FR2771360A1 - PARKING BRAKE INSTALLATION FOR MOTOR VEHICLES - Google Patents

Abstract

Installation comprising a device for tensioning the brake transmission cables, which can be actuated by an electric motor or by hand and, when actuated by an electric motor, the braking force is detected and regulated electronically. clamp (10) comprises a cylinder segment (30) for winding a transmission cable (1) and which comprises at least one toothing (32, 33) which is engaged by a servo-control (40) or by a control element. operation (11) for tightening. A switching element which drives the servo drive is triggered by a signal generated in a control module.Application to allow maximum comfort in normal and emergency operation.

Description

The invention relates to a parking brake installation,

  comprising a device for traction of the transmission cables, which can be actuated by electric motor or by the force of the muscles and, in the event of actuation by electric motor, which is triggered by means of an electric switch or by operation, which can be electrically called, of the actuating element movable by the force of the muscles, the braking force is

  detected and adjusted or controlled electronically.

  DE 40 27 810 Ai describes such a parking brake installation. This document describes a handbrake with servo assistance. The handbrake clamping device is a lever mechanism which is actuated either by an electric motor and by means of a worm drive, or by hand pulling on the handbrake handle. The lever mechanism is connected, by an operating mechanism that can be moved by hand, either to the worm gear transmission or to the handle of the hand brake. In servo-controlled mode, according to which the handbrake handle is used as a switch or potentiometer, this handbrake handle is not mechanically in functional connection with the lever mechanism. This has the drawback that traction is exerted on the handle of the handbrake, while the ignition is switched off or in the event of failure of the on-board voltage or the on-board electronics, the clamping device is i.e. the parking brake is not applied. This requires everything

  first activate the operating mechanism by hand.

  The object of the present invention is therefore to create a parking brake installation which, in normal operation or in emergency operation, allows maximum operating comfort and immobilization.

reliable vehicle.

  According to an essential feature of the invention, the clamping device comprises a cylinder or a cylinder segment which winds up a transmission cable, the cylinder or the cylinder segment comprising at least one toothing with which meshes an output pinion of a servo-control and into which a latching element penetrates causing a blocking or forming a stop not in the opposite direction from that of application and which can be released for the opening of the parking brake and moreover the cylinder or the segment of cylinder can be rotated in the tightening direction using a handling element, the axis of rotation of which is identical to that of this cylinder or of this cylinder segment, by means of a snap which can be released to open the parking brake and also a switching element, which is actuated electrically or electronically, which attacks the servo control and which e st arranged in parallel with said switch which detects the actuation of the handling element, is triggered at least by a signal generated in a control module by an automatic circuit for finding extremes and holding forming part of

ABS control.

  The parking brake installation therefore comprises a clamping device which comprises a cylinder or a cylinder segment for winding a transmission cable, this cylinder or this segment of cylinder comprising at least one toothing which meshes with a pinion of output of a servo drive and into which a latching element penetrates which causes a blocking or forms a notch in the opposite direction to that of clamping and which can be released for the opening of the brake. The cylinder or cylinder segment can be rotated in the tightening direction with the aid of a handling element, the axis of rotation of which is identical to that of this cylinder or of this cylinder segment, by a latching element which can be released to open the brake. A switching element which drives the servo control, which is actuated electrically or electronically and which is mounted in parallel with the electric switch which detects the actuation of the handling element, is triggered at least by a signal generated in a control module. control by an automatic circuit for finding extremes and holding part of

ABS control.

  In this parking brake installation, the latter can be applied by the force of the muscles, with the assistance of an auxiliary force or fully automatically. In the first case, it is tightened and snapped on in a purely mechanical manner independently of the on-board voltage or the on-board electronics. This tightening is carried out exclusively by direct or indirect actuation of a handling element, for example by pressing on a pedal or by a traction exerted on the handbrake lever. In the second case, a servo control ensures that a clamping device follows the actuated element, so that the brake

  can be handled almost without force.

  In the third case, the on-board electronics ensure that the vehicle is stopped and

  activates the parking brake.

  The parking brake is usually

  loosened by operating a hand lever.

  The installation of the parking brake has the advantage that a specific actuation by the driver is generally carried out only with the aid of a specific operating element, for example the pedal. Furthermore, it does not matter whether the ignition is connected or the electrical installation is faulty. The driver only notices the absence of assistance by an auxiliary force in the event of a servo control failure. He no longer has to look for a particular actuation or switching member, which otherwise is not necessary, with the help of which he can trigger a mechanical immobilization of the vehicle, for example in an unfavorable walking situation, for example when stopping or starting

  uphill, when the on-board electronics fail.

  In automatic service, this results in the advantage that the service brake actuated by an automatic circuit for finding extremes and

  maintenance is not subject to misuse or overload.

  A conventional ABS braking installation equipped with this automatic circuit has the disadvantage that the service brake is not released hydraulically after the vehicle has come to a stop. The driver may leave the vehicle apparently stopped from

  reliably without applying the parking brake.

  However, if the hydraulic pressure drops due to leaks over several hours, the vehicle may start to roll. The parking brake installation according to the invention prevents this and therefore the parking brake installation is applied when the driver leaves the vehicle or after he has left it so that it alone assumes

immobilization of the vehicle.

  The invention will be described in more detail by way of example with regard to an embodiment illustrated schematically in the drawings in which: FIG. 1 is a diagram of a device for applying a parking brake as well as its actuating bodies; Figure 2 shows the clamping device while the parking brake is not applied; Figure 3 shows the clamping device while the parking brake is applied. Figure 1 shows schematically the modules and components which are necessary for the automatic and manual actuation of a mechanical parking brake. A central module is the

  clamping device 10 as well as its control 40.

  The task of the clamping device is to tension a transmission cable 1 for the application of the vehicle parking brakes. The transmission cable 1 is mechanically connected for this purpose to the cables (not shown in this figure) leading to the

parking brakes.

  The transmission cable is generally electrically wound - therefore in service with assistance and automatic - in the clamping device 10. A servo control 40 ensures this winding. It comprises an electric motor which is optionally equipped with a reduction gear, as well as a clutch 43. The latter can for example be a mechanical clutch with centrifugal force or a clutch with electromagnetic control. A torque sensor 45 is arranged between the clutch 43 and the clamping device 10 to be driven. The torque on the output shaft is measured using this sensor during the tightening process. This torque is proportional to the clamping force acting on the

  parking brake shoes.

  The electric motor 41 of the servo control 40 is connected by load conductors 64-67 to the positive pole of the on-board voltage supply. Three switching elements 20; 46,

  47 are arranged in the charge conductors 64-66.

  The switching element 20 is a mechanical button switch, made as a contactor, the button of which is arranged for example on the lever of the pedal 11 so that the contactor is open.

  when this pedal 11 is not actuated.

  An ABS 48 switching element is

  arranged in parallel with the switching element 20.

  This element 48, which is a contactor, is actuated by a relay 49 which is connected in particular by a signal conductor 68 to a control module 3. A breaking element 46 produced in breaking contact and actuated by a relay 47 is mounted upstream of the two switching elements 20, 48. The relay 47 is connected in particular by a control conductor 67

to the control module 3.

  The torque sensor 45 and a switch 60 are also connected to the module

3.

  The control module 3 comprises in particular an ABS control equipped with an automatic circuit for finding extremes and holding. This automatic circuit ensures that at each braking process and when the vehicle is immobilized, the service brakes remain applied until the control identifies a starting process triggered by the driver. The control signal of the automatic circuit for finding the extremes and holding, intended to maintain the service brakes, is also used for the automatic application of the parking brake. The control signal triggers, for example, a short time generator for time intervals between one and a few minutes. At the end of a prescribed or adjustable time interval, the control module 3 actuates the relay 49 and therefore activates the servo control 40. The latter tightens the transmission cable 1. When the twist which corresponds to a sufficient force parking brake application is achieved at the location of the torque 45 detector, the control module 3 requires the relay 47 to open the

  switching 46. The servo control 40 is cut.

  The signal from the automatic extremes-finding and holding circuit can also be used in combination with signals which are produced when, for example, the ignition key is removed, the driver's door is open or the driver's seat electronics detects that this seat is relieved. Command 3 can also be programmed, depending on the type of vehicle or the use case, to identify a regular stop of the vehicle using the combination of some, individual, or several of these signals in order to activate automatically. the parking brake as soon as possible early enough to relieve

service brakes.

  The parking brake can be activated directly, using switch 60, bypass on the automatic circuit for finding extremes and holding. A short press on

  the switch 60 activates the servo control 40.

  This is cut as described above.

  The parking brake can also be applied in service with servo. To this end, press the pedal 11. The switch 20, which thus undergoes closure, activates the servo control 40. The latter stops as soon as the pedal 11 is released again or at the latest as soon as the maximum clamping force, set by sensor, parking brakes is reached, see automatic control. Switch 20 can also have

  possibly the function of switch 60.

  Figures 2 and 3 show the clamping device. This comprises a cylinder segment 30 which can be rotated either by means of a pedal 11 actuated by the force of the

  muscles, either using a servo control 40.

  The cylinder segment 30 is in the exemplary embodiment a discoid component which is mounted on the body 5 of the vehicle by means of a journal 13 and a support 12. It has three external contours. The contour having the smallest outside diameter is that of winding 31. The transmission cable 1 arriving from the parking brakes rests on it. The transmission cable is led by

  a protective tube 2 on the clamping device 10.

  The contour having the mean diameter consists of an involute toothing 32. This contour meshes with the

  toothing of the output pinion 42 of the servo-control 40.

  The contour having the largest diameter is a snap-toothing 33. In the particular case, it forms part of a snap-fitting with directional teeth and a snap-forming forming a catch. The teeth 32 can optionally also be used for the two snaps. The pedal 11 is also mounted on the journal 13. It is in functional connection with the cylinder segment 30 by a snap-fastening with directional teeth 17-18; 33. The latter causes a blockage clockwise. It comprises a stop pawl 18 which is mounted on a pivot 17 fixed to the pedal 11. The stop pawl 18 shaped as a lever is pushed back by the force of a spring in the latching teeth 33. It is equipped, at the end opposite to that of its tip, a lever arm which has a hole through which passes the release cable 52 coming from the hand lever 51. A tenon 55 for driving the stop pawl is fixed to this

  location for release cable 52.

  A spring element 15 curved in omega and wound around the pin 13 makes the pedal 11 bear against the body 5 of the vehicle. The spring element 15 exerts a load on the pedal counterclockwise. It is supported for this purpose against the pedal 11 by a stud 16 and against the support 12 by a stud 14. The latter also serves as a stop for the pedal 11 when the latter is not

under charge.

  The pedal 11 can also be replaced by a lever which is remotely controlled by it, for example by means of a transmission cable. The clamping device can be arranged in this case in a location

  in which there is enough space.

  Furthermore, a snap forming partial stop notch is in abutment against the snap teeth 33 of the cylinder segment 30. This snap forming partial stop notch comprises a pawl 57 subjected to the force of a spring and pivotally mounted on the bodywork 5 of the vehicle at a place of articulation 59. The pawl 57 has a point 58 whose contour allows automatic triggering from a determined clearance stroke. To this end, the tip 58 of the engaged pawl 57 is chamfered below the outside diameter of the teeth. The pawl 57 has at the free end a hole or a comparable recess through which the release cable 52 passes. The latter is in abutment against the pawl 57 by means of a driving pin 54. This cable 52 is directed , behind the snap forming partial stop notch 33; 57-59, in a protective tube 53 which leads to the hand lever 51, see the

figure 1.

  A snap-toothing with a complementary shape is used in FIGS. 1 and 2 to retain and actuate the cylinder segment 30. As a variant, it is also possible to use for this purpose a snap-in friction exercise of a force. The stopping direction can also be freely adopted and the holding force can be adjusted at will even with

friction snaps.

  During an automatic attack on the servo control 40 or on pressing the key switch 60 shown in FIG. 1 for actuating the parking brake installation, the servo control 40 rotates the cylinder segment 30 so as to wind the transmission cable 1 until the electric motor 41 is cut off, which is controlled by a detector. In this case, the pedal 11 remains in the initial position shown in FIG. 2. The cylinder segment 30 rotates clockwise without being prevented by the pawls 18 and 57 which are in support, but which are not blocking. After switching off the electric motor 41 and releasing the clutch 43, the cylinder segment bears against the bodywork 5 of the vehicle by means of the snap forming partial stop notch 33; 57-59. The abutment pin 14 causes another support against the body 5 of the vehicle by means of toothed snap

  directional 17-18; 33 and pedal 11.

  To release the parking brake, the hand lever 51 shown in FIG. 1 is actuated in order to pull the release cable 52 in the protective tube 53. As a result, the stop pawl 18 opens first. because of the ratios of the lever arms of the pawls 18, 57. The premature opening of the stop pawl 18 can also be obtained by a corresponding positioning of the drive pins 54, 55 on the release cable 52. In this case , the tenon 54 for driving the stop pawl has a greater clearance with respect to its pawl 57 than the tenon for driving 55 with respect to the pawl 18 - this before actuation of the hand lever 51. The tenons 54 , 55 for driving the pawls can optionally be produced so as to be

adjustable.

  After complete release of the toothing 33 by the stop pawl 18, the latching zone, that is to say the chamfer of the tip 58 of the pawl, reaches the head circle of the toothing 33 of the latching. The cylinder segment 30 is then released and rotates counterclockwise under the effect of the traction of the brake transmission cables. The rapid rotational movement no longer allows the pawl 57 with a partial stop notch to engage before immobilizing the cylinder segment. Consequently, a brief actuation of the hand lever 51 is sufficient to obtain complete release of the parking brake. It is possible to snap 17-18; 33 with directional teeth in the form of a snap forming partial stop notch. It is also possible to make the two snaps 17-18; 33 and 33; 57-59 in the form of a latch only, provided that the latching force of only one of the latching locks is greater than the useful force exerted on the cable

transmission 1.

  In the exemplary embodiment, the release cable 52 almost passes through the center of the journal 13. As a result, when the pedal 11 is actuated, there is hardly a change in the play between the pawls 18, 57 and their tenons

54, 55.

  The clamping device can be stretched by the force of the muscles, for example when the on-board voltage supply is cut or faulty. To this end, the pedal 11 is actuated by the driver. It turns under the effect of force

  muscle clockwise around pin 13.

  The pedal 11 is in functional connection with the cylinder segment 30 by the catch pawl in engagement 18. The pedal 11 is depressed until the driver has the impression that the positioning brake is sufficiently applied. The cylinder segment 30 and the pedal 11 have reached the position shown in FIG. 3. The pawl 57 with partial stop catch, which is engaged, prevents the cylinder segment 30 from turning in the opposite direction after the release of the pedal 11. The spring element 15 rotates the pedal 11 backwards until it stops against the stopper pin 14. The pedal 11 is then again in the position shown in broken lines. The parking brake is activated by foot force as well in servo-controlled as in automatic service by mechanical unlocking by means of the lever

hand 51, see figure 1.

  The switches or detectors, for example the switch 20 of FIG. 1, which are possibly necessary for the control or the

  adjustment, are not shown in Figures 2 and 3.

Claims (7)

  1. Parking brake installation, comprising a device which can be actuated by electric motor or by the force of the muscles to tension the transmission cables of the brake and, in the event of actuation by electric motor, which is triggered by an electric switch or by the handling, which can be called electrically, of the actuation element movable by the force of the muscles, the braking force is detected and regulated or controlled electronically, characterized in that the tensioning device (10) comprises a cylinder or cylinder segment (30) which winds a transmission cable (1), the cylinder or cylinder segment (30) comprising at least one toothing (32, 33) with which an output pinion (42) d '' a servo control (40) and into which a latching element (57) penetrates which causes a blocking or forms a notch in the opposite direction to that of tightening and which can be released for o open the parking brake, - in that the cylinder or cylinder segment (30) can be rotated in the direction of tightening using a control element (11), the axis of rotation of which is identical to that of the cylinder or of the cylinder segment (30), by means of a latching element (18) which can be released for the opening of the parking brake, - in that a switching element ( 48) which attacks the servo control (40), which is actuated electrically or electronically and which is mounted in parallel with said switch (20) which detects the actuation of the operating element (11), is triggered at least by a signal generated in a control module (3) by an automatic circuit for finding extremes and holding part of the ABS control.   2. Parking brake installation according to claim 1, characterized in that the handling element (11) is a pedal. 3. Parking brake installation according to claim 1, characterized in that the latching element (57) bears under the effect of the load of a spring against the bodywork (5) of the vehicle.   4. Parking brake installation according to claim 1, characterized in that the latching element (18) bears under the effect of the force of a spring against the pedal (11), the latter then remaining at his rest position   against the vehicle body (5).   5. Parking brake installation according to claim 1, characterized in that the latching elements (18) and (57) can be extracted from the latching toothing (33) using a common cable of release (52) leading to a   lever (51) which can be actuated by hand.   6. Parking brake installation according to claim 1, characterized in that a switching element (60), by which the electromechanical tensioning of the clamping device (10) is triggered by a pressure pulse on a key d switch, is connected to the control (3). 7. Brake installation   parking according to claims 1 and 5 taken   together, characterized in that the switch (60) is integrated in the lever (51).