DK145443B

DK145443B - KNIFE ARRANGEMENT FOR A HARVEST MACHINE

Info

Publication number: DK145443B
Application number: DK220980A
Authority: DK
Inventors: K Oxfeldt
Original assignee: Taarup As Maskinfab
Priority date: 1980-05-21
Filing date: 1980-05-21
Publication date: 1982-11-22
Also published as: DK145443C; FR2482821A1; FR2482821B3; GB2075813A; DK220980A

Description

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Opfindelsen angår et knivarrangement for en høstmaskiné', navnlig en majshøster, og som består af to cirkulære, indbyrdes overlappende knivskiver, som er forsynet med fortanding, og som under høstmaskinens drift roterer 5 således, at de i overlapningszonen bevæger sig imod høstmaskinens køreretning.BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a knife arrangement for a harvesting machine, in particular a corn harvester, consisting of two circular, overlapping cutter blades, which are toothed and rotate during operation of the harvesting machine so that they move in the overlapping zone towards the direction of the harvesting machine.

Formålet med den foreliggende opfindelse er at angive en udførelsesform, ved hvilken man i væsentlig grad nedsætter risikoen for, at stem eller andre hårde genstande 10 kommer i klemme mellem knivenes tænder, og derved kunne beskadige knivene eller disses drivorganer, og dette formål opnås ifølge opfindelsen ved, at vinklen mellem hver tands i rotationsretningen forreste tandside og tangenten gennem tandspidsen til tandspidsens bevægelsescirkel er mindre end 15 eller lig med vinklen mellem en radius til tandskiven gennem skæringspunktet for de to tandskivers tandspidsers bé-vægelsescirkler og forbindelseslinien mellem de to tandskivers rotationscentre.The object of the present invention is to provide an embodiment whereby substantially reducing the risk of the stem or other hard objects 10 getting trapped between the teeth of the blades, thereby damaging the blades or their driving means, and this object is achieved according to the invention. in that the angle between the front tooth side of each tooth in the direction of rotation and the tangent through the tooth tip to the tooth circle movement circle is less than 15 or equal to the angle between a radius to the tooth disk through the intersection of the two circular tooth movement points of the tooth and the connecting line between the two tooth rotation centers.

Ved at udforme knivene på den angivne måde sikres, at de 1 20 rotationsretningen forreste tandsider under rotation tidligst når knivene begynder at overlappe hinanden kan nå en stilling, hvor vinklen mellem en tandside på den ene kniv og en tandside på den anden kniv bliver hul. Derfor vil der ikke dannes "lommer" mellem knivenes tænder, og knive-25 nes nævnte tandsider vil i alt væsentlig skubbe hårdere genstande væk, således at risiko for alvorlig beskadigelse af knivene undgås. Denne virkning er end ikke afhængig af, om knivskiverne roterer med samme hastighed.Designing the blades in the manner indicated ensures that the front tooth sides during rotation at the earliest when the blades begin to overlap can reach a position where the angle between a tooth side of one knife and a tooth side of the other knife becomes hollow. Therefore, "pockets" will not form between the teeth of the blades, and the said tooth sides of the blades will substantially push harder objects away, thus avoiding the risk of serious damage to the blades. This effect does not depend on whether the knife blades rotate at the same speed.

Ved et sådant knivarrangement vil der ofte anvendes eh 30 tandform, hvor tandsiderhe er krumme, og ved en sådan udførelsesform skal ovenstående betingelser også være opfyldt, idet det ifølge opfindelsen fastlægges, at den teoretiske tandspids er beliggende på skæringslinien mellem en radius gennem tandens toppunkt og den tangent til den i 35 omdrejningsrétningen forreste tandsidé, som danner den 145443 2 største vinkel med tangenten i den teoretiske tandspids til dennes bevægelsesbane, idet den forreste tandside fastlægges som den nævnte tangent.In such a knife arrangement, a tooth shape will often be used in which tooth sides are curved, and in such an embodiment, the above conditions must also be met, according to the invention that the theoretical tooth tip is located on the intersection of a radius through the vertex of the tooth and the tangent to the front tooth face in the direction of rotation which forms the largest angle with the tangent of the theoretical tooth tip to its path of movement, the front tooth side being determined as said tangent.

Opfindelsen skal i det følgende beskrives nærmere i forbindelse med tegningen, hvor 5 fig. 1 viser delvis overlappende dele af tandskiverne i et knivarrangement ifølge opfindelsen, og fig* 2 viser en del af en særlig udførelsesform for en tandskive til et sådant knivarrangement.The invention will now be described in more detail in connection with the drawing, in which: 1 shows partially overlapping portions of the tooth discs of a knife arrangement according to the invention, and FIG. 2 shows part of a particular embodiment of a tooth disc for such a knife arrangement.

I fig. 1 ses indbyrdes delvis overlappende dele af to kniv-10 skiver 1 og 2 som er indrettet til at rotere i de med pilene 3 og 4 angivne retninger. Anbragt i en høstmaskine er dette knivarrangement beregnet på at fremføres i den med pilen 5 angivne retning for afskæring af afgrøde.In FIG. 1, partially overlapping portions of two knife 10 washers 1 and 2 are arranged to rotate in the directions indicated by arrows 3 and 4. Located in a harvesting machine, this knife arrangement is intended to be advanced in the direction of crop cutting indicated by arrow 5.

Tandskiverne 1 og 2 er forsynet med tænder henholdsvis 6 15 og 7, hvis i rotationsretningen forreste tandsider, henholdsvis 8 og 9 er retlinede. Tandspidserne er betegnet henholdsvis 10 og 11, og en tangent til bevægelsesbanen for tand-spidseme 10 er betegnet 12, medens en radius for tandskiven 1 gennem skæringspunktet for bevægelsesbanerne for 20 tandspidserne 10 og 11 er betegnet 13. En forbindelseslinie mellem centrum for de to tandskiver 1 og 2 er betegnet 14, og vinklen α mellem denne linie og den nævnte radius 13 er med den viste udførelsesform netop lig med vinklen β mellem tandsiden 8 og tangenten 12. Herved op-25 nås, at de to tandsider 8a og 9a netop mødes, når de er indbyrdes parallelle. Gøres vinklen β mindre end vinklen a, vil tandsideme 8a og 9a endnu skræve, når de når den viste stilling. 1 fig. 2 ses et stykke af en tandskive 15, som har tænder 30 16, hvis i rotationsretningen forreste tandsider 17 er krumme. Ved tilpasning af sådanne tandskiver efter oven-angivne regel fastlægges en teoretisk tandspids 18 somThe toothed discs 1 and 2 are provided with teeth 6 and 7, respectively, if the front teeth, 8 and 9, respectively, are rectilinear in the direction of rotation. The tooth tips are designated 10 and 11, respectively, and a tangent to the path of movement of the tooth tips 10 is designated 12, while a radius of the tooth disc 1 through the intersection of the paths of movement of the tooth tips 10 and 11 is designated 13. A connecting line between the center of the two tooth discs 1 and 2 are denoted 14, and the angle α between this line and said radius 13 is, in the embodiment shown, exactly equal to the angle β between the tooth side 8 and the tangent 12. Hereby it is achieved that the two tooth sides 8a and 9a meet precisely , when parallel to each other. If the angle β is smaller than the angle a, the tooth sides 8a and 9a will still slant when they reach the position shown. 1 FIG. 2 shows a piece of a toothed disc 15 having teeth 30 16 in the direction of rotation of the front tooth sides 17 being curved. When fitting such tooth discs to the above rule, a theoretical tooth tip 18 is determined as