EP2295640A2 - Road finisher and method for starting a combustion engine of a road finisher - Google Patents

Abstract

The method involves driving power consuming devices e.g. generator, and/or a hydraulic pump of an internal combustion engine. Individual power consuming devices are uncoupled from the engine for starting the engine. The power consuming devices are driven by a power divider that is uncoupled from the engine. An independent claim is also included for a road paver comprising a chassis.

Description

The invention relates to a method for starting an internal combustion engine of a road finisher according to the preamble of claim 1 and to a road finisher according to the preamble of claim 7.

The paver referred to here is a self-propelled construction machine for the production of road surfaces. Such a paver has drives for a chassis and all other components, in particular for rammer and vibrators of a screed, for a distribution screw and a scraper conveyor on. The paver also requires energy for hydraulic cylinders to lift or adjust in particular the screed and a heater for the screed. The chassis and at least part of the remaining components of the road paver are wholly or at least predominantly driven by hydraulic motors. The electrical energy for heating the screed is generated by at least one generator.

The paver has an internal combustion engine that drives power consumers, which are mainly hydraulic pumps for driving the hydraulic motors and hydraulic cylinders and at least one generator for heating the screed. So far, it is the case that the power users are permanently on the internal combustion engine are coupled. When starting the internal combustion engine, the power consumers, even if they do not generate hydraulic oil flow and / or no electrical energy, must be moved in idle. This - albeit load-free - moving the power consumers already leads to a load on the engine, which makes it difficult to start the engine. This is especially true at low outside temperatures.

The invention has for its object to provide a method for easier starting a paver and a trained paver.

A method for solving the above-mentioned problem comprises the measures of claim 1. Because at least some power consumers, such as hydraulic pumps and / or at least one generator, are disconnected from the internal combustion engine to start the internal combustion engine, the power consumers do not need to be carried along in the starting phase. This makes it easier to start the engine. It is not compulsory for all power consumers to be disconnected from the internal combustion engine to start the same. It is sufficient if only those load consumers are uncoupled, which - even at idle - have a relatively high drag resistance, such as a powerful generator. As a result, the starting of the internal combustion engine can already be significantly facilitated.

It is preferably provided during the start-up and start-up phase of the internal combustion engine from the output side thereof to decouple at least some power consumers for a short time. In this way, the engine can start up completely free of load after starting until it reaches a constant and stable speed before the disconnected power consumers are coupled back to the engine.

It is preferably provided to make the coupling of the power consumers to the internal combustion engine at a speed sufficient to not "stall" the engine when coupling the power consumers. It is preferably provided that the power consumers are coupled at such a speed to the engine, which is in the range of idle speed. The speed range in which the power consumers are coupled to the engine, but may also be slightly above the idle speed. At such a speed ensures that when coupling the power consumers, the speed of the engine decreases only slightly, in particular, the idling speed of the engine is not or only slightly below.

In a preferred embodiment of the method, it is provided to disengage the power consumers of the same by a switchable clutch for starting or starting the internal combustion engine. Such a shiftable clutch, in particular an externally actuated clutch, allows the time of coupling of the power consumers to the internal combustion engine to be determined individually. In addition, the power consumers can be completely disconnected from the internal combustion engine by such a clutch.

It is preferably provided to decouple power consumers such as the or each generator and all hydraulic pumps from the internal combustion engine for starting the internal combustion engine. This allows the engine to be started without having to carry any power consumers. This gives the engine favorable start-up characteristics, which facilitates a cold start, especially in cold regions or in cold seasons, because during the start and preferably also the run-up phase of the engine must drag along any power consumers.

According to a preferred development of the method, it is provided that the power consumers, in particular at least some hydraulic pumps and / or at least one generator, are driven by a transfer case and for starting the internal combustion engine, the transfer case with the coupled thereto power consumers is temporarily disconnected from the internal combustion engine. Since the transfer case drives at least a majority, preferably all, power take-off, only one externally operated clutch or clutch is required to separate the power take-off, preferably all, from the drive train of the internal combustion engine for starting the internal combustion engine. In particular, in this way for starting the internal combustion engine and the transfer case does not need to be dragged.

A paver to solve the aforementioned problem has the features of claim 7. Accordingly, a switchable clutch is arranged between the drive of the internal combustion engine and at least some power consumers. By means of the shiftable clutch, a momentary separation of the internal combustion engine from at least some power consumers, preferably all power consumers, can take place in a targeted manner. As a result, the internal combustion engine can be started without it having to carry along the power consumers. The internal combustion engine can be so easier to start, especially when it is still cold. In addition, the internal combustion engine is easier to start in cold regions or cold seasons without the power users to be carried along. Finally, the internal combustion engine after starting without the entrainment pantograph runs faster until a stable speed, in particular its idle speed, to reach.

In a preferred embodiment of the paver, it is provided to arrange the switchable coupling between the internal combustion engine and a transfer case for at least a portion of the power consumers, preferably all hydraulic pumps and the single generator or all generators. Because the transfer case preferably drives all power consumers, only one clutch needs to be provided between the engine and the transfer case. In addition, it is also not necessary when starting the engine mitzuschleppen the transfer case.

An advantageous development of the paver, it provides, the switchable clutch an additional clutch, namely a non-shiftable clutch, in particular a compensating coupling assign. This non-shiftable clutch can be arranged in front of or behind the shiftable clutch. If the power consumers are driven by a transfer case, it is advantageous to arrange the non-switchable coupling between the engine and the transfer case, so that only a non-switchable coupling is required. Optionally, further non-shiftable clutches may be provided between the transfer case and at least some power consumers driven therefrom. The additional clutch leads to a smoother running of the drive train, especially if it is a flexible coupling. In addition, the non-switchable coupling can prevent overloading of the switchable coupling.

Preferably, it is provided to form the shiftable clutch as an externally operated clutch. The operation of this clutch can be done in any way, preferably, an electromagnetic or hydraulic actuation is provided. Furthermore, the shiftable clutch can be designed as a form-locking, externally actuated shift clutch or a friction-locked externally operated clutch. Non-positive externally actuated clutches may be a friction-locked, hydrostatic or hydrodynamic or electrostatic or electrodynamic externally actuated clutch. Such clutches are individually operable from the driver's cab of the paver. Especially non-positive externally operated clutches smoothly couple the power consumers to the internal combustion engine, even when coupled to the power consumers at a speed in the range of its rated speed.

Fig. 1

eine schematische Seitenansicht eines Straßenfertigers,

Fig. 2

ein Blockschaltbild eines Antriebs des Straßenfertigers gemäß einem ersten Ausführungsbeispiel der Erfindung, und

Fig. 3

ein Blockschaltbild eines Antriebs des Straßenfertigers gemäß einem zweiten Ausführungsbeispiel der Erfindung.

Preferred embodiments of the invention will be explained in more detail with reference to the drawing. In this show:

Fig. 1

a schematic side view of a paver,

Fig. 2

a block diagram of a drive of the paver according to a first embodiment of the invention, and

Fig. 3

a block diagram of a drive of the paver according to a second embodiment of the invention.

The Indian Fig. 1 Road paver 10 shown schematically serves to produce a road surface, for example an asphalt surface or, if appropriate, also a concrete covering. The paver 10 has a chassis 11, which is formed in the embodiment shown as a crawler chassis. The chassis of the paver 10 but can also be a wheel drive.

Viewed in the production direction 12, a trough-like or trough-shaped reservoir 13 is arranged at the front of the paver 10. The reservoir 13 serves to receive a supply of the material used for the production of the road surface, in particular an asphalt mixture. By a not shown in the figures conveying member, in particular a scraper conveyor, the material from the reservoir 13 is transported against the production direction 12 to the rear end 14 of the paver 10. The paver 10 has at the rear end 14, behind the chassis 11, via a distributor screw 15 which extends transversely to the production direction 12 and serves to distribute the material for the production of the road surface over the entire working width of the paver 10 evenly. Viewed in the direction of production 12, a screed 16 is located behind the auger 15. The screed 16 is suspended on support arms 17. The support arms 17 are pivotally mounted by hydraulic cylinders 20 on the chassis 11 for moving up and down the screed 16. The screed 16 can be both breitunveränderlich and be variable in width. In the latter case, the screed 16 has a central main screed and two on opposite sides of the same transversely to the production direction 12 movable mats.

The screed 16 is provided with hydraulic or electrically driven vibrators. In addition, the screed 16 has an electric heater. Both the heater and the vibrators are not shown in the figures. Furthermore, seen in the production direction 12 in front of the screed 16 a preferably of a hydraulic motor up and down movable rammer is provided, which is also not shown in the figures.

The paver 10 has the chassis 11 via a only in the Fig. 2 and 3 The drive unit 18 is located below a driver's stand 19 between the reservoir 13 and the auger distribution 15th

The drive unit 18 has an internal combustion engine 21, which is preferably a diesel engine. An output shaft 22 of the internal combustion engine 21 is connected via a switchable coupling 23 to a drive shaft 24 of a transfer case 25, in particular a pump distributor gear. The transfer case 25 drives the power consumers required to operate the paver 10 and its components. Preferably, all power consumers are driven by the transfer case 25. However, it is conceivable to drive selected, in particular smaller, power consumers directly from the output shaft 22 of the internal combustion engine 21. In the embodiments shown, power take-offs designed by the transfer case 25 as hydraulic pumps 26 and a generator 27 are simultaneously driven.

In the embodiment of Fig. 2 the transfer case 25 drives two hydraulic pumps 26 and a generator 27, while in the embodiment of the Fig. 3 From the transfer case 25 three hydraulic pumps 26 and two generators 27 are operated. The invention is to those in the Fig. 2 and 3 only exemplified number of hydraulic pumps 26 and generators 27 is not limited. Rather, the number of hydraulic motors 26 and the generators 27 depends on the respective equipment of the paver 10 and can therefore be arbitrary.

The drive unit of Fig. 2 with only a single generator 27 and two hydraulic pumps 26 is preferably used in a conventional road paver 10th for the production of only one covering layer. Such a paver 10 has, as shown in the Fig. 1 only a screed 16 on. In road pavers for the simultaneous production of multiple layers of road surface with two screeds 16 is preferably the drive unit 18 of the Fig. 3 with two generators 27 and three hydraulic pumps 26.

The only generator 27 of the embodiment of Fig. 2 and the two generators 27 of the embodiment of Fig. 3 generate electrical power that serves to heat the screed 16 or even several screeds 16. In addition, the generators 27 but also generate electricity for other drive units of the paver 10. The hydraulic pumps 26 generate hydraulic oil flows for driving hydraulic motors for the chassis 11, the auger 15, the scraper conveyor between the reservoir 13 and the auger 15 and the rammer and the vibrators of the screed 16. In addition, the hydraulic oil flows generated by the hydraulic pump 26 also serve , To drive hydraulic cylinder 20 for lifting the support arms 17 for the screed 16 and other unspecified here hydraulic cylinder or smaller drives for other components of the paver 10. In general, a hydraulic pump 26 is provided for driving the chassis 11, while the or any other hydraulic pump 26 drives or actuates the other components of the paver 10.

In the exemplary embodiment of the drive unit 18 shown here, each shiftable clutch 23 is assigned a non-shiftable clutch 28. In the embodiment of Fig. 2 it is in the non-shiftable clutch 28 to a flexible compensating coupling, in particular a flexible coupling. This is arranged in the direction of the transfer case 25 before the switchable coupling 23. The non-shiftable clutch 28 may also be located behind the shiftable clutch 23. In the embodiment of Fig. 3 the non-shiftable clutch 28 is disposed behind the shiftable clutch 23. In this embodiment, the non-shiftable clutch 28 is a rigid, fixed clutch. This rigid, fixed coupling can also be seen in the direction of the transfer case 25 before the switchable coupling 23.

In both embodiments ( Fig. 2 and 3 ), each hydraulic pump 26 and each generator 27 is connected to the transfer case 25 by a further non-shiftable This may be a rigid, fixed coupling or a flexible compensating coupling, in particular a flexible coupling.

Other embodiments of the invention are also conceivable in which non-shiftable clutches 29 between the transfer case 25 and the hydraulic pumps 26 and / or the generators 27 are missing. Likewise, it may possibly be sufficient to arrange only the shiftable clutch 23 between the internal combustion engine 21 and the transfer case 25, but no further non-shiftable clutch 28.

The shiftable clutch 23 may be any kind of shiftable clutches, with the exception of directionally actuated clutches, so-called one-way clutches. The switchable clutches 23 are preferably designed as externally operated clutches which operate in a form-fitting or non-positive manner. Positive intermeshable clutches 23 are frictional clutches, while non-positive clutches 23 are hydrostatic or hydrodynamic or electrostatic or electrodynamic clutches. The actuation of the switchable coupling 23 is preferably carried out electrically, in particular electromagnetically, or hydraulically. The switchable coupling 23 can also be operated mechanically. It is also conceivable to form the switchable clutch 23 as a speed-operated centrifugal clutch, which operates non-positively, by friction, hydrodynamic or electrodynamic. It is also conceivable to form the switchable clutch 23 as a torque-actuated safety clutch, which can operate in a form-fitting or non-positive manner. If this clutch operates frictionally, this is done by friction, hydrostatic or hydrodynamic, magnetic or electrostatic or electrodynamic.

Hereinafter, the inventive method with reference to the previously described paver 10 with the drive unit 18 according to the embodiment of Fig. 2 described in more detail:

To start or start the internal combustion engine 21 of the road paver 10, the switchable clutch 23 is actuated so that the output shaft 22 of the internal combustion engine 21 is disconnected from the drive shaft 24 of the transfer case 25. This can be done electrically, hydraulically or possibly also mechanically from the driver's cab 19. The internal combustion engine 21 can then be started without the transfer case 25 having to be entrained with the hydraulic pumps 26 and the generator 27.

After the internal combustion engine 21 has been started and started up, that is, the starting and acceleration phase has been completed and the internal combustion engine 21 has reached a stable rotational speed, preferably in the region of the idling rotational speed, the shiftable clutch 23 is electrically, in particular magnetically, hydraulically or optionally also mechanically actuated. As a result, the transfer case 25 and the hydraulic pumps 26 and the generator 27 are coupled to the internal combustion engine 21. Optionally, it can be waited with this coupling until the internal combustion engine 21 is slightly warmed up or even reached its operating temperature. This results in the greatest possible protection of the internal combustion engine 21st

The coupling of the transfer case 25 with the hydraulic pump 26 and the generator 27 to the engine 21 is carried out at such a speed sufficient to the coupling of the transfer case 25 with the hydraulic pump 26 and the generator 27 to the engine 21, a "stalling" of the same reliable to avoid. Preferably, it is provided to couple the internal combustion engine in the region of its idle speed to the hydraulic pumps 26 and the generator 27 and in the embodiment shown, the transfer case 25. The speed range at which this coupling takes place can also be up to 30% above the idling speed.

In an analogous manner, the starting of the internal combustion engine 21 takes place in the drive unit 18 of the embodiment of Fig. 3 , In addition, the inventive method is also suitable for drive units without a transfer case 25, in which at least one hydraulic pump 26 and / or at least one generator 27 via one or optionally a plurality of switchable clutches 23 to the output shaft 22 of the engine 21 can be coupled.

LIST OF REFERENCE NUMBERS

10

pavers

11

landing gear

12

production direction

13

reservoir

14

rear end

15

auger

16

screed

17

Beam

18

drive unit

19

platform

20

hydraulic cylinders

21

internal combustion engine

22

output shaft

23

switchable coupling

24

drive shaft

25

Transfer Case

26

hydraulic pump

27

generator

28

non-shiftable clutch

29

non-shiftable clutch

Claims (12)

Method for starting an internal combustion engine (21) of a paver (10), power consumers such as in particular at least one generator (27) and / or at least one hydraulic pump (26) being driven by the internal combustion engine (21), characterized in that for starting the internal combustion engine ( 21) at least some power consumers from the internal combustion engine (21) are uncoupled. A method according to claim 1, characterized in that during the start-up and start-up phase of the internal combustion engine (21) at least some power consumers are disconnected from the internal combustion engine (21). A method according to claim 1 or 2, characterized in that after the start and startup phase of the internal combustion engine (21), preferably in the region of the idle speed of the internal combustion engine (21), an coupling of the power consumers to the internal combustion engine (21). Method according to one of the preceding claims, characterized in that for starting the internal combustion engine (21) by a switchable clutch (23), the power consumers are disconnected from the internal combustion engine (21). Method according to one of the preceding claims, characterized in that for starting the internal combustion engine (21) power consumers such as the or each generator (27) and preferably all the hydraulic pumps (26) are disconnected from the internal combustion engine (21). Method according to one of the preceding claims, characterized in that at least some power consumers, preferably all power consumers, in particular the or each generator (27) and / or at least some hydraulic pumps (26) are driven by a transfer case (25) and for starting the internal combustion engine (21) the transfer case (25) is uncoupled from the internal combustion engine (21). Road paver with a chassis (11), at least one screed (16) and an internal combustion engine (21), wherein the internal combustion engine (21) power consumers such as hydraulic pumps (26) and / or at least one generator (27) are assigned, characterized in that between the output of the internal combustion engine (21) and at least some power consumers a switchable coupling (23) is arranged. Road paver according to claim 7, characterized in that the switchable coupling (23) between the internal combustion engine (21) and a transfer case (25) for driving at least a portion of the power consumers, preferably the hydraulic pumps (26) and / or at least one generator (27) , is arranged. Apparatus according to claim 7 or 8, characterized in that the switchable coupling (23) is associated with at least one additional non-switchable coupling (28, 29), in particular a compensating coupling or a rigid, fixed coupling. Road finisher according to one of the preceding claims, characterized in that the switchable coupling (23) is designed as a externally operated clutch, which is preferably actuated magnetically or hydraulically. Road paver according to one of the preceding claims, characterized in that the switchable coupling (23) is designed as a form-locking externally operated clutch. Paver according to one of the preceding claims, characterized in that the switchable clutch (23) is designed as a non-positive, externally operated clutch, preferably as a frictional, hydrostatic or hydrodynamic or electrostatic or electrodynamic externally operated clutch.

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