Automatic measuring device for key parameters of inner raceway of ball nut

Abstract

The application discloses a kind of automatic measuring equipment of key parameters of ball nut inner raceway, comprising: X-axis transmission module, Z-axis transmission module, positioning and clamping module and measurement module.X-axis transmission module is used for the preliminary positioning and conveying of the nut workpiece to be measured;Z-axis transmission module is used to transport the measurement module to the specified measurement position;Positioning and clamping module is used for accurate clamping positioning of the workpiece to be measured;Measurement module is used for contact measurement of the key parameters of the workpiece to be measured.The application can efficiently, accurately, in large quantities, automatically detect the key parameters of the inner raceway of multiple models of ball nut, and reduce labor costs.

Description

Technical Field

[0001] This invention belongs to the field of ball screw pair ball nut testing technology, and in particular, an automatic measuring device for key parameters of the inner raceway of a ball nut. Background Technology

[0002] Ball screw assemblies possess high precision and stability, meeting performance requirements such as high rigidity, high load capacity, low noise, low temperature rise, and long lifespan. Numerous studies have shown that the performance of the raceway on the working surface of a precision ball screw assembly is a crucial factor determining its accuracy retention. To improve the performance of the raceway profile, precise measurement is essential. Currently, many small and medium-sized enterprises in China manually measure the nut's pitch diameter, resulting in low accuracy and efficiency, which largely fails to meet the testing requirements of modern factories. Furthermore, there is limited research in China on effective measurement methods for key parameters of the ball nut's internal raceway, and the industry lacks dedicated, rapid, and accurate testing methods and equipment. Therefore, there is an urgent need for efficient and high-precision automated testing equipment. Summary of the Invention

[0003] The purpose of this invention is to provide an automatic measurement device for key parameters of the inner raceway of ball nuts, which can efficiently, accurately, and in large quantities automatically detect the key parameters of the inner raceway of multiple types of ball nuts, thereby reducing labor costs.

[0004] The technical solution to achieve the purpose of this invention is as follows:

[0005] An automatic measurement device for key parameters of the inner raceway of a ball nut includes:

[0006] The X-axis transmission module is used for the initial positioning of the nut before measurement and to transport the nut to the bottom of the positioning and clamping module during measurement.

[0007] The positioning and clamping module is used to center and clamp the nut being tested, so that the axis of the nut being tested coincides with the axis of the measuring hole provided by the measuring module;

[0008] The Z-axis transmission mechanism is used to drive the measuring module to move downward along the axis of the nut to be measured in a set step length.

[0009] The measurement module has two symmetrically arranged measuring rods. The two measuring rods can be brought together back-to-back under the drive of the power unit and can be separated when the force of the power unit is removed. The two measuring rods pass through the provided measurement holes. The side ends of the measuring rods are provided with contact probes and two first displacement sensors to collect the displacement caused by the deformation of the measuring rods at the corresponding positions of the two contact probes. The contact probes can move up and down relative to the measuring rods so that the contact probes can adaptively contact the inner raceway of the nut.

[0010] The measurement module is also equipped with two second displacement sensors to collect radial displacement data relative to the nut being measured during the measurement process of the two measuring rods.

[0011] The significant advantages of this invention compared to existing technologies are:

[0012] The contact probe of this invention can adaptively conform to the inner raceway of the nut, avoiding the influence of lead error on the measurement results and ensuring the measurement accuracy of key parameters of the inner raceway of the nut.

[0013] The contact probe of this invention can be matched according to the lead and ball size of the nut to be measured, and the probe rod can be replaced according to the nut's mean diameter specification, resulting in a wide measurement range.

[0014] This invention can detect key parameters of the inner raceway of ball nuts with high precision and efficiency, enabling full inspection of the product, saving labor costs and improving product quality. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the automatic measurement device for key parameters of the inner raceway of the ball nut according to the present invention.

[0016] Figure 2 This is an exploded structural diagram of the X-axis transmission module of the automatic measurement device for key parameters of the inner raceway of the ball nut according to the present invention.

[0017] Figure 3 This is an exploded structural diagram of the Z-axis transmission module of the automatic measurement device for key parameters of the inner raceway of the ball nut according to the present invention.

[0018] Figure 4 This is an exploded structural diagram of the positioning and clamping module of the automatic measurement equipment for key parameters of the inner raceway of the ball nut of the present invention.

[0019] Figure 5 This is an exploded structural diagram of the measurement module of the automatic measurement equipment for key parameters of the inner raceway of the ball nut according to the present invention.

[0020] The meanings represented by the numbers in the diagram are as follows:

[0021] 1. X-axis drive module; 2. Z-axis drive module; 3. Positioning and clamping module; 4. Measurement module;

[0022] 5. Bed, 6. First proximity switch, 7. First proximity switch fixing block, 8. First support base, 9. First anti-collision block fixing base, 10. First anti-collision block, 11. First linear sliding guide rail, 12. First proximity switch baffle, 13. First guide rail pressure block, 14. Preliminary positioning stage, 15. First nut seat, 16. X-axis moving carrier plate, 17. First ball screw pair, 18. First motor integrated fixing base, 19. First coupling, 20. First servo motor;

[0023] 21. Gantry; 22. Second servo motor; 23. Second linear sliding guide rail; 24. Lifting lug; 25. Second coupling; 26. Second proximity switch baffle; 27. Second motor integrated mounting base; 28. Second ball screw pair; 29. ​​Second nut seat; 30. Second proximity switch mounting block; 31. Second proximity switch; 32. Second guide rail pressure block; 33. Second support base; 34. Z-axis moving carrier plate; 35. Second anti-collision block; 36. Second anti-collision block mounting base.

[0024] 37. Third servo motor; 38. Third coupling; 39. Motor mounting bracket; 40. Bidirectional opening and closing linear module; 41. V-shaped gripper; 42. Limit switch.

[0025] 43. Electric push rod; 44. Electric push rod mounting base; 45. Probe push block; 46. Push block return spring; 47. Guide shaft; 48. Support plate; 49. Support frame; 50. Contact probe; 51. Micro-displacement sensor; 52. Micro-displacement sensor mounting block; 53. Return spring; 54. Probe; 55. Probe seal; 56. Fixed guide block; 57. Box-type displacement sensor mounting bracket; 58. Box-type displacement sensor; 59. Limit hook; 60. Limit pin. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] Combination Figures 1-5 The automatic measurement device for key parameters of the inner raceway of the ball nut of the present invention includes an X-axis transmission module 1, a Z-axis transmission module 2, a positioning and clamping module 3, and a measurement module 4.

[0028] The X-axis transmission module 1 includes a bed 5, a first proximity switch 6, a first proximity switch fixing block 7, a first support base 8, a first anti-collision block fixing base 9, a first anti-collision block 10, a first linear sliding guide rail 11, a first proximity switch baffle 12, a first guide rail pressure block 13, a preliminary positioning table 14, a first nut seat 15, an X-axis moving carrier plate 16, a first ball screw pair 17, a first motor integrated fixing base 18, a first coupling 19, and a first servo motor 20. The first support base 8 and the first motor integrated mounting base 18 are fixed to the bed by screws. The two ends of the first ball screw pair 17 are assembled and installed with the first support base 8 and the first motor integrated mounting base 18. The front and rear ends of the first coupling 19 are respectively assembled and installed with the shaft ends of the first servo motor 20 and the first ball screw pair 17, serving as the X-axis power transmission unit. Two first linear sliding guide rails 11 are fixedly installed on the designated mounting surface of the bed 5, arranged parallel to both sides of the first ball screw pair 17, for supporting and guiding the moving parts. The first guide rail pressure block 13 is fixedly installed in the trapezoidal groove provided in the bed 5 by screws to ensure the parallelism of the first linear guide rails 11 and prevent the guide rails from deviating from their original positions. To reduce bending deformation, the X-axis moving carrier plate 16 is fixed to the slider of the first nut seat 15 and the first linear sliding guide rail 11 by screws, and is used to support the preliminary positioning block 14 and the nut workpiece to be measured; the preliminary positioning stage 14 is fixed to the X-axis moving carrier plate 16 by screws, and the annular groove on the top of the preliminary positioning stage 14 is designed according to the flange dimensions of the nut workpiece to be measured, and is used for preliminary positioning of the nut before measurement; the first proximity switch fixing block 7 is placed in the T-shaped groove provided in the bed 5, the first proximity switch 6 is fixed to the first proximity switch fixing block 7 by screws, and the first proximity switch baffle 12 is fixed to a set position on the side of the X-axis moving carrier plate 16, and is used to control the equipment stroke and provide limit protection. The first anti-collision block 10 is fixed to both ends of the first linear guide rail 11 with screws to prevent the equipment from running away uncontrollably.

[0029] Furthermore, the Z-axis transmission module 2 includes a gantry 21, a second servo motor 22, a second linear sliding guide rail 23, a lifting lug 24, a second coupling 25, a second proximity switch baffle 26, a second motor integrated mounting base 27, a second ball screw pair 28, a second nut seat 29, a second proximity switch fixing block 30, a second proximity switch 31, a second guide rail pressure block 32, a second support base 33, a Z-axis moving carrier plate 34, a second anti-collision block 35, and a second anti-collision block fixing base 36; the second support base 33 and the second motor integrated mounting base 27 are fixed to the gantry 21 with screws; both ends of the second ball screw pair 28 are assembled and installed with the second support base 33 and the second motor integrated mounting base 27; the front and rear ends of the second coupling 25 are respectively assembled and installed with the shaft ends of the second servo motor 22 and the second ball screw pair 28, serving as... The Z-axis transmission power unit; the second linear sliding guide rail 23 is fixedly installed on the designated mounting surface of the gantry 21, located on both sides of the second ball screw pair 28, for supporting and guiding the moving parts; the second guide rail pressure block 32 is fixedly installed in the trapezoidal groove of the gantry 21 by screws, for ensuring the parallelism of the second linear guide rail 23, preventing the guide rail from deviating from its original position and reducing bending deformation; the Z-axis moving carrier plate 34 is fixed to the second nut seat 29 and the slider of the second linear sliding guide rail 23 by screws, for carrying the measurement module; the second proximity switch fixing block 30 is placed in the T-shaped groove of the gantry 21, the second proximity switch 31 is fixed to the second proximity switch fixing block 30 by screws, and the second proximity switch baffle 26 is fixed to a set position on the side of the Z-axis moving carrier plate 34, for controlling the equipment stroke and providing limit protection. The second anti-collision block 35 is fixed to both ends of the second linear sliding guide rail 23 by screws to prevent the equipment from running away uncontrollably. The lifting lug 24 is threadedly connected to the top of the gantry 21 for lifting the gantry.

[0030] Furthermore, the positioning and clamping module 3 includes a third servo motor 37, a third coupling 38, a motor mounting base 39, a bidirectional opening and closing linear module 40, a V-shaped gripper 41, and a limit switch 42. The bidirectional opening and closing linear module 40 is fixedly installed on the mounting surface of the gantry 21. The motor mounting base 39 is screwed to the bidirectional opening and closing linear module 40. The third servo motor 37 is screwed to the motor mounting base 39. The front and rear ends of the third coupling 38 are respectively assembled and connected to the lead screw shaft ends inside the third servo motor 37 and the bidirectional opening and closing linear module 40, serving as the power unit for positioning and clamping the workpiece to be measured. The V-shaped gripper 41 is fixedly installed on the slide of the bidirectional opening and closing linear module. Its structural dimensions are designed according to the outer diameter of the nut to be measured, serving as the contact element for positioning and clamping the workpiece to be measured. The limit switch 42 is fixed at a designated position of the bidirectional opening and closing linear module 40 and is used to control the stroke and reciprocating motion of the gripper 41.

[0031] Furthermore, the measurement module 4 includes: an electric push rod 43, an electric push rod fixing seat 44, a probe pushing block 45, a push block return spring 46, a guide shaft 47, a support plate 48, a support frame 49, a contact probe 50, a micro-displacement sensor 51, a micro-displacement sensor mounting block 52, a return spring 53, a probe 54, a probe sealing strip 55, a fixed guide seat 56, a box-type displacement sensor fixing frame 57, a box-type displacement sensor 58, a limit hook 59, and a limit pin 60. The support plate 48 and the support frame 49 are mortised and tenoned together and fixed with screws. The support frame 49 is fixed to the Z-axis moving carrier plate 34 with screws to support the measuring assembly. Two fixed guide seats 56 are symmetrically fixedly installed in the positioning and mounting grooves of the support plate 48 about the measuring hole. The fixed guide seats 56 are placed in the opening slots of the probe push block 45, so that the guide shaft 47 passes through the probe push block 45 and the fixed guide seats 56 to prevent the probe push block 45 from wobbling left and right. The push block return spring 46 is sleeved between the probe push block 45 and the fixed guide seats 56. On the axis, a mechanism is used to reset the probe push block 45 (providing an outward thrust to the probe push block); two electric push rod fixing seats 44 are respectively installed on the side ends of the two support plates 48, and the electric push rod 43 is connected to the electric push rod fixing seat 44 by screws, serving as the power unit for moving the probe push block 45; the probe 54 is screwed to the inner end face of the probe push block 45 and passes through the measuring hole provided in the center of the support plate 48; the contact probe 50 is threadedly connected to the micro-displacement sensor 51, and the micro-displacement sensor 51 is placed in the assembly groove of the micro-displacement sensor mounting block 52. The inner side is fixed with a hexagonal set screw; the micro-displacement sensor mounting block 52 is installed in the mounting groove of the measuring rod 54 and can move up and down, used to monitor and collect the micro-displacement caused by the deformation of the measuring rod 54 at the corresponding position of the contact probe 50 during measurement; the reset spring 53 is installed in the hole groove of the measuring rod 54 and is used to reset the micro-displacement sensor mounting block 52 after it moves up and down; the measuring rod seal 55 is fixed to the measuring rod 54 with screws; the box-type displacement sensor fixing bracket 57 is installed in the mounting groove below the support plate 48, and the box-type displacement sensor 58 is connected to the mounting groove. The probe is installed by fitting the mounting flange and the fixing bracket 57. The probe contacts the measuring rod 54 to collect the radial displacement data of the measuring rod 54 along the nut being measured. The limiting hook 59 is fixedly installed at a designated position at the lower end of the left measuring rod, and the limiting pin 60 is installed in the hole of the right measuring rod. The limiting pin 60 is inserted into the groove of the limiting hook 59, so that the movement distance of the two measuring rods is limited. The structural dimensions of the limiting hook are designed according to the range of the displacement sensor 58 to prevent the measuring rod from excessively displacing radially under the spring force of the push block reset spring 46 after the electric push rod 43 retracts, thus damaging the displacement sensor.

[0032] This invention discloses an automatic measurement device for key parameters of the inner raceway of a ball nut. During operation, the nut workpiece is manually placed onto a preliminary positioning table for initial positioning. A servo motor is controlled to move the X-axis transmission mechanism in the positive direction to a designated position. The servo motor is then controlled to move the V-shaped grippers towards each other to clamp the nut, aligning the axis of the nut with the axis of the measurement hole on the support plate 48 for precise positioning and clamping before measurement. The servo motor is then controlled to move the Z-axis transmission mechanism downwards, transporting the measurement module to a designated height. The electric push rod is controlled to retract, separating from the probe push block, causing the probe push block to move to both sides under the force of the return spring, thereby driving the probe to move to both sides until the contact probe makes adaptive contact with the inner raceway of the nut. Data from a box-type displacement sensor and a micro-displacement sensor are collected to obtain A1, B1, a1, and b1, respectively. Finally, the electric push rod is controlled to extend, causing the probe push blocks on both sides to move towards each other. Move the probe to separate it from the inner raceway of the nut; control the servo motor to move the Z-axis transmission mechanism downward a specified distance; control the electric push rod to retract, causing the probe push block to move to both sides under the force of the return spring, thereby driving the probe to move to both sides until the probe makes adaptive rolling contact with the inner raceway of the nut; collect data from the box-type displacement sensor and the micro-displacement sensor to obtain A2, B2, a2, and b2 respectively; repeat this operation to collect and process data from multiple raceways of the nut to obtain the pitch diameter, pitch diameter error, and pitch diameter taper of the nut to be tested; control the electric push rod to retract, separating the probe from the inner raceway of the nut; control the servo motor to move the Z-axis transmission mechanism upward to the origin; control the servo motor to move the V-shaped grippers in opposite directions to release the nut; control the servo motor to move the X-axis transmission mechanism in the negative direction to the origin; remove the tested workpiece, place the next nut workpiece to be tested, and repeat the above operation.

[0033] Calculation formula:

[0034] D i = A i +B i +Xa i -b i (i=1, 2, 3, ..., n)

[0035] D ∆ = Max|D i - D0| (i=1, 2, 3, ..., n)

[0036] D δ =D imax - D jmin (i, j = 1, 2, 3, ..., n)

[0037] In the formula: D i —The mean diameter measured at the i-th raceway;

[0038] Ai —Measure the displacement of the left measuring rod when measuring the i-th raceway;

[0039] B i —Measure the displacement of the right measuring rod when measuring the i-th raceway;

[0040] X—The distance between the centers of the two contact probes when the left and right probes are back to back, without measurement;

[0041] a i —The minute displacement caused by the contact deformation of the left measuring rod at the i-th raceway during measurement;

[0042] b i —The minute displacement caused by the contact deformation of the right measuring rod at the i-th raceway during measurement;

[0043] D ∆ —Mean diameter error;

[0044] D0—Theoretical mean diameter of the ball nut;

[0045] D δ —Middle diameter taper;

[0046] D imax —The maximum value of the mean diameter measured on the raceway;

[0047] D jmin —Minimum mean diameter value measured on the raceway.

Claims

1. An automatic measurement device for key parameters of the inner raceway of a ball nut, characterized in that, include: The X-axis transmission module is used for the initial positioning of the nut before measurement and to transport the nut to the bottom of the positioning and clamping module during measurement. The positioning and clamping module is used to center and clamp the nut being tested, so that the axis of the nut being tested coincides with the axis of the measuring hole set in the measuring module; The Z-axis transmission mechanism is used to drive the measuring module to move downward along the axis parallel to the nut being measured by a set step length. The measurement module has two symmetrically arranged measuring rods. The two measuring rods can be brought together back-to-back under the drive of the power unit and can be separated when the force of the power unit is removed. The two measuring rods pass through the provided measurement holes. The side ends of the measuring rods are provided with contact probes and two first displacement sensors to collect the displacement caused by the deformation of the measuring rods at the corresponding positions of the two contact probes. The contact probes can move up and down relative to the measuring rods so that the contact probes can adaptively contact the inner raceway of the nut. The measurement module is also equipped with two second displacement sensors to collect radial displacement data relative to the nut being measured during the measurement process of the two measuring rods; The key parameters of the inner raceway include raceway pitch diameter, pitch diameter error, and pitch diameter taper. D i = A i +B i +X-a i -b i D ∆ = Max|D i - D0| D δ =D imax - D jmin Where D i A is the mean diameter measured at the i-th raceway. i B i denoted by , respectively, the displacements of the two measuring rods at the i-th raceway; X is the distance between the centers of the two contacting probes when the two measuring rods are back-to-back; a i b i Let Di be the displacement caused by the deformation of the two measuring rods at the i-th raceway; D0 be the theoretical mean diameter of the ball nut; Di be the displacement caused by the deformation of the two measuring rods at the i-th raceway. imax The maximum value of the mean diameter measured on the raceway; D jmin This is the minimum measured mean diameter value of the raceway.

2. The automatic measurement device for key parameters of the inner raceway of a ball nut according to claim 1, characterized in that, The power unit includes a push rod, a probe push block, a push block return spring, a fixed guide seat, a guide shaft, a support plate, and a support frame; The measuring hole is set on the support plate, which is supported on the Z-axis transmission mechanism by two support frames. The two second displacement sensors are respectively mounted on two fixed frames by mounting flanges. The fixed frames are installed in the mounting groove below the support plate. The support plate has two fixed guide seats symmetrically fixed about the measuring hole; a measuring rod push block is slidably connected to the fixed guide seat through a guide shaft. The measuring rod push block can move inward under the action of the push rod and can move outward under the action of the push block return spring.

3. The automatic measurement device for key parameters of the inner raceway of a ball nut according to claim 1, characterized in that, The contact probe is threadedly connected to the first displacement sensor, and the first displacement sensor is fixed to the displacement sensor mounting block; the displacement sensor mounting block can move up and down relative to the probe rod.

4. The automatic measurement device for key parameters of the inner raceway of a ball nut according to claim 1, characterized in that, One of the measuring rods is equipped with a limit hook, and the other measuring rod is equipped with a limit pin. The limit pin and the limit hook work together to limit the movement distance of the left and right measuring rods.

5. The automatic measurement device for key parameters of the inner raceway of a ball nut according to claim 1, characterized in that, The positioning and clamping module includes a third servo motor, a third coupling, a motor mounting base, a bidirectional opening and closing linear module, and a V-shaped gripper. The motor mounting base is fixed to the bidirectional opening and closing linear module, the third servo motor is fixedly connected to the motor mounting base, and the two ends of the third coupling are respectively connected to the third servo motor and the lead screw shaft inside the bidirectional opening and closing linear module; the V-shaped gripper is fixedly installed on the slide of the bidirectional opening and closing linear module.

6. The automatic measurement device for key parameters of the inner raceway of a ball nut according to claim 1, characterized in that, The X-axis transmission module is driven by a lead screw pair. The nut seat of the lead screw pair is connected to the X-axis moving carrier plate. The X-axis moving carrier plate is provided with a bearing preliminary positioning block. The annular groove on the top of the bearing preliminary positioning block is used for preliminary positioning of the nut to be measured before measurement.

7. The automatic measurement device for key parameters of the inner raceway of a ball nut according to claim 1, characterized in that, The Z-axis transmission mechanism is driven by a lead screw pair. The nut seat of the lead screw pair is connected to the Z-axis moving carrier plate, which is used to connect the measurement module.

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