DE2744060C3

DE2744060C3 - Hydraulic braking device for driving and steering brakes on two-axle vehicles, in particular agricultural tractors

Info

Publication number: DE2744060C3
Application number: DE19772744060
Authority: DE
Inventors: Helmut Stadt Haag Antensteiner; Franz Neuzeug Niedermoser
Original assignee: STEYR-DAIMLER-PUCH AG WIEN
Current assignee: STEYR-DAIMLER-PUCH AG WIEN
Priority date: 1976-11-04
Filing date: 1977-09-30
Publication date: 1979-07-12
Also published as: DE2744060A1; IT1088217B; AT355441B; DE2744060B2; ATA820376A; GB1556951A

Description

In der Zeichnung ist der Erfindungsgegenstand beispielsweise dargestellt, und zwar zeigtThe subject of the invention is shown in the drawing for example shown, namely shows

F i g. 1 die beiden Bremspedale für die hydraulische Bremseinrichtung eines Ackerschleppers in Ansicht,F i g. 1 the two brake pedals for the hydraulic braking device of a farm tractor in view,

Fi g. 2 einen zugehörigen Schnitt nach der Linie U-Il der F i g. 1 undFi g. 2 shows an associated section along the line U-II the F i g. 1 and

Fig.3 die von den Pedalen betätigbaren Ventile im größeren Maßstab im AxialschnittFig. 3 the actuated by the pedals valves in larger scale in axial section

Um eine Fahr- oder Lenkbremsung durchführen zu können, sind zwei Bremspedale 1,2 vorgesehen, die als sogenannte hängende Pedale ausgeführt und mit Hilfe eines nicht dargestellten Kupplungsstückes zur gemeinsamen Betätigung bei der Fahrbremsung gekuppelt werden können. Jedem Bremspedal 1, 2 ist ein Hauptbremszylinder zugeordnet (nicht dargestellt), dessen Kolben mit dem entsprechenden Pedal über ein Gestänge 3 verbunden ist. An den Pedalen 1, 2 ist oberhalb ihrer Achse 4 je ein Bügel 5, 6 angeschweißt, welche Bügel 5, 6 gemeinsam an einem von einer Steuerstange 7 gebildeten Gestänge einer insgesamt mit 8 bezeichneten Ventileinheit anliegen.To perform a driving or steering braking to can, two brake pedals 1,2 are provided, which are designed as so-called hanging pedals and with the help a coupling piece, not shown, coupled for common actuation during driving braking can be. A master brake cylinder is assigned to each brake pedal 1, 2 (not shown), the piston of which is connected to the corresponding pedal via a linkage 3. On pedals 1, 2 is above their axis 4 each a bracket 5, 6 welded, which bracket 5, 6 together on one of one Control rod 7 formed linkage of a total of 8 designated valve unit rest.

Die Ventileinheit 8 besteht gemäß F i g. 3 aus einem gemeinsamen Gehäuse 9, in dem die Steuerstange 7 verschiebbar gelagert ist, wobei eine Feder 10 die Steuerstange 7 nach außen gegen die den Pedalen zugeordneten Bügel 5, 6 zu drücken versucht Im Gehäuse 9 sind ferner zwei federbelastete Ventile 11 vorgesehen, die sich von ihrem Sitz abheben und demnach öffnen, wenn die Steuerstange 7 bei Freigabe durch die Pedale unter der Wirkung der Feder 10 nach rechts verschoben wird, so daß die Schrägflächen 12 der Steuerstange 7 die Ventile 11 nach außen drücken. Die Verbindungsleitungen 13 von den Hauptbremszylindern zu den beiden Radbremszylindern der Fahrzeughinterräder weisen Zweigleitungen 14 auf, die zu den Ventilen 11 führen und bei geöffneten Ventilen 11 eine Querverbindung herstellen. Der Schraubeinsatz 15 kann verschlossen sein, in welchem Fall bei geöffneten Ventilen 11 lediglich ein Druckausgleich zwischen den Verbindungsleitungen 13 an den beiden Fahrzeugseiter. stattfindet. Es ist aber auch möglich, an den Schraubeinsatz 15 eine Untergabelung zu den Vorderrad-Bremszylindern führende Druckleitung anzuschließen, um bei gemeinsamer Pedalbetätigung nicht nur einen Druckausgleich für die beiden Fahrzeugseiten, sondern auchThe valve unit 8 consists according to FIG. 3 from a common housing 9 in which the control rod 7 is slidably mounted, a spring 10 attempting to push the control rod 7 outward against the brackets 5, 6 assigned to the pedals lift off their seat and therefore open when the control rod 7 is moved to the right when released by the pedals under the action of the spring 10, so that the inclined surfaces 12 of the control rod 7 press the valves 11 outward. The connecting lines 13 from the master brake cylinders to the two wheel brake cylinders of the vehicle rear wheels have branch lines 14 which lead to the valves 11 and establish a cross connection when the valves 11 are open. The threaded stud 15 may be closed, in which case with open valves 1 1, only a pressure balance between the connecting lines 13 to the two vehicle facilities. takes place. However, it is also possible to connect a pressure line leading to the front wheel brake cylinders to the screw insert 15 in order not only to equalize pressure for both sides of the vehicle when the pedal is operated together

lu eine Allradbremsung herbeizuführen.lu to bring about a four-wheel braking.

Erfindungsgemäß sind nun die Naben 16, 17 der beiden Bremspedale 1, 2 mit ineinandergreifenden klauenartigen Mitnehmern 18, 19 versehen, wobei die Mitnehmer bzw. Klauen 18 der Nabe 16 des Pedales 1 und die Klauen 19 der Nabe 17 des Pedales 2 zugehören. Insbesondere aus Fig.2 ist ersichtlich, daß in der Ruhestellung der Pedale 1,2 bzw. bei zur Fahrbremsung gekuppelten Pedalen zwischen den Mitnehmern oder Klauen 18, 19 in beiden Umfangsrichtungen je ein Mindestspiel vorhanden ist. Dieses Spiel reicht aus, um das eine euer andere Pedal 1, 2 für sich allein so zu verschwenken, daß bei fehlerfreie. Pedalbetätigung volle Lenkbremsung erfolgt, da ja nur irr.jner ein Pedal bewegt wird, der Bügel 5 oder 6 des jeweils anderenAccording to the invention, the hubs 16, 17 of the two brake pedals 1, 2 are now interlocking claw-like drivers 18, 19, the drivers or claws 18 of the hub 16 of the pedal 1 and the claws 19 of the hub 17 of the pedal 2 belong. In particular from Figure 2 it can be seen that in the Rest position of the pedals 1, 2 or, when the pedals are coupled for driving braking, between the drivers or Claws 18, 19 each have a minimum play in both circumferential directions. This game is enough to one of your other pedal 1, 2 for itself alone pivot that with error-free. Pedal actuation full steering braking takes place, since there is only one pedal per pedal is moved, the bracket 5 or 6 of the other

2, Pedals an der Steuerstange 7 weiterhin anliegt und eine Verschiebung dieser Steuerstangc unter der Wirkung der Feo.er 10 zum öffnen der Ventile 11 verhindert. Wird der Schwenkweg des betreffenden Pedals über das Spiel zwischen den Mitnehmern 18, 19 hinaus 2, the pedals on the control rod 7 continues to be applied and a displacement of this control rod c under the action of the Feo.er 10 to open the valves 11 is prevented. If the pivoting path of the pedal in question is beyond the play between the drivers 18, 19

;n vergrößert, so erfolgt aber zwangsläufig die Mitnahme des zweiten Pedals, und es gelangt die Steuerstange 7 auf jeden Fall in die Öffnungsstellung der Ventile 11, in der Fahrbremsung erfolgt, da durch die Bewegung beider Pedaie und der damit verbundenen Bewegung; n is enlarged, but it is inevitably carried along of the second pedal, and the control rod 7 is in any case in the open position of the valves 11, in the driving braking takes place because of the movement of both pedals and the associated movement

)> der Kolben beide Überströmöffnungen in den Ausgleichbehälter verschlossen sind.)> the piston both overflow openings into the expansion tank are locked.

Hierzu 2 Blatt ZeichnungenFor this purpose 2 sheets of drawings

Claims

Claim:

Hydraulic braking device for driving and steering brakes of two-axle vehicles, in particular Agricultural tractor, with two brake pedals that can optionally be coupled to one another, each with a master brake cylinder are assigned, which is line-connected to the wheel brake cylinder of a rear wheel is, whereby the driving braking takes place by joint actuation of both brake pedals and if necessary, the wheel brake cylinders of the front wheels from the master brake cylinders can be pressurized and where of the two connecting lines of the master brake cylinder mil: the rear brake cylinders two through one each Blocked valve, unite behind these valves and, if necessary, under new ones Branch branches leading to the front brake cylinders, the valves of which by means of a; Linkage or the like are simultaneously apparent by jointly actuating the two brake pedals, characterized in that the hub; (16, 17) of the two brake pedals (1, 2) interlocking Driver, in particular claws (18, 19) ,, 2 ") own, between those in the rest position of the pedals or when coupled for driving braking Pedals in both circumferential rides each correspond to the pivoting path of a pedal when steering brakes corresponding minimum game is provided. jo

The invention relates ^r, I au "a hydraulic braking device for Frhr- and steering brakes biaxial vehicles insbesonde · ': tractors, with two optionally coupled together brake pedals, which are each assigned to a master brake cylinder which is line-connected to the wheel brake cylinder of a rear wheel, wherein the Driving braking takes place through joint actuation of both brake pedals and, if necessary, the wheel brake cylinders of the front wheels can be pressurized by the master brake cylinders and two of the two connecting lines of the master brake cylinder with the rear brake cylinders are each blocked by a valve, join behind these valves and, if necessary, to the new bifurcation Lines leading to the front wheel brake cylinders branch off, the valves of which can be opened simultaneously by means of a linkage or the like by joint actuation of the brake pedals.

Such a braking device is already known (OE-PS 3 05 791). If only one of the two brake pedals is pressed, the wheel brake cylinder is activated also only the corresponding rear wheel braked for steering braking because the valve is in the branch line is blocked and therefore no connection to the brake line system on the other vehicle or on the front wheel brake cylinders. Will against it When the two pedals are pressed together, the two valves in the branch lines and the pressure open from the two master brake cylinders not only propagates to the two rear wheel brake cylinders, but there is also a corresponding pressure equalization for both Fahrzcugscitcn or es If all-wheel braking is provided, the front-wheel brake cylinders are also pressurized, because the connecting lines between the master brake cylinders and the rear wheel • brake cylinders Via the connecting and then bifurcating branch lines also with the front wheel brake cylinders are connected. This construction has fully proven itself when the driving braking always with coupled brake pedals and actually only ever operated one pedal when the steering wheel is braked will. But it can happen that inadvertently when the pedals are disconnected for steering braking first both pedals are pressed together and only then is a transition to only one pedal. During the joint actuation of both pedals, the valves in the branch lines are then located already open and do not return to the locked position when one pedal is released, so that a cross connection is established between the two sides of the vehicle and subsequently when the a pedal, insufficient pressure is built up in the associated rear wheel brake cylinder because the for Bore in the brake master cylinder of the first incorrectly actuated pedal leading to the expansion tank whose return to the rest position has been released and the hydraulic means via the established Dodge the cross connection from the connection line to the rear wheel to be braked into the expansion tank can, so that neither steering braking nor driving braking takes place, even if Front brake cylinders are provided because just by evading the hydraulic means in the Sufficient pressure is not built up anywhere in the expansion tank.

Thus, the invention is based on the object of eliminating this deficiency and the initially To improve the braking device described so that in the event of incorrect operation for steering braking at least one Driving braking takes place on both sides of the vehicle.

The invention solves the problem in that the hubs of the two brake pedals have interlocking drivers, in particular claws, between those in the rest position of the PeUaIe or at the Driving braking coupled pedals in both circumferential directions each one to the pivoting path of a pedal a corresponding minimum clearance is provided for the steering brakes.

If, during steering braking, an opening of the cross connection occurs due to unintentional stepping on both pedals producing valves takes place and then only one pedal is further operated, so after a certain Schwenkwcg this pedal an inevitable entrainment of the second pedal, so that the to Bore of the master cylinder associated with the second valve, leading to the expansion tank, is closed and a corresponding pressure is built up in the whole system, which is necessary for braking on both sides sufficient. Nevertheless, the steering braking per se is not impaired, since the mutual play between the interlocking drivers are matched to the swivel travel of a pedal for steering braking, so each of the two pedals can be operated or pivoted on its own so far, that the desired steering braking is brought about. By following the previous incorrect operation A certain amount of idle travel is carried out with the second pedal in each case, but is avoided with safety, that the driver, because he personally does not feel any braking resistance, and so does the vehicle rides unchecked, stops an action.