Interchangeable insert for a tool for manufacturing a cylinder crankcase

Abstract

The invention relates to an interchangeable insert (1) for a tool for manufacturing a cylinder crankcase, which is designed to be axially movable. In an interchangeable insert whose service life is increased, thereby enabling a high number of casting cycles, a sleeve (7) is positioned in an axial through-opening (5) of a base body (3), which includes a further axial through-opening (17) for introducing a cooling medium via a spiral core (19).

Description

The invention relates to a replaceable insert for a tool for producing a cylinder crankcase, which is designed to be axially movable.It is known that for the production of a cylinder crankcase so-called sleeves are used in a stationary machine tool, which serve for shaping a cylinder tube on the crankcase and which can execute an axial movement.DE 10238873 A1 discloses a cylinder liner for a cylinder crankcase, which has contouring on an end face. The contouring serves to support the cylinder liner on a sleeve in a die casting tool. In an enclosed state of the cylinder liner, depressions of the cylinder liner are filled by the material of the cylinder crankcase, whereby the seating of the cylinder liner in the direction of an oil chamber is prevented.DE 10153721 A1 discloses a casting tool for producing a cylinder crankcase of an internal combustion engine, having at least one sleeve which is movable with respect to its axis and is fitted with a cylinder liner in each case, wherein the sleeve saves a cylinder bore of the cylinder crankcase and runs from a cylinder-head-side wall of the casting tool to a crankshaft-side wall of the casting tool.DE 10 2017 216 645 A1 discloses a cooling spindle for a casting tool comprising a base element and a changing element, wherein the changing element is designed to define a contour of the cooling spindle and the base element is designed to cool the changing element, and wherein the changing element is connected to the base element in a form-fitting manner in a separable manner via a screw system.Minute cracks on the sleeve may cause water leakage, which are critical from the aspect of safety against harmful water shot during the casting process and reduced quality against undesirable gas pores. This reduces the service life of the spindle sleeve, since the spindle sleeves have to be replaced, which represents a critical cost factor due to machine stoppages.It is an object of the invention to specify a replaceable insert for a tool for producing a cylinder crankcase, the service life of which is increased, as a result of which a high number of casting cycles is made possible.The invention is evident from the single claim 1. further features, possible applications and advantages of the invention are evident from the following description and the explanation of exemplary embodiments of the invention which are illustrated in the figures.The object is achieved by the subject matter of claim 1.In the above-described replaceable insert for a tool for producing a cylinder crankcase, which is designed to be axially movable, a sleeve is positioned in an axial through-opening of a base body, which sleeve comprises a further axial through-opening for the introduction of a cooling medium via a spiral core. This minimizes a risk of leakage and increases the quality of the replacement insert, which results in a higher number of casting cycles. Advantageously, fewer machine stoppages result from the smaller change of the sleeves. At the same time, the replaced sleeves can be remachined and reused again.The sleeve has a wall thickness of at least 4 mm. This increases the safety against quality losses if the base body of the spindle sleeve has very small cracks at certain points.The tool is designed as a die casting tool.A continuous axial through-opening is worked into the base body, into which a sleeve having a further axial through-opening is inserted.The spindle sleeve, which is designed as a replaceable insert, can be produced cost-effectively in large numbers independently of the casting tool. Nevertheless, the quality of the thus manufactured sleeves is reliably improved.According to the invention, the sleeve having a further axial through bore is incorporated into the base body by shrink fitting by means of nitrogen. This enables compliance with a high quality standard of the sleeves despite series production.According to the invention, the sleeve consists of a copper material. Copper is resistant to aggressive influences by the cooling medium and thus contributes to a further lengthening of the service lives of the spindle sleeve used as a replacement insert.Further advantages, features and details are evident from the following description, in which at least one exemplary embodiment is described in detail. Features described can form the subject matter of the invention alone or in any meaningful combination, optionally also independently of the claims, and can in particular additionally also be the subject matter of one or more separate application / s.The following are shown: FIG. 1 shows an exemplary embodiment of the replaceable insert according to the invention, FIG. 2 shows an exemplary embodiment of the method according to the invention.FIG. 1 shows an exemplary embodiment of the interchangeable insert according to the invention, which is to be referred to below as a spindle sleeve, in longitudinal section. The spindle sleeve 1 is in the given case a water-cooled replaceable insert for shaping the cylinder tube on the crankcase for an internal combustion engine.A cylindrical base body 3 of the spindle sleeve 1 comprises a through-opening 5 in the axial direction, in which a sleeve 7 is positioned, which preferably consists of copper and which has an outwardly protruding shoulder 9 in its upper section for receiving two radially attachable water pipes 11, 13 for cooling the spindle sleeve 1. The water pipes 11, 13 serve for connection to a cooling circuit, not shown in detail, which is sealed by the attachment 9. The sleeve 7 has an axial through bore 17, in which a spiral core 19 is formed.For stabilizing the sleeve 1, the wall of the sleeve 7 has a thickness of about 5 mm.An exemplary embodiment of the method according to the invention is illustrated in FIG. 2. The prefabricated sleeve 7 (FIG. 2 a) is brought together with the base body 3 of the spindle sleeve 1. For this purpose, the axial through-opening 5 is first worked out in the base body 3 (FIG. 2 b ) and then the sleeve 7 is introduced into this through-opening 5 (FIG. 2 c ). The base body 3 additionally has a recess 15 of the length of the projection 9 of the sleeve 7, so that the latter can be placed in the base body 3 in an approximately form-fitting manner.

Claims

Interchangeable insert (1) for a tool for producing a cylinder crankcase, which is designed to be axially movable, wherein a sleeve (7) is positioned in an axial through-opening (5) of a base body (3), which sleeve comprises a further axial through-opening (17) for introducing a cooling medium via a spiral core (19), which sleeve has a wall thickness of at least 4 mm and in the process the tool is designed as a die casting tool, wherein a continuous axial through-opening (5) is worked into a base body (3), into which a sleeve (7) having a further axial through-hole (17) is inserted, characterized in that the sleeve (7) having an axial through-hole (17), which sleeve consists of a copper material, is worked into the base body (3) by shrink-fitting by means of nitrogen.

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