Electronic mechanical brake caliper

Abstract

The invention discloses an electronic mechanical brake caliper which comprises a shell, a friction plate and a ball screw assembly installed on the shell, the ball screw assembly comprises a lead screw, a nut embedded in the lead screw and balls arranged in a roller path between the lead screw and the nut, the nut comprises a roller path section and a free section, the roller path section is matched with the balls, and the free section is matched with the friction plate. The aperture of the free section is larger than the outer diameter of the lead screw so that the second end of the lead screw can move in the free section, the second end of the free section makes contact with the friction plate and pushes the friction plate to clamp the brake disc, and the second end of the free section is closer to the friction piece than the second end of the lead screw. According to the invention, the number of parts is reduced, the ball screw assembly is miniaturized, and the cost is reduced.

Description

[Technical field]

[0001] The invention belongs to the field of vehicle technology, and in particular relates to vehicle braking technology. [Background technology]

[0002] like Figure 5 As shown, the Chinese patent publication with application number CN202323151314.5 discloses an electronic mechanical brake structure, which includes a bracket subassembly, a caliper subassembly, and an MCU subassembly. In the three-dimensional coordinate system formed by X, Y, and Z, the friction plate is arranged horizontally and can slide up and down along the Z axis direction on the bracket subassembly. The caliper subassembly includes a moving housing extending along the Z axis direction and located above the friction plate, and a power group for driving the moving housing to drive the friction plate to move up and down along the Z axis direction to clamp the brake disc of the car. The moving housing is a piston, and the power group is a ball screw component, wherein the piston movement direction is the same as the driving direction of the ball screw component, and is arranged vertically with the friction plate. The working mode of the ball screw is: the screw makes a rotational motion, the screw nut makes a linear motion, the screw nut 21 pushes the piston 20 downward, and the piston pushes the upper friction plate m1 downward. This technical solution has a relatively large number of parts, making it difficult to miniaturize the ball screw assembly. [Summary of the invention]

[0003] In order to overcome the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide an electronic mechanical brake caliper without the piston in the prior art, and to achieve the same force transmission effect through a simpler structure.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] An electronic mechanical brake caliper comprises a housing, a friction plate and a ball screw assembly mounted on the housing, wherein the ball screw assembly comprises a screw, a nut nested in the screw, and balls arranged in a raceway between the screw and the nut, wherein the nut comprises a raceway section and a free section, wherein the raceway section cooperates with the balls, the aperture of the free section is larger than the outer diameter of the screw so that the second end of the screw can move in the free section, the second end of the free section contacts the friction plate, pushes the friction plate to clamp the brake disc, and the second end of the free section is closer to the friction member than the second end of the screw.

[0006] Preferably, a locking plate is installed on the first end of the outer raceway section of the lead screw, and a locking point is correspondingly provided on the nut. When the locking plate contacts the locking point, the nut is limited to an extreme position of movement toward the first end.

[0007] Preferably, the inner hole of the second end of the nut is provided with a first axial positioning step, and a first gasket is installed on the first axial positioning step.

[0008] Preferably, the housing is provided with a receiving cavity, the ball screw assembly is installed in the receiving cavity, an axial groove is opened on the outer circle of the nut, the receiving cavity is connected with a limit screw, and the limit screw is embedded in the axial groove.

[0009] Preferably, the lead screw comprises a transmission section located at a first axial side and an outer raceway section located at a second axial side, and a diameter of the outer raceway section is larger than a diameter of the transmission section.

[0010] Preferably, a transmission connection structure is provided at the end of the transmission section.

[0011] Preferably, a thrust bearing is provided between the first end of the outer raceway section and the accommodating cavity.

[0012] Preferably, a pressure sensor is installed on the transmission section, and the thrust bearing is arranged between the pressure sensor and the first end of the outer raceway section.

[0013] Preferably, the accommodating cavity is connected to a locking screw, and the locking screw is embedded in the groove of the pressure sensor to limit the circumferential movement of the pressure sensor.

[0014] Preferably, a vibration-damping rubber ring is provided between the second end of the nut and the accommodating cavity.

[0015] The technical solution adopted by the present invention has the following beneficial effects:

[0016] The present invention eliminates the need for a piston, wherein the nut includes a raceway section and a free section, the raceway section cooperates with the ball, the aperture of the free section is larger than the outer diameter of the lead screw, so that the second end of the lead screw can move in the free section, the second end of the free section contacts the friction plate, pushing the friction plate to clamp the brake disc, and the second end of the free section is closer to the friction part than the second end of the lead screw, thereby achieving the same force transmission effect as the prior art through a simpler structure.

[0017] The prior art piston needs to have a certain length of overlapping installation space with the lead screw in the axial direction. After eliminating the piston, a shorter lead screw (i.e., the length of the outer raceway section) can be used, and the nut length can remain unchanged or be appropriately lengthened. However, since the nut includes a raceway section and a free section, the raceway section has a high machining accuracy requirement, and the raceway section length only needs to meet the motion stroke, and the free section does not have a high machining accuracy requirement. Therefore, the present invention reduces the number of parts, miniaturizes the ball screw assembly, and reduces costs.

[0018] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings.

Brief Description of the Drawings

[0019] The invention will be further described below in conjunction with the accompanying drawings:

[0020] Figure 1 It is a structural schematic diagram of an electronic mechanical brake caliper in an embodiment of the present invention when the actuator unit is in a released position;

[0021] Figure 2 It is a structural schematic diagram of an electronic mechanical brake caliper in an embodiment of the present invention when the actuator unit is in a clamping position;

[0022] Figure 3 It is a schematic diagram of a partially enlarged structure of an electronic mechanical brake caliper in an embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the appearance of a ball screw assembly in an embodiment of the present invention;

[0024] Figure 5 It is a structural schematic diagram of a brake in the prior art;

[0025] Figure markings: housing 1, bridging member 11, accommodating chamber 12, third axial positioning step 121, limit screw 122, limit screw 13, vibration-damping rubber ring 14, moving mechanism 2, piston 20, screw nut 21, thrust bearing 22, screw 23, outer raceway section 231, transmission section 232, transmission connection structure 233, second axial positioning step 234, second gasket 235, copper sleeve 236, shaft retaining ring 237, nut 25, free section 251, raceway section 252, first axial positioning step 253, axial groove 254, first gasket 26, pressure sensor 27, locking plate 28, locking point 29, friction plate 3, brake disc 4. [Specific implementation method]

[0026] The technical solutions of the embodiments of the present invention are explained and described below in conjunction with the drawings of the embodiments of the present invention, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the present invention.

[0027] The embodiment of the present invention provides an electromechanical brake, including an actuator unit and a caliper. The actuator unit includes a motor and a gear transmission mechanism, the actuator unit outputs a rotational motion to the caliper, the rotation-linear motion mechanism of the caliper converts the rotational motion into a linear motion, pushes the friction plate to move, and the friction plate moves toward the brake disc fixed to the wheel hub and then clamps, so as to achieve deceleration and braking of the wheel.

[0028] like Figures 1 to 4As shown, an electronic mechanical brake caliper includes a housing 1, a friction plate 3, and a moving mechanism 2 installed on the housing. The housing 1 is a component for installing the brake and the vehicle steering knuckle. The housing 1 is axially slidably installed on the caliper bracket. The housing 1 is used to accommodate the moving mechanism and the friction member. One end of the housing is a bridge member 11, which is suspended across the two ends of the brake disc. The bridge member 11 is equipped with two friction plates 3 at the two ends of the brake disc 4. The other end of the housing is a receiving chamber 12, and the moving mechanism 2 is installed in the receiving chamber 12.

[0029] The motion mechanism 2 includes a ball screw assembly, the structure of which is based on the prior art, including a screw 23, a nut 25 embedded in the screw, balls arranged in the raceway between the screw 23 and the nut 25, and a rotation limiting mechanism. The screw is connected to the actuator to be driven by the actuator; the outer circle of the screw is provided with a spiral raceway, and the outer circle of the screw cooperates with the nut which is also provided with a spiral raceway. Balls are arranged between the raceways of the two and are embedded in the accommodating cavity in the form of a rotating thread groove. In addition, an axial groove 254 is provided on the outer circle of the nut 25, and the accommodating cavity 12 is connected to a limit screw 13, and the limit screw 13 is embedded in the axial groove 254 to form a rotation limiting mechanism to achieve the effect of limiting rotation.

[0030] Compared with the prior art, the nut 25 includes a raceway section 252 and a free section 251, wherein the raceway section 252 cooperates with the ball, and the aperture of the free section 251 is larger than the outer diameter of the screw 23, so that the second end of the screw can move in the free section, and the second end of the free section 251 contacts the friction plate 3, and the friction plate 3 is pushed by the free section 251 to clamp the brake disc, and the second end of the free section is closer to the friction part than the second end of the screw.

[0031] Furthermore, in order to reduce the difficulty of processing, the nut is designed as a through-hole structure. At the same time, in order to prevent foreign matter from entering the interior of the nut, the second end inner hole of the nut is provided with a first axial positioning step 253 , on which a first gasket 26 is installed.

[0032] Further, such as Figure 4 As shown, a locking plate 28 is installed on the first end of the outer raceway section of the screw, and a locking point 29 is correspondingly provided on the nut. When the locking plate 28 contacts the locking point 29, the nut 25 is limited to move to the extreme position of the first end.

[0033] The lead screw 23 is driven to rotate by the actuator. When the electronic mechanical brake has a braking demand, the lead screw 23 is driven to rotate in the direction of brake clamping. When the lead screw rotates, its spiral raceway generates a positive axial driving force on the spiral raceway of the nut, so that the nut 25 moves in the direction close to the brake disc, that is, the lead screw and the nut move in the opposite direction, and at the same time push the friction member 3 until it contacts and clamps the brake disc 4; when the electronic mechanical brake releases the braking demand, the lead screw 23 is driven to rotate in the direction of loosening. When the lead screw 23 rotates, its spiral raceway generates a reverse axial driving force on the spiral raceway of the nut, so that the nut 25 moves in the direction away from the brake disc, that is, the lead screw and the nut move towards each other, and the friction plate 3 is loosened and away from the brake disc 4 under the action of the return spring force.

[0034] like Figure 1 and Figure 2 As shown, when the brake is released, the actuator drives the lead screw 23 to rotate in the forward direction, so that the nut 25 moves downward until the locking plate 28 on the lead screw abuts against the locking point 29 on the nut. When the brake is clamped, the actuator drives the lead screw 23 to rotate in the reverse direction, so that the nut 25 moves upward and stops when the required maximum brake clamping force is reached. At this time, in order to prevent the ball from falling out, the height of the top of the lead screw is designed to exceed the height of the nut raceway section 252. In addition, some nuts 25 are provided with a ball returner (not shown), and the area between the two ends of the returner can be considered as the raceway section. Similarly, the height of the top of the lead screw exceeds the height of the returner.

[0035] In addition, the lead screw 23 includes a transmission section 232 located at the first axial side and an outer raceway section 231 located at the second axial side, and the diameter of the outer raceway section 231 is larger than the diameter of the transmission section 232. The length (effective length H2) of the outer raceway section 231 is smaller than the length (effective length H1) of the nut 25. A transmission connection structure 233, such as a spline hole, is provided at the end of the transmission section 232 for connection with the output shaft of the actuator.

[0036] Furthermore, a thrust bearing 22 is provided between the first end of the outer raceway section 231 and the accommodating chamber 12. A pressure sensor 27 is mounted on the transmission section 232, and the thrust bearing 22 is provided between the pressure sensor 27 and the first end of the outer raceway section 231. The accommodating chamber 12 is provided with a third axial positioning step 121 for positioning the first end of the pressure sensor, and at the same time, the accommodating chamber 12 is connected with a limit screw 122 which is screwed in from the radial direction and circumferentially limits the second end of the pressure sensor. The locking screw is embedded in the groove of the pressure sensor to limit the circumferential movement of the pressure sensor.

[0037] Furthermore, a second axial positioning step 234 is provided at the first end of the outer raceway section 231, a second gasket 235 is installed on the second axial positioning step 234, and the second gasket 235 is connected to the second end of the thrust bearing. A copper sleeve 236 is provided between the transmission section 232 and the inner hole of the accommodating cavity, and the transmission section 232 is provided with a shaft retaining ring 237, and the shaft retaining ring 237 is matched with the end surface of the first end of the accommodating cavity.

[0038] Furthermore, the accommodating chamber 12 is provided with an annular groove for installing a vibration-damping rubber ring 14 . The vibration-damping rubber ring 14 is used to prevent the nut 25 from colliding with the accommodating chamber 12 when the caliper is working, thereby improving working stability.

[0039] The embodiment of the present invention eliminates the need for a piston, wherein the nut includes a raceway section and a free section, the raceway section cooperates with the ball, the aperture of the free section is larger than the outer diameter of the screw, so that the second end of the screw can move in the free section, the second end of the free section contacts the friction plate, pushing the friction plate to clamp the brake disc, and the second end of the free section is closer to the friction part than the second end of the screw, thereby achieving the same force transmission effect as the prior art through a simpler structure.

[0040] The prior art piston needs to have a certain length of overlapping installation space with the lead screw in the axial direction. After eliminating the piston, a shorter lead screw (i.e., the length of the outer raceway section) can be used, and the nut length can remain unchanged or be appropriately lengthened. However, since the nut includes a raceway section and a free section, the raceway section has a high machining accuracy requirement, and the raceway section length only needs to meet the motion stroke, and the free section does not have a high machining accuracy requirement. Therefore, the present invention reduces the number of parts, miniaturizes the ball screw assembly, and reduces costs.

[0041] The above is only a specific embodiment of the invention, but the protection scope of the invention is not limited thereto. Those skilled in the art should understand that the invention includes but is not limited to the contents described in the drawings and the above specific embodiments. Any modification that does not deviate from the functional and structural principles of the invention will be included in the scope of the claims.

Claims

1. An electronic mechanical brake caliper, comprising a housing, a friction plate and a ball screw assembly mounted on the housing, wherein the ball screw assembly comprises a screw, a nut nested in the screw, and a ball disposed in a raceway between the screw and the nut, wherein: The nut includes a raceway section and a free section, wherein the raceway section cooperates with the ball, the aperture of the free section is larger than the outer diameter of the screw, so that the second end of the screw can move in the free section, the second end of the free section contacts the friction plate, pushing the friction plate to clamp the brake disc, and the second end of the free section is closer to the friction part than the second end of the screw.

2. An electromechanical brake caliper according to claim 1, characterized in that: A locking plate is installed at the first end of the outer raceway section of the lead screw, and a locking point is correspondingly arranged on the nut. When the locking plate contacts the locking point, the nut is limited to move to the extreme position of the first end.

3. The electromechanical brake caliper according to claim 1, characterized in that: The inner hole of the second end of the nut is provided with a first axial positioning step, and a first gasket is installed on the first axial positioning step.

4. The electromechanical brake caliper according to claim 1, characterized in that: The housing is provided with a receiving cavity, the ball screw assembly is installed in the receiving cavity, an axial groove is opened on the outer circle of the nut, the receiving cavity is connected with a limit screw, and the limit screw is embedded in the axial groove.

5. The electromechanical brake caliper according to claim 4, characterized in that: The lead screw comprises a transmission section located at a first axial side and an outer raceway section located at a second axial side, wherein a diameter of the outer raceway section is greater than a diameter of the transmission section.

6. An electromechanical brake caliper according to claim 5, characterized in that: A transmission connection structure is provided at the end of the transmission section.

7. The electromechanical brake caliper according to claim 5, characterized in that: A thrust bearing is provided between the first end of the outer raceway section and the accommodating cavity.

8. An electromechanical brake caliper according to claim 7, characterized in that: A pressure sensor is installed on the transmission section, and the thrust bearing is arranged between the pressure sensor and the first end of the outer raceway section.

9. The electromechanical brake caliper according to claim 8, characterized in that: The accommodating cavity is connected with a locking screw, and the locking screw is embedded in the groove of the pressure sensor to limit the circumferential movement of the pressure sensor.

10. The electromechanical brake caliper according to claim 4, characterized in that: A vibration-damping rubber ring is arranged between the second end of the nut and the accommodating cavity.

Images