An automatic straightening device for lead screw and nut engagement

Abstract

This invention relates to an automatic straightening device for the engagement of a lead screw and nut. It belongs to the field of assembly and testing of automotive brake-by-wire systems. The device includes a main bed, electrical control box, shaft, power cylinder one, passive pre-elevation device, lead screw, rotary clamping device, nut, displacement sensor, active pre-elevation device, cylinder assembly, guide rail one, tilting cylinder, bottom platform, moving platform, front and rear moving platforms, fixed platform, guide rail two, connecting rod one, connecting rod two, drive motor one, power cylinder two, support arm one, support arm two, buffer device, and drive motor two. Its advantages include a novel structure, providing a highly efficient, high-precision, and reliable installation process, solving the problems of poor position recognition accuracy, low assembly efficiency, high susceptibility to human factors, and high error risk in current systems.

Description

Technical Field

[0001] This invention belongs to the field of assembly and testing of automotive brake-by-wire systems, and particularly relates to an automatic correction device for the fit between a lead screw and a nut. Background Technology

[0002] Braking-by-wire systems, as a major market trend, have gained widespread recognition for their advantages such as high integration and rapid response. The system composition is relatively complex, with diverse structural forms. The most mainstream structure uses a hollow motor paired with a ball screw as the pressure-building power source. The rotation of the motor pushes a nut on the ball screw forward, which in turn pushes a piston to build pressure and achieve the braking function. The installation position of the ball screw component, as a crucial core component, is particularly important during its assembly with the hollow motor; the accuracy of the assembly position is closely related to the control of the motor's motion.

[0003] Traditional assembly methods involve manually assembling and adjusting the relative positions of nuts and lead screws before installing subsequent components. This method suffers from poor position recognition accuracy, low assembly efficiency, high susceptibility to human factors, and a high risk of errors. Summary of the Invention

[0004] This invention provides an automatic correction device for the engagement of a lead screw and nut, in order to solve the problems of poor position recognition accuracy, low assembly efficiency, high susceptibility to human factors, and high risk of error in current systems.

[0005] The technical solution adopted in this invention includes a main bed, an electrical control box, a shaft, a power cylinder, a passive pre-jacking device, a lead screw, a rotary clamping device, a nut, a displacement sensor, an active pre-jacking device, a cylinder assembly, a guide rail, a tilting cylinder, a bottom platform, a moving platform, a forward and backward moving platform, a fixed platform, a guide rail, a connecting rod, a connecting rod, a drive motor, a power cylinder, a support arm, a support arm, a buffer device, and a drive motor. The electrical control box is connected to the side of the main bed. The main bed supports a fixed platform and a moving platform that can rotate around the shaft. The guide rail, which serves as a guide, is installed on the fixed platform. The active pre-jacking device is slidably connected to the guide rail. The cylinder assembly that drives the active pre-jacking device is fixedly connected to the fixed platform. A displacement sensor for determining the position of the nut is provided in front of the active pre-jacking device. The passive pre-jacking device and the guide rail are fixedly connected to the moving platform. The bottom of the front and rear moving platforms is slidably connected to guide rail two. The rotary clamping device is installed on the front and rear moving platforms and moves forward and backward by being guided by guide rail two. The rotary clamping device, active pre-jacking device, and passive pre-jacking device are arranged on the same axis. Power cylinder one and power cylinder two arranged on both sides of the rotary clamping device are fixedly connected to the front and rear moving platforms. Power cylinder one and power cylinder two are respectively connected to the outer ring of the rotary clamping device through connecting rod one and connecting rod two. Drive motor one is installed on the moving platform as a whole through the bracket of the passive pre-jacking device. Drive motor two is fixedly connected to the front and rear moving platforms, and its shaft output shaft is connected to the positioning block of the rotary clamping device. The bottom platform is fixedly connected inside the main body bed. The tilting cylinder is installed on the bottom platform. The lower ends of support arm one and support arm two are connected to the tilting cylinder, and the upper ends are hinged to the bottom of the moving platform. The buffer device is installed below the fixed platform.

[0006] The passive pre-jacking device of the present invention includes gears, bearings, a push rod, a pre-pressure block, a bracket, and a housing. The push rod is arranged on the shaft of the passive pre-jacking device. The front end of the push rod is provided with a wear-resistant and non-metallic pre-pressure block. The rear end of the push rod is mounted inside the housing by a bearing. The gear arranged around the push rod is connected to a drive motor to achieve rotation. The housing and the drive motor are mounted as a whole on a moving platform through the bracket.

[0007] The rotary clamping device of the present invention includes an outer ring, an inner ring, clamping blocks, positioning blocks, steel balls, screws, reserved holes, a support frame, a support spring, rollers, reserved slots, track one, and track two. The outer ring consists of two symmetrical parts, which are fastened after being installed by connecting screws. The outer ring contains a rotating inner ring. Cylindrical reserved holes are evenly arranged on the inner ring to provide guidance for the support frame. The cylindrical end of the support frame passes through a pressure spring and then into the reserved hole. Rollers are installed on the upper end of the support frame to reduce the friction during the clamping process. The rollers, support frame, and support spring act together on the three clamping blocks through the reserved slots on the positioning blocks to push the three clamping blocks to move towards the axis and clamp the nut. The steel ball is arranged in the reserved hole inside track one of the inner ring. Track one of the inner ring has a symmetrical structure and connects with track two on the outer ring to provide a movement space track for the steel ball.

[0008] The active pre-jacking device of the present invention includes a top core, rolling bearings, a second outer shell, and a support platform. The second outer shell is rigidly connected to the support platform, and the support platform is slidably connected to a guide rail. Two rolling bearings are arranged inside the second outer shell, and the top core passes through the rolling bearings and is firmly embedded in the second outer shell. The front end of the second outer shell has a limiting boss, and a displacement sensor passes through a pre-drilled hole at the front end of the second outer shell. The front end of the displacement sensor is aligned with the front end face of the second outer shell, and the sensor is fixed by screwing in a top screw.

[0009] The buffer device of the present invention includes a reinforcing screw, a buffer, and a connecting block. The connecting block is fixedly connected to the fixed platform. The buffer and the reinforcing screw are arranged sequentially at the front end. The reinforcing screw is screwed into the threaded hole reserved in the fixed platform for reinforcement. The buffer device is arranged below the fixed platform to absorb the impact generated by the moving platform returning to its original position.

[0010] The advantages of this invention are its novel structure. The main bed supports the entire device, and the rotary clamping device can clamp the nut by means of clamping cylinders arranged on the left and right, rotating around the central axis. The active and passive pre-elevation devices work together to limit and fix the lead screw. The active pre-elevation device is installed separately on the fixed platform, while the passive pre-elevation device and the rotary clamping device are jointly installed on the moving platform, which can rotate around the fixed axis. The passive pre-elevation device includes a drive motor that rotates the lead screw, which is arranged laterally on the side. After the position is corrected, the rotating moving platform rotates 90 degrees upwards to await installation by means of a tilting cylinder arranged below and a rotating axis on the main bed. This invention can provide a highly efficient, high-precision, and reliable installation process, solving the problems of poor position recognition accuracy, low assembly efficiency, large influence of human factors, and high risk of error in current installations. Attached Figure Description

[0011] Figure 1 This is an axial view of the present invention;

[0012] Figure 2 This is a top view of the present invention;

[0013] Figure 3 This is a front view of the present invention;

[0014] Figure 4 This is an enlarged axial section view of the passive pre-cushioning device 5 of the present invention;

[0015] Figure 5 This is an axial section enlarged view of the active pre-top device 10 of the present invention;

[0016] Figure 6 This is an exploded axial view of the rotary clamping device 7 of the present invention;

[0017] Figure 7 This is the present invention. Figure 1 A magnified view of position A in the middle;

[0018] Figure 8 This is a CC cross-sectional view of the buffer device 25 of the present invention;

[0019] Figure 9 This is the present invention. Figure 2 A magnified view along the F-axis at the center position. Detailed Implementation

[0020] like Figure 1 , Figure 2 and Figure 3As shown, the system includes the main bed 1, electrical control box 2, shaft 3, power cylinder 1 4, passive pre-jacking device 5, lead screw 6, rotary clamping device 7, nut 8, displacement sensor 9, active pre-jacking device 10, cylinder device 11, guide rail 12, tilting cylinder 13, bottom platform 14, moving platform 15, forward and backward moving platform 16, fixed platform 17, guide rail 2 18, connecting rod 19, connecting rod 20, drive motor 1 21, power cylinder 2 22, support arm 1 23, support arm 2 24, buffer device 25, and drive motor 2 26. An electrical control box 2 is connected to the side of the main bed 1. The main bed 1 supports a fixed platform 17 and a movable platform 15 that can rotate around an axis 3. A guide rail 12, which serves as a guide, is mounted on the fixed platform 17. An active pre-jacking device 10 is slidably connected to the guide rail 12. A cylinder device 11 that drives the active pre-jacking device 10 is fixedly connected to the fixed platform 17. A displacement sensor 9 for determining the position of the nut is located in front of the active pre-jacking device 10. A passive pre-jacking device 5 and a guide rail 18 are fixedly connected to the movable platform 15. The bottom of the front-to-back moving platform 16 is connected to the guide rail 18. The rotary clamping device 7 is mounted on the front and rear moving platform 16 and moves forward and backward by means of the guide rail 18. The rotary clamping device 7, the active pre-jacking device 10, and the passive pre-jacking device 5 are arranged on the same axis U. The power cylinders 4 and 22 arranged on both sides of the rotary clamping device 7 are fixedly connected to the front and rear moving platform 16. The power cylinders 4 and 22 are respectively connected to the outer ring 7-1 of the rotary clamping device 7 through the connecting rod 19 and the connecting rod 20. The drive motor 21 is driven by the passive pre-jacking device. The bracket h of device 5 is installed on the moving platform 15 to adjust the relative position of the nut and the lead screw. The drive motor 26 is fixedly connected to the front and rear moving platform 16 and its shaft is connected to the positioning block 7-4 of the rotating clamping device 7. Its function is to check the relative position of the nut and the lead screw. The bottom platform 14 is fixedly connected inside the main bed 1. The tilting cylinder 13 is installed on the bottom platform 14. The lower ends of the support arm 1 23 and the support arm 2 24 are connected to the tilting cylinder 13, and the upper ends are hinged to the bottom of the moving platform 15. The buffer device 25 is installed under the fixed platform 17.

[0021] like Figure 4 As shown, the passive pre-jacking device 5 includes a gear c, a bearing d, a push rod e, a pre-pressure block f, a bracket h, and a housing g. The push rod e is arranged on the shaft of the passive pre-jacking device 5. The front end of the push rod e is equipped with a wear-resistant and non-metallic pre-pressure block f. The rear end of the push rod e is mounted inside the housing g by the bearing d. The gear c arranged around the push rod e is connected to the drive motor 21 to achieve rotation. The housing g and the drive motor 21 are mounted as a whole on the moving platform 15 through the bracket h. It works in conjunction with the active pre-jacking device 10 to clamp and position the lead screw.

[0022] like Figure 5As shown, the active pre-jacking device 10 includes a top core 10-1, rolling bearings 10-2, a second outer shell 10-3, and a support platform 10-4. The second outer shell 10-3 is rigidly connected to the support platform 10-4, and the support platform 10-4 is slidably connected to the guide rail 12. Two rolling bearings 10-2 are arranged inside the second outer shell 10-3, and the top core 10-1 penetrates the rolling bearings 10-2 and is firmly embedded in the second outer shell 10-3. Figure 9 As shown, the front end of the outer shell 2 10-3 has a limiting boss E. The displacement sensor 9 passes through the reserved hole S at the front end of the outer shell 2 10-3. The front end of the displacement sensor 9 is aligned with the front end face B of the outer shell 2 10-3. The sensor 9 is fixed by screwing in the set screw 9-1.

[0023] like Figure 6 and Figure 7 As shown, the rotary clamping device 7 includes an outer ring 7-1, an inner ring 7-2, a clamping block 7-3, a positioning block 7-4, a steel ball 7-5, a screw 7-6, a pre-drilled hole K, a support frame L, a support spring M, a roller N, a pre-drilled slot P, a track one Q, and a track two R. The outer ring 7-1 consists of two symmetrical parts, which are fastened after installation by connecting screws 7-6. The outer ring 7-1 contains a rotating inner ring 7-2. Cylindrical pre-drilled holes K are evenly arranged on the inner ring 7-2 to provide guidance for the support frame L. The cylindrical ends of the support frame L pass through. The pressure spring M is inserted into the pre-drilled hole K. A roller N is installed on the upper end of the support frame L to reduce friction during the clamping process. The roller N, support frame L, and support spring M work together through the pre-drilled slot P on the positioning block 7-4 on the three clamping blocks 7-3, pushing them simultaneously towards the axis to clamp the nut. The steel ball 7-5 is arranged in the pre-drilled hole inside the track Q of the inner ring 7-2. The track Q of the inner ring 7-2 has a symmetrical structure and connects with the track R on the outer ring 7-1, providing a movement space for the steel ball 7-5. This enables the rotation and movement of the lead screw and nut.

[0024] like Figure 8 As shown, the buffer device 25 includes a reinforcing screw 25-1, a buffer 25-2, and a connecting block 25-3. The connecting block 25-3 is fixedly connected to the fixed platform 17. The buffer 25-2 and the reinforcing screw 25-1 are arranged sequentially at the front end. The reinforcing screw 25-1 is screwed into the threaded hole reserved in the fixed platform 17 for reinforcement. The buffer device 25 is arranged below the fixed platform 17 to absorb the impact generated by the moving platform 15 during its return.

[0025] Working principle

[0026] Normally, the lead screw and nut are not in the correct relative position when naturally assembled and installed, and adjustment is required before installation.

[0027] The combination of lead screw 6 and nut 8 in its natural state is placed into the rotary clamping device 7 for automatic centering and clamping. The active pre-jacking device 10 uses the cylinder device 11 to push the nut combination screwed into the lead screw, together with the rotary clamping device 7, toward the passive pre-jacking device 5. The pre-jacking is completed when the pre-pressure head f of the passive pre-jacking device 5 contacts the lead screw and interacts with the top core 10-1 of the active pre-jacking device 10 through the lead screw to generate a certain pressure. The lead screw's freedom in the X, Y, and Z directions is restricted. Relying on the passive pre-jacking device 5, drive motor 21, and active pre-jacking device 10, the lead screw can rotate freely axially. At the same time, the nut is restricted by the rotary clamping device 7. Relying on the rotational structure of the rotary clamping device 7 and the drive of drive motor 26, it can also rotate around the central axis of the rotary clamping device 7. When the nut needs to rotate, drive motor 26 drives the positioning block 7-4 and together drives the three clamping blocks 7-3, roller N, support leg L, and support spring M to rotate, ultimately driving the inner ring 7-2 to rotate. With the help of the arranged steel balls 7-5, relative movement occurs between the inner ring 7-2 and the outer ring 7-1. This process realizes both the clamping of the nut and the rotation and movement of the nut. Drive motor 26 drives the nut to rotate at a set speed, moving it closer to the front face B of housing 10-3. When the nut's positioning boss D approaches the limiting boss E on the front face of housing 10-3 of the active pre-jacking device 10, drive motor 26 starts to rotate in the opposite direction until the nut's positioning boss D returns to the position of displacement sensor 9 and stops. At this time, displacement sensor 9 detects whether the displacement between the nut's positioning boss D and displacement sensor 9 meets the set requirements. If the displacement is within the set range, the correction is complete. If the requirements are not met, drive motor 21 of passive pre-jacking device 5 rotates clockwise by a set number of revolutions. During this process, the nut does not rotate, but it will continue to move closer to the front face B of housing 10-3 relative to the lead screw until displacement sensor 9 detects that the displacement is qualified, and the correction is complete. After the correction is completed, the tilting cylinder 13 installed on the bottom platform 14 uses support arms 23 and 24 to push the moving platform 15 upward to 90 degrees, ensuring that the corrected nut and lead screw assembly remains vertically upward for subsequent installation. The buffer device 25 receives the returning moving platform 15, awaiting the start of the next correction. The aforementioned series of devices that need to be controlled, such as the active pre-jacking device 10, the passive pre-jacking device 5, and the rotary clamping device 7, are electrically connected to the electrical control box 2 for control.

Claims

1. An automatic straightening device for the cooperation of a lead screw and a nut, characterized in that: The system includes a main bed, electrical control box, shaft, power cylinder 1, passive pre-jacking device, lead screw, rotary clamping device, nut, displacement sensor, active pre-jacking device, cylinder assembly, guide rail 1, tilting cylinder, bottom platform, moving platform, front and rear moving platform, fixed platform, guide rail 2, connecting rod 1, connecting rod 2, drive motor 1, power cylinder 2, support arm 1, support arm 2, buffer device, and drive motor 2. The electrical control box is connected to the side of the main bed. The main bed supports the fixed platform and the moving platform, which can rotate around the shaft. Guide rail 1, which serves as a guide, is mounted on the fixed platform. The active pre-jacking device is slidably connected to guide rail 1. The cylinder assembly that drives the active pre-jacking device is fixedly connected to the fixed platform. A displacement sensor for determining the nut position is located in front of the active pre-jacking device. The passive pre-jacking device and guide rail 2 are fixedly connected to the moving platform. The bottom of the front and rear moving platform is slidably connected to guide rail 2. The clamping device is installed on the front and rear moving platforms and moves back and forth by means of the guide rail 2. The rotary clamping device, the active pre-jacking device, and the passive pre-jacking device are arranged on the same axis. The passive pre-jacking device and the active pre-jacking device interact to clamp and position the lead screw. The power cylinder 1 and power cylinder 2 arranged on both sides of the rotary clamping device are fixedly connected to the front and rear moving platforms. The power cylinder 1 and power cylinder 2 are respectively connected to the outer ring of the rotary clamping device through connecting rod 1 and connecting rod 2. The drive motor 1 is installed on the moving platform as a whole through the bracket of the passive pre-jacking device. The drive motor 2 is fixedly connected to the front and rear moving platforms and its output shaft is connected to the positioning block of the rotary clamping device. The bottom platform is fixedly connected inside the main body bed. The tilting cylinder is installed on the bottom platform. The lower ends of the support arm 1 and support arm 2 are connected to the tilting cylinder and the upper ends are hinged to the bottom of the moving platform. The buffer device is installed below the fixed platform. The rotary clamping device includes an outer ring, an inner ring, clamping blocks, positioning blocks, steel balls, screws, pre-drilled holes, a support frame, a support spring, rollers, pre-drilled slots, track one, and track two. The outer ring consists of two symmetrical parts, which are fastened after being installed by connecting screws. The outer ring contains a rotating inner ring. Cylindrical pre-drilled holes are evenly arranged on the inner ring to provide guidance for the support frame. The cylindrical ends of the support frame pass through the support springs and then into the pre-drilled holes. Rollers are installed on the upper end of the support frame to reduce friction during the clamping process. The rollers, support frame, and support springs work together through the pre-drilled slots on the positioning blocks to push the three clamping blocks to move towards the axis and clamp the nut. The steel balls are arranged in the pre-drilled holes inside track one of the inner ring. Track one of the inner ring has a symmetrical structure and connects with track two on the outer ring to provide a movement space track for the steel balls.

2. The automatic straightening device for the screw and nut engagement according to claim 1, characterized in that: The passive pre-jacking device includes gears, bearings, a push rod, a pre-pressure block, a bracket, and a housing. The push rod is arranged on the shaft of the passive pre-jacking device. A wear-resistant and non-metallic pre-pressure block is arranged at the front end of the push rod. The rear end of the push rod is mounted inside the housing by a bearing. The gear arranged around the push rod is connected to a drive motor to achieve rotation. The housing and the drive motor are mounted as a whole on the moving platform through the bracket.

3. The automatic straightening device for lead screw and nut mating according to claim 1, characterized in that: The active pre-jacking device includes a top core, rolling bearings, a second outer shell, and a support platform. The second outer shell is rigidly connected to the support platform, and the support platform is slidably connected to a guide rail. Two rolling bearings are arranged inside the second outer shell, and the top core passes through the rolling bearings and is firmly embedded in the second outer shell. The front end of the second outer shell has a limiting boss, and a displacement sensor passes through a pre-drilled hole at the front end of the second outer shell. The front end of the displacement sensor is aligned with the front end face of the second outer shell, and the sensor is fixed by screwing in a top screw.

4. The automatic straightening device for the screw and nut engagement according to claim 1, characterized in that: The buffer device includes a reinforcing screw, a buffer, and a connecting block. The connecting block is fixedly connected to the fixed platform. The buffer and the reinforcing screw are arranged sequentially at the front end. The reinforcing screw is screwed into the threaded hole reserved in the fixed platform for reinforcement. The buffer device is arranged below the fixed platform to absorb the impact generated by the moving platform during its return.

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