DE102008024019A1 - Brake pedal activatable electric parking brake - Google Patents

Abstract

The invention relates to a parking brake, with a hydraulically adjustable piston (101) acting on at least one brake pad, wherein the piston (101) can be locked in the parking position by means of a locking device, wherein a control device (11) the parking brake (8, 8a) and additionally controls the components required for the activation and deactivation of the parking brake, the parking brake (8, 8a) being activated by the actuation of the brake pedal (1).

Description

The The present invention relates to a Parkierbremse, with a hydraulic adjustable piston acting on at least one brake pad, wherein the piston in the parking position by means of a locking device lockable, wherein a control device, the parking brake and in addition for activation and deactivation the parking brake controls required components.

electrical Parking brakes are known and are particularly due to the better comfort. These are electric parking brakes known with electric motor and gear, the gearbox on a Brake piston acts. This solution is technically complex and expensive and disadvantageously high in weight. In addition are electric parking brakes are known in which an electric gear motor a cable pull mainly for disc with integrated drum brake stressed.

Continue electric parking brakes from the DE 103 20 907 and DE 10 2007 015 809 known. In these parking brakes, the pressure support of a braking device is used, which supplies the Par kierbremse in their activation with pressure. Here, the brake piston parking brake is held firmly by a motor with spindle drive so that when disabling the brake device, the clamping force of the piston is maintained. These concepts are much easier and easier. They have not found any application until today, since in case of failure of the pressure generation and the parking brake fails, creating a security deficiency is given. As a pressure transmitter, a vacuum brake booster is usually used, which can generate via an electromagnetic valve corresponding pressure in the master cylinder by a chamber is supplied with atmospheric pressure. If this valve fails, no parking brake can be activated. If the vacuum fails, z. B. at a longer downtime, the parking brake can not be disabled, ie not be solved. On the other hand, pressure can also be generated via the ESP hydraulic unit via the electromotive pump with appropriate valve circuit. In case of failure of the electric motor or the valves but no parking brake can be activated. In an electric motor brake booster after DE 100 2005 018 649 Falls in case of failure z. B. the electric motor also from the parking brake. Be switched above electrical parking brakes on a switch on the dashboard or automatically, z. B. at vehicle standstill.

Of the The invention is therefore based on the object of providing a parking brake, in the case of simple means and optionally in case of failure of Amplifier for generating pressure activating the parking brake can be carried out.

These The object is achieved according to the invention that the parking brake by pressing the anyway existing brake pedal is activated. Further advantageous embodiments Parkierbremse according to claim 1 result from the features the dependent claims. By simply pressing the brake pedal according to the invention the parking brake activated. This activation may be dependent on the vehicle speed and / or u. a. also done the inclination angle of the vehicle. Thus, the controller may be programmed so that at a vehicle speed to zero, the controller at a Pressing the brake pedal activates the parking brake. Likewise, a dependence of the selector lever at be considered an automatic transmission. So can z. B. when switching the selector lever in the park position, the parking brake be activated, while pressing the brake pedal is, if the fully automatic function is not switched on. Also the control device can be programmed such that the parking brake is activated only when the brake pedal is stationary has been operated for a predetermined time.

Of the necessary brake pressure of Parkierbremse can advantageously a fixed be predetermined value. However, it is particularly advantageous if the necessary brake pressure based on the measurement data of a tilt sensor determined and specified, the tilt sensor anyway can be present as an acceleration sensor in the ESP system.

In An advantageous further embodiment of the invention is a Display and / or an acoustic warning device used, to indicate to the driver if the required Brake pressure for parking position is not reached. Of the The driver then has to build up the necessary activation pressure Press brake pedal.

Thus, by pressing the brake pedal in the event of failure of the electric motor or other pressure generator, the required brake pressure can be established, it is necessary that the brake pedal is mechanically and / or hydraulically connected to the piston of the parking brake and the piston to brake pressure build-up when pressing the Adjusted brake pedals. Thus, the force required to operate the brake pedal is not too large, so that possibly weaker people can not build the necessary brake pressure, it is advantageous if a pressure booster between the piston and the brake pedal is arranged. In this case, in particular, a simple plunger is proposed as a pressure intensifier, which increases the foot forces for generating higher pressures, in particular in the case of strong pressure Slope or slope can reduce by a factor of 2 to 3.

In addition to the possible failure of the electric motor, which is used to generate pressure, the electrical system may fail in case of power failure. Without this, the vehicle, ie engine, light can not be operated. Critical, however, is the failure of the generator while driving, here is an emergency until the empty battery. In this limiting case, the internal combustion engine fails if the battery can no longer deliver the current for supplying the ignition, injection and tank pump with approx. 10 A, which then causes the vehicle to be shut down. An advantage of the solution DE 10 2007 015 809 In addition, there is the fact that the current levels for the electric motor of the parking brake with about 2 A is small. This small amount of current can still supply the battery, even if the engine is already stopped, so that the function of the parking brake is still possible.

The proposed solution has in addition to the aforementioned advantages in case of failure of the electromotive pressure generation or the electrical system additional benefits. So less control switches and cable needed. The necessary for the invention Pressure transmitter, Pedalweggeber and brake light switch are already through the existing ESP system is present in the vehicle. In addition, the inventive Parking brake significantly more cost and weight than the known from the prior art electric motor Parkierbremsen and has the potential to find application in small cars. Farther the entire functions are fully diagnosable. An automatic function for the parking brake for z. B. Parking, starting and stop-and-go can advantageously be switched on optionally.

following The invention will be explained in more detail with reference to drawings.

It demonstrate:

1 : Block diagram of all components required for the parking brake according to the invention;

1a : electro-hydraulic parking brake according to the prior art;

2 : Block diagram of all components required for the parking brake according to the invention with diagonal brake circuit distribution;

3 : Circuit diagrams for the functions of the parking brake according to the invention.

The 1 shows the essential components involved in the function of the parking brake according to the invention. To activate the Parkierbremse the driver operates the brake pedal, which of a Pedalweggeber or brake light switch 2 is sensed. For a system DE 100 2005 018 649.1 becomes the electromotive brake booster 3 turned on, then z. B. at vehicle standstill automatically a target pressure of z. B. 100 bar and generated by the pressure transducer 9 is measured. The pressure of the master cylinder 4 passes over the brake lines 16 and 17 and control valves 5 to the wheel brakes 6 . 6a . 7 . 7a , Once the set pressure has been reached, the control unit will start 11 the electric motor of the electric Parkierbremse switched and the pressure is reduced to zero. If the process is completed, then the amplifier 3 switched off again.

The function of the operation and the release of the electric parking brake will be described below with reference to 1a explained in more detail in the DE 10 2007 015 809.4 is described.

The 1a shows the overall construction of caliper 102 with brake piston 101 and actuator. Known details such as construction of the brake, brake pad and seals are not described. Via the pressure line 125 is controlled by the brake pressure during parking, as shown in detail by the 3 and 4 shown and described in more detail later. The brake piston 101 presses on the brake pad, not described, simultaneously or with a time delay moves the rotor 113 over the pin coupling 113a the spindle 103 showing the force over the movable pressure plate 104 on the piston 101 transfers. The pressure is maintained at the level for a short time until, preferably, the spindle 103 no longer moving as they touch the pressure plate 104 is applied. The movement of the spindle is detected by the rotation angle sensor of the rotor. After pressure reduction, the clamping force of the caliper acts 102 fully over the pressure plate 104 and spindle 103 on the flange with main spindle nut 107 and ejector nut 108 , The one-piece main spindle nut 107 Can also be made by two easier to manufacture parts 105 and 106 be replaced, being part 106 forms a flange with the ejector nut 108 interacts. The movable pressure plate 104 prevents large lateral forces on the thread 103c . 107a and jamming to realize minimum driving forces of the spindle operation. The spindle 103 and the rotor 113 are about a clutch 113a separated to allow a radial offset of spindle 103 and rotor 113 not on the rotor 113 effect. Furthermore, the rotor 113 axially fixed, whereby the overall length is kept short. In view of the large adjustment path for the spindle 103 , which is needed to take into account the brake pad wear, nevertheless results in a total of a short overall length of the entire device. For this the spindle has 103 an extension 103a , the one in the axial direction he stretching slot 103b having. The separation of rotor 113 and spindle 103 over the pin coupling 113a reduces the heat transfer of the spindle 103 , which with the hot brake piston 101 in contact.

The rotor 113 has sliding rings at both ends 116 and 117 that stick to the inner wall 112b the bell 112 move. The slider 117 additionally carries the target 119 , z. B. a permanent magnet, for the rotary encoder 120 if z. B. the Hall principle is used. Both sliders 116 . 117 are preferably shaped so that they allow the free air space in the z. B. grooves and bore of the rotor to ensure good ventilation via a bleeder screw, not shown, which is arranged in the region of the highest spatial location for good ventilation. On the rotor 113 A torque acts from the magnetic flux of the stator of a brushless electric motor. All known principles such as asynchronous, synchronous or reluctance motors can be used here. The latter is preferred because of the simple construction and the high temperature load. The stator can conventionally be made of pole plates as in the lower half of the picture 114 and winding head 114a be constructed. The magnetic flux goes over the non-magnetic bell 112 and at the same time disconnects the stator 114 from the high pressure chamber of the rotor 113 ,

In the upper half of the picture is a disk-shaped structure of the iron circle 115 with coil 115a which, in the example shown, corresponds to a 3-pole stator of the reluctance motor. This design is advantageous when redundant windings are used, which can be easily listed here as a cylindrical coil. The stator laminations are in both versions on the outer surface of the bell 112 in order to support these under the high pressure load. In addition, at the end of the stator is still a support ring 12a used. stator 114 . 115 with winding 114a . 115 are together with the rotary encoder 120 and support ring 112a in the case 121 injected. It is advisable here to inject the ABS speed sensor as well in order to save a separate watertight plug-in connection and, if necessary, to use a common ground line with a rotary encoder. Here all lines can be routed to the body via a separating clutch. Also eliminates a separate attachment of the line on the wheel. The stator housing 121 is also encapsulated on the front side, so that a heat insulation to the bell 12 can be used.

As in 1 shown, the function of the electric parking brake in a display 13 are displayed z. B. "parking brake active". Of course, the previously used for use combination instrument can also be a display symbol 14 for parking brake included. When activating the electric parking brake, it is sufficient to direct the pressure in the wheel brakes with parking brake. In this case, the control valves 5 closed in front of the wheel brakes without parking brake. A deactivation is carried out as described in the same way, by using the brake pedal with intact amplifier 3 automatically the pressure level for switching off the parking brake is controlled or in case of failure via the foot force with appropriate notice on the display or display the required pressure is generated. The process is similar to the mechanical Fußfeststellbremse.

About that In addition, at every vehicle standstill, especially after parking the motor automatically activates the parking brake. Here There are possibilities that exist over the networking are possible with the electrical system and the systems.

An ad 13 in the display 12 can z. B. preferably be made in the instrument cluster. As an alternative, an optical or acoustic display or warning may be used. Furthermore, the display in another display z. B. head unit or radio to be made.

The 2 shows the same arrangement with components, this time for a brake system with diagonal brake circuit split. The function of the parking brake 8th and 8a is based on the 1 and 1a described. It is here omitted to explain the basic functions again. In the 2 are the switching positions of the control valves 5a . 5b . 5c and 5d located. In addition, the electromagnetic 2/2-way switching valves 19 / 19a available for the pressure intensifier. The positions of the valves 5a and 5b correspond to the positions during normal operation of a braking, in which the control valves 5a and 5b open and temporarily closed during ABS operation. The switching valve 19 for the pressure intensifier is closed.

The lower half of the picture with the control valves 5c and 5d shows the parking function. Here is the control valve 5c for the brake 7 , which has no Parkierbremse, closed to no additional volume from the master cylinder 4 record with appropriate pedal travel. The control valve 5d for the brake 7a is also closed. The switching valve 19a to the pressure intensifier 15a is open, which causes the brake pedal over the master cylinder 4 generated pressure corresponding to the area ratio of the piston of the pressure booster 15a to the parking brake 8a is translated. As for the two parking brakes 8th and 8a less volume z. B. two instead of four brakes from the master cylinder is required, with acceptable pedal travel a ratio of 2 to 3 is possible, ie with rela Tiny pedal forces can generate enough pressure. The intervention of the pressure intensifier is only in case of failure of the amplifier 3 , in case of failure of the motor drive or even in case of failure of the above generator with almost empty battery necessary. The battery can at least have the necessary energy to drive the display 13 / 14 to inform the driver due to the low power consumption even in case of failure of the engine still apply. The control functions for all electrical components are handled by the central control unit 11 , which may include the function for ABS / ESP, electromotive brake booster and Parkierbremse with pressure booster. The communication with the display 13 / 14 via a bus line, z. B. CAN. The electrical connection lines 10 connect the controller 11 with all electrical components of the system. Symbolic here is the inclinometer 18 drawn to calculate the necessary Parkierdrucks, which may be obtained in ESP systems in the sensor cluster. In hybrid vehicles, the electrical system is additionally supported by a DC / DC converter.

The left half of the 3 shows the circuit 20 for all functions of the parking brake according to the invention. The right half of the 3 shows the automatic function of the parking brake.

The logic circuit 20 has the two operating states "tensioning or actuating" and "releasing" the parking brake. The logic circuit 20 distinguishes between "normal case" and "Electromotive pressure generation failure". In the normal case is the circuit 20 gem. the left half of the 3 active. In "failure of the electromotive pressure generation" is the circuit 20 gem. the right half of the 3 active.

In the "normal case" it is necessary for the tensioning of the electrical parking brake, that the brake pedal 1 with pedal encoder 2 is pressed and the engine is "off", z. B. Ignition "Off" as And condition. Parallel to this, the partial automatic intervene, which preferably via evaluation of the speed v = 0 after a time, for. B. 1 s, with or without operation of the brake pedal 1 initiates the tensioning or, in particular, engages the stop-and-go system with full automatic, switches off the internal combustion engine and initiates the tensioning of the electric parking brake. This system works z. B. only when the engine is warm and has priority over the aforementioned sub-automatic circuit. It can, for. B. also for the clamping in addition to the described input commands 1/2 and motor "off" only the stop-and-go circuit can be used. These clamping signals are then output at the output of the z. B. electric motor brake booster 3 implemented either the pressure for the parking brake to a fixed value according to the pressure signal 9 adjusts and / or the measured vehicle inclination is taken into account by means of the inclination sensor a _L and accordingly sets a pressure to the stress of the parking brakes 8th and 8a to reduce. This feature has already been described.

Alternatively to the operation of the parking brake can to protect them also on the brake booster 3 the service brake are turned on when the fully automatic circuit contains the stop-and-go function, since only a relatively short time, z. B. at the traffic light stop, the parking position is used.

The "activation or tensioning" of the parking brake takes place as conventionally in a control lamp 22 displayed. Parallel to this can also be the automatic function 23 are displayed. If the parking brake fails, this is done with the warning lamp 24 displayed for "failure".

The parking brake is released via a renewed brake pedal actuation. Furthermore, as an AND condition, a switched-on internal combustion engine is required, for. B. Ignition "On" or accelerator opening α _GP, ie the parking brake on can also be achieved without running the engine when going downhill. Here too, the fully automatic circuit intervenes in parallel 21 a, z. B. at stop-and-go the engine starts to accelerate. Of great importance for the ease of use is the approach control. In the case of automatic transmissions, this controls the engine torque MM and also the transmission at a moment, which comes with releasing the parking brake 8th . 8a over the amplifier 3 is tuned, preferably also the inclinometer a _{L is used} with. In a manual transmission, the signal of the clutch sensor is additionally used. These processes are introduced in series and are not described separately.

At the simultaneous operation of the AND circuit and fully automatic circuit as a clamping command, the fully automatic circuit has priority. The driver can for the "cocking" and "solving" the Press the brake pedal without this being the automatic circuit disturbs. The process of "clamping" and "releasing" is similar that of the so-called keyless-go systems. These must be turned off and turning on the engine, the brake pedal is pressed.

The right half of the 3 shows the function of the parking brake in case of failure of the brake booster 3 , This is detected by a diagnostic test when the door is opened or at the latest when the brake pedal is pressed and the displays 25 and 26 preferably activated in the display. When the brake pedal is pressed 1 and pedal encoders 2 and additional engine shutdown or V = 0, the brake pressure acts on the Parkier brake or is this activated. When the target pressure 9 over the pressure sensor 9 or alternatively via the position of the brake pedal is achieved, the control of the indicator lamp for the parking brake. Again, the signal of the inclinometer a _L can be used with, so only in extreme cases of parking on a slope high foot forces are needed. The function of the parking brake 8th and 8a remains the same. The automatic circuit can not work for clamping because the electric amplifier 3 is missing.

To solve is the same And logic as in the left half of 3 effective. In contrast to "tensioning", a simplified traction aid, in particular for manual transmissions, can be used here since the simultaneous handling of clutch, brake and accelerator pedal is difficult, as experience with the foot parking brake shows. Here is z. B. when releasing after reaching the release pressure the parking brake 8th / 8a unlocked, the pressure on the control valves 5b and 5d via the pressure transmitter in coordination with the engine torque and speed also forward or backward movement controlled so that an automatic start on the mountain is possible.

The Operation of this parking brake is from the operation for the "normal case" and for the rare Case of a "failure of electromotive pressure generation" similar and for the driver so easy to use and understandable. It is much easier than for a normal vehicle Remote control, keyless go systems or vehicles with or without Automatic transmission, in which he brakes the Keyless Go systems must press. Here he has the brakes on all vehicles Actuate conditions. For cost savings and ease of use can also be dispensed with the usual switch.

Of the The present inventive idea is also in the described borderline cases fully effective and cost effective. This allows the use in all vehicle types.

1

brake pedal

2

pedal sensor or brake light switch

3

Brake booster

4

Master Cylinder with storage tank

5

control valves for pressure control ABS / ESP

6

wheel brake 1

6a

wheel brake 2

7

wheel brake 3

7a

wheel brake 4

8 / 8a

electromotive parking brake on

9

thruster

10

electrical management

11

central control unit

12

instrument cluster or device with display

13

display

14

warning light

15

Pressure intensifier

16

brake line 1

17

brake line 2

18

inclination sensor

19 / 19a2 / 2

switching valves

α _L

tilt sensor

engine Out

engine management Out

α _GP

accelerator sensor

engine One

engine management One

Ku

clutch sensor

V

vehicle (Wheel) speed

breeder

ignition

T

time basis

20

logical Circuit for clamping / releasing

21

logical Circuit for automatic parking brake

22

indicator light cocked for parking brake

23

display with automatic function

24

warning light for failure parking brake

25

display in case of failure brake booster

26

display for emergency function Parking brake

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10320907 [0003]
• - DE 102007015809 [0003, 0009, 0018]
• - DE 1002005018649 [0003, 0017]

Claims (13)

Parking brake, with a hydraulically adjustable piston ( 101 ) acting on at least one brake pad, wherein the piston ( 101 ) can be locked in the parking position by means of a locking device, wherein a control device ( 11 ) the parking brake ( 8th . 8a ) and additionally controls the components required for activating and deactivating the parking brake, characterized in that by actuating the brake pedal ( 1 ) the activation of the parking brake ( 8th . 8a ) he follows. Parking brake according to claim 1, characterized that the activation takes place only when the vehicle is stationary, the engine is off or the vehicle speed against Zero goes, especially after a predetermined time interval. Parking brake according to claim 1 or 2, characterized in that by means of the brake pedal ( 1 ), which in particular mechanically and / or hydraulically with the piston ( 101 ) of the parking brake ( 8th . 8a ), one for the adjustment of the piston ( 101 ) the parking brake required hydraulic pressure is buildable. Parking brake according to claim 3, characterized in that a signaling device ( 26 ) the vehicle driver (s) then gives an audible and / or visual signal, if the pressure build-up required for the parking position is not achieved without actuation of the brake pedal ( 1 ). Parking brake according to one of claims 1 to 4, characterized in that the brake pedal ( 1 ) mechanically with a pressure booster ( 3 . 4 ) is connected, wherein the working space of the pressure booster with at least one parking brake ( 8th . 8a ). Parking brake according to one of claims 1 to 5, characterized in that the control device ( 11 . 21 ) the braking force of the parking brake ( 8th . 8a ) in response to the signal of a tilt sensor (a _L ) of the vehicle adjusts or regulates. Parking brake according to claim 6, characterized in that the control device ( 11 . 21 ) the signal of the tilt sensor of the ESP control for adjusting or setting the braking force of the parking brake ( 8th . 8a ) used. Parking brake according to one of the preceding claims, characterized in that the control device ( 11 . 21 ) at each vehicle standstill, in particular after stopping the engine, at least one parking brake ( 8th . 8a ) of the vehicle is automatically activated. Parking brake according to one of the preceding claims, characterized in that during stop-and-go trips during vehicle standstill instead of the parking brake ( 8th . 8a ) the brake booster generates the brake pressure. Parking brake according to one of the preceding claims, characterized in that the control device ( 11 . 21 ) the parking brake ( 8th . 8a ) is activated when the selector lever is set to "N" in an automatic transmission vehicle and the vehicle speed is zero or the vehicle speed approaches zero. Parking brake according to one of the preceding claims, characterized in that optionally by the actuation of the brake pedal ( 1 ) or an additional operating element, in particular a switch, the activation of the at least one parking brake ( 8th . 8a ) he follows. Parking brake according to one of the preceding claims, characterized in that the control device ( 11 . 21 ) the at least one parking brake ( 8th . 8a ), if the engine torque (MM) is greater than the braking force of the parking brake or all Parkierbremsen ( 8th . 8a ) and / or the vehicle speed is greater than zero and / or increasing. Parking brake according to one of the preceding claims, characterized in that in case of failure of the amplifier ( 3 ) is used in a manual transmission vehicle to release the Parkierbremse the signal of the clutch slave cylinder and the engine speed for the engine torque control.