MOTOR ROAD ROLLER

Abstract

The invention relates to a motor-driven pavement roller having rigid supporting frame (1) that is braced on a pair of operating tools, and at least one of these operating tools is pivotable and is connected to a -shaped frame (7), and the -shaped frame (7) is connected to rotary axes, which are perpendicular to one another, of the operating tool and of a pivot shaft (9), and the pivot shaft (9) serves to pivot the operating tool relative to the supporting frame (1). To enable increasing the working output of the pavement roller and widening the roller pivot angle, the invention provides that the axes of the operating tool are mounted in intersecting fashion on the -shaped frame (7).

Description

The invention relates to a motor-driven pavement roller as defined by the preamble to claim 1.

The invention can be used in road construction, and in particular for technical means for compacting road construction compositions, that is, for pavement rollers.

Motor-driven pavement rollers, both with a center pivot driven supporting frame and with a rigid supporting frame, are used in road construction. The refinement according to the invention relates to pavement rollers having a rigid supporting frame and to the roller pivot system.

From Russian Patent Disclosure RU 2024673, a construction of a motor-driven pavement roller having a rigid supporting frame is known. The supporting frame is braced from below on a pair of operating tools embodied as rollers. Each roller unit includes one roller. To steer the motor-driven pavement roller, at least one of the roller units must be embodied pivotably about a steering axle that is vertical to the supporting frame. Each of the roller units has a -shaped (U-shaped) frame, between the legs of which the roller is rotatably supported about its center axis. This frame embraces the roller and is braced on the center axis of the roller. The steering mechanism includes a vertical pivot shaft, which matches the steering axle. The vertical pivot shaft is mounted on the -shaped frame and more precisely on the supporting frame thereof. The pivot shaft is a part of the rocker bearing of the supporting frame. The pivot shaft is kinematically connected to a drive mechanism. Usually, a hydraulic cylinder is used as the drive mechanism. The steering mechanism is embodied such that geometric center axes and steering axles extend perpendicular to one another and intersect one another. It is understood that the physical center axes and pivot axes extend only vertically to one another and do not intersect.

The primary disadvantage of this known construction is that the steering mechanism employed has a limited pivot angle. This offers no opportunity of increasing the width of the rolled strip and thus of increasing the work output of the compacting operations. This disadvantage pertains to a pavement roller having two steerable roller units. Moreover, this kind of steering mechanism substantially reduces the freedom of motion of the pavement rollers that are equipped with only one steerable roller unit. Furthermore, the pivoting device of the -shaped frame, which includes a bearing unit, a drive mechanism, and the kinematic connection of the drive mechanism to the pivot shaft, is disposed on the supporting frame and thus these elements are connected to one another mechanically. This makes the entire construction of the steering mechanism more difficult and makes it harder to repair.

From German Patent DE 198 13 475 C1, a motor-driven pavement roller with a rigid supporting frame and with at least one operating tool embodied as a roller is known. At least one roller unit is disposed on the supporting frame. The roller unit comprises a -shaped (U-shaped) frame and a horizontal, cylindrical roller. The roller is supported rotatably between the free ends of the legs of the -shaped (U-shaped) frame, about the center axis thereof. On its sides remote from the free ends, the legs are connected to one another by a crossbar, extending parallel to the center axis, of the -shaped (U-shaped) frame. The roller unit is disposed pivotably on the supporting frame about a steering axle. The frame is disposed upright below the supporting frame, and the free ends of the legs of the frame, which extend approximately parallel to the steering axle, point downward, and the steering axle stands vertically on both the crossbar and the center axis. If the motor-driven pavement roller has two roller units, then both of them are steerable, and one of the roller units can be supported in pendulum fashion, in order to compensate for differences in the slope of the underlying surface. Steering a steerable roller unit utilizes a steering mechanism having a hydraulic cylinder that is disposed obliquely in the travel direction between the supporting frame and the frame.

From German Patent Disclosure DE 37 12 099 A1, a motor-driven pavement roller with a rigid supporting frame and with two operating tools, each embodied as a roller, is known. Both rollers are supported rotatably about their center axis in a -shaped (U-shaped) frame. Each of the two frames rests with its crossbar, which connects the two legs, on the supporting frame. Both frames are supported pivotably each about its own steering axle that stands upright both on the crossbar of the respective frame and on the center axis of the respective roller supported rotatably between the legs of that frame.

From German Utility Model DE 2002 00 88 U1, a motor-driven pavement roller with a rigid supporting frame and with two operating tools, each embodied as a roller, is known. Each of the rollers is rotatably supported about its center axis in a frame. The frames are each connected in articulated fashion via a center pivot with a vertical steering axle to the centrally disposed supporting frame, on its opposed face ends. One of the two rollers can be steered relative to the supporting frame and the remaining roller, or else both rollers can be steered in the same or opposite directions with identical or different steering angles. Thus the motor-driven pavement roller can even drive obliquely to the orientation of its supporting frame, in the so-called press-on tire offset, as a result of which an increase in the width of the compacted strip can be obtained.

A common feature of the known motor-driven pavement rollers is that in the working mode they allow an only limited width of the compacted strip. Moreover, they have a greatly restricted maneuverability, since the steering mechanisms used and/or the articulated connections of the steerable rollers to the supporting frame permit only a restricted oblique position of the rollers relative to the supporting frame. An additional disadvantage of the known motor-driven pavement rollers is their poor driving behavior, associated with a restricted freedom of motion along the routes between locations where they are used.

It is the object of the invention to increase the working output in compacting operations by means of increasing the width of the compacted strip, specifically by widening the roller pivot angle. A further object is to improve the freedom of motion of the pavement roller and to improve the repair conditions of the roller pivot system.

This object is attained by the features of claim 1.

The stated object is attained as follows.

The motor-driven pavement roller has a rigid supporting frame, which is braced at the bottom on a pair of operating tools, each preferably including at least one roller. At least one of these operating tools is embodied as a pivoting device that is pivotable about a steering axle that stands vertically on the supporting frame. The pivoting device includes a U- or -shaped frame between the legs of which at least one roller of an operating tool is enclosed, supported rotatably about a horizontal rotary axis. The crossbar, extending parallel to the horizontal axis, of the U- or -shaped frame is coupled to the supporting frame by means of a joint having a vertical pivot shaft. The pivot shaft matches the steering axle of the respective pivoting device. The -shaped frame is disposed horizontally, so that the crossbar is located on the outside. The crossbar is coupled to a front part of the supporting frame.

This front part can be built in in such a way that relative to the middle part of the supporting frame, it can be displaced back and forth in the travel direction of the pavement roller.

The effect of the proposed refinement can be enhanced markedly if at least one operating tool includes a pair of dissimilar rollers.

A first roller of a pair of dissimilar rollers can be embodied as a roller, supported rotatably about its center axis, in the form of a horizontal circular cylinder, which is for instance hollow and optionally can filled with a liquid, for instance, or a pourable substance, such as sand, and which can be manufactured for instance of metal. A second roller of a pair of dissimilar rollers can be embodied as a plurality of wheels, rotatably supported on a common wheel axle, for instance wheels of solid rubber.

Such dissimilar rollers can be combined into a carriage similar to a bogie with the aid of a pair of lateral beams.

A middle part of such lateral beams can be coupled, by means of a joint provided with a horizontal axis, to the -shaped frame that for instance embraces the lateral beams. If the frame embraces the lateral beams, then the lateral beams are disposed between the legs of the frame. The -shaped frame, in turn, is coupled to the front part of the supporting frame. The carriage is mounted pivotably about the horizontal axis of the joint. This can serve to compensate for unevenness of the ground, and both rollers of a pair of dissimilar rollers mounted on the carriage stays in contact with the ground. Alternatively or in addition, the carriage can be mounted in pivotably drivable fashion about the horizontal axis of the joint. As a result, by actively pivoting it about the horizontal axis of each carriage, selectively one of the two dissimilar rollers, or both, come into contact with the ground. This can be advantageous for instance if the motor-driven pavement roller drives itself from one location to another where it is to be used. For instance, if one of each of the dissimilar rollers of two carriages provided on one motor-driven pavement roller is embodied as a plurality of solid rubber wheels or the like mounted on a common wheel axle, then as a result the driving performance and along with it the freedom of motion of the motor-driven roller along routes between the locations of use can be improved considerably in comparison to the prior art.

Furthermore, both operating tools can each be pivotable about their own steering axles that extend parallel to one another.

Preferably, a steering mechanism of a pivoting device includes two hydraulic cylinders. The two hydraulic cylinders are disposed in opposite directions obliquely to a longitudinal axis of the supporting frame of the motor-driven pavement roller. Per hydraulic cylinder, a first end of each is connected pivotably to the supporting frame about an articulated axle extending parallel to the steering axle. Each second end of the two hydraulic cylinders is connected pivotably to the frame, for instance to the crossbar thereof, about an articulated axle extending parallel to the steering axle. The two hydraulic cylinders are pivotably connected to the frame by their second ends, on the sides of the frame opposite the steering axle. In the event of a steering angle of 90° or more, this ensures that at least one of the two hydraulic cylinders effects a return motion of the pivoting device into its outset position, in which the crossbar extends orthogonally to the longitudinal axis of the supporting frame of the motor-driven pavement roller. Thus the steering mechanism permits a steering angle of a steerable pivoting device by up to 90° in both directions relative to the longitudinal axis of the supporting frame, and thus in a motor-driven pavement roller having two steerable pivoting devices, it enables travel transversely to the longitudinal axis of the supporting frame, along with a considerable increase in the width of the compacted strip. To prevent the motor-driven pavement roller from tipping sideways, the steering angle can be restricted to an angle of less than 90° in both directions. Alternatively or in addition, at least one pivoting device can be equipped with two identical or different rollers, which prevents the motor-driven pavement roller from tipping over onto its side. In a version having one or two pivoting devices, a considerably improved maneuverability of the motor-driven pavement roller is obtained as well.

The invention will be described in further detail in conjunction with the drawings. In the drawings:

FIG. 1 shows the general view of the motor-driven pavement roller with one pivoting device;

FIG. 2 shows the general view of the steering mechanism of a pivoting device, with the intersecting rotary axes and pivot axes;

FIG. 3 shows the general view of the motor-driven pavement roller with two pivoting devices;

FIG. 4 schematically shows a plan view of the pavement roller with two pivoting devices;

FIG. 5 shows the general view of the motor-driven pavement roller with operating tools which are embodied by a pair of dissimilar rollers;

FIG. 6 schematically shows the pavement roller of FIG. 5 in plan view; and

FIG. 7 shows the diagram for explaining the mode of operation in performing compacting operations with the motor-driven pavement roller of FIG. 5.

The motor-driven pavement roller (FIG. 1) includes a rigid supporting frame 1. An engine 2 and a cab 3 for the driver are mounted on the supporting frame 1. The frame 1 is braced from below on a pair of operating tools in the form of smooth rollers 4 and 5. One of the operating tools is embodied as a pivoting device, disposed pivotably on the supporting frame 1 about a steering axle. The pivoting device includes the pivotable roller 4, which is coupled, rotatably supported about a horizontal rotary axis 6, to a -shaped frame 7, which is disposed horizontally. When the frame 7 is disposed horizontally, its legs and a crossbar connecting the two legs extend in a plane that is parallel to the longitudinal axis 16 of the supporting frame 1. The frame 7 is connected to the end of the supporting frame 1 by means of a steering mechanism. The steering mechanism includes a joint, which comprises a bush 8 and a pivot shaft 9 forming a steering axle. More precisely, the supporting frame 1 is rigidly coupled to a vertical pivot shaft 9. The pivot shaft 9 is located outside the horizontal projection of the operating tool, or its roller.

One of the possible embodiments of the pivot drive mechanism is shown in FIG. 2. Here, the force-operated pivoting motion of the -shaped frame 7 in the joint is effected by means of a hydraulic cylinder 10, both of which are connected pivotably to the frame 7 and to the structural part of the supporting frame 1. The pivot angle of the roller can attain 90°. This is witnessed by the fact that point “A” of the rod mounting of the hydraulic cylinder 10 shifts on the -shaped frame 7 to point “B”. The rotary axis 6 of the roller 4 and its pivot shaft 9 are mounted in intersecting fashion on the pavement roller, and their geometrical axes are perpendicular to one another.

In the construction of the motor-driven pavement roller having two pivotable rollers, the pivoting device of each roller is entirely identical to the above-described apparatus (FIG. 3).

FIG. 4 schematically shows the pavement roller with two pivot rollers in plan view. In this position, the outward-pivoted rollers double the width of the compacted strip. Their pivot angle at the same time is much less than 90°.

In FIG. 5, a modification of a motor-driven pavement roller with four rollers is shown. It is described in Soviet Union Patent Disclosure SU 1401097. Here, the conventional pivoting device is replaced by a refinement of the invention. Besides the rigid supporting frame 1 with the engine 2 and the cab 3, the pavement roller has two operating tools. Each of these operating tools has a pair of dissimilar rollers. One roller 11 is pneumatic. A second roller 12 is smooth and vibrates. These rollers 11 and 12 are combined into a carriage with the aid of a pair of lateral beams 13. These lateral beams 13 are connected to the -shaped frame 7 by means of a horizontal joint 14. The frame is coupled to a front part of the supporting frame 1 with the aid of a joint. The joint includes a bush 8 and the vertical pivot shaft 9. Both front parts are embodied movably relative to the middle part of the supporting frame 1. The displaceability back and forth of the front parts of the supporting frame 1 is ensured by providing that they are connected to displaceable beams 15. The beams 15 are inserted into linear guides of the supporting frame 1. These guides have the same orientation as the motion of the pavement roller. An adjusting drive mechanism of the beams 15 is not shown in the drawing. Preferably, a hydraulic drive mechanism is employed. The steering mechanism of the operating tools of the multi-roller machine is identical to the construction in FIG. 2. The special feature of this pavement roller is that thanks to the articulated connection of the lateral beams 13 to the -shaped frame 7 and to the possibility of changing their angle of inclination under the influence of a special drive mechanism (not shown in the drawing), it becomes possible for one or the other roller, or their combination, depending on the material to be compacted, to come into contact with the surface to be compacted.

In FIG. 6, the plan view of a motor-driven pavement roller with four rollers is shown schematically. In this machine, the width of the compacted strip can be attained not only by providing that the operating tools are can be pivoted about a wide angle, but also by providing that their undercarriage can also be enlarged, because the front parts of the supporting frame 1 can be pushed apart by means of the movable beams 15.

The function of the motor-driven pavement roller with the novel pivoting system of the operating tools is illustrated taking as an example the use of the pavement roller with four rollers.

If compacting operations are performed by means of rolling, depending on the type of material, the user chooses one or the other complete set of rollers, because the carriages of each operating tool are rotatable about the horizontal joint 14. The requisite rollers are put into contact with the surface to be compacted, and the other rollers are suspended. At the same time, an optimal rolling width is selected by deflecting the rollers by the requisite angle. This is attained with the aid of the pivoting system according to the invention and in that the front parts of the supporting frame 1 (FIG. 6) are moved apart. After that, the rolling operation can be performed in accordance with the functional diagram in FIG. 7. For instance, the smooth rollers 12 are suspended when the surface compositions are being compacted, and the pneumatic rollers 11 (position I, FIG. 7) become supporting rollers. To intensify the soil compaction, taking special aspects of the soil (dense or loose) into account, a complete set of both rollers 11 with pneumatic tires and a smooth vibration roller 12 (position Ill, FIG. 7) can be employed. For compacting an aggregate base, a combination of two rollers can be employed (position V, FIG. 7). These form a so-called combination pavement roller. When compacting mixtures of asphalt and concrete, it is appropriate to use a combination of rollers in accordance with positions II and IV, as well as other combinations, depending on the brand name of the asphalt and concrete mixture, the initial temperature of the asphalt, and the ambient temperature.

With a wide range of variation of the roller width and considerable process-related technical capabilities of the motor-driven pavement roller with four rollers, a possibility of automating the compacting operation via an on-board computer is achieved for the first time, using a software package in the on-board computer.

Claims

1. A motor-driven pavement roller having a rigid supporting frame, which is braced from below on a pair of operating tools, and an operating tool of these is pivotable and is enclosed in a U- or -shaped frame, and a crossbar of the frame is connected to the supporting frame by means of a joint having a vertical pivot shaft, characterized in that

the frame is disposed horizontally, so that the crossbar is located on the outside and is coupled to a front part of the supporting frame.

2. The motor-driven pavement roller of claim 1, characterized in that

the front part of the supporting frame, which front part is coupled to the frame, is disposed displaceably back and forth in the travel direction of the motor-driven pavement roller relative to the middle part of the supporting frame.

3. The motor-driven pavement roller of claim 1, characterized in that

an operating tool includes a pair of dissimilar rollers.

4. The motor-driven pavement roller of claim 3, characterized in that

the pair of dissimilar rollers is combined in a carriage with the aid of a pair of lateral beams.

5. The motor-driven pavement roller of claim 4, characterized in that

the middle part of each lateral beam is coupled to the frame by means of a joint having a vertical pivot shaft, and the frame is in turn coupled to the front part of the supporting frame, and the carriage is mounted pivotably about a horizontal axis of the joint.

6. The motor-driven pavement roller of claim 5, characterized in that

the lateral beams are disposed between the legs of the frame.

7. The motor-driven pavement roller of claim 1, characterized in that

both operating tools are pivotable.

8. The motor-driven pavement roller of claim 1, characterized in that

the end of the supporting frame is connected to the pivot shaft and mounted such that it is displaceable back and forth in the travel direction of the pavement roller relative to the remainder of the supporting frame.

9. The motor-driven pavement roller of claim 1, characterized by

a steering mechanism for an operating tool that is pivotable about a steering axle, the operating tool including two hydraulic cylinders disposed in opposite directions obliquely to a longitudinal axis of the supporting frame of the motor-driven pavement roller, and per hydraulic cylinder: a first end is connected in articulated fashion to the supporting frame about an articulated axle extending parallel to the steering axle, and a second end is connected to the frame in articulated fashion about an articulated axle extending parallel to the steering axle, on opposite sides of the frame from the steering axle.