FR2746477A1 - DEVICE FOR DETECTING THE SELECTION AND / OR ENGAGEMENT OF A GEARBOX REPORT AND GEARBOX EQUIPPED WITH SUCH A DEVICE - Google Patents

Abstract

The invention provides a detection device (12) which produces a signal representative of the selection and / or engagement of a gearbox (10), in particular of a motor vehicle, intended in particular to be used. by a control circuit of a control mechanism of a clutch associated with the gearbox, of the type comprising a sensor (I1, I2) and an associated member (100) which cooperates with this sensor, one (100 ) of these two components being movable relative to each other in at least a first direction (A1) to occupy any one of several predetermined relative positions, each of which corresponds to the selection and / or the engagement of one gearbox ratios, characterized in that the sensor comprises at least two electrical switches (I1, I2) aligned in the direction (A1) of relative movement, and in that the associated member is a finger (100) actuation of the switches (I1, I2) which may occupy at least three distinct consecutive positions with respect to the switches (I1, I2), each of which corresponds to a different switching state of the two switches.

Description

The invention relates to a detection device which produces a signal

  representative of the selection and / or commitment of a

gearbox report.

  The invention relates more particularly to a device intended to equip a motor vehicle gearbox which produces a signal intended in particular to be operated by a circuit

  control of an automatic or semi-automatic control mechanism

  automatic clutch associated with the vehicle gearbox. In order to ensure reliable automatic control of the clutch, it is necessary for its control circuit to have information representative of the gear which is actually engaged in the gearbox as well as gear changes. To this end, it appeared necessary to detect the gear engaged directly at the gearbox and no longer only at the gearshift lever on which

the driver acts.

  Different designs of a type detection device are thus known, comprising a sensor and an associated member which cooperates with this sensor, one of these two components being movable relative to the other in at least one first direction to occupy the '' any of several predetermined relative positions each of which corresponds to the selection and / or

  The engagement of one of the gearbox reports.

  In these different designs, the sensor or sensors used in combination are for example of the linear transducer type, each of which provides an electrical signal proportional to the travel of

  displacement of the sensor input member.

  The object of the invention is to propose a new sensor design which makes it possible to have, in the form of an electrical signal, binary or discontinuous information which can more easily be processed by the control circuits associated with the device.

  detection for clutch control.

  For this purpose, the invention proposes a detection device of the type mentioned above, characterized in that the sensor comprises at least two electrical switches aligned in the direction of relative movement, and in that the associated member is a finger actuation of the switches which is likely to occupy at least three distinct consecutive positions with respect to the switches each of which corresponds to a state different from

switching of the two switches.

  Thanks to the invention with two switches, it is possible to detect several positions (states) of the report line selected by the

  conductive and simple and economical.

  According to other characteristics of the invention - the actuating finger is capable of occupying four distinct consecutive positions, and, in an intermediate position among these four positions, the actuating finger cooperates simultaneously with the two switches; each switch is capable of occupying two open or closed states, each switch provides a binary electrical signal representative of its state, and the detection device comprises a logic detection circuit by analysis of the binary signals supplied by the switches to deduce therefrom position occupied by the actuating finger; each of the two switches is associated in parallel with an electrical resistance belonging to an electrical detection circuit belonging to the detection device, comprising in series at least the two consecutive resistances associated with the two switches and at the terminals of which the voltage varies in a discrete manner depending on the switching state of the switches; - The detection circuit includes at least a third resistor in series with said two consecutive resistors - said direction is linear; - The sensor comprises a feeler, the rod of which carries the finger for actuating the electrical switches and which cooperates with a cam surface linked in translation and in rotation with the control shaft of the gearbox; - the sensor occupies in the gearbox the position normally occupied by a switch for switching on the vehicle reversing lights; - one of the reports is the reverse gear, and the sensor provides a signal, when the reverse gear is engaged, which is used to control the switching on of the reversing lights; The associated member comprises a rod which carries the finger for actuating the switches and one end of which acts on a switch for switching on the reversing lights when reversing

is engaged.

  The invention also relates to a gearbox, in particular for a motor vehicle, characterized in that it is equipped with a detection device in accordance with the teachings of the invention. Other characteristics and advantages of the invention

  will appear on reading the following detailed description for the

  understanding of which reference will be made to the appended drawings in which: - Figure 1 is a schematic perspective view of a detection device according to the teachings of the invention which is illustrated in association with certain components of a gearbox of motor vehicle; - Figure 2 is a schematic side view along arrow F2 of Figure 1; - Figure 3 is a top view along arrow F3 of Figure 1 in which certain components are illustrated in partial section by a plane passing through the axes of the probes of the two associated sensors; - Figure 4 is a diagram illustrating the grid for selecting and engaging the gearbox reports; - Figures 5A to 5E are diagrams illustrating different switching and switch states of the detection device according to the invention; and - Figure 6 is an electrical diagram illustrating the association of switches with resistors in series for the formation of an electrical signal whose voltage varies in stages depending on the state

for switching switches.

  The figures show parts of the casing 10 of a motor vehicle gearbox equipped with a detection device 12 with two sensors 14 and 16, one of which 14 is produced

  in accordance with the teachings of the invention.

  We recognize in the figures the tree 18 for selecting and engaging the various ratios of the gearbox which is for example a gearbox with five forward gears and a reverse gear including the selection grid, according to a known design illustrated in Figure 4, is of the type with four adjacent selection lines and two directions of engagement (or passage)

selected reports.

  The shaft 18 is slidably mounted in the casing 10 in a selection direction D1 and it is rotatably mounted about its axis X-X, parallel to the direction D1, in a circular direction

of engagement D2.

  The end 20 of the shaft 18 is fixed in translation and in rotation to a lever 22 for controlling changes in the ratios of the gearbox which is thus itself slidably mounted in the direction D1 and in rotation in the direction D2, the lever 22 being connected by its

  end 24 to a selector (not shown) of the gearbox.

  FIGS. 2 and 3 show a control finger 26 which is linked in rotation and in translation to the shaft 18 and which is capable of acting on the forks (not shown) of the gearbox to cause the selection and the commitment of

different reports.

  The device 12 for detecting the engaged gear comprises two feelers P1, P2 joined together in the form of an assembly 13 which cooperate with two cam profiles C1, C2 associated with the feelers Pl1, P2 and which are joined together in the form of an assembly 16 by tree

18.

  The sensor assembly 13 essentially consists of a housing 30, 58 which is mounted fitted (FIG. 3), from the outside, in an opening of complementary shape 32 arranged for this purpose in a portion 34 of the casing 10 of the gearbox stretching

  opposite the assembly 16 of the control shaft 18.

  The opening 34 is similar to that which, according to a known design, receives the ignition switch for the reversing lights of the vehicle. The internal portion 36 of the housing 30 slidably receives a first probe P1 and a second probe P2 which are parallel and slidingly mounted in the housing 30 along axes A1 and A2 located in the same plane perpendicular to the axis XX of the shaft of

  command, and therefore perpendicular to direction D1.

  The free end 38, 40 in the form of a ball of each probe P1, P2 protrudes outside the internal portion 36 of the housing 30 to cooperate with a first cam profile C1 and, respectively,

  with a second cam profile C2 belonging to assembly 16.

  Each probe P1, P2 is slidably mounted in the housing against an elastic return force which is applied by a spring 42 which urges the free end 38, 40 of each probe P1,

  P2 permanently in contact with the associated cam profile C1, C2.

  The rod T2 of the probe P2 constitutes the movable core of a

  linear transducer or linear potentiometer 52.

  The rod T1 of the probe P1 carries at its rear free end, opposite at its end 38 which cooperates with the cam C1, an actuating or transmitting finger of two switches II and 12 arranged in a fixed manner in the casing 58 which receives the

  potentiometer 52 and switches Il and 12.

  The potentiometer 52 delivers an electrical signal representative of the linear position of the rod T2 relative to the housing and therefore representative of the position of the probe P2 relative to the

  fixed gearbox 10.

  The potentiometer 52 is connected to a processing circuit and

  analysis (not shown) by a connection block 50.

  As can be seen in the figures, the external free end 54 of the rod T1 which carries the actuating finger 100 of the switches II and 12 projects axially outside the housing 36 and is capable of cooperating with a switch 56, fixedly carried by the casing 58, as illustrated in silhouette in FIG. 1, which constitutes a switch for switching on the reversing lights

  of the vehicle when reverse gear is engaged.

  The set 16 of cams constituted by the two cam surfaces C1 and C2 is produced, in the example illustrated in the figures, in the form of a single part essentially constituted by a ring or bush 60 which is crossed by the control shaft 18 to which it is linked in translation in the direction of selection D1 and

  rotating in the direction of engagement D2.

  Made in one piece with the sleeve, the cam profile C1 is formed by the convex frustoconical external surface and continues with a first raised projection 61 which is a portion of frustoconical surface centered around

of the X-X axis.

  Also produced integrally with the ring 60, the second cam profile C2 consists of the planar external surface of a second protrusion 62, the planar surface portion C2

  extending in a plane parallel to direction D1.

  s The first probe P1 is capable of sliding relative to the casing 10 along its sliding axis A1 which is concurrent with the axis XX and the relative positioning of the axis A1 and of the assembly 16, in the position illustrated on the figures which corresponds to the neutral point of the gearbox, is such that the axis A1

  intercepts the surface C1 substantially in the middle of the latter.

  It is thus understood that any rotation of the ring 16 around the axis X-X, without displacement in the direction D1, has no effect on the probe P1 insofar as the cam surface C1 in profile

  tapered convex is centered around the X-X axis.

  The cam surface C1 of course extends angularly over a sufficient angle corresponding to the maximum angular movement in both directions and in the direction D2 of the shaft 18 by

relative to the housing 10.

  By cons, any linear movement of the assembly 16 along D1, by driving the ring 60 by the control shaft 18, causes a relative movement of the probe P1 relative to the housing, and therefore a displacement of the rod T1 to l inside the housing causing a corresponding movement of the actuating finger which, depending on the position it occupies along the axis A1, acts

  differently on switches Il and 12.

  As can be seen in the figures, the first cam surface C1 has an oversized portion S which is located in the lower left corner, considering FIG. 1, of the portion of frustoconical surface C1 and which is intended to act on the probe P1 when the reverse gear is engaged to cause actuation of the switch 56 by the external free end 54 of

the rod T1 of the probe P1.

  The second cam surface C2 is a portion of flat surface parallel to the axis XX which, in the neutral position illustrated in the figures, is perpendicular to the parallel axes A1 and A2 of sliding of the probes P1 and P2, the latter being laterally offset from probe P1, i.e. it is offset

with respect to the X-X axis.

  In the neutral position, the free end 40 of the feeler P2 cooperates substantially with the center of the flat surface

continues C2.

  Any linear movement in the direction of selection D1 of the assembly 16 therefore has no effect on the probe P2 insofar as the cam surface C2 then moves parallel to its plane

  and in a direction perpendicular to the sliding axis A2.

  On the contrary, any displacement in rotation in the direction of selection D2 of the assembly 16, around the axis X-X, causes a displacement in rotation of the surface C2 which is eccentric by

relative to the X-X axis.

  The rotational movement in one or the other direction therefore causes a linear displacement along the axis A1 of the probe P2 which acts on the rod T2, thus causing a modification of the signal

  electric supplied by potentiometer 52.

  In the embodiment illustrated in the figures, the potentiometer 52 delivers a signal representative of the engagement of one or the other of the two reports belonging to a selected line while the probe P1 which carries the actuating finger 100 , in association with switches 11 and 12, delivers electrical signals of a linear nature which, as will be explained below, are representative of the line of reports selected by the driver. Each electrical switch 11, 12 is capable of occupying an open or closed state which can be detected and analyzed by a processing circuit (not shown in the figures) to which are

  connected terminals 101 and 102 of switches Il and 12.

  Any movement of the probe P1 along the axis A1, and therefore of its rod T1 which carries the actuating finger 100, therefore causes a corresponding linear movement of the latter relative to the switches Il and 12 which are fixed relative to the housing of the box

of speeds.

  FIGS. 5A to 5D show four consecutive relative positions that the transmission finger 100 is capable of occupying with respect to the switches II and 12 as a function of the line selected by the driver by means of his

  gear shift lever (not shown).

  Thus, when the lever is in the neutral position, that is to say in the line allowing engagement of the ratios 1 and 2, the transmission finger 100 is for example in the position illustrated in FIG. 5C and it acts simultaneously on the two switches Il and 12 which are thus switched and which occupy a closed linear coded state

"1" on the switches.

  When the driver selects the line corresponding to the ratios 34, the transmission finger is in the position illustrated in FIG. 5B in which he acts only on the switch Il which is then in the logic state "1", while switch 12 is

  in logic state "0" (Figure 5A).

  When the driver selects the line corresponding to the engagement of the fifth forward gear, the actuating finger 100 does not act on any of the two switches 11 and 12

  which are then both in logical state "0".

  When the driver selects the line corresponding to the engagement of the reverse gear, the transmission finger is in the position illustrated in FIG. 5D in which he does not act

  as on the switch 12 which is in the logic state "1".

  In the four positions illustrated in FIGS. 5A to 5D, the

  switch 56 is in logic state "0".

  When the driver engages the reverse gear, the presence of the overthickness S causes an additional linear displacement of the rod T1 and therefore of the transmission finger 100 whose free end face 54 then acts on the switch 56 which passes from its logic state "0" illustrated in FIGS. 5A to 5D to its logic state "1" illustrated in FIG. 5E. In this figure 5E

  the switch is always in logic state "1".

  Thus, each of the four selection positions corresponds to a unique position of the transmission finger 100 and to a

  unique logical combination of adjacent switches Il and 12.

  In the operating mode which has just been described with reference to FIGS. 5A to 5E, the switches 11, 12 and 56 deliver binary electrical signals which are then analyzed by a logic processing circuit with a view for example to the control of a

automatic clutch.

  It is also possible, without modifying the structure of the switches 11, 12 and 56 and their mode of cooperation with the transmission finger 100, to integrate them into an electrical detection circuit shown diagrammatically in FIG. 6 making it possible to have levels

  different voltage depending on the selected line.

  Thus, the circuit shown diagrammatically in FIG. 6 comprises in series four electrical resistors RO to R3 of distinct values. The switch II is mounted in parallel across the terminals of the resistor R1 while the switch 12 is mounted in parallel with the

resistance R2.

  Thus, as is easily understood, for each of the relative positions of the transmission finger 100 with respect to the switches 11, 12 and 56 illustrated in FIGS. 5A to 5E, the sum of the

  resistors in series is different.

  The embodiment shown diagrammatically in FIG. 6 is particularly advantageous in that it makes it possible to automatically carry out an electrical diagnosis of the detection circuit making it possible to detect the presence of a fault such as a power cut.

wire or short circuit.

  The invention is not limited to the embodiments which

have just been described.

  Thus, a sensor arrangement delivering a binary type signal can of course be associated with the detection of the engagement.

  reports in place of the linear potentiometer 52.

  The invention is also not limited to the case where the transmission finger 100 is controlled to move by means of a cam system C1, the sensor assembly constituted by the transmission finger 100 and the switches 11 , 12 can be connected

  directly in translation to the control shaft 18.

Claims (11)

  1. Detection device (12) which produces a signal representative of the selection and / or the engagement of a gearbox report (10), in particular of a motor vehicle, intended in particular to be operated by a circuit piloting a clutch control mechanism associated with the gearbox, of the type comprising a sensor (11, 12) and an associated member (100) which cooperates with this sensor, one (100) of these two components being movable relative to the other in at least a first direction (A1) to occupy any one of several predetermined relative positions each of which corresponds to the selection and / or the engagement of one of the ratios the gearbox, characterized in that the sensor comprises at least two electrical switches (11, 12) aligned in the direction (A1) of relative movement, and in that the associated member is an actuating finger (100) switches (11, 12) which is susceptible occupy at least three distinct consecutive positions with respect to the switches (11, 12) each of which corresponds to a state different from switching of the two switches.   2. Detection device according to claim 1, characterized in that the actuating finger (100) is capable of occupying four distinct consecutive positions, and in that, in an intermediate position among these four positions, the finger actuation (100) cooperates simultaneously with the two switches (11, 12).   3. Detection device according to one of claims 1   or 2, characterized in that each switch (11, 12) is capable of occupying two open ("0") or closed ("1") states, in that each switch (11, 12) provides a binary electrical signal representative of its state, and in that the detection device comprises a logic detection circuit by analysis of the binary signals supplied by the switches to deduce the position   occupied by the actuating finger (100).   4. Detection device according to one of claims 1   or 2, characterized in that each of the two switches (11, 12) is associated in parallel with an electrical resistance (R1, R2) belonging to an electrical detection circuit belonging to the detection device, comprising in series at least the two consecutive resistors (R1, R2) associated with the two switches (11, 12) and at the terminals of which the voltage varies in a discrete manner   depending on the switching state of the switches (11, 12).   5. Detection device according to the preceding claim, characterized in that the detection circuit comprises at least a third resistor (R0, R3) in series with said two resistors consecutive (R1, R2).   6. Detection device according to any one of   previous claims, characterized in that said direction (A1) is linear.   7. Detection device according to any one of   previous claims, characterized in that the sensor   comprises a feeler (P1) whose rod (T1) carries the actuating finger (100) of the electrical switches (11, 12) and which cooperates with a cam surface (C1) linked in translation and in   rotation with the control shaft (18) of the gearbox.   8. Detection device according to any one of   previous claims, characterized in that the sensor occupies   in the gearbox the position normally occupied by a   vehicle reversing lights ignition switch.   9. Detection device according to any one of   previous claims, characterized in that one of the ratios   is the reverse gear, and in that the sensor (56) provides a signal, when the reverse gear is engaged, which is used for   switch on the reversing lights.   10. Detection device according to claim 9, characterized in that the associated member comprises a rod (T1) which carries the actuating finger (100) of the switches (11, 12) and one end of which (54) acts on a light switch (56)   when the reverse gear is engaged.   11. Gearbox, in particular of a motor vehicle, characterized in that it is equipped with a detection device   according to any one of the preceding claims.