FR2804194A1 - REPORT LOCKING MECHANISM - Google Patents

Abstract

The invention relates to a gear engagement mechanism for an automated transmission with a gearbox (12), comprising: a selector (110) and switching rails (112, 1 13) each axially movable and such as a different pair. of reports is associated with each rail and that an axial movement of the rail in each direction causes a respective engagement of a report. It is characterized in that a means is arranged to move the selector (110) along an axis transverse to the axes of the rails, the selector thus being able to be indexed with a rail and come into engagement with it; the selector has a configuration made to engage a two-path track (134) (152, 154); during a movement of the selector, bringing this configuration into engagement in the track causes this selector to pivot about the transverse axis, in one direction or the other depending on the path followed; the rail engaged with the selector is then moved axially to engage the report; and means are arranged to selectively switch from one path to the other, depending on the ratio to be selected.

Description

The present invention relates to a gear engagement mechanism

  speed called simply gear in general in the following, which is also a gear meshing mechanism as would indicate a literal translation of the two English words gear engagement and, in particular, a gear engagement mechanism for an automated transmission system which comprises a gearbox with several separate gears in which gears are engaged using actuators under the control of an electronic control unit

  Up to now, automatic or semi-automatic transmission systems

  ticks of this type, for example those described in documents

  W097 / 05410 or W097 / 40300, the description of which is incorporated here by

  reference, use a conventional gear selection mechanism, such as those used in a manual gearbox, and a movement of the selector is controlled by a pair of double-acting actuators in order to control the movement of the selector means in a first direction to select a pair of reports and in a second direction to

  trigger one of the selected pairs of reports.

  It is an object of the present invention to provide a gear engagement mechanism with simplified structure and operation, to be used

  in an automatic or semi-automatic transmission system.

  To achieve this goal, the present invention provides a gear engagement mechanism for an automated transmission system.

  which includes a gearbox with several separate ratios, and

  taking a selector member and a series of switching rails each capable of being moved axially and such that a different pair of ratios is associated with each of the switching rails and that an axial movement of the switching rail in a first direction causing a engagement of one of the associated ratios while an axial movement of the switching rail in the opposite direction causing engagement of the other of said associated ratios, characterized in that a means is arranged for moving the selector member along an axis transverse to the longitudinal axes of the switching rails, so that the selector member can be indexed with a rail selected from the switching rails and come into engagement with it; the selector member comprises a configuration made to engage with a track, the track defines two paths and bringing into engagement in the track the configuration arranged on the selector member causes, during a displacement of the selector member along of the transverse axis, a pivoting of this selector member around the transverse axis, in one direction or the other depending on the path followed, as the selector member moves to engage with each switching rails so that the switching rail which is engaged with the selector member is moved axially to cause engagement of a gear associated therewith; and a means is arranged for selectively passing from one path to another, in

  function of the report to be selected.

  The configuration arranged on the selector member can be formed so as to engage with configurations carried on the track, in such a way that the configuration is caused to follow, according to the orientation of the

  configuration, a first track path or the other track path.

  The configuration arranged on the selector member can be requested towards

  a first orientation; a means being arranged to bring the configuration

  tion to move from the first orientation to a second orientation.

  An electromagnet can then be arranged to cause the configuration arranged on the selector member to pass from its first orientation to its

second orientation.

  The configuration arranged on the selector member may comprise a follower of rhomboid shape with two pairs of parallel sides and acute corners

  diagonally opposite; the follower being pivotally attached to the selected member

  and movable between a first orientation in which a first pair of parallel sides is arranged parallel to the walls of the track and a second orientation in which the other pair of parallel sides is arranged parallel to the walls of the track; the acute corners of the follower forming, in the direction of movement of the selector member, the front edge of the follower in the first orientation of the follower; the front edges of the follower in the first orientation being arranged on sides of the track opposite to the edges which are the front edges of the follower when the follower is in its second orientation; and the track being divided into different paths, the track being divided at its center in such a way that the path taken by the follower depends on the side

  of the track on which the front edges of the follower are arranged.

  Such a follower can be pivotally mounted on the selector member in

  an obviously; the recess limiting movement of the follower between its first

  first orientation and its second orientation. One can provide, for such a follower, an elastic means which requests it

towards its first orientation.

  When the mechanism comprises a follower of the type described above - a projection may extend from the upper end of the follower by being adjacent to one of the front edges of the latter; - The projection being able to be engaged with a plunger actuated by an electromagnet; and the plunger actuated by the electromagnet intervening when the latter is excited to cause the follower to pass from its first orientation to its

second orientation.

  The projection arranged on the follower can then be able to engage with a guide rail by which the follower can be brought to pass from its first orientation to its second orientation, and / or the plunger actuated by the electromagnet can be mounted. so as to move with the selector member and to be able to pass the follower from its first orientation to its

  second orientation at different points along the track.

  In the case of a mechanism to be used in a five-speed gearbox, provision can be made for the gear engagement mechanism to include three switching rails; the track extends coaxially to the transverse axis of movement of the selector member and includes at each end a pair of branches corresponding to a first and a third switching rails; and the track is divided, at an intermediate location between its

  ends, at a position which corresponds to a second switching rail.

  The track can then be formed by an opening in a curved path which is arranged in juxtaposed relation to the path of movement of the selector member; the opening defining branched ends of the track and a central portion of increased width; a guide being mounted on the curved plate and having a diamond-shaped projection which projects downward into the

  increased width of the track to divide the track into two paths.

  Such a guide can be mounted coaxially with respect to the opening of the curved plate and define a guide rail which extends between the diamond-shaped projection and the branched end which corresponds to the third switching rail; the guide rail being away from the track but such that the configuration arranged on the selector member can engage with it to

  cause the selector member to switch to another path.

  A plunger actuated by an electromagnet may be disposed between the branched end of the track which corresponds to the first switching rail and the intermediate division of the track which corresponds to the second switching rail; the plunger actuated by the electromagnet being arranged to cause, when the electromagnet is actuated, the configuration arranged on the selector member to change from a first orientation to a second orientation, when the selector member is positioned between the first and the

second switching rails.

  The selector member can be mounted on a shaft to move along an axis transverse to the longitudinal axes of the switching rails; the shaft allowing the selector member to move freely in rotation while

that it is moved axially.

  An actuator means can then be mounted for a rotational movement relative to the shaft; the selector member moving axially with the shaft. The selector member can be axially movable and in rotation with the shaft an actuator acting on the selector member to move axially

  the selector member with respect to the shaft.

  The selector member can be moved along an axis transverse to the longitudinal axes of the switching rails by means of a hydraulic actuator

  or double acting pneumatic or electric actuator.

  An electronic control unit can be arranged to control a movement of the selector member along an axis transverse to the longitudinal axes of the switching rails and to cause the configuration arranged on the selector member to change to another of the paths, to

  make the required gear changes.

  More generally, the invention relates to a gear engagement mechanism characterized in that it is substantially conforming

  to the present description which refers to the Figures of the accompanying drawings, and to

  representations given by these Figures.

  The aims, features and advantages of the present invention set out below

  above and others will become more apparent from the following description of

  preferred embodiments in conjunction with the drawings in which:

  - Figure I shows schematically a semi-transmission system

  automated according to the present invention; - Figure 2 illustrates a grid of speeds and associated switching rails, used in the gear engagement mechanism of the present invention; - Figure 3 is an isometric view in cross section of the gear engagement mechanism of the present invention; - Figure 4 is a plan view in cross section of the mechanism illustrated in Figure 2; Figure 5 is a side elevational view in cross section of the mechanism illustrated in Figure 2; - Figure 6 is a partial elevational view at the end of the mechanism illustrated in Figure 2; - Figures 7A to 7F show, in plan view and in elevation and from the side, different positions of the mechanism illustrated in Figures 3 to 6 for the selection of each report; and

  - Figure 8 schematically illustrates an electro-

  of the gear engagement mechanism illustrated in

Figure 3.

  Figure 1 of the accompanying drawings shows a motor 10 which comprises a starter and an associated starter circuit 10a and which is coupled by means of the main friction drive clutch 14 to a synchronized gearbox 12 with multiple speeds of the type with secondary shafts, via a gearbox input shaft 15. Fuel is supplied to the engine by a throttle device 16 which includes a throttle valve 18, operated by an accelerator pedal 19. The invention is also applicable to petrol or diesel engines, with electronic or mechanical fuel injection. The clutch 14 is actuated by a declutching fork 20 which is maneuvered by a controlled hydraulic cylinder 22, under the control of a

  clutch actuator control means 38.

  A selector lever 24 of report intervenes in a grid 50 of speeds with two branches 51 and 52 and a transverse track 53 extends between the end of the branch 52 and an intermediate point between the ends of the branch 51. The grid 50 defines five positions; "R" at the end of branch 52; "N" at an intermediate point between the ends of the transverse track 53; "S" at the junction of the branch 51 with the transverse track 52; and "+" and "-" at the ends of the branch 51. In the branch 51, the lever 24 is biased towards the central position "S". The position "N" of the selector lever 24 corresponds to the neutral position; "R" corresponds to the selection of the reverse gear; "S" corresponds to a selection of a forward mode; a temporary movement of the selection lever towards the "+" position sends the gearbox an instruction to shift to the higher gear ratio; and a temporary movement of the selector lever 24 to the "-" position sends the gearbox an instruction to downshift by one gear. The positions of the lever 24 are picked up by a series of sensors, for example microswitches or optical sensors, positioned around the grid 50. Signals sent by the sensors are brought to the electronic control unit 36. An output of the electronic control unit 36 controls a gear engagement mechanism 25 which engages the ratios of the gearbox 12 as a function of the displacement communicated

  to the selector lever 24 by the driver of the vehicle.

  In addition to the signals coming from the gear selector lever 24, the control unit 36 receives signals from a sensor 19a, indicative of the degree of depressing on the accelerator pedal 19; - A sensor 34, indicative of the degree of opening of the control butterfly 18; - A sensor 26 indicative of the engine speed; - A sensor 42 indicative of the speed of the clutch support plate; - A sensor 34 indicative of the position of the slave clutch cylinder; and

  - A sensor 32 indicative of the selected report.

  The control unit uses the signals from these sensors to control actuation of the clutch 14, either when starting from the idle state, or when changing gears, for example as described in the requests. of European patents EP 0 038 113, EP 0 043 660, EP 0 059 035, EP 0 101 220 and application W092 / 13208, the

  descriptions are incorporated here by reference.

  In addition to the sensors mentioned above, the control unit 36

  also receives signals from a vehicle speed sensor 52, a contact

  start-up switch 54 and a brake switch 56 associated with the system

  main brake, for example the vehicle's foot brake 58.

  A buzzer 50 is connected to the control unit 36 to

  indicate to the driver of the vehicle that certain operating conditions

  occur or to warn about it. A flashing warning light

  or another indicating means may be used, in addition to the sound vibrator 50, or instead of it. A gear indicator 60 is engaged

  also arranged to indicate the selected gear ratio.

  As illustrated in FIGS. 2 to 7, the gear engagement mechanism 25 comprises three switching rails 11, 112, 113 mounted in parallel with one another in order to move in the axial direction. Each switching rail 111, 112, 113 is conventionally associated with two of the ratios of the gearbox 15, via a selector fork and a synchronization unit, so that a displacement of the switching rails 111, 112, 113 in a first axial direction causes one of the associated ratios to engage and an axial displacement of the switching rail 111, 112, 113 in the opposite axial direction

  causes the other associated gear to be engaged.

  As illustrated in FIG. 2, typically, the first and second ratios are associated with the switching rail i 11, so that a displacement of the switching rail 11 1 in a first direction engages the first ratio or that a displacement of the switching rail 111 in a second direction engages the second gear; the third and fourth gears are associated with the switching rail 1 12, so that a movement of the switching rail 112 in the first direction engages the third gear or that a movement of the switching rail 1 1 in the second direction engages the fourth report; the fifth gear and the reverse gear are associated with the switching rail 113, so that a movement of the switching rail 113 in the first direction engages the fifth gear or that a movement of the switching rail 111 in the second direction initiates the report of

reverse.

  As illustrated in FIGS. 3 to 8, a selector member 110 is mounted on a shaft 120 to move with the shaft 120 along an axis transverse to the longitudinal axes of the switching rails 111, 112, 11 3, the shaft 120 being housed with sliding and rotation in bearing structures mounted in end plates 122 of a casing 124. The selector member 110 is of generally cylindrical shape and has a configuration of tab 126 which extends axially. Collar configurations 128 mounted on the switching rails 111, 1 1 2, 113 each define a pair of projections

  axially separated 130 between which the leg configuration 126 is arranged

  created on the selector member 111 can penetrate when the selector member 110

  moves transversely with respect to the switching rails 111, 112, 113.

  The casing 124 includes a curved plate 132 which extends concentrically with the shaft 120 in a relation juxtaposed with the path of the selector member 110. The curved plate 132 comprises an opening 133 which defines a track 134. The track 134 branches at its two ends, the branches 136 and 138 of the first end corresponding to the switching rail i 1 1 and the branches 140 and 142 at the other end corresponding to the switching rail 113. The track 134 is of a width generally uniform but includes a portion 144 of increased width which corresponds to the switching rail 112. A guide 146 is mounted on the curved plate 1 32, the guide 1 46 extending coaxially to the shaft at the center of the track 1 34. The guide 146 has a diamond-shaped projection 148 which extends downwards to enter the part 1 44 of increased width of the track 134, in order to divide the track 1 34 into two paths 1 50 and 152, from lar geur equal to the other parts of track 1 34. Guide 1 46 also defines a configuration 154 of rail which extends longitudinally with respect to track 134, between the projection 148 and the branched end of the track

  134 which corresponds to the switching rail 113.

  A follower 160 of rhomboid shape is pivotally mounted on the selector member 110 to enter the track 1 34. The follower 1 60 is mounted in a recess 162 of the selector member 1 0 in such a way that a displacement pivoting of follower 160 is limited between: - the first position in which opposite parallel sides of the follower are parallel to the sides of track 134, the other sides extending forwards and towards opposite sides of track 134 by relative to opposite directions of movement of the selector member 1 10; and - a second position in which said other sides are parallel to the sides of track 134 and said opposite parallel sides extend forwards and towards opposite sides of track 13 with respect to opposite directions of movement of the track. selector member 110; - the sides of the follower which extend forward, relative to the movement in opposite directions, extending towards sides

  opposites of the track in the first and in the second positions.

  The follower 160 is biased towards its first position by means of a

  torsion spring 163. A projection 164 extends from the upper surface

  of the follower 160, from a front end thereof, relative to the movement of the selector member 110 in a first direction. The projection 164 extends beyond the upper surface of the curved plate 132

  so as to engage with the configuration 154 of guide rail 146.

  An electromagnet 170 is in the intermediate position between the branches

  1 36 and 138, which correspond to the switching rail 11 1, and the

  jets 150, 152, which correspond to the switching rail 112. A plunger 172 is controlled by the electromagnet 1 70. The arrangement of the plunger 1 72 is such that, when the electromagnet 170 is de-energized, the plunger 1 72 comes in taken with the projection 164 when the follower 160 is in its first position and, when the electromagnet 170 is energized, the plunger 172 intervenes on the projection 164, so as to switch the follower 160 in its second position, in opposition to the spring biasing force 163. A double-acting hydraulic actuator 214, illustrated in FIG. 8, acts on the shaft 120 to move the shaft 120 and the selector member 110 which is mounted therein axially. A rotary connection 180 is arranged on the shaft 120 so as to allow a free rotation movement of the member

  selector 110 during its axial displacement under the effect of the actuator 214.

  As a variant, the selector member 110 can be axially fixed relative to the shaft 120 but can rotate relative to it, or the shaft 120 can be fixed, the selector member 110 being mounted therein to move axially and in rotation with respect to it, the actuator 214 acting directly on

  The selector member 110 using an appropriate connection mechanism.

  Starting from the position illustrated in Figure 4, in which the electro-

  magnet 170 is de-energized, a movement of the selector member 110 to the left, as shown in Figure 8, causes the front edge 182 of the follower to engage with the branch 136, while the tab 126 enters between the projections 130 on the flanged configuration 128 mounted on the switching rail 111. Coming into the ramification 136, the follower causes the selector member 110 to rotate in a counterclockwise direction, by axially moving the switching rail 111 to the right, as shown in Figure 3, and engaging the second gear as

illustrated in Figure 7B.

  When the electromagnet is de-energized, a displacement of the selected organ

  teur 1 10 to the right brings the front edge 1 84 of the follower 1 60 to engage with the path 1 52, when the tab 126 enters between the projections 1 30 of

  the flange configuration 128 mounted on the switching rail 1 12.

  When it comes into engagement with the path 152, the follower 160 causes the selector member 1 10 to pivot in a clockwise direction, by moving the switching rail 1 12 to the left and by engaging the third gear,

as shown in Figure 7C.

  1! Continued movement of the selector member 1 10 to the right then causes the follower 160 to follow the path 152 so that the selector member 1 10 is pivoted in the opposite direction to the clockwise direction to bring the

  leg configuration 126 in a neutral plane. Continued displacement

  to the right then causes the projection 164 to come into engagement with the path 154, by switching the follower 160 so that, when the tab 126 enters between the projections 130 of the flange configuration 128 mounted on the switching rail 113, the front edge 184 of the follower 160 engages the ramification 140 by causing the selector member 110 to pivot in the opposite direction to the clockwise direction and by moving the switching rail 113 towards the

  right to engage reverse as shown in Figure 7F.

  Starting from the position illustrated in Figure 4, energizing the electromagnet 170 switches the follower 160 to its second position. A movement of the selector member 1 10 to the left, according to the view in FIG. 8, now brings the front edge 182 of the follower 160 to engage with the branch 138 while the tab 126 penetrates between the projections 130 of the flange configuration 128 mounted on the switching rail 1 1 1, causing the selector member 110 to pivot clockwise, a displacement of the switching rail 111 to the left and an engagement

  from the first report, as shown in Figure 7A.

  When the electromagnet 170 is energized, a displacement of the selector member to the right causes the front edge 184 of the follower 160 to engage in the path 150, while the tab 126 penetrates between the projections 130

  of the flange configuration 128 mounted on the switching rail 112.

  When it engages in the path 150, the follower 160 causes a rotation of the selector member 110 in a counterclockwise direction and a displacement of the switching rail 112 to the right by engaging the

  fourth report, as shown in Figure 7D.

  As soon as the configuration 164 is away from the plunger 172, the spring 163 causes the follower 160 to return to its first position. Continued movement of the selector member 110 to the right causes the selector member 110 to pivot clockwise so that the tab configuration 126 is brought back to the neutral plane. Then, when the tab configuration 126 enters between the projections 130 of the flange configuration 128 on the switching rail 1 1 3, the front edge 184 of the follower engages with the branch 142. When it engages with the branching 142, the follower 160 causes the selector member to pivot clockwise and the switching rail 1 1 3 to move towards

  the left by engaging the fifth gear, as shown in Figure 7E.

  Consequently, to change speed using the gearbox, starting from the neutral position illustrated in Figure 4: a) to engage the first gear, the electromagnet 170 is energized and the actuator 214 is controlled to moving the selector member to the left, to a position which corresponds to the switching rail 111; b) to pass from the first gear to the second gear, the electromagnet is de-energized and the actuator 21 4 is commanded to move the selector member 1 10 to the right back to the neutral position illustrated in FIG. 4, the actuator 21 4 is then commanded to move the selector member 1 10 to the left, to a position which corresponds to the switching rail i 1; c) to pass from the second gear to the third, the actuator 214 is controlled to move the selector member 1 1 O to the right, passing through the neutral position illustrated in Figure 4, to a position which corresponds to the switching rail 1 1 2; d) to pass from the third gear to the fourth, the actuator 214 is controlled to move the selector member 110 to the left in return to the neutral position illustrated in FIG. 4, and the electromagnet 170 is energized to switch the follower 160 towards its second position, the actuator 21 4 is then controlled to move the selector member 1 10 to the right, back to a position which corresponds to the switching rail 1 12; e) finally, to pass from the fourth gear to the fifth, the actuator 214 is controlled to move the selector member 110 to the right,

  to a position which corresponds to the switching rail 11 3.

  To engage reverse gear from the neutral position illustrated in Figure 3, the electromagnet 170 is de-energized and the actuator 214 is controlled to move the selector member 110 to the right, towards a

  position which corresponds to the switching rail 113.

  It is understood that other speed changes, for example from the first gear to the third or from the second gear to the fourth, can be effected by an appropriate control of the electromagnet 170 and of the actuator 214, the selector member 110 being brought back in neutral position

  illustrated in Figure 4 when the follower 160 must change course.

  A sensor means 160 is arranged to indicate when the selector member 110 is in the neutral position illustrated in FIG. 4, so that the electromagnet 170 can be excited as necessary to make the follower 160 move from its first to its second positions . Such a sensor means may comprise a rheostat 227 which picks up the position of the actuator 214, as illustrated in FIG. 8. It is possible as a variant to arrange a proximity switch or a similar means which is actuated by the member

  selector 110 when it is in the neutral position illustrated in Figure 4.

  As illustrated in FIG. 8, a hydraulic circuit which controls the clutch 14 and the gear engagement mechanism integrated in the transmission system described above comprises a main valve for

  flow control 220 operated by electromagnet to connect selectively

  tively the slave cylinder 220 of the clutch and / or the hydraulic actuator 21 4 for engaging in relation to a hydraulic pressure accumulator 224 or to a reservoir 226. The accumulator 224 is charged at a predetermined pressure and is maintained, by via a check valve 224a, at a pressure higher than a minimum operating pressure by means of a pump 223 with an electric motor, as soon as the start switch has been actuated. A pressure transducer 260 monitors the pressure of the accumulator 224 and the pump 223 is controlled by the electronic control unit 236 so as to maintain in the accumulator

  224 a pressure higher than the predetermined minimum operating pressure.

  The main control valve 220 comprises a coil 250 which is offset by an electromagnet 220a in opposition to a spring 251. The coil 250 is offset by the electromagnet 220a under control of the unit

  36 to one of three positions.

  In a first position of the main control valve 220,

  illustrated in Figure 8, the working chamber of the slave cylinder 22 of clutch

  Yage is put under pressure from the reservoir 226 bypassing the range 225 of the coil 220, via the flow path Z, and the supply line 265 is connected to the reservoir 226 between the ranges 257 and 258. In a second position of the control valve 220, the coil 250 is shifted to the right so that the working chamber of the slave cylinder 22 of the clutch remains connected to the reservoir 226 via the flow path Z, while track 265 is isolated from tank 226 by track 258 and is connected to pressure accumulator 224 between the

tracks 257 and 258.

  In a third position of the control valve 220, the coil 250 is moved further to the right so that: the flow path Z is closed and the working chamber of the slave cylinder 222 of the clutch is connected to the 'pressure accumulator 224, between ranges 256 and 257,

  while the line 265 remains connected to the accumulator 224.

  Line 265 connects the gear engagement mechanism 25 to the hydraulic pressure accumulator 224 or to the reservoir 226, depending on the

  position of the main control valve 220.

  The selector member 110 is movable transversely to the switching rails 11 1 1, 1 2 1 1 3 under the effect of the actuator 214 at fluid pressure, so as to align the selector member 110 with one of the three rails 111, 11, 112 3 and to select the pair of reports associated with

this selector rail.

  The actuator 214 comprises a double-acting plunger with an operating rod 214a which is functionally connected to the shaft 120, on which the selector member 110 is mounted, by means of a connection 180 pivotally between them. The operating rod 214a extends from a first side of a piston 216 of the actuator 214, so that the working surface of the rod end of the piston 216 is smaller than that which is on the opposite head end. Due to the differential surfaces of the sides of the piston 216, the piston 216 is offset along the actuator 214 when the two sides of the piston 216 are connected to the accumulator 224, so as to extend the associated operating rod 214a . On the other hand, if the head end side of the piston 216 is connected to the reservoir 226 while the rod end side is connected to the accumulator 224, the differential pressure between the faces of the piston 216 causes it to be offset by along the actuator 214 by exerting traction on the associated operating rod 21 4a. The supply of hydraulic fluid to the rod end of the piston 216 is controlled directly by the main control valve 220. The supply of hydraulic fluid to the head end of the piston 216 is controlled by the main control valve 220 by means of another control valve 221 with proportional flow operated by an electromagnet. Valve 221 connects the head side of piston 216 to the main control valve

220 or tank 226.

  The proportional flow control valves 220 and 221 are controlled

  by the electronic control unit 36 so as to apply appropriate pressures on opposite sides of the piston 216 in order to control the movement of the piston 216 and the associated operating rod 214a to select the switching rail 111, 112 or 113 required, as described

  in documents W097 / 05410 and W097 / 40300, whose descriptions

  are incorporated herein by reference.

  A potentiometer 127 is connected to the operating rod 214a to send a signal indicative of the position of the operating rod and of the selector member 110 which is connected to it. Signals from potentiometer 227 are sent to the control unit 236 to provide an indication of the position of the operating rod 214a and the selector member 110. The transmission system can thus be calibrated so that predetermined signals of position from potentiometer 127 correspond to the setting of the organ

  selector 110 in engagement with each of the switching rails 111, 112 and 113.

  Measurements of potentiometer 127 can then be used in the closed loop control system to control valves 220 and 221 to move the selector member 110 to predetermined positions

  to engage the desired movement rails 111, 112, 1 1 3.

  When the main control valve 220 is in the position illustrated in Figure 8, which represents the de-energized condition of the electromagnet

  220a, the slave clutch cylinder 22 and the engagement mechanism 25

  report via line 265, are both

  connected to the reservoir 226. The slave clutch cylinder 22 and the action-

  neur 214 are therefore not under pressure.

  When the control valve 220 moves to its second position, the clutch actuator 22 remains without pressure, but the gear engagement mechanism is pressurized. Appropriate control of the electromagnet 221a by the control unit 36 as described in documents W097 / 05410 or W097 / 40300 can then cause the actuator 214 to select a switching rail.

  suitable 111, 1 12 or 113. The control unit 36 also activates selectively

  the electromagnet 170 so that the follower 160 passes to the appropriate path,

  so that the appropriate gear is selected.

  A displacement of the main control valve 220 to its third position connects the working chamber of the slave cylinder 22

  clutch to accumulator 224 thereby disengaging clutch 14.

  The slave cylinder 22 of the clutch and the engagement mechanism 25 of

  report can thus be controlled by the control unit 36 in action-

  appropriately supplying the electromagnets 220a, 221a and 170, to cause gear changes, either when starting from idle, or while

  the vehicle is in motion, either when the vehicle comes to a stop.

  Various modifications can be made without departing from the invention. For example, while the invention has been described with reference to a semi-automatic transmission system in which the clutch and the

  gear engagement mechanisms are both hydraulically operated

  The invention can also be used with transmission systems.

fully automated.

  According to another embodiment, the electromagnet 1 70 can be mounted to move with the selector member 110 in such a way that the follower 160 can be passed into one of two positions: a first intermediate position between the first and second switch rails

  1 1, 112 as illustrated in FIG. 4, and a second position inter-

  between the second and third switching rails 1 1 2, 113.

  In addition, while hydraulic means are used in the embodiment for actuating the clutch and moving the gear selector member 110, hydraulic, pneumatic and / or electric actuators, for example motors electric or electromagnets

  can be used as described for example in documents DE19504847; W097 / 01456 or DE19734023, the descriptions of which are

incorporated here by reference.

Claims (14)

  1. Gear engagement mechanism, intended for an automated transmission system which comprises a gearbox with several separate ratios, and comprising a selector member (1 10) and a series of switching rails (1 I 1, 1 2 , 1 13) each capable of being moved axially and such that a different pair of ratios is associated with each of the switching rails and that an axial displacement of the switching rail in a first direction causes engagement of one associated ratios while an axial movement of the switching rail in the opposite direction causes the other of said associated ratios to engage; characterized in that means are arranged to move the selector member along an axis transverse to the longitudinal axes of the switching rails, so that the selector member can be indexed with a rail selected from the switching rails and come into contact with him; The selector member has a configuration made to engage with a track, the track defines two paths and bringing into engagement in the track the configuration arranged on the selector member causes, when the selector member moves along of the transverse axis, a pivoting of this selector member around the transverse axis, in one direction or the other depending on the path followed, as the selector member moves to engage with each switching rails so that the switching rail which is engaged with the selector member is moved axially to cause an engagement   a report associated with it; and a means is arranged for passing selected   tively from one trip to another, depending on the gear to be selected.   2. Mechanism according to claim 1, characterized in that the configu-   ration arranged on the selector member (1 10) is formed so as to engage with configurations carried on the track (1 34), in such a way that the configuration is caused to follow, according to the orientation of the configuration a   first path of the track or the other path of the track.   3. Mechanism according to claim I or 2, characterized in that the   configuration arranged on the selector member (1 10) is biased towards a pre-   better orientation; and a means is arranged for bringing the configuration to   move from the first orientation to a second orientation.   4. Mechanism according to claim 3, characterized in that an electro-   magnet (1 70) is arranged to cause the configuration arranged on the selector member (1 10) to pass from its first orientation to its second orientation.   5. Mechanism according to any one of claims 2 to 4, character-   laughed in that the configuration arranged on the selector member comprises a follower (1 60) of rhomboid shape with two pairs of parallel sides and acute corners opposite diagonally; the follower is pivotally attached to the selector member and is movable between a first orientation in which a first pair of parallel sides is arranged parallel to the walls of the track (1 34) and a second orientation in which the other pair of sides parallel is arranged parallel to the walls of the track; the acute corners of the follower form, in the direction of movement of the selector member, the front edge of the follower in the first orientation of the follower; the front edges of the follower in the first orientation are arranged on sides of the track opposite to the edges which are the front edges of the follower when the follower is in its second orientation; and the track is divided into different paths (152, 154), the track being divided at its center in such a way that the path taken by the follower depends on the side of the track on which the front edges of the follower are willing.   6. Mechanism according to claim 5, characterized in that the follower   (160) is pivotally mounted on the selector member (1 10) in a recess   and in that the recess limits movement of the follower between its   first orientation and its second orientation.   7. Mechanism according to claim 4 or 5, characterized in that a   elastic means (1 63) urges the follower (1 60) towards its first orientation.   8. Mechanism according to any one of claims 5 to 7, charac-   terized in that a projection (164) extends from the upper end of the track   by being adjacent to one of the front edges of the latter; the projection is suitable for   engaging with a plunger (172) actuated by an electromagnet; and the plun-   solenoid actuated when the latter is energized for   to bring the follower to pass from his first orientation to his second orientation.   9. Mechanism according to claim 8, characterized in that the projection (164) arranged on the follower (160) is capable of engaging with a guide rail by which the follower (160) can be brought to pass from its first   orientation to its second orientation.   1 O. Mechanism according to claim 8 characterized in that the plunger (172) actuated by the electromagnet is mounted so as to move with the selector member and can move the follower from its first orientation to its   second orientation at different points along the track (134).   1 1. Mechanism according to any one of the preceding claims to   use in a five-speed gearbox, characterized in that the mechanism   gear engagement mechanism includes three switch rails (111, 112, 113); the track (134) extends coaxially to the transverse axis of movement of the selector member and includes at each end a pair of branches corresponding to a first and a third switching rails; and the track is divided, at an intermediate location between its ends, at a   position which corresponds to a second switching rail.   12. Mechanism according to claim 11 characterized in that the track (1 34) is formed by an opening in a curved path which is arranged in relation juxtaposed to the path of movement of the selector member; the opening defines branched ends of the track and a central portion of increased width; a guide is mounted on the curved plate and has a diamond-shaped projection which projects downward in the increased width portion of   the track in order to divide the track into two paths (152, 1 54).   13. Mechanism according to claim 12, characterized in that the guide is mounted coaxially with respect to the opening of the curved plate and defines a guide rail which extends between the diamond-shaped projection and the branched end which corresponds to the third switching rail (1 3); and the guide rail is away from the track (134) but is such that the configuration arranged on the selector member can come into engagement with it to   cause the selector member to switch to another path.   1 4. Mechanism according to any one of claims 1 to 1 3, charac-   terized in that a plunger (172) actuated by an electromagnet is disposed between the branched end of the track (134) which corresponds to the first rail of   switching and the intermediate division of the track which corresponds to two   xth switching rail; and the plunger actuated by the electromagnet is   arranged to bring, upon actuation of the electromagnet, the configuration   ration arranged on the selector member to pass from a first orientation to a second orientation, when the selector member is positioned between the   first and second switching rails.   1 5. Mechanism according to any one of the preceding claims,   characterized in that the selector member is mounted on a shaft (120) to   move along an axis transverse to the longitudinal axes of the rails   mutation (1 1 1, 1 12, 1 3); and the tree allows the selector organ to   move freely in rotation while it is moved axially.   16. Mechanism according to claim 15, characterized in that an actuator means is mounted for a rotational movement relative to   the tree (120); and the selector member (1 1 0) moves axially with the shaft.   1 7. Mechanism according to claim 1 5, characterized in that the selector member (1 10) is axially movable and rotatable with the shaft (1 20); and an actuator acts on the selector member to move the member axially selector in relation to the tree.   18. Mechanism according to any one of the preceding claims,   characterized in that the selector member (1 10) is moved along an axis transverse to a longitudinal axis of the switching rails (1 1 1, 1 12, 1 1 3) by means of a hydraulic or pneumatic actuator double-acting or a electric actuator.   19. Mechanism according to any one of the preceding claims,   characterized in that an electronic control unit is arranged to control a movement of the selector member along an axis transverse to the longitudinal axes of the switching rails (111, 1 12, 113) and to bring the configuration arranged on the selector to pass to another of the paths   (1 52, 1 54) to make the required gear changes.