A fixture for high-precision measurement of the diameter of a shaft tube

Abstract

The present invention relates to the field of automated precision measurement technology. For a high-precision measurement fixture for the diameter of a shaft tube, a bolted fixed connection is adopted between the flange fine-tuning mechanism and the precise positioning mechanism. The V-shaped positioning block included in the flange fine-tuning mechanism makes the axis of the shaft to be measured perpendicular to the measurement section and at the symmetric center of the measurement mechanism. The flange fine-tuning mechanism provides fine position adjustment for the precise positioning mechanism, which can eliminate the cumulative error of the collaborative robot caused by multiple measurements. The measurement mechanism indirectly measures the diameter of the shaft to be measured by using two opposed contact sensors. This fixture has a simple structure and is easy to maintain and repair; it improves the automation level and accuracy of quality inspection; it improves production efficiency, saves costs, ensures the product qualification rate, and increases economic benefits.

Description

Technical Field

[0001] The present invention relates to the field of automated precision measurement technology, and particularly to a high-precision measuring fixture for the diameter of a shaft tube. Background Art

[0002] An automotive drive shaft is a shaft that can transmit power in a universal drive device. Its function is to transmit the power of the engine to the wheels together with the gearbox and the drive axle, so as to make the vehicle generate driving force. In order to ensure the normal operation of the drive shaft and extend its service life, generally, higher requirements are imposed on the mating accuracy of the drive shaft.

[0003] Currently, the diameter measurement of the drive shaft still relies on manual operation with a micrometer. Limited by the professional knowledge of the inspectors and the influence of the on-site environment, the diameter measurement results have large errors and low measurement accuracy. Moreover, manual inspection also has disadvantages such as high labor intensity of the inspectors, low work efficiency, and high production costs. Summary of the Invention

[0004] To solve the above problems, the present invention provides a high-precision measuring fixture for the diameter of a shaft tube, which uses equipment to replace manual labor, improves the automation degree and accuracy of quality inspection, avoids the defects of manual measurement, and reduces labor costs and improves production efficiency.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A high-precision measuring fixture for the diameter of a shaft tube, comprising

[0007] A flange fine-tuning mechanism;

[0008] A precise positioning mechanism, fixedly connected to the end of the flange fine-tuning mechanism. The precise positioning mechanism includes a V-shaped positioning block, and the V-shaped positioning block has a V-shaped opening for clamping the shaft to be measured.

[0009] A measuring mechanism, connected to the precise positioning mechanism, and the measuring mechanism has two detection components arranged oppositely.

[0010] The precise positioning mechanism is used to fix the shaft to be measured in the first direction. After the precise positioning mechanism fixes the shaft to be measured, the detection components in the measuring mechanism are used to detect the diameter of the shaft to be measured oppositely in the second direction perpendicular to the first direction.

[0011] Preferably, the flange fine-tuning mechanism includes a flange plate, a return spring, and a connecting plate. The connecting plate is fixedly connected to the precise positioning mechanism. The end face of the flange plate has a rod-shaped member, and one side surface of the connecting plate has a first tubular member. The flange plate is inserted into the first tubular member through the rod-shaped member and is matched with the first tubular member. The return spring is placed in the first tubular member and its two ends respectively abut against the end of the rod-shaped member and the connecting plate to form an elastic connection between the flange plate and the connecting plate.

[0012] Preferably, a guide pin perpendicular to the rod-shaped member is provided on the rod-shaped member. The first tubular member has a triangular guide opening, and the extended side of the guide opening faces the connecting plate. The guide pin passes through the first tubular member through the guide opening.

[0013] Preferably, the corners of the guide opening are circular chamfers with a curvature matching the outer contour of the guide pin.

[0014] Preferably, the precise positioning mechanism further includes a mounting bracket and an ultra-precision slide table A. The mounting bracket is fixedly connected to the flange fine-tuning mechanism. The base of the ultra-precision slide table A is mounted on the fixed bracket. The V-shaped positioning block is fixedly connected to the sliding end of the ultra-precision slide table A. The sliding direction of the ultra-precision slide table A is the first direction.

[0015] Preferably, the mounting bracket further has a folded plate integrally formed with the main body of the mounting bracket. The folded plate is bent above the V-shaped positioning block. The folded plate is provided with a limit screw A and a compression spring A sleeved on the limit screw A. The end of the compression spring A abuts against the V-shaped positioning block. The compression spring A is used to reset the V-shaped positioning block after the V-shaped positioning block is separated from the shaft to be measured.

[0016] Preferably, the two side edges at the lower part of the mounting bracket are bent to form an ear plate structure. The measuring mechanism includes two groups of contact sensors, an ultra-precision slide table B, a slider and a contact member. The contact sensors are mounted on the ear plates and the measuring ends face the direction of the V-shaped opening. The slider is fixed on the mounting bracket through the ultra-precision slide table B, and the sliding direction of the ultra-precision slide table B is the second direction. The slider is provided with a contact member on the side facing the V-shaped opening. The slider is provided with a triggering structure corresponding to the contact sensors, and the measuring ends of the contact sensors correspond to the triggering structure.

[0017] Preferably, an elastic reset device is further provided between the slider and the ear plate. The elastic reset device includes a limit screw B screwed on the ear plate and a compression spring B sleeved on the limit screw. One end of the compression spring B abuts against the back of the slider.

[0018] Preferably, the contact member is a second tubular member.

[0019] Preferably, the lower ends of the two second tubular members are outwardly open, so that a trumpet-shaped opening is formed between the two second tubular members.

[0020] The beneficial effects of using the present invention are:

[0021] The present invention provides a high-precision measuring fixture for the diameter of a shaft tube, which has a simple structure and is easy to maintain and repair; it improves the automation level and accuracy of quality inspection, enhances production efficiency, saves costs; ensures the product qualification rate and increases economic benefits. Brief Description of the Drawings

[0022] Figure 1 It is the overall external view of the high-precision measuring fixture for the diameter of the shaft tube of the present invention.

[0023] Figure 2 It is the structural schematic diagram of the flange fine-tuning mechanism in the high-precision measuring fixture for the diameter of the shaft tube of the present invention.

[0024] Figure 3 It is the front structural schematic diagram of the precise positioning mechanism in the high-precision measuring fixture for the diameter of the shaft tube of the present invention.

[0025] Figure 4 It is the side structural schematic diagram of the precise positioning mechanism in the high-precision measuring fixture for the diameter of the shaft tube of the present invention.

[0026] Figure 5 It is the structural schematic diagram of the measuring mechanism in the high-precision measuring fixture for the diameter of the shaft tube of the present invention.

[0027] The reference numerals include:

[0028] 1 - flange fine-tuning mechanism, 101 - flange plate, 102 - return spring, 103 - connecting plate, 104 - guide pin, 2 - precise positioning mechanism, 201 - V-shaped positioning block, 202 - compression spring A, 203 - limit screw A, 204 - mounting bracket, 205 - ultra-precision slide table A, 3 - measuring mechanism, 301 - contact sensor, 302 - limit screw B, 303 - compression spring B, 304 - slider, 305 - trumpet-shaped measuring round bar, 306 - ultra-precision slide table B, 4 - shaft to be measured, 5 - collaborative robot. Detailed Embodiments

[0029] To make the purpose, technical solutions and advantages of the present technical solution clearer, the present technical solution will be further described in detail below in combination with specific embodiments. It should be understood that these descriptions are exemplary and not intended to limit the scope of the present technical solution.

[0030] As Figures 1 - 5As shown in the figure, this embodiment proposes a high-precision measuring fixture for the diameter of a shaft tube, which includes a flange fine-tuning mechanism 1; a precise positioning mechanism 2 fixedly connected to the end of the flange fine-tuning mechanism 1. The precise positioning mechanism 2 includes a V-shaped positioning block 201. The V-shaped positioning block 201 has a V-shaped opening for clamping the shaft 4 to be measured. The V-shaped positioning block 201 makes the axis of the shaft 4 to be measured perpendicular to the measurement section and at the symmetric center of the measurement mechanism 3; a measurement mechanism 3 connected to the precise positioning mechanism 2. The measurement mechanism 3 has two detection components arranged oppositely; the precise positioning mechanism 2 is used to fix the shaft 4 to be measured in the first direction. After the precise positioning mechanism 2 fixes the shaft 4 to be measured, the detection components in the measurement mechanism 3 are used to detect the diameter of the shaft 4 to be measured oppositely in the second direction perpendicular to the first direction.

[0031] As Figure 1 shown, the flange fine-tuning mechanism 1 is installed on the six-axis flange of the collaborative robot 5, and the collaborative robot 5 drives the measuring fixture to measure the diameter of the shaft 4 to be measured, which can meet the multiple measurements within the stroke range. The flange fine-tuning mechanism 1 and the precise positioning mechanism 2 are fixedly connected by bolts.

[0032] As Figure 2 shown, the flange fine-tuning mechanism 1 includes a flange plate 101, a return spring 102 and a connecting plate 103. The connecting plate 103 is fixedly connected to the precise positioning mechanism 2. The end face of the flange plate 101 has a rod-shaped part, and one side surface of the connecting plate 103 has a first tubular part. The flange plate 101 is inserted into the first tubular part through the rod-shaped part and cooperates with the first tubular part. The return spring 102 is placed in the first tubular part and its two ends respectively abut against the end of the rod-shaped part and the connecting plate 103 to form an elastic connection between the flange plate 101 and the connecting plate 103.

[0033] A guide pin 104 perpendicular to the rod-shaped part is arranged on the rod-shaped part. The first tubular part has a triangular guide opening, and the extended side of the guide opening faces the connecting plate 103. The guide pin 104 passes through the first tubular part through the guide opening. The flange fine-tuning mechanism 1 provides a position micro-adjustment for the precise positioning mechanism 2, which can eliminate the cumulative error of the collaborative robot 5 caused by multiple measurements.

[0034] Preferably, the corners of the guide opening are circular chamfers with a curvature matching the outer contour of the guide pin 104. The guide pin 104 can be completely embedded into the corners of the guide opening to avoid point contact between the guide pin 104 and the guide opening.

[0035] As Figure 3 、 Figure 4As shown, the precise positioning mechanism 2 also includes a mounting bracket 204 and an ultra-precision slide A205, wherein the mounting bracket 204 is fixedly connected to the flange fine-tuning mechanism 1, the base of the ultra-precision slide A205 is installed on the fixed bracket, the V-shaped positioning block 201 is fixedly connected to the sliding end of the ultra-precision slide A205, and the sliding direction of the ultra-precision slide A205 is a first direction. The function of the ultra-precision slide A205 is to locate the sliding direction of the V-shaped positioning block 201 to avoid errors caused by the left and right shaking of the V-shaped positioning block 201 during the measurement process.

[0036] Mounting bracket 204 also features a folding plate integrally formed with the main body of mounting bracket 204. This folding plate bends over V-shaped positioning block 201 and includes a stop screw A203 and a compression spring A202 mounted on stop screw A203. The end of compression spring A202 abuts against V-shaped positioning block 201. Compression spring A202 is used to reset V-shaped positioning block 201 after it disengages from the measured shaft 4. An ultra-precision slide A205 rigidly connects mounting bracket 204 and V-shaped positioning block 201, ensuring consistent movement. To accommodate multiple measurements, compression spring A202 and stop screw A203 are used to return V-shaped positioning block 201 to its initial position after each measurement.

[0037] like Figure 5 As shown, the lower edges of the mounting bracket 204 are bent to form an ear plate structure. The measuring mechanism 3 includes two sets of contact sensors 301, an ultra-precision slide B306, a slider 304, and a contact piece. The contact sensors 301 are mounted on the ear plates with their measuring ends facing the V-shaped opening. The slider 304 is fixed to the mounting bracket 204 via the ultra-precision slide B306, which slides in the second direction. The contact piece is mounted on the slider 304 facing the V-shaped opening. The slider 304 has a trigger structure for the contact sensors 301, and the measuring end of the contact sensors 301 corresponds to the trigger structure. The measurement accuracy of the contact sensors 301 is 1μm, and the measurement fixture can achieve an accuracy of 2μm.

[0038] An elastic reset device is also installed between the slider 304 and the lug. This device includes a stop screw B302 screwed onto the lug and a compression spring B303 mounted on the stop screw. One end of the compression spring B303 abuts against the back of the slider 304. The contact member is a second tubular member. The lower ends of the two second tubular members are open outward, forming a trumpet-shaped opening between the two second tubular members.

[0039] The contact sensor 301 adopts a high-precision, fatigue-resistant, oil-resistant, waterproof, dustproof and long-life sensor with an accuracy of 1 μm to ensure the repeated measurement accuracy and service life of the measuring fixture; the trumpet-shaped measuring round bar 305 is designed with a trumpet mouth to facilitate the entry of the shaft 4 to be measured into the middle of the two trumpet-shaped measuring round bars 305; the trumpet-shaped measuring round bar 305 is fixedly installed on the slider 304; a super-precision slide B306 is used for a rigid connection between the mounting bracket 204 and the slider 304 to ensure the consistency of their movements, and at the same time restrict the degrees of freedom of the slider 304 so that it can only move axially along the contact sensor 301; in order to meet the requirements of multiple measurements, limit screws B302 and compression springs B303 are used to enable the two trumpet-shaped measuring round bars 305 to return to the initial position after each measurement; the two limit screws B302 on both sides can control the center axis distance of the trumpet-shaped measuring round bar 305 to meet the shafts 4 to be measured with different diameters; during measurement, the contact sensor 301 directly measures the displacement of the two sliders 304 on both sides, and indirectly calculates the diameter of the shaft 4 to be measured.

[0040] The data measured by the contact sensor 301 is transmitted back to the data processing system, which is used to process the data measured by the two contact sensors 301 and display the measured value and the judgment result; the data processing system is connected in series with each mechanical component. This measuring fixture indirectly measures the diameter of the shaft 4 to be measured by using two coaxial and oppositely arranged contact sensors 301. The measuring mechanism 3 adopts structures such as trumpet-shaped measuring round bars 305, sliders 304 and super-precision slide B306 to realize the transformation of the two end points of the diameter of the shaft 4 to be measured from "point-line-plane". By directly measuring the axial movement of the slider 304 with the contact sensor 301, the diameter of the shaft 4 to be measured can be indirectly calculated. This measuring fixture can improve the automation degree and accuracy of quality inspection, improve production efficiency, save production costs, ensure the product qualification rate and increase economic benefits.

[0041] The above content is only the preferred embodiment of the present invention. For those of ordinary skill in the art, many changes can be made in the specific implementation manners and application scopes according to the idea of the present technical content. As long as these changes do not deviate from the concept of the present invention, they all fall within the protection scope of this patent.

Claims

1. A fixture for high-precision measurement of the diameter of a shaft tube, characterized in that: including a flange fine-tuning mechanism; a precise positioning mechanism fixedly connected to the end of the flange fine-tuning mechanism. The precise positioning mechanism includes a V-shaped positioning block which has a V-shaped opening for clamping the shaft to be measured; a measuring mechanism connected to the precise positioning mechanism. The measuring mechanism has two detection components arranged oppositely; the precise positioning mechanism is used to fix the shaft to be measured in a first direction. After the shaft to be measured is fixed by the precise positioning mechanism, the detection components in the measuring mechanism are used to detect the diameter of the shaft to be measured oppositely in a second direction perpendicular to the first direction; the precise positioning mechanism further includes a mounting bracket and an ultra-precision slide A. The mounting bracket is fixedly connected to the flange fine-tuning mechanism. The base of the ultra-precision slide A is mounted on the fixed bracket. The V-shaped positioning block is fixedly connected to the sliding end of the ultra-precision slide A. The sliding direction of the ultra-precision slide A is the first direction; the two sides of the lower part of the mounting bracket are bent to form ear plate structures. The measuring mechanism includes two groups of contact sensors, an ultra-precision slide B, a slider and a contact member. The contact sensors are mounted on the ear plates and the measuring ends face the direction of the V-shaped opening. The slider is fixed on the mounting bracket by the ultra-precision slide B. The sliding direction of the ultra-precision slide B is the second direction. The contact member is mounted on the side of the slider facing the V-shaped opening. The slider has a triggering structure corresponding to the contact sensors, and the measuring ends of the contact sensors correspond to the triggering structure; an elastic reset device is further provided between the slider and the ear plate. The elastic reset device includes a limit screw B screwed on the ear plate and a compression spring B sleeved on the limit screw. One end of the compression spring B abuts against the back of the slider.

2. The high-precision measuring fixture for the shaft tube diameter according to claim 1, wherein: the flange fine-tuning mechanism includes a flange plate, a reset spring and a connecting plate. The connecting plate is fixedly connected to the precise positioning mechanism. A rod-shaped member is provided on the end face of the flange plate. A first tubular member is provided on one side surface of the connecting plate. The flange plate is inserted into the first tubular member through the rod-shaped member and cooperates with the first tubular member. The reset spring is placed in the first tubular member and abuts against the end of the rod-shaped member and the connecting plate at both ends respectively to form an elastic connection between the flange plate and the connecting plate.

3. The high-precision measuring fixture for the shaft tube diameter according to claim 2, wherein: a guide pin perpendicular to the rod-shaped member is provided on the rod-shaped member. A triangular guide opening is provided on the first tubular member, and the expanding side of the guide opening faces the connecting plate. The guide pin passes through the first tubular member through the guide opening.

4. The high-precision measuring fixture for the shaft tube diameter according to claim 3, wherein: the corners of the guide opening are circular chamfers with a curvature matching the outer contour of the guide pin.

5. The high-precision measuring fixture for the shaft tube diameter according to claim 1, wherein: the mounting bracket further has a folding plate integrally formed with the mounting bracket body. The folding plate is bent above the V-shaped positioning block. A limit screw A and a compression spring A sleeved on the limit screw A are provided on the folding plate. The end of the compression spring A abuts against the V-shaped positioning block. The compression spring A is used to reset the V-shaped positioning block after the V-shaped positioning block is separated from the shaft to be measured.

6. The high-precision measuring fixture for the shaft tube diameter according to claim 1, wherein: the contact member is a second tubular member.

7. The high-precision measuring fixture for the shaft tube diameter according to claim 6, characterized in that: the lower ends of the two second tubular members are open outward, so that a trumpet-shaped opening is formed between the two second tubular members.

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