EP3551445B1 - Pressing head, device for pressing material to be pressed, and method for pressing material to be pressed - Google Patents

Description

The present invention relates to a press head, a device for pressing material and a method for pressing material according to the preambles of the independent claims.

When machining workpieces, especially metal workpieces, waste materials in the form of shavings are produced. Depending on the material being machined, these shavings represent an important link in the value chain. On the one hand, raw materials should not be wasted; on the other hand, the raw materials, and in this case the shavings, should or can be reused.

It is known from the prior art to compress these shavings in order to reduce their volume. Furthermore, lubricants such as oils or similar substances, as well as coolant, can be squeezed out of the shavings. Such presses are known to those skilled in the art as briquetting presses. Briquetting presses are used in particular for briquetting wood chips or dry shredded materials such as chopped grass or hay.

Such a press is associated with the DE1627914 became known. DE1627914 The figure shows a press head with a press channel and a press element movably arranged within the press channel. The movable press element exerts a force on the material to be pressed, which can be adjusted using a screw spindle.

The device from the DE1627914 proves unsuitable for pressing materials with high inhomogeneity. exhibits the characteristics present in wood chips. Clover or grass chips, for which the press head according to DE1627914 Chips that are designed for this purpose are uniformly chopped and exhibit a homogeneous size distribution. Pressed material, which is produced, for example, during the mechanical processing of workpieces, exhibits a high degree of inhomogeneity. This is due, for example, to machining the workpiece with different tools. Thus, very large as well as very small chips can be produced simultaneously.

The press head from the DE1627914 It is equipped with a spring that exerts a constant static preload force on the pressing element. This preload force can be preset using an adjusting screw, but then remains unchanged. Another disadvantage of this known device concerns the limited amount of material that can be processed or pressed per stroke.

DE260831C Disclosing a press head for a device for pressing material according to the preamble of claim 1, in particular a briquette extrusion press for briquetting lignite or peat. It has a pressure piece for distributing the pressure.

US 3,090,182 shows a press for pressing hay.

The purpose of the invention is to eliminate these and other disadvantages of the prior art.

This problem is solved by the devices and methods defined in the independent claims. Further embodiments are described in the dependent claims.

A press head according to the invention for a device for pressing material and in particular for pressing chips, preferably an extrusion press, comprises the features of claim 1.

Preferably, the press head has a die positioned in front of the entry opening of the press channel. The entry opening of the press channel then coincides with an entry opening of the die. That is, the press channel encompasses the die or its opening. The die has one opening for each press channel.

This allows one briquette to be pressed per press channel, meaning at least two briquettes simultaneously, whereby the cross-section of each press channel can be adjusted or changed separately for each briquette.

The change in the cross-section of the press channel at its outlet relative to the cross-section at its inlet allows for a more or less pronounced clamping of a briquette within the press channel. While the briquette naturally has a cross-section during the pressing process that essentially corresponds to the cross-section of the press channel at its inlet, the inhomogeneity of the material being pressed into a briquette means that the briquette's cross-section is more or less elastic; that is, individual briquettes exhibit different degrees of elasticity.

By changing the cross-section of the press channel, it is possible to exert a holding or clamping force on the briquette, which is independent of the briquette's composition. The cross-section of the press channels is essentially constant. This ensures that a second briquette, subsequently pressed in the press channel, encounters sufficient resistance from the first briquette. This improves the quality of the subsequent briquette. The cross-section of the press channels is individually adjustable for each channel. The quality of the briquettes remains essentially constant and at a high level, regardless of the nature of the material being pressed.

Preferably, the press channels are formed in their cross-section essentially half by the support element and half by the press element. It is conceivable that a gap forms between the support element and the press element, which need not be completely closed even if the cross-section at the outlet opening is reduced.

Alternatively, it would also be conceivable that although the cross-sectional area of the press channel is essentially halved by the support element and the press element, the press element only corresponds approximately to the diameter of the press channel and is designed as an insertion element on the press head, which completes the cross-section of the press channel.

The press channel has a longitudinal axis between its inlet and outlet openings and is open along this axis at a right angle to it. This means that the inlet and outlet openings are connected by an open channel. The press element can be located within this open channel and is, in particular, movably arranged within it.

Preferably, the press channels have a common support element. This support element is preferably one-piece, in particular formed in one piece.

This allows for simpler manufacturing on the one hand and improved force absorption on the other. The common support element also positions the press channels relative to each other in a fixed position.

Since each press channel has a separate pressing element, uneven wear of the parts or areas of the respective press channels located in the support element is not a problem. The holding force can be adjusted independently for each press channel.

Alternatively, it would also be conceivable to provide a separate support element for each press channel, or to provide individual inserts on the support element.

This would make it possible to replace only those parts or areas of the actuator that show corresponding wear and tear, and to use other parts or areas for a longer period.

The press channels can be arranged side by side in the press head.

This allows, on the one hand, the material to be collected and pressed in a wider section compared to the prior art. On the other hand, it simplifies the manufacturing of the press head. For example, a common support element only needs to be machined on one side. The pressing elements can also be arranged side by side and can share common fastening elements.

Alternatively, it is conceivable that the press channels are arranged opposite each other. This means that the press channels lie in a common plane, have a common pressing direction, but the pressing elements are arranged opposite each other or diametrically.

Arranged side by side means that the press channels lie in a first plane, and the press elements in a second plane parallel to it.

With opposing press channels, the advantage arises that the reaction force on the support element, which occurs when the press element exerts a force on the briquettes, is provided by the opposing press element. This means that in an ideal pressing process, the support element would, in principle, be in a force-neutral position. While such an ideal force distribution naturally does not occur in practice, the forces on the support element can at least be reduced when the press elements are actuated simultaneously.

Preferably, the press head is designed such that each pressing element is pivotably mounted about a rotational axis, preferably fixed relative to the support element. This axis is located, in particular, in the area of the inlet opening of the press channel. The rotational axis is arranged essentially perpendicular to the press channel. That is, the rotational axis lies in a plane parallel to a plane through the longitudinal axis of the press channel and has a direction perpendicular to the longitudinal axis of the press channel. In the case of multiple press channels, the plane is defined by the multiple longitudinal axes of the respective press channels.

According to the invention, each pressing element is assigned an adjusting element for adjusting the pressing element. This enables the pressing or holding force to be adjusted at each pressing element.

According to the invention, each actuating element is independently adjustable and, in particular, can be controlled independently.

As explained above, the pressing force in each press channel can therefore be adjusted independently. This allows for control over the briquette during the pressing process. The actuating elements can be designed, for example, as hydraulic or pneumatic components. A spring can also be used. Electrical or mechanical actuating elements are also conceivable.

Preferably, three press channels are arranged side by side. However, more than three press channels side by side are also conceivable.

This increases the capacity of the press head.

It is also conceivable that two pairs of press channels are arranged opposite each other. Preferably, three press channels are arranged opposite each other.

However, it is also conceivable that more than three press channels are arranged opposite each other.

An uneven number of opposing press channels is also conceivable; for example, there could be three press channels on one side and two on the other. Other combinations are possible.

This allows a press head to be individually aligned with a specific press or the material being pressed. This can be advantageous, for example, if the material to be pressed is known during the design phase and has a specific distribution or size, or is a mixture of materials, such as large and small chips. If, for instance, the press channels are arranged opposite each other in the direction the material falls, it can be assumed that smaller chips will collect in a lower section of the device and larger chips in an upper section. In this case, it can be advantageous to have, for example, two press channels in the lower section and three in the upper section. This allows the desired compression to be achieved.

Another aspect of the invention therefore also relates to a device for pressing material, in particular for pressing chips and in particular an extrusion press, wherein the device for pressing material comprises at least one press head as described above.

The advantages of such a device have already been explained.

Preferably, the device comprises a press head as described herein, wherein each press element is assigned an adjusting element for adjusting the press element. The device includes a control device for adjusting the adjusting element.

This allows for individual adjustment of the device and, in particular, the press channels, as well as independent operation of the device.

Advantageously, each press channel is assigned a press piston for pressing the material being pressed.

This enables and simplifies the maintenance of the device and, in particular, the maintenance of the press head.

In a preferred embodiment, the press pistons can be moved by means of a common cylinder.

Thus, several briquettes can be produced or pressed simultaneously with a single press stroke of the cylinder.

This simplifies and facilitates the construction or manufacture of the device.

However, it would also be conceivable to provide multiple cylinders that actuate different groups of press pistons. This would allow, for example, for alternating operation of the press pistons. Furthermore, it would be possible to reduce the respective forces on the cylinders.

The device as described herein may have a pre-collection chamber for receiving and/or pre-compacting the material to be pressed. The pre-collection chamber is preferably assigned to all pressing channels simultaneously.

Typically, a device for pressing material has a filling device, which is typically designed as a funnel.

Typically, the material to be pressed is collected in the hopper and guided to the press head. The material may then be transported to the press head solely by gravity. The material to be pressed is conveyed. Alternatively or additionally, other elements are conceivable that convey the material, such as screw conveyors or the like. Typically, at least one mechanical conveying element is located within the hopper in connection with the press head, which ensures that there is always enough material available for pressing.

Preferably, such a screw conveyor leads into a pre-collection chamber that receives the material to be pressed before pressing. The forced conveying action of the screw conveyor can result in a pre-compaction of the material.

The material is pressed from the pre-collection chamber into briquettes and collected for further processing, for example in a trough.

The device can be designed as an integral component of another machine, such as a machining center. A separate version is also conceivable. In this case, the device can include additional elements for setup, such as a machine frame.

Another aspect of the invention relates to a method for pressing material, in particular with a device as described herein and preferably with a press head as described herein.

The method comprises the steps listed in claim 14.

The pressing force on the second portion of the material being pressed is adjusted by the movable pressing element, in particular by a holding force of the first portion of the material being pressed in the pressing channel. Preferably, the material to be pressed is pressed simultaneously through two or more pressing channels. Preferably by an arrangement of pressing channels as described herein.

The starting position corresponds to the position of the press piston in its retracted state, when the press piston releases the pre-collection chamber or is in its position furthest possible from the inlet opening of the press channel. The final position of the press piston can be defined, on the one hand, by when a certain distance has been traveled, which is determined, for example, by a measurement on the cylinder or press piston. It would also be conceivable to link the final position to reaching a specific force.

The process can then be repeated, with the portion that was previously second becoming the first. In practice, this equilibrium between the first and second portions is only established after several iterations of the process. The first few of these cycles can therefore be described as the start-up phase, until a stable state is reached.

However, in the ongoing process it is possible to achieve a high degree of quality of the briquettes as well as a high consistency of the quality of the briquettes.

This process makes it possible to achieve a correspondingly equivalent quality of briquettes for each press channel when several press channels are arranged next to or above each other.

According to the invention, an adjusting element for setting the holding force as a function of an adjusting variable on the press cylinder or on the press piston is set independently for each press element.

This enables individual quality assurance for each press channel.

Preferably, the control variable is defined as a function of the force applied to the press piston. The force applied to the press piston is a direct indicator of the briquette's properties and allows for a clear statement about the pressing process.

For example, force measuring strips or similar devices can be attached to the piston, providing a value for defining the manipulated variable.

Preferably, the press pistons are hydraulically operated. The actuating variable can be defined as a function of the hydraulic pressure.

The following figures describe different embodiments of the present invention.

Figur 1:

eine Vorrichtung zum Pressen von Pressgut

Figur 2:

einen Teil der Vorrichtung aus Figur 1 mit einem Presskopf

Figur 3:

einen Querschnitt durch einen Presskanal der Figur 2 in einer perspektivischen Ansicht

Figur 4:

der Querschnitt aus Figur 3 in einer orthogonalen Ansicht

Figur 5a bis 5c:

unterschiedliche Ausführungsformen eines Presskopfes.

This shows

Figure 1:

a device for pressing material

Figure 2:

a part of the device Figure 1 with a press head

Figure 3:

a cross-section through a press channel of the Figure 2 in a perspective view

Figure 4:

the cross-section from Figure 3 in an orthogonal view

Figures 5a to 5c:

Different designs of a press head.

Figure 1 Figure 200 shows a device 200 for pressing material S. The device 200 has a funnel 202 for receiving the material. of the material to be pressed. The hopper 202 is connected to a pressing unit which includes a pressing head 100. The device 200 stands on a machine frame 201.

Figure 2 shows part of the device 200 Figure 1 A press head 100 is located inside the press unit. The press unit begins here with a nozzle 101, to which the filling funnel 202 ( Figure 1 ) is connected. Inside this nozzle 101 and the filling hopper 202 is a screw conveyor 203 ( Figure 3 In the figure, an adjusting device 30, 30' is arranged above and below the press head 100. The press head 100 comprises a common support element 2 and six pressing elements 3. Six pressing elements 3 are shown, but for clarity, only one is labeled and described at any given time. The pressing element 3, together with the support element 2, forms the pressing channel 1. In this case, three pressing channels 1 are arranged opposite each other and three further pressing channels 1. Three of the pressing channels are arranged side by side. The adjusting devices 30, 30' interact with the pressing elements 3. The press head 100 is formed from two side plates, between which the support element (2) is arranged. The pressing elements 3, which together with the support element 2 form six pressing channels 1, also belong to the press head 100.

Figure 3 shows a cross-section along the longitudinal axis of the in Figure 2 drawn press channel. This shows Figure 3 further details of the device according to the Figure 1 , which in Figure 2 are not shown. Thus, in Figure 3 The machine frame 201 is visible, on which the press unit with the press head 100 is arranged. The conveying direction of the material being pressed is defined by the auger 203 and the press head 100. This means the conveying direction is from the conveying slot 202 towards the press head 100 with the outlet openings 12.

For clarity, only some of the same parts are shown (analogous to the Figure 2 ) labelled.

What is not visible in the Figure 3 the filling hopper into which the screw conveyor 203 extends. The material to be pressed is fed into the filling hopper 202 (see Figure 1 The material is fed into the pre-collection chamber 204 by the screw conveyor 203. The material is collected in the pre-collection chamber 204 and pressed in the press head 100 by means of the press pistons 4, 4'. For this purpose, the press pistons 4, 4' move in the conveying direction into the die 6 and force the material to be pressed through the die 6. The press head 100 is located downstream of the die 6. The pressing elements 3 and 3' of the press head 100 are mounted on the pivot axes 5 and 5'. The pressing elements 3 and 3' are mounted on the pivot axes 5 and 5' in such a way that they can move towards and away from the respective adjusting devices 30, 30'. After several pressing operations, an accumulation of individual briquettes, becoming increasingly dense, forms within the press channel 1, 1'. These briquettes are held in their position in the press channel 1, 1' by the pressing elements 3, 3'. By adjusting the holding force by the adjusting elements 31, 31' on the respective pressing elements 3, 3', the reaction force to the force of the press pistons is also adjusted, and thus directly the pressing of the briquette in the die 6.

Figure 4 shows the cross-section according to Figure 3 in an orthogonal view. For the sake of clarity, only the elements of a single press channel 1 are labelled. The press channel 1 has an inlet opening 11 and an outlet opening 12. In the area of the inlet opening 11, the The inlet channel 1 has a cross-section QA, while in the area of the outlet opening 12, the press channel 1 has a cross-section QE. The press channel 1 is formed by the actuating element 2 and the pressing element 3. The pressing element 3 is rotatably mounted on the axis of rotation 5. This results in a regular cross-section Q of the press channel 1 in the area of the axis of rotation 5. When the actuating element 3 acts on the pressing element 3 in the area of the outlet opening 12, the cross-section QE at the outlet opening 12 naturally changes relative to the cross-section QA at the inlet opening 11. The briquette, which is formed by the press pistons 4 in the die 6, essentially has a diameter that corresponds to the cross-section of the die 6. However, due to the different properties of the briquettes, their elasticity varies in the cross-sectional direction. The briquette that has been pressed is conveyed into the press channel 1 by the following briquette. This briquette must be held in the press channel 1. Since the inhomogeneity of the briquettes among themselves is significant, a substantially constant holding force can nevertheless be exerted on the briquettes in the press channel 1 by adjusting the press element 3 with the adjusting element 31, thereby providing a certain counterforce or reaction force to the press piston 4 within the die.

The Figures 5a to 5c The figures show different versions of the press head. For clarity, only some of the identical elements are marked with reference symbols.

Figure 5a Figure 1 shows a press head with two adjacent press channels 1. The support element 2 is formed integrally with a side wall of the press head. Press channels 1 are visible inside the press head, which are connected to the Pressing element 3 are closed. In this case, two pressing elements 3 side by side form the closure of the upwardly open pressing channel 1.

Figure 5b shows an arrangement according to Figure 5a , wherein two pairs of press channels 1 are located opposite each other. It is conceivable that both pairs of press channels 1 are arranged as in the Figure 5a are designed as described. Alternatively, it would be conceivable to design the press channels 1 and the press element 3 as described in the Figure 5c The design shown below is to be implemented as follows. It would be conceivable for the support element 2 to have an additional web 21 that divides the press channels from each other. The press elements 3 can then be designed with a width equal to the diameter of the press channel 1, so that the press elements 3 form an insertion element for the press channel 1.

The Figure 5c shows a further development of the press head, whereby this is essentially the same as the development according to Figure 5b This corresponds to the design, with the difference that three press channels 1 are arranged opposite each other, and three press channels 1 are arranged side by side. The support element 2 is also formed in one piece with the side walls of the press head. The press elements 3 each correspond to the design as described above. Figure 5a described.

Claims (16)

1. Press head (100) for a device for pressing material, in particular for pressing chips, in particular an extrusion press, comprising
   at least two pressing channels (1, 1'), each with an inlet opening (11, 11') and an outlet opening (12, 12') each pressing channel (1, 1') having a supporting element (2, 2'), in particular a fixed supporting element, and a movable pressing member (3, 3'), the pressing member (3, 3') being movable on one side, preferably relative to the supporting element (2, 2'), in particular in the region of the outlet opening (12, 12'), such that a cross section (QA) of the pressing channel at its outlet opening is variable relative to the cross section (QE) of the pressing channel at its inlet opening, characterized in that each pressing element (3, 3') is assigned an adjustment element (31, 31') for adjusting the pressing element (3, 3'), each adjustment element (31, 31') being independently adjustable, in particular independently controllable, so that a pressing or holding force on each pressing element is independently adjustable.
2. Press head (100) according to claim 1
   characterized in that
   the pressing channels (1, 1') are formed in their crosssection (Q) essentially half by the supporting element (2, 2') and half by the pressing element (3, 3').
3. Press head (100) according to claim 1 or 2,
   characterized in that
   the pressing channels (1, 1') have a common supporting element (2, 2'), wherein the supporting elements (2, 2') are preferably formed in one piece, in particular in one piece.
4. The press head (100) according to any one of claims 1 to 3,
   characterized in that
   the pressing channels (1, 1') are arranged next to each other.
5. The press head (100) according to any one of claims 1 to 3,
   characterized in that
   the pressing channels (1, 1') are arranged opposite each other.
6. Press head (100) according to any one of claims 1 to 5,
   characterized in that
   the pressing element (3, 3') is pivotably mounted about an axis of rotation, preferably fixed relative to the supporting element (2, 2'), in particular in the region of the inlet opening (11, 11'), wherein the axis of rotation is arranged substantially perpendicular to the pressing channel.
7. Press head (100) according to any one of claims 1 to 6,
   characterized in that
   three pressing channels (1, 1') are arranged next to each other.
8. Press head (100) according to any one of claims 1 to 7,
   characterized in that
   three pressing channels (1, 1') are arranged opposite each other.
9. Device (200) for pressing material, in particular for pressing chips, in particular an extrusion press, comprising at least one press head (100) according to one of claims 1 to 8.
10. Device (200) according to claim 9 with a press head according to claim 7, comprising a control device for adjusting the adjustment element (31, 31').
11. Device (200) according to claim 9 or 10, characterized in that a pressing piston (4, 4') for pressing the pressing material is assigned to each pressing channel (1, 1').
12. Device (200) according to claim 11, characterized in that the pressing pistons (4, 4') are movable by means of a common cylinder.
13. The device (200) according to any one of claims 9 to 12, characterized in that the device has a pre-collection chamber (204) for receiving and/or pre-compacting pressing material.
14. Method for pressing material with a device (200) for pressing material with at least two pressing channels, in particular a device (200) according to one of claims 10 to 13 or a press head according to one of claims 1 to 8, wherein each pressing channel has an inlet opening and an outlet opening, a fixed supporting element and a movable pressing member movable on one side in each case, comprising the steps of

    - Feeding pressing material, preferably into a pre-collection chamber

    - Pressing of a first portion of the pressing material through at least a first of the at least two pressing channels (1, 1') with a first pressing stroke from an initial position by a forward movement in the direction of a longitudinal axis of the pressing channel (1, 1') of a pressing piston (4, 4'), preferably up to an end position of the pressing piston (4, 4')

    - Holding the pressed first portion of the pressing material in the first pressing channel (1, 1') by a movable pressing element (3, 3')

    - Return movement of the pressing piston (4, 4') to the starting position

    - Feeding a second portion of pressing material

    - Pressing the second portion of the pressing material with a second pressing stroke of the pressing piston (4, 4')

    whereby
    the pressing force on the second portion of the pressing material is adjusted by the movable pressing member (3, 3'), in particular by a holding force of the first portion of the pressing material in the pressing channel (1, 1'), characterized in that an adjustment element (31, 31') for adjusting the holding force is adjusted independently for each pressing member (3, 3') as a function of an adjusting parameter on the pressing cylinder.
15. Method according to claim 14, characterized in that the adjusting parameter is defined as a function of a force on the pressing piston (4, 4').
16. Method according to claim 14, characterized in that the pressing piston (4, 4') is operated hydraulically and the adjusting parameter is defined as a function of the pressure.