CA1219513A - Solenoid-operated valve - Google Patents
Solenoid-operated valveInfo
- Publication number
- CA1219513A CA1219513A CA000459727A CA459727A CA1219513A CA 1219513 A CA1219513 A CA 1219513A CA 000459727 A CA000459727 A CA 000459727A CA 459727 A CA459727 A CA 459727A CA 1219513 A CA1219513 A CA 1219513A
- Authority
- CA
- Canada
- Prior art keywords
- valve
- pilot
- chamber
- supply
- delivery
- 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
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- Fluid-Driven Valves (AREA)
- Braking Systems And Boosters (AREA)
- Valves And Accessory Devices For Braking Systems (AREA)
- Magnetically Actuated Valves (AREA)
Abstract
(Case No. 8148) ABSTRACT OF THE DISCLOSURE
A solenoid-operated fluid control valve having manual override and fluid latching for establishing a fluid path between a supply port and a delivery port when a brake-release solenoid pilot valve coil is momentarily energized to cause a pilot piston to close an exhaust valve and to open a supply valve for causing feedback pressure to be fed from a delivery chamber to a pilot chamber for fluid latching the pilot piston in a brake-release position until a brake-application solenoid pilot valve coil is momentarily ener-gized which causes the pilot chamber to exhaust to atmosphere so that the pilot piston returns and opens the exhaust valve and allows the closure of the supply valve.
A solenoid-operated fluid control valve having manual override and fluid latching for establishing a fluid path between a supply port and a delivery port when a brake-release solenoid pilot valve coil is momentarily energized to cause a pilot piston to close an exhaust valve and to open a supply valve for causing feedback pressure to be fed from a delivery chamber to a pilot chamber for fluid latching the pilot piston in a brake-release position until a brake-application solenoid pilot valve coil is momentarily ener-gized which causes the pilot chamber to exhaust to atmosphere so that the pilot piston returns and opens the exhaust valve and allows the closure of the supply valve.
Description
(Case No. 8148) 1219~1~
SOLENOID~OPERATED VALVE
Thi3 invention relates to a ~olenoid-operated pilot valve having manual override and ~luid latching and, more particularly, to an electromagnetically-controlled pneumatic valve ~or establishing a ~luid path between a 9upply port and a delivery port when a releaæe electromagnet is energi2ed to cau~e a pilot piston to close an exhaust valve and to open a supply valve for establishing a feedbac~ path between a delivery chamber and a pilot chamber ~or pneumatically latch-ing the pilot piston in po~ition until an application electro_ magnet is energized which causes the pilot chamber to exhaust so that the pilot piston returns and opens the exhaust valve and allows the closure of the supply valve BACKGRO~ND OF TEIE INVENTIO~
In mass and/or rapid transit operations, it is con~en_ tional practice to employ a solenoid control valve to operate a spring-applied pneumatically-released brake assembly on the transit vehicles. In operation, an electrical command ~i~nal is momentax~ly applied to ~he solenoid to establish a connec-tion to release the brakes or to establish a connection to apply ~he brakes. It will be understood that in the event that the pneumati~ power supply is interrupted~ the brakes will be applied by the spring in the brake unit. N~w, when the fluid brake pressure is reapplied to the valve, the valve 951;~
must assume the brake-applied positisn. It will he appr0-ciated that if the valve remains in or assuma3 a hrake_ released position, khe resulting brake release would cause a potentially dangerous and unsafe condikion. Thus, it is necessary that the valve causes the delivery chamber and port to be exhausted since the brakes are applied when there is no air pressure being con~eyed to the brake unit.
OB~ECTS OF I~E I~VENTIO~
Accordingly, it is an object of this inv~ntion to pro-10 vlde a n~.w and improved ~olenoid-operated fluid control valvP.
Another o~ject of this invention is to provide an el~ctro-magnetic pilot valve ~aving manual override and fluid latching.
A further object o~ this in~ention is to provide a unique solenoid-type o~ fluid control valve having an application and release coil for causing the pneumatic operation of a pilot piston for opening and closing a supply val~e and an exhau t valve.
Yet another o~ject of this invention is to provide an improved electromagnet control val~e having a pair of pilot valves which are selectively operated by momentary energi2a ti~n o~ one of a pair of electromagnetic coils.
Yet a further object o~ this invention is to provide a solenoid,operated fluid valve comprising, a release solenoid coil, an application solenoid coil, ~alva means mo~able to a first position for establishing a fluid path between a supply port and a delivery port when the release solenoid coil is momen-tarily energized, fluid means for latching the valve means in the first position, and the valve means movable to a second position for establishing a fluid path between the delivery port and an exhaust port when the application solenoid coil is momentarily energized.
Still another object of this invention is to provide a magnet valve for selectively establishing communication between a supply port and a delivery port and between an exhaust port and the delivery port comprising, a magnet portion having an application solenoid valve and a release solenoid valve, a valve portion having a pilot piston, an exhaust seat and a supply cham-ber connected to the supply port, a delivery chamber connected to the delivery port, a pilot chamber connectable to the supply port through the release solenoid valve to cause movement of the pilot piston wherein the exhaust is closed and the supply valve opens communication between the supply chamber and the delivery chamber, and means connecting the delivery chamber to the pilot chamber for retaining the pilot piston in the moved position.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is pro-vided a magnet valve for selectively establishing communication between a supply port and a delivery port and between an exhaust port and the delivery port comprising, a magnet portion having an application solenoid valve and a release solenoid valve, a valve portion having a pilot piston, an exhaust seat and a supply valve, g5~
a supply chamber connected to the supply port, a de:Livery chamber connected to the delivery port, a pilot chamber connectable to the supply port through the release solenoid valve to cause move-ment of the pilot piston wherein the exhaust seat is initially closed and the supply valve subsequently opens communication between the supply chamber and the delivery chamber, feedback means formed in the pilot piston for connecting the delivery cham-ber to the pilot chamber ~or retaining the pilot piston in the moved position, a manual override for the application solenoid valve for opening a pilot valve for establishing a fluid path from the supply chamber to the pilot chamber, and a manual override for the release solenoid valve for opening a pilot valve for establishing a fluid path from the delivery chamber and the pilot chamber to the exhaust port.
BRIEF DESCRIPTION OF T~IE DRAWINGS
. . . _ . . _ The above objects and other attendant features and advan-tages will be more readily understood from the following detailed description of the invention when considered in conjunction with the accompanying drawings, wherein:
Figure 1 is a side elevational view of the solenoid-operated fluid pilot valve oE the invention with portion shown partially in cross-section.
Figure 2 is a cross-sectional view taken along lines II-II of Figure 1 r showing the details of the invention with the pilot piston in its brake-application position.
Figure 3 is a top plan view of the solenoid-operated fluid valve shown in Figure 1.
~2~
NTI ON
Re:~erring now to the drawings, and in particular to FIGS.
1 and 2, there is shown the electromagnet or solenoid~operated ~luid pilot ~ralve 1 having an upper magnet portion 2 and a lower valve portion 3. As shown in FIG. 2, the magnet portion
SOLENOID~OPERATED VALVE
Thi3 invention relates to a ~olenoid-operated pilot valve having manual override and ~luid latching and, more particularly, to an electromagnetically-controlled pneumatic valve ~or establishing a ~luid path between a 9upply port and a delivery port when a releaæe electromagnet is energi2ed to cau~e a pilot piston to close an exhaust valve and to open a supply valve for establishing a feedbac~ path between a delivery chamber and a pilot chamber ~or pneumatically latch-ing the pilot piston in po~ition until an application electro_ magnet is energized which causes the pilot chamber to exhaust so that the pilot piston returns and opens the exhaust valve and allows the closure of the supply valve BACKGRO~ND OF TEIE INVENTIO~
In mass and/or rapid transit operations, it is con~en_ tional practice to employ a solenoid control valve to operate a spring-applied pneumatically-released brake assembly on the transit vehicles. In operation, an electrical command ~i~nal is momentax~ly applied to ~he solenoid to establish a connec-tion to release the brakes or to establish a connection to apply ~he brakes. It will be understood that in the event that the pneumati~ power supply is interrupted~ the brakes will be applied by the spring in the brake unit. N~w, when the fluid brake pressure is reapplied to the valve, the valve 951;~
must assume the brake-applied positisn. It will he appr0-ciated that if the valve remains in or assuma3 a hrake_ released position, khe resulting brake release would cause a potentially dangerous and unsafe condikion. Thus, it is necessary that the valve causes the delivery chamber and port to be exhausted since the brakes are applied when there is no air pressure being con~eyed to the brake unit.
OB~ECTS OF I~E I~VENTIO~
Accordingly, it is an object of this inv~ntion to pro-10 vlde a n~.w and improved ~olenoid-operated fluid control valvP.
Another o~ject of this invention is to provide an el~ctro-magnetic pilot valve ~aving manual override and fluid latching.
A further object o~ this in~ention is to provide a unique solenoid-type o~ fluid control valve having an application and release coil for causing the pneumatic operation of a pilot piston for opening and closing a supply val~e and an exhau t valve.
Yet another o~ject of this invention is to provide an improved electromagnet control val~e having a pair of pilot valves which are selectively operated by momentary energi2a ti~n o~ one of a pair of electromagnetic coils.
Yet a further object o~ this invention is to provide a solenoid,operated fluid valve comprising, a release solenoid coil, an application solenoid coil, ~alva means mo~able to a first position for establishing a fluid path between a supply port and a delivery port when the release solenoid coil is momen-tarily energized, fluid means for latching the valve means in the first position, and the valve means movable to a second position for establishing a fluid path between the delivery port and an exhaust port when the application solenoid coil is momentarily energized.
Still another object of this invention is to provide a magnet valve for selectively establishing communication between a supply port and a delivery port and between an exhaust port and the delivery port comprising, a magnet portion having an application solenoid valve and a release solenoid valve, a valve portion having a pilot piston, an exhaust seat and a supply cham-ber connected to the supply port, a delivery chamber connected to the delivery port, a pilot chamber connectable to the supply port through the release solenoid valve to cause movement of the pilot piston wherein the exhaust is closed and the supply valve opens communication between the supply chamber and the delivery chamber, and means connecting the delivery chamber to the pilot chamber for retaining the pilot piston in the moved position.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is pro-vided a magnet valve for selectively establishing communication between a supply port and a delivery port and between an exhaust port and the delivery port comprising, a magnet portion having an application solenoid valve and a release solenoid valve, a valve portion having a pilot piston, an exhaust seat and a supply valve, g5~
a supply chamber connected to the supply port, a de:Livery chamber connected to the delivery port, a pilot chamber connectable to the supply port through the release solenoid valve to cause move-ment of the pilot piston wherein the exhaust seat is initially closed and the supply valve subsequently opens communication between the supply chamber and the delivery chamber, feedback means formed in the pilot piston for connecting the delivery cham-ber to the pilot chamber ~or retaining the pilot piston in the moved position, a manual override for the application solenoid valve for opening a pilot valve for establishing a fluid path from the supply chamber to the pilot chamber, and a manual override for the release solenoid valve for opening a pilot valve for establishing a fluid path from the delivery chamber and the pilot chamber to the exhaust port.
BRIEF DESCRIPTION OF T~IE DRAWINGS
. . . _ . . _ The above objects and other attendant features and advan-tages will be more readily understood from the following detailed description of the invention when considered in conjunction with the accompanying drawings, wherein:
Figure 1 is a side elevational view of the solenoid-operated fluid pilot valve oE the invention with portion shown partially in cross-section.
Figure 2 is a cross-sectional view taken along lines II-II of Figure 1 r showing the details of the invention with the pilot piston in its brake-application position.
Figure 3 is a top plan view of the solenoid-operated fluid valve shown in Figure 1.
~2~
NTI ON
Re:~erring now to the drawings, and in particular to FIGS.
1 and 2, there is shown the electromagnet or solenoid~operated ~luid pilot ~ralve 1 having an upper magnet portion 2 and a lower valve portion 3. As shown in FIG. 2, the magnet portion
2 includes a pair of electrical solenoids 4 and 5, each of which is selectively momentarily energized via leads 6a-6d.
q~he leads pass ~hrough an insulating grommet 7 which is mount~d in the side wall of a protective cover ~. me leads 6a and 6b supply electrical power to a brake-release coil 9 of the sole_ noid 4 while the leads 6c and 6d 9upply electrical power to a brake-application coil 10 of the solenoid 5~ A surge suppre~-sor, one of which is characterized by numeral 11, shunts eazh of the solenoid coil~ to dissipate the energy when the magnetic field collapses. A magnetic armatuxe 12 is centrally disposed within the release solenoid coil 9 and is biased downwardly ~y gravity and the caged helical spring 130 Similarly, ~he appli-cation solenoid ~oil 10 includes a centrally disposed magnetic armature 14 w~ich is biased downwardly by gravity and the ~0 caged helical spring 15. ~he solenoid armature 12 carries a supply pilot valve 16 while the solenoid armature 14 has a centrally disposed exhaust pilot ~alva 17.
The valve body portion 3 includes a main supply port 19, a delivery port 20, and an exhaust port 21. The supply port 19 is connected to a supply chamber 22 via a passageway 23.
The supply chamber 22 is in communication with a release pilot chamber 24 ~ia pas~ag~ways 25, 26 and 27 ~ormed in the valve ~ody 37 AS shown, a supply valve 28 is locat~d in the chamber 22 and is urged against a su~ply valve seat 29 by a helical compression spring 30. An equalizing pa~sage 31 i8 ~ormed in the supply valve 28 and its body 32 to relieve an~
pressure diferential buildup behween oppo~ite sides of the ~al~e. The val~e 28 is disposed in cooperative association with an e~haust val~e seat 33 formed on the lower end of a pilot piston 34 located in a central bore 35 ~ormed in the ~alva body 3. A deli~ery chamber 36 is formed under pilot piston 34 which is urged upward by a helical compression spring 37. m e deli~ery cha~ber 36 is connected to delivery port 20 via passagewa~ 38 as shown in FIG. 1. It Will be ~een tha~ the delivery chamber 36 is also in communication with an exhaust chamber 39 via passageways 40 and 41 when the eXhaust valve is unseated. me exhaust cha~ber 39 is connected to exhaust port 21 via passageway 42 and cho~e 18 as shown in FIGS. 1 and 2. The choke 18 assi~ts in holding the piston 34 in a brake-release position. A pilot chamber 43 is formed on the upper side of t~e pilot piston 34. The pilot chamber 43 ls in communication with the delivery chan-~er 36 via a feed-back path or latching circuit ormed by passageway 44 and choke 45 located in the body of the pilot piston 34.
~ 3 It will be ~een that ~he pilot cha~ber 43 is c~nnected to a ported supply valve ~eat 46 via pa~sageway 47 and is connected to an a~plication pilot chamber 48 via paq~ageway ~9. ~ha exhaust pilot valve 17 is disposed in cooperative association with a ported exhaust valve seat 50O me valve seat is connected to atmo~p~ere via a passageway 51 and a wasp excluder 52.
It will be appreciated in case o electrical power failure or coil damage, it is advantageous to have an alter-nate means of operating either o~ the pilot valves. As shownin FIG. 3, a pair of manual override operators, including push knobs 55 and 56, are located in the upper end of the ~alve body 3. The two overrides are substantially identical and are operated in the samè manner and, therefore, only the structure of the manual operator associated with supply pilot valve 16 will be described in detail~ As shown in FIGS. 1 and
q~he leads pass ~hrough an insulating grommet 7 which is mount~d in the side wall of a protective cover ~. me leads 6a and 6b supply electrical power to a brake-release coil 9 of the sole_ noid 4 while the leads 6c and 6d 9upply electrical power to a brake-application coil 10 of the solenoid 5~ A surge suppre~-sor, one of which is characterized by numeral 11, shunts eazh of the solenoid coil~ to dissipate the energy when the magnetic field collapses. A magnetic armatuxe 12 is centrally disposed within the release solenoid coil 9 and is biased downwardly ~y gravity and the caged helical spring 130 Similarly, ~he appli-cation solenoid ~oil 10 includes a centrally disposed magnetic armature 14 w~ich is biased downwardly by gravity and the ~0 caged helical spring 15. ~he solenoid armature 12 carries a supply pilot valve 16 while the solenoid armature 14 has a centrally disposed exhaust pilot ~alva 17.
The valve body portion 3 includes a main supply port 19, a delivery port 20, and an exhaust port 21. The supply port 19 is connected to a supply chamber 22 via a passageway 23.
The supply chamber 22 is in communication with a release pilot chamber 24 ~ia pas~ag~ways 25, 26 and 27 ~ormed in the valve ~ody 37 AS shown, a supply valve 28 is locat~d in the chamber 22 and is urged against a su~ply valve seat 29 by a helical compression spring 30. An equalizing pa~sage 31 i8 ~ormed in the supply valve 28 and its body 32 to relieve an~
pressure diferential buildup behween oppo~ite sides of the ~al~e. The val~e 28 is disposed in cooperative association with an e~haust val~e seat 33 formed on the lower end of a pilot piston 34 located in a central bore 35 ~ormed in the ~alva body 3. A deli~ery chamber 36 is formed under pilot piston 34 which is urged upward by a helical compression spring 37. m e deli~ery cha~ber 36 is connected to delivery port 20 via passagewa~ 38 as shown in FIG. 1. It Will be ~een tha~ the delivery chamber 36 is also in communication with an exhaust chamber 39 via passageways 40 and 41 when the eXhaust valve is unseated. me exhaust cha~ber 39 is connected to exhaust port 21 via passageway 42 and cho~e 18 as shown in FIGS. 1 and 2. The choke 18 assi~ts in holding the piston 34 in a brake-release position. A pilot chamber 43 is formed on the upper side of t~e pilot piston 34. The pilot chamber 43 ls in communication with the delivery chan-~er 36 via a feed-back path or latching circuit ormed by passageway 44 and choke 45 located in the body of the pilot piston 34.
~ 3 It will be ~een that ~he pilot cha~ber 43 is c~nnected to a ported supply valve ~eat 46 via pa~sageway 47 and is connected to an a~plication pilot chamber 48 via paq~ageway ~9. ~ha exhaust pilot valve 17 is disposed in cooperative association with a ported exhaust valve seat 50O me valve seat is connected to atmo~p~ere via a passageway 51 and a wasp excluder 52.
It will be appreciated in case o electrical power failure or coil damage, it is advantageous to have an alter-nate means of operating either o~ the pilot valves. As shownin FIG. 3, a pair of manual override operators, including push knobs 55 and 56, are located in the upper end of the ~alve body 3. The two overrides are substantially identical and are operated in the samè manner and, therefore, only the structure of the manual operator associated with supply pilot valve 16 will be described in detail~ As shown in FIGS. 1 and
3, the operating knob 55 is connected to the exterior end of a push rod 57 which extends through screw-attached cover plate 58. As shown in FIG. 1, the push rod 57 included an enlarged intermediate portion 59 having an annular groove 60 for accom~
modating a sealing ring 61. A helical compression spring 62 is disposed in bore 63 to normally urge the operator to an outer limit position. m e push rod includes an inner reduced portion 64 having a tapered ox pointed tip 65 which engages the underside of armature 12 or unseating the supply valve ~ 9~
16 when the hand knob 55 is pushed inwardly to an inner limit position.
In describing the operation o~ the device, it will be assumed that the solenoid colls are deenergized, that the manual operators are in the inoperative position, and that the various valves and pilot pistons are in the positions a~
shown in the drawings. Under these conditions, the main 8upply valve 28 is c'osed by the compreæsion force of spring 30 so that the supply chamber is cut o~f from the delivery chamber 36. It will be seen that the pilot piston 34 is urged to its uppermost position under the influence of the compressive force of biasing spring 37. The pilot valves 16 and 17 are both closed by the compressive forces o their respective biasing springs 13 and 140 Thus, ~he delivery port 20 is connected via passageway 38 to delivery chamber 36 via passageways 40 and 41 to exhaust c~amber 39 and via passageway
modating a sealing ring 61. A helical compression spring 62 is disposed in bore 63 to normally urge the operator to an outer limit position. m e push rod includes an inner reduced portion 64 having a tapered ox pointed tip 65 which engages the underside of armature 12 or unseating the supply valve ~ 9~
16 when the hand knob 55 is pushed inwardly to an inner limit position.
In describing the operation o~ the device, it will be assumed that the solenoid colls are deenergized, that the manual operators are in the inoperative position, and that the various valves and pilot pistons are in the positions a~
shown in the drawings. Under these conditions, the main 8upply valve 28 is c'osed by the compreæsion force of spring 30 so that the supply chamber is cut o~f from the delivery chamber 36. It will be seen that the pilot piston 34 is urged to its uppermost position under the influence of the compressive force of biasing spring 37. The pilot valves 16 and 17 are both closed by the compressive forces o their respective biasing springs 13 and 140 Thus, ~he delivery port 20 is connected via passageway 38 to delivery chamber 36 via passageways 40 and 41 to exhaust c~amber 39 and via passageway
4~ to exhaust port 21 so that the brakes are applied by the spring in the brake unit.
Let us now assume that it is desired to pressuriæe the delivery port 20 to effect a brake release. It is simply necessary to momentarily energize the coil 9 o~ the brake-release solenoid 4. The energization of the brake-release coil 9 raises the armature 12 against the spring 13 to ~nseat the pilot valve 16 wherein a ~luid path is established from supply port l9 to the pilot piston chambex 43 via passageway 23, supply cha~ber 22, passagewa~s 25, 26, 27, pilok chamber 24, ported pilot seat 46, and passageway 47. The pre~ure in chamber 43 causes the piston to be moved downwardly against the force of spring 37. As the piston 34 moves downwardly, the exhaust valve is initially closed by the seatiny of valve seat 33 against valve member 280 As the piston 34 continues to move downwardly, the exhaust valve seat 33 moves the valve member 28 against the spring 30 to open th~ supply valve.
Since the supply valve is a balanced device, very little effort or ~orce is re~uired to unseat member 28 from the supply valve seat 29. However, the piston 34 has consider able ~orce to fully open the supply valve. With the supply valve opened and the exhaust valve closed, the delivery port 20 is pressurized by a fluid path extending ~rom supply port 19 via passageway 23, to supply chamber 22, through the supply valve 28, past seat 29, to delivery chamber 36, and via pa3-sageway 38 to port 20. Since the solenoid coil 9 is only momentarily energiæed, the brake-release pilot valve 16 is quickly closed by return spring 13 to shut off the supply path ~rom port 19. However, the pressure in chamber 43 is trapped since the exhaust pilot valve 17 is also closed. In the event that the pilot chamber 43 develops a leak, it will be seen that the piston 34 is pneumatically latched by a fluid feed-back path formed by passageway 44 and choke 45. The passage-way 44 and choke 45 supply pressure rom the delivery chamber 36 ko the pilot chamber 43 to maintain the piston 3~ in itB
downward position. Thu9, with the delivery port 20 pressur-ized, the brakes of the train are released by pre ~ure over-coming the force o~ the spring in the brake unit. The solenoid-operated pilot valve l will remain in this brake-release position as long as supply pressure i~ applied to port 19.
Let us now assume that a brake application is deæired.
In this caseJ it is simply necessary to momentarily energize the brake-application solenoid coil 10 which raises the arma-ture 14 and opens the exhaust pilot valve 17. Thu9, the pilot chamber 43 is ~uickly exhausted to atmosphere ~ia passageway 49, chamber 48, ported exhaust pilot valve seat 50, pa~sageway 51, and wasp excluder 52. With the pilot chamber 43 exhausted, the return sprin~ 37 ~uickly moves the piston 34 upwardly to its upper position as shown in FIG. 2. As the piston 34 begins to move upwardly, the ~upply valve member 28 is forced by spring 30 against seat 29 to close off the delivery chamber 36 from the supply chamber 22. ~urther~ upward movement of piston 34 causes unseating o~ the exhaust valve which exhaust3 the delivery chamber 36 to atmosphere via passageways 40 and 41, exhaust chamber 39, passageway 41, and exhaust port 21.
Ihus, the valve will resume its position as shown m FIG. 2O
It will be seen that the feedback path formed by passageway 44 and choke 45 will prevent the piston 34 from being ~L2~
accidentally moved to its bra~e_release position since pre~-sure leaking across pilot release valve 16 will be vented to atmosphere via the exhausted delivery chamber 36.
It will be seen ~hak the design of the piston 34 to provide a high initial force when the piston is moved in either direction to initially overcome the buildup of ~tatic friction which commonly occurs during long periods o inac-tivity. The pneumatic feedbac~ path or latch-up circuit ~s designed to hold the piston 34 in the traveled or last assumed position after a command is received to proceed to that posi~
tion. It has been found that certain trapped pressure valve devices are capable of assuming an incorrect position due to leakage of pressure which is intended to hold the piston in the last commanded position. me presently described valve will maintain the piston 34 in the last commanded position, and yet permit the piston to travel to its normal p~fiitiOn upon command without the use of mechanical detents or toggles.
It will be appreciated that ~arious chang~s and modifica-tions may be made to the subject device without daparting from the spirit and scope of the invention. The ~edback latchlng circuit employing the passageway 44 and choke 45 could be located in the body of the valve 1 rather than in the piston 34. Accordingly, it is understood that the invention is not limited to the specific details herein set forth but should be given the breadth as set forth by the features and limita-tions of the appended claims.
,
Let us now assume that it is desired to pressuriæe the delivery port 20 to effect a brake release. It is simply necessary to momentarily energize the coil 9 o~ the brake-release solenoid 4. The energization of the brake-release coil 9 raises the armature 12 against the spring 13 to ~nseat the pilot valve 16 wherein a ~luid path is established from supply port l9 to the pilot piston chambex 43 via passageway 23, supply cha~ber 22, passagewa~s 25, 26, 27, pilok chamber 24, ported pilot seat 46, and passageway 47. The pre~ure in chamber 43 causes the piston to be moved downwardly against the force of spring 37. As the piston 34 moves downwardly, the exhaust valve is initially closed by the seatiny of valve seat 33 against valve member 280 As the piston 34 continues to move downwardly, the exhaust valve seat 33 moves the valve member 28 against the spring 30 to open th~ supply valve.
Since the supply valve is a balanced device, very little effort or ~orce is re~uired to unseat member 28 from the supply valve seat 29. However, the piston 34 has consider able ~orce to fully open the supply valve. With the supply valve opened and the exhaust valve closed, the delivery port 20 is pressurized by a fluid path extending ~rom supply port 19 via passageway 23, to supply chamber 22, through the supply valve 28, past seat 29, to delivery chamber 36, and via pa3-sageway 38 to port 20. Since the solenoid coil 9 is only momentarily energiæed, the brake-release pilot valve 16 is quickly closed by return spring 13 to shut off the supply path ~rom port 19. However, the pressure in chamber 43 is trapped since the exhaust pilot valve 17 is also closed. In the event that the pilot chamber 43 develops a leak, it will be seen that the piston 34 is pneumatically latched by a fluid feed-back path formed by passageway 44 and choke 45. The passage-way 44 and choke 45 supply pressure rom the delivery chamber 36 ko the pilot chamber 43 to maintain the piston 3~ in itB
downward position. Thu9, with the delivery port 20 pressur-ized, the brakes of the train are released by pre ~ure over-coming the force o~ the spring in the brake unit. The solenoid-operated pilot valve l will remain in this brake-release position as long as supply pressure i~ applied to port 19.
Let us now assume that a brake application is deæired.
In this caseJ it is simply necessary to momentarily energize the brake-application solenoid coil 10 which raises the arma-ture 14 and opens the exhaust pilot valve 17. Thu9, the pilot chamber 43 is ~uickly exhausted to atmosphere ~ia passageway 49, chamber 48, ported exhaust pilot valve seat 50, pa~sageway 51, and wasp excluder 52. With the pilot chamber 43 exhausted, the return sprin~ 37 ~uickly moves the piston 34 upwardly to its upper position as shown in FIG. 2. As the piston 34 begins to move upwardly, the ~upply valve member 28 is forced by spring 30 against seat 29 to close off the delivery chamber 36 from the supply chamber 22. ~urther~ upward movement of piston 34 causes unseating o~ the exhaust valve which exhaust3 the delivery chamber 36 to atmosphere via passageways 40 and 41, exhaust chamber 39, passageway 41, and exhaust port 21.
Ihus, the valve will resume its position as shown m FIG. 2O
It will be seen that the feedback path formed by passageway 44 and choke 45 will prevent the piston 34 from being ~L2~
accidentally moved to its bra~e_release position since pre~-sure leaking across pilot release valve 16 will be vented to atmosphere via the exhausted delivery chamber 36.
It will be seen ~hak the design of the piston 34 to provide a high initial force when the piston is moved in either direction to initially overcome the buildup of ~tatic friction which commonly occurs during long periods o inac-tivity. The pneumatic feedbac~ path or latch-up circuit ~s designed to hold the piston 34 in the traveled or last assumed position after a command is received to proceed to that posi~
tion. It has been found that certain trapped pressure valve devices are capable of assuming an incorrect position due to leakage of pressure which is intended to hold the piston in the last commanded position. me presently described valve will maintain the piston 34 in the last commanded position, and yet permit the piston to travel to its normal p~fiitiOn upon command without the use of mechanical detents or toggles.
It will be appreciated that ~arious chang~s and modifica-tions may be made to the subject device without daparting from the spirit and scope of the invention. The ~edback latchlng circuit employing the passageway 44 and choke 45 could be located in the body of the valve 1 rather than in the piston 34. Accordingly, it is understood that the invention is not limited to the specific details herein set forth but should be given the breadth as set forth by the features and limita-tions of the appended claims.
,
Claims (9)
1. A magnet valve for selectively establishing com-munication between a supply port and a delivery port and between an exhaust port and the delivery port comprising, a magnet portion having an application solenoid valve and a release solenoid valve, a valve portion having a pilot piston, an exhaust seat and a supply valve, a supply chamber con-nected to the supply port, a delivery chamber connected to the delivery port, a pilot chamber connectable to the supply port through the release solenoid valve to cause movement of the pilot piston wherein the exhaust seat is initially closed and the supply valve subsequently opens com-munication between the supply chamber and the delivery cham-ber, feedback means formed in the pilot piston for connecting the delivery chamber to the pilot chamber for retaining the pilot piston in the moved position, a manual override for the application solenoid valve for opening a pilot valve for establishing a fluid path from the supply chamber to the pilot chamber, and a manual override for the release sole-noid valve for opening a pilot valve for establishing a fluid path from the delivery chamber and the pilot chamber to the exhaust port.
2. The magnet valve, as defined in claim 1, wherein said feedback means is a restricted passageway formed in said pilot piston.
3. The magnet valve, as defined in claim 1, wherein said feedback means includes a passage and a choke formed in said pilot piston.
4. The magnet valve, as defined in claim 1, wherein said pilot piston is spring-biased away from said supply valve.
5. The magnet valve, as defined in claim 1, wherein said supply valve is normally biased to a closed position.
6. The magnet valve, as defined in claim 1, wherein said application and release valves are normally biased to a closed position.
7. An electromagnetic control valve comprising, first and second solenoids for controlling the condition of assoc-iated first and second pilot valves, a pilot piston movable between a first and a second position, a pilot chamber lo-cated on one end of said pilot piston, a delivery chamber located on the other end of said pilot piston, an exhaust valve seat formed on the other end of said pilot piston and leading to an exhaust port, a supply valve disposed adjacent said exhaust valve seat and normally biased to close off a supply chamber from the delivery chamber, a supply port leading to said supply chamber and to said first pilot valve, a delivery port leading to said delivery chamber, a feedback connection formed in said pilot piston and leading from said delivery chamber to said pilot chamber for latching said pilot piston in the second position, a manual override for said first solenoid for opening said first pilot valve for establishing a fluid path from said supply chamber to said pilot chamber, and a manual override for said second solenoid for opening said second pilot valve for establishing a fluid path from said delivery chamber and said pilot chamber to said exhaust port.
8. The electromagnetic control valve, as defined in claim 7, wherein said pilot piston is spring-biased to the first position.
9. The electromagnetic control valve, as defined in claim 7, wherein said first and second pilot valves are spring-biased to closed positions.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US52704683A | 1983-08-29 | 1983-08-29 | |
| US527,046 | 1983-08-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1219513A true CA1219513A (en) | 1987-03-24 |
Family
ID=24099879
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000459727A Expired CA1219513A (en) | 1983-08-29 | 1984-07-26 | Solenoid-operated valve |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS6078184A (en) |
| BR (1) | BR8402728A (en) |
| CA (1) | CA1219513A (en) |
| ZA (1) | ZA845847B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0433503Y2 (en) * | 1988-08-10 | 1992-08-11 |
-
1984
- 1984-06-06 BR BR8402728A patent/BR8402728A/en unknown
- 1984-07-26 CA CA000459727A patent/CA1219513A/en not_active Expired
- 1984-07-27 ZA ZA845847A patent/ZA845847B/en unknown
- 1984-08-29 JP JP59178542A patent/JPS6078184A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6078184A (en) | 1985-05-02 |
| BR8402728A (en) | 1985-05-14 |
| JPS6316631B2 (en) | 1988-04-09 |
| ZA845847B (en) | 1985-03-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |