FR2571667A1 - SPEED CHANGE DEVICE FOR A MOTOR VEHICLE GEARBOX - Google Patents

Abstract

GEAR CHANGE DEVICE FOR A MULTI-GEAR MOTOR VEHICLE GEARBOX WHOSE GEAR CHANGE RODS CORRESPONDING TO THE GEARS CAN BE OPERATED BY MEANS OF GEAR CHANGE FINGERS LOCATED ON A FIXED LEVER ON A FIXED LEVER PERPENDICULAR TO THE GEAR SHIFT RODS, SO AS TO BE ABLE TO MOVE LONGITUDINALLY TO PRESELECT AND TO BE ABLE TO TURN TO ENGAGE GEARS, SHIFT SHIFT, CHARACTERIZED IN THAT THE LONGITUDINAL POSITIONS OF THE PEVENTAL AND RENEWAL OF THE 3 LEVIERI GUIDE 11 PLACED NEXT TO IT, IN WHICH AN ANKLE 9 FIXED IN THE REFERENCE LEVER 3 IS GUIDED AND CAN BE LOCKED.

Description

Gear change device for vehicle gearbox

  The present invention relates to a gear change device for a gearbox of a multi-speed motor vehicle, the rods of which correspond to the ratios can be operated by means of speed change fingers located on a

  return lever placed on a fixed perpetual return axis

  diculaire to the shift rods, so that you can move longtidudinal to preselect the gear change passages and can turn to engage the reports. Such a device is described

  in patent application No. 84 06315 of the applicant.

  In a device of this type, to engage five forward gears and one reverse gear, three horizontal speed change rods are superimposed in parallel. The speed change rods can each be maneuvered frontally by speed change fingers of a vertical tubular return lever positioned so as to be able to move longitudinally and rotate on a return axis

  fixed position on the gearbox housing. When-

  as the return lever moves longitudinally, its speed change fingers of the return lever come into contact with the speed change rods or their noses; they cause, by a rotational movement, a longitudinal displacement of the speed change rods and, consequently, a change in the ratios which correspond to them. To allow an exact correspondence between the shift fingers and the shift rods and a precise selection of the ratios, very close tolerances must be observed for the manufacture of the deflection lever and the bearings of the shift rods, which increases quite strongly

the manufacturing cost.

  The invention relates to a device of a simple construction making it possible to block the positions

  longitudinal displacement of the intermediate lever,

  being a precise engagement for all selected reports

  tionnés. To achieve this objective, according to the invention, the longitudinal positions of the return lever can be locked by means of a slide placed next to it, in which a dowel fixed to the lever

  is guided and can be blocked.

  The advantages of the invention consist mainly in that all the longitudinal positions of the return lever can be engaged by a single component

  in which you can practice the corresponding blocking steps

  in one operation, so that the different

  tolerances that arise when machining

  different blocking components are completely removed

  mées. When the anchor used for blocking is made of drawn steel and the slide is obtained by precision casting, a precise blocking device for the various ratios can be manufactured at a very reduced manufacturing cost, without additional machining (with chip removal). . In addition, this type of blocking allows fixing

  the slide next to a locking device

  gear change pickup on the gearbox housing, which allows the two to match

  interlocking with high dimensional accuracy.

  We will now describe an embodiment of the invention, shown in Figures 1 and 2 of the drawing

Annex.

  A return shaft 2 is fixed in a gearbox casing 1. A tubular return lever 3 is mounted on it in plain bearings 4 and 5 so that it can move longitudinally and rotate, and it is supported by a spring upper 6 and a lower spring 7 against the gearbox casing 1. In an eye 8 of the return lever 3 is inserted a dowel 9 which fits frontally in a profit with steps in H 10 of a slide 11, the steps corresponding to a determined longitudinal position of the return lever 3 and, consequently, to a determined ratio. The slide 11 corresponds on one side to a gear change passage 12 the ratios G2 and G4 and, on the other side the ratios G1, G3, G5 and the reverse gear R. In the point position central death, ankle 9 is located in passage 12 between reports G3 and G4. A centering shank 13 placed on the slide 11 is centered in the gearbox housing

  1 and it is fixed therein by means of a screw 14.

  In addition, the slide 11 is centered on a sleeve 15

  pushed into the casing 1 parallel to the center shank

  ge 13, in which are housed a helical spring 16 and a ball 17. The helical spring 16 presses the ball 17 on an oblique surface 18 of a recess 19 of the return lever 3 and constitutes for it a presetting blocking device of the shift change. Because the ball also rests on the axis at the same time

  fixed 2, the lever 3 does not undergo transverse forces.

  The upper spring 6 and the lower spring 7 placed on the lever 3 ensure its exact positioning in neutral. By tilting lever 3 from neutral

  to the right with a change control shaft lever-

  speed 21 located in a spherical joint

  , a change rod can be moved longitudinally

  gear 24 in the gearbox housing 1 by means of its gear change finger 22 and a locking nose 23, so that one can engage

  third gear with a gearbox fork-

  ses (not shown) entering a synchronization coupling. When turning the return lever 3 to the left, you can engage the fourth gear

  in the other end position of the fork.

  With another speed change rod, fifth gear and reverse gear can be engaged by means of a return tab 26 placed so

  to be able to pivot on the gearbox casing 1.

  A lower shift rod 27 serves to engage the first gear and the second gear. The positions of the shift rods 24, 25, 27 can be locked by locking devices

  which are housed in bores 28, 29, 30.

  Because the locking devices, the preselection locking device for the gear change passage and the slide 11 are placed in the same area of the gearbox housing, the bores necessary for this can be produced in a single phase of work as the gear change case 1, which ensures precise matching of devices

lock and interlock.

  To allow rapid passage from fourth to fifth gear and to avoid having to bring out the angles of the H-shaped stepped profile from the slide 11, the wall 31 of the slide guide is bevelled and rounded

from G4 to G5.

REVE3ND I CA T I ON-

  Gear change device for a multi-speed motor vehicle gearbox whose gear shift rods corresponding to the gears can be operated by means of gear change fingers located on a return lever placed on a fixed return axle perpendicular to the shift rods, so as to be able to move longitudinally to preselect, and to be able to turn to engage the gears, the gear change passages, characterized in that the positions

  longitudinal of the return lever (3) can be

  rusted by a slide (11) placed next to it, in which a dowel (9) fixed in the lever

  return (3) is guided and can be blocked.

  2. Device according to claim 1, charac-

  terized in that the slide has a stepped profile (10) corresponding to a speed change diagram in H.

  3. Device according to all of the claims

  1 and 2, characterized in that the pin (9) is perpen- ted

  dicular to the slide (11) and engages frontally

in the stepped profile (10).

  4. Device according to any one of the res-

  dications 1 to 3, characterized in that, in the same area of the gearbox housing (1), the slide (11) and an elastic pre-selection locking member for the gear change passage (15, 16, 17) return lever

  (3) are centered and fixed parallel to each other.

  5. Device according to any one of the res-

  dications 1 to 4, characterized in that, to better guide the passage from one report to another, the wall (31) of the slide is bevelled and rounded from the fourth to the

fifth gear.