DE2740024A1 - Hydraulic transmission for construction vehicle - has emergency brake with motor fluid volume set to minimum on braking - Google Patents

Hydraulic transmission for construction vehicle - has emergency brake with motor fluid volume set to minimum on braking

Info

Publication number
DE2740024A1
DE2740024A1 DE19772740024 DE2740024A DE2740024A1 DE 2740024 A1 DE2740024 A1 DE 2740024A1 DE 19772740024 DE19772740024 DE 19772740024 DE 2740024 A DE2740024 A DE 2740024A DE 2740024 A1 DE2740024 A1 DE 2740024A1
Authority
DE
Germany
Prior art keywords
hydraulic
minimum
hydraulic motors
motors
braking
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
DE19772740024
Other languages
German (de)
Inventor
Bruno Arenz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Losenhausen Maschinenbau AG
Original Assignee
Losenhausen Maschinenbau AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Losenhausen Maschinenbau AG filed Critical Losenhausen Maschinenbau AG
Priority to DE19772740024 priority Critical patent/DE2740024A1/en
Priority to SE7809308A priority patent/SE7809308A/en
Publication of DE2740024A1 publication Critical patent/DE2740024A1/en
Pending legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/4157—Control of braking, e.g. preventing pump over-speeding when motor acts as a pump
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/04—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing
    • B60K17/10—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing of fluid gearing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T1/00—Arrangements of braking elements, i.e. of those parts where braking effect occurs specially for vehicles
    • B60T1/02—Arrangements of braking elements, i.e. of those parts where braking effect occurs specially for vehicles acting by retarding wheels
    • B60T1/08—Arrangements of braking elements, i.e. of those parts where braking effect occurs specially for vehicles acting by retarding wheels using fluid or powdered medium
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/42—Control of exclusively fluid gearing hydrostatic involving adjustment of a pump or motor with adjustable output or capacity

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Control Of Fluid Gearings (AREA)

Abstract

The construction vehicle is powered by a hydraulic transmission in which the speed of the vehicle is set by the pressure output from the main pump and the throughput of the hydraulic motors. For higher torque and lower speeds, the throughout volume is at a maximum. Emergency braking is backed-up by a safety servo which sets the throughput of the motors to a minimum. The minimum setting of the motor throughput corresponds to the stationary setting. The vehicle brakes then do not have to operate against the transmission torque.

Description

Hydrostatischer Fahrantrieb für Baumaschinen Hydrostatic drive for construction machinery

Die Erfindung betrifft einen hydrostatischen Fahrantrieb für Baumaschinen, insbesondere Straßenwalzen, enthaltend eine Hydraulikpumpe und davon gespeiste Hydraulikmotore an Walzen und/oder Rädern, bei welchem die Schluckvolumina der Hydraulikmotore durch hydraulische Stellglieder zwischen einem Minimalwert und einem Maximalwert umschaltbar sind und bei welchem ein zusätzliches Bremssystem als Notbremssystem vorgesehen ist.The invention relates to a hydrostatic drive for construction machinery, in particular road rollers, containing a hydraulic pump and hydraulic motors fed by it on rollers and / or wheels, in which the absorption volumes of the hydraulic motors through hydraulic actuators switchable between a minimum value and a maximum value and in which an additional braking system is provided as an emergency braking system is.

Es sind Baumaschinen mit hydrostatischem Fahrantrieb bekannt.Construction machines with hydrostatic drive are known.

Diese enthalten eine Hydraulikpumpe, üblicherweise in Gestalt einer verstellbaren Axialkolbenpumpe, die mit einer Kraftmaschine gekuppelt ist. Die Hydraulikpumpe fördert Drucköl zu Hydraulikmotoren, die an den Walzen und/oder Rädern der Baumaschine sitzen. Durch Verstellung der Fördermenge der Hydraulikpumpe kann die Geschwindigkeit der Baumaschine verändert werden. Wird die Fördermenge der Hydraulikpumpe auf Nullhub zurückgestellt, so sind die Räder oder Walzen hydraulisch blockiert. Der hydraulische Fahrantrieb kann daher gleichzeitig die Funktion einer Bremse übernehmen.These contain a hydraulic pump, usually in the form of a adjustable axial piston pump which is coupled to an engine. The hydraulic pump promotes pressure oil Hydraulic motors that operate on the rollers and / or The wheels of the construction machine sit. By adjusting the delivery rate of the hydraulic pump the speed of the construction machine can be changed. Will the flow rate If the hydraulic pump is reset to zero stroke, the wheels or rollers are hydraulic blocked. The hydraulic drive can therefore also function as a Apply the brake.

Das von den Walzen aufgebrachte Drehmoment ergibt sich aus dem Förderdruck der Hydraulikpumpe und dem Schluckvolumen der Hydraulikmotore. Je höher das Schluckvolumen ist, desto langsamer laufen die Hydraulikmotore, desto größer ist aber auch das von den Hydraulikmotoren aufgebrachte Drehmoment. Es kann erforderlich sein, die Baumaschine mit hohen Drehmomenten anzutreiben, beispielsweise um eine Steigung hinaufzufahren. Es kann aber auch wffnschenswert sein, die Drehmomente an allen oder einigen Hydraulikmotoren herabzusetzen, um eine höhere Fahrgeschwindigkeit zu erreichen oder beispielsweise ein Durchdrehen einer Walze zu verhindern. Es ist daher bekannt, die Schluckvolumina der Hydraulikmotore durch hydraulische Stellglieder zwischen einem Minimalwert und einem Maximalwert umzuschalten. Das kann dadurch geschehen, daß die Schiefscheibe eines Axialkolbenmotors durch einen Hydraulikzylinder zwischen zwei Endstellungen verschwenkbar ist. Der Hydraulikzylinder ist über als Magnetventile ausgebildete Wegeventile von dem Druck einer Speisepumpe beaufschlagbar, die mit der Hydraulikpumpe des Fahrantriebs gekuppelt ist.The torque applied by the rollers results from the delivery pressure the hydraulic pump and the displacement of the hydraulic motors. The higher the swallowing volume is, the slower the hydraulic motors run, but the bigger it is torque applied by the hydraulic motors. It may be required that To drive construction machinery with high torques, for example around a slope drive up. But it may also be desirable to adjust the torques at all or reduce some hydraulic motors to achieve a higher travel speed to achieve or, for example, to prevent a roller from spinning. It is therefore known, the displacement of the hydraulic motors by hydraulic actuators to switch between a minimum value and a maximum value. It can do that happen that the swash plate of an axial piston motor by a hydraulic cylinder is pivotable between two end positions. The hydraulic cylinder is about as Solenoid valves designed directional valves can be acted upon by the pressure of a feed pump, which is coupled to the hydraulic pump of the travel drive.

Aus Sicherheitsgründen ist ein zusätzliches Bremssystem als Notbremssystem vorgesehen.For safety reasons, an additional braking system is used as an emergency braking system intended.

Wenn bei Betätigung des zusätzlichen Bremssystems die Kraftmaschine läuft und die Hydraulikpumpe Druck in dem System des hydraulischen Fahrantriebs erzeugt, müssen die Bremsen des zusätzlichen Bremssystems gegen die von den Hydraulikmotoren aufgebrachten Drehmomente arbeiten.If, when the additional braking system is actuated, the engine runs and the hydraulic pump pressure in the system of the hydraulic drive the brakes of the additional braking system must be set against those of the hydraulic motors applied torques work.

Das zusätzliche Bremssystem muß daher bei einem hydraulischen Fahrantrieb mit umschaltbaren Hydraulikmotoren so ausgelegt sein, daß es die Drehmomente der Hydraulikmotore auch bei dem Maximalwert des Schluckvolumens aufzunehmen vermag.The additional brake system must therefore be used with a hydraulic drive be designed with switchable hydraulic motors so that the torques of the Hydraulic motors can also accommodate the maximum value of the displacement.

Der Erfindung liegt die Aufgabe zugrunde einen hydrostatischen Fahrantrieb für Baumaschinen mit umschaltbaren Hydraulikmotoren und zusätzlichem Bremssystem so auszubilden, daß die von dem zusätzlichen Bremssystem aufzubringenden Bremsmomente geringer gehalten werden und die Sicherheit des zusätzlichen Bremssystems verbessert wird.The invention is based on the object of a hydrostatic travel drive for construction machines with switchable hydraulic motors and additional braking system to be trained so that the braking torques to be applied by the additional braking system can be kept lower and the safety of the additional braking system is improved will.

Erfindungsgemäß wird diese Aufgabe dadurch gelöst, daß die Schluckvolumina der Hydraulikmotore bei Betätigung des zusätzlichen Bremssystems automatisch auf die Minimalwerte rückstellbar sind.According to the invention this object is achieved in that the swallowing volumes the hydraulic motors automatically open when the additional brake system is actuated the minimum values can be reset.

Damit werden die an den Hydraulikmotoren wirksamen Drehmomente bei Betätigung des zusätzlichen Bremssystems automatisch verringert, und zwar unabhängig davon, in welchem Schaltzustand die Hydraulikmotore vorher waren.This means that the torques acting on the hydraulic motors are at Actuation of the additional braking system automatically reduced, independently of the switching state in which the hydraulic motors were previously.

Die Erfindung ist nachstehend an einem Ausführunglsbeispiel unter Bezugnahme auf die zugehörigen Zeichnungen näher erläutert.The invention is shown below using an exemplary embodiment Explained in more detail with reference to the accompanying drawings.

Fig. 1 zeigt ein Hydraulikschaltbild eines erfindungsgemäßen hydrostatischen Fahrantriebs. Fig. 1 shows a hydraulic circuit diagram of a hydrostatic according to the invention Traction drive.

Fig. 2 zeigt den Betätigungshebel für das zusätzliche Bremssystem. Fig. 2 shows the operating lever for the additional braking system.

Mit 10 ist eine Kraftmaschine bezeichnet, durch welche eine Hydraulikpumpe 12 des Fahrantriebes angetrieben wird. Mit der Hydraulikpumpe 12 ist eine Speisepumpe 14 verbunden. Die Hydraulikpumpe 12 fördert Drucköl über eine Leitung 16 und Leitungen 18 bzw. 20 zu Hydraulikmotoren 22 bzw. 24. Durch den Hydraulikmotor 22 ist eine Walze 26 antreibbar, während von dem Hydraulikmotor 24 ein Radteil 28 angetrieben wird. Die Hydraulikmotore 22 und 24 sind durch je einen Hydraulikzylinder 30 bzw. 32 zwischen einer Stellung mit maximalem Schluckvolumen und einer Stellung mit minimalem Schluckvolumen verstellbar.With 10 an engine is designated, through which a hydraulic pump 12 of the drive is driven. With the hydraulic pump 12 is a feed pump 14 connected. The hydraulic pump 12 conveys pressure oil via a line 16 and lines 18 and 20 to hydraulic motors 22 and 24, respectively. The hydraulic motor 22 is a Roller 26 can be driven, while a wheel part 28 is driven by the hydraulic motor 24 will. The hydraulic motors 22 and 24 are each driven by a hydraulic cylinder 30 or 32 between a position with maximum displacement and a position with minimum Adjustable displacement.

Die Verstellung der Hydraulikzylinder wird von dem Druck der Speisepumpe 14 bewirkt, der über als Magnetventile ausgebildete 4/2-Wegeventile 34 bzw. 36 auf die Hydraulikzylinder 30 bzw. 32 aufsschaltbar ist. Die Hydraulikzylinder enthalten einen beidseitig beaufschlagten Stellkolben, der jeden der Hydraulikzylinder 30,32 in zwei Kammern unterteilt. In der in Fig. 1 dargestellten Ruhelage der Ventile ist die eine Kammer mit der Druckseite der Speisepumpe 14 und die andere Kammer mit einem Behälter 38 verbunden. In der anderen Schaltstellung der Ventile 36 und 34 sind die Anschlüsse vertauscht. Im ersteren Falle wird ein maximales und im letzteren Falle ein minimales Schluckvolumen der Hydraulikmotore 22 und 24 eingestellt. Die 4/2-Wegeventile 34 und 36 werden von Magnetwicklungen 40 bzw. 42 gesteuert, die über Schalter 44 bzw. 46 wahlweise erregbar sind.The adjustment of the hydraulic cylinder is made by the pressure of the feed pump 14 causes the 4/2-way valves 34 and 36 designed as solenoid valves on the hydraulic cylinder 30 or 32 can be switched on. The hydraulic cylinders included an actuating piston which is acted upon on both sides and which each of the hydraulic cylinders 30,32 divided into two chambers. In the rest position of the valves shown in FIG. 1 is one chamber with the pressure side of the feed pump 14 and the other chamber connected to a container 38. In the other switching position of the valves 36 and 34 the connections are reversed. In the former case it becomes a maximum and in the latter Case a minimum displacement of the hydraulic motors 22 and 24 is set. the 4/2-way valves 34 and 36 are controlled by solenoid windings 40 and 42, respectively, which can be optionally excited via switch 44 or 46.

Die Hydraulikpumpe 12 ist durch einen Hydraulikzylinder 48 verstellbar, der über ein manuell betätigbares 4/3-Wegeventil 50 und eine Drossel 52 in der einen oder anderen Richtung vom Ausgangsdruck der Speisepumpe 14 beaufschlagbar ist.The hydraulic pump 12 is adjustable by a hydraulic cylinder 48, via a manually operated 4/3-way valve 50 and a throttle 52 in one or in another direction can be acted upon by the output pressure of the feed pump 14.

Bei Betätigung des zusätzlichen Bremssystems über einen Hebel 54 (Fig. 2) und einen Seilzug 56 wird über einen an dem Hebel 54 angebrachten Nocken 58 und eine Kontaktrolle 60 ein zweipoliger Schließschalter 62 betätigt. Hierdurch werden die Wicklungen 40 und 42 der 4/2-Wegeventile 34 und 36 an Spannung gelegt und erregt, wodurch die beiden Hydraulikmotore automatisch auf minimales Schluckvolumen gestellt werden.When the additional brake system is actuated via a lever 54 (Fig. 2) and a cable 56 is attached to the lever 54 via a cam 58 and a contact roller 60 actuates a two-pole closing switch 62. This will be the windings 40 and 42 of the 4/2-way valves 34 and 36 are energized and energized, whereby the two hydraulic motors are automatically set to the minimum displacement will.

Claims (1)

Patentanspruch Hydrostatischer Fahrantrieb für Baumaschinen, insbesondere Straßenwalzen, enthaltend eine Hydraulikpumpe und davon gespeiste Hydraulikmotore an Walzen und/oder Rädern, bei welchem die Schluckvolumina der Hydraulikmotore durch hydraulische Stellglieder zwischen einem Minimalwert und einem Maximalwert umschaltbar sind und bei welchem ein zusätzliches Bremssystem als Notbremssystem vorgesehen ist, dadurch gekennzeichnet, daß die Schluckvolumina der Hydraulikmotore (22,24) bei Betätigung des zusätzlichen Bremssystems automatisch auf die Minimalwerte rückstellbar sind. Patent claim Hydrostatic drive for construction machines, in particular Road rollers containing a hydraulic pump and hydraulic motors fed by it on rollers and / or wheels, in which the absorption volumes of the hydraulic motors through hydraulic actuators switchable between a minimum value and a maximum value and in which an additional braking system is provided as an emergency braking system is, characterized in that the displacement of the hydraulic motors (22,24) automatically resettable to the minimum values when the additional brake system is actuated are.
DE19772740024 1977-09-06 1977-09-06 Hydraulic transmission for construction vehicle - has emergency brake with motor fluid volume set to minimum on braking Pending DE2740024A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE19772740024 DE2740024A1 (en) 1977-09-06 1977-09-06 Hydraulic transmission for construction vehicle - has emergency brake with motor fluid volume set to minimum on braking
SE7809308A SE7809308A (en) 1977-09-06 1978-09-05 HYDROSTATIC DRIVE DEVICE FOR BUILDING MACHINES

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19772740024 DE2740024A1 (en) 1977-09-06 1977-09-06 Hydraulic transmission for construction vehicle - has emergency brake with motor fluid volume set to minimum on braking

Publications (1)

Publication Number Publication Date
DE2740024A1 true DE2740024A1 (en) 1978-09-14

Family

ID=6018206

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19772740024 Pending DE2740024A1 (en) 1977-09-06 1977-09-06 Hydraulic transmission for construction vehicle - has emergency brake with motor fluid volume set to minimum on braking

Country Status (2)

Country Link
DE (1) DE2740024A1 (en)
SE (1) SE7809308A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2442740A1 (en) * 1978-11-28 1980-06-27 Komatsu Mfg Co Ltd HYDRAULIC CIRCUIT FOR A HYDRAULICALLY DRIVEN VEHICLE
DE3610174A1 (en) * 1985-04-03 1986-10-16 Zahnradfabrik Friedrichshafen Hydrostatic drive system
DE102004061558A1 (en) * 2004-12-21 2006-07-06 Brueninghaus Hydromatik Gmbh Method for braking a driven by a hydrostatic transmission vehicle and a hydrostatic drive
CN100417845C (en) * 2003-01-28 2008-09-10 Zf腓德烈斯哈芬股份公司 Hydrostatic transmission

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2442740A1 (en) * 1978-11-28 1980-06-27 Komatsu Mfg Co Ltd HYDRAULIC CIRCUIT FOR A HYDRAULICALLY DRIVEN VEHICLE
DE3610174A1 (en) * 1985-04-03 1986-10-16 Zahnradfabrik Friedrichshafen Hydrostatic drive system
CN100417845C (en) * 2003-01-28 2008-09-10 Zf腓德烈斯哈芬股份公司 Hydrostatic transmission
DE102004061558A1 (en) * 2004-12-21 2006-07-06 Brueninghaus Hydromatik Gmbh Method for braking a driven by a hydrostatic transmission vehicle and a hydrostatic drive
US7661266B2 (en) 2004-12-21 2010-02-16 Brueninghaus Hydromatik Gmbh Method for braking a vehicle driven by means of a hydrostatic gearbox and also a hydrostatic drive

Also Published As

Publication number Publication date
SE7809308A (en) 1979-03-06

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