FR2823820A1 - Control for motor vehicle gearbox has pair of hall effect sensors for producing control states dependent on position of selector - Google Patents

Abstract

The control for a motor vehicle gearbox has a switching assembly (60) which can assume three different switching states. The switching assembly has at least two hall effect sensors (C1-3) which can adopt an active and a rest position. The three switching states are identified by combinations of the states of the sensors. The switching states correspond to different positions of a selector (14) for the gearbox.

Description

The present invention relates to a control device for a vehicle

  automobile, especially for automatic gearboxes.

  It is already known in the state of the art a control device for a motor vehicle, of the type comprising electrical switching means capable of adopting at least three different states, called switching states. It is known to use a control device of the aforementioned type in an automatic gearbox. In this case, the different switching states correspond to different positions of a selector of the automatic gearbox, imposing for example, the following configurations of operation of the gearbox: << P> position: parked vehicle; - position << R>: reverse; - "<N>" position: dead point;

  - position << D>: driving forward.

  In conventional manner, the switching means comprise friction contacts or cams actuating switches. These switching means are generally satisfactory but prove, in the long run, insufficiently resistant,

  particularly with regard to tests imposed by motor vehicle manufacturers.

  Thus, over 100,000 maneuvers, the electrical contacts made by the

  Known switching means are considered unacceptable.

  The aim of the invention is to propose a control device provided with switching means which is free of the wear problems observed in the

conventional control devices.

  For this purpose, the invention relates to a control device for a motor vehicle, of the aforementioned type, characterized in that the switching means comprise at least first and second sensors each capable of adopting two different states called "active" >> and << rest >>, the three switching states being identified by as many different combinations of the states of the first and second sensors. According to other characteristics of this control device: the switching means furthermore comprise a third sensor capable of adopting two different states called << active >> and << rest >>, the sensors taken in pairs being able to adopt as many combinations of sensor states as switching states, each switching state being identified by at least one combination of states of two sensors selected from the three sensors; the sensors are of the effect type Hall - the device comprises two supports, said << fixed >> and << mobile >>, capable of moving relative to each other, carrying, one, means of influence of sensor whose the relative position with respect to one sensor influences the state of this sensor, and the other, the sensors, the relative displacement of the supports causing the changes of state of the sensors and therefore of the switching means, by relative displacement of the sensors and means of influencing sensor means; the sensor influence means comprises a source of at least one magnetic field; the sensor influence means are linked to the mobile support and the sensors are carried by the fixed support; - The movable support is movable relative to the fixed support in a circular path, the sensors being distributed in a circle substantially coaxially with the circular path of the movable support; - The magnetic field source comprises magnets distributed in a circle substantially coaxially with the circular path of the movable support; the magnetic field source comprises magnets of opposite polarities distributed alternately; the different switching states correspond to different positions of an automatic gearbox selector;

  - The mobile support is connected to the automatic gearbox selector.

  The invention will be better understood on reading the description which follows,

  given only by way of example and with reference to the drawings in which: - Figure 1 is an elevational view of a control device according to the invention, arranged near a steering wheel of the vehicle; Figure 2 is an exploded perspective view of the control device shown in Figure 1; - Figure 3 is a front view, along the arrow 3 of Figure 2, magnets forming electrical switching means; FIG. 4 is a sectional view of the control device along line 4-4 of FIG. 5; - Figures 5 to 7 are sectional views of the control device, respectively, lines 5-5, 6-6 and 7-7 of Figure 4; - Figure 8 and a perspective view of indexing means of the control device shown in the preceding figures; FIG. 9 is a sectional view of the control device, according to FIG.

line 9-9 of Figure 4.

  In what follows the front, rear, upper and lower orientations are considered in relation to the usual orientations of a driver of the vehicle. Moreover, an organ is said to be "proximal" when it is close to the hand of a driver operating the control device according to the invention and "distal" when this organ is

away from this hand.

  FIG. 1 shows a control device according to the invention, designated by the general reference 10. This device 10 is intended to control a box

  automatic transmission of a motor vehicle.

  The device 10 is preferably arranged on the upper end of a steering column body, near a steering wheel 12 (shown in phantom in FIG. 1), so as to be easily accessible by the fingers. of the driver pressing his hands on the steering wheel 12. In the example illustrated in Figure 1, the control device 10 extends, relative to the driver, in front of the steering wheel, substantially right.

of the last.

  The device 10 comprises a movable selector 14 articulated on a support

main fixed 16 forming box.

  With particular reference to FIG. 2, it can be seen that the selector 14 is generally hull-shaped and that the main support 16 comprises two half-plates 16A, 16B in which first 18 and second 20 guide means are housed.

selector 14.

  The first guide means 18 impose a rotational movement of the selector 14 around a first geometric axis, called the X axis of rotation. This rotational movement makes it possible to select an operating configuration of the gearbox. Thus, in the illustrated example, the selector 14 can be placed, by rotation about the X axis, in four different positions corresponding to the following configurations of operation of the gearbox: - position << P>: vehicle parked; - position << R>: reverse; - position << N>: dead point;

  - position << D>: driving forward.

  The second guide means 20 impose a tilting movement of the selector around a second geometric axis, called the tilting axis Y. This axis Y is substantially perpendicular to the axis of rotation X. The tilting movement makes it possible to change a ratio of speed. Thus, the selector 14 can be placed, by tilting about the Y axis in three different positions of rest, passing a higher gear and passage to a lower gear. The rest position is intermediate between the positions of transition to a higher ratio and passage to a

lower ratio.

  Note that in the control device 10 arranged as shown in Figure 1, the axis Y is substantially vertical, the gear change

  by switching the selector 14 forwards or backwards.

  The first 18 and second 20 guiding means comprise a common member, forming a rocker 22, connected, on the one hand, to the selector 14, by a pivot type connection embodying the axis of rotation X and on the other hand to the main support 16 by a link of pivot type materializing the tilting axis Y. The first guide means 18 comprise a rotation shaft 24, provided with a proximal end 24P integral with the selector 14, rotatably mounted in a housing 26, formed in the rocker 22, forming a movable bearing materializing the axis of rotation X. The shaft 24 has a proximal end 24P provided with conventional connecting means 28 fitted into the selector 14 so as to secure the latter in rotation

with the tree 24.

  The second guide means 20 comprising a pair of journals 30, integral with the rocker 22, carried by a pair of flanges 32 secured to a half-shell 16A of the support 16, forming two fixed bearings embodying the tilting axis Y. The rotation shaft 24 is connected to the rocker 22 by a pair of radial fingers 34, inserted in a corresponding pair of lights 36 curved about the X axis, formed in the rocker 22 (see Figures 2 and 4 ). These fingers 34 and slots 36 form complementary means, on the one hand, axial immobilization (parallel to the axis of rotation X) of the rotation shaft 24 relative to the latch 22 and, secondly, of limiting the angular travel of rotation of the shaft 24 relative to the rocker 22. The

  angular rotation of the shaft 24 is for example limited to 90.

  On the other hand, the rocker 22 is moved by a pair of blades 38 substantially perpendicular to the tilting axis Y. intended to cooperate by engagement with hollow guide rails 40 formed in the half-shells 16A, 16B (see in particular Figures 2 and 9). These wings 38 and rails 40 form complementary means of axial immobilization (parallel to the tilt axis Y) of the rocker 22 relative to the main support 16. Preferably, the wings 38 and rails 40 are provided with complementary stops of limitation of the angular tilting stroke of the

  flip-flop 22 with respect to the main support 16.

  According to a simplified variant, it is possible to provide, on the one hand, a single radial finger 34 cooperating with a slot 36 and, on the other hand, a single flange 38 cooperating with a rod 40. The control device 10 comprises elastic return means of the selector 14 from its position of passage to a higher or lower ratio to its rest position. In the illustrated example (see in particular FIGS. 2 and 5), the elastic return means comprise a roller 42, integral with the tilting movement of the selector 14, elastically biased against a return track 44, secured to the main support 16, delimited by two opposite ramps arranged at "<V" The roller 42 is carried by a yoke 46 mounted to slide axially in an axial bore 47 formed in a distal end 24D of the rotation shaft. spring 48 housed in the axial bore 47, to a position of

  cooperation of the roller 42 with the return track 44.

  The control device 10 also comprises means for indexing the position of the selector 14 around the axis of rotation X. In the illustrated example (in particular in FIGS. 2, 4, 8 and 9), the means of indexing comprise a ring, slidably mounted axially on the rotation shaft 24, provided with at least one axial lug, preferably three axial lugs 52 as illustrated. The axial bumps 52 are intended to cooperate with a notched crown 54, or at least a portion of

  notched crown, formed in a shoulder 56 of the housing 26 of the rocker.

  The ring 50 is resiliently biased towards the notched crown 54 by a

  spring 58 interposed axially between this ring 50 and the fingers 34.

  The control device 10 comprises first electrical switching means 60 actuated by the rotary movement of the selector 14 around the axis X. These first switching means 60 are capable of adopting four states, called rotational switching states. corresponding to the four operating configurations of the gearbox associated with the four positions P respectively.

R. N and D of the selector14.

  The control device 10 also comprises second electrical switching means 62 actuated by the tilting movement of the selector 14 around the Y axis. These second switching means 60 are capable of adopting three states, called switching switching states. , corresponding to the three positions of the selector 14 said rest, shift to a higher ratio and passage to a

lower ratio.

  As will become more clearly apparent later, the first 60 and second 62 electrical switching means comprise complementary means arranged on: a distal end 22D of the rocker, the distal end 24D of the rotation shaft, and a printed circuit 64 having two opposite faces 64P proximal and

distal 64D.

  The printed circuit 64 forms a fixed secondary support carried by the support

principal 16.

  It will be noted, considering in particular FIGS. 4 and 5, that the distal end 24D of the rotation shaft protrudes through the distal end 22D of the rocker and that the printed circuit board 64 is traversed by the rotation shaft 24 so as to be interposed axially between the distal end 24D of the rotation shaft and the distal end 22D of

the rocker.

  The first switching means 60 comprise at least two sensors, preferably three sensors C1 to C3, carried by the distal end 64D of the printed circuit, and means for influencing these sensors carried by the distal end 24D of

the rotation shaft.

  Each sensor C1 to C3 is capable of adopting two different states called "active" and "idle." In the example described, the sensors C1 to C3 are of conventional Hall type and the influence means of these sensors comprise a source of at least one magnetic field, the Hall effect type sensors have the advantage

  in particular to be very small.

  The magnetic field source is constituted by a set 66 with magnets illustrated in particular in FIGS. 2 and 3. This set 66 with magnets comprises a magnet holder 68 coupled in rotation with the distal end 24D of the rotation shaft by means of a transverse slot 70, formed in the magnet carrier 68, cooperating with a double flat 72, formed on the distal end 24D of the rotation shaft. The coupling slot 70 allows the tilting movement of the shaft 24 around the Y axis. The magnet carrier 68 is movably mounted in a fixed member 73 which guides it in rotation around a geometric axis which is compatible with the X axis when the latch 22 is in the rest position as illustrated in particular in Figure 5. The magnet holder 68 thus forms a magnet support movable in a circular path relative to the

  distal surface 64D of the fixed printed circuit carrying the sensors C1 to C3.

  The sensors C1 to C3 are distributed in a circle substantially coaxially with this circular path. In addition, the magnet holder 68 carries eight magnets, of opposite polarity -7, distributed in a circle substantially coaxially with its axis of rotation. It will be noted that the magnets are angularly distributed so as to alternate their polarities NS The magnets each have a general shape of angular sector of large or small dimension, a large magnet having an angular dimension substantially twice that of a magnet small size. The relative position of a magnet N. S with respect to a sensor C1 to C3 influences the state of this sensor. The relative displacement of the set 66 with magnets with respect to the distal face 64D of the printed circuit, carrying the sensors C1 to C3, causes changes of state of these sensors C1 to C3 and therefore first means of

switching 60.

  By choosing first C1 and second C2 any of the three sensors, it is possible to identify the four rotational switching states P. R. N. D by as many different combinations of the states of these first C1 and second

C2 sensors.

  The use of the third sensor C3 makes it possible to identify the same rotational switching state by redundant combinations. Thus, since the sensors C1 to C3 taken in pairs are capable of adopting as many combinations of sensor states as rotational switching states PRN D, each rotational switching state PRN D is identified by: a combination of states of the two sensors C1, C2 or - a combination of states of the two sensors C1, C3 or - a combination of states of the two sensors C2, C3, according to the following table in which a zero bit << 0 >> is associated with

  the state of rest of a sensor and a unit bit << 1 >> is associated with the active state of this sensor.

D C 1 1

C2 0 1 1 0

C3 1

  Considering the table above, it can be seen that each switching state in rotation P. R. N. D can be identified by at least one combination of states of two sensors chosen from the three sensors C1 to C3. Therefore, in case of failure of one of the sensors, the other two sensors are sufficient to identify each state of rotation switching PRND -8 In some cases, the transition from a first switching state to a second switching state is characterized by the two-bit state change. This is the case, for example, of the transition from the switching state "<P" defined by C2 = 0 and C3 = 0 to the switching state << R >> defined by C2 = 1 and C3 = 1 During this passage, the changes of state of the bits could not be simultaneous thus creating fortuitously a combination of bits interpreted unexpectedly as defining a stable state PR N or D of the switching means 60. Thus, by taking the example above, the transition from the switching state <"P ,, defined by C2 = 0 and C3 = 0 to the switching state << R >> defined by C2 = 1 and C3 = 1 could lead to fortuitous intermediate combination C2 = 1, C3 = 0 or C2 = 0, C3 = 1, this fortuitous combination likely to be unintentionally identified with the stable switching state << N >> or

  "D" first switching means 60.

  To avoid that an intermediate state of the first switching means 60 (between P and R. between R and N or between N and D) fortuitously leads to a combination of bits corresponding to a steady state PRN D of these switching means 60, the indexing means 50, 54 of the position of the selector 14 around the axis of rotation X make these intermediate states macanically unstable. Thus, during a change of state of the first switching means 60, any confusion between an intermediate (fortuitous) state of the first switching means 60 and a stable state is avoided.

  validly identified of these switching means 60.

  Alternatively, the Hall effect type sensors could be replaced by

  sensors of another type, in particular of the optical type.

  It will be noted that because of the use of sensors C1 to C3 associated with sensor influencing means, the maneuvers of the first switching means 60 do not cause any friction of electrical contacts, which eliminates the disadvantages associated with the wear of the frictional electrical contacts, both with regard to the presence

  undesirable wear dust that the embrittlement of the parts in contact.

  Another advantage resulting from the use of the sensors C1 to C3 is the elimination of the risk that the first switching means, poorly positioned, reach an intermediate position in which they do not provide a closure or a

  open opening of an electrical circuit.

  The control device 10 comprises releasable means 74 for locking the selector 14, illustrated in particular in FIGS. 2, 7 and 8, preventing certain passages between the rotational switching states of the first switching means.

switching 60.

  In the example illustrated, the locking means 74 comprise a button 76 for releasing these locking means carried by the selector 14. A finger, forming a retractable bolt 78, is connected to the button 76. This bolt 78 is intended to cooperate with a keeper 80, formed in a flange 82 defining a proximal end 22P of the rocker. The button 76 is movable between a locking position (see Figure 7), to which it is resiliently biased by a spring 84, and an unlocking position. The striker 80 comprises an evolutive profile, intended to cooperate with the bolt 78, delimited by stoppers Sl of immobilization of this bolt and ESC ramps of retraction

  of this bolt 78 (see Figures 7 and 8).

  The immobilizing surfaces Sl and the retracting ramps SE are distributed so as to allow or prohibit the following passages between states of

switching in rotation.

  Passage P R: prohibited, the bolt 78 cooperating with a stop Sl; R N passage: allowed, the bolt 78 cooperating with an SE ramp; Passage N D: allowed, the bolt 78 cooperating with a ramp SE; Passage D N: forbidden, the bolt 78 cooperating with a stop Sl; Passage N R: prohibited, the bolt 78 cooperating with a stop Sl;

  Passage R P: prohibited, the bolt 78 cooperating with a stop Sl.

  With particular reference to FIGS. 2 and 6, it can be seen that the second electrical switching means 62 comprise two pushbutton switches 86 carried by a proximal face 64P of the printed circuit. These contactors 86 are each actuated by a corresponding lug 88 extending the distal end 22D of the rocker. Both

  contactors 86 drive the passages to the upper and lower ratios respectively.

  As a variant, the second electrical switching means 62 could

  understand only one contactor, for example double push.

  Preferably, the selector 14 and the support 16 are delimited by complementary surfaces allowing the selector 14 to tilt only when the latter is in the position D, that is to say in the position illustrated in FIGS. 5. Furthermore, the control device 10 comprises a button 90 for selecting the automatic or manual operation of the speed box. This selection button 90 is carried by

  example by the main support 16, as shown in Figure 1.

  The activation of the second switching means 62 is inhibited as long as the selection button 90 is not in its selection state of the manual operation of the gearbox. Some aspects of the operation of the device of the invention will be described below.

  command 10 more specifically related to the invention.

  To change the rotational position of the selector 14, for example to move from the position N "<neutral" to the position D << rolling forward >>, the driver turns the selector around the axis X. It n It is not necessary to unlock the selector 14 to move from the position N << neutral >> to the position D << forward travel> because the bolt 78 is retracted by cooperation with a ramp SE. , it is impossible for the driver to turn the selector 14 in the opposite direction, that is to say to move from the position D to the position N. without unlocking the bolt 78, because of the cooperation of the bolt 78 with a stop Sl of the striker 80. Therefore, to move from the position D to the position N. the driver must press the button 76, against

  the return force of the spring 84, so as to release the bolt 78 of the abutment Sl.

  The rotation of the selector 14 about the X axis causes a relative movement of the magnets N. S with respect to the sensors C1 to C3, thus modifying the state of these

  sensors and first switching means 60.

  When the selector 14 is in the position D <"rolling forward", the driver may, if necessary, select a manual operation of the gearbox by pressing the selection button 90. The driver changes then swinging the selector 14 around the Y axis towards the front or the rear of the vehicle.This tilting movement has the effect of bringing one or the other of the tabs 88 into contact with the pusher of one or other of the contactors 86 and thus to change the state of the second switching means 60. The roller 42 recalls the selector 14 in

  rest position as soon as the driver releases this selector.

  The invention is not limited to the embodiment described.

  In particular, the device 10 may be used to control a gearbox likely to have only three operating configurations or more than four operating configurations, including an additional "mountain taxiing" configuration. The number of sensors is in this case adapted to the number of different possible operating configurations of the box.

speeds.

  Among the advantages of the invention, it will be noted in particular that the maneuvers of the first switching means 60 do not entail any friction of electrical contacts, which eliminates the disadvantages associated with the wear of the frictional electrical contacts, this without the risk that the first Switching means, incorrectly positioned, reach an intermediate position in which they do not provide a

  closing or open opening of an electrical circuit.

-11

Claims (11)

  1. Control device for a motor vehicle, of the type comprising electrical switching means (60) capable of adopting at least three different states, called switching states, characterized in that the switching means (60) comprise at least first and second sensors (C1 to C3) each capable of adopting two different states called << active >> and << rest >>, the three switching states being identified by as many different combinations of the states of the first and second sensors (C1 to C3).   2. Device according to claim 1, characterized in that the switching means (60) further comprises a third sensor (C1 to C3) capable of adopting two different states called "active" and << rest >> , the two-by-two sensors being capable of adopting as many combinations of sensor states as of switching states, each switching state being identified by at least one combination   states of two sensors selected from the three sensors.   3. Device according to claim 1 or 2, characterized in that the sensors   (C1 to C3) are of the Hall effect type.   4. Device according to any one of claims 1 to 3, characterized in   it comprises two supports, said "fixed", (64) and "mobile" (68), capable of moving relative to one another, carrying, one, means ( 66), whose relative position with respect to a sensor (C1 to C3) influences the state of this sensor, and the other, the sensors (C1 to C3), the relative displacement of the supports (64, 68) causing the state changes of the sensors (C1 to C3) and thus switching means (60),   by relative displacement of the sensors and sensor influencing means.   5. Device according to claims 3 and 4 taken together, characterized in that the sensor influencing means comprises a source (66) of at least one magnetic field.   6. Device according to claim 4 or 5, characterized in that the sensor influence means (66) are connected to the mobile support (68) and the sensors (C1 to C8) are carried by the fixed support (64).   7. Device according to any one of claims 4 to 6, characterized in that the movable support (68) is movable relative to the fixed support (64) in a circular path, the sensors (C1 to C3) being distributed in a circle. sensibly   coaxially with the circular path of the movable support (68). s -12   8. Device according to claims 5 and 7 taken together, characterized in that   the source (66) of magnetic fields comprises magnets (N. S) distributed in a circle   substantially coaxially with the circular path of the movable support (68).   9. Device according to claim 8, characterized in that the source (66) of magnetic fields comprises magnets (N, S) of opposite polarities distributed alternately.   10. Device according to any one of the preceding claims,   characterized in that the different switching states correspond to different   positions of a selector (14) automatic gearbox.   11. Device according to claims 4 and 10 taken together, characterized in