WO2009124810A1

WO2009124810A1 - Self-energizing electromechanical brake

Info

Publication number: WO2009124810A1
Application number: PCT/EP2009/052511
Authority: WO
Inventors: Leopold Krausen
Original assignee: Continental Automotive Gmbh
Priority date: 2008-04-09
Filing date: 2009-03-03
Publication date: 2009-10-15

Abstract

Disclosed is an electromechanical brake (1), in particular for vehicles, comprising a first wedge element (3) that has at least one first wedge surface (31; 31', 31") and can be translationally moved by means of a first actuator (21, 22), and a second wedge element (4) that has at least one second wedge surface (41; 41', 41") which lies opposite the first wedge surface (31; 31', 31") and has a frictional member (51, 52). The wedge elements (3, 4) are mounted in such a way as to generate a force (F, F') during a relative movement (R). Furthermore, a third wedge element (7) is provided that has at least one third wedge surface (71). The first wedge element (3) has at least one fourth wedge surface (32; 32', 32") which lies opposite the at least one third wedge surface (71). The first and the third wedge element (3, 7) are also each mounted in such a way as to generate a force (F, F') during a relative movement (R'). The generated force (F, F') causes the frictional member (51, 52) to act against a component (6) that is to be decelerated.

Description

description

Self-energizing electromechanical brake

The invention relates to self-energizing, electro-mechanical brakes, especially disc brakes for motor vehicles.

In such brakes, an electric actuator applies an actuating force which applies friction linings of the brake to a component to be braked, such as a rotating brake disk or brake drum. Depending on a normal force (contact force) of the friction linings on the component to be braked and on the friction coefficients dependent on the materials used for the friction lining and component to be braked, a frictional force occurs which counteracts the relative movement of the friction lining and the component to be braked.

In order not to have to apply the entire normal force by means of the actuator, the use of self-energizing brakes has been proposed. In self-energizing brakes, the kinetic energy of the braked component is partially used to apply the normal force. It is desirable that almost all the required normal force is obtained from the kinetic energy of the component to be braked, so that the actuator only has to be used to control the height of the normal force.

The basic principle of such a brake is known from DE 198 19 564 C2 and described in detail in this document. In this known brake, a purely mechanical arrangement is present between the component to be braked and the electrical actuator, which leads to self-amplification of the actuating force generated by the electric actuator. This mechanical self-energizing arrangement consists of a wedge with a pitch angle α slidably or rollingly supported on an associated abutment. Further a device for comparing a desired value of the friction force with the actual value of the friction force is present, which controls the electric actuator for corresponding increase or decrease of the generated actuating force at a deviation of the actual value of the target value and thus equalizes the actual value to the desired value of the friction force.

From DE 101 51 950 B4 a self-energizing electromechanical disc brake is known. The brake is shown schematically in FIG. The brake has a rotatable brake disk 401, an actuating force generating an electrical actuator 402 and actuated by the actuator 402 friction member 403 with a friction lining. The actuator 402 acts on the friction member 403 via a wedge arrangement 404 with a wedge angle α, in order to press the friction member 403 against the brake disk 401. By pressing the wedge assembly 404 with the wedge angle α through the actuator 402 in the X direction onto an abutment with the same wedge angle α, the wedge assembly 404 tries to escape in the Y direction towards the rotating brake disk 401. As a result, a contact force is generated perpendicular to the brake disc 401. As soon as the friction lining of the friction member 403 comes into contact with the brake disk 401, the friction member 403 and thus also the wedge assembly 404 is entrained in the direction of rotation of the brake disk due to the frictional force occurring between the friction member 403 and the brake disk 401. In this way, the wedge assembly 404 is pressed beyond the contact pressure of the actuator 402 out in the X direction against the abutment and the contact force amplified.

A disadvantage of the previously known construction, however, is that the self-reinforcing effect only occurs when the feed direction of the wedge arrangement with respect to the abutment coincides with the direction of movement of the brake disc. On the other hand, when the brake disc rotates in the opposite direction, the entrainment effect transmitted to the wedge assembly as a result of the frictional force acts against the delivery force of the actuator. This means that the Mitnahmeeffekt causes the wedge assembly to move out of the abutment. As a result, occurs instead of an increase in the braking effect, a self-attenuation of the braking effect. To actuate the brake, the actuator must act in addition to the force required to provide the actual braking force, in addition to the motive force, which is transmitted from the brake disc by means of the frictional force on the wedge assembly. As a result, the actuator must be designed to be very powerful in order to provide a desired braking performance in such an arrangement, regardless of the direction of rotation of the brake disc can.

Another electromechanical brake for vehicles is known from DE 10 2005 055 295 A1 and shown schematically in FIG. The brake has an electric actuator 502 which generates an actuation force and acts on at least one friction member 503 to urge it to cause a frictional force against a member 501 of the brake to be braked. Between the friction member 503 and the actuator 502 is a self-reinforcing device consisting of two opposing wedge plates 504, 504 'arranged. Between the wedge plates 504, 504 'rolling elements 505 are provided for reducing friction.

The use of wedge plates with alternating rising and falling wedge surfaces has the advantage that in two opposite directions of movement of a braked component, a self-reinforcing braking effect can be achieved. In a reversal of the direction of movement occurs in conventional brakes, however, a significant relative movement between the two wedge plates, so that such brakes have a big game.

Another electromechanical brake for braking a rotating component, in particular a drive shaft of a machine or a motor vehicle wheel, is known from DE 103 19 082 B3. The brake has one around Rotary axis rotatable component to be braked, a friction member assembly, an actuator assembly for generating an actuating force and a self-energizing device with at least two oppositely oriented wedge surfaces. It is provided that the friction member arrangement comprises at least two mutually separated friction members and the actuator assembly at least two actuators that can be controlled separately from each other, wherein each actuator is associated with an actuator. When the actuator arrangement is actuated, at least one friction element of the friction element arrangement displaces along one of the wedge surfaces due to the actuating force of the actuator assigned thereto and generates pressure in the direction of the component to be braked.

In the present construction, it is disadvantageous that the actuator arrangement for actuating the two oppositely oriented wedge surfaces is mechanically very complicated. The two actuators act as two wedge mechanisms to be controlled separately. In the case of a load reversal there is a risk that until the re-achievement of the maximum braking force a high clearance occurs, since the two wedge surfaces must be moved from one extreme position to an opposite extreme position.

Based on this, embodiments of the present invention are directed to a self-energizing electromechanical brake, which has a self-reinforcing irrespective of a direction of movement of a component to be braked and has only a lesser degree of play in a reversal of the direction of movement.

This object is achieved in an electromechanical brake with the features of the preamble of the independent claim 1 by the features of the characterizing part of claim 1. Preferred embodiments can be found in the subclaims. According to one embodiment, the electromechanical brake has an electric actuator, a first, second and third wedge element and a friction member. The electric actuator can be, for example, an electric or hydraulic motor which is suitable for causing a translatory movement. This translational movement can be provided directly (for example by means of a linear motor) or indirectly (for example via a spindle drive). The first wedge element is translationally displaceable by the actuator and has at least one first wedge surface and at least one fourth wedge surface. The second wedge element has at least one second wedge surface, which is arranged opposite the at least one first wedge surface. The third wedge element has at least one third wedge surface, which is arranged opposite the at least one fourth wedge surface of the first wedge element. If the first, second and third wedge elements each have a plurality of wedge surfaces, then the opposite arrangement takes place such that the corresponding wedge surfaces of the wedge elements lie opposite one another in pairs. The first and second wedge members are each supported so as to generate a force upon relative displacement along the first and second wedge surfaces. According to one embodiment, this force with the direction of movement of the relative displacement includes a minimum angle of between 25 ° and 85 ° and in particular between 60 ° and 80 °. Further, the first and third wedge members are each supported so as to also generate a force upon relative displacement along the fourth and third wedge surfaces. According to one embodiment, this force with the direction of movement of the relative displacement includes a minimum angle of between 25 ° and 85 ° and in particular between 60 ° and 80 °. As a result of the force generated by the relative displacement between the first and the second or between the first and third wedge element, the friction member presses against the component to be braked. The provision of the third wedge element with the third wedge surface and the provision of the fourth wedge surface on the first wedge element has the consequence that depending on a direction of movement of the component to be braked selectively between the first wedge surface and the second wedge surface or the third wedge surface and the fourth wedge surface Abutment for generating a force is formed, which is directed in the direction of the component to be braked and thus provides a normal force for generating a frictional force between the friction member and abzubremsendem component. By abutment of the third wedge surface of the third wedge element to the fourth wedge surface of the first wedge element during braking, a play which occurs when a movement direction of the component to be braked is kept particularly low.

The first actuator may be connected to the first wedge member to effect a translational movement of the first wedge member. Further, a second actuator may be provided and connected to the third wedge member to effect a translational movement of the third wedge member. In this way, the first wedge element and the third wedge element can be displaced separately from each other translationally. The provision of separate actuators for the first and third wedge element has the further advantage that in case of failure of, for example, the first actuator on the opposing third and fourth faces by the second actuator still indirectly a translational displacement of the first wedge member can be effected. Thus, an emergency function of the brake is possible even in case of failure of the first actuator.

However, the provision of a second actuator for the third wedge element is not absolutely necessary. Thus, the first actuator may alternatively also be connected to the third wedge element instead of the first wedge element, and the translational displacement of the first wedge element indirectly via the opposing third and fourth wedge surfaces cause. However, in order to enable release of the first wedge element from the abutment with the second wedge element, in this embodiment a spring can be arranged between the first and the third wedge element in order to bias the first wedge element in the direction of the third wedge element. Alternatively to the spring may also be provided a driver, which allows only a certain clearance between the first and third wedge member. Since in this case only one actuator is required to operate the brake, this brake has a particularly simple structure. Further, it is ensured in such a construction that the first and third wedge element are always optimally biased, so that in a reversal of the direction of movement of the component to be braked a play of the brake is particularly low.

Furthermore, the first and third wedge elements can be translationally displaceable in directions which correspond approximately to the direction of movement and the opposite direction of the component to be braked. In this case, a direction which corresponds approximately to a direction of movement is understood to mean a direction which, with the direction of movement or opposite direction, includes a smallest angle of less than 30 ° and in particular less than 20 °. In order to achieve the desired self-amplification of the brake, it is advantageous if the second wedge element is stationary in this direction.

Embodiments further include a spring disposed between the first and third wedge members to bias the third wedge member against the first wedge member. Further, a releasable reverse lock is provided which allows movement of the third wedge member only in the direction of the opposite first wedge surface of the first wedge member. It is ensured by the spring that a clearance between the first and third wedge element is minimal. By the reverse lock is ensured in a sudden reversal of the direction of movement of the component to be braked that a play of the brake is as small as possible. To realize a parking brake, the brake can continue one

Locking device to lock at least one of the first and third wedge member de-energized in a locked position. It should be understood under no-current that further energy supply to the brake after effecting the lock is not required. Next is under a detected

Position to be understood a position in which the opposing wedge surfaces generate a braking force.

To control the brake, it may be advantageous to provide a sensor to measure a generated braking force. At least one of the first and second actuators can be controlled by means of this sensor.

The friction member may optionally be formed with a friction lining. Alternatively, the friction member may be formed as a receptacle for a friction lining to act on the friction lining against the component to be braked. A separate design of friction member and friction lining has the advantage that the maintenance and repair costs of the brake are low. The friction member may also be integrated in the first and / or second wedge member.

To reduce the frictional force between the opposing wedge surfaces rolling elements are arranged according to an embodiment between the at least one first wedge surface and the at least one second wedge surface. Alternatively or additionally, rolling elements can also be arranged between the at least one third wedge surface and the at least one fourth wedge surface.

Alternatively, the at least one first wedge surface and the at least one second wedge surface may be in sliding contact with each other in pairs. Additionally or alternatively, the at least one third wedge surface and the at least a fourth wedge surface in pairs are in sliding contact with each other.

The friction member may optionally be connected only to the first wedge member or only to the second wedge member or to both first and second wedge members. If the friction member is connected to both the first and the second wedge member, it is possible to provide a brake which acts on a component to be braked on two opposite sides. As a result, a deflection of the component to be braked during braking can be effectively avoided. For this purpose, the second wedge element can be integrated in a brake caliper, so that the normal forces are supported on both sides of the component to be braked, via one arm of the caliper a friction member on the first wedge element, which is supported on the second wedge element, attacks, and on the other Arm of the caliper attacks a directly attached friction member.

According to one embodiment, a first friction member may be connected to the first wedge member and a second friction member may be connected to the second wedge member. Furthermore, the second wedge element can be translationally displaceable in directions which are substantially perpendicular to the direction of movement and the opposite direction of the component to be braked. In this case, under a direction which is substantially perpendicular to a movement direction, a force is understood whose vector with the direction of movement includes a smallest angle of between 85 ° and 90 °, preferably between 85 ° and 90 ° and in particular 90 °. As a rule, this direction of movement of the second component also corresponds to the direction of the braking force to be applied to the component to be braked.

In embodiments, the third wedge element has at least one fifth wedge surface and the first wedge element at least one sixth wedge surface, which is arranged opposite the at least one fifth wedge surface in pairs. Further, the first and third wedge members are each supported so as to generate a force upon relative displacement between the two first and third wedge members along the fifth and sixth wedge surfaces. In this case, the force with the direction of movement of the relative displacement, for example, include a minimum angle of between 25 ° and 85 ° and in particular between 60 ° and 80 °. As a result of the force generated, the friction member acts against the component to be braked.

Further, there is proposed a method of controlling a brake having the above-described structure, which method comprises the steps of: moving the first wedge member having the first and fourth wedge surfaces to control the force applied against the component to be braked, continuously determining the position of the first one Wedge element, and automatically tracking the third wedge member in response to the determined position of the first wedge member to ensure that the third wedge surface of the third wedge member is always applied to the fourth wedge surface of the first wedge member.

According to an embodiment, there are further provided the steps of: automatically blocking a displacement of the third wedge member in a direction substantially opposite to the direction of a most recent displacement of the first wedge member, and selectively releasing the blocking of the displacement of the third wedge member if Blocking precludes a desired method of the first wedge member.

Hereinafter, preferred embodiments will be explained with reference to the accompanying drawings. In the drawings, like elements are designated by like or similar reference numerals.

It shows 1A is a schematic side view of a first embodiment of the brake in the open state;

Fig. IB is a schematic side view of the brake of Figure IA in the closed state;

Fig. 2A is a schematic side view of a second

Embodiment of the brake in the open state;

FIG. 2B shows a schematic side view of the brake from FIG. 2A in the closed state; FIG.

FIG. 2C schematically shows a perspective view of the brake from FIGS. 2A, 2B in the closed state; FIG.

Fig. 3A is a schematic side view of a third embodiment of the brake, which is obtained by modification of the first embodiment;

Fig. 3B is a schematic side view of a fourth embodiment of the brake obtained by a modification of the second embodiment;

Fig. 4 is a brake of the prior art; and

Fig. 5 shows another brake from the prior art.

Hereinafter, a first embodiment of the brake will be described with reference to FIGS. 1A and 1B. Here, Figure IA shows a schematic side view of the brake in the open and Figure IB is a schematic side view of the brake in the closed state.

As can be seen from FIGS. 1A and 1B, the brake has a first wedge element 3 with a first wedge surface 31 and a fourth wedge surface 32, which enclose an angle β with one another. In the embodiment shown the angle ß = 140 °. However, the present invention is not limited to such an angle β. Rather, it is generally sufficient if the angle β between 90 ° and 160 ° and in particular between 130 ° and 150 °. The first wedge element 3 is connected via a push rod 21 '' hingedly connected to a motor 21 'of a first electrical actuator 21 and translationally displaceable by means of the actuator 21, wherein the direction of the displacement has a running in the X direction movement component. In the embodiment shown, the displacement takes place directly in the direction of R.

As a result of a displacement of the first wedge element 3, the first wedge surface 31 is pressed onto a second wedge surface 41 of a second wedge element 4, which second wedge surface 41 is arranged opposite the first wedge surface 31. Since the second wedge member 4 is fixed in the movement direction X of the first wedge member 3, the first and second wedge surfaces 31 and 41 slide against each other in the direction R, resulting in displacement of the first and second wedge members 3 and 4 in the Y direction. Did the friction members 51 and 52 due to a displacement of the first and second wedge members 3 and 4 in the Y direction in abutment with a component to be braked 6, which is disposed between friction members 51 and 52, respectively connected to the first and second wedge members 3 and 4 are, the friction members 51 and 52 are pressed upon further actuation against the component 6 to be braked. As a result, a frictional force F, F 'occurs between the friction members 51 and 52 and the component 6 to be braked. This frictional force F, F 'includes with the direction of movement R of the relative displacement of the first and second wedge members 3, 4 a smallest angle δ of 73 °. However, the present invention is not limited to such an angle. Rather, it is sufficient if the smallest angle δ between 25 ° and 85 ° and in particular between 60 ° and 80 °. As a result, the friction force F, F 'is substantially perpendicular to a movement direction B of the component 6 to be braked. In the present example, the component 6 to be braked is a brake disk and the friction members 51 and 52 are brake linings integrally formed with the first and second wedge elements 3 and 4. However, the friction members 51, 52 may also be separate members releasably secured to the first and second wedge members 3 and 4.

In the first embodiment, the second wedge member 4 surrounds the component 6 to be braked so that a friction member 52 fixed to the second wedge member 4 is opposed to a friction member 51 fixed to the first wedge member 3, with the component 6 to be braked between the friction members 51 and 52 located. Here, the second wedge element was integrated into a caliper.

As a result of a rotational movement of the braked component 6 in the direction B occurs due to friction between the friction members 51 and 52 and the component 6 to be braked entrainment of the first wedge member 3 in the direction of the second wedge surface 41 of the second wedge member 4, whereby a self-amplification of the brake occurs ,

It may be advantageous if the braking force occurring measured by means of a sensor, not shown, and the motor 21 'of the first actuator 21 is controlled so that by slightly moving the first wedge member 3 back and forth of the second wedge surface 41 of the second wedge member 4 (in X-direction or R-direction) is ensured that the self-amplification of the brake is not too large.

Further, in this embodiment, a third wedge member 7 having a third wedge surface 71 is provided, which third wedge surface 41 of the fourth wedge surface 32 of the first wedge member 3 is disposed opposite to each other. The third wedge element is connected via a push rod 22 "to a motor 22 'of a second actuator 22. The motor 22 ' of the second actuator is controlled so that it always automatically ensures, when the brake is actuated, that the third wedge surface 71 'of the third wedge element 7 bears against the fourth wedge surface 32 of the first wedge element 3. If there is a movement reversal of the component 6 to be braked so that it now moves in the direction B ', the fourth wedge surface 32 of the first wedge element 3 slides on the third wedge surface 71 of the third wedge element 7 in the direction R' due to the entrainment effect. As a result, a frictional force F occurs between the friction member 51 and the component 6 to be braked. This contact force F includes with the direction of movement R 'of the relative displacement of the first and third wedge element 3, 7 a smallest angle δ' of 68 °. However, the present invention is not limited to such an angle. Rather, it is sufficient if the smallest angle δ 'between 25 ° and 85 ° and in particular between 60 ° and 80 °. As a result, the frictional force F is substantially perpendicular to the direction of movement B 'of the component 6 to be braked.

Since the readjustment of the third wedge element 7 takes place already in the pretensioned state of the brake, a self-amplification of the brake occurs even with a movement reversal of the component 6 to be braked, almost without play.

Should the motor 21 'of the first actuator 21 fail due to a defect, an emergency braking is possible by the brake shown in Figures IA and IB by the first wedge member 3 indirectly by actuating the motor 22' of the second actuator 22 of the third wedge member 7 against the second wedge surface 41 of the second wedge member 4 is pressed.

As can be seen, the fourth wedge surface 32 has a slope opposite to the first wedge surface 31 of the first wedge element. The first and second wedge surfaces 31 and 41 and the third and fourth wedge surfaces 71 and 32 are complementary to each other and are formed opposite to each other. Further, in the embodiment, in each of the motors 21 'and 22' of the first and second actuators 21 and 22, a locking device is integrated (not specifically shown in the figures) to lock the first and third wedge members 3 and 7 in a fixed position without power , This locking device can serve as a parking brake, for example, but is only optional.

In the following, a second embodiment of the brake 1 will be explained with reference to FIGS. 2A to 2C. Figures 2A and 2B are schematic side views of the brake 1, Figure 2A showing the brake in the open (i.e., unactuated) and Figure 2B the brake in the closed (i.e., actuated) state. Figure 2C shows a perspective view of the brake 1 in the closed state.

In this embodiment, the first actuator 21 is shown simplified in the form of a push rod 21 ''.

Next, the friction member 53 is a receptacle for a friction lining

(not shown), wherein the friction member 53 via the

Friction lining acts on the component 6 to be braked.

The second embodiment shown in FIGS. 2A to 2C differs from the first embodiment described above in particular in that the first wedge element and the second wedge element are designed as wedge plates 3, 4 lying opposite one another. The first wedge plate 3 alternately has first wedge surfaces 31 'and 31''of opposite inclination. The second wedge plate 4 also alternately has second wedge surfaces 41 'and 41''of opposite inclination. In this case, first wedge surfaces 31 ', 31''and second wedge surfaces 41', 41 '' are arranged in pairs opposite each with the same orientation inclined. Accordingly, rising wedge surfaces 31 '' of the first wedge plate 3 are rising wedge surfaces 41 'of the second wedge plate 4 and sloping Wedge surfaces 31 'of the first wedge plate 3 sloping wedge surfaces 41''of the second wedge plate 4 opposite.

Between the pairwise opposed wedge surfaces 31 ', 41' 'and 31' ', 41' rolling elements 10 are arranged to keep the friction between the wedge plates 3, 4 low.

Although not shown in the figures, rolling elements can optionally also be arranged between the pairs of opposed third wedge surfaces 71 of the third wedge element 7 and fourth wedge surfaces 32 of the first wedge plate 3. In this embodiment, the fourth wedge surfaces 32 of the first wedge plate 3 are formed on projections 3 'on both sides of the first wedge plate 3.

In the second embodiment, the third wedge element 7 is designed in several parts and therefore has a plurality of individual wedges each having a third wedge surface 71. The multi-part formed third wedge element 7 is supported by guides 11 ', H' ', wherein the individual parts of the multi-part third wedge element 7 via a push rod 22' 'are interconnected.

In the embodiment shown in Figure 2A to 2C is between the motor 22 'of the second actuator 22 and the

Push rod 22 '' further arranged a coupling device 9, which enables a mechanical decoupling of the push rod 22 '' of the motor 22 '. Next, the coupling device 9 is formed in this embodiment, the push rod 22 'selectively fix in a desired position. These

Fixation is preferred without permanent power supply possible

(e.g., by locking).

The operation of the brake according to the second embodiment is the same as in the first embodiment. As shown in FIG. 2B, during braking first the first wedge plate 3 is displaced relative to the second wedge plate 4 in the X direction, which is approximately parallel to the direction of movement B of the component 6 to be braked. Since the distance between the pairwise opposed first and second wedge surfaces 31 ', 41''of the first and second wedge plates 3, 4 can not decrease due to the interposed rolling elements 10, the first wedge plate 3 in the direction R, and thus on the component to be braked to 6, distracted. As a result, the friction lining 51 carried by the friction member is pressed with the force F to the component 6 to be braked. Due to the movement of the braked component 6 mediated by the friction between the braked member 6 and the friction member 51 entrainment of the first wedge plate 3 in the direction of movement of the abzubremsenden component 6. This entrainment is by the first and second wedge surfaces 31 ', 41''in converted an increased contact pressure F, whereby a self-reinforcing effect of the brake 1 occurs. (This contact force F can include with the direction of movement R of the relative displacement of the first and second wedge plates 3, 4 a smallest angle δ of, for example 55 °). However, the present invention is not limited to an angle δ of 55 °.

Further, during braking, the multi-part third wedge element 7 is tracked by the second actuator 22, so that the third wedge surfaces 71 of the third wedge element 7 always rest on the fourth wedge surfaces 32 which are formed on the projections 3 'of the wedge plate 3. In this way, even with a reversal of the direction of movement of the component 6 to be braked, a self-reinforcing effect can always be achieved.

As can be seen particularly clearly from the perspective view in FIG. 2C, the projections 3 'and the individual wedges of the wedge element 7 are symmetrical on both sides of the wedge element Wedge plate 3 is formed. This prevents that acting on the first wedge plate 3 a rotational force.

FIG. 3A shows a modification of the first embodiment of the brake 1. Since the third embodiment shown in Figure 3A builds on the first embodiment shown in Figures IA and IB and described in detail, only the differences between these two embodiments will be explained in more detail below.

According to this modification, only one actuator 22 is provided, which is connected to the third wedge element 7 and displaces the third wedge element 7 in the translational X direction. Further, a spring 8 is disposed between the first wedge member 3 and the third wedge member 7, which biases the fourth wedge surface 32 of the first wedge member 3 toward the third wedge surface 71 of the third wedge member 7. Alternatively, the spring 8 may be replaced by a dog which allows some play between the first and third wedge members 3, 7.

In this embodiment, it is advantageous that only one actuator 22 is required for the displacement of the first and third wedge element 3 and 7. The reason is that the first wedge element 3 can be displaced translationally by displacement of the third wedge element 7 indirectly in the X direction toward the second wedge surface 41 of the second wedge element 4. A retraction of the first wedge element 3 is possible due to the spring 8, wherein the spring 8 must be designed to be correspondingly stiff.

FIG. 3B shows a fourth embodiment of the brake 1. This is based on the third embodiment, and therefore the description of the same element and modes of operation is omitted.

According to this embodiment, the third wedge element 7 has at least a fifth wedge surface 72 and the first one Wedge plate 3 at least a sixth wedge surface 33, wherein the sixth wedge surface 33 of the fifth wedge surface 72 is arranged in pairs opposite one another. Like the fourth wedge surface 32, the sixth wedge surface 33 is formed on the projection 3 'of the first wedge plate 3.

Next, a spring 8 is provided to bias the multi-part third wedge element 7 so that the third wedge surface 79 of the third wedge element 7 is always pressed against the fourth wedge surface 32 of the first wedge plate 3.

In FIG. 3B, the angles β and β 'are equal. This is not necessary. So these angles can also be designed differently large.

The brake shown in FIG. 3B has the advantage that, independently of a primary direction of movement B, B 'of the component 6 to be braked, a self-intensifying braking effect can always be achieved with a reversal of the direction of movement with extremely little play. The reason is that with corresponding entrainment of the (multi-part) third wedge element 7 always wedge surfaces 71 of the third wedge element 7 in pairs rest against corresponding wedge surfaces 32, 33 of the first wedge plate 3. During relative movement of the first and third wedge element 3, 7 as a result of a Mitnahmeeffekts at a reversal of the abzubremsenden component 6 from direction B 'in direction B, the first wedge plate 3 is moved in the direction R''and generates a contact force F. This contact force F closes with the Movement direction R '' of the first wedge plate 3 a smallest angle δ ' ¹ of 57 °. As already emphasized, however, the present invention is not limited to precisely this angle. Reference sign list

1 electromechanical brake 3 first wedge element

4 second wedge element

6 component to be braked

7 third wedge element 9 locking device 21 first electrical actuator

22 second electrical actuator

31 first wedge surface 31 'first wedge surface 31' 'first wedge surface 32 fourth wedge surface

32 'fourth wedge surface

32 '' fourth wedge surface

33 fifth wedge surface

41 second wedge surface 41 'second wedge surface

42 '' second wedge surface

51 friction member 51 'friction lining

52 friction member 52 'friction lining

71 third wedge surface

71 'third wedge surface

71 '' third wedge surface

71 '' 'third wedge surface 72 sixth wedge surface δ smallest angle δ' smallest angle δ '' smallest angle

B Movement direction B 'opposite direction

F force

F 'force

R relative shift R 'relative displacement R''relative displacement

Claims

claims

1. Electromechanical brake (1), in particular for vehicles, with a first electrical actuator (21, 22); a first wedge element (3) with at least one first wedge surface (31; 31 ', 31''), which first wedge element (3) is translationally displaceable by the first actuator (21, 22); a second wedge element (4) having at least one second wedge surface (41; 41 ', 41 ") arranged in pairs opposite the at least one first wedge surface (31; 31', 31"); and a friction member (51, 52); wherein the first and second wedge members (3, 4) are each supported so as to be movable along the first and second wedge surfaces (31, 41, 31 ', 31) at a relative displacement (R) between the two first and second wedge members (3, 4) '', 41 ', 41'') to generate a force (F, F'); and wherein the friction member (51, 52) acts against a component (6) to be braked as a result of the generated force (F, F '); characterized by a third wedge element (7) with at least one third wedge surface (71); wherein the first wedge element (3) has at least one fourth wedge surface (32; 32 ', 32'') arranged in pairs opposite the at least one third wedge surface (71); and wherein the first and third wedge elements (3, 7) are each mounted to move along the fourth and third wedge surfaces (32, 71, 32 ') at a relative displacement (R') between the two first and third wedge elements (3, 7). , 32 '', 71'-7I ¹ '') to generate a force (F, F '); and wherein the friction member (51, 52) acts against the component (6) to be braked as a result of the generated force (F, F ').

2. Brake according to claim 1, wherein the first and second wedge element (3, 4) are each mounted so as to be displaceable along a relative displacement (R) between the first and second wedge elements (3, 4) along the first and second wedge surfaces (31 , 41; 31 ', 31 ", 41', 41") to generate a force (F, F ') whose direction with the direction of movement (B) of the relative displacement has a smallest angle (δ) of between 25 ° and 85 ° ° and in particular between 60 ° and 80 °; and wherein the first and third wedge elements (3, 7) are each mounted to move along the fourth and third wedge surfaces (32, 71, 32 ') at a relative displacement (R') between the two first and third wedge elements (3, 7). , 32 '', 71'-7I ¹ '') to generate a force (F, F ') whose direction with the direction of movement of the relative displacement (R') a smallest angle (δ ') of between 25 ° and 85 ° and especially between 60 ° and 80 °.

3. brake according to claim 1 or 2, wherein a second electrical actuator (21) is provided; wherein the first wedge element (3) is connected to the first actuator (21) and is translationally displaceable by the first actuator (21); and wherein the third wedge element (7) is connected to the second actuator (22) and translationally displaceable by the second actuator (22).

4. Brake according to claim 1 or 2, wherein the third wedge element (7) with the first actuator (22) is connected, and on the opposite third and fourth wedge surfaces (71, 32, 72, 32 ', 32'') translational displacement of the first wedge element (3) causes; and wherein between the first and third wedge members (3, 7) a spring is disposed to bias the first wedge member (3) toward the third wedge member (7).

5. brake according to one of the preceding claims, wherein the first and third wedge element (3, 7) are translationally displaceable in directions which correspond approximately to the direction of movement (B) and opposite direction (B ') of the component (6) to be braked, and wherein the second wedge element (4) is stationary in this direction.

6. Brake according to one of the preceding claims, further comprising between the first and the third wedge member (3,

7) arranged spring to bias the third wedge member (7); and a releasable reverse lock permitting movement of the third wedge member (7) only toward the opposite first wedge surface (31; 31 ', 31' ') of the first wedge member (3).

7. Brake according to one of the preceding claims, further comprising a locking device (9) to lock the first and / or third wedge member (3, 7) normally in a fixed position.

8. Brake according to one of the preceding claims, wherein a sensor is provided to measure the force generated.

9. Brake according to one of the preceding claims, wherein the friction member (51, 52) as a receptacle for a friction lining (51 ', 52') is formed to over the friction lining (51 ', 52') against the component (6) to be braked to act.

10. Brake according to one of the preceding claims, wherein between the at least one first wedge surface (31; 31 ', 31' ') and the at least one second wedge surface (41; 41', 41 '') Wälzköper and / or between the at least one third wedge surface (71) and the at least one fourth wedge surface (32; 32 ', 32' ') Wälzköper are arranged.

11. A brake according to any one of claims 1 to 9, wherein the at least one first wedge surface (31; 31 ', 31' ') and the at least one second wedge surface (41; 41', 41 '') and / or the at least one third Wedge surface (71) and the at least one fourth wedge surface (32; 32 ', 32' ') are in sliding contact with each other in pairs.

12. Brake according to one of the preceding claims, wherein the friction member (51, 52) with the first and / or second wedge member (3, 4) is connected.

13. A brake according to any one of the preceding claims, wherein a first friction member (51) with the first wedge member (3) is connected; wherein a second friction member (52) is connected to the second wedge member (4); and wherein the second wedge element (4) is translationally displaceable in directions which are substantially perpendicular to the movement direction (B) and the opposite direction (B ') of the component (6) to be braked.

14. Brake according to one of the preceding claims, wherein the third wedge element (7) at least a fifth wedge surface (72) and the first wedge element (3) at least a sixth wedge surface (33), which of the at least one fifth wedge surface (72) in pairs opposite each other is arranged; and wherein the first and third wedge elements (3, 7) are each mounted so as to move in a relative displacement (R ') to generate a force (F, F ') between the first and third wedge elements (3, 7) along the fifth and sixth wedge surfaces (33, 72); and wherein the friction member (51, 52) acts against the component (6) to be braked as a result of the generated force (F, F ').

15. Brake according to claim 14, wherein the first and third wedge element (3, 7) are each mounted so as to be displaceable along the fifth and sixth wedge surfaces (3, 7) during a relative displacement (R ') between the two first and third wedge elements (3, 7). 33, 72) to generate a force (F, F ') whose direction with the direction of movement of the relative displacement (R' ') a smallest angle (δ' ') of between 25 ° and 85 ° and in particular between 60 ° and 80 ° includes.

16. A method for controlling a brake, which brake has the features of one of the preceding claims, the method comprising the following steps: - moving the first wedge element (3) with the first and fourth wedge surface (3, 32) to the opposite to control component (6) to be braked (F, F ');

- continuously determining the position of the first wedge element (3); and

- Automatic tracking of the third wedge member (7) in response to the determined position of the first wedge member (3) to ensure that the third wedge surface (71) of the third wedge member (7) always on the fourth wedge surface (3, 32) of the first Wedge element (3) rests.

17. The method of claim 16, further comprising the steps of: - automatically blocking a displacement of the third wedge member (7) in a direction which is the direction of a last time prior displacement of the first wedge member (3) is substantially opposite; and selectively releasing the blocking of the displacement of the third wedge member (7) if the blocking opposes a desired operation of the first wedge member (3).