DE2547476B1

DE2547476B1 - Gear change unit for motor vehicle - has thrust rods guided by bearing rotated rollers in counterposed longitudinal tracks

Info

Publication number: DE2547476B1
Application number: DE19752547476
Authority: DE
Inventors: Kurt Osterloff
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 1975-10-23
Filing date: 1975-10-23
Publication date: 1977-03-31
Also published as: GB1570759A; FR2386739A1

Abstract

Motor vehicle, gear change arrangement for engaging and disengaging pick-up couplings, with crossways directed thrust rods located in a gear housing which are movable lengthways by roller bearings. To these rods are connected selector forks. At least one of the thrust rods (24, 25, 26) is guided by rollers (30, 31, 32) which have counterposed clearance in the gear housing, and which are rotatable by the roller bearing. The rollers (30, 31, 32) for lengthways guide purposes, are rollable on counterposed longitudinal tracks (33, 38). For crossways guidance, at least one of the longitudinal tracks (33, 34, 35) has a guide edge for the corresponding rollers (30, 31).

Description

115, in einem Fünfganggetriebe dargestellt und erfüllt in Getrieben für Personen-Kraftfahrzeuge ohne weiteres seinen Zweck. Um den gesamten Schaltmechanismus leichtgängiger zu machen, hat man bei Getrieben höherer Leistung die bisher üblichen Schaltstangen durch ein Paket Flachbänder ersetzt, die als Schubkurbelgetriebe arbeiten. Diese bereits in größerem Umfange bei Nutzfahrzeug-Getrieben angewendete Konstruktion ist auf Seite 178 beschrieben und besitzt als Schwinge ausgebildete Schaltgabeln, also nicht mit der Schubstange fest verbundene Schaltgabeln. Es wird mit dieser Schalteinrichtung das Problem des Wirkungsgrades der Schalteinrichtung zufriedenstellend gelöst, jedoch noch nicht eine preiswertere und einfachere Montage. 115, shown in a five-speed transmission and met in transmissions for passenger vehicles without further ado. To the entire switching mechanism To make it easier to run, you have the usual options for gears with higher performance Shift rods replaced by a package of flat belts that work as slider crank drives. This already in a larger Scope applied to commercial vehicle transmissions Construction is described on page 178 and has a swing arm Shift forks, i.e. shift forks not firmly connected to the push rod. It will with this switching device the problem of the efficiency of the switching device solved satisfactorily, but not yet a cheaper and easier assembly.

Einzelheiten sind der nachfolgenden Beschreibung zu entnehmen, die anhand der F i g. 1 bis 5 erläutert sind. Es zeigt F i g. l einen Teilschnitt eines Kraftfahrzeug-Wechselgetriebes in Achsrichtung, mit synchronisierten Schaltkupplungen und einer Schalteinrichtung nach der Erfindung, F i g. 2 einen achssenkrechten Schnitt durch die Schalteinrichtung nach Fig. 1 entlang der Linie A-B in F i g. 1 (Zahnräder und Getriebewellen nicht dargestellt), um eine Schaltgabel und eine der Rollen zu zeigen, F i g. 3 einen weiteren achssenkrechten Schnitt durch die Schalteinrichtung entlang der Linie C-D in F i g. 1, um eine andere Schaltgabel sowie eine weitere Rolle zu zeigen, F i g. 4 eine Baugruppe, gebildet aus einer Schubstange einer durch Nieten unlösbar daran befestigten Schaltgabel, F i g. 5 diese Baugruppe in der in F i g. 4 eingetragenen Ansicht. Details can be found in the following description, which on the basis of FIG. 1 to 5 are explained. It shows F i g. l a partial section of a Motor vehicle change gear in axial direction, with synchronized clutches and a switching device according to the invention, FIG. 2 a section perpendicular to the axis by the switching device according to FIG. 1 along the line A-B in FIG. 1 (gears and gear shafts not shown) to a shift fork and one of the rollers show F i g. 3 a further axially perpendicular section through the switching device along the line C-D in FIG. 1 to another shift fork as well as another Role to show F i g. 4 an assembly formed from a push rod by a Rivets permanently attached to the shift fork, FIG. 5 this assembly in the in F i g. 4 registered view.

Das in F i g. 1 teilweise gezeigte Wechselgetriebe ist für Kraftfahrzeuge höherer Leistung, d. h. für Nutzfahrzeuge vorgesehen. Der Gangwechsel wird durch den Fahrer manuell vorgenommen, wobei die Schaltbewegung von einem Handschalthebel (nicht dargestellt) über übliche, nicht gezeigte Übertragungselemente auf eine Schaltwelle 10 des Getriebes übertragen wird. Das Getriebe, hier ein Synchrongetriebe mit fünf Vorwärtsgängen und einem Rückwärtsgang, enthält drei Schaltkupplungcn 11, 12 und 13, die als formschlüssige Mitnehmerkupplungen in jeweils doppelter Ausführung auf einer Getriebewelle 14 angeordnet sind, um wahlweise diese Welle 14 mit einem der auf ihr drehbar gelagerten Zahnräder 15 bis 20 zu verbinden. Diese Zahnräder stehen im Dauereingriff mit anderen Zahnrädern des Wechselgetriebes. The in Fig. 1 partially shown change gearbox is for motor vehicles higher performance, d. H. intended for commercial vehicles. The gear change is through made manually by the driver, the switching movement being controlled by a manual gearshift lever (not shown) via conventional transmission elements, not shown, on a shift shaft 10 of the transmission is transmitted. The gearbox, here a synchromesh gearbox with five Forward gears and a reverse gear, contains three Schaltkupplungcn 11, 12 and 13, as form-fitting driver couplings in duplicate a transmission shaft 14 are arranged to selectively this shaft 14 with one of the to connect on her rotatably mounted gears 15 to 20. These gears are in place in constant mesh with other gear wheels of the gearbox.

Um die mit der Getriebewelle drehfest und axial beweglich verbundenen Schiebemuffen 21, 22 und 23 der Schaltkupplungen 11, 12, 13 wahlweise mit den Formschlußverzahnungen der Zahnräder 15 bis 20 in Eingriff bringen zu können, sind längsbeweglich geführte Schubstangen 24,25 und 26 im Getriebegehäuse angeordnet, an dener. jeweils Schaltgabeln 27,28 und 29 durch Nietung starr und unlösbar befestigt sind. Die Schaltgabeln greifen jeweils mit an ihren Enden angeordneten Gleitsteinen in Umlaufnuten der zugeordneten Schiebemuffen 21,22 und 23. To the non-rotatably and axially movably connected to the gear shaft Sliding sleeves 21, 22 and 23 of the clutches 11, 12, 13 optionally with the form-locking teeth of the gears 15 to 20 to be able to engage, are longitudinally movably guided Push rods 24, 25 and 26 arranged in the gear housing to dener. each shift forks 27.28 and 29 are rigidly and permanently attached by riveting. The shift forks grip each with sliding blocks arranged at their ends in circumferential grooves of the associated Sliding sleeves 21, 22 and 23.

Die Schubstangen 24, 25 und 26 weisen gleiche rechteckige Querschnittsflächen auf und sind so im Gehäuse nebeneinander angeordnet, daß die Schubstangen jeweils mit den längeren Rechteckseiten parallel benachbart und mit den Schmalseiten des Rechteckquerschnitts in einer Ebene bündig sind. Die Schubstangen bestehen aus blank gezogenem Flachmaterial und die daran durch Nietung befestigten Teile der Gabel bestehen aus einfachem gewalzten Flachmaterial und sind somit kostengünstig herstellbar. The push rods 24, 25 and 26 have the same rectangular cross-sectional areas on and are arranged side by side in the housing that the push rods each with the longer sides of the rectangle parallel to each other and with the narrow sides of the Rectangular cross-section are flush in one plane. The push rods are made of bare drawn flat material and the parts of the fork attached to it by riveting consist of simple rolled flat material and are therefore inexpensive to manufacture.

Die Längsführung und Abstützung der Schaltkräfte der Schubstangen 24, 25 und 26 erfolgt auf im Gehäuse auf Wälzlagern 42 und 43 leicht drehbar gelagerten Rollen 30,31 und 32, deren Mittelachsen etwa senkrecht zu der Ebene, die den Mittelachsen der zu betätigenden formschlüssigen Mitnehmerkupplung 11 bis 13 und der mittleren Schubstange 25 gemeinsam ist, ausgerichtet sind. Die Schubstangen 24, 25 und 26 weisen jeweils auf den beiden Schmalseiten ihres Rechteckquerschnitts Längsbahnen 33, 34, 35 bzw. 36, 37 und 38 auf, die den Rollen als Laufflächen dienen. Auf den Längsbahnen 33, 34 und 35, die sich auf der von den Schaltkupplungen entfernten Schmalseiten der Schubstangen befinden, rollen die auf relativ weitem Abstand im Gehäuse gelagerten Kammrollen 30 und 31, d. h. Rollen mit Führungsborden 41 zur Seitenführung, während auf den Längsbahnen 36, 37 und 38, die auf den den Schaltkupplungen zugewendeten Schmalseiten der Schubstangen liegen, eine einzige glattzylindrische Rolle 32 (ohne Führungsborde) rollt und zu den Rollen 30 und 31 eine Gegenführung bildet. Die Rolle 32 liegt in bezug auf die Längsrichtung der Schubstangen zwischen den entgegengesetzten Kammrollen 30 und 31. The longitudinal guidance and support of the switching forces of the push rods 24, 25 and 26 takes place in the housing on roller bearings 42 and 43 easily rotatable Rollers 30, 31 and 32, the central axes of which are approximately perpendicular to the plane containing the central axes the positive drive coupling to be actuated 11 to 13 and the middle one Push rod 25 is common, are aligned. The push rods 24, 25 and 26 each have longitudinal tracks on the two narrow sides of their rectangular cross-section 33, 34, 35 or 36, 37 and 38, which serve as running surfaces for the rollers. On the Longitudinal tracks 33, 34 and 35, which are on the remote from the clutches Narrow sides of the push rods are located, which roll at a relatively large distance in the Comb rollers 30 and 31 mounted on the housing, d. H. Rolls with guide ribs 41 for Lateral guide, while on the longitudinal tracks 36, 37 and 38, which are on the clutches facing narrow sides of the push rods lie, a single smooth cylindrical Roller 32 (without guide rims) rolls and a counter guide to rollers 30 and 31 forms. The roller 32 lies between with respect to the longitudinal direction of the push rods the opposite comb rollers 30 and 31.

Die über einen Schaltfinger 39 von der Schaltwelle 10 eingeleitete Schaltkraft bewirkt wegen der außerhalb der Schubstange (an der Schaltgabel) angreifenden Gegenkraft eine Belastung der Rollen, die jedoch infolge der rollenden Reibung Im Gegensatz zu den bekannten Gleitführungen die Schaltbewegung nicht wesentlich hemmt. Durch möglichst großen gegenseitigen Abstand der Rollen sind die Kräfte an den Rollen relativ gering, wobei gleichzeitig eine exakte Führung der Schubstangen gegeben ist. The one introduced by the shift shaft 10 via a shift finger 39 Shifting force caused because of the outside of the push rod (on the shift fork) acting Counterforce loads the rollers, which, however, as a result of the rolling friction Im In contrast to the known sliding guides, it does not significantly inhibit the switching movement. The forces on the rollers are due to the greatest possible mutual spacing between the rollers relatively low, with an exact guidance of the push rods at the same time is.

Die aus Flachmaterial bestehenden Schubstangen 24 bis 26 haben zum Einleiten der Schaltkraft durch den Sc':altfinger 39 jeweils eine zugeordnete Ausnehmung 40 eingearbeitet, um die sonst üblichen aufzumortierenden Mitnehmer einzusparen. The push rods 24 to 26 made of flat material have to Initiation of the switching force through the Sc ': old fingers 39 each have an associated recess 40 incorporated in order to save the otherwise usual Aufzumortierenden drivers.

Claims

Claims: 1. Mechanical switching device for change gears of motor vehicles for engaging and disengaging form-fitting driver clutches, with transversely guided and longitudinally movably supported by roller bearings in the gear housing Push rods and shift forks that are permanently connected to them, d u r c h g e -k e n n n z e i c h n e t that at least one of the push rods (24, 25, 26) through in the gear housing rollers (30, 31, 32), which is used for longitudinal guidance on opposite longitudinal tracks (33 to 38) of the push rod in question can be rolled off, with at least the rollers (30,31) associated with a longitudinal track (33 or 34 or 35) guide rims (41) have.

2. Switching device according to claim 1, characterized in that the central axes of the rollers (30, 31, 32) approximately perpendicular to the plane that of the central axis the positive drive couplings to be actuated (11, 12, 13) and the middle one Push rod (25) is common, are aligned.

3. Switching device according to claim l or 2, characterized in that that a longitudinal track (33, 34, 35) of the push rod (24, 25, 26) two with guide ribs (41) provided rollers (30, 31) and the other, opposite longitudinal track (36,37, 38) is assigned at least one roller (32) without guide rims.

4. Switching device according to one of claims 1 to 3, with in cross section rectangular push rods, characterized in that the push rods from bright drawn and essential parts of the forks (27, 28, 29) made of simple rolled Consist of flat material.

5. Switching device according to claim 3, characterized in that the forks (27, 28, 29) are permanently connected to the push rods (24,25,26).

6. Switching device according to claim 4, characterized in that the push rod has simple recesses (40) for initiating the switching movements.

For vehicles with higher performance, especially for commercial vehicles are the switching forces as a result of larger clutches and larger moments of inertia the drive parts so large that the unfavorable efficiency of conventional switching devices with sliding guides that are under the load of the switching forces, no longer can be accepted.

In a known switching device after the starting point of Invention (DT-OS 1455674) is carried out both transversely and longitudinally special rolling bearings whose rolling elements (balls) run on relatively short axial raceways roll between an inner ring and an outer ring. So that the rolling elements at unloaded switching device in a defined position to their raceways are held, the raceways are arranged crossed at an angle. Because of This special training cannot be used as a rolling bearing in series or

Standard components are used. Furthermore occurs during the rolling elements of the switching movements not only a rolling, but also a sliding relative to on the raceways, which - depending on the angle of the raceways to each other - a disadvantage for the ease of movement can be.

The object of this invention is a switching device of the opening paragraph mentioned type, which has a good efficiency in the transmission of the shifting forces has, can be produced with little effort and within the gearbox is easy to assemble. This task is performed by a switching device with the Features according to claim 1 solved.

The guidance of the push rod on rollers is particularly easy as well as insensitive to manufacturing inaccuracies and deformations under force, since the switching forces are absorbed by the precise rolling of the guide parts, where the rollers are mounted on roller bearings, so that there is a good switching efficiency, the z. B. is particularly important for synchronous gears for higher performance.

The arrangement of the switching device allows assembly in which Push rod and fork can be mounted firmly connected to one another.

This eliminates the need for complex screwing or pinning between Fork and push rod. This is made possible by the fact that some of the roles can also be mounted in the housing after inserting the push rod / fork assembly can, for example, by axial insertion from the outside when the bearing bores for the roller bearings are at least as large as the largest diameter of the relevant Role.

The more precise guidance of the switching device and an inexpensive recording or support of the shifting forces result from the features according to claim 2. In a further embodiment of the invention according to claim 3, it is advantageous if a longitudinal track of the push rod with two rollers provided with guide ribs (comb rollers) and the opposite longitudinal track with at least one smooth-cylindrical roller cooperates. The push rod is thus supported by 3 or 4 rollers and only guided laterally by the rollers on one side. The smooth-cylindrical role takes over no side forces and has the advantage of being pushed axially into its receiving bearing to be mountable.

In this case it is particularly advantageous to remove the push rods bare drawn and essential parts of the fork - as known per se - from simple to manufacture rolled flat material and to permanently connect it to one another, for example by welding or riveting. The assembly is possible without difficulties, because the groove is built in without guide ribs after the push rod has been inserted can.

A push rod made of flat material can thereby per se have known simple recesses for initiating the switching movements, so that no drivers to be mounted are required.

A switching device with longitudinally movable guided push rods Shift forks that are permanently connected to it are, for example, in the specialist book »Gearbox«, Looman, Springer-Verlag Berlin / Heidelberg 1970, on p.