GB2146700A

GB2146700A - I.C. engine cylinder head lubricant bores

Info

Publication number: GB2146700A
Application number: GB08423533A
Authority: GB
Inventors: Herbert Ampferer
Original assignee: Dr Ing HCF Porsche AG
Current assignee: Dr Ing HCF Porsche AG
Priority date: 1983-09-20
Filing date: 1984-09-18
Publication date: 1985-04-24
Also published as: IT8422693A0; ES290704U; GB8423533D0; IT1175750B; ES290704Y; DE3333844A1; GB2146700B; FR2552166B1; FR2552166A1

Abstract

Lubricant grooves 9, 16, 17, 18 in hydraulic tappet bores 8, 12, 13, 14 and camshaft bearings 31 to 33 are supplied through bores 26 to 30 extending longitudinally of the head 2 and bores 34 to 36 parallel to the tappet bores. Lubricant is supplied to the bore 30 through bores 39, 40 and a recess (42, Fig. 1) at the end of the tappet bore collects lubricant for the cam surface (44). <IMAGE>

Description

SPECIFICATION Cylinder head for an internal combustion engine The invention relates to a cylinder head for a preferably multi-cylinder internal combustion engine having moving parts such as an overhead camshaft, valve tappets and the like, with ducts and/or bores being provided for lubricating the moving parts or supplying them with oil under pressure, respectively.

In the case of a known cylinder head of the type described (German Offenlegugsschrift (Laid-Open Specification) 29 52 290), a bore, which extends obliquely to a horizontal plane and communicates with a supply line, is used to supply oil under pressure to, and lubricate, a valve tappet. This design has the disadvantage that it is difficult to observe the usual relatively close tolerances, since this oblique bore tends to run out of true and also produces a relatively large elliptical opening. Although it is possible to provide a sprue with an approach surface at right angles, to the angular position of the bore, on the inside of the tapper bore, this would involve an additional outlay in terms of material and machining.

The object of the invention is to provide a cylinder head whose bores and/or ducts used for the lubrication of and supply of oil under pressure to moving parts can be produced in a simple manner and ensure proper functioning.

The present invention consists in a cylinder head for an internal combustion engine having moving parts such as an overhead camshaft, valve tappets or the like, ducts and/or bores being provided for lubricating the moving parts or supplying them with oil under pressure respectively, and including: a) bores each accommodating a valve tappet and provided with a circumferential groove, the grooves being disposed at the same height: b) the circumferential grooves are interconnected by supply bores provided longitudi nally of the cylinder head and traverse vertical walls of the latter: c) the vertical walls in the region of bearings of the camshaft being provided with lubricating bores which communicate with the supply bores.

The advantages mainly achieved by the invention are that the circumferential grooves, the supply bores and the lubricating bores are easy to produce in terms of manufacturing, i.e. no oblique bores and ensure efficient lubrication of oil supply respectively for the moving parts in the cylinder head. In addition, by virtue of the circumferential grooves, it is also possible for oil to issue at the same time at the top of the valve tappet bore, i.e.

adjacent the camshaft, so that the cam contact surfaces of the camshaft are lubricated without a special arrangement. If the valve tappet bores and the lubricating bores have a common machining direction, additional drilling stations therefor are dispensed with.

In the accompanying drawings: Figure 1 is a partial cross-section through the cylinder head of an internal combustion engine according to the present invention; Figure 2 is a cross-section taken along the line ll-ll in Fig. 1 with certain parts omitted; and Figure 3 is a cross-section taken along the line Ill-Ill in Fig. 2.

In the portion shown the internal combustion engine 1 comprises a cylinder head 2 having a camshaft 3 mounted therein which actuates a valve 5 through a valve tappet 4. A cover 6 is mounted on the cylinder head 2 with a sealing gasket 7 interposed therebeteen. The valve tappet4 is slidable in a bore 8 which is provided with a circumferential groove 9. An hydraulic valve clearance device 11 is supplied with oil under pressure by way of the groove 9 and a wall bore 10 on the valve tappet.

As shown in Fig. 2 (the moving parts are not shown) the cylinder head 2 for a fourcylinder internal combustion engine is provided with an intake and exhaust valve for each cylinder. Further bores 12, 1 3, 14 and 1 5 are provided sequentially next to the bore 8 for the valve tappets 4 and have, respectively circumferential grooves 16, 1 7, 1 8 and 1 9. For reasons of simplicity the illustration of the cylinder head 2 terminates at 20, so that only slightly more than half of the complete cylinder head is shown.

The bores 8,12,13, 14and 15 are bounded, respectively by walls 21, 22, 23, 24 and 25, which are provided with supply bores 26, 27, 28, 29 and 30 adjacent respectively the circumferential grooves 9, 16, 17, 18 and 19 in such a way that the circumferential grooves communicate with one another. The walls 21, 23 and 25 extend upwardly towards the camshaft 3 and form bearings 31, 32 and 33 therefor.

In order to supply the bearings 31, 32 and 33 with lubricating oil, lubricating bores 34, 35 and 36 are provided, which communicate, respectively, with the supply bores 26, 28 and 30. The lubricating bores 34, 35 and 36 have the same machining direction A, i.e.

vertical, as the bores 8, 12, 13, 14 and 1 5.

The supply bores 26, 27, 28, 29 and 30 are preferably formed by a single drill which is guided at 37 beginning from left to right in the longitudinal direction B-B of the cylinder head. A pressed-in closure member 38 closes the supply bore 26 from the outside in a fluidtight manner.

The supply bore 30 disposed in the longitudinal median plane of the valve tappet bores communicates with a feed bore 39 which extends at least in part in the wall 25 and communicates at 40 with an oil supply system not shown in detail (Figs. 2 and 3).

The end portion 41 of the bore 8 which extends adjacent the camshaft 3 is provided with a channel-shaped recess 42 (Fig. 1) which is used for collecting lubricating oil 43 for the contact surface 44 of the camshaft 3.

This lubricating oil 43 at the same time enters the recess 42 from the annular groove 9, i.e.

the contact surface 44 is supplied with oil from cracks in a defined manner.

Claims

1. A cylinder head for an internal combustion engine having moving parts such as an overhead camshaft, valve tappets or the like, ducts and/or bores being provided for lubricating the moving parts or supplying them with oil under pressure respectively, and in cluding:- a) bores each accommodating a valve tappet and providing with a circumferential groove, the grooves being disposed at the same height; b) the circumferential grooves are inter connected by supply bores provided longitudinally of the cylinder head and traverse vertical walls of the latter; c) the vertical walls in the region of bearings of the camshaft being provided with lubricating bores which communicate with the supply bores.

2. A cylinder head according to claim 1, wherein the valve tappet bores and the lubricating bores have a common machining direction.

3. A cylinder head according to claim 1 or 2, wherein the supply bores are positioned on a common median axis of the valve tappet bores.

4. A cylinder head according to any of claims 1 to 3, wherein at least one of the supply bores is provided with a feed bore.

5. A cylinder head according to any of claims 1 to 4, wherein supply bores in end walls of the cylinder are provided with closure elements.

6. A cylinder head substantially as described with reference to, and as illustrated in, the accompanying drawings.