WO2014041289A1

WO2014041289A1 - Insert for controlling a gas control valve in a turbine casing and assembly method

Info

Publication number: WO2014041289A1
Application number: PCT/FR2013/052067
Authority: WO
Inventors: Bernard POINEAU
Original assignee: Saint Jean Industries
Priority date: 2012-09-12
Filing date: 2013-09-09
Publication date: 2014-03-20
Also published as: FR2995358B1; FR2995358A1

Abstract

The invention relates to an insert for controlling a gas control valve in a turbine casing, of the type arranged in a receiving element formed on the turbine casing. The insert is arranged in the opening-closing control mechanism of the safety valve and is internally hollow so as to receive a through-shaft coupled to a rod cooperating with a lever associated with the operating control of the safety valve, while the other end of the shaft faces the safety valve. The invention is characterised in that: the insert (20) is a cylindrical one-piece part having a shape that allows axial and rotational immobilisation; the insert is positioned in a casting mould to allow the corresponding part of the turbine casing to be cast around said insert, by means of overmoulding; and the connection between the insert and the corresponding area of the turbine casing ensures the axial and rotational immobilisation.

Description

INSERT FOR CONTROLLING A GAS REGULATION VALVE IN A TURBINE HOUSING AND METHOD OF IMPLEMENTATION The invention relates to the technical sector of the manufacture of turbine casings for vehicles, and also to the foundry of ferrous alloy parts . The invention relates more particularly to devices constituted by valves and control valves for gas decompression absorption in said housings.

According to the prior art, and for a good understanding of the problem underlying the invention, there is shown in Figure 1 a turbine casing known per se, partially open with the representation of the turbine and its main components as well as the air intake and exhaust gas circuits. This housing which is made of cast steel is referenced by (1). It is represented by (2) the turbine which is mounted in the longitudinal axis of the turbine casing, by (3) the volute of the turbine, by (4) the diffuser, by (5) the compressor, by (6) the compressor volute, by (7) the pressure take-off tube, by (8) the air intake chamber admitted by the turbine casing, by (9) the compressed air outlet, by (9) 10) the exhaust gas outlet, by (1 1) the exhaust gas supply. It is also referenced by (12) the control of the operating device of the safety valve (14), by (15) the lever associated with said control (12) and cooperating with a rod system (16) soliciting an insert (17) in contact with said safety valve (14).

The problem is as follows: The exhaust gases arrive in the casing 1, drive the turbine 2 in rotation. This causes the suction of the outside air 8 which enters the compressor via the wheel of compressor (impeller), and is compressed by this wheel and is sent into the cylinders for supercharging the engine (9). When the intake air into the turbine housing arrives, it is sucked in by the rotating turbine and accelerates it. The pressure and the speed of the air are then increased. The air arrives in the engine, it enters the cylinders after explosion with gasoline, when the pistons go up the exhaust gases are evacuated and are led to the turbine. The pressures must be regulated. The exhaust gas pressure may be too strong and a control system may allow exhaust gas deflection when the nominal pressure is reached. Thus, the control valve (14) has a pressure tap at the outlet of the compressor. It will more or less open the valve valve according to this pressure and will allow a gas evacuation in a delayed circuit to be discharged downstream of the turbine rather than drive it. According to the prior art, the known mechanism of operation of said regulating valve (14) requires the use of an insert (17) which is disposed in the opening-closing control mechanism of the safety valve. This insert (17) is in the form of a ring associated with said mechanism. This insert has a flange (17a) and is hollow internally for receiving a spindle (18) passing through coupled at one end to a rod (19) cooperating with the lever (15). The other end of the shaft (18) faces the regulating valve. The positioning of the insert is effected by press fitting into a housing provided for this purpose in the corresponding wall of the housing and there is thus a locking position.

This implementation causes several problems. When press fitting, there is a risk that the insert is skewed and in this case, it is mandatory that the housing is changed as a whole, which generates a significant number of rejects. To can to be fitted, the insert (17) needs to be smooth to properly fit into its housing. In addition to the flange that allows some immobilization of the insert, in case of differential thermal expansion of the material of the insert and the part or housing, there is a risk that the insert can move in its housing. rotation in particular. During the final use of the housing and therefore the device, such movement can cause problems in use. In the turbine casings, this causes a blockage of the axis and a risk of malfunction on the complete turbo compressor. To overcome this constraint, it is possible to perform a complementary operation consisting in producing an axial bore to insert a pin that blocks the insert in translation. This therefore requires a complementary machining operation.

The Applicant's approach was therefore to seek an improvement in the design of the insert in its arrangement on and in the turbine casing. The solution provided lies in a different design of the insert and also in its assembly with the casing of the turbine. According to a first characteristic of the invention, the insert for controlling a gas control valve in a turbine casing, of the type disposed in a housing formed on the turbine casing, said insert being disposed in the control mechanism opening-closing of the safety valve, being internally hollow for receiving a through shaft coupled to a link cooperating with a lever associated with the operating control of the safety valve and the other end of the axis being opposite the safety valve, is remarkable in that said insert constitutes a cylindrical one-piece piece having a shape allowing axial immobilization and rotation, and in that said insert is positioned in a casting mold to allow casting of the corresponding part of the turbine casing around the casing around it, and in that the connection of the insert and the corresponding zone of the turbine casing ensures said axial immobilization and rotation.

According to another characteristic, said insert has a first cylindrical surface with visible ridges on its outer periphery, said first surface being extended by a secondary surface having in its middle part flats.

According to another characteristic of the invention, the method of manufacturing and placing an insert for controlling a gas control valve, is remarkable in that said insert is manufactured in a one-piece and cylindrical configuration, and in that said insert is positioned in a foundry mold, and in that the constitutive material of the corresponding receiving part of said insert of the turbine casing is molded around said insert by casting, and in that the machining is carried out central through hole for receiving the discharge valve axis controlling the opening or closing of the safety valve integrated in the turbine housing,

According to another characteristic of the method, the insert has a first cylindrical bearing surface with visible ridges around its periphery and extending by a secondary bearing surface having flats,

These and other characteristics will be apparent from the description suite. For fixing the object of the invention illustrated in a nonlimiting manner to the figures of the drawings where:

FIG. 1 is an exploded view according to the prior art of a turbine casing arranged with components and notably an exhaust gas decompression valve,

FIG. 2 is a partial view on a large scale illustrating the receiving device of the insert controlling the displacement of the decompression valve, according to the prior art,

FIG. 3 is a view showing, according to the prior art, an insert used according to known practice,

FIG. 4 is a view showing according to the invention the insert used for the displacement control of the decompression valve.

Figure 5 is a longitudinal sectional view illustrating the positioning of the insert according to the invention in the configuration of the turbine housing mounted around the housing.

In order to make the object of the invention more concrete, it is now described in a nonlimiting manner illustrated in the figures of the drawings.

The insert, according to the invention, is referenced as a whole by (20). It is made in the form of a single piece and with different specific successive zones for locking in translation and rotation. It comprises in an optimized implementation a first cylindrical surface (20a) with visible streaks (20b) on its outer periphery, said first surface being extended by a secondary surface (20c) which has in its middle part flats (20d). ) and more particularly four flats thus defining a square section in the corresponding part and where appropriate also streaks (20b). said insert (20) thus produced is positioned in a casting mold to allow casting around said insert, the corresponding portion of the turbine casing which is then overmolded around Γ insert. In the optimized implementation, in addition to the overmolding, the connection of the insert is completed with the parts forming ridges and flats which are embedded in the overmoulded material constituting the housing to ensure a firm connection of the assembly. The insert is then machined with a central hole (20e) for receiving the axis (21) of the relief valve controlling the opening or closing of the safety valve (14).

FIG. 5 is thus shown in partial view, the connection of the insert (20) in the turbine casing but also the axis (21) through which one end (21a) is coupled to the control rod (15) of the control valve, and the other end (21b) receives the flag or valve to obscure the compression gas control valve. The action on the control rod (15) causes the partial angular articulation of the rod (16) and the shaft (21) which is integral therewith and in the closure of the safety valve or its opening for the release and passage of gases in overcompression.

The originality of the invention lies therefore in a new design of the insert but also in a manufacturing process of the turbine casing whose receiving part of the insert is overmolded around the insert previously positioned in a foundry mold . The bond obtained is very much superior in terms of quality and rigidity to the known prior art. The protruding zones and ridges formed on the insert reinforce the connection with the casing by eliminating any risk of deflection. Moreover, putting the insert directly into the mold foundry reduces the walls of the casting part in the foundry, that is to say, the housing which avoids the establishment of a feeder. There is therefore a gain in melt, the elimination of the sawing operation of this weight, and thus waste gains. The insert according to the invention with its configuration of ridges and flats for example is perfectly immobilized in translation and in rotation, even in case of differential thermal expansion.

Claims

CLAIMS -1- Insert for controlling a gas control valve in a turbine casing, of the type disposed in a housing formed on the turbine casing, said insert being disposed in the opening-closing control mechanism of the safety valve, being internally hollow for the reception of a traversing shaft coupled to a link cooperating with a lever associated with the operating command of the safety valve and the other end of the axis being opposite the valve safety device, characterized in that said insert (20) constitutes a cylindrical piece having a shape allowing axial immobilization and rotation, and in that said insert is positioned in a foundry mold to allow by molding the casting around him of the corresponding part of the turbine casing, and in that the connection of the insert and the corresponding zone of the turbine casing ensures said axial immobilization and in rotation. -2- insert according to claim 1, characterized in that it has a first cylindrical surface (20a) with visible streaks (20b) on its outer periphery, said first scope being extended by a secondary surface (20c) having in its middle part of the flats (20d). -3- Insert according to any one of claims 1 and 2, characterized in that the insert has a central hole (20e) for receiving the axis (21) of the relief valve. -4- A method of manufacturing and installing an insert for controlling a gas control valve as defined by any one of claims 1 or 2, characterized in that said insert (20) is manufactured in a one-piece and cylindrical configuration, and in that said insert is positioned in a foundry mold, and in that the material constituting the corresponding part receiving said insert of the turbine casing is molded around said insert by casting, and in that machining the central hole (20e) through to receive the axis (21) of the relief valve controlling the opening or closing of the safety valve integrated in the turbine housing.

-5- A method according to claim 4, characterized in that the insert has a first cylindrical surface (20a) with visible streaks (20b) around its periphery and extending by a secondary surface (20c) having flats (20d) .