EP2711460B1 - Construction machine with material conveyor system - Google Patents

Description

The invention relates to a construction machine with material conveying system according to the preamble of patent claim 1.

Bituminous bonded mixes are produced in mixing plants. For this purpose, grit is heated in a drum furnace and then fed to a mixer. Hot bitumen is additionally injected into this mixer and mixed with the hot chippings. This mixture is then stored in hot silos or transported directly by truck to the road construction site. The asphalt leaves the mixer with a high and very even temperature. By the subsequent storage and especially by the transport, the mix cools unevenly. Typically, the asphalt still has a very high core temperature when delivered to the job site, but the edge areas are severely cooled. A mix with a uniform temperature is then no longer available. A uniform temperature distribution in the mix is one of the most important parameters for the installation and compaction of asphalt. Many material properties of the asphalt depend on this temperature. In essence, this is related to the temperature-changing viscosity of the bitumen. Therefore, an uneven temperature of the mix is a factor that negatively affects the quality of the pavement. It leads to density differences in the load capacity, as well as errors in the layer thickness and as a result to unevenness of the road.

These findings were used and implemented in a feed system to improve the homogeneity of the mixed product temperature. For this purpose, z. B. augers, which are arranged transversely to the main flow in Gutbunker. Such a system is for example in the WO 2007/117287 A1 disclosed. Due to the screw conveyors, colder mix is constantly conveyed from the edge areas into the hotter main flow during the feeding process. This permanent mixing leads to a better temperature homogeneity of the mix. It is important to avoid a so-called tunnel defect as far as possible. This occurs in screws with constant pitch and constant outside diameter. Once the first turn of the screw is filled with material, no further material can enter from above into the winding, whereby the desired mixing effect does not occur. The above Revelation therefore describes auger flights with variable pitch or variable outer diameter of the flight flank.

The WO 2009/061278 A1 describes a conveyor for a road vehicle. The conveying device comprises a material bunker for receiving built-in mixed material, the material bunker comprising two bunker halves with transverse conveyor worms arranged therein. Through the cross augers the Einbaumischgut is transported out of the bunker halves on a longitudinal conveyor. It is possible to adjust the speed of the transverse auger regardless of the speed of the longitudinal conveyor.

The EP 2 377 994 A1 The applicant discloses a similar method with a plurality of transverse augers, which are operable independently of each other. In addition, a temperature measuring system is used there.

The EP 0 957 204 A1 discloses a paver with cross conveyors arranged in bucket halves, wherein different portions of the bucket halves can pivot about the cross conveyor such that residual material slides in the direction of the cross conveyor.

Further concepts for the optimization of the mixed product temperature are in the DE 20 2008 010 719 U1 as well as in the EP 1 213 390 A2 both by the Applicant. The former provides an additional heating for the mix, which utilizes the engine waste heat of the truck. The latter refers to a special configuration of a conveyor belt for tacky and / or solidifying material.

In addition, from the DE 1 459 716 A1 a universal machine for bituminous road construction known. This has a container for bituminous pavement material. In this, a screw conveyor is mounted transversely to the direction of travel of the machine. Under this screw conveyor is a gap whose cross section is variable in the conveying direction of the screw conveyor.

The object of the invention is to improve a construction machine with the help of structurally simple means to the effect that the quality of the processed therein mixed material is improved.

This object is achieved with the features of claim 1. Advantageous developments are given in the dependent claims.

The inventive, preferably mobile construction machine comprises a Gutbunker for receiving bulk material. It also has a material handling system for conveying the bulk material, wherein the material delivery system in the field of Gutbunkers at least having a screw conveyor. The invention is characterized in that under the screw conveyor, a gap preferably extends; this runs essentially parallel to an axis of the screw conveyor, that is, that the center axis of the gap and the axis of the screw conveyor in a plan view from above at an angle ≤ 30 °, preferably ≤ 15 ° intersect. Another feature of the invention is that the cross section of the gap changes in the conveying direction of the screw conveyor. This offers the advantage that the tunnel effect described above can be counteracted even when using a conventional screw conveyor. The gap allows material to escape down the auger, allowing new material to enter the auger from above. This results in a mixing process in the screw and it is achieved a higher uniformity with respect to temperature and grain sizes of the mix. Thus, the invention makes it possible that the desired mixing effect can be achieved even with a constant screw conveyor. This considerably reduces the production costs of the screw conveyors, since the production of screw conveyors with conical core shafts or of screw conveyors whose outer diameter changes in the conveying direction is considerably more complicated and also offers considerably fewer possibilities for the use of identical parts.

It is advantageous if the gap is open at the bottom and below a downstream conveyor system runs, which supports the further transport of the mixed material. As a result, the material which has escaped downwards out of the screw can be transported away more quickly and there is room for material to move further in both the gap and in the screw conveyor, as a result of which the mixing effect is further increased. In addition, both the energy requirement and the torque to be applied to the screws decreases because the material is transported not only by the screws but also by the downstream conveyor system. The downstream conveyor system may comprise, for example, a scraper belt or any other suitable conveying means for bulk material.

It is useful if the screw conveyor is arranged in a trough and the gap extends at an underside of the trough. This provides an improved conveying effect of the screw conveyor and also ensures that all material is conveyed in the desired direction and does not escape laterally in the radial direction of the screw conveyor. The trough can be any, z. B. have U-shaped cross-section. He In particular, the screw conveyor geometry can be adapted. The opening angle between the trough walls can also be freely selected in the range between 0 ° and 180 °.

It is also conceivable that the material handling system comprises a plurality of augers, each having an axis. This makes it possible to provide a plurality of flow rates, the merger further increases the mixing effect of the conveyor system. In addition, in this way material can be conveyed from several areas in the desired direction. Finally, the provision of multiple augers allows increased system capacity.

It is particularly favorable if the screw conveyors can be operated independently of each other. As a result, the various flow rates can be much more flexible. Thus, for example, different mixing ratios of different flow rates can be selectively changed, so that an optimal treatment of the mix is made possible under different conditions.

It is advantageous if the screw conveyors are arranged so that their axes are at an angle or parallel to each other. The former configuration allows the combination of different flow rates. The latter can ensure, for example, an increased delivery rate.

It is also conceivable that the screw conveyors are arranged in several groups, wherein the axes of the screw conveyors run within a group parallel to each other.

It is particularly favorable if the different groups are arranged so that the axes of the screw conveyors of different groups are at an angle not equal to zero. As a result, the delivery volume can be increased at the same time and different delivery flows can be brought together. In addition, the largest possible area can be covered with the screw conveyors in this way.

In a further variant, the pitch of the at least one screw conveyor can change in the conveying direction. This increases the gear volume of the screw along the conveying path, so that material can move up again and again. Thus, the mixing effect of the conveyor system is further increased.

In a further variant, the worm shaft of the at least one screw conveyor can be conical. Here, too, an improvement in the mixing effect is achieved by increasing the passage volume along the conveying path.

In a further variant, the flank of the screw thread of the screw conveyor may have an outer diameter which varies in the conveying direction or remains constant. In the former case, in turn results in an increase in the passage volume along the conveying path, which increases the mixing effect. In the second case, the production costs are significantly lower.

It may be advantageous if the at least one screw conveyor is mounted only on one side. By eliminating a two-sided storage and a second bracket is unnecessary, which would hinder the flow of material under certain circumstances.

In a further variant, the construction machine may comprise at least one further conveyor system downstream of the conveyor worm, and the at least one conveyor worm may be operable in dependence on operating parameters of this downstream conveyor system. The conveying streams caused by the screw conveyor or by the several screw conveyors can thus be aligned with the downstream conveyor system.

It is particularly favorable if the construction machine further comprises a control system which controls the various flow rates generated by the screw conveyors and their relationship with one another. Such a control system simplifies the control of the construction machine. In addition, a more accurate adjustment of the system parameters can be achieved in this way. In addition, a control system allows continuous monitoring and adjustment of the operating parameters of the construction machine. In this way it can be ensured that predetermined operating states or operating conditions optimally adapted to the respective ambient conditions are maintained at all times.

The construction machine may be, for example, a paver or a feeder.

The invention relates to construction machines with a material delivery system of the type described above.

Figur 1

zeigt eine perspektivische Ansicht einer Baumaschine, in diesem Beispiel eines Straßenfertigers. Es kann sich jedoch auch um eine andere Baumaschine handeln.

Figur 2

zeigt eine perspektivische Ansicht eines erfindungsgemäßen Materialfördersystems mit sämtlichen Förderschnecken sowie eines schematisch dargestellten Regelungssystems mit einem Sensor.

Figur 3

zeigt eine Draufsicht von oben eines erfindungsgemäßen Materialfördersystems. Die Längsförderschnecken sind hier nicht abgebildet, damit der jeweils unter ihnen angeordnete Spalt sichtbar ist.

Figur 4a

zeigt eine perspektivische Schnittansicht eines erfindungsgemäßen Materialfördersystems.

Figur 4b

zeigt die gleiche perspektivische Ansicht wie Figur 4a. Die Längsförderschnecke ist wiederum nicht abgebildet, um den darunter liegenden Spalt sichtbar zu machen.

Figur 5a

zeigt eine schematische Ansicht in Richtung der Förderschneckenachse auf die Förderschnecke, den darunter liegenden Spalt sowie das nachgeordnete Fördersystem, in diesem Fall ein Kratzerband.

Figur 5b

zeigt die gleiche schematische Ansicht wie Figur 5a. Hier ist jedoch ein Ausführungsbeispiel abgebildet, in dem die Förderschnecke in einem Trog angeordnet ist.

In the following, an advantageous embodiment of the invention will be explained in more detail with reference to drawings.

FIG. 1

shows a perspective view of a construction machine, in this example, a paver. However, it can also be another construction machine.

FIG. 2

shows a perspective view of a material conveying system according to the invention with all augers and a control system shown schematically with a sensor.

FIG. 3

shows a plan view from above of a material delivery system according to the invention. The longitudinal screw conveyors are not shown here, so that each arranged below them gap is visible.

FIG. 4a

shows a perspective sectional view of a material delivery system according to the invention.

FIG. 4b

shows the same perspective view as FIG. 4a , The longitudinal auger is again not shown to make the underlying gap visible.

FIG. 5a

shows a schematic view in the direction of the screw conveyor axis on the auger, the underlying gap and the downstream conveyor system, in this case, a scraper belt.

FIG. 5b

shows the same schematic view as FIG. 5a , Here, however, an embodiment is shown, in which the screw conveyor is arranged in a trough.

In FIG. 1 is a construction machine 1 with a Gutbunker 2 for mixed or generally bulk material shown. A downstream conveyor system 3, in this case two scraper belts, extend in a central region of the goods bunker 2. This downstream conveyor system 3 serves to transport the mixed material under a driver's cab 4 through to the installation site.

FIG. 2 shows a material handling system 5, which can be arranged in Gutbunker 2. It comprises two longitudinal screw conveyors 6 and six transverse screw conveyors 7 and a rear wall 8. In the installed state, this rear wall 8 to the bunker rear wall 18. From the FIG. 2 it can be seen that the screw conveyors 6, 7 cover the entire floor area of the material handling system. Characterized in that the screw conveyors 6, 7 are operable independently of each other, so the different material flows from the different areas of the material delivery system 5 can be controlled specifically. For example, at the beginning of the installation process material, which is far away from the rear wall 8, preferably to the longitudinal screw conveyors 6 are promoted to then mix it with the material closer to the rear wall 8 and thus closer to the prime mover in the Usually an internal combustion engine, is located and therefore stays warm longer. The mixture balances the temperature of the material from different areas, so that the final built-in material has a uniform temperature throughout the entire installation.

FIG. 3 shows a plan view of the material conveying system 5 without the longitudinal screw conveyor 6. Between the transverse screw conveyor 7, two gaps 9 are shown, which are arranged below the longitudinal screw conveyor 6 and widening towards the rear wall 8 out. In this embodiment, the gaps 9 are downwardly open in plan view, so that the material passing through them falls directly onto the downstream conveyor system 3, which is not shown in this figure. However, it is also possible that the gap 9 is closed in plan view downwards and includes on its underside, for example, an inclined plane which drops to the rear wall 8, so that the material escaping from the longitudinal screw conveyor 6 in the gap, with the help the downgrade power is further promoted. In any case, the gap 9 is opened to the rear wall 8, in order to transfer material to the downstream conveyor system 3 at the latest at this opening.

FIG. 4a such as FIG. 4b show a perspective sectional view of a material conveying system 5 according to the invention FIG. 4b the longitudinal screw conveyor 6 is not shown. In the embodiment shown, the transverse screw conveyors 7a, 7b and 7c form a group. Their axes run parallel to each other. In this way, material from different areas of the material conveying system 5 can be conveyed in the direction of the longitudinal conveyor screw 6. Due to the fact that the transverse screw conveyors 7a, 7b and 7c can be operated independently of each other, delivery streams can be made of different ones Be targeted areas of the material handling system 5 at different times.

Based on FIGS. 4a and 4b the function of the material conveying system 5 will be described below. Mixing material that is introduced into the material conveying system 5 is first conveyed by all transverse conveyor screws 7 in the direction of the longitudinal conveyor screw 6. It may happen that the first transverse auger 7a already completely fills a turn of the longitudinal auger 6. By a rotation of the longitudinal screw conveyor 6, the completely filled turn is conveyed on to the next transverse screw conveyor 7b. If the material could not escape from the winding, it would not be possible for the transverse conveyor screw 7b to pass on material to the longitudinal conveyor screw 6. Consequently, the material conveyed by the transverse screw conveyor 7a to the longitudinal screw conveyor 6 would be conveyed past the two remaining transverse screw conveyors 7b and 7c directly to the downstream conveyor system 3. This would be disadvantageous if in the area of the transverse screw conveyor 7a, for example, particularly cold or particularly coarse-grained mix would be. This would then preferably installed in a first installation section, which would adversely affect, for example, the carrying capacity of the later road surface. In a material conveying system according to the invention, material can escape downwards through the gap 9 from the completely filled turn of the longitudinal conveyor screw 6, thus freeing space for material which is conveyed by the screw 7b to the longitudinal conveyor screw 6. As a result, a thorough mixing of the paving takes place, resulting in a more uniform and thus better quality road surface.

Figure 5a and Figure 5b show a schematic view of the longitudinal screw conveyor 6, the gap 9 and the downstream conveyor system 3 with a view from the rear wall 8 in the direction of the axis of the longitudinal screw conveyor 6. It shows FIG. 5a an embodiment without trough and FIG. 5b an embodiment with trough. You can also see the worm shaft 10 with the outer diameter 11 and the outer diameter of the screw flank 12. In FIG. 5b In addition, the trough walls 13 can be seen. They extend so far down that the smallest possible gap to the downstream conveyor system 3 remains. This ensures that as little material escapes through this gap. The trough walls 13 are arranged parallel to each other in this embodiment. Both for the opening angle upwards, as well as for the opening to the rear wall 8 towards any angle can be selected, even negative, ie, the gap opens in the opposite direction.

The gap 9 is shown here with a rectangular cross-section. But he can just as well have any cross section. He may be running about trapezoidal or with curves. In addition, in addition to the gaps 9 under the longitudinal screw conveyors 6, further gaps can be arranged below the transverse screw conveyors 7. Likewise, 1 column may be provided under all screw conveyors of the material handling system 5 and the construction machine.

In the illustrated embodiment, the material conveying system 5 has a rear wall 8 and side walls. However, it can just as well be arranged without additional walls directly in the area of Gutbunkers 2.

In a further variant, the downstream conveyor system 3, which is shown in the embodiment as a scraper belt, be any type of conveyor system.

Although the system shown here makes it possible to optimize the homogeneity of the mixed material even with constant conveying screws 6, 7, screw conveyors 6, 7 with a conical worm shaft 10 or with an outer diameter of the screw flank 12 changing in the conveying direction can be provided. Likewise, the pitch of the screw conveyor can be provided variably.

In a further variant, it is conceivable to store the screw conveyors 6, 7 only on one side; For example, in the case of the longitudinal screw conveyors 6, the bearing block on the side of the rear wall 8 could be omitted, so that it does not hinder the conveyance. In the transverse screw conveyors 7 storage on the side of the longitudinal screw conveyor 6 could be omitted, whereby an obstacle to the flow would be avoided here.

The material handling system 5 can also be used in any mobile or immobile construction machine that processes bulk material. In particular, the bulk material may be bituminous mixtures such as asphalts. For example, the construction machine can also be a feeder.

All screw conveyors 6, 7 can be operated independently of each other or else by the downstream conveyor system 3. However, it is also possible that the operation of all conveyor systems of the construction machine is coordinated.

In a further variant, the operation of the conveyor systems and the individual augers 6, 7 by a control system 15 (see FIG. 2 ) be managed. In this case, the flow rates can be regulated in a predetermined ratio to each other or, for example, on the basis of various belonging to the control system 15 sensors 16 adapted to the situation by the control system 15. The sensors 16 mentioned here may in particular be temperature sensors, weight sensors, density sensors, volume flow sensors, flow velocity sensors or distance sensors.

Claims (16)

1. Construction machine (1), comprising:

   a material hopper (2) for receiving bulk material,

   a material conveying system (5) for conveying bulk material, the material conveying system (5) comprising at least one conveying screw (6) in the area of the hopper (2), wherein

   a gap (9) extends underneath the conveying screw (6), the gap (9) having a cross section which varies in a conveying direction of the conveying screw (6),

   characterized in that

   a) the gap (9) is downwardly open and a downstream conveying system (3) which facilitates the further transportation of the bulk material extends underneath the gap (9)
   or

   b) the gap (9) is downwardly closed and comprises an inclined plane on its bottom side sloping towards a rear wall (8) of the material hopper (2), wherein the gap (9) is open towards the rear wall so as to pass material on to a downstream conveying system (3) at this opening at the latest.
2. Construction machine according to claim 1, characterized in that the gap (9) extends substantially in parallel with an axis of the conveying screw (6).
3. Construction machine according to claim 1 or 2, characterized in that the gap (9) is variably adjustable in its size during operation of the construction machine (1).
4. Construction machine according to any one of the preceding claims, characterized in that the conveying screw (6) is arranged in a trough (14) and the gap (9) extends on a bottom side of the trough (14).
5. Construction machine according to any one of the preceding claims, characterized in that the material conveying system (5) comprises a plurality of conveying screws (6, 7) each having a respective axis.
6. Construction machine according to claim 5, characterized in that the conveying screws (6, 7) are operable independently of one another.
7. Construction machine according to claim 5 or 6, characterized in that the conveying screws (6, 7) are arranged such that their axes extend at an angle or in parallel with one another.
8. Construction machine according to any one of claims 5 to 7, characterized in that the conveying screws (6, 7) are arranged in a plurality of groups, the axes of the conveying screws (6, 7) within one group extending in parallel with one another.
9. Construction machine according to claim 8, characterized in that the groups are arranged such that the axes of the conveying screws (6, 7) of different groups extend at an angle relative to one another.
10. Construction machine according to any one of the preceding claims, characterized in that a pitch of the at least one conveying screw (6, 7) varies in the conveying direction.
11. Construction machine according to any one of the preceding claims, characterized in that a screw shaft (10) of the at least one conveying screw (6, 7) is conical.
12. Construction machine according to any one of the preceding claims, characterized in that the conveying screw (6, 7) comprises a screw thread with a flank whose outer diameter (12) changes in conveying direction or remains constant.
13. Construction machine according to any one of the preceding claims, characterized in that the at least one conveying screw (6, 7) is supported at one side only.
14. Construction machine according to any one of the preceding claims, characterized in that the construction machine (1) comprises at least one further conveying system (3) arranged downstream of the conveying screw (6, 7), and the at least one conveying screw (6, 7) is operable in response to operating parameters of the downstream conveying system (3).
15. Construction machine according to any one of claims 5 to 14, characterized in that the construction machine (1) further comprises a control system (15) which controls the various conveyor flows produced by the conveying screws (6, 7) and their ratio among one another.
16. Construction machine according to any one of the preceding claims, characterized in that the construction machine (1) is a road paver or a feeder.

Images