US3170343A - Apparatus for manufacturing metal parts by deformation - Google Patents

Description

Feb. 23, 1965 R. GAURIAT APPARATUS FOR MANUFACTURING METAL PARTS BY DEFORMATION Filed Sept. 7, 1962 INVBNTOR Roger G'aurmi ATTORNEYS United States Patent 1 Claim. (01. 80- 24) This invention pertains to the manufacture of metallic parts, particularly blades for turbo-machines such as steam and gas turbines and also axial compressors, and is related to the improved method for making such blades as disclosed and claimed in a co-pending application Serial No. 222,132, filed September 7, 1962 and assigned to the same assignee as is the instant application.

In accordance with the improved method for making turbine and compressor blades as disclosed in the aforesaid co-pending application, one starts with a metallic bar section of suitable length and passes this bar through a rolling mill, the rolls of which are constituted by segments of a cylinder and wherein one or both ends of these roll segments are provided with recesses so that only the intermediate, or body section of the blade will be produced by the rolling and reduction of an intermediate portion of the metallic bar section. One or both ends of the metallic barsection which are to form the foot, or foot and head respectively of the blade are not rolled because of the end recesses in the roll segments thus leaving substantially unworked masses of the bar at one or both ends respectively. Thereafter, the partly completed blade is transferred to a press where the fillets between the body and foot and head end portions of the blade are finished pressed to the desired curvature and dimensions.

In a case where the blade is to have a head as well as a foot portion, it is necessary to provide, between the body of the blade and the end portion of the length of the original bar section which is last to pass between the roll segments of the rolling mill, a sufficient clearance so that said end portion will not be damaged by the posterior end of the roll segments during ejection. Such a clearance can lead to a fillet zone of connection between that end part, which may be the head or foot, and the reduced body portion that flares too much to be acceptable.

In accordance with the present invention, the roll segments of the rolling mill are designed in such manner that there is no longer any appreciable difference in the fillet zones between the body portion of the blade and the head and foot portions thereof. More particularly, at the posterior end of each roll segment, upper and lower, after the trailing recess intended for the head or foot of the blade, wherever may be the case, there is provided a terminal part with a radius larger than the greatest radius of the remainder of the roll segment which serves the function of retaining the metal which tends to stretch as a result of rolling of the body portion of the blade and, at the end of rotation of the roll segment compresses this metal in order to include the same in the trailing recess. p

This trailing terminal part on the upper and lower roll segments serve conjointly both as a stop retaining the metal and as a punch compressing it. Under its action, the metal is obliged to fill the entire trailing recess and thereby to line the internal angles which, without this compression, might not receive any metal at all.

The invention is illustrated in the accompanying drawings which show one suitable arrangement for the im- 3,170,343 Patented Feb. 23, 1965 "ice these drawingsz' FIGS; 1-4 is a sequence of views showing the bar section in various positions as it passes through and between the roll segments;

FIG. 5 is an end view of the roll section illustrating one suitable configuration for the trailing parts of the roll segments which cooperate to establish a stop-punch operation on the trailing end of the bar section; and

7 'FIG. 6 is an end view, similar to FIG. 5 illustrating another suitable configuration for the trailing parts of the roll segments. I

With reference now to FIGS. 1-4, the lower and upper cylinders of the reduction rolling mill are illustrated some- What schematically at 1 and 2, respectively. The roll segment on cylinder 1 is shown in section at 3 and the roll segment on cylinder 2 is shown in section at 4. At their posterior or trailing end, i.e. the end last to pass between the cylinders, the segments are provided with trailing portions g and h of greater radius than the remainder of the roll segment which follow their respective trailing recesses a-b-c and d-e-f and which function conjointly to establish the stop-punch above referred to.

In FIG. 1, the bar section 5 to be formed into the blade is shown as it is about to be engaged by the roll segments 3 and 4 to form the body portion of the blade, it being noted that due to the presence of recesses r and r at the leading ends of the roll segments, the leading end portion 5a of the bar section will pass through without any appreciable working by the roll segments.

FIG. 2 shows the bar section 5 after engagement by the leading rolling surfaces of the roll segments, the leading end 5a of the bar 5, which is to form a foot or head portion, having already been delimited from the intermediate portion 5b which has just commenced to be rolled and reduced by the roll segments 3 and 4.

In FIG. 3, rolling of the intermediate part 5b of the bar section which is to form the body part of the blade is half finished. The posterior terminal edges a and f of roll segments 3 and 4 respectively have just engaged the surface of the bar 5 while producing a certain flare. At this moment, the stop-punch elements g and h come into contact with the posterior end 50 of the bar 5. V

In FIG. 4, which shows the bar section 5 at the end of the rolling operation, it will be seen that due to the stop punch action provided by the cooperative trailing portions g and h of the roll segments, the metal constituting the trailing end portion 50 of the bar section 5 will have been pressed into the space abcdef constituted by the junction of the posterior recesses of the roll segments 3 and 4. The metal nicely fills the angles b and e which otherwise would lack metal because of the rotation of points a and f.

Moreover, the stop-punch provided by the trailing portions g and h of the roll segments are in relief on the segments and the sum of their outside radius is greater than the interaxial distance of the segments. Hence, it is necessary to machine them in such a way that they interpenetrate so that the rotary movement can continue. For this purpose, various configurations of the trailing portions g and h can be adopted. FIG. 5 shows one suitable embodiment, as viewed when looking in the direction of the arrow of FIG. 4, the trailing portion on roll segment 3 being constituted by two parallel spaced projecting portions g and g which overlap and engage the side faces of a centrally located trailing portion h on roll segment 4 which slides between the projecting portions 51 and 82- FIG. 6 shows a slightly different embodiment wherein the trailing portion on roll segment 3 is constituted by an upwardly projecting portion g, which overlaps a similar but complementary configured downwardly projecting portion it on roll segment 4, the inner faces of these two projecting portions being in sliding contact with each other.

After the bar section 5' has been rolled in the rolling mill section in accordance with the present invention to produce the body portion of the blade, it is then transferred to the press unit as more fully described in the aforesaid co-pending application Serial No; 222,132 for further processing to finish the fillet portions between the body and the head and foot portions.

In conclusion, while the invention has been described in its relation to the production of turbine and like blades, the principles thereof-are equally applicable to any other metallic part having a profiled central or body portion included between two terminal enlargements.

I claim:

In a reduction mill apparatus-for producing a profiled central body portion included between two terminal enlargements on a metallic part, comprising upper and lower roll segments adapted to engage and roll said metallic part, said roll segments each being provided with leading and trailing recesses in the rolling surfaces thereof adapted to clear the leading and trailing ends of the metallic part and thus result in the reduction of only the central body portion to the desired profile, and the trailing end of each of said roll segments being provided with a terminal part having a radius greater than the greatest radius of the remainder of the roll segment, said terminal parts acting conjointly to retain the metal at the trailing terminal enlargement which tends to stretch during the rolling and to compress it into the trailing recessed portions of said roll segments.

References Cited by the Examiner UNITED STATES PATENTS CHARLES W. LANHAM, Primary Examiner.

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