GB2258640A - Locomotive sander. - Google Patents

Description

" 23jj43 LOCOMOTIVE SANDBR The invention relates to the railway transport,

and, ore particularly, to designs of devices for improvement Of rail-holding capacity of wheels. locomotive sanders. in particular.

Employment of sanders in locomotives with a view to improve the ZailbD1ding Capacity Of wbeels by way of feeding sand into their contact has been known probably since the time Of emergence of railway trans- port and has been in use up to these days. This was facilitated by availability Of sand and its low pr ice S.

At present, widespread at the railwaY t-ratispDrt axe the sanders whose principle of operation is based On entrainment and transportation Of sand by compressed air. A typical example Of such designs is a sander widely used at all the locomotives Of the Soviet Union, comprising a housing with built-in unions for delivery Of compressed air, necessary for entrainment of trans- portatiDn of sand (A.A. Kamaev, "Construction, analysis and d,esign Of 1DCOMDtives11, Mashinostroenie Publishers MOSCOW, 1981, pp 233-237)o Locomotives in other eDuntries have also been provided with sanders, operating on the similar prin- ciple.

Sand6rS of this type feature the following disad- vantages:

- low efficiency and economy owing to a fixed capacity of the sander; poor adaptability to a required rate of sand feed; - unsatisfactory reproducibility of results; - failures in operation as a result of penetration of moisture into sand from compressed air and end sandfeeding pipes.

Construction perfection of sanders with a view to eliminate the abovernentiDned disadvantages has led to 10. the development of such sanders in which sand is separated from the mixing chamber by a valve provided with an electromagnetic drive. The sander has a housing with ducts for connection to a bin and a sand conduit. union for delivery of compressed air. and an electromagnet with a spring-IDaded armature, connected with valve Also known in the art is a modification of the aboved.escribed sander, Comprising a bin communicated through a vertical duct with a union for feeding compressed eir and a branch pipe for carrying the sand-air mixture, a sbut-off valve made in the form of plates whose upper end is secured on a duct wall and the lower end is arranged in the zone of operation of the eleCtrDmaFnetic drive which includes two electromagnets with permanently magnetized cores located on both sides of the plate.

The abovedescribed devices feature the following d isadvantage s:

- low efficiency and economy owing to a fixed capacity of the sander; accelerated wear of working elements as a result of appearance of great forces in their interaction with sand.

The present invention is based on the task to provide such a sander Whose structural embodiment of basic eleMentS Would make it possible to raise efficiency, economy an..j reliability of its Operation.

The object of the invention is 3D1ved due to the fact that in a locomotive sander, comprising a housing with a vertical duct communicating by one end face side with a branch pipe for feeding sand. and by the opposite end face side, through an electrically-operated shut-off valve with a mixing chamber, connected with a source of compressed air and with a branch pipe for carrying out a sand-air mixture. according to the invention, the valve is located in the zone of operation of the electromagnetic drive and comprises an elastic plate secured on the housing and carrying on the end a shut-off device which periodically shuts off the measuring hole of the vertical duct.

In one of the alternative embDdiments of the invention provision is made for an electromagnetic drive cDmp.rising a speed transmitter and a control unit, while its core is mounted with a possibility of displacement in the axial direction and being fixed relative to a coil.

In another embodiment of the invention the shutoff device is provided with a weight adapted for interactiDn with the housing.

Such a construction arrangement of the sander elements makes it possible to vary the rate of sand feed by the sander proportionally to the locomotive speed, which ensures, irrespective of the speed, constant optimum mass of sand in the wheels-to- rails contact.

This resulzs in that the maximum efficiency and economy in using sand for improvement of the v;heels-tDrails adhesion are attained.

The essence of the invention resides in the following.

The prerequisites for provinc. the sander of the invention are based on the results of the conducted experimental-theDretical studies, according to which attaining the highest coefficient of traction is pDssible when feeding a strictly definite rnnass of sand into a wheel-to-rail contact. Deviations from this mass of sand botb to,...,ards its increase or decrease, reduce the coefficient Of traction (vbeels-tD-rails adhesion), In realization of this condition, it is presumed that the rate of sand feed ensured by the sander will be varied, depending on the 1DCMDtive speed.

For this purpose, sand is fed from the vertical duct into a mixing chamber with subsequent conveying it by compressed air under the lDcomotive,wheels; the above operation is effected by the shutDff valve which opens the measuring hole in strict compliance with the duration of electric pulses produced by the control i c) unit to the electrDMag:Aet, said pulses being the function of the locomotive speed.

This renders it possible tD increase the rate of sand feed in compliance with a speed increase of the locomotive.

Enbancement of reliability of the sander operation is effected by way of supporting the sbutDff device as a cantilever, perpendicular to the elastic plate, which helps reduce the forces and, consequently, the wear appearing in interactiDn of the ShUtDff device with the sand mass, since in this case they interact at the minimum angle uowards each other.

Besides, a clearance is provided bet,;,-een the shutoff device ari the measuring bole, -..,bicb equals 2-3 diameters of sand particles (1.0-1.5 rm), preventing their crushin., thus facilitating eli:nina-uiDn of intensive abrasive w- jar.

4 e t With a view to enhance efficiency of the sander by way Of regulating the initial sand feed rate, the electromagnet core is mounted with a pDssibility of displacement and being fixed relative to the Coil.

Thus, the locomotive sander. owing to the distinguisbing featuresg in the process Of the 1DCOMOtiVe travel. ensures the highest coef-Eicients Of traction (wbeel-tD-rail grip) and rational consumption Of sand tbrDuo.b a delivery Of the optimum sand mass into the contact Owing to variation of the sand feed rate depending on the locomotive speed.

It has been established that eMPIDyment of the sander with the abDveinentiDned properties makes it Possible to attain the following advan-cages: improvement of efficiency in using sand by 55-15% (according to the coefficient of traction criterion); - reduction Of sand consumption by two or more times; - reduced wear of roll surfaces of the wheels and rails, os well as of locomotive underframe units unprDtec20 ted against penetration of sand; -enhanced traffic safety; - minimum possible fouling Of the railway bed prism.

The abDVementiDned Objects and advantages of the present invention will be rendered more understandable from the following specific description of the 1DComDtive sander embodiment and accompanying drawings, in which:

Figure 1 shows a general view of the locomotive sander, according to the invention; Figure 2 diagrammatically shows a wDrkinG characteristic of the sander in the form of a graph, showing relationship between the sand feed rate and the locomotive speed.

1.5 O The locomotive sander (Fig. 1) comprises a speed transmitter 1 Connected to a control unit 2, electrically connected to sand nozzles which consist of a body a duct 4 vertically arranged inside the body connected by one end face side with a branch pipe 5 adapted for supplying sand and by the opposite end face side provi ded with a measuring hole CE, through the agences of electrically operated ShUtDff valve, thrDL'gb a Mixing chamber 7, with a source 8 of compressed air and a branch pipe 9 for carrying DUt sand-air mixture. 12he exit section of the measuring hole G0 is periodically covered by a sh.utDff device 10 supported as a cantileve_r on an elastic plate 11 and made integral with a weight. 12.

An armature 13 is installed on the elastic plate 11 and orientated to an electromagnetic coil 14 that Consists of a frame 15 with a boss 16 thereDn, a coil 17 a core 18 secured in the frame by a tail,,iece 19 and a check nut 20. A slot 21 is made in the end of the tailpiece 19.!he coil 17 is separated from the mixinchamber 7 by a:-.asket 22.

W The lc)cc)mc)tive sender operates as fOllDWS. Sand flows into the body 3 through the branch pipe 5 anI is accumulated in the space of the vertical duct 4, bein.retained by the SbUtDff device 10. When it is necessary tD supply sand under the locomotive wheels, variableduration electric pulses are fed to the electromagnet 14, the pulses being formed by the control unit 2 and depending on the parameters of a signal produced by the speed transmitter. This ensures proportionality of duration of pulses, received by the electromagnet 14, to the locomotive Speed. As a result. the armature 13, entraining the elastic plate 11 and shutoff device 10, performs oscillatory Motions between the measuring bole 05 and the core 18 of the electrDma,-net 14, which ensures p-riDdic opening, according to the duration of an electric pulse, C) of the measuring bole 6 and getting of sand into the mixing chamber 7.

Simultaneously witb the be6inning of -eneratir, electric pulses, Compressed air is supplied tbrough the source 8, conveying sand through the branch pipe under the 10COMDtiVe -v,, teels. To stop the supply of sand, the coil 17 is deenergized and the supply of compressed air is ceased.

The opening of the measuring bole 6 by the shut- W off device 10 according to the duration of electric pulses which. are the function Of the 1DCOMOtive speed and are fed to the electromagnet 14, makes it possible i5 to very the rate of sand feed and to realize the working characteristic of the sander represented by the graph ShDWn in Fig 2 Adjustment of the sander to the specified initial feed rate is effected by Way of displacement of the core 18 relative to the coil 17. Displacement of the core 18 is performed by rotation of the tailpiece 19 tbZDutSh a slot 21, with subsequent fixing in position by check nut 20, This causes a change in the magnetic f leld of the electric Coil and specifies the value of an amplitude of the armature 13 and intensity of its attraction to the core 18.

With a view to improve the discharge of sand from the measuring hole 6, attached to the ShUtDff device 10 is a weight 12 which, when the shutoff device 10 returns to the initial position, imparts impact impulses to the end face wall wherein the measuring hole 6 is provided.

1 z

Claims (4)

-10WEAT WE CLAIM IS

1. A 1DCOMDtiVe sender$ comprising a hDUSino. with a vertical duct communicating by one end face side with a branch pipe for feeding sand. and by the opposite side, through an electrically operated shutDff vclve, with a mixing chamber connected with a Source of cDmpressed air and a branch pipe for carrying out sand-air mixture; said sbutoff valve is located in the zone of operation of an electromagnetic drive and comprises an elastic plate secured on the housing and carrying a shutoff device on the end for periodically closing the measuring hole of the vertical duct.

2. A IDCDMDttiive sander according to Claim 1, in which the electromagnetic drive comprises a speed transmitter and a control unit, while its core is mounted with a possibility of moving in the axial direction and being fixed relative to the coil.

3. A locomozive sander according to Claim l$ in which the shutoff device is provided witb a vieight for interaction with the housing.

4. A 1DCDMDtive Sander according to any of the above Claims, substantially as described hereinabove with reference to the accompanying drawings.