DE1675145C

DE1675145C - Inner jaw drum brake

Info

Publication number: DE1675145C
Authority: DE
Inventors: Gunter 5828 Ennepetal Fröhlich
Original assignee: Heemaf SKA Motorenwerk AG, 4600 Dortmund
Publication date: 1972-02-24

Description

Die Erfindung betrilTt eine elektromiignetiscli lüftbare lnnenhuckentromnielbremse mil einem ringförmigen Magnetkörper, auf dem sich in Umfangsrichlung des Magnetkörpers erstreckende Blattfedern einseitig oder miltig befestigt sind, die an ihrem freien linde oder ihren freien Enden mit dem Magnelkurpcr zusammenwirkende Magnetanker und Bremsbacken tragen und bei der Hubbegrenzungsclemenie für die Bremsbacken vorgesehen sind.The invention relates to an electrically ventilated device Inner cocking drum brake with an annular Magnet body on which leaf springs extending in the circumferential direction of the magnet body are attached unilaterally or slightly, which at their free linden tree or their free ends with the Magnelkurpcr Carrying interacting magnet armatures and brake shoes and in the case of the stroke limiter are provided for the brake shoes.

Hs ist eine elektromagnetisch lüftbare Innenbakkenirommelbremse bekannt, die einen ringförmigen Magneikörpor besitzt,mit dem mehrere Bremsbacken tragende Magnelanker zusammenwirken, die bei nicht erregtem Magnetkörper durch die Kraft je einer Feder gegen die Bremstrommel gedruckt werden. Hie die Hremshacken tragenden Federn sind Blattfedern, die sich in Umfangsrichtung des Magnelkörpers erstrecken, einseitig oder niittig an diesem befestigt sind und an ihrem freien Ende jeweils einen Magnetanker mit einer Bremsbacke tragen. Auf Clriind der einseitigen oder mittigen Befestigung tier Federn und der in Umfangsrichtung angeordneten Bremsbacken stehen letztere schräg zur Trommelbremse, wodurch sich eine im Verlauf der Betriebsdauer immer größer werdende Bremsfläche ergibt. Du sich !»ierbei /wangläufig die resultierende Anpreßkraft in Richtung auf den Federeinspannpunkt bewegt, ist dereu GröP; trotz fortschreitenden Verschleißes der Bre.nsbacken in etwa während der gesamten Betriebsdauer kon:..ant.Hs is an electromagnetically released inner drum brake known, which has an annular Magneikörpor with which several brake shoes load-bearing armature work together, which when the magnet body is not excited by the force a spring pressed against the brake drum. Here are the springs that carry the claws Leaf springs extending in the circumferential direction of the Magnel body extend, are attached to one side or niittig and at their free end in each case wear a magnet armature with a brake shoe. On the one-sided or central fastening tier springs and the brake shoes arranged in the circumferential direction, the latter are at an angle to the drum brake, which results in a braking surface that becomes larger and larger in the course of the operating time. You yourself! »At the same time the resulting contact pressure in the direction of the spring clamping point moves, is the new GröP; despite advancing Wear of the bre.nsbacken approximately during the entire service life kon: .. ant.

Obwohl theoretisch sämtliche Bremsbacken die gleiche I ebensdauer haben sollten, hat sich jedoch gezeigt, daß dies in der Praxis nicht der Fall ist. Unvermeidliche Toleranzen, Unregelmäßigkeiten in der Miiicrialbeschaffenhcit der Bremsbacken und Bremsaiiker, Unterschiede in den Federvorspannungen usw. führen nämlich in der Praxis da/u, daß die Bremsbacken nicht völlig gleichmäßig verschleißen. Um nun durch eine vorzeitig verschleißende Bremsbacke keine Beschädigung der Tromnielbremsfläche in Kauf nehmen zu müssen, sind bei der bekannten Innenhaekentrommelbrcmse zwischen den benachbarten freien F.nden der die Magnetnnker und die Bremsbacken tragenden Blattfedern Hubbcgrcn-/imgsstifte eingesetzt. Wird eine der Bremsbacken Mn /eilig abgeniil/t. so schlägt sie während der restlichen lebensdauer der übrigen Bremsbacken, d.h. bis /um Auswechseln sämtlicher Bremsbacken an din zugeordneten Hubbegrenzungsstift an. Diese I liibbeuren/unussiifte bestehen bei der bekannten I n neubacken trommelbremse aus Spe/iahnessingschrauhui mit einem flanschähnlithen Kopf, dessen Ouersiliiiiii im Interesse der Klcinhaltimg des Plat/-bedurfes zugunsten der Bremsbeläge möglichst klein bemessen sein muß.Although theoretically all brake shoes should have the same service life, it has, however has shown that this is not the case in practice. Inevitable tolerances, irregularities in the physical condition of the brake shoes and Bremsaiiker, differences in the spring preloads, etc. lead namely in practice since / u that the Brake shoes do not wear out completely evenly. To now by a prematurely wearing brake shoe not having to accept damage to the drum brake surface, are with the known Inner hook drum brake between the adjacent free ends of the magnetic anchor and the Leaf springs bearing the brake shoes used. If one of the brake shoes Mn / t is in a hurry. so she suggests during the remaining service life of the remaining brake shoes, i.e. until / when all brake shoes are replaced din associated stroke limiting pin. These libbeuren / unussiifte exist with the known I n new jaw drum brake made of Spe / iahnessingschrauhui with a flange-like head, whose Ouersiliiiiii in the interest of the content of the space requirement must be made as small as possible in favor of the brake pads.

Is hat sich mm in der Praxis gezeigt, daß die I cbensdaiier einer derartigen bekannten Innenbackenlrommelbrcmse häiilig durch den vorzeitigen Verschleiß einer ein/igen Bremsbacke begrenzt ist. Der finind hierfür liegt darin, daß nach dem Zeitpunkt, nach dem kein LingiilT der Bremsbacke mit der Bremsliommel mehr stattfindet, diese Bremsbacke für den Rest Lebensdauer tier übrigen Bremsbacken sehr oft, /. B. huiulertlaiisendmal. gegen den llubbegren/ungsslift schlägt. Dieser Belastung sind aber die bekannten lliibliegrenzungsslifle in den meisten Fällen nicht gewachsen; sie werden zerstört mill die vor/eilig verbrauchte Bremsbacke schlägt gegen die Bremstrommel an und beschädigt diese hierbei.It has been shown in practice that the I cbensdaiier such a known inner jaw drum brake often due to the premature Wear of a single brake shoe is limited. The finind for this lies in the fact that after the point in time after there is no longer any contact between the brake shoe and the brake drum, this brake shoe very often for the rest of the service life of the remaining brake shoes, /. B. huiulertlaiisendmal. against the llubbegren / ungsslift hits. These are stress but the well-known liiblie limiterslifle in the most cases failed to cope; they are destroyed when the prematurely used brake shoe hits against the brake drum and damages it in the process.

Ausgehend von dem vorgenannten Stand der Technik und der genannten Problemstellung, ist es nun Aufgabe de Erfindung, eine Innenbackentrommclbrcmse der genannten Art dahingehend zu verbessern, daß die Lehensdauer erhöht wird. Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß die Huhbegrenzungselemente an der Befestigungsstelle der Blattfedern angeordnet sind und daß jedes Hubbegrenzungsclement mindestens einen in Umfangsrichtung auskragenden Arm hesitzt. Dadurch, daß die Hubbegrenzungselcmente nicht, wie bei der bekannten Anordnung, zwischen den freien Enden zweier benachbarter Blattfedern, sonc'ern jeweils an der Befestigungsstelle der einzelnen Blattfedern angeordnet sind, ergeben sich vor allem folgende Vorteile.Based on the aforementioned prior art and the stated problem, it is now the object of the invention to improve an inner jaw drum brake of the type mentioned so that that the lease term is increased. This object is achieved according to the invention in that the height limitation elements are arranged at the point of attachment of the leaf springs and that each Stroke limiting element has seated at least one arm that protrudes in the circumferential direction. As a result of that the stroke limitation elements do not, as with the known one Arrangement, between the free ends of two adjacent leaf springs, but each are arranged at the point of attachment of the individual leaf springs, the main results are as follows Benefits.

Im Bereich der Blattfederbefestigungsstelle stehtIn the area of the leaf spring attachment point it says

ao ein bislang und auch bei der bekannten Bremse ungenützter, relativ großer Raum zur Verfügung, der wesentlich größer ist als der Raum zwischen den freien Lnden zweier benachbarter Federn, zumal letztere auf Kosten der Größe der Bremsbacken geht.ao a relatively large space that has not been used up to now and also with the known brake is available is much larger than the space between the free ends of two adjacent springs, especially since the latter comes at the expense of the size of the brake shoes.

as Da erfindungsgemäß die Hubbegrenzungselemente in diesem großen und bislang unbenutzten Raum angeordnet werden, können die Hubbegrenzungselemente sehr groß und kräftig, z. B. mit starken, auskragenden Armen, ausgeführt werden, so daß mit Sicherheit auch bei einem vielfachen Anschlagen eine Beschädigung der Hubbcgrenzungselemente und somit eine Beschädigung der Bremstrommel vermieden wird. Wie ohne weiteres verständlich, können die Arme eine beliebige Formgebung haben, sofern nur gewährlcistct ist, daß sie auch bei einem vielfachen Anschlagen nicht beschädigt werden. Besonders vorteilhaft sind Arme gleicher Biegefestigkeit.As, according to the invention, the stroke limiting elements in This large and so far unused space can be arranged, the stroke limiting elements very big and strong, e.g. B. with strong, cantilevered arms, so that with security Damage to the stroke limiting elements and thus damage even if they are struck multiple times Damage to the brake drum is avoided. As can be understood without further ado, the arms can have any shape, as long as it is guaranteed that they will also have a multiple shape Hitting will not be damaged. Arms with the same flexural strength are particularly advantageous.

Vorteile ergeben sich ferner, wenn die Hubbegrenzung'jelemcnte mit Befestigungsmitteln, z. B. mit Schrauben, mit dem Magnetkörper verbunden sind, die zugleich auch zur Befestigung der Blattfedern an dem Magnetkörper dienen. F.twaige sonst erforderliche zusätzliche Gewindebohrungen im Magnetkörper und Schrauben können somit entfallen.There are also advantages if the stroke limiter element with fasteners, e.g. B. with screws connected to the magnet body, which also serve to attach the leaf springs to the magnet body. F. any other necessary Additional threaded holes in the magnet body and screws can therefore be omitted.

Gemäß einer bevorzugten Ausführungsform ist der unter dem oder den Armen der Hubbegrenzungselementc liegende Bereich der Magnetanker zur Bcfestijuingsstelle der Blattfeder hin abgeschrägt. According to a preferred embodiment is the area of the magnet armature located under the arm or arms of the stroke limiting element beveled towards the fastening point of the leaf spring.

Gemäß einer bevorzugten Ausführungsform erstreckt der sich in Umfangsrichtung auskragende Arm des Hubbegrenzungselcmentes über die Breite des Mangetkörpcrs. F.s ist von Vorteil, wenn der unter dem oder den Armen des Hubbegrenzungs- bzw. Führungselementes liegende Bereich der Magnetanker /iir riefesligungsstclle der Blattfeder hin abgeschrägt ist.According to a preferred embodiment, the one protruding in the circumferential direction extends Arm of the stroke limitation element across the width of the magnetic body. F.s is an advantage if the under the area of the magnet armature lying on the arm or arms of the stroke limiting or guide element / bevelled towards the opening of the leaf spring is.

Die Erfindung wird nachstehend an einem Ausfiilmmgsbeispicl und an Hand der ZeichnungenThe invention is illustrated below using an exemplary embodiment and on the basis of the drawings

fin näher ei läutert. F.s zeigtfin closer egg purifies. F.s shows

I·'i g. I eine Stirnansicht einer geöffneten Innenbackenbremse, I · 'i g. I a front view of an open inner shoe brake,

F i g. 2 eine Draufsicht auf ein in F i g. I dargestelltes Begrenziings- und Führungselement,F i g. FIG. 2 is a plan view of the one shown in FIG. I pictured Limiting and guiding element,

^f'.^r) F i g. } eine perspektivische Teilansicht einer innenbackenbremse, ähnlich der in Fig. I, jedoch mit einer Hilfslüftcinriehtung, ^f '. ^r ) F i g. } a perspective partial view of an inner shoe brake, similar to that in Fig. I, but with an auxiliary ventilation device,

F i g. 4 eine perspektivische Darstellung eines Hub-F i g. 4 a perspective view of a lifting

Claims

3 43 4

limiting and guide element for an inner 13 a foot 33, which through the already mentioned groove,

shoe brake according to FIG. 3 and through which the wire cable 32 runs, in two areas

Fig. 5 shows a cable nipple for the 33 (/ and 33 /) shown in Fig. 3 is separated. The area 33 h des

posed inner shoe brake. Foot 33 has geschoi in the circumferential direction. one

At the flange of an electrical 5, not shown, is much smaller in width than the area M ti.

motors is a ring-shaped magnetic body with side surfaces pointing in the circumferential direction

attached by 2. The magnet body 2 has a ring which serves as a guide surface in FIG. 5 shown

shaped groove J> (see Fig. 3), on both sides of which put U-shaped nipple 34, which is in the axial direction

I'olsehenkcl 4 and 5 lie. The groove 3 takes a guide unit attached to the magnet body 2

excitation winding, not shown. io piece 7 is displaceable (see Fig. 3), while its

On the shaft of the electric motor, a braking face facing the area 33 α is rounded

drum 8 attached. At the circumference of the Magnetkör- is. As in Fig. 4 is indicated by dashed lines, cross

nets 2 several leaf springs 13 are attached in the middle. the ends of the wire rope 32 at the rounded

The leaf springs 13 extend in the circumferential direction end face, and are in bores 35 in the free

device of the magnet body 2 and wear at their free 15 ends of the nipple 34 soldered. The nipple 34 carries

Area in each case a magnet armature 15 and a braking web on its connecting web, two further bores

jaw 16. 36, in which z. B. the u nd of a not shown

The centrally clamped leaf springs 13 will th further wire rope can be cuigeloted that

held by screws through which at the same time a Betäliguugs-

Limiting and guiding element 7 is attached. 20 lever leads. By pulling the nipple in an axial direction

The limiting and guiding element 7 has the direction lying around the magnet body 2

A mushroom-shaped shape seen in cross section. The loop of the wire rope 32 is reduced, and thereby

laterally protruding arms 7 'of the guide piece, the brake shoes 16 are lifted,

extend up to close to the brake shoes 16.

the magnet armature 15. There is expediently 25 or limiting elements 7 on the fastening

the guide element 7 from a non-magnetic point of the leaf springs brings considerable advantages

material, e.g. brass. In the functional and economic respect shown in Fig. 1 it is

Asked embodiment of the guide element 7 Since in the area of the leaf spring attachment a previously

if its laterally protruding arms T are available as a body of unused larger space,

designed with the same flexural strength. The one below the 30 can be the guide element as a delimitation piece

Arms of the guide element 7 area which are powerfully executed, for example with

Magnetic armature 15 is in the direction of the Federbefe- kragenden arms of the same flexural strength that groove

slope bevelled. This bevel is used for safety even in the event of premature wear

only needs the clean contact of the magnet armature 15 brake shoe and the subsequent repeated

on the laterally protruding arms T of the guide 35 hit the delimitation piece of which

Rungselementes 7, but causes an advantageous end can be prevented. Damage

Shifting of the magnetic flux in the direction of the brake drum is therefore assumed with certainty.

on the front leaf spring ends. Because it has closed. By the fact that for the limitation or

borrowed shown that the inevitably very small guide element now has no own thread

Gap, which the hanging and screws (.! Are required and extra-

Licensing ends of the armature 15 with the ring due to the laterally protruding arms

Magnet 2 form, when the ring magnet is excited, brake pads are selected to be about a third shorter

At this point there is practically a short-circuit of the magnc- than before, a considerable one also occurs

table flow occurs and thus the remaining cheaper one. The fact that the brake pads

available magnetic force due to 45 compared to the known brake pads now

their smaller amount requires a certain amount of time, about a third of their length are shorter, means

around the Bremsbackenheim approaching the electro- theoretically due to the inclined position; the

to ventilate the motor. A Veikürzuim through the made Anschrii- brake hooks to the brake drum

of the brake shoes 15 on their inner linden tree of the expected service life by a ninth,

the saturation limit quickly becomes there at 5 °. This quadratic dependence results from this.

Magnetization reached, and the magnetic flux that due to the oblique position of the brake shoes

Mainly flows through the larger areas - the entire removed brake system tolT volume

rcn cross-section of the armature 15, which is wedge-shaped, with the shortening of the

practically the full magnetic force is available. Brake shoe by a third only the chisel tip,

F i g. 3 shows an embodiment of an inner 55 that is only a ninth of that which can be used for braking

Jaw brake, with which an additional auxiliary ventilation pre- Breniswerkstoffvolumens, is forfeited. Have attempts

direction is provided for the brake shoes. Which, however, demonstrated that through safe prevention

Brake shoes 16 each have a circumferential damage to the drum in the event of premature failure

direction running groove 31, in which an over and wear of a single brake shoe the effective

the whole; The circumference of the magnet body 2 extends 6 ° tiv expected service life at least the Dop

of the wire rope 32 runs. The wire rope 32 is less than pclte, but probably six times as much

felt through the guide element 7, which is beyond the previously known brakes,

speaking also in the circumferential direction.
Has running groove.

At least one of the guide elements 7 in the case of ⁶ 5 1. Electromagnetically ventilated inner jaws

Inner shoe brake according to Fip. 3 is accordingly a drum brake with an annular magnetic

Fig. 4 trained. This guide element 7 Iv.- body on which is in the circumferential riditung of

seated as a support on the underlying leaf spring magnet body extending leaf springs on one side

or are fastened in the middle, which at their free linden «or at their free ends with the magnetic body interacting magnet armature and brake shoes wear and with the Hubbbegrenzungsclcmentc are provided for the brake shoes, characterized in that the Ilubbcbegrenzungselemente (7) on the fastening the leaf springs (13) are arranged and that each stroke limiting element (7) at least has an arm (7 ') protruding in the circumferential direction.

2. Electromagnetically ventilated inner jaw drum brake according to claim 1, characterized in that that the stroke limiting elements (7) are connected to the magnet body (2) by fastening means, in particular by screws are, which also serve to attach the leaf springs (13) to the magnet body (2).

3. Electromagnetically released inner shoe drum brake according to claim 1 and 2, characterized in that the under the arm or arms (7 ') of the stroke limiting element (7) the area of the magnet armature (15) beveled towards the fastening point of the leaf springs (13) is.

4. Electromagnetically releasable inner jaw drum brake c according to one or more of the preceding claims, characterized in that the protruding in the circumferential direction Arm (7 ') of the guide element (7) extends over the width of the magnet body (2).

5. Electromagnetically releasable inner shoe drum brake according to one or more of the preceding claims, characterized in that the cantilevered in the circumferential direction Arm (7 ') of the guide element (7) is designed as an arm of the same flexural strength.

6. Electromagnetically released inner jaw drum brake according to one or more of the preceding claims, characterized in, that the stroke limiting element (7) has a cylindrical surface on its upper side, the The radius of curvature is adapted to the inner radius of the brake drum (8).

1 sheet of drawings