US2363673A - Method of installing and retaining valve seat inserts - Google Patents

Description

Nov. 28, 1944.

c. A. JENSEN METHOD OF INSTALLING AND RETAINING VALVE SEAT INSERTS Filed March 13, 1942 IIIIIF Patented Nov. 28, 1944 UNITED STATE S' ATENT OFFICE METHOD oEiNsmLLmo AND RETAINING j VALVE. SEAT INSERTS Charles Augustus Jensen, Inglewood, Calif. Application March 13,1942, Serial No. 434,503

(c1. za-iscm My invention relates to a method for installing and retaining valve seat inserts, particularly. those inserts thatiprovide" seats for theintake and exhaust valves of internal,combustion:engines, and my present invention is an improvement on the exhaustwalve seat insert retainin and cooling meansforming the subject matten of United States LettersPatent #2,l91,485issued to me February .27, 1940. r The principal objects of my invention, are to generally improve upon the means and method disclosed in myaforesaid patent, as well aso-ther methods of installing valve seat inserts, further, to eliminate the possibility of cracking the cylinder block while installing inserts, and further, to provide improvedmeans for cooling the insert. 1

It is: more or less a general practice to drive the insert very tightly: into anrecess in the cylinder block. around theinlfit or outlet port so as to produce a close contact between. the insert and the block, and where a slightly over size insert is driven into the block, it creates an outward pressure in the metal immediately adjacent the recess, and this pressure coupled with the impact of the heavy hammer used indrivingthe.

insert, frequentlycracks the casting. Where the insertbecomes loose, it is the general practice to re-Ibore the recess and install-the next sizelarger insert. Such practice weakens the casting; and, if repeated several times, the boring goes through the wall of the casting to the Water chamber therein. Further, caulking or peening around the. insert is sometimes practiced, but: thisisf only effective near the surface of the metal, and does not tighten the insert to anyaplpreciable degree.

outer circumference of the recess to expand and exert greatpressure against the insert, and

therebysecurely anchor thev same to, the block.

The pin receiving holes are spaced apart from the outer circumference of the recess so that said lpins do not touch the insert, and if the insert should be removed; no pins will be visible. The holes are drilled all the way through the metal to the adjacent cooling fluid circulation chambers, and the length of the pins is such that they project substantial distances into the circulation fluid chambers thereby effecting. atransference r, of heat from the insert to the: cooling fluid, and,

consequently, exerting a cooling effect on; said insert;

The recesses that receive the inserts are bored to practically the samediameter in length as the insert, and, therefore,v it is not necessary to use any appreciable amount of pressure or; driving forcesto position the inserts in the recesses, and the subsequent insertion of the tapered pins compresses and crowds the metal against the inserts so as to rigidly-anchor the same in the block.

In order to more rigidly anchor the inserts in the block, the outer and under surfaces of the inserts and the surfaces of the recesses are coated with a suitable cement. before theinsertionof the inserts, thus effectually sealing the joints between said inserts and blocks.

With the foregoing, and other objects in View, my invention consists in certain steps and procedure hereinafter more fully described and Inserts are sometimes threaded and screwed into the threaded" recesses, but -such practice is r not entirely satisfactory, for the inserts frequentsert has been seated in the recess and sealed with suitable cement, driving ordinary tapered pins into said holes so as to exert pressure on the metal surrounding the holes, and consequently compressing the same, which action causes those portions of the metal between theholes and the In the drawing: Fig. 1 is a plan View of a portion of an internal combustion engine cylinder block, and showing a valve seat insert 9 therein according to my invention. l

Fig. 2 is a verticalsectionrtaken on theline 2-2 of Fig. 1. i

Fig. 3 is an enlarged detail view showing thesealed joint between the inserted valve seat and thecylinder block.

Referring by numerals to the accompanying drawing, l0 designates the block of an internal combustion engine ll, one of the piston chamhers therein, and I2, the conventional duct which may be for the inlet of gaseous fuel, or for the exhaust of burned gases or products of combustion. r

In practicing my improved method, an annular recess I3 is formed in the top of, the block l0 around the end of the duct 12, and which. recess is of such size insert; H.

as to snugly receive the valve seat This insert is in the form of a metal ring, the upper inner edge of which is chamfered so as to form a valve seat Hi.

In order to more firmly secure the insert in the recess, and to effectively seal the joint, between the insert and the block, the outer and under faces of the insert and the surfaces of the recess, are prior to the placing of the insert in the recess, coated with a suitable cement that is-not affected by heat. After the insert has been positioned in the recess, and sealed as just described, a plurality of tapered holes l6 are drilled through that portion of the cylinder block around and immediately adjacent the recess I3 and tapered metal pins 11 are now driven into said holes It, said pins having sufiicient length so that substantial porembedded and in turn, this cooling effect is transmitted to the valve seat insert.

In the event that portions of the upper ends of'the pins, after being driven into the block, project above the upper surface thereof, said projected ends may be ground off flush with the upper surface of said block. In as much as the pins are small in? diameter, and they act only in relatively small areas of the metal in the cylinder blocks surrounding the valve insert, said pins may be driven into the block without the attendant danger of cracking the same, and which latter condition exists where the inserts are driven into the recesses in the block with large heavy hammers, and which latter are necessary to produce a drive fit between the inserts and the block.

tions thereof project into the cooling fiuid circulation chambers l8 that are formed in the cylinder block.

As a result of the driving of the pins into the block, as just described, those portions of the metal immediately surrounding the holes l6, will be expanded and, consequently, compressed, and, thus the metal between the pinholes and the recess 13 will be'compressed to such a degree as to materially increase the solidity of such metal,'and this compression directly engages the outer face of the insert to very securely anchor the same in its inserted position.

Obviously the pressure exerted by the pins l'l when driven into holes l6 compresses the metal outwardly from those portions of the metal between said pins and the insert receiving recess l3 and thus the substantially circular area. of metal disposed immediately outward from the pins, is compressed and solidified so as to effectively counteract tendency of the insert to expand under high temperatures and counteracting tendency of the compressed areas of metal between the pins H and recess to expand away from the insert. In other words, the insertion of the pins I"! in the casting compresses and solidifies a substantially circular area of metal immediately surrounding. the insert and particularly, those portions of the metal lying between the pins and said insert.

' In Fig. l, I have illustrated arrows surrounding the upper ends of the inserted pins, and which arrows indicate the compression forces that are developed when the pins are driven into'the block. It is'to be understood that in practicing my improved method, the pin holes l6 are spaced apart from the recess l3, and thus, the inserted pins do not directly contact with the valve seat insert [4.

I Inasmuch as substantial portions of the pins driven into the cylinder block project downwardly into the cooling fluid circulation chambers, said pins are continuously cooled as the fluid circulates and such cooling effect is transmitted to the' metal in which the upper ends of the pins are I have demonstrated a practice that the average valve seat insert requires only five or six pins to rigidly anchor said insert in the block, but in the event that an insert should become loose, the additional holes for the accommodation of additional pins are drilled into the block between the holes and pins already provided, thus compressing and forcing the metal in the. block between the holes and insert against the outer face of the latter to provide the additional anchorage.

In Fig. 3, I have illustrated the cement or sealing compound between the inserted valve seat and the block, but this illustration is exaggerated for, as will be understood, the insert fitssnugly in the recess in the block, and, therefore, the

sealing cement or compound has no appreciable thickness.

Thus it will be seen that I have provided a relatively simple and easily practiced method for installing and retaining valve seat inserts incylinder blocks of internal combustion engines, and the practicing of which method provides for the transference of the temperatures of the cooling medium, which is circulated within the cylinder block, to those portions of the metal in the block immediately surrounding the insert.

I claim as my invention:

The method of installing and securing valve seat inserts in the metal cylinder blocks of internal combustion engines which consists in forming an annular recess in the cylinder blockaround the end ofa port therein, positioning a valve seat insert in said recess, forming a series of apertures at equally spaced intervals in the metal of the block at points beyond the outer marginal edge of the annular recess so as to provide substantial thicknesses of metal between said recesses andapertures and then inserting tapered pins into said apertures with sufficient force to compress and solidify the surrounding metal in said block and force these portions of the metal between the inserted pins and the insert toward CHARLES AUGUSTUS JENSEN.

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