US3016601A

US3016601A - Method of making hollow valves

Info

Publication number: US3016601A
Application number: US703034A
Authority: US
Inventors: Max J Tauschek; James M Cherrie; Robert O Beutell
Original assignee: Thompson Ramo Wooldridge Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1957-12-16
Filing date: 1957-12-16
Publication date: 1962-01-16
Anticipated expiration: 1979-01-16

Description

Jan. 16, 1962 M. J. TAUSCHEK ETAi. 3,016,601

METHOD OF MAKING HOLLOW VALVES 2 Sheets-Sheet 1 Filed Dec. 16, 195'? [77 1 E3 21 22.71"; MAX 7211/86/15;

05527- El/TELL Jan. 16, 1962 M. J. TAUSCHEK ET AL 3,016,601

METHOD OF MAKING HOLLOW VALVES 2 Sheets-Sheet 2 Filed Dec. 16, 1957 3,016,691 METHQD OF MAKING HOLLGW VALVES Max 3'. Tauseheh, Lyndhurst, and James M. (Iherrie and Robert 9.. Beutell, Euclid, Ohio, assignors to Thompson Rama Wooldridge End, a corporation of flhio Filed Dec. 16, 1957, Ser. No. 7tl3,034 4 @laims. (Ci. 29-156.?)

The present invention relates broadly to the art of valve manufacture, and is more particularly concerned with a new and improved method of sealing the central opening of hollow valves.

It has been customary practice in the production of valves for automotive and aircraft use to first provide an enlarged portion on the open end of the valve, remove the valve from the dies in which the enlarging operation was accomplished, and thereafter locate the valve in a separate set of dies within which an extruding operation was performed to completely seal the central opening within the valve stem. Such a procedure is time-consuming and relatively expensive, and is not readily adapted to economical production runs.

Applicants have discovered that the deficiencies of the heretofore known method may be avoided by essentially upsetting the open-ended portion of the valve in a die, and then extruding said valve in the same die in a continuous operation. Briefly stated, this is accomplished by locating a valve blank having a straight cylindrical hollow stem within a die which has a lower portion sized for snugly receiving the stem and an upper portion which may have a larger diameter than the stem, in which event a shoulder or ledge is provided between the two die portions. Alternately the upper die portion may be of the same diameter as the lower portion. The portion of the stem extending into the upper portion of the die is subjected to induction heating, while the lower portion of the stem in the lower part of the die is unheated. The necessary amount of sodium to cool the valve is dropped into the hollow stem and only lills the lower portion of the stem below the part that is in the enlarged die cavity. The portion of the stem in the upper die cavity which is heated by induction heating is then subjected to pressure from a ram which upsets the end of the stem forming in the die with the larger upper portion, an enlarged diameter closed portion. This closed portion may have a pipe running through it. Where the die has a uniform diameter, the locally heated tip end of the valve stem cannot enlarge, but is thickened and closed. During the upsetting and closing operation, the valve is supported so that the stem cannot slide in the die' Upon completion of the upsetting and closing operation, however, the support is removed and the same ram is allowed to force the closed end of the stem into the lower die cavity thereby extruding the enlarged end and closing up any pipe that might remain therein to effect sealing of the sodium in the valve.

It is therefore an important aim of the present invention to provide a novel method of forming hollow valves characterized by continuously upsetting and extruding the end portion of the valve stem in a single operation.

Another object of the invention is to provide a method of forming a valve member having an opening at one end thereof which comprises confining the valve within a die member and applying a vertically directed force to the valve to close the opening at the upper end thereof.

Another object of the invention lies in the provision of a method of readily and effectively closing the central passageway Within a tubular valve stem member which comprises locating said member within a die, heating said member while in the die, applying a vertically directed force to said member to form an enlarged portion on the upper section thereof, and continuing said vertically di- Eflihfihl Patented Jan. 16, E962 ice rected force to remove the enlarged portion thereon and simultaneously close the passageway therein.

A further object of the invention is to provide a new and improved method of sealing the opening within a valve member having a stem portion and a head portion, which comprises supporting the valve member along its head portion and applying a vertical force to the stem portion to first form an enlarged portion thereon and immediately thereafter to remove said enlarged portion and completely close the central opening within the stem portion.

Other objects and advantages will become more apparent with the teachings of the principles of the invention in connection with the disclosure of the preferred embodiment in the specification, claims and drawings, in which:

FIGURE 1 is a sectional view of the valve body and showing a suitable heating means in surrounding relation thereto;

FIGURE 2 is a sectional view of the valve body located in a die member and a ram in alignment therewith;

FIGURE 3 is a sectional view showing the action of the ram in forming an enlarged portion on the valve body;

FIGURE 4 is a sectional view showing the final position of the ram in removal of the enlarged portion on the valve body;

FIGURE 5 is a sectional view of a valve member as produced by this invention;

FIGURE 6 is a sectional view of a modified form of die member; and

FIGURE 7 is a sectional view showing the sealing of the valve body opening of FIGURE 6 by action of a vertically movable ram.

Referring now to the drawings, a hollow valve 19 of the type with which this invention is particularly con cerned normally comprises a head portion 11, a throat portion 12 and an elongated stem portion 13. Extending substantially entirely throughout the length of the valve 14) is a recess or open end passageway 14 within which is customarily located a heat conducting medium 15 such as sodium or the like. The heat conducting medium functions to dissipate heat produced during actual usage of the valve in automotive and aircraft applications, and. as the first step in the practice of the present process, the sodium or other medium 15 is poured or otherwise inserted into the passageway 14 preferably to a distance of approximately A to /2. of the depth of said passageway. To facilitate closure of the passageway in the subsequent steps of this process, the upper portion of the valve stem 13 is heated by suitable means. One heating arrangement which has proven well adapted in actual practice is an induction heating coil 16 shown in FIG- URE l in surrounding relationship to the valve stem member 13. It is desirable that the portion of the stem to be formed be heated as closely as possible to its extrusion temperature, and while variations in temperature will of course be required depending upon the valve body materials and other factors, it has been found that a temperature range of between 1800 and 2200 F. is adequate for most purposes.

While the drawing shows the heating of the valve body before it is placed in the die, it is also possible to first place the valve 10 within a die member in the manner shown in FIGURE 2, and then heat the valve stem. The die 17 illustrated therein may be of general wedge shape in cross section having upwardly and outwardly tapering side walls 18 and substantially straight top and bottom walls 19 and 2d. The die 17 is maintained fixed within a die holder 21 by means of dowel pins 22, and provided within the die holder is a shoulder portion 23 against which the bottom wall 20 of the die 17 abuts. Extending vertically throughout the depth of the die is a central opening24 having a relatively slender lower portion 25 and a relatively wider upper portion 26. Also arranged within the die holder is a vertically movable support 27 upon which the head 11 of the valve rests, while arranged above the valve in vertical alignment with the die opening 24 is a ram 28secured to a head 29 of a suitable punch press.

Subsequent to location of the heat conducting medium 15 within the passageway 14 in the valve, the valve 10 is positioned Within the die 17 as shown in FIGURE 2, heat applied thereto, and the ram vertically aligned as illustrated. The ram is then caused to move downwardly, and during said movement, the heated metal of the side walls of the valve stem portion 13 are forced outwardly into close fitting contact with the walls of the relatively wider upper. portion 26 of the die opening 24, as well as in contact with the extruding jaw or ledge 30 between the two portions of said die central opening. The outer circumference of the ram is substantially the same as the inner diameter of the relatively wider upper portion of the opening 24, and as the downward movement of the ram continues, the walls of the stem portion collapse, and in effect unify to form a solid structure as appears in FI URE 3. The walls of the stem portion during this downward movement lose their separation and the metal in effect congeals upon itself and the passageway 14 in the stem 13 assumes a tapered configuration in cross-section adjacent its upper portion. The tapering of the passageway 14 is indicated at 31 in FIGURE 3, and it may be further noted that the stern of the valve during approximately half of the downward stroke of the ram has formed thereon an enlarged portion 32.

As the ram 28 continues its downward movement within the die central opening 24, the support 27 of the die holder 21 is gradually lowered and the enlarged portion 32 on the valve stem is extruded or substantially entirely removed as the ram bottom surface closely approaches the ledge 30 between the upper and lower portions of said central opening 24. Upon reaching the bottom of its stroke, the ram 28 has forced substantially all of the metal formerly within the upper portion of the die cavity into the lower portion thereof and the tapered passage 31 is essentially entirely sealed ed as appears in FIGURE 4. The valve body as thus formed may then be removed from the die and subsequent processing accomplished, such as by machining at points designated by the numeral 33.

A-modified form of applicants invention is shown in FIGURES 6 and 7, and upon reference thereto it will be seen that the essential difference between this and the foregoing described form of the invention is that the central opening within the die is of uniform diameter from one end to the other, that is, there is no relatively wider upper portion and relatively narrower lower portion. Further, itwill be seen that the ram 28 is designed to pass entirely from the top to the bottom of the die to thereby eject the valve and avoid the necessity of opening the die after completion of the forming operation. In this embodiment of the invention the heat conducting medium is inserted within the passageway 14 as previously described, and the valve 10 is thereupon located within the die 17 with the head portion 11 of the valve resting upon the-support 27 of the die holder 21. Heat is then applied to the upper part of the stem portion 13. The ram 28 is then caused to travel downwardly, and by reason of the confinement of the stem within the die opening, the walls of thestern form a unitary structure as is well shown in FIGURE 7. During the closing operation of the passageway 14, the support 27 remains in a stationary position. However, after sealing of the opening or passageway 14, the support is caused to descend and the valve 10 is thereby readily removed from the die. Customary machining operations may then be performed.

It may be seen from the foregoing description and accompanying drawings that applicants have provided a new and novel method of forming hollow valves which avoids the heretofore unsolved difliculties presented to those skilled in the art. Following the teachings of this invention, it is no longer necessary to first form an enlarged or upset portion on the valve stem, remove the valve from a die in which this operation is accomplished, and locate the valve in an entirely different die where the extrusion is performed and the passageway in the valve effectively closed. This is all now accomplished inone operation with resulting economies in manufacturing costs and with no reduction in the quality of the product produced.

We have in the drawings and specifications, presented a detailed disclosure of the preferred embodiment of our, invention, and it is to be understood that we do. not intend to limit the invention to the specific form disclosed, but intend to cover all modifications,rchanges and alternative constructions and methods falling within the scope of the principles taught by our invention.

We claim as our invention:

1. A method of sealing the interior of a hollow metal poppet valve member provided with a generally cylindrical hollow stem of substantially constant Wall thickness throughout the length thereof, and utilizing only a single die and a single ram member, w hich'compn'ses locally heating a. portion of the stem to extruding temperatures, locating the generally cylindrical stem within a die having a cavity conforming in diameter with the portion of the stern adjacent the head of the valve member to clamp the valve member in the die with sufficient force to prevent its dropping therefrom but with a clamping force insufiicient to prevent movement of the valve member upon the application thereto of extruding pressures, inserting a ram member within said cavity against the end wall only of the heated stern por-- tion, restraining the valve member against slippage in said same die by supporting said valve member from therebeneath at a location spaced from said same die,

moving said ram member in the same die to upset the heated end of the valve stem causing collapse thereof, removing the restraint on the valve member while maintaining said valve member in said same die, continuing the movement of the ram member while allowing the valve member to slip in the same die, and during said continued movement extruding the heated upset end of the valve stem in said die cavity to close the tip end portion of the stem and seal the hollow interior of the valve member.

2. A method of sealing the interior of a hollow metal poppet valve member provided with a generally cylindrical hollow stern of substantially constant wall thickness throughout the length thereof and being open at the tip end, and utilizing only a single die and a single ram member, which comprises inserting coolant into said valve member through the open tip end thereof, confining the major length of the generally cylindrical stem Within a die having a cavity conforming in diameter with the portion of the stem adjacent the head of the valve member to clamp the valve member in the die with sufiicient force to prevent its dropping therefrom but with a clamping force insufiicient to prevent movement of the valve member upon the application thereto of extruding pressures, forcing a ram against the end wall only of the open end of the stern in said same die to thicken the heated portion of said stem and close the open tip end of the stem, restraining the valve member against slippage in said same die during said stem thickening step by supporting said valve member from therebeneath at a location spaced from said same die, removing the restraint on the valve member while maintaining said valve member in said same die, and advancing the.

ram in said same die to force the thickened stem portion into the portion of said die clampingly engaging the stem and by application of sufficient ram pressures to overcome said clamping force, causing the stem to slip in said die portion and extruding the thickened stem portion to seal the coolant in the valve member.

3. A method of making hollow coolant filled poppet valves from valve blanks having hollow cylindrical stems of substantially constant wall thickness throughout the length thereof, and utilizing only a single die and a single ram member, which comprises inserting the stem of such a blank in the die, supporting the head of the blank from therebeneath upon a generally coextensive surface spaced from said same die, upsetting the tip end of the stem in said same die by applying a force to the stem end wall only and Without entering the hollow stem, oausing collapse of said tip end, removing the support on the valve head, and extruding the upset portion of the stern in said same die, completely closing the tip end of the stem.

4. A method of making hollow coolant filled poppet valves from valve blanks having hollow cylindrical stems and utilizing only a single die and a single ram memher, which comprises inserting the stem of such a blank 20 in the die, supporting the head of the blank from therebeneath upon a support spaced from said same die, upsetting the tip end of the stem in said same die by applying a. force to the stem end well only and without entering the hollow stern, causing collapse of said tip end, removing the support on the valve head, and extrading the upset portion of the stem in said same die, completely closing the tip end of the stem.

References Cited in the file of this patent UNITED STATES PATENTS 981,697 Simpson Jan. 17, 1911 1,984,751 McBride Dec. 18, 1934 2,344,285 Cormode Mar. 14, 1944 2,392,175 Norton Jan. 1, 1946 2,893,553 Kreidler July 7, 1959 FOREIGN PATENTS 546,016 Great Britain June 24, 1942