Anti-clamping stagnation voltage building unit, anti-clamping stagnation design method and working method

Abstract

The invention discloses an anti-clamping-stagnation pressure buildup unit, an anti-clamping-stagnation design method and a working method.The anti-clamping-stagnation pressure buildup unit comprises a motor and a ball screw assembly, the ball screw assembly comprises a screw connected with a rotor of the motor in a fastened mode and a nut matched with the screw in a threaded mode, the nut is connected with a PSU piston in a fastened mode, and the screw is connected with the PSU piston in a fastened mode; an anti-clamping component is arranged on the side, opposite to the rotor, of the nut and comprises a first protrusion arranged on the end face of the side, facing the rotor, of the nut and a second protrusion arranged on the end face of the side, facing the nut, of the rotor, and the first protrusion makes contact with the second protrusion in advance when the motor drives the nut to return through the screw. And motor locking caused by direct contact between the nut and the rotor is avoided. According to the anti-clamping stagnation voltage buildup unit, the anti-clamping stagnation design method and the working method, the protrusions are arranged on the opposite sides of the nut and the rotor, and the motor is prevented from being clamped through advanced contact of the two protrusions in the return stroke.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile braking, and in particular to an anti-sticking pressure building unit, an anti-sticking design method and a working method. Background Art

[0002] The EHB (Electro-Hydraulic Brake) is a braking system that integrates electronic control technology with hydraulic actuators. It is widely used in modern automobiles, playing a particularly key role in new energy vehicles and smart cars. The system's core advantage lies in its extremely fast braking response: the transmission speed of electronic signals significantly outperforms traditional mechanical or hydraulic transmission methods, reducing the response delay from the driver pressing the brake pedal to the system outputting braking force to less than 100 milliseconds, compared to the typical 200-300 millisecond response delay of traditional braking systems. This feature effectively shortens stopping distances in emergency braking scenarios, significantly improving driving safety.

[0003] The core component of the EHB system is the Pressure Supply Unit (PSU), which primarily consists of a ball screw, motor, and PSU piston. The unit operates as follows: When the motor rotates, the ball screw converts the rotational motion into an axial driving force, thereby building and reducing pressure in the braking system. During pressure buildup, the driving force pushes the PSU piston in a specific direction to build brake pressure. During pressure reduction, the driving force reverses direction, resetting the relevant components and releasing pressure.

[0004] However, when the system completes pressure buildup and enters the pressure reduction process, the ball screw nut, driven by the motor, returns. During this process, the rear end of the nut easily contacts the bottom surface of the motor rotor, generating friction. This friction generates a tightening torque. When this tightening torque exceeds the maximum operating torque of the motor, it can cause the motor to jam during subsequent pressure buildup (during pressure buildup, the motor rotates in the reverse direction. At this time, because the tightening torque exceeds the maximum operating torque of the motor, the motor cannot overcome the tightening torque, causing the motor to jam). This can cause the electronic hydraulic braking system to malfunction, and in serious cases, can lead to traffic safety accidents. Summary of the Invention

[0005] The purpose of the present invention is to provide an anti-stuck pressure building unit, an anti-stuck design method and a working method to solve the above technical problems.

[0006] To achieve the above-mentioned objectives, the present invention provides an anti-jamming pressure-building unit, comprising a motor and a ball screw assembly connected to the power output end of the motor, the ball screw assembly comprising a screw rod fastened to the rotor of the motor and a nut mated with the screw thread, the nut being fastened to the PSU piston, an anti-jamming assembly being provided on the opposite side of the nut and the rotor, the anti-jamming assembly comprising a first protrusion respectively provided on the end face of the nut facing the rotor and a second protrusion provided on the end face of the rotor facing the nut, for making the first protrusion contact the second protrusion in advance when the motor drives the nut back via the screw rod, so as to avoid jamming of the motor due to direct contact between the nut and the rotor.

[0007] Preferably, the first protrusion and the nut are integrally formed and made of the same material; The second protrusion is formed integrally with the rotor and is made of the same material.

[0008] An anti-stuck design method for an anti-stuck pressure building unit includes the following steps: S1. Define the circumferential angle reference: take the end of the thread on the nut as the circumferential 0° reference line, and set the angle of the first protrusion to At the same time, take the starting point of the screw thread as the circumferential 0° reference and set the angle of the second protrusion to ; S2. Obtain the following key parameters: lead of the ball screw assembly and the effective thread length of the ball screw assembly ; S3. Split the relative rotation number of the screw and nut into integer parts and decimal part : ; Where, Indicates rounding operation; Then we can get the circumferential rotation deviation ; S4. Calculate the total phase angle of the second protrusion relative to the starting edge of the screw thread : ; S5. Calculate the first bulge angle between intervals : ; S6. According to the angle and angles The first protrusion and the second protrusion are integrally machined on the rotor and the nut respectively.

[0009] A method for operating an anti-seizure pressure-building unit includes pressure-building and return strokes. During pressure-building, a motor drives the rotor to rotate in the forward direction, thereby driving the screw to rotate. At this time, under the action of the screw and nut, the nut moves along the axial direction of the screw, thereby driving the PSU piston to extend, compressing the brake fluid to build pressure. During the return stroke, the motor drives the rotor to rotate in the opposite direction, which in turn drives the screw to rotate in the opposite direction, thereby driving the nut and PSU piston to move in the opposite direction, releasing the braking pressure until the first protrusion on the nut and the second protrusion on the rotor are in rigid contact, preventing the nut from moving further. At this time, a safety gap is left between the first protrusion and the rotor, and between the second protrusion and the nut, waiting for the next pressure buildup.

[0010] Therefore, the present invention adopts the above-mentioned anti-stuck pressure building unit, anti-stuck design method and working method, which has the following beneficial effects: 1. Effectively solve the jamming problem: By adding integrated protrusions to the bottom of the motor rotor and the rear end of the ball screw nut, the two are brought into contact in advance during the nut return stroke, avoiding direct friction between the rear end of the nut and the bottom of the motor rotor to generate tightening torque, thus preventing motor jamming, ensuring the normal operation of the EHB system, and improving driving safety. 2. Strong product compatibility: The original overall structure and assembly logic of the pressure-building unit remain unchanged, making it adaptable to existing systems without requiring major adjustments to other components. 3. Small size and high strength: The protrusion is integrally formed with the motor rotor and nut, which does not increase the structural volume while ensuring the overall structural strength; 4. Low processing difficulty and low cost: The protrusions can be processed simultaneously with the original parts without complicated processes, which reduces processing difficulty and production costs.

[0011] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A cross-sectional view of an anti-stuck pressure-building unit according to the present invention; Figure 2 A schematic diagram of a return stroke of an anti-stuck pressure-building unit according to the present invention; Figure 3 An axial cross-sectional view of a first protrusion and a second protrusion of an anti-stuck pressure-building unit of the present invention when the return stroke is in place; Figure 4 A radial cross-sectional view of a first protrusion and a second protrusion of an anti-stuck pressure-building unit of the present invention when the return stroke is in place; Figure 5 This is a schematic diagram of the nut structure of an anti-seizing pressure-building unit of the present invention; Figure 6 This is a schematic diagram of the rotor structure of an anti-stuck pressure-building unit of the present invention; Figure 7 This is a schematic diagram of the first protrusion angle setting of an anti-stuck pressure-building unit of the present invention; Figure 8 This is a schematic diagram of the second protrusion angle setting of an anti-stuck pressure building unit of the present invention.

[0013] Reference numerals

[0014] 1. Motor; 11. Rotor; 111. Second protrusion; 2. Ball screw assembly; 21. Screw; 22. Nut; 221. First protrusion; 3. PSU piston. DETAILED DESCRIPTION

[0015] In order to make the purposes, technical solutions and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. 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 this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions.

[0016] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or devices.

[0017] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0018] like Figures 1-8As shown, an anti-jamming pressure building unit includes a motor 1 and a ball screw assembly 2 connected to the power output end of the motor 1, the ball screw assembly 2 includes a screw 21 fastened to the rotor 11 of the motor 1 and a nut 22 threadedly matched with the screw 21, the nut 22 is fastened to the PSU piston 3, and an anti-jamming component is provided on the opposite side of the nut 22 and the rotor 11, the anti-jamming component includes a first protrusion 221 respectively provided on the end surface of the nut 22 facing the rotor 11 and a second protrusion 111 provided on the end surface of the rotor 11 facing the nut 22, which is used to make the first protrusion 221 contact with the second protrusion 111 in advance when the motor 1 drives the nut 22 back through the screw 21 (the side of the first protrusion 221 contacts the side of the second protrusion 111 to prevent the nut 22 from continuing to move), thereby avoiding the motor 1 from being stuck due to direct contact between the nut 22 and the rotor 11. The first protrusion 221 is integrally formed with the nut 22 and made of the same material. The second protrusion 111 is integrally formed with the rotor 11 and made of the same material. In this embodiment, the screw rod 21 and the rotor 11 are fastened together by screws.

[0019] An anti-stuck design method for an anti-stuck pressure building unit includes the following steps: S1. Define the circumferential angle reference: Take the thread end on the nut 22 as the circumferential 0° reference line, and set the angle of the first protrusion 221 to , that is, the circumferential angle of the first protrusion relative to the starting point of the nut thread is At the same time, the starting point of the thread on the screw 21 is used as the circumferential 0° reference, and the angle of the second protrusion 111 is set to , that is, the circumferential angle of the second protrusion relative to the starting point of the screw thread is ; S2. Obtain the following key parameters: lead of ball screw assembly 2 and the effective thread length of the ball screw assembly 2 ; S3, split the relative rotation number of the screw 21 and the nut 22 into integer parts and decimal part : ; Where, Indicates rounding operation; Then we can get the circumferential rotation deviation ; S4. Calculate the total phase angle of the second protrusion 111 relative to the starting edge of the thread of the screw 21. : ; S5. Calculate the angle of the first protrusion 221 by interval : ; S6. According to the angle and angles The first protrusion 221 and the second protrusion 111 are integrally machined on the rotor 11 and the nut 22 respectively.

[0020] A method for operating an anti-seizure pressure-building unit includes pressure-building and return strokes. During pressure-building, the motor 1 drives the rotor 11 to rotate in the forward direction, thereby driving the screw 21 to rotate. At this time, under the action of the screw 21 and the nut 22, the nut 22 is driven to move axially along the screw 21, thereby driving the PSU piston 3 to extend, compressing the brake fluid to build pressure; During the return stroke, the motor 1 drives the rotor 11 to rotate in the opposite direction, thereby driving the screw 21 to rotate in the opposite direction, thereby driving the nut 22 and the PSU piston 3 to move in the opposite direction, releasing the braking pressure until the first protrusion 221 on the nut 22 and the second protrusion 111 on the rotor 11 are in rigid contact, preventing the nut 22 from moving further. At this time, a safety gap is left between the first protrusion 221 and the rotor 11, and between the second protrusion 111 and the nut 22, waiting for the next pressure buildup.

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An anti-seizure pressure-building unit, comprising a motor and a ball screw assembly connected to the power output of the motor, the ball screw assembly comprising a screw fastened to the motor's rotor and a nut threadedly engaged with the screw, the nut fastened to the PSU piston, characterized in that: An anti-jamming component is provided on the opposite side of the nut and the rotor. The anti-jamming component includes a first protrusion provided on the end face of the nut facing the rotor and a second protrusion provided on the end face of the rotor facing the nut. The anti-jamming component is used to make the first protrusion and the second protrusion contact in advance when the motor drives the nut back through the screw, so as to avoid the motor being stuck due to direct contact between the nut and the rotor.

2. The anti-stuck pressure building unit according to claim 1, characterized in that: The first protrusion and the nut are integrally formed and made of the same material; The second protrusion is formed integrally with the rotor and is made of the same material.

3. The anti-stuck design method of the anti-stuck pressure building unit according to claim 1 or 2, characterized in that: The following steps are involved: S1. Define the circumferential angle reference: take the end of the thread on the nut as the circumferential 0° reference line, and set the angle of the first protrusion to At the same time, take the starting point of the screw thread as the circumferential 0° reference and set the angle of the second protrusion to ; S2. Obtain the following key parameters: lead of the ball screw assembly and the effective thread length of the ball screw assembly ; S3. Split the relative rotation number of the screw and nut into integer parts and decimal part : ； Where, Indicates rounding operation; Then we can get the circumferential rotation deviation ; S4. Calculate the total phase angle of the second protrusion relative to the starting edge of the screw thread : ； S5. Calculate the first bulge angle between intervals : ； S6. According to the angle and angles The first protrusion and the second protrusion are integrally machined on the rotor and the nut respectively.

4. A method for operating an anti-stuck pressure-building unit according to claim 1 or 2, characterized in that: It includes pressure building and return stroke. During pressure building, the motor drives the rotor to rotate in the forward direction, which in turn drives the screw to rotate. At this time, under the action of the screw and nut, the nut moves along the axial direction of the screw, thereby driving the PSU piston to extend and compress the brake fluid to build pressure; During the return stroke, the motor drives the rotor to rotate in the opposite direction, which in turn drives the screw to rotate in the opposite direction, thereby driving the nut and PSU piston to move in the opposite direction, releasing the braking pressure until the first protrusion on the nut and the second protrusion on the rotor are in rigid contact, preventing the nut from moving further. At this time, a safety gap is left between the first protrusion and the rotor, and between the second protrusion and the nut, waiting for the next pressure buildup.

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