DE102013002883A1 - Pneumatic change-over valve used for compressed air supply of commercial vehicle, has circumferential groove which is formed in housing and inner portion of main piston through passage opening - Google Patents

Abstract

The valve (2) has a housing (4) which is provided with a bore wall (5) in which a circumferential groove (6) is formed. The bore wall is spaced apart from the piston wall of the circumferential groove that is extended over the entire wall peripheral circumferential gap (10). A slave piston (12) is separated from each other sections (13,15) of an intermediate space between the wall of housing and a main piston (8). A circumferential groove is formed in the housing and the inner portion (36) of the main piston through a passage opening (34).

Description

The invention relates to a pneumatic shuttle valve for alternately supplying one of two consumer lines and for simultaneously venting the respective other consumer line or vice versa according to the preamble of patent claim 1.

Typical applications for such shuttle valves or functionally equivalent shuttle valve assemblies are air treatment systems, for example, for the compressed air supply of commercial vehicles, in which two parallel desiccant chambers or cartridges are supplied via associated consumer lines alternately with compressed air to be dried or regenerated by means of dried operating air. The switching from one mode to the other mode via controllable valve arrangements, by means of which one supply line to a compressed air source and the other supply line is connected to the vent at the same time or vice versa. Shuttle valve arrangements with two 3/2-way valves, of which a first 3/2-way valve is directly controlled, for example via a pilot valve, and the first consumer line or the cartridge connected thereto are supplied with compressed air or vented while the pressure in the line system of this cartridge are generally known controls the second 3/2-way valve, which takes over the supply or ventilation of the second consumer line or the associated cartridge.

A disadvantage of such shuttle valve assemblies is the relatively large number of required components including the required piping, and consequently a large space requirement, a large assembly cost in the production and high production costs. In addition, such shuttle valve assemblies tend in some operating conditions to an unnecessary air consumption and ambiguous switching states, for example, if one of the 3/2-way valves in a floating position between two switching positions remains or is not switchable.

From the EP 0 199 948 A1 A device for drying compressed air with two desiccant chambers is already known, in which the changeover from one mode to the other mode is taken over by a controllable 4/2 way valve. Although this device is cheaper in terms of space requirements and manufacturing costs than the above-described arrangement with two mutually coupled 3/2-way valves, however, there remain the disadvantages formed as a slide valves directional valves inherent disadvantages of not always reliable function.

Against this background, the invention has for its object to provide a directional control valve referred to in the preamble of claim 1 species, which ensures reliable operation with low space requirements and low material costs.

The solution of this problem arises from the features of the main claim, while advantageous embodiments and further developments of the invention are the dependent claims can be removed.

The invention is therefore based on a pneumatic shuttle valve for alternately supplying one of two consumer lines and for venting the other consumer line, the shuttle valve as a controllable 4/2-way valve, each with a connection opening for the two load lines, further for a supply line and for a vent is formed.

• – ein Gehäuse mit einer weitgehend zylindrischen Bohrung, an deren Bohrungswand eine Umfangsnut ausgebildet ist,
• – einen in der zylindrischen Bohrung des Gehäuses zwischen zwei Endstellungen axial verstellbaren, hohlen und weitgehend geschlossenen Hauptkolben, in dessen zur Bohrungswand beabstandeter Kolbenwand ein der Umfangsnut im wesentlichen gegenüberliegender, über den ganzen Wandumfang verlaufender Umfangsspalt ausgebildet ist,
• – und einen im Zwischenraum zwischen der Bohrungswand und der Kolbenwand angeordneten, einerseits in die Umfangsnut und andererseits in den Umfangsspalt eingreifenden sowie in diesen mit Spiel axial verschiebbaren Nebenkolben,
• – wobei die radial inneren Umfangskanten des Nebenkolbens mit den als Ventilsitze dienenden beiden Außenkanten des Umfangsspaltes des Hauptkolbens sowie die radial äußeren Umfangskanten des Nebenkolbens mit den als Ventilsitze dienenden Innenkanten der Umfangsnut des Gehäuses derart zusammenwirken, dass bei jeder der Endstellungen des Hauptkolbens die dieser Endstellung jeweils nahe radial äußere Umfangskante des Nebenkolbens am zugeordneten Ventilsitz der Umfangsnut anliegt sowie die radial innere Umfangskante vom zugeordneten Ventilsitz des Umfangsspaltes abgehoben ist, und die der Endstellung abgewandte radial innere Umfangskante des Nebenkolbens am zugeordneten Ventilsitz des Umfangsspaltes anliegt sowie die radial äußere Umfangskante des Nebenkolbens vom zugeordneten Ventilsitz der Umfangsnut abgehoben ist,
• – und bei dem jeder der beiden durch den Nebenkolben voneinander getrennten Abschnitte des Zwischenraumes zwischen der Wand des Gehäuses und der Wand des Hauptkolbens, die Umfangsnut des Gehäuses und der Innenraum des Hauptkolbens, letzterer über eine Durchgangsöffnung in demselben, jeweils mit einer in der Bohrungswand ausgebildeten Anschlussöffnung in Verbindung stehen.

To solve the problem is provided that the shuttle valve is designed as a seat valve, which includes:

• A housing having a substantially cylindrical bore, on whose bore wall a circumferential groove is formed,
• - A in the cylindrical bore of the housing between two end positions axially adjustable, hollow and largely closed main piston, in which the bore wall spaced piston wall one of the circumferential groove substantially opposite, extending over the entire wall circumference circumferential gap is formed,
• - And arranged in the space between the bore wall and the piston wall, on the one hand in the circumferential groove and on the other hand in the circumferential gap engaging and axially displaceable in this game with spare piston,
• - Wherein the radially inner peripheral edges of the slave piston with serving as valve seats both outer edges of the circumferential gap of the main piston and the radially outer peripheral edges of the slave piston with serving as valve seats inner edges of the circumferential groove of the housing cooperate such that in each of the end positions of the main piston that end position respectively near radially outer peripheral edge of the slave piston rests against the associated valve seat of the circumferential groove and the radially inner peripheral edge is lifted from the associated valve seat of the circumferential gap, and facing away from the end position radially inner peripheral edge of the slave piston rests against the associated valve seat of the circumferential gap and the radially outer peripheral edge of the slave piston is lifted from the associated valve seat of the circumferential groove,
• - And in which each of the two by the slave piston separate portions of the gap between the wall of the housing and the wall of the main piston, the circumferential groove of the housing and the interior of the main piston, the latter via a passage opening in the same, each with a formed in the bore wall Connection opening communicate.

The plan view of the housing is preferably hollow cylindrical, so that the axial bore of the housing has a substantially cylindrical shape. In this cylindrical axial bore of the housing, therefore, said circumferential groove in the bore wall is an annular groove, said circumferential gap on the main piston an annular gap, and the main piston and the slave piston are each formed as a cylindrical annular piston.

The housing described may also be a part of a larger housing, which may contain other valves and not necessarily cylindrical in terms of its external geometry. This larger housing may be the housing of an air conditioning system of a commercial vehicle, in which the shuttle valve according to the invention is arranged together with other pneumatically and / or electromagnetically operable valves.

As can be seen from the above, only the main piston is controlled in a suitable way, to be described later in more detail, and adjusted by means of an actuating force between its two end positions. He takes the slave piston, which engages in the formed in the piston wall of the main piston circumferential gap with, and adjusts this in the two end positions of the main piston corresponding functional positions in which the slave piston supplies a first consumer line with compressed air and the other consumer line vented or vice versa as explained in detail below. The secondary piston is arranged on the main piston and is guided by this in the axial and radial directions.

Since in the end positions of the main piston of the slave piston is firmly clamped in each case via one of its inner peripheral edges and the respective diametrically opposite outer peripheral edge between the main piston and the housing, there are always clear switching states. Accordingly, serving as a valve body slave piston with its respective sealingly active peripheral edges fixed to the associated and said valve seats, so that the risk of undefined switching states, for example due to floating between two switching positions is not given. The force with which said peripheral edges are pressed onto the associated valve seats or associated other peripheral edges is dependent on the actuating force acting on the main piston. The desired sealing force can be determined as a result by a corresponding design of the actuating force. The secondary piston simultaneously forms the end position of the main piston-determining stop in both adjustment directions. In an advantageous embodiment, the valve seats, either on the secondary piston, on the main piston or on the housing, in the form of a suitable elastomer contour formed on these components to seal the valve seats in a conventional manner.

The assignment of the connection openings formed in the housing to the load lines, the supply line and the vent can be quite different and, for example, depending on design or manufacturing conditions, from the given installation space, optimal guidance of said lines or the like can be selected.

A preferred embodiment of the invention provides that the connection opening of the supply line via a through hole in the wall of the main piston with the interior of the main piston, the connection opening of the vent with the circumferential groove of the housing and the connection openings of the consumer lines each with one of the two sections of the space between Housing and main piston communicate. The connection openings are formed in the axial hollow cylindrical bore wall of the housing, said connection openings of the consumer lines open from the outside directly into the associated portions of the gap between the bore wall and the piston wall, the connection opening of the vent opens from the outside into the circumferential groove of the housing, and the connection opening the supply supply line substantially coincides with the passage opening formed in the piston wall. In this case, the said connection opening and the passage opening are formed so that they overlap sufficiently in any case in both end positions of the main piston.

According to another embodiment of the invention, for example, the connection opening of the supply line and the vent each with one of the sections of the space between the bore wall and piston wall, the connection port of a first consumer line with the circumferential groove in the housing and the connection port of the other consumer line with the interior of the main piston in connection ,

During the switching movement of the main piston, the clamping of the slave piston between the main piston and the housing is temporarily released, so that at least three of the four valve seats can be opened and a short-circuit flow between supply and ventilation can be established. However, since the switching process is very fast, this is not harmful. However, it will be advantageous to choose the pressurization of the secondary piston so that it is always clearly loaded in an axial direction and pressed against a valve seat, so that as undefined Schwebellungen and possibly axial vibrations can be adjusted.

In order to ensure this effect regardless of the existing pressure conditions, it is provided according to a further embodiment of the invention that the slave piston is biased by a spring in the direction of an end position.

Another embodiment of the invention provides that the slave piston is divided in a plane transverse to the piston longitudinal axis in two mutually coaxial sub-piston sections. During an adjusting movement of the main piston, in which the valve seat formed by the peripheral gap lifts off the slave piston and this is temporarily not clamped between the main piston and the housing, the radially acting on the slave piston pressure can push apart the two slave piston sections axially and so a system of the two slave piston sections to the associated Maintaining valve seats, so that a situation is avoided, arise in the short circuit currents, as will be explained in more detail using an exemplary embodiment.

In order to further support this effect, it is provided according to a further embodiment of the invention that a spring which spreads apart from one another is arranged between the two secondary piston sections. This in turn, regardless of the prevailing pressures reliably ensures that the sub-piston sections are pressed apart and pressed against the associated valve seats.

A structurally different embodiment of the invention provides that the sub-piston is formed in cross-section approximately U-shaped with two radially outwardly directed at the bottom of the circumferential sealingly abutting legs, that from the bottom of the circumferential groove of a radial flange radially inwardly between the legs of the U-shaped slave piston protrudes and sealingly abuts against the bottom wall, and that the legs of the U-shaped slave piston are penetrated by axial through holes. Through these passage openings, the pressure on both axial sides of the legs of the U-shaped slave piston can compensate, so that the forces acting on the slave piston pressures are balanced and at least have no effect on the position of the slave piston during the switching operation.

The actuation of the shuttle valve with the features of the invention is preferably carried out so that the main piston is pneumatically axially adjustable against the force of a return spring from a first end position to its second end position. If the main piston, for example via a pilot valve, preferably a solenoid valve, is pressurized, it is moved from its first end position to the second end position. When the control pressure is released, the return spring causes an adjustment of the main piston back to the first end position.

The main piston can be acted upon directly via one of its end faces with the pressure of a pressure medium. According to another embodiment of the invention, the main piston is adjustable via a pneumatically actuated membrane which bears against an end face of the main piston.

According to the invention it can further be provided that the main piston has a device for setting the same in an intermediate position lying between the end positions, in which both consumer lines are vented.

Further, it is advantageous if the shuttle valve according to the invention for the purpose of its actuation by means of a solenoid valve can be acted upon with compressed air. The shuttle valve according to the invention and the solenoid valve are preferably arranged in the air treatment plant of a commercial vehicle.

The invention will be further explained with reference to several embodiments. For this purpose, the description is accompanied by a drawing. In this shows

1 to 4 schematically in a longitudinal section an embodiment of a pneumatic shuttle valve with undivided slave piston in different functional positions,

5 to 8th a shuttle valve with divided slave piston in different functional positions,

9 to 12 another embodiment of a shuttle valve with an axially divided, spread by a spring slave piston in different functional positions,

13 to 19 each change-over valves with undivided slave piston and with different assignment of the connection openings, as well

20 a shuttle valve with a one-piece, pressure balanced secondary piston.

That in the 1 to 4 illustrated shuttle valve 2 has an example hollow cylindrical housing 4 with an axial bore on, at the bore wall 5 a circumferential groove 6 is trained. In the axial bore of the housing 4 is an axially adjustable, hollow and substantially closed main piston between two end positions 8th arranged, whose cross-section is circular in accordance with the cross-section of the axial housing bore, and in the piston wall spaced from the bore wall of the circumferential groove 6 essentially opposite, over the entire wall circumference of the main piston 8th extending circumferential gap 10 is trained.

Further, radially between the bore wall 5 and the wall of the main piston 8th a gap formed in which on the one hand in the circumferential groove 6 of the housing 4 and on the other hand, in the circumferential gap 10 of the main piston 8th engaging and in this game with axially displaceable slave piston 12 arranged. The secondary piston 12 divides the space between the bore wall 5 of the housing 4 and the main piston 8th in two sections 13 respectively. 15 on. The radially inner peripheral edges 14 and 16 of the semi-longitudinal section about rectangular secondary piston 12 act with the serving as valve seats radial outer edges 18 respectively. 20 of the circumferential gap 10 together, while the radially outer peripheral edges 22 and 24 of the slave piston 12 with the serving as valve seats radial inner edges 26 respectively. 28 the circumferential groove 6 of the housing 4 interact.

At the housing 4 is a connection opening S (supply) for a supply supply line, a vent opening V (venting), a first connection opening C1 (Cartridge 1) for a first consumer line and a second connection opening C2 formed for a second consumer line. The connection opening S for the supply supply line is one in the wall of the main piston 8th trained passage opening 34 with the interior 36 in connection, the connection port V for the vent is with the circumferential groove 6 in the case 4 in connection, and the two connection openings C1 and C2 are each with one of the sections 13 respectively. 15 of the interspace.

The main piston 8th can pneumatically by pressurizing the first end face 30 between an in 1 shown first end position and a in 3 shown second end position against the force of a on the opposite second end face 32 of the main piston 8th acting return spring 38 be adjusted. Alternatively, the main piston 8th over a membrane 39 be adjusted, which in turn is pressurized and in 3 is shown in dashed lines.

At the in 1 shown first end position of this end position is close radially outer left circumferential edge 22 of the slave piston 12 at the assigned valve seat of the left inner edge 26 the circumferential groove 6 while the radially inner left circumferential edge 14 of the slave piston 12 from the assigned valve seat of the left outer edge 18 of the circumferential gap 10 is lifted off.

The radially inner right peripheral edge facing away from this first end position 16 of the slave piston 12 lies on the assigned valve seat of the right outer edge 20 of the circumferential gap 10 while the radially outer right peripheral edge 24 of the slave piston 12 from the assigned valve seat of the right inner edge 28 the circumferential groove 6 is lifted off.

At this first end position of the main piston 8th For example, supplied by a compressor moist compressed air through the connection opening S, the passage opening 34 , the interior 36 , the first section 13 of the intermediate space and the first connection opening C1 of a first consumer line, not shown, while the second consumer line via the second connection opening C2, the second section 15 of the intermediate space, the circumferential groove 6 and the connection port V is vented.

In the in 3 shown second end position of the main piston 8th is via the connection opening S, the passage opening 34 , the interior 36 , the second section 15 the intermediate space and the second port C2, the second consumer line supplied with compressed air, while the first consumer line via the first port C1, the first section 13 of the intermediate space, the circumferential groove 6 and the connection port V is vented.

2 shows an intermediate position of the main piston 8th on his way from the first end position according to 1 in the second end position according to 3 , wherein the valve seat of the right outer edge 20 of the main piston 8th the slave piston 12 has released so that it can adjust freely depending on the pressure conditions acting on him.

In a similar way shows 4 an intermediate position of the main piston 8th on his way from the in 3 shown second end position in in the 1 shown first end position, wherein the secondary piston 12 under the action of the pressures that burden this, the main piston moving in the figure from right to left 8th follows until it stops at the valve seat of the left inner edge 26 the circumferential groove 6 of the housing 4 is applied.

In the two in 2 and 4 shown intermediate positions, as previously explained, short-circuit currents arise, which are not harmful because of the shortness of the switching operations. To a free floating position of the slave piston 12 during the switching process, this can be prevented by a spring acting on it 11 ( 3 ) always in contact with the spring 11 distant valve seat of the left outer edge 18 of the managment gap 10 of the main piston 8th or the left radial inner edge 26 the circumferential groove 6 of the housing 4 being held.

The 5 to 8th show a shuttle valve 40 , which in its essential parts the shuttle valve 2 according to the 1 to 4 corresponds so that it does not need to be described in detail again. Unlike the shuttle valve 2 is however at the shuttle valve 40 of the 1 to 4 his slave piston 42 in a direction to the piston longitudinal axis 44 transverse plane in two mutually coaxial sub-piston sections 42a and 42b divided.

At the in 5 shown first end position and the in 7 shown second end position of the main piston 46 is the slave piston 42 as in the example of 1 to 4 , between main pistons 46 and housing 48 clamped and connects either the connection port C1 for the first load line to the connection port S for the supply line, wherein the connection port C2 for the second load line via the connection port V is vented ( 5 ), or connects the second-consumer-line connection port C2 to the supply-supply connection port S while venting the first-consumer-port connection port C1 through the port V (FIG. 7 ).

6 shows an intermediate position of the slave piston 42 on the way of the main piston 46 from the first end position according to 5 in the second end position according to 7 , where the slave piston 42 no longer between the valve seats of the main piston 46 on the one hand and the case 48 on the other hand is trapped. In these intermediate positions, the two mentioned sub-piston sections 42a and 42b through the interior 50 of the main piston 46 applied supply pressure axially apart and pressed to the radial outer edges 18 . 20 the valve seats of the circumferential gap 10 of the main piston 46 applied, so that short-circuit currents can only occur over a very short part of the switching path. The two secondary piston sections 42a and 42b In addition, each seal against the axial outer walls of the circumferential groove 6 in the case 48 radially off. In this case, one speaks of an "almost pressure balanced" shuttle valve.

The construction of the shuttle valve 52 according to the 9 to 12 is substantially equal to that of the shuttle valve 40 according to the 5 to 8th , The secondary piston 54 is again in a direction to the piston longitudinal axis 56 transverse plane in two axially to each other and coaxial sub-piston sections 54a and 54b divided. At the right side of the secondary piston section 54b is an axial flange 58 formed, which the left sub-piston section 54a sealing partially overlaps. Between the two sub-piston sections 54a and 54b is a spring 60 arranged, which with their spring force these two sub-piston sections 54a . 54b spreads apart. In the in the 9 and 11 shown two end positions of the main piston 62 is the slave piston 54 each between one on the main piston 62 trained valve seat (outer edge 18 respectively. 20 the circumferential gap of the main piston 62 ) on the one hand and a diametrically opposite, on the housing 64 trained valve seat (inner edge 28 respectively. 26 the circumferential groove of the housing 64 ) and squeezed "on block".

The secondary piston 54 acts in these end positions in the already on the basis of 1 to 4 or the 5 to 8th in the manner described, in that the connection port C1 for the first consumer line is supplied with compressed air via the connection opening S for the supply supply line and the connection port C2 for the second consumer line is vented via the connection opening V ( 9 ) or the other way around ( 11 ).

Up to the in 10 shown intermediate position of the main piston 62 on the way from its first end position to its second end position are the two sub-piston elements 54a and 54b still sealing on the assigned valve seats (inner edge 26 respectively. 28 the circumferential groove 6 of the housing 64 ), so that no short-circuit currents can arise. Only in the last phase of the switching movement of the main piston 62 becomes the first, left sub-piston section 54a from its radially outer valve seat (left inner edge 26 the circumferential groove 6 of the housing 64 ), while at the same time the right sub-piston section 54b because of the further axial movement of the main piston 62 from the associated radially inner valve seat (outer edge 20 of the circumferential gap 10 of the main piston 62 ) also lifts, bringing the shuttle valve 52 in the switching mode according to the 11 passes.

At the in 12 shown switching position, in which the main piston 62 on its way from the second end position according to 11 in the first end position according to 9 is, are also still the two sub-piston sections 54a and 54b at the assigned valve seats (outer edges 18 . 20 ; inner edges 26 . 28 ), so that no short-circuit currents in the shuttle valve 52 may occur. Only in the following phase is the shuttle valve 52 in the mode according to 9 above.

13 shows another structural design of a shuttle valve 68 in which the connection opening S for the supply supply line not in the cylindrical side wall but in an end face 70 of the housing 72 is trained. An arranged in the connection opening S for the supply line pipe socket 74 protrudes into a coaxial end pipe 76 of the main piston 78 and thus provides a connection of the connection opening S for the supply line to the interior 80 of the main piston 78 ago. This arrangement allows a very short design. Incidentally, the assignment of the connection openings V for the ventilation and the two connection openings C1 and C2 for the two consumer lines corresponds to those in the shuttle valves 2 . 40 and 52 in the previous figures. In the in 13 shown end position of the main piston 78 the connection port C1 for the first consumer line is supplied with compressed air and vented the connection opening C2 for the second consumer line.

14 shows the embodiment of a shuttle valve 82 in which the connection opening S for the supply supply line to that of the acted upon by the control pressure end face 84 of the main piston 86 near end of the housing 88 is arranged. In the in 14 shown end position of the main piston 86 For example, the connection opening C1 for the first load line is vented and the connection opening C2 for the second load line is supplied with compressed air.

15 shows a further constructive variant of a shuttle valve 90 in which the connection opening S for the supply supply line and the associated passage opening 92 each in the side walls of the housing 94 or the main piston 96 are formed, however, wherein the connection opening C2 for the second consumer line at an end face of the shuttle valve 90 is arranged. Another difference from the previously described embodiments is that the pneumatic control pressure and this counteracting return spring 98 at the same end of the main piston 96 take effect, namely acts the return spring 98 on the outer front side 100 and the control pressure on one of these remote annular surface 102 of the main piston 96 , In the in 15 shown end position of the main piston 96 For example, the connection port C1 for the first load line is supplied with compressed air and the connection port C2 for the second load line is vented.

16 shows a trained according to the invention shuttle valve 104 , which with regard to the assignment of the connection openings exactly the embodiments according to the 1 to 12 corresponds, but with the main piston 107 at its acted upon by the control pressure end of design and manufacturing reasons in a socket 106 is guided, in turn, in the housing 108 is used. In the in 16 shown end position of the main piston 107 the connection port C1 for the first consumer line is supplied with compressed air and vented the connection opening C2 for the second consumer line. The return spring-side end face 109 of the main piston 107 can be in communication with the ambient pressure, which results in an advantageously small design.

17 shows a further structural embodiment of a trained according to the invention shuttle valve 110 in which the main piston 112 in one in the housing 114 arranged sliding bush 116 is mounted axially displaceable, wherein the sliding bush 116 from a front-side housing cover 118 is held in the housing. The connection opening S for the supply supply line, an associated passage opening 120 in the sliding bush 116 , an associated through hole 121 in the main piston 112 as well as the connection opening V for the vent and the connection opening C1 for the first consumer line are each in the region of the cylindrical side wall of the shuttle valve 110 formed during the connection opening C2 for the second consumer line in the pressurized end face 122 of the main piston 112 facing away from the front side of the housing 114 is arranged. How out 17 further shows, in this switch position, the connection opening V for the vent with the in the housing 114 formed circumferential groove 124 in connection. The connection opening C1 for the first consumer line is supplied with compressed air and the connection opening C2 for the second consumer line is vented.

18 shows very schematically a very simple in its construction shuttle valve 126 in its case 128 the connection openings S for the supply supply line and the connection opening V for venting along a generatrix of the housing 128 one behind the other and the connection openings C1 and C2 are arranged diametrically opposite each other for the two load lines. The connection openings S for the supply supply line and the connection opening V for the vent are each with a section 130 respectively. 132 the gap between the wall of the housing 128 and the main piston 134 connected while the connection opening C1 for the first consumer line to the interior 136 of the main piston 134 and the connection port C2 for the second load line with the circumferential groove 138 of the housing 128 are connected. The shuttle valve 126 is in a first end position of the main piston 134 illustrated, in which a not shown first consumer line via the connection opening S, the first section 130 of the space, the interior 136 of the main piston 134 and the connection port C1 for the first consumer line is supplied with compressed air, while the other consumer line via the connection port C2 for the second consumer line, the second section 132 of the intermediate space and the connection opening V is vented. To enable the flow connection between the first section 130 of the gap and the interior 136 of the main piston 134 has the main piston 134 in the area of its circumferential gap 139 not further designated flow openings. In the 18 Plotted arrows illustrate the respective flow paths.

19 shows an embodiment of a shuttle valve according to the invention 140 in which similar to the embodiment according to 18 the connection opening S for the supply supply line with a first section 142 the space between the wall of the main piston 144 and the wall of the housing 146 is further connected, the connection opening V for venting with the second section 148 the gap and the circumferential groove 154 in the case 146 is further connected, the connection opening C1 for the first consumer line to the interior 150 of the main piston 144 and the connection port C2 for the second load line with the circumferential groove 154 of the housing 146 are connected. In contrast to the shuttle valve 126 of the 18 However, the connection port V for the vent at the acted upon by the control pressure end face 152 of the main piston side facing away from the housing 146 trained and flows directly through a muffler 156 in the nearby areas. This arrangement is particularly suitable for vertical installation, as can be emptied via the connection opening V and any possibly forming water pocket. In the illustrated end position of the main piston 144 the connection port C1 for the first consumer line is supplied with compressed air and vented the connection opening C2 for the second consumer line.

Finally shows 20 an inventive shuttle valve 158 , Which in its construction and in terms of the assignment of the repeatedly mentioned connection openings S, V, C1, C2 substantially the shuttle valves according to the 1 to 12 like. In contrast to these previous shuttle valves, the shuttle valve 158 according to 20 however, a secondary piston 160 on, which in cross-section approximately U-shaped with two radially outwardly directed, at the bottom of the circumferential groove 162 of the housing 182 sealingly fitting thighs 164 . 166 is formed, wherein from the bottom of the circumferential groove 162 from a radial flange 168 inside between the thighs 164 . 166 of the slave piston 160 protrudes and on the hollow cylindrical bottom wall 170 sealingly applied.

The first and the second leg 164 . 166 of the slave piston 160 are of axially aligned passage openings 172 respectively. 174 interspersed, through which the on the outer end faces of the two legs 164 respectively. 166 acting pressure to the inner end faces can balance out, so this sub-piston 160 during the switching phase of the valve not due to different pressures in the to the secondary piston 160 adjacent sections 176 respectively. 178 the space between the wall of the housing 182 and the wall of the main piston 180 is moved in an undesirable manner.

The shuttle valve 158 according to 20 is shown in a first end position, in which a connected to the connection opening C1 first consumer line via the connection S for the supply line, the interior 184 of the main piston 180 and the left section 176 of said space is supplied with compressed air, while a second, connected to the connection opening C2 consumer line on the right section 178 of the intermediate space, the circumferential groove 162 in the case 182 and the connection port V is vented.

For the purpose of better mountability, the housing and the main piston may be formed in two parts, as exemplified in 17 and 19 is shown.

LIST OF REFERENCE NUMBERS

2

shuttle valve

4

casing

5

bore wall

6

Circumferential groove in the housing

8th

main piston

10

Circumferential gap on the main piston

11

feather

12

slave piston

13

First section of the gap between the bore wall and the main piston

14

Left, radially inner peripheral edge on the secondary piston 12

15

Second section of the gap between the bore wall and the main piston

16

Right, radially inner peripheral edge on the secondary piston 12

18

Left outer edge on the circumferential gap 10 of the main piston 8th , Valve seat

20

Right outer edge on the circumferential gap 10 of the main piston 8th , Valve seat

22

Left, radially outer peripheral edge on the secondary piston 12

24

Right, radially outer peripheral edge on the secondary piston 12

26

Left inner edge on the circumferential groove 6 of the housing 4 , Valve seat

28

Right inner edge on the circumferential groove 6 of the housing 4 , Valve seat

30

First face of the main piston 8th

32

Second, return spring-side end face of the main piston 8th

34

Through opening in the main piston 8th

36

Interior of the main piston 8th

38

Return spring on the main piston 8th

39

Diaphragm on the main piston 8th

40

shuttle valve

42

slave piston

42a

Left sub-piston section

42b

Right secondary piston section

44

piston longitudinal axis

46

main piston

48

casing

50

Interior of the main piston

52

shuttle valve

54

slave piston

54a

Left sub-piston section

54b

Right secondary piston section

56

piston longitudinal axis

58

axial flange

60

feather

62

main piston

64

casing

68

shuttle valve

70

front

72

casing

74

pipe socket

76

end stub

78

main piston

80

Interior of the main piston

82

shuttle valve

84

front

86

main piston

88

casing

90

shuttle valve

92

Through opening in the main piston 96

94

casing

96

main piston

98

Return spring

100

front

102

ring surface

104

shuttle valve

106

Rifle

107

main piston

108

casing

109

Return spring-side end face of the main piston 107

110

shuttle valve

112

main piston

114

casing

116

bush

118

housing cover

120

Through opening in sliding bushing 116

121

Through opening in the main piston 112

122

front

124

Circumferential groove in the housing

126

shuttle valve

128

casing

130

First section of the gap between the bore wall and the main piston

132

Second section of the gap between the bore wall and the main piston

134

main piston

136

Interior of the main piston

138

Circumferential groove in the housing

139

Circumferential gap on the main piston 134

140

shuttle valve

142

First section of the gap between the bore wall and the main piston

144

main piston

146

casing

148

Second section of the gap between the bore wall and the main piston

150

Interior of the main piston

152

front

154

Circumferential groove in the housing

156

silencer

158

shuttle valve

160

slave piston

162

Circumferential groove in the housing

164

First leg on the secondary piston 160

166

Second leg on the secondary piston 160

168

Radial flange on the housing 182

170

Bottom wall of the slave piston 160

172

Through opening in the first leg 164

174

Through opening in the second leg 166

176

First section of the gap between the bore wall and the main piston

178

Second section of the gap between the bore wall and the main piston

180

main piston

182

casing

184

Interior of the main piston

C1

First connection opening for a consumer line

C2

Second connection opening for a consumer line

S

Connection opening for a supply line

V

Connection opening for a vent

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0199948 A1 [0004]

Claims (13)

Pneumatic shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) for alternately supplying one of two consumer lines and for venting the other consumer line, wherein the shuttle valve as a controllable 4/2-way valve, each with a connection opening (C1, C2) for the two load lines, further for a supply line (S) and for a vent (V) is formed, characterized in that the shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) is designed as a seat valve, which comprises: - a housing ( 4 ; 48 ; 64 ; 72 ; 88 ; 94 ; 108 ; 114 ; 128 ; 146 ; 182 ) with a largely cylindrical bore, at the bore wall ( 5 ) a circumferential groove ( 6 ; 124 ; 138 ; 154 ; 162 ), - one in the cylindrical bore of the housing ( 4 ; 48 ; 64 ; 72 ; 88 ; 94 ; 108 ; 114 ; 128 ; 146 ; 182 ) between two end positions axially adjustable, hollow and largely closed main piston ( 8th ; 4 ; 62 ; 78 ; 86 ; 96 ; 112 ; 134 ; 144 ; 180 ), in which to the bore wall ( 5 ) spaced piston wall one of the circumferential groove ( 6 ; 124 ; 138 ; 154 ; 162 ) substantially opposite, over the entire wall circumference extending circumferential gap ( 10 ; 139 ) is formed, - and one in the space between the bore wall ( 5 ) and the piston wall, on the one hand into the circumferential groove ( 6 ; 124 ; 138 ; 154 ; 162 ) and on the other hand in the circumferential gap ( 10 ; 139 ) engaging and in this with play axially displaceable slave piston ( 12 ; 42 ; 54 ; 160 ), - wherein the radially inner peripheral edges ( 14 . 16 ) of the slave piston ( 12 ; 42 ; 54 ; 160 ) with the two outer edges serving as valve seats ( 18 . 20 ) of the circumferential gap ( 10 ; 139 ) of the main piston ( 8th ; 4 ; 62 ; 78 ; 86 ; 96 ; 112 ; 134 ; 144 ; 180 ) and the radially outer peripheral edges ( 22 ; 24 ) of the slave piston ( 12 ; 42 ; 54 ; 160 ) with the inner edges serving as valve seats ( 26 ; 28 ) of the circumferential groove ( 6 ; 124 ; 138 ; 154 ; 162 ) of the housing ( 4 ; 48 ; 64 ; 72 ; 88 ; 94 ; 108 ; 114 ; 128 ; 146 ; 182 ) cooperate such that at each of the end positions of the main piston ( 8th ; 4 ; 62 ; 78 ; 86 ; 96 ; 112 ; 134 ; 144 ; 180 ) of this end position in each case close radially outer peripheral edge ( 22 ; 24 ) of the slave piston ( 12 ; 42 ; 54 ; 160 ) on the associated valve seat ( 26 ; 28 ) of the circumferential groove ( 6 ; 124 ; 138 ; 154 ; 162 ) and the radially inner peripheral edge ( 14 ; 16 ) from the associated valve seat ( 18 ; 20 ) of the circumferential gap ( 10 ; 139 ) is lifted off, and facing away from the end position radially inner peripheral edge ( 16 ; 14 ) of the slave piston ( 12 ; 42 ; 54 ; 160 ) on the associated valve seat ( 20 ; 18 ) of the circumferential gap ( 10 ; 139 ) and the radially outer peripheral edge ( 24 ; 22 ) of the slave piston ( 12 ; 42 ; 54 ; 160 ) from the associated valve seat ( 28 ; 26 ) of the circumferential groove ( 6 ; 124 ; 138 ; 154 ; 162 ), and in which each of the two by the secondary piston ( 12 ; 42 ; 54 ; 160 ) separate sections ( 13 ; 15 ; 130 ; 132 ; 142 ; 148 ; 176 ; 178 ) of the space between the wall of the housing ( 4 ; 48 ; 64 ; 72 ; 88 ; 94 ; 108 ; 114 ; 128 ; 146 ; 182 ) and the wall of the main piston ( 8th ), the circumferential groove ( 6 ; 124 ; 138 ; 154 ; 162 ) of the housing ( 4 ; 48 ; 64 ; 72 ; 88 ; 94 ; 108 ; 114 ; 128 ; 146 ; 182 ) and the interior ( 36 ; 50 ; 80 ; 136 ; 150 ; 184 ) of the main piston ( 8th ; 4 ; 62 ; 78 ; 86 ; 96 ; 112 ; 134 ; 144 ; 180 ), the latter via a passage opening ( 34 ; 92 ; 121 ; 172 ) in the same, in each case with one in the bore wall ( 5 ) are formed in connection port (S; V; C1; C2). Shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 158 ) according to claim 1, characterized in that the connection opening (S) of the supply supply line with the interior ( 36 ; 50 ; 80 ; 184 ) of the main piston ( 8th ; 4 ; 62 ; 78 ; 86 ; 96 ; 112 ; 180 ), the connection opening (V) of the vent with the circumferential groove ( 6 ; 124 ; 162 ) of the housing ( 4 ; 48 ; 64 ; 72 ; 88 ; 94 ; 108 ; 114 ; 182 ) and the connection openings (C1; C2) of the consumer lines in each case with one of the two sections ( 13 ; 15 ; 176 ; 178 ) of the space between the bore wall ( 5 ) of the housing ( 4 ; 48 ; 64 ; 72 ; 88 ; 94 ; 108 ; 114 ; 182 ) and the wall of the main piston ( 8th ; 4 ; 62 ; 78 ; 86 ; 96 ; 112 ; 180 ) keep in touch. Shuttle valve ( 140 ) according to claim 1, characterized in that the connection opening (S) of the supply supply line and the connection opening (V) of the ventilation in each case with one of the sections ( 142 ; 148 ) of the space between the bore wall ( 5 ) of the housing ( 146 ) and the wall of the main piston ( 144 ), the connection opening (C2) of one of the consumer lines with the circumferential groove ( 154 ) and the connection opening (C1) of the other consumer line to the interior ( 150 ) of the main piston ( 144 ) keep in touch. Shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) according to one of claims 1 to 3, characterized in that the secondary piston ( 12 ; 42 ; 54 ; 160 ) by a spring ( 11 ; 60 ) is biased towards an end position. Shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) according to one of claims 1 to 4, characterized in that the secondary piston ( 12 ; 42 ; 54 ; 160 ) in the radial and axial directions on the main piston ( 8th ; 4 ; 62 ; 78 ; 86 ; 96 ; 112 ; 134 ; 144 ; 180 ) is arranged guided. Shuttle valve ( 40 ; 52 ) according to one of claims 1 to 5, characterized in that the secondary piston ( 42 ; 54 ) in a direction to the piston longitudinal axis ( 44 ; 56 ) transverse plane in two mutually coaxial sub-piston sections ( 42a . 42b ; 54a . 54b ) is shared. Shuttle valve ( 52 ) according to claim 6, characterized in that between the sub-piston sections ( 54a . 54b ) a spring which spreads apart ( 60 ) is arranged. Shuttle valve ( 158 ) according to one of claims 1 to 3, characterized in that the secondary piston ( 160 ) in cross-section approximately U-shaped with two radially outwardly directed, at the bottom of the circumferential groove ( 162 ) sealingly adjacent legs ( 164 . 166 ) is formed, that from the bottom of the circumferential groove ( 162 ) from a radial flange ( 168 ) radially inwardly between the legs ( 164 . 166 ) of the slave piston ( 160 ) and at the bottom wall ( 170 ) sealingly abuts, and that the legs ( 164 . 166 ) of the slave piston of axial passage openings ( 172 . 174 ) are interspersed. Shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) according to one of claims 1 to 8, characterized in that the main piston ( 8th ; 4 ; 62 ; 78 ; 86 ; 96 ; 112 ; 134 ; 144 ; 180 ) pneumatically against the force of a return spring ( 38 ; 98 ) Is axially adjustable from a first end position in its second end position. Shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) according to one of claims 1 to 8, characterized in that the main piston ( 8th ; 4 ; 62 ; 78 ; 86 ; 96 ; 112 ; 134 ; 144 ; 180 ) via a pneumatically actuated membrane ( 39 ) is axially adjustable. Shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) according to one of claims 1 to 10, characterized in that the main piston ( 8th ; 4 ; 62 ; 78 ; 86 ; 96 ; 112 ; 134 ; 144 ; 180 ) has a device for setting in an intermediate position between the end positions, in which both consumer lines are vented. Shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) according to one of claims 1 to 11, characterized in that this shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) is acted upon by compressed air for the purpose of actuation by means of a solenoid valve. Shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) according to one of claims 1 to 12, characterized in that this shuttle valve ( 2 ; 40 ; 52 ; 68 ; 82 ; 90 ; 104 ; 110 ; 126 ; 140 ; 158 ) is arranged in the air treatment plant of a commercial vehicle.

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