US2383224A - Mold - Google Patents

Description

1945. c. E. SORENSEN 2,383,224

MOLD

Filed F'b. 25, 1942 2 Sheets-Sheet l I INVENTOR. y a ;u@ :5 BY 6 ATTORNEYS.

Aug. 21, 1945 c, E. SORENSEN MOLD Filed Feb. 25, 1942 2' Sheets- Sheet 2 ATTOR EYS.

Patented Aug. 21 1945 MoLn Charles E. Sorens en, Detroit, ;Mich., assignor to Ford Motor Company, Dearborn, Mich, a corporation of Delaware Application February'25, 1942, Serial 43,2 ,214

aolaims, (o1; '22-'130) i The object of this invention isto provide a segmental mold, particularly designed for the casting of internal-combustion engine crankshafts and adaptable toshafts of any configuration or throw arrangement.

An advantage of this mold is that it is built up from a numberof preformed platesegments. These segments are so formed that many different combinations may be built up using only a small number of different standard segments. A 'further object ofthis invention is to construct a segmental mold in which a plurality of castings may be made at one time. Yet another object of the inventionis to obtain a segmental mold in which the individual segments are provided with automatic registry means and in which the sprue by which the metal is introduced to the moldis automatically formed. Another object of this t invention is to provide a construction in which the forces incident to casting are opposed and equalized and in which the segments are provided with the requisite support while they may be easily and readily assembled;

The advantages of thecast shaft per se over one formed conventionally by forging are manifold. These include superior strength, a much more accurate blank, more economical and faster production, and the utilization of manufacturing means which are readilyavailable. These ad vantages have longbeenrecognized and special a means have been devised forcastin g the smaller shafts used in automobile engines. It is apparent, of course, that conventional molding means cannot be used because of the parting lines required. Further, the special means which have been developed are limited to the smaller shafts and are not readily adaptable to the larger and more complex pieces contemplated here. Therefore, the present mold has been developed to meet this need. s s

With these and other objects in viewhthe invention consists in the arrangement, construction and combination of the variousparts' of the int proved device, described in the specification,

claimed in the cla ms, andiliustr'ated in the accompanying drawings, in which:

v esentative 'the mold, snowing the alignment of the com-- pqr en segments.

Figures 5, s, 7 and s are views tr individual a segments showing the configuration a em-1 i i Referring to ii'i g rei, l0 designates acrank; f'sh'aft offaparticulardesig'n and II the 'mold constructed according to this invention in which i it is cast. The crankshaft shown is one designed fora lfi-cylindery-typje motor; and, as anindex or the size of t e mow; the shaft isupwards of 12 feet inlength. As is cii'stomary in shafts of this size,"it a nmnber of axially-aligned main bearings l2, one between each of the throws [3. The throws are arranged in two groups of four each, the throw'sin each group are at9 0" angles and the groups are relatively oifset 425. n This represents a most complicated casting problem, but one which this mold handles effectively.

The fnold ln which this crankshaft is to be cast is built up from anumber of plate segments I 4 made of baked core sand, each of which defines a certain portion of the shaft. Thus, one plate a designated l5 has a simple cylindrical opening l'fidefining the throw I3 of the shaft, other plates fi and I8, which dei'lne the bearings l2, havea cylindrical central opening Hand, on opposite faces, depressions 20 communicating with 19 and defining adjacent cheeks '21 of the crankshaft.

Yarious fo-rms' of bearing plates are required, I! being one inwhich thethrows are 1'80 apart and I8 them at a90 a'nglel Other plates such as 22 or 23 are used at the top andbottom to define the special end portions of the shaft. v p E'achbf the plates isprererabl square in plan.

In the bearing plates I! or 18 the opening I9 is at t Figure lis an elevation o the mold orthi's in a vention, being shown in section on approximately a the line l-l of Figure 2. H V s h h Figllre 2 iS a "secticn'al View takehbn the line 2 2 bfFiglli' 1.

Figure 3515 an end we t e abovearranga i'nht indicated by the line 3-3 0'11 "1 and 2. a s a Figure; isa'nexpanded View c f'aportionfof the center of the plate, whilein the throw plates the openings 16 'areoffset fromthe center of the throw radius. At the midpoint of each side of each plate isa registry notch 24 preferably "semicircular in section. A bottom feeder plate/25 which accommodates two of the regular plates is also provided. 'Ithas a central reservoir 26 from which runs 21 lead to a point where they will communicate with the co-operating plate openingsand it has registry notches on its ends only Simil'arly,a large top plate 28 has a central pouring funnel 29 andrisers 30.

plates are formed of baked core sand and are, of course, used to pour only one casting. It willbe understood that the mold fabricated from them includes a number of duplicates and hence the number of difie'rent pattern plates required greatly reduced. I p The permanent parts oi the (mold include "a All of [these 1 lining dowels 33.

49 and having adjustable compressing means 43.

'In assembling the mold, the bottom feeder plate is placed on the base plate 32, its end notches engaging the dowels 33. Qnenow proceeds to build up two stacks of plates, side by side, on the base plate, the end registry notches 24 of each plate engaging the lining'dowels 33 closed into the proper close relationship.

31 are applied. They may be used along the entire length of the mold to form a complete flask or they may be distributed at such points therealong as the conformation of the shaft requires. In applying them, it is only necessary to engage the seat 39 in the back 38 with the appropriate dowel, bring the hinged side members along the sides of the plates, engage them with the front bar 42, and operate the clamping means 43 to force the two or more plates en- When this is done, it is apparent that the individual plates are protected from breaking under any of the forces normally encountered and that a comand the abutting notches in adjacent faces form- I ing the sprue 44. The first plates are those identified as 23 which form the bottom end co nnections of the crankshaft. 'Thereafter, refer-- ringto Figure 4 which in the interests of clarity'does not: show the bottom plates, a throw plate 15 is added. After this, a bearing plate is placed, which is followed by another throw plate 15 revolved 90 as shown by the relative position of the X on one corner of'the plate. This, in turn, is followed by a bearing plate I! and another throw plate I5 now revolvedv a further 180.

When the phase angle between the groups is encountered, a plate 31, such as be used.

This procedure is followed, adding successive plates as required by the particular design, until K the entire mold is completed. The top plates 22 and 28 are then added anol the metal weighting plate 34 is finally placed and secured by the wedges 36 extending through slots in the upper part of the dowels 33. The building of the two stacks is carried on simultaneously to permit easier placement of successive plates. M -It will thus be seen that all of the individual plates are aligned by reason of the registry notches 24 will respect to the dowels 33 and to each other; and that the centrally occurring notches co-operate to form thenecessary sprue 44. Furthermore, the'dowels are held in the properrelative position by .the top weighting plate 34 which also preventsany longitudinal displacement of the individual segments by its own weight and by the anchoring action of wedges 36. It is thus apparent that the segmen'ts are securely aligned and firmly held. against the forces exerted in casting. The provision made for casting twqor more of the shafts at once is important, particularly in the matter of forming the pouring sprue; but also has advantages flowing from the fact that the crankshafts maybe oppositely arranged in the adjacent stacks, as best shown in Figure 2, so that the throws and the metal therein may to some extent counteract each other in each stack and prevent undue distortion, It is well known that when a crankshaft is cast, because of the unsymmetrically disposed weights, considerable allowance must be made for shrinkage as explained in my Patent No. 1,992,677. Substantially the same advantages claimed there may be, obtained in the present case, when that is foundnecessary, by appropriately shaping those plateswhich are used in but one position of revolution. Thus, the shaft, when cool, will be approximately straight. I To complete the mold, the individual jackets required.

plete mold results in which failure is well-nigh impossible in ordinary usage.

In some instances, but one plate of one specific pattern may be required in making up the mold'as, for instance, the 180 bearing plate 11. In these, the side registry notches may be omitted since they are not needed for alignment with the dowel or to form the sprue and this would correspondingly lower the chances of misplacing the plate in the assembly; However,

one of the greatest advantages lies in the use of the smallest number of individual patternsto make the largest number of assemblies and, in general, each segment should be usable in any of four rotated positions with either side up, making a total of eight different positions. In each, though, the alignment and sprue means are available.

, It.is believed that the manifoldadvantages of this construction have been pointed out in full in describing it, but it may be well to state further that it is applicable to crankshaftsof many designs and that in any event it obviates the requirement of a large number of differently formed segments; that it, it utilizes in different alignment or arrangement a small number of standard segments. Moreover, a suitable pouring sprue is obtained without unduly extending the size of the segment, weakening it or requiringfaddition'al labor which would otherwise be Finally, this sprue is located intermediate the shaft molds, and the hot metal therein keeps the metal in the sprue at the desired fluidity to supply additional metal required to make up the contraction in the shaft changes as may reasonably be included within,

the scope thereof.

, I claim: 1. A mold for casting engine crankshafts having a plurality of axially aligned main ibearing sections. spaced therealong and having axially offset crankpin bearing sections integral therewith, comprising, adjacent stacks, each comprising a plurality of superimposed baked core sand plates, all of said plates having openings therethrough, certain of said plates having depressions on the faces thereof in communication with said openings, notches correspondingly located on the sides of each plate, said notches aligning throughout when said depressions and'openings are in register, the notches on the adjacent faces of said stacks co -operating to form a pouring sprue. Y 1

2 Arnold for casting engine crankshafts having a plurality f axially aligned main bearing sections spaced therealong and having axially offset crankpin sections integral therewith, comprising, a supporting base, a plurality of registering dowels secured to said base and extending therefrom, adjacent stacks of superimposed baked core sand plates onsaid base, said plates having openings therethrough, certain of said plates having depressions n the faces thereof in communication with said openings, registry notches on the sides of said plates, certain of said notches aligning with and receiving said dowels, the notches on the adjacent facesof said stacks aligningand co-operating to form aclosed central pouring sprue through said stacks.

3. The structure of claim2 which is further characterized in that certain of said plates making up a stack are of the samecentrally ofiset pattern, said similar plates being rotated through an angle equal to a multiple of the angle between registry notches to obtain different mold conformations, said notches aligning throughout to receive said dowels and to form said pouring sprue.

4. The structure of claim 2 whichis further characterized in that onecontinuous plate underlies said stacks and engages said dowels, a depression formed in said block to receive molten metalfrom said sprue, and runs leading from said depression and communicating with said openings to admit the molten metal to the mold defined by said stacked plates.

5. The structure of claim 2 which is furthercharacterized in that a flask is formed therearound, said flask comprising a plurality of jackets having aligning engagement with said dowels and releasably embracing said stacks, and ad-j justaible means to support said stacks and maintain the adjacentengagement therebetween.

6. In a mold for casting engine crankshafts having a plurality of axially aligned main bearings and having axially ofiset crankpins, the

angles between said crankpins being multiples of 90, a uniform mold segment to define the successive offset portions of said crankshafdsaid segment having an axially offset opening therethrough, and registry means on the sides of said segment spaced at 90 intervals, whereby said segment may be rotated to various right-angle positions to define the different offset portions while being maintained in proper registry.

7. In a mold for casting engine crankshafts having a plurality of axially aligned main bearings and having axially offset crankpins, the angles between said crankpins being multiples of 90, a uniform mold segment to define the successive oifset portions of said crankshaft, said segment being formed of ba'kedcore sand rectangular in elevation and square in plan, said segment having an axially ofiset opening theretlrrough, vertically extending notches formed midway of each vertically extending side thereof,

whereby said segment may be rotated through various right-angle intervals to define the various offset portions, said notches aligning throughout.

8. In a mold for casting engine crankshafts, two stacks of substantially square mold segments adjacently disposed, registry notches extending vertically substantially midway of the vertical mid-point of each vertical side-thereof, and an opening ofiset 'centrally through said segment. CHAS.VE. SORENSEN.

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