DE2725948A1 - PNEUMATIC BRAKE VALVE FOR VEHICLES - Google Patents

Description

my reference: 0330 Pt 27259Λ8

WABCO WESTINGHOUSE

2, Westinghouse Boulevard

93270 Sevran / France

Pneumatic brake valve for vehicles

The invention relates to a pneumatic brake valve with a pivot lever, with which a Vehicle or a unit consisting of this vehicle can be braked by road vehicles.

The brake valve under consideration has, in a manner known per se, a main valve and two auxiliary valves for separation or conversion as well as a control lever for the main valve

The main valve determines as a function

from the angular position of this lever, a throttable pressure level in a line of an emergency brake or a parking brake.

709881/0710

272594a

Each auxiliary valve for switching is - since it is an "all or nothing" type - of the Angular position of the lever dependent to supply an auxiliary line for the control or for the braking process with pressure medium

A brake valve of this type can be used in a wide variety of brake systems. For example, the Main line, the release chambers of the cylinder equipped with a spring, the unlocking chambers of the cylinder or one Control the control chamber of a control valve for the trailer. The auxiliary line can for its part use one of the aforementioned devices, if necessary. in connection with the main air line with compressed air, the connection of these two lines via a selector valve of the steering committee; but you can also apply the cylinder of the service brake via a selector valve of the circuit, The operation of this service brake is normally ensured by a further circuit.

The object of the invention is to improve these known brake valves in such a way that the space requirement is reduced, assembly is facilitated and manufacturing costs are reduced, with a multi-valued brake valve for controlling Hand or in general for mechanical control is realized.

The invention relates in particular to a pneumatic brake valve for vehicles or for a unit consisting of road vehicles. This valve consists of a housing in which a control lever is arranged. A main valve is also provided which is controlled by the compressed air in the main brake line as a function of the angular position dB of the lever. There are also two auxiliary valves for switching, which are controlled in the same way as a function of the position of the lever, in order to supply an auxiliary brake line with pressure medium or to vent it. ,. _{Λ ä Λ}

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According to the invention, the main valve and the two j the auxiliary valves controlled by a single cam element, wel + ones old is rotatably connected to the lever. This cam member is operated to switch each of the auxiliary valves trigger for a different angular position of the lever,

The brake valve according to the invention is considerably simplified in its construction and in the mode of operation. In fact, this can be done, for example, in that this single cam member is molded, for example, from plastic will; but there is also the possibility of surrounding a core made of metal with plastic, in order to also do this in this way to get the cam organ.

The main valve is advantageous in one in the middle of the housing lying bearing provided, while the auxiliary valves on both sides of this lying in the middle bearing in corresponding Camps are arranged. The axes of the main valve and the auxiliary valves are parallel to each other.

By this measure, the space requirement of the brake valve according to the invention is reduced quite considerably.

According to one embodiment of the brake valve according to the invention, the connecting lines of each auxiliary valve open out into that surface of the housing which is opposite the aforementioned auxiliary valve.

In this way, the space requirement of the brake valve is reduced to the extent that the outer ends of the connections are now of these lines come to lie in a free corner of the valve housing

After the horizontal cross-section of the housing has a generally square or rectangular shape, the two auxiliary valves are arranged along a diagonal of the square or rectangle at surface angles which are opposite to the housing. Λ Ü..ä al. 1 I Q 7 1 Q

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Each of these two auxiliary valves is duroh, for example Thrust for such angular positions of the lever actuated, which the two extreme positions are obvious

A counterbalance spring can be provided to assist a main spring which retracts the lever ensures in the rest position, this compensating spring cooperates with the single cam element

This balancing spring eliminates any shortcomings in the main spring, especially for comparatively small ones Pivot angle from the rest position of the lever (position: "Street") if this main spring is inadequately wound. This measure can prevent larger dimensions of the spring.

The switching valves preferably have two positions and three openings, one of these valves, for example the connection of the release chambers or the unlocking chambers with a compressed air source or their separation relative to This compressed air source ensures, while the other valve the connection of a reverse control chamber of the trailer brake with a compressed air source or with the output of the main valve ensures.

The control lever can advantageously be two telescopic Have parts, of which the first is attached to a button or to a control handle, while the second teleU head-shaped part is connected to the cam member. The two telescopic parts receive a spring which is mounted between two spring plates, one of which each spring plate can cooperate with either of the two shoulders provided on the two telescopic parts in such a way that that the first part of the lever can be returned axially in both directions to a neutral position

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You can also assign a protective cap to the control lever, which contains two flaps, one of which is slidably mounted on the other and of which at least the a flap is guided in the housing. One of these flaps shows an elongated column, while the other has an opening with the lever traversing the column and the opening simultaneously. The flaps formed with the slidable flaps Protective cap ensures that the interior of the brake valve is sealed against dust and other foreign bodies, whereby at the same time a large swivel range of the control lever is ensured. Each flap has the shape of a segment with a rotating surface and covers at least half the pivoting stroke of the lever · In all relative positions of the slidingly arranged Flaps, the elongated column is always covered by the other flap, which is almost completely covered by the lever sealed form is penetrated.

The bearings of the auxiliary valves are preferably identical it should be noted that the valves themselves are also identical, although they are suitable for different functions and are determined.

The invention is illustrated in more detail below with reference to the drawing. In this show in pure see matic way:

1 shows a schematic representation of a braking system for a multi-part road vehicle, which is equipped with the manually operated brake valve according to the invention is,

Fig. 2 is a perspective view of a further embodiment of the invention Brake valve,

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Fig. 3 is a plan view of the brake valve according to Fig. 2,

FIG. 4 shows a section along the line IV-IV in FIG. 3,

Fig. 5 is a section on an enlarged scale along ^ the line V-V in Fig. 3,

Fig. 6 is a view of the control lever, the protective cap and the cam member of the brake valve in partial section along the line VI-VI in Fig. 3.

The pneumatic brake system shown in Fig. 1 of the drawing is that of a motor vehicle to which « a trailer vehicle or a semi-trailer can be attached.

The brake system has the brake valve 1, which with a control lever 2, a main brake valve 3, a first auxiliary valve 4 for switching and a second aid valve 5 is equipped for switching. The lever 2 is a single cam element 2a is assigned, which ensures the control of the three valves via this lever 2. The auxiliary valve 4 is referred to as the "safety valve".

The main valve 3 is arranged in the main circuit, which is equipped with a spring brake cylinders 6 and a compressed air tank 7 contains. The control valve 3 can in throttled form compressed air in a supply line a as well control a vent line, which the aforementioned valve with the brake cylinders equipped with a spring thereby connects that the compressed air of the compressed air tank 7 is used.

709881/071 P _..__. - .2 _ = _

As is known, those equipped with a spring point Brake cylinder chambers with the possibility of reducing the pressure on; d. H. in other words that the brake cylinder trigger a braking process when the applied pressure is reduced. The valve 3 is via the cam profile 33 of the Cam member 2a of the lever 2 is mechanically controlled, as shown by the connection indicated by a dashed line in FIG. 1 with the reference letter χ.

The switching valve 4 is connected in an auxiliary circuit which contains a safety container 3. This security container 8 is acted upon with pressure medium, the pressure of this pressure medium being greater than that of the pressure vessel 7ο The valve 4 controls the pressure prevailing in line b, which this valve 4 with the equipped with the springs brake cylinders connects in such a way that the compressed air of the Safety compressed air container 8 is used. The valve 4 is controlled mechanically, as is the connection y in FIG. 1 the drawing shows. The control is based on the movement of the lever 2 by means of a cam element or a cam element the cam member 2a provided stop 38 in a manner as will be described in more detail below. the Lines a and b end in a selector valve 9 of the circuit by means of which the cylinders 6 of that compressed air line are supplied in which the higher pressure prevails. In normal operation, this is line b.

The valve 4 is in two positions Uberf and clock has three openings or connections as well as a return spring 37ο For reasons of safety, the valve opens in normal operation a direct connection between the safety container 8 and the cylinders 6 equipped with a spring the valve 4 establishes a connection between the cylinders 6 under certain operating conditions (emergency braking} hold or test) with the atmosphere via a vent which is provided in the brake valve.

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The switching valve 5 is in another auxiliary circuit, the one changeover control valve 11 for the brake of the trailer vehicle contains. This valve 5 controls that air pressure, which prevails in the line c, the opposite Connection of the input side of the valve 11 either with a line d connected to the line a or with a direct connection line e connects to the air tank 7.

The output side of the valve 11 is in turn connected to a coupling head 12 of the direct brake, which the pneumatic connection with the brake circuit of a trailer vehicle not shown in the drawing ensures.

The valve 5 is in two positions in the same way Transferable and has three connection openings | it is - as the connecting line ζ in Fig. 1 of the drawing shows - of the Cam element or mechanically controlled by the stop 38, which latter is provided on the cam member 2a. The control takes place depending on the position of the lever 2, a plunger being provided which is subjected to the action of a return spring 37 *.

In normal operation or while emergency braking or a holding process is being carried out, the valve connects lines c and d. I. E. in other words, that one Connection of the opposite side (minus) of the valve 11 to the brake circuit of the line a, which has a spring, is established will. In the "test" position, valve 5 disconnects the line d and connects lines c and e.

3 of the drawings shows a plan view of the brake valve according to the invention. This brake valve has a cuboid housing 20, in which a provided in the middle Bore 21 is arranged. This hole 21 takes that

709881/0710 -9 -

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Main valve 3 and two bores 22 and 23, which are provided in the corners of the housing 20 on both sides of the bore 21 and protect isolation valves 4 and 5. These bores 22, 23, the axes of which are parallel to that of the bore 21, are arranged symmetrically relative to the main valve 3 in such a way that a comparatively small amount of space is claimed and taken up will. Another bore 24 is provided in another corner of the housing for receiving a compensating spring, which is assigned to the auxiliary valve 4 and whose function will be explained in more detail below.

The connections 50 to 54, which operate the three valves 3 to 5 of the brake valve, are in the opposite ones two surfaces 26, 27 of the housing are provided. In this arrangement, the brake valve only takes an extremely small space to claim, since the necessary for drilling out the connections of the auxiliary valves 4 and 5 Space was in an unused area of the housing. In addition, the pipes can be connected to each other opposite sides of the brake valve are connected in such a way that in this way the connections are quite significant be simplified.

In Figures 2 and 3, a distinction is made between the bores 21 and 22, 23 »which for the main valve 3 and the auxiliary valves 4 are provided. The main valve is shown in detail in Fig. 5 of the drawing and has a spring with a certain Progressive! Opened with which connection 52 a throttled pressure can be controlled. The main valve 3 has in particular a pressure reducing valve 30 with two Valve closure bodies and a tappet with two telescopic Pistons 31, 32 and a cam 33, which is part of the cam element and is connected to the control lever 2.

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The axis of each of the switching auxiliary valves lies parallel to the axis of the main valve 3 and points in the same way a double valve closure member 34, 34 'with a rear holfeder 35, 35 "and a plunger 36, 36 'with a return spring 37, 37 * on · There are cam elements on the common cam element 2a or stops 38, 38 * are provided, the profile of the cams of these elements being designed so that the auxiliary valves 4 and 5 can be actuated by pushing or pushing.

A small bushing 39 with a Ausgleiohsfeder 40 is assigned to the switching valve 4, this small bushing 39 is arranged in the bore 24. This compensating spring 40 supports a main spring acting as a torsion spring 41, which the return of the control lever 2 to its rest position A ensures «For this purpose, the small bushing 39 - which is mounted movably in the axial direction in the bore 24 in this bore of the cam member 2a during a first Part of the stroke of the lever 2 is maintained, this partial stroke extending from position D to position B. This is done by means of an inclined surface 39a or a chamfer, which cooperates with part of the cam member 2a. At a certain position of the lever 2 between the Positions A and B, the small Buohse 39 rests against a stop 78 of the cam member 2a and brings up from then on the cam member 2a generates an additional torque, by means of which the action of the tappet 36 of the safety valve 4 can be compensated for on this cam member 2a.

A possible embodiment of the connection for the brake valves is nooh somewhat closer in the figures of the drawing shown. The pressurized air container 7 is over the opening 50 connected to the inlet chamber of the main valve, namely below the double closure member 30 of this valve.

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272594a

The compressed air tank 8 is at the inlet opening 51 of the safety valve 4 below the double closure valve member 34 of this valve connected. The output line a of the main valve leads into the opening 52, while the line d is formed by an inner line, for the sake of clarity in Fig. 5 of the drawing with a dashed Line drawing is shown. This inner line ends below the double closure member 34 * of the valve 5 · In the middle Part of the auxiliary valve 4, an opening 53 enables the connection of the connecting line b to the one equipped with a spring Brake cylinder.

The opening 54, which is symmetrical to the opening 53 or to the connection 53, allows the connection line to be connected c with the opposite input side of the control valve for the trailer to the brake valve.

In the lower part of the housing of the brake valve is in Advantageously, a ventilation opening 55 is provided in such a way that a connection is established via an adjustable mouthpiece 56 is made with a vent pipe. The openings or connections 50 to 54 are shown in Figures 1 to 3 of the drawing equally represented. It is clear that one of the isolation valves 4 or 5 can be omitted in the brake valve in such a way only a single function can be performed, namely the function of safety or the test control for the Trailer vehicle

As can be seen from Fig. 6 of the drawing, the control lever consists of two telescopically interconnected Share. The first part 60 is in the form of a tube and carries a button or handle for actuation while the second part 61 is designed as a rod to which the cam member 33, 38, 38 'is attached.

7098 8 1/0710 - 12 -

Between the two parts 60, 61 a spring 62 is mounted to at each outer end against the one and / or to support the other part of the two parts, so that an effect in both directions is possible in this way. For this purpose, two washers 63 »64 are provided for the spring, which serve as support surfaces and which are provided with a Shoulder 65 »67 of part 61 work together or else taken down by a shoulder 66 or 68 of part 60 will. In this way it is possible to move the part 60 into its upper position, which is thus over the washer 63 compresses the spring 62. In the positions A and C, the spring 62 is in the neutral state, wherein an extension 69 of the part 60 rests in a widened part of a guide slot 77 which is incorporated in a cover is · In the positions B and in the intermediate positions between B and C, the spring 62 is compressed by the washer 63. On the other hand, in position D, the operator presses the part 60 downwards in such a way that the projection 69 penetrates into a notch which extends the slot 77. The spring 62 is in this case by the lowering of the washer 64 compressed, the lever remaining locked in this way · It should therefore be noted that the same Spring 62 brings the tubular part 60 back out of the two extreme radial positions into the neutral one Position.

In FIG. 6 of the drawing, a protective cap 71 can be seen which contains two flaps 72, 73. The section the flap 72 shows an elongated section 74 of about 40 °, while the portion of the flap 73 has an opening 75 for the Passage of part 60 of the lever disclosed. The two sections are made of plastic with extremely good sliding properties designed in such a way that one flap is arched along the other flap in lateral sliding guides and length Can slide surfaces 76 of the housing, the latter also made of plastic. The flaps 72, 73 thus represent a

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good sealing of the interior of the housing against dust and others! Foreign bodies safe, but the control lever can be adjusted very far ^{at angle 1.} This angular stroke is absolutely necessary in view of the variety of operating modes of the brake valve

The auxiliary valve 5 can also without any Defect in a circuit diagram that differs from that of FIG. 1 a replication of the supply to the cylinders of the service brake of a motor vehicle, especially a bus to ensure.

The operation of the brake described above is as follows:

In normal operation, i.e. when driving normally, the Fahrf driver of the road vehicle the lever of the brake valve in position A "road" (Fig. 2). In this operating state the cam 33 is in its lower position in such a way that the piston 32 rests against the double locking member 30 can, whereby the vent opening 55 is separated from there, while the connection between the openings or Connections 50 and 52 is made. I. E. in other words, that the brake cylinder equipped with a spring are acted upon by compressed air via the compressed air tank 7.

It should be noted, however, that in the same position A of the tappet 36 of the safety valve 4 from the cam 38 is held in its lower position in such a way that the connection 53 is separated from the vent opening 55 and the connection with the connection 51 is made. In this way, the cylinder 6 equipped with a spring via the Compressed air tank 8 are supplied with compressed air.

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In the described embodiment, the print is in the compressed air tank 8 higher than that in the compressed air tank 7, so that the selector valve of the circuit in position A of the lever 2 a normal application of a spring equipped brake cylinder via line b and a security loading of the same cylinder via the line a causes if the circle 8, 4, b is disturbed.

If the vehicle driver wants to carry out a moderated emergency braking, he moves the lever of the brake valve in the position B. In this position, the cam 38 is released from the upper outer end of the plunger 36 of the safety valve 4. This is the connection between the connection openings 51 and 53 interrupted while the connection between the connection 53 and the vent opening 55 is established is, whereby the prevailing loading of the cylinder via line b is suppressed by from now on moderate ventilation is possible via the only line a.

The dosage of the emergency brake is thus dependent on the angular position of the lever between points B and C as well as the profile of the cam 33 realized, whereby the decrease of the pressure at the point 52 is determined. A maximum Emergency braking is obtained in position C after the brake cylinder 6, which is equipped with a spring, has been vented. The test valve 5 for the trailer has not yet been put into operation and it remains in his raised position. In this position, the connection between the connections 50 and 54 via the valve 3 and the line d established (Figures 1 and 5).

70988 1/07 1 Q " ¹⁵ .." _.

To convince yourself that the multipart Road vehicle is braked by the only mechanical brake of the motor vehicle »the driver pulls the lever 2 of the brake valve in position O. In this position, the cam 38 'assigned to the valve 5 rests against the tappet 36 · this valve on in such a way that the connection d-c is interrupted and the connection e-c is established. It goes from there shows that the input side (-) of the control valve for the trailer brake 11 directly from the compressed air tank 7 with Compressed air is applied so that, as a result, the brake of the trailer vehicle or the semi-trailer is released is effected. In this way, the vehicle driver can convince himself that his multi-part road vehicle is the only one and only remains locked by the brake cylinders 6 equipped with a spring, these brake cylinders 6 working to the maximum.

It is clear that further modifications of the brake valve described above are possible and conceivable without this goes beyond the scope of the invention. For example, the auxiliary valves 4 and 5 - their role of switching has already been explained above - be used in a circuit which differs from that of FIG. This would be the case in particular with a bus in which the cylinders of the service brake are being applied wanted to multiply; but this would also be possible in the case of a truck in which the Cylinder of the safety brake with locking is required. It is clear that the cross-section of the channels, which in the brake valve are provided, is proportional to the volume of air used for the supply. I. E. in other words that this cross section for supplying the control valve 11 or the release chambers of the locking cylinder is much smaller than the one to ensure the supply of the chambers of the brake release cylinder equipped with a spring.

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One of the auxiliary valves can by means of the cam element by a pulling force, while the other auxiliary valve is put into operation by a pushing or pushing force. If the Both valves are actuated by a pressure or push force or impact force, it is obviously by no means indispensable that this actuation takes place for those positions of the lever, which are close to its extreme positions. However, this type of operation is very interesting in that on the one hand, it allows to extinguish the security of the supply of the brake cylinders equipped with a spring before the emergency brake is switched on, and on the other hand there is the possibility of the brake test of the towing vehicle alone after the braking process.

It is clear that the above explanations relating to a pneumatic brake valve can be easily understood Can also be transferred to a hydraulically operated brake valve, provided that the brake valve is in principle directly from the manually operated lever is controlled; the brake valve can of course also be controlled remotely, for example via a cable pull or a suitable pressure medium.

The protective cap assigned to the control lever 2 and consisting of the two flaps which slide on one another has the advantage of taking up the space of the connecting organ reduce to a minimum which latter cap is formed by this protective device and is suitable and intended to prevent the penetration to prevent foreign bodies of all kinds from entering the interior of the brake valve. Such, made of plastic, In this way, semi-rigid protective cap is easier to manufacture and also more durable in operation than a conventional one Bellows made of an elastomeric material; the protective cap can also be used for all devices, in which a pivotable lever occurs in a plane, it being necessary to attach the lever to the housing via a to articulate an almost completely tight joint in order to hermetically seal this articulated organ from the outside environment 703881/07 TQ

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£ ~ 7725948

complete. Such a protective cap - which is a further subject of the invention - can even cover pivot angles that are greater than 90 ° if the section covered by the flaps is greater than 180 °, _etc.

- patent claims -

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Claims (6)

PATENT Pneumatic brake valve for vehicles or for multi-part road vehicles, with a housing, a control lever and a main brake valve arranged in this housing, which depends on the angular position of the lever is actuated by the compressed air in a main brake circuit, and two switching auxiliary valves, which are also dependent are controlled by the position of the lever in such a way that an auxiliary brake circuit is acted upon with pressure medium or is vented, characterized in that the main valve and the two Auxiliary valves controlled by one and the same cam member which is connected to the lever, and ■ that this cam member is arranged so that it switching of each auxiliary valve in an angular position deviating from the lever triggers. 2. Valve according to claim 1, wherein the main valve in one is arranged in the middle of the housing lying bearing, while the auxiliary valves are in bearings on both sides of the central bearing are provided, and the axes of the main valves and the auxiliary valves are parallel run towards each other, characterized in that the external connecting lines • ines each auxiliary valve open into that surface of the housing which is opposite the auxiliary valve, and that the two auxiliary valves are moved by the cam member into that angular position of the lever by impact forces, which are close to the two extreme positions of the same. - A 2 .70.9-8414.7-0-7 1 (1 ORIGINAL INSPECTED 2 7? 5 9 A 8 3. Valve according to claim 1 or 2, characterized in that a compensating spring is provided, ei c h η e t, to support the action of a main spring which brings the lever back into its rest position, and that this compensating spring cooperates with the single cam member · 4. Valve according to claim 3, characterized in that the compensating spring is in a bearing is arranged in a wedge-shaped part of the housing, and that this wedge-shaped part in the direction of movement of the lever is opposite this wedge-shaped part, where the corresponding auxiliary valve is located 5. Valve according to claim 1 to 4, wherein the control lever comprises two telescopic parts, the first of which Part on the control button or on the control handle and the second part is attached to the cam member, characterized that the lever from two radial extreme positions starting in the radial direction in a central position is retrievable, and that the two parts of the lever include a single spring which is between two as Supporting washers are arranged, each of which cooperates with two shoulders, the are provided on the two telescopic parts. 6. Valve according to one of claims 1 to 5, characterized in that the control lever is a Protective cap is assigned with two flaps, the latter of which are slidably mounted on top of each other and of which one Each has a rotating surface-shaped segment that one flap has an elongated slot and the other flap one Has opening that the lever passes through this slot and this opening at the same time, and that one of the flaps is guided in the housing 70 9 ^ 1/0710