WEINLICHSTEUERUNGEN

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10.676 GB 1995tech10 \ 676gb01

Testing the quality of overhauled vehicle engines

In many cases, worn-out vehicle engines, mainly oftrucks and busses, are overhauled instead of beingscrapped. Of course, an overhauled engine should beas good as a new one, i. e. it should have the sametechnical properties, in other words, the same quality.This quality can be ensured best by subjecting theoverhauled engines to a power test, where the engineis loaded by a dynamometer and at least the maxi-mum power and/or the maximum torque are meas-ured at one or more rotational speeds. The specificfuel consumption, an exhaust gas analysis, the blow-by, and the correct functioning of the control equip-ment (ignition, injection, electronic motor managementetc.) can be further subjects of power tests. In caseoverhauling is performed by the manufacturer, theengines are normally tested after overhauling in thesame manner as the newly produced engines.However, a remarkable number of engines is notoverhauled by the manufacturers or large overhaulingplants, but rather by smaller, independent companiesor workshops of organizations operating big fleets ofvehicles, e. g. public transport organizations. Theywant to ensure the quality of their overhauling worksby performing the same final measurements as the bigoverhauling facilities. Consequently, they also need anengine test bed. But their technical and economicpreconditions are quite different:

The number of engines to be tested is muchlower, in extreme cases only one engine per sev-eral days.The number of different types of engines to beoverhauled by an overhauling workshop can beas small as at an engine manufacturer's plant,e. g. in a specialized overhauling shop, or if afleet is equipped uniformly; but for other work-shops it can be practically unlimited.

Despite these preconditions, the expenses for everypower test shall not exceed the amount incurred by amanufacturer for utilizing his testing plant.In order to reach this objective

the total investment for a test bed must be muchlower than for a test bed in the testing plants ofbig overhauling facilities,the life must be long,the maintenance costs must be low, andthe expenses for personnel must be low.

Furthermore, a test bed for small overhauling work-shops should be suitable for different workshop or-ganizations with small or high numbers of differenttypes of engines to be overhauled.

Engine test beds (dynamometers)MP 80 ... MP 2x400 SP of WEINLICH meet theserequirements to an extent that has been unknownbefore:

Total Investment

Total investment is restricted to the price of the dyna-mometer itself and to an electric wall outlet. Thedynamometer does not require a foundation or instal-lations for cooling water. Training of personnel isnormally not required thanks to easy operation.

Life and Maintenance

The life is practically unlimited because only the rollerbearings are subject to wear. They can be easilyreplaced. In practice, however, this is usually notnecessary because of the very long life of the bearingswhen used in the dynamometer.If the test bed is not used, the air cooled eddy currentbrake contained in the dynamometer is not endan-gered by frost or corrosion as would be the case withwater brakes and water cooled eddy current brakes.The equipment has no cooling system which wouldrequire protection against frost or corrosion, or waterconditioning to ensure the chemical quality of thewater.Maintenance is restricted to lubrication of the rollerbearings in the brake and of the cardanic shaft con-necting the dynamometer with the engine to be tested.

Personnel costs

Thanks to the easy operation, every employee canmake the power test. No specialist is required.

Flexibility

Thanks to the mobility of MP 80 ... MP 2x400 SP, theycan be easily adapted to varying situations in theworkshop as described below:If there is only a limited number of types to be testedbut with remarkable numbers per type, WEINLICHoffers truck construction kits RWB suitable for as-sembling mobile engine supports for maximum engineweights of 300 kg up to 800 kg. These engine sup-ports can be equipped with all accessories necessaryfor running the engine. So a certain truck can beprepared for a certain type of engine and preparingevery engine of this type for power test needs a mini-mum of time.

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WEINLICHSTEUERUNGEN

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10.676 GB 1995tech10 \ 676gb01

If there are many different types of engines to betested, WEINLICH offers a supporting frame to betransported by a pallet truck for an engine weight up to2000 kg. Vertical and horizontal position of its support-ing columns are easily adjustable, even with mountedengine.Both, the supporting truck RWB or the universalsupporting frame, with mounted engine, can be movedto the dynamometer and then the engine and itssupport are quickly and easily connected to the dyna-mometer.If the engines shall be turned in cold state beforefiring, a separate cold driving unit can be supplied. Itcan also be moved by a pallet truck. Connection of theengine and its support to the cold driving unit is aseasy as to the dynamometer.So every engine can be mounted on the appropriatesupporting system, either specialized truck RWB oruniversal supporting frame, then maybe moved to thecold running unit or vice versa for driving without firing,then it can maybe run idle and finally it is moved to thedynamometer for power test. After power testing thesupport is removed from the dynamometer for dis-mantling the engine.Hence, mounting and preparing of the engine for thepower test and removal after the test do not occupythe dynamometer.

Further Features

Engine test beds (dynamometers) with air-cooled eddycurrent brakes are distinguished from water brakesand water-cooled eddy current brakes by the fact thatthey can be loaded with high power for short timesonly. This possible disadvantage is compensated forby the evaluation, display and control unit with thecomputer MP by which every desired state of theengine can be adjusted very easily and quickly thanksto the handy method of operation proven for manyyears. A simple test report printing feature facilitatesand speeds up the power test. Even the gravimetricdetermination of the specific fuel consumption onlyrequires a short time thanks to the precision of theelectronic balance connected to the MP computer andto automatic printing of the result.As a result, the efficient performance of power testsprovided by engine test beds MP 80 ... MP 2x400 SPalso reduces the expenses for power testing.The test report is printed automatically. It is protectedagainst falsification and forms the basis for the internalqualitiy assurance system, and provides evidence ofquality to the customers.

Weinlich GmbH & Co. KGIndustriestr. 6D - 68799 Reilingen (near Heidelberg)

Phone 0 62 05 - 40 25Fax 0 62 05 - 1 77 44int’l 49 62 05 -

email info@weinlich.deInternet http://www.weinlich.de