Ball screw assembly with built-in force sensor

Abstract

The utility model relates to the field of brake calipers, in particular to a ball screw assembly with a built-in force sensor, which comprises a ball screw, a compression ring and a sensor component, the ball screw comprises a screw rod and a nut, the screw rod is provided with a first inner cavity, the compression ring is in interference close fit with the nut, the compression ring is provided with a second inner cavity, and the second inner cavity is connected with the first inner cavity, the pressure ring is connected with a pressure plate through a fixing pin, the pressure plate is in contact connection with the friction plate, the sensor assembly penetrates through the first inner cavity and the second inner cavity and comprises a pressure block and a force sensor, the lower portion of the pressure block is correspondingly provided with a concave spherical surface, the upper portion of the pressure plate is correspondingly provided with a hemispherical protrusion, and the force sensor is matched with the pressure ring in an inserted mode. The upper surface of the force sensor abuts against the step on the inner side of the pressing ring, the lower surface of the force sensor abuts against the pressing block, the force sensor is arranged in the ball screw, and the spherical joint structure is arranged between the force sensor and the pressing plate, so that the response time of monitoring the braking clamping force by the force sensor is shorter and more accurate.

Description

Technical Field

[0001] The utility model relates to the field of brake calipers, in particular to a ball screw assembly with a built-in force sensor. Background Art

[0002] In existing electromechanical brake caliper assemblies employing built-in force sensors, the force sensors are broadly arranged into two configurations. The first involves placing the force sensor at the farthest end of the axial transmission path of the electromechanical caliper. The second involves placing the force sensor on the shoulder of the ball screw within the caliper body, with a flat bearing used to decouple the ball screw rotation from the force sensor. In both configurations, multiple assembly components are located between the force sensor and the brake disc. The axial clearance created during the manufacturing and assembly of these components negatively impacts the brake clamping force detection feedback in electromechanical calipers, which prioritize brake response speed. This can lead to delayed brake force detection, excessively large variations in brake force within the force sensor, and deformation of the caliper body as brake clamping force increases. The ball screw assembly tilts, causing errors in brake force detection by the force sensor attached to it. Utility Model Content

[0003] In view of the technical problems existing in the background technology, the present invention aims to provide a ball screw assembly with a built-in force sensor. By integrating the force sensor into the ball screw, the electric mechanical caliper brake clamping force can be accurately and quickly detected and fed back.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions: the ball screw assembly with a built-in force sensor includes a ball screw, a pressure ring and a sensor assembly, the ball screw includes a screw and a nut, the screw and the nut are threaded together, the screw is provided with a first inner cavity, the pressure ring is tightly fitted with the nut, the pressure ring is provided with a second inner cavity, the second inner cavity is connected with the first inner cavity, wherein the pressure ring is connected to a pressure plate through a fixing pin, the pressure plate is in contact with the friction plate, the sensor assembly is passed through the first inner cavity and the second inner cavity, the sensor assembly includes a pressure block and a force sensor, the lower part of the pressure block is correspondingly provided with a concave spherical surface, the upper part of the pressure plate is correspondingly provided with a hemispherical protrusion, the force sensor is plugged into the pressure ring, the upper surface of the force sensor abuts against the step inside the pressure ring, and the lower surface of the force sensor abuts against the pressure block.

[0005] In this solution, the first inner cavity and the second inner cavity force sensor are built-in, which is closer to the brake disc. The reduction of axial matching components results in less axial clearance, a short brake clamping feedback force path, less rigidity of each component after being subjected to force, and faster braking force clamping force detection response, making the brake clamping force obtained by the force sensor more accurate. The force sensor and the pressure ring are plugged in and matched to limit the force sensor circumferentially. The pressure plate can rotate within a certain angle around the concave spherical surface of the pressure block. As the brake clamping force of the caliper increases, the axial force applied by the ball screw can still be applied vertically to the friction plate through the pressure plate, so that the brake clamping force obtained by the brake disc is evenly distributed.

[0006] Preferably, the screw is connected with a stop ring, the stop ring is provided with a protruding stop block, the nut is provided with a zero-position stop block, and the protruding stop block cooperates with the zero-position stop block.

[0007] In this solution, the combination of the two can limit the zero position of the ball screw assembly stroke.

[0008] Preferably, the sensor assembly further comprises a PCB module, the PCB module is connected to the force sensor signal, the PCB module comprises a shell, the shell is connected with a fixing buckle, and a groove is correspondingly provided on the upper part of the pressure ring.

[0009] In this solution, the PCB module is used to receive the detection signal of the force sensor and transmit the signal to the electric mechanical caliper controller through the wiring harness.

[0010] Preferably, a sealing ring is provided between the pressure ring and the pressure block, and a sealing ring is provided between the pressure ring and the pressure plate.

[0011] In this solution, the two-stage sealing of the sealing ring and the sealing ring improves the sealing performance of the space where the force sensor is located.

[0012] The beneficial effect of this utility model is that the force sensor is built into the ball screw and a spherical joint structure is provided between the force sensor and the pressure plate, which makes the force sensor monitor the brake clamping force with faster and more accurate response time. Therefore, compared with the existing technology, this utility model has substantial characteristics and progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following describes the relevant details and working principles of the implementation methods and embodiments of the present invention in conjunction with the accompanying drawings.

[0014] Figure 1 It is a schematic diagram of the three-dimensional structure of the utility model.

[0015] Figure 2 This is an exploded view of the figure.

[0016] Figure 3 It is a cross-sectional view of the present utility model.

[0017] Figure 4 It is a schematic diagram of the three-dimensional structure of the ball screw in the utility model.

[0018] Figure 5 It is a schematic diagram of the three-dimensional structure of the medium pressure ring of the utility model.

[0019] Figure 6 for Figure 5 Schematic diagram of the three-dimensional structure from another angle.

[0020] In the figure: 1. Ball screw; 2. Screw; 3. Nut; 4. First inner cavity; 5. Pressure ring; 6. Second inner cavity; 7. Sensor assembly; 8. Pressure block; 9. Force sensor; 10. Step; 11. Stop ring; 12. Protruding stop block; 13. Zero stop block; 14. Fixing pin; 15. Pressure plate; 16. PCB module; 17. Housing; 18. Fixing buckle; 19. Groove; 20. Sealing ring; 21. Sealing ring. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the implementation of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] In the description of this application, it should be understood that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0023] In the description of this application, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0024] See attached Figure 1-6In an embodiment of the present embodiment, a ball screw assembly with a built-in force sensor includes a ball screw 1, a pressure ring 5 and a sensor assembly 7. The ball screw 1 includes a screw 2 and a nut 3. The screw 2 and the nut 3 are threaded together. The screw 2 is connected with a stop ring 11. The stop ring 11 is provided with a protruding stop block 12. The nut 3 is provided with a zero-position stop block 13. The protruding stop block 12 and the zero-position stop block 13 are matched. The screw 2 is provided with a first inner cavity 4. The pressure ring 5 is tightly fitted with the nut 3. The pressure ring 5 is provided with a second inner cavity 6, and the second inner cavity 6 is connected with the first inner cavity 4.

[0025] Among them, the pressure ring 5 is connected to a pressure plate 15 through a fixing pin 14, and the pressure plate 15 is in contact with the friction plate. A sealing ring 21 is provided between the pressure ring 5 and the pressure plate 15. The sensor assembly 7 is inserted into the first inner cavity 4 and the second inner cavity 6. The sensor assembly 7 includes a pressure block 8, a force sensor 9 and a PCB module 16. The lower part of the pressure block 8 is correspondingly provided with a concave spherical surface, and the upper part of the pressure plate 15 is correspondingly provided with a hemispherical protrusion. A sealing ring 20 is provided between the pressure ring 5 and the pressure block 8. The force sensor 9 is plugged into the pressure ring 5, and the upper surface of the force sensor 9 abuts against the step 10 on the inner side of the pressure ring 5, and the lower surface of the force sensor 9 abuts against the pressure block 8. The PCB module 16 is signal-connected to the force sensor 9. The PCB module 16 includes a shell 17, and the shell 17 is connected with a fixing buckle 18. The upper part of the pressure ring 5 is correspondingly provided with a groove 19.

[0026] In this embodiment, the brake drive motor assembly and the ball screw 1 assembly are splined and transmit torque. The screw 2 rotates to drive the nut 3 downward. Since the pressure ring 5 and the ball screw 1 nut 3 have an interference fit, the pressure ring 5 will sequentially drive the power sensor 9, the pressure block 8, and the pressure plate 15 downward until the friction plate abuts against the brake disc to generate a brake clamping force. In this process, the reaction force of the brake disc brake clamping force is fed back along the friction plate-pressure plate 15-pressure block 8-force sensor 9. The force sensor 9 transmits the monitored brake clamping force to the electric mechanical caliper controller through the wiring harness to adjust the braking force of the caliper assembly. Among them, the pressure plate 15 can swing circumferentially around the hemispherical protrusion at a certain angle to maintain a close fit with the inner friction plate to transmit the brake clamping force fed back by the inner friction plate to the force sensor 9.

[0027] The above is a preferred embodiment of the present invention. It should be noted that the scope of protection of the present invention is not limited thereto. Those skilled in the art will appreciate that improvements, modifications, or equivalent substitutions may be made without departing from the scope of the present invention and equivalent inventive concepts, and these are also considered to be within the scope of protection of the present invention.

Claims

1. A ball screw assembly with a built-in force sensor, comprising A ball screw (1) comprising a screw (2) and a nut (3), wherein the screw (2) and the nut (3) are threadably matched, and the screw (2) is provided with a first inner cavity (4); A pressure ring (5) is tightly fitted with the nut (3) through interference, and the pressure ring (5) is provided with a second inner cavity (6), and the second inner cavity (6) is connected to the first inner cavity (4); sensor assembly (7); Its characteristics are: The pressure ring (5) is connected to a pressure plate (15) via a fixing pin (14), and the pressure plate (15) is in contact with the friction plate. The sensor assembly (7) is inserted into the first inner cavity (4) and the second inner cavity (6), and the sensor assembly (7) includes The pressing block (8) has a concave spherical surface at its lower portion, and the pressing plate (15) has a hemispherical protrusion at its upper portion; A force sensor (9) is plugged into and matched with the pressure ring (5), wherein the upper surface of the force sensor (9) abuts against the step (10) on the inner side of the pressure ring (5), and the lower surface of the force sensor (9) abuts against the pressure block (8).

2. The ball screw assembly with a built-in force sensor according to claim 1, characterized in that: The screw rod (2) is connected to a stop ring (11), the stop ring (11) is provided with a protruding stop block (12), the nut (3) is provided with a zero-position stop block (13), and the protruding stop block (12) and the zero-position stop block (13) cooperate with each other.

3. The ball screw assembly with a built-in force sensor according to claim 1, characterized in that: The sensor assembly (7) further includes a PCB module (16), the PCB module (16) being connected to the force sensor (9) for signal transmission, the PCB module (16) including a housing (17), the housing (17) being connected to a fixing buckle (18), and a groove (19) correspondingly provided on the upper portion of the pressure ring (5).

4. The ball screw assembly with a built-in force sensor according to claim 1, characterized in that: A sealing ring (20) is provided between the pressure ring (5) and the pressure block (8), and a sealing ring (21) is provided between the pressure ring (5) and the pressure plate (15).

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