DE2020120A1 - Prestressed press - Google Patents

Description

DR. R. POSrUHNRIEDER

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Verson Allsteel Press Company, 1355 East 93rd Street,. Chicago , 111. (V.St.A.)

Prestressed press

The invention relates to a prestressed press.

Prestressed presses have traditionally had a lower frame member, an upper cross yoke, between the two Subdividing inserted columns and tie rods with thread, which extend through the lower frame member, the cross yoke and the ' Columns extend therethrough, and tie rods on these are to create a rigid structure for receiving high operating forces by tensioning the tie rods and by compressing the lower frame member, the cross yoke and the column tie-rod nuts screwed on. For tie rods with Threads naturally have a high concentration of stress in the area of the thread turns and are therefore heavy Tie rods and nuts as well as heavy and bulky frames required.

The invention is primarily based on the object of a To create improved prestressed press, in which the disadvantages of the aforementioned, known, prestressed presses on a Minimum levels are reduced, so the necessity

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the use of threaded tie rods with their naturally There is no high stress concentration factor and for which a more compact frame with a lower weight is sufficient.

In short: the prestressed press according to the invention basically has a lower frame member, a cross yoke and a ram carried by one of these two members for performing the required work function in the Association with the other of the two links. Although the invention in mechanical press. " with power operated crank or the like can be used to drive the ram, it is of particular use in a hydraulic press, in which the ram is driven by a hydraulic cylinder «The hydraulic cylinder can be in the cross yoke of the press be arranged and drive the ram down against the lower frame member of the press, or it can be in the lower frame member the press and then drive the ram up against the cross yoke of the press. For example It is assumed in the following that the hydraulic cylinder is arranged in the lower frame member.

The preloaded press has multiple downward saddles on the lower frame member and multiple upward turned saddles fitted on the transverse yoke · intermediate the lower frame member and the cross yoke extend along the sides of the same a plurality of tie rods which over the Saddles protrude from these and have shouldered shoulders, which are attached to the downward-facing saddles of the lower Attack the frame member or the upturned saddles on the transverse yoke between our frame member and the Several compression members are inserted into the cross yoke, and to maintain it the tensile stress in the tie rods and the compressive stress in the compression members are between the latter on the one hand and the lower frame member and / or the cross yoke on the other hand fodder blocks arranged "

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When preloading the press, the ram is preferred blocked against the link not assigned to it (lower frame link or transverse yoke), then a pressure above the Approved nominal pressure of the press on the ram brought into effect, so that the tie rods are placed under tensile stress and are stretched, the chucks between the pressure members on the one hand and the lower frame member and or, or the cross yoke on the other hand are selected and used in such a way that they compensate for the expansion of the tension rods under tension, and then the ram is relieved of the pressure brought into effect, and the blocking means between the The plunger and the link not assigned to it are eliminated, whereupon the tensile stress in the tie rods or the compressive stress are maintained in the pressure members by the inserted lining blocks "

The chucks are preferably chucks that are driven into place. The ones turned up and down Saddles are preferably substantially cylindrically convex, and the shoulders in each one Tension members that engage the saddles are preferred substantially concave, so that stress concentrations at these points are avoided · those of the lower frame member and the ends of the individual tie rods adjacent to the transverse yoke are preferably clamped together, as a result of which the moments of force is counteracted in the tie rods around the shouldered shoulders that attack the saddles.

According to the invention, a pretensioned press is included a lower frame member, a cross yoke and a ram carried by one of these two members for performing a work function in conjunction with the other of these two members characterized by a number of downward-facing saddles on the lower frame member, several up-

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BATH ORIGINAL

saddles turned to the side on the cross yoke, several tension members, extending between the lower frame member and the transverse yoke along the sides thereof beyond the saddles on them and which have stepped shoulders attached to the downwardly facing saddles on the lower frame member and engaging the upturned saddles on the cross yoke, a plurality between the lower frame member and the cross yoke inserted pressure members and lining blocks between the individual pressure members on the one hand and the lower frame member and or · or the cross yoke on the other hand to. Maintenance the tensile stress in the tie rods or the compressive stress in the compression members

In the drawing, two preferred embodiments of the invention are shown for example *

Fig. 1 is a front view of a first embodiment the invention;

Fig. 2 is a side view of the biased press viewed from the right in Fig. 1;

Fig. 3 is a vertical section, taken substantially along line 3-3 in Fig. 2, on a larger scale, but with the lower part of Fig. 3 shows a modified construction, which in the prestressed press according to Flg. 5 is provided;

Fig. 4 is a horizontal section through the prestressed press, taken substantially along the line hh in Fig. 1;

FIG. 5 is a front view of another embodiment of FIG Invention, similar to FIG. 1; and

FIG. 6 is a horizontal section through the prestressed press of FIG. 5, substantially along line 6-6 in FIG. 5.

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The first embodiment 10 of FIG Invention has a supporting base frame, the two Has support structures 11, between which a lower frame member 15 extends, which with brackets 12 above each supporting structure is equipped, and which, for example by means of screws or the like are screwed on · The lower frame member 15 is in a suitable manner, for example by means of screws or the like load-bearing base frame attached. The press also has a ram or a work surface 19, the lower Frame member 15 is assigned, and has a cross yoke 20 above the lower frame member 15 «The ram or the lower work surface can be driven in a suitable manner, and in the illustrated embodiment, the drive is assumed to be a hydraulic cylinder in the lower frame member 15 is arranged. The hydraulic cylinder shown here consists of a cylinder 16 of large diameter and a Cylinder 17 of small diameter. A piston 18 is arranged within the cylinder 17 and 17, which by acting upon it is moved upwards with a hydraulic fluid. Shown here, the upper part of the piston 18 forms the plunger or the lower Work surface 19 for performing the work function of the press, within the scope of the inventive concept, however, the The plunger or the working surface 19 is separated from the piston 18 and separated by guide devices or the like be led. The cross yoke 20 can also be equipped with a work surface 21, and the work function is executed between the working surface or the plunger 19 and the working surface 21 when the underside of the piston 18 is pressurized with hydraulic pressure «The opening at the upper end of the cylinder 16 of large diameter can by means of a suitable circular plate 22, -through which the piston 18 is passed

The lower frame member 151 which contains the hydraulic cylinder,

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is equipped with two downward-facing saddles 25, which are preferably cylindrical and convex. The cross yoke 20 is also preferably cylindrical with two equipped convex saddles 26, but which are turned upwards. Between the lower frame member 15 and the cross yoke extend along the sides of the same two tension members 27 'which, as shown at 28 and 29, over the saddles 25 and 26 protrude from these two links. These tension members 27 have stepped shoulders 30 and 31 »on the downwardly turned saddles 25 engage on the lower frame member 15 or on the upwardly turned saddles 26 on the transverse yoke 20. The shouldered shoulders 30 and 31 are here preferably cylindrical concave and the cylindrical convex surfaces of the saddles 25 and 26 adapted, whereby Stress concentrations at these points are reduced.

Between the lower frame member 15 and the cross yoke 20 are two pressure members 35 are used in the vicinity of the tie rods 27. Between the pressure members 35 and the cross yoke 20 chuck blocks are inserted which have the shape of chuck wedges 36 can.

When the press is pretensioned, the ram or the work surface 19 is secured by means of suitable blocks (not shown) blocked against the working surface 21 of the cross yoke 20, and in this state, the piston 18 becomes a hydraulic one Pressure above the nominal pressure of the press brought into effect so that the tie rods 27 are tensioned and stretched.

Now the wedge-shaped chuck blocks 36 are used

e.g.

brought, in-which they are driven in and occupy the gap that was created when tensioning and stretching the tie rods 27 is. Then the piston 18 is relieved of the pressure acting on it, and the blocking blocks between the working surface or the plunger 19 and the working surface 21 become eliminated, and this has the consequence that the tensile stress in the

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Tie rods 27 and the compressive stress in the compression members 35 preserved.

As shown more clearly in FIGS. 1 and 2, the lower sections 28 of the tie rods 27 are provided with continuous tension screws 38 and are braced by means of nuts 39 screwed onto the screws 38 and acting against spacer sleeves kO. This pretensioning of the lower ends 28 of the tie rods 27 counteracts the moments of force in the tie rods 27 around the offset shoulders 30, which act on the saddles 25.

In a similar way, as shown in Fig. 1, 2 and k , the upper ends 29 of the tension members 27 are equipped with through tension screws 2 * 2, which are braced against each other by means of nuts ** 3 acting against spacer sleeves hk and screwed onto the screws kz . Here, too, this tensioning of the upper ends 29 of the tie rods 27 counteracts the moments of force in the tie rods 27 around the offset shoulders 31 engaging the saddles 26.

To fix and align the tie rods 27 with respect to the lower frame member 15 and the transverse yoke 20, the lower frame member 15 is equipped with brackets k6 and the transverse yoke 20 with brackets 47 on opposite sides of the tie rods 27. *

The other embodiment of the invention, which is shown in FIGS. 5 and 6 and in the lower part of FIG. 3, is similar to that according to FIGS. 1 to k , but differs from this by the use of a different construction for bracing the lower one Ends 28 or the upper ends 29 of the tie rods 27. Correspondingly, the same reference numerals are used for the corresponding parts of both embodiments, and a more detailed description should therefore be superfluous. In the case of the modified embodiment

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of the prestressed hydraulic press 50, the lower ends 28 of the tie rods 27 are provided with shoulders 52 turned outward. A plate 53 is stretched between the lower ends 28 of the tie rods 27 and is equipped with two inwardly turned shoulders 5 ^ in. Near the shoulders 52. Between the shoulders 52 and $ k feed blocks in the form of wedges 55 are inserted, and when these are driven in, the lower ends 28 of the tie rods 27 are pulled towards one another, so that the moments of force in the tie rods around the shouldered shoulders engaging on the saddles 25 30 is counteracted. The lower ends 28 of the tie rods are equipped with threaded pins 56, and the transverse plate 53 is held in contact with the lower ends 28 of the tie rods 27 by means of sleeves 57 and nuts 58 screwed onto the threaded pins 56.

As shown in FIGS. 5 and 6 , the upper ends 29 of the tie rods 27 have outwardly facing shoulders 60 in a similar manner. A plate 61 arranged transversely over the upper ends 29 of the tie rods 27 has inwardly facing shoulders 62 near the shoulders 60, and by driving in chucks in the form of wedges 63 the upper ends 29 of the tie rods 27 are pulled against each other, whereby the moments of force in the tie rods 27 is counteracted by the offset shoulders 31 engaging the saddles 26. The ends 29 of the tie rods 27 carry threaded pins 65f and the plate 61 is fastened to the ends 29 of the tie rods 27 by means of sleeves 66 and nuts 67 screwed to the threaded pins 65.

Although only two are preferred for purposes of illustration Embodiments of the invention have been described result This results in manifold modifications for the person skilled in the art without deviating from the inventive concept

Claims.

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Claims (1)

- 9 claims ,! prestressed press with a lower frame link, a Cross yoke and with one of these two links worn ram for performing a work function in conjunction with the other of these two members, characterized by a number of downward facing saddles on the lower frame member, multiple upward facing saddles on the cross yoke, multiple tension members, extending between the lower frame member and the transverse yoke along the sides thereof via the saddles on them extend out and have stepped shoulders attached to the weighed down saddles on the lower frame member and the upturned saddles engaging the transverse yoke, a plurality between the lower frame member and Pressure links and lining blocks inserted in the cross yoke between the individual pressure members on the one hand and the lower frame member and / or the cross yoke on the other hand to maintain the tensile stress in the tie rods or the compressive stress in the compression members 2 Pretensioned press according to claim 1, characterized in that that the chunks of feed are wedge-shaped links driven into position 3 · Prestressed press according to claim 1, characterized in that the downward and upward-turning saddles .. essentially are cylindrically convex and the shoulders engaging the saddles on the tie rods in the are essentially cylindrically concave, so that stress concentrations are kept to a minimum k "Prestressed press according to claim 2, characterized in that the" bwärta- and upward-turned Sättel- are substantially cylindrically convex, and the arrival of the saddles 009852/0250 - 10 - gripping, offset shoulders on the tie rods in the are essentially cylindrically concave so that stress concentrations are kept to a minimum. 5. Prestressed press according to claim 1 or 2, characterized by means for clamping the lower ends the individual tie rods in the vicinity of the lower frame member against each other and devices for bracing the upper ends of the tie rods near the cross yoke against each other, in order to reduce the moments of force in the individual tie rods around those acting on the saddles Counteracting shoulders, 6. Prestressed press according to claim 3 or k, characterized by means for bracing the lower ends of the individual tie rods in the vicinity of the lower frame member against each other and means for bracing the upper ends of the tie rods against each other near the cross yoke to the moments of force in the individual Tie rods to counteract the offset shoulders attacking the saddles 7 pretensioned press according to claim 5, characterized in that that the means for bracing the tie rods consist of tie rods which are located between the upper ends the lower ends of the tie rods extend 8 _# Preloaded press according to claim 6, characterized in that, the means for bracing the tie rod of the tie rods which respectively extend to · the lower ends of the tie rods between the upper ends. 9 · Pretensioned press according to claim 5 or 7 »characterized by off indicates that the clamping device is turned outwards Shoulders at the ends of the tie rods, off over the top - 11 - 009852/0250 Ends of the tie-rods laid plates with inward-facing shoulders near the outward-facing shoulders on the tie rods and from putter blocks inserted between the shoulders on the tie rods and on the plates exist. 10. Prestressed press according to claim 6 or 8, characterized in that off indicates that the clamping device is turned outwards Shoulders at the ends of the tie rods, made of plates placed over the upper ends of the tie rods with inward-facing panels Shoulders near the shoulders turned outwards on the tie rods and from lining blocks inserted between the shoulders on the tie rods and on the plates exist. 11. Prestressed press according to claim 9 »characterized by screws outside the shoulders on the plates Fixing of the panels to the tie rods by screwing the panels into the tie rods 12. Prestressed press according to claim 10, characterized by screws that are outside the shoulders on the plates for Attachment of the panels to the tie rods by screwing the panels into the tie rods. 13. Prestressed press according to one of claims 1 to 12, characterized in that the plunger is hydraulically driven and that the movement of the plunger against the The link not assigned to it (lower frame link or cross yoke) is blocked while it is being tensioned for the first time the tie rod hydraulic pressure above the nominal pressure is brought into effect on the plunger. - 12 - 0098S2 / Ö2S0 BATH ORIGINAL 14. Method of pre-tensioning a pre-tensioned press according to claim 1 to 13, characterized in that the The ram is blocked against the link not assigned to it (lower frame link or cross yoke) for stretching and tensioning the tie rod for the first time, a pressure above the nominal pressure of the press is brought into effect, to compensate for the stretched condition of the tie rods , the chucks are brought into use, the pressure is released and the blockage between k the plunger and the link not assigned to it (lower Frame link or cross yoke) is eliminated. 009852/0250 ORIGINAL INSPECTED