EP1769172A1

EP1769172A1 - Cable drive

Info

Publication number: EP1769172A1
Application number: EP05749363A
Authority: EP
Inventors: Gerhard Pfanzer
Original assignee: Siemens AG
Current assignee: Brose Fahrzeugteile SE and Co KG
Priority date: 2004-07-16
Filing date: 2005-06-16
Publication date: 2007-04-04
Also published as: DE102004034452A1; WO2006008216A1; CN101084386A; US20080006804A1

Abstract

The invention relates to a cable drive (1) comprising a drive motor (3) for tensioning a cable (7) by means of a transmission (5) connecting an output shaft (4) of the drive motor (3) to the cable (7) by means of a drive train (8). The invention also relates to a stop brake, especially for a motor vehicle, comprising a cable drive. In order to block the cable drive (1) in a simple manner, a brake train (14) is provided parallel to the drive train (8), connecting the motor output shaft (4) to the cable (7), said brake train comprising a self-locking device. According to the invention, one such cable drive is actively connected to a brake device for the actuation of the stop brake.

Description

cable drive

The invention relates to a cable drive with a drive motor for tensioning a rope mitteis a motor output shaft of the drive motor via a drive train with the rope connecting the transmission. In addition, the invention relates to a parking brake, in particular for a motor vehicle, with a cable drive.

An abovementioned cable drive is known, for example, for actuation of a brake cable in a vehicle, wherein a pulling spindle acting on the brake cable is self-locking. As a result, when the brake cable is tensioned, a lock is produced which permanently maintains a blockage of the brake and counteracts a release of the brake. A disadvantage of this cable drive is that the drive motor of the cable tensioning device must have a high drive torque.

Another known solution of a device for holding ei¬ ner braking force in a operated by a cable Brem¬ se sees the use of a ratchet with against a An¬ driving direction locking teeth. In particular, a defined release of the brake and a precise setting of a predetermined braking force are thus not possible.

In addition, under the name Cablepuller a Seilzugan¬ drive is known, which has an internal, frictional or positive brake-holding device with an additional motor drive having Direction gear. This cable drive is very complex in construction and expensive due to its two drive motors. Also, a motor vehicle-operated parking brake and a method for controlling it are generally known for a motor vehicle. In this case, an electric motor with a current sensor serves as a drive for a brake cable by means of a threaded rod having a gear, wherein the electric motor is stopped as soon as the current sensor for the electric motor signals a predetermined value. The gear is self-locking. As with the cable drive described above, it is also necessary here for the electric motor serving as the drive motor to provide a high drive torque.

The object of the invention is therefore to provide a cable drive of the aforementioned type, which can aufwei¬ a drive motor with a comparatively low drive torque and has a simple structure. In addition, the invention has for its object to provide a Feststellbrem¬ se of the type mentioned, which can be equipped with a simple construction with a comparatively low Antriebsdrehmo¬ ment having drive motor.

The first object is achieved according to the invention by providing a brake train which is parallel to the drive train and which connects the motor output drive cable to the cable, and which has a self-locking feature.

In the cable pull drive according to the invention, a tension force is applied to the cable via the drive train of the transmission, whereas holding the cable tension takes place by means of the self-locking brake cable. The brake train serves as a braking or blocking element for the cable drive itself, to the rope tension at a certain level hold. The powertrain has no self-locking. It can be constructed smoothly, and it is only a small, a comparatively low drive torque having drive motor required. This results in a weight reduction and a reduction in the power consumption for the cable feed drive, which makes it particularly suitable for use in objects to be moved, such as vehicles. In addition, the cable drive according to the invention has a short reaction time, he can tighten the rope very quickly and accurately. The ver ^¬ reduced power consumption of the drive motor is advantageous for control and regulation of the engine, which can be designed simplified and inexpensive. The Geräuschentwick¬ development of the cable drive according to the invention is low, especially since a second or further drive motor is eliminated. Due to the relatively small number of individual parts, the manufacture, assembly and maintenance of the cable drive is basically simple and inexpensive. The high level of operational reliability and the simple construction make the cable drive according to the invention particularly suitable, for example, for use as a drive for an electric parking brake, such as. It is used for example in Bauma¬ machines or motor vehicles.

According to an advantageous development of the invention, the construction of the cable drive is further simplified if an adjusting spindle acting on the cable is provided as the output member of the transmission.

One could imagine that, for example, by using clutches and / or freewheels, the drive train and the brake train have different ratios. Demge¬ geneüber the cable drive on very few components and is very reliable, if according to another advantageous development of the invention, the drive train and the brake train with the same speed act on the Stellspmdel. Thus, the drive train and the brake train, which are each driven only by the drive motor, the same (overall) translation.

In a simple and cost-effective manner, self-inhibition in the brake train according to another advantageous embodiment of the invention can be realized by the brake train having a worm gear.

According to another advantageous embodiment of the invention, the drive train on a spur gear. As a result, the drive train is inexpensive to manufacture, and it can be transmitted via it drive power with very high efficiency. Thus, the required Antrj ebs- performance, which must make the drive motor to operate the Seilzugan- drive at your disposal.

It is particularly advantageous if, according to another embodiment of the invention, a force sensor is provided for detecting a tensile force of the cable. Thus, for example, due to a signal emanating from the force sensor, the drive motor can be switched off when a preset cable tension is reached, thereby avoiding overstressing the cable. In addition, the force acting on a device to be operated by the cable, for example a braking device, can also be detected by the force sensor and optionally controlled together with the drive motor.

Basically, you can drive a motor, for example, a hydraulically or pneumatically operated motor to introduce. Of particular advantage for exne simple Steue¬ tion and control of the drive motor and for a kosten¬ favorable construction of the cable drive, however, it is when, according to another embodiment of the invention, the drive motor is an electric reversible motor. Em Reversiermotor also offers the further advantage that it can be used without additional facilities, such as a reverse gear, not only for tensioning the rope, but also for its specific, finely resolved loosening and relaxing.

In order to ensure a safe blocking of the rope due to the Selbsthem¬ determination in the brake train at a shutdown of the drive motor, according to another advantageous Wei¬ terbildung the invention an ange¬ driven by the engine output shaft Antriebsstrangemgangsrad and driven by the Motorab¬ drive train Bremsstrangeingangsrad gegeneinan¬ which can be rotated about a common axis of rotation.

According to another advantageous development of the invention, the motor drive 1e has a driver, which can be attacked by a driver of the drive train input gear and by a driver of the braser drive gear, driving the drive train gear and / or the brake train gear. In this way, with a simple structural design, a targeted, reliable torque and torque transmission is ensured.

For unimpeded, short-term building and working of the self-locking in the brake train, it is particularly advantageous if according to another embodiment of the invention, the An¬ powertrain speed is biased against its bias against the driving direction during tensioning of the cable against the engine output shaft. The second object mentioned above is achieved according to the invention by providing a cable pull drive according to the invention in the case of a parking brake mentioned at the beginning, wherein the cable drive is operatively connected to a brake device for its actuation.

In the invention, the tensioned by the drive motor rope is a brake cable of the actual braking device of the parking brake. Not to be confused with this Bremsein¬ direction is the brake line in the cable drive, which brake line holds the tension in the Bremssei]. The parking brake according to the invention is particularly suitable for use as a parking brake of a motor vehicle because of its precise metering, reliable function and its simple, maintenance-free construction. The parking brake according to the invention has the additional advantage that, with simple measures, for example the use of a force sensor for measuring the tensile force of the brake cable and a control of the drive motor dependent on the tensile force values, a (mechanical) readjustment of the parking brake becomes superfluous; It can then always develop its optimum braking action within very wide limits, without, for example, elongation of the brake cable leading to a reduction in the braking effect.

An embodiment of the invention is shown schematically in the drawing and will be described in more detail below. Show it

1 shows a cable drive in a perspekti¬ vischen representation, Figure 2 shows the cable drive of Figure 1 in one

Side view and

FIGS. 3a to 3d each show a section through the cable pull drive according to FIG. 1 in different operating states.

Corresponding elements are provided in all figures with the same reference numerals.

Figure 1 shows a perspective view of a cable drive 1 with a base plate 2, which holds the drive motor 3 of the cable drive 1, an electric motor with a base plate 2 by cross-motor output shaft 4. A transmission 5 connects the engine output shaft 4 with a cable 7 connected to a non-self-locking adjusting spindle 6. The cable 7 can be, for example, a brake cable of a parking brake of a motor vehicle not shown here.

About a drive train 8 of the transmission 5, the cable 7 by means of the drive motor 3 can be tightened or tightened. The drivetrain 8 has a spur gear i'9 with a first spur gear seated on the engine output shaft 4 as drive input wheel 10, further spur gears 11, 12 and a last spur gear arranged on the adjusting spindle 6 as the driveline output gear 13.

Parallel to the drive train 8 runs a Motorabtriebs¬ wave 4 with the cable 7 connecting the brake line 14, which has a self-locking. The brake train 14 has a bevel gear that is seated on the engine output shaft 4 as a brake train input gear 15, a gear wheel that engages with it. gelrad 16, which is arranged on a worm shaft 17 with a worm 18, and a worm wheel as Bremsstrangaus- gangsrad 19, which is arranged on the adjusting spindle 6. The two bevel gears at the entrance to the brake line could also be replaced by a helical gear arrangement.

The self-locking of the brake train 14 is effected by a worm gear 20 having the worm wheel and the worm 18. The translation of the drive train 8 corresponds to that of the brake train 14, so that the An¬ drive train 8 and the brake train 14 each act on the adjusting spindle 6 with the same speed.

The side view of Seilzugan- drive 1 shown in Figure 2 is in addition to the general structure of the cable drive 1 with drive motor 3, base plate 2, drive train 8, pa¬ rallelem brake train 14 and adjusting spindle 6 stylized on the rope 7 drawn force sensor 21 for detecting a tensile force to take the rope 7. The force sensor 21 is provided via an electrical line 22 with a motor control electronics 23 for controlling the drive motor 3, in particular for switching it off when a predetermined force value of the tensile force of the cable 7 is reached.

The interaction of drive motor 3, which is a reversing motor, and drive train 8 and brake train 14 will be described in greater detail below with reference to FIGS. 3 a to 3 d, which each show a section of a section A - A from FIG. 2 in different operating states of cable drive 1 erläu¬ tert.

Figure 3a shows the operating state "tightening", which lasts until reaching the end position dos to exciting rope. The motor output shaft 4, which is moved in the direction of an arrow 24, has a driver 25 connected to it in a torque-proof manner. This driver 25 is located on a driver 26 of the trained as bevel gear Bremsstrangeingangsrades 15 (see also Figure 2) and on a driver of aus¬ formed as a spur Antriebsstrangeingangsrades 10 (see also Figure 2). In the view of Figure 3a, the driver of the Antriebsstrangeingangsrades 10 is covered by the driver 26 of the Bremsstrangeingangsrades 15.

When the drive motor is actuated in the tightening direction, the drive train and the brake train thus run in the same direction until the drive motor, for example triggered by a signal from the force sensor, is switched off. After Abschal¬ th of the drive motor tries standing on the rope force, for example from the parking brake to turn back the non-self-locking adjusting spindle.

Since the Antriebsstrangeingangsrad 10 and the Betriebsstrang- input gear 15 are separated from each other and have a radial freewheeling (in this embodiment of about 300 °) ge against each other, the drive train - as shown in Figure 3b, which shows the operating state "relax" - Over the driver 27 of the Antriebsstrangeingangsrades 10 only so far, the sum of the entire backlash overcome, turn back in the direction of an arrow 28 (for example, 10 ° to 15 °) until the trained as a worm wheel Bremsstrang- output gear comes to the worm self-locking to the plant , The Bremsstrangeingangsrad 15 stops. The An¬ drive train input gear 10 and the Bremsstrangeingangsrad 15 are thus against each other about a - here by the Motorabtriebs¬ wave 4 formed - common axis of rotation rotatable. In this case, a torsion spring which is not visible here acts on the drive train input wheel 10 in order to keep the brake train input wheel 15 unhindered and free in order to build up the self-locking mechanism. The Antriebsstrangeingangsrad 10 is thus biased counter to its driving direction when tightening the rope against the Motor¬ output shaft 4.

If the drive motor is subsequently supplied with current as a reversing motor in such a way that the motor output shaft 4 moves in a direction opposite the direction of attraction, symbolized by an arrow 29 in FIG. 3c, which shows the further operating state "release", the first step on the Motor¬ drive shaft 4 seated driver 25 the Bremsstrangein¬ gangsrad 15 and thus repeals the self-locking of the screw with the Betriebsstrangausgangsrad (worm wheel), namely until the aforementioned driver 25 also hits the Antriebs¬ input wheel 10 with the driver 27.

Then both the drive train and the Brems¬ strand run in the release direction until the drive motor is turned off in a End¬ position. This operating state "release all" is shown in FIG. 3d, the driver 26 of the brake-train input wheel 15 in turn covering the driver of the drive-train input wheel 10.

In order to allow loosening of the rope when the cable 7 is tightened, when a power failure occurs and thus the drive motor 3 is not functional, can advantageously by an attachable to the worm shaft 17 (hand) tool manual turning back of the drive and thus relaxing the rope follow.

Claims

claims

1. Seilzugantneb with a drive motor for clamping ei¬ nes rope by means of a motor output shaft of the drive motor via a drive train with the rope connecting transmission, characterized in that the drive train (8) parallel, the motor output shaft (4) with the rope ( 7) connecting Brems¬ strand (14) is provided, which has a self-locking auf¬.

2. Cable drive according to claim 1, characterized gekenn¬ characterized in that on the rope (7) acting adjusting spindle (6) is seen as output member of the transmission (5) vorge¬.

3. Cable drive according to claim 1 or 2, characterized ge indicates that the drive train (8) and the brake line (14) act at the same speed on the Stellspd bundle (6).

4. cable drive according to one of the preceding claims, characterized in that the brake line (14) has a worm gear (20).

5. cable drive according to one of the preceding claims, characterized in that the drive train (8) has a spur gear (9).

6. cable drive according to one of the preceding claims, characterized in that a force sensor (21) for detecting a tensile force of the cable (7) is provided.

7. cable drive according to one of the preceding claims, characterized in that the drive motor (3) is an electric reversible motor.

8. Cable drive according to one of the preceding claims, characterized in that one of the Motorab- traebsweJle (4) driven AntπebssLrangi ngangsrad (10) and one of the engine output shaft (4) angetriebe¬ nes Bremsstrangnearng gear (15) against each other about a common axis of rotation are rotatable ,

9. cable drive according to one of the preceding claims, characterized in that the Motorabtriebswel¬ le (4) to a driver (27) of the drive strangeinangsrades (10) and to a driver (26) of the Bremsstrangemgangsrades (15) vulnerable, the An - Drive train input wheel (10) and / or the Bremsstrang- emgangsrad (15) driving carrier (25).

10. Cable drive according to one of the preceding claims, characterized in that the Antriebsstrang- emgangsrad (10) is biased counter to its driving direction during the tensioning of the rope (7) against the Motorabtriebswel¬ le (4).

11. Parking brake, in particular for a motor vehicle, with a cable drive according to one of the preceding claims, wherein the cable drive is operatively connected to a Bremsein¬ direction to the actuation thereof.