US2319546A

US2319546A - Method for making valve sleeves

Info

Publication number: US2319546A
Application number: US336380A
Authority: US
Inventors: Insley Robert; Arthur W Green
Original assignee: United Aircraft Corp
Current assignee: Raytheon Technologies Corp
Priority date: 1940-05-21
Filing date: 1940-05-21
Publication date: 1943-05-18
Anticipated expiration: 1960-05-18

Description

' May 18, 1943 R. INSLEY ETAL METHOD FOR MAKING VALVE SLEEVES Filed may 21, 1940 TOR 190113232153 1% 110:- WEreE-n WW 2 m ATTORNEY Patented May 18, 1943 mn'rnooroa'maxmo vALvE SLEEVES Robert Insley, Farmington, and Arthur W. Green, West Hartford, Comm, assignors to United Aircraft Corporation, East Hartford, Conn., a

I corporation of Delaware Application May 21, 1940, Serial No. 336,380

6 Claims.

This invention relates to an improved method of manufacturing a valve sleeve and has for an object the provisionof an improved method for "forming thickened or generally upset portions on a valve sleeve of the character indicated and for Other objects and advantages will be more-- particularly pointed out hereinafter or will become apparent as the description proceeds.

In the accompanying drawing there is illustrated a suitable form of engine valve sleeve for the purpose of disclosing the invention and several important steps in the improved manufacturing process. The drawing, however, is for the purpose of illustration only and is not to be tak n as limiting the invention since it will be apparent to those skilled in the art that various changes in the shape and size of the sleeve and changes in the number and arrangements of the steps of the process may be resorted to without in any .way exceeding the scope of the invention.

In the drawing,

Fig. 1 is a sectional view of a blank upon which the steps of the improved process are performed.

Fig. 2 is a diagrammatic illustration of one step in the improved manufacturing process.

Fig. 3 is a diagrammatic view of a different step in the manufacturing process.

Fig. 4 is a view of a step in the manufacturing process subsequent to that illustrated in Fig. 3.

Fig. 5 is a view of the sleeve blank after the forging and upsetting operations of the process have been completed, and

Fig. 6 is a longitudinal sectional view of the finished valve sleeve after machining operations have been completed on the blank illustrated in Fi 5.

iteferring to the drawing in detail, the numeral it generally designates the blank particularly illustrated in Fig. 1. This blank may be cut from a stock tube of the proper dimensions and wall thickness formed of a suitable compound or alloy. As seamless tubes are usually formed by forcing a blank over successive mandrels while spinning it between rollers to decrease the wall thickness and increase the length of the member until a tube of proper dimensions is produced, such tubes are usually produced with a generally uniform, spiral, grain flow pattern which pattern somewhat diminishes the strength of the tube material in tension along the axis of the tube. As there are relatively heavy tenslonal loads on a valve sleeve as well as loads in other directions, it is desirable that the strength of the sleeve be substantially uniform in all directions and that the material should not have a too definite grain flow pattern in the region of the valve ports and at the point of connection of the sleeve actuating mechanism.

While it has been entirely possible to forge or cast valve sleeve blanks prior forging methods in which the blank is entirely formed by forging operations have been found to be extremely complicated and expensive, and the casting process in addition to, being comparatively slow does'not produce a member having satisfactory strength in the dimensions required in modern engine construction.

By manufacturing the sleeve members of stock tubular sections the speed of production can be greatly increased, the cost of manufacturing the sleeves can be materially reduced and an im proved product can be produced with greater facility. 7

In the improved process the blank I0 is cut from a piece of stock tubing and is made somewhat longer than the finished length desired. One end is made substantially straight at right angles to the axis of the tube, as indicated at H, and the opposite end It is cut on a bias so that the tube is longer on one side than upon the other. The portion of minimum length may be connected with the portion of maximum length by means of a curved cut as illustrated in Fig. 1 if found desirable in order to provide the necessary mandrel through a spinning billet to provide a hollow cylindrical blank and then forcing this secured together so that the external shape .of-

the blank cannot change except over certain areas where a change in the external shape is desired. For example, as shown in Fig. 2, the open end portion of the die cavities are made somewhat larger than the inner portions of the die receiving cavities, the two portions being Joined by an annular radial shoulder 22. After the two portions of the die 16 have been secured together a mandrel 24 is forced into the blank to maintain the interior of the blank in its original shape and a sleeve member 26 surrounding the mandrel 20 is then forced into the enlarged open ends of the die cavity against the straight end of the blank Ill. The end portion of the blank towards the sleeve 26 will have been heated to a malleable or slightly plastic condition before the sleeve is forced inwardly upon it in order that the metal of the blank may flow under the pressure exerted upon the sleeve. As the sleeve 26 is forced into the die It against the heated end of the blank in the end portion of the blank is upset against the shoulder 22 to provide an enlarged end portion 28 on the blank. Because of the heating and deformation of the metals during this upsetting operation the grain fiow pattern of the upset portion of the blank will be modified so that no definite directional grain flow is apparent in the upset portion.

After a sufilcient amount of material has been upset at the end of the blank against the sleeve 26 the blank is removed from the die It and inserted in another die 30 which also comprises two

separable parts

32 and 34 having semi-cylindrical blank receiving depressions opening to one side of the respective die portions. At their inner ends these depressions are provided with undercut enlarged portions which receive the upset end portion 28 of the blank and one of the die members is provided with a recess or pocket 36 of substantially the shape of the operating mechanism attaching lug on the finished valve sleeve.

After the

portions

32 and 34 of the die'30 have been firmly clamped about the blank, a mandrel 38 is forced into the blank to maintain the interior shape thereof against change and after the mandrel has been positioned in the blank a mandrel surrounding sleeve 40 is forced into the open end of the die cavity against the biased end of the blank. As the sleeve is forced inwardly the excess material in the longer portion of the blank is gathered together and forced into the recess 36 to provide material for the lug 42, the

final forging position being shown in Fig. 4 in which the biased end of the blank has been straightened and all of the excess material forced into the cavity 36. It is to be understood that this gathering operation does not need to be performed in a single forging operation but that as many steps and as many die and sleeve forms as may be necessary may be employed between the initial operation shown in Fig. 3 and the final operation shown in Fig. 4. As shown in Fig. 3, the end of the sleeve member 40 is somewhat biased though on a lesser angle than the end of the blank It so that the biased end of the blank will be reduced in this operation but will not be completely straightened. By using a number of sleeves of 'the proper end form the material at the end of the blank can be worked around into the cavity 36 to give the desired grain pattern and without imposing localized stresses in the end of the blank. The sleeve 46 used in the final forging operation shown in Fig. 4 may have a substantially straight ,end with a portion cut 7 thickness, provide the valve port apertures 44, shown in Fig. 6, and shape and aperture the lug 42. These machining operations may terminate with grinding and polishing operations to produce the finished valve sleeve illustrated in Fig. 6.

It will be appreciated that by the above-described method a sleeve valve may be formed from a section of stock tubing to the proper shape and dimensions and will have a homogeneous granular structure in the area of the valve ports where such a structure is particularly important because of the stresses imposed over this area and the dimculty of maintaining the material immediately around the valve ports adequately lubricated, and will have an attachment lug for the operating mechanism in which the granular structure is also homogeneous so that the lugs will not have a tendency to pull oil? of the sleeve along any particular definite line of cleavage as would be the case if a definite grain fiow pattern characteristic of spun tubes were present.

While a suitable mechanical embodiment of the improved valve sleeve and certain typical steps in the method of producing the sleeve have been hereinabove described and illustrated in the accompanying drawing, it is to be understood that the invention is not limited to the particular sleeve construction or the particular method steps so illustrated and described, but that such changes in the size and shape of the sleeve and in the number and arrangements of the method steps may be resorted to as come within the scope of the subjoined claims.

Having now described the invention so that others skilled in the art may clearly understand the same, what it is desired to secure by Letters Patent is as follows:

1. The method of manufacturing an engine valve sleeve which comprises, cutting from stock metal tubing having a generally spiral grain fiow pattern a blank longer than the finished sleeve, upsetting one end of said blank to shorten the blank and thicken the end portion and modify the grain structure so that said spiral grain flow pattern is no longer apparent in said thickened portion, machining said blank to remove at least all of the increase in thickess produced by said upsetting operation, and providing valve ports in said upset portion.

2. The method of manufacturing an engine valve sleeve which comprises, cutting from stock metal tubing having a generally spiral grain flow pattern a blank somewhat longer than the finished sleeve, one end of said blank being cut on a bias so that one side of said blank is longer than the other side thereof, upsetting said one end by a gathering operation to bring said one end substantially at right angles to said center line and provide thereon a lug blank on said longer side thicker than the original wall thickness of said blank and simultaneously modify the grain structure in and around said lug blank to a condition in which said spiral grain flow pattern is no longer apparent, and machining said lug blank to provide an apertured lug of proper shape and dimensions.

3. The method of manufacturing an engine valve sleeve having at one end an apertured lug for attachment to a sleeve actuating element comprising, cutting from stock metal tubing having in its original condition insuflicent tensile strength to safely receive the sleeve actuating forces applied to said lug, a blank longer than the finished sleeve having one end cut on a bias so that one side of said blank is longer than the sufliciently to safely transmit sleeve actuating forces applied to said lug, and machining said blank to reduce the thickness thereof and provide an apertured lug of proper shape and size.

4. The method of manufacturing engine sleeve valves which comprises, cutting from stock metal tubing having a generally spiral grain flow pattern a blank longer than the finished valve sleeve having one end substantially straight and perpendicular to the longitudinal center line of the blank and the other end out on a bias to said center line, upsetting said one end of said blank to thicken the end portion and modify the grain structure thereof so that no definite direction of grain flow is apparent in said thickened portion after said upsetting operation, forming an attachment lug on the bias cut end of said blank by gathering the excessmetal in the biased portion of said other end into a local thickening of a small part of said other end, and machining said blank to remove at least all of the thickness added by said upsetting operation on said oneend and provide valve ports through the upset portion of said one end, and provide an apertured lug or proper shape and dimensions.

5. The method of manufacturing an engine valve sleeve having valve ports extending through the wall thickness thereof at one end and an apertured valve actuator attachment lug at the other end comprising, cutting from stock metal tubing, having in its original condition law!!!- cient tensile strength to safety receive the valve actuating forces, a blank longer than the finished sleeve having on end perpendicular to the longitudinal center line of said blank and the other end cut on a bias to said center line, upsetting said one end to shorten said blank and thicken the end portion thereof over an area suflicient to completely include said valve ports, upsetting said other end while utilizing said thickened portion as an abutment, to render said other end substantially perpendicular to said center line and provide thereon 9. lug blank thicker than the original wall thickness of said blank, said upsettingoperations increasing the tensile strength of the material of said blank in the critical areas around said valve ports and in and around said attachment lug, and then machining said blank to remove the additional thickness at said one end produced by said upsetting operation and to provide valve ports in said upset portion, reduce the wall thickness of said blank, and shape and aperture said lug.

6. The method of manufacturing an engine valve sleeve having valve ports extending through the wall thickness adjacent one end thereof comprising, cutting from stock metal tubing having insuflicient tensile strength to provide adequate strength in the portions between said ports a ROBERT INSLEY. ARTHUR w. GREEN.