DE102005028316B4 - Method for reworking a crankcase and cylinder crankcase - Google Patents

Abstract

method for reworking a crankcase (1, 15), wherein the crankcase (1, 15) 15) at least one cast in a die-casting and in an insert (7) has inserted bushing (3), characterized that the crankcase (1, 15) is treated by a melt metallurgical process, wherein at least in the region of an interface (13) between the at least a bushing (3) and the encapsulation (7) repaired defects (9, 19) be repaired by means of the melt metallurgical Method between the bushing (3) and the encapsulation (7) provided a radial support becomes.

Description

The invention relates to a method for reworking a crankcase and a cylinder crankcase for an internal combustion engine according to the preamble of claim 1 and that of claim 7, as it is based on the generic as the basis DE 195 23 484 A1 as known.

The DE 195 23 484 A1 relates to a crankcase, the cast in a die-cast and cast in a cast liners has. In this encapsulation, defects such as voids and / or binding errors or the like may occur.

From the AT 405 379 B is a method for repairing surface defects in metal moldings known in which the defects are treated by laser deposition welding.

A repair method in which the laser deposition method by means of a pulsed laser is made from the DE 100 05 874 A1 known.

Cylinder crankcase from Internal combustion engines, for example V6 or V8 gasoline engines, usually become in die casting produced. A cylinder tread therefor typically consists of a Silitec liner, which is used during the die casting process is poured over.

A remelting process for producing a component for an internal combustion engine, namely a gas exchange valve, is in the document DE 35 17 077 described. In this case, a valve seat is attached to a valve disk of the gas exchange valve in such a way that tank material introduced into a circumferential recess is connected to the base material of the gas exchange valve by the remelting process. Seams at the interface between base material and armor material are remelted by a high power laser to provide a protective layer surrounding the valve disk.

isolated can on cylinder crankcases Defects, such as voids or binding errors, occur. The binding errors are on an interface between the Silitec liner and a surrounding Umguss limited. Lunker can also in other places of the cylinder head side surface due a decrease in volume on cooling of the crankcase after die casting arise.

In A series production is provided, all cylinder crankcases in the frame a quality control, priority after implementation the die casting process and mechanical processing, for errors, especially on the previously mentioned defects, to investigate. faulty cylinder crankcase are then usually removed and scrapped. Thereby There is a need for a suitable post-processing of faulty or damaged Engine blocks.

task The invention is to present a method with which a connection a bushing to a crankcase can be improved.

In front This background is a method with the features of the claim 1 and a cylinder crankcase presented with the features of the independent claim 7.

The inventive method is intended for reworking a crankcase. This crankcase has at least one liner on, in a die-casting process poured around and placed in an encapsulation. The process draws characterized by the fact that the crankcase by a melt metallurgical Procedure is treated.

By The method can between the bushing and the encapsulation of the crankcase a radial support and thus a homogeneous metallic transition of the liner to the Umlauf be provided. As a result, a metallic and / or fusion metallurgical connection of the liner to the casting in an interface or in a parting plane of the crankcase in a so-called web area improved and extended operating life of the crankcase. The bush can be made from Silitec, an aluminum-silicon compound his, the perimeter is usually made of aluminum or an aluminum alloy, such as AlSi9Cu3.

If the crankcase, in particular a cylinder crankcase for an internal combustion engine, at least one flaw should have, so it is possible, the at least one defect with the melt metallurgical process mend and thus rework with flawed crankcase and / or repair. These must can not be scrapped and can instead one be supplied to another production step. With this postprocessing option can Production costs are significantly reduced.

With the method takes place in the region of the interface by material deposition an intimate, in particular fusion metallurgical clamping of the bushing, for example. A cylinder liner, to the encapsulation or the cylinder crankcase. Thus, will Preventing a set or slipping a multi-layer steel seal on the cylinder crankcase and improves a tightness in an operation of an internal combustion engine in small land areas. In addition, a heat transfer and / or heat dissipation within the cylinder crankcase is favored. A distortion or deformation of a cylinder surface, which is provided by the cylinder liner within the cylinder crankcase, and a Ölkohleaufbau under Mehrlagenstahldichtung can be avoided. Thus, process reliability can also be optimized within a production. Especially in terms of tightness reserves of the crankcase, the quality is increased within a series production.

By the procedure can particular imperfections in the region of an interface between the Bushing and the Umguss be repaired. The die casting process is usually provided a connection of the bushing to the crankcase in the area the interface provide. As the practice shows, however, some of the crankcase in the area of these interfaces Defects occur.

It can be provided that the crankcase, in particular after performing the die casting process, So after inserting the bushing in the overcast, on defects is examined. This can be done by a surface inspection or under Use of electromagnetic radiation, for example X-rays. If Such examined crankcase at least one defect should this be in a suitable processing station in the area of the at least one defect carrying out the fusion metallurgical Treated procedure.

When Melt metallurgical processes offer suitable welding processes or build-up welding process in which on a surface of the crankcase preferably at a defect and / or along the interface between the at least one bushing and the Umguss, a material order he follows. As a fusion metallurgical process, for example, laser deposition welding is suitable. It can the defects are repaired by the laser deposition welding such that these defects are closed by material application. On this way becomes a welded joint provided by in the area between the bushing and the Umguss a firm connection can be realized.

Of Furthermore, it is possible Mistakes on a combustion chamber side of the crankcase mend. For defects on the combustion chamber side of the crankcase acts it usually to so-called voids or pores, which upon cooling after performing the die casting can arise.

In a further method step may be provided that the Defects before implementation of the fusion metallurgical process are widened. Consequently Is it possible, a correction of the defects not only superficial but also within of the crankcase to realize.

at execution of the method may be a pulsed laser beam source for providing a pulsed laser beam are used. This will that achieves an energy input in the crankcase only is low, leaving a heat affected zone remains small and structural properties in the liner and in a base material from which the Umguss is formed, preserved.

With the melt metallurgical process, in particular laser deposition welding, is on a surface of the crankcase by appropriate focusing of the laser beam on the surface locally limited melting pool produced. This molten bath is while the processing is fed to a preferably wire-shaped filler material and in this case, for example, introduced into the defect.

The Cylinder crankcase according to the invention for a Internal combustion engine has at least one in a die casting process cast-in-place and thereby inserted into an encircling cylinder liner on. For post-processing of the cylinder crankcase is a melt metallurgical Procedure provided.

At the cylinder crankcase existing defects are due to the melt metallurgical process repaired. Furthermore is with the melt metallurgical process between the cylinder liner and the Umpass a radial support provided.

This cylinder crankcase can therefore at least one provided by post welded joint have the metallic connection of the cylinder liner.

Further Advantages and embodiments of the invention will become apparent from the Description and attached drawing.

The Invention is based on an embodiment schematically shown in the drawing and is below under Referring to the drawings described in detail.

there demonstrate:

1 a flawed web portion of a surface of a crankcase in a schematic representation.

2 the web area of the crankcase 1 After processing the defects in a schematic representation.

3 a flawed area of a surface of a crankcase in a schematic representation.

4 the area of the crankcase from 3 After processing the defects in a schematic representation.

The Figures become coherent and overarching described, like reference numerals designate like components.

1 shows a schematic plan view of a web area 2 a crankcase 1 , For example, a cylinder crankcase, for an internal combustion engine. For producing such a crankcase 1 is provided that a liner 3 or cylinder liner with a cylinder surface 5 cast in a die-casting process and thereby in an encapsulation 7 is introduced. After completion of the pressure casting process is the liner 3 from the infusion 7 completely enclosed. Nevertheless, even if the die casting process is carried out carefully, it may become defective 9 and thus connection errors of the liner 3 to the casting 7 or the crankcase 1 come.

In the present inventive method is provided, such defects 9 by a melt metallurgical process, for example. By laser deposition welding with a pulsed laser beam to mend. Likewise, with the inventive method, a connection of the liner 3 to the Umguss 7 and thus to the cylinder crankcase 1 regardless of whether the crankcase 1 defects 9 or not, be improved.

2 shows the crankcase 1 out 1 after processing by the melt metallurgical process. This is done by laser deposition welding on the web area 2 of the crankcase 1 applied linear material. Between the bush 3 and the encircling 7 or the crankcase 1 thus arises with elimination of the defects 9 a weld formed as a weld 11 , Through this weld 11 is between the liner 3 and the encircling 7 under metallic and / or melt metallurgical connection to the encapsulation 7 provided a radial support.

A dashed line shown arc 13 serves to clarify an interface between the liner 3 and the encircling 7 , The defects formed as connection errors 9 occur with faulty crankcases 1 usually along such interfaces or parting planes.

The 3 and 4 show another crankcase 15 in the area of a combustion chamber side 17 or combustion chamber area. In the crankcase 15 can even with careful implementation of die casting in the combustion chamber side 17 defects 19 arise, which are in 3 so-called voids or pores.

Also such defects 19 can be repaired by the melt metallurgical process. It is done as 4 schematically shows a punctiform material application, so that the defects 19 out 3 through welded joints 21 , which are designed as welding points, to be repaired.

To carry out the process are in a series production crankcase 1 . 15 carefully examined for any defects 9 . 19 available. If this is the case, a repair of these defects 9 . 19 by the melt metallurgical process.

This fusion metallurgical method can be carried out, for example, on a manual workstation equipped with a laser beam source, in which the crankcase 1 . 15 can be positioned manually and / or motor relative to a generated laser beam. The laser beam source may be a pulsed solid-state laser having an average power of the order of or up to 200 watts.

The laser beam is on a surface of the crankcase 1 . 15 focused, so that locally there is a narrow melting pool is generated. An operator of the manual workstation can view an active site on the surface, for example via a stereomicroscope, and thus view a machining process for repairing the imperfections 9 . 19 monitor.

It is possible to influence this editing process online for a visual impression. Here, a system for influencing a position of the crankcase 1 . 15 be moved via pedals or a joystick. Furthermore, parameters of the laser beam source can also be adjusted controllably. It is envisaged that a feed movement of the laser beam is done manually.

During the machining process a wire-shaped additional material, eg AlSi12, with a wire diameter in one Order of 0.4 to 0.6 mm also supplied manually. This manual procedure makes the process very flexible. This is especially true for crankcases 1 . 15 advantageous in those with defects 9 . 19 Affected processing sites are difficult to locate, so that a comparatively high cost would have to be operated for an alternative automated implementation of the method.

In preparation, the defects formed as separating surfaces 9 ( 1 ) or formed as voids voids 19 ( 3 ) extended in the present example with a finger grinder. In the subsequent laser deposition welding, therefore, a material order is limited to provide the welded joints 11 . 21 or welds not just on the surface.

Metallographic evaluations of welds provided by the process 11 . 21 show that in the laser deposition welding a fusion metallurgical connection and thus closing the defects 9 respectively. 19 is reached. By using a pulsed laser beam source is an energy input into the crankcase 1 . 15 low, so that a heat affected zone is small and structural properties in the liner 3 and in an umber 7 or in a base material of the combustion chamber side 17 remain.

Claims (7)

Method for reworking a crankcase ( 1 . 15 ), whereby the crankcase ( 1 . 15 ) at least one in a die-casting process and in an encapsulation ( 7 ) inserted bushing ( 3 ), characterized in that the crankcase ( 1 . 15 ) is treated by a melt metallurgical process, wherein at least in the region of an interface ( 13 ) between the at least one bushing ( 3 ) and the casting ( 7 ) Defects ( 9 . 19 ), wherein repairing by means of the fusion metallurgical process between the liner ( 3 ) and the casting ( 7 ) a radial support is provided. Method according to one of claim 1, characterized in that additional defects ( 9 . 19 ) on a combustion chamber side ( 17 ) of the crankcase ( 15 ) be repaired. Method according to one of claims 1 or 2, characterized in that defects ( 9 . 19 ) before carrying out the fusion metallurgical process. Method according to one of the preceding claims, characterized in that the crankcase ( 1 . 15 ) is processed by performing laser deposition welding when performing the melt metallurgical process. Method according to claim 4, characterized in that that in laser deposition welding a pulsed laser beam is used. Method according to one of the preceding claims, characterized in that when carrying out the melt-metallurgical process on a surface of the crankcase ( 1 . 15 ) A molten bath is generated, wherein this molten bath, an additional material is supplied. Cylinder crankcase for an internal combustion engine, the at least one cast in a die-casting and in an encapsulation ( 7 . 17 ) introduced cylinder liner ( 3 ), characterized in that the cylinder crankcase ( 1 . 15 ) is post-processed by a fusion metallurgical process, that defects ( 9 . 19 ) in the crankcase ( 1 . 15 ) are repaired by the melt metallurgical process and that, with repair of the defects ( 9 ) between liner ( 3 ) and casting ( 7 ) a welded connection ( 11 ) is formed in the form of a weld, whereby a radial support is provided, and that the cylinder crankcase with repair of defects ( 19 ) in the region of a combustion chamber side ( 17 ) at least one welded joint ( 11 . 21 ) having.