JPH0122441B2 - - Google Patents

Abstract

Oil collecting basins 16 adjacent the tappet guides 14 collect excess oil exuded from the guides and the basins have holes 18 aligned with the cams on the camshaft 7 to drip oil thereon. Inserts 18 may be used in the oil drip holes, or cast drip edges located adjacent the holes. The rocker arm fulcrum (29), Fig. 4 (not shown), is lubricated by oil fed through grooves (33) in the fulcrum surface engaged by the fulcrum locating nut (28). <IMAGE>

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to a cylinder head for an internal combustion engine of the type having a hemispherical or dome-shaped combustion chamber, with intake and exhaust valves arranged approximately radially relative to the surface of the combustion chamber. . The valve is actuated by a sheet metal rocker arm moved by a tappet directly engaged by a cam on the overhead camshaft. The camshaft is located intermediate the inlet and outlet valve rows. The bridge spans the camshaft adjacent to the camshaft bearing web and is a protrusion on the cylinder head that accommodates the valve stem guide, the bushing arm stud mounting hole or hole for the stud, and the tappet guide. In other words, it consists of bosses.

A cylinder head of the type generally described above is shown and described in U.S. Pat. No. 3,164,143. In that patent, the portion of the cylinder head extending below the camshaft is a tank-shaped structure. This creates a sump for the camshaft by collecting excess lubricant that falls from the tappet guide, which is typically supplied with excess pressurized lubricant. A conventional discharge orifice from this oil sump is placed to provide a level of oil such that the surface of the cam of the camshaft is wetted by the immersion lubrication process. The lubrication of the rocker support piece is therefore intended in that patent to be carried out by splashing oil in the cavity of the valve arrangement.

In internal combustion engines, it is important to control the amount of air added to the lubricating oil delivered to the engine by the pump, if hydraulic valve tappets are employed that automatically compensate for play in the valve gear. It is.

In the conventional lubrication of valve gears of internal combustion engines by pressure lubrication and immersion and splash lubrication, it is unavoidable to introduce more air into the lubricating oil. This will impair the effectiveness of the hydraulic valve tappet or
Or, alternatively, having to resort to harsh methods to sedate the lubricant.

One object of the invention is to provide a cylinder head of an internal combustion engine of the type mentioned at the outset, so as to be able to eliminate the customary dip and splash lubrication hitherto carried out on parts of internal combustion engine valve gear. The goal is to obtain an improved structure. In accordance with the present invention, a sump is provided adjacent each tappet guide for collecting lubricating oil seeping from the tappet guide and discharging it from a drain hole aligned with a corresponding cam portion of the camshaft. It will be done. This makes the lubrication of the camshaft very reliable and further reduces the air contained in the lubricating oil to a minimum.

In one modification, a spout-like insert is pressed into the drain hole, and the insert is thin-walled so that its end actually creates a sharp edge for properly dripping lubrication onto the corresponding cam of the camshaft. It consists of a tube.

Other features include a lubricating oil passage connected from the tappet guide to the upper part of the screw in the rocker arm stud mounting hole, radial lubrication on the surface of the rocker arm fulcrum tightened by the nut. oil groove,
and lubricating the lower support surface of the swinging arm while avoiding splashing of aerated oil. Also, the portion of the cylinder head underlying the camshaft communicates with the return passage by means of a lubricant discharge orifice, thus eliminating the need for an oil sump to lubricate the camshaft.

Other objects, features, and advantages of the invention will become apparent from the following detailed description and drawings showing preferred embodiments thereof.

1 and/or 2, a hemispherical or dome-shaped combustion chamber 2, a cooling medium cavity 3 in communication with one another, placed between the cooling cavities and provided with a suction valve 4 and a discharge valve 5, respectively. 1 shows a cylinder head 1 of an internal combustion engine with controlled intake and exhaust passages (only part shown) and a spark plug hole for receiving a spark plug 6;

The overhead camshaft 7 extends parallel to the longitudinal direction or longitudinal axis of the internal combustion engine and is rotatably mounted in a plurality of bearing webs 8 (FIG. 1) of the camshaft. Camshaft bearing web 8
Adjacent to the camshaft 7 is a bridge 15 extending from a boss or projection that spans the camshaft 7 and receives the valve stem guides 9 and 10, holes 11 and 12 for the studs attaching the rocker arm fulcrum, and a tappet guide 13. 14 have been created.

A sump 16 and 17 is formed in the bridge 15 adjacent each of the tapepet guides 13 and 14. They normally collect excess lubricant that seeps from the tappet guides 13 and 14 during reciprocating movement of the tappet. The tappet is supplied with oil in a known manner by an oil pump, not shown.

This oil seeping from the tappet guide is removed by an oil discharge hole 1 formed in each of the cams and vertically aligned with the corresponding cam portion on the camshaft 7.
8 (Fig. 3). The oil discharge hole 18 has an oil passage insert 1 made of a thin sheet metal tube or the like.
9 are press-fitted, their ends 22 protruding beyond the bottom wall of the bridge member. This causes the corresponding cams of the camshaft 7 to drip lubricating oil appropriately.

In this case, the oil channel inserts 19 are made, for example, as polygonal tubes and have at their upper ends a flared or funnel-shaped conical part 21 and at their lower ends a dripping edge 22. have.

1 and 2 show that lubricating oil seeping from the top of tappet guide hole 14 flows down the outside of the cylinder head boss and collects in sump 16 and 17. From there, it can drip through the oil passage insert 19 onto the rotating cam of the camshaft 7. It will also be seen that the wide portion 23 extending below the camshaft 7 returns lubricating oil in this portion to the crankcase (not shown) through the connecting lubricating oil return passages 24 and 24'.

Another construction of the present invention is shown in FIG. 3A, in which a molded drip lip 18' is integrally formed into the cylinder head casting across an adjacent oil discharge hole 18. There is. It is also possible to make the oil passage insert 19' (FIG. 3) from a plastic material, in which case the insert is connected to the oil discharge hole 18 by one or more detent lips 20'.
prevented from accidentally slipping out or moving.

FIG. 4 shows another feature of a cylinder head made in accordance with the present invention. In this case, the tappet guide hole is the stud bolt 2 that supports the fulcrum of the swinging arm.
It opens into a lubricating oil passage 25 connected to the threaded portion of the hole 26 into which the lubricating oil passage 7 is installed. A stud 27 screwed into the hole 11 is connected by a nut 28 to a semi-cylindrical swinging arm support piece or fulcrum 29.
is tightened toward the hole step or wall step 30. A sheet metal rocker arm 31, which is engaged at one end by a hydraulic tappet 32 and which presses the valve stem of the valve 4 at the other end, is pushed towards the rocker arm support piece 29. The swinging arm fulcrum 29 and the thin sheet metal swinging arm 31
The lubrication of the semi-cylindrical surface between the corresponding bushing of is of particular importance, and according to the invention it is This is ensured by the lubricating oil groove 33 of. Stud bolt 2
By feeding pressurized lubricating oil into the hole 11 for 31, from where it flows onto the surface of the bushing of the swinging arm 31.

According to the above, the valve gear components of the internal combustion engine can be properly lubricated by a special method, so that the conventional customary immersion or sink lubrication method can be abandoned, which means that the entire lubricating oil of the internal combustion engine can be properly lubricated. Prevent the lubricating oil in the circuit from containing air as much as possible.

While the invention has been illustrated and described with respect to preferred embodiments thereof, it will be apparent to those skilled in the art that many modifications may be made thereto without departing from the scope of the invention.

[Brief explanation of drawings]

FIG. 1 is a plan view of a cylinder head of an internal combustion engine embodying the present invention, and FIG. 2 is a diagram showing the line -
FIG. 3 is an enlarged cross-sectional view of a detail of FIG. 2, FIG. 3A is a cross-sectional view of a modified example of FIG. −
FIG. Reference numeral 1 in the drawing is the "cylinder head," 2 is the "dome-shaped combustion chamber," 4 is the "intake valve," and 5 is the "exhaust valve."
7 is the "overhead camshaft", 8 is the "camshaft bearing web", 9 and 10 are the "valve stem guide", 11 and 1
2 is the "hole for the stud bolt that attaches the fulcrum of the swinging arm", 13 and 14 are the "tappet guides", 15 is the "bridge member", 16 and 17 are the "oil sump", 18
is the "oil discharge hole", 18' is the "dripping edge made with a mold", 19 and 19' are the "inserts", 20' is the "stopping edge", and 21 is the "funnel-shaped conical part" ,2
2 is the "dripping edge", 23 is the "portion extending below the camshaft of the cylinder head", 24 and 24' are the "lubricating oil return passages", 25 is the "lubricating oil passage", and 26 is the "portion for the stud bolt". 27 is a ``socket bolt'', 28 is a ``nut'', 29 is a ``fulcrum device'' or ``swinging arm support piece'', 30 is a ``stage'', 31 is a ``swinging arm'', 32 is a ``tapepet'' , 33 indicate a "radial lubricant groove".

Claims (1)

[Scope of Claims] 1. A cylinder head for an internal combustion engine, comprising a dome-shaped combustion chamber and a bridge member, the combustion chamber being connected to one end of a swinging arm pivotally connected to the cylinder head by a stud. an intake valve and an exhaust valve arranged symmetrically on opposite sides of an overhead camshaft and arranged substantially radially with respect to the surface of the combustion chamber for individual actuation with respect to the rocker arm; The other end engages a tappet movable by the overhead camshaft, and the bridge member is positioned astride the overhead camshaft and defines a hole for the stud and a tappet. Equipped with a tapepet guide that is slidably accommodated,
the tappet guide is configured to receive lubricant that oozes from the tappet guide during movement of the tappet by the overhead cam shaft;
In the cylinder head, an oil sump for collecting lubricating oil seeped from the tappet guide is disposed adjacent to the tappet guide, and the oil sump collects lubricating oil on a cam provided on the overhead cam shaft. A cylinder head having an oil discharge hole located in vertical alignment with a portion of the cam for dripping oil to lubricate the cam. 2. The cylinder head according to claim 1, wherein the cylinder head is provided with a dripping edge on the lower side of the oil sump adjacent to the oil discharge hole to lubricate the cam of the overhead camshaft. A cylinder head characterized in that the lubricating oil is configured to flow along the dripping edge to cause the oil to drip. 3. In the cylinder head according to claim 1 or 2, the oil discharge hole is formed at an enlarged upper end configured as a conical funnel and at the cam of the overhead cam shaft. A cylinder head containing a tubular insert defining an oil passageway and having a lower edge configured as a lower edge projecting beyond the lower wall of the bridge member for dripping lubricating oil. 4. In the cylinder head according to claim 1 or 2, the oil discharge hole is fixed by a retaining edge to define an oil passage so as to prevent the oil discharge hole from being accidentally withdrawn from the oil discharge hole. A cylinder head containing an insert, one end of the insert being configured to drip lubricating oil onto the cam of the overhead camshaft. 5. In the cylinder head according to claim 1 or 2, lubricating oil from the tappet guide is applied to one of the holes for the stud bolt in order to lubricate the hole for the stud bolt. means for pivotally connecting the swinging arm to the cylinder head by the stud bolt;
from a fulcrum device 29, a nut fixing the fulcrum device to the stud, and a radial lubricant groove connecting the surface of the fulcrum device tightened by the nut to the hole for the stud; A cylinder head characterized by: 6. In the cylinder head according to claim 1 or 2, the portion of the cylinder head extending below the overhead cam shaft comprises:
A cylinder head characterized in that it communicates with a lubricating oil return passage for transferring lubricating oil to other parts of an internal combustion engine.