braking device

Abstract

A brake device for a motor vehicle has an actuator (6) which has a housing (11) which is common to an expansion actuator (14) and an adjustment device (15). An electric motor (10) for operating the actuator (6) can be driven in two rotational directions, wherein the expansion actuator (14) is driven in one rotational direction and the adjustment device (15) is driven in the other rotational direction. As a result, the adjustment of the brake device is designed particularly simply.

Description

Technical Field

[0001] The present invention relates to a braking device for a motor vehicle, the braking device comprising: a braking mechanism for generating frictional engagement with a rotating member; an actuator capable of being driven in two directions of motion to move the braking mechanism toward and away from the rotating member; and an adjustment device for compensating for wear of the member generating frictional engagement. Background Technology

[0002] Such braking devices are known, for example, from WO 2015 101 486A2. The adjusting device is integrated as a separate component with the actuator into the expansion mechanism of the braking device, and prevents the brake pedal displacement or actuator displacement from increasing with the increase in air clearance due to brake pad wear. This adjusting device can be adjusted as needed. Summary of the Invention

[0003] The present invention is based on the problem of improving the braking device of the type described at the beginning to make its construction particularly simple and avoid complex adjustments to the brake pads.

[0004] According to the present invention, this problem is solved by means of an adjustment device arranged in the components of an actuator, the actuator being designed to drive the expansion actuator in one driving direction starting from an initial position in the middle and to drive the adjustment device in the opposite driving direction starting from the initial position.

[0005] This design avoids the need for additional components for installing the adjustment device, as it is installed along with the rest of the actuator. Here, the adjustment device or the expansion actuator can be selectively operated by correspondingly manipulating the actuator. Consequently, the braking device is particularly simple in construction and allows for easy adjustment of the brake pads in case of wear. The described drive direction of the actuator can be determined by angle or axial displacement. The braking device can be designed in almost any manner, for example, as a single-servo brake or a dual-servo brake.

[0006] According to another advantageous improvement of the invention, if the initial position is the position where no energy has been applied to the actuator, then the delay in frictional engagement of the braking device after the actuator is operated is particularly small.

[0007] According to another advantageous improvement of the invention, if the actuator has an electric motor, then the initial position and the drive in both directions of motion can be easily determined.

[0008] According to another advantageous improvement of the invention, if the actuator has a housing and a pressure-bearing member disposed therein for supporting the braking mechanism and the adjusting device, then the braking device can be manufactured particularly easily. Thus, the actuator, together with the pressure-bearing member, can be easily installed between the braking mechanisms. The adjusting device is installed simultaneously.

[0009] According to another advantageous improvement of the invention, if the electric motor is designed to drive the drive sleeve, which is designed to operate the expansion actuator in one rotational direction and the adjustment device in another rotational direction, then the drive design for the adjustment device and the pressure bearing is particularly simple.

[0010] According to another advantageous improvement of the invention, the expander actuator is structurally particularly simple if it has two inclined discs capable of rotating relative to each other, these inclined discs being indirectly supported on a bearing member, and the shape of the inclined discs being designed to cause their axial increase when rotating relative to each other. The inclined discs may, for example, have inclined grooves on their end sides to receive rolling elements, such that the rolling elements roll within them and increase the distance between the inclined discs relative to each other.

[0011] According to another advantageous improvement of the invention, if the actuator has a drive sleeve that is threaded to the shaft and is axially displaceable within the housing, and at least one of the components, i.e., the shaft or the drive sleeve, is indirectly or directly supported on the bearing member, this helps to further simplify the structure of the expansion actuator.

[0012] According to another advantageous improvement of the invention, if the adjusting device has an adjusting nut screwed onto the shaft by an adjusting thread, which is fixed in the initial position by form-locking or force-locking to prevent rotation, then the adjusting device is designed to be particularly simple.

[0013] The thread may be designed, for example, as a trapezoidal thread. According to another advantageous improvement of the invention, if the thread of the drive sleeve on the shaft is designed as a ball screw drive structure, then the operation of the expansion actuator and adjusting device is designed to have particularly low friction.

[0014] According to another advantageous improvement of the invention, if the adjusting nut is arranged in the force flow between the shaft and one of the bearing members, the actuator can be designed to be particularly compact. This allows the entire adjusting device to be moved when operating the expansion actuator without causing the adjusting device to be adjusted.

[0015] According to another advantageous improvement of the invention, if the adjusting nut has a locking device, which has a locking disc or adjusting spring, then the anti-rotation retention of the adjusting nut is structurally very simple.

[0016] According to another advantageous improvement of the invention, if the adjusting cage surrounds the adjusting nut at one end and supports the adjusting spring at the other end, then the design of the support for the adjusting spring is particularly simple. Attached Figure Description

[0017] This invention allows for various implementations. To further clarify their basic principles, several implementations are illustrated in the accompanying drawings and described below. In the drawings:

[0018] Figure 1 A braking device designed as a drum brake is schematically shown.

[0019] Figure 2 Show Figure 1 Force-displacement diagram of the actuator of the braking device.

[0020] Figure 3 A cross-sectional view of a first embodiment of the actuator is shown.

[0021] Figure 4 Show Figure 3 The cross-sectional view of the actuator along line IV-IV.

[0022] Figure 5 A cross-sectional view of another embodiment of the actuator is shown.

[0023] Figure 6 A cross-sectional view of another embodiment of the actuator is shown.

[0024] Figure 7 This demonstrates the operation of the expansion actuator. Figure 6 The actuator,

[0025] Figure 8 Showing when operating the adjustment device Figure 6 The actuator,

[0026] Figure 9 Show Figure 6 A perspective view of the adjusting nut of the actuator's adjusting device.

[0027] Figure 10 As shown in another diagram Figure 7 Adjusting nut,

[0028] Figure 11 Shown in enlarged cross-sectional view Figure 6 The local area of ​​the adjustment device. Detailed Implementation

[0029] Figure 1The diagram shows components of a braking device for a motor vehicle, designed as a drum brake. The braking device has a rotatably supported brake drum 1. The brake drum 1 surrounds two braking mechanisms 2 and 3, designed as brake shoes, with friction linings 4 and 5. The brake shoes 2 and 3 can be moved toward the brake drum 1 by an expansion device 7 driven by an actuator 6 to generate frictional torque. In the illustrated embodiment, tension springs 8 and 9 pull the brake shoes 2 and 3 toward the actuator 6, thereby allowing the brake shoes to be moved back from the brake drum 1. The actuator 6 has an electric motor 10 that can be driven in two directions of rotation and a housing 11 for guiding two pressure bearings 12 and 13 supported on the brake shoes 2 and 3. Inside the housing 11 are arranged an expansion actuator 14 for driving the expansion device 7 and an adjustment device 15. The adjustment device 15 adjusts the position of the pressure bearings 12 and 13, thereby compensating for wear of the friction linings 4 and 5. A gear 16 driven by the electric motor 10 enters the housing 11 containing the pressure bearings 12 and 13. The housing 11 is supported on the support plate 17 in a floating manner.

[0030] Figure 2 Show Figure 1 The force / displacement diagram of the actuator. It can be seen from this that... Figure 1 The actuator 6 occupies the zero position marked "0" in an uncontrolled initial state. At the zero position, no force is applied to the bearing members 12 and 13 by means of the expansion actuator 14, and the adjustment device 15 is not operated. When the electric motor 10 is driven in one direction of rotation starting from the zero position, the adjustment device 15 is operated. When the electric motor is driven in another direction of rotation starting from the zero position, the bearing members 12 and 13 are moved apart by the expansion actuator 14, and a force F is introduced into the expansion device.

[0031] Figure 3 A schematic cross-sectional view is shown of the housing 11 of the actuator 6 and the pressure-bearing members 12 and 13 arranged therein that are non-rotatable but axially movable. The partial cross-section shows the components... Figure 1 The electric motor 10 drives the gear 16. The actuator 6 has a support at its end. Figure 1The braking mechanisms 2 and 3 shown have pressure-bearing members 12 and 13 and a drive sleeve 18 driven by gear 16 within the housing 11. The drive sleeve 18 is supported on shaft 20 and on locking disc 23 by a first drive member 21, and on first inclined disc 24 by a second drive member 22. The drive sleeve 18 can be supported on shaft 20 by radial support members or sliding sleeves. In the illustrated embodiment, the drive sleeve 18 is displaceable. Alternatively, the drive sleeve 18 can be axially fixed to shaft 20 on both sides by retaining rings not shown. Drive members 21 and 22 extend from the drive sleeve 18 as flaps arranged on both sides of shaft 20. This avoids lateral forces. The first inclined disc 24 is rotatably supported and rests on a fixed inclined disc 25. Rolling elements 26 are arranged between inclined discs 24 and 25. Rolling element 26 rolls on groove 27 inclined relative to the end sides of inclined discs 24, 25, causing inclined discs 24, 25 to move axially apart as the rotation angle increases. Here, one of the inclined discs 25 is supported on a bearing member 12, and the other inclined disc is supported on shaft 20 by axial support member 33, and thus indirectly supported on another bearing member 13. Bearing members 12, 13 are axially displaceable, but not rotatably connected to housing 11 by axial guide member 34. One bearing member 12 may be integrally formed with the nearest inclined disc 25. Shaft 20 has an anti-rotation device 42 in a bearing member 13. Drive members 21, 22 are designed to rotate locking disc 23 in one rotational direction of drive sleeve 18, and to rotate the rotatably supported inclined disc 24 in another rotational direction of drive sleeve 18. Thus, by using the components, namely the locking disc 23 or the rotatable inclined disc 24, the drive components 21 and 22 achieve the driving function in one rotational direction of the drive sleeve 18, and achieve the idling function in the other rotational direction.

[0032] The locking disc 23 is part of the adjusting device 15, which grips the adjusting nut 28. The adjusting nut 28 is supported on a bearing member 13 by a disc spring 29 and is screwed onto the adjusting thread 30 of the shaft 20. The locking disc 23 and the adjusting nut 28 have locking devices 31 facing each other, such that the adjusting nut 28 follows the rotation of the locking disc 23 in one direction and rotates on the adjusting thread 30 of the shaft 20, thus displacing itself. Here, the adjusting nut 28 is pressed against the bearing member 13 by the disc spring 29. When the locking disc 23 returns, the adjusting nut 28 is held on the shaft 20 due to frictional locking, and the locking disc 23 continues to move past a locking device. As a result, the distance between the bearing members 12 and 13 increases, thus adjusting the actuator 6.

[0033] Figure 4The design of the first driving member 21 is illustrated using the locking disc 23 as an example. The locking disc 23 is pre-tensioned to the stop member 43 by the return spring 32. The first driving member loosely abuts against the locking disc 23 and can move away from the locking disc when the drive sleeve 18 rotates clockwise, or rotate against the force of the return spring 32 when it rotates counterclockwise. The second driving member 22, which drives the rotatable inclined disc 24, is constructed in the opposite direction of rotation and functions similarly to the above. Thus, when driving the drive sleeve 18 in one direction of rotation, only the adjusting device 15 is adjusted, and when driving in the other direction of rotation, only the bearing members 12 and 13 move away from each other, and thus the expansion device 7 is driven by the expansion actuator 14.

[0034] If adjustment is initiated, the locking disc 23 rotates, driving the adjusting nut 28. The adjusting nut 28 is screwed onto the shaft 20 and presses against the disc spring 29. The disc spring 29 presses against the bearing member 13. The bearing member 13 thus moves in the same direction as the adjusting nut 28. Here, the bearing member 13 drives the locking disc 23 by means of the limiting plate 44. Therefore, the components of the adjusting device 15 shift with each adjustment. Since the locking disc 23 shifts during adjustment, the adjusting nut 28 and the locking disc 23 remain in contact. If the adjusting device 15 shifts, the gap between the drive sleeve 18 and the locking disc 23 also increases.

[0035] Figure 5 Another embodiment of actuator 6 is shown in schematic cross-section, having two bearing members 12, 13 that are axially displaceable and non-rotatably held in housing 11 by means of axial guide 134. Adjustment device 115 has two opposing inclined plates 124, 125. One inclined plate 125 is anti-rotatable but axially displaceable and connected to one of the bearing members 13, while the other inclined plate 124 is connected to adjusting nut 128 by friction locking or form locking. The gear 16 of electric motor 10 is as follows... Figure 3 The drive sleeve 118 engages with the drive sleeve 118 as described above. The drive sleeve 118 is connected to the shaft 120 via a thread 119 designed as a ball screw drive structure. The adjusting nut 128 is screwed onto the shaft 120 via an adjusting thread 130.

[0036] A powerful adjusting spring 139 within the adjusting threaded component 128 generates an axial force on the inclined plate 124, thereby holding the ball-shaped rolling element 126, arranged therebetween, between the inclined plates 124 and 125. The inclined plate 125, anti-rotationally connected to a bearing member 13, is supported on the bearing member 13 by a disc spring 129, which in turn supports the force of the adjusting spring 139.

[0037] In the uncontrolled initial position, the swashplates 124 and 125 are twisted relative to each other and preloaded into their positions. An adjusting spring 139 inside the adjusting nut 128 preloads the swashplates 124 and 125 onto the rolling element 126. The swashplate 124, connected to the adjusting nut 128, is held in its rotated position by friction. Additionally, a return spring 132 holds the swashplates 124 and 125 in their twisted and preloaded position. Here, the return spring 132 is in a resting position without tension. Axial displacement of the swashplates 124 and 125 causes tension in the torsion spring. If the driven sleeve 118, designed as a ball screw drive structure, now presses against the swashplate 125, then the swashplates 124 and 125 rotate and are pressed together axially, and the return spring 132 is preloaded. The frictional force generated by the axial force between the inclined plate 124 and the adjusting nut 128 causes the adjusting nut 128 to rotate, producing an adjustment stroke, and thus increasing the distance between the pressure bearings 12 and 13.

[0038] If the driven sleeve 118 of the thread 119, designed as a ball screw drive structure, now returns to the initial position shown, the friction between the swashplate 124 and the adjusting nut 128 decreases again. Here, the pre-tightened return spring 132 causes the rotatable swashplate 124 to move back again. Sufficiently high friction, which may be artificially generated in the adjusting thread 130, ensures that the adjusting nut 128 does not reset when the return spring 132 relaxes.

[0039] If the drive sleeve 118 is driven in one direction of rotation, the drive sleeve shifts and presses against a bearing 12 via the axial bearing 133. The other bearing 13 moves in the opposite direction via the shaft 120 without rotating itself at this time. The shaft 120 has an anti-rotation device 142 in the bearings 12 and 13. The adjusting device 115 is unaffected by this movement. Thus, the drive... Figure 1 The expansion device 7 is shown in the image. To reduce the expansion force, the drive sleeve 118 is driven in the opposite direction toward the initial position.

[0040] Adjustment is made when the drive sleeve 118 is driven in another direction of rotation toward the inclined plates 124, 125 from the initial position. The driven sleeve 118, which is designed as a ball screw drive structure, is axially compressed by the thread 119. If an axial force is applied to the anti-rotation inclined plate 125, the rotatable inclined plate 124 rotates by the inclined groove 127 and the rolling element 126 arranged therein, and drives the adjusting nut 128 by friction locking or form locking. The return spring 132 is tensioned here. The rotation of the adjusting nut 128 causes the anti-rotation shaft 120 to shift axially and thus increases the distance between the bearing members 12, 13. If the drive sleeve 118 then returns to the initial position, the inclined plates 124, 125 are released from the axial preload of the drive sleeve 118. Therefore, the preloaded return spring 132 can return to the rest position. Here, the return spring 132 drives the rotatable inclined plate 124, causing the two inclined plates 124 and 125 to rotate relative to each other again.

[0041] Figure 6 Show Figure 1 Another embodiment of the actuator 6 of the braking device, wherein it is rotatable within the housing 11 and can be driven by Figure 1 The gear 16 is driven by the electric motor 10, and the drive sleeve 218 is supported on the tubular shaft 220 by a thread 219 designed as a ball screw drive structure. Two pressure-bearing members 12 and 13, arranged inside the drive sleeve 218 and rotatable relative to the drive sleeve, are... Figure 1 Braking mechanisms 2 and 3 are fixed to prevent rotation, and are also fixed by the same mechanism. Figure 1 The tension springs 8 and 9 shown are preloaded into the drive sleeve 218. The tubular shaft 220 has an axial guide 234 for preventing rotation but allowing axial displacement of the bearing members 12 and 13. An axial support 233 for the expansion actuator 214 is arranged between one bearing member 13 and the end of the shaft 220, while an adjusting device 215 is arranged between the other bearing member 12 and the shaft 220. Furthermore, the drive sleeve 218 has radially inwardly pointing protrusions 235 and 236 opposite the axial bearing 233 and the adjusting device 215. The adjusting device 215 has an adjusting nut 228, a sliding ring 237, and an adjusting cage 238. The adjusting nut 228 is screwed onto one of the bearing members 12... Figure 11 The adjusting thread 230 is shown in the image. The adjusting spring 239 deflects / wound on the sliding ring pin 240. The sliding ring 237 is axially guided by the sliding ring pin 240.

[0042] In order to control the expansion actuator 214, the drive sleeve 218 is... Figure 1 The electric motor 10 shown in the image rotates, as... Figure 7As shown. Through rotational motion, shaft 220 presses against adjusting nut 228 via thread 219, which is designed as a ball screw drive structure, thereby applying force to bearing member 12. On the other side, drive sleeve 218 is supported on axial support member 233, thereby applying force to another bearing member 13. Thus, bearing members 12 and 13 are driven. Figure 1 The expansion device 7. The adjustment device 215 is located in the position shown, for clarity. Figure 9 The position is shown in magnified view. One leg 241 of the adjusting spring 239 is supported in the locking device 231 of the adjusting nut 228, while the other end of the adjusting spring 239 is supported on the adjusting cage 238.

[0043] To control the adjusting device 215, the drive sleeve 218 is rotated in the opposite direction, such as... Figure 8 As shown. Here, the drive sleeve 218 pushes the sliding ring 237 axially toward the nearest bearing member 12. Through the axially displaceable connection between the sliding ring 237 and the sliding ring pin 240, the support leg 241 of the adjusting spring 239 pivots around the sliding ring pin 240, as shown. Figure 10 The image is enlarged for clarity. Because the free end of the support leg 241 is supported in the locking device 231 of the adjusting nut 228, the adjusting nut rotates. If the drive sleeve 218 rotates back to its initial position, the adjusting nut 228 remains in its position because it is held on the shaft 220 and on the adjusting thread 230 of the bearing member 12 by force locking. This force locking is achieved by… Figure 1 The tension springs 8 and 9 shown in the image provide support. The adjusting spring 239 can be relaxed again, and the free leg 241 can continue to move until it locks with the adjusting nut 228 by releasing the displacement.

[0044] Figure 11 A magnified partial cross-section shows a portion of the adjusting device 215 with the adjusting nut 228. The adjusting cage 238 is axially displaceable and guided in the pressure member 12 in a rotation-resistant manner. Furthermore, by this guidance, the sliding ring 237 is axially displaceable but guided in the adjusting cage 238 in a rotation-resistant manner via the sliding ring pin 240.

Claims

1. A drum brake device for a motor vehicle, the drum brake device comprising: Braking elements (2, 3) used to generate frictional engagement with rotating components; An actuator (6) capable of being driven in two directions of motion, causing the braking elements (2, 3) to move toward and away from the rotating member; and Adjustment device (15, 115, 215) for compensating for wear of a friction-engaging brake element, characterized in that Adjustment devices (15, 115, 215) are arranged in the components of actuator (6), which is designed to drive the expansion actuator (14, 114, 214) in one driving direction from an initial position in the middle and to drive the adjustment devices (15, 115, 215) in the opposite driving direction from the initial position.

2. The drum brake device according to claim 1, characterized in that The initial position is the position where the actuator (6) has not been energized.

3. The drum brake device according to claim 1 or 2, characterized in that The actuator (6) has an electric motor (10).

4. The drum brake device according to claim 1 or 2, characterized in that The actuator (6) has a housing (11) and pressure-bearing members (12, 13) arranged in the housing for supporting the braking elements (2, 3) and the adjusting devices (15, 115, 215).

5. The drum brake assembly of claim 3 wherein, An electric motor (10) is designed to drive a drive sleeve (18, 118, 218) which is designed to operate the expansion actuator (14, 114, 214) in one rotational direction and the adjustment device (15, 115, 215) in another rotational direction.

6. The drum brake device according to claim 1 or 2, characterized in that, The expansion actuator (14, 114, 214) has two inclined disks (24, 25, 124, 125) that are capable of rotating relative to each other. The inclined disks (24, 25, 124, 125) are indirectly supported on the bearing member (12, 13). The shape of the inclined disks (24, 25, 124, 125) is designed to cause their axial expansion when they rotate relative to each other.

7. The drum brake assembly of claim 5 wherein, The actuator (6) has a drive sleeve (118, 218) that is connected to the shaft (120, 220) by threads (119, 219) and is axially displaceable within the housing (11). At least one of the components, namely the shaft (120, 220) or the drive sleeve (118, 218), is indirectly or directly supported on the bearing member (12, 13).

8. The drum brake assembly of claim 7 wherein, The adjusting device (15, 115, 215) has adjusting nuts (28, 128, 228) screwed onto the shaft (20, 120, 220) by adjusting threads (30, 130, 230), which are fixed in the initial position by form-locking or force-locking so that they cannot be rotated.

9. The drum brake assembly of claim 7 wherein, The threads (119, 219) of the drive sleeves (118, 218) on the shafts (120, 220) are designed as ball screw drives.

10. The drum brake device according to claim 8, characterized in that, Adjusting nuts (28, 128, 228) are arranged in the force flow between the shaft (20, 120, 220) and one of the bearing members (12, 13).

11. The drum brake assembly of claim 8 wherein, The adjusting nut (28, 128, 228) has a locking device (31, 131, 231) which has a locking disc (23, 123) or an adjusting spring (239).

12. The drum brake assembly of claim 11 wherein, The adjustment cage (238) is wrapped around the adjustment nut (228) at one end and supports the adjustment spring (239) at the other end.

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