DE3642874C2 - - Google Patents

Description

The invention relates to a device for a parking brake on a motor vehicle according to the Preamble of claim 1.

It is a generic device for a parking brake known (JP-OS 59-140 153), the parking brake in the brake operating position locking, from an electromotive Worm drive existing locking mechanism automatically by a control signal from a control unit can be unlocked. The control signal that triggers the parking brake becomes dependent on the control unit supplied identification signals generated. As identification signals are the control unit in particular one more Incline identification signal and a propulsion identification signal to be viewed engine speed signal supplied, wherein taking these signals into account and in the control unit stored characteristic curves then generates the control signal when the sensed inclination of the road is this assigned engine speed a predetermined target value  has reached. This is to ensure that the Parking brake is only triggered automatically when that Engine torque is sufficient to keep the vehicle on an incline actually moving forward. So it is obvious automatic activation of the parking brake on vehicle-specific Criteria. It is not apparent like a failure of the power supply for the electromotive The worm drive released the parking brake can be, since a manual release of the locking function is not provided.

There is also a combined control for the foot brake a vehicle with a brake only when stationary holding device holding the vehicle in the braking position known (DE-PS 26 13 074), which depending from the simultaneous actuation of several switches of one switching device takes its release position to release the brake, wherein an accelerator pedal switch, a clutch pedal switch, a service brake switch and a speed-dependent switch is provided are. Can be operated depending on the speed Switch has the function, an automatic detection to prevent the service brake while driving, comes the accelerator and clutch pedal switch when starting the The function of the vehicle, the automatic triggering of the To effect holding device of the brake. It also points the holding device still has a hand locking lever, in order to be able to manually lock the brake pedal if this depressed and an electromagnet of the holding device is switched off from the power source. Here is a particular disadvantage that with manual detection of the brake pedal the automatic release of the brake pedal becomes inoperative.

Furthermore, there is a device for a parking brake  on a car with an automatic transmission known (vehicle Mercedes Benz type 600), the parking brake with the foot is operated. The parking brake is released both by hand and here through automatic triggering when starting the vehicle - based on a gear identification signal when Shifting into gear using the selector lever - possible.

There is also an automatic, electronically controlled device a vehicle brake system that has a brief stop and easy starting on slopes without using the parking brake (Handbrake) enables, known ("Hill-Holder" the Lucas Girling). The system facilitates both holding and moving forward on gradients as well as stopping and Driving backwards on a slope. The establishment is made by Depressing the clutch pedal turned on, provided the vehicle is on an uphill or downhill slope 2 ° inclination and in the hydraulic braking system is sufficient Pressure built up (via the foot brake pedal). As long as the clutch pedal is depressed, the vehicle is in held in place without handbrake and / or footbrake must be operated. When "releasing" the clutch pedal, e.g. B. when starting, the facility is automatic switched off when the torque transmitted by the clutch sufficient to hold the vehicle and accelerate it. An electromagnetic solenoid valve locks when the device is actuated a brake circuit down to the master cylinder and closes thus the existing pressure in the brakes of this circuit. This pressure can be controlled via a check valve even when the valve is closed Solenoid valve can be increased. A control unit in Connection with clutch pedal switch, inclination and speed sensors controls the solenoid valve and ensures that the facility only when the vehicle is stationary and sufficient Lane slope is activated. Since these are for vehicles with mechanical Gear designed device the parking brake disregarded, this system carries a longer one Holding the vehicle, for example for hours or days, not bill.

The object of the invention is to provide a generic device trained so that they account for the possible driving criteria can wear, both for vehicles with mechanical or automatic Gearbox can be used as well on motor vehicles with only manual Trip can be adapted.

This object is achieved with the characteristic Features of claim 1 solved. Advantageous configurations and further developments of the subject matter of the invention are through the Characteristics of the subclaims marked.

An embodiment of the invention is in the drawing shown and is described in more detail below. It shows

Fig. 1 shows the circuit scheme of the device according to the invention,

Fig. 2 shows the detail II of FIG. 1 in a constructive representation and

Fig. 3 shows the arrangement of the handle for manual triggering.

As can be seen from FIG. 1, the device 1 for the parking brake 2 has, as an essential component, a control unit 3 with the inputs A to K and the output M. From the output M , a signal line 3.1 leads to a bidirectional pump 4 - which also serves to supply the ZV control elements in vehicles with a central locking system - to whose one pump output the lifting element 2.1, designed as a pneumatic control element, of the parking brake 2 is connected, the piston 2.1 .1 of the lifting element 2.1 are connected via a mechanical operative connection 2.2 and the manual triggering via a mechanical operative connection 2.3 to the locking mechanism 2.4 of the parking brake 2 , as can be seen in detail in FIG. 2. The mechanical operative connection 2.2 here consists of a Bowden cable 2.2.1 articulated on the one hand on the piston 2.1.1 and on the other hand on the release lever 2.4.1 of the locking mechanism 2.4 , the Bowden cable casing 2.2.2 being supported at one end on the lifting element 2.1 in a manner fixed to the housing. At the other, free end 2.2.2.1 of the Bowden cable casing 2.2.2 , the Bowden cable 2.3.1 of the mechanical operative connection 2.3 is articulated, which on the other hand is connected to the handle 2.5 for manual release, the Bowden cable casing 2.3.2 on the one hand at a stop 2.4 .2 of the locking mechanism and on the other hand fixed to the handle 2.5 at 2.5.1 . The principle of such a Koppelbowdenzug is known for example from DE-PS 28 15 743. As can be seen from FIG. 3, the handle 2.5 is mounted in a guide 5.1 of the dashboard console 5 and is covered towards the passenger compartment by a clip 5.2 that can be clipped out; the manual triggering is only intended for emergencies, with the aperture 5.2 serving the purpose of 'child safety'.

Referring again to FIG. 1, the following signals are fed to the control unit 3 via its inputs A to K :

Entrance A :
Via a signal line 6.1, the parking brake actuation identification signal from the parking brake pedal switch 6 , which has the level 0 when the switch is closed and thus connected to ground - that is to say when the parking brake is actuated - but level 1 when the switch is open.

Entrance B :
Via a signal line 7.1, the slope identification signal from the inclination switch 7 , which has the level 1 when the vehicle is on a slope and thus the switch is open, but has the level 0 when the vehicle is on a level or on a slope and the switch is closed.

Entrance C :
Via a signal line 7.2, the slope identification signal from the inclination switch 7 , which has the level 1 when the vehicle is on a slope and thus the switch is open, but has the level 0 when the vehicle is on a level or on a slope and the switch is closed.

Entrance D :
Via a signal line 8.1, the gear identification signal, which has the level 0 in a motor vehicle with an automatic transmission when the selector lever is in the P or N position, since the input D via the closed gear switch 8 and the starter 8.2 of the motor vehicle is grounded, but has the level 1 when a gear is engaged and thus the gear switch 8 is opened;
which has in a motor vehicle with a mechanical gearbox level 0 when the gear lever is in the neutral position - thus the passage switch 8 is closed - and when the clutch is disengaged - hence the gait switch 8 connected in parallel with clutch switch 8 ' Is also closed -, on the other hand, has level 1 when the gear switch 8 and when engaging the clutch, the clutch switch 8' are opened when a gear is engaged.

Input E :
Via a signal line 9.1, the reverse gear identification signal from an R-gear switch 9 connected to ground, which has level 1 when the reverse gear is engaged and thus when switch 9 is open.

Entrance F :
Via a signal line 10.1, the engine identification signal, which has level 1 when the engine 10 is running and level 0 when the engine is not running.

Entrance G :
Via a signal line 11.1, the propulsion identification signal from the motion sensor 11 which detects a relative movement between the brake shoes and the brake carrier and which has the level 0 when the motor vehicle is stationary, but has the level 1 when the motor vehicle is moving.

Entrance H :
Via a signal line 12.1, the accelerator pedal actuation identification signal from the accelerator pedal switch 12 which is at ground and which has the level 0 when the accelerator pedal is not actuated and the switch is thus closed, but has the level 1 when the accelerator pedal is actuated and the switch is thus open; Despite the accelerator pedal actuation, however, the signal remains at level 0 when the bonnet switch 14.1 which is connected in parallel with the accelerator switch 12 is closed with the bonnet open.

Entrance J :
Via a signal line 13.1, the service brake actuation identification signal from the brake switch 13 which is connected to ground and which has the level 0 when the service brake is not actuated and the switch is closed, but has the level 1 when the service brake is actuated and the switch is open; Despite the service brake being actuated, however, the signal remains at level 0 when the bonnet switch 14.2 , which is connected in parallel with the brake switch 13 , is closed with the bonnet open.
The two aforementioned bonnet switches are purely safety switches in order to rule out possible dangers when handling the engine area with the bonnet open; An automatic unlocking of the parking brake is therefore not possible when the bonnet is open, the engine is running and the gear is engaged. Rather, in the case of such a signal combination applied to the control unit, a signal can be generated by the control unit which is fed to the engine 10 via the signal output M ' and causes it to be switched off , for example by interrupting the ignition circuit.

Input K :
Via a signal line 15.1, the tachometer signal from a tachometer 15 , which has level 1 from a certain speed of the motor vehicle, for example above 4 km / h, and thus prevents the possibility of the parking brake being applied, which furthermore allows the parking brake to be metered during the driving operation is maintained in a known manner.

Furthermore, a fault indicator 16 for the same is connected to the control unit.

The triggering logic of the control unit 3 of the device is now shown in the following table and is explained with the aid of some case examples, on the basis of which the logic of the case examples which are not further explained is understandable:

Case study 1: Driving forward on the flat with gas

The motor vehicle is parked with the parking brake 2 actuated, so the parking brake pedal switch 6 is closed, so that level 0 is present at input A of control unit 3 .

Likewise, level 0 is present at inputs B and C , since the motor vehicle is parked on one level and consequently the tilt switch 7 is closed.

The level 0 is also present at input K since the speed of the motor vehicle is 0 km / h.

If the motor vehicle is started using the ignition lock switch 10.2 , the engine identification signal 'engine running' is present at input F at level 1.

Likewise, the gear identification signal at level 1 is present at input D when the gear switch 8 is opened in a motor vehicle with an automatic transmission by engaging a gear by means of the selector lever or in a motor vehicle with a mechanical transmission by engaging a gear -Switch 8 and by engaging the clutch when starting the clutch switch 8 'are opened.

Since gas is started, the accelerator switch 12 also opens, so that level 1 is also present at input H.

Although there are also signals at inputs E, G and J (level 0), these are not evaluated by the control unit, since they are not relevant in this case example.

On the basis of the abovementioned signals, the logic of the control unit 3 , which is built up in the binary system, for example by means of a μP, which can be part of the on-board computer that is already present in the motor vehicle, then generates a control signal at its output M which activates the bidirectional pump 4 . whereupon this generates negative pressure in the lifting element 2.1 , whereby the piston 2.1.1 is sucked in and the release lever 2.4.1 is moved via the Bowden cable 2.2.1 , which leads to an unlocking of the locking mechanism and thus to an automatic release of the parking brake.

Case study 2: Starting on an incline, uphill and forward

The motor vehicle is parked with the parking brake 2 actuated, so the parking brake pedal switch 6 is closed, so that the level A is present at input A.

Since the motor vehicle is parked on an incline, level 1 is present at input B and level 0 is present at input C , since on the one hand the switch part of the inclination switch 7 that supplies the slope identification signal is open and on the other hand the switch part of the switch that supplies the slope identification signal Tilt switch 7 is still closed.

The level 0 is present at input K since the speed of the motor vehicle is 0 km / h.

If the motor vehicle is started using the ignition lock switch 10.2 , the engine identification signal 'engine running' is present at input F at level 1.

Likewise, the gear identification signal with level 1 is present at input D when the forward gear is engaged, and the R gear identification signal with level 0 is present at input E since the R gear switch 9 remains closed when the forward gear is engaged.

Since you start uphill with gas, the accelerator switch 12 also opens, so that level 1 is also present at input H.

If the motion sensor 11 senses a forward movement of the motor vehicle, then the propulsion identification signal of level 1 is present at input G , and only then is the control signal 3 generated at its output M by the logic of control unit 3 .

It can be seen here that the control signal is also generated as a function of the propulsion identification signal, but this is only present at input G when the motor vehicle is actually moving, that is to say the torque transmitted by the clutch or converter is sufficient to hold the motor vehicle in place and accelerate. It is therefore a signal in which the vehicle weight and any trailer load are taken into account, regardless of whether the vehicle is a passenger or a truck.

Regarding the accelerator operation identification signal and the Service brake actuation identification signal is to be noted that these signals are monoflop signals, which ensures that if something is still kicked The parking brake is nevertheless applied to the gas or service brake pedal and the parking brake can only be triggered initiated by pressing the desired pedal again can be.

The control signal generated by control unit 3 at output M , on the other hand, is a signal with a defined longer period of time. As a result, on the one hand, a renewed ascertainment of the parking brake is prevented within this time period and, on the other hand, this control signal, which is prolonged in time, is required in the event of a return movement of the parking brake which is delayed by a damper element 17 - see FIG. 2, so as to prevent the release lever 2.4. 1 operated pawl of the locking mechanism locked again before the return movement of the parking brake.

Although pneumatic control is described for the parking brake , it is of course also possible to provide hydraulic or electromagnetic control.

Claims (12)

1.Device for a parking brake - in particular of the foot lever type - on a motor vehicle, the locking mechanism of which locks in the brake actuation position can be unlocked by automatic triggering, the automatic triggering being effected by actuating an actuating element of the locking mechanism, which receives a trigger signal via an output of a control device, the Inputs can be supplied with at least one engine identification signal, gear identification signals, inclination identification signals, a service brake actuation identification signal, an accelerator actuation identification signal and a propulsion identification signal, the actuation signal depending on the inclination identification signal and others of the supplied identification signals when the parking brake actuation identification signal is applied to the control device, characterized in that the propulsion identification signal (input G on control device 3 ) is generated by a motion sensor ( 11 ) and that both the control element ( 2.1 ) for the automatic release as well as a handle ( 2.5 ) for a manual release of the locking mechanism ( 2.4 ) via active connections ( 2.2; 2.3 ) act on the same release lever ( 2.4.1 ) of the locking mechanism ( 2.4 ). 2. Device according to claim 1, characterized in that the control device ( 3 ) generates the control signal at its output (M) as a function of the identification signals of an inclination switch ( 7 ) when at least

• - when starting off on the plane
  in addition to the engine and gear identification signal (inputs F and D) , the accelerator pedal (input H) or the service brake actuation identification signal (input J) ,
• - on an uphill or downhill slope
  • • when starting uphill
    in addition to the engine and gear identification signal (inputs F and D) , the accelerator actuation identification signal (input H) and the propulsion identification signal (input G) , when reversing, the reverse gear identification signal (input E) of an R- Gear switch ( 9 ),
  • • when starting downhill with the brake
    in addition to the engine identification signal (input F) , the service brake actuation identification signal (input J) and
  • • when starting downhill with gas
    In addition to the engine and gear identification signal (inputs F and D) , the accelerator pedal activation identification signal (input H) , and when reversing, the reverse gear identification signal (input E)

is present.   3. Device according to claim 1, characterized in that in a motor vehicle with an automatic transmission, the gear identification signal is present at the input (D) of the control unit ( 3 ) when a closed in the P or N position and via the starter ( 8.2 ) the vehicle's gear switch ( 8 ) connected to earth is opened when engaging a gear. 4. Device according to claim 1, characterized in that in a motor vehicle with a mechanical gearbox, the gear identification signal is present at the input (D) of the control unit ( 3 ) when a gear switch ( 8 ) which is closed in the idling position and directly connected to ground ) is opened when a gear is engaged and a clutch switch ( 8 ' ) connected in parallel with the gear switch ( 8 ) and closed when the clutch is disengaged is opened when the clutch is engaged. 5. Device according to claim 1, characterized in that both the accelerator switch ( 12 ) and the brake switch ( 13 ) a hood switch ( 14.1, 14.2 ) is connected in parallel, which is closed when the hood is open and the service brake or accelerator pedal actuation ID signal suppressed. 6. Device according to claim 5, characterized in that with the hood open and the control unit ( 3 ) adjacent gear and engine identification signal (inputs D and F) from the control unit ( 3 ) a signal (output M ') is generated, which Stopping the engine ( 10 ) causes. 7. Device according to claim 1, characterized in that a further input (K) of the control device ( 3 ) is still a tachometer signal from a tachometer ( 15 ) that the control device ( 3 ) depending on the engine and accelerator pedal -Betätigungs identifying signal (inputs F and H) and upon application of the tachometer signal generates a drive signal (output M) for preventing the locking of the parking brake (2) as soon as the control unit (3) and the parking brake actuation identifier signal (input a ) is present. 8. Device according to claim 1, characterized in that when the lifting element ( 2.1 ) is actuated, the Bowden cable ( 2.2. ) Is articulated via a piston ( 2.1.1 ) on the one hand on the piston ( 2.1.1 ) and on the other hand on the release lever ( 2.4.1 ) of the locking mechanism ( 2.4 ) . 1 ) unlocks the locking mechanism of the parking brake ( 2 ), the Bowden cable casing ( 2.2.2 ) being supported with its one end fixed to the housing on the lifting element ( 2.1 ), while the other, free end ( 2.2.2.1 ) of the Bowden cable casing ( 2.2.2 ) Another Bowden cable ( 2.3.1 ) is articulated, which is connected to the handle ( 2.5 ) for manual triggering, the Bowden cable casing ( 2.3.2 ) on the one hand fixed to the housing (at 2.4.2 ) on the locking mechanism ( 2.4 ) and on the other hand fixed to the housing ( at 2.5.1 ) on the handle ( 2.5 ). 9. Device according to claim 8, characterized in that the handle ( 2.5 ) is arranged behind a panel ( 5.2 ) of a dashboard console ( 5 ). 10. The device according to claim 8, characterized in that when the locking mechanism ( 2.4 ) is unlocked, the return movement of the parking brake ( 2 ) is delayed by a damper element ( 17 ). 11. The device according to claim 1, characterized in that the control signal generated by the control unit ( 3 ) is present at the output (M) over a defined longer period of time.