DE102019006409A1 - Device for automatic lowering and load-dependent lifting of a lifting axle - Google Patents

Abstract

Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21), which has one or more devices (34) for automatically lowering a raised lifting axle (21) which is at the front or rear in relation to the direction of travel (39) when the loading area is tilted up and inclined (8) of a motor vehicle or a motor vehicle trailer (50) and one or more devices (51) for load-dependent lifting of a front or rear lifting axle (21) a) with a horizontally aligned loading area (8) one in relation to the direction of travel (39) Motor vehicle or a motor vehicle trailer (50) and b) only if the weight on the loading area (8) falls below a predeterminable maximum and includes a hydraulic device (41), the device (34) for automatic lowering and the device (51) for load-dependent lifting are in direct or indirect connection with the hydraulic device (41) or the device (34) for automatic lowering and the device (51) for load-dependent lifting, individually or together, are components of the hydraulic device (41).

Description

The present invention relates to a device for automatically lowering and load-dependent lifting of a lifting axle, with the features specified in claim 1.

Tandem axles with a lifting axle are known from the prior art, which can be raised independently of the load resting on the loading area.

A major disadvantage of these known tandem axles for motor vehicles or motor vehicle trailers with non-load-dependent but always liftable lifting axles can be seen in the fact that there, for legal reasons, the lifting axle may only be raised when the trailer is unloaded as a maneuvering aid while the trailer is being moved manually .

These known tandem axles are also disadvantageous because the lifting axle can be raised there - accidentally or intentionally - although the axle load remaining on the load axle alone is then greater than the maximum permissible axle load of the load axle. This creates the risk of axle breakages on the load axles and / or other component damage.

The object of the present invention is therefore to provide a device with the use of which the lifting axle of a tandem axle - not only when the loading area is unladen - but also when the loading area is partially loaded up to the permissible axle load of the load axle remaining on the ground and - not only as a maneuvering aid during manual shifting - but even while a trailer is being driven, may be lifted for legal reasons and which safely prevents the accidental or intentional lifting of the lifting axle of a tandem axle if - after lifting the lifting axle - the axle load remaining on the load axle alone is greater than the maximum permissible axle load of the load axle.

According to the invention, this object is achieved in a device of the generic type by the features specified in claim 1. Particularly preferred embodiments are the subject of the subclaims.

• 1 eine Seitenansicht eines Kraftfahrzeug-Anhängers (50) mit einer horizontal ausgerichteten, nicht aufgekippten Ladefläche (8) und mit einer eine Liftachse (21) und eine Lastachse (42) umfassenden Tandemachse, wobei die Liftachse (21) - mittels der erfindungsgemäßen Vorrichtung (4) zum automatischen Absenken und lastabhängigen Anheben - von dem Untergrund (38) in vertikaler Richtung nach oben angehoben ist, während die Lastachse (42) auf dem Untergrund (38) aufliegt, wobei sich das Bedienelement (59) des Umschaltventiles (35) - aufgrund der horizontal ausgerichteten Ladefläche (8) und des daher noch eingehakten hakenförmigen Verschlusses (48) der Verriegelungseinrichtung (47) - in der Stellung „Anheben“ (59) befindet und das an der Welle (53) der Verriegelungseinrichtung (47) ansetzende Fußpedal (54) in eine nach unten tretbare, zumindest etwas nach oben weisende Stellung ausgerichtet ist, wobei eine an dem freien Ende des mittels der Hubwelle (23) nach oben geschwenkten Steuerhebels (17) rotierbar angebrachte Steuerrolle (18) auf der Unterseite einer an dem freien Ende (7) des Schwenkarmes (2) der Liftachse (21) angebrachte Steuerfläche (20) - bei vertikaler Anhebung der Liftachse (21) - einwirkt;
• 2 eine Seitenansicht eines Kraftfahrzeug-Anhängers (50) mit einer horizontal ausgerichteten, nicht aufgekippten Ladefläche (8) und mit einer eine Liftachse (21) und eine Lastachse (42) umfassenden Tandemachse, wobei die Liftachse (21) und die Lastachse (42) auf dem Untergrund (38) aufliegen, wobei sich das Bedienelement (59) des Umschaltventiles (35) - aufgrund der horizontal ausgerichteten Ladefläche (8) und des daher noch eingehakten hakenförmigen Verschlusses (48) der Verriegelungseinrichtung (47) - in der Stellung „Anheben“ (59) befindet und das an der Welle (53) der Verriegelungseinrichtung (47) ansetzende Fußpedal (54) in eine nach unten tretbare, zumindest etwas nach oben weisende Stellung ausgerichtet ist, wobei eine an dem freien Ende des mittels der Hubwelle (23) nach unten geschwenkten Steuerhebels (17) rotierbar angebrachte Steuerrolle (18) von der in 2 - durch den Hubzylinder (13) und die Rückzugsfeder (14) - verdeckten Steuerfläche (20) - bei auf dem Untergrund (38) ruhender Liftachse (21) - beabstandet ist;
• 3 einen Hydraulikplan für eine erfindungsgemäße Vorrichtung (4) zur Versorgung des Hubzylinders (13) mit einer Hydraulikflüssigkeit, wobei die Ladefläche (8) in horizontale Ausrichtung abgekippt ist und ein Umschaltventil (35) zum Umschalten zwischen „Anheben“ und „Absenken“ des Hubzylinders (13) zwischen dem Hubzylinder (13) und der Hydraulikflüssigkeit-Pumpe (37) vorgesehen ist und wobei das Bedienelement (59) des Umschaltventiles (35) in die Stellung (58) - entspricht „Anheben“ der Liftachse (21) - ausgerichtet ist;
• 4 einen Hydraulikplan für eine erfindungsgemäße Vorrichtung (4) zur Versorgung des Hubzylinders (13) mit einer Hydraulikflüssigkeit, wobei die Ladefläche (8) in schräge Ausrichtung aufgekippt ist und ein Umschaltventil (35) zum Umschalten zwischen „Anheben“ und „Absenken“ des Hubzylinders (13) zwischen dem Hubzylinder (13) und der Hydraulikflüssigkeit-Pumpe (37) vorgesehen ist und wobei das Bedienelement (59) des Umschaltventiles (35) in die Stellung (60) - entspricht „Absenken“ der Liftachse (21) - ausgerichtet ist;
• 5 eine schematische, ausschnittsweise Unteransicht der in 1 dargestellten Tandemachse mit auf dem Untergrund (38) ruhender Lastachse (42) und von dem Untergrund (38) nach oben angehobener Liftachse (21), von schräg unten und hinten, wobei der Steuerhebel (17) der Hubeinrichtung (4) nach oben weisend ausgerichtet ist und die an dem freien Ende des Steuerhebels (17) angebrachte Steuerrolle (18) mit der an dem freien Ende (7) des Schwenkarmes (2) der Liftachse (21) vorgesehenen Steuerfläche (20) - unter Anhebung der Liftachse (21) - in Verbindung kommt;
• 6 eine schematische, ausschnittsweise Draufsicht der in 2 dargestellten Tandemachse mit auf dem Untergrund (38) ruhender Lastachse (42) und Liftachse (21), von schräg oben und vorne, wobei der Steuerhebel (17) in horizontaler Ausrichtung in Richtung Fahrzeugheck (46) nach hinten weist, so dass die an dem freien Ende des Steuerhebels (17) angebrachte Steuerrolle (18) in vertikaler Hinsicht von der an dem freien Ende (7) des Schwenkarmes (2) der Liftachse (21) angebrachten Steuerfläche (20) in vertikaler Hinsicht beabstandet ist;
• 7 eine schematische, ausschnittsweise Draufsicht der in den 2 und 6 dargestellten Tandemachse mit auf dem Untergrund (38) ruhender Lastachse (42) und Liftachse (21), von oben, wobei der Steuerhebel (17) in horizontaler Ausrichtung in Richtung Fahrzeugheck (46) nach hinten weist, so dass die an dem freien Ende des Steuerhebels (17) angebrachte Steuerrolle (18) in vertikaler Hinsicht von der an dem freien Ende (7) des Schwenkarmes (2) der Liftachse (21) angebrachten Steuerfläche (20) in vertikaler Hinsicht beabstandet ist;
• 8 eine schematische, ausschnittsweise Seitenansicht der in den 2, 6 und 7 dargestellten Tandemachse mit auf dem Untergrund (38) ruhender Lastachse (42) und Liftachse (21), wobei - aus Gründen der Übersichtlichkeit - der zwischen der Befestigungslasche (16) an dem Querrahmen (9) einerseits und dem Anlenkhebel (15) der Hubwelle (23) andererseits wirkende Hubzylinder (13) und die zugehörige, zu dem Hubzylinder (13) parallel verlaufende Rückzugsfeder (14) nicht dargestellt sind und wobei der Steuerhebel (17) in horizontaler Ausrichtung in Richtung Fahrzeugheck (46) nach hinten weist, so dass die an dem freien Ende des Steuerhebels (17) angebrachte Steuerrolle (18) in vertikaler Hinsicht von der an dem freien Ende (7) des Schwenkarmes (2) der Liftachse (21) angebrachten Steuerfläche (20) in vertikaler Hinsicht beabstandet (67) ist, wobei der zwischen dem Steuerhebel (17) und dem Anlenkhebel (15) - bei einer Seitenbetrachtung - eingeschlossener Winkel α dargestellt ist;
• 9 eine schematische, ausschnittsweise Seitenansicht der in den 1 und 5 dargestellten Tandemachse mit auf dem Untergrund (38) ruhender Lastachse (42) und von dem Untergrund (38) angehobener Liftachse (21), wobei - aus Gründen der Übersichtlichkeit - der zwischen der Befestigungslasche (16) an dem Querrahmen (9) einerseits und dem Anlenkhebel (15) der Hubwelle (23) andererseits wirkende Hubzylinder (13) und die zugehörige, zu dem Hubzylinder (13) parallel verlaufende Rückzugsfeder (14) nicht dargestellt sind, wobei der Steuerhebel (17) in nahezu vertikaler Ausrichtung, nach oben in Richtung der Vertikalen weisend ausgerichtet ist, so dass zwischen der Linie (22), welche zwischen dem geometrischen Mittelpunkt (24) der Querschnittsfläche der Hubwelle (23) und dem vorsprungartigen oder aussparungsförmigen Anbringungsort (27) der Steuerrolle (18) an dem Steuerhebel (17) verläuft, einerseits und der Linie (19), welche entlang der Unterseite der Steuerfläche (20) verläuft, andererseits, ein Winkel γ eingeschlossen ist und wobei die an dem freien Ende des Steuerhebels (17) angebrachte Steuerrolle (18) mit der Steuerfläche (20) - zu dem Zwecke einer Anhebung der Liftachse (21) - in Kontakt steht;
• 10 eine schematische, ausschnittsweise Ansicht der in den 1 und 2 von der Seite her dargestellten Einrichtung (34) zum automatischen Absenken einer angehobenen Liftachse (21), welche ein Bestandteil der erfindungsgemäßen Hubeinrichtung (4) ist - und zugleich auch eine Verriegelungseinrichtung (47) darstellt - das an der Deichsel (52) eines Anhängers (50), zur reversibel lösbaren Aufnahme eines frontseitig (55) an der kippbaren Ladefläche (8) angebrachten Verriegelungselementes (47) vorgesehen ist, von schräg unten und hinten, wobei das Bedienelement (59) des Umschaltventiles (35) - mittels einer zwischen dem Längsrahmen (11) und dem Bedienelement (59) wirkenden Feder (31) - in der Stellung (58) „Anheben der Liftachse (21)“ gehalten wird, der hakenförmige, schwenkbare Verschluss (48) der Verriegelungseinrichtung (47) in Eingriff mit dem Verriegelungselement (57) in dem Frontbereich (55) der horizontal ausgerichteten Ladefläche (8) gehalten wird und wobei das Fußpedal (54) für den rotativen Antrieb der Welle (53) der Verriegelungseinrichtung (47) in einer tretbaren Ausrichtung, etwas nach oben weisend und angehoben, vorgesehen ist;
• 11 eine schematische, ausschnittsweise Ansicht einer Einrichtung (34) zum automatischen Absenken einer angehobenen Liftachse (21), welche ein Bestandteil der erfindungsgemäßen Hubeinrichtung (4) ist und zugleich auch eine Verriegelungseinrichtung (47) darstellt, die an der Deichsel (52) eines Anhängers (50), zur reversibel lösbaren Aufnahme eines frontseitig (55) an der kippbaren Ladefläche (8) angebrachten Verriegelungselementes (47), angebracht ist, von schräg unten und hinten, wobei die Ladefläche (8) in eine schräge Ausrichtung aufgekippt ist, wobei das Bedienelement (59) des Umschaltventiles (35) - mittels einer zwischen dem Steueraufsatz (56) an der Welle (53) zur Betätigung des Umschaltventiles (35) einerseits und dem Bedienelement (59) des Umschaltventiles (35) andererseits wirkendenden Feder (66) - in der Stellung (60) „Absenken der Liftachse (21)“ gehalten wird, der hakenförmige, schwenkbare Verschluss (48) dieser Einrichtung (34, 47, 4) das Verriegelungselement (57) im Frontbereich (55) der aufgekippten Ladefläche (8) freigibt, wobei das Fußpedal (54) für den rotativen Antrieb der Welle (53) der Verriegelungseinrichtung (47) in einer getretenen Ausrichtung, etwas nach unten weisend, vorgesehen ist und wobei der Winkel δ dargestellt ist, welcher zwischen dem Steueraufsatz (56) und dem Verriegelungshaken (48) - bei einer seitlichen Betrachtung entlang der Steuerwelle (53) - eingeschlossen ist;
• 12 eine schematische, ausschnittsweise Seitenansicht einer erfindungsgemäßen Hubeinrichtung (4), welche insbesondere den in Richtung der Vertikalen aufgerichteten Steuerhebel (17) - mit der an dessen freiem Ende angebrachter Steuerrolle (18) - und eine entlang der Unterseite der Steuerfläche (20) verlaufender Linie (19) zeigt, wobei zwischen der Linie (19) und der Linie (22) - zwischen dem geometrischen Mittelpunkt (24) der Querschnittsfläche der Hubwelle (23) einerseits und dem vorsprungartigen oder aussparungsförmigen Anbringungsort (27) der Steuerrolle (18) an dem Steuerhebel (17) andererseits - ein Winkel γ eingeschlossen ist, wobei zwischen der Totpunkt-Linie (68) - welche eine gedachte Linie darstellt, die von dem Kontaktpunkt (69) zwischen dem äußeren Umfang der Steuerrolle (18) einerseits und der Unterseite der Steuerfläche (20) andererseits, bei in Richtung der Vertikalen hochgeschwenktem Steuerhebel (17), ausgeht und der Linie (22) ein Reserve-Winkel η - zur Verhinderung eines „Überschnappens“ [= Durchrollen der Steuerrolle (18) entlang der Unterseite der Steuerfläche (20) über den Totpunkt hinaus] des Steuerhebels (17) - eingeschlossen ist, wobei die Steuerfläche (20) mittels einer Halterung (29) an dem freien Ende (7) des zugehörigen Schwenkarmes (2) anbringbar ist, wobei die Steuerfläche (20) - in einer Seitenbetrachtung - eine gerade Ausbildung aufweist und wobei die entlang der Unterseite der Steuerfläche (20) verlaufende gedachte Linie (19) in etwa parallel zu der Längsachse des Schwenkarmes (2) ausgerichtet und von dieser beabstandet ist.

Embodiments of the invention are described in more detail with reference to the drawings. Show it:

• 1 a side view of a motor vehicle trailer ( 50 ) with a horizontally aligned, not tipped loading area ( 8th ) and with one a lift axle ( 21 ) and a load axis ( 42 ) comprehensive tandem axle, whereby the lift axle ( 21 ) - by means of the device according to the invention ( 4th ) for automatic lowering and load-dependent lifting - from the ground ( 38 ) is lifted upwards in the vertical direction, while the load axis ( 42 ) on the ground ( 38 ) rests, with the control element ( 59 ) of the switching valve ( 35 ) - due to the horizontally aligned loading area ( 8th ) and the hook-shaped clasp ( 48 ) the locking device ( 47 ) - in the "raise" position ( 59 ) and that on the shaft ( 53 ) the locking device ( 47 ) attaching foot pedal ( 54 ) is aligned in a downwardly stepable, at least slightly upwardly facing position, with one at the free end of the lifting shaft ( 23 ) swiveled up control lever ( 17th ) rotatably mounted control roller ( 18th ) on the bottom one at the free end ( 7th ) of the swivel arm ( 2 ) the lift axle ( 21 ) attached control surface ( 20th ) - when the lifting axle is raised vertically ( 21 ) - acts;
• 2 a side view of a motor vehicle trailer ( 50 ) with a horizontally aligned, not tipped loading area ( 8th ) and with one a lift axle ( 21 ) and a load axis ( 42 ) comprehensive tandem axle, whereby the lifting axle ( 21 ) and the load axis ( 42 ) on the ground ( 38 ) with the control element ( 59 ) of the switching valve ( 35 ) - due to the horizontally aligned loading area ( 8th ) and the hook-shaped clasp ( 48 ) the locking device ( 47 ) - in the "raise" position ( 59 ) and that on the shaft ( 53 ) the locking device ( 47 ) attaching foot pedal ( 54 ) is aligned in a downwardly stepable, at least slightly upwardly facing position, with one at the free end of the lifting shaft ( 23 ) swiveled down control lever ( 17th ) rotatably mounted control roller ( 18th ) from the in 2 - through the lifting cylinder ( 13th ) and the return spring ( 14th ) - hidden control surface ( 20th ) - at on the ground ( 38 ) stationary lifting axle ( 21 ) - is spaced;
• 3 a hydraulic plan for a device according to the invention ( 4th ) to supply the lifting cylinder ( 13th ) with a hydraulic fluid, whereby the loading area ( 8th ) is tilted in a horizontal position and a switch valve ( 35 ) to switch between "raising" and "lowering" the lifting cylinder ( 13th ) between the lifting cylinder ( 13th ) and the hydraulic fluid pump ( 37 ) is provided and where the control element ( 59 ) of the switching valve ( 35 ) to the position ( 58 ) - corresponds to "lifting" the lifting axle ( 21 ) - is aligned;
• 4th a hydraulic plan for a device according to the invention ( 4th ) to supply the lifting cylinder ( 13th ) with a hydraulic fluid, whereby the loading area ( 8th ) is tilted up at an angle and a switch valve ( 35 ) to switch between "raising" and "lowering" the lifting cylinder ( 13th ) between the lifting cylinder ( 13th ) and the hydraulic fluid pump ( 37 ) is provided and where the control element ( 59 ) of the switching valve ( 35 ) to the position ( 60 ) - corresponds to "lowering" the lifting axle ( 21 ) - is aligned;
• 5 a schematic, partial bottom view of the in 1 shown tandem axle with on the ground ( 38 ) static load axis ( 42 ) and from the subsurface ( 38 ) lift axle raised upwards ( 21 ), diagonally from below and behind, whereby the control lever ( 17th ) of the lifting device ( 4th ) facing upwards and the one on the free end of the control lever ( 17th ) attached control roller ( 18th ) with the one at the free end ( 7th ) of the swivel arm ( 2 ) the lift axle ( 21 ) provided control surface ( 20th ) - while raising the lifting axle ( 21 ) - comes in contact;
• 6th a schematic, partial plan view of the in 2 shown tandem axle with on the ground ( 38 ) static load axis ( 42 ) and lift axle ( 21 ), diagonally above and in front, with the control lever ( 17th ) horizontally towards the rear of the vehicle ( 46 ) points backwards so that the one on the free end of the control lever ( 17th ) attached control roller ( 18th ) vertically from the one at the free end ( 7th ) of the swivel arm ( 2 ) the lift axle ( 21 ) attached control surface ( 20th ) is vertically spaced;
• 7th a schematic, partial plan view of the in the 2 and 6th shown tandem axle with on the ground ( 38 ) static load axis ( 42 ) and lift axle ( 21 ), from above, with the control lever ( 17th ) horizontally towards the rear of the vehicle ( 46 ) points backwards so that the one on the free end of the control lever ( 17th ) attached control roller ( 18th ) vertically from the one at the free end ( 7th ) of the swivel arm ( 2 ) the lift axle ( 21 ) attached control surface ( 20th ) is vertically spaced;
• 8th a schematic, partial side view of the in the 2 , 6th and 7th shown tandem axle with on the ground ( 38 ) static load axis ( 42 ) and lift axle ( 21 ), whereby - for the sake of clarity - the one between the fastening tab ( 16 ) on the cross frame ( 9 ) on the one hand and the linkage lever ( 15th ) of the lifting shaft ( 23 ) on the other hand acting lifting cylinder ( 13th ) and the associated one for the lifting cylinder ( 13th ) parallel return spring ( 14th ) are not shown and the control lever ( 17th ) horizontally towards the rear of the vehicle ( 46 ) points backwards so that the one on the free end of the control lever ( 17th ) attached control roller ( 18th ) vertically from the one at the free end ( 7th ) of the swivel arm ( 2 ) the lift axle ( 21 ) attached control surface ( 20th ) vertically spaced ( 67 ), where the one between the joystick ( 17th ) and the linkage lever ( 15th ) - when viewed from the side - included angle α is shown;
• 9 a schematic, partial side view of the in the 1 and 5 shown tandem axle with on the ground ( 38 ) static load axis ( 42 ) and from the subsurface ( 38 ) raised lifting axle ( 21 ), whereby - for the sake of clarity - the one between the fastening tab ( 16 ) on the cross frame ( 9 ) on the one hand and the linkage lever ( 15th ) of the lifting shaft ( 23 ) on the other hand acting lifting cylinder ( 13th ) and the associated one for the lifting cylinder ( 13th ) parallel return spring ( 14th ) are not shown, the control lever ( 17th ) is aligned in an almost vertical orientation, pointing upwards in the direction of the vertical, so that between the line ( 22nd ), which is between the geometric center ( 24 ) the cross-sectional area of the lifting shaft ( 23 ) and the protrusion-like or recess-shaped mounting location ( 27 ) the control roller ( 18th ) on the control lever ( 17th ) runs, on the one hand and the line ( 19th ) running along the bottom of the control surface ( 20th ) runs, on the other hand, an angle γ is included and where the at the free end of the control lever ( 17th ) attached control roller ( 18th ) with the control surface ( 20th ) - for the purpose of raising the lifting axle ( 21 ) - is in contact;
• 10 a schematic, partial view of the in the 1 and 2 Facility shown from the side ( 34 ) for the automatic lowering of a raised lifting axle ( 21 ), which is a component of the lifting device according to the invention ( 4th ) is - and at the same time also a locking device ( 47 ) represents - the one on the drawbar ( 52 ) of a trailer ( 50 ), for reversibly detachable mounting of a front ( 55 ) on the tilting loading area ( 8th ) attached locking element ( 47 ) is provided, from diagonally below and behind, whereby the control element ( 59 ) of the switching valve ( 35 ) - by means of one between the longitudinal frame ( 11 ) and the control element ( 59 ) acting spring ( 31 ) - in the position ( 58 ) "Raising the lifting axle ( 21 ) "Is held, the hook-shaped, swiveling lock ( 48 ) the locking device ( 47 ) in engagement with the Locking element ( 57 ) in the front area ( 55 ) the horizontally aligned loading area ( 8th ) is held and the foot pedal ( 54 ) for the rotary drive of the shaft ( 53 ) the locking device ( 47 ) is provided in a step-on orientation, slightly facing up and raised;
• 11 a schematic, partial view of a facility ( 34 ) for the automatic lowering of a raised lifting axle ( 21 ), which is a component of the lifting device according to the invention ( 4th ) is and at the same time also a locking device ( 47 ) that is attached to the drawbar ( 52 ) of a trailer ( 50 ), for reversibly detachable mounting of a front ( 55 ) on the tilting loading area ( 8th ) attached locking element ( 47 ) from below and at an angle, with the loading area ( 8th ) is tilted up in an oblique orientation, whereby the control element ( 59 ) of the switching valve ( 35 ) - by means of a between the tax attachment ( 56 ) on the shaft ( 53 ) to operate the switching valve ( 35 ) on the one hand and the control element ( 59 ) of the switching valve ( 35 ) on the other hand acting spring ( 66 ) - in the position ( 60 ) "Lowering the lifting axle ( 21 ) "Is held, the hook-shaped, swiveling lock ( 48 ) this facility ( 34 , 47 , 4th ) the locking element ( 57 ) in the front area ( 55 ) of the tipped loading area ( 8th ) releases, whereby the foot pedal ( 54 ) for the rotary drive of the shaft ( 53 ) the locking device ( 47 ) is provided in a stepped orientation, pointing slightly downwards, and where the angle δ is shown, which is between the control attachment ( 56 ) and the locking hook ( 48 ) - when viewed from the side along the control shaft ( 53 ) - is included;
• 12th a schematic, partial side view of a lifting device according to the invention ( 4th ), which in particular controls the control lever ( 17th ) - with the control roller attached to its free end ( 18th ) - and one along the bottom of the control surface ( 20th ) running line ( 19th ) shows, where between the line ( 19th ) and the line ( 22nd ) - between the geometric center point ( 24 ) the cross-sectional area of the lifting shaft ( 23 ) on the one hand and the protrusion-like or recess-shaped mounting location ( 27 ) the control roller ( 18th ) on the control lever ( 17th ) on the other hand - an angle γ is included, with between the dead center line ( 68 ) - which represents an imaginary line starting from the contact point ( 69 ) between the outer circumference of the control roller ( 18th ) one hand and the underside of the control surface ( 20th ) on the other hand, with the control lever swiveled up in the direction of the vertical ( 17th ), goes out and the line ( 22nd ) a reserve angle η - to prevent "snapping over" [= rolling through the control roller ( 18th ) along the bottom of the control surface ( 20th ) beyond dead center] of the control lever ( 17th ) - is included, where the control surface ( 20th ) by means of a bracket ( 29 ) at the free end ( 7th ) of the associated swivel arm ( 2 ) can be attached, whereby the control surface ( 20th ) - viewed from the side - has a straight design and where the along the underside of the control surface 20th ) running imaginary line ( 19th ) roughly parallel to the longitudinal axis of the swivel arm ( 2 ) is aligned and spaced from this.

As already from the 1 to 12th is apparent, the present invention relates in particular to a device ( 4th ) for automatic lowering and load-dependent lifting of a lifting axle ( 21 ).

As a rule, this device ( 4th ) initially one or more institutions ( 34 ) for the automatic lowering of a raised lifting axle ( 21 ) include.

The phrase "automatic lowering" of a raised lifting axle means in the context of the present invention that the device ( 34 ) - for the automatic lowering of a raised lifting axle ( 21 ) - for example, in relation to the direction of travel ( 39 ), the front or rear lifting axle ( 21 ) can at least then automatically, automatically and forcibly lower down, a) as soon as the loading area ( 8th ) a motor vehicle or a motor vehicle trailer ( 50 ) is tilted up and inclined and / or b) as soon as the on the loading area ( 8th ) the weight on the load is greater than a specifiable, maximum permissible limit value, e.g. for the axle load of the load axle ( 42 ) is.

In general, the device comprises ( 4th ) - especially for the load-dependent lifting of the lifting axle ( 21 ) - in addition to the facility ( 34 ), one or more institutions ( 51 ) for load-dependent lifting of one in relation to the direction of travel ( 39 ) front or rear lifting axle ( 21 ).

In the context of the present invention, the term "load-dependent lifting" means that the lifting axle ( 21 ) is only possible if a) the loading area ( 8th ) a motor vehicle or motor vehicle trailer aligned horizontally and b) the one on the loading area ( 8th ) onerous weight is less than a specifiable maximum weight. The "specifiable maximum weight" is, for example, the weight that is used as the maximum axle load for the load axle ( 42 ) is permissible.

As a rule, the device according to the invention comprises ( 4th ) in addition to the facilities ( 34 ) and ( 51 ) a hydraulic device ( 41 ).

In general, the facilities ( 34 ) and ( 51 ) in direct or indirect connection with the hydraulic system ( 41 ). Alternatively, the facilities ( 34 ) and ( 51 ) - individually or together - components of the hydraulic system ( 41 ) be.

As a rule, the one or more institutions ( 34 ) for the automatic lowering of a raised lifting axle ( 21 ) with tilted, inclined loading area ( 8th ) a motor vehicle or a motor vehicle trailer ( 50 ) each be designed in such a way that they have at least one locking device ( 47 ) include.

This locking device ( 47 ) can be used for releasable locking of the front section of the tilting loading area ( 8th ) on the frame of a motor vehicle or on the drawbar ( 52 ) of a motor vehicle trailer ( 50 ) to serve. The locking device ( 47 ), for example, a right angle to the longitudinal axis of the drawbar ( 52 ) or the control shaft aligned with the vehicle ( 53 ) include.

In preferred embodiments of the device according to the invention ( 4th ) this control shaft ( 53 ) by means of a foot pedal ( 54 ) rotatable, indirectly or directly on the drawbar ( 52 ) or the longitudinal frame ( 11 ) of a motor vehicle can be attached.

As a rule, the control shaft ( 53 ) a locking hook ( 48 ) and a tax attachment ( 56 ).

The tax attachment ( 56 ) and the locking hook ( 48 ) - when viewed from the side along the control shaft ( 53 ) - an angle δ which is in the range from 5.0 ° to 40.0 °, preferably in the range from 9.0 ° to 35.0 °, in particular in the range from 12.0 ° to 30.0 ° (see 11 ).

The 10 shows that the hook-shaped, pivoting lock ( 48 ) the locking device ( 47 ) and that frictionally on the control shaft ( 53 ) attached foot pedal ( 54 ) - when viewed from the side along the control shaft ( 53 ) - an angle ε which is in the range from 30.0 ° to 80.0 °, preferably in the range from 35.0 ° to 75.0 °, in particular in the range from 39.0 ° to 71.0 °.

The locking hook ( 48 ) corresponding and releasably engaging to a locking element that protrudes vertically downwards ( 57 ) of the front section ( 55 ) the loading area ( 8th ) be trained.

In particularly preferred embodiments of the device according to the invention ( 4th ) is the one on the control shaft ( 53 ) intended tax attachment ( 56 ) directly or indirectly with a control element ( 59 ) of a hydraulic switching valve ( 35 ) the hydraulic equipment ( 41 ) in a positively driven connection.

As a rule, this control element enables ( 59 ) a switchover of the switchover valve ( 35 ) the hydraulic equipment ( 41 ) for a hydraulic fluid flow ( 61 ) between a position ( 58 ) to raise the lifting axle ( 21 ) and a position ( 60 ) to lower the lifting axle ( 21 ).

This coupling between the control shaft ( 53 ) and control element ( 59 ) of the hydraulic switching valve ( 35 ) the hydraulic equipment ( 41 ) means that when - by pressing the foot pedal ( 54 ) conditional - separation of the connection between the locking hook on the drawbar side ( 48 ) and the locking element ( 57 ) the loading area ( 8th ) automatically, automatically and forcibly also a lowering of a raised lifting axle ( 21 ) he follows.

Within the scope of the present invention, the one or more devices ( 51 ) for load-dependent lifting of a lifting axle ( 21 ) with horizontally aligned loading area ( 8th ) a motor vehicle or a motor vehicle trailer ( 50 ) one or more hydraulic devices ( 41 ), in each of which one or more electrically or manually operated hydraulic pumps ( 37 ) are provided (see in particular 3 and 4th ).

In general, the hydraulic equipment ( 41 ) contained one or more hydraulic pumps ( 37 ) with one or more lifting cylinders ( 13th ) - for the direct or indirect lifting of the lifting axle ( 21 ) - for example via one or more hydraulic lines ( 61 ) are directly or indirectly connected.

especially the 3 and 4th show that downstream of each lifting cylinder ( 13th ) one or more pressure relief valves ( 63 ) can be provided. These pressure relief valves ( 63 ) downstream directly or indirectly with a hydraulic fluid tank ( 64 ) stay in contact.

In particular, the pressure relief valve (s) ( 63 ) by means of one or more setting devices ( 65 ) on each maximum permissible - on the loading area ( 8th ) allowed - pressure to raise the lift axle ( 21 ) be adjustable.

As a rule, this maximum permissible pressure can be, for example, the maximum permissible axle load of the load axle remaining on the ground ( 42 ) correspond.

In this case, an indirect or direct lifting of the lifting axle ( 21 ) by means of one or more lifting cylinders ( 13th ) - due to the opening of the pressure relief valve (s) ( 63 ) - not possible if this is on the loading area ( 8th ) weight is greater than that of the adjustment device ( 65 ) of the pressure relief valve ( 63 ) specified limit value of the maximum permissible axle load of the load axle remaining on the ground ( 42 ).

In particularly preferred embodiments of the device according to the invention ( 4th ) the setting device ( 65 ) of the pressure relief valve ( 63 ) be designed to be sealable and thus prevent improper intervention.

The provision of this pressure relief valve ( 63 ) also has the advantage that when the loading area is loaded - for example by means of a crane ( 8th ) with a weight that is greater than that using the setting device ( 65 ) specified limit value [e.g. maximum permissible axle load of the) load axle ( 42 )] of the pressure relief valve ( 63 ) is, the pressure relief valve ( 63 ) opens automatically, automatically and with forced control so that the lifting cylinder ( 13th ) - and thus an automatic lowering of the lifting axle ( 21 ) - he follows.

From the 3 and 4th also shows that the lifting cylinder ( 13th ) the hydraulic equipment ( 41 ) via one or more hydraulic lines ( 61 ) with one or more electrically and / or manually operated hydraulic pumps ( 37 ) is in direct or indirect connection, with the upstream side of the lifting cylinder ( 13th ) a switching valve ( 35 ) can be provided.

With the help of this switching valve ( 35 ) can - in the "raise" position ( 58 ) - on the one hand, a continuous connection between the lifting cylinder ( 13th ) and the hydraulic pump ( 37 ) can be produced. The switching valve ( 35 ) can - in the "lowering" position ( 60 ) - on the other hand, the connection between the lifting cylinder ( 13th ) and the hydraulic pump ( 37 ) and instead a connection between the lifting cylinder ( 13th ) and the hydraulic fluid tank ( 64 ) produce. In preferred embodiments of the device according to the invention ( 4th ) can be placed between the lifting cylinder ( 13th ) and the switching valve ( 35 ) one or more one-way flow control valves ( 44 ) - to adjust the return speed of the hydraulic fluid in the hydraulic fluid tank ( 64 ) - be provided (see 3 and 4th ).

Preferably between the lifting cylinder ( 13th ) and the hydraulic fluid tank ( 64 ) a pressure relief valve ( 63 ) should be provided, which opens automatically, automatically and with forced control when the loading area ( 8th ) is loaded with a weight that is greater than the permissible axle load of the load axle ( 42 ) is.

In addition to this, if necessary, upstream of the switching valve ( 35 ) one or more hand valves ( 62 ) for manual lowering of the raised lifting axle ( 21 ) with horizontal loading area ( 8th ) be provided.

In particularly preferred embodiments of the device according to the invention ( 4th ) can in the case of the establishment ( 51 ) for load-dependent lifting of a lifting axle ( 21 ) both the load axis ( 42 ) as well as the lift axle ( 21 ) one between their two swivel arms ( 2 ) located axis of rotation ( 1 ) for their two swivel arms ( 2 ) exhibit.

At the two free ends ( 7th ) of each swivel arm ( 2 ) one or more rotating wheels ( 3 ) be attached directly or indirectly.

As a rule, the institution ( 51 ) for load-dependent lifting of a lift axle ( 21 ) a right angle to the longitudinal axis of the vehicle ( 40 ; please refer 5 ) aligned and around its geometric cross-section center ( 24 ) rotatably mounted lifting shaft ( 23 ) include.

Preferably, on the outer circumference of the lifting shaft ( 23 ) a link lever ( 15th ) for engagement of, for example, between the transverse frame ( 9 ) and the linkage lever ( 15th ) Pressure effect-developing lifting cylinder ( 13th ) be provided stationary.

As a rule, the lifting cylinder ( 13th ) on the one hand to a protrusion-like or recess-shaped mounting location ( 28 ) on the linkage lever ( 15th ) of the lifting shaft ( 23 ) and on the other hand directly or indirectly on the transverse frame ( 9 ) or the longitudinal frame ( 11 ) act.

The distance between the geometric center ( 24 ) of the lifting shaft ( 23 ) and the location ( 28 ) of the lifting cylinder ( 13th ) on the linkage lever ( 15th ) can, for example, be in the range from 4.0 cm to 15.0 cm, preferably in the range from 5.0 cm to 13.0 cm, in particular in the range from 7.0 cm to 11.0 cm.

In particularly preferred embodiments of the device according to the invention ( 4th ) can be placed on the outer circumference of the lifting shaft ( 23 ), on which the link lever ( 15th ) is attached, a control lever ( 17th ) be provided stationary.

This control lever ( 17th ) can in the area of its free end - at the protrusion-like or recess-shaped attachment point ( 27 ) for the tax roller ( 18th ) - one or more rotatable control rollers ( 18th ) wear (see in particular 5 , 7th and 12th ).

In particular from 8th shows that - when viewed from the side - the control lever ( 17th ) and the linkage lever ( 15th ) in the form of a letter V one behind the other and V-shaped offset from one another, on the lifting shaft ( 23 ) are provided and the opening angle pointing vertically upwards α this V-shaped offset - when viewed from the side - can for example be in the range from 45 ° to 85 °, preferably in the range from 48 ° to 82 °, in particular in the range from 50 ° to 75 °.

Already 12th it can be seen that in the area of the inside of the lifting / swivel arm ( 2 ) the lift axle ( 21 ) and in the area of its free end ( 7th ), a slide-rail-shaped or taxiway-shaped control surface ( 20th ) - in an almost parallel alignment to the longitudinal axis of the swivel arm ( 2 ) the lift axle ( 21 ) - indirectly via a bracket ( 29 ) or can be provided immediately.

Usually the one on the free end of the control lever ( 17th ) in the installation location ( 27 ) rotatably mounted control roller ( 18th ) on the underside of the control surface ( 20th ) roll off at least in sections when the linkage lever ( 15th ) of the lifting shaft ( 23 ) with the help of the between the pivot lever ( 15th ) and for example the cross frame ( 9 ) acting lifting cylinder ( 13th ) is extended to its full length.

During this rolling movement of the control roller ( 18th ) along the bottom of the control surface ( 20th ) the control lever ( 17th ) with the one in the mounting location ( 27 ) control roller attached to it ( 18th ) pushed up and thereby the lift axle ( 21 ) lifted up in the vertical direction.

As in particular from the 5 , 6th and 7th one can see a parallel to the lifting cylinder ( 13th ) running return spring ( 14th ) - for the purpose of retraction of the lifting cylinder ( 13th ) and a vertical lowering of the lifting axle ( 21 ) on the ground ( 38 ) - the linkage lever ( 15th ) of one - because of the maximum expansion of the hydraulic cylinder ( 13th ) - retract the deflected position into an oppositely inclined position.

In particular 8th shows that when the wheel is resting ( 3 ) the lift axle ( 21 ) on the ground ( 38 ) the tax role ( 18th ) from the bottom of the control surface ( 20th ) at a distance ( 67 ) can be spaced apart, for example in the range from 40.0 mm to 110.0 mm, preferably in the range from 50.0 mm to 100.0 mm, in particular in the range from 70.0 mm to 90.0 mm , lies.

• wobei: I = Länge des Hubzylinders (13); r = Radius der Steuerrolle (18) an dem Steuerrollen-Anbringungsort (27) auf dem freien Ende des Steuerhebels (17);
• v = horizontaler Abstand zwischen dem geometrischen Querschnittsmittelpunkt (= Anbringungsort 27) der Steuerrolle (18) einerseits und der jeweiligen Drehachse (1) am Rahmenvorsprung (10) für den Hub-Schwenkarm (2) andererseits;
• β_o = eingeschlossener Winkel zwischen einer Linie, welche parallel zu der schienenförmigen Steuerfläche (20) der Führung (29) für die Steuerrolle (18) verläuft, einerseits und einer durch den geometrischen Mittelpunkt (=Anbringungsort 27) der Steuerrolle (18) gedachten vertikalen Linie, andererseits; h = vertikaler Abstand zwischen dem geometrischen Querschnittsmittelpunkt (= Anbringungsort 27) der Steuerolle (18) einerseits und einer gedachten horizontalen Linie andererseits, welche durch die Drehachse (1) des Lift-Schwenkarmes (2) horizontal verläuft.

In preferred embodiments of the device according to the invention ( 4th ) the geometrical relationships between a) the protrusion-like or recess-shaped mounting location ( 28 ) of the lifting cylinder ( 13th ) on the linkage lever ( 15th ) of the lifting shaft ( 23 ) on the one hand and b) the protrusion-like or recess-shaped mounting location ( 27 ) the control roller ( 18th ) on the control lever ( 17th ) of the lifting shaft ( 23 ) on the other hand and c) the axis of rotation ( 1 ) of the respective lifting / swivel arm ( 2 ), follow the following formula: $$\text{l}-\text{r}-\text{v}\cdot \text{sin}{\mathrm{\beta }}_{\text{O}}-\text{H}\cdot \text{cos}{\mathrm{\beta }}_{\text{O}}=0;$$

• where: I = length of the lifting cylinder ( 13th ); r = radius of the control roller ( 18th ) at the control roller mounting location ( 27 ) on the free end of the control lever ( 17th );
• v = horizontal distance between the geometric cross-section center ( = Location 27 ) the control roller ( 18th ) on the one hand and the respective axis of rotation ( 1 ) on the frame protrusion ( 10 ) for the swivel arm ( 2 ) on the other hand;
• β _o = included angle between a line which is parallel to the rail-shaped control surface ( 20th ) the leadership ( 29 ) for the tax roller ( 18th ) runs, on the one hand and one through the geometric center point (= attachment point 27 ) the control roller ( 18th ) imaginary vertical line, on the other hand; h = vertical distance between the geometric cross-section center ( = Location 27 ) the tax role ( 18th ) on the one hand and an imaginary horizontal line on the other hand, which passes through the axis of rotation ( 1 ) of the lift swivel arm ( 2 ) runs horizontally.

especially the 9 and 12th show that - in a side view - between one along the bottom of the control surface ( 20th ) running and in the direction of the respective swivel arm ( 2 ) associated axis of rotation ( 1 ) pointing line ( 19th ) on the one hand and a line ( 22nd ) between the geometric center point ( 24 ) the cross-sectional area of the lifting shaft ( 23 ) on the other hand, an angle γ is included, which are for example in the range from 140.0 ° to 90.0 °, preferably in the range from 130.0 ° to 90.0 °, in particular in the range from 120.0 ° to 90.0 ° can.

How 12th can be seen, - with the lifting cylinder extended to the maximum ( 13th ) and thus the control lever swiveled maximally in the direction of the vertical ( 17th ) - in the contact point then reached ( 69 ) between the outer circumference of the control roller ( 18th ) of the control lever ( 17th ) one hand and the underside of the control surface ( 20th ) on the other hand a dead center line ( 68 ) perpendicular to the line through the contact point ( 69 ) and along the bottom of the control surface ( 20th ) running line ( 19th ) stand.

Also the 12th it can be seen that in this contact point ( 69 ) the line ( 22nd ) between the geometric center point ( 24 ) the cross-sectional area of the lifting shaft ( 23 ) and the protrusion-like or recess-shaped mounting location ( 27 ) the control roller ( 18th ) on the control lever ( 17th ) on the one hand, and the dead center line ( 68 ) on the other hand, an angle η may include, which, for example, in the range from 0.5 ° to 50.0 °, preferably in the range from 0.7 ° to 40.0 °, in particular in the range from 0.9 ° to 30.0 ° can.

Compliance with this angle η can be used as a "reserve" to the dead center line ( 68 ) and as a measure to prevent the control lever from "snapping over" ( 17th ) to serve.

In the context of the present invention, the above term "snapping over" means in particular swinging the control lever ( 17th ) over the dead center line ( 68 ) out in the direction of the swivel movement of the control lever ( 17th ) or overturning the control lever ( 17th ) over the dead center line ( 68 ) out in a direction opposite to the axis of rotation ( 1 ) of the associated swivel arm ( 2 ) is to understand.

The 12th also shows that - when viewed from the side along the underside of the control surface ( 20th ) running line ( 19th ) - for example essentially tangential to that during the pivoting process of the control lever ( 17th ) from the control roller ( 18th ) swept swivel radius can be aligned.

In particularly preferred embodiments of the device according to the invention ( 4th ) the distance between the control surface ( 20th ) and the line ( 19th ) on the one hand and the geometric center point ( 24 ) the cross-sectional area of the lifting shaft ( 23 ) on the other hand, be at least slightly shorter than this swivel radius swept over, so that the angle γ (please refer 9 and 12th ) is always at least slightly larger than 90 °.

In likewise particularly preferred embodiments of the device according to the invention ( 4th ) the lifting cylinder ( 13th ) can be extended over the entire surface when pressurized by the hydraulic fluid and by a return spring ( 14th ) be retractable from an extended, long state to a retracted, short state.

In summary, it can be stated that within the scope of the present invention a device ( 4th ) for automatic lowering and load-dependent lifting of a lifting axle ( 21 ) the tandem axle of a motor vehicle or a motor vehicle trailer is provided.

A particular advantage of the device according to the invention ( 4th ) consists in the fact that in the event of their use, even during driving operation, there is significantly less tire wear on the lift axle that can then be raised ( 21 ) occurs.

A particularly serious advantage of the device according to the invention ( 4th ) it can also be seen that with their help an accidental or deliberate lifting of the lifting axle ( 21 ) a tandem axle is definitely excluded if - after the lifting axle has been raised ( 21 ) - those alone on the load axis ( 42 ) remaining axle load greater than the maximum permissible axle load of the load axle ( 42 ) is.

This means that the load-dependent lifting of the lifting axle ( 21 ) in the device according to the invention ( 4th ) is only possible if the load-related pressure in the hydraulic line ( 61 ) the pressure on the pressure relief valve ( 63 ) using the setting facility ( 65 ) adjustable limit value for the load axis ( 42 ) does not exceed the maximum permissible axle load.

Unauthorized lifting of the lifting axle ( 21 ) - in the event of an otherwise impending overload, the one alone on the ground ( 38 ) remaining load axis ( 42 ) - can with the device according to the invention ( 4th ) must be avoided.

Another major advantage of the device according to the invention ( 4th ) it can be seen that in the case of exceeding the maximum permissible axle load on the load axle ( 42 ) - with the lifting axle raised ( 21 ) - automatically to a lowering of the lifting axle ( 21 ) is coming.

This advantage is particularly due to the use of the setting device ( 65 ) adjustable pressure relief valve ( 63 ) in the hydraulic fluid circuit for the lifting cylinder ( 13th ) realizable.

• Denn hierfür ist die Front (55) der Ladefläche (8) von der Deichsel (52) eines Anhängers (50) oder von dem Rahmen (9, 11) eines Kraftfahrzeuges mittels einer Verriegelungseinrichtung (47) entriegelnd zu trennen. Diese Verriegelungseinrichtung (47) bewirkt bei der entriegelnden Schwenkbewegung des hakenförmigen Verschlusses (48) automatisch und zwangsweise mit der Entriegelung gekoppelt, eine Umschaltung und Ausrichtung des Bedienelementes (59) des Umschaltventiles (35) in die „Absenkung“-Stellung (60) für ein Absenken der Liftachse (21).

In addition, there is an automatic, compulsory with the unlocking of the loading area ( 8th ) coupled lowering of the lifting axle ( 21 ) in the case of the device according to the invention when the loading area ( 8th ) - starting from a horizontal, tilted position - into a inclined, tilted position is to be swiveled:

• Because this is the front ( 55 ) the loading area ( 8th ) from the drawbar ( 52 ) of a trailer ( 50 ) or from the frame ( 9 , 11 ) of a motor vehicle by means of a locking device ( 47 ) to be unlocked. This locking device ( 47 ) causes the unlocking pivoting movement of the hook-shaped lock ( 48 ) automatically and forcibly coupled with the unlocking, a switchover and alignment of the control element ( 59 ) of the switching valve ( 35 ) to the "lowering" position ( 60 ) for lowering the lifting axle ( 21 ).

Further advantages of the device according to the invention ( 4th ) consist in their - from a construction point of view - clear structure and thus given operational reliability and lack of susceptibility to failure. In particular, in the device according to the invention ( 4th ) the use of generally fault-prone electronics and complicated mechanics is not required. According to the invention for producing the device according to the invention ( 4th ) The structurally simple components used have the effect that their manufacturing costs and operating costs are extremely low.

• Aufgrund der Ausbildung der in Fahrtrichtung (39) frontwärtigen Achse einer Tandemachse als „Liftachse“ (21) ist unter Ausbildung eines größeren Radstandes ein größerer Abstand zu der rückwärtigen Achse des Zugfahrzeuges realisierbar. Dies führt zu einer verbesserten Fahrstabilität des Anhängers im Fahrbetrieb.

In the 1 to 12th of the present invention was always the direction of travel ( 39 ) front axle of a tandem axle as "lifting axle" ( 21 ) shown. Of course, within the scope of the present invention, it is possible to change the direction of travel ( 39 ) rear axle of a tandem axle as "lifting axle" ( 21 ) and to design the front axle of a tandem axle as a "load axle" (42):

• Due to the training in the direction of travel ( 39 ) front axle of a tandem axle as "lifting axle" ( 21 ) a greater distance to the rear axle of the towing vehicle can be achieved with the formation of a larger wheelbase. This leads to an improved driving stability of the trailer when driving.

Lifting the in the direction of travel ( 39 ) rear, rear axle of a tandem axle leads to advantages in manual maneuvering due to the lower edge stand.

List of reference symbols

1

Axis of rotation on the frame projection 10 for a swivel arm 2

2

Swivel arm

3

wheel

4th

Device for automatic lowering and load-dependent lifting of a lifting axle 21 ; comprehensive 34 + 51 + 41

5

Leaf spring

6th

Swivel axis for loading area

7th

free end of the respective swivel arm 2

8th

tiltable loading area of a car trailer

9

Cross frame of a car trailer

10

Frame protrusion on the cross frame 9 for mounting the axes of rotation 1

11

Longitudinal frame of a car trailer

12th

Bearings for lift shaft 23 ; protrusion-like, on the longitudinal frame 11 appropriate

13th

Lifting cylinder

14th

Return spring

15th

Link lever of the lifting shaft 23 to engage the lifting cylinder 13th and the return spring 14

16

Fastening tab on the cross frame 9 for lifting cylinders 13th and return spring 14

17th

Control lever

18th

Control roller, rotatable on the control lever 17th appropriate

19th

imaginary line running along the bottom of the control surface 20th runs and their extension on both sides

20th

Control surface at the free end 7th of the swivel arm 2 the lift axle 21 ; Slide-rail-shaped or runway-shaped for unrolling the control roller 18th

21

Lift axle

22nd

Line between the geometric center 24 the cross-sectional area of the lifting shaft 23 on the one hand and the protrusion-like or recess-shaped attachment point 27 the tax role 18th on the control lever 17th , on the other hand;

23

Lifting shaft

24

geometric center of the cross-sectional area of the lifting shaft 23

25th

imaginary line between the geometric cross-section center 24 the lifting shaft 23 and the location 27 the tax role 18th at the free end of the control lever 17th

26th

imaginary line through the geometric center 24 the lifting shaft 23 on the one hand and the free end of the link lever 15th for the action 29 of the lifting cylinder 13th on the other hand;

27

protrusion-like or recess-shaped attachment point of the control roller 18th on the control lever 17th ;

28

protrusion-like or recess-like attachment point of the lifting cylinder 13th on the linkage lever 15th the lifting shaft 23

29

Bracket for control surface 20th , at the free end of the lifting arm 2

30th

Lift cylinder length 13

31

Spring between the longitudinal frame 11 and control element 59 of the switching valve 35 ; Part of the locking device 47

32

horizontal distance v between the geometric cross-section center ( = Location 27 ) the tax role 18th and the axis of rotation 1 on the frame protrusion 10 for the lift / swivel arm 2

33

vertical distance h between the geometric cross-sectional center ( = Location 27 ) the tax role 18th on the one hand and an imaginary horizontal line on the other hand, which goes through the axis of rotation 1 of the swivel arm 2 runs horizontally

34

Device for the automatic lowering of a raised lifting axle 21

35

Changeover valve

36

Lever for actuating the switching valve 35

37

hydraulic pump

38

Underground

39

Direction of travel

40

Longitudinal axis of the vehicle or trailer

41

Hydraulic equipment

42

Load axis

43

Control lever for hydraulic pump 37

44

One-way flow control valve between switching valve 35 and lifting cylinder 13

45

Front of a trailer 50

46

Rear of a trailer 50

47

Locking device for tiltable loading area 8th - in the front area of the drawbar 52 or in the front area of the longitudinal frame 11 - for reversibly detachable mounting of a front side on the tiltable loading area 8th attached locking element 57 ; coupled with control element 59 of the switching valve 35

48

hook-shaped, pivotable closure of the locking device 47

49

Pressure relief valve to protect the hydraulic pump 37 against overpressure, connected in parallel to the hydraulic pump 37

50

pendant

51

Device for load-dependent lifting of a lifting axle 21

52

Drawbar of a trailer 50

53

Locking device shaft 47 , perpendicular to the longitudinal axis of the trailer 50 or the motor vehicle

54

Foot pedal, non-positive on the shaft 53 appropriate

55

Front of the loading area 8th

56

Control attachment on the shaft 53 for actuating the switching valve 35

57

Locking element in the front area 55 the loading area 8th

58

Position of the control element 59 of the switching valve 35 : Raising the lift axle 21

59

Control element of the switching valve 35

60

Position of the control element 59 of the switching valve 35 : Lowering the lift axle 21

61

Hydraulic line

62

Hand valve, upstream of the hydraulic pump 37

63

Pressure relief valve, adjustable to the maximum permissible axle load of the load axle 42 ; opens in the tank 64 when this pressure is reached;

64

Hydraulic fluid tank

65

Setting device of the pressure relief valve 63 ; for setting a limit pressure, which corresponds to the maximum permissible axle load of the load axle 42 corresponds to;

66

Spring between control element 59 of the switching valve 35 and the tax attachment 56 on the shaft 53 the locking device 47

67

Distance between the top of the control roller 18th and the bottom of the control surface 20th while the bike is resting 3 on the underground 38 ;

68

Dead-point line, imaginary line extending from the contact point 69 between the external scope of the tax role 18th one hand and the bottom of the control surface 20th on the other hand - with the control lever swiveled up in the direction of the vertical 17th - goes out and at an angle of 90 ° on the line 19th stands;

69

Contact point between the outer circumference of the control roller 18th one hand and the bottom of the control surface 20th on the other hand, with the control lever swiveled up in the direction of the vertical 17th

α = angle - in side view - enclosed between an imaginary line 25 through the geometric center 24 of the lifting shaft 23 and the attachment point of the control roller 18 on the free end of the control lever 17 and one through the geometric center 24 of the lifting shaft 23 and the free end of the Link lever 15 for the action of the lifting cylinder 13, imaginary line 26 on the other hand;

γ = angle - in side view - enclosed between an imaginary line 19, which runs on both sides along the underside of the control surface 20, on the one hand and a line 22 which passes through the geometric center 24 of the cross-sectional surface of the lifting shaft 23 and the projection-like or recess-shaped The mounting location 27 of the control roller 18 runs on the control lever lift axis 17, on the other hand - when the control lever 17 is pivoted in the direction of the vertical for the purpose of lifting the control roller 21; δ = angle enclosed between the control attachment 56 and the locking hook 48 when viewed from the side along the control shaft 53; ε = angle enclosed between the hook-shaped, pivotable lock 48 of the locking device 47 and the foot pedal 54 attached to the control shaft 53 in a non-positive manner when viewed from the side along the control shaft 53; η = reserve angle, between line 22 and dead center line line 68 - to prevent the control lever from "snapping over" (17)

Claims (10)

Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21), characterized in that it includes one or more devices (34) for automatically lowering a raised lifting axle (21) which is at the front or rear in relation to the direction of travel (39) tilted, inclined loading surface (8) of a motor vehicle or a motor vehicle trailer (50) and one or more devices (51) for load-dependent lifting of a front or rear lifting axle (21) a) with a horizontally aligned loading surface in relation to the direction of travel (39) (8) a motor vehicle or a motor vehicle trailer (50) and b) only if the weight on the loading area (8) falls below a predeterminable maximum weight and comprises a hydraulic device (41), the device (34) for automatically lowering a raised Lift axle (21) and the device (51) for load-dependent lifting of a lift axle (21) in an indirect or direct manner Are connected to the hydraulic device (41) or wherein the device (34) for automatically lowering a raised lifting axle (21) and the device (51) for load-dependent lifting of a lifting axle (21) are individually or jointly components of the hydraulic device (41 ) are. Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21) according to Claim 1 , characterized in that the one or more devices (34) for automatically lowering a raised lifting axle (21) when the loading area (8) of a motor vehicle or a motor vehicle trailer (50) is tilted up is designed in such a way that they have a locking Device (47) for releasably locking the front section of the loading area (8) on the frame of a motor vehicle or on the drawbar (52) of a motor vehicle trailer (50), which is oriented at right angles to the longitudinal axis of the drawbar (52) or the motor vehicle Control shaft (53) which can be rotatably, indirectly or directly attached to the drawbar (52) or the longitudinal frame (11) of a motor vehicle by means of a foot pedal (54), the control shaft (53) having a locking hook (48) and a control attachment ( 56), the control attachment (56) and the locking hook (48) - when viewed from the side along the control shaft (53) - Include an angle δ which is in the range from 5.0 ° to 40.0 °, the hook-shaped, pivotable lock (48) of the locking device (47) and the non-positive foot pedal (54) attached to the control shaft (53) - when viewed from the side along the control shaft (53) - include an angle ε, which is in the range of 30.0 ° to 80.0 °, the locking hook (48) correspondingly and releasably engaging a locking element projecting vertically downwards (57) of the front section (55) of the loading area (8) and wherein the control attachment (56) provided on the control shaft (53) is directly or indirectly connected to an operating element (59) of a switching valve (35) of the hydraulic device (41 ) is in a positively driven connection, this operating element (59) switching the switching valve (35) of the hydraulic device (41) for a hydraulic fluid flow (61) between a position (58) for Raising the lifting axle (21) and a position (60) for lowering the lifting axle (21) enables, so that when the connection between the locking hook (48) on the drawbar side and the locking element (57) of the loading area (8) is separated a raised lifting axle (21) is lowered automatically, automatically and under forced control. Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21) according to one of the Claims 1 or 2 , characterized in that the one or more devices (51) for load-dependent lifting of a lifting axle (21) with a horizontally aligned loading area (8) of a motor vehicle or a motor vehicle trailer (50) each with one or more hydraulic devices (41) are in connection, these comprising one or more electrically or manually operated hydraulic pumps (37), which with one or more lifting cylinders (13) - for the indirect or direct lifting of the lifting axle (21) - via a hydraulic line (61) directly or indirectly are in connection, one or more pressure relief valves (63) being provided downstream of each lifting cylinder (13), which are directly or indirectly connected to a hydraulic fluid tank (64) downstream, the pressure relief valve or valves (63) being connected by means of one or several setting devices (65) to the maximum permissible pressure for lifting the lifting axle e (21) are adjustable, whereby this maximum permissible pressure corresponds to the maximum permissible axle load of the load axle (42) remaining on the ground, so that an indirect or direct lifting of the lifting axle (21) by means of one or more lifting cylinders (13) - due to a Opening of the pressure relief valve (s) (63) - is not possible if the weight on the loading surface (8) is greater than the limit value of the maximum permissible axle load of the load axle remaining on the floor, which can be specified via the setting device (65) of the pressure relief valve (63) ( 42). Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21) according to one of the Claims 1 , 2 or 3 , characterized in that the lifting cylinder (13) of the hydraulic device (41) is in direct or indirect connection via one or more hydraulic lines (61) with one or more electrically and / or manually operated hydraulic pumps (37), with the upstream side of the Lifting cylinder (13) a switching valve (35) is provided, with the aid of which - in the "lifting" position (58) - a continuous connection can be established between the lifting cylinder (13) and the hydraulic pump (37) and which - in the " Lowering "position (60) - the connection between the lifting cylinder (13) and the hydraulic pump (37) is interrupted and instead a connection is established between the lifting cylinder (13) and the hydraulic fluid tank (64), whereby between the lifting cylinder (13 ) and the switching valve (35) one or more throttle check valves (44) are provided - for setting the return speed of the hydraulic fluid in the hydraulic fluid tank (64) - where a pressure relief valve (63) is provided between the lifting cylinder (13) and the hydraulic fluid tank (64), which opens automatically, automatically and under forced control when the loading area (8) is loaded with a weight that is greater than the permissible axle load the load axle (42) and one or more manual valves (62) for manually lowering the raised lifting axle (21) with a horizontal loading surface (8) are provided upstream of the switching valve (35). Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21) according to one of the Claims 1 , 2 , 3 or 4th , characterized in that in the case of the device (51) for load-dependent lifting of a lifting axle (21), both the load axle (42) and the lifting axle (21) each have a pivot axis (1) between their swivel arms (2) for their two swivel arms (2), one or more rotatable wheels (3) being directly or indirectly attached to the two free ends (7) of each swivel arm (2), the device (51) for load-dependent lifting of a lift axle (21) comprises a lifting shaft (23) oriented at right angles to the longitudinal axis (40) of the vehicle and rotatably mounted about its geometric cross-sectional center (24), a linkage lever (15) on the outer circumference of the lifting shaft (23) for engaging a between the transverse frame (9) and the articulation lever (15) of the lifting cylinder (13) developing the pressure effect is provided in a stationary manner, the lifting cylinder (13) on the one hand on a projection-like or recess-shaped attachment point (28) on the articulation lever (15) of the Lifting shaft (23) and on the other hand directly or indirectly acting on the transverse frame (9) or the longitudinal frame (11), the distance between the geometric center (24) of the lifting shaft (23) and the attachment point (28) of the lifting cylinder (13) on the The articulation lever (15) is in the range from 4.0 cm to 15.0 cm and a control lever (17) is provided in a stationary manner on the outer circumference of the lifting shaft (23) on which the articulation lever (15) is also attached, which in the area of its free end at the projection-like or recess-shaped attachment point (27) for the control roller (18) carries one or more rotatable control rollers (18), wherein - when viewed from the side - the control lever (17) and the Articulation lever (15) in the form of a letter V one behind the other and offset in a V-shape to one another, on which the lifting shaft (23) is provided and the vertically upward opening angle α of this V-shaped offset - when viewed from the side - in the range of 45 ° to 85, whereby in the area of the inside of the lifting / swivel arm (2) of the lifting axle (21) and in the area of its free end (7), a slide-rail-shaped or rolling track-shaped control surface (20) is almost parallel alignment to the longitudinal axis of the swivel arm (2) of the lifting axis (21) - indirectly via a bracket (29) or directly - is provided, with the control roller (27) rotatably attached to the free end of the control lever (17) in the attachment point (27). 18) rolls on the underside of the control surface (20) at least in sections when the pivot lever (15) of the lifting shaft (23) is extended to its full length with the aid of the lifting cylinder (13) acting between the pivot lever (15) and the transverse frame (9) is, thereby pushing the control lever (17) with the control roller (18) attached to it in the attachment location (27) upwards and thereby lifting the lifting axle (21) upwards in the vertical direction and one running parallel to the lifting cylinder (13) Retraction spring (14) - for the purpose of a retraction of the lifting cylinder (13) and a vertical lowering of the lifting axle (21) on the ground (38) - the pivot lever (15) of a - because of the maximum extent of the Hydraulikz ylinder (13) - retracts the deflected position into an oppositely inclined position and when the wheel (3) rests on the ground (38) the control roller (18) is spaced from the underside of the control surface (20) at a distance (67), which is in the range of 40.0 mm to 110.0 mm. Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21) according to one of the Claims 1 , 2 , 3 , 4th or 5 , characterized in that the geometric relationships between a) the projection-like or recess-shaped attachment point (28) of the lifting cylinder (13) on the articulation lever (15) of the lifting shaft (23) on the one hand and b) the projection-like or recess-shaped attachment point (27) of the control roller ( 18) on the control lever (17) of the lifting shaft (23) on the other hand and c) the axis of rotation (1) of the respective lifting / swivel arm (2), follow the following formula: $$\text{l}-\text{r}-\text{v}\cdot \text{sin}{\mathrm{\beta }}_{\text{O}}-\text{H}\cdot \text{cos}{\mathrm{\beta }}_{\text{O}}=0;$$

where: I = length of the lifting cylinder (13); r = radius of the control roller (18) at the control roller mounting location (27) on the free end of the control lever (17); v = horizontal distance between the geometric cross-sectional center (= attachment point 27) of the control roller (18) on the one hand and the respective axis of rotation (1) on the frame projection (10) for the lifting / pivoting arm (2) on the other hand; β _o = included angle between a line which runs parallel to the sliding control surface (20) of the guide (29) for the control roller (18) and an imaginary vertical line through the geometric center point (= attachment location 27) (18), on the other hand; neniform on the one hand the control roller h = vertical (= talen line (2) horizontal distance between the geometric cross-sectional center point of attachment 27) of the control roller (18) on the one hand and an imaginary horizon on the other, which runs through the axis of rotation (1) of the lift pivot arm; Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21) according to one of the Claims 1 to 6th , characterized in that - in a side view - between a line (19) running along the underside of the control surface (20) and pointing in the direction of the axis of rotation (1) belonging to the respective pivot arm (2) and a line (22) between the geometric center (24) of the cross-sectional area of the lifting shaft (23) on the other hand, an angle γ is included, which is in the range of 140.0 ° to 90.0. Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21) according to one of the Claims 1 to 7th , characterized in that - with the lifting cylinder (13) extended to the maximum and thus the control lever (17) pivoted to the maximum in the direction of the vertical - in the contact point (69) then reached between the outer circumference of the control roller (18) of the control lever (17) on the one hand and the underside of the control surface (20), on the other hand, a dead center line (68) is perpendicular to the line (19) running through the contact point (69) and along the underside of the control surface (20), the line (22) at this contact point (69) between the geometric Center (24) of the cross-sectional area of the lifting shaft (23) and the protrusion-like or recess-shaped attachment point (27) of the control roller (18) on the control lever (17) on the one hand, and the dead center line (68) on the other hand, enclose an angle η, which in the area from 0.5 ° to 50.0 °, with compliance with this angle η as a "reserve" to the dead center line (68) and as a measure to prevent the control lever (17) from "snapping over" in the sense of the control lever swinging through (17 ) beyond the dead center line (68) in the direction of the pivoting movement of the control lever (17) or an overturning of the control lever (17) beyond the dead center line (68) in the direction opposite to the direction of the axis of rotation (1) of the associated swivel arm (2 ) is, serves. Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21) according to one of the Claims 1 to 8th , characterized in that the line (19) running along the underside of the control surface (20) when viewed from the side - is oriented tangentially to the swivel radius swept over by the control roller (18) during the swiveling process of the control lever (17), the distance between the Control surface (20) and the line (19) on the one hand and the geometric center (24) of the cross-sectional area of the lifting shaft (23) on the other hand is at least slightly shorter than this swivel radius swept over, so that the angle γ is always at least slightly greater than 90 °. Device (4) for automatically lowering and load-dependent lifting of a lifting axle (21) according to one of the Claims 1 to 9 , characterized in that the lifting cylinder (13) can be extended over its entire surface when pressurized by the hydraulic fluid and can be retracted from an extended, long state to a retracted, short state by a return spring (14).

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