US2004528A - Method of making valves - Google Patents

Description

O HEDLUND METHOD 0F MAKING VALVES Filed Deo. 30, 1953 June 11, 1935.

W -m@ Nw W Patented June 11, 1935 UNITED STATES PATENT OFFICE METHOD OF VALVES Oscar Hedlund, Battle Creek, Mich., assignor to .Wilcox-Rich Corporation, Detroit, Mich., a corporation of Michigan Application December 30, 1933, Serial No. 704,627

6 Claims. (Cl. 29-156.7)

This invention relates to poppet valves and more particularly to engine poppet valves having an integral head formation Aof valve material such as to provide an enlarged chamber or area in the valve head.

One object of the invention resides in the making of a poppet valve of the character mentioned in such a way as to facilitatethe manufacture of the valve and to provide an economicalt method of procedure and an improved produc Another object of the invention resides in the method of making a poppet valve having an enlarged area within the valve head in whichA a substantially cup-shaped part of valve material is applied while at forging temperature to a cold preformed insert of copper or the like having a head portion substantially represent- 'ing the inside of the finished valve head, the valve material being then formed down on the insert material after which the stem forming portions of the valve'material are stemmed out.

Other objects and advantages lof the invention Vwill be apparent from the following description,

the appended claims and the accompanying drawing, in which,-

Fig. 1 is a sectional View of the valve material part;

Fig.y v2 is a sectional view of the preformed insert;

Fig. 3 is a central vetrical section through the dies of a forgingpress showing the-insert as applied to thefvalve material part before the forging operation;

Fig. 4 is a sectional view showing how the valve material is formed around the insert metal in the forging or swaging operation;

Figs. 5 and 6 are sectional views of a valve in successive stages of manufacture; and l Fig. 7 isffa sectional view of a finished valve made in accordance with this invention.

vReferring more particularlyyto the drawing by referencenumerals, I0' designates a substantially cup-shaped part-or shell of valve material, such as a suitable steel." In accordance with thisvinvention the'shell part I0 is first'y formed by a suitable extrusion or 'forging process, this part being integrally formed tov provide the wall II land the top .portionl I2 which closes oneend of theinteriorchamber or space.- I 3.l

The wall II, gas shown, is A,substantially cylindrical on its outer surface although vits inner surface is preferably tapered outwardly away' from thehead end'ofthe part, asshown. The minimuminside diameterfof the chamber or with copper.

ing portion I8 of the valve material is lessin..

space I3 is about the same as the desired maximum inside diameter of the space to be formed in the finished valve head.

Fig. 2 shows a preformed insert of suitable material having a melting point somewhat below the melting point of the valve material and preferably below the forging temperature of the valve material. Copper or a suitable alloy is preferably used in making the insert I5, which is so constructed as to have an enlargedhead portion I6 the diameter of which substantially corresponds to the minimum diameter of the chamber in the part I0. The shape and size of the head portion I6 of the insert is such as to substantially represent the inside dimensions of the chamber to be provided in the finished valve head.

In making the valve, the valve material part I0 is heated to a desired forging temperature, and the insert, while cold, is applied to the part I0 so that the head of the -insert is received at the closed end of the part I0.

The valve material is then formed around the insert metal by a suitable forging or swaging operation to provide a structure` such as is shown in Fig. 4, in which the approximate formation of the head portion of the insert is Aretained to give an enlarged chamber in the head of the structure, this chamber being filled As shown in Fig. 4 the stem formdiameter than the wall of the part I0 although the portion I8 is a comparatively thick walled short 'portion which is subsequently stemmed down to form the elongated valve stem.

In forging the parts l0 and I5 together, use.

may be made of dies of a forging press substantially as shown in Fig. 3, in which 20 designates a punch or upper forging die that can be so operated as to force the parts I0 and I5 down# wardly lin the lower die 2|. 22 designates a guide bushing adapted to receive and center` the heated part I0.` `23 is` an insert supporting rod the upper end of which has a projection that lis received in a'reces's or cavity 24 provided in the preformed insert, the construction being such that the insert is held upon thev rod.l

23' centered with respect lto the guide bushing 2v2. The. insert, while cold, is'appliedl'A to the rod 23 after whichl the Vpart I0 which`= has previously been heatedl to'fa forging temperature is dropped intolthe guide bushing,` and they punch 'or upper die thenvmade to` descend. Thus the y parts Ill'and I5 are' forced downwardly so as to form the walls: II of thevaIve material in and .I

around the insert, the shape of the forming portion of the lower die being such as to produce the desired formation. The rod 23 is supported by a suitable spring 26, and after the forging operation has been completed, 'the vertically movable knockout rod 21 may be forced upwardly to remove the forged part from the die..

As previously mentioned the shape and size of the head of the insert ls such as to substantially represent the inside dimensions of the space to be made in the valve head. The valve material is formed around the solid insert without substantially disturbing the head portions of the insert since the insert is cold when the head part of the valve material is applied to it. Heretofore it has been proposed to heat an enclosing shell of valve vmaterial while containing an insert of copper, and in such cases theY copper will either be heated to its melting point and thus rendered ineffective in controlling the inside shape of the valve head, orl great care is required in the selection ofmaterials and in governing the temperatures in order to prevent the copper from rbeing heated,I to its melting' point while heating the containing valve material to a proper forging temperature. Ifv the copper is heated to its melting point it cannoty retain its shape satisfactorily and it will be deformed and result in `an uneven or irregular formation of the space within the valve. o In accordance with the -present invention, however, thex hot valve material is readily formed around a comparatively rigid oore or insert which gives a controlled formation of the inside chamber to be provided in the iinished valve, resulting in an accurate and reliable method of procedure and economically producing valves in which the gliamber in the head is of the intended size and After forming the valve material around'the insert to produce a structure as shown in Fig.'4, the stem forming portion of the valve material may be stemmed out and the stem e'nd of the valve closed, it being understood that. the p0rtions of the copper insert of smaller` diameter maybe made as long as desired to produce a copper filled valve in -whichvthe copper entirely fills the chamber provided between the walls and in the head of the finished valve. However, the present invention is particularly adaptable in the making of a. hollow valve containing liqueflable cooling medium` such 'as metallic sodium Vor cooling salts of the character set forth in the patent to Heron No. 1,670,965. In accordance with the present method. in making a hollow valve having an integral head structure obviating any possibility of leakage of the valve cooling material in the head of the valve, after forming .the structure shown in Fig. 4, the structure is heated tothe liquefying temperature of the insert which is thenpoured -ovut ofthe formed valve-material. After this the stem forming portions of valve material 'are stemmed out without disturbing Vthe cavity in the head by a suitable swaging operation or the like to provide the formation shown in Fig. 5. The stemis' Vtheir drilled and the outside sur- .faeesmachined'soasto'leaveanenlargedpor-J and machining the valve.

valve comprising forming of valve material Vdiameterthantherernainderorftheinsert While the method herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise method, and that changes may be made without departing from the scope of the invention which is defined in the appended claims.

-of the insert is applied to the closed end of said part, and forming the valve material around the insert while the insert is in solid form. v

2. The method in the making f a poppet valve cdmprising` forming of valve material an integral hollow part closed at one en'd, the chamber within the hollow part having a minimum diameter substantially as large as the maximum internal diameter of the head of the finished valve, heating said part to forging temperature, forming an insert of lower melting point than the valve material to provide a head at one end of the insert of larger diameter than the remainder of the-insert, applying the insert while cold into the said part so the head of the insert is applied to the closed end of said part, forming the said part around the insert, reducing the stem portion of the valve, and machining the valve. v 3. The method in the making of a poppet valve comprising forming ofvalve material an integral hollow part closedat on'e end, the cham- -ber within the hollow part having a minimum diameter substantially as large as the maximum 4of' the insert of larger diameter than Athe remainde'r of the insert, applying the insert while cold into .the said part so the head of the insert is applied tothe-closed en'd of said part, form-- ing the said part around theinsert, heating the part with its insert to above the 'melting pointl of the insert material and removing the insert material, reducing the stem portion of the valve,

' 4. rne method in themkmgr a. Donnet valve comprising forming of valve material an integral hollow-part closed at one end, heating 1 said part to forging4 temperature, forminga copper insert havingl head at one end of larger diameter than the remainder of the insert andof such size and shape as to substantially represent -end of lthe part, andforming the said part 5.'.lhe method in themaking of a poppet integral hollow part closed at one end. heating saidpart to forging temperature, lfo copperinserthavingahead-aone endof ofsuchslze an'dshape as to substantially-represent the inside dimensions of the finished valve new.spplymz meinsertymieeomtomehdted part so the head of the insert is applied to diameter than the remainder of the insert and the closed end of the part, forming the said part of such size and shape as to substantially reparound the insert while the insert is in' solid resent the inside dimensions of the iinished form, melting and removing the insert material, head, supporting the smaller end of the insert, applying a cooling medium to the interior of the applying the heated part to the insert while valve, and sealing the stem end of the valve to the insert is cold', forging the walls of said part retain the cooling medium. around the insert, melting and removing the 6. 'I'he method of making a hollow poppet copper insert, reducing the stem portions of the valve comprising forming of valve material an Said part, applying Cooling medium Within the integral hollow part closed at one end, heating said part, and Sealing the Stem end of the valve 10 said part to forging temperature, forming a copto retain the cooling medium. per insert having a head at one end of larger OSCAR HEDLUND.

CERTIFICATE or oommcrlon;A

Paten: No. 2,004,528. :une 11, 193s.

oscAR HEDLUND.

lt is hereby certified that error yappears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, ,line 7l, claim 5, for "a" second occurrence read at; and that the said Letters Patent should be readwi th this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of'July, A.V D. 1935.

Leslie Frazer' (Seal) l Acting Commissioner of Patents.

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