ROUND BALER AND METHOD FOR OPENING A DISCHARGE VALVE OF A ROUND BALER

Description

[0001] The present invention relates to a round baler according to the preamble of independent claim 1, an agricultural machine according to the preamble of independent claim 14, a method for opening a discharge flap of a round baler according to the preamble of independent claim 15, and a computer program, in particular a computer program product, according to the preamble of independent claim 16.

[0002] Conventional round balers have so-called intake and conveying devices that pick up the crop from the ground of an agricultural field and convey it into a baling chamber of the round baler, where the crop is formed into a round bale. The baler housing has a stationary housing section and a discharge flap pivotally mounted on the stationary housing section. The housing surrounds the baling chamber, which is defined by a multitude of press rollers driven by a motor. These rollers are distributed on both the stationary housing section and the discharge flap, thus defining the circumference of the baling chamber. By means of the driven press rollers, the crop conveyed into the baling chamber by the intake and conveying devices is formed into a round bale. Before the bale formed in the baling chamber...When pressed round bales are ejected from the round baler via the opening of the discharge flap, they are encased or wrapped by a device inside the press chamber with a covering, in particular a film, a net and / or the like.

[0003] During the pressing process of a round bale, all the press rollers that define the press chamber rotate in the same direction, so that the crop is evenly compressed into the shape of a round bale via an upward movement. Once a pressing cycle is complete, the discharge flap opens, creating an ejection opening through which the compressed round bale is ejected, primarily via the driven lower press rollers on the stationary part of the baler housing. The speed at which the discharge flap opens essentially corresponds to the speed at which the compressed round bale is ejected, ensuring that the housing flap maintains contact with the round bale for almost a significant portion of its pivoting motion from the closed to the open position.In particular, the press roller located at the bottom edge of the discharge flap, which continues to rotate even during the ejection of the round bale, makes contact with the wrapped round bale during ejection. The rotational movement of the round bale and press rollers, especially the press roller at the bottom edge of the discharge flap, which is in the same direction during the pressing process, gradually changes to an opposing rotational movement during the opening process.

[0004] This is problematic because the counter-rotating motion of the round bale and the press roller, located at the bottom of the discharge flap and still driven during ejection, places additional stress on the wrapped bale. Since the bale's outer layer is already under stress from the pressure of the compressed bale, the additional stress induced by the counter-rotating motion is critical. In particular, there is a significant risk that the bale's outer layer, already under tension, will be partially damaged by contact with the driven press roller at the bottom of the discharge flap, resulting in insufficient bale cohesion.

[0005] EP 3 162 187 A1 proposes a round baler to solve this problem, in which the press roller that defines the discharge opening for the wrapped round bale can be disengaged from the drive via a clutch. This disengages the drive of the press roller that defines the discharge opening, allowing the press roller to rotate freely. When the discharge flap opens, the wrapped surface of the round bale rolling out of the discharge opening rests against the freely rotating press roller, so that only compressive forces are exerted on the bale and it experiences no additional stress.

[0006] However, such a mechanical decoupling of the press roller located at the discharge flap can only be achieved with considerable additional design effort. Furthermore, the complexity of the baler increases significantly due to the increased number of additional parts and components that must be attached to the round baler, particularly to the housing. An increase in the number of components always entails a higher susceptibility to failure, as additional parts are added that are subject to wear. Moreover, such a mechanical solution increases the cost of the round baler and necessitates additional maintenance measures, which negatively impact the baler's productivity and cost-effectiveness.

[0007] From US 2005 / 247215 A1, a baler with a sensor is also known that allows different positions of the discharge flap of the baler to be detected during its movement from the closed position to the open position, in which a formed bale can be discharged, and the speed of an actuator of the discharge flap to be controlled depending on this during the movement.

[0008] Based on the aforementioned prior art, the object of the present invention is therefore to provide a round baler which enables the ejection of the pressed and sheathed round bale without damaging the sheath and without decoupling the press rollers from the drive.

[0009] This problem is solved according to the invention by the features of independent claim 1, wherein advantageous further developments of the round baler according to the invention are the subject of the corresponding dependent claims 2 to 13.

[0010] Accordingly, the present invention relates to a round baler with a baler housing comprising a baling chamber, which has at least one fixed housing part and a discharge flap pivotably mounted on the fixed housing part between a closed position and an open position, with means for receiving and conveying crop material into the baling chamber, with press rollers driven by means of a drive, which are distributed on the fixed housing part and the discharge flap and are arranged circumferentially limiting the baling chamber, and with a device for encasing round bales pressed in the baling chamber from the supplied crop material with a covering.The round baler is characterized by at least one double-acting hydraulic cylinder, in particular a hydraulic cylinder, which is connected to the discharge flap and is configured to pivot the discharge flap reversibly between the closed position and the open position, and a proportional valve, preferably a 4 / 3-way proportional valve, which is connected to the at least one hydraulic cylinder for supplying, discharging and / or regulating a hydraulic medium, in particular a hydraulic fluid, and to a control device, wherein the control device is configured to actuate the proportional valve in such a way that an opening process of the discharge flap takes place either at a constant speed or with a variable speed, depending on a position of the discharge flap determined immediately after completion of a baling process.

[0011] The use of a proportional valve, controlled by a control unit, which supplies the double-acting hydraulic cylinder for pivoting the discharge flap with hydraulic fluid, allows the opening of the discharge flap for ejecting the compressed and wrapped round bale to be carried out in such a way that the opening speed is variable (i.e., during the opening process of the discharge flap, i.e., the pivoting of the discharge flap from its closed position to its open position, it is moved or pivoted at different speeds). This allows the discharge flap, and in particular the press roller located and driven at the lower edge of the discharge flap, to move ahead of the bale during ejection without contacting it. The flow rate of the hydraulic fluid is regulated by the control unit of the proportional valve.controlled so that, depending on the different positions the ejection flap assumes during its opening process, the ejection flap is moved or pivoted at different speeds.

[0012] The design envisions that the discharge flap will initially move or pivot very quickly from its closed position towards its open position. Shortly before reaching the open position, the speed of the discharge flap will be gradually reduced, and the flap will then be moved or pivoted into its open position at this reduced speed. This not only prevents the bale from being damaged by the press roller located at the lower edge of the discharge flap during the opening process, but also avoids damaging the mechanism for pivoting the discharge flap and / or its bearing on the stationary housing part due to excessive opening speed just before reaching the open position.at the moment the open position is reached, it is damaged because an inertia of the pressure medium circuit, which supplies the at least one pressure medium cylinder with pressure medium to move or pivot the discharge flap, could no longer guarantee timely and controlled deceleration of the discharge flap and the discharge flap, for example, travels at too high a speed against a stop defining the open position.

[0013] If the discharge flap has already assumed a certain (unintentional) open position after completion of the pressing process, for example because it has already opened slightly due to pressure exerted on the discharge flap during the pressing process, or because the discharge flap was opened for maintenance purposes before the actual pressing process but not completely closed again, the opening process can be carried out at a constant, in particular slower, speed.

[0014] This also ensures gentle ejection of the pressed and wrapped round bale, while simultaneously ensuring that a "misalignment" of the discharge flap does not lead to damage to the mechanism and / or bearings due to an excessively high opening speed of the discharge flap shortly before or when reaching the open position.

[0015] The integration of the proportional valve with the (intelligent) control unit, taking into account the position of the discharge flap after the baling process, allows for fully automatic control of the discharge flap opening. This eliminates the need for the operator of the round baler or any agricultural machinery to which the baler is connected to check the position of the discharge flap and manually control the opening process. The round baler, and in particular its control unit, automatically activates the proportional valve based on the position of the discharge flap, regulating the flow rate of the hydraulic fluid delivered to the at least one hydraulic cylinder according to the required discharge flap opening.

[0016] This eliminates the need for complex mechanical decoupling devices to deactivate the press roller located at the bottom of the discharge flap. Instead, it can continue to be driven during the opening process of the discharge flap without the risk of damaging the round bale.

[0017] According to an advantageous embodiment of the invention, it is provided that during the variable-speed opening process, the speed of the ejection flap varies between a first predetermined speed value and a second predetermined speed value, which is different from the first predetermined speed value, and during the constant-speed opening process, the speed of the ejection flap assumes the second predetermined speed value.

[0018] Varying the speed at which the discharge flap opens is particularly advantageous in preventing contact between the press roller and the bale casing during ejection. It also ensures that the mechanism and / or bearings of the discharge flap are not damaged. The discharge flap is initially moved or pivoted quickly and at a slower speed before reaching its open position. However, if the discharge flap is misaligned, it is only moved or pivoted at the slower speed. This is because the variable opening speed cannot guarantee that it will not damage the mechanism and / or bearings, as the discharge flap is not moved from its closed position but from an already open position, resulting in a shortened opening path.

[0019] According to a further advantageous embodiment of the invention, it is provided that the first predetermined speed value is greater than the second predetermined speed value.

[0020] In particular, the first predetermined speed value corresponds to a system-related maximum speed.

[0021] This ensures that the discharge flap moves in front of the round bale during ejection without making contact, until the flap's angle of rotation eliminates any possibility of contact. Furthermore, by moving or pivoting the flap at the beginning of the opening process, i.e., after the baling process is complete, at the system's maximum speed, high productivity of the round baler can be ensured, as ejection times can be kept to a minimum.

[0022] According to a further advantageous embodiment of the invention, it is provided that the first predetermined speed value and / or the second predetermined speed value is predetermined depending on operating parameters of the round baler and / or parameters of the round bale, preferably depending on an ejection speed of a pressed round bale.

[0023] This design allows the discharge flap to be moved or pivoted at a variable or constant speed, depending on the bale diameter, the press roller speed, the pressing pressure, the crop used and / or other parameters, in order to operate the round baler with maximum productivity and to produce round bales of maximum quality.

[0024] According to a further advantageous embodiment of the invention, the control device is designed to compare the position of the ejection flap determined immediately after completion of the pressing process with a first predetermined position value and, based on the comparison, to control the proportional valve in such a way as to initiate either the opening process at constant speed or the speed-variable opening process.

[0025] By comparing the position of the ejection flap with a first predetermined position value using the control device, it can be determined whether the ejection flap is in its intended closed position after completion of the pressing process and can therefore be opened at variable speeds, or whether there is a "malposition" in which an opening process can only take place at a constant speed to protect the mechanism and / or bearings.

[0026] According to a further advantageous embodiment of the invention, it is provided that if the position of the ejection flap determined immediately after completion of the pressing process falls below the first predetermined position value, the control device is configured to actuate the proportional valve in such a way that the speed of the ejection flap assumes the first predetermined speed value for the duration of a first predetermined time interval or until the ejection flap assumes a defined position value.

[0027] This causes the discharge flap, which is in the correct position (i.e., the closed position), to be moved or pivoted at the system's maximum speed immediately after the baling process is completed, particularly after receiving a signal to open the discharge flap generated by a user of the round baler or agricultural machine, or automatically generated by the control unit after the baling and wrapping process is completed. This ensures that the round bale or the wrapper of the round bale does not come into contact with the lower press roller of the discharge flap, while simultaneously maintaining a high level of productivity for the round baler.

[0028] According to a further advantageous embodiment of the invention, the control device is configured to iteratively compare a position of the discharge flap determined after the expiry, preferably immediately after the expiry, of the first predetermined time interval or upon reaching the defined position value with a second predetermined position value and to control the proportional valve based on the comparison, wherein, preferably, the control device is configured to trigger a new iteration loop after the expiry of a second predetermined time interval.

[0029] This checks whether the ejection flap has already reached a critical position during the opening process, which is close to the open position of the ejection flap, so that opening at the reduced speed becomes necessary to protect the mechanism and / or bearing from damage caused by an excessively high opening speed of the ejection flap.

[0030] According to a further advantageous embodiment of the invention, it is provided that if the position of the discharge flap determined after the expiry of the first predetermined time interval or upon reaching the defined position value in an iteration loop falls below the second predetermined position value and the speed of the discharge flap at this time exceeds the second speed value, the control device is configured to actuate the proportional valve in such a way that the speed of the discharge flap is reduced by a predetermined speed value or a percentage, preferably by 10%, per iteration loop until the position of the discharge flap determined after an iteration loop reaches or exceeds the second predetermined position value and / or the speed of the discharge flap reaches or falls below the second predetermined speed value.

[0031] Furthermore, according to the invention, if the position of the discharge flap determined after the expiry of the first predetermined time interval or upon reaching the defined position value assumes or exceeds the second predetermined position value and / or the speed of the discharge flap assumes or falls below the second predetermined speed value, the control device is configured to actuate the proportional valve in such a way that the speed of the discharge flap assumes the second predetermined speed value until the discharge flap has assumed the open position.

[0032] The opening speed of the discharge flap is gradually reduced to the slower second speed or speed value when the critical position is reached—that is, a predetermined position close to the fully open position. This protects both the components of the hydraulic fluid circuit and the mechanics and / or bearings. There is no abrupt reduction in speed, which would result in increased stress on the hydraulic fluid circuit components. Instead, the opening speed is gradually reduced to the second predetermined speed or speed value, ensuring that the discharge flap can be moved in a controlled manner to its fully open position.The second speed is chosen in such a way that the mechanics and / or bearings do not experience any excessive stress and / or damage when the ejection flap reaches the open position.

[0033] According to a further advantageous embodiment of the invention, it is provided that if the position of the ejection flap determined immediately after completion of the pressing process corresponds to or exceeds the first predetermined position value, the control device is configured to actuate the proportional valve in such a way that the speed of the ejection flap assumes the second predetermined speed value until the ejection flap has reached the open position.

[0034] This comparison, carried out by means of the control device, ensures that in the event of a "misalignment", the correct opening process, i.e., the opening process at a constant speed, is initiated.

[0035] According to a further advantageous embodiment of the invention, it is provided that the first predetermined position value is smaller in amount than the second predetermined position value.

[0036] In particular, the first predetermined position value is close to the position value of the closed position of the ejection flap, preferably deviating by up to 10% from the position value of the closed position in the direction of the open position, and the second predetermined position value is close to the position value of the open position of the ejection flap, particularly preferably at least 10% below the position value of the open position.

[0037] The definition of these limit values ​​ensures that the discharge flap opens at a variable speed, provided the opening position is only slightly open and damage to the mechanism and / or bearings can be ruled out, in order to maintain the productivity of the round baler. At the same time, it ensures that the speed reduction is initiated in good time before the opening position is reached, so that the mechanism and / or bearings are never damaged.

[0038] The limit values ​​can be set depending on parameters of the round baler, parameters of the pressed and / or the round bale to be pressed and / or the crop used.

[0039] According to a further advantageous embodiment of the invention, it is provided that the first predetermined time interval is at least one second, preferably 1.5 seconds, the second predetermined time interval is 5 milliseconds and / or the defined position value is smaller than or equal to the second predetermined position value.

[0040] Choosing the duration of the first time interval or setting the defined position value ensures that the opening process takes place at increased speed for a sufficient length of time, so that at no point during the entire opening process can contact the press rollers located and driven at the discharge flap with the outer shell of the round bale, which could lead to damage to the shell and thus impair the cohesion of the round bale.

[0041] The choice of the duration of the second time interval ensures that the speed reduction is rapid but controlled, in order to complete the opening process in a short time and to protect the components of the pressure medium circuit, the mechanics and / or bearings from unnecessarily high loads, especially in impulsive form.

[0042] The choice of the duration of the respective time interval or the determination of the defined position value can depend on parameters of the round baler, parameters of the pressed and / or the round bale to be pressed and / or the crop used.

[0043] According to a further advantageous embodiment of the invention, the round baler is characterized by a position sensor, in particular a rotary angle sensor, which is connected to the control device and which is configured to determine, preferably continuously, the position, in particular a positioning angle, of the discharge flap directly or indirectly.

[0044] This makes it particularly easy to determine the position of the discharge flap, which is necessary for carrying out the opening process and for the comparisons to be performed by the control unit. The position is preferably determined using a rotary angle sensor that detects the angle of the discharge flap, i.e., the angle of the discharge flap relative to the closed and / or open position, and transmits this information to the control unit via data transmission. The control unit needs this position(s) for the comparisons with the predefined position values. The position sensor can, for example, generate voltage signals based on which the control unit can deduce or calculate the position of the discharge flap.

[0045] It is also conceivable that the position of the discharge flap is determined via a position sensor in the area of ​​at least one pressure medium cylinder, which determines the position of the cylinder piston, from which the position of the discharge flap can be deduced by means of the control device.

[0046] The determination of the speed of the discharge flap, which is necessary at certain times during the opening process for comparison and decision-making purposes of the control device, can be carried out via the volume flow conveyed to the at least one pressure medium cylinder by means of the proportional valve or via one and / or more sensors that are arranged in the area of ​​the discharge flap.

[0047] The problem according to the invention is further solved by an agricultural machine with a round baler attached to the agricultural machine according to independent claim 14.

[0048] The problem according to the invention is further solved by a method for opening a discharge flap of a round baler according to independent claim 15.

[0049] The problem according to the invention is also solved by a computer program, in particular a computer program product, according to independent claim 16.

[0050] The present invention is described in more detail below with reference to the embodiments illustrated in the figures.

[0051] They show: Fig. 1: a schematic and exemplary view of a round baler according to the invention; Fig. 2: a schematic and exemplary block diagram of a pressure medium circuit for controlling a discharge flap of the round baler according to the invention, in particular the pressure medium cylinder(s) for moving or pivoting the discharge flap of the round baler according to the invention, according to FIG. 1 ; and Fig. 3: a schematic and exemplary flowchart of the inventive method for opening the discharge flap of the inventive round baler according to FIG. 1 .

[0052] FIG. 1Figure 1 shows a schematic and exemplary representation of an embodiment of the round baler 1 according to the invention. The round baler 1 has a baler housing 2, which consists of a stationary housing part 4 and a discharge flap 5 pivotally mounted on the stationary housing part 4. The discharge flap 5 is pivotally mounted on the stationary housing part 2 of the baler housing 2 such that it can be moved between a closed position PS and an open position P Ö. The baler housing 2, in particular the stationary housing part 4, is generally arranged on and connected to a chassis, via which the round baler 1 can in turn be coupled to an agricultural machine, in particular a tractor, which is not shown in the figures.

[0053] The press housing 2, in particular the two housing parts 4 and 5, define a press chamber 3 into which the harvested crop is conveyed by means 6 for picking up and conveying the crop from the ground. The means 6 comprise at least a so-called pick-up, with the aid of which the harvested crop is picked up from the ground of an agricultural area, and a rotor, with the aid of which the picked-up crop is guided into the press chamber 3.

[0054] Both the stationary housing part 4 and the discharge flap 5 have a plurality of press rollers 7, which are spaced apart from one another and distributed on both housing parts 4, 5, and arranged circumferentially to delimit the press chamber 3. Each of the press rollers 7 is driven by a drive (not shown in the figures), which forms or compresses the crop material conveyed into the press chamber 3 into a round bale. The round baler 1 also has a device (not shown in the figures) for encasing the round bales compressed in the press chamber 3 with a covering. As already mentioned, the covering can be a film, a net, and / or the like.

[0055] After the compressed round bale has been encased by the device, it must be ejected from the compression chamber 3. Within the scope of the present invention, this point in time is defined as after completion of the compression process. To enable the ejection of the round bale, the discharge flap 5 is moved or pivoted from its closed position PS to its open position P Ö after completion of the compression process by means of at least one double-acting hydraulic cylinder 8, in particular a double-acting hydraulic cylinder. The at least one hydraulic cylinder 8 is attached on one side to the stationary housing part 4 or the chassis and on the other side to the discharge flap 5. Preferably, the at least one hydraulic cylinder 8 is arranged in a lateral area so that it does not obstruct the ejected round bale. FIG. 1If only one such pressure medium cylinder 8 is shown, one such pressure medium cylinder 8 can be arranged on both the right and left sides, so that the ejection flap 5 can be moved or pivoted evenly.

[0056] During the opening of the discharge flap 5, the problem described above arises that the press roller 7, located at the lower edge of the discharge flap 5, continues to be driven and can come into contact with the wrapped round bale during the ejection process. This results in an increased risk of damage to the bale's covering due to the changing relative direction of rotation of both elements during the opening of the discharge flap 5.

[0057] To address this problem and to avoid the need for a complicated additional mechanical decoupling device on the round baler 1, a proportional valve 9, controlled by a control device not shown in the FIGS., is provided according to the invention. This valve is integrated into the pressure medium circuit, which is preferably a hydraulic circuit, and regulates the volume flow of the pressure medium supplied to the at least one pressure medium cylinder 8 in such a way that, depending on the position of the discharge flap 5 determined after completion of the pressing process, the opening process of the discharge flap 5 is either variable in speed or constant.

[0058] Within the scope of the present invention, the control device can either be part of the round baler 1 or part of an agricultural machine to which the round baler 1 is coupled. It is also conceivable that the control device is an external device that is neither part of the round baler 1 nor part of the agricultural machine, but communicates wirelessly with the components of the round baler 1 and / or the agricultural machine.

[0059] FIG. 2 Figure 1 shows a block diagram of a pressure medium circuit for supplying the at least one pressure medium cylinder 8, which includes the proportional valve 9 according to the invention. Even if in FIG. 2Since two hydraulic cylinders 8 are shown, each connected to the proportional valve 9, it is understood that only one hydraulic cylinder 8 can also be connected to the proportional valve 9 to move the discharge flap 5. The proportional valve 9 is preferably designed as a 4 / 3-way proportional valve, which has four ports and three switching positions, so that, depending on the selected switching position, hydraulic fluid can be supplied to or discharged from the annular space of the respective double-acting hydraulic cylinder 8 via a connection to a tank 10 provided on the agricultural machine and / or a hydraulic pump 11 via the hydraulic supply lines 12, 13, in order to move the discharge flap 5, which is operatively connected to the hydraulic cylinders 8, reversibly between the closed position PS and the open position P Ö during an opening or closing process.to pivot or to hold them in a closed or open position PS, Pö. Other configurations of the proportional valve are also conceivable.

[0060] The pressure medium circuit can further comprise a check valve 14, 15 assigned to each pressure medium supply line 12, 13, each of which can be unlocked via a so-called control line, as well as a pressure relief valve 16. Such valves 14, 15, 16 are well known in pressure medium circuits for actuating pressure medium cylinders in the context of baling presses, so that a detailed description is omitted within the scope of this invention.

[0061] Referring to FIG. 3 The control of the proportional valve 9 according to the invention by means of the control device for opening the discharge flap 5 of the round baler 1 is described below.

[0062] After the baling process of the round bale is complete, a signal is generated that triggers the opening of the discharge flap 5. This signal can be generated either by a user of the round baler 1 or the agricultural machine by operating a switch, button, lever, indicator, and / or the like after the baling process is complete, or automatically by the baler 1 and / or the agricultural machine, in particular by the control unit.

[0063] After initiation of the opening process, the current position P (the current angle P) of the discharge flap 5 is determined by means of a position sensor (not shown in the FIGS.), which is preferably designed as a rotary angle sensor. Under normal circumstances, this determined position P should correspond to the closed position PS of the discharge flap 5. However, it can also occur that the discharge flap 5 is already in the open position after completion of the pressing process. This condition can be caused, for example, by pressure generated in the pressing chamber 3 during the pressing process, or by the fact that the discharge flap 5 was opened before the pressing process, for example for maintenance reasons, but was not properly closed. In order to determine the position P after completion of the pressing process, the discharge flap 5 is opened by means of a position sensor.To initiate an opening process adapted to the specific case based on the position of the discharge flap 5, the position P of the discharge flap 5, determined after completion of the pressing process (or, according to the invention, immediately after completion of the pressing process), is compared by the control device with a first predeterminable or predefined position value P1 (a first predeterminable or predefined angle P1). This first position value P1 corresponds to a position value that is close to the position value of the closed position PS of the discharge flap 5. Preferably, this first position value P1 is up to 10% above the position value of the closed position PS, specifically in the direction of the open position P0 of the discharge flap 5.

[0064] Depending on the result of the comparison, the discharge flap 5 is either moved or pivoted at a variable speed or at a constant speed by the control device controlling the proportional valve 9 accordingly and regulating or controlling the volume flow of the pressure medium supplied to the at least one pressure medium cylinder 8.

[0065] If the position P determined after completion of the pressing process is less than the first position value P1, the discharge flap 5 is moved or pivoted towards its open position P0 at a first predeterminable or predefined speed or velocity value G1. This first velocity value G1 preferably corresponds to a system-related maximum speed at which the discharge flap 5 can be moved or pivoted. In response to the comparison, the control device generates a corresponding control signal for the proportional valve 9, so that it regulates or controls the volume flow of the pressure medium supplied to the at least one pressure medium cylinder 8 accordingly, and the discharge flap is moved or pivoted at the first velocity G1.

[0066] The discharge flap 5 is moved or pivoted at this initial velocity G1 for a specific, in particular predeterminable or predetermined, first time interval t1. Alternatively, the discharge flap 5 is moved or pivoted at this initial velocity G1 until it reaches a defined position value Pdef. This defined position value Pdef is also predeterminable or predetermined. After this initial time interval t1 has elapsed, or as soon as the discharge flap 5 reaches the defined position value Pdef, the current position P (the current angle P) of the discharge flap 5 is determined again using the position sensor. Simultaneously, the velocity G of the discharge flap 5 is determined.The position P of the discharge flap 5, determined after the first time interval t1 or upon reaching the defined position value Pdef, is compared by the control device with a second predetermined position value P2 (a second predetermined angle P2). This second position value P2 corresponds to a position value that is close to the position value of the open position PÖ of the discharge flap 5. Preferably, this second position value P2 is up to 10% below the position value of the open position PÖ. The velocity G of the discharge flap 5, determined at the same time, is compared by the control device with a second predetermined velocity G2. This second velocity G2 is lower, preferably significantly lower, than the first velocity G1.The second speed value G 2 is in particular a speed value that is so low that an overload and / or damage to the mechanism of the baler 1 and / or bearing of the discharge flap 5 on the stationary housing part 4 is excluded when the open position P Ö is reached.

[0067] Depending on the result of the comparison, the speed G of the discharge flap 5 is either gradually reduced or lowered, or moved or pivoted with the second speed G 2 to its open position P Ö by the control device controlling the proportional valve 9 accordingly and regulating or controlling the volume flow of the pressure medium.

[0068] If, after the first time interval t1 has elapsed or upon reaching the defined position value Pdef, the position Pd determined is less than the second position value P2 and the determined velocity G is greater than the second velocity or velocity magnitude G2, the velocity G of the discharge flap 5 is reduced by a predetermined velocity magnitude or percentage. Preferably, the velocity G of the discharge flap 5 is reduced by 10%. This process is repeated iteratively until a so-called termination condition is met, whereby after each iteration loop the current position Pd (the current angle Pc) and the velocity G of the discharge flap 5 are determined and compared with the second position value P2 or the second velocity or velocity magnitude G2.As soon as the position P of the discharge flap 5, determined after an iteration loop, reaches or exceeds the second position value P2, and / or the determined velocity G of the discharge flap 5 reaches or falls below the second velocity G2, the proportional valve 9 is actuated via the control device such that the flow rate of the pressure medium is regulated or controlled so that the discharge flap is moved or pivoted at the second velocity G2 to its open position P0. As soon as this position of the discharge flap 5 is reached, the opening process ends according to the flow diagram shown in [reference]. FIG. 3 . A new iteration loop is preferably performed every 5 milliseconds, so that the reduction or throttling of the velocity G of the ejection flap occurs in 5 steps.

[0069] It should be noted that the defined position value Pdef can coincide with the second predeterminable or predetermined position value P2. However, it is equally conceivable that the defined position value Pdef lies below the second predetermined position value P2 in the direction of the closing position PS of the ejection flap 5.

[0070] If the position P determined after completion of the pressing process is greater than or equal to the first position value P1, the discharge flap 5 is moved or pivoted towards its open position P0 at the second predeterminable or predetermined speed or speed value G2. The control device generates a corresponding control signal for the proportional valve 9, so that it regulates or controls the volume flow of the pressure medium supplied to the at least one pressure medium cylinder 8 accordingly, and the discharge flap 5 is moved or pivoted at the second speed G2.

[0071] If the discharge flap 5 is to remain closed, i.e., in its closed position PS, for example during the baling process of the round bale, a signal is generated indicating that the opening process of the discharge flap 5 is blocked. The speed G of the discharge flap 5 is then zero. As soon as the control unit receives an opening signal, the opening process of the discharge flap 5 is initiated. Alternatively, a time interval t 3 can be defined, whereby the control unit checks after the time interval t 3 has elapsed whether an opening signal has been generated or received, in which case the opening process of the discharge flap 5 must be initiated. The time interval t 3 is reset after elapsed if no opening signal has been generated or received.

[0072] By means of the above with reference to FIG. 3The described method for opening the discharge flap 5 of the round baler 1 can be implemented particularly easily by controlling the proportional valve 9 via the control unit and thereby controlling or regulating the flow rate of the hydraulic fluid supplied to the at least one hydraulic cylinder 8. This ensures that the discharge flap 5 is always opened for ejecting the round bales in such a way that a press roller 7 located at the lower edge of the discharge flap 5 never comes into contact with the outer layer of the wrapped round bale during the opening process. This allows the round bale to be ejected undamaged from the compression chamber 3 of the round baler 1. Furthermore, a so-called "misposition" of the discharge flap 5 can be detected, and an opening process for the discharge flap 5 can be initiated to address this condition.

[0073] The previously described procedure can be carried out by means of a computer program, in particular a computer program product, which includes commands that cause the control device to carry out the individual process steps, comparisons and other components of the procedure and to actuate the proportional valve 9 accordingly to regulate or control the volume flow of the pressure medium.

[0074] Although not described above, it is also conceivable within the scope of this invention that the ejection flap 5 can be moved or pivoted from the open position P Ö to the closed position PS according to the method described above. FIG. 3This can be achieved by first moving or pivoting the discharge flap 5 quickly and then slowly. It is also conceivable that the discharge flap 5 is moved or pivoted from its open position P Ö to its closed position PS at a constant speed. Reference symbol list

[0075] 1 Round baler 2 Baler housing 3 Baling chamber 4 Fixed housing part 5 Discharge flap 6 Means for picking up and conveying crop 7 Press rollers 8 Hydraulic cylinder 9 Proportional valve 10 Tank 11 Hydraulic pump 12 Hydraulic supply line 13 Hydraulic supply line 14 Unlockable check valve 15 Unlockable check valve 16 Pressure relief valve

Claims

1. A round baler (1) with a baler housing (2) having a baling chamber (3), the baler housing having at least one fixed housing portion (4) and an ejection gate (5) mounted on the fixed housing portion (4) pivotable between a closed position PS and an open position PO, with means (6) for picking up and conveying harvested material into the baling chamber (3), with baler rollers (7), driven by means of a drive, which are distributed on the fixed housing portion (4) and the ejection gate (5) and are disposed bordering the circumference of the baling chamber (3), and with a device for covering round bales compacted from the supplied harvested material in the baling chamber (3) with a cover, characterized by at least one double-acting pressurizing medium cylinder (8), in particular a hydraulic cylinder, which is connected to the ejection gate (5) and is configured to reversibly pivot the ejection gate (5) between the closed position PS and the open position PO, and a proportional valve (9), preferably a 4 / 3-way proportional valve, which is connected to the at least one pressurizing medium cylinder (8) in order to supply, remove and / or regulate a pressurizing medium, in particular a hydraulic fluid, and to a control device, wherein the control device is configured to actuate the proportional valve (9) in a manner such that an opening procedure of the ejection gate (5) is implemented either at a constant speed or at a variable speed as a function of a position P of the ejection gate (5) determined immediately after completion of a baling procedure.

2. The round baler (1) according to claim 1, characterized in that in the case of the variable-speed opening procedure, the speed G of the ejection gate (5) varies between a first predetermined speed value G1 and a second predetermined speed value G2, which is different from the first predetermined speed value G1, and in the case of the opening procedure at constant speed, the speed of the ejection gate (5) adopts the second predetermined speed value G2.

3. The round baler (1) according to claim 2, characterized in that the first predetermined speed value G1 is larger than the second predetermined speed value G2, wherein preferably, the first predetermined speed value G1 corresponds to a system-related maximum speed.

4. The round baler (1) according to claim 2 or claim 3, characterized in that the first predetermined speed value G1 and / or the second predetermined speed value G2 is predetermined as a function of operating parameters of the round baler (1) and / or of parameters of the round bale, preferably as a function of an ejection speed of a compacted round bale.

5. The round baler (1) according to one of claims 1 to 4, characterized in that the control device is configured to compare the position P of the ejection gate (5) determined immediately after completion of the baling procedure with a first predetermined position value P1 and, based on the comparison, to actuate the proportional valve (9) in a manner such that either the constant-speed opening procedure or the variable-speed opening procedure is initiated.

6. The round baler (1) according to claim 5, characterized in that if the position P of the ejection gate (5) determined immediately after completion of the baling procedure is below the first predetermined position value P1, the control device is configured to actuate the proportional valve (9) in a manner such that the speed G of the ejection gate (5) adopts the first predetermined speed value G1 and in fact for the duration of a first predetermined time interval t1 or until the ejection gate (5) takes up a defined position value Pdef.

7. The round baler (1) according to claim 6, characterized in that the control device is configured to iteratively compare a position P of the ejection gate (5) determined after the expiration, preferably immediately after the expiration, of the first predetermined time interval t1 or upon reaching the defined position value Pdef, with a second predetermined position value P2 and to actuate the proportional valve (9) on the basis of the comparison, wherein preferably, the control device is configured to initiate a new iteration loop after each expiration of a second predetermined time interval t2.

8. The round baler (1) according to claim 7, characterized in that if the position P of the ejection gate (5) determined in an iteration loop after the expiration of the first predetermined time interval t1 or upon reaching the defined position value Pdef is below the second predetermined position value P2 and the speed G of the ejection gate (5) exceeds the second speed value G2 at this point in time, the control device is configured to actuate the proportional valve (9) in a manner such that the speed G of the ejection gate (5) per iteration loop is reduced by a predetermined speed value or by a percentage, preferably by 10%, and in fact until the position P of the ejection gate (5) after an iteration loop takes up or exceeds the second predetermined position value P2 and / or the speed G of the ejection gate (5) adopts or is below the second predetermined speed G2.

9. The round baler (1) according to claim 8, characterized in that if the position P of the ejection gate (5) determined after the expiration of the first predetermined time interval t1 or upon reaching the defined position value Pdef takes up or exceeds the second predetermined position value P2 and / or the speed G of the ejection gate (5) adopts or is below the second predetermined speed value G2, the control device is configured to actuate the proportional valve (9) in a manner such that the speed G of the ejection gate (5) adopts the second predetermined speed value G2 and in fact until the ejection gate (5) has taken up the open position PO.

10. The round baler (1) according to claim 5, characterized in that if the position P of the ejection gate (5) determined immediately after completion of the baling procedure corresponds to the first predetermined position value P1 or exceeds it, the control device is configured to actuate the proportional valve (9) in a manner such that the speed G of the ejection gate (5) adopts the second predetermined speed value G2 and in fact until the ejection gate has taken up the open position PO.

11. The round baler (1) according to one of claims 7 to 10, characterized in that the value for the first predetermined position value P1 is smaller than the second predetermined position value P2, wherein the first predetermined position value P1 is close to the position value of the closed position PS of the ejection gate (5), preferably differs from the position value of the closed position PS in the direction of the open position PO by up to 10%, and the second predetermined position value P2 is close to the position value of the open position PO of the ejection gate (5), particularly preferably at least 10% below the position value of the open position PO.

12. The round baler (1) according to one of claims 6 to 11, characterized in that the first predetermined time interval t1 is at least one second, preferably 1.5 seconds, the second predetermined time interval t2 is 5 milliseconds and / or the defined position value Pdef is smaller than the second predetermined position value P2 or corresponds thereto.

13. The round baler (1) according to one of claims 1 to 12, characterized by a position sensor, in particular a rotary angle sensor, which is connected to the control device and is configured to directly or indirectly determine, preferably continuously, the position P, in particular a turning angle, of the ejection gate (5).

14. An agricultural working machine, characterized in that a round baler (1) according to one of claims 1 to 13 is attached to the agricultural working machine.

15. A method for opening an ejection gate (5) of a round baler (1) according to one of claims 1 to 13, characterized in that the method comprises the following method steps: a) receiving a signal for opening the ejection gate (5) after completion of a baling procedure, b) determining, immediately after completion of a baling procedure, a position P, preferably a turning angle P, of the ejection gate (5) after receiving the signal for opening the ejection gate (5) and comparing the determined position P with a first predetermined position value P1, preferably a first predetermined turning angle P1, c) if the position P determined in method step b) is below the first predetermined position value P1, pivoting the ejection gate (5) at a first predetermined speed G1 and in fact for a first predetermined time interval t1 or until the ejection gate (5) reaches a defined position value Pdef, d) after the expiration of the first predetermined time interval t1 or reaching the defined position value Pdef in method step c), determining the position P and the speed G of the ejection gate (5), comparing the determined position P with a second predetermined position value P2, preferably a second predetermined turning angle P2, and comparing the speed G with a second predetermined speed G2, e) if the position P of the ejection gate (5) determined in method step d) is smaller than the second predetermined position value P2 and the speed G is larger than the second predetermined speed G2, reducing the speed G of the ejection gate (5) by a predetermined speed value or by a percentage, preferably by 10%, and repeating the method step d), preferably after the expiration of a second predetermined time interval t2, f) if the position P of the ejection gate (5) determined in method step d) takes up the second predetermined position value P2 or exceeds it and / or the speed G adopts or is below the second predetermined speed G2, pivoting the ejection gate (5) at the second predetermined speed G2 and in fact until an open position PO of the ejection gate (5) is reached, g) if the position P determined in method step b) takes up the first predetermined position value P1 or exceeds it, pivoting the ejection gate (5) at the second predetermined speed G2 and in fact until the open position PO of the ejection gate (5) is reached.

16. A computer program, in particular a computer program product, characterized in that the computer program comprises commands which, during the execution of the program by a control device of the round baler according to one of claims 1 to 13, cause it to implement the method according to claim 15.