WO2018006991A1

WO2018006991A1 - Park release valve for a trailer vehicle

Info

Publication number: WO2018006991A1
Application number: PCT/EP2017/000731
Authority: WO
Inventors: Mark CUYX; Armin Sieker; Axel Stender
Original assignee: Wabco Europe Bvba
Priority date: 2016-07-06
Filing date: 2017-06-23
Publication date: 2018-01-11
Also published as: WO2018006991A8

Abstract

The invention relates to a park release valve for a trailer vehicle having a pneumatic brake system, and for controlling the pressure in spring-loaded brake cylinders, and having the following features: a) a connection for supply pressure, a connection for reservoir pressure, an output for ventilation, a connection as pressure output, b) a control piston for opening and blocking a connection from the connector for reservoir pressure to the connector as pressure output and for opening and blocking a connection from the output for ventilation to the connection as pressure output, c) the control piston is movable by an operating element between a travel position and a park position, wherein in the park position the connection from the output for ventilation to the connection as pressure output is opened and the connection from the connection for reservoir pressure to the connection as pressure output is blocked, d) the control piston is loaded in the park position and without pressure on the connector for supply pressure by a slider having an axially acting force in a direction from the travel position to the park position, e) in the event of pressure on the connector for supply pressure an axial force acts on the slider in a direction from the park position to the travel position of the control piston.

Description

Park release valve for a trailer Description

The invention relates to a park-release valve for a trailer with pneumatic brake system and in particular for controlling the pressure in spring-loaded brake cylinders. Moreover, the invention relates to a valve assembly, a pneumatic brake system and a trailer vehicle.

The pneumatic brake system of a trailer is typically connected to a towing vehicle via two pneumatic lines. A line carries control pressure via a control connection to the trailer. This connection is also called "brake". The other line supplies reservoir pressure to the trailer via a supply port labeled "supply".

A safety function is integrated when the supply line is torn off. For this purpose, the pressure in the line is monitored. If the pressure drops too much, the trailer is automatically braked by spring brakes.

The trailer has a reservoir for compressed air, which is fed via the supply connection. As a result, the trailer vehicle can be braked several times in quick succession via its service brakes, without the required compressed air having to be supplied simultaneously via the supply connection.

Modern pneumatic brake systems have combined brake cylinder, namely with diaphragm service brake cylinder and spring brake cylinder in a common assembly. This has the advantage that brake pistons, brake levers and brake discs or brake drums exist only once per module. need to be. Only spring brake cylinder and service brake cylinder are next to each module available. Such combined brake cylinders are also referred to as Tristop cylinder. But it is also possible a separate arrangement of service brakes and spring brakes.

In a parked and separated from the towing vehicle trailer, the spring brakes are activated because the spring brake cylinders are vented. To maneuver the trailer vehicle, a release of the spring brakes is required. For this purpose, a special Park-release valve is provided, which in a release position the spring-loaded brake cylinder with compressed air from the reservoir (the trailer vehicle) vented and so solves.

After shunting, the spring-loaded brake cylinders must be vented again. For this purpose, the park-release valve can take a parking position.

In practice, the park-release valve may consist of two separately operable valve units. More compact is a valve in which the described functionalities are summarized as far as possible.

In EP 1 386 810 B1, a combination valve with spring-suspended double valve body is disclosed. A control rod is between three positions, driving-parking maneuvering, axially displaceable and lockable by a sliding sleeve. The structure is compact but very complex.

Depending on the operating situation, the spring-loaded brake cylinders are fed from the reservoir pressure (via the supply connection) or from the reservoir of the trailer vehicle. A separation of the lines for the Vorratsbe container on the one hand and for the supply pressure on the other hand is therefore useful.

Object of the present invention is to provide a (other) Park-release valve compact design and high functionality. Advantageously, the valve is constructed so that integrates an additional function with little effort can be. Should be prevented unintentional release of the spring brakes after connecting the supply pressure line leading or the transition to a driving position. Preferably, an unwanted pressure equalization between the connection for supply pressure and the connection for reservoir pressure should be avoided.

To achieve the object, Park-release valve according to the invention has the features of claim 1, preferably as follows:

a) - a connection for supply pressure,

- a connection for reservoir pressure,

- an outlet for ventilation,

- a connection as a pressure outlet,

b) a control piston for opening and closing a connection from the reservoir pressure port to the port as a pressure port and for opening and closing a port from the vent port to the port as a pressure port,

c) the control piston is axially movable by a control element between a driving position and a parking position, wherein in the parking position the connection from the outlet for venting to the port is opened as a pressure outlet and the connection from the port for reservoir pressure to the port is blocked as a pressure outlet,

d) the control piston is loaded in the parking position and without pressure at the connection for supply pressure by a slide with an axially acting force in a direction from the driving position to the parking position,

e) when pressure is applied to the reservoir pressure port, an axial force acts on the spool in a direction from the parking position to the travel position of the spool.

Slide and control piston have a common axial direction and opposite direction. The force exerted by the slider and the force acting on the slider run in these directions. Preferably, in the driving position of the control piston, the connection from the outlet for venting to the connection is blocked as a pressure outlet and the connection from the connection for reservoir pressure to the connection is opened as a pressure outlet. According to a further aspect of the invention a movable between a blocking position and a release position locking member is provided, wherein the control piston and slide in blocking position (the locking member) are coupled to each other at least such that the slide the control piston, starting from the driving position, in the direction of the parking position can take. Preferably there is no coupling in the opposite direction through the blocking member.

According to a further aspect of the invention, an unlocking device for controlling the movement of the blocking member between blocking position and release position (of the blocking member) is provided. The locking member must therefore not be operated manually. Rather, a control indirectly via the Entsperrorgan.

According to a further aspect of the invention, the Entsperrorgan cooperates with a spring means, wherein the spring means the blocking member in particular in the direction of the release position (of the locking member) acted upon and the blocking member is acted upon by the Entsperrorgan in the direction of the locking position. The spring means is preferably a compression spring. Thus, the locking member is only active or in the blocking position when the unlocking device overcomes the force of the spring means.

According to a further aspect of the invention, the control piston is hollow and the unlocking in the manner of a piston in the interior of the control piston movable. In this case, the control piston and the release device can be aligned concentrically / coaxially with one another.

According to a further aspect of the invention, the blocking member is movably mounted in a cylindrical wall of the control piston and has a sliding head for engagement with a sliding surface of the Entsperrorgans, wherein the sliding surface is aligned at an angle to the axial direction of the Entsperrorgans. Depending on the position of the sliding surface / position of the Entsperrorgans the blocking member is in blocking position or release position. According to a further aspect of the invention, the Entsperrorgan is provided with a control element which projects beyond the control element of the control piston. As a result, both controls or release on the one hand and control piston on the other hand at least a little independently operable.

According to a further aspect of the invention, the Entsperrorgan is acted upon axially by a spring means, namely in the direction of the parking position of the control piston. In this case, the spring means is supported as a compression spring preferably on the control piston.

According to a further aspect of the invention, the Entsperrorgan is coupled to the control piston, such that the Entsperrorgan is movable in at least one axial direction and relative to the control piston only to the abutment of a stop. Preferably, the release member and the control piston are coupled in both axial directions by a respective stop.

According to a further aspect of the invention, it is provided that the slide partially encloses the control piston in the parking position and that the slide has a radially outwardly directed stop at a free end, which does not include the control piston in the parking position, in particular a collar for abutment with a stop Paragraph of a housing. Preferably, the slider is loaded by a spring means / a compression spring in the direction of the parking position of the control piston.

According to a further aspect of the invention, the slider is slidably mounted in the manner of a piston in a housing, wherein the slider is hollow and at least partially receives the control piston in itself, and wherein the control piston is hollow and at least partially receives an unlocking in itself. Preferably, slide, control piston and Entsperrorgan are concentric or coaxially aligned and arranged. According to a further aspect of the invention, the slide is slidably held in a housing and provided at its periphery with two seals between which a working space is formed, wherein the housing has an opening in the interior of the working space with connection to the connection for supply pressure. When sufficient supply pressure of sufficient height, the slider moves against the force of the spring, so that there is an increase in the working space.

According to a further aspect of the invention, it is provided that the control piston is held at least partially displaceable in a housing and has at its periphery two seals between which a connection space is formed, that the housing inside in the region of the connection space an opening with connection to the connection for Reservoir pressure and having an opening with connection to the connection as a pressure outlet, and that the control piston is movable with at least one of the seals over one of the openings, so that in a parking position of the control piston, the openings are not connected via the connection space with each other and in a driving position of the Control piston, the openings are connected to each other via the connecting space. Preferably, the two openings are positioned differently in the axial direction of the housing. In this case, the axial distance of the openings from each other is less than the distance between the two seals on the control piston from each other. Thus, it is possible that the seals between them include a connection space in which both openings can lie.

The park-release valve according to the invention also fulfills the known tear-off function. In driving position and with sufficient supply pressure, the working space between slide and housing has its full size. The control piston rests against the slide with the blocking element. In case of failure of the supply pressure of the working space coincides by acting on the slide spring means, the slide is moved axially by the spring means and takes the control piston to the parking position with. This establishes the connection from the port as a pressure port to the vent port and the spring brakes are vented, the vehicle is braked. At the same time, the control piston closes the connection from the reservoir pressure to the port as a pressure outlet.

According to a further aspect of the invention, a valve for blocking or passing the supply pressure is provided on the slide, wherein the valve is controllable in dependence on a control pressure and thus blocks or releases a connection for passing the supply pressure. As a result, the forwarding of the supply pressure in dependence on the position of the valve can be influenced.

According to a further aspect of the invention, the valve has a first valve body which is provided in a valve space between the connection for supply pressure and an opening into a working space of the slide opening, wherein the first valve body is movable between an open position and a blocking position, only can be moved in the open position, as long as supply pressure is applied and remains in its open position, as long as supply pressure is applied, and wherein the first valve body remains in the blocking position without supply pressure. With this functionality of the additional valve, the park-release valve according to the invention has an additional safety function. This is important in the transition from the parking position to the driving position or when connecting the supply pressure to the trailer.

According to a further aspect of the invention, the first valve body is loaded by a spring means in the direction of the blocking position. This simplifies the construction and control of the first valve body.

According to a further aspect of the invention, a second valve body is provided between the first valve body and a control input, wherein the first valve body can be acted upon by the second valve body and thus moved from the blocking position into the open position. Thus, the control of the first valve body is performed by the second valve body. The second valve body can be controlled via an auxiliary power. According to a further aspect of the invention, the second valve body is arranged in a flying manner in its valve chamber, that is to say without being acted on by spring means. This simplifies the construction of the valve in the region of the second valve body.

According to a further aspect of the invention, the valve space on a vent, namely the second valve body opposite, wherein the vent is closed in particular in the open position. Preferably, the first valve body closes the vent in its open position.

According to a further aspect of the invention, the first valve body in its blocking position seals a transition from the valve chamber to the valve chamber.

According to a further aspect of the invention, the first valve body has an overflow channel, which can be acted upon with supply pressure in the open position. In the blocking position of the first valve body, the overflow channel is blocked. It can then pass the supply pressure the first valve body.

The invention also relates to a pneumatic brake system with a valve assembly or a Park-release valve, as described above.

Finally, the subject of the invention is also a trailer vehicle with a pneumatic brake system, as mentioned above.

Further features of the invention will become apparent from the description, moreover, and from the claims. Advantageous embodiments of the invention will be explained in more detail with reference to drawings. Show it:

1 is a pneumatic brake system of a trailer with an emergency brake valve of the first type and a park release valve of the first type in parking position without reservoir pressure,

2 a pneumatic brake system of a trailer vehicle with an emergency brake valve of the second type and the parking release valve of the first type in parking position without reservoir pressure, 3 shows the parking release valve of the first type in parked position without supply pressure, FIG. 4 shows the parking release valve of the first design in the parked position but with adjoining supply pressure, FIG.

5 shows the parking release valve of the first type in driving position with supply pressure, FIG. 6 shows the parking release valve of the first type in release position / maneuvering position without supply pressure, FIG.

7 shows a pneumatic brake system of a trailer vehicle with the emergency brake valve of the first type and a parking release valve of the second type in parking position without reservoir pressure,

8 shows a pneumatic brake system of a trailer vehicle with the emergency brake valve of the second type and the parking release valve of the second type in parking position without reservoir pressure,

9 shows the parking release valve of the second type in parking position without supply pressure, FIG. 10 shows the parking release valve of the second type in drive position with supply pressure and after the first brake pressure, FIG.

1 1, the parking release valve of the second type in release position / Rangierstellung without supply pressure,

Fig. 2, the park-release valve of the second type in parking position with reservoir pressure.

Fig. 1, 2 show a pneumatic brake system for a trailer. A control pressure line 20 leads to a trailer brake module 21. A supply pressure line 22 leads to a parking release valve 23 of the first type and from there further via a reservoir 24 to the trailer brake module 21. The control pressure line 20 is assigned a control connection 25, the supply pressure line 22 is a supply connection 26. In order to distinguish between the supply pressure in the supply pressure line 22, the pressure in the control pressure line 20 will be referred to below as the brake pressure.

The trailer brake module 21 is constructed in a known manner, namely per vehicle side with two solenoid valves 27, 28 and a relay valve 29. About the solenoid valves 27, 28, the supply of the control pressure to the relay valves 29 is controlled. The latter are at the same time connected to one another via a line 30 with branches. reservoir pressure from the reservoir 24 connected and give controlled service brake pressure to service brake cylinder 31, 32 from.

Another component of the trailer brake module 21 is a redundancy valve 33 as a solenoid valve, with which the connection between the control pressure line 20 and a line 34 is separable and convertible. In this way, the conduit 34 may alternatively be connected to the conduit 30 and the reservoir pressure from the reservoir 24. The line 34 also connects via a branch 35, the solenoid valves 28 of both sides of the vehicle with each other.

Furthermore, the line 34 connects (with appropriately switched redundancy valve 33) the control pressure line 20 or the line 30 of FIG. 1 with a first control input 36 of a valve arrangement 37 of the first type as emergency brake valve. The control input 36 is indirectly connected to the control pressure line 20, so that brake pressure can be present. The valve assembly 37 has here in particular the function of an emergency brake valve with overload protection and has for this purpose a second control input 38, and a first terminal 39, a second terminal 40 and a third terminal 41.

The second control input 38 is connected via a line 42 and the park-release valve 23 to the supply pressure line 22. The first port 39 is connected via a line 43, a check valve 45 and the trailer brake module 21 to the reservoir 24. The second port 40 is connected via a line 44 and branches with spring-loaded brake cylinders 46, 47 of both sides of the vehicle. The third port 41 is a vent port.

In the brake system shown, the service brake cylinders 31, 32 are components of so-called combination cylinders, namely with integrated spring-loaded brake cylinders 46, 47, wherein the forces on actuation of the service brake on the one hand and spring memories on the other hand on each of the same brake piston 48, 49 act. In the parking position shown in FIG. 1, the pneumatic brake system is vented. That is, the spring-loaded brake cylinders 46, 47 are connected via the line 44 and the port 40 to the port 41 for venting. At the valve assembly 37 are neither control pressure nor supply pressure or reservoir pressure. The valve assembly 37 is in a passive switching position.

In an active switching position, not shown, or in a driving position is at the second control input 38, a supply pressure of at least 2.5 bar from the supply pressure line 22 on. The supply pressure is for this purpose from the supply pressure line 22 through the Park-release valve 23 and through the Line 42 led to the second control input 38. The supply pressure applied there acts on a cylinder space 50 between two coaxially arranged in series pistons 51, 52, so that a valve unit 53 occupies a position not shown in FIG. 1 by pressure of the piston 52. In this case, no pressure is applied to the first control input 36 in the driving position in the normal case. Compressed air from the reservoir 24 passes through the line 43, the port 39, the port 40 and the line 44 in the spring-loaded brake cylinders 46, 47 and the ventilation thereof.

The piston 51 is pressure-dependent between the control inputs 36, 38 displaceable and provided in the direction of the piston 52 with a spacer 54. In addition, the cylinder chamber 50 are dimensioned and the control inputs 36, 38 positioned so that when pressure is applied to at least one of the control inputs 36, 38 of the piston 52 (by pressure or the spacer 54) and the valve unit 53 assumes the driving position, not shown.

Since no control pressure from the control pressure line 20 is present in FIG. 1, the service brake cylinders 31, 32 are also unaerated.

The park-release valve 23 here has three connections, namely a connection 55 for the line 42, a connection 56 for the supply pressure line 22 and a connection 57 for a line 58 to the reservoir 24 with reservoir pressure. Within the parking-release valve 23, the terminals 56, 57 are connected to each other via a branch 59 with a check valve 60. The latter is so ordered that the reservoir pressure at the terminal 57 can not flow to a possibly lower supply pressure at the port 56.

Notwithstanding Figure 1, Figure 2, the valve assembly 37 in a second type, namely in a simplified form. The valve unit 53 is here a simple 3/2-way valve, wherein in one position, the terminals 38, 40 are interconnected and in the other position, the terminals 39 and 40. About the control input 36, again with connection to the control pressure line 20, the Adjustment of the valve unit 53.

The line 42 is thus connected via the terminal 38 in the position shown in FIG. 2 to the terminal 40, so that the spring brake cylinders 46, 47 are connected via the valve unit 53 to the park-release valve 23 and there via an outlet for venting 61 vented when no pressure in the line 20 and the control input 36 is present.

Hereinafter, structure and function of a first embodiment of the parking release valve 23 will be explained in detail with reference to FIGS. The spatial orientation of the parts by the terms "top" and "bottom" refers to the representation in the figures. Depending on the installation position of the parking release valve 23, a different orientation may result. In FIGS. 3 to 6 and 9 to 12, an air flow LS is indicated by the park-release valve 23.

In a cylindrical housing 62 are concentrically arranged and coaxially movable a slide 63, a control piston 64 with control element 65 and a shut-off valve 66 with control element 67. The control piston 64 is thus externally surrounded at least partially by the slide 63 and receives inside the unlocking 66 , In the axial direction, the operating element 67 of the unlocking member 66 protrudes downward / outward beyond the operating element 65 of the control piston 64.

For receiving said parts slide 63, control piston 64 and unlocking 66, the housing 62 has a multi-stepped interior space, namely initially viewed in the axial direction from top to bottom of a receiving space 68 for a spring means 69, which is a compression spring here. It includes a widened space 70, for receiving a radially upwardly directed collar 71 of the slider 63. This is followed by a slightly narrower slide chamber 72, followed by an even narrower piston chamber 73.

In the region of the piston chamber 73, the housing 62 has on the inside an opening 74 which is connected to the connection for reservoir pressure, and an opening 75 which is connected to the connection as a pressure outlet 55. The openings 74, 75 are arranged slightly offset from one another in the axial direction.

The control piston 64 is provided in the region of the piston chamber 73 with two circumferential seals 76, 77, between which a circumferential connecting space 78 is formed, as part of the piston chamber 73. The seals 76, 77 have in the axial direction at a distance from each other, which is slightly larger is as the axial offset of the openings 74, 75 to each other. Above the upper seal 76, the control piston 64, the opening 75 opposite, provided with a bore 79.

In the parking position according to FIG. 3, the park-release valve is in the same switching position as in FIGS. 1 and 2. There is no supply pressure at the connection 56. The connection space 78 is open to the port 74 with the reservoir pressure port 57, but has no connection to the port as a pressure outlet 55. Instead, the port as a pressure outlet 55 via the opening 75, the piston chamber 73, the bore 79 is indirectly connected to the outlet for venting 61 connected, see air flow LS.

In this case, the control piston 64 is maximally pulled out of the housing 62, so that an inner piston stop 80 bears against a corresponding housing stop 81. At the same time, the collar 71 of the slide 63 rests on a shoulder 82 between the slide chamber 72 and the receiving space 68. Another shoulder 83 is formed between the piston chamber 73 and the slightly wider slide chamber 72. A lower end face 84 of the slider 63 rests on the shoulder 83 in FIG. 3. The control piston 64 has in its upper half a radially directed bore for receiving a blocking member 85. It is a pin with sliding head 86, which is pressed by a spring means 87 / a compression spring radially inwardly against the unlocking member 66. In the park position according to FIGS. 3 and 4, the unlocking member 66 protrudes radially out of the control piston 64 with part of its length. The slider 63 has a pocket 88 in which the blocking member 85 with the protruding part of its length in parking position receiving, so that the control piston 64 not further in an axial direction G to the driving position or in the direction of the collar 71 of the slider 63 is movable. Rather, the control piston 64 is loaded in this parking position by the slider 63 in an axial direction R, ie from the driving position in the direction of the parking position.

The housing 62 is provided between the connection for supply pressure 56 and the connection for reservoir pressure 57 with a channel 89 with check valve 90, which prevents a backflow from the connection for reservoir pressure 57 to the connection for supply pressure 56.

The slide 63 has two circumferential seals 91, 92. In this case, the upper seal 91 extends radially outward on the collar 71, while the lower seal 92 is provided near the pocket 88. Between the seals 91, 92, a working space 93 is formed as part of the receiving space 68. The working space 93 is connected via an opening 94 to the connection for supply pressure 56 and variable in size, depending on the position of the slide 63, see FIGS. 3 and 4.

The Entsperrorgan 66 is axially movable in the manner of a piston in the control piston 64 between a locking position according to Figures 3, 4, 5 and a release position shown in FIG. 6. Here, the Entsperrorgan 66 is acted upon in the axial direction by a spring means 95. For receiving the spring means 95, the Entsperrorgan 66 is hollow in its upper part, in particular in the upper third. The spring means 95 presses inwardly on an upper end wall 96 of the Control piston 64 from. In this case, the movement of the Entsperrorgans 66 relative to the control piston 64 is limited by a lower stop 97 and an upper stop 98 of the Entsperrorgans 66. Depending on the position of the Entsperrorgans 66, the stop 98 abuts the outside of the end wall 96 or the lower stop 97 inside of the End wall 96.

The Entsperrorgan 66 has a conical or funnel-shaped area with a correspondingly inclined sliding surface 99. The sliding surface 99 connects downward to a cylindrical portion 100. The blocking member 85 rests with the sliding head 86 in the parking position and in the driving position on the cylindrical portion 100. By pressing the control element 67 or upward movement of the Entsperrorgans 66 reaches the inclined sliding surface 99 in front of the sliding head 86, so that the locking member 85 slides radially inwardly, namely out of the pocket 88 out.

Subsequently, the control piston 64 can be moved axially upward relative to the slider 63. As a result, enters the connection space 78 in the release position shown in FIG. 6 despite the vented working space 93 and lower position of the slide 63 via the openings 74, 75, so that the connection for reservoir pressure 57 is in communication with the connection as a pressure outlet 55 and the spring accumulator -Bremszylinder be ventilated. The trailer can then be ranked.

The cylindrical portion 100 comprises the spring means 95. In the region of the sliding surface 99, the Entsperrorgan 95 axially directed holes 101 and in the end wall 96 has a bore 102. In the parking positions of Figures 3 and 4, the air flow LS passes from the bore 79 through the Bores 101, 102 to the vent outlet 61.

With regard to the transition from the parking position according to FIG. 3 to the travel position according to FIG. 5, a special feature exists. When the towing vehicle is coupled to the trailer, the connection for supply pressure 56 receives supply pressure. The spring-loaded brake cylinders 46, 47 are not automatically vented, see Fig. 4. Rather, the control piston 64 initially in the parking position gem. Fig. 3.

For ventilation of the spring brake cylinder, a manual actuation of the control element 65 on the control piston 64 is additionally required. Only then does the drive position according to FIG. 5 result, in which a connection from the connection for reservoir pressure 57 to the connection exists as a pressure outlet 55 via the connection space 78. Accordingly, the trailer can not move even after connection of the supply pressure, when the control element 65 has been manually operated. This increases the safety when coupling the trailer.

7 to 12 relate to a second embodiment, namely with an additional function in the area of the park-release valve 23. In this case, FIGS. 7 and 8 differ only with respect to the different design of the valve assembly 37, according to the difference between FIGS 1 and 2. The parking release valve 23 in Fig. 9 assumes the same position as in Figs. 7 and 8.

In order to make the transition from the parking position to the driving position after the connection of the reservoir pressure for the driver more comfortable and safer, an additional valve 103 is provided as part of the park-release valve 23. The valve 103 is connected between the reservoir pressure port 56 and the port 94. In addition, the valve 103 has a control input 104 and an outlet for venting 105, which leads via a connection 106 to an opening 107 in the piston chamber 73. From there, there is the connection already described above in connection with FIGS. 1 to 6 to the outlet for vent 61.

The check valve 90 is provided as in the first embodiment between the connection for supply pressure 56 and the connection for reservoir pressure 57. However, the channel 89 and the terminals 56, 57 are spatially associated with the valve 103 in this second embodiment. In this case, the components important for the function of the valve 103 lie between the opening 94 and the channel 89 or the connection 56. ¹ In a valve chamber 108 of the valve 103, a first valve body 109 is movable between an open position and a blocking position. FIG. 9 shows the blocking position. That is, the connection from the reservoir pressure port 56 to the port 94 is blocked. FIG. 10 shows the open position of the first valve body 109.

The first valve body 109 has approximately at half the height of a circumferential seal 1 10, so that the valve chamber 08 is divided into an upper half with connection to the connection for supply pressure 56 and a lower half with connection to the opening 94 and with the outlet for vent 05 In addition, the first valve body 109 has a connecting channel 1 1 1, which extends from an upper side 1 12 to a peripheral side 1 13 below the seal 1 10. Finally, the first valve body 109 is acted upon by a spring means 1 14 and a compression spring in the region of the outlet for vent 105 in the upward direction.

A bottom 1 15 of the first valve body 109 is formed as a sealing surface and closes in the open position the outlet for vent 105. Correspondingly, the top 1 12 outside of the connecting channel 1 1 1 is designed as a sealing surface and closes in the blocking position, a transition from the valve chamber 108 to one after above subsequent valve chamber 1 16.

The upper half of the valve space 108 has a slightly larger cross section than the lower half. Corresponding to this, the top 1 12 extends with sealing surface on the cylindrical cross section of the first valve body 109 otherwise. Edge side is the top 1 12 with sealing surface in the blocking position shown in FIG. 9 at an upper peripheral paragraph 1 17 at. This paragraph 1 17 is also the transition from the valve chamber 108 into the valve chamber sixteenth

In the valve chamber 1 16, a second valve body 1 18 between an upper, unencumbered position and a lower, acted upon with control pressure position movable. Also, the second valve body 1 18 with a circumferential sealing tion 1 19 provided. On the underside, ie in the direction of the first valve body 109, the second valve body 1 18 has a recess 120 which is disposed above the connecting channel 1 1 1 and opposite thereto. In a wall of the recess 120, a bore 121 is provided as an overflow.

In the parking position gem. Fig. 9, the spring brake cylinders 46, 47 vented. Accordingly, there is a connection from the port as a pressure outlet 55 to the vent port 61. Supply pressure is not on. Control piston 64 and slide 63 are in the same position as in Fig. 3. In addition, the first valve body 109 is in its blocking position. The top 1 12 is located with its sealing surface on paragraph 1 17, so that no connection from the valve chamber 1 16 to the valve chamber 108 is made. The second valve body 1 18 is assigned to no position and exerts no force on the first valve body 109.

After connecting the supply pressure is in the valve chamber 108 supply pressure. The first valve body 109 remains in the position shown in FIG. 9. Operating elements 65, 67 remain pulled out, as in FIG. 4.

To adjust the driving position, the control element 65 is not actuated here. Rather, the driver taps once on the brake and thus acts on the control input 104 with brake pressure. As a result, the second valve body 1 18 is moved downward and pushes against the top 1 12 of the first valve body 109. The top 1 12 dissolves with its sealing surface from paragraph 1 17. As a result, the seal 1 10 slides down to below the connection to the opening 94. The supply pressure passes through the valve chamber 108 in the connection to the opening 94 and is effective in the working space 93. As a result, the slider 63 moves upward and takes over the locking member 85 with the control piston 64. The Entrorrorgan 66 is also moved by the spring means 95, so that the position acc. FIG. 10 shows, analogous to FIG. 5.

In this driving position after the first brake operation, the first valve body 109 is in its open position. Here, the sealing surface of the bottom closes 1 15 the outlet for vent 105. The supply pressure passes though through the connecting channel 1 1 1 into the lower half of the valve chamber 108, but not into the outlet for vent 105th

Thus, an adjustment of the operating position 65 or control element 67 is not required for the setting of the driving position. It only needs to be pressed once the brake pedal to provide pressure at the control input 104 ready. In the resulting switching position / driving position according to FIG. 10, the connection for reservoir pressure 57 is connected to the connection as pressure outlet 55.

Starting from the parking position without supply pressure according to FIG. 9, a maneuvering of the trailer vehicle may be desired. Required is then aeration of the spring brake cylinders 46, 47 from the reservoir 24. For this purpose, the control element 67 is actuated with the unlocking device 66, so pressed up. As a result, the spring-loaded locking member 85 slides out of the pocket 88 and the position according to FIG. 1 results. The lower stop 97 comes to the end wall 96 inside to the plant and takes the control piston 64 so far with, until the openings 74, 75 between the seals 76, 77 and reservoir pressure from the connection for reservoir pressure 57 for connection as a pressure outlet 55 is controlled. Alternatively, the control piston 64 can be actively actuated, since the blocking member 85 is no longer in the blocking position. The spring brake cylinders 46, 47 are vented and the trailer is ranked. The two valve body 109 and 1 18 are in the position shown in FIG. 9, since no reservoir pressure is applied.

Based on the driving position shown in FIG. 10, the parking position shown in FIG. 12 is adjustable. The trailer is still connected to the towing vehicle. Accordingly, supply pressure is applied to the connection 56. The supply pressure is controlled through to the working space 93 and the slide 63 is thereby in its upper position. Since no brake pressure is applied to the control input 104, the position of the second valve body 1 18 is not defined. To take the parking position, the control element 67 of the Entsperrorgans 66 was actuated, so moved upwards. The spring-loaded locking member 85 slides out of the pocket 88. Subsequently, the operating element 65 can be pushed out with the control piston 64. pulled so be moved down so that the position shown in FIG. 12 results. Thus, the opening 75 is above the two seals 76, 77. The reservoir pressure is shut off. The pressure from the spring-loaded brake cylinders 46, 47 can flow out via the connection as a pressure outlet 55, the bore 79, the bores 101, 102 to the outlet for vent 61. Subsequently, the trailer is braked by the spring brakes.

In the described embodiments, there is a venting possibility of the bore 79 via an annular space 122 formed between the Entsperrorgan 66 and the control piston 64. Preferably, however, this annular space 22 is closed in the direction of the control element 67 by a sleeve, not shown, or other cover, so that the venting takes place exclusively via the outlet as vent 61.

In the embodiment of Figs. 3-6, the pocket 88 is positioned somewhat differently than in Figs. 9-12. Referring to Figs. 3-6, the pocket 88 is followed by an axially directed slot 123, such that slides 63 and Locking member 85 are coupled together only in an axial direction. The locking member 85 may take the slider 63 upwards, but not down, see in particular Fig. 4. There, the locking member 85 is moved down from the pocket 88 and is located in the slot 123, which may be open at the bottom. In the embodiment of Figs. 9-12, no slot is provided adjacent the pocket 88. Accordingly, there are blocking member 85 and slide 63 coupled in both axial directions.

Claims

claims

1 . Park release valve (23) for a trailer with pneumatic brake system, and having the following features:

a) - a connection for supply pressure (56),

a connection for reservoir pressure (57),

an outlet for venting (61),

a connection as a pressure outlet (55),

b) a control piston (64) for opening and closing a connection from the reservoir pressure port (57) to the port as a pressure port (55) and opening and closing a port from the vent port (61) to the port as a pressure port (55);

c) the control piston (64) is axially movable by a control element (65) between a driving position and a parking position, wherein in the parking position, the connection from the vent outlet (61) for connection as a pressure outlet (55) opened and the connection from the connection for reservoir pressure (57) is blocked for connection as a pressure outlet (55),

d) the control piston (64) is loaded in the parking position and without pressure at the connection for supply pressure (56) by a slide (63) with an axially acting force in one direction (R) from the driving position to the parking position,

e) at pressure at the connection for supply pressure (56) acts on the slide (63) an axial force in a direction (G) from the parking position to the driving position of the control piston (64).

2. Park-release valve according to claim 1, characterized by a movable between a blocking position and a release position blocking member (85), wherein the control piston (64) and slide (63) are coupled together in the blocking position such that the slide (63) the Starting from the driving position, the control piston (64) can be taken to the parking position in direction (R).

3. Park-release valve according to claim 1 or 2, characterized by an unlocking device (66) for controlling the movement of the blocking member (85) between locking position and release position.

4. Park-release valve according to claim 3, characterized in that the Entsperrorgan (66) with a spring means (87) of the locking member (85) cooperates, wherein the spring means (87) the blocking member (85) in particular in the direction of the release position acted upon and the blocking member (85) can be acted upon by the Entsperrorgan (66) in the direction of the blocking position.

5. Park-release valve according to claim 3 or 4, characterized in that the control piston (64) is hollow and that the Entsperrorgan (66) in the manner of a piston in the interior of the control piston (64) is movable.

6. Park-release valve according to claim 5, characterized in that the blocking member (85) is movably mounted in a wall of the control piston (64) and has a sliding head for engagement with a sliding surface (99) of the Entsperrorgans (66), and the sliding surface (99) is oriented at an angle to the axial direction of the unlocking member (66).

7. Park-release valve according to claim 5 or 6, characterized in that the Entsperrorgan (66) is provided with a control element (67) which projects beyond the control element (65) of the control piston (64) also.

8. Park-release valve according to claim 5 or one of the further preceding claims, characterized in that the Entsperrorgan (66) by a spring means (95) is acted upon axially in the direction (R) on the parking position of the control piston (64).

9. Park-release valve according to claim 3 or one of the further preceding claims, characterized in that the Entsperrorgan (66) is coupled to the control piston (64), such that the Entsperrorgan (66) in at least an axial direction and relative to the control piston (64) only to the abutment of a stop (97, 98) is movable.

10. park-release valve according to claim 1 or one of the further preceding claims, characterized in that the slide (63) the control piston (64) partially in parking position includes, and that the slide (63) at a free end, which the Control piston (64) does not include in parking position, a radially outwardly directed stop, in particular a collar (71), for engagement with a shoulder (82) of a housing (62).

1 1. Park-release valve according to claim 1 or one of the further preceding claims, characterized in that the slide (63) is slidably mounted in the manner of a piston in a housing (62), that the slide (63) is hollow and the control piston (64) at least partially receives in it, and that the control piston (64) is hollow and at least partially absorbs a Entsperrorgan (66) in itself.

12. Park release valve according to claim 1 or one of the further preceding claims, characterized in that the slide (63) in a housing (62) is slidably held and at its periphery two seals (91, 92), between which a working space (93) is formed, and in that the housing (62) has an opening (94) inside the area of the working space (93) connected to the connection for supply pressure (56).

13. Park-release valve according to claim 1 or one of the further preceding claims, characterized in that the control piston (64) is at least partially held displaceably in a housing (62) and at its periphery has two seals (76, 77), between which a connecting space (78) is formed, that the housing (62) inside in the region of the connecting space (78) has an opening (74) connected to the connection for reservoir pressure (57) and an opening (75) with connection for connection as a pressure outlet (55), and that the control piston (64) with at least one of the seals (76, 77) via one of the openings (74, 75) is movable away, so that in a Travel position of the control piston (64), the openings (74, 75) via the connecting space (78) are interconnected, but not in a parking position of the control piston (64).

14. Park-release valve according to claim 1 or one of the further preceding claims, characterized by a valve (103) for blocking or passing the supply pressure to the slide (63), wherein the valve (103) is controllable in dependence on a control pressure and thus blocks or releases a connection to block or pass the supply pressure.

15. park-release valve according to claim 14, characterized in that the valve (103) has a first valve body (109) in a valve chamber (108) between the connection for supply pressure (56) and one in a working space (93 ) of the slide (63) opening (94) is provided, that the first valve body (109) is movable between an open position and a blocking position that the first valve body (109) is movable only in the open position, as long as supply pressure is applied, that first valve body (109) remains in its open position as long as reservoir pressure is applied, and that the first valve body (109) remains in the blocking position without reservoir pressure.

16. Park-release valve according to claim 15, characterized in that the first valve body (09) is loaded by a spring means (114) in the direction of the locking position.

17. Park-release valve according to claim 15 or 16, characterized in that a second valve body (1 18) between the first valve body (109) and a control input (104) is provided, wherein the first valve body (109) through the second Valve body (1 18) acted upon and is movable from the blocking position to the open position.

18. Park-release valve according to claim 17, characterized in that the second valve body (1 18) is arranged in a flying manner in its valve chamber (1 16), that is without being acted upon by spring means.

19. Park-release valve according to claim 17 or 18, characterized in that the valve space (108) the second valve body (1 18) opposite an outlet for venting (105), wherein the venting in particular in the open position of the first valve body (109 ) is closed.

20. Park-release valve according to claim 18 or 19, characterized in that the first valve body (109) in the blocking position seals a transition from the valve chamber (1 16) to the valve chamber (108).

21. Park-release valve according to claim 15 or one of the further preceding claims, characterized in that the first valve body (109) has a connecting channel (1 1 1) as an overflow, which can be acted upon in the open position with reservoir pressure.

22. Valve arrangement for a trailer, with a Park-release valve (23) according to one of the preceding claims and with a valve arrangement (37) as an emergency brake valve, wherein a connection as a pressure outlet (55) of the Park-release valve (23) a control input (38) of the valve assembly (37) is connected.

23. Valve arrangement according to claim 22, characterized in that the valve arrangement (37) has a connection (40) as a pressure outlet, a connection (39) for reservoir pressure (57) and a connection (41) for venting, and that depending on the switching position of the Connection (40) can be connected as a pressure outlet to the connection (39) for reservoir pressure or to the connection (41) for venting.

24. Pneumatic brake system with a valve arrangement according to claim 22 or 23 or with a park-release valve according to one or more of claims 1 to 21.

25. Trailer vehicle with a pneumatic brake system according to claim 24.