7/31/2019 Poster Presentation Articol

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Authors: C. Besleaga, ECONET PROD, Bucharest, Romania

R.M. Negriu, ECONET PROD, Bucharest, Romania

I.C. Popescu, ECONET PROD, Bucharest, Romania

S.G. Badea, ECONET PROD, Bucharest, Romania

CASE STUDY REGARDING THE TAMPING TOOL TYPE BNRI 85

1.Abstract

The tamping operation is one of the most important operations for

building and maintenance of railway and is executed with the help of

different tamping tools, like the BNRI- 85 tool. Using two methods,we made and tested a new model of tamping tool BNRI- 85, under

real workplace conditions and used a CAD program to design and

verify this new model of tamping tool. By using the CAD program

we could determine critical areas, the wear mechanism, potential

breakage sections and compare the results in order to improve this

new tamping tool.

2.IntroductionTamping is a technological operation for maintenance of the railway

and is made with tamping machine. Mechanized tamping consists in

the vibration and squeeze of the ballast, under the inferior part of the

sleeper, at frequencies of 35 Hz, with an amplitude of the oscillation

between 35 mm and a force of about 10 kN. Some failures of the old

model of tamping tools are presented below.

5.Conclusions5.1. In some cases, the tension condition exceeds the allowable limits this situation explaining the deterioration by loss of material (wear),

which occurs during the actual operation (the tip of the stone is practically splitting the tine). In other cases, it could be taken into consideration

the occurrence of a shock stress situation. This type of stress will cause deformation, until obtaining forms that can get it out of use or even, in case

of this type of repeated stresses, breaking of tamping tool can occur. Breaking or intense damage can be also caused by the repeated deformation. In

case the tool is being distorted, the tension condition is different at a new stress, because the model is different and the forces (even if they have

the same value) lead to other tension and deformation conditions.

5.2. Another novelty is represented by the determination of owns vibrations frequencies of a tamping tool. The own frequencies (173.81; 248.71;

568.41[Hz]) arent overlapped to the operating frequency f = 35 Hz and, therefore, there is no danger of occurrence of the resonance phenomenon.

5.3.Designing a tamping tool and checking it, to the different stress, with special CAD soft, can offer many advantages, possibilities and reduces a

lot of time for testing and improvements and gives more accurate results.

5.4.The new composite material with tungsten carbide, which we have proposed, has good properties for wear, being cheap and is obtained from the

waste of different damage parts of tungsten carbide.

3.Testing new and old model of tamping tool BNRI- 85

4.CAD Method- Presentation of some analyzed cases

Ciocane BNRI - 85

0

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

1 3 5 7 9 11 13 15 17 19 2 1 23 25 27 29 31 3 3 35 37 39 [km]

[mm] G4

G6

G8(7)

B21

B22

B23

B24

B25

B26

B27

B28

B21(R1)

B22(R1)

B23(R1)

B24(R1)

B25(R1)

B26(R1)

B27(R1)

B28(R1)

We made a new composite material with improved characteristics in

terms of wear, obtained by infiltration of refracted particles of hard

metal having the contact metal (Co, Ni) in a melted metal matrix

(steel alloy) to achieve the tines of tamping tools. These crystals lead

to the formation of a material that contains a hard metal structure,

having the content of inter-granular spaces filled with the designed

metal matrix. This material is more resistant to abrasion, erosion and

other types of wear than other earlier materials

Case 1 of extreme stress determined by the force in the vertical movement

Case 2 of extreme stress determined by the force in the horizontal movement

The main mechanism of failure is wear.

The own frequencies of the tamping tool