JPS604392B2 - Ring-shaped reinforcement for piston ring grooves of light metal pistons - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an integrally molded ring-shaped reinforcement for a piston ring groove of a light metal piston, the ring support having a cylindrical hole provided inside the piston. The hole is filled with piston material when installed in the piston.

The main problem that arises with the use of ring supports for reinforcing piston ring grooves is the secure fixation of the ring supports within the piston material.

A basic distinction is made between the fixation types: chemical bonding of the ring support within the piston material, mechanical bonding, and bonding that combines these two types of bonding. In order to obtain a good mechanical connection, ring supports with various external shapes are known. It is important then that the ring support profile is configured in such a way that the adjacent piston material can engage in the backcut opening for good mechanical support. It is known from German Patent No. 1 224 104 to produce contours of this type, for example, by means of a slotted molding of a ring support with a number of irregular back-tapering edges. It is. A similar purpose is achieved by providing a dovetail-like engagement device on the outer surface of the ring support, as known from Austrian Patent No. 247 072. In short, the ring support must cut back into the piston material in all directions. This type of engagement does not occur with known ring supports that have holes for receiving piston material.

For example, Patent No. 11659 of the Federal Republic of Germany
According to the ring support device disclosed in No. 34,
This is because the bore extends parallel to the longitudinal axis of the piston and is therefore not suitable for supporting the ring support without shifting in the direction of the longitudinal axis of the piston. The same holds true for the cone-shaped bores which are arranged in the ring carrier parallel to the longitudinal axis of the piston, as known from German Patent No. 1,038,833. In this case, ignoring the fact that it is just a thin metal insert for the side surface of the piston ring groove, if it is a round-shaped hole that is arranged parallel to the piston axis, it is true that the small diameter is from the large flange. The ring support can be reliably locked in the direction toward the hole, but cannot be locked in the opposite direction, that is, in the direction from the small diameter portion of the hole to the large and light portion. However, it is in this latter direction that it is especially important to obtain a mechanical lock, such as that obtained by the bite of the dovetail mechanism. In short, the mechanical locking of the individual holes 1 of the ring support, which is integrally molded in the piston material, cannot be achieved unless, for reasons of manufacturing technology, the larger hole diameter is always located on the outer surface of the ring support. It is not possible to simply create a circular sushi-shaped hole that will not cause the problem. For this purpose, patent no. 103883 of the Federal Republic of Germany
In the ring groove reinforcing insert disclosed in No. 3, not only the holes but also additional dovetail-shaped engagement features are provided. Because of this difficulty in manufacturing a notch, such as a circular hole, which has a biting effect and is easily machined, US Pat. No. 2,996
In the case of the ring support disclosed in No. 341,
Two sections, separated from each other, are required to reinforce the upper and lower surfaces of the groove.

However, these two members only touch each other loosely at the bottom of the miso 1. Therefore, it is practically impossible to prevent displacement in all directions. The object of the invention is to provide a ring support which can be locked uniformly and reliably in all directions in the piston material simply by using the ring support with a cylindrical hole therethrough. be.

A particularly important requirement in this case is that the locking recesses can be easily manufactured. The first aspect of the present invention that solves this problem is that the axis of the hole is aligned with the longitudinal axis of the piston,
The reason is that it is inclined with respect to a plane perpendicular to the longitudinal axis of the piston.

This slanting of the bore ensures that the piston material placed in the bore reliably prevents axial displacement of the ring support as well as radial displacement of the piston.

Simply put, the slanted holes should achieve a locking action based on the following principle. In other words, it is based on the principle that when driving a nail into a bookcase, by driving the nail at an angle rather than straight, the lid cannot be raised upwards easily. It is advantageous if holes with mutually different slopes are provided in the ring support.

Adjacent holes may be inclined with respect to each other, for example in the shape of an "X". The holes are usually drilled into the solid material of the ring support (not yet having ring grooves). In the case of cast ring supports, the holes are of course formed simultaneously with the casting inserts. In special cases where the inclination of the hole is at an angle of 90° and is perpendicular to the longitudinal axis of the piston, that is, in a plane perpendicular to the axis of the piston, the axis of the hole is arranged so that it does not intersect with the longitudinal axis of the piston. be done.

A ring support constructed in accordance with the invention has the great advantage that it is easier to manufacture than known ring supports having back-cut cutouts on the outer surface. All holes can be easily made in the working process by inserting a drill into the ring support at various angles. In this way the desired locking effect can be achieved in a very simple manner. Next, the configuration of the present invention will be explained in detail based on the illustrated embodiments.

The ring support 1, which is only partially illustrated, is penetrated by holes 2 which are substantially X-shaped and oblique to one another.

If the ring support is installed in a light metal piston, said bore 2 is filled with the light metal of the piston. Piston material passing through the holes in the ring support locks the ring support inside the piston. The filling of the bore 2 is usually carried out by compaction of piston light metal material (for example a forged piston), since the entire piston material is compressed during the forming of the piston. However, it is also possible to inject the piston material into the bore 2 (eg a cast piston). The ring 3 to be molded into the ring support for accommodating the piston ring is designated by the reference numeral 3 in the drawing.

[Brief explanation of the drawing]

The drawings are schematic diagrams showing one embodiment of the present invention, and FIG. 1 is a cross-sectional perspective view of a ring-shaped reinforcing body, and FIG. 2 is a partial plan view of the ring-shaped reinforcing body. DESCRIPTION OF SYMBOLS 1... Ring support body, 2... Hole, 3... Groove. FIG. IFIG. 2

Claims (1)

[Claims] 1. An integrally molded ring-shaped reinforcement for the piston ring groove of a light metal piston, which has a cylindrical hole provided inside the ring support and is incorporated into the piston. In the type in which the hole is filled with piston material in the state, the axis of the hole 2 is the longitudinal axis of the piston,
A ring-shaped reinforcement for a piston ring groove of a light metal piston, characterized in that the groove is inclined with respect to a plane perpendicular to the longitudinal axis of the piston. 2 An integrally molded ring-shaped reinforcing body for a piston ring groove of a light metal piston, which has a cylindrical hole provided inside the ring support, and the piston is inserted into the hole when installed in the piston. A light metal piston of the type filled with material, characterized in that the axis of the hole 2 passing through the ring support lies in a plane perpendicular to the longitudinal axis of the piston and does not intersect with the longitudinal axis of the piston. Ring-shaped reinforcement for the piston ring groove.