DE102017209976A1 - Cast component with cast-in pipe and manufacturing process - Google Patents

Abstract

The invention relates to a cast component (100) having a cast body (110) formed from metallic cast material (M) and at least one tube (120) cast in the cast body (110), through which a medium can flow and through an inlet (Z) and a Expiry has. In order to prevent oil ingress into the air gaps (S), a ring (130) surrounding the tube (120) is cast in the cast body (110) at the inlet (Z) and / or at the outlet, whose inner diameter is greater than the outer diameter of the tube (120) ), wherein an annular gap (140) between the ring (130) and tube (120) is filled with casting material (M). The invention further relates to a manufacturing method for such a cast component (100).

Description

The invention relates to a cast component, with a cast body and at least one cast in the cast body tube, which is flowed through by a medium. The invention further relates to a manufacturing method for such a cast component.

The DE 10 2012 223 156 A1 describes a housing (exhaust valve housing), which has at least one heating or cooling channel, which is a tube enclosed by the housing. The ends of the tube are designed to connect a conduit. The housing is made of die-cast aluminum and the tube is made of aluminum or copper. To produce the housing, the preformed tube is inserted in the manner of a core in a mold for the housing and then encapsulated during casting of the housing.

Between the cast-in pipe and the surrounding casting material, air gaps can form already during casting or even later in the course of subsequent use, which may be less pronounced. a. due to an unfavorable material bond between cast iron and pipe material and / or to different thermal expansions. Such air gaps can spread along the tube to the component surface, where often also the connections or pipe connections are. At the pipe connections then the medium which is to be passed through the pipe, undesirably reach such air gaps and pass through voids, pores and trapped air on the housing outer surface to the outside. Common sealing technologies, such as metal impregnation, prove to be ineffective over time.

With the invention, at least one associated with the prior art disadvantage should be avoided or at least reduced.

For this purpose, a cast component with the features of claim 1 is proposed. With the independent claim, the invention also extends to a manufacturing process. Further developments and embodiments of the invention will become apparent for both subject invention from the dependent claims, the following description of the invention and the drawings.

The cast component according to the invention comprises a cast body formed from a metallic cast material and at least one tube cast in the cast body, through which a medium can flow and which has an inlet and a drain for the medium. At the inlet and / or the outlet, a ring surrounding the tube is cast in the cast body, whose inner diameter is greater than the outer diameter of the tube, so that between the ring and the tube, a gap or annular gap is formed, which is filled with the metallic casting material. The cast component according to the invention is in particular a die-cast component.

The inlet or inflow and the outlet or outflow are the areas in which the cast-in tube penetrates through the casting surface or closes off with the casting surface. Both at the inlet and at the outlet, the tube can be formed with connections. (The relevant region of the casting surface can also be referred to as a connection surface.) The medium flowing through the tube can be a liquid, in particular oil, or else a gas, in particular air.

The casting material in the annular gap between the pipe and the ring effects a seal, so that no medium can reach the inflow and / or outflow between the cast-in pipe and the surrounding casting material. Furthermore, the encapsulated ring surrounding the tube prevents expansion (especially at higher operating temperatures) of the casting material present in the annular gap, so that no air gaps can form between the tube and the surrounding casting material at the inlet or outlet, into which the medium penetrates (or possibly also penetrate). can.

Preferably, the annular gap between the ring and the tube in the radial direction at least 1 mm and in particular at least 1.5 mm wide. By this minimum gap dimension ensures that the casting material during casting, in particular die casting, the cast component or cast body flow into the annular gap and can fill it. Preferably, the annular gap in the radial direction is not more than 5 mm and in particular not more than 3 mm wide.

As a casting material is preferably aluminum, d. H. used an aluminum casting alloy and in particular an aluminum diecasting alloy. The tube and the ring are preferably formed from steel or a steel alloy. The cast body and the tube can thus have a different thermal expansion, whereas the tube and the ring can have substantially the same thermal expansion. For the ring or pipe, other materials with advantageous coefficients of thermal expansion can be used. The tube may also have a coating (eg, a galvanizing) or jacket. The ring may have a radial thickness of 3 mm to 10 mm and / or an axial length of 10 mm to 15 mm.

The cast-in ring may be set back with respect to a connection surface on the cast body, z. B. by at least 1 mm. Thereby The casting material can flow around the ring during casting, in particular die-casting, of the cast component or cast body and flow better into the annular gap. In addition, a machining of the pad is simplified. Furthermore, the cast-in ring is virtually invisible. The ring may also be arranged (directly) on or in the connection surface, ie, the ring is arranged in the cast body such that it extends to the connection surface.

The cast component according to the invention is preferably a housing component and in particular a gear housing component. The cast-in tube acts in particular as a hydraulic control line, for example. For actuating a clutch. The cast component according to the invention is preferably an aluminum casting component and in particular an aluminum die casting component.

• - Bereitstellen des einzugießenden Rohrs;
• - Bereitstellen wenigstens eines Rings, wobei der Innendurchmesser dieses Rings größer ist als der Außendurchmesser des Rohrs;
• - Befestigen des Rings am Rohr, wozu der Ring am betreffenden Rohrende (gegebenenfalls an beiden Rohrenden) auf das Rohr aufgeschoben und mithilfe einer Halterung am Rohr befestigt wird, derart, dass der Ring keine oder nur eine sehr kleine Verbindung zum Rohr hat und insbesondere derart, dass ein Ringspalt zwischen dem Ring und dem Rohr besteht, wobei die Halterung an einem außerhalb des zu erzeugenden Gusskörpers liegenden Rohrstutzen oder einem das betreffende Rohrende verschließenden Stopfen angebracht wird (bspw. durch Anlöten, Festklammern oder dergleichen);
• - Einlegen des Rohrs mit dem daran befestigten Ring in eine Gussform, insbesondere Druckgussform, und Gießen, insbesondere Druckgießen, des Gussbauteils, wobei das Rohr von der Metallschmelze des Gussmaterials umgossen wird und dabei die Metallschmelze auch in den Ringspalt zwischen dem Ring und dem Rohr einfließt;
• - Entformen des Gussbauteils, nachdem die Metallschmelze erstarrt ist;
• - Entfernen der Halterung (die Halterung dient nur dazu, den Ring während des Gießens in der richtigen Lage zu halten), bspw. durch Nachbearbeitung, wobei der Rohrstutzen oder der Stopfen, zusammen mit der daran angebrachten Halterung, entfernt wird (in der Regel wird das Ende des Rohrs zur Ausbildung eines Anschlusses ohnehin nachbearbeitet).

The method according to the invention for producing a cast component according to the invention comprises the steps:

• - Providing the einzugießenden tube;
• - Providing at least one ring, wherein the inner diameter of this ring is greater than the outer diameter of the tube;
• - Attaching the ring to the tube, including the ring at the relevant end of the tube (optionally at both ends of the tube) is pushed onto the tube and fastened by means of a holder on the pipe, such that the ring has no or only a very small connection to the pipe and in particular such in that there is an annular gap between the ring and the tube, the holder being attached to a pipe stub located outside the cast body to be produced or to a stopper closing the relevant pipe end (for example by soldering, clamping or the like);
• - Inserting the tube with the attached ring in a mold, in particular die casting, and casting, in particular die casting, the cast component, wherein the tube is encapsulated by the molten metal of the casting material and the molten metal also flows into the annular gap between the ring and the tube ;
• Demolding the cast component after the molten metal has solidified;
• Removal of the holder (the holder serves only to keep the ring in the correct position during casting), for example by post-processing, wherein the pipe socket or plug, together with the holder attached thereto, is removed (usually reworked the end of the pipe to form a connection anyway).

It is preferably provided that the tube formed in particular made of steel during casting has a lower temperature than the ring formed in particular of steel. When pouring the tube, for example, on the pipe socket or plug (s. O.) Held and thereby the relevant pipe end to be cooled during the entire casting process. As a result, a bias acting on the tube is generated under the ring, which in the subsequent use of the cast component over the entire temperature range, d. H. even at higher operating temperatures, maintained. For the ring or the tube and alternative materials with advantageous coefficients of thermal expansion can be used.

Preferably, the tube is placed in the cold state (i.e., at about room temperature) in the mold or its cavity and then cast around. An elaborate preheating to improve the material bond between cast iron and pipe material can be omitted.

The invention will now be described in more detail by way of non-limiting example with reference to the drawing. The features shown in the single figure of the drawing and / or explained below features, even detached from concrete combinations of features, general features of the invention and further develop the invention accordingly.

1 schematically shows a section through the wall of a transmission housing component.

The gearbox component 100 , of which only a section is shown, is a die-cast component with an aluminum casting 110 and a steel pipe cast therein 120 , The transmission housing component 100 is, at least at the location shown, thin-walled, which is understood in particular that the wall thickness corresponds to a maximum of 2 times the pipe diameter. The steel pipe 120 has a round cross section and has z. B. an outer diameter of 8 mm to 12 mm. The steel pipe 120 may also have a non-round cross-section and a non-straight course.

The gearbox component 100 has a connection surface 115 , at the z. B. a control unit is flanged, which, for example. For actuating a clutch an oil flow through the steel pipe 120 controls. The marked area Z can be referred to as the control unit-side inlet. The clutch side process is not shown. The pipe 120 can at the interface 115 also be formed with a protruding connection (connecting piece, pipe socket).

Between the steel pipe 120 and the surrounding aluminum casting material M can become air gaps S form as explained above. To prevent the intake Z such an air gap S can form in which then undesirably oil can penetrate is in the aluminum casting 110 a the steel pipe 120 surrounding steel ring 130 cast. (Such a steel ring can also be at the drain in the cast body 110 be poured.)

The inner diameter of the steel ring 130 is larger than the outer diameter of the steel pipe 120 wherein the resulting annular gap 140 between the outer peripheral surface of the steel pipe 120 and the inner peripheral surface of the steel ring 130 with the aluminum casting material M is filled. The radial gap of the annular gap 140 is circumferentially at least 1 mm. The steel ring 130 may have a radial thickness of at least 3 mm. With an outer diameter of 10 mm of the steel pipe 120 has the steel ring 130 thus an inner diameter of at least 12 mm and an outer diameter of at least 18 mm. The axial length of the steel ring 130 is, for example, 10 mm to 15 mm.

The aluminum casting material M which is in the annular gap 140 between the steel pipe 120 and the steel ring 130 is through the steel ring 130 prevented at its radial extent, so that in the area of the steel ring 130 no air gaps S on the steel pipe 120 can train. Any air gaps that extend between the outer peripheral surface of the steel ring 130 and the surrounding aluminum casting material M form, are irrelevant, since such are uncritical with respect to an undesirable oil entry.

A possible manufacturing method for the transmission housing component 100 is described above.

LIST OF REFERENCE NUMBERS

100

cast component

110

cast body

115

terminal area

120

pipe

130

ring

140

annular gap

M

cast material

S

air gap

Z

Intake

I

axial direction

r

radial direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102012223156 A1 [0002]

Claims (10)

Cast component (100), formed with a metallic cast material (M) cast body (110) and at least one in the cast body (110) cast-in pipe (120) which is flowed through by a medium and an inlet (Z) and having an outlet, characterized in that a ring (130) surrounding the tube (120) is cast in the cast body (110) at the inlet (Z) and / or at the outlet, whose inner diameter is greater than the outer diameter of the tube (120), wherein an annular gap (140 ) between ring (130) and tube (120) is filled with casting material (M). Cast component (100) according to Claim 1 , characterized in that the annular gap (140) between the ring (130) and tube (120) is at least 1 mm wide. Cast component (100) according to one of the preceding claims, characterized in that the casting material (M) is aluminum. Cast component (100) according to one of the preceding claims, characterized in that the tube (120) and the ring (130) are formed from steel. Cast component (100) according to one of the preceding Claims 1 to 4 , characterized in that the ring (130) with respect to a casting (110) formed on the connecting surface (115) is set back. Cast component (100) according to one of the preceding Claims 1 to 4 , characterized in that the ring (130) on a connection surface (115) of the cast body (110) is arranged. Cast component (100) according to one of the preceding claims, characterized in that the ring (130) has a radial thickness of 3 mm to 10 mm and an axial length of 10 mm to 15 mm. Cast component (100) according to one of the preceding claims, characterized in that this is a housing component and in particular a transmission housing component. Method for producing a cast component (100), comprising a cast body (110) formed from metallic cast material (M) and at least one tube (120) cast in the cast body (110), which can be flowed through by a medium and has an inlet (Z) and a Has outlet, wherein at the inlet (Z) and / or at the outlet a tube (120) surrounding the ring (130) is cast in the cast body (110), comprising the steps: - providing the tube (120); - Providing the ring (130), wherein the inner diameter is greater than the outer diameter of the tube (120); - Attaching the ring (130) on the tube (120) by means of a holder which is attached to a pipe socket lying outside of the cast body (110) or a stopper closing the pipe end; Inserting the tube (120) with the ring (130) attached thereto into a casting mold and casting the cast component (110), wherein the tube (120) is encapsulated with molten metal, and the molten metal is also introduced into an annular gap (140) between the ring (140). 130) and tube (120) flows; Demolding the cast component (100) after the molten metal has solidified; - Remove the holder. Method according to Claim 9 , characterized in that the tube (120) during casting has a lower temperature than the ring (130).

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