caliper brake

Abstract

To provide a caliper brake in which reduction in braking force in a closed state is lessened.SOLUTION: A caliper brake includes a housing, two brake shoes which are moved within the housing in a direction of a component to be braked, and bearing parts movable within the housing via an actuator. The brake shoes each have a wedge surface on an opposite side from the component to be braked. The wedge surfaces and the brake shoes support the bearing parts on both sides of the component to be braked, and braking force acting on the bearing parts is transmitted to the brake shoes while being changed in direction and amplified in force. The bearing part includes two bearing journals which are arranged while being shifted by an amount corresponding to a wedge angle of the wedge surface. The wedge surfaces each have a step in the region of the bearing journal, and the step is overcome by a closing movement of the brake shoes before the brake shoes come in contact with the component to be braked.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention is a caliper brake for slowing down and / or fixing a component moving relative to the caliper brake, comprising a housing surrounding the component to be braked in a U-shape, two brake shoes that move like forceps within the housing toward the component to be braked, and a bearing part that is movable within the housing by an actuator, wherein the brake shoes each have one wedge surface on the side opposite the component to be braked, and these wedge surfaces allow the brake shoes to support the bearing parts on both sides of the component to be braked, and thereby the braking force acting on the bearing parts is transmitted to the brake shoes while changing direction and amplifying the force. [Background technology]

[0002] An electromagnetically operated brake device is known from Patent Document 1, in which the spring force of the brake spring is transferred to the brake shoe and bearing parts via a wedge ramp, with the force being deflected and amplified. Here, a flat cage with balls or rollers is arranged between the wedge faces. In spring-actuated brakes, it is disadvantageous that the spring is in a relaxed state when the brake is closed until the brake shoe contacts the brake disc and overcomes the air gap between the brake shoe and the brake disc. Therefore, the spring force in the open state is greater than that in the closed state. Therefore, the solenoid for opening the brake must be designed to accommodate the maximum spring force in the open state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] German Patent No. 10127664 Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is therefore to provide a caliper brake which can achieve a greater braking force and, in the case of spring-actuated brakes, at least reduces the drop in braking force in the closed state due to the spring stroke. [Means for solving the problem]

[0005] This problem is solved by a caliper brake with the features of claim 1. Advantageous embodiments are set forth in the dependent claims.

[0006] In the present invention, the bearing parts of the caliper brake of the type mentioned at the beginning are provided with two bearing journals for each brake shoe, which are arranged offset by an amount corresponding to the wedge angle of the wedge surfaces, and against which the wedge surfaces bear, and in the region of the bearing journals the wedge surfaces each have a step which is overcome during the closing movement of the brake shoes before they come into contact with the component to be braked.

[0007] Instead of two corresponding wedge surfaces, the present invention uses two offset bearing journals as thrust bearings. These preferably consist of rolling elements, especially rollers or balls, supported in the bearing element. This significantly reduces the frictional forces acting between the bearing element and the wedge surfaces of the brake shoes. Therefore, the wedge surfaces are steeply configured, preventing self-locking during braking. The step formed in the wedge surfaces abruptly overcomes the air gap between the brake shoes and the component to be braked. As a result, in the case of spring-actuated brakes, the brake springs are more compressed, thereby achieving a higher clamping force with the same spring. This reduces the maximum spring force for the same clamping force compared to the prior art, allowing the actuator, e.g., a solenoid, required to open the brake to be smaller and more resource-efficient. The caliper brake according to the present invention can also be made very compact and lightweight, and its design makes it easily and reliably protected from external disturbances.

[0008] In a preferred embodiment, the caliper brake is a self-closing brake and is equipped with a brake spring. In this case, the bearing part is moved to a closed position by the brake spring, which applies a brake force, in which the brake shoe rests against the component to be braked, and the actuator moves the bearing part, overcoming the spring force of the brake spring, to open the brake shoe to an open position, in which the brake shoe is lifted by the component to be braked. Furthermore, when a brake spring is used, an adjustment device, in particular an adjustment bolt, may be provided, by means of which the pretension of the brake spring can be adjusted. This allows the brake force to be adapted to the respective use.

[0009] However, it is equally possible within the scope of the present application for the caliper brake to be implemented as an actuator-driven brake. In this case, the bearing part is moved to a closed position under the application of a braking force by the actuator, in which the brake shoe rests against the component to be braked. Furthermore, a return spring may be provided, via which the brake shoe is lifted by the component to be braked when the brake is opened. Alternatively, the lifting of the brake shoe can also be performed by the actuator itself, which then has a double effect.

[0010] In a preferred embodiment of the invention, the actuator may be formed as a solenoid with an armature connected to an electromagnetic coil and a bearing element, but alternatively the actuator may be formed as a hydraulically or pneumatically driven cylinder-piston unit.

[0011] In one development of the invention, the actuator is connected to the bearing element via a linear guide extending in the direction of movement of the brake shoes. This allows the bearing element to remain movable in the direction of movement of the brake shoes, thereby enabling a corrective movement even if the air gaps between the two brake shoes and the component to be braked are different, so that the same force acts on both sides of the component to be braked. If the air gaps are not the same, assembly errors can cause a rotation axis offset, especially when a brake disc is used as the component to be braked. This prevents bending forces of the brake disc on the brake shaft or uneven wear of the brake pads.

[0012] In a further preferred embodiment, the housing may be provided with centering devices, in particular inclined surfaces arranged in the inner open position area, which center the bearing element within the housing when moving from the closed position to the open position. This prevents the weight of the bearing element from being biased against the component to be braked when the brake shoes are open. The brake pads are in a defined position in the open state. The centering is preferably designed so that after a small operating stroke of the actuator, for example a few millimeters, the bearing element again has sufficient play with the brake housing.

[0013] When a linear guide is used between the actuator and the bearing part, it is further advantageous to provide a pretensioning spring, which can be used to pretension the linear guide in the direction of actuator movement while eliminating the bearing clearance.

[0014] Due to the low friction between the bearing part and the brake shoe, the wedge surface can be designed to provide a high force amplification, which in the scope of the present invention is preferably in the range of 2 to 10 times, in particular in the range of 5 to 6 times.

[0015] In one embodiment, each brake shoe includes one brake pad and one wedge segment. In this case, it is particularly advantageous for the wedge segment to be equipped with an adjustment device for wear adjustment. As the brake pad wears, the brake shoe's adjustment stroke increases. Therefore, the adjustment device uses an opening movement to increase the distance between the wedge surfaces with the brake pads, thereby compensating for pad wear. In this regard, the wedge segment may, for example, consist of two parts connected by a screw. The total length of both parts can be increased by rotating them relative to one another. For automatic adjustment, the vertical movement of the actuator is used to generate the rotational movement. The greater the pad wear, the longer the vertical movement and the stronger the screw rotation, resulting in further wear adjustment.

[0016] In a further development of the invention, the brake shoes can be linearly movably supported on the underside of the housing via an axial rolling bearing and / or a sliding bushing. Even if the brake pads wear obliquely due to external conditions and forces that may displace the brake shoes are generated, the thrust bearings and bushings provide a constant wedge angle, thereby maintaining a constant force amplification. In addition, the sliding bushings can be protected from the ingress of dirt and moisture.

[0017] In another advantageous development, a side plate forming a front stop for the brake shoe is attached to the housing, so that the braking force acting on the brake shoe during braking can also be transmitted to the brake housing.

[0018] Furthermore, in the context of the present application, the bearing journals are preferably formed from rollers, which are supported in the bearing element by rolling bearings, which results in particularly low friction losses. As an alternative to the mentioned rolling bearings, the rollers in the bearing element can also be supported by plain bearings in order to reduce costs.

[0019] Further embodiments and advantages of the invention will become apparent from the following description of exemplary embodiments with the aid of the drawings. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a cross-sectional view of one embodiment of a caliper brake according to the present invention. [Figure 2] FIG. 10 is a detailed view of the stepped wedge surface of the brake shoe and the roller of the bearing component abutting against the wedge surface. [Figure 3] 2 is a partial cross-sectional view perpendicular to the drawing plane of FIG. 1, with a linear guide between the actuator and the bearing part; [Figure 4] 2 shows an embodiment based on FIG. 1 with rolling bearings for supporting the rollers; [Figure 5] 1 shows an embodiment of a brake shoe with an adjustment device for wear adjustment. DETAILED DESCRIPTION OF THE INVENTION

[0021] The braking system shown in Figure 1 is a caliper brake for a brake disc 6, which here rotates perpendicular to the plane of the drawing. However, in other implementations, this brake can also be used as a linear brake, in which case a brake rail is provided as the component to be braked instead of the brake disc 6.

[0022] The caliper brake comprises a housing 11, which is arranged in a U-shape around the brake disc 6. Two brake shoes 3 are arranged in the housing 11 on either side of the brake disc 6, which are moved inwards towards the brake disc 6 in the manner of forceps to close the brake. The brake shoes 3 here each comprise one wedge segment 3', on the side facing the brake disc 6 of which one brake pad 4 is respectively attached, and on the side facing away from the brake disc 6 which is formed as a wedge surface 3a. The wedge surfaces 3a each have two steps or stepped portions 2, the function of which will be explained below.

[0023] The brake is actuated via a brake spring 9, whose spring force is transmitted to the wedge inclined portion 3a of the brake shoe 3 via a bearing element 7. The bearing element 7 is configured as a rolling bearing, which has two staggered and rotatably supported rollers 1 as thrust bearings or bearing journals for each brake shoe 3. The offset of the rollers in the X direction, i.e. in the direction of movement of the brake shoe (see FIG. 1), corresponds to the wedge angle α of the wedge surface 3a plus the height of the step 2.

[0024] FIG. 1 shows the brake in its open position, with an air gap 5 between the brake disc 6 and the brake pads 4. This prevents the brake pads 4 from being worn away by the rotating brake disc 6. In the open position, each roller 1 rests against a wedge surface 3a in the area of ​​the step 2. When the rolling bearing 7 is pressed downwards against the lower area of ​​the brake housing 11 by the force of the brake spring 9, the wedge surface 3a redirects the braking force towards the brake shoes 3, which then move inwards relative to the brake disc 6. In this case, the step 2 is overcome first, which causes the brake shoes to move inwards suddenly. This initial sudden movement corresponds approximately to the air gap 5 due to the step 2, so that the brake pads 4 rest against the brake disc 6 without delay. This achieves braking action even with a small spring stroke of the brake spring 9.

[0025] Figure 2 shows a detailed view of the roller 1 abutting against the wedge surface 3a just before the step 2. This position corresponds to the open position of the brake. The wedge surface 3a has a wedge angle α before and after the step 2, which causes a change in direction of the force and a force amplification. In the area of ​​the step, this angle is much gentler, in fact up to 90°. The height of the step is somewhat smaller than the width of the air gap 5, so that the roller 1 rolls over just above the step 2 as the brake closes and abuts against the wedge surface 3a in the area after the step 2.

[0026] The brake of this embodiment is designed as an electromagnetic liftable brake. For this purpose, an actuator is provided in the form of a solenoid 10, which has an electromagnetic coil 10a and an armature 8 movable axially within the electromagnetic coil 10a. This armature 8 is connected to a rolling bearing 7. Due to the attraction of the magnet 10, the armature 8 is pulled upwards towards the electromagnetic coil 10a, compressing the brake spring 9. This lifts the rolling bearing 7, and as a result the brake shoe 3 is lifted or retracted from the brake disc 6. The retraction or lifting of the brake shoe can be achieved by a slight imbalance of the brake disc 6 or by a return spring (not shown).

[0027] In the same way, an electromagnetically actuated active brake can be realized. In this case, in the energized state, a solenoid presses against the rolling bearing 7 via a spring. Another spring keeps the brake permanently open in the de-energized state. As an alternative to a solenoid, a pneumatic or hydraulic cylinder is also conceivable.

[0028] FIG. 3 is a schematic diagram of the connection between the rolling bearing 7 and the armature 8 of the solenoid 10. They are connected via a linear guide 18, shown here as a T-groove. This allows the rolling bearing 7 to move in the direction of movement of the brake shoe 3 (direction X) during braking. This allows for a compensating movement of the brake disc when the air gap 5 varies, so that the same force always acts on both sides of the brake disc 6, thereby preventing bending of the brake shaft. Instead of the T-groove, any other linear guide, such as a swallow-tail guide, could be used. The linear guide 18 is pretensioned by a tension spring 14, which compensates for any bearing clearance. The tension spring 14 is guided here by a recess in the armature 8 and the top of the rolling bearing 7.

[0029] The brake spring 9 is pretensioned by means of an adjusting bolt 16, which allows the spring stroke and thus the braking force to be adjusted according to the respective use.

[0030] When opening the brake, the rolling bearing 7 is pulled back to the top of the housing 11. The side inclined surfaces 15 now act as a centering device, ensuring that the rolling bearing 7 is in a defined central position within the housing 11 in the open state.

[0031] At the bottom of the housing 11, the brake shoe 3 is supported by an axial bearing 13 so as to be linearly movable. A slide bush 17 not only seals the brake housing but also further guides the brake shoe 3. The thrust bearing 13 and slide bush 17 prevent the brake shoe 3 from tilting when closing and keep the wedge angle α constant, so that the force amplification by the wedge angle α is kept constant.

[0032] The front surface of the side plate 12 of the housing 11 abuts against the brake shoe 3 and transmits the braking force acting from the brake disc 6 to the brake shoe 3 to the housing 11.

[0033] Another embodiment of the caliper brake is shown in Figure 4. Based on the embodiment shown in Figure 1, here the rollers 1 are each supported by radial roller bearings 19, in this case needle roller bearings, which reduces friction when the rollers 1 roll against the wedge surface 3a and therefore allows for a higher braking force to be achieved.

[0034] As already mentioned, an automatic pad wear adjustment is incorporated into each brake shoe 3 in a manner known per se. A corresponding embodiment of such a brake shoe 3 is shown in FIG. 5. The wedge segment here consists of two parts, the two parts 3', 3" being connected by a screw. During the return movement of the brake shoe 3, the inner part 3' of the brake shoe 3 is loosened by one small step in each case, so that as the wear of the brake pad 4 increases, the overall length of the parts 3', 3" forming the brake shoe 3 is extended.

[0035] The rear part 3' of the brake shoe 3 bears against the wedge surface 3a on its underside, and is cylindrically shaped on the other side and has an external thread. This works together with the sleeve-shaped part 3" with an internal thread, in which the brake pads (not shown in FIG. 5) are arranged. The adjusting ring 20 is rotatably moved in one direction on the rear part 3" and has a notch into which the bearing part 7 engages. When the brake is opened, the part 3" is turned by the adjusting ring and, in doing so, moves outwards due to the thread, thereby reducing pad wear.

Claims

1. A caliper brake for slowing and / or fixing a component (6) in relative motion with respect to the caliper brake, in particular a brake disc or a brake rail, a housing (11) enclosing in a U-shape the component to be braked (6); - two brake shoes (3) movable in the manner of forceps in the direction of the component (6) to be braked within said housing (11); - a bearing part (7) movable within said housing (11) by an actuator (8, 10), In this case, the brake shoes (3) each have a wedge surface (3a) on the side opposite the component (6) to be braked, by means of which the brake shoes support the bearing part (7) on both sides of the component (6) to be braked, and by which the braking force acting on the bearing part (7) is transmitted to the brake shoes (3) in a direction-changing and force-multiplying manner, The bearing part (7) comprises, for each brake shoe (3), two bearing journals (1) which are arranged offset by an amount corresponding to the wedge angle (α) of the wedge surface (3a); The bearing journal rests against the wedge surface (3a), and the wedge surface (3a) has a step (2) in the area of ​​the bearing journal (1), A caliper brake, characterized in that the step is overcome by the closing movement of the brake shoe (3) before the brake shoe (3) hits the component (6) to be braked.

2. 2. A caliper brake according to claim 1, wherein the bearing journal (1) is formed by rolling elements, in particular rollers or balls, which are supported in the bearing part (7).

3. 3. A caliper brake according to claim 1 or 2, wherein the bearing part (7) is driven to a closed position by a brake spring (9) that applies a brake force, in which position the brake shoe (3) abuts against the component (6) to be braked, and wherein the actuator (8, 10) moves the bearing part (7) to an open position, overcoming the spring force of the brake spring (9), in order to open the brake shoe (3), in which position the brake shoe (3) is lifted by the component (6) to be braked.

4. 4. A caliper brake according to claim 3, comprising an adjusting device, in particular an adjusting bolt, for adjusting the pretension of the brake spring.

5. 3. A caliper brake according to claim 1 or 2, wherein the bearing part (7) is moved to a closed position by the application of a braking force by the actuator (8, 10), in which position the brake shoe (3) abuts against the component (6) to be braked.

6. 6. A caliper brake according to claim 1, wherein the actuator (8, 10) is formed as a solenoid from an electromagnetic coil (10) and an armature (8) connected to the bearing part (7).

7. 6. Caliper brake according to any one of claims 1 to 5, wherein the actuator is formed as a hydraulically or pneumatically operated cylinder-piston unit.

8. A caliper brake according to any one of claims 1 to 7, wherein the actuator (8, 10) and the bearing component (7) are connected to each other via a linear guide (18) extending in the direction of movement of the brake shoe.

9. 9. A caliper brake according to claim 8, wherein the housing has a centering device, in particular an inclined surface (15) arranged on the inside in the area of ​​the open position, which inclines the bearing part (7) in the housing when moving from the closed position to the open position.

10. 10. The caliper brake according to claim 8, further comprising a pretension spring (14) that compresses the linear guide (18) in the direction of movement of the actuator (8, 10) while eliminating bearing clearance.

11. Caliper brake according to any one of claims 1 to 10, wherein the force multiplication by the wedge surface (3a) is in the range of 2 to 10 times, in particular 5 to 6 times.

12. 12. A caliper brake according to claim 1, wherein each of the brake shoes (3) has one brake pad (4) and one wedge segment, and the wedge segment includes an adjusting device (3", 20) for wear adjustment, which uses an opening movement to increase the gap between the wedge surface (3 a) and the brake pad (4) when the adjustment stroke of the brake shoe (3) increases due to wear of the brake pad (4).

13. 13. A caliper brake according to claim 1, wherein the brake shoe (3) is linearly movably supported on the underside of the housing (11) via an axial rolling bearing (13) and / or a slide bush (17), respectively.

14. 14. A caliper brake according to any one of claims 1 to 13, further comprising a side plate (12) fixed to the housing, said side plate forming a stop on the brake shoe (3) for receiving a braking force acting on the brake shoe (3).

15. Caliper brake according to any one of claims 1 to 14, characterized in that the bearing journal (1) is formed from a roller, said roller being supported in said bearing part (7) by means of a rolling bearing (19).

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