EP0740600B1 - Guidance of a pressure beam in the machine frame of a press, in particular a tile-making press - Google Patents

Abstract

A press, in particular a tile-making press, has a machine frame, a pressure beam (13) that moves back and forth in the machine frame and is guided at its ends on straight guides (60) of the machine frame. The guides (60) have stationary guiding surfaces (87) that extend parallel to the travelling direction (86) of the pressure beam (13) and face the corresponding end of the pressure beam (13). The stationary guiding surfaces (87) co-operate with opposite guiding surfaces (71) that are moved with the pressure beam (13). The moving guiding surfaces (71) are designed on a body (72) with a surface (73) shaped as a cylinder section that lies in a matching recess (74) shaped as a cylinder section at the end of the pressure beam (13). The cylinder axes extend parallel to the stationary guiding surface (87), at right angles to the travelling direction (86). The body (72) is mounted in the recess (74) so as to revolve around the cylinder axis and its moving guiding surface (71) projects over the edge (75) of the recess (74).

Description

The invention relates to a press with the features specified in the preamble of claim 1. Such a press for producing roof tiles is known from EP-B-0 434 863. The known press has a six-surface drum mounted as a support for lower molds in the machine frame, the six lateral surfaces of which are mounting surfaces for the lower molds. The lower forms work with an upper form together, which is provided on the underside of a press ram or bear, which is guided up and down in the machine frame. For this purpose, vertical guide rails are provided on a right and a left stand of the machine frame, which guide the bear along eight guide surfaces. With such longitudinal guides there is always a certain tendency that the bear tilts and cant in the guides, especially if the driving forces for the bear act at several points between the guides. The longer the guide rails on the stands and the guide elements of the bear that are in engagement with the guide rails, the less the risk of tipping and tilting. However, long tours have the disadvantage that they increase the overall height of the bear and the press. The bear shown in EP-B-0 434 863 also has a large overall height. Another disadvantage of the known longitudinal guides is that the tilting moments that occur cause the greatest wear at the upper and lower ends of the guide elements of the bear, because the frictional forces caused by the tilting moment are greatest there. As a result of the inevitable wear, the guide elements gradually become somewhat crowned. Uneven wear that occurs in this way cannot be compensated for by adjusting the guides, but rather the guide elements have to be replaced from time to time, which is complex and expensive.

The present invention has for its object to show a way how to guide the bear or pressure beam of a press at the ends, so that tilting moments about an axis that is perpendicular to the plane spanned by the machine frame and the direction of movement of the bear, also low overall height of the bear are easily controllable and inevitable wear on the guides occurs more evenly.

This object is achieved by a press with the features specified in claim 1. Advantageous developments of the invention are the subject of the dependent claims.

If a tilting moment and subsequently a tilting movement occurs in a pressure beam or bear designed and guided according to the invention, this does not lead to an uneven loading of the guides due to the lost parallelism of the guide elements; the guide elements of the pressure beam can rather be rotated relative to the end of the pressure beam because of the cylindrical-shell-shaped engagement are, despite a tilting movement of the pressure beam, maintain their exact parallelism with the guides attached to the machine frame. The invention does not go the usual way to switch tilting movements from the outset or to keep them as small as possible, but assumes that to a certain extent tilting movements are inevitable and instead takes measures to deal with the harmful effects of tilting moments which are exerted on the pressure beam counter the tours effectively.

• Die am Druckbalken vorgesehenen Führungsflächen können kurz sein. Entsprechendes gilt für die in seiner Bewegungsrichtung gemessenen Abmessungen des Druckbalkens (bei senkrechter Bewegungsrichtung seine Bauhöhe).
• Verkürzte Führungen sparen Bauhöhe, Materialeinsatz und Gewicht und damit Anschaffungskosten.
• Der Druckbalken bewegt sich sehr reibungsarm.
• Ein leichter und reibungsarm bewegter Druckbalken erfordert weniger Antriebsleistung und damit weniger Betriebskosten.
• Ein reibungsarm geführter Druckbalken unterliegt weniger stark einem Verschleiß. Die Führungen müssen deshalb nur selten nachgestellt werden, wodurch der Wartungsaufwand sinkt.
• Durch die drehbare Lagerung der Führungsflächen am Druckbalken, welche mit den stationären Führungsflächen des Maschinengestells zusammenwirken, führen Kippmomente nicht zu einem ungleichmässigen, einseitigen Druck der mittleren Führungsflächen gegen die stationären Führungsflächen, vielmehr werden die durch die Kippmomente in das Maschinengestell eingeleiteten Kräfte gleichmässig und großflächig über die gesamte zur Verfügung stehende Führungsfläche am Druckbalken übertragen, was wichtig für einen geringen Verschleiß ist. Die großflächige Krafteinleitung in die Führungen des Maschinengestells erlaubt es, die der Führung dienende Endfläche des drehbaren Körpers im Druckbalken mit einer Schicht aus reibungsminderndem Kunststoff zu belegen, z.B. mit einer Platte aus Polytetrafluoräthylen, welches zur weiteren Reibungsminderung mit Graphit gefüllt sein kann, oder mit einer Platte aus einem Polyimid. Auf diese Weise kann die Reibung nochmals herabgesetzt werden und die Kunststoffplatte kann, wenn sie durch Verschleiß zu dünn geworden sein sollte, ohne größere Probleme ersetzt werden.

This has several advantages:

• The guide surfaces provided on the pressure beam can be short. The same applies to the dimensions of the pressure beam measured in its direction of movement (its height if the direction of movement is vertical).
• Shortened guides save overall height, use of materials and weight, and thus acquisition costs.
• The pressure bar moves with very little friction.
• A light and low-friction pressure bar requires less drive power and thus less operating costs.
• A low-friction pressure beam is less subject to wear. The guides therefore rarely have to be readjusted, which reduces the maintenance effort.
• Due to the rotatable mounting of the guide surfaces on the pressure beam, which cooperate with the stationary guide surfaces of the machine frame, tilting moments do not lead to an uneven, one-sided pressure of the middle guide surfaces against the stationary guide surfaces, rather the forces introduced into the machine frame by the tilting moments become uniform and over a large area transfer the entire available guide surface to the pressure beam, which is important for low wear. The large-area introduction of force into the guides of the machine frame allows the end surface of the rotatable body serving for the guide to be covered in the pressure beam with a layer of friction-reducing plastic, for example with a plate made of polytetrafluoroethylene, which can be filled with graphite for further friction reduction, or with a Polyimide plate. In this way, the friction can be reduced again and the plastic plate, if it has become too thin due to wear should be replaced without major problems.

The body with the partially cylindrical outer surface can in principle be inserted loosely into the associated recess of the pressure beam, because it is held captive in the recess by the guide of the machine frame facing it and aligns itself automatically so that its end surface is parallel to the guide of the machine frame . However, the body is preferably held in the recess by a recessed bolt which passes through the body with a certain axial and radial play, the play being dimensioned such that it can compensate for the tilting movements of the pressure beam which may occur. Such a loose mounting of the body facilitates the assembly of the pressure beam in the machine frame. The axial play of the bolt is preferably compensated for by a compression spring through which the bolt extends, the compression spring being intended to be arranged such that it presses the body into its recess.

In order to make the guide as free of play as possible, provision is preferably made for the recess, which receives the body serving as guide, in one to form a detachable component from the pressure beam and to utilize this separate design from the pressure beam in order to provide a sensitive adjustment option at the interface between the pressure beam and this separate component by means of an adjusting wedge, for which purpose two inclined surfaces complementary to one another are required, which have a small angle to the direction of movement of the bear and thus include to the longitudinal direction of the guides. For this purpose, a separate wedge could be inserted between the pressure beam and the detachable separate component, which carries the body serving in the guide, but it is simpler and therefore preferred that the one inclined surface on the component itself and the opposite inclined surface at the end to provide the pressure beam, whereby the component itself becomes an adjustable wedge relative to the pressure beam. The inclined surfaces expediently extend over a large part of the cross section of the pressure beam, so that they can easily transmit the lateral forces that occur. The actual pressing forces do not have to transmit the inclined surfaces, since the forces driving the pressure beam act directly on the pressure beam. Adjusting means provided for adjusting the detachable component formed with the inclined surface therefore do not have to absorb the compressive forces during pressing either, but can be trained relatively weak. For wedge adjustment, a screw is preferably provided which is screwed into the pressure beam and which at the same time is in engagement with the detachable component. Turning the screw changes the relative position between the pressure beam and the detachable component along the inclined surfaces. So that the set screw does not have to ensure the cohesion between the pressure beam and the detachable component at the same time, further screws connecting the component and the pressure beam are provided to secure the set position, with washers for compensating the adjustment path between the components and the pressure beam.

The invention is applicable not only to roof tile presses, but also to other presses which work with a press beam or bear in which the control of tilting moments which occur along the pressure beam and the wear caused thereby are a problem. The invention is particularly suitable for presses in which the pressure bar is moved up and down on vertical stands, but could also be used in presses with a horizontally movable pressure bar.

Figur 1

zeigt eine für das Herstellen von Dachziegeln bestimmte Revolverpresse in einer Vorderansicht,

Figur 2

zeigt dieselbe Revolverpresse in der Seitenansicht II gemäss Figur 1 mit teilweise weggebrochenem Ständer,

Figur 3

zeigt als Detail vergrößert den Aufbau eines Endabschnitts des Druckbalkens der Presse und die Art seiner Führung an einem Ständer der Presse, und

Figur 4

zeigt als Detail einen Horizontalschnitt durch die am Ständer vorgesehene Führung mit einer Draufsicht auf das am Ende des Druckbalkens befestigte Bauteil, das den mit der Führung des Maschinengestells zusammenwirkenden, teilzylindrischen, verdrehbar gelagerten Führungskörper enthält.

An embodiment of the invention is shown in the accompanying drawings.

Figure 1

shows a turret press intended for the production of roof tiles in a front view,

Figure 2

1 shows the same turret press in side view II according to FIG. 1 with the stand partially broken away,

Figure 3

shows as a detail enlarged the structure of an end portion of the pressure beam of the press and the way it is guided on a stand of the press, and

Figure 4

shows as a detail a horizontal section through the guide provided on the stand with a plan view of the component fastened at the end of the pressure beam, which contains the partially cylindrical, rotatably mounted guide body cooperating with the guide of the machine frame.

The pressure bar of the press is also referred to as a bear in the following description.

The press has a machine frame 1 with a left-hand stand 2, a right-hand stand 3 and a horizontal traverse 4 connecting the two stands at their upper end. In the lower region of the machine frame 1 there is a hexagonal drum 5, which has a horizontal axis of rotation, with pins stored in roller bearings 7, which are arranged in the two stands 2 and 3. A particularly suitable way of storing the drum 5 is the subject of the patent application filed on the same day EP-A-0 740 601 with the title "Storage of a drum in a press for ceramic compositions, in particular for the production of roof tiles".

For the gradual drive of the drum 5, an electric motor 8 is provided on the machine frame 1, which acts in a manner known per se on a non-rotatably connected Maltese cross 9 connected to the drum 5.

The drum has 6 mounting surfaces 10, each of which is set up to accommodate three sub-molds 11. (The lower molds are only shown on the top mounting surface). Three upper molds 12 matching the lower molds are located on the underside of a bear 13 which is designed as a bar and is guided with its two ends in vertically extending guides 14 which are attached to the two stands 2 and 3.

The bear 13 is suspended from the crossbar 4 by means of two knee levers 15 and 16 arranged in mirror image. For this purpose, the crossmember 4 has two bearing blocks 17 on its underside, to each of which a two-armed lever 18 is articulated. Opposite the bearing blocks 17 there are two further bearing blocks 21 on their upper side of the bear 13, to each of which a one-armed lever 19 is articulated. The two levers 18 and 19 are each articulated to form a knee 20. While one arm of the two-armed lever 18 is articulated on the bearing block 17, the other arm of the lever 18 is articulated to a further one-armed lever 22, which in turn is articulated on a bearing block 23; the two bearing blocks 23 are located in a diametrical arrangement on a spindle nut 24 which is arranged on a vertically arranged spindle 25 which is rotatably but non-displaceably mounted in the cross member 4. The lower end of the spindle 25 projects through a collapsible bellows 26 into a recess in the bear 13. The relative position between the bear 13 and his two bearing blocks 21 can be adjusted by an adjusting device 27 in order to compensate for wear on the molds 11 and 12. A particularly suitable adjustment device is the subject of the patent application filed on the same day with the title "Press for pressing ceramic masses, in particular for producing roof tiles".

Spindle 25 and spindle nut 24 form a planetary roller spindle gear.

The spindle 25 is extended upwards by a shaft 34 which extends through the cross member 4 and ends in a brake 28. On the shaft 34 sits a gear 35, which meshes with a toothed belt 29 and is further tensioned via a pinion 30, which is fastened on the output shaft 31 of an electric servo motor 32, which is attached in a hanging arrangement to the outside of the machine frame 1. The servo motor 32 has partially broken away in FIG. 1 in order to make the planetary roller spindle gear visible. The pinion 30 and the toothed belt 29 are covered by a housing 33.

Figures 1 and 2 show the bear 13 in its raised position, the lower mold 11 and the upper mold 12 are separated from each other. In order to close the mold and to form a lump of ceramic material inserted into the lower mold 11, the spindle nut 24 is moved downward by rotating the spindle 25, as a result of which the toggle levers 15 and 16 are stretched and the bear 13 moves downward.

The pressure beam or bear 13 has a relatively low overall height. In order to move it up and down on vertical guides 60, which are mounted opposite each other on the left stand 2 and on the right stand 3, without being able to lead to tilting at tilting moments which, when viewing FIG Axial plane perpendicular to the drawing plane through the center of the bear, 13 special guide means are provided at the ends of the bear, which are shown in detail in FIGS. 3 and 4. These guide means are formed at both ends of the bear 13 in a corresponding manner, so that it is sufficient to show them at one end of the bear.

The bear has at its ends an inclined surface 61 which, with the vertical direction of movement of the bear, encloses a small angle which is only about 1 ° to 2 °. A component 62 is detachably attached to this inclined surface 61, which has an inclined surface 63 that is complementary to the inclined surface 61. Because of the inclined surface 63, the component 62 has the function of a wedge tapering from top to bottom. As FIGS. 3 and 4 show, the component 62 has on its head 62a horizontal projections 64 which protrude beyond the end of the bear to the front and to the rear and by means of screws 65 which are rotated from above by the head 62a in the bear 13 , are attached to the bear. In order to fix the height of the component 62 relative to the bear 13, screws 65 are screwed from above into the end section of the bear through compensation plates 66 which can be inserted from the side. The head 62a has a horizontal, semicircular recess 67 into which a matching projection 68 with a semicircular end face engages. The projection is part of a collar 69 which is rotatably mounted on the shaft of an adjusting screw 70, but is axially immovable. The adjusting screw 70 is screwed into a bore of the bear 13 from above. After loosening the screws 66, the adjusting screw 70 can be actuated, thereby lifting the component 62 or - After removing one or more compensating plates 66 - lower and thereby, via the interaction of the inclined surfaces 61 and 63, at the same time approach or remove a guide surface 71 provided on the outer end of the component 62 of the guide 60 on the machine frame 1. In the setting selected in this way, the wedge-shaped component 62 can be fixed by tightening (countering) the screws 66.

The guide surface 71 moved with the bear is formed on a body 72, the surface 73 of which faces away from the guide 60 has the shape of a cylinder jacket section and lies in a matching recess 74 of the component 62, the guide surface 71 moved along over the band 75 of the recess 64 protrudes. The moving guide surface 71 is the surface of a plate made of low-friction plastic, which is attached to the body 72, for example by gluing. The body 72 and the component 62 are connected to one another by a screw bolt 76; In order to be able to arrange it sunk, a recess 77 is provided in the body 72 and a recess 78 in the component 62. The bolt 76 connects the component 62 and the body 72 with radial and axial play in order to allow a limited rotation of the body 72 in the recess 74. The axial play is compensated for by a spherical shim 79 between the head of the bolt 76 and a concave end surface of the recess 77, the center of curvature of the concave end surface being on the longitudinal axis of the cylindrical outer surface 73. To compensate for the axial play, a plate spring is also provided between the washer 79 and the head of the screw bolt 76, so that the body 72 is pressed resiliently into its recess 74 when the screw bolt is tightened.

If a tilting moment acts on the bear 13 about an axis perpendicular to the plane of the drawing (FIG. 1), then the bear 13 can yield to it within the limited rotatability of the body 72, without this affecting the parallelism between the plastic plate and the guide surface 87 and changes something in the uniform introduction of force from the plastic plate into the guide surface 87. The plastic plate is typically 4 to 5 mm thick and can be replaced when it is worn out.

To lubricate the guide surfaces 62 channels are provided in the component through which a lubricant can be supplied. The inclined surfaces 61 and 63 can also be lubricated. So that the lubricant does not penetrate into the recess 78, an O-ring is provided around the edge of the recess 78.

In order to prevent the bear from tipping forward and backward, the bear 13 is also guided on its front and on its back. For this purpose, the guides 60 provided on the machine frame 1 are U-shaped in cross-section (see FIG. 4), the two opposite legs of the U interacting with the guide surfaces on the bear facing them.

Claims (8)

1. Press, in particular for making tiles,

   having a machine frame (1),

   a pressure beam (13), arranged for reciprocating movement in the machine frame (1) and guided at its ends on straight guides (60) of the machine frame (1), each of the guides being provided with a stationary guide surface (87) facing the respective end of the pressure beam (13) and extending in parallel to the direction of movement (86) of the pressure beam (13), for interacting with an adjacent guide surface (71) that is entrained with the pressure beam (13),

   wherein said entrained guide surface (71) is formed on a body (72), the surface (73) of which exhibits the shape of a section of a cylinder envelope which is received in a corresponding recess (74), in the form of a section of a cylinder envelope, provided at the end of said pressure beam (13), the cylinder axis extending in parallel to said stationary guide surface (87) and at a right angle relative to the direction of movement (86), said body (72) being seated in the recess (74) for rotary movement about the cylinder axis, with its entrained guide surface (71) projecting beyond the edge (75) of said recess (74).
2. Press according to claim 1, wherein said entrained guide surfaces (71) are lined with a layer of a friction-reducing plastic material.
3. Press according to claim 1 or 2, wherein said body (72) is held in said recess (74) by a recessed bolt (76) that passes through said body (72) with radial and axial play.
4. Press according to claim 3, wherein said axial play is compensated by a compression spring through which said bolt (76) extends.
5. Press according to any of the preceding claims, wherein said recess (74) is formed in a component (62) that can be released from said pressure beam (13) and wherein the distance of said entrained guide surface (71) from the opposite stationary guide surface (87) on said frame (1) can be adjusted by a wedge (72) mounted for displacement in the direction of movement (86).
6. Press according to claim 5, wherein said wedge is arranged between said pressure beam (13) and said releasable component.
7. Press according to claim 5, wherein said releasable component (62) is constituted by said wedge whose inclined surface (63) faces said pressure beam (13), which latter is provided with a complementary inclined surface (61) for making contact with said inclined surface (63) of the component (62).
8. Press according to claim 7, wherein for adjusting the releasable component (62), a screw (70) is provided, which is screwed into said pressure beam (13) and which simultaneously engages said releasable component (62), and wherein additional screws (65), connecting said component (62) and said pressure beam (13), are provided for securing the adjusted position and washer plates (66) are provided for compensating the length of adjustment between said component (62) and said pressure beam (13).

Images