The present invention relates to a scraper arrangement for a soil tilling roller of a soil tilling machine.
Such soil tilling machines are used, for example, as soil compactors in order to compact a subsoil, such as asphalt material. In order to prevent material to be compacted from adhering to the surface of a soil tilling roller of such a soil tilling machine, such a soil tillage roller can be assigned at least one scraper arrangement with a scraper bar that is elongated in the direction of a longitudinal axis of the roller and extends along the soil tilling roller.
Such a scraper arrangement is known from JP 2021055301A. The scraper bar of this known scraper arrangement is carried on a frame of the soil tilling machine by two articulated units spaced apart in the direction of a longitudinal axis of the bar or the axis of rotation of the roller so that it can pivot between an inactive position, in which the scraper bar is pivoted away from the surface of the soil tilling roller with a scraper edge thereof, and an active position, in which the scraper bar rests with its scraper edge on the surface of the soil tilling roller. Each of the articulated units is constructed in such a way that it allows the scraper bar to pivot about a pivot axis.
Material adhering to the surface of the soil tilling roller is scraped off on the one hand by the scraper bar resting with its scraper edge on the surface of the soil tilling roller in the active position. On the other hand, a liquid film, which is applied to the surface of the soil tilling roller, for example by means of a plurality of spray nozzles, is distributed evenly over the surface of the soil tilling roller, so that the liquid film prevents or at least makes it more difficult for material to be compacted to adhere to the surface of the soil tilling roller.
Such soil tilling rollers are carried on the machine frame of a soil compactor, which carries them and also the scraper arrangements associated with them, via elastic suspension elements. As a result, during steering movements in the region of these suspension elements, a relative movement can occur between the machine frame rotatably carrying the soil tilling roller and the soil tilling roller rotatably carried thereon. Such a relative movement can result in a gap-like intermediate space increasing from one axial end region of the soil tilling roller to the other axial end region being formed between the surface of a soil tilling roller and the scraper edge of a scraper bar assigned to this soil tilling roller and carried on the machine frame.
The object of the present invention is to provide a scraper arrangement for a soil tilling roller of a soil tilling machine, in which the occurrence of an intermediate space between a scraper bar and a surface of a soil tilling roller, especially when performing steering movements, is avoided.
According to the invention, this object is achieved by a scraper arrangement for a soil tilling roller of a soil tilling machine according to claim 1. This scraper arrangement comprises a scraper bar which is elongated in the direction of a longitudinal bar axis and is to be attached or is attached by means of at least two articulated units to a machine frame of a soil tilling machine so that it can pivot between an active position and an inactive position, wherein each articulated unit comprises:
The scraper arrangement is characterised in that each articulated unit further comprises:
Due to the fact that in a scraper arrangement designed according to the invention, at least one first articulated connection element and at least one second articulated connection element are provided for each articulated unit and each of these articulated connection elements is pivotably connected in two pivot coupling regions to one of the articulated carrier elements, there are a total of four different pivot axes that are substantially parallel to one another. A connection is thus created which substantially corresponds in its function to a parallelogram guide and which makes it possible for a scraper bar, which is pivotably supported on a machine frame with two such articulated units, for example, to move in its two axial end regions in different ways with respect to the machine frame and the soil tilling roller rotatably carried on such a machine frame. This can also contribute to the fact that in each of the four pivot coupling regions there is unavoidable movement play between a respective articulated carrier element and a respective articulated connection element, which is not only a pure pivoting movement, but also allows a slight displacement movement orthogonal to the respective pivot axis or a slight tilting movement with respect to the respective pivot axis of the pivotally coupled components. The movement plays present in the pivoting coupling regions add up and thus allow different mobility in the articulated units while the scraper bar is nevertheless able to move between its inactive position and its active position, which allows the compensation of intermediate spaces occurring during steering movements.
In an embodiment that can be assembled with components that are easy to produce, it can be provided that in at least one, preferably each articulated unit, two first articulated connection elements are arranged at a distance from one another in the direction of the first pivot axis and the second pivot axis, and that a first pivot coupling region of the first articulated carrier element is arranged axially between the first pivot coupling regions of the first articulated connection elements and a first pivot coupling region of the second articulated connection element is arranged axially between the second pivot coupling regions of the first articulated connection elements, and/or that in at least one, preferably each articulated unit, two second articulated connection elements are arranged at a distance from one another in the direction of the third pivot axis and the fourth pivot axis and a second pivot coupling region of the first articulated carrier element is arranged axially between the first pivot coupling regions of the second articulated connection elements and a second pivot coupling region of the second articulated connection element is arranged axially between the second pivot coupling regions of the second articulated connection elements.
In order to be able to achieve an embodiment with as few components as possible, it is proposed that a single first articulated connection element is provided for at least one, preferably each articulated unit, and that a first pivot coupling region of the first articulated carrier element overlaps the first pivot coupling region of the first articulated connection element on its two axial sides and a first pivot coupling region of the second articulated carrier element overlaps the second pivot coupling region of the first articulated connection element on its two axial sides, and/or that a single second articulated connection element is provided in at least one, preferably each articulated unit, and that a second pivot coupling region of the first articulated carrier element overlaps the first pivot coupling region of the second articulated connection element on its two axial sides and a second pivot coupling region of the second articulated carrier element overlaps the second pivot coupling region of the second articulated connection element on its two axial sides.
For the pivotable connection of the various components of a respective articulated unit, it can be provided that the at least one first articulated connection element is pivotably connected in its first pivot coupling region to the first articulated carrier element by a pivot pin about the first pivot axis, and/or that the at least one first articulated connection element is pivotably connected in its second pivot coupling region to the second articulated carrier element by a pivot pin about the second pivot axis, and/or that the at least one second articulated connection element is pivotably connected in its first pivot coupling region to the first articulated carrier element by a pivot pin about the third pivot axis, and/or that the at least one second articulated connection element is pivotably connected in its second pivot coupling region to the second articulated carrier element by a pivot pin about the fourth pivot axis.
In order to achieve a combined pivoting-sliding movement of the scraper bar when moving between the inactive position and the active position, it is proposed that a distance between the first pivot axis and the third pivot axis differs from a distance between the second pivot axis and the fourth pivot axis. In particular, it can be provided that the distance between the first pivot axis and the third pivot axis is smaller than the distance between the second pivot axis and the fourth pivot axis.
In an alternative embodiment, in which the scraper bar moves substantially translationally tangentially towards or away from the surface of a soil tilling roller, a distance between the first pivot axis and the third pivot axis can correspond to a distance between the second pivot axis and fourth pivot axis. In particular, in this and also in the embodiment with a combined pivoting-sliding movement, it can be provided that the distance between the first pivot axis and the second pivot axis substantially corresponds to the distance between the third pivot axis and the fourth pivot axis. It should be noted that a distance referred to in this context is the orthogonal distance between the pivot axes under consideration.
In order to avoid mutual interference, particularly in the area of pivot coupling regions, when the first and second articulated connection elements provided in a respective articulated unit are comparatively close together when a pivoting movement is carried out, it is proposed that the at least one first articulated connection element is curved between its first pivot coupling region and its second pivot coupling region at least on a side facing the at least one second articulated connection element, and/or that the at least one second articulated connection element is curved between its first pivot coupling region and its second pivot coupling region at least on a side facing the at least one first articulated connection element. Of course, the respective articulated connection elements can also have a curved course in their entirety.
In particular, the at least one first articulated connection element and the at least one second articulated connection element can be curved in opposite directions to one another. It can further be provided that the at least one first articulated connection element and/or the at least one second articulated connection element is concavely curved on the side facing the respective other articulated connection element. Such a concave curvature creates space into which a respective other articulated connection element or a pivot coupling region of the same can enter when a pivoting movement is carried out.
A prestressing arrangement can be provided to hold the scraper bar in its active position and its inactive position, wherein the prestressing arrangement prestresses the scraper bar into the inactive position when the scraper bar is positioned in the inactive position and prestresses the scraper bar into the active position when the scraper bar is positioned in the active position. The prestressing arrangement is therefore an over-dead centre arrangement which, when a dead centre is exceeded, prestresses the scraper bar into the other position of the active position and the inactive position, in particular that position into which the scraper bar moves.
In a structure that is easy to implement but still works reliably, the prestressing arrangement can comprise at least one, preferably two prestressing springs arranged at an axial distance from one another and acting between the first articulated carrier element and the second articulated carrier element.
At least one, preferably each articulated connection element of the first articulated connection element and second articulated connection element can be tilted and/or displaced orthogonally to the respective pivot axis in at least one, preferably each pivot coupling region of the first pivot coupling region and second pivot coupling region with respect to the articulated carrier element of the first articulated carrier element and second articulated carrier element coupled thereto. This relative mobility is generally already achieved by the fact that during the manufacture of such articulated units there is unavoidable movement play, for example between a pivot pin and an opening receiving it in an articulated carrier element or an articulated connection element. If an even greater relative mobility is required, this can be achieved, for example, by providing a defined oversize of one or a plurality of openings receiving a respective pivot pin with respect to this pivot pin.
The invention further relates to a soil tilling machine, in particular a soil compactor, comprising at least one soil tilling roller and, in association with at least one soil tilling roller, at least one scraper arrangement constructed according to the invention.
The present invention is described in detail below with reference to the attached figures.
The front carriage 18 comprises a machine frame 22 on which a soil tilling roller 24 is rotatably supported about an axis of rotation D orthogonal to the plane of the drawing in
It should be noted that the soil compactor 10 could be designed in a wide variety of other ways. For example, it could also have a soil tilling roller on the rear carriage 12 or a machine frame carrying a respective soil tilling roller could be constructed in a different way than illustrated in
The scraper arrangement 30 comprises a scraper bar 32, which is elongated in the direction of a longitudinal bar axis B that is substantially parallel to the roller axis of rotation D and can be moved between an active position shown in
In order to enable this mobility, the scraper bar 32 is supported on the frame part 28 or on the machine frame 22 by means of two articulated units 40 which are preferably identical in construction and are arranged at a distance from one another in the direction of the longitudinal bar axis B. The two articulated units 40 are each carried in the vicinity of an axial end of the scraper bar 32, for example.
The construction and functioning of the two articulated units 40 are described below with reference to
First,
In the embodiment shown in
Each first articulated connection element 46 has a first pivot coupling region 50 in which it is pivotably attached to a first pivot coupling region 52 of the first articulated carrier element 42 by means of a pivot pin 53 about a first pivot axis S1. To provide the first pivot coupling region 52, the first pivot carrier element 42 can have two bent, tab-like regions which, like the first pivot coupling regions 50 of the first articulated connection elements 46, provide passage openings for the pivot pin 53. The first pivot coupling region 52 of the first articulated carrier element 42 is arranged between the two first articulated carrier elements 46 in the direction of the first pivot axis S1.
The first articulated connection elements 46 also have a second pivot coupling region 54 in which they are pivotably connected to a first pivot coupling region 56 of the second articulated carrier element 44 about a second pivot axis S2. The first pivot coupling region 56 of the second articulated carrier element 44 may be provided by bending two tabs. In association with a pivot pin 58, the first pivot coupling region 56 of the second articulated carrier element 44, like each first articulated connection element 46 in its second pivot coupling region 54, has a passage opening.
The second articulated connection elements 48 are pivotably connected in a respective first pivot coupling region 60 to a second pivot coupling region 62 of the first articulated carrier element 42 about a third pivot axis S3. The second pivot coupling region 62 of the first articulated carrier element 42 can be provided on the bent tabs that also provide the first pivot coupling region 52 and can have passage openings for a pivot pin 64, which also passes through respective passage openings in the first pivot coupling regions 60 of the second articulated connection elements 48. In respective second pivot coupling regions 66 of the second articulated connection elements 48, these are pivotally connected to a second pivot coupling region 68 of the second articulated carrier element 44 about a fourth pivot axis S4. For this purpose, a pivot pin 70 is provided, which passes through respective passage openings in the second pivot coupling regions 66 of the second articulated connection elements 48 and in the second pivot coupling region 68 of the second articulated carrier element 44.
The four pivot axes S1, S2, S3 and S4 are arranged substantially parallel to one another and to the longitudinal bar axis B of the scraper bar 32 or to the roller axis of rotation D. Furthermore, the first pivot axis S1 and the third pivot axis S3 are at a smaller distance d from one another than the distance D between the second pivot axis S2 and the fourth pivot axis S4. As a result, during the transition from the inactive position of the scraper bar 32 shown in
In order to support this movement or to hold the scraper bar 32 in the active position and the inactive position, a prestressing arrangement, generally designated 72, is provided. In the exemplary embodiment shown, this comprises two prestressing springs 74 which are arranged at an axial distance from one another and are designed as screw tension springs, which are fixed in one of their end regions with respect to the first pivot carrier element 42 and in their other end region with respect to the second pivot carrier element 44 and thus act between them. The two prestressing springs 74 form an over-dead centre arrangement which, when a movement dead centre is exceeded, prestresses the second pivot carrier element 44 in the direction of that position of active position and inactive position towards which the scraper bar 32 is moving. The active position is defined by the contact of the scraper bar 32 on the outer peripheral surface 36 of the soil tilling roller 24. The inactive position can be defined by a stop 76 provided on the first pivot carrier element 42, against which the second pivot carrier element 44 comes to rest when moving out of the active position. Alternatively or additionally, the or a stop 76 could be provided on the second pivot carrier element 44 and/or on one or a plurality of the articulated connection elements 46, 48.
It can be clearly seen in
It should be pointed out that, in principle, an embodiment can also be selected in which, on the one hand, the two distances d and D are equal to one another and, on the other hand, as already described, the distances between the pivot axes S1 and S2 or S3 and S4 are equal to one another, so that the movement between the active position and the inactive position is substantially a displacement movement running substantially arc-like tangentially with respect to the soil tilling roller 24. An embodiment is also conceivable in which the pivot axes S1 and S2 are at a different distance from one another than the pivot axes S3 and S4.
The embodiment of the articulated units 40 described above, in which each of the articulated units 40 has a total of four pivot axes S1, S2, S3, S4, in which components move in relation to one another, makes it possible that during the transition between the active position and the inactive position or in a respective position, in particular the active position, in the two articulated units 40 arranged near the axial ends of the scraper bar 32, at least slightly different movements occur in relation to one another.
With a scraper arrangement constructed according to the invention, this enables the occurrence of a gap-like intermediate space to be avoided during a steering movement and a relative movement occurring between the soil tilling roller 24 and the frame part 28, which in the arrangement known from the prior art, depending on the steering direction, primarily occurs in one of the two axial end regions of the soil tilling roller 24 or is more pronounced than in the other axial end region, between the scraper edge 34 of the scraper bar 32 positioned in its active position and the outer peripheral surface 36 of the soil tilling roller 24.
This different mobility is favoured on the one hand by the kinematics of the articulated units 40 constructed according to the invention and on the other hand by the fact that inevitably in each of the regions in which components are pivotably connected to one another there is a play of movement that does not only allow a pure pivoting movement. This play of movement, which is necessary for assembly on the one hand and unavoidable for manufacturing reasons on the other hand, makes it possible, for example, for the first articulated connection elements 46 in the respective first pivot coupling region 50 to move not only in the circumferential direction about the first pivot axis S1 with respect to the first pivot coupling region 52 of the first articulated carrier element 42, but also slightly orthogonally can move with respect to the pivot axis S1 or can tilt with respect to the pivot axis S1. Since such a relative movement can occur in the region of each of the four pivot axes S1, S2, S3, S4, the play of movement adds up, so that even comparatively small plays of movement result in the scraper bar 32 in the region of each of the articulated units 40 being able to perform a tilting movement with respect to the roller axis of rotation D or also the frame part 28 in the range of up to a few degrees. This is generally sufficient to compensate for the relative movement occurring in steering movements between the soil tilling roller 24 and the machine frame 22 and to avoid the formation of a gap-like intermediate space between the scraper edge 34 and the outer peripheral surface 36. If, due to the structural embodiment, a greater relative movement between the soil tilling roller 24 and the rotatably supporting machine frame 22 can be expected, for example, beyond the production-related play of movement that occurs, a defined excess which favours such tiltability can be provided in the region of the passage openings receiving various pivot pins 54, 64, 58, 70. Since the relative mobility in the region of each of the pivot pins 54, 64, 58, 70 also adds up, this relative movement can be kept comparatively low in the region of each of these pivot pins, which results in a defined pivoting-sliding movement or a defined sliding movement in the transition between the active position and the inactive position being guaranteed.
In principle, an embodiment is possible, in which one type of the articulated connection elements, for example in the first articulated connection elements, two arranged in axial distance to each other and the respectively associated pivot coupling region of the first or second articulated carrier element between receiving articulated connection elements are provided, while in the other type of articulated connection elements, i.e. for example, the second articulated connection elements, only a single articulated connection element is provided, which is overlapped at its axial ends by the respective pivot coupling regions of the first or second articulated carrier element and thus also positioned axially between the other two articulated connection elements. Since all articulated connection elements are axially offset from each other in this embodiment, a mutual interference cannot occur or can only occur in a limited way when performing a movement between the active position and the inactive position. Therefore, no or only less strong structural measures, such as a curved forming of the articulated connection elements, must be provided to avoid mutual interference.
Number | Date | Country | Kind |
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10 2021 115 960.1 | Jun 2021 | DE | national |