GB2168117A

GB2168117A - A shifting arrangement for a motor vehicle change-speed transmission

Info

Publication number: GB2168117A
Application number: GB08525130A
Authority: GB
Inventors: Dieter Knape
Original assignee: Dr Ing HCF Porsche AG
Current assignee: Dr Ing HCF Porsche AG
Priority date: 1984-10-12
Filing date: 1985-10-11
Publication date: 1986-06-11
Also published as: IT8522237A0; DE3437434A1; FR2571667A1; GB8525130D0; IT1185366B; FR2571667B1

Abstract

An arrangement for shifting a multi-speed motor vehicle change- speed transmission which includes a shift shaft (3) longitudinally and rotatably movable on a fixed rod (2). The shift shaft (3) cooperates with three shift rods (24, 25, 27) for selection of the transmission speeds. For the location of the shift shaft (3), a template (11) with stepped formation (10) is arranged adjacent to the same, into which a pin (9) secured at the shift lever (3) engages endwise. <IMAGE>

Description

SPECIFICATION A shifting arrangement for a motor vehicle change-speed transmission The present invention relates to an arrangement for shifting a multi-speed motor vehicle change-speed transmission whose shift rods coordinated to the transmission speeds are adapted to be actuated by shift fingers provided at a shift lever.

In such an arrangement for engaging five forward speeds and a reverse speed as described in German Patent Application P 33 14 411.7, three horizontal shift rods are arranged parallel one above the other. The shift rods are each actuatable at the end-face by means of shift fingers of a vertically arranged, tubularly shaped shift lever that is longitudinally and rotatably movably supported on a rod fixed in the transmission housing. The fingers of the shift lever come into abutment at the shift rods, respectively, at the shifting noses thereof by longitudinal displacement of the shift lever. They effect by a rotary movement a longitudinal displacement of the shift rods and therewith an engagement of the transmission speeds coordinated thereto.In order to enable an exact coordination of the shift fingers to the shift rods and a precise engagement of the speeds, very small tolerances must be maintained for the manufacture of the shift lever and for the bearing supports of the shift rods, as a result of which the manufacturing costs become quite high. The object of the present invention is to provide a constructively simple locking arrangement for the longitudinal movement positions of the shift lever, which produces a precise detent-like locking in all engaged speeds.

The present invention consists in an arrangement for shifting a multi-speed motor vehicle transmission, comprising shift rods coordinated to the transmission speeds, a shift lever and associated shift fingers operable to engage and actuate said shift rods, said shift lever being longitudinally displaceable supported on a fixed rod perpendicular to the shift rods for the preselection of the shifting lanes and being rotatably supported on the shift shaft for the engagement of the speeds wherein the longitudinal positions of the shift lever are located by a template provided adjacent the shift lever and a pin secured at the shift lever which is guided and operable to be retained in said template.

The advantages of the present invention can be seen above all in that all of the longitudinal positions of the shifting lever are adapted to be located and detained by a single structural component, into which the corresponding locating and stopping steps can be machined in a single operation so that the tolerance differences which result during the machining of different locking components are precluded altogether. If the pin used for the locking action is made of cold-drawn steel and the template of fine casting, a precise stopping arrangement of the individual speeds can be manufactured with lowest manufacturing costs and without a metal-cutting after finishing operation.

Additionally, this type of stopping produces the possibility of securing the template at the transmission housing adjacent a resilient preselection lane blocking mechanism of the shift lever so that both locating and detent mechanisms are coordinated to one another in a dimensionally accurate manner.

In the accompanying drawings: Figure 1 is a part elevational view of an arrangement for shifting a multi-speed motor vehicle change-speed transmission in accordance with the present invention; and Figure 2 is a partial cross-sectional view taken along the line ll-ll of Fig. 1.

Referring now to the drawings, a rod 2 is secured in a transmission housing 1. A tubular shift lever 3 is longitudinally and rotatably movably supported on the rod 2 within slide bearings 4 and 5. The shift lever 3 is supported with respect to the transmission housing 1 by an upper spring 6 and a lower spring 7. A pin 9 is pressed into an eye 8 of the shift lever 3 which engages endwise in a stepped formation 10 of a template 11, the steps corresponding to a predetermined longitudinal position of the shifting lever 3 and thus to a predetermined transmission speed.

The transmission speeds G2 and G4 are coordinated to the template 11 to one side of a centre lane 12, whereas the speeds G1, G3, G5 and the reverse speed R are coordinated to the template on the other side of the centre lane 12. In a central, neutral position, the pin 9 is located in the lane 12 between the speeds G3 and G4.

A pin 13 provided at the template 11 is centered in the transmission housing 1 and is secured therein by a bolt 14. Furthermore, the template 11 is centered on a sleeve 15 pressed into the transmission housing 1 parallel to the pin 13, in which is accommodated a coil spring 16 and a ball 17. The ball 17 is pressed by the coil spring 16 against an inclined surface 18 of an aperture 19 of the shift lever 3 and forms for the same, a preselection lane blocking mechanism. Since the ball 17 is at the same time supported also at the relatively fixed rod 2, the shift lever 3 is free of any cross forces. The upper spring 6 and the lower spring 7 which abut at the shift lever 3 ensure its exact positioning in the neutral position.

If the shift lever 3 is pivoted out of the neutral position toward the right by means of a shift shaft 21 supported in a ball joint 20, then a shift rod 24 can be longitudinally displaced in the transmission housing 1 by a finger 22 of the shift lever 3 and a nose 23 so that the third transmission speed is adapted to be engaged by means of a shift fork (not shown) engaging in a synchronizing clutch.

With a pivoting of the shift lever 3 toward the left, the fourth speed is adapted to be engaged in the other end position of the shift fork 24.

The fifth speed can be engaged by means of a further shift rod 25 and the reverse speed can be engaged by way of a shift lug 26 pivotally supported at the transmission housing 1. A lower shift rod 27 serves for the engagement of the first and second transmission speed. The positions of the shift rods 24, 25 and 27 are adapted to be locked by blocking mechanisms which are accommodated in the bores 28, 29 and 30.

Since the blocking mechanisms, the preselection lane blocking mechanism, and the template 11 are arranged within the same area of the transmission housing, the bores necessary therefor can be formed in a single setting of the transmission housing so that a precise coordination of the blocking and detent mechanisms is ensured.

In order to enable a rapid shifting from fourth to fifth gear, and to avoid passing around the corners of the stepped formulation 10 of the template 11, the wall 31 of the template guidance from G4 to G5 is bevelled and rounded off.

Claims

1. The present invention consists in an arrangement for shifting a multi-speed motor vehicle transmission, comprising shift rods coordinated to the transmission speeds, a shift lever and associated shift fingers operable to engage and actuate said shift rods, said shift lever being longitudinally displaceable supported on a fixed rod perpendicular to the shift rods for the preselection of the shifting lanes and being rotatably supported on the shift shaft for the engagement of the speeds, wherein the longitudinal positions of the shift lever are located by a template provided adjacent the shift lever and a pin secured at the shift lever which is guided and operable to be retained in said template.

2. An arrangement according to claim 1, wherein the template includes a stepped formation.

3. An arrangement according to claim 2, wherein the pin is disposed perpendicular to the template and engages endwise into the stepped formation.

4. An arrangement according to any of claim 1 to 3, wherein the template and a resilient preselection lane blocking mechanism of the shift lever are centered parallel to one another and secured in the same area of the transmission housing.

5. An arrangement according to any of claims 1 to 4, wherein the walls of the template from fourth to fifth gear are bevelled and rounded off.

6. An arrangement substantially as described with reference to, and as illustrated in, the accompanying drawings.