US2445995A - Automatic die casting machine - Google Patents

Description

July 27, 1948. R. BOURRET ET AL AUTOMATIC DIE CASTING MACHINE Filed July 11,- 1946 2 Sheets-Sheet 1 1 7\ F2 v aw I X L- 6 RENE 150mm and JACQUES BARDOU V I I Inventors P J Attorneys July 27, 1948. BQURRET r AL 2,445,995

AUTOMATIC DIE CASTING MACHINE Filed July 11, 1946 2 Sheets-Sheet 2 RENE BOURRET and JACQUES mnnou"- Inventor;

Attorneys Patented July 27, 1948 UNITED STATES 2,445,995 AUTOMATIC DIE. CASTING Rene Bourret, Boulogne-sur-seine -and Jacques Bardou; Paris, France, assignors to Societe dApplications Mecaniques pour IAutongfobile, Boulogne-sur-Seine, France, va -corporation of:-

France Application July 11,.1946,SerialNoi 682,9'68' In France November-1945" In operations for casting metal pieces and, more particularly, in operations for die casting it isressential that the extraction of the cores be effected according to a fixed time schedule for each'shape of casting, in order toavoid certain casting: accidents due to shrinking phenomena. It has beenproposed to make this schedule of extraction more precise by putting at the disposal of the foundry workman an apparatus which,

through emitting a series of signals spaced in a predetermined manner, indicates the moments outer element of the chill is fast with a piston.

actuated by a compressed fluid, the distribution of said compressed fluid to the various pistons taking place by a single slide valve controlled by the rotation of a cam preferably rotating at a constant speed, the respective shapes and: arrangements :of said slide valve and said'cam being d-etermin'ed in a manner known per se within the reach of any man skilled in the art. It is thus possible by using a cam with apredetermined profile chosen according to the operation to be efiected to ensure the sequence of the operations for extraction of the cores and the removal of the castings fromthe mould through the rotational? thecam at a constant speediwithout the operator having to intervene from the moment when the machine has been started.

According to a preferred form of execution of the invention the pistons actuating each outer element and the core or spindle which passes through the same, as the case may be, are combined into a single one which is arranged so that the die element is displaced only after the core has been entirely released from the casting.

Finally, the tilting movement of the casting table after the withdrawal of the casting from the mould is preferably ensured in the same manner through a compressed fluid actuated piston controlled by the same distribution slide Valve.

The appended drawings show examples of execution of die casting machines according to the invention. In these drawings, in which for avoid- 1 Claim. (01. 22-432) ing complication. of :therfigures the" conduits tion.

thedistribut'ion-of the-fluidxhave notbeenfshowm.. Fig; 1 is a diagrammatical viewwpartlyrrmv plea vation: and spartlynwin section through 1111 .clie' .compriseaiion the piecew i being castg'; three outertelement's 5-; 6 oreziBL d lateral rspiiidles.r9; spindle forms; a

mounted in: ancylinder tom lofd said cylinder and whichfi's l the die :el-ement; furthermorexthe :rod 1-5 'comprisesi ashould'eril 'l. Y l

When compressed air i introduced "into tlie cylinder I4 through the pipingppening at flflthe pressure first exerted on the faces o'f tlie pistons i3 and I 6} tends to separate them and-the piston i 3 "moves alone carryingwith it the core 9"when the shoulder W comes to "strike against"the-"Walt of the piston T6 the latter is-rendered 'faiSt'iWith the piston 13 and the whole "movesfurtl'r'ery thus" carrying with it the die element.

The central core 8 is fast with the rod of a pisston moving in a cylinder Me. On the other hand, the table 3 is maintained by the rod of a piston moving in a cylinder I41. The compressed fluid is distributed to the Various cylinders [4a, b, c, d, e, ,f by a single slide valve known per se and not shown, actuated by a cam the shape of which is determined, also in a manner known per se, in function of the schedule according to which the successive operations of extraction of the cores and of withdrawal of the castings are to be effected, said cam being driven at a constant speed for instance by an electric motor.

A casting operation is carried on in the following manner. On the beginning of the operation the table 3 is sloped towards the left of the figure. At the moment when he effects the casting proper of the metal, the operator starts the motor actuating the cam, The latter actuates the slide valve which first determines the supply of compressed fluid to the upper part of the cylinder l4 The, table I returns progressively to a horizontal position, which determines a correct distribution of the molten metal in the die. After a time which is determined by the profile of the cam the various spindles and the central core are extracted at the required moments and the casting 4, which is withdrawn from the mould, can be removed from the table I. The cam moving further, the slide valve determines the simultaneous operation of the cylinders in the reverse direction with respect to the preceding one and the various organs resume their starting position, the machine thus being ready for a new operation.

\ The machine shown in Figs. 4 and 5 is designed for casting pistons made of a light alloy. The

die is formed of two elements l9 and 20 and the casting is effected on three cores, viz. a central core with counter-delivery and two side spindles providing the recesses for the axis for the small end of the connecting rod. The above mentioned core primarily comprises a central element having no projections in its part which is to be engaged in the casting and one or more, preferably two, side elements between or against which the central element can slide and which are linked about axes perpendicular to the direction of displacement of the latter. The latter is provided with sloping surfaces co-acting with stops carried by the side elements for determining the rocking movement of the latter about their axis of articulation while moving nearer to the central element when the latter yields back between the said side elements which are recessed inwardly-for permitting this rocking movement. Said coreis fast with a piston located in a cylinder2l' while; the side spindles are fast with pistonslocated in cylinders 22 and 23 and mounted, as explained previously, so that the die element is carried along after the core has been extracted.

. The machine is provided, furthermore, with vibrators 24 and 25 mounted on the die elements and adapted for being started just before the withdrawal of the casting from the mould in order to facilitate said operation. The table I is rockingly mounted on axes 2 carried by a frame 3 and a cylinder [4] controls the rocking movement of said table.

All the cylinders are supplied with compressed fluidby a single slide valve 26 actuated by the rotation, ata constant speed, of a cam 21 driven by an electric motor 28 provided with a speedreducing gear 29. Cam 2! controls thestarting andthe stopping of the vibrators also in a manner known per se.

"spindles are extracted and then, the vibrators 24 and 25 having been started, the die elements are separated and finally the central core is extracted; the casting can then be removed. The cycle terminates by the return of the core, the

spindles and the die elements to their initial position as well as by the rocking of the table.

It has been supposed above that the motor which drives the cam runs at a constant speed,

but this condition of simplicity is not absolutely h necessary. The speed of the motor may be rendered variable at will, a rheostat being interposed,

for instance, in the supply of the electric motor.

What we claim is:

An automatic die casting machine having cores and dies, a compressed fluid piston and cylinder device for controlling each of said cores and its corresponding die, said piston and cylinder device comprising a cylinder having two sections of different cross-sectional area, a piston in each section, the larger of said pistons being beyond the smaller with respect to said die, said smaller piston being hollow, and said larger piston having a rod passing through said smaller piston and secured to said core, said smaller piston being secured to said die, means for supplying compressed fluid to said cylinder between said pistons, said piston rod being provided with a stop within said smaller piston to limit the relative displacement of said pistons to the approximate length of the said core.

' RENE BOURRET.

JACQUES BARDOU.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,724,332 Will et al Aug. 13, 1929 1,896,690 White Feb. 7, 1933 1,925,496 Nichols Sept. 5, 1933 2,065,213 Dolan et al Dec. 22, 1936 2,171,628 Lannert Sept. 5, 1939 2,201,906 Lebkuechner May 21, 1940 2,419,373 Schrumn Apr. 22, 1947 FOREIGN PATENTS Number Country Date 607,088 Germany Dec. 17, 1934

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