DE102008015854A1 - Valve seat ring for sealing in cylinder head of internal combustion engine, has circular geometry and is made up of wear resistant metal, where valve seat ring is connected with another valve seat ring to ring packet by bar - Google Patents

Abstract

The valve seat ring (1) has a circular geometry and is made up of wear resistant metal. The valve seat ring is connected with another valve seat ring to a ring packet by a bar. A mold core is conducted by the valve seat ring. The valve seat ring is conically arranged. The bar has a small fusing point opposite to the valve seat ring.

Description

The The invention relates to a pouring into a cylinder head an internal combustion engine provided valve seat ring, the one in Has substantially annular design and made of wear-resistant Metal is made.

Valve seat rings are important components within the valve train and essential for the perfect combustion process in the cylinder. Along with the valve they have a perfect seal of the combustion chamber to ensure that the required compression or combustion pressures be achieved in the cylinder. An increased wear leads to changes in the combustion conditions and thus to worse power and emission data of the engine. Valve seat rings are at the mouths of the inlet and outlet channels the cylinder heads arranged rings. These are not just the hammering effect of the valves exposed but are also under the influence of hot explosive gases.

Usually Valve seat rings are pressed or shrunk into the cylinder head. Here are tight and therefore expensive manufacturing tolerances in the Manufacture of valve seat rings and it is after the Pouring the cylinder head an elaborate processing of Mounts are required for the valve seat inserts in the cylinder head. In addition, the valve seat rings have to be cooled for shrinking are and the cylinder head may be heated got to.

Furthermore, it is possible to pour the valve seat rings in the cylinder head. Valve seat rings with annular inner and outer surfaces, which are poured into the cylinder head, are made of DE 39 37 402 A1 known. Molded valve seat inserts open up numerous advantages in engine production. Thus, the measures usually required by the pouring of the valve seat rings during assembly account for the most part. A design of the valve seat rings with an enlarged contact surface to the cylinder head is possible, whereby an improved heat transfer takes place in the cylinder head. Thus, these valve seat rings are particularly good use on the outlet side. Due to the improved heat transfer, the amount of heat in the thermally most highly stressed region of the valve seat ring, the con tact surface between the valve and valve seat ring, can be dissipated faster in the cylinder head. In addition, the overall rigidity of the cylinder head and valve seat ring structure is greatly enhanced by the positive engagement and the frictional engagement caused by shrinkage stresses as the cylinder head cools. On the one hand, the increased contact area between the valve seat ring and the cylinder head is responsible for the improved heat transfer, on the other hand, the improved material contact due to the casting and the superimposed shrinkage stresses. The increased overall stiffness and reduced temperature level increase the life of the valve seat rings. The valve seat rings can be produced cost-effectively as a sintered ring or as a cast ring from all common seat ring materials, for example, from high and low alloyed sintered steels or high and low alloyed casting grades. The blanks are then poured during casting of the cylinder head in this head. The finishing of the seat ring contour in the area of the contact surface to the valve and in the outlet channel area is carried out as in the known solutions in the final cylinder head machining.

Also the EP 0 092 081 B1 shows valve seat rings, which are poured into the cylinder head. By eliminating the pressing of the valve seat rings while maintaining exact fits the cylinder head can be made simplified. For valve seat rings, among other things because of the use of unleaded fuels very hard and wear-resistant materials are required, the machining is correspondingly expensive. Furthermore, the improved heat dissipation from the valve seat ring in the cylinder head is possible.

In the from the DE 10 2005 050 509 A1 Known valve seat rings can be the intake or Auslasskanalgeometrie up to the sealing surface for the gas exchange valve, so zoom zoom up to the inner peripheral surface of the valve seat ring, and edit in a simple way. Furthermore, in the combustion chamber in the area of the valve seat rings more freedom in the geometry determination. Since the valve seat ring according to the invention does not protrude into the intake passage, there is advantageously a lesser wear of the cutting tools during the machining of the intake or exhaust ducts, since the hard valve seat rings are not machined. The L- or Y-shaped cross-section of that region of the valve seat ring which projects into the cylinder head results in a good force introduction of the gas exchange valve strokes from the valve seat ring into the cylinder head.

In contrast, valve seat rings from the DE 103 38 386 B3 known, which are designed disk-shaped in a structurally simple manner. Thereafter, the fact that two individual layers are materially different with increasing temperature stretch and thus a so-called. Bimetallic effect is given in terms of minimizing a thermally induced distortion of the cast components exploited, which usually sets at the operating temperature of the finished reciprocating engine. The two layers of the iron-based or aluminum-based material are targeted in this regard both in circumferential as well varied and optimized in the axial direction with respect to their local layer thickness, so that circumferential ovalizations and axial Taillierungen or toning due to the said locally differently sized bimetallic effect can be compensated. Such optimized valve seat rings seal better in all temperature ranges than conventional valve seats, so that with a lower pressure drop in the working space, with a higher efficiency and thus can be expected with a lower fuel consumption.

The from the DE 929 157 known valve seat ring is inserted into the cylinder head such that only a small part of its surface is exposed to the hot gases, while the vast majority of the surface of the valve seat ring is covered by the wall of the cylinder head. The largest part of the overall surface of the ring is thus embedded in the cylinder head, so that the ring supplied relatively small amounts of heat due to the large transition surfaces are quickly dissipated to the surrounding cooled cylinder head. Heat accumulation and deformation in the ring are largely avoided in this way. Advantageously, the valve seat ring is poured during casting of the cylinder head with; but it can also be shrunken. The valve seat ring may be tapered and cast in the wall of the cylinder head. But it can also be designed cylindrical and embedded behind a projection of the wall of the gas channel in the cylinder head, so that it is largely protected from the direct influence of hot gases.

The DE 43 01 632 A1 describes a valve seat ring which is designed disk-shaped in a structurally simple manner. The valve seat ring forms only part of the total sealing surface of the cylinder head. The valve seat ring acts as a sealing barrier in the overall system with excellent heat dissipation and easy machinability. In this case, optionally by means of a laser, a reflow alloying between the cylinder head base material and the valve seat ring can be performed. Furthermore, a simple valve seat ring is proposed with regard to the configuration, one of which - preferably, however, both - ring surface is coated with a porous hard layer. These hard layers ending at the sealing surface of the valve seat ring form circular, extremely wear-resistant barriers, which ensure the wear resistance of the valve seat ring, with good machinability of the valve seat ring being maintained. In a preferred embodiment of the valve seat ring this is designed in manufacturing technology simple manner as a plate spring and forms with its inner peripheral surface only a ring-shaped portion of the total sealing surface, which consists of 30% up to 70% of the cylinder head material. This results in excellent heat dissipation for the globe valve and extensive, comprehensive embedding of the valve seat ring in the cylinder head.

The Valve seating rings must be accurate before pouring be positioned to avoid rejects and rework. there It is particularly difficult, the valve seat rings of a cylinder to position each other exactly. Also, the pouring is the Valve seat rings in the cylinder head due to the high number of Items with a considerable effort in the mechanical Manufacturing connected.

In front In this background, the invention is based on the object Valve seat ring of the type mentioned in such a way, that the valve seat rings of a cylinder easily and quickly accurate can be positioned to each other, causing rejects and rework avoided as well as the number of items and the effort at the mechanical manufacturing can be reduced.

These Task is solved with a valve seat ring according to the Features of claim 1. The dependent claims relate particularly expedient developments of the invention.

According to the invention So provided a valve seat ring with at least one other Valve seat ring is connected by a bridge to a ring package. This makes it possible to have several already at the same time Positioned valve seat rings in the mold to arrange. Due to the high position accuracy of each other connected valve seat rings to each other, it is also possible that the valve seat rings as a guide for the mandrels serve. In contrast to pressing in the valve seat inserts pouring no extra tension in the cylinder head. The connected valve seat rings need a much smaller space for their seat, which the cylinder head in the area between the valve seat rings lower Exposed to peak loads. Connected to a ring packet Valve seat rings are positioned exactly to each other, causing rejects and rework can be avoided, the number of items and Thus, the effort in the mechanical manufacturing is reduced, because manufacturing is easier and faster.

Valve seat rings often have a substantially annular Design on. A particularly good sealing effect between the valve seat ring and The valve can be reached by the valve seat ring conical is designed.

The bridge between the valve seat rings can be maintained during casting of the cylinder head. This could lead to an expansion of the ring package. It is favorable that the web has a lower melting point than the valve seat ring. This makes it possible that when casting the cylinder head, the web loses its function and rises or evaporates in the melt. In the finished cylinder head, the cast-in valve seat rings are only indirectly interconnected via the material of the cylinder head.

Of the Valve seat ring acts as a sealing barrier in the overall system excellent heat dissipation and easy machinability. It is advantageous that the valve seat rings of a cylinder to Ring packets are connected. Thus, the valve seat rings are a Cylinders due to production perfectly aligned. One Another advantage is that the valve seat rings of several cylinders a motor are connected to a ring package. This is a easy handling in mechanical production possible, because the number of items is greatly reduced. Furthermore is increases the position accuracy of the valve seat rings.

It is recommended, a ring package of several valve seat rings and webs at the same time, in particular by sintering to produce. If several valve seat inserts connected by webs, then it is favorable that in a ring package, the webs between the Valve seat rings independent of the valve seat rings, in particular by sintering, are producible. Thus, it is possible the webs, in particular made of metallic materials quickly, easily and to produce in large series.

The Invention allows for numerous embodiments. To further clarify its basic principle, one of them is in the drawing and will be described below. These shows in

1 a sectional view of a valve seat ring;

2 a view of a ring package for a cylinder;

3 a view of a ring package for two cylinders;

4 a view of several cast in a cylinder head valve seat inserts.

1 shows a section of a cylinder head 2 a reciprocating internal combustion engine with a gas outlet channel 3 , of a not shown, in a valve axis 4 arranged lifting valve is controlled. The lift valve acts with one in the cylinder head 2 symmetrical to the valve axis 4 provided valve seat ring 1 together. The valve seat ring 1 consists of a high-alloy steel and is designed similar to a diaphragm spring. The valve seat ring 1 is when casting the cylinder head 2 made of an aluminum light alloy with cast-in.

The 2 and 3 show a ring package 5 from valve seat rings 1 in which several valve seat inserts 1 by means of a bridge 6 connected to each other. In the 2 are four valve seat rings 1 a cylinder to a ring package 5 connected. This in 3 illustrated ring package 5 each includes four valve seat rings of two cylinders.

In 4 is a the combustion chamber of a reciprocating internal combustion engine associated side of a cylinder head 2 displayed. The cylinder head 2 has sixteen (openings of the gas outlet channels 3 and the gas inlet channels 7 the reciprocating internal combustion engine on. In the cylinder head 2 are the valve seat rings 1 poured, the webs are evaporated during the casting process.

1

Valve seat ring

2

cylinder head

3

Gas exhaust duct

4

valve axis

5

ring package

6

web

7

Gas inlet channel

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 3937402 A1 [0004]
• EP 0092081 B1 [0005]
• - DE 102005050509 A1 [0006]
• - DE 10338386 B3 [0007]
• - DE 929157 [0008]
• - DE 4301632 A1 [0009]

Claims (8)

A for pouring into a cylinder head ( 2 ) provided an internal combustion engine valve seat ring ( 1 ), which has a substantially annular shape and is made of wear-resistant metal, characterized in that the valve seat ring ( 1 ) with at least one other valve seat ring ( 1 ) by a bridge ( 6 ) to a ring package ( 5 ) connected is. Valve seat ring ( 1 ) according to claim 1, characterized in that by means of the valve seat ring ( 1 ) A mold core is feasible. Valve seat ring ( 1 ) according to claims 1 or 2, characterized in that the valve seat ring ( 1 ) is conical. Valve seat ring ( 1 ) according to at least one of the preceding claims, characterized in that the web ( 6 ) one opposite the valve seat ring ( 1 ) has lower melting point. Valve seat ring ( 1 ) according to at least one of the preceding claims, characterized in that a plurality of valve seat rings ( 1 ) of a cylinder to a ring package ( 5 ) are connected. Valve seat ring ( 1 ) according to at least one of the preceding claims, characterized in that a plurality of valve seat rings ( 1 ) of several cylinders of an engine to a ring package ( 5 ) are connected. Valve seat ring ( 1 ) according to at least one of the preceding claims, characterized in that a ring packet ( 5 ) of several valve seat rings ( 1 ) and bridges ( 6 ) at the same time, in particular by means of sintering, can be produced. Valve seat ring ( 1 ) according to at least one of the preceding claims, characterized in that the webs ( 6 ) between the valve seat rings ( 1 ) independent of the valve seat rings ( 1 ), in particular by sintering, can be generated.