EP0539787A1 - Radial press with two radially and mutually movable press yokes - Google Patents

Abstract

In a radial press with a press spindle (A), a plurality of external control surfaces (1, 2, 3, 4) at an angle to one another are arranged in groups in two press yokes (18, 19) which are driven radially in relation to one another. The planes of symmetry of the control surfaces (1, 2 or 3, 4) which are arranged in the same press yoke extend parallel to the direction of drive. A plurality of external control bodies (31), which are situated between two of the external control surfaces in each case, are used for the radial advancing of pressing jaws (30) towards the press spindle. Internal control bodies (37) with further pressing jaws (41) are driven synchronously by the external control bodies (31). To reduce weight and size, one press yoke (18) is guided in relation to the other press yoke (19) by tie rods (25, 26), which penetrate the leading press yoke (19) on its ends situated outside the control surfaces (1, 2, 3, 4), are fixedly connected to the other guided press yoke (18) in each case and are connected on the opposite side of the leading press yoke to a pulling drive (52) which is preferably designed as a dedicated hydraulic drive (47/51, 48/50) which is assigned to each tie rod (25, 26). <IMAGE>

Description

The invention relates to a radial press with a press axis and with a plurality of outer control surfaces which are at an angle to one another and are aligned with surface normals on the press axis and are arranged in groups in two press yokes which are radially movable relative to one another by means of a drive with a drive direction, the planes of symmetry of those in the same press yoke arranged control surfaces run parallel to the drive direction, as well as with a plurality of outer control bodies located between two of the outer control surfaces for the radial advance of press jaws in the direction of the press axis.

Radial presses of this type are used for deforming or machining workpieces with rotationally symmetrical outer surfaces such as pipes, sleeves, thimbles, etc. Such a radial press finds a particularly wide field of application in the field of manufacture of hose lines by radially pressing on hollow cylindrical hose sleeves which are generally provided with an inner flange a hose end freed from the elastomeric outer layer with a reinforcement made of steel wire. In the hose end there is a coupling part made of metal, against which the hose end is to be pressed under high pressure by means of the hose sleeve. Such hose lines have to withstand pressures of up to 1,000 bar and above for a long time with alternating loads. Failure of such a hose line with leakage of hydraulic fluid can lead to fatal injuries, which is why high demands are made on the radial presses concerned.

The term "rotationally symmetrical outer surfaces" means workpiece shapes with circular cross sections and cross sections in the form of regular polygons, as can be found, for example, in hexagonal profiles. The workpiece outer surfaces can be straight, cambered (barrel-shaped) or stepped in the axial direction. Such workpiece surfaces can be taken into account by appropriate design of the press jaws.

Another problem is based on the fact that neither the press manufacturer, nor the user, the numerous forms of metallic coupling parts used for can predict the hose lines in question. A large part of the coupling parts is designed, for example, as a pipe bend, and coupling parts with long pipe sockets are also known. Coupling parts of this type require a large free space on the back of the press facing away from the operating side, and likewise the shortest possible axial extension of the press. Both are in contradiction to the calculation formulas of such presses, in which high press forces or reaction forces have to be taken into account. In addition, the presses in question should be as small as possible and can also be transported without great effort for numerous applications, for example for use on large construction sites. Construction machines in particular generally have a large number of high-pressure hose lines, which may also have to be replaced and repaired on site by separating the hose from the still usable coupling parts. Last but not least, the reuse of the coupling parts also takes place with regard to the demands of a low amount of industrial waste.

A radial press of the type described in the introduction belongs to the prior art due to its obvious prior use, its construction and operating principle will be explained in more detail in the detailed description with reference to FIG. 1. Here it should only be stated so much that the press in question has a large and heavy press frame encompassing the hydraulic cylinder, which is closed on the circumference for reasons of strength.

From DE-OS 35 13 129 a radial press with four star-shaped hydraulic drives is known, in which by the interaction of four outer and four inner control bodies, twice the number, namely eight, of press jaws can be actuated synchronously. This press also has a large and heavy press frame, which is ring-shaped.

In contrast, the invention has for its object to provide a radial press of the type described above, which is smaller and lighter, an extremely short overall length and on the back facing away from the operator side a practically unlimited free space both for inserting fittings with elbows and for processing of fittings with elongated, long pipes and of continuous lines.

In the radial press described at the outset, the object is achieved in that one press yoke is guided relative to the other press yoke by tie rods which run parallel to the drive direction and penetrate the leading press yoke at the ends thereof lying outside the control surfaces, with the other, guided press yoke are firmly connected and are connected beyond the leading press yoke with a train drive.

A radial press designed in this way combines an extremely small size with a particularly short overall length, a low weight and an extremely simple construction.

As a traction drive, for example, threaded spindles would be conceivable; However, it is particularly advantageous if a separate hydraulic drive is assigned to each tie rod as the traction drive. Since the radial press does not require a closed press frame as in the prior art, no components that are subject to tension and / or bending have to be guided around the hydraulic drive, so that significantly larger piston cross-sectional areas can be used without being obstructed by a press frame, which means that either the pressing force can be increased or the drive power of the hydraulic drive can be reduced. Here, too, further details are explained in more detail in the detailed description.

A particularly advantageous embodiment of such a press is characterized in the course of the further configuration in that the press axis runs horizontally, that the leading, lower press yoke is arranged on a platform, below which the hydraulic cylinders are located in a tub for hydraulic fluid and that the lower one Support the press yoke and the hydraulic cylinders on the platform from opposite sides.

With such a construction, the forces and reaction forces are canceled out in the smallest space and directly against each other. It is therefore not even necessary to give the platform particular flexural rigidity.

The term "platform" is understood to mean all components which absorb the opposing forces of the press yoke and hydraulic drive. In the simplest case it can be a horizontal steel plate that serves as an upper tub cover or ceiling.

It is particularly advantageous if each press yoke has an approximately cuboidal envelope surface with a cuboid longitudinal axis and two control surfaces at right angles to one another, which are spaced apart by a flat surface parallel to the cuboid longitudinal axis, and whose bisector runs parallel to the drive direction, that four there are outer control bodies and four inner control bodies, which alternate on the circumference, that the outer control bodies lying above and below the press axis rest on the said flat surfaces of the press yokes, that the press yokes have radially outside the control surfaces further flat boundary surfaces which run parallel to each other and perpendicular to the drive direction, and that the paired holes for two tie rods are passed through these flat boundary surfaces.

Further advantageous embodiments of the subject matter of the invention emerge from the remaining subclaims.

The prior art and an exemplary embodiment of the subject matter of the invention are explained in more detail below with reference to FIGS. 1 to 7.

Figur 1

das Bau- und Wirkungsprinzip einer Radialpresse nach dem Oberbegriff bzw. nach dem Stande der Technik,

Figur 2

das Wirkungsprinzip der Steuerflächen gegenüber den einzelnen Preßbacken,

Figur 3

eine erfindungsgemäße Radialpresse mit den Details nach Figur 2 in geöffnetem Zustand der Preßbacken,

Figur 4

die Radialpresse nach Figur 3 in geschlossenem Zustand der Preßbacken,

Figur 5

die rechte Hälfte von Figur 2 mit zusätzlich aufgesetzten Führungsleisten,

Figur 6

eine Seitenansicht des Gegenstandes nach Figur 5 in Richtung des Pfeils VI in Figur 5 und

Figur 7

eine Variante des Gegenstandes nach Figur 2.

Show it:

Figure 1

the construction and operating principle of a radial press according to the generic term or according to the state of the art,

Figure 2

the principle of action of the control surfaces in relation to the individual press jaws,

Figure 3

1 a radial press according to the invention with the details according to FIG. 2 in the opened state of the press jaws,

Figure 4

the radial press according to Figure 3 in the closed state of the press jaws,

Figure 5

the right half of Figure 2 with additional guide strips attached,

Figure 6

a side view of the object of Figure 5 in the direction of arrow VI in Figure 5 and

Figure 7

a variant of the object of Figure 2.

1 shows a radial press according to the prior art, in which four control surfaces 1, 2, 3 and 4 run in pairs at right angles to one another. The control surfaces 1 and 2 are arranged in the upper yoke 5 of a press frame 6 which is closed on the circumference and which also encloses a double-acting hydraulic cylinder 7 with a piston 8. A very strong piston rod 9 calculated for pressure connects the hydraulic drive 10 to a lower yoke 11 in which the control surfaces 3 and 4 are arranged.

The control surfaces 1 to 4 lie on the sides of a square when viewed on the drawing plane. To avoid excessive weakening of the yokes 5 and 11, however, two corners of this square are withdrawn, so that the pair of control surfaces 1 and 2 are spaced apart by a flat surface 12 and the pair of control surfaces 3 and 4 are separated by a further flat surface 13. This creates a residual cross-section with the height A₂ in the upper yoke 5. The remaining cross section in the lower yoke 11 is not specified. The remaining cross section A₂ must nevertheless be dimensioned sufficiently because 5 high bending moments occur in the center of the yoke, which are caused by the large distance B₂, which have the center lines 14a and 15a of the side walls 14 and 15 of the press frame 6. Overall, the press frame 6 has a considerable height H₂, which are due to the design of the control surfaces 1 to 4, the hydraulic drive 10 and the necessary residual wall thicknesses in the area of the upper yoke 5, the lower yoke 11 and the base yoke 16 of the press frame. It is obvious that such a press frame is large and heavy, with additional means for guiding the lower yoke 11 in the press frame 6, which are not shown here for the sake of simplicity. The remaining hydraulic units for supplying the hydraulic drive 10 must be accommodated outside the press frame 6, which is also not shown here for the sake of simplicity.

So much is said here that the press axis A runs perpendicular to the plane of the drawing and that the drive direction is indicated by the dash-dotted line 17, which is predetermined by the axis of the piston rod 9. The bisectors of the control surfaces 1 and 2 and the control surfaces 3 and 4 run in the direction of line 17 through the press axis A.

Figure 2 shows an upper yoke 18 and a lower yoke 19 according to the invention. Each of these yokes has an approximately cuboidal envelope surface with a rectangular longitudinal axis, not shown here, which runs perpendicular to the drive direction 17 and parallel to the plane of the drawing. The two press yokes 18 and 19 have the flat control surfaces 1 to 4 already described above, which in the present case are provided with coverings 20 made of a permanently lubricating material. With regard to the geometric arrangement of the control surfaces and the spacing by flat surfaces 12 and 13 lying between these control surfaces, which run parallel to the longitudinal axes of the cuboid, the statements made above apply.

The press yokes 18 and 19 have radially outside said control surfaces further flat boundary surfaces 21, 22 and 23, 24, which run in pairs 21/23 and 22/24 parallel to each other and perpendicular to the drive direction 17. The identical distances between the boundary surfaces 21/23 and 22/24 define a stroke H that the upper press yoke 18 can execute relative to the lower, stationary press yoke 19. In FIG. 2 there are between the press yokes 18 and 19 Sections of tie rods 25 and 26 are visible, the longitudinal axes of which are indicated by the dash-dotted lines 25a and 26a. At the lower yoke 19 there is a microswitch 27 and at the upper yoke 18 there is an adjusting spindle 28 with a pressure plate 28a for the microswitch 27. The arrangement in question forms an adjustable stroke limiter for the total stroke of the press jaws, starting from the maximum possible opening position according to the double arrow 29.

Four outer control bodies 31, 32, 33 and 34 are supported on the control surfaces 1 to 4 and each carry a press jaw 30 in the center. Each of these outer control bodies has an inner control surface 35 and 36 in mirror-symmetrical arrangement on its axis of symmetry on both sides, and an inner control body 37, 38, 39 and 40 rests on two adjacent control surfaces 35 and 36 of two outer control bodies, respectively wear a press jaw 41 of identical design as the press jaw 30. The inner surfaces of all press jaws are at the same distance from the press axis A. The outer surfaces of the inner control bodies 37 to 40, which are at an angle of 135 degrees, likewise have a coating 20a made of a permanently lubricating material. The angular position of the individual control surfaces in relation to one another is selected such that the inner control body carried by the inner control surfaces 35 and 36 can be moved with the same radial speed and the same radial distance as the outer control bodies 31 and 34.

It can be seen that the outer control bodies 31 and 33 lying immediately above and below the press axis A are aligned resting on the flat surfaces 12 and 13, while the intermediate control bodies 32 and 34 move the yokes 18 and 19 together under the action of the control surfaces 1 to 4 in the direction of the press axis A. During this press stroke, the press axis A executes a downward movement in the size of half the stroke of the upper yoke 18.

It can be seen that the outer and inner control bodies alternate on the circumference. It can also be seen that the bores for the two tie rods 25 and 26, which are not particularly emphasized here, are passed through the boundary surfaces 21 to 24 of the yokes 18 and 19.

In the following figures, the same parts as before are provided with the same reference numerals. FIG. 2 shows an enlarged section from FIG. 3, so that the parts lying within the control surfaces 1 to 4 are not discussed again. It can be seen that the upper ends of the tie rods 25 and 26 are supported by nuts 42 and 43 on the upper press yoke 18. The lower ends of the tie rods 25 and 26 are passed through a platform 44, which consists of a thin steel plate and at the same time forms the cover of a trough 45, in which a hydraulic fluid 46 is located. While the lower press yoke 19 is supported on the upper side of the platform 44, two hydraulic cylinders 47 and 48 are supported on the platform 44 from below. In these hydraulic cylinders 47 and 48, the lower ends of the tie rods 25 and 26 protrude through bores 49, only one of which by means of a radial section through the Hydraulic cylinder 48 is shown. The lower ends of the tie rods 25 and 26 are connected to single-acting pistons 50 and 51, which are shown in FIG. 4.

The hydraulic cylinders 47 and 48 together with the pistons 50 and 51 acted upon on one side form a traction drive 52.

The hydraulic cylinders 47 and 48 are approximated to one another except for a small space in which there is a piston rod 53 of a pressure drive 54 which is under tension. The upper end of the piston rod 53 is screwed to the lower yoke 19, while the lower end carries a piston 54a which is surrounded by a hydraulic cylinder 54b (in particular FIG. 4). The cylinder 54b is supported on the pistons 50 and 51 and presses them upward into the position shown in FIG. 3 when the annular space above the piston 54a is applied. This movement follows - via the tie rods 25 and 26 - the upper press yoke 18, while the lower press yoke 19 remains on the platform 44. As a result, the control surfaces 1 and 4 or 2 and 3 move away from one another, and the press jaws return to their open position under the action of compression springs 55, which is indicated by the double arrow 29.

The platform 44 has a circular recess 56 behind the drawing plane according to FIG. 3, on which a drive motor 57 is fastened by means of a flange 57a. A hydraulic pump 58, which is designed as a submersible pump, is flanged to the drive motor 57 below the recess 56. These The pump is connected to the individual hydraulic drives via hydraulic lines, which are only indicated by dash-dotted lines, and a control valve 59. All hydraulic drive elements are - as shown in Figure 3 - housed within the trough 45, which not only enables extremely simple cable routing, but also any leakage currents are no longer important.

Figure 4 shows the radial press with the press jaws in the closed position. The distances between diametrically opposed press jaws, the working surfaces of which in this case complement one another, have a distance (diameter) which is indicated by the double arrow 60. It can also be seen that the upper control body 31 and the lower control body 33 remain on the associated flat surfaces 12 and 13, while the other two control bodies 32 and 34 under the action of the control surfaces 1/4 and 2/3 in the direction have been moved to the press axis A.

It can also be seen that the tie rod 26 has a shoulder surface 61 which is located in the parting line between the two press yokes. With this shoulder surface, the upper end of the tie rod 26, with its reduced diameter, is braced against the upper press yoke 18 by means of the nut 43. Fitting bores 62 serve to receive said stepped ends. The same naturally applies to the conditions in the area of the tie rod 25. The section of the tie rods 25 and 26 which is larger in diameter in each case is guided with play and possibly with the interposition of a bearing material in bores 63 of the lower press yoke 19, as shown in Figure 4, right, is shown. As a result, the upper press yoke 18 is the guided part and the lower press yoke 19 is the leading part.

It can be seen from Figure 4 that the distance B₁ of the axes 25a and 26a of the tie rod is smaller than the distance B₂ of the so-called "neutral fibers" of the press frame according to Figure 1 in the area of the frame opening for the hydraulic drive 10 and the press yoke 11 (the Figures 1, 3 and 4 are comparable to scale). This makes it possible to keep the cross section at the weakest point of the upper press yoke 18, which is characterized by the dimension A₁, significantly smaller than is the case in the prior art according to FIG. 1 with the dimension A₂. Also with regard to the total height of the functionally essential parts of the press, a smaller overall height is achieved in the subject matter of the invention with the dimension H 1 than in the prior art with the dimension H 2. Finally, in the subject matter of the invention, a significantly larger piston cross section can be accommodated below the press yokes 18 and 19, because the sum of two piston surfaces with the diameter D 1, even after deduction of the cross-sectional areas for the tie rods, is significantly larger than the cross-sectional area of a single piston with the diameter D 2 according to FIG. 1 Finally, the two tie rods can also be designed with a significantly smaller diameter d 1 in terms of material expenditure than is the case with a piston rod according to FIG. Also, a carrier on two bearings - as in the subject of the invention - is always less loaded than a carrier mounted in the middle, as is the case for the lower press yoke 11 in the prior art.

In Figure 5 it is shown that - each in a mirror-symmetrical arrangement - on the plane-parallel side surfaces of the upper yoke 18 and the lower yoke 19 guide strips 64 are releasably fitted by means of screws 65, which the outer control bodies 31 to 34 and the inner control bodies 37 to 40 between lock themselves in and thereby prevent them from sliding out axially. This presupposes that the width of the yokes 18 and 19 is wider than the axial length of these control bodies by the required play of the control bodies. The boundary surfaces 64a parallel to the drive direction 17 do not extend to a plane of symmetry defined by the press axis A-A, but rather leave a distance between them which facilitates the pressing of fittings with pipe elbows.

FIG. 6 shows the conditions in the direction of arrow VI in FIG. 5.

FIG. 7 shows a variant of the object of FIG. 2. In this case, the top control body 31 and the bottom control body 33 are formed in one piece or in one piece with the respective press yokes 18 and 19, respectively. Although this makes the shaping of the press yokes 18 and 19 more difficult, the one-piece molded outer control bodies 31 and 32 serve to increase the section modulus of the press yokes 18 and 19. Of course, the object of FIG. 7 also has the guide strips 64 shown in FIGS. 5 and 6 which are not shown in FIG. 7 for the sake of simplicity.

Claims (11)

Radial press with a press axis (A) and with a plurality of outer control surfaces (1, 2, 3, 4) which are at an angle to one another and are aligned with surface normals on the press axis and which can be moved radially in groups in two by means of a drive with a drive direction (17) Press yokes (18, 19) are arranged, the planes of symmetry of the control surfaces (1, 2 and 3, 4) arranged in the same press yoke running parallel to the drive direction, and with a plurality of outer control bodies (31, 32 , 33, 34) for the radial advance of press jaws (30, 41) in the direction of the press axis, characterized in that one press yoke (18) is guided relative to the other press yoke (19) by tie rods (25, 26) which run parallel to the drive direction and penetrate the leading press yoke (19) at its ends outside the control surfaces (1, 2, 3, 4), with the respective eils other, guided, press yoke (18) are fixedly connected and beyond the leading press yoke are connected to a train drive (52). Radial press according to claim 1, characterized in that a separate hydraulic drive (47/51; 48/50) is assigned to each tie rod (25, 26) as the pull drive (52). Radial press according to claim 1, characterized in that the press axis (A) runs horizontally, that the leading, lower press yoke (19) is arranged on a platform (44) below which the hydraulic cylinders (47, 48) are located in a trough (45 ) for hydraulic fluid (46) and that the lower press yoke (19) and the hydraulic cylinders (47, 48) are supported on opposite sides of the platform (44). Radial press according to claim 3, characterized in that the upper press yoke (18) can be lifted off the lower press yoke (19) by means of a pressure drive (54) acting on the pistons (50, 51) for the purpose of radially resetting the press jaws (30, 41) is. Radial press according to claim 3, characterized in that the platform (44) is designed as a cover of the trough (45) for the hydraulic fluid (46). Radial press according to claim 5, characterized in that the platform (44) has a recess (56) above which there is a drive motor (57) for a hydraulic pump (58) which projects through the recess into the trough (45). Radial press according to claim 1, characterized in that the outer control bodies (31, 32, 33, 34) each have a press jaw (30) in the center and an inner control surface (35, 36) on both sides thereof, whereby two adjacent inner control surfaces (35, 36) each carry an inner control body (37, 38, 39, 40) with a press jaw (41) and run at such an angle to the plane of symmetry of the respective outer control body that the inner control body carried is the same Radial speed and is movable over the same radial distance as the outer control body (31, 32, 33, 34). Radial press according to claim 2, characterized in that the hydraulic drives (47/51 and 48/50) are designed with a piston and cylinder diameter such that they have the smallest possible distance below the press axis (A). Radial press according to claim 1, characterized in that each press yoke (18, 19) has an approximately cuboidal envelope surface with a parallelepiped longitudinal axis and two control surfaces (1, 2 and 3, 4) at right angles to one another, which are formed by a parallelepiped -Longitudinal axis parallel flat surface (12, 13) are spaced and the bisector of the angle parallel to the drive direction that four outer control bodies (31, 32, 33, 34) and four inner control bodies (37, 38, 39, 40) are present, which alternate on the circumference that the outer control bodies (31, 33) lying above and below the press axis (A) rest on said flat surfaces (12, 13) of the press yokes (18, 19) so that the press yokes (18 , 19) radially outside the control surfaces, further flat boundary surfaces (21, 22, 23, 24), which run parallel to each other and perpendicular to the drive direction, and that the pairs of aligned bores for two tie rods (25, 26) are guided through these flat boundary surfaces (21, 22, 23, 24). Radial press according to claim 1, characterized in that the outer (31, 32, 33, 34) and the inner control bodies (37, 38, 39, 40) are guided or guided between guide strips (64) placed on the press yokes (18, 19). are held. Radial press according to claim 1, characterized in that the respective uppermost (31) and the lowermost outer control body (33) are connected in one piece to the respectively associated uppermost (18) and lower press yoke (19).

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