Hydraulic valve clearance compensation element for internal combustion engines

Abstract

A hydraulic lash adjuster for reciprocating piston internal combustion engines, comprising a hollow cylindrical housing (6) arranged in a cylinder head (8) of the internal combustion engine, wherein an interior of the cylinder head is wetted with oil or oil mist, wherein a pressure piston (1) which is axially movable relative to the housing and is connected to a transmission element of a valve train of the internal combustion engine is installed in the housing (6), wherein at least one opening (5) is provided for the supply of oil, from which opening (5) at least one longitudinal groove (7) is machined, via which longitudinal groove (7) the oil reaches the opening (5), characterized in that the at least one opening (5) is provided in the wall of the housing (6), wherein the at least one longitudinal groove (7) is machined on the outer circumference of the housing (6) and extends to an upper edge of the housing (6), wherein a collecting chamber (9) designed as a recess is provided on the cylinder head (8),in which the housing (6) is arranged, wherein the collecting chamber (9) is connected to the interior of the cylinder head (8) wetted with oil or oil mist.,

Description

[0001] The invention relates to a hydraulic lash adjuster for reciprocating piston internal combustion engines, having a hollow cylindrical housing arranged in a cylinder head of the internal combustion engine, wherein an interior of the cylinder head is wetted with oil or oil mist, wherein a pressure piston which is axially movable relative to the housing is installed in the housing and which is connected to a transmission element of a valve train of the internal combustion engine, wherein at least one opening is provided for the purpose of supplying the oil, from which opening at least one longitudinal groove is machined, via which longitudinal groove the oil reaches the opening.

[0002] JP 2014 - 70 559 A discloses a hydraulically self-contained support element. Its housing, with a funnel-shaped, wide-spread oil collection collar, protrudes beyond the flat upper surface of the cylinder head. A longitudinal groove is provided on the outer circumference of the pressure piston, which extends from the funnel-shaped collar of the housing on the inside and leads downstream to an opening in the pressure piston.

[0003] JP 2009 - 19 584 A shows a hydraulic support element, also without an external oil supply, whose pressure piston extends above the top of the cylinder head. The support element is surrounded on the head side by a recess that forms an oil storage pocket. The pressure piston has an opening axially above the housing for the oil collected in the recess.

[0004] A hydraulic lash adjuster with an external pressurized oil supply is known from DE 39 35 027 A1. An oil gallery located in the cylinder head of the internal combustion engine is connected to the opening in the housing wall. Besides the fact that an oil gallery is usually designed as a bore and is complex to manufacture, the pump supplying the internal combustion engine with oil must also be connected to the oil gallery and provide a correspondingly increased amount of oil.

[0005] Another hydraulic lash adjuster with external pressure oil supply is described in DE 10 2008 005 768 A1. The pressure oil supply is provided via a base of the housing. A longitudinal groove is provided on the outer surface of the housing, which is cut by an oil channel in the cylinder head and leads downstream to an inlet in the base.

[0006] The object of the invention is to improve and design a hydraulic lash adjuster in such a way that the described disadvantages are eliminated. This should be achieved using simple, cost-effective means.

[0007] According to the invention, the object is achieved in that the at least one opening is provided in the wall of the housing, wherein the at least one longitudinal groove is incorporated on the outer circumference of the housing and extends to an upper edge of the housing, wherein a collecting space designed as a recess is provided on the cylinder head, in which the housing is arranged, wherein the collecting space is connected to the interior of the cylinder head wetted with oil or oil mist.

[0008] This design ensures that oil reaches the opening of the hydraulic lash adjuster via the longitudinal grooves without the need for a separate oil supply line in the cylinder head. Oil and oil mist are already present in the space above the cylinder head inside the cylinder head cover, since other elements of the cylinder head are also supplied with oil. The collecting space is designed as a recess so that oil can collect there. In a further design of the invention, a contour is formed around the edge of the housing which serves as a countersink and improves the inflow of oil. The base of the collecting space is preferably designed as a slope to improve the inflow of oil. In a further design of the invention, it is proposed that a circumferential groove be machined on the outer circumference of the housing at the level of the opening(s), and that the longitudinal groove(s) extend as far as the circumferential groove.This means that the arrangement of the longitudinal groove is not tied to the opening(s). The longitudinal grooves can easily be designed as flattened sections, with their cross-section corresponding to a circular segment.

[0009] The invention is described in the drawing: • Fig. 1 shows a side view of a hydraulic lash adjuster, • Fig. 2 shows a longitudinal section through the play compensation element according to Fig. 1, • Fig. 3 shows a plan view of the hydraulic play compensation element according to Fig. 1, • Fig. 4 shows a partial section through a cylinder head with a collecting chamber and an inserted hydraulic lash adjuster, • Fig. 5 shows a plan view of the partial section of the cylinder head, • Fig. 6 shows a partial section of the cylinder head similar Fig. 4 with modified contour around the hydraulic play compensation element and • Fig. 7 shows a plan view of the partial section of the cylinder head according to Fig. 6.

[0010] In the Fig. 1 to 7, as far as shown in detail, 1 denotes the pressure piston of a hydraulic lash adjuster, which is hollow and is part of a storage chamber 2. Adjacent to the pressure piston 1 is an auxiliary piston 3, which is also part of the storage chamber 2 and has a partition wall in which a valve is installed, to which a high-pressure chamber 4 of the hydraulic lash adjuster is connected. The auxiliary piston 3 and the pressure piston 1 are installed in a housing 6, which is designed as a hollow cylinder and is installed in a cylinder head 8 or a component of a cylinder head of an internal combustion engine. Bores are provided radially in the wall of the pressure piston 1, to which openings 5 ​​in the wall of the housing 6 are connected. Starting from the openings 5, longitudinal grooves 7 are machined on the outer surface of the housing 6, which extend to the upper edge of the housing 6. The housing 6 of the hydraulic lash adjuster is, as shown in the Fig. 4 to 7, is installed far enough into the cylinder head 8 for oil to reach the longitudinal grooves 7. A collecting chamber 9, which is designed as a depression, is incorporated around the installation point of the hydraulic lash adjuster in the cylinder head 8. The bottom of the collecting chamber 9 or the depression is inclined so that oil, which is present as oil or oil mist above the cylinder head 8 below a cylinder head cover of the internal combustion engine, can collect in the collecting chamber 9. In order to improve the collection of oil around the hydraulic lash adjuster, a countersunk contour 10 is provided which encloses the hydraulic lash adjuster. The lash adjuster is installed far enough into the cylinder head 8 that the upper edge of the housing 6 is in contact with the bottom of the countersunk contour 10.

[0011] This inventive design ensures that sufficient oil is supplied to the hydraulic lash adjuster element(s) on the cylinder head of a reciprocating piston internal combustion engine, so that a dedicated oil supply line is not required. Reference number list 1 pressure piston 2 storage room 3 auxiliary pistons 4 High-pressure room 5 openings 6 housings 7 longitudinal grooves 8 cylinder head 9 Assembly room 10 Countersunk contour

Claims

[1] Hydraulic play compensation element for reciprocating piston internal combustion engines, with a hollow cylindrical housing (6) arranged in a cylinder head (8) of the internal combustion engine, wherein an interior of the cylinder head is wetted with oil or oil mist, wherein a pressure piston (1) which is axially movable relative to the housing (6) is installed in the housing (6) and is connected to a transmission element of a valve train of the internal combustion engine, wherein at least one opening (5) is provided for the purpose of supplying the oil, from which opening (5) at least one longitudinal groove (7) is machined, via which longitudinal groove (7) the oil reaches the opening (5), characterized byin that the at least one opening (5) is provided in the wall of the housing (6), wherein the at least one longitudinal groove (7) is incorporated on the outer circumference of the housing (6) and extends up to an upper edge of the housing (6), wherein a collecting space (9) designed as a recess is provided on the cylinder head (8), in which the housing (6) is arranged, wherein the collecting space (9) is connected to the interior of the cylinder head (8) wetted with oil or oil mist. [2] Hydraulic play compensation element according to claim 1, characterized by that a countersunk contour (10) is provided on the cylinder head (8) around the edge of the housing (6). [3] Hydraulic play compensation element according to claim 1 or 2, characterized by that the bottom of the collecting chamber (9) is designed as a slope. [4] Hydraulic play compensation element according to one of the preceding claims, characterized bythat a circumferential groove is incorporated on the outer circumference of the housing (6) at the level of the at least one opening (5) and that the at least one longitudinal groove (7) extends to the circumferential groove. [5] Hydraulic play compensation element according to one of the preceding claims, characterized by that the at least one longitudinal groove (7) (5) is designed as a flattening on the outer wall of the housing.

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