CA1253889A - Gas suspension for vehicles, specifically for railway vehicles - Google Patents
Gas suspension for vehicles, specifically for railway vehiclesInfo
- Publication number
- CA1253889A CA1253889A CA000490622A CA490622A CA1253889A CA 1253889 A CA1253889 A CA 1253889A CA 000490622 A CA000490622 A CA 000490622A CA 490622 A CA490622 A CA 490622A CA 1253889 A CA1253889 A CA 1253889A
- Authority
- CA
- Canada
- Prior art keywords
- spring
- pressure
- valve
- bags
- piston
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
- B60G17/02—Spring characteristics, e.g. mechanical springs and mechanical adjusting means
- B60G17/04—Spring characteristics, e.g. mechanical springs and mechanical adjusting means fluid spring characteristics
- B60G17/052—Pneumatic spring characteristics
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B61—RAILWAYS
- B61F—RAIL VEHICLE SUSPENSIONS, e.g. UNDERFRAMES, BOGIES OR ARRANGEMENTS OF WHEEL AXLES; RAIL VEHICLES FOR USE ON TRACKS OF DIFFERENT WIDTH; PREVENTING DERAILING OF RAIL VEHICLES; WHEEL GUARDS, OBSTRUCTION REMOVERS OR THE LIKE FOR RAIL VEHICLES
- B61F5/00—Constructional details of bogies; Connections between bogies and vehicle underframes; Arrangements or devices for adjusting or allowing self-adjustment of wheel axles or bogies when rounding curves
- B61F5/02—Arrangements permitting limited transverse relative movements between vehicle underframe or bolster and bogie; Connections between underframes and bogies
- B61F5/04—Bolster supports or mountings
- B61F5/10—Bolster supports or mountings incorporating fluid springs
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Vehicle Body Suspensions (AREA)
- Safety Valves (AREA)
- Fluid-Damping Devices (AREA)
- Valves And Accessory Devices For Braking Systems (AREA)
- Inorganic Insulating Materials (AREA)
- Air Bags (AREA)
Abstract
A B S T R A C T
(See Fig. 1) In conjunction with a gas suspension for vehicles, specifically for railway vehicles, a double-acting relief valve (1; 53) is provided in the connection between two spring bags (3, 5) located transversely opposite to the vehicle longitudinal centre-line between the vehicle body and the running gear and, when the pres-sure decreases in one of the spring bags (3, 5) below a predeterminable level assists in interconnecting the two spring bags and, preferably, in deflating an intact spring bag through the other burst spring bag.
The relief valve (1; 53) is provided either with two check valves (11, 13) acting against each other above a predeterminable spring bag pressure with differential pressure behaviour or with two pressure-balances stop valves (55, 77) the check valves or pressure-balanced stop valves being capable of being moved under the action of a spring device into an open position establishing a constant connection between the spring bags (3, 5) if the pressure of the spring bag subject to a pressure drop acting against the spring device falls below the predetermin-able pressure level.
(See Fig. 1) In conjunction with a gas suspension for vehicles, specifically for railway vehicles, a double-acting relief valve (1; 53) is provided in the connection between two spring bags (3, 5) located transversely opposite to the vehicle longitudinal centre-line between the vehicle body and the running gear and, when the pres-sure decreases in one of the spring bags (3, 5) below a predeterminable level assists in interconnecting the two spring bags and, preferably, in deflating an intact spring bag through the other burst spring bag.
The relief valve (1; 53) is provided either with two check valves (11, 13) acting against each other above a predeterminable spring bag pressure with differential pressure behaviour or with two pressure-balances stop valves (55, 77) the check valves or pressure-balanced stop valves being capable of being moved under the action of a spring device into an open position establishing a constant connection between the spring bags (3, 5) if the pressure of the spring bag subject to a pressure drop acting against the spring device falls below the predetermin-able pressure level.
Description
~253a8~33 Gas Suspension for Vehicles, specifically for Railway Vehicles This invention relates to a gafi-suspension system in accordance with he generic definition in ~laim 1 hereof.
Conventionally, gas springs such as in the form of spring bellows or ~pring.~ags, are proyided between the running gear and the vehicle body of ral~ay vehicles. Generally, the spring bags in these systems are arranged in pairs or in pai.red groups transversely opposite to the longitudinal centre-line of the vehicle or travelling direction, i.e. so that for each. spr~ng bag on one side of the rail~ay ~ehicle there is a spring bag on the other side.
For valve b~g ~ystems of the conventional type, valve devices have been disclosed (German Patent Specification 1.088 086~ by means of which sta~ilizing of the vehicle against xolling of the body about its longitudinal centre-line is achieved. Such valve devices are formed as double-acting adjustable relief va~ves which., starting from a pre~et pressure difference between the gas sprinys or gas spxing groups, interconnect these. A sudden re-duction of the pressure in one of ~he:spring bags ~ill cause the pressure in the P spring ~ag to be reduced, too~ b~ e~ecting pressur~ equalization ~et~een the spring ~,6 _ 3 ~ 3~
bags. An inherent feature of the relief valves used is that they operate w~th a certain pressure d~f~exential since th.ey are equipped w;th a comprcssion spring of a pre-determined spring force acting i~ the closing direction. If one of the spring hags or one of the spring bag groups bursts, problems of unsufficient sta-~ilization of the'vehicle hody are liable to arise due to t~e differential pressure behaviour, i.e. due to the existence of a residual pressure in one of the spring bags. 5hould the pressure in one of the spring hags decrease to zero in...consequence of the bag bursting, then it i~ undesirable 'if such a residual pressure re-mains in the other spring bag which ~s liable to con-tribute to an unstahle-position of the vehicle body.
Similar di.sadvantages will naturally exist under condi-ti,ons ~here no bursting of the spring bags occurs, but a sudden decrease to a very- low minim~Lm pressure level.
Starting on these premises, it is the object of the invention to de~elop a gas ~suspension of the generic kind referred to so that the pressure characteristi~ of conventional valves causing the'stabilizing problems can hè'avoided. It is intended with.the aid of simple design means to enable the't~o spring ~ags to ~e adjusted for a certain pressure:without any remaining pressure'differential or to deflate'them co,mpletely if a preset minimum press~re is reached or oIle of the spring bags has hurst.
Th~s ob.ject:is achieved by means of the featur~s defined in the'characterizing par-t of Cla~m l.hereof.
The valve'device:interconnecting the'two ,spring bags which may-he'referred to as a reIief val~e'between the spring bags is provided with'a physIcall~ simple'feature ~hlch.eIiminates the. resi.dual pxe5sure'hehaviour hecause the force.of a spring ~ecomes efectiv~:at a level belo~
an arbitrarily pre-determinable'pres~u~e,' i.eO on reaching 9~2~i3E3~3~
_ 4 a switching level, said spring disa~ling the compression spring of the check valve which is respQn~ihle ~or the residual pressure ~ehaviour. If either of the spring bags bursts or if its pressure drops to an extremely low minimum level, th~n one of the check valves is disabled in a manner t~at the valve is maintained in its open position and a connection established between the two spring bags. At the moment one of the spring ~ags bursts, the o-ther intact spring bags will as a result be instantly deflated through the ~urst spring bag.
T~e spring deuice coming into action by a switching pressur~, i.e. on the pressure in one of the spring bags dropping, may also ~e ~sed for a val~e arrangement comprising two pressure-~alanced stop valves, i.e. two valve arrangements with ~alanced valve elements which will not open ~f different pressures exist on the two sides of the ~alve eIement, i.e. under a differential pressure. In addition to th reIief valve formed by the two stop valves with the spring auxiliary device, a conventional relief valve'may be provided, i.e. a reIief valve with two check valves.
~eference is made to the patent claims ~or advantageous embodiments and further developments.
T~e'invention is expla~ned on the strength of typical embodiments ~ith reference to the accompanying drawing.
Fig. 1 is a sch~matic diagram of a gas suspension with a reIief ~alve'device according to the invention;
Fig. 2 is a diagram comparahle'~ith Fig. 1 where a xeIief valve'is used with,'two pxessure~
~a~anced stop valves.
Fig. 1 of t~e dra~ing sho~s a reIie~ ~al~e'1 which is located ~n the'connection ~etween t~o ,~chematically re-pxesented spring bags 3 and 5. The spr~ng ~ags 3 and 5 i3~38~3 - are disposed in a manner known per se transverse to the veh~cle centre-line opposite each ~thex, acting between t~e vehicle superstructure, e,g. in the form o~
a car body, and the running gear of a railway vehicle.
The two spring ~ags are connected via lines 7 and 9 to the relief valve 1; the lines 7 and 9 may be formed also in a conventional manner by a frame mem~er of the rail-way vehicle~
The xelief valve 1 is provided with two check valves 11 and 13. The check valve 1t shown on the left hand side in Fig. 1 of the drawing acts ~etween two pressure spaces 15 and 17 of w~ich the pressure space 15 is connected with.the Iine 7, whereas the pressure space 17 communicates with the line 90 The check valve 13 shown on the right hand side acts ~etween two pressure spaces 19 and 21 of which the pressure space 19 communicates with the line 7 and, consequehtly, with the pressure space 15, whereas the pre.ssure space 21 communicates with.the line 9 and, consequently, also with the pressure space 17. The check valve 11 as weIl as the check valve 13 may be constructed in the simplest form, i.e. the check valve 11 comprises a compressi.on spring 23 which. is capable of pressing a valve disc on~o a valve seat, whereas the check valve -13 is also provided with a compre~sion spring 25 which forces a ~alve disc onto a valve seat. The two check valves 11 and 13'operat~e according to the principle of differenti.al pressure valves which is known per se.
If~f~r -ihstance~ there is a pressure differential of 5 bar bet-ween the'pressure space:17 and the pressure space 15 such that the'pressure'in the'pressure'space'17 is, say, 5 bar higher than the'pressure in the pressure. space 15, then the check ~alves 11 will open ayainst the force of the compress'ion spring ?3 and pressure equalization will take place ~etween the pressure'spaces~7 and 15 and, consequently, between the spring ~ags. 5 and 3.' The same applie.s to the chec~ valve 13. nithDut the's~stem accordin~ to th invention descri~ed ~n the following, a so-called residual pressure'~ehaYi~ux ~ould occur with ~2~i388~
the two check valves, i~e. th.e ch ck.~al~e 1~ would normally close at a pressure differential of, say, 1.5 ~ar, i.e. under conditions when the pressure in the pressure-;space 17 i5` 1.5 bar higher than the pressure in the pressure space 15 because the valve element of the check valve 11 is pressed with a pre-determined force of the compression spring 23 onto its valve seat.
According to the invent~on, a system is provided which i.s capakle of effecting complete pressure equalization ~etween the spring ~ags 3 and 5 below a pre-determined adjustable pressure'level, i.e, if one of the spring bags 3 and 5 should burst, then the other opposite spring hag ~ill be completely deflated through the burst spring bag.
As shown in the illustration, the ~alve disc 29 acting relative to the valve seat 27 of the check valve 11 can ~e actuated by a piston shank 3~ connected to a piston 33~ In the same fashion, a piston shank 39 connected to a p~ston 41 can actuate the valve disc 37 which cooperates with the ~alve seat 35.of the check.valve 13. In the exa~ple`illustrated, a common spring 43'acts on the two pistons 33 and 4~, ~he piston 33 ~eing movable between two stops 4S and 47 whereas the piston 41 is movable ~etween two stops 49 and 51. The force of the spring 43 is greater than that of the compression spring 23:
similarl~, the'force of the spring 43 is greater th~n that of the compresfiion spring 25. Consequently, the two check Yalves 11 a~d 13 feature a similar layout and similar co-action.
The operation of the reIief valve according to the in-vention is as ollows:
The'reli.ef valve operates up to an adjustable pressure of, sa~, 1 b~r ~n the normal manner, i.e.' up to an ad~ustahle pressure Qf 1 bar in one of the:lines 7 and 9, the check val~es 11 and 13'operate'without the:additional functions of the pistons 33 and 41. If the pressure in one of the pressure'spaces 17 or ~g drops to a ~alue of below 1.har, -~ ~ 7 ~ ~ ~5388~
then the force of the spring 40 is capable of over-coming the counterforce produced hy the pressure, i.e.
in this case, thR piston 33 is displaced to the left h~nd side as shown or, respecti~ely, the piston 41 is displaced towards the right hand side as shown. Upwards of the pressure o~ ; ~ar, the two pistons will consequent-ly ~e kept in contact with the inner stops 47 or 49 respectively so that the end of t~e respective piston shank 31 or 39 respectively ~s at a distance from the valve disc of the check valve facing it. In this re-lative position, the check valves operate in the normal manner as explained in the foregoing.
s Let is be assumed that- the pressure in the two spring bags 3 and 5 is, say, 5 bar and that the spring bag 3 bursts suddenly. Due to the bursting of the bag, the pressure inside the pressure chamber 19 drops to a level ~elow 1 bar ~ithin a short period of time; when a level of ~elow 1 bar, the so-called switching pressure is reached, the force of the spring 43 i5 able to dis- -place the piston 41 to the right hand side as shown.
The piston sh~nk 39 connected to the piston 41 now moves against the valv~ disc 37 and lifts it off its valve seat 35. In this manner, an open connection is esta~lished between the burst sprLng bag 3 and the spring bag 5 so that complete deflation of the spring bag 5 is effected within a very short period of time through the pressure space 21, the pressure space 19, t~e line 7 and the burst spring bag 3. Deflation is complete, that is without ~the residual pressure behaviour characteristic of check val~es, because the force of the spring 43 e~lminates the counterforce of the co~pression spring 25 and, as a result, the valve disc 37 is m~intained open.
The orce to be overcome:additionally ~y the spring 43 as the Yalve disc 37 is lifted off the.valve seat 35 which force is exerted by the compres.~ion spring 25 and t~e pressure in the`pres~ure:space 21 has been B
- 8 _ ~ ~538~
assumed in the foregoing to be negligihle, i.e. it has been as~umed that the connection via the check valve 13 is esta~l~shed immediateIy when the pressure inside the pressure space 19 drops to the so-called switching pressure. Under certain pressure conditions and physical configurations, it is of course also possible for pressure equalization to take place initially in the check valve 11 in the conventional manner ~efore the valve seat 37 is pushed open in the manner desci~ed above by the now prevailing force o~ the spring 43.
~hen the piston 41 has lifted off the valve disc 37 with its piston shank 3~, then a comparable condition will occur in the region of the check valve'~1. If the pressure inside the pressure space 17 has dropped to a level below 1 bar due to the rapid deflation described a~ove, i.e.
the switching pressure, then the piston 33 will become active in a comparable manner, i.e. the spring 43~will be capable of displacing the piston 33'towards the left hand side asdshDwn so that the pistonshank 31 lifts the valve disc 29 off its valve seat and establishes a constantly open connection between the pressure space 17 and the pressure space 15 in a comparable manner. Complete deflation of the spring bag 5 can now take place via both check valves ~1 and 13 in the direction of the burst spring bag 3. Since the pressures in the t~o spring bags are completely equalized within a minimum of t~me, the un-desirable 'hazard of tilting of the vehicle body, i.e.
the'ha7ard of instability of the complete rail vehicle, is excluded.
The invention is not limited to the construction illustrated of the pistons 33'and 41 with the common spring 43'although such a p~ysical integration may be desirea~le.
Thus, it is also possibIe for the reIief valve to con-sist of t~o physical separated check valves each'having allied to it separately a cas~ng ~th an individual spring to load the pistons 33 and 4~ respectiveIy. Tn the ~ _ 9 ~ 3~
s.ame manner, it is of cours.e also possihle to make the switching pressure which initiates the open connection between the two spring ~ags varia~le in such a manner that the function of the pistons 33 and 41 respectively can take place already at a pressure higher than 1 bar.
In principle, the connection of the two spring bags is effected that only wh n one of the spring bags bursts, ~ut also at a preset minimum pressure where the hazard o~ tiltin~ of the car body is to ~e eliminated.
The relief valve 53 illustrated in Fig~ 2 of the drawing according to another embodiment of the invention is e~uipped with two balanced stop valves 55 and 57. The t~o stop valves are pressure-balanced, i.e. the valve element 59 or 61 respectively has equal pressures acting on its two sides. Due to the hole inside the valve element 59, the pressure of the pressure space 63 also exists in pressure space 65; Since the same pressure acts on the same areas, the stoPvalve 55 cannot act as a pressure differential valve'if a pressure difference should exi~t inside the lines 67 and 69 leading to the spring ~ag~ 3 and 5. The valve element 59 is forced on-to its valve se.at solely by the force of the spring 71 and, in the process, interrupts th.e connection between the pressure fipace 63 and the pre~sure space 73. The configuration and method of operation of the stop valve 57 are analo~ous. .~
5imi.1ar to the embodiment illustrated in Fig. 1, the stopvalves 55 and 57 have a device allied to them comprising pistons 33 and 41 respectively and piston shanks 31 and 39 respectively~ Likewise., a spring 43 is provided analogous to the embodiment described above ~hich îs capable of prefising both ~istons 33 and 41 respectively in the direction of their allied valve' element. Onl.y ~ith.the aid of thi.s device is it possible for eIther of the t~o stop valves 55 or 57 or both ~top valv~s to open~ 'Shsuld, in the'case'of the'arrangement ~5i38B9 illus.trated in Pig~ 2, a ~witching press.ure havz been selected helow ~ ~ar, then the force of the spring 43 is a~le to oye.rcome the pneumatic ~orce acting on the opposi.te side of the piston 33 and 41 respectively when same decreases to below 1 bar so t~at in th~s case the piston shank 31 or 39 becomes effective ~n respect of the contiguous valve ~lement 59 or 61 respecti~ely to displace it against the force of the spring 71 or 75 respectively. Again it is necessary in this case for the spring 43 to have a greater spring force than the spring 71 or 75 respectively. Thus, i~ the spring bag 3 communicating with the line 67 should burst, the action described ~ith reference to Fig. 1 would again take place. Since the pressure inside the pressure space 77 (which also prevails in pressure space 73~ quickly de-creases below the value of 1 bar, the spring 43 will force the piston 41 with its piston shank 39 directed to th.e right hand side against the valve element 61 to lift the latter against the force of the spring 75 off its valve seat. As a result, the connecti.on between the spring bag 5 and the burst spring bag 3 will be opened with a large cross-sectional area, i.e. the spring bag 5 will have its pres~use reduced through the burst spring bag 3 when the pressure in the pressure space 77 falls below 1 bar. The condi.tions in the case of spring bag 5 bursting are analogous.
In contrast to the embodi~ent illustrated in Fig. 1, the reIief valve 53 will be effecti~ only if a switching . .. . .
pre~sure'beIow 1 ~ar is re~hed in one of the lines 67 or 69 respectivel~. Above this switching pre.ssure, the reIief valve remain~ inactive in the absence of pressure differential behaviour, in other words, i~t will remain inactive even if a relatively high.pressure di~erential should exist bet~een the lines 67'and 69 and, respectively, the spring bags 3'and 5~
~i38~
-- 1l It is within the scope of the concept of the present invention to provide a relief ~alve 79 acting in a m~nner known per se in addition to the relie~ valve 53, i.e. connected in parallel with it (Fig. 2). In this case, the relief valve 79 serves to effect pressure equalization between the spring bags if there should be a pressure differential of more than, say, 1.5 bar.
Below a pressure of, say, 1 har, preferably in the case of one the spring hags bursting, the relief valve 53 would serve to interconnect the two spring bags 3 and 5 to bring ahout complete pressure equalization~
- 12 _ ~2538 51 Stop 53 ReIief valve Stop valve 57 Stop valve 59 Valve element 61 Valve element 63 Press.ure space Pressure space 67 Line 6q Line 71 Sprin~
73 Pressure space Spring 77 Pressure ~pace 7q Relief ~alYe
Conventionally, gas springs such as in the form of spring bellows or ~pring.~ags, are proyided between the running gear and the vehicle body of ral~ay vehicles. Generally, the spring bags in these systems are arranged in pairs or in pai.red groups transversely opposite to the longitudinal centre-line of the vehicle or travelling direction, i.e. so that for each. spr~ng bag on one side of the rail~ay ~ehicle there is a spring bag on the other side.
For valve b~g ~ystems of the conventional type, valve devices have been disclosed (German Patent Specification 1.088 086~ by means of which sta~ilizing of the vehicle against xolling of the body about its longitudinal centre-line is achieved. Such valve devices are formed as double-acting adjustable relief va~ves which., starting from a pre~et pressure difference between the gas sprinys or gas spxing groups, interconnect these. A sudden re-duction of the pressure in one of ~he:spring bags ~ill cause the pressure in the P spring ~ag to be reduced, too~ b~ e~ecting pressur~ equalization ~et~een the spring ~,6 _ 3 ~ 3~
bags. An inherent feature of the relief valves used is that they operate w~th a certain pressure d~f~exential since th.ey are equipped w;th a comprcssion spring of a pre-determined spring force acting i~ the closing direction. If one of the spring hags or one of the spring bag groups bursts, problems of unsufficient sta-~ilization of the'vehicle hody are liable to arise due to t~e differential pressure behaviour, i.e. due to the existence of a residual pressure in one of the spring bags. 5hould the pressure in one of the spring hags decrease to zero in...consequence of the bag bursting, then it i~ undesirable 'if such a residual pressure re-mains in the other spring bag which ~s liable to con-tribute to an unstahle-position of the vehicle body.
Similar di.sadvantages will naturally exist under condi-ti,ons ~here no bursting of the spring bags occurs, but a sudden decrease to a very- low minim~Lm pressure level.
Starting on these premises, it is the object of the invention to de~elop a gas ~suspension of the generic kind referred to so that the pressure characteristi~ of conventional valves causing the'stabilizing problems can hè'avoided. It is intended with.the aid of simple design means to enable the't~o spring ~ags to ~e adjusted for a certain pressure:without any remaining pressure'differential or to deflate'them co,mpletely if a preset minimum press~re is reached or oIle of the spring bags has hurst.
Th~s ob.ject:is achieved by means of the featur~s defined in the'characterizing par-t of Cla~m l.hereof.
The valve'device:interconnecting the'two ,spring bags which may-he'referred to as a reIief val~e'between the spring bags is provided with'a physIcall~ simple'feature ~hlch.eIiminates the. resi.dual pxe5sure'hehaviour hecause the force.of a spring ~ecomes efectiv~:at a level belo~
an arbitrarily pre-determinable'pres~u~e,' i.eO on reaching 9~2~i3E3~3~
_ 4 a switching level, said spring disa~ling the compression spring of the check valve which is respQn~ihle ~or the residual pressure ~ehaviour. If either of the spring bags bursts or if its pressure drops to an extremely low minimum level, th~n one of the check valves is disabled in a manner t~at the valve is maintained in its open position and a connection established between the two spring bags. At the moment one of the spring ~ags bursts, the o-ther intact spring bags will as a result be instantly deflated through the ~urst spring bag.
T~e spring deuice coming into action by a switching pressur~, i.e. on the pressure in one of the spring bags dropping, may also ~e ~sed for a val~e arrangement comprising two pressure-~alanced stop valves, i.e. two valve arrangements with ~alanced valve elements which will not open ~f different pressures exist on the two sides of the ~alve eIement, i.e. under a differential pressure. In addition to th reIief valve formed by the two stop valves with the spring auxiliary device, a conventional relief valve'may be provided, i.e. a reIief valve with two check valves.
~eference is made to the patent claims ~or advantageous embodiments and further developments.
T~e'invention is expla~ned on the strength of typical embodiments ~ith reference to the accompanying drawing.
Fig. 1 is a sch~matic diagram of a gas suspension with a reIief ~alve'device according to the invention;
Fig. 2 is a diagram comparahle'~ith Fig. 1 where a xeIief valve'is used with,'two pxessure~
~a~anced stop valves.
Fig. 1 of t~e dra~ing sho~s a reIie~ ~al~e'1 which is located ~n the'connection ~etween t~o ,~chematically re-pxesented spring bags 3 and 5. The spr~ng ~ags 3 and 5 i3~38~3 - are disposed in a manner known per se transverse to the veh~cle centre-line opposite each ~thex, acting between t~e vehicle superstructure, e,g. in the form o~
a car body, and the running gear of a railway vehicle.
The two spring ~ags are connected via lines 7 and 9 to the relief valve 1; the lines 7 and 9 may be formed also in a conventional manner by a frame mem~er of the rail-way vehicle~
The xelief valve 1 is provided with two check valves 11 and 13. The check valve 1t shown on the left hand side in Fig. 1 of the drawing acts ~etween two pressure spaces 15 and 17 of w~ich the pressure space 15 is connected with.the Iine 7, whereas the pressure space 17 communicates with the line 90 The check valve 13 shown on the right hand side acts ~etween two pressure spaces 19 and 21 of which the pressure space 19 communicates with the line 7 and, consequehtly, with the pressure space 15, whereas the pre.ssure space 21 communicates with.the line 9 and, consequently, also with the pressure space 17. The check valve 11 as weIl as the check valve 13 may be constructed in the simplest form, i.e. the check valve 11 comprises a compressi.on spring 23 which. is capable of pressing a valve disc on~o a valve seat, whereas the check valve -13 is also provided with a compre~sion spring 25 which forces a ~alve disc onto a valve seat. The two check valves 11 and 13'operat~e according to the principle of differenti.al pressure valves which is known per se.
If~f~r -ihstance~ there is a pressure differential of 5 bar bet-ween the'pressure space:17 and the pressure space 15 such that the'pressure'in the'pressure'space'17 is, say, 5 bar higher than the'pressure in the pressure. space 15, then the check ~alves 11 will open ayainst the force of the compress'ion spring ?3 and pressure equalization will take place ~etween the pressure'spaces~7 and 15 and, consequently, between the spring ~ags. 5 and 3.' The same applie.s to the chec~ valve 13. nithDut the's~stem accordin~ to th invention descri~ed ~n the following, a so-called residual pressure'~ehaYi~ux ~ould occur with ~2~i388~
the two check valves, i~e. th.e ch ck.~al~e 1~ would normally close at a pressure differential of, say, 1.5 ~ar, i.e. under conditions when the pressure in the pressure-;space 17 i5` 1.5 bar higher than the pressure in the pressure space 15 because the valve element of the check valve 11 is pressed with a pre-determined force of the compression spring 23 onto its valve seat.
According to the invent~on, a system is provided which i.s capakle of effecting complete pressure equalization ~etween the spring ~ags 3 and 5 below a pre-determined adjustable pressure'level, i.e, if one of the spring bags 3 and 5 should burst, then the other opposite spring hag ~ill be completely deflated through the burst spring bag.
As shown in the illustration, the ~alve disc 29 acting relative to the valve seat 27 of the check valve 11 can ~e actuated by a piston shank 3~ connected to a piston 33~ In the same fashion, a piston shank 39 connected to a p~ston 41 can actuate the valve disc 37 which cooperates with the ~alve seat 35.of the check.valve 13. In the exa~ple`illustrated, a common spring 43'acts on the two pistons 33 and 4~, ~he piston 33 ~eing movable between two stops 4S and 47 whereas the piston 41 is movable ~etween two stops 49 and 51. The force of the spring 43 is greater than that of the compression spring 23:
similarl~, the'force of the spring 43 is greater th~n that of the compresfiion spring 25. Consequently, the two check Yalves 11 a~d 13 feature a similar layout and similar co-action.
The operation of the reIief valve according to the in-vention is as ollows:
The'reli.ef valve operates up to an adjustable pressure of, sa~, 1 b~r ~n the normal manner, i.e.' up to an ad~ustahle pressure Qf 1 bar in one of the:lines 7 and 9, the check val~es 11 and 13'operate'without the:additional functions of the pistons 33 and 41. If the pressure in one of the pressure'spaces 17 or ~g drops to a ~alue of below 1.har, -~ ~ 7 ~ ~ ~5388~
then the force of the spring 40 is capable of over-coming the counterforce produced hy the pressure, i.e.
in this case, thR piston 33 is displaced to the left h~nd side as shown or, respecti~ely, the piston 41 is displaced towards the right hand side as shown. Upwards of the pressure o~ ; ~ar, the two pistons will consequent-ly ~e kept in contact with the inner stops 47 or 49 respectively so that the end of t~e respective piston shank 31 or 39 respectively ~s at a distance from the valve disc of the check valve facing it. In this re-lative position, the check valves operate in the normal manner as explained in the foregoing.
s Let is be assumed that- the pressure in the two spring bags 3 and 5 is, say, 5 bar and that the spring bag 3 bursts suddenly. Due to the bursting of the bag, the pressure inside the pressure chamber 19 drops to a level ~elow 1 bar ~ithin a short period of time; when a level of ~elow 1 bar, the so-called switching pressure is reached, the force of the spring 43 i5 able to dis- -place the piston 41 to the right hand side as shown.
The piston sh~nk 39 connected to the piston 41 now moves against the valv~ disc 37 and lifts it off its valve seat 35. In this manner, an open connection is esta~lished between the burst sprLng bag 3 and the spring bag 5 so that complete deflation of the spring bag 5 is effected within a very short period of time through the pressure space 21, the pressure space 19, t~e line 7 and the burst spring bag 3. Deflation is complete, that is without ~the residual pressure behaviour characteristic of check val~es, because the force of the spring 43 e~lminates the counterforce of the co~pression spring 25 and, as a result, the valve disc 37 is m~intained open.
The orce to be overcome:additionally ~y the spring 43 as the Yalve disc 37 is lifted off the.valve seat 35 which force is exerted by the compres.~ion spring 25 and t~e pressure in the`pres~ure:space 21 has been B
- 8 _ ~ ~538~
assumed in the foregoing to be negligihle, i.e. it has been as~umed that the connection via the check valve 13 is esta~l~shed immediateIy when the pressure inside the pressure space 19 drops to the so-called switching pressure. Under certain pressure conditions and physical configurations, it is of course also possible for pressure equalization to take place initially in the check valve 11 in the conventional manner ~efore the valve seat 37 is pushed open in the manner desci~ed above by the now prevailing force o~ the spring 43.
~hen the piston 41 has lifted off the valve disc 37 with its piston shank 3~, then a comparable condition will occur in the region of the check valve'~1. If the pressure inside the pressure space 17 has dropped to a level below 1 bar due to the rapid deflation described a~ove, i.e.
the switching pressure, then the piston 33 will become active in a comparable manner, i.e. the spring 43~will be capable of displacing the piston 33'towards the left hand side asdshDwn so that the pistonshank 31 lifts the valve disc 29 off its valve seat and establishes a constantly open connection between the pressure space 17 and the pressure space 15 in a comparable manner. Complete deflation of the spring bag 5 can now take place via both check valves ~1 and 13 in the direction of the burst spring bag 3. Since the pressures in the t~o spring bags are completely equalized within a minimum of t~me, the un-desirable 'hazard of tilting of the vehicle body, i.e.
the'ha7ard of instability of the complete rail vehicle, is excluded.
The invention is not limited to the construction illustrated of the pistons 33'and 41 with the common spring 43'although such a p~ysical integration may be desirea~le.
Thus, it is also possibIe for the reIief valve to con-sist of t~o physical separated check valves each'having allied to it separately a cas~ng ~th an individual spring to load the pistons 33 and 4~ respectiveIy. Tn the ~ _ 9 ~ 3~
s.ame manner, it is of cours.e also possihle to make the switching pressure which initiates the open connection between the two spring ~ags varia~le in such a manner that the function of the pistons 33 and 41 respectively can take place already at a pressure higher than 1 bar.
In principle, the connection of the two spring bags is effected that only wh n one of the spring bags bursts, ~ut also at a preset minimum pressure where the hazard o~ tiltin~ of the car body is to ~e eliminated.
The relief valve 53 illustrated in Fig~ 2 of the drawing according to another embodiment of the invention is e~uipped with two balanced stop valves 55 and 57. The t~o stop valves are pressure-balanced, i.e. the valve element 59 or 61 respectively has equal pressures acting on its two sides. Due to the hole inside the valve element 59, the pressure of the pressure space 63 also exists in pressure space 65; Since the same pressure acts on the same areas, the stoPvalve 55 cannot act as a pressure differential valve'if a pressure difference should exi~t inside the lines 67 and 69 leading to the spring ~ag~ 3 and 5. The valve element 59 is forced on-to its valve se.at solely by the force of the spring 71 and, in the process, interrupts th.e connection between the pressure fipace 63 and the pre~sure space 73. The configuration and method of operation of the stop valve 57 are analo~ous. .~
5imi.1ar to the embodiment illustrated in Fig. 1, the stopvalves 55 and 57 have a device allied to them comprising pistons 33 and 41 respectively and piston shanks 31 and 39 respectively~ Likewise., a spring 43 is provided analogous to the embodiment described above ~hich îs capable of prefising both ~istons 33 and 41 respectively in the direction of their allied valve' element. Onl.y ~ith.the aid of thi.s device is it possible for eIther of the t~o stop valves 55 or 57 or both ~top valv~s to open~ 'Shsuld, in the'case'of the'arrangement ~5i38B9 illus.trated in Pig~ 2, a ~witching press.ure havz been selected helow ~ ~ar, then the force of the spring 43 is a~le to oye.rcome the pneumatic ~orce acting on the opposi.te side of the piston 33 and 41 respectively when same decreases to below 1 bar so t~at in th~s case the piston shank 31 or 39 becomes effective ~n respect of the contiguous valve ~lement 59 or 61 respecti~ely to displace it against the force of the spring 71 or 75 respectively. Again it is necessary in this case for the spring 43 to have a greater spring force than the spring 71 or 75 respectively. Thus, i~ the spring bag 3 communicating with the line 67 should burst, the action described ~ith reference to Fig. 1 would again take place. Since the pressure inside the pressure space 77 (which also prevails in pressure space 73~ quickly de-creases below the value of 1 bar, the spring 43 will force the piston 41 with its piston shank 39 directed to th.e right hand side against the valve element 61 to lift the latter against the force of the spring 75 off its valve seat. As a result, the connecti.on between the spring bag 5 and the burst spring bag 3 will be opened with a large cross-sectional area, i.e. the spring bag 5 will have its pres~use reduced through the burst spring bag 3 when the pressure in the pressure space 77 falls below 1 bar. The condi.tions in the case of spring bag 5 bursting are analogous.
In contrast to the embodi~ent illustrated in Fig. 1, the reIief valve 53 will be effecti~ only if a switching . .. . .
pre~sure'beIow 1 ~ar is re~hed in one of the lines 67 or 69 respectivel~. Above this switching pre.ssure, the reIief valve remain~ inactive in the absence of pressure differential behaviour, in other words, i~t will remain inactive even if a relatively high.pressure di~erential should exist bet~een the lines 67'and 69 and, respectively, the spring bags 3'and 5~
~i38~
-- 1l It is within the scope of the concept of the present invention to provide a relief ~alve 79 acting in a m~nner known per se in addition to the relie~ valve 53, i.e. connected in parallel with it (Fig. 2). In this case, the relief valve 79 serves to effect pressure equalization between the spring bags if there should be a pressure differential of more than, say, 1.5 bar.
Below a pressure of, say, 1 har, preferably in the case of one the spring hags bursting, the relief valve 53 would serve to interconnect the two spring bags 3 and 5 to bring ahout complete pressure equalization~
- 12 _ ~2538 51 Stop 53 ReIief valve Stop valve 57 Stop valve 59 Valve element 61 Valve element 63 Press.ure space Pressure space 67 Line 6q Line 71 Sprin~
73 Pressure space Spring 77 Pressure ~pace 7q Relief ~alYe
Claims (7)
1. A gas spring system for vehicles, typically rail vehicles, having an overflow valve which is affixed in the connection between at least two gas springs in the form of spring bags transversely located to the longitudinal axis of the vehicle and exerting their effects between the undercarriage and the vehicle body, whereby the overflow valve is provided with two individual nonreturn valves, working in opposite directions to carry out the overflow function, characterized in that a supplementary device opening the connection between the spring bags when a lower control pressure is reached in one of the spring bags (3, 5) consists in each case of a spring-tensioned ram device acting against the force of the compression springs (23, 25; 71, 75) of the nonreturn valves (11, 13) which, when above the control pressures of one of the spring bags, is kept in an inactive state by means of a piston (33, 41) subject to the spring bag pressure.
2. A gas spring system as per Claim 1, characterized in that the piston (33, 41) is acted upon at one end by a spring (43) and at the opposite end by the pressure of one of the spring bags (3, 5) in each instance, whereby the pressure simultaneously exerts its effect in the direction of the opening (overflow function) vis-a-vis the nonreturn valve (33, 41) carries a ram facing the valve head (29, 37) of the nonreturn valve (11, 13) and likewise exerting its effect in the direction of the opening of the nonreturn valve.
3. A gas spring system as per claim 2, characterized in that the overflow valve is formed of two nonreturn valves (11, 13) which are structurally separate from one another, to each of which is allocated a device for the connection of the two spring bags when a lower control pressure is reached
4. Gas suspension as in Claim 2, characterized in that the piston (33, 41) is acted upon on one side by the spring (43) and on the opposite side by the pressure of one of the spring bags (3, 5) respectively, the pressure acting simultaneously in the opening direction relative to the check valve (11, 13) allied to the piston and in that the piston (33, 41) is formed with an actuating member contiguous to the valve disc (29, 37) of the check valve (11, 13) and similarly acting in the opening direction of the check valve.
5. Gas suspension as in Claim 3, characterized in that the piston (33, 41) is acted upon on one side by the spring (45) and on the opposite side by the pressure of one of the springs bags (3, 5) each, the pressure acting likewise in the opening direction of the stop valve (55, 57) allied to the piston in that the piston is formed with an actuating member contiguous to the stop valve and likewise actin in the opening direction of same.
6. Gas suspension as in Claim 5, characterized in that the relief valve is formed by two physically separate check valves (11, 13) each of which having a system allied to it for connecting the two spring bags on the pressure reaching the switching level.
7. Gas suspension as in Claim 6, characterized in that a relief valve with check valves operating according to the differential pressure principle is connected in parallel with the relief valve (53) comprising two stop valves each with a system for connecting the spring bags on the pressure reaching the switching level.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19843433691 DE3433691A1 (en) | 1984-09-13 | 1984-09-13 | GAS SUSPENSION FOR VEHICLES, ESPECIALLY FOR RAIL VEHICLES |
| DEP3433691.5 | 1984-09-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1253889A true CA1253889A (en) | 1989-05-09 |
Family
ID=6245345
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000490622A Expired CA1253889A (en) | 1984-09-13 | 1985-09-12 | Gas suspension for vehicles, specifically for railway vehicles |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0175108B1 (en) |
| KR (2) | KR860002388A (en) |
| AT (1) | ATE38358T1 (en) |
| BR (1) | BR8504549A (en) |
| CA (1) | CA1253889A (en) |
| DE (2) | DE3433691A1 (en) |
| ES (1) | ES8703781A1 (en) |
| GR (1) | GR852202B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2689476B1 (en) * | 1992-04-01 | 1994-06-10 | Faiveley Transport | CROSS SUSPENSION FOR RAIL VEHICLE. |
| FR2689475A1 (en) * | 1992-04-01 | 1993-10-08 | Faiveley Transport | Railway vehicle transverse suspension - includes two pneumatic absorbers supplied by electrovalves responding to signals from regulator |
| DE102008035563B4 (en) | 2008-07-30 | 2016-01-07 | Siemens Aktiengesellschaft | Air suspension system for a rail vehicle |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2115159A (en) * | 1931-06-19 | 1938-04-26 | Dupuy Pierre | Suspension for vehicles |
| US2505256A (en) * | 1947-07-18 | 1950-04-25 | Robert A Poage | Hydraulic balancing system for vehicle bodies |
| US2784978A (en) * | 1955-07-14 | 1957-03-12 | Homer T Seale | Leveling valve arrangement for pneumatic spring suspension |
| DE1088086B (en) * | 1957-02-16 | 1960-09-01 | Maschf Augsburg Nuernberg Ag | Gas suspension for rail vehicles |
| AT300025B (en) * | 1969-04-17 | 1972-07-10 | Simmering Graz Pauker Ag | Device for stabilizing a rail vehicle with lateral air springs |
| CH543987A (en) * | 1971-09-28 | 1973-11-15 | Oerlikon Buehrle Ag | Load-dependent pneumatic control device for vehicles |
| DE3361482D1 (en) * | 1982-07-23 | 1986-01-23 | Oerlikon Buehrle Ag | Pneumatic control device |
-
1984
- 1984-09-13 DE DE19843433691 patent/DE3433691A1/en not_active Withdrawn
-
1985
- 1985-08-01 AT AT85109657T patent/ATE38358T1/en not_active IP Right Cessation
- 1985-08-01 DE DE8585109657T patent/DE3565960D1/en not_active Expired
- 1985-08-01 EP EP85109657A patent/EP0175108B1/en not_active Expired
- 1985-09-11 GR GR852202A patent/GR852202B/el unknown
- 1985-09-12 CA CA000490622A patent/CA1253889A/en not_active Expired
- 1985-09-12 BR BR8504549A patent/BR8504549A/en not_active IP Right Cessation
- 1985-09-12 ES ES546906A patent/ES8703781A1/en not_active Expired
- 1985-09-13 KR KR1019850006708A patent/KR860002388A/en not_active Application Discontinuation
-
1993
- 1993-08-27 KR KR2019930016705U patent/KR930008096Y1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DE3433691A1 (en) | 1986-03-20 |
| ES8703781A1 (en) | 1987-03-16 |
| GR852202B (en) | 1986-01-10 |
| BR8504549A (en) | 1986-07-15 |
| KR860002388A (en) | 1986-04-24 |
| ES546906A0 (en) | 1987-03-16 |
| ATE38358T1 (en) | 1988-11-15 |
| EP0175108A3 (en) | 1987-09-02 |
| EP0175108A2 (en) | 1986-03-26 |
| KR930008096Y1 (en) | 1993-12-08 |
| DE3565960D1 (en) | 1988-12-08 |
| EP0175108B1 (en) | 1988-11-02 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |