EP3415304B1 - Press and method for operating a press - Google Patents

Description

The invention relates to a press for pressing material to be pressed, having a press frame, an upper press platen in the upper part of the press and a lower press platen in the lower part of the press, the upper press plate and/or the lower press plate being provided with a plurality of (supported on the press frame and) in several rows ( matrix-like) arranged press cylinders is acted upon and wherein a plurality of control valves connected to the press cylinders are provided.

The press can basically be a multi-stage press, e.g. B. act a day press or multi-daylight press that works in cycle mode. However, the invention particularly preferably relates to a continuously operating press for the continuous pressing of mats to be pressed, with such a continuous press having a heatable upper press platen in the press upper part and a heatable lower press platen in the press lower part and in the press upper part and in the press lower part, endlessly circulating press belts, the press belts being interposed is supported on the press plates by rolling element assemblies (e.g. roll bars). Here z. B. applied to the upper press plate or the lower press plate to set a press gap formed between the press plates with the press cylinders.

The invention particularly preferably relates to a press for pressing mat-shaped material to be pressed, e.g. B. of pressed material mats with the formation of plate-like materials (pressed material plates). This can in particular be a press for the production of wood-based panels, so that mat-shaped grit (fibers/chips) is pressed in the press to form a wood-based panel. wood-based panel means in particular chipboard or fibreboard, e.g. B. MDF board. However, the invention also relates to presses for processing other materials, e.g. B. for the production of laminate boards, with such a laminate press (which is usually designed as a short-cycle press), stacked material to be pressed is pressed into laminate boards. It can also be a press for the production of fiber composite materials, e.g. B. an SMC press.

A press is always meant which is equipped with a plurality of press cylinders arranged in a plurality of rows, each row having a plurality of press cylinders. The press cylinders are equipped as hydraulic cylinders and are consequently connected to a hydraulic system, i.e. the hydraulic cylinders are acted upon by the hydraulic medium via control valves, with the hydraulic system also usually having at least one reservoir for the hydraulic medium and one or more pumps.

Such a press for the production of boards to be pressed in the embodiment as a continuous press is z. B. from the DE 43 42 279 C1 known. The upper press platen is loaded with working cylinder piston arrangements, which are designed as differential cylinder arrangements. The cylinders are controlled with the aid of a control and/or regulating unit via a hydraulic system, the control and/or regulating unit having a computer-equipped control and/or regulating device and a valve control device for the valves of the hydraulic system. The basic structure of the hydraulic system includes a working high-pressure branch for applying the working high pressure to the working cylinder piston arrangements and a counter-high-pressure branch, which is connected to the same high-pressure source as the working high-pressure branch, as well as a low-pressure control branch, i.e. the control of the press cylinders takes place in turn hydraulically via the control branch, which in turn itself includes a large number of valves. In the process DE 43 42 279 C1 an embodiment is described in which the working cylinder piston arrangements on the individual press frames have independent hydraulic systems except for the high-pressure source.

From the DE 39 14 105 A1 Incidentally, an embodiment of a continuous press is known in which one press plate (z. B. the upper press plate) z. B. on the one hand press cylinder are connected as a plunger cylinder and on the other hand as a retraction cylinder.

The WO 00/00346 A1 describes a press that can also be designed as a continuous press, in which the cylinders of the press cylinders arranged in a row are arranged in a common cylinder block, the supply lines and hydraulic lines for the press cylinders being integrated into the cylinder block. The DE 10 2010 003368 A1 shows a press for pressing pressed material according to the preamble of claim 1.

In practice it has been z. B. in continuously operating presses z. B. be used in the wood-based materials industry, usual, the variety of valves that (flow) z. B. are connected via lines with the numerous press cylinders to centralize and summarize in a common valve block or hydraulic distributor block. The individual valves are logically linked to one another in a fixed manner via bores, so that in practice a fixed interconnection is predetermined, so to speak, in terms of hardware, via such hydraulic distributor blocks. The use of such hydraulic distributor blocks has basically proven itself in practice, because the system is easy to maintain and install and works very reliably. Overall, presses and in particular continuous presses have of the type described at the beginning have proven themselves excellently for decades, but they can be further developed. - This is where the invention comes in.

The invention is based on the object of creating a press of the type described above which, with a simple structure, enables particularly variable operation.

To solve this problem, the invention teaches, in a generic press of the type described above, that the press cylinders, which are preferably arranged in a matrix in a large number of rows, are each equipped with at least one control valve of their own (physically arranged directly on the cylinder), with these control valves are particularly preferably designed as proportional valves.

The invention therefore breaks away from the principle of centralization that has been implemented in practice up to now and replaces the fundamentally known central hydraulic distributor blocks, which are equipped with a large number of control valves, with a large number of decentrally arranged individual valves, which enable variable individual cylinder control. Consequently, each press cylinder is assigned at least its own control valve, also spatially, that is, the press cylinder itself is directly equipped with the control valve assigned to it. This can e.g. B. realized in that the control valves are each attached directly to the press cylinder, z. B. are screwed. It can be attached directly to the cylinder housing of the press cylinder, so that the control valve is flanged to the cylinder housing.

The invention basically includes embodiments in which the press cylinders are designed as single-acting plunger cylinders, so that then usually each press cylinder is assigned a single control valve. The same applies to the retraction cylinders that may then be provided, in which case the plunger cylinders on the one hand and the retraction cylinders on the other hand can also be arranged in a matrix and connected to one of the press plates.

However, the invention particularly preferably relates to embodiments in which the press cylinders are designed as double-acting differential cylinders with which both compressive forces and tensile forces can be transmitted to the respective press plate. With such double-acting differential cylinders, it can be expedient to provide two control valves on each press cylinder, one for the working high pressure and one for the counter-high pressure. In principle, however, a differential cylinder can also be operated with just one control valve.

Overall, the invention is characterized by an extremely variable individual cylinder control, so that the hardware-based connection of individual pressure zones, which is necessary in the prior art, is no longer necessary. The interconnection or interconnection logic is electrically set in a fully variable manner using a computer, that is to say that each individual cylinder can be controlled and set in a fully variable manner with the aid of a computer using an electric matrix, as it were. In a preferred further development, the control valves distributed in the press for setting variable pressure distributions and pressure profiles can be controlled individually or in any groups with a computer, which forms an electrical matrix, so to speak. As an electrical matrix, the computer then only has to be electrically or electronically connected to all the valves, either by wire or also wirelessly. In addition, it is only necessary to connect all the control valves arranged decentrally on the respective cylinders via hydraulic lines to connect the other components of the hydraulic system, in particular the accumulator and the pumps.

Fig. 1

eine kontinuierlich arbeitende Presse in einer Seitenansicht und

Fig. 2a

(vereinfacht) eine abgewandelte Ausführungsform einer kontinuierlich arbeitenden Presse,

Fig. 2b

eine Ansicht von oben auf die obere Presseplatte der Presse nach Fig. 2a.

The invention is explained in more detail below with reference to a drawing that merely shows an exemplary embodiment. Show it

1

a continuously working press in a side view and

Figure 2a

(simplified) a modified embodiment of a continuously operating press,

Figure 2b

a view from above of the upper press platen of the press Figure 2a .

In the figures, a continuously operating press is shown, the z. B. can be used for the production of wood-based panels. In this continuous press, a pressed material mat, e.g. B. a pressing material mat made from glued grit is continuously pressed using pressure and heat to form a plate or a plate-shaped strand.

In its basic structure, the continuous press has an upper heated press platen 1 in the upper part of the press and a lower heated press platen 2 in the lower part of the press. Furthermore, in the upper part of the press and in the lower part of the press, endlessly circulating press belts, e.g. B. steel strips are provided, the interposition of endlessly revolving rolling element assemblies, z. B. roll bars on the press plates 1, 2 are supported.

Furthermore, the press has a press frame 3 which, in the exemplary embodiment, has an upper beam 4 and a lower beam 5 as well as a press frame 6 arranged between the upper beam and the lower beam. In 1 it can be seen, for example, that a large number of press frames 6 arranged one behind the other in the longitudinal direction of the press are provided.

The presses shown are designed as an example of an upper piston press, that is, a plurality of press cylinders 7 are connected to the upper press plates 1, each of which is attached to the press frame, e.g. B. on the press frame 6 are supported. In the exemplary embodiment, the lower press platen 2 is attached to the press frame with a defined contour.

1 shows an embodiment in which the press plates 1, 2 are formed on the one hand by main press plates in the main pressing area and on the other hand by inlet plates in the inlet area. The press cylinders 7 already mentioned are connected both to the inlet plates and to the main press plates. A variable infeed contour is set in the infeed area of the press via the elastic infeed plates. The press cylinders are arranged in a matrix-like manner in several rows one behind the other, with each row of cylinders having several press cylinders, e.g. B. 3 to 6 press cylinders, preferably 4 or 5 press cylinders.

Figure 2a , b shows an example opposite 1 modified embodiment, in which the division into inlet plates on the one hand and main press plates on the other hand is dispensed with. Rather, both the upper press plate 1 and the lower press plate 2 are formed over the entire length with a substantially constant thickness and are particularly preferably formed over the entire length as flexible and consequently flexible press plates 1, 2, so that over the length of the press a particularly flexible adjustment of the press gap is possible. It is also indicated that press frames 6 with an identical frame thickness are provided over the entire length of the press. In this embodiment, the required rigidity for serving different pressure zones is realized by narrower or wider frame spacings and also by the use of single frames or multiple frames on the other hand. It can be seen that double frames are realized in the entry area, which are each composed of individual frames of identical thickness. The also provided press belts, the z. B. roller bars are supported on the press plates 1, 2, and which guide the material to be pressed through the press, are in Figure 2a not shown.

In Figure 2a It is indicated that press cylinders 7 of identical design and dimensions are used over the entire press length and consequently both in the compression area and in the main press area. This also increases the variety of parts in the in Figure 2a , b embodiment shown reduced. In the illustrated embodiment, the press cylinders 7 are designed as double-acting differential cylinders with which to set any continuous bending lines both compressive forces and tensile forces on the respective press plates, z. B. the upper press platen 1 can be used up.

It can also be seen that pressure distribution plates 8 are provided in the rear section of the press.

Both according to the embodiment 1 as well as according to the embodiment Figure 2a , b According to the invention, the press cylinders 7 of the press itself are each equipped with at least one control valve 9 of their own, with the control valves 9 being designed as proportional valves.

It is only indicated that the control valves 9 are fastened directly to the respective press cylinder 7, e.g. B. are flanged or screwed to the cylinder housing.

As a result, the press is characterized by a very variable individual cylinder control. The interconnection logic is no longer produced by hardware-based predetermined control blocks, but exclusively electrically and consequently exclusively via a computer that forms a completely variable electrical matrix for setting any interconnection logic. The computer itself is not shown in the figures, but it only has to be connected to the valves 9 electrically or in terms of communication technology. A separate low-pressure control branch of the hydraulic system for controlling the valves can consequently be dispensed with. It is only necessary to connect all the control valves 9 to the other components of the hydraulic system, in particular the pumps and the accumulator, via corresponding hydraulic lines. Details are not shown.

Incidentally, the figures merely show embodiments of a continuously operating press, which are particularly preferably covered by the invention. In principle, however, the invention also relates to cycle presses, which also have an upper press platen and a lower press platen and a large number of press cylinders arranged in rows. In particular, these can be single-daylight presses or multi-daylight presses for the production of wood-based panels or laminate panels and, among other things, also short-cycle presses in which stacked pressed material is pressed to form a laminate panel. In addition, the invention also includes embodiments for Production of fiber composite materials, the z. B. in vehicle construction and aircraft construction.

Claims (6)

1. Press for pressing press material

   with a press stand (3), an upper press plate (1) in the upper part of the press and a lower press plate (2) in the lower part of the press,

   wherein the upper press plate (1) and/or the lower press plate (2) is/are acted upon by a plurality of press cylinders (7) arranged in several rows and

   wherein a plurality of control valves (9) connected to the press cylinders (7) is provided,

   characterised in that the press cylinders (7) are each equipped with at least one own control valve (9) spatially arranged directly at the press cylinder.
2. Press according to claim 1, characterised in that the control valves (9) are designed as proportional valves.
3. Press according to any one of claims 1 or 2, characterised in that the control valves (9) are directly fastened, e.g. screwed, onto the respective press cylinder (7), for example to its cylinder housing.
4. Press according to any one claims 1 to 3 characterised in that the control valves (9) distributed in the press can be controlled by a computer individually or also in any desired groups in order to set variable pressure distributions and pressure profiles.
5. Press according to any one of claims 1 to 4 in the form of embodiment of a continuous press for pressing press material mats, more particularly during the course of manufacturing wood based boards or similar material boards

   with a heatable upper press plate (1) in the upper part of the press and a heatable lower press plate (2) in the lower part of the press,

   with continuously circulating press belts in the upper part of the press and in the lower part of the press, which are supported on the press plates (1, 2) with the interposition of roller assemblies.
6. Method of operating a press according to any one of claims 1 to 5, characterised in that the press cylinders are controlled individually or variably in any desired group by a computer connected to the control valves.

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