and the hemispherical portion 10 at the lower end of the adjusting screw 11 (see FIG. 5).
The adjust cap 1 abuts on a spherical seat 13 a (see FIG. 5) formed on the adjust tip 13 at the upper end of the crosshead 8 and is attached to the adjust tip 13.
4, the valve gap can be adjusted by tightening or loosening the adjustment screw 11.

[0005] The crosshead 8 is provided with arms 16 projecting from both sides thereof so that the upper ends of the valve stems 15 of the pair of engine valves 4 can be simultaneously pushed down. The upper end of the guide hole 19 through which the guide pin 18 is inserted is closed by the top chip 20, and the above-described adjust chip 13 is attached to the upper surface of the top chip 20. ing.

In such a valve mechanism of a four-valve engine, the contact portion of the crosshead 8 with the rocker arm 7 and the engine valve 4, that is, the spherical seat 13a of the adjusting tip 13, and the lower end surfaces 16a of the two arm portions 16 are formed. Conventionally, when lubricating these contact portions, the rocker arm 7 is lubricated from an oil supply passage 23 in a rocker arm shaft 22 in which the rocker arm 7 is tiltably supported via a rocker bush 21. Lubricating oil 24 supplied to 21
Is leaked to the adjusting screw 11 through the communication passage 25 formed in the rocker arm 7 and hangs downward, whereby the upper end of the crosshead 8 and the arm portion 1 are dropped.
The lubricating oil 24 is guided to the tip of the lubricator 6, and lubrication is also achieved by natural lubrication by oil splash (spray of the lubricating oil 24) in a head cover (not shown).

[0007]

However, in the conventional lubrication structure for the crosshead 8 as described above, the hemispherical portion 10 at the lower end of the adjusting screw 11 is held by the adjusting cap 14 mounted on the adjusting tip 13. The lubricating oil 24 or oil splash flowing down the adjusting screw 11 is blocked by the adjusting cap 14 from flowing into the spherical seat 13a and flows outward, so that a sufficient amount of the lubricating oil 24 is supplied to the spherical seat 13a. It was difficult.

In particular, when the engine is operated in a low-speed rotation range at the time of idling or the like, the supply flow rate of the lubricating oil 24 by the oil pump of the engine lubrication system driven by a part of the engine power decreases, and the head cover Since the oil splash in the inside is also reduced, the problem of insufficient lubrication in the spherical seat 13a of the adjusting tip 13 described above becomes more remarkable. 24 is likely to be insufficient, and abnormal wear may occur between the parts in contact with each other, which may shorten the life of the parts.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a lubricating structure capable of satisfactorily lubricating a contact portion of a crosshead with a pressing portion of a rocker arm in a four-valve engine. An object of the present invention is to provide a lubricating structure capable of satisfactorily lubricating a contact portion of a head so that abnormal wear does not occur between mutually contacting parts.

[0010]

According to the present invention, there is provided a lubrication system for a crosshead which is externally fitted to a guide pin projecting from a cylinder head so as to be able to move up and down, and has an arm formed on the upper part so as to push down the upper end of a valve stem. A contact that vertically communicates with one end into the guide hole through a closed portion that closes an upper end of the guide hole of the crosshead into which the guide pin is inserted, and the other end contacts a pressing portion of the rocker arm. A lubricating oil delivery hole opened in the arm portion, and a lubricating oil introducing hole opened in the upper surface of the arm portion with one end communicating with the guide hole at a position almost directly above the upper end of the guide pin in a valve closed state and the other end extending obliquely upward. It is characterized by having.

In this way, even if the lubricating oil or oil splash that has flowed down from the rocker arm does not flow well into the contact portion of the rocker arm with which the pressing portion is in contact, the lubricating oil or oil splash may flow down. The lubricating oil is
The lubricating oil is introduced from the upper surface of the arm portion into the guide hole of the crosshead through the lubricating oil introduction hole, where the lubricating oil is intermittently forcibly supplied to the contact portion through the lubricating oil delivery hole. Can reliably supply a sufficient amount of lubricating oil.

In the present invention, instead of the above-described lubricating oil introduction hole, one end communicates with a main hole of an engine lubrication system formed in a cylinder head, and the other end passes through a shaft center portion of a guide pin. A lubricating oil introduction hole opened in the hole may be provided.

[0013] In this case, the lubricating oil flowing down from the rocker arm side or natural lubrication by oil splash does not rely on the lubricating oil introduction hole from the main hole of the engine lubrication system drilled in the cylinder head. The introduced lubricating oil is stored in the guide hole, and it is possible to intermittently supply the lubricating oil to the contact portion through the lubricating oil delivery hole by the raising / lowering operation of the crosshead, so that a sufficient amount of lubricating oil is supplied to the contact portion. It is possible to reliably supply.

Further, when the lubricating oil introduction hole is used to directly guide the lubricating oil from the main hole of the engine lubrication system into the guide hole, one end is communicated with the upper end of the guide hole and the other end is connected. In addition to the lubricating oil delivery hole opened at the contact portion where the pressing portion of the rocker arm abuts, one end is communicated near the upper end of the guide hole and the other end is opened at the contact portion where the upper end of the valve stem abuts through the inside of the arm portion. A lubricating oil delivery hole may be provided.

With this configuration, the lubricating oil directly guided from the main hole of the engine lubrication system formed in the cylinder head through the lubricating oil introduction hole is stored in the guide hole, and the respective lubricating oils are moved by raising and lowering the crosshead. Through the delivery hole,
Since it is possible to intermittently refuel the contact portion where the pressing portion of the rocker arm contacts and the contact portion where the upper end of the valve stem abuts, a sufficient amount can be applied to any of the above-mentioned contact portions. Can be reliably supplied.

[0016]

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

FIG. 1 shows a first embodiment of the present invention, in which the same reference numerals as in FIGS. 4 and 5 denote the same components.

The basic peripheral structure in this embodiment is substantially the same as that of FIG. 4 described above, except that the top chip 20 and the adjust chip 13 (closed) closing the upper end of the guide hole 19 of the crosshead 8. Part) in the longitudinal direction, and one end communicates with the inside of the guide hole 19 and the other end is connected to the rocker arm 7.
The lubricating oil delivery hole 26 opened in the spherical seat 13a (contact portion) on the upper surface of the adjusting tip 13 with which the hemispherical portion 10 (pressing portion) at the lower end of the adjusting screw 11 contacts, and the valve in a closed state (the state shown in FIG. 1). Guide pin 18
A pair of lubricating oil introduction holes 27 each having one end communicating with the guide hole 19 and the other end extending obliquely upward and opening on the upper surface of both arm portions 16 are formed in the crosshead 8 at a position almost directly above the upper end. Has been established.

If the lubricating oil delivery hole 26 and the lubricating oil introduction hole 27 are formed in the crosshead 8 as described above, the lubricating oil 24 and oil splash that have flowed down from the rocker arm 7 will be adjusted. 11 Spherical seat 13 of adjusting tip 13 with which hemispherical portion 10 at the lower end is in contact
a, even if it flows down to the outside by being blocked by the adjustment cap 14, the lubricating oil 24 is
The lubricating oil is introduced from the upper surface of the arm portion 16 into the guide hole 19 of the crosshead 8 through the lubricating oil introduction hole 27, and the crosshead 8 is intermittently forced to the spherical seat 13a through the lubricating oil delivery hole 26 by the raising and lowering operation of the crosshead 8. Since lubrication is performed, a sufficient amount of lubricating oil 24 can be reliably supplied to the spherical seat 13a.

That is, the lubricating oil 24 guided from the upper surface of the arm portion 16 into the guide hole 19 of the crosshead 8 through the lubricating oil introduction hole 27, the space above the guide pin 18 in the guide hole 19 in the valve closed state. When the crosshead 8 is pushed down by the rocker arm 7 and the space above the guide pin 18 in the guide hole 19 is narrowed, the lubricating oil 24 passes through the lubricating oil delivery hole 26 to the spherical seat 13 a of the adjusting tip 13. The forced refueling is performed by being pushed out.

When the crosshead 8 is pushed down by the rocker arm 7, the opening position at one end of the lubricating oil introduction hole 27 communicating with the guide hole 19 is lowered, and the lubricating oil introduction hole 27 is guided by the guide pin 18. Is closed at one end, the lubricating oil 24 in the guide hole 19 is necessarily pushed out to the lubricating oil delivery hole 26 and does not flow backward through the lubricating oil introduction hole 27.

Therefore, according to the first embodiment described above, the lubricating oil 24 and the oil splash that have flowed down from the rocker arm 7 are prevented from flowing into the spherical seat 13a of the adjusting tip 13 by the adjusting cap 14 and outward. Even if it runs down, since the lubrication oil 2 can be intermittently supplied to the spherical seat 13a intermittently by the raising and lowering operation of the crosshead 8, the lubricating oil 2
4 can be reliably supplied, and thereby, occurrence of abnormal wear in the hemispherical portion 10 at the lower end of the adjusting screw 11 and the spherical seat 13a of the adjusting tip 13 can be prevented, and the life of these components can be greatly improved. be able to.

As an additional effect, the crosshead 8
The lubricating oil 24 is also forcibly supplied between the guide hole 19 and the guide pin 18 by the raising / lowering operation of the crosshead 8, so that abnormal wear occurs between the guide hole 19 and the guide pin 18. Can be prevented.

FIG. 2 shows a second embodiment of the present invention. In the present embodiment, the lubricating oil introduction hole 27 in the first embodiment described above is replaced with a hole drilled in the cylinder head 17. One end communicates with a main hole 29 of the engine lubrication system, and the other end is provided with a lubricating oil introduction hole 28 that opens into the guide hole 19 through the axial center of the guide pin 18.

In such a case, the lubricating oil is introduced from the main hole 29 of the engine lubrication system formed in the cylinder head 17 without relying on the lubricating oil 24 flowing down from the rocker arm 7 or natural lubrication by oil splash. The lubricating oil 24 directly guided through the hole 28 is stored in the guide hole 19, and the lubricating oil can be intermittently supplied to the spherical seat 13a of the adjusting tip 13 through the lubricating oil delivery hole 26 by the raising / lowering operation of the crosshead 8. , The spherical seat 13
a, a sufficient amount of lubricating oil 24 can be reliably supplied, and even when the engine is operated in a low-speed rotation range at the time of idling or the like, good lubrication is realized and The occurrence of abnormal wear on the hemispherical portion 10 at the lower end of 11 or the spherical seat 13a of the adjusting tip 13 can be prevented.

FIG. 3 shows a third embodiment of the present invention, in which the lubricating oil 24 is introduced directly from the main hole 29 of the engine lubrication system into the guide hole 19 as in the second embodiment. When the lubricating oil introduction hole 28 is adopted, one end communicates with the upper end of the guide hole 19 and the other end is added to the lubricating oil delivery hole 26 opened to the spherical seat 13 a of the adjusting tip 13. A lubricating oil delivery hole 30 is provided in the vicinity of one end communicating with one end and the other end passing through the inside of the arm portion 16 and opening in the lower end surfaces 16a (contact portions) of the two end portions 16 with which the upper ends of the valve stems 15 abut. is there.

In this way, the lubricating oil 24 directly guided from the engine lubrication system main hole 29 formed in the cylinder head 17 through the lubricating oil introduction hole 28 is stored in the guide hole 19 and The adjusting tip 1 with which the hemispherical portion 10 at the lower end of the adjusting screw 11 abuts through the lubricating oil delivery holes 26 and 30 by the lifting operation.
3 can be intermittently lubricated with the lower end surface 16a of the arm portion 16 with which the upper end of the valve stem 15 abuts.
The occurrence of abnormal wear at the upper end of the valve stem 6a and the valve stem 15 can also be prevented.

The lubricating structure of the crosshead according to the present invention comprises:
The structure of the pressing portion of the rocker arm and the contact portion of the crosshead with respect to the pressing portion is not limited to the above-described embodiment, and a structure other than the illustrated example can be adopted. Of course, various changes can be made without departing from the gist.

[0029]

According to the lubricating structure for a crosshead of the present invention, various excellent effects as described below can be obtained.

(I) According to the first aspect of the present invention, the lubricating oil or oil splash that has flowed down from the rocker arm side is satisfactorily flowed into the contact portion where the pressing portion of the rocker arm is in contact. Even if it has flowed outward without being driven, the crosshead can be intermittently lubricated to the contact portion by the raising and lowering operation of the crosshead, so that a sufficient amount of lubricating oil can be reliably supplied to the contact portion. Thus, it is possible to prevent the occurrence of abnormal wear between the parts in contact with each other, and it is possible to greatly improve the life of the parts.

(II) According to the invention of the second aspect of the present invention, the main part of the engine lubrication system provided in the cylinder head is formed without relying on lubricating oil flowing down from the rocker arm side or natural lubrication by oil splash. Since the lubricating oil can be guided directly from the hole and intermittently lubricated to the contact part where the pressing part of the rocker arm is in contact,
A sufficient amount of lubricating oil can be reliably supplied to the contact portion. Further, even when the engine is operated in a low-speed rotation range at the time of idling or the like, good lubrication is realized and mutual lubrication is achieved. The occurrence of abnormal wear between the components can be prevented.

(III) According to the third aspect of the present invention, oil is intermittently forcibly supplied to the contact portion with which the upper end of the valve stem comes into contact, thereby causing abnormal wear between the components. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional example.

FIG. 5 is an enlarged sectional view showing a main part of FIG. 4;

[Description of Signs] 7 Rocker arm 8 Cross head 10 Hemisphere part (pressing part) 13 Adjust tip (blocking part) 13a Spherical seat (contact part) 15 Valve stem 16 Arm part 16a Lower surface of tip 17 Cylinder head 18 Guide pin 19 Guide hole Reference Signs List 20 Top chip (closed portion) 26 Lubricating oil delivery hole 27 Lubricating oil introduction hole 28 Lubrication oil introduction hole 29 Main hole 30 Lubrication oil delivery hole

Claims (3)

[Claims] 1. A lubricating structure for a crosshead which is fitted to a guide pin protruding from a cylinder head so as to be able to move up and down, and has an arm portion formed on an upper portion thereof so as to push down an upper end of a valve stem. A lubricating oil delivery hole which extends vertically through a closing portion closing the upper end of the guide hole of the crosshead through which one end is inserted, communicates one end into the guide hole, and opens the other end into a contact portion where the pressing portion of the rocker arm abuts. And a lubricating oil introduction hole which communicates with one end of the guide hole at a position almost directly above the upper end of the guide pin when the valve is closed and extends the other end obliquely upward and opens on the upper surface of the arm portion. Cross head lubrication structure. 2. A lubricating structure for a crosshead which is fitted to a guide pin protruding from a cylinder head so as to be able to move up and down, and has an arm formed on an upper part thereof so as to push down an upper end of a valve stem. A lubricating oil delivery hole which extends vertically through a closing portion closing the upper end of the guide hole of the crosshead through which one end is inserted, communicates one end into the guide hole, and opens the other end into a contact portion where the pressing portion of the rocker arm abuts. And a lubricating oil introduction hole having one end communicating with the main hole of the engine lubrication system formed in the cylinder head and the other end opened into the guide hole through the axis of the guide pin. Crosshead lubrication structure. 3. The lubricating oil delivery hole according to claim 2, wherein one end communicates with the vicinity of the upper end of the guide hole and the other end passes through the inside of the arm portion and is opened at a contact portion where the upper end of the valve stem abuts. The lubrication structure of the crosshead described.