DE1601708C

DE1601708C - Pneumatic servo drive. Eliminated from: 1300443

Info

Publication number: DE1601708C
Authority: DE
Inventors: Maxwell Leslie South Bend Ind. Cripe (V.St.A.)
Original assignee: Bendix Corp
Current assignee: Bendix Corp
Publication date: 1972-08-31

Description

Richtung und unter Kompression den ringförmigen äußeren Teil des Ventilkörpers beaufschlagt, um letzteren in Abdichteingriff mit der Nabenbohrung und der äußeren Schulter zu halten. Dieser Verstärkungsring endet vorzugsweise in einem radial gerichteten Flanschteil, der als Anschlagfläche für eine Rückführfeder des Ventilsteuerbandes dient.Direction and under compression urged the annular outer part of the valve body to to keep the latter in sealing engagement with the hub bore and the outer shoulder. This reinforcement ring preferably ends in a radially directed flange part, which acts as a stop surface for a return spring of the valve control band is used.

Bei einer speziellen Ausführungsform der Erfindung ist eine ringförmige, versteifende Beilage vorgesehen, die in das verdickte Endteil des Ventilkörpers eingebettet ist und als Anschlägfläche für eine weitere Feder dient, welche das Endteil in Wirkeingriff mit einem der Ventilsitze bringt. Zweckmäßigerweise erstreckt sich hierbei ein zylindrisches Ankerbauteil in axialer Richtung zwischen dem Flanschteil des Ver-Stärkungsringes und der Versteifungsbeilage zur Begrenzung der nach außen gerichteten Bewegung des Ventilsteuerbauteiles.In a special embodiment of the invention, an annular, stiffening shim is provided, which is embedded in the thickened end part of the valve body and as a stop surface for another The spring is used, which brings the end part into operative engagement with one of the valve seats. Appropriately extends In this case, a cylindrical anchor component is located in the axial direction between the flange part of the reinforcement ring and the stiffener shim to limit outward movement of the Valve control component.

Nach einer weiteren Ausführungsform der Erfindung ist die Nabenbohrung mit einer weiteren, radial gerichteten Schulter verringerten Durchmessers versehen, die als Anschlagfläche für den Ventilsteuerbauteil zur Begrenzung der nach innen gerichteten Bewegung dient. .According to a further embodiment of the invention, the hub bore is radial with a further one directed shoulder of reduced diameter, which acts as a stop surface for the valve control component serves to limit the inward movement. .

Der erfindungsgemäße, pneumatische Servoantrieb ist in seinem Aufbau erheblich einfacher, in seiner Herstellung wesentlich wirtschaftlicher und im Betrieb zuverlässiger als bisher bekanntgewordene Antriebe dieser Art, da er aus weniger Teilen besteht, die weniger oder keine Bearbeitung erfordern und da er viel einfacher in der Kolbeneinheit zusammengebaut werden kann.The pneumatic servo drive according to the invention is considerably simpler in its construction Production much more economical and more reliable in operation than previously known drives of this type, as it consists of fewer parts that require less or no machining and as it is much easier to assemble in the piston unit.

Nachstehend wird die Erfindung in Verbindung mit der Zeichnung an Hand eines Ausführungsbeispieles erläutert.The invention is described below in conjunction with the drawing using an exemplary embodiment explained.

Fig. 1 zeigt einen Längsschnitt durch eine Ausführungsform eines pneumatischen Servoantriebes gemäß der Erfindung und -Fig. 1 shows a longitudinal section through an embodiment a pneumatic servo drive according to the invention and -

Fig. 2 in vergrößertem Maßstab das Kernstück dieses Servoantriebes.Fig. 2 shows the core of this servo drive on an enlarged scale.

In den beiden gegenüberliegenden Kammern 40 und 42 herrscht während des normalen entregten Zustandes des Servoantriebes ein Unterdruck. Das Antriebselement, das als gegossene oder gepreßte Nabe 36 ausgebildet ist, besitzt einen axial verlaufenden Hauptkörper, der einen radial verlaufenden Flansch 46 enthält, welcher als Träger für die Membran 38 wirkt.In the two opposite chambers 40 and 42 there is de-excitation during normal State of the servo drive a negative pressure. The drive element, which is available as a cast or pressed Hub 36 is formed, has an axially extending main body, which is a radially extending Flange 46 contains, which acts as a support for the membrane 38.

Der Durchtrittskanal 84 verläuft von der Schulter 70 aus nach rückwärts, und es ist ein kleiner zylindrisch versenkter Abschnitt 110 im Mittelteil 56 der öffnung 54 vorgesehen, der eine Schulter 112 bildet. Die Schulter 70 stellt den Vakuumsitz des Ventils dar, und ein. biegsamer, membranartiger Ventilkörper 116 ist mittels einer Schraubenfeder 118 dagegen vorgespannt. Die Schulter 72 besitzt einen kleinen Abstand von dem Sprengring 76, und der Umfang des Ventilkörpers 116 ist zwischen der Schulter 72 und dem Sprengring 76 durch den Verstärkungsring 120 und die Ventilrückführfeder 122 zusammengepreßt. Das Ventilsteuerbauteil 114 ist von der Schulter 70 aus nach innen gelagert, und der nach rückwärts vorstehende Ventilsitz 88 ist gegen den elastischen Ventilkörper durch die Ventilrückführfeder 122 vorgespannt. Der elastische' Ventilkörper 116 ist in dem Bereich in der Nähe des Ventilsitzes 70 und 88 verstärkt, und die leichte Schraubenfeder 118 ist zwischen der Steuerstange 92 und der Versteifungsbeilage 126 angeordnet, um die erforderliche Abdichtkraft für den Sitz zu gewährleisten. Die Steueröffnung 86 liegt zwischen dem Abschnitt 110 und der Kammer 42, so daß ein Fluß an einem der beiden Ventilsitze 70 oder 88 vorbei zur gegenüberliegenden Kammer 42 zustande kommt.The through-channel 84 runs backwards from the shoulder 70, and a small, cylindrically sunk section 110 is provided in the central part 56 of the opening 54, which forms a shoulder 112 . The shoulder 70 represents the vacuum seat of the valve, and a. flexible, membrane-like valve body 116 is biased against it by means of a helical spring 118. The shoulder 72 is spaced a small distance from the snap ring 76, and the periphery of the valve body 116 is compressed between the shoulder 72 and the snap ring 76 by the reinforcement ring 120 and the valve return spring 122 . The valve control member 114 is supported inwardly from the shoulder 70, and the rearwardly projecting valve seat 88 is biased against the elastic valve body by the valve return spring 122. The resilient valve body 116 is reinforced in the area near the valve seat 70 and 88, and the lightweight coil spring 118 is arranged between the control rod 92 and the stiffening shim 126 in order to ensure the required sealing force for the seat. The control opening 86 lies between the section 110 and the chamber 42, so that a flow occurs past one of the two valve seats 70 or 88 to the opposite chamber 42 .

In der normalen entlasteten Lage des Servoantriebes nehmen die Teile die gezeichneten Stellungen ein. Wenn der Servoantrieb betätigt werden soll, wird das Steuerbauteil 114 durch die Steuerstange 92 nach rechts bewegt und der Ventilkörper 116· in Eingriff mit der Schulter 70 gebracht. Dadurch wird die Verbindung zwischen den gegenüberliegenden Kammern 40 und 42 unterbrochen, und eine kleine, weitere Einwärtsbewegung des Steuerbauteües 114 bewirkt eine Trennung des Steuerbauteües 114 von dem Ventilkörper 116, so daß Druckluft in die Kammer 42 fließen kann. Durch den Aufbau eines Druck-Unterschiedes an der Nabe 36 bewegt sich diese nach rechts, und die Bremsen werden eingelegt. Wenn die Bremskraft verringert werden soll, wird die Kraft auf die Steuerstange 92 herabgesetzt, so daß sie sich nach links bewegen kann. Durch diese Rückwärtsbewegung stützt sich das Steuerbauteil 114 gegen den Ventilkörper 116 ab und bringt ihn außer Eingriff mit der Schulter 70, woraufhin der Druck in der Kammer 42 vermindert wird.In the normal, unloaded position of the servo drive, the parts assume the positions shown. When the servo drive is to be actuated, the control component 114 is moved to the right by the control rod 92 and the valve body 116 is brought into engagement with the shoulder 70. This interrupts the connection between the opposing chambers 40 and 42, and a small, further inward movement of the control unit 114 causes the control unit 114 to separate from the valve body 116 so that compressed air can flow into the chamber 42. As a pressure difference builds up on the hub 36, it moves to the right and the brakes are applied. When the braking force is to be reduced, the force on the control rod 92 is reduced so that it can move to the left. As a result of this backward movement, the control component 114 is supported against the valve body 116 and brings it out of engagement with the shoulder 70, whereupon the pressure in the chamber 42 is reduced.

. Durch vollständige Entfernung der auf die Steuerstange 92 wirkenden Betätigungskraft kann die Feder 118 das Steuerbauteil 114 nach rückwärts bewegen, bis sich der rohrförmige Ankerbauteil 128, der von der Innenseite des Ventilkörpers 116 aufgenommen wird, gegen den Verstärkungsring 120 abstützt. Dadurch wird eine vollständige Druckverringerung in der Kammer 42 erreicht, die Nabe 36 bewegt sich in die dargestellte, zurückgezogene Stellung, und die Gummipuffer 94 stehen mit dem Gehäuseabschnitt 34 in Eingriff.. By completely removing the actuating force acting on the control rod 92, the spring 118 can move the control component 114 backwards until the tubular armature component 128, which is received by the inside of the valve body 116 , is supported against the reinforcement ring 120. As a result, a complete pressure reduction in the chamber 42 is achieved, the hub 36 moves into the retracted position shown, and the rubber buffers 94 are in engagement with the housing section 34.

Hierzu 1 Blatt Zeichnungen1 sheet of drawings

Claims

1 2 spoke 1 or one of the following, characterized patent claims: indicates that the hub bore with a further radially directed shoulder (112) reduces

1. A pneumatic servo-drive is provided with an input siege diameter which is in the arranged as uniform of a movable wall and hub, 5 stop surface, the hub comprising the valve control member (114) has an axial bore, a for limiting the inward control valve which serves a differential movement.

can control pressure on the movable wall,
and which has a valve body which is normally resiliently engaged with a first valve io ~ ~
The invention relates to a pneumatic first pressure to the control chamber of the servo-servo drive with a unit of movable drive, and which in the wall and hub, the hub is an axial position, with a movement of the valve control 15 has a bore in which a control valve is arranged component inwardly to a second valve seat that can act on a .Differentialdruck on the movable, which is arranged on the hub, control wall and that a valve body to the connection of a second pressure which is normally resiliently brought into engagement with the control chamber of the servo drive to interrupt a first valve seat, which is arranged at and the first pressure to the control chamber to a valve control component to the routing, characterized that the binding of a first pressure to the tax Chamber of the bore of the hub (36) with two axially offset servo drives zu.interrupt, and which is in the C and radially extending shoulders (70, 72) is provided with a movement of the valve control stage diameter that the inner part after Beat inside a second valve seat to beauf-shoulder (70) in a known manner 25, which is arranged on the hub around which the second valve seat represents, while the connection of a second pressure to the control chamber outer shoulder (72) as an axial stop for to interrupt that of the servo drive and to place the first fastening of the valve body (116) with regard to pressure on the control chamber,
the hub (36) is used, and that the one-piece, there are already pressure medium-operated servo drives made of resilient material existing valve 30 known, in which the hub is integral with two body an annular outer part which is provided in inwardly directed stops, one Engage with the outer shoulder (72) and stop as an abutment for the valve body has a thickened end part designed as a poppet valve and a tight fit with the wall of the hub, which faces the first and second, and the valve body with the inner valve seat cooperates for effective engagement with each stop while facing the second of them, the outer part forming the valve seat, while the outer part on which and the end part is held together by a flexible, outer stop. The hub is provided with two radial shoulders which are connected axially. Offset in direction, but not different in diameter.

2. Pneumatic servo drive according to grade 40 are. . .
Claim 1, characterized by. An inner aim of the present invention is to provide a pneumatic reinforcement ring (120), the servo drive which is matic in the radial direction and which has a control

and under compression has the annular outer valve, which is easy and economical in the (

Part of the valve body is applied to the latter production and from as few individual parts as possible can be assembled in sealing engagement with the hub bore and the 45, which is a flawless one

keep outer shoulder. Sealing effect results and the ingress of air

3. Pneumatic servo drive after contact in the valve chamber prevents as well as the usual claim 2, characterized in that the use of sealing rings does not require a strengthening ring (120) in a radially directed.

Flange part ends, which serves as a stop surface for a 5 °. According to the invention, this is achieved in that the return spring (122) of the valve control component is used in the bore of the hub with two axially offset (114) . and radially running shoulders with graduated

4. Pneumatic servo drive is provided according to the knife that the inner shoulder in claims 1 to 3, characterized by a known manner represents the second valve seat, annular, stiffening shim (126) in the 55 while the outer shoulder as an axial Stop for thickened end part of the valve body embedded the fastening of the valve body with respect to which is and serves as a stop surface for a further spring hub, and that the one-piece, made of flexible (118) , which the end part in operative engagement like material existing valve body with a ring with brings one of the valve seats. shaped outer part that engages with the

5. Pneumatic servo drive according to An 60 outer shoulder, and a thickened end part designed as plate claim 4, characterized by a cylindrical valve, which see the armature component (128), which is located in the axial first and second valve seat for an effective direction facing between the flange portion of the engagement with each of them, the strengthening ring (120) and the stiffening shim of the outer portion and end portion facing one another via (126) to limit the outwardly directed 65 flexible, integrally formed intermediate movement of the Valve control component (114) are partly connected.

stretches. In a further embodiment of the invention is a

6. Pneumatic servo drive provided on the inside reinforcement ring, which is in radial