EP2256248B2 - Road finisher - Google Patents

Description

The invention relates to a road finisher according to the preamble of patent claim 1. Road finisher ( EP 1 118 714 A , EP 0 489 969 A , DE 103 00 745 A1 ) have, at least at times, high power-requiring heating devices or powerful electric motors, e.g. B. in the paver with a longitudinal conveyor, or in a screed of the paver for tampers, sealing strips, smoothing plates and the like., Which are powered by the generator with electricity. The internal combustion engine drives a number of hydraulic pumps including a drive pump unit via a pump distributor gear, which define high-performance functional assemblies with hydraulic motors or hydraulic cylinders distributed accordingly in the road finisher and/or the screed. All functional assemblies are permanently driven by the crankshaft of the combustion engine via a torsionally flexible coupling, eg via the pump transfer case, and generate high drag loads for the combustion engine. In unfavorable weather conditions and after a long standstill, the towing loads make it difficult to start the combustion engine. Even during a heating-up phase of the heating devices, which have to be brought up to operating temperature before the road finisher starts work, the internal combustion engine must first overcome the towing loads of functional assemblies that are actually not required, which inexpediently lengthens the heating-up process and increases fuel consumption. Finally, the road finisher should run as efficiently as possible in a transport phase, which is made more difficult by the towing loads of the functional assemblies that are not required, ie the maximum transport speed is limited and fuel consumption is increased. In such operating phases, there are also mechanical and hydraulic power losses in the gear stages and/or power splits and in the hydraulic system, which are particularly significant when the transmission or hydraulic oil is cold, and demand more power from the combustion engine than would actually be required for these operating phases.

From the brochures "Vögele road finisher SUPER 1700, SUPER 1704" and "Vögele SUPER 170 and SUPER 174" from the company Joseph Vögele AG, Neckarauerstraße 168-228, 6800 Mannheim 1, DE, from the 1970s and 1980s, page 3 each It is known to arrange a switchable single-plate dry clutch between the internal combustion engine and a cardan shaft leading to a manual transmission with hydrostatic primary transmissions for the traction drive. The generator and several hydraulic pumps for functional assemblies are driven by a multiple belt drive on the input side of the gearbox. A compressor to supply the steering and braking system and a Hydraulic pumps for the power steering are permanently and separately driven by the combustion engine and generate permanent drag loads. When the clutch is disengaged, neither the generator nor the hydraulic pumps are driven via the multi-belt drive. In the neutral position of the gearbox and when driving with the clutch engaged, the generator and the hydraulic pumps are dragged along, which noticeably worsens the energy balance of the combustion engine. However, the clutch is only disengaged for a gear change of the manual transmission, e.g. with a clutch pedal, or if necessary to start the combustion engine, but is then immediately engaged again so that the clutch pedal does not have to be pressed and the separating dry disk clutch is not overloaded.

Transfer cases are known in agricultural machinery technology for other reasons, which have at least one permanently drivable power split and power splits that can be selectively switched on and off. The requirements for agricultural machinery are not comparable to the requirements that occur specifically for road finishers, which are caused, among other things, by the material to be paved, its heating and metering, and the drive, heating and control of the functional assemblies to be operated for paving the material in the road paver and/or the Screed are dictated.

Road finishers of modern design are now equipped with an extraordinarily large number of hydraulically operated functional assemblies, and also no longer have a travel drive with a mechanical gearbox. Examples of such functional assemblies that can be operated hydraulically are: hydrostatic travel, steering, differential and all-wheel drives with hydraulic brakes, conveying and metering devices, transverse distributor screws, screw conveyors, screw bracket adjustment devices, bunker wall cylinders, leveling cylinders, lifting cylinders, spraying devices for adhesives, tampers, vibrators, pressure bars, cross -, Longitudinal, inclination and height adjustment devices in the screed and the like. The resulting towing loads for the internal combustion engine can consume up to about a third or more of the nominal power of the internal combustion engine because of the many and sometimes very powerful functional assemblies. Because of this, and since several hundred liters of hydraulic oil circulate in the system and lead to heavy pumping losses, and there are also weather-dependent and load-dependent changes in driving resistance, even if the ground is sloping, this results in an inappropriately high specific fuel consumption when starting, warming up and during transport, especially on inclines , and also when the road finisher is at a standstill during heating by means of the heating devices and during transport when maintaining the operating temperature of heated functional parts, etc. This may result in Engine starting problems in cold weather and the like. With a medium-sized road finisher and average blanking, the fuel savings potential alone amounts to several thousand liters of diesel fuel per year, and the maintenance frequency is high due to the towing loads that have to be constantly overcome. Road finisher-specific requirements with savings potential arise from the fact that transport journeys often take relatively long, the driving resistance varies greatly depending on the subsoil and inclines, long warm-up or heating-up phases are necessary under unfavorable weather conditions and after longer work breaks or longer standstill breaks are often forced during paving operations until Trucks arrive with new batches of material. Having the internal combustion engine then running overcome the considerable, actually unnecessary towing loads, as is usually the case, is extremely inefficient, pollutes the environment, increases fuel consumption and increases the maintenance frequency for the hydraulic system and the permanently operated functional assemblies. The generator drag load is almost negligible with little power consumption or no power consumption. The fuel savings potential for a medium-sized road paver with average utilization for such operating situations is several thousand liters of diesel fuel per year. Against this background, for reasons of environmental protection and cost, there is a considerable need for a noticeable improvement in the energy balance of the internal combustion engine and its flexible adaptability to different operating situations.

The invention is based on the object of specifying a road finisher of the type mentioned at the outset in order to improve the energy balance and environmental compatibility with regard to specific requirements when operating a road finisher.

The task is solved with the features of claim 1.

Since in the road finisher, depending on the operating situation, at least one pump, expediently at least one powerful functional assembly, can be uncoupled while the generator is permanently driven, e.g. in order not to endanger the operational readiness of the finisher or to supply heating devices, and the at least one uncoupled pump If the pump remains uncoupled for a longer period of time depending on the operating situation, the towing load for the combustion engine is noticeably reduced. The internal combustion engine starts more easily, completes its warm-up phase more quickly if necessary, completes a warm-up phase of the heating devices more quickly via the generator, allows the operating temperature of heated working components to be maintained with lower fuel consumption and consumes significantly during transport journeys or while waiting for a new batch of material less fuel than before. A heating-up phase of electrical heating devices can also be carried out in a performance-optimized manner. Overall, taking into account the specific requirements during the operation of a road finisher in certain operating situations, by uncoupling at least one pump, a considerable amount of fuel is saved, the burden on the environment is reduced and the maintenance frequency is reduced. When the road finisher is at a standstill, even the drive pump unit can be uncoupled.

A transport phase can be carried out with a higher transport speed and lower fuel consumption if only the drive pump unit required for driving is driven and the generator is also driven, while other pumps that are not required for the transport phase are uncoupled from functional assemblies. The towing load of the generator may be negligible anyway during the transport phase.

When the internal combustion engine is started and possibly warmed up, at least one hydraulic pump or all hydraulic pumps that are not required are disconnected, so that the internal combustion engine starts more easily and reaches operating temperature more quickly, while having less specific fuel consumption.

In the road finisher according to the invention, the generator and the hydraulic pumps of the functional assemblies are driven jointly by the crankshaft via a torsionally flexible coupling, which insulates the internal combustion engine or its flywheel from torsional shocks.

In an expedient embodiment, the generator and the drive pump unit can be driven together permanently via the drive train, while at least one pump can be uncoupled from other functional assemblies via the at least one switchable clutch. The drive pump unit is operated for the transport journey while other pumps are uncoupled. If necessary, the generator generates only a negligible towing load during transport anyway and can, if necessary, supply heating devices or other electrical consumers as required.

In a further expedient embodiment, all of the pumps arranged on the pump transfer case, including the drive pump unit, can be uncoupled together via the switchable clutch. Only a single switchable clutch is required, which uncouples the towing loads when disengaged and is designed in such a way that it is not damaged when disengaged, even over a long period of time.

In a further expedient embodiment, individual switchable clutches are arranged between the crankshaft of the internal combustion engine and the pumps for functional assemblies, possibly including the drive pump unit. These individual switchable clutches are preferably located on or in the pump transfer case or in its power branches to the pumps of the functional assemblies. The towing load of a specific functional assembly or the towing loads of several or all functional assemblies can be uncoupled as required, for example to improve the starting behavior of the combustion engine, to carry out the transport journey quickly and with lower fuel consumption, or to bring the heating devices up to operating temperature as quickly as possible.

The clutch provided in each case is expediently switched electrically, pneumatically, hydraulically or mechanically. In normal operation of the finisher, i.e. during paving work travel, the clutch or all clutches are engaged. For example, in the case of a hydraulically switchable clutch or hydraulically switchable clutches, the permanently driven generator can be assigned a low-power hydraulic pump that provides supply pressure for basic functions and the clutch.

Fig. 1

eine schematische Seitenansicht eines Straßenfertigers,

Fig. 2

ein schematisches Schaubild eines Teils eines nicht erfindungsgemäßen Primärantriebsaggregats eines Straßenfertigers, und

Fig. 3

ein schematisches Getriebeschaubild eines erfindungsgemäßen Primärantriebsaggregats eines Straßenfertigers.

Embodiments of the subject invention are explained with reference to the drawings. Show it:

1

a schematic side view of a road finisher,

2

a schematic diagram of a part of a primary drive unit of a road finisher not according to the invention, and

3

a schematic transmission diagram of a primary drive unit according to the invention of a road finisher.

A self-propelled paver F ( 1 ) for the production of traffic areas from, for example, bituminous, hot paving material with a slow paving working speed can also carry out transport travel at a significantly higher transport travel speed. On a chassis 1, the road finisher F has a chassis 2, here a crawler chassis, alternatively a wheeled chassis (not shown), which is driven by at least one hydraulic drive motor 16. In the front area of the chassis 1, a bunker 5 for paving material is arranged. Inside the chassis, a longitudinal conveying device 6 extends from the bunker 5 through the chassis 1 to a transverse distribution device 7 located at the rear, typically a hydraulically driven transverse distribution screw. The longitudinal conveyor device 6 can be driven, for example, by hydraulic motors, not shown, and can comprise an electrical heating device H. The transverse distribution device 7 is located in front of a paving screed B that is towed by the road finisher F with bars 8 and that levels and/or compacts the paving material. The bars 8 are articulated on the chassis 1 and are height-adjustable by means of hydraulic motors 15, for example hydraulic cylinders. Hydraulic motors 14, for example hydraulic cylinders, which are supported on the chassis 1 and, for example, during transport travel, the screed B in the in 1 hold in the raised position, but can also be actuated during paving work travel in certain operating phases. On top of the chassis there is a driver's cab 3 with a control and operating console 51. Furthermore, under a cover 4 is a prime mover P with an internal combustion engine M, typically a diesel engine, and a generator G for supplying at least the electrical heating devices H in the road finisher F and /or arranged in the screed B and/or for supplying electric motors comprising functional assemblies.

The screed B has, for example, a base screed connected to the beams 8 and laterally extendable extending screeds 13, each equipped with tampers 10, 11 and/or pressure bars (not shown) and vibration devices for the bottom smoothing plates, the tampers 10, 11, the pressure bars and/or or the smoothing plates can have electrical heating devices H. The extending screed parts 13 can be moved, for example by means of hydraulic motors 9, for example hydraulic cylinders.

The hydraulic motors, hydraulic cylinders and the electrical heating devices and/or electric motors, together with the generator and hydraulic pumps driven by the primary drive unit P, form a number of functional assemblies of the road finisher which draw their power from the primary drive unit P.

In the embodiment not according to the invention in 2 the drive diagram of several functional assemblies is indicated, with the functional assemblies shown being shown without their hydraulically supplied working components (the hydraulic cylinders, hydraulic motors, etc.) in the road finisher F and/or in the screed B and also without the hydraulic oil reservoir, connecting lines, regulating and control devices and the like

The internal combustion engine M has a clutch or flywheel housing 18 to which a pump distributor gear 19 is flanged, which is used to drive and/or supply the pumps of the functional assemblies. A crankshaft 20 of the internal combustion engine M drives a drive train 22 via a torsionally flexible coupling 21, which leads to a switchable clutch K1 on (or as shown in) the pump transfer case 19. Clutch K1 is hydraulically, pneumatically, electrically or mechanically switchable between an engaged and a disengaged position, and is in 2 between the output train 22 and a coaxial extension 22 'of the output train 22 is arranged. The extension 22 ′ leads to a driving pump unit 23 of a driving function assembly, which is centrally flanged to the pump transfer case 19 in the embodiment shown and to which the drive motors 16 belong, for example.

The switchable clutch K1 (e.g. a hydraulic multi-disk clutch) has at least one clutch part 25 which is permanently connected to the drive train 22 and which, in the engaged position of the clutch K1, is non-rotatably connected to a clutch part 24 for the extension 22' and at the same time to a hollow shaft 26. The hollow shaft 26 drives several gear stages 27, 28, 29 in the pump distributor gear 19, the gear stages 27, 28, 29 driving hydraulic pumps or pump units 30, 31, 32, 33. The generator G is either mounted on the pump distributor gear 19 (at 37), or with its own mounting 36 in the chassis 1 of the road finisher F, or on a console of the internal combustion engine M, and is driven, for example, via a permanent drive connection 34 (e.g. a belt drive or a cardan shaft ) driven.

is in 2 If the clutch K1 is engaged, then all gear stages 27, 28, 29, the drive pump unit 23 and the generator G are driven by the crankshaft 20 of the internal combustion engine. If the clutch K1 is disengaged, at least one pump is uncoupled from the drive train 22 or the crankshaft 20, in this case even the pumps 30 to 33, and also the drive pump assembly 23, as well as the gear stages 27, 28, 29 of the pump distributor gear 19 (no churning losses, no combing losses). Clutch K1 can then be in the disengaged state for a longer period of time without any risk.

3 illustrates different drive schemes.

The drive train 22, which is connected to the crankshaft 20 via the torsionally flexible coupling 21, goes through here in a variant not according to the invention to the drive pump unit 23 centrally flanged to the pump transfer case 19, so that the drive pump unit 23 is permanently driven. The switchable clutch K2 sits on the continuous drive train 22 and, when engaged, drives the gear stages 27, 28, 29 of the pump transfer case 19 and the pumps 30 to 33 via the hollow shaft 26. If the clutch K2 is in the disengaged state, the gear stages 27, 28 , 29 and the pumps 30 to 33 are uncoupled, while the drive pump unit 23 continues to be driven permanently. The generator G can be as in 2 be permanently driven, or is even combined with the drive pump unit 23 and driven by the drive train 22.

In one embodiment of the invention, in 3 Instead of the drive pump assembly 23, the generator G is flanged to the pump transfer case 19 and is permanently connected to the crankshaft 20 via the drive train 22. In this case, for example, the drive pump unit 23 is connected to a further power branch 39 of the pump distributor gear 19 . In the disengaged state of the clutch K2, the drive pump unit 23 is also uncoupled, while the generator G is permanently driven.

In 2 a pump 38 is shown as an option on the permanently driven generator G, which also runs permanently and supplies basic functions, for example the respective hydraulically actuated clutch K1, K2, K3.

Another alternative is in 3 indicated by dashed lines that each pump group or each pump unit (several pump stages) 30 to 33, and also the drive pump unit 23, is assigned a switchable clutch K3, expediently in the respective power branch of the pump distributor gear 19. In this case, the switchable clutch K2 can be omitted and the output train 22 can be permanently connected to the gear stage 27 in the pump transfer case 19 . Alternatively, however, a clutch K3 could also be provided there.

Depending on requirements, all, several or just one of the pumps 30 to 33, 23 can be uncoupled from the power branches in the pump transfer case 19 via the individual clutches K3, which can be switched in groups or together. The internal combustion engine M then drives only the output train 22 and, if necessary, the gear stages 27, 28, 29 of the pump transfer case 19 and the generator G permanently.

In order to calculate the energy balance of the internal combustion engine M in 2 To improve this, clutch K1 is switched to the disengaged state for starting and, if necessary, during the warm-up phase of internal combustion engine M, so that all drag loads are decoupled from crankshaft 20 or drive train 22 and the internal combustion engine starts more easily or reaches its operating temperature more quickly. As soon as the road finisher begins its paving work run or transport run, clutch K1 is engaged so that all functional assemblies are driven. The generator G runs permanently.

In the embodiment in 3 With clutch K2, for example, clutch K2 is disengaged to start and, if necessary, warm up internal combustion engine M, so that pump groups 30 to 33 and, if necessary, drive pump unit 23 are uncoupled, or only drive pump unit 23 and generator G are permanently driven. If the drive pump unit 23 is centrally flanged to the pump transfer case 19, then the road finisher can carry out the transport journey at a high transport speed and more economical fuel consumption when the clutch K2 is in the disengaged state, since the towing loads of the other functional assemblies do not have to be overcome. On the other hand, the permanently driven generator G can heat the heating devices H to the operating temperature when the road finisher is at a standstill before the other functional assemblies are coupled via the clutch K2. If the drive pump unit 23 is also permanently driven, the road finisher F can travel at high transport speed and with good fuel consumption without unnecessary towing loads.

Are, however, as in 3 indicated by dashed lines, individual switchable clutches K3 are provided in the power branches of the pump transfer case 19 to the pumps 30 to 33, 23 (the clutch K2 from 3 is omitted), then any, several or all of the pumps can be added or decoupled as required. To drive the road finisher F at transport speed, for example, only the clutch K3 to the drive pump unit 23 is engaged, while the other pumps 30 to 33 remain uncoupled. The clutch K3 of the drive pump unit can also be used to heat up the heating devices H 23 may be engaged while the other pumps 30-33 remain disengaged.

The individual switchable clutches K3 in 3 enable each functional assembly to be driven or uncoupled as required, and individually optimize the energy balance of the internal combustion engine M either for starting and warming up, for transport or for heating up the heating devices.

The respective clutch K1, K2, K3 can optionally also be actuated during interruptions in the paving work of the road finisher F, e.g. while waiting for a delivery of fresh paving material.

The respective clutch K1, K2, K3 can be actuated by the vehicle driver in the driver's cab 3 or by the accompanying personnel at an external control station, for example on the screed B, or by means of appropriate programming fully or semi-automatically by the control device of the road finisher, in which case monitoring and/or detection devices are provided, which determine an operating situation in which the decoupling or connection of certain towing loads is expedient.

The concept of being able to decouple at least one hydraulic pump from the combustion engine when the generator is permanently driven makes it possible, among other things, to significantly improve the overall energy balance of the road finisher through considerable fuel savings during very specific operating situations.

Claims (4)

1. Paver, comprising a primary driving aggregate (P) with a combustion engine (M), particularly a diesel engine, functional units actuable via hydraulic pumps (23, 30 to 33) which are driven from a crankshaft (20) of the combustion engine (M) via a power take-off gear (19) for pumps, the functional units including a travel pump aggregate (23) for supplying a travel drive (16), and at least one generator (G) for supplying at least electric heating devices (H) of the paver (F) and/or of a paving screed (B) of the paver (F), characterised in that the generator (G) is centrally mounted on the power take-off gear (19) for pumps via a flange connection, and a permanent drive connection is provided between the crankshaft (20) and the generator (G) by means of a drive train (22) penetrating the power take-off gear (19) for pumps,, and at least one pump (23, 30 to 33) can be disconnected by means of at least one shiftable clutch (K1, K2, K3) from the crankshaft (20), wherein the generator (G) and the pumps (23, 30 to 33) are driven by the crankshaft (20) via a torsionally flexible clutch (21).
2. Paver as in claim 1, characterised in that all pumps (23, 30 to 33), including the travel pump aggregate (23) are arranged at a power take-off gear (19) for pumps and are disconnectable altogether via the shiftable clutch (K1).
3. Paver as in claim 1, characterised in that several single shiftable clutches (K3) are arranged between the crankshaft (20) and at least several pumps or pump aggregates (23, 30 to 33) of the functional units, optionally inclusive of the travel pump aggregate (23), and that the shiftable clutches (K3), preferably, are arranged at or in a power take-off gear (19) for pumps which is arranged at the combustion engine (M), the shiftable clutches (K3) being located in power branches of the take-off gear (19) for pumps leading to the pumps.
4. Paver as in at least one of the preceding claims, characterised in that the respective clutch (K1, K2, K3) is shiftable mechanically or electrically or pneumatically or hydraulically.

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