A forage harvester comprising an edge sharpness detection device for detecting a degree of edge sharpness of a cutting mechanism. The cutting mechanism comminutes a stream of harvested material, with a material inflow area being defined where the cutting blades interact with the shear bar to comminute the harvested material. The edge sharpness detection device excites one or more magnetic circuits, with the respective magnetic circuit being closed by the respective cutting blade during rotation of the cutter drum once one of the cutting blades passes the magnetic assembly. The edge sharpness detection device detects the magnetic flux in the respective magnetic circuit and, based on a detected change, determines a degree of edge sharpness of the respective cutting blade. Further, the magnetic flux of the magnetic circuit may be guided lengthwise in the cutting blade at least along a longitudinal section of the respective cutting blade.

A forage harvester including a frame, a cutting arrangement and a plurality of displacement mechanisms. The cutting arrangement includes a cutting drum that is rotatable about a rotation axis with respect to the frame, and a shear bar holder configured to receive a shear bar attached thereto. Each of the displacement mechanisms including an actuator for displacing the shear bar with respect to the cutting drum and the frame. The displacement mechanisms include a sensor arrangement to measure one or more values representative of a force exerted on the shear bar and the shear bar holder when the cutting drum is rotating and cutting crops supplied to an area between the cutting drum and the shear bar.

A method for sharpening cutting knives carried by a cutter drum in a housing of an agricultural vehicle includes: rotating the cutter drum while keeping a sharpening door closed so an overpressure is created inside the housing, the sharpening door shielding a sharpening stone from the cutting knives while creating the overpressure; opening a transition door of the housing below the cutter drum to eject crop material through the open transition door; opening the sharpening door to expose the cutting knives to the sharpening stone and closing the transition door; grinding one or more of the cutting knives with the exposed sharpening stone; and closing the sharpening door to shield the sharpening stone from the cutting knives after grinding.

A driver assistance system of an agricultural work machine constructed as forage harvester, wherein the agricultural work machine comprises a header for gathering crop, a chopping device having a chopping drum and chopping knives for comminuting the crop, and a monitoring device operable to generate a signal containing information about the wear status of the respective chopping knife and/or about the distance of the cutting edge of a chopping knife from a shear bar. This information is compared with a reference value, and the agricultural work machine has activation devices for activating and deactivating a knife grinding process and means for change of position of the shear bar. The monitoring device is integrated in the driver assistance system so that the driver assistance system automatically detects when a knife grinding process or a change of position of the shear bar must be activated or deactivated.

A driver assistance system of an agricultural work machine constructed as forage harvester, wherein the agricultural work machine comprises a header for gathering crop, a chopping device having a chopping drum and chopping knives for comminuting the crop, and a monitoring device operable to generate a signal containing information about the wear status of the respective chopping knife and/or about the distance of the cutting edge of a chopping knife from a shear bar. This information is compared with a reference value, and the agricultural work machine has activation devices for activating and deactivating a knife grinding process and means for change of position of the shear bar. The monitoring device is integrated in the driver assistance system so that the driver assistance system automatically detects when a knife grinding process or a change of position of the shear bar must be activated or deactivated.

A detection arrangement for detecting a wear status of a chopping knife arrangement of a chopping device provided for processing a product flow, wherein the chopping device has a revolving chopping drum receiving the chopping knife arrangement and at least one shear bar which cooperates with the chopping knives, with a sensor arrangement which has a magnetic exciter arrangement and a flux conducting device magnetically coupled thereto. The sensor arrangement provides a pole arrangement which forms at least one magnetic pole with a pole surface for conducting magnetic flux, wherein at least a portion of the chopping knife passes the pole arrangement during a rotation of the chopping drum. A voltage induced when a chopping knife arrangement passes the sensor arrangement forms the measured magnetic value, which is used by the evaluation unit to determine the state of wear of the chopping knife arrangement.

A self-sharpening knife used inside an agricultural machine to cut and mix balls of hay or other food destined for animals consumption. The knife comprises a generally triangular steel plate whose base is right or rounded. The base is provided with a series of teeth, each of the teeth includes a pastille made of a material harder than steel and self-sharpening. The pastilles end by a cutting edge having a contour which forms the cutting edge of a tooth.

The width of a pastille exceeds that of the steel and ends in a point which becomes round over cuts because of wear. The pastilles wearing out less quickly than steel thus causing that over cuts the width of the pastilles will always exceed the width of the steel. The pastilles cut until all their length and width are worn. The material of the pastille can be carbide or diamond.

A self-sharpening knife used inside an agricultural machine to cut and mix balls of hay or other food destined for animals consumption. The knife comprises a generally triangular steel plate whose base is right or rounded. The base is provided with a series of teeth, each of the teeth includes a pastille made of a material harder than steel and self-sharpening. The pastilles end by a cutting edge having a contour which forms the cutting edge of a tooth.

The width of a pastille exceeds that of the steel and ends in a point which becomes round over cuts because of wear. The pastilles wearing out less quickly than steel thus causing that over cuts the width of the pastilles will always exceed the width of the steel. The pastilles cut until all their length and width are worn. The material of the pastille can be carbide or diamond.

A detection arrangement for detecting a state of wear of a chopping assembly comprises at least one magnet arrangement which includes a magnetic excitation arrangement and a flux-conducting device magnetically coupled thereto. The magnet arrangement provides a pole arrangement which forms at least one magnetic pole for outwardly conducting magnetic flux. At least one portion of the chopping blades moves past the pole arrangement during a rotation of the cutting cylinder, and forms an air gap arrangement including at least one air gap with respect to the pole arrangement and, as a result, at least one magnetic circuit excited by the excitation arrangement is closed via the chopping blade. At least one portion of the magnetic flux generated by the magnetic excitation arrangement is longitudinally guided in the chopping blade at least across one longitudinal portion of the chopping blade.

A detection arrangement for detecting a state of wear of a chopping assembly comprises at least one magnet arrangement which includes a magnetic excitation arrangement and a flux-conducting device magnetically coupled thereto. The magnet arrangement provides a pole arrangement which forms at least one magnetic pole for outwardly conducting magnetic flux. At least one portion of the chopping blades moves past the pole arrangement during a rotation of the cutting cylinder, and forms an air gap arrangement including at least one air gap with respect to the pole arrangement and, as a result, at least one magnetic circuit excited by the excitation arrangement is closed via the chopping blade. At least one portion of the magnetic flux generated by the magnetic excitation arrangement is longitudinally guided in the chopping blade at least across one longitudinal portion of the chopping blade.