Abstract
The present invention relates to an articulated pendulum joint for an articulated vehicle, especially a construction machine. It comprises a front connection element for connecting a front frame part of the articulated vehicle, a rear connection element for connecting a rear frame part of the articulated vehicle, and an articulation joint, via which the front connection element and the rear connection element are mutually connected in a pivotable manner relative to each other about a steering axis (A.sub.S). A pendulum joint is further provided, via which the front connection element and the rear connection element are mutually connected in a twistable manner relative to each other about a pendulum axis (A.sub.T), wherein the steering axis (A.sub.S) of the articulation joint is inclined about an acute angle α relative to the pendulum axis (A.sub.T). The present invention further relates to an articulated vehicle, especially an articulation-steered construction machine, comprising a front frame part and a rear frame part on which driving means are respectively arranged and on which a joint arrangement of the type described above is provided.
Claims
1. A combined pendulum/articulation joint arrangement for an articulated vehicle, comprising: a front connection element connected to a front frame part of the articulated vehicle; a rear connection element connected to a rear frame part of the articulated vehicle; an articulation joint, via which the front frame part and the rear frame part are mutually connected in a pivotable manner relative to each other about a steering axis (A.sub.S); and a pendulum joint, via which the front frame part and the rear frame part are mutually connected in a twistable manner relative to each other about a pendulum axis (A.sub.T), wherein the joint arrangement comprises a combination of the pendulum joint and the articulation joint, wherein the pendulum joint comprises the front connection element and the articulation joint comprises the rear connection element, and the pendulum joint comprises a rotary body or a torsional bearing element which is rotatably arranged on the front connection element about the pendulum axis (A.sub.T), wherein a joint part of the articulation joint, which is complementary to a joint part of the articulation joint on a frame side, is arranged on the rotary body or on the torsional bearing element, and further wherein the steering axis (A.sub.S) of the articulation joint is inclined about an angle (α) relative to the pendulum axis (A.sub.T) in a range between 85° and 65°, and that a pendulum stop of a pendulum angle is present depending on the inclination of the steering axis (A.sub.S) and a steering angle (β).
2. The joint arrangement according to claim 1, wherein the pendulum stop is formed by a finger on the front frame part and a stop for the finger on the rotary body or the torsional bearing element.
3. The joint arrangement according to claim 1, wherein an angle of inclination α is 80°.
4. The joint arrangement according to claim 1, wherein the steering axis (A.sub.S) is inclined in the direction of the rear frame part.
5. The joint arrangement according to claim 1, wherein the rear frame part comprises a yoke element with at least two mutually spaced bearing elements, and at least one bearing shaft and two bearing elements which are complementary thereto are provided between the front frame part, said bearing elements being in force-locking operative connection with the bearing elements.
6. The joint arrangement according to claim 5, wherein at least one bearing element comprises a spherical head, and the bearing element comprises a complementary spherical head receptacle.
7. The joint arrangement according to claim 5, wherein the bearing shaft is arranged in an inclined manner parallel to the steering axis (A.sub.S).
8. The joint arrangement according to claim 1, wherein at least two bearing shafts are provided, which extend perpendicularly to the pendulum axis (A.sub.T) and which are arranged with respect to an axis perpendicularly to the pendulum axis (A.sub.T) in an offset manner with respect to each other along the pendulum axis (A.sub.T).
9. The joint arrangement according to claim 5, wherein the bearing elements of the yoke element are arranged as an upper bearing element and a bottom bearing element, and wherein the bottom bearing element is arranged with respect to an axis perpendicularly to the pendulum axis (A.sub.T) in an offset manner along the pendulum axis (A.sub.T) with respect to the upper bearing element, or vice versa.
10. A joint arrangement according to claim 5, wherein the at least one bearing shaft is arranged on a torsional bearing element which engages with a joint pin in a rotatable manner in a torsional pin receptacle, or vice versa.
11. An articulated vehicle, comprising a front frame part and a rear frame part, on which respective driving means are arranged, and comprising a joint arrangement according to claim 1.
12. The joint arrangement according to claim 1, wherein the articulated vehicle comprises a construction vehicle.
13. The articulated vehicle according to claim 11, wherein the articulated vehicle comprises an articulation-steered construction machine.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The present invention will be described below in closer detail by reference to embodiments shown in the drawings. In the schematic figures:
(2) FIG. 1 shows a side view of an embodiment of a vehicle with a joint arrangement in accordance with the present invention;
(3) FIG. 2 shows a front view of the vehicle of FIG. 1;
(4) FIG. 3 shows the embodiment of FIGS. 1 and 2 in the turned-in state;
(5) FIG. 4 shows a top view of the vehicle in the turned-in state according to FIG. 3;
(6) FIG. 5 shows a theoretical operating state of a vehicle in the turned-in state according to FIGS. 3 and 4;
(7) FIG. 6 shows a view of a first embodiment of the joint arrangement;
(8) FIG. 7 shows a second embodiment of the joint arrangement in a partial sectional view;
(9) FIG. 8 shows a third embodiment of the joint arrangement in a partial sectional view;
(10) FIG. 9 shows a fourth embodiment of the joint arrangement in a partial sectional view;
(11) FIG. 10 shows a fifth embodiment of the joint arrangement in a partial sectional view;
(12) FIG. 11 shows a side view of a sixth embodiment of the joint arrangement during straight travel;
(13) FIG. 12 shows a side view of the sixth embodiment in the turned-in state; and
(14) FIG. 13 shows a geometric view of relevant variables of the joint arrangement.
DETAILED DESCRIPTION OF THE INVENTION
(15) FIGS. 1 and 2 show a vehicle in form of a vibration roller 1, especially a single-drum compactor, in a non-turned-in state, i.e., in the forward travelling direction R.sub.F. The vibration roller 1 comprises a divided frame with a front frame part 4 and a rear frame part 8, which are connected to each other via a combined articulated pendulum joint, which shall be referred to below as joint arrangement 3. It comprises a chassis with a front drum 5 and pneumatic rear wheels 7. The drum 5 is arranged via a front-wheel carrier 4′ on the front frame part 4 and the rear wheels 7 are arranged on a rear-wheel carrier 8′ on the rear frame part 8. The vibration roller 1 can be moved in a very tight turning radius as a result of the joint arrangement 3 between the front frame part 4 and the rear frame part 8. A driver's cabinet 11 and a drive unit which is covered by a hood 13 are situated on the rear frame part 8.
(16) For the purpose of forming this articulated coupling, the joint arrangement 3 comprises the series connection of an articulation joint 10 and a pendulum joint 12. The two frame parts 4, 8 can thus perform a pendulum motion and a pivoting motion relative to each other for performing a steering process of the vibration roller 1. The pendulum joint 12 comprises a front connection element 2 (FIGS. 6 to 11) which is connected to the front frame part 4 and the articulation joint 10 comprises a rear connection element 6 (FIGS. 6 to 11) which is connected to the rear frame part 8. The front and the rear connection element 2, 6 can be arranged as a separate component or integrally with the front or rear frame part 4, 8. The combined articulated pendulum joint is further formed in such a way that the articulation joint 10 and the pendulum joint 12 are directly connected to each other in that the pendulum joint 12 comprises a rotary body 14 (FIG. 6) or a torsion bearing element 22 (FIGS. 7 to 11), which is rotatably arranged on the front connection element (2) about the pendulum axis (A.sub.T), wherein the joint part of the articulation element 10 which is complementary to the joint part of the articulation element 10 on the frame side is arranged on the rotary body 14 or the torsion bearing element 22.
(17) The pendulum motion occurs by way of a torsion of the two connection elements 2, 6 (FIGS. 6 to 11) or the front and rear frame parts 4, 8 relative to each other about a pendulum axis A.sub.T, which extends in the direction of the longitudinal axis of the vibration roller 1. In a position of “straight travel” of the joint arrangement 3, the pendulum axis A.sub.T also extends parallel to a flat ground surface 40.
(18) A steering motion, i.e., the pivoting of the two frame parts 4, 8 relative to each other, occurs about a steering axis A.sub.S, which is inclined about an acute angle α relative to the pendulum axis A.sub.T and intersects the pendulum axis A.sub.T. The steering axis A.sub.S is further situated in the steering position of “straight travel” of the vibration roller 1 in the vertical central plane E.sub.v (FIG. 2) of the vibration roller 1. In the illustrated preferred embodiment, the steering axis A.sub.S is inclined to the rear. The direction to the rear shall mean the direction opposite to the forward travelling direction R.sub.F, namely in the direction of the rear wheels 7, or a direction in which the vibration roller 1 is moved in the main operating state.
(19) In a turned-in position, as shown in FIG. 3 and FIG. 4 in forward travel by way of example for a steering angle φ (FIG. 4) to the right into the plane of the drawing, it is no longer possible to refer to a vertical central plane E.sub.v (FIG. 2) of the vibration roller 1, but to a vertical central plane E.sub.v1 (FIG. 4) of the front frame part 4 and a vertical central plane E.sub.v2 (FIG. 4) of the rear frame part 8. Furthermore, the pendulum axis leaves its alignment parallel to the ground surface 40 in the case of a steering angle. It remains within the vertical central plane E.sub.v1 of the front frame part 4 however.
(20) This leads to a tilting moment on the front frame part 4 and the front wheel carrier 4′ of the drum 5. However, it is prevented by compensation in the pendulum joint 12 that the part 9 of the front frame part 4 situated in the outer curve region will lift off, as is illustrated in FIG. 5 by way of example as a theoretical state for a steering angle to the left. Since the drum 5 rests on the ground, other than shown in FIG. 5, pendulum compensation takes place and the pendulum axis A.sub.T is deflected during the steering process by an angle γ (FIG. 3) which changes with the steering angle β. The greater the steering angle the greater the angle γ. γ is the angle which is formed by the pendulum axis A.sub.T and an imaginary plane 80 or a straight line extending parallel to the ground surface 40. During straight travel this angle is theoretically 0°, unless a different angle is chosen constructionally for straight travel.
(21) In actual fact, the tilting moment acting on the frame parts 4, 8 leads to a shift in the centre of gravity and thus to an increase in the stability of the vibration roller 1. Furthermore, the rear wheel 7′ which is on the outside in the curve is relieved and the load distribution on the rear wheels 7 becomes more constant. As a result of the geometric arrangement of the two frame parts 4, 8, there is an improved directional behaviour in straight travel, because the vibration roller 1 tries, as a result of the inclined steering axis A.sub.S, to return from a turned-in state to straight travel. This is especially advantageous in the case of inadvertent turning in. Furthermore, the pendulum angle is upwardly limited with increasing steering angle, which reduces the likelihood of collision between the front and rear frame part 4, 8 of the vibration roller 1.
(22) The embodiments according to FIGS. 6 to 11 respectively illustrate details of the joint arrangement 3, which allows a torsional movement of the front and the rear frame part 4, 8 relative to each other about the pendulum axis A.sub.T and a pivoting movement about the steering axis A.sub.S, so that it acts as an articulated pendulum joint. Each embodiment is shown with a front connection element 2 and a rear connection element 6, via which the respective joint arrangement 3 is connected to the front and rear frame part 4, 8. The connection elements 2, 6 are preferably arranged as flanges. It is understood that the joint arrangement 3 can respectively alternatively also be directly arranged on the front and rear frame part 4, 8 in that the joint part of the pendulum joint 12 on the frame side and the parts of the articulation joint 10 on the frame side are arranged integrally with the front and rear frame part 4, 8. The joint aspect in all embodiments is the steering axis A.sub.S inclined to the rear in operative connection with the pendulum axis A.sub.T, which is aligned in straight travel horizontally or in the longitudinal direction of the vibration roller 1.
(23) Like parts are provided with like reference numerals in the embodiments of the joint arrangement 3.
(24) In the first embodiment of the joint arrangement 3 which is shown in FIG. 6, the pendulum joint 12 is arranged as a rotary body 14 which is rotatably arranged about the pendulum axis A.sub.T on the front connection element 2. The articulation joint 10 is formed on the one hand by two diametrically protruding joint pins 20, 20′ on the rotary body 14 and on the other hand by two bearing eyes 28, 28′, which are arranged on two parallel yoke legs 15, 17 on the rear connection element 6. The rotational axes of the joint pins 20, 20′ and the associated bearing eyes 28, 28′ extend coaxially to the steering axis A.sub.S which is inclined to the rear. The two yoke legs 15, 17 are connected to each other via the rear connection element 6.
(25) In the example shown in FIG. 6, the two yoke legs 15, 17 are arranged orthogonally with respect to the steering axis A.sub.S and the rotational axes of the joint pins 20, 20′, wherein they protrude upwardly from the rear connection element 6 in an inclined fashion under an angle β. They comprise flat bearing surfaces 19, 19′, on which bearing counter-elements 21, 21′ can be positioned in a custom-fit manner on the ends of the joint pins 20, 20′ with respective bearing surfaces. An anvil shape is thus produced in this case, in particular, in which the bearing counter-elements 21, 21′ transmit the axial forces acting on the joint pins 20, 20′ to the yoke legs 15, 17.
(26) In accordance with one embodiment of the present invention, the angle α′ of the arrangement of the yoke legs 15, 17 which is inclined to the vertical is obtained by the inclination of the steering axis A.sub.S about the angle α relative to the pendulum axis A.sub.T.
(27) In the second embodiment shown in FIG. 7, a torsion pin receptacle 27 is arranged on the front connection element 2, in which a torsion pin (not shown) of a torsion bearing element 22 is held. The pendulum joint 12 is formed in this manner, which allows torsion of the two connection elements 2, 6 relative to each other about the pendulum axis A.sub.T. A cylindrical oblique borehole 23 is provided in this embodiment on the torsion bearing element 22, which borehole penetrates the torsion bearing element 22 completely and is inclined at an angle α in relation to the pendulum axis A.sub.T. A bearing shaft 24 is accommodated in said borehole 23 such that its two ends protrude diametrically from the torsion bearing element 22. The two ends are connected to the yoke legs 15′, 17′ via ball-and-socket joints. The bearing shaft 24 is provided for this purpose at both of its free ends with bearing elements 26, 26′, which are designed as spherical heads 30, 30′.
(28) The yoke legs 15′, 17′ are aligned orthogonally to the rear connection element 6. An upper bearing element 16 and a bottom bearing element 18 are formed on said legs, which bearing elements comprise spherical head receptacles 32, 32′. The spherical heads 30, 30′ are mounted in the spherical head receptacles 32, 32′. The bottom yoke leg 15′ is longer than the upper yoke leg 17′ as a result of the alignment of the steering axis A.sub.S to the rear, and the distance of the bottom bearing element 18 from the rear connection element 6 is greater than the distance of the upper bearing element 16 from the rear connection element 6.
(29) The articulation joint formed in this manner enables both the introduction of torsion loads into the pendulum joint 12 and the transmission of pivoting movements between the front and the rear connection element 2, 6.
(30) The third embodiment shown in FIG. 8 differs from the second embodiment according to FIG. 7 in that two bearing shafts 25, 25′ are arranged diametrically on the torsion bearing element 22 and are aligned in a precisely radial manner. In this embodiment, the bearing shaft 25, which carries the bottom bearing element 18, is offset to the front in the direction of the pendulum axis A.sub.T, whereas the bearing shaft 25′, which carries the upper bearing element 16, is offset to the rear. As a result, the bottom yoke leg 15′ is longer than the upper yoke leg 17′. The inclination α of the steering axis A.sub.S is obtained from the offset of the two bearing shafts 25, 25′ on the pendulum axis A.sub.T and the respective offset of the bearing elements 16, 18 arranged on the respective yoke legs 15′, 17′ as well as the distance of the two yoke legs 15′, 17′ from each other.
(31) The yoke legs 15′, 17′ and the bearing elements 16, 18 are arranged in this embodiment offset in the direction of the pendulum axis A.sub.T with respect to an axis perpendicularly to the pendulum axis A.sub.T. In particular, the bottom yoke leg 15′ is arranged slightly longer than the upper yoke leg 17′, so that the bearing elements 16, 18 are mounted on an axis inclined to the vertical, which in this case is an axis parallel and coaxial to the steering axis A.sub.S.
(32) In the fourth embodiment of the joint arrangement 3 according to FIG. 9, the two bearing shafts 29, 29′ form a pair of shaft stubs. They are placed on the torsion bearing element 22 and are inclined to the rear by the angle α according to the first and second embodiment of FIG. 6 and FIG. 7. Accordingly, the two parallel yoke legs 15, 17 of different length are upwardly inclined about an angle α′ as in the first embodiment, so that the steering axis A.sub.S is formed which is inclined to the rear about the angle α. The free ends of the bearing shafts 29, 29′ are arranged as cylindrical pins 39, 39′, which are mounted in an axially non-displaceable manner in respective bearing eyes 28, 28′ in the yoke legs 15, 17.
(33) The fifth embodiment according to FIG. 10 comprises a torsion bearing element 22 with a continuous cylindrical borehole 23 like the third embodiment according to FIG. 8, which borehole is inclined to the rear under an angle α and thus determines the inclination of the steering axis A.sub.S. A bolt 31 is guided through the borehole 23, whose free ends are respectively provided with a collar 33, 33′. The bolt 31 is supported by the two collars 33, 33′ in the axial direction on annular bearing surfaces 34, 34′ on the torsion bearing element 22, which surfaces are arranged coaxially to the bolt 31.
(34) The sixth embodiment of the joint arrangement 3 illustrated in FIGS. 11 and 12 comprises a pendulum stop 35, consisting of a finger 36 and a stop 37, for limiting the pendulum angle in the upward direction depending on the inclination α of the steering axis A.sub.S and the steering angle β. Accordingly, the pendulum angle decreases in a counterclockwise manner according to double arrow 40 during the steering to the left with increasing steering angle β. During steering to the right, the pendulum angle decreases in a clockwise manner according to the double arrow 40 with increasing steering angle β. Apart from that, the joint arrangement 3 corresponds to the embodiment according to FIG. 8. FIG. 11 shows the joint arrangement 3 and the pendulum stop 35 during straight travel of the vibration roller 1 at a preferred pendulum angle of ±12°. In FIG. 12, the joint arrangement 3 with the pendulum stop 35 is shown in the turned-in state at a preferred maximum pendulum angle of ±6°.
(35) FIGS. 11 and 12 illustrate the decrease in the pendulum angle in the counterclockwise manner during steering to the left. The measure X shown in FIG. 11 represents the pendulum angle during straight travel. FIG. 12 shows the state when the vibration roller 1 is steered to the left on the plane, i.e., the ground surface 40. X′ represents the decreased measure of the residual pendulum angle.
(36) The decrease in the pendulum angle in the clockwise manner during steering to the right occurs by a pendulum stop of identical design, which is arranged in a mirror-inverted manner on the right side of the joint arrangement 3 and is covered in the view of FIGS. 11 and 12 by the torsion pin receptacle 27 and the torsion bearing element 22.
(37) The required free space between the front and rear frame part 4, 8, and the front frame part 4 and the driver's cabinet 11 (FIG. 1), in particular, can thus be decreased by reducing the pendulum angle with increasing steering angle β and by lifting the vibration roller 1 in the region of the articulated joint arrangement 3 by the height h according to FIG. 13.
(38) The dependence of the limitation angle δ about the pendulum axis A.sub.T on the angle of inclination α of the steering axis A.sub.S and the steering angle β is shown in the three-dimensional geometric illustration of relevant variables of the joint arrangement 3 according to FIG. 13.
(39) While the present invention has been illustrated by description of various embodiments and while those embodiments have been described in considerable detail, it is not the intention of Applicant to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications will readily appear to those skilled in the art. The present invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of Applicants' invention.
