Compression packaging machine and method for operating a compression packaging machine

Abstract

The present invention relates to a baler (1) having a baler housing (3) surrounding a bale chamber (2) and a pressing plate (4) movable in the baler housing (3) and capable of being driven by hydraulic cylinders (5, 6, 7, 8) arranged in pairs on two opposite outer sides of the bale chamber (2). The baler (1) according to the invention is characterized in that it is provided with a hydraulic control device (12) by means of which the hydraulic cylinders (5, 6, 7, 8) of each pair of cylinders (5, 6, 7, 8) can each be selectively controlled either individually or together depending on the pressing pressure. Furthermore, the present invention relates to a method for operating the baler (1).

Description

Technical Field

[0001] The present invention relates to a compression packing machine having a compression packing machine housing surrounding a compression packing chamber and a pressing plate movable in the compression packing machine housing and drivable by a hydraulic cylinder. Further, the present invention relates to a method for operating a compression packing machine.

Background Art

[0002] Known from DE 100 29 439 A1 is a compression packing machine having a housing surrounding a compression packing chamber and a press ram used therein, the drive of the press ram being formed by four hydraulic cylinders arranged laterally adjacent to the compression packing machine housing. The hydraulic cylinder drive is not controlled. The cylinders are used as pressure cylinders. In other words, when the press ram moves downward, the piston surface of the cylinder is pressurized with hydraulic oil, and when the press ram moves upward, the piston ring surface is pressurized. Although a high pressing pressure can be generated in a compression packing machine having pressure cylinders, this configuration method has the drawback that the pressure cylinders basically protrude above the compression packing machine due to the design of the system. This is disadvantageous for a space having a low free height.

[0003] Known from US 2013 / 0270730 A1 is a compression molding device for melting a resin material, in which fibers are supplied to the molten resin, and the resin and fibers are then pushed into a mold. The compression molding device includes a lower mold and an upper mold, and at least three compression hydraulic cylinders attached to the upper mold and the lower mold. A position sensor is provided to detect the distance between the upper mold and the lower mold. And according to that information, the compression hydraulic cylinders can be individually controlled. The compression molding equipment is neither intended nor suitable for compressing and packing materials.

[0004] Known from US 5 868 067 A is a compression baler for compressing other compressible materials such as fibers and waste. The compression baler includes a primary hydraulic cylinder and a secondary hydraulic cylinder that operates faster, both of which are attached to a pressing plate designed to compress the material. In this case, the second compression means operates faster than the first compression means and applies a tamping motion to the pressed material pre-compressed by the first compression means. Both compression means have a common hydraulic system and solenoid valves. The supply of hydraulic fluid to the two hydraulic cylinders and the operation of the tamping stroke are performed by a control system provided for this purpose. The drawback of this system is that there are two pairs of cylinders with a total of four cylinders provided, but the two secondary cylinders only serve to increase the lifting and lowering speed in the unloaded state. The material compression is performed only by the primary cylinder.

[0005] DE 195 28 813 A1 discloses a device for compensating for the tilting moment on the ram of a press. This device comprises at least a pair of identical hydraulic cylinders, the pistons of which are each connected to the ram. The hydraulic cylinders are isochronous cylinders (also called constant-speed cylinders) having piston rods on both sides of the piston surface. The volume of hydraulic fluid flowing in and out is thus always the same. The cylinders also contract and extend at the same speed for this reason. The chambers of each hydraulic cylinder located above the piston are in each case connected via a connecting line to the chamber of the other hydraulic cylinder of the pair located below the piston. The device known from DE 195 28 813 A1 is capable of detecting and compensating for the tilted position of the ram, but such a ram press lacks a compression bale chamber and is not suitable as a compression baler.

[0006] It is known from US 5 570 630 A that a baling press has two double-acting hydraulic cylinders. The hydraulic cylinders are connected by a bridge structure and two press plates attached thereto. When the plates move downward, and thus to control the angle of the plates during compression, two electric switches actuated by pins are provided whenever the bridge structure connecting the hydraulic cylinders moves from its normally horizontal position to an inclined position. The drawback of this control system is that it can only roughly control the cylinders and cannot provide fine control.

[0007] Known from AU 001991082616 A1 is a press for wool having a frame and a pressing plate that can be stored in a pressing chamber. After pressing, in order to hold the compressed wool in its compressed position, wool holding elements are provided in the form of pins that engage laterally with the pressed bale, and they are pushed through from the side into the wool bale after compression and before the pressing plate is moved upward. The pins engaging laterally in the pressing chamber thus serve as a holding device for the material being compressed and prevent the material from expanding when the pressing plate returns.

[0008] US 3 851 577 A discloses a baling press for pressing waste, such as cardboard boxes, having a pressing chamber and a hydraulic cylinder mounted on a pressing plate above the pressing chamber. To reduce the overall height of the baling press for transportation, the cylinder can be lowered into the housing. However, this conversion is time-consuming and costly. Another drawback of a system having a hydraulic cylinder located above the bale chamber is the associated high overall height. Thus, a baling press having such a structure is not suitable for spaces having a low headroom.

[0009] The compression baling machine known from DE 20 2015 102 601 U1 is for compressing unpacked materials such as cardboard boxes. Such a compression baling press is used, inter alia, in supermarkets to compress cardboard boxes, cardboard, and other packaging of merchandise left on or removed from the sales shelves in order to minimize the volume of the waste to be disposed of. It is also possible to directly tie the pressed cardboard boxes etc. with wire or plastic straps in the compression baling chute of the compression baling machine housing. To compress cardboard boxes etc., the press plate is moved downward by two hydraulic cylinders arranged at the top of the press shaft. This requires a large overall height of the compression baling machine. In this prior art, arranging the hydraulic cylinders above the compression baling machine housing requires a large free height in order to be able to install the compression baling machine in a building protected from the weather.

[0010] Document DE 10 2005 037 147 A1 shows a compression baling machine having a compression baling machine housing surrounding a compression bale chamber, and the press plate can be moved in the compression bale chamber by a power drive device consisting of four hydraulic cylinders. In either case, the two hydraulic cylinders operate together as a master - slave cylinder pair. Furthermore, the hydraulic cylinders can also be arranged on the side of the compression baling machine housing in order to reduce the overall height of the compression baling machine. The operation of a compression baling machine with master - slave hydraulic cylinders requires considerable technical expense, especially specialized and thus expensive hydraulic cylinders.

Summary of the Invention

[0011] In the case of the present invention, therefore, the object is to provide a compression baling machine having a low overall free height and a simplified structural design. Furthermore, a corresponding method for operating such a compression baling machine is specified.

[0012] These objects are achieved by a compression baling machine having the features of claim 1 and by a method having the features of claim 8.

[0013] As described above, the essential idea of the present invention is that in a compression packing machine having a compression packing chamber in a compression packing machine housing, a pressing plate, and a hydraulic cylinder for driving the pressing plate, a total of four hydraulic cylinders are provided, and each of the hydraulic cylinders is arranged in pairs on one side of the pressing plate, and using a control device, the hydraulic cylinders among each pair of cylinders can be selectively actuated individually or together according to the pressing pressure.

[0014] By arranging the hydraulic cylinders on the side surface of the compression packing machine housing, the overall height of the compression packing machine is kept small. This is especially the case when the compression packing machine is designed such that the hydraulic cylinders are used as pull cylinders rather than push cylinders. In this context, the pressure cylinder is understood to be a cylinder in which the piston surface acts on the hydraulic oil during the pressing process. A pull cylinder is a cylinder in which the piston ring surface is pressurized with hydraulic oil during the pressing process.

[0015] For a compression packing machine having a pull cylinder, the advantage is that the hydraulic cylinder does not protrude beyond the compression packing chamber or the pressing plate. For two compression packing machines having the same overall height, one of them compresses the compression packing material with a pull cylinder and the other compresses it with a push cylinder. Therefore, the pull cylinder compression packing machine can achieve a higher and thus larger compression packing chamber than the push cylinder compression packing machine. The compression packing machine having a pull cylinder according to the present invention is thus particularly suitable for rooms with a low free height.

[0016] For this purpose, the hydraulic cylinders engaging the pressing plate are preferably designed such that they do not actually protrude above the pressing plate when the pressing plate is moved to its uppermost position. In particular, the hydraulic cylinders are arranged in pairs left and right opposite each other on two sides of a usually rectangular pressing plate. In the lower region of the compression packing machine, there is preferably a lower horizontal yoke to which the cylinders are attached.

[0017] The control device is designed to operate the various hydraulic cylinders of the compression baler with hydraulic oil in a desired manner, i.e., to move the pressing plate downward to compress materials such as cardboard boxes, and also to operate the hydraulic cylinders in the opposite direction to raise the pressing plate in a targeted manner. The control device is designed to control only one or both of the hydraulic cylinders of each pair of cylinders arranged adjacent to one side of the pressing plate. This provides the advantage that only one hydraulic cylinder on each side of the compression bale plate is actuated at a time when the compression bale chamber of the compression baler is still mostly empty or filled only with easily compressible materials. At this stage, only two hydraulic cylinders are pressurized with hydraulic oil, so the volume required to drive only the two driven hydraulic cylinders can be made available more quickly with the existing pump for hydraulic oil than with four hydraulic cylinders, resulting in a rapid movement of the pressing plate. The same applies to the return stroke of the pressure plate, which requires little force and, conveniently, only one cylinder of each pair of cylinders is controlled.

[0018] The piston rod of each non-actuated cylinder is operated together by the adjacent actuated cylinder. For this purpose, the two hydraulic cylinders arranged on one side of the pressing plate are mechanically coupled to each other such that the piston rod of the other cylinder moves when the piston rod of one of the controlled hydraulic cylinders moves up or down.

[0019] However, if a greater force is required to move the pressing plate, especially during the final stage of the pressing stroke of the pressing plate, for example, between the last one-third and the last one-fifth during the descent in the compression bale chamber, this can be detected by the sensor of the control device, for example, by the fact that the pressure in the activated hydraulic cylinder increases and the piston rod of the hydraulic cylinder moves very slowly or not at all. Then, the control unit can switch according to the pressing pressure so that the pressurized hydraulic oil is also supplied here to two previously unpressurized hydraulic cylinders via further corresponding hydraulic lines in order to double the pressing force.

[0020] The hydraulic control device is preferably an electronic unit such as PLC control.

[0021] By selectively controlling only one hydraulic cylinder on each side or either of the two hydraulic cylinders, it is possible to move the press plate faster with lower power requirements while maintaining the same power of the hydraulic oil pump assigned to the press, and to achieve a much more effective operation of the press with a high pressing force when compressing the material to be pressed.

[0022] Another advantage of the present invention is that by arranging the hydraulic cylinders horizontally, the compression baler can be installed in a room with a low ceiling height and can also be transported through a low door or gate.

[0023] The advantageous embodiments of the present invention are the subject of the subclaims.

[0024] In particular, the hydraulic cylinders can be controlled such that if only one cylinder on each side is controlled first, this is done crosswise, for example, for the left rear cylinder and the right front cylinder, or alternatively for the left front cylinder and the right rear cylinder. In this way, a more uniform application of force to the pressing plate by the hydraulic cylinders can be achieved to avoid tilting of the pressing plate.

[0025] According to a further aspect, a hydraulic main switching valve and a hydraulic pressure switching valve are provided to operate a hydraulic cylinder, which can be controlled by a hydraulic control device. The main switching valve basically determines the moving direction of the hydraulic cylinder, i.e., the rising or falling of the pressing plate, according to the direction in which the hydraulic cylinder is pressurized by the hydraulic oil. The pressure switching valve is also used to control whether only one of the hydraulic cylinders of the cylinder pair is pressurized by the hydraulic oil on each side or both hydraulic cylinders are pressurized.

[0026] Preferably, the hydraulic cylinders are respectively connected to each other by a top-side horizontal yoke and / or a bottom-side lower yoke. These yokes are then respectively arranged above and below the press housing. In order to enable the hydraulic cylinder to move relative to these yokes, spherical bearings and shafts can be provided at the joint between the cylinder and the yoke.

[0027] Preferably, a guide for the movable pressing plate is provided in the press housing. For example, on the press plate, a guide rail in the shape of a prism with a triangular cross-section can be arranged, and the guide rail interacts with a corresponding guide contour member on the inner surface of the compression packaging chamber. This counteracts the inclination of the pressing plate when pressing the materials together.

[0028] In particular, when the compression packaging chamber is unevenly filled, the pressing plate may tilt due to the different resistances of the materials being pressed, i.e., tilt with respect to the main plane of the pressing plate itself. In this regard, the present invention proposes that a position sensor for detecting the tilt position of the pressing plate is associated with the pressing plate, and a position signal can be transmitted from the position sensor to the hydraulic control unit. In this way, the control device and the position sensor can detect any tilt of the pressing plate that exceeds a preset limit value. The control unit can then control the hydraulic cylinder so that the tilt is compensated. For example, only one of the hydraulic cylinders on the leading side of the pressing plate is pressurized with hydraulic fluid to realign the pressing plate horizontally again, and both hydraulic cylinders on the opposite remaining side of the pressing plate are pressurized with hydraulic fluid.

[0029] To operate the compression packaging machine according to the present invention, the hydraulic cylinders of each pair of cylinders are selectively controlled individually or together according to the pressing pressure. This means that only one or both of the two hydraulic cylinders arranged on both sides of the pressure plate and mechanically coupled to each other are controlled to raise and lower the pressure plate. When the power requirement is low, only one of the hydraulic cylinders of each pair of cylinders is actuated by hydraulic fluid to quickly lower or raise the pressing plate again. When the power requirement is high, i.e., when pressing the material to be pressed, both hydraulic cylinders of each pair of cylinders are pressurized with hydraulic fluid.

[0030] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. The figures in the drawings are all shown in schematic diagrams in each case.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0032] In the following description of the drawings, the same reference numerals are always given to the same parts in the various drawings, so it is not necessary to explain all the reference numerals for each drawing again.

[0033] Furthermore, the drawings, their descriptions, and the claims include combinations of a number of features. It will be apparent to those skilled in the art that these features can be considered individually or combined in further combinations not detailed here. The present invention is explicitly extended to such embodiments not given by combinations of features from the explicit description of the claims, whereby the features disclosed by the present invention can be combined with each other in any way as long as they are technically reasonable. From this, the exemplary embodiments shown in the drawings are for illustrative purposes only and are never intended to limit the present invention.

[0034] The terms “upper”, “top”, “bottom”, “left”, or “right” used hereinafter refer to the arrangement of the components of the compression baler corresponding to the operating mode shown in the drawings.

[0035] FIG. 1 shows a compression baler 1 having, for example, a compression baler housing 3 made of steel and a compression bale chamber 2 in which a chamber door 9 forming the front side of the compression baler housing 3 is open. A supply opening 10 is provided at the upper part of the chamber door 9. When the chamber door 9 is closed, compression bale material such as cardboard boxes, cardboard, packaging, or empty plastic beverage bottles produced, for example, in a supermarket can be supplied into the compression bale chamber 2 through the supply opening 10.

[0036] The material to be compressed and packed is then moved in the direction of R1 by a pressing plate 4, shown here in the upper upward position, and compressed, preferably tied with a wire or a plastic strap, and then taken out as a compressed package that has been pressed when the chamber door 9 is open. From this, the volume of the material to be disposed of is considerably reduced, and the compressed package can be easily stored and transported.

[0037] The pressing plate 4 is here moved by four hydraulic cylinders 5, 6, 7, 8 arranged in pairs on the sides of the compression and packing machine housing 3, although only two of the hydraulic cylinders 5, 6 are fully visible in FIG. 1. Two further hydraulic cylinders 7, 8 are arranged on the side of the compression and packing machine housing 3 facing away from the viewer here, and most of them are hidden. The hydraulic cylinders 5, 6, 7, 8 each have a piston 23 and a piston rod 22. The piston 23 has a piston surface 25 on one side and a piston ring surface 24 surrounding the piston rod 22 on the other side. Due to the fact that the hydraulic cylinders 5, 6, 7, 8 are arranged horizontally on the compression and packing machine housing 3, the overall height of the compression and packing machine 1 is advantageously low. The fact that the hydraulic cylinders 5, 6, 7, 8 are designed as pull cylinders and each of them is pressurized with hydraulic fluid on its piston ring surface 24 during its movement in the pressing direction R1 also makes the overall height particularly low.

[0038] The pressing plate 4 is here connected at its side edges to four vertical prism-shaped guide rails 13, which project upward beyond the pressing plate 4 and interact with corresponding guide contour members 14 on two inner side surfaces of the press housing 3.

[0039] The two hydraulic cylinders 5, 6 on one side and the two further hydraulic cylinders 7, 8 on the other side are connected to each other at the top by a top-side cross yoke 11 within each pair of cylinders, and at the bottom by a bottom yoke 17 running parallel to the top-side cross yoke below the compression and packing chamber 2. In addition, the top-side cross yoke 11 is connected to the upper side of the pressing plate 4.

[0040] Figure 2 shows a top view of the compression baler 1. Four hydraulic cylinders 5, 6, 7, 8 are here engaged with each other in pairs in a lateral direction facing each other via the top-side horizontal yoke 11 on the pressing plate 4. The hydraulic cylinders 5, 6 on one side and the hydraulic cylinders 7, 8 on the other side are connected to each other by the top-side horizontal yoke 11. The horizontal yoke 11 provides a mechanical connection for the hydraulic cylinders 5, 6, 7, 8.

[0041] Furthermore, the pressing plate 4 has four vertical prismatic guide rails 13 on its side edges that interact with corresponding guide contour members 14 on the inner surface of the press housing 3. When the pressing plate 4 tilts on the leading side, the frictional resistance of the guide rails 13 in the guide contour members 14 increases, so that the pressing plate 4 is braked on this side and almost automatically realigns itself horizontally again, thus counteracting the tilt of the pressing plate 4.

[0042] The four hydraulic cylinders 5, 6, 7, 8 are each connected to the top-side horizontal yoke 11 via a coupling bearing 16.

[0043] There is a chamber door 9 at the bottom of Figure 2, which is here closed.

[0044] Figure 3 shows the compression baler 1 in a perspective view obliquely seen from the front with a changed viewing angle compared to Figure 1. Here, the pressing plate 4 of the compression baler 1 is in the raised position. Furthermore, it can be seen that the two hydraulic cylinders 5, 6 and 7, 8 respectively arranged on one side of the pressing plate 4 are mechanically connected to each other. This connection is here made via a coupling bearing 16 that engages with the top-side horizontal yoke 11. Furthermore, the guide rails 13 at the edges of the pressing plate 4 are also here connected to each other in parallel with respect to the horizontal yoke 11, which serves to increase the mechanical stability of the pressing plate 4.

[0045] Figure 4 shows a side view of two adjacent hydraulic cylinders 5, 6 out of the pair of cylinders seen in Figure 1, and each of the hydraulic cylinders 5, 6 is connected to the other via a top-side horizontal yoke 11 and a lower yoke 17. The joint bearing 16 is used to articulately connect these components to each other. The outer piston rod ends of the cylinders 5, 6 are connected to the top-side horizontal yoke 11 by the joint bearing 16 at the top, and the cylinder housings of the cylinders 5, 6 are connected to the lower yoke 17 by the joint bearing 16 at the bottom. On the other side of the press housing not shown here, there is a mirror-symmetrical arrangement having two further hydraulic cylinders 7, 8.

[0046] The lower joint bearing 16 shown on the right side of Figure 4 is shown again in an enlarged view of the detail Z on the right side of Figure 4.

[0047] In Figure 5, a hydraulic circuit diagram of the hydraulic system of the compression baler is shown together with some other parts of the compression baler to illustrate the hydraulic components and hydraulic connections (shown as solid lines) of the various components of the compression baler 1. Cross-sections A-A and B-B are schematically shown on the sides of Figure 5.

[0048] In total, four hydraulic cylinders 5, 6, 7, 8 engage with the top-side horizontal yoke 11 on the pressing plate 4 of the compression baler 1, and together with the pressing plate 4, move the top-side horizontal yoke 11 downward in the pressing direction R1 or raise the top-side horizontal yoke 11 in the direction opposite to the pressing direction R1.

[0049] To record the inclination of the pressing plate 4 from its horizontal position, a position sensor 18 such as an inclination angle sensor is arranged on the pressing plate 4 or, as shown here, on the horizontal yoke 11. The position sensor 18 communicates with the control device 12 as shown by the dashed line.

[0050] The control device 12 is then connected to the main switching valve 19 via a control line and can control the hydraulic cylinders 5, 6, 7, 8 via the main switching valve.

[0051] In addition, the hydraulic system includes a pressure switching valve 20 that is connected upstream of the main switching valve 19 and switches according to the hydraulic pressure.

[0052] In the operating stage of the compression baler with low power requirement, only the two hydraulic cylinders 5 and 8 are controlled such that these hydraulic cylinders 5 and 8 move the pressing plate 4 up or down. The other hydraulic cylinders 6 and 7 of each pair are driven by their respective hydraulic cylinders 5 and 8 through their mechanical connection. The synchronized hydraulic cylinders 6 and 7 are filled with hydraulic oil from the hydraulic oil tank of the hydraulic system through a tank line in a pressureless state due to the vacuum created in the post-suction process, and a check valve is arranged therein.

[0053] When a greater force, which can be determined by the increase in the hydraulic pressure, is required, especially when pressing the compression baling material, the pressure switching valve 20 also controls the two other hydraulic cylinders 6 and 7 and is controlled to be pressurized with the pressurized hydraulic oil, and then all four pressurized hydraulic cylinders 5, 6, 7, and 8 generate a higher pressing force, approximately twice as high, on the pressure plate 4.

[0054] The two hydraulic cylinders are cross-controlled by the control device 12 when the power requirement is low. For example, only the hydraulic cylinders 5 and 8 or the hydraulic cylinders 6 and 7 are controlled. When a greater load occurs during the downward movement of the pressing plate 4, that is, only when there is already a large amount of compression baling material or difficult-to-compress material in the press chamber, the other two respective hydraulic cylinders 6 and 7 or 5 and 8 are controlled. This means that the hydraulic pump then supplies hydraulic oil to all four hydraulic cylinders 5, 6, 7, and 8.

[0055] When the inclination of the pressing plate 4 during the pressing process is detected by the position sensor 18 and transmitted to the control device 12, the hydraulic cylinders 5, 6, 7, and 8 can be correspondingly controlled by the control device 12 and the main switching valve 19 to compensate for this inclination.

[0056] The direction switching valve 21 is used to switch the moving direction of the hydraulic cylinders 5, 6, 7, 8, and thus the moving direction of the pressing plate 4. This direction switching valve is arranged between the hydraulic pump P responsible for the delivery of hydraulic oil and the generation of the pressure of the hydraulic oil and the pressure switching valve 20.

[0057] A typical operating cycle of the compression packing machine 1 is as follows.

[0058] First, the compression packing machine 1 is in the filling state, and the hydraulic cylinders 5, 6, 7, 8 are in the raised position, that is, in the position when the pressing plate 4 is in its uppermost position for the purpose of filling the compression packing chamber 2. Through the opened chamber door 9, the compression packing material is manually or mechanically supplied into the compression packing chamber 2 until a preset filling level is reached, and the chamber door 9 is closed.

[0059] From this position, the hydraulic cylinders 5, 8 or 6, 7 are filled with hydraulic oil by the pump P in the annular space of the cylinders located below the pressing plate 4 in order to press the compression packing material. From this, only one of the cylinders 5 and 8 of each pair of cylinders attached to the side of the press 1 is filled with oil. Here, when the annular spaces of the cylinders 5, 8 connected to the pump P are filled with hydraulic oil, the piston rods of these cylinders 5, 8, and thus the pressing plate 4 connected thereto, move downward.

[0060] Among the pairs of cylinders, the cylinders 5, 6 and 7, 8 are each mechanically coupled to each other. From this, when the piston rod of one of the cylinders 5, 8 moves downward in the pressing direction R1, the piston rods of the other respective cylinders 6, 7 also move downward in the pressing direction R1 by mechanical force transmission through the mechanical connection. In that process, the hydraulic cylinders 6, 7 that are moved together are filled with the hydraulic oil from the hydraulic oil tank of the hydraulic system without pressure through the tank line in which the check valve is arranged due to the vacuum created in the post-suction process.

[0061] Cylinders 5 and 8 filled with hydraulic oil and operating with low power requirements and low pressing pressures are arranged crosswise, i.e., cylinder 5 is hydraulically connected to cylinder 8. Cylinders 5 and 8 are filled with pressurized hydraulic oil in an operating state in which the pressure switching valve 20 has not yet been switched so as to fill all cylinders 5, 6, 7, 8. In that process, the pressing plate 4 moves downward relatively quickly without forming a large pressure for most of the pressing cycle.

[0062] If the compression bale chamber 2 is already filled to a certain extent, the pressure for pressing the compression bale material is initially required only in the lower part, which is about one-third to one-fifth below the compression bale chamber 2. Then, via the pressure switching valve 20, the flow of hydraulic oil is not only released into the hydraulic cylinders 5 and 8, but also the adjacent hydraulic cylinders 6 and 7 are supplied with pressurized hydraulic oil.

[0063] At the time when such a switching of the pressure switching valve 20 takes place, the pressing plate 4 is already at the lower part of the compression bale chamber 2. The pairs of cylinders 5, 6 and 7, 8 on each side of the pressing plate 4 are connected to each other via a horizontal yoke 11 located above the pressing plate 4.

[0064] The guide rails 13 are located on the pressing plate 4 and interact with a guide contour member 14 formed to fit the side walls of the compression bale chamber 2. For example, if a different pressure is formed under the right side part of the pressing plate 4 than under the left side part, the pressing plate 4 is crossed so that the cylinders 5, 6 or 7, 8 on one side receive less oil than the cylinders 7, 8 or 5, 6 on the other side.

[0065] The guide rail 13 that interacts with the guide contour member 14 of the side wall and extends upward from the pressing plate 4 ensures that when a pair of cylinders 5, 6 or 7, 8 are advanced and as a result the pressing plate 4 tilts, the guide rail 13 and the guide contour member 14 on the leading side cause a greater friction between them than between the guide rail 13 and the guide contour member 14 on the trailing side of the pressing plate 4. As a result, the first leading guide part passing through the guide rail 13 and the guide contour member 14 slows down, so that the hydraulic oil preferentially flows into the other pair of cylinders 7, 8 or 5, 6, resulting in a leading compensation on one side of the pressure plate 4 acting on the tilted position.

[0066] However, if the tilted position of the pressing plate 4 becomes too large, this is detected by a position sensor 18, for example an angle sensor, mounted on the horizontal yoke 11 above the pressing plate 4 and reported to the control device 12. If the tilted position exceeds a certain predefined limit value, the direction switching valve 21 of the hydraulic system is set by the control device 12 to return, and the pressing plate 4 moves back to its upper starting position. At the latest at the end of the retraction, the pressing plate 4 realigns itself horizontally again by running against the upper stop, and then it can be moved down again from there for a new pressing step.

[0067] At the end of the last pressing step, i.e., when the compression package is fully pressed, the pressing plate 4 is in its lower position. At this position of the pressing plate 4, the compression package can be tied up in a known manner. From this position, the pressing plate 4 is moved back up again after the direction switching valve 21 has been switched. Here too, only the two cylinders 5, 8 are pressurized with hydraulic oil during the return stroke, so that a relatively rapid return of the pressing plate 4 to the top is achieved due to the small volume of hydraulic oil required for this purpose. The twin cylinders 6, 7 connected to the respective cylinders 5, 8 are not moved upward by the pressurized hydraulic oil flowing into their pressure chambers, but are driven by the respective adjacent hydraulic cylinders 5, 8 by means of a mechanical connection and the power transmission effected thereby. The hydraulic oil discharged into the annular spaces of the hydraulic cylinders 6, 7 flows into the unpressurized hydraulic oil tank. For this purpose, the hydraulic cylinders 6, 7 are connected to the hydraulic oil tank only at their bottom sides via simple oil leakage lines and can also draw in air when the cylinders 5, 8 are extended. The piston chambers of the hydraulic cylinders 6, 7 carried along together do not, therefore, need to be pressurized with hydraulic oil.

[0068] After reaching the upper starting position of the pressing plate 4, the chamber door 9 can be opened and the pressed and tied compression package can be removed from the compression package chamber 2.

[0069] [List of reference numerals] 1 Compression baler 2 Compression package chamber 3 Compression baler housing 4 Pressing plate 5 Hydraulic cylinder 6 Hydraulic cylinder 7 Hydraulic cylinder 8 Hydraulic cylinder 9 Chamber door 10 Supply opening 11 Horizontal yoke 12 Control device 13 Guide rail 14 Guide contour member 15 Shaft 16 Coupling Bearing 17 Lower Yoke 18 Position Sensor 19 Main Switching Valve 20 Pressure Switching Valve 21 Direction Switching Valve 22 Piston Rod 23 Piston 24 Piston Ring Surface 25 Piston Surface A - A Cross - Section B - B Cross - Section R1 Pressing Direction Z (Details from Figure 3) The invention described in the original claims of the present application is appended below. [1] In a compression packaging machine (1) having a compression packaging machine housing (3) surrounding a compression packaging chamber (2) and a pressing plate (4) that is movable in the compression packaging machine housing (3) and can be driven by hydraulic cylinders (5, 6, 7, 8) arranged in pairs on two opposing side surfaces outside the compression packaging chamber (2), a hydraulic control device (12) is provided, and using it, the hydraulic cylinders (5, 6, 7, 8) among each pair of cylinders (5 and 6, 7 and 8) can each be selectively controlled individually or together according to the pressing pressure, characterized in that the compression packaging machine (1). [2] Regarding the individual control of each hydraulic cylinder (5 or 6, 7 or 8) on each side surface, the hydraulic cylinders (5 and 8 or 6 and 7) can be cross-controlled, characterized in that the compression packaging machine (1) according to [1]. [3] Regarding the operation of the hydraulic cylinders (5, 6, 7, 8), a main hydraulic switching valve (19) and a hydraulic pressure switching valve (20) are provided, and they can be controlled by the hydraulic control device (12), characterized in that the compression packaging machine (1) according to [1] or [2]. [4] The hydraulic cylinders (5, 6, 7, 8) are each connected to each other by a top-side horizontal yoke (11) and / or a bottom-side lower yoke (17), characterized in that the compression packaging machine (1) according to any one of [1] to [3]. [5] A guide part for the pressing plate (4) is formed in the compression packaging machine housing (3), characterized in that the compression packaging machine (1) according to any one of [1] to [4]. [6] The pressing plate (4) is assigned a position sensor (18) for detecting the inclined position of the pressing plate (4), and then a position signal can be transmitted to the hydraulic control device (12), characterized in that the compression packaging machine (1) according to any one of [1] to [5]. [7] - The hydraulic cylinders (5, 6, 7, 8) are double-acting cylinders having piston rods (22) and pistons (23), in which the piston (23) has a piston surface (25) on one side and a piston ring surface (24) surrounding the piston rod (22) on the other side, The hydraulic control device (12) is designed such that, during the movement of the pressing plate (4) in the pressing direction (R1), the piston ring surface (24) of the piston (23) is actuated by hydraulic fluid so that the hydraulic cylinders (5, 6, 7, and 8) function as pull cylinders, the compression packaging machine (1) according to any one of [1] to [6]. [8] In a method for operating a compression packaging machine (1) having a compression packaging machine housing (3) surrounding a compression packaging chamber (2) and a pressing plate (4) movable in the compression packaging machine housing (3) and driven by hydraulic cylinders (5, 6, 7, 8) arranged in pairs on two opposing side surfaces outside the compression packaging chamber (2). The method is characterized in that the hydraulic cylinders (5, 6, 7, 8) of each pair of cylinders are each selectively controlled individually or together, respectively, according to the press pressure. [9] For the individual control of the respective hydraulic cylinders (5 or 6, 7 or 8) on each side, the hydraulic cylinders (5 and 8 or 6 and 7) are cross-controlled, the method according to [8].

[10] The hydraulic cylinders (5, 6, 7, 8) for moving the pressing plate (4) have a piston (23) having a piston surface (25) and a piston ring surface (24), and when the pressing plate (4) is moved in the pressing direction (R1), they are actuated at those piston ring surfaces (24) by hydraulic fluid, the method according to [8] or [9].

Claims

1. A compression packaging machine (1) having a compression packaging machine housing (3) surrounding a compression packaging chamber (2), and a pressing plate (4) that is movable within the compression packaging machine housing (3) and is driven by hydraulic cylinders (5, 6, 7, 8) arranged in pairs on two opposing side surfaces outside the compression packaging chamber (2). A hydraulic control device (12) is provided, and using it, the hydraulic cylinders (5, 6, 7, 8) among each pair of cylinders (5 and 6, 7 and 8) can each be controlled selectively either individually or together according to the press pressure. The compression packaging machine (1), characterized in that the hydraulic cylinders (5, 6, 7, 8) are each connected to each other by a top-side horizontal yoke (11) and / or a bottom-side lower yoke (17).

2. Regarding the individual control of each hydraulic cylinder (5 or 6, 7 or 8) on each side surface, the compression packaging machine (1) according to claim 1, characterized in that the hydraulic cylinders (5 and 8 or 6 and 7) can be cross-controlled.

3. Regarding the operation of the hydraulic cylinders (5, 6, 7, 8), a hydraulic main switching valve (19) and a hydraulic pressure switching valve (20) are provided, and they can be controlled by the hydraulic control device (12), the compression packaging machine (1) according to claim 1 or 2.

4. The compression packaging machine (1) according to any one of claims 1 to 3, characterized in that a guide part for the pressing plate (4) is formed in the compression packaging machine housing (3).

5. The compression packaging machine (1) according to any one of claims 1 to 4, characterized in that the pressing plate (4) is assigned a position sensor (18) for detecting the inclined position of the pressing plate (4), and then a position signal can be transmitted to the hydraulic control device (12).

6. - The hydraulic cylinders (5, 6, 7, 8) are double-acting cylinders provided with piston rods (22) and pistons (23), in which the piston (23) has a piston surface (25) on one side and a piston ring surface (24) surrounding the piston rod (22) on the other side. The hydraulic control device (12) is designed such that, during movement of the pressing plate (4) in the pressing direction (R1) so that the hydraulic cylinders (5, 6, 7, and 8) function as pull cylinders, the piston ring surface (24) of the piston (23) is actuated by hydraulic fluid. The compression packaging machine (1) according to any one of claims 1 to 5.

7. A compression packaging machine housing (3) surrounding the compression packaging chamber (2), and a pressing plate (4) that is movable in the compression packaging machine housing (3) and is driven by hydraulic cylinders (5, 6, 7, 8) arranged in pairs on two opposing side surfaces outside the compression packaging chamber (2). In a method for operating a compression packaging machine (1) in which the hydraulic cylinders (5, 6, 7, 8) are each connected to each other by a top-side horizontal yoke (11) and / or a bottom-side lower yoke (17). The method is characterized in that the hydraulic cylinders (5, 6, 7, 8) of each pair of cylinders are each selectively controlled either individually or together according to the press pressure.

8. Regarding the individual control of the hydraulic cylinders (5 or 6, 7 or 8) on each side, the method according to claim 7, characterized in that the hydraulic cylinders (5 and 8 or 6 and 7) are cross-controlled.

9. The hydraulic cylinders (5, 6, 7, 8) for moving the pressing plate (4) have a piston (23) having a piston surface (25) and a piston ring surface (24), and when the pressing plate (4) is moved in the pressing direction (R1), they are actuated at their piston ring surfaces (24) by hydraulic fluid. The method according to claim 7 or 8.

Images