EP1145784A1 - Casting apparatus, especially for fabrication of turbine blades - Google Patents

Abstract

To produce undercut sections in relation to the principal direction (22), at least one additional slide (33) is employed, moving in a direction parallel to this direction (22). An Independent claim is included for the turbine blade so produced. This includes common supply and return channels, interconnected by a series of flow channels, all internal to the blade.

Description

The present invention relates to a casting device for Manufacture of components whose largest dimension is in one extends in the first direction, with at least one cast core and at least a first slider, which in one direction in the displaceable substantially perpendicular to the first direction is. It further relates to the use of such a casting device to manufacture a turbine blade and a Turbine blade manufactured with such a casting device.

The efficiency increases with gas turbines in particular Increase in the inlet temperature of the gas turbine flowing through Medium. The turbine blades must therefore due to the increased thermal load from the inside with a coolant, e.g. Cooling air to be cooled. If further the cooling air consumption increases so strong that the overall efficiency of the gas turbine relevant decreases. The required cooling air continues Burner lost, so that the pollutant emissions increases and Combustion chamber hum can occur. After flowing through the The cooling air enters the medium flow using blades for cooling through the gas turbine.

An alternative is the use of steam cooling, which the Cooling air mass flow is not tapped. With steam cooling the problem that the steam in the place to be cooled the shovel is guided and then discharged again got to. An escape of the steam into the medium flow the gas turbine is not possible.

In order not to cool over the entire axial or radial length, several cooling channels must be provided. Result it correspondingly several inlets and outlets that are arranged one after the other and in a common supply line and lead to a joint drain to prevent leaks to avoid.

Such a design of the cooling channels with a casting process is so far only with multi-part, glued cast cores possible to generate the necessary undercuts can. Glued cast cores are unstable and regarding the dimensional accuracy is inaccurate. When installing additional cores between the individual inlets and outlets This leads to deformations that shift the additional cores or let break. The result is disproportionate high reject rate.

Another solution to provide a shared feeder and discharge provides for the outlet of the individual Welding cooling ducts on lateral distributors. All-round welding around every single channel, however, is for reasons accessibility hardly possible. As a rule, the accessibility only given for very large blades, but for those the risk of breakage of the required additional cores very much rises sharply.

Another option is to use a distributor, such as that used in passenger cars Recording the exhaust gases of the individual cylinders is provided. However, due to the very high temperatures that occur the thermal expansions and the resulting ones Sealing problems are very difficult to master technically.

The object of the present invention is therefore a casting device to provide the production of branches allows without using glued cast cores.

According to the invention, this object is achieved with a casting device of the type mentioned solved in that for generation of undercuts with respect to this first direction at least another slide is provided, which is essentially is displaceable parallel to the first direction.

The use of the additional slider allows a waiver on the glued cores so that the reject rate drops. Further is the handling of the casting device according to the invention much simplified.

Advantageous refinements and developments of the invention emerge from the dependent claims.

The further slide in contact with the at least is advantageous bring a first slider. So when pouring a defined position of the slide in front of each other, so that higher accuracy can be achieved.

In an advantageous embodiment, two first slides are provided. The first slides on each other are advantageous arranged opposite sides of the casting core. It results a simple, symmetrical structure of the casting device.

In an advantageous development, the first slides are mirror images educated. This will make the Slider and thus the casting device cheaper and simplified.

In an advantageous development, the first slide are in the essentially displaceable parallel to each other. The movement the two sliders can be coupled together. Result it a simple structure and easy handling, e.g. Controllability, the casting device.

According to an advantageous embodiment, the other Slider symmetrical, in particular a mirror image, to his Mid-level trained. Especially when using the first a mirrored slide is a corresponding result symmetrical structure of the casting. The plane of symmetry is in a casting device for the production of turbine blades generally not just, but for adaptation curved to the desired shape of the turbine blade.

The invention further relates to the use of such Casting device for the manufacture of a turbine blade, at according to the invention the at least one first slide essentially perpendicular to a longitudinal axis of the turbine blade displaceable and the at least one further slide essentially is displaceable parallel to this longitudinal axis. Under a turbine blade, both rotor and also understood guide vanes. The at least one more Slider allows undercuts to be created the longitudinal axis of the turbine blade. This can several cooling channels in a common feeder and one joint exhaustion can be merged.

A casting device made with the above-described casting device Turbine blade has at least two cooling channels on which can be acted upon by a cooling fluid. The inlet sections the cooling channels are in a common feed and the outlet sections in a common exhaust merged. Leaks are completely avoided. The turbine blade according to the invention can therefore be used for Cooling with steam.

Figur 1

einen schematischen Längsschnitt durch eine Gasturbine;

Figur 2

einen vergrößerten Schnitt durch eine Laufschaufel mit zwei Kühlkanälen gemäß dem Stand der Technik;

Figur 3

einen Querschnitt durch eine Laufschaufel;

Figur 4

eine schematische Anordnung der Gußkerne nach dem Stand der Technik;

Figur 5

einen Schnitt durch eine erfindungsgemäße Turbinenschaufel in einer Ansicht ähnlich Figur 2;

Figur 6

eine schematische Explosionsdarstellung einer erfindungsgemäßen Gußvorrichtung;

Figur 7

eine Ansicht der Gußvorrichtung von Figur 6 aus einem anderen Blickwinkel mit Darstellung der verdeckten Kanten;

Figur 8

einen Längsschnitt durch ein mit der Gußvorrichtung gemäß den Figuren 6 oder 7 hergestelltes Bauteil; und

Figur 9

einen Schnitt längs der Linie IX-IX in Figur 8.

The invention is described in more detail below with the aid of an exemplary embodiment which is shown in a schematic manner in the drawing. The same reference symbols are used throughout for identical or functionally identical components. It shows:

Figure 1

a schematic longitudinal section through a gas turbine;

Figure 2

an enlarged section through a blade with two cooling channels according to the prior art;

Figure 3

a cross section through a blade;

Figure 4

a schematic arrangement of the casting cores according to the prior art;

Figure 5

a section through a turbine blade according to the invention in a view similar to Figure 2;

Figure 6

a schematic exploded view of a casting device according to the invention;

Figure 7

a view of the casting device of Figure 6 from a different angle showing the hidden edges;

Figure 8

a longitudinal section through a component produced with the casting device according to Figures 6 or 7; and

Figure 9

a section along the line IX-IX in Figure 8.

Figure 1 shows a schematic longitudinal section through a Gas turbine 10 with a housing 11 and a rotor 12. Das Housing 11 is with a number of guide vanes 13 and Provide rotor 12 with a number of blades 14. The Gas turbine 10 has hot gas flowing through it in the direction of arrow 15 and rotates the rotor 12 about an axis 16.

The guide blades 13 and the blades 14 are cooled. The cooling medium is supplied via a feed line 17 and flows through the blades 13, 14 and is then over a Derivation 18 discharged.

The largest dimension of the guide vanes 13 and the rotor blades 14 extends in the radial direction 22.

Figure 2 shows an enlarged section through a moving blade 14 according to the prior art. The blade 14 has two cooling channels 19, 20, each with an inlet section 19a, 20a and one outlet section 19b, 20b each. The two Cooling channels 19, 20 are independent of one another with the feed line 17 and the derivative 18 connected. An identical one The configuration of the cooling channels is also a guide vane 13 before.

Figure 3 shows a cross section through the blades 14 and Figure 4 is a schematic representation of the manufacture of the Blade 14 in a casting process required casting cores. The guide vanes 13 are essentially similar.

Hollow chambers 23 are provided in the walls of the blade 14, the inlet portions 19a, 20a with the outlet portions Connect 19b, 20b via openings 24. The one shown Cross section (Figure 3) enables efficient cooling the blade 14. There are many to manufacture of cast cores 25, 26 required, the pins 27 together get connected. The cast cores 25 provide the free space for the inlet sections 19a, 19b and the outlet sections 20a, 20b ready. About the casting cores 26 are in a casting process the hollow chambers 23 are made in the walls while pins 27 provide openings 24. The outer contour The blade 14 is schematically in dashed lines shown. The cooling fluid, in particular cooling air, is in accordance with Direction of arrow 28 fed to the inlet sections 19a, 20a and discharged from the outlet sections 19b, 20b according to arrow direction 29. The further flow of the cooling fluid is schematic represented by arrows not shown.

The casting cores 25, 26 frequently shift during the casting against each other, especially due to buoyancy forces of the liquid casting material onto the casting cores. The dimensional accuracy is relatively imprecise.

FIG. 5 shows a section through a rotor blade according to the invention 14 in a view similar to Figure 2. The inlet sections 19a, 20a are connected to each other and stand via a common feed 17a with the feed line 17 in Connection. The outlet sections 19b, 20b are also together connected and are via a common discharge 18a with the lead 18 in connection. Separate, in particular, are independent, inlets and outlets not necessary anymore.

Figures 6 and 7 each show a perspective view the casting device 50 according to the invention. For the better Clarity was not absolutely necessary Elements omitted.

Essential components of the casting device 50 are a casting core 30 and three sliders 31, 32, 33. The first two Sliders 31, 32 are on opposite sides of the cast core 30 arranged and mirror image. They are essentially parallel to one another in the direction of arrow 35 and perpendicular to a longitudinal axis 21 of the blade 14 and displaceable perpendicular to the radial direction 22.

The further slide 33 is essentially in the direction of arrow 34 parallel to the longitudinal axis 21 and to the radial direction 22 movable. It is symmetrical about its median plane 41 educated.

In the illustrated embodiment, the plane of symmetry is to which also the first two sliders 31, 32 are mirror-symmetrical are arranged, curved. The reason for this is that in the Practice present, for example shown in Figure 3 Bucket curvature 14. The plane of symmetry runs in the middle between the two outer walls. The curvature is in Figures 6 and 7 difficult to see.

The slides 31, 32, 33 have defined contact surfaces 39, 40 on. Before the casting process, the first two slides 31, 32 move according to arrow direction 35 to the casting core 30. As soon as the slides 31, 32 are shortly before their end position, the slide 33 is fed in the direction of the arrow 34. The movement of the slide 33 in the direction 34 will determined by the contact surfaces 39, 40. As a stop for the movement of the first two sliders 31, 32 according to the direction of the arrow 35 serve side surfaces 46 of the slide 33, on which associated surfaces 47 of the first two slides 31, 32 put on.

The first two slides 31, 32 each have two cutouts 36, 37 on. You are still ahead with a 38 Mistake. The recesses 36, 37 are over the projection 38, the further slide 33 and the associated ones, not further designated elements of the casting core 30 in the inlet channels 19a, 20a and the outlet channels 19b, 20b divided.

The exact arrangement and functioning of the casting device is based on a rotor blade made with a casting process 14 illustrated in more detail in FIGS. 8 and 9. The feeder 17a has a branching connecting channel 42. It is therefore connected to the inlet sections 19a, 20a. A serves to connect the outlet sections 19b, 20b further connection channel 43. For separation between the connection channels 42, 43 and the inlet section 20a and the Outlet section 19b are undercuts 44, 45 with respect the radial direction 22 required. These undercuts 44, 45 can by means of the in the casting device 50 (see 6 and 7) provided, further slide 33 is detected and for the first time in terms of casting technology with a simple, in particular non-glued, cast core 30 can be realized.

The connection channels 42, 43 are in the plan view according to Figure 9 approximately side by side. The below the connection channels 42, 43 lying inlet and outlet openings of the Inlet section 20a and outlet section 19b are schematic shown in dashed lines.

Claims (9)

Casting device (50) for the production of components (13; 14), the largest dimension of which extends in a first direction (22), with at least one cast core (30) and at least one first slide (31; 32) which extends in one direction ( 35) is displaceable substantially perpendicular to the first direction (22),
characterized in that at least one further slide (33) is provided for producing undercuts (44; 45) with respect to this first direction (22) and can be displaced essentially parallel to the first direction (22). Casting device (50) according to claim 1,
characterized in that the further slide (33) can be brought into contact with the at least one first slide (31; 32). Casting device (50) according to claim 1 or 2,
characterized in that two first slides (31, 32) are provided. Casting device (50) according to claim 3,
characterized in that the first slides (31, 32) are arranged on opposite sides of the cast core (30). Casting device (50) according to claim 3 or 4,
characterized in that the first slides (31, 32) are symmetrical, in particular a mirror image. Casting device (50) according to one of Claims 3 to 5,
characterized in that the first slides (31, 32) can be displaced essentially parallel to one another. Casting device according to one of claims 1 to 6,
characterized in that the further slide (33) is formed symmetrically to its central plane (41). Use of a casting device (50) according to one of Claims 1 to 7 for producing a turbine blade (13; 14),
characterized in that the at least one first slide (31; 32) is displaceable substantially perpendicular to a longitudinal axis (21) of the turbine blade (13; 14) and the at least one further slide (33) is displaceable essentially parallel to this longitudinal axis (21) is. Turbine blade (13, 14) produced with a casting device (50) according to one of Claims 1 to 7,
characterized in that the turbine blade (13; 14) has at least two cooling channels (19, 20) which can be acted upon by a cooling fluid, the inlet sections (19a, 20a) of the cooling channels (19, 20) in a common feed (17a) and the outlet sections (19b, 20b) are brought together in a common outlet (17b).

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