US3354693A - High energy rate forming machine - Google Patents

Description

Nov. 28, 1967 AKlRA ASARI HIGH ENERGY RATE FORMING MACHINE Filed July 21, 1964 INVENTOR.

AK IRA ASARI Attorney United States Patent 3,354,693 HIGH ENERGY RATE FORMING MACHINE Akira Asari, Osaka, Japan, assignor to Kobe Steel Works, Ltd., Kobe, Japan Filed July 21, 1964, Ser. No. 384,103 Claims priority, application Japan, July 24, 1963, 38/39357 4 Claims. (Cl. 72-453) ABSTRACT OF THE DISLOSURE A high energy rate forming machine having a ram actuated by a piston which has one of its ends in a gas pressure chamber, the inner end of the piston being equipped with a plunger tightly receivable in a cylinder which is connected via a check valve to the interior of the chamber, the vacuum formed in said cylinder when said plunger is thrust thereinto holding the piston until a switching valve connects said chamber to said cylinder. Hydraulic jack means entirely outside the chamber is used to raise the descended piston so that the plunger re enters the cylinder to lock the piston in its upward position. The hydraulic jack may also be used to trigger the release of the piston by forcibly withdrawing the plunger from the cylinder.

Background of the invention The present invention relates to a high energy rate forming machine in which a ram is actuated at a high rate by the action of a gaseous pressure and thus actuated ram acts on various materials, especially metals, with a high energy rate forming force.

It has been found that when a material or work is plastically deformed, if the plastic deformation operation is eifected at a great rate the material is deformed with a high impact force, and accordingly, the plastic deformation rate of the material by the utilization of such an impact force is quite higher than when the same material is plastically deformed at an ordinary or slower rate. Therefore, it can be assumed that when the same principle is utilized in the plastic deformation of a metallic material the deformation operation would be carried out with a quite high eificien'cy. In a press type machine which is a typical machine in which the above principle is utilized one metal mould is supported by a stationary platform and the other metal mould is secured to a ram which is a material or work is imparted a desired plastic deforma tion thereto by a cooperative action between the two moulds.

In such a press type machine, gas is outwardly discharged at the upper dead point of the ram stroke whereby the force which pushes down the ram is overcome by the force which pushes up the ram so that the ram may maintain its initial position. However, such a type machine has a drawback that a large amount of gas is outwardly discharged resulting in loss of a great amount of gas. In order to remedy the drawback there has been proposed that gaseous pressure is caused to act on the upper surface of the ram and oil pressure is caused to act on the lower surface of the ram thereby to maintain the ram at its predetermined initial position, but this increases the resistance by a great extent and the ram can not be actuated at a high rate. Furthermore, since the ram initiates its proper impact stroke directly from its initial or non-operative position, if the ram has not been so designed that it may maintain its initial operation without fail the operator may be exposed to possible hazards.

Patented Nov. 28, 196i Summary 0 the invention Therefore, the main object of the present invention to provide a high energy rate forming machine in whic the ram is actuated by means of gas pressure and th initial position of the ram is maintained by the same g2 pressure.

Another object of the present invention is to provide high energy rate forming machine in which when the rat is actuated by gas pressure, initially the ram slowly move along a preliminary stroke passage and thereafter initiate its proper impact stroke.

According to the present invention, the ram is provide with a piston and the piston is adapted to be moved int a gas pressure chamber which has a substantially large diameter than that of the piston and seals gas under high pressure therein. The ram piston is actuated at high rate by the gas pressure of the gas pressure chambe which acts on one end surface of the piston whereby high rate energy is generated by the actuation of the pie ton and such energy is utilized for plastic formation of work. In order to permit the ram piston to move along suitable distance of preliminary stroke before it initiate the proper plastic formation stroke, a mechanism Whic] comprises a combination of a plunger and a cylinder i provided between the adjacent end of the piston and th above gas pressure chamber, the cylinder has a size jus sufiicient to receive the plunger. When the plunger ha entered into the cylinder, the gas pressure within the ga pressure chamber does not act on the end surface of th piston, and accordingly, the ram piston is not imparte driving force thereto, but when the ram piston is desire to be actuated the plunger is caused to come out of till cylinder and at the same time the pressure within the gas pressure chamber actuates the ram piston. In othe: words, the movement of the plunger from within tht cylinder to the point at which the plunger clears the cylin der is designed as the preliminary stroke and the follow ing high rate actuation of the ram piston is designed a: the proper impact stroke. In order to maintain the plunge: within the cylinder or maintain the plunger at its initia position, the ram piston is provided with an abut surface which is subjected to the pressure within the pressure chamber for prevention of actuation of the ram pistor thereby to maintain the piston in the initial position.

Thus, according to the present invention, the ram is positively held in the initial position and when the rarr. is actuated,'since the ram firstly moves along the preliminary stroke passage and thereafter initiates the proper impact stroke, there is no danger in the time of actuation, and since the ram is actuated by the gas pressure in the proper impact stroke, a substantially high energy rate can be obtained, and since the gas pressure is sealed within the gas pressure chamber, there will be loss of gas pressure whereby a quite practical high energy rate forming machine can be provided.

Brief description of the drawing The above and other objects and advantages of the invention will be more readily apparent from the following description when read in connection with the accompanying drawings in which:

FIG. 1 is a longitudinally cross-sectional view of a preferred embodiment according to the present invention; and

FIG. 2 is a longitudinal cross-sectional view of a modified embodiment according to the present invention.

Description of the preferred embodiments In FIG. 1, the ram 2 to which an upper metal mould 1 is secured faces the top end surface of a bolster 4 to which a lower metal mould 3 is secured. The ram 2 is provided with a piston 5 which has a diameter of d and is vertically movable along a pair of guides 7 and 7 sup- )rted by'the-machine frame 6. A gas pressure chamber is provided v on the frame 6 and the pressure chamber 8 1s a diameter substantiallylarger than that of the piston The pressure chamber has gas under a high pressure aled therein. The rampiston 5 upwardlyextends through e bottom wall .9 of the gas pressure chamber 8 into .e jinterior vof .the chamber 8 and .is provided at the per end with a plunger 10 whose diameter is larger an the diametend of the piston Sand is substantially naller than the diameter of the chamber 8. The diamer of the piston 10.is indicated by d in FIGS. 1 and 2.

The plunger 10.is so constructed that the plunger just sin a cylinder .11 provided inthe upper portion of the iamberfiand having a diameter substantiallythe same a that of the plunger 10. The bottom wall ,9 of the ressure ,chamberS with .which the ram piston 5 con- .cts and .the plunger 10 'with which the cylinder 11 )ntacts are respectively provided with-packiugs 12.and iforprevention of the high pressure gas from leaking it. of. the, gas pressure chamber 8. The above gaspressure iamber 8 andcylinder 11 are connected to each other v means of. a. conduitlshaving acheck valve 14 which pens onlytothe chamber 8 and a conduit 15' having a iitable switching valve 16. Vertical jack cylinders '17 .e provided in thelower portion .of the frame 6 and ave :jack pistons vlttinserted therein respectively. The gposite ends of the jack cylinders 17 are communicated ithzfi- uidpressureconduits 20 and 21 respectively and t6 conduits .Ztland .21are controlled by a change-over 1lve,19. .The'upper ends of the'jackpistons .18 upwardly (tend through the bolster 4 andface the .ram.2.

FIG. vl shows when the ram.2 .isin the initial posion'and-therampistonS is pushedup to .the upper dead Jint A and the .plunger .10 is inserteddeep-into the vlinder :11. Accordingly, the gas pressure ,of .the gas ressure .chambenS imparts .an upwardly directing force n=thelowersurfaceof the-plunger 10 thereby to maintinthe-ram 2 inthe initial position as shown in FIG. 1. rior to the.actuation of the ram 2, the jack pistons 18 re allowedto descend and then.a work 22 is.placed on ie top of the lower mould 3. Thereafter, the valve 16 opened to allowthe gas pressure withinthe pressure 1arnber-8to1fiow throughthe conduit 15' to act on the linder i11-th6f6by to push the plunger 19 down. Since 1e upper surface 'of plunger 10' is subjected to downard force at the areacorresponding to the diameter d E the piston .5, the plunger 10* descends down together 'ith .thepiston. 5- and ram 2 along the preliminary stroke assa ge L which corresponds to the length of the plunger andimme'diately after the upper surface of the plunger 0 has :cleared the lower end B of the cylinder 11, the as pressure of the pressure chamber 8 acts on the upper irface of. the plunger 10,1and accordingly, therarn piston descends down at a high rate together with the .ram .Inthisstroke-of the piston thework22 is plastically )rmed to a desired shape by a cooperative action between ie upper and lower metal moulds 1 and. 3.

In ,order toallo-w the'descended ram 2 to-rise again the initial position, the change over valve 19.is shifted as to introduce the fluid pressure below the jack ylinders 17 thereby to push the jack pistons 18 and ccordingly, the ram 2 is pushed to the upper initial posion' again. Thereupon ifthe valve16' is maintained closed, ven if the plunger 10 enters into the cylinder 11, the as which has been trapped in the cylinder 11 pushes open 1e check valve 14 in the conduit and flows back into 1e gas pressure chamber 8, and accordingly, the ram iston 5 can rise-easily. When the ram piston 5 again ssumes the position as -shown in FIG. 1, the-gaspreslre Within the gas pressure chamberS acts on the lower irface of theplunger and thus maintains the ram 2 i the raised position up to the upper dead point A nd thejack pistons -18-are againallowed to descend to the )werposition and are ,held there.

.-In the. modified v.errrbodiment of FIG. 2, the plunger .34

is disposed within the upper portion of the gas pressure chamber 28 and-is downwardlydirected, and the cylinder 31 is provided at the top end of the ram piston 25. When the ram piston 25 is pushed up to the upper dead point A, the piston 25 is-held-in this position by the gas pressure acting onthe lower-su'rfaeeofthe cylinder 31. The preliminary stroke-passage 'L of the ram; piston 25 is the distance covered by the cylinder until the upper end of the cylinder f3lg-moves away'from the lower end of the plunger '30, and thereafter, the cylinder I31 is'subjected to the pressure of the gas pressure chamber 28 and the ram piston 25 is actuated at a high rate thereby.

When the ram 2 is desired to be actuated, the jack pistons 33 may be employed instead of the pressure of the gas pressure chamber -8 being introduced into the cylinder llras in the embodiment of FIG. 1. The actuating mechanism is designed so as to the fulfill purpose, thatris, the, jack piston 38 ofithe jack cylinders 37 are provided with smaller diameter'rods 36 and the rods 36 extend through the ram 32;andhave heads 35 at their respective en'dsJWhen'the jackpistons 3.8 are caused to descend,.-the heads 35Lcome to contact withthe Upper surface :of therram 32 -andtheram 32 is pushed .down by'thexdownward movement of the'jack pistons 38 and initiates .the properimpact forming stroke. When the actuating'mechanism as :shown in FIG. 2 is employed, the switching valve 16 and conduits v15' :which are.necessary in-the embodiment of .FIG. lxcan be eliminated.

According to the present invention, :the gas pressure within the gas pressure chamber can be adjusted. For example, if the gas pressure chamber 28 is filled with a certain amount of .liq-uid and the liquidamount is adjusted by the manipulation of the valves 24, 26, and accordingly, the gas pressure within the ,gas pressure chamber canbe varied. Any variation in the gaspressure may. vary. the downward movementrateof the rampiston, and accordingly, any desired high energyrate-forming efficiency can 7 be obtained.

While twoembodim-entsof the invention have been shown and described in detail it will be understood that they are'forthe purpose of illustration only and .are not to betaken as a definition of the scope of the invention,reference'being'had for this purposeto the appended claims.

-What is'claimed:

1..A high energy rate forming-machine which comprises: ararn adapted to be actuated at a high rate by gas pressure; apiston provided on said ram;-a pressure chambenadapted'to .containgas underhigh pressure and having .a.diameter'substantiallyjlarger than the diameter of said;piston, said piston passing throughazsliding seal in one'endof said chambena plunger-cylinder assembly disposed between one end of said piston and the other end of-saidpressure chamber, said plunger beingformed integral .with said pistonand said cylinder being formed integral with said pressure chamber; and a jack device locatedentirely outside said chamber for returning said ram to its initial position after it has descended; said cylinder and saidpressure chamber communicating with each other by means of a check valve which opens only to said 'gaspressure chamber, and said cylinder and said pressure-chamber also-communicating with each other by means of a switching valve.

2. A high energy rate forming machine as claimed in claim 1, in which a liquid supply device is further provided, said liquid supply device beng adapted to supply any desired amount of liquid intosaid pressure chamber so as to vary the'gas pressure within said chamber, the surface of said liquid within said chamber being in direct contact with said gas.

3. A high energy rate forming machine which comprises: a ram adapted to be actuated at a high rate by gas pressure; a-pistonprovided on said ram; a pressure chamber adapted to contain gas under high pressure and having a diametersubstantiallylargerthanthediameter of said piston, said piston passing through a sliding seal in one end of said chamber; a plunger-cylinder assembly disposed between one end of said piston and the other end of said pressure chamber, said plunger being formed integral with said piston and said cylinder formed integral with said pressure chamber; a jack device located entirely outside said chamber for returning said ram to its initial position after it has descended; said jack means actuating said piston by forcibly separating said plunger from said cylinder.

4. A high energy rate forming machine as claimed in claim 3 in which a liquid supply device is further provided, said liquid supply device being adapted to supply any desired amount of liquid into said pressure chamber so as to vary the gas pressure within said chamber, the surface of said liquid within said chamber being in direct contact with said gas.

References Cited UNITED STATES PATENTS Ottestad 73-12 Ottestad 73-72 Cvjetkovic 73-12 Murek 72-453 Ottestad 72-453 Robra 72-453 Steinfort 72-453 Bollar 72-453 Reimenschneider 721-453 CHARLES W. LANHAM, Primary Examiner. 15 G. P. CROSBY, Assistant Examiner.

Claims (1)

1. A HIGH ENERGY RATE FORMING MACHINE WHICH COMPRISES: A RAM ADAPTED TO BE ACTUATED AT A HIGH RATE BY GAS PRESSURE; A PISTON PROVIDED ON SAID RAM; A PRESSURE CHAMBER ADAPTED TO CONTAIN GAS UNDER HIGH PRESSURE AND HAVING A DIAMETER SUBSTANTIALLY LARGER THAN THE DIAMETER OF SAID PISTON, SAID PISTON PASSING THROUGH A SLIDING SEAL IN ONE END OF SAID CHAMBER; A PLUNGER-CYLINDER ASSEMBLY DISPOSED BETWEEN ONE END OF SAID PISTON AND THE OTHER END OF SAID PRESSURE CHAMBER, SAID PLUNGER BEING FORMED INTEGRAL WITH SAID PISTON AND SAID CYLINDER BEING FORMED INTEGRAL WITH SAID PRESSURE CHAMBER; AND A JACK DEVICE LOCATED ENTIRELY OUTSIDE SAID CHAMBER FOR RETURNING SAID RAM TO ITS INITIAL POSITION AFTER IT HAS DESCENDED; SAID CYLINDER AND SAID PRESSURE CHAMBER COMMUNICATING WITH

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