Drum brake, braking system and vehicle

Abstract

The invention relates to a drum brake (1) having at least one brake shoe (4), a deformation sensor (10) and a support (2a), the support (2a) having a support bearing (3a) for the at least one brake shoe (4), the deformation sensor (10) being designed to ascertain a deformation of the support (2a), wherein the support bearing (3a) is formed separately from the support (2a). The support bearing (3a) is connected to the support (2a) in a force-transmitting manner by means of a form-fitting connection. The invention further relates to a brake system (20) having at least one such drum brake (1) and to a vehicle (30) having such a brake system (20) or at least one such drum brake (1).

Description

Technical Field

[0001] The invention relates to a drum brake according to the preamble of claim 1. The invention also relates to a brake system having at least one such drum brake and a vehicle having such a brake system or at least one such drum brake. Background Art

[0002] Publications US 4 995 480 A, US 5 979 613 A, US 2020 018 0575 A1, US 1 915857 A, and US 5 913 390 A disclose drum brakes.

[0003] Publication DE 10 2013 224 922 A1 discloses a drum brake having an electromechanical actuator and a brake shoe, wherein a sensor is arranged in the force flow between the actuator and the brake shoe, with which the braking force can be ascertained.

[0004] The published document DE 10 2017 217 413 A1 discloses a drum brake having a brake shoe and a support bearing, wherein the support force generated by the brake shoe in the support bearing can be measured by means of a force sensor on the support bearing.

[0005] A disadvantage of the devices according to the prior art is, in particular, the fact that when the braking force is measured with the aid of the devices according to the prior art, a significant hysteresis of the measurement signal occurs. Summary of the Invention

[0006] Description, Task, Solution, Advantages of the Invention The present invention is based on the object of providing an alternative drum brake that is distinguished, in particular, by a low hysteresis of the measurement signal when the brake force is measured using the drum brake. Another object is to provide a brake system having such a drum brake. Another object is to provide a vehicle having such a brake system or such a drum brake.

[0007] The first object is achieved by a drum brake having the features of claim 1 .

[0008] One exemplary embodiment of the present invention relates to a drum brake having at least one brake shoe, a deformation sensor, and a carrier, wherein the carrier has a support bearing for the at least one brake shoe, wherein the deformation sensor is designed to detect a deformation of the carrier, wherein the support bearing is designed separately from the carrier, and wherein the support bearing is connected to the carrier in a force-locking manner by means of a positive connection.

[0009] This makes it possible to easily, cost-effectively, and reliably determine the braking force or braking torque of a drum brake during actuation, because the support force generated during the braking process and introduced and transmitted to the support bearing by at least one brake shoe is transferred from the support bearing to the support, which causes a deformation of the support that is dependent on the braking force or braking torque of the drum brake. This occurs because during a braking process of the drum brake, at least one brake shoe can be supported on the support bearing, whereby the support force transmitted to the support causes a deformation of the support. In other words, it is preferred that the at least one brake shoe is arranged on the support bearing in a supported or supportable manner.

[0010] Furthermore, hysteresis is reliably reduced by the form-locking connection.

[0011] In particular, the braking force and / or the braking torque can be determined using the determined bearing deformation.

[0012] Advantageously, the support is made of metal. In other words, in this case, the support consists of metal. Alternatively, it is conceivable that the support consists at least predominantly of metal. This contributes to the durability and reliability of the support. The material or metal used to manufacture the support is preferably a ductile material, ductile metal, or ductile steel. In other words, it is a material, metal, or steel that can elastically deform under load. Particularly preferably, it is a ferritic metal or ferritic steel.

[0013] It is also advantageous to dimension the support so that it undergoes only elastic deformation, in particular linear elastic deformation, during operation of the drum brake, particularly during the braking process. In other words, the support is dimensioned or designed so that it deforms only elastically due to the forces occurring during operation of the drum brake. This reliably prevents failure of the support or permanent deformation of the support relative to its original shape. Furthermore, this ensures that the braking force or braking torque measurement performed using the deformation sensor is performed with considerable accuracy. It is particularly advantageous if the maximum mechanical stress occurring in the support and / or the deformation element (which can be part of a preferred embodiment) during the braking process of the drum brake corresponds to a maximum of half, one-third, one-quarter, or one-fifth of the upper yield strength of the material of the support and / or deformation element. This is achieved by appropriately dimensioning the support, its target deformation region, and / or the deformation element. This minimizes hysteresis in the shape of the support and / or deformation element due to deformation occurring during the braking process, which contributes to measurement accuracy.

[0014] Furthermore, it is advantageous if the deformation sensor is a capacitive, inductive, piezoelectric or resistive sensor. Alternatively, it is also advantageous if the deformation sensor is a sensor with one or more strain gauges or a surface acoustic wave sensor (SAW sensor).

[0015] It is also advantageous if the support bearing and / or the support are designed separately from the deformation sensor, in particular completely separately. In other words, the support bearing and / or the support are not part of the deformation sensor. As an alternative, the deformation sensor is designed without a support and / or without a support bearing. It is also preferred that the support bearing and / or the support are arranged and / or designed to be spaced apart from the deformation sensor. It is also preferred that the sensor has no support bearing and / or no support. It is also preferred that the support and / or the support bearing are designed without sensor functionality, which means in particular that the support and / or the support bearing are not part of the sensor.

[0016] It is particularly advantageous if the drum brake comprises two brake shoes which are arranged such that during the braking process one or both of the brake shoes can be supported on a support bearing. This option exists for all previously and subsequently mentioned embodiments, provided that the type of drum brake permits this.

[0017] Furthermore, it is advantageous that at least one brake shoe is directly and / or indirectly coupled or can be coupled to the support bearing in a force-transmitting manner. Thus, the force of the brake shoe, the so-called support force, can be transmitted to the support bearing and from the support bearing to the support.

[0018] Preferably, each brake shoe comprises a brake lining and / or each brake shoe is mounted in a floating manner.

[0019] Furthermore, it is advantageous if the support forms the force path or the sole force path from the at least one brake shoe and / or the support bearing to peripheral equipment of the drum brake, such as the wheel carrier or the steering knuckle, to which the support is preferably connected or fixed. In other words, it is preferred that the supporting force of the at least one brake shoe can be transmitted primarily or solely, that is, exclusively, from the support bearing to the peripheral equipment via the force path formed by the support.

[0020] In principle, it is preferred that the drum brake is a single brake, a compound brake, a dual-compound brake, a servo brake or a dual-servo brake. Thus, a correspondingly suitable drum brake type can be provided for different areas of use or vehicles.

[0021] In principle, the drum brake according to the present invention is a drum brake for a motor vehicle. Independently of this, it is also conceivable, in principle or in addition, that the drum brake according to the present invention is a drum brake that can be actuated hydraulically and / or mechanically and / or electrically. Mechanical actuation can be implemented, for example, by means of a parking brake cable, the so-called handbrake. Electrical actuation can be performed, for example, by means of an electric actuator. In this case, such an electric actuator is preferably integrated into the drum brake according to the present invention. Sensors are preferably used to operate, in particular to regulate and / or control, the actuators and thus preferably to provide the required or necessary braking torque by means of the drum brake.

[0022] Furthermore, it is particularly preferred that the braking force and / or braking torque of the drum brake can be determined from the deformation of the support and / or its deformation element, ascertained by the deformation sensor. For this purpose, it is particularly preferred that the measurement signal of the deformation sensor can be evaluated by an evaluation unit in such a way that a braking force signal and / or a braking torque signal can be generated or produced by the evaluation unit. Such an evaluation unit is preferably integrated into the control device. The evaluation unit and / or the control device are preferably provided together with the drum brake.

[0023] Furthermore, it is advantageous if the support is or is connected to the peripheral device in a force-transmitting manner. In this way, the braking force or braking torque of the drum brake can be transmitted to the support by means of the support bearing and from the support to the peripheral device or supported on the peripheral device. The peripheral device is preferably a part of a vehicle or motor vehicle, such as a steering knuckle or a wheel carrier.

[0024] One or more of the aforementioned embodiments is preferably characterized in that the support can be connected to the steering knuckle or formed integrally with the steering knuckle. Alternatively, it is conceivable that the support can be connected to the wheel carrier or formed integrally with the wheel carrier. In other words, the steering knuckle or the wheel carrier forms the peripheral device. The connection between the support and the steering knuckle or the wheel carrier is particularly fixed. In this way, supporting forces arising during the manufacturing process can be supported. The connection is preferably a screw connection. The integral design eliminates additional assembly steps and additional manufacturing costs.

[0025] It is usually suitable that the support bearing is subjected to shear forces by at least one brake shoe during the braking process of the drum brake.It is suitable that the force introduction point between at least one brake shoe and the support bearing is located on the lateral outer contour of the support bearing.

[0026] In addition, it is advantageous that the support bearing is directly connected or fixed to the support. Thus, additional components that may be required when indirectly connected or fixed can be abandoned, which additionally reduces costs.

[0027] Another preferred embodiment is characterized in that the support has at least one material weakening. This weakening enables targeted deformation of the support, for example, linear elastic deformation of the support, under the action of the supporting force caused by at least one brake shoe of the drum brake during a braking operation of the drum brake. Furthermore, the weakening is preferably dimensioned such that the deformation of the support during the braking operation of the drum brake is within the measuring range of the deformation sensor. This allows the use of inexpensive deformation sensors.

[0028] Another preferred embodiment is characterized in that at least one material weakening is designed as a recess.

[0029] It is also possible that the recess is configured such that it extends through the support. As an alternative to this, it is conceivable that the recess is configured such that a reduction in the thickness or strength of the support occurs. In other words, the recess does not extend through the support in this case.

[0030] Furthermore, it is particularly advantageous to arrange the deformation sensor and / or the deformation element in a region of the mount which remains as cool as possible during operation of the drum brake, since the distance to heat sources is as great as possible.

[0031] One or another preferred embodiment of the aforementioned embodiment is characterized in that the support is arranged such that a supporting force can be transmitted from the at least one brake shoe to the support via the support bearing. In other words, the support bearing preferably forms a force introduction point for the at least one brake shoe or a force introduction point for each brake shoe. When the support is connected to the steering knuckle or the wheel carrier or is fixed to either, the support transmits the supporting force to the wheel carrier or the steering knuckle. In other words, the support forms a force path from the at least one brake shoe via the support bearing to the wheel carrier or the steering knuckle.

[0032] A preferred embodiment is characterized in that the support bearing is fixed to the support, in particular by means of a screw connection. This achieves a distribution of tasks between fixing and the form-locking connection. During fixing, only the support bearing is secured to the support, while the form-locking connection between the support bearing and the support ensures a force transmission that is as smooth as possible.

[0033] Another preferred embodiment is characterized in that the support can be connected to the steering knuckle or is formed integrally with the steering knuckle. This connection is preferably achieved by means of a screw connection. Although the one-piece design makes repair or replacement processes more difficult, it simplifies mass production because it eliminates assembly steps and reduces unit costs.

[0034] Another preferred embodiment is characterized in that the form-fitting connection is formed by means of at least one recess of the support and at least one projection of the support bearing. The form-fitting connection is preferably formed such that the support force of the brake shoe that can be transmitted to the support bearing can be transmitted to the support in a force-fitting manner by means of the form-fitting connection.

[0035] Another preferred embodiment is characterized in that the form-fitting connection is formed by means of at least one recess of the support bearing and at least one projection of the abutment. The form-fitting connection is preferably formed such that the support force of the brake shoe that can be transmitted to the support bearing can be transmitted to the abutment in a force-fitting manner by means of the form-fitting connection.

[0036] It may also be preferred that the support includes both at least one projection and at least one recess, and the support bearing includes a recess matching the projection of the support and a projection matching the recess of the support.

[0037] Another preferred embodiment is characterized in that the at least one recess and the at least one projection, which together form a positive-locking connection, are designed congruently with one another and / or form a fitting. This fitting is preferably a clearance fit or a transition fit, which enables the support to be joined to the support bearing. Furthermore, this fitting ensures that the support bearing is positioned as precisely as possible on the support during assembly and operation.

[0038] Another preferred embodiment is characterized in that the at least one recess and the at least one projection, i.e., the form-locking connection, are designed in a plane in a square, rectangular, trapezoidal, or dovetail-shaped manner. Preferably, this plane extends, in particular partially parallel to or in particular partially along the dividing plane separating the support bearing from the carrier. Additionally or alternatively, the plane extends in the direction of extension of the screw of the threaded connection.

[0039] If an embodiment is referred to that refers to another plane, then the plane is the first plane or the first plane.

[0040] Another preferred embodiment is characterized in that the at least one recess and the at least one projection are square, rectangular or trapezoidal in a further plane extending orthogonally to the first plane. As an alternative or in addition, the further plane, which can also generally be referred to as the second plane, extends perpendicular to the direction of extension of the screw of the threaded connection.

[0041] Another preferred embodiment is characterized in that the at least one recess and the at least one projection are formed in a further plane extending orthogonally to the first plane such that their mutual contact is V-shaped. Alternatively or additionally, the further plane, which can also generally be referred to as the second plane, extends perpendicularly to the direction of extension of the screw of the threaded connection.

[0042] Another preferred embodiment is characterized in that the support has a deformation element which is connected to the support in a force-transmitting manner, wherein the deformation of the deformation element can be detected or measured by a deformation sensor, whereby the deformation of the support can be indirectly detected or measured.

[0043] Another preferred embodiment is characterized in that the deformation element is arranged on the side of the carrier facing away from the support bearing and / or is connected to the carrier in a force-transmitting manner by screws, rivets, or bolts. This arrangement largely protects the deformation element from the heat generated by the drum brake.

[0044] The second object is achieved by providing a brake system having at least one drum brake according to the invention. Preferably, the brake system comprises one, two, three, four or more than four drum brakes according to the invention.

[0045] The third object is achieved by providing a vehicle having a brake system according to the invention or at least one drum brake according to the invention. Preferably, the vehicle is a motor vehicle, which in particular comprises an electric output device.

[0046] Advantageous developments of the invention are described in the dependent claims and in the following description of the figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention will be explained in detail below with reference to the accompanying drawings with the aid of embodiments. In the accompanying drawings: Figure 1 A vehicle is shown, Figure 2 shows a drum brake, Figure 3 shows the drum brake mount, Figure 4a -d shows different forms of form-locking connections between the support bearing and the support in a first view, and Figure 5a -g shows another view of different forms of positive locking connections between the support bearing and the support. DETAILED DESCRIPTION

[0048] Figure 1A vehicle 30 according to the present invention is shown, which is configured as a motor vehicle with two axles and an electric drive. Vehicle 30 includes a braking system 20 according to the present invention, which has four drum brakes 1 according to the present invention. Two of the four drum brakes 1 according to the present invention are each assigned to an axle of vehicle 30. The drum brakes 1 are configured not only as service brakes but also as parking brakes and can therefore be operated as such. Braking system 20 also includes a control device 21, which can operate drum brakes 1 and evaluate braking signals, such as braking force signals or braking torque signals. Control device 21 is also designed to operate braking system 20 as a driver assistance system. To this end, it is conceivable that other signals from other sensors of vehicle 30 be processed in control device 21.

[0049] Figure 2 Shown in a simplified diagram Figure 1 The drum brake 1 according to the present invention is shown in FIG. The drum brake 1 comprises a support 2a, which is connected to a steering knuckle 11 via a support connection 2b. Two brake shoes 4 each have a brake lining 5. The brake shoes 4 can be moved in a radial direction 8a toward a brake drum 6 that is rotatable in a rotational direction 8b by means of an actuator 7 designed as an electric actuator, so that the brake drum is braked when the brake lining 5 comes into contact with the rotating brake drum 6. Alternatively, the actuator 7 can be designed as a hydraulic actuator. A supporting force is generated by friction between the brake lining 5 and the brake drum 6. This supporting force is conducted into the support 2a by means of the brake shoes 4 via the support bearing 3a and is transmitted to the steering knuckle 11. The steering knuckle 11 can be connected to a peripheral device that can absorb the resulting supporting force.

[0050] Figure 3 Shown Figure 2 The drum brake support 2a is shown in FIG. Support 2a is made of metal and has a weight-reducing recess. Furthermore, the separately designed support bearing 3a can be seen. Support bearing 3a is also made of metal, but due to the material selection and its shape, it has a higher rigidity than support 2a. At a point on support 2a facing away from support bearing 3a, a deformation element 9 is connected to support 2a in a force-transmitting manner. Consequently, the deformation of support 2a caused by the braking process of the drum brake results in a deformation of deformation element 9. This deformation of deformation element 9 is measured by deformation sensor 10. This measurement allows inferences to be drawn about the deformation of support 2a and, therefore, about the braking force or braking torque of the drum brake.

[0051] Figure 4a -d shows in a first view different forms of form-fitting connections between a support bearing and a support of a drum brake. Figure 4a-d respectively correspond to an embodiment, the illustration of which corresponds to a sectional view in the XY plane, which extends along the extension direction of the threaded connection between the support bearing 3a and the support 2a. The threaded connection represents the fixing part 3b, which is Figure 4a -d is outlined.

[0052] exist Figure 4a As can be seen in FIG, the support bearing 3a has a trapezoidal recess, into which the projections of the support 2a are congruently embedded. Thus, a form-locking connection is formed between the support 2a and the support bearing 3a.

[0053] exist Figure 4b It can be seen in FIG. 1 that the support bearing 3 a has a trapezoidal projection which engages in a trapezoidal recess of the support 2 a and thus forms a positive connection between the support 2 a and the support bearing 3 a .

[0054] exist Figure 4c It can be seen in FIG. 1 that the support bearing 3 a comprises two trapezoidal projections, which each engage congruently in a trapezoidal recess of the support 2 a and thus form a form-fitting connection between the support 2 a and the support bearing 3 a.

[0055] exist Figure 4d It can be seen in FIG that the form-fitting connection between the support bearing 3 a and the support 2 a is realized by a dovetail guide.

[0056] Figure 5a -g shows another view of different forms of positive locking connections between the support bearing and the support of a drum brake. Figure 4a -d show different forms of form-locking connections. They each show a cross-section in the XZ plane, which is perpendicular to Figure 4a -d and intersects the positive connection between the support 2a and the support bearing 3a. A view along the Y direction is shown in each case.

[0057] Figure 5a shows a rectangular form-locking connection, while Figure 5b A trapezoidal, form-fitting connection between the support 2a and the support bearing 3a is disclosed. These two embodiments preferably involve Figure 4a and 4b Embodiment of the trapezoidal form-locking connection.

[0058] Figure 5c and 5d A V-shaped, positively locking connection between the support 2a and the support bearing 3a is disclosed. These two embodiments preferably involve Figure 4a and 4b Embodiment of the trapezoidal form-locking connection.

[0059] Figure 5e 、 5f and 5g disclose specific embodiments, which preferably involve Figure 4d An embodiment with a dovetail guide.

[0060] Different features of the various exemplary embodiments can also be combined with one another.

[0061] Figures 1 to 5g The exemplary embodiments are particularly not to be construed as limiting and serve to illustrate the inventive concept.

[0062] Reference Signs List 1 drum brake 2a support 2b support connection 3a support bearing 3b fixed part 4 brake shoes 5 brake linings 6 brake drums 7 Actuator 8a radial direction 8b Rotation direction 9Deformation element 10 deformation sensors 11 Steering knuckle 20 Braking system 21 control devices 30 vehicles

Claims

1. A drum brake (1) comprising at least one brake shoe (4), a deformation sensor (10) and a support (2a), wherein the support (2a) comprises a support bearing (3a) for the at least one brake shoe (4), wherein the deformation sensor (10) is designed to detect a deformation of the support (2a), wherein the support bearing (3a) is designed separately from the support (2a), and characterized in that The support bearing (3a) is connected to the support (2a) in a force-transmitting manner by means of a form-fitting connection.

2. The drum brake (1) according to claim 1, characterized in that The support bearing (3a) is fixed to the support (2a), in particular by means of a screw connection (3b).

3. Drum brake (1) according to any one of the preceding claims, characterized in that The support (2a) can be connected to the steering knuckle (11) or can be formed integrally with the steering knuckle (11).

4. Drum brake (1) according to any one of the preceding claims, characterized in that The form-fitting connection is formed by means of at least one recess of the support (2a) and at least one projection of the support bearing (3a).

5. Drum brake (1) according to any one of the preceding claims, characterized in that The form-fitting connection is formed by means of at least one recess of the support bearing (3) and at least one projection of the support (9).

6. The drum brake (1) according to any one of claims 4 or 5, characterized in that The at least one recess and the at least one projection, which together form a positive-locking connection, are designed to be congruent with one another and / or form a fitting.

7. Drum brake (1) according to any one of the preceding claims, characterized in that The at least one recess and the at least one projection are designed in a square, rectangular, trapezoidal or dovetail-shaped manner in a two-dimensional plane.

8. The drum brake (1) according to claim 7, characterized in that The at least one recess and the at least one projection are formed in a square, rectangular or trapezoidal shape in another plane extending perpendicularly to the first plane.

9. The drum brake (1) according to claim 7, characterized in that The at least one recess and the at least one projection are formed in another plane extending perpendicularly to the first plane such that their mutual contact is V-shaped.

10. Drum brake (1) according to any one of the preceding claims, characterized in that The support (2a) has a deformation element (9) which is connected to the support (2a) in a force-transmitting manner, wherein the deformation of the deformation element (9) can be detected or measured by the deformation sensor (10), thereby indirectly detecting or measuring the deformation of the support (2a).

11. The drum brake (1) according to claim 10, characterized in that The deformation element (9) is arranged on a side of the support (2a) facing away from the support bearing (3a) and / or the deformation element (9) is connected to the support (2a) in a force-transmitting manner by means of screws, rivets or bolts.

12. A brake system (20) comprising at least one drum brake (1) according to any one of the preceding claims.

13. A vehicle (30) having a brake system (20) according to claim 12 or at least one drum brake (1) according to any one of claims 1 to 11.

Images