DE202016102060U1 - Trailer control valve - Google Patents

Abstract

Trailer control valve (17) with a working according to the spring-loaded principle adjustment actuator (90).

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a trailer control valve whose basic function is the conversion of a hydraulic brake pressure, which can be specified by a brake pedal to a towing vehicle by a driver, in a pneumatic brake control pressure, which is to be fed via a coupling head brake trailer. For an optional additional function of the controlled by the trailer control valve brake control pressure should be influenced beyond the dependence on the hydraulic brake pressure addition. Furthermore, the invention relates to a brake system and a towing vehicle with such a trailer control valve.

STATE OF THE ART

The publication DE 39 18 226 C2 discloses a trailer control valve having an intake valve and an exhaust valve. A double valve body is pressed against a valve seat formed by the housing of the trailer control valve in the closed position of the intake valve via a spring. Through a displacement of a weighing piston, the double valve body can be moved away from the valve seat, thus forming an inlet position of the inlet valve, in which the inlet valve connects a connection for a supply pressure connected to a reservoir with a connected to a coupling head brake port for the brake control pressure. If, on the other hand, in the closed position of the double valve body and the inlet valve, the weighing piston is moved away from the double valve body, the outlet valve formed between the front and contact surfaces of the weighing piston and the double valve body is opened. In this outlet position of the exhaust valve, the exhaust valve connects a vent port to the brake control pressure port. The weighing piston is acted upon by a prestressed spring away from the double valve body. For a movement of the weighing piston in the direction of the double valve body for closing the exhaust valve and for subsequently opening the inlet valve depending on the extent of the movement, a relay piston exerts an actuating force against the spring acting on the weighing piston on the weighing piston. The relay piston has two rectified control surfaces. Here, a first control surface is acted upon by a hydraulic, predetermined by a brake pedal by the user brake pressure. On the other hand, the second control surface of the relay piston is pneumatically acted upon by a valve whose operating position is dependent on the position of the brake pedal. Upon actuation of the brake pedal, the second control surface of the relay piston is subjected to the pneumatic supply pressure, which results in the closure of the exhaust valve and the opening of the intake valve. Thus, compressed air passes from the reservoir via the open inlet valve to the clutch head brake, so that due to the pneumatic loading of the second control surface relatively quickly a brake control pressure for the trailer can be brought about. The controlled brake control pressure also acts on the weighing piston in a weighing chamber. In this way, a final position can be brought about when a predetermined pressure is present at the port connected to the coupling head brake and maintained, in which case in the final position, both the inlet valve and the outlet valve is closed. Temporally superimposed with this pneumatic actuation of the trailer control valve and the hydraulic pressure generated by the actuation of the brake pedal acts on the first control surface. Without the pneumatic admission of the second control surface would be here only an entry (ie the modulation of a pneumatic brake control pressure for the clutch head brake by the trailer control valve) at a hydraulic pressure of 5.5 bar. Elimination of this possibly delayed entry can be accomplished by providing a "lead" by pneumatic actuation of the first control surface as explained.

DE 34 12 345 A1 suggests (in a basically the embodiment according to DE 39 18 226 C2 corresponding embodiment) that the pressure with which the second control surface is pneumatically actuated, is controlled by a solenoid valve. If the actuation of the hydraulic brake circuit via the brake pedal only leads to a sufficient increase in the hydraulic pressure after a certain application path of the hydraulic brakes, the actuation of the brake pedal can be sensed directly via an electrical switch. Sensing this switch, the operation of the brake pedal, the solenoid valve can be switched to the ventilation position, which pneumatically an advance is brought about before the time delay, the construction of the hydraulic brake pressure and its effect is brought about on the trailer control valve. Here, the degree of pneumatically induced overfeed can be determined depending on the actuation of the brake pedal, for which the operation of the switch takes place. For a further embodiment, the two control surfaces are each assigned to a relay piston part. In this case, the two relay piston parts are arranged directly adjacent to each other in mechanical series connection to the weighing piston, wherein preferably the further removed from the weighing piston relay piston part has different sized effective surfaces and one of the two active surfaces with the hydraulic control pressure is applied and the other effective surface of this relay piston part is acted upon by the pneumatic control pressure.

EP 0 832 803 A1 discloses a dual-circuit hydraulic brake system of a towing vehicle. Here, the trailer control valve has two hydraulic control ports, with the hydraulic actuation of a pneumatic brake control pressure at a port which is connected to the coupling head brake, can be generated. The trailer control valve has an additional pneumatic control port. A control pressure generated at this control port passes into a weighing chamber, where it acts on the weighing piston in the direction of the opening of the inlet valve. The control port is acted upon by a ventilation valve, which is without the operation of a parking brake lever in its vent position, which takes place via the pneumatic control terminal of the trailer control valve no influence on the operating position of the trailer control valve and without applied hydraulic brake pressure, the exhaust valve assumes its outlet position, so that no brake control pressure is generated. By transferring the parking brake lever in its actuated position, the ventilation valve is transferred to its ventilation position, which results in the pressurization of the weighing chamber and the transfer of the exhaust valve in the closed position and the intake valve to the open position, so that a brake control pressure is generated. If in this case only a reduced or throttled control pressure is supplied to the weighing chamber, intermediate positions of the trailer control valve can also be brought about, for which a reduced, graduated brake control pressure can thus be supplied to the coupling head brake. On the operation of the parking brake lever so that the braking force of the trailer can be specified independently of an operation of the brake pedal. EP 0 832 803 A1 suggests alternatively to the mechanical coupling of the valve with the parking brake lever to switch the air valve depending on or independently of the operation of the parking brake of the towing vehicle or to control in any intermediate position.

DE 10 2008 048 207 B4 discloses an electronically controlled pneumatic valve device, via which the pressurization of a pneumatic inverted control input of a trailer control valve can be controlled such that different functions such as a stretch braking function, an auxiliary brake function and / or a test function can be realized with little effort. Here, a stretch braking function is used to spend a motor vehicle train, which is formed with a towing vehicle and at least one trailer in a stretched state. The anti-jackknifing function is brought about by operating the service brake of a trailer more than the service brake of the towing vehicle, which in the simplest case takes place solely by operating the service brake of the trailer. An auxiliary brake function is intended to enable the driver to set the braking force of the trailer gradually and, under certain circumstances, be sensitive as well. Finally, in a test function, the braking device of the trailer is released while the parking brake of the towing vehicle is actuated. The aim of the test function is to check whether it is possible to hold the motor vehicle train solely by means of the parking brake of the towing vehicle. Proposed is a valve means via which the pressure at the control port of the trailer control valve via the combination of an electronically controlled 2/2-way valve is controlled with an electronically controlled 3/2-way valve. The pressure exerted by the 3/2-way valve and 2/2-way valve for the control port of the trailer control valve can selectively via a 2/2-way valve to a control port of a relay valve 20 supplied, which controls the pressurization of spring chambers of combination brake cylinders.

EP 2 165 901 B1 relates to a braking device for a hydraulically braked tractor with a pneumatically braked trailer, the towing vehicle is designed in particular as a tractor. A sensor detects the operation of a brake pedal. The signal of this sensor is supplied to an electronically controlled pressure control module, which generates a brake control pressure according to the electrical signal of the sensor, which brake is supplied to the coupling head. This loading path is also referred to as an "electro-pneumatic loading path". Depending on the control algorithm, the conversion of the electrical signal in different brake pressures can be done, for example. With specification of an overrun by the control electronics, generation and elimination of any non-linearities or consideration of operating parameters, change or gain of the brake control pressure u. Ä. In an additional "hydraulic-pneumatic Beaufschlagungspfad" a trailer control valve can be actuated cumulatively via a hydraulic, predetermined by the brake pedal brake pressure and a parking brake lever of the trailer control valve. The pressure delivered by the trailer control valve is supplied to a pneumatic control port of the pressure control module in the hydraulic-pneumatic admission path. The pressure control module has a switching device, via which is specified whether the control of the brake control pressure at the coupling head brake on the electric pneumatic admission path or the hydraulic-pneumatic admission path takes place. For example, in a normal operation, the electro-pneumatic admission path can be used, while in an emergency operation in a kind of fallback level, for example in case of a collapse of the electrical power supply, the hydraulic-pneumatic admission path can be used. It is also entirely possible, however, that only one application path is used by means of the changeover device in different braking processes or during different phases of the same braking process, and subsequently another application path. For example, initially due to the inertia of the hydraulic Beaufschlagungspfads the electro-pneumatic Beaufschlagungspfad be used, while after a period of actuation of the brake pedal by the switching device, the change to the hydraulic-pneumatic Beaufschlagungspfad is brought about. It is also possible that the pressure control valve, an actuation signal of the hand brake valve is supplied. The actuation signal may be a pneumatic or hydraulic output pressure which is switched by the manual brake valve. It is also possible that the actuating signal is an electrical signal which is generated in accordance with the operation of the hand brake valve. A particularly simple embodiment of the switching device is formed with a connected to the reservoir and the supply connection of the trailer control valve upstream ventilation valve which is de-energized, so even in case of failure of the electrical power supply, in the ventilation position and can be transferred with energization in its venting position , In the presence of electrical power supply and control of the 3/2-way valve in the venting position of the hydraulic-pneumatic Beaufschlagungspfad is disabled for lack of pressure supply. In addition to the explained mechanical integration of a parking brake lever in the trailer control valve suggests EP 2 165 901 B1 also vorzuordnen the coupling head brake a shuttle valve, whose one input is connected to the pressure control module, while the other input is connected to a pneumatic parking brake valve.

EP 2 269 880 A1 describes that in braking triggered by the driver with a hand or foot brake, a braking of the towing vehicle via the service brake. In this case, the trailer receives a signal to operate the brake system. It is problematic, for example, if the driver only brings a power control lever from the "forward drive" position to the "neutral" position, moves off the gas pedal or pulls a joystick backwards. In such delays caused in particular by a drag torque of the drive train, the trailer gets no signal to actuate the brake system. Accordingly, no braking effect is generated on the trailer, so that the trailer can accumulate. The delays caused by the drag torque can also be so strong that the wheels of the towing vehicle come to block on gravel. If the trailer runs too hard on the towing vehicle, it may cause the overall combination to buckle and dangerous situations on the road. Finally, the emergence of the trailer leads to an additional burden on the transmission and the engine with a consequent increased wear and in the worst case damage. The document proposes to detect in a driving state with unoperated service brake when the trailer runs on the towing vehicle. Upon reaching or exceeding a predetermined thrust effect of the trailer on the towing vehicle, the brake system of the trailer is automatically actuated despite unconfirmed service brake of the towing vehicle on the modulation of a brake control pressure to produce a braking effect of the trailer, which preferably corresponds to the braking effect of the tractor due to the drag torque. For example, the thrust of the trailer from the difference or the quotient of the actual engine speed of the towing vehicle and a predetermined target engine speed can be determined. Also possible is the determination of a measure of the thrust effect of the trailer from the difference or a quotient of pressure signals of a hydrostatic drive of the towing vehicle.

EP 2 305 524 A1 is devoted to the problem that in a pneumatic loading of the trailer control valve in addition to the hydraulic actuation of the trailer control valve caused by the reservoir pressure in the trailer control valve effect can not adequately account for different operating situations. EP 2 305 524 A1 proposes against this background that the pneumatic control pressure of the trailer control valve is controlled or regulated depending on driving conditions. In this case, the pneumatic control pressure in terms of its duration, the time course and / or the amount can be controlled or regulated. For example, in consideration of a comparison of the hydraulic braking pressure of the towing vehicle and the pneumatic brake control pressure for the trailer controlled by the trailer control valve, a comparison of the hydraulically generated braking force of the towing vehicle and the pneumatically generated braking force of the trailer, the controller may include a load of the towing vehicle or trailer Information of an ABS or EBS unit, information of a navigation system, a coupling force or a coupling path between towing vehicle and trailer, the actuation course of the actuation of the brake actuator and / or a speed or acceleration signal. It is also possible that without the operation of the brake pedal, a pneumatic brake control pressure is controlled or regulated, which is dependent on an effective drag torque of the towing vehicle.

OBJECT OF THE INVENTION

The invention has for its object to propose a trailer control valve, a brake system and a towing vehicle, in which or which an adjustment of a brake control pressure is brought about with not known from the prior art measures.

SOLUTION

The object of the invention is achieved with the features of the independent claims. Further preferred embodiments according to the invention can be found in the dependent claims.

DESCRIPTION OF THE INVENTION

• – eine Erzeugung eines schnellen "Einsprungs" oder eines schnellen Ansprechens der pneumatischen Bremsanlage des Anhängers,
• – das Beseitigen von Beeinträchtigungen des ausgesteuerten Bremssteuerdrucks infolge von Reibung in dem Anhängersteuerventil,
• – das vorzeitige Zurücklegen eines Betätigungswegs zum Anlegen von Bremsbacken (s. a. DE 34 12 345 A1 ),
• – eine Beeinflussung der Charakteristik, insbesondere einer etwaigen Hysterese, des Anhängersteuerventils hinsichtlich des ausgesteuerten Bremssteuerdrucks in Abhängigkeit von dem hydraulischen Bremsdruck des Zugfahrzeugs,
• – eine Herbeiführung einer temporären Erhöhung des Bremssteuerdrucks,
• – die Erzeugung eines Bremssteuerdrucks zur Bereitstellung einer Feststellbremswirkung (s. a. EP 0 832 803 A1 ),
• – die Bereitstellung oder die Beeinflussung einer Streckbremsfunktion, einer Hilfsbremsfunktion und/oder einer Prüffunktion (s. a. DE 10 2008 048 207 B4 ) und/oder
• – eine Erzeugung eines Bremssteuerdrucks, welches ein Schleppmoment des Antriebsstrangs des Zugfahrzeugs in einem Schubbetrieb berücksichtigt (s. a. EP 2 269 880 A1 )

verstanden. The invention relates to a trailer control valve which is intended for use in a hydraulically braked towing vehicle to produce, taking into account the hydraulic brake pressure, a pneumatic brake control pressure for a pneumatically braked appendages. According to the invention, an adaptation actuator is used in the trailer control valve with which, independently of or in addition to influencing the brake control pressure for the trailer by the hydraulic brake pressure adjustment of the brake control pressure is possible. In this case, in the context of the invention under an "adaptation" of the brake control pressure in particular

• A generation of a quick "entry" or a quick response of the pneumatic brake system of the trailer,
• The elimination of impairments of the controlled brake control pressure due to friction in the trailer control valve,
• - the premature return of an actuating path for applying brake shoes (see also DE 34 12 345 A1 )
• An influence on the characteristic, in particular a possible hysteresis, of the trailer control valve with regard to the controlled brake control pressure as a function of the hydraulic brake pressure of the towing vehicle,
• A cause of a temporary increase in the brake control pressure,
• - The generation of a brake control pressure to provide a parking brake effect (see also EP 0 832 803 A1 )
• - The provision or influence of a draft braking function, an auxiliary brake function and / or a test function (see also DE 10 2008 048 207 B4 ) and or
• - A generation of a brake control pressure, which takes into account a drag torque of the drive train of the tractor in a coasting operation (see also EP 2 269 880 A1 )

Understood.

According to the above cited prior art, a lead-in actuator for generating an overfeed adjustment is based on generating a force from a pneumatic control pressure. With this pneumatically generated force, the inlet valve is then opened, whereby compressed air can pass from a supply pressure port to a brake control pressure port, thereby generating or increasing the brake control pressure to effect the overfeed. Here, the pneumatic control pressure acts on a control surface which acts in the opening direction of the intake valve and is mechanically coupled to a valve body of the intake valve. Power source for the generation of the opening of the inlet valve is here the pneumatic pressure.

This concept for the formation of the adjustment actuator leaves the trailer control valve according to the invention, in that this is used according to the "spring-loaded principle" working adjustment actuator. In the context of the invention, a "spring-loaded principle" is understood to mean a principle in which a prestressed spring generates a force by means of which the adjustment actuator and in particular the inlet valve is actuated in the opening direction, whereby this force and the prestress of the spring are reduced or can be eliminated by a pneumatic control pressure. Thus, in the inventive use of the "spring-loaded principle" as the energy source for the opening of the inlet valve not the pneumatic pressure is used, but the energy stored in a spring due to a bias. It is thus possible that without concern of said pneumatic control pressure, the force of the spring acts in the adjustment actuator for bringing about the opening position of the inlet valve, while this force is mitigated or eliminated with applied control pressure. In this case, according to the invention, it may also be possible that, as a result of the action of the spring, a brake control pressure is controlled, which is independent of fluctuations in the control pressure.

(Such a "spring storage principle" is known per se for compressed air systems exclusively for spring-loaded parking brakes, in which to secure a parking brake function regardless of the pressure in a compressed air system, the parking brake effect is brought about by means of a prestressed spring, while for releasing the parking brake the pneumatic The pneumatic loading of the spring-loaded brake chamber with the release pressure leads to a release force, which is oriented counter to the force of the spring and thus reduces or eliminates the parking brake force. Principle for the first time on a trailer control valve.)

In a further embodiment of the invention, the trailer control valve has a relay piston. With the relay piston an inlet valve and / or an outlet valve is formed, which may also be a combined inlet / outlet valve. The trailer control valve also has a hydraulic actuator. This hydraulic actuator generates a hydraulic actuation force when acted upon by a hydraulic brake pressure, which is predetermined in particular by the driver via a pedal. This hydraulic actuating force acts to generate a brake control pressure for the trailer in the closing direction of the exhaust valve and / or in the opening direction of the intake valve on the relay piston (which can be done directly or with the interposition of other components). By means of the hydraulic actuating device, a dependence of the controlled brake control pressure on the hydraulic brake pressure can first be brought about. Alternatively or additionally, the modulated brake control pressure can be influenced via the adjustment actuator. The adjustment actuator has an adjustment spring that generates an adjustment force. The adjustment force acts to produce an adjustment in the closing direction of the exhaust valve and / or in the opening direction of the intake valve to the relay piston. So that the adjustment force of the adjustment spring does not act permanently, the adjustment actuator further comprises a release device. In a first operating position, in which no adaptation is to be brought about, the release device eliminates or reduces the effect of the adjustment spring on the relay piston. On the other hand, the action of the adjustment spring on the relay piston is at least partially released by the release device in a second operating position, in which an adaptation is brought about, so that the adjustment force at least partially in the closing direction of the exhaust valve and / or in the opening direction of the inlet valve can work. In other words, with the release device of the adjustment actuator is actuated, by means of which, depending on the desired operating position, the effect of the adjustment spring fully comes into effect or only partially or not at all.

• – als lösbare Verrastung oder Verriegelung, welche in der ersten Betriebsstellung die Anpassungs-Feder blockiert, ausgebildet ist oder
• – als entgegengesetzt zu der Anpassungs-Feder wirkende elektromagnetische Einrichtung ausgebildet ist, mittels welcher je nach Bestromung eine der Anpassungs-Kraft entgegenwirkenden Kraft erzeugt werden kann,

For the technical design of the release device there are many possibilities covered by the invention. While in principle it is also possible that the release device eg.

• - As a releasable locking or locking, which blocks the adjustment spring in the first operating position, is formed or
• - Is designed as opposed to the adjustment spring acting electromagnetic device by means of which depending on the energization of the adjustment force counteracting force can be generated,

is designed for a particular proposal of the invention, the release device electropneumatic. In this case, the release device has a solenoid valve which generates a release control pressure. In addition, a release piston is present. The release piston has a pneumatic release control surface on which the release control pressure generated by the solenoid valve acts. The release piston also has a stop surface. This stop surface is acted upon in the first operating position of the adjustment spring, so that at least a part of the adjustment force on the stop surface and thus on the release piston is supported, so this part of the adjustment force but can not act on the relay piston. By contrast, the application of the release control surface to the release control pressure in the second operating position results in the stop surface and thus the release piston not being acted upon (or reduced only in relation to the first operating position) by the adaptation force of the adaptation spring is with what this adjustment force can act on the relay piston. Such an electropneumatic release device uses as an energy source the compressed air present directly in the compressed air system of the towing vehicle. A control of the release device via a solenoid valve can also be done in a particularly simple manner by an electronic control device, the control options, in particular the operating conditions for which a change from the first operating position to the second operating position (and vice versa) is brought about, and the type and / or the extent of the necessary adjustments of the brake control pressure are manifold. The control of the solenoid valve of the release device can take place via a separately provided for this function control unit. It is also possible that the control is carried out by a control unit also used for other purposes, for example. An ABS or EBS control unit.

In a further embodiment of the invention, the adjustment spring is supported on an actuating body. The actuating body in this case forms a counter-abutment surface. The counter-abutment surface of the actuating body is in the first operating position due to the bias of the adjustment spring on the stop surface of the release piston, whereby the adjustment force of the adjustment spring does not fully affect the relay piston, but at least partially over the Actuator and the contact between the abutment surface and abutment surface is supported on the release piston. By contrast, in the second operating position, the actuating body is arranged at a distance from the stop surface of the release piston, so that no partial absorption of the adjustment force is effected by the release piston, but rather the full adjustment force of the adjustment spring can act on the relay piston. For an integration of the actuating body in the power flow to the relay piston there are many possibilities. In particular, the actuating body is supported directly on the relay piston.

The possibilities for the design of the force relationships on the release piston are diverse, wherein the force ratios can be influenced in particular by a pneumatic actuation of control surfaces and / or springs. For a preferred embodiment of the invention, the release piston on the release control surface in a first direction with the release control pressure can be acted upon. For this embodiment, the release piston has a further control surface, which is acted upon in a direction opposite to the first direction oriented second direction with a pneumatic pressure. In particular, this pressure is the reservoir pressure or a parking brake control pressure for providing a parking brake function. In the latter case, the release piston is not used exclusively the explained adaptation. In addition, by applying the further control surface and the release piston can be used in a multifunctional manner for ensuring a parking brake function.

While in principle it is possible that the inlet valve and the outlet valve are formed separately from each other, in particular with separate relay pistons or valve bodies, but which can be coupled together by a transmission mechanism, the invention proposes in a further embodiment that the inlet valve and the outlet valve as a combined inlet - / outlet valve are formed. The inlet / outlet valve has an annular first valve seat, an annular second valve seat, and a common valve body. Here, the first valve seat and the second valve seat extend coaxially with one another and the first valve seat and the second valve seat are arranged radially concentrically one inside the other. In a blocking position of the inlet / outlet valve, which may also be a "weighing position" or a "closing position", the valve body is pressed against both valve seats with a seal. This has the consequence that the connection for the brake control pressure no compressed air can be supplied and no venting of the connection for the brake control pressure. In addition, the inlet / outlet valve has an inlet position. In the inlet position, the first valve seat bears against the valve body, while the second valve seat is arranged at a distance from the valve body. Thus, an inlet cross section is formed between the valve body and the second valve seat. The inlet cross section connects a reservoir pressure port to a brake control pressure port, whereby compressed air can be supplied to the brake control pressure port, and pressure increase of the brake control pressure can be effected. Finally, the inlet / outlet valve has an outlet position. In the outlet position, the second valve seat bears against the valve body, while the first valve seat is arranged at a distance from the valve body. In this case, an outlet cross-section is formed between the valve body and the first valve seat. The outlet cross-section connects a port for venting to the brake control pressure port, whereby a reduction in brake control pressure can be achieved. Such an embodiment with an intake / exhaust valve has been found to be reliable in function and compact in structure.

In principle, it is possible that a valve seat is formed by the housing, whereby it is not movable (see the prior art mentioned above). For a particular proposal of the invention, the first valve seat, the second valve seat and the valve body are movable relative to the housing. While for a fixed valve seat, a change in the valve position is exclusively possible by acting on the other two, not fixed to the housing components can with movable arrangement of the first valve seat, the second valve seat and the valve body influencing the valve position of the inlet / outlet valve with extended possibilities , namely, with the change in the force ratios at the first valve seat, the second valve seat and / or the valve body, brought about.

In principle, it is possible for the trailer control valve to be responsible exclusively for ensuring the characteristic dependent on the hydraulic brake pressure as well as the previously explained adaptation, in particular an overfeed. An extension of the possibilities arises, if in the Trailer control valve, a valve seat is formed by a relative to a housing slidable parking brake body. This then has a parking brake control surface. The parking brake control surface may be applied with a parking brake control pressure to activate or deactivate a parking brake function. Again, the operation of the intake valve for generating a brake control pressure, which is to bring about a parking brake effect, with increase of the parking brake control pressure is possible. But also possible is an "inverted function", in which for the parking brake function and a spring-loaded principle is used in the trailer control valve.

It is possible that a valve seat is formed directly from the relay piston.

An additional influence on the characteristics of the trailer control valve and / or the balance of power on the relay piston can be made when a reinforcing piston is slidably mounted relative to the relay piston. The boost piston has a boost control surface that is pressurized with the brake control pressure port. Opposite to the effect of the pressure on the gain control surface, the boost piston is pressed against a counter-abutment surface of the relay piston via a preloaded spring having a stop surface. Depending on the pressure on the gain control surface can thus be a one-sided coupling between the relay piston and the boost piston or dissolved state of the stop surface of the boost piston of the counter-abutment surface of the relay piston, the one-sided coupling between boost piston and relay piston can be eliminated. Here, a kind of driver can be formed between the relay piston and the intensifier piston, which provides a unidirectional coupling between the relay piston and the intensifier piston. For example, the relay piston (or the boost piston) may be formed with a step on which the boost piston (or relay piston) abuts. In this case, between the shoulder of the relay piston (or the boost piston) and the boost piston (or the relay piston), the contact pressure between the stop surface and the counter-abutment surface is generated. If, on the other hand, the contact between the abutment surface and the abutment abutment surface is removed for a sufficiently large pressure on the amplification control surface, the preloaded spring no longer influences the relationships of forces at the relay piston.

There are many possibilities for supporting the preloaded spring acting on the intensifier piston. For a particular proposal of the invention, this spring is supported on the side facing away from the reinforcing piston on the actuating body, on which also the adjustment spring is supported.

As previously mentioned, a parking brake function may also be incorporated in the trailer control valve. It is possible here that the trailer control valve has a solenoid valve, via which a (or the aforementioned) parking brake control pressure is controllable. Alternatively or cumulatively, a solenoid valve may be present, via which one or the release control pressure can be controlled. Here, the two solenoid valves may be formed separately or be provided by a solenoid valve unit. It is possible that such a solenoid valve is integrated in a housing of the trailer control valve or attached or flanged to a housing of the trailer control valve. It is also possible that the parking brake control pressure is controlled via an external valve.

For a further inventive proposal, the bias of the adjustment spring is adjustable in the trailer control valve. It is possible that by adjusting the bias of the adjustment spring manufacturing inaccuracies can be taken into account. Preferably, however, can be made to influence the characteristic of the trailer control valve by modifying the adjustment force on the adjustment of the bias of the adjustment spring targeted. For example, can be changed by adjusting the bias of the adjustment spring a lead of the trailer control valve. It is also possible that via the adjustment of the bias of the adjustment spring adjustment of the trailer control valve to different installation environments, release control pressures, hydraulic brake pressures or hydraulic brake systems, desired characteristics and / or pneumatic trailer brake systems.

Advantageous developments of the invention will become apparent from the claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the description are merely exemplary and can take effect alternatively or cumulatively, without the advantages having to be achieved by embodiments according to the invention. Without altering the subject matter of the attached claims, the following applies with respect to the disclosure content of the original application documents and the utility model: Further features can be found in the drawings - in particular the geometries shown and the relative dimensions of several components relative to one another and their relative arrangement and operative connection. The Combination of features of different embodiments of the invention or features of different protection claims is also possible deviating from the chosen relationships of the protection claims and is hereby stimulated. This also applies to those features which are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different protection claims. Likewise, features listed in the claims for further embodiments of the invention can be omitted.

The features mentioned in the claims and the description are to be understood in terms of their number that exactly this number or a greater number than the said number is present, without requiring an explicit use of the adverb "at least". For example, when talking about an element, it should be understood that there is exactly one element, two elements or more elements. These features may be supplemented by other features or be the only characteristics that make up the product in question.

The reference numerals contained in the claims do not represent a limitation on the scope of the protected by the claims objects. They only serve the purpose of making the protection claims easier to understand.

BRIEF DESCRIPTION OF THE FIGURES

In the following the invention will be further explained and described with reference to preferred embodiments shown in the figures.

1 and 2 show highly schematized towing vehicles with different braking systems.

3 and 4 show in longitudinal sections different embodiments of a trailer control valve.

5 to 9 show in a schematic longitudinal section a trailer control valve in different operating positions.

10 shows a schematic longitudinal section of another embodiment of a trailer control valve.

DESCRIPTION OF THE FIGURES

1 shows a towing vehicle 1 , here a tractor 2 , The towing vehicle 1 has a hydraulic brake system 3 on, which is formed here zweikreisig, without this forcing the invention must be the case. The hydraulic brake system 3 is with brake pedals 4a . 4b formed, which can be operated by the driver. The brake pedals 4a . 4b operate hydraulic master cylinder 5a . 5b working in hydraulic brake lines 6a . 6b generate a hydraulic brake pressure. The brake lines 6a . 6b pressurize hydraulic service brake cylinder 7a . 7b the two circles, with here for simplification per circle only one service brake cylinder 7a . 7b is shown. The operation of the brake pedals 4a . 4b is via a sensor 8a . 8b or switch detected, via a brake light line 9 a brake light 10 is activated when the brake pedals 4a . 4b be operated.

The towing vehicle 1 has a compressed air system 11 with a pressure source, here a compressor 12 , About the compressor 12 becomes a storage container 13 filled with compressed air. The compressed air system 11 has a coupling head brake 14 as well as a coupling head stock 15 which are connectable to the corresponding counter-coupling heads of a trailer. The coupling head stock 15 is about a supply line 16 with the reservoir 13 connected so that over the coupling head stock 15 the trailer can be supplied with compressed air. On the other hand, brake is applied via the coupling head 14 the trailer is supplied with a brake control pressure, via which a service brake force generated on the trailer can be predetermined or influenced. The brake control pressure is controlled by a trailer control valve 17 , whose output side connection 18 for the brake control pressure via a brake control line 19 with the coupling head brake 14 connected is. A connection 20 for a supply pressure is via a supply line 21 with the reservoir 13 to the compressed air supply of the trailer control valve 17 connected. The trailer control valve 17 has connections 22a . 22b for a hydraulic brake pressure of the two circles. Furthermore, the trailer control valve has 17 via a connection 23 for an electrical control signal. For the illustrated embodiment, the connection 23 subjected to the same electrical signal as the brake light pipe 9 and the brake light 10 so that when you press the brake pedals 4a . 4b the connection 23 together with the brake light 10 is electrically applied. By means of the trailer control valve 17 will depend on the hydraulic brake pressure at the connections 22a . 22b and optionally additionally influencing an electrical control signal at the port 23 a pneumatic brake control pressure at the port 18 generated.

For the time being, the embodiment corresponds to FIG 2 the embodiment according to 1 , However, here is the coupling head stock 15 not directly with the reservoir 13 connected. Rather, the supply of the coupling head stock 15 via the trailer control valve 17 so that the compressed air from the reservoir 13 over the supply line 21 through the trailer control valve 17 and about that in this case to a connection 24 for the coupling head stock 15 connected supply line 16 the coupling head stock 15 is supplied. This may, for example, be advantageous for the routing, since under some circumstances a portion of a parallel wiring of the reservoir 13 to the trailer control valve 17 on the one hand and to the coupling head stock 15 on the other hand can be saved. It is also possible that via the supply of the coupling head stock 15 via the trailer control valve 17 in the trailer control valve 17 an emergency brake function can be integrated.

For the in 3 illustrated embodiment has a two-part housing here 25 of the trailer control valve 17 in the one end area over the connections 5a . 5b for the hydraulic brake pressure. In the opposite end area are the connection 18 for the brake control pressure and the connection 20 arranged for the supply pressure. Furthermore, in this end region is coaxial with a longitudinal axis 26 a vent 27 intended.

The trailer control valve 17 has an inlet valve 28 and an exhaust valve 29 , here as a combined intake / exhaust valve 30 are formed. Here is the outlet valve 29 between a valve body 31 and a first valve seat 32 educated. In a blocking position of the exhaust valve 29 lies the valve body 31 under seal on the first valve seat 32 while in an outlet position the valve body 31 spaced from the first valve seat 32 is arranged, whereby between these an outlet cross-section 33 is formed.

The inlet valve 28 is formed between the valve body 31 and a second valve seat 34 , In a blocking position of the inlet valve 28 lies the valve body 31 under seal on the second valve seat 34 at. On the other hand is in an inlet position of the inlet valve 28 between the valve body 31 and the second valve seat 34 an inlet cross section 35 educated.

For the illustrated embodiment, the first valve seat 32 formed by a valve body 31 facing end face of a relay piston 36 , The second valve seat 34 is from a valve body 31 facing end face of a parking brake body 37 educated.

The parking brake body 37 is axial along the longitudinal axis 26 slidable in the housing 25 guided. Here is the parking brake body 37 In a rough approximation sleeve-like design, wherein the second valve seat 34 of the parking brake body 37 from a radially inwardly oriented and in the direction of the valve body 31 protruding circumferential nose is formed. In the parking brake body 37 is axially movable, the relay piston 36 guided, wherein in the valve body 31 remote end region of the relay piston 36 a seal between the parking brake body 37 and the relay piston 36 via a sealing element 38 he follows. Axial between the sealing element 38 and the first valve seat 32 are (axially adjacent to each other) between the parking brake body 37 and the relay piston 36 a relay chamber 39 and a brake control pressure chamber 40 formed, which via an annular gap or channel 41 are pneumatically connected to each other.

The valve body 31 is also sleeve-like, possibly with a collar and a suitable sealing attachment for the formation of the contact surface with the valve seats 32 . 34 formed, with a hollow cylindrical interior here 42 of the valve body 31 permanently with the vent 27 connected is.

3 shows the inlet / outlet valve 30 in its outlet position. Here is the relay piston 36 spaced from the valve body 31 arranged so that the outlet cross section 33 is released. By contrast, the parking brake body is located 37 with his valve seat 34 on the valve body 31 at what the inlet cross section 35 closed is. Compressed air from the relay chamber 39 , the channel 41 and the brake control pressure chamber 40 as well as from the connection 18 for the brake control pressure, which in the brake control pressure chamber 40 can thus, via the between the valve seat 32 and the valve body 31 created outlet cross section through the interior 42 of the valve body 31 over the vent 27 be vented. Radially outboard of the valve body 31 is between the valve body 31 and the housing 25 a pantry 43 educated. The pantry 43 into which the connection 20 for the supply pressure opens, is in the operating position according to 3 completed because of the parking brake body 37 trained valve seat 34 under seal on the valve body 31 is applied.

If, however, in the manner described in more detail below, the relay piston 36 from the operating position according to 3 through the parking brake body 37 moved to the right, this comes with the valve seat 32 for engagement with the valve body 31 , For such closed inlet valve 28 and exhaust valve 29 is both the pantry 43 shut off as well as a transfer of compressed air from the port 18 to the vent 27 blocked. This position may also be a so-called final position or weighing position. With further displacement of the relay piston 36 to the right this takes the valve body 31 with, where continue the exhaust valve 29 remains closed because the valve seat 32 of the relay piston 36 to the valve body 31 is pressed. The valve body 31 moves away with this movement but from the valve seat 34 of the parking brake body 37 , whereby the inlet cross section 35 is opened. Thus, compressed air from the port 20 over the pantry 43 and the created inlet cross-section 35 to the brake control pressure chamber 40 from where these to the terminal 18 (and over the channel 42 to the relay chamber 39 ).

With opening of the inlet valve 28 Thus, the brake control pressure at the port 18 be increased while opening the exhaust valve 29 the brake control pressure at the port 18 is reduced. In this case, the respective brake control pressure acts via the relay chamber 39 on the one hand on a control surface 44 of the relay piston 36 and on the other hand on a control surface 45 of the parking brake body 37 with which the relay chamber 39 is limited.

In the relay chamber 39 is a spring 46 arranged here as the relay piston 36 enclosing wound spring is formed. A spring base of the spring 46 is at the control area 44 of the relay piston 36 supported, while the other spring base of the spring 46 at the control area 45 of the parking brake body 37 is supported. Also in the pantry 43 is a spring 47 arranged, which is also designed here as a helical spring and which is around the lateral surface of the valve body 31 extends. A spring base of the spring 47 is on the case 25 supported, while the other spring base of the spring 47 on the valve body 31 , here one with the valve body 31 connected sealing or contact element is supported.

In the following, the different possibilities for influencing the axial position of the relay piston 36 and / or the parking brake body 37 explains about which the operating position of the intake / exhaust valve 30 can be influenced:
Between a stepped piston 48 and a stepped bore 49 of the housing 25 are mutually sealed hydraulic brake chambers 50 . 51 formed, in each of which a connection 22a . 22b for a hydraulic brake pressure of the two circuits opens. Depending on the hydraulic pressure at the connections 22a . 22b is thus on the stepped piston 48 generates a hydraulic actuating force. In this way is a hydraulic actuator 92 of the trailer control valve 17 educated. The hydraulic actuating force is via a sleeve-like actuating tappet formed here 52 whose front side is at the valve seat 31 opposite end face of the relay piston 36 is applied to the relay piston 36 transfer. With an increase in the hydraulic actuation force, it is thus possible to use the relay piston 36 from the operating position according to 3 with opened outlet valve 29 into the operating position, in which the exhaust valve 29 is closed, and with further movement the inlet valve 28 to open. Rises with the inlet valve open 28 the brake control pressure in the brake control pressure chamber 40 and therefore also in the relay chamber 39 on, arises at the control surface 44 of the relay piston 36 an increasing force, which in the closing direction of the inlet valve 28 and in the opening direction of the exhaust valve 29 acts and which is thus contrary to the hydraulic actuating force. Basically, thus, depending on the selected dimensions and the rigidity and bias of the spring 46 given a characteristic for which brake control pressure at which hydraulic actuation of the connections 22a . 22b the closing or weighing position of the inlet valve 28 and the exhaust valve 29 is reached.

The following are alternative or cumulative ways of influencing the brake control pressure at the port 18 explains:
An adjustment spring 53 rests with a spring base on a support body 54 , from. Radial outboard is the support body 54 via a threaded connection 67 with a release piston 57 screwed. The other spring base of the adjustment spring 53 relies on an actuator body 55 from. On the adaptation spring 53 opposite side is the actuator body 55 at the relay piston 36 at. For the illustrated embodiment, the adjustment spring 53 designed as a coiled spring, which surrounds the actuating plunger 52 extends. The adjustment spring 53 is biased with a bias, which in an operating position on the actuator body 55 an adjustment force on the relay piston 36 which is sufficient to the relay piston 36 to move to the right, so by the action of the adjustment spring 53 even without a hydraulic brake pressure at the connections 22a . 22b or also for a pressure build-up at the connections 22a . 22b the adjustment force is sufficient to the exhaust valve 29 close and the inlet valve 28 to open, bringing a brake control pressure to the port 18 can be generated.

Is however no or a reduced effect of the adjustment spring 53 on the relay piston 36 desired, the actuator body 55 at a release facility 56 supported, so that the adjustment force of the adjustment spring 53 at least partially by the release facility 56 is added, bringing this part of the adjustment force is no longer on the relay piston 36 acts. The release device 56 has the releasing pistons 57 , The release piston 57 is axially displaceable in the housing 25 guided. The release piston 57 owns a stop 58 , which is formed for the illustrated embodiment of a radially inwardly oriented ring or extension. At the stop 58 of the release piston 57 is in the operating position according to 3 one-sided in the effective direction of the adjustment spring 53 the actuator body 55 supported. For this purpose, the actuating body forms 55 a counter-abutment surface 59 off, on which the from the stop 58 formed stop surface 60 of the release piston 57 is applied. Is thus the release piston 57 in the operating position according to 3 , becomes the operating body 55 through the release piston 57 partially or completely restrained, so that the adjustment force of the adjustment spring 53 only partially or not at all on the relay piston 36 is transmitted. Will, however, the release piston 57 from this position in the direction of the relay piston 36 moves, with the movement becomes an increasing part of the adjustment force of the adjustment spring 53 on the relay piston 36 transferred so that over the position of the release piston 57 a position of the intake / exhaust valve can be changed even if no hydraulic brake pressure at the ports 22a . 22b is applied. Also in the event that a hydraulic actuation force on the stepped piston 48 is generated by means of the specification of the operating position of the release piston 57 an additional influence on the position of the inlet / outlet valve 30 and thus the brake control pressure at the port 18 respectively.

The adaptation spring 53 is between two support points with a maximum distance on one side limited by a stop clearance (which for the illustrated embodiment of the support body 54 and the actuator body 55 with limitation of the distance by the stop 58 of the release piston 57 provided). For generating an adjustment causes the relay piston 36 on the one support point (here the actuator body 55 ) such a large force that increases while increasing the bias of the adjustment spring 53 the support point of the stop 58 removed and reduces the distance of the support points, whereby the adjustment force of the adjustment spring 53 from the stop 58 on the relay piston 36 is handed over.

A control of the operating position of the release piston 57 takes place pneumatically. For this is on the relay piston 36 remote side of the release piston 57 between the case 25 and the release piston 57 a release control room 61 formed, its release control pressure on a release control surface 62 of the release piston 57 acts. A release control pressure in the release control room 61 generated in the area of the release control area 62 a release force releasing the release piston 57 in the direction of the relay piston 36 applied and thus a reduction of the contact force between the stop surface 60 and the counter-abutment surface 59 and thus an increase in the share of the adjustment force of the adjustment spring 53 , which on the relay piston 36 is transmitted. On the opposite side is between the parking brake body 37 , the housing 25 and a frontal control surface 63 of the release piston 57 a control chamber 64 educated. A control pressure in the control chamber 64 generated at the control surface 63 a force, which the release piston 57 opposite to the release force due to the release control pressure at the release control surface 62 applied. Is the release control room 61 depressurized, ensures any pressure in the control chamber 64 that according to 3 the release piston 57 is in an end position, in which no adjustment force of the adjustment spring 53 on the relay piston 36 can be transferred. It is possible that the position of the release piston 57 via influencing both the pressure in the release control room 61 as well as in the control chamber 64 he follows. It is also possible that in the release control room 61 or the control chamber 64 a constant pressure is applied while influencing the operating position of the release piston 57 excluding the pressure in the other release control room 61 or the control chamber 64 is changed. Finally, it is also possible that the force relationships on the release piston 57 is influenced by a spring. In this case, for example, instead of the release control room 61 or the control chamber 64 only a spring force on the release piston 57 act while in the other direction on the release piston 57 a suitable control pressure or release control pressure is effective.

The parking brake body 37 limited with a parking brake control surface 65 the control chamber 64 , Thus, via the control chamber 64 also be influenced on the axial position of the parking brake body 37 and thus the position of the intake / exhaust valve 30 ,

As an optional feature is the support body for the illustrated embodiment 54 for the relay piston 36 opposite Federfußpunkt the adjustment spring 53 designed adjustable, so that by means of an adjustment of the support body 54 the bias of the adjustment spring 53 and thus the characteristics of the trailer control valve 17 can be adjusted.

For this purpose, the support body 54 via a coupling device 66 such with the actuating tappet 52 coupled to that of the support body 54 along the longitudinal axis 26 opposite the actuating tappet 52 is displaceable, but the support body 54 rotatably with the actuating plunger 52 is coupled. For example, the coupling device 66 as a locking toothing or with a feather key, a driver u. Ä. Be formed. The release piston 57 is, however, via a corresponding coupling device 68 rotatably with the housing 25 coupled to allow axial relative displacement. A rotation of the actuating plunger 52 and thus the support body 54 thus has a relative movement of the support body 54 opposite the release piston 57 As a result, what the support body 54 in the field of threaded connection 67 more or less far in the release piston 57 is screwed in. To a rotation of the actuating plunger 52 to allow possesses the actuating plunger 52 an attack surface on the front side 69 , in particular a polygonal socket. For disassembled vent body 70 can along the longitudinal axis 26 a tool inside the case 25 through the interior 42 of the valve body 31 and the interior of the relay piston 36 with the attack surface 69 be brought into operative connection, so that from the outside, the rotation of the actuating plunger 52 can be caused.

The embodiment according to 4 essentially corresponds to the embodiment according to 3 , However, here is displaceable in the direction of the longitudinal axis 26 an annular reinforcing piston 71 relative to the radially inwardly disposed of this relay piston 36 guided. The boost piston 71 slides with its outer surface under sealing by a sealing element 72 along an inner surface of the parking brake body 37 , The reinforcing piston slides with its inner surface 71 with interposition of a sealing element 73 along an outer surface of a circumferential piston collar of the relay piston 36 ,

The relative movement of the intensifier piston 71 opposite the relay piston 36 is limited on one side. For this purpose has the gain piston 71 a radially inwardly oriented extension or a collar 74 or a stop ring, with which this comes to rest in the end position to the front side of the relay piston 36 , which the inlet / outlet valve 30 turned away. The relay chamber 39 extends in this case up to the boost piston 71 , Thus, the brake control pressure in this case does not only affect the control surface 44 of the relay piston 36 , but also on a gain control surface 75 of the boost piston 71 ,

In the in 4 illustrated outlet position of the intake / exhaust valve 30 is the boost piston 71 about a stop, here a circlip 76 on the intake / exhaust valve 30 facing away from the parking brake body 37 supported, which constructively an end position of the intensifier piston 71 and as a result of the interaction of the Federation 74 with the relay piston 36 also the relay piston 36 is predetermined.

Between the reinforcing piston 71 and the actuator body 55 is a preloaded spring 91 arranged.

In the 5 to 9 is another embodiment of a trailer control valve 17 shown in different operating positions, in which case the trailer control valve 17 corresponding 4 via a reinforcing piston 71 features. The explanation of the function of the trailer control valve 17 is corresponding to the trailer control valve according to the 3 and 4 transferable, although for the embodiment according to 3 the optional, via the boost piston 71 provided additional function and gain is not present.

In 5 to 9 are the ones in the 3 and 4 only partially shown inner pneumatic lines shown completely schematically. To recognize here is a connection 77 that has an inner line 78 with the release control room 61 connected is. Furthermore, the trailer control valve 17 a connection 79 up, over an inner pipe 80 with the control chamber 64 connected is. connections 81 . 82 be over a branch line 83 from the line 84 between the connection 20 and the pantry 43 supplied with compressed air.

For the control of functions of the trailer control valve 17 are a solenoid valve 85 , via which the parking brake control pressure is controllable, and a solenoid valve 86 , via which the release control pressure is controllable provided. The solenoid valve 85 is designed as a 3/2-way valve. Here is in each case a connection of the solenoid valve 85 with a connection 79 . 81 connected while the third port of the solenoid valve 85 ensures a vent. As a result of the application of a spring, the solenoid valve is in the non-energized position in a venting position in which the control chamber 64 over the connection 79 is vented while the solenoid valve 85 the connection 81 shuts off (see operating position 5 ). On the other hand, the solenoid valve connects in the energized operating position 85 the connections 81 . 79 with each other, leaving pressure from the port 20 over the branch line 83 and the connections 81 . 79 to the control chamber 64 can reach (see operating position 7 ).

Also the solenoid valve 86 is designed as a 3/2-way valve. Here are connections of the solenoid valve 86 with the connections 77 . 82 while the third port of the solenoid valve 86 ensures a vent. As a result of the application of a spring, the solenoid valve is located 86 in the in 5 effective operating position in a vent position, in which the solenoid valve 86 the connection 77 vented while connecting 82 is locked. Thus, the venting position of the solenoid valve allows 86 a vent of the release control room 61 , In the energized state, however, the solenoid valve is located 86 in a ventilation position in which this the connections 82 . 77 connects to each other, allowing compressed air from the port 20 over the branch line 83 and the connections 77 . 82 to the release control room 81 can reach (see operating position 8th ).

It is possible that at least one solenoid valve 85 . 86 in the trailer control valve 17 is integrated, is flanged to this or via external line connections with the said connections of the trailer control valve 17 connected is. For the in 5 illustrated embodiment is the solenoid valve 86 to the housing 25 of the trailer control valve 17 flanged while the solenoid valve 85 spaced from the housing 25 the trailer control valve is arranged and a connection of the solenoid valve 85 via external lines with the connections 79 . 81 he follows.

Furthermore, in 5 to recognize that via an external line connection to the port 18 a coupling head brake 87 connected.

The function of the trailer control valve 17 is as follows:
5 shows the trailer control valve 17 without the connection 20 adjacent supply pressure, with the solenoid valves 85 . 86 in the vent position and the connections 22a . 22b are not subjected to a hydraulic brake pressure. In this operating position is the inlet / outlet valve 30 in its inlet position, so the connection 20 with the connection 18 connected is. Because the connection 20 is not pressurized, is due to the coupling head brake 87 no brake control pressure, which means the trailer is unbraked (unless other measures have been taken).

6 shows the trailer control valve 17 in the same operating position as in 5 , but now the connection 20 is subjected to a supply pressure. Without the position of the valve elements of the trailer control valve 17 changed and thus the inlet / outlet valve 30 leaves its inlet position, the pressurization of the connection 20 to that the connection 18 and thus the coupling head brake 87 is also acted upon with an adjusted brake control pressure, whereby a parking brake effect is brought about on the trailer.

Is based on this state according to 7 the solenoid valve 85 transferred to ventilation position, is connected via the port 20 , The administration 84 , the branch line 83 , the connection 81 , the solenoid valve 85 , the connection 79 and the line 80 , the control chamber 64 subjected to a parking brake control pressure, which in this case is a kind of "release pressure". The pressurization of the control chamber 64 with the parking brake control pressure generated at the parking brake control surface 65 a force as a result of which the parking brake body 37 in the direction of the intake / exhaust valve 30 emotional. About the circlip 76 takes the parking brake body 37 the boost piston 71 (if any) with, while due to a distance of the federal government 74 from the associated end face of the relay piston 36 in the operating position according to 6 a relative movement between the reinforcing piston 71 and relay piston 36 can take place. The movement of the parking brake body 37 in the direction of the intake / exhaust valve 30 As a result, that of the parking brake body 37 trained valve seat 34 to the plant comes to the valve body 31 and a transfer of the intake / exhaust valve 30 into the outlet position, in which the connection 18 and thus the coupling head brake 87 over the vent 27 is vented. Thus, the switching of the solenoid valve leads 85 in that the brake control pressure drops to the atmospheric pressure, so that the parking brake effect according to 6 by applying a parking brake control pressure in the control chamber 64 has been eliminated. The vehicle is thus ready to drive.

8th shows an operating position in which an adjustment of the brake control pressure via the solenoid valve 86 he follows. It is possible that this adjustment in the provision of a lead to a hydraulic actuation of the connections 22a . 22b with a hydraulic brake pressure. It is also possible that via a control unit an otherwise adaptation of the brake control pressure takes place, as has been described in the introduction.

Switching of the solenoid valve 86 in the ventilation position causes starting from the operating position according to 7 with eliminated parking brake effect the release control room 61 with the pressure on the connector 20 is charged. This pressurization results in the generation of a release force on the release control surface 62 , which has the consequence that the release piston 57 moved to the right. During this movement it comes to relieving the contact between counter-surface 59 and stop surface 60 and the formation of a distance between the counter-abutment surface 59 and the stop surface 60 , As a result, as the release control pressure increases, the adjustment force of the adjustment spring progressively increases 53 from the release piston 57 on the actuator body 55 is transferred, which then increasingly the adjustment force on the relay piston 36 acts. The increasing adjustment force then causes the intake / exhaust valve 30 from its outlet position according to 7 is transferred to an inlet position in which the connection 20 with the connection 18 is connected, so that there is an increase in the brake control pressure. With the pressure rise at the port 18 But it also comes to a pressure increase in the relay chamber 39 , with which also on the relay piston 36 and possibly the boost piston 71 acting force, which counteracts the adjustment force is greater. If these forces, possibly with further spring forces influencing the operating position, hold the balance, the closing position will follow 8th taken in which a function of the solenoid valve 86 predetermined release control pressure predetermined amount of the brake control pressure is maintained.

It is possible that in the event that an increasing brake control pressure in the relay chamber 39 This also builds on the gain control surface 75 of the boost piston 71 acts. As a result, with increasing brake control pressure of the boost piston 71 with the covenant 74 from the relay piston 36 can solve. This is done by applying the spring 91 , It is possible u. U. also that the intensifier piston 71 over the circlip 76 a force on the release piston 57 which force is due to the release control pressure at the release control surface 62 is opposite. As a result, by the operation of the release device 65 reduced, acting in the direction of the inlet position force is reduced and finally eliminated, thus a final position of the intake / exhaust valve 30 can be brought about. You may be able to use these measures to ensure a quick opening of the intake / exhaust valve 30 overcoming relatively large frictional forces results in the achievement of large initial forces which are in the direction of inlet position of the intake / exhaust valve 30 Act. Once an inlet position has been brought about, it is possible to use the reinforcement piston 71 Under certain circumstances, the compensation of a relatively small pressure and / or a sensitive adjustment of the overfeed and the controlled brake control pressure take place. Preferably, only in the full inlet position of the intake / exhaust valve 30 the counter stop surface 59 of the actuator body 55 spaced from the stop surface 60 of the stop 58 of the release piston 57 arranged, with increasing approach to the weighing or closing position between the stop surface 60 and the counter-abutment surface 59 a larger supporting force acts.

9 shows the supplementary admission of the hydraulic connections 22a . 22b with a hydraulic brake pressure. This has the consequence that on the stepped piston 48 a hydraulic force is generated which, via the actuating tappet 52 on the relay piston 36 is transmitted. So then take the inlet / outlet valve 30 depending on the hydraulic loading of the connections 22a . 22b its inlet position, whereby an increase in the brake control pressure can take place. Again, the relay effect of the relay piston comes 36 for carrying, so for a by the hydraulic brake pressure at the connections 22a . 22b predetermined amount of the brake control pressure the trailer control valve 17 his final position according to 9 occupies. This can be done with hydraulic loading of the connections 22a . 22b at first directly with actuation of the brake pedals, the switching of the solenoid valve 86 take place in its ventilation position, whereby a desired lead can be achieved. It is possible that then with the construction of the effect of the stepped piston 48 the solenoid valve 86 is transferred back to its vent position. It is also possible that via the solenoid valve 86 an adjustment of the brake control pressure, in particular an increase of the brake control pressure compared to that by the hydraulic actuation of the terminals 22a . 22b brought about brake control pressure is brought about.

An influence on the force relationships on the trailer control valve 17 In particular, the use of complementary springs, the choice of preload and spring stiffness of the springs used and the dimensioning of the control surfaces can be done.

10 shows an embodiment of the trailer control valve 17 in which the solenoid valves 85 . 86 to the housing 25 of the trailer control valve 17 are flanged. For this embodiment, unlike the previous embodiments, the components for effecting and eliminating the parking brake effect on the intake / exhaust valve 30 remote side of the release device 56 arranged. For this purpose, a parking brake sleeve extends 88 through the release device 56 therethrough. The parking brake sleeve 88 is with an end face on the parking brake body 37 supported and with the other end face on the relay piston 36 supported. In this case, the parking brake body 37 via a preloaded parking brake spring 89 on the housing 25 supported. The Parking brake spring 89 acts on the parking brake body 37 and the parking brake sleeve 88 and the relay piston 36 toward an inlet position of the intake / exhaust valve 30 , With generation of a parking brake control pressure due to switching of the solenoid valve 85 in the control chamber 64 can be the force of the parking brake spring 89 be partially or completely canceled depending on the applied pressure, so that with the generation of the parking brake control pressure a parking brake effect can be partially or completely canceled.

With the release device 56 and the release piston 57 as well as the interaction between the stop 58 of the release piston 57 and the actuator body 55 is a customization actuator 90 formed, via which an adaptation of the brake control pressure, in particular an increase thereof with bringing about a ventilation position of the solenoid valve 86 , can be brought about.

It is possible that the solenoid valves 85 . 86 be controlled pulse width modulated by a control unit, which depending on the pulse width control adjustment of a control pressure in the release control room 61 and / or in the control chamber 64 can be done, which is smaller than the pressure at the port 20 , Which then also a reduced brake control pressure at the port 18 can be brought about, the amount of which can be specified via the pulse width control.

With the parking brake body 37 , at the parking brake control surface 65 with pneumatic admission of the control chamber 64 a force is generated which the inlet / outlet valve 30 transferred to an outlet position (see. 7 ), is a parking brake actuator 93 educated.

For the embodiments illustrated in the figures, the trailer control valve 17 both a customization actuator 90 as well as a parking brake actuator 93 on. Depending on the requirements of the trailer control valve 17 This can only be done with an adjustment actuator 90 or even with a parking brake actuator 93 be educated. Both for the adjustment actuator 90 as well as for the parking brake actuator 90 it is possible that a spring-loaded principle is used, in which a force for bringing about an inlet position of the inlet / outlet valve 30 is provided by a spring and this force can be reduced or eliminated with a pneumatic actuation of a control chamber of the actuator. But it is also possible that with the generation of a control pressure in a control chamber of the actuator pneumatically a force is brought about which the inlet / outlet valve 30 acted upon in the direction of the inlet position.

Another special feature is the trailer control valve 17 according to 10 via a second adjustment spring 94 , over which the force ratios for the adjustment function can be influenced. The likewise preloaded adjustment spring 94 is with a spring base on the boost piston 71 supported, while the other spring base of the adjustment spring 94 on the release piston 57 is supported. The adjustment spring 94 on the one hand acts on the relay piston 36 in the direction of the inlet position of the intake / exhaust valve 30 , On the other hand, the adjustment spring acts 94 the release piston 57 opposite to the action of the adjustment spring 53 , so with the adjustment spring 94 the contact force between the counter stop surface 59 and the stop surface 60 being affected. Is by transfer of the solenoid valve 86 the release control room 61 ventilated, causes the thereby caused movement of the release piston 57 to that the force in the adjustment spring 94 gets bigger, which also on the gain piston 71 and the relay piston 36 force applied to the inlet position due to the adjustment spring 94 gets bigger. In addition, also increases from the adjustment spring 53 on the actuator body 55 (and from this to the relay piston 36 ) exerted by the actuation of the release device 56 is released or handed over. By using the further adjustment spring 94 can thus via the operation of the release device 56 caused forces in the inlet direction to be increased, but then under certain circumstances, larger forces on the release control surface 62 must be brought about.

Depending on the desired characteristic curve and slope of the trailer control valve 17 This can be with or without reinforcement piston 71 be educated.

It is also possible that the adaptation function is formed inverted. This may mean that the adjustment function by switching off the solenoid valve 86 is activated, so that in this case, a reversal of the effective direction of the control pressure on the release piston 57 is to be provided.

It is possible that the connection 18 directly via a brake control line 19 with the coupling head brake 14 . 87 connected is. However, it is also possible that the brake control pressure from the port 18 a pressure control module is supplied, as this in EP 2 165 901 B1 is described in detail.

LIST OF REFERENCE NUMBERS

1

 towing vehicle

2

 tractor

3

 hydraulic brake system

4

 brake pedal

5

 Master cylinder

6

 brake line

7

 Service brake cylinder

8th

 sensor

9

 Brake Light line

10

 Stoplight

11

 Compressed air system

12

 compressor

13

 reservoir

14

 Coupling head brake

15

 Coupling head stock

16

 supply line

17

 Trailer control valve

18

 Connection for the brake control pressure

19

 Brake control line

20

 Connection for the supply pressure

21

 supply line

22

 Connection for a hydraulic brake pressure

23

 Connection for an electrical control signal

24

 Connection for the coupling head stock

25

 casing

26

 longitudinal axis

27

 vent

28

 intake valve

29

 outlet valve

30

 Intake / exhaust valve

31

 valve body

32

 first valve seat

33

 outlet section

34

 second valve seat

35

 Inlet cross-section

36

 relay piston

37

 Parking brake body

38

 sealing element

39

 relay chamber

40

 Brake control pressure chamber

41

 channel

42

 inner space

43

 storeroom

44

 control surface

45

 control surface

46

 feather

47

 feather

48

 stepped piston

49

 drilling

50

 hydraulic brake chamber

51

 hydraulic brake chamber

52

 actuating ram

53

 Adjustment spring

54

 support body

55

 operating body

56

 release device

57

 releasing pistons

58

 attack

59

 Against stop surface

60

 stop surface

61

 Enable control room

62

 Enable control area

63

 control surface

64

 control chamber

65

 Parking brake control surface

66

 coupling device

67

 threaded connection

68

 coupling device

69

 attack surface

70

 vent body

71

 intensifier piston

72

 sealing element

73

 sealing element

74

 Federation

75

 Gain control surface

76

 circlip

77

 connection

78

 management

79

 connection

80

 management

81

 connection

82

 connection

83

 branch line

84

 management

85

 Solenoid valve for controlling the parking brake function

86

 Solenoid valve for controlling the adaptation function

87

 Coupling head brake

88

 Parking brake sleeve

89

 Parking brake spring

90

 Adjustment actuator

91

 feather

92

 hydraulic actuator

93

 Parking brake actuator

94

 Adjustment spring

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

• DE 3918226 C2 [0002, 0003]
• DE 3412345 A1 [0003, 0011]
• EP 0832803 A1 [0004, 0004, 0011]
• DE 102008048207 B4 [0005, 0011]
• EP 2165901 B1 [0006, 0006, 0083]
• EP 2269880 A1 [0007, 0011]
• EP 2305524 A1 [0008, 0008]

Claims (15)

Trailer control valve ( 17 ) with a spring-loaded adjustment actuator ( 90 ). Trailer control valve ( 17 ), in particular trailer control valve ( 17 ) according to claim 1, with a) a relay piston ( 36 ), with which an inlet valve ( 28 ) and / or an outlet valve ( 29 ) is formed, b) a hydraulic actuator ( 92 ) which, when acted upon by a hydraulic brake pressure, generates a hydraulic actuation force which is used to generate a brake control pressure for the trailer in the closing direction of the exhaust valve (FIG. 29 ) and / or in the opening direction of the inlet valve ( 28 ) on the relay piston ( 36 ) and c) wherein the or an adjustment actuator ( 90 ) ca) an adjustment spring ( 53 ), which generates an adaptation force, which is used to generate a fitting in the closing direction of the outlet valve (FIG. 29 ) and / or in the opening direction of the inlet valve ( 28 ) on the relay piston ( 36 ) and cb) a release device ( 56 ), which in a first operating position in which no adjustment is to be made, the effect of the adjustment spring ( 53 ) on the relay piston ( 36 ) reduces or eliminates, and in a second operational position, in which an adjustment is to be made, the effect of the adjustment spring ( 53 ) on the relay piston ( 36 ) at least partially releases. Trailer control valve ( 17 ) according to claim 2, characterized in that the release device ( 56 ) is formed electropneumatically with a) a solenoid valve generating a release control pressure ( 86 ) and b) a release piston ( 57 ba) a pneumatic release control surface ( 62 ), on which the release control pressure acts, and bb) a stop surface ( 60 ), which in the first operating position of the adjustment spring ( 53 ) and, in the second operating position, not or to a lesser extent the adjustment spring ( 53 ) is acted upon. Trailer control valve ( 17 ) according to claim 3, characterized in that the adjustment spring ( 53 ) on an actuating body ( 55 ) which supports a counter-abutment surface ( 59 ), which in the first operating position at the stop surface ( 60 ) of the release piston ( 57 ) and in the second operating position spaced from the stop surface ( 60 ) of the release piston ( 57 ) is arranged. Trailer control valve ( 17 ) according to claim 3 or 4, characterized in that a) the release piston ( 57 ) at the release control surface ( 62 ) is acted upon in a first direction with the release control pressure and b) the release piston ( 57 ) another control surface ( 63 ), which in a direction opposite to the first direction oriented second direction with the supply pressure or a parking brake control pressure for a parking brake function can be acted upon. Trailer control valve ( 17 ) according to one of the preceding claims, characterized in that the inlet valve ( 28 ) and the exhaust valve ( 29 ) as a combined inlet / outlet valve ( 30 ) are formed with a) an annular first valve seat ( 32 ), b) an annular second valve seat ( 34 ), and c) a valve body ( 31 ), d) where da) the first valve seat ( 32 ) and the second valve seat ( 34 ) extend coaxially to each other and db) the first valve seat ( 32 ) and the second valve seat ( 34 ) are arranged radially in one another and e) wherein ea) in a blocking position of the valve body ( 31 ) sealed to both valve seats ( 32 . 34 ) is pressed, eb) in an inlet position of the first valve seat ( 32 ) on the valve body ( 31 ), while the second valve seat ( 34 ) spaced from the valve body ( 31 ) is arranged, which between the valve body ( 31 ) and the second valve seat ( 34 ) an inlet cross-section ( 35 ), which has a connection ( 20 ) for a supply pressure with a connection ( 18 ) for the brake control pressure, and ec) in an outlet position the second valve seat ( 34 ) on the valve body ( 31 ), while the first valve seat ( 32 ) spaced from the valve body ( 31 ) is arranged, which between the valve body ( 31 ) and the first valve seat ( 32 ) an outlet cross-section ( 33 ) is formed, which a vent ( 27 ) with the connection ( 18 ) for the brake control pressure. Trailer control valve ( 17 ) according to claim 6, characterized in that the first valve seat ( 32 ), the second valve seat ( 34 ) and the valve body ( 31 ) relative to a housing ( 25 ) are movable. Trailer control valve ( 17 ) according to claim 6 or 7, characterized in that a valve seat ( 34 ) from one opposite a housing ( 25 ) slidable parking brake body ( 37 ) is formed, which a parking brake control surface ( 65 ) is formed, which is acted upon for activating or deactivating a parking brake function with a parking brake control pressure. Trailer control valve ( 17 ) according to one of claims 6 to 8, characterized in that a valve seat ( 32 ) from the relay piston ( 36 ) is trained. Trailer control valve ( 17 ) according to claim 9, characterized in that sliding relative to the relay piston ( 36 ) a reinforcing piston ( 71 ), which a) has a gain control surface ( 75 ), which with the pressure at the terminal ( 18 ) is applied to the brake control pressure, and b) opposite to the effect of the pressure at the gain control surface ( 75 ) via a preloaded spring ( 91 ) with a stop surface against a counter-abutment surface of the relay piston ( 36 ) is pressed. Trailer control valve ( 17 ) according to claim 10 when appended to one of claims 4 to 8, characterized in that the spring ( 91 ) on the reinforcing piston ( 71 ) facing away from the actuating body ( 55 ) is supported. Trailer control valve ( 17 ) according to one of the preceding claims, characterized in that the trailer control valve ( 17 ) a) a solenoid valve ( 85 ), via which one or the parking brake control pressure is controllable, b) a solenoid valve ( 86 ), via which one or the release control pressure is controllable and / or c) has a connection for an external parking brake control valve. Trailer control valve ( 17 ) according to one of claims 2 to 12, characterized in that the bias of the adjustment spring ( 53 ) is adjustable. Brake system with a trailer control valve ( 17 ) according to any one of the preceding claims. Towing vehicle ( 1 ) with a brake system with a trailer control valve ( 17 ) according to any one of the preceding claims.

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