Workpiece inner hole concentricity measuring device and measuring method

Abstract

The invention relates to the related technical field of workpiece measurement, in particular to a workpiece inner hole concentricity measuring device and method.The workpiece inner hole concentricity measuring device comprises a support and a box arranged on the support, and further comprises an installation base movably arranged on the support and used for measuring the concentricity of a workpiece inner hole; the mounting seat is arranged on the support and can be driven by a height adjusting mechanism arranged on the support to ascend and descend, two guide shafts are fixed on the mounting seat, a follower plate is arranged on the two guide shafts in a sliding manner, and a lever indicator is arranged on the follower plate through an assembling mechanism; through the cooperation of the power mechanism and the transposition mechanism, the steering of the workpiece and the switching of the horizontal position of the lever meter 13 are orderly carried out, that is, before the steering of the workpiece, the measuring head of the lever meter 13 can be separated from the inner wall of the workpiece, so that the phenomenon that the measuring head of the lever meter 13 is in a contact state with the inner wall of the workpiece in the process of switching measuring points is avoided; therefore, the measurement accuracy is influenced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of workpiece measurement, and particularly relates to a workpiece inner hole concentricity measuring device and a measuring method. BACKGROUND

[0002] In some mechanical parts, the inner hole concentricity is a key factor for realizing the function. For example, if the inner hole concentricity of an automobile part does not meet the requirements, the transmission may fail or the function may be damaged. Detecting the inner hole concentricity is an important means to ensure that the product meets the design drawings and quality standards. Through the concentricity detection, unqualified products can be identified and screened to ensure the quality consistency of the products.

[0003] When measuring the inner hole concentricity of a workpiece, a lever gauge is usually selected, and a multi-point height difference measurement method is used, that is, a plurality of point positions are measured at two different heights of the inner hole of the workpiece along the circumference at equal intervals, the center coordinates of different sections are calculated through the above point positions, the radial distance between the centers of the upper and lower sections is calculated to obtain the concentricity error, and if the concentricity error is within the tolerance range, the concentricity of the workpiece is qualified.

[0004] When some measuring devices use the above method for measurement, the measuring head of the lever gauge is usually in contact with the workpiece at all times, when the measuring points are switched, the clamping table of the workpiece drives the workpiece to rotate, in this process, the rotating workpiece may generate additional vibration or shaking due to contact, which affects the stability of the measurement, and the dynamic characteristics (such as rotation speed and direction change) of the rotating workpiece make it more difficult to control this error, in addition, the lubricating oil on the lever gauge is mainly used for the escapement system, the barrel, the winding and setting system, and the gear system and other key components to ensure the normal operation and long-term stability of the mechanical watch, when the lever gauge is in contact with the rotating workpiece, heat may be generated due to friction, which causes the lubricating oil to deteriorate or dry up, thereby affecting the sensitivity and measurement accuracy of the measuring head. SUMMARY

[0005] The present application aims to provide a workpiece inner hole concentricity measuring device and a measuring method to solve the problems in the background.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme: A workpiece inner hole concentricity measuring device, comprising a support and a box body arranged on the support, further comprising: A mounting seat movably arranged on the support and capable of being driven to rise and fall by a height adjusting mechanism arranged on the support, two guide shafts are fixed on the mounting seat, a follower plate is slidably arranged on the two guide shafts, and a lever gauge is arranged on the follower plate through an assembly mechanism; Three-jaw chuck is arranged on the box body and used for clamping workpiece to be measured, the box body is provided with a power mechanism capable of driving the three-jaw chuck to rotate, and the box body is also provided with a transposition mechanism matched with the power mechanism, which can separate the measuring head of the lever gauge from the inner wall of the workpiece before and after the three-jaw chuck performs the rotating action.

[0007] As a further scheme of the present application, a rotating shaft is rotatably arranged in the box body, the three-jaw chuck is fixed with the rotating shaft, and a complete gear is fixed at one end of the rotating shaft away from the three-jaw chuck, and the complete gear is matched with the power mechanism.

[0008] As a further scheme of the present application, the power mechanism comprises a second driving motor arranged in the box body and an incomplete gear fixed on the output shaft of the second driving motor, and the toothed part of the incomplete gear is matched with the complete gear.

[0009] As a further scheme of the present application, the transposition mechanism comprises a guide arm fixed in the box body, a telescopic arm slidably sleeved with the guide arm, and a disc body fixed with the telescopic arm, and a sliding matching structure is arranged between the disc body and the output shaft of the second driving motor, and the telescopic arm is connected with the follow-up plate through a transmission member.

[0010] As a further scheme of the present application, the sliding matching structure comprises a follow-up arm fixed at the end of the output shaft of the second driving motor and a convex column fixed with the follow-up arm, the disc body is arranged in a "D" shape, and a D-shaped groove matched with the convex column is arranged on the disc body; The convex column extends into the D-shaped groove and is slidably connected with the disc body, and the D-shaped groove comprises a first groove arranged in an arc shape and a second groove arranged in a straight line and connecting two ends of the first groove.

[0011] As a further scheme of the present application, the transmission member comprises a vertical arm fixedly connected with the telescopic arm, a gap is reserved between the follow-up plate and the mounting seat, the vertical arm extends into the gap and is slidably connected with a connecting member fixed on the follow-up plate, and a strip-shaped through groove is arranged on the upper part of the box body for the activity of the vertical arm.

[0012] As a further scheme of the present application, the assembly mechanism comprises a bottom plate arranged on the follow-up plate and a dovetail clamp arranged on the bottom plate, and the dovetail clamp is used for fixing the lever gauge.

[0013] As a further solution of the present invention: The height adjustment mechanism includes two guide rails fixed on the support and two sliding seats respectively slidingly fitted on the two guide rails. The mounting seat is fixed to the two sliding seats, and the mounting seat is further connected to a servo drive assembly provided on the support.

[0014] As a further solution of the present invention: The servo drive assembly includes a screw rod rotatably mounted on the support and a first drive motor mounted on the top of the support. The screw rod is connected to the output end of the first drive motor, and a drive block threadedly connected to the screw rod is provided on the screw rod. The drive block is fixed to the mounting seat.

[0015] A method for measuring the concentricity of the inner hole of a workpiece, using the measuring device described above, includes the following steps: Step 1, fix the workpiece to be measured by using a three-jaw chuck, drive the mounting seat to descend through the height adjustment mechanism, and install the dial indicator on the follower plate through the assembly mechanism; Step 2, finely adjust the position of the dial indicator so that the measuring head of the dial indicator contacts the inner wall of the lower end of the workpiece, and record the value of the dial indicator as a; Step 3, the power mechanism drives the three-jaw chuck to intermittently rotate the workpiece by 90°, and record the values of the dial indicator at each measurement point as b, c, and d respectively; Step 4, the three-jaw chuck continues to rotate. At the same time, the height adjustment mechanism drives the mounting seat to rise so that the measuring head of the dial indicator reaches the upper port of the workpiece and contacts the inner wall of the upper port of the workpiece, and record the value of the dial indicator as a1; Step 5, repeat Step 3, and record the values of the dial indicator as b1, c1, and d1; Step 6, calculate the center coordinates (X 下 , Y 下 ) of the lower cross-section and the center coordinates (X 上 , Y 上 ) of the upper cross-section: Let the center of the three-jaw chuck be the reference origin (0,0). At this time, the lower readings a, b, c, d and the upper readings a1, b1, c1, d1 represent the radial distances from the inner hole wall in each angular direction to the reference center. The calculation formula for the lower center coordinates (X 下 , Y 下 ) is: , ; The calculation formula for the center coordinates (X 上 , Y 上 ) of the upper cross-section is: , ; Therefore, the concentricity error is the radial distance between the upper and lower centers: ; If the concentricity error the tolerance, the workpiece is qualified; if the concentricity error the tolerance, the workpiece is unqualified.

[0016] Compared with the prior art, the present application has the following beneficial effects: In the present application, through the cooperation of the power mechanism and the transposition mechanism, the turning of the workpiece and the horizontal position switching of the lever gauge are orderly carried out, that is, before the workpiece is turned, the measuring head of the lever gauge can be separated from the inner wall of the workpiece, so as to avoid affecting the measurement accuracy due to the contact between the measuring head of the lever gauge and the inner wall of the workpiece during the switching of the measurement point; Secondly, since the measuring head of the lever gauge is separated from the inner wall of the workpiece during the turning of the workpiece every time the measurement point is switched, the friction between the measuring head of the lever gauge and the inner wall of the workpiece is effectively prevented, so as to avoid the generation of heat due to friction, which causes the deterioration or drying of the lubricating oil of the lever gauge, thereby affecting the sensitivity and measurement accuracy of the measuring head, and the lever gauge is effectively protected; In addition, after the workpiece is turned each time, the convex column can be returned to the first groove on the disc body through the sliding cooperation between the convex column and the disc body, so that the lever gauge can be automatically reset, and the measuring head thereof recontacts the inner wall of the workpiece. Due to the matching relationship between the convex column and the groove, the reset accuracy of the lever gauge is high, and compared with the manual adjustment reset mode, the error can be effectively reduced, and the measurement accuracy can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 Structure schematic view of one embodiment of the workpiece inner hole concentricity measuring device.

[0018] Figure 2 Structure schematic view of another angle of one embodiment of the workpiece inner hole concentricity measuring device.

[0019] Figure 3 Structure schematic view of still another angle of one embodiment of the workpiece inner hole concentricity measuring device.

[0020] Figure 4 Structure schematic view of still another angle of one embodiment of the workpiece inner hole concentricity measuring device. Figure 2 Structure enlarged view of A in the middle.

[0021] Figure 5 Connection relationship schematic view of the support and the box body in one embodiment of the workpiece inner hole concentricity measuring device.

[0022] Figure 6 Assembly schematic view of the lever gauge and the follow-up plate in one embodiment of the workpiece inner hole concentricity measuring device.

[0023] Figure 7 Internal structure schematic view of the box body in one embodiment of the workpiece inner hole concentricity measuring device.

[0024] Figure 8Structure diagram of another angle of the box body in one embodiment of the workpiece inner hole concentricity measuring device.

[0025] Figure 9 Structure diagram of the power mechanism in one embodiment of the workpiece inner hole concentricity measuring device.

[0026] Figure 10 Structure diagram of the cooperation between the power mechanism and the transposition mechanism in one embodiment of the workpiece inner hole concentricity measuring device.

[0027] In the figure: 1, support; 2, box body; 201, strip-shaped through slot; 3, guide rail; 4, sliding seat; 5, driving block; 6, first driving motor; 7, screw; 8, mounting seat; 9, guide shaft; 10, follower plate; 11, bottom plate; 12, dovetail clamp; 13, lever gauge; 14, rotating shaft; 15, three-jaw chuck; 16, second driving motor; 17, incomplete gear; 18, complete gear; 19, follower arm; 20, convex column; 21, guide arm; 22, telescopic arm; 23, disc body; 2301, first recess; 2302, second recess; 24, connecting piece; 25, vertical arm. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0029] In addition, the elements in the present application are referred to as "fixed to" or "provided on" another element, which can be directly on another element or can have a middle element. When an element is considered to be "connected" to another element, it can be directly connected to another element or can have a middle element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation.

[0030] Please refer to Figures 1-10 In the embodiments of the present application, a workpiece inner hole concentricity measuring device comprises a support 1 and a box body 2 provided on the support 1, and further comprises: A mounting seat 8 is movably provided on the support 1 and can be lifted and lowered by a height adjusting mechanism provided on the support 1. Two guide shafts 9 are fixed on the mounting seat 8. A follower plate 10 is slidably provided on the two guide shafts 9. A lever gauge 13 is provided on the follower plate 10 by a fitting mechanism. Three-jaw chuck 15 is arranged on the box 2, and is used for clamping the workpiece to be measured. The box 2 is provided with a power mechanism capable of driving the three-jaw chuck 15 to rotate. The box 2 is also provided with a transposition mechanism cooperating with the power mechanism. The transposition mechanism can separate or contact the measuring head of the lever watch 13 from the inner wall of the workpiece before and after the three-jaw chuck 15 performs the rotating action.

[0031] It should be noted that the lever watch 13 is an application of the prior art, and its specific working principle will not be described here.

[0032] During measurement, the three-jaw chuck 15 can stably clamp the workpiece to be measured. Then, the mounting seat 8 is adjusted to an appropriate height through the height adjusting mechanism. The lever watch 13 is installed on the mounting seat 8 through the assembly mechanism, so that the measuring head of the lever watch 13 contacts the inner wall of the workpiece to determine the starting point of measurement. Subsequently, the power mechanism works, and the transposition mechanism can first cause the follower plate 10 to slide on the two guide shafts 9. Correspondingly, the lever watch 13 moves horizontally, and the measuring head thereof is separated from the inner wall of the workpiece. Then, the three-jaw chuck 15 rotates to make the workpiece turn. After the workpiece is turned, the measuring head of the lever watch 13 contacts the inner wall of the workpiece again to switch the measurement points. In this way, multiple measurement points can be selected on the circumference of the workpiece. By adjusting the height of the mounting seat 8, different height measurement points on the workpiece can be selected to ensure the completeness of the measurement data.

[0033] In the present application, the cooperation of the power mechanism and the transposition mechanism can make the workpiece turning and the horizontal position switching of the lever watch 13 orderly proceed. That is, before the workpiece turns, the measuring head of the lever watch 13 can be separated from the inner wall of the workpiece to avoid a series of problems caused by the contact between the measuring head of the lever watch 13 and the inner wall of the workpiece during the switching of the measurement points.

[0034] For example, if the measuring head of the lever watch 13 keeps contacting the inner wall of the workpiece during the rotation of the three-jaw chuck 15, the workpiece may vibrate or shake due to the contact, which affects the stability of measurement. The dynamic characteristics (such as rotation speed and direction change) of the rotating workpiece make it more difficult to control such errors. In addition, the lubricating oil on the lever watch 13 is mainly used for key components such as escapement system, barrel, winding and pin setting system, and gear system to ensure the normal operation and long-term stability of the mechanical watch. When the measuring head of the lever watch 13 contacts the rotating workpiece, heat may be generated due to friction, which causes the lubricating oil to deteriorate or dry, thereby affecting the sensitivity and measurement accuracy of the measuring head.

[0035] Please refer toFigure 8 With Figure 9 The box 2 is provided with a rotating shaft 14, a three-jaw chuck 15 is fixed to the rotating shaft 14, and a complete gear 18 is fixed to the end of the rotating shaft 14 away from the three-jaw chuck 15, and the complete gear 18 is matched with the power mechanism. The power mechanism comprises a second driving motor 16 installed in the box 2 and an incomplete gear 17 fixed to the output shaft of the second driving motor 16, and the toothed part of the incomplete gear 17 is matched with the complete gear 18.

[0036] When it is necessary to replace the measuring point, the second driving motor 16 works to drive the incomplete gear 17 to rotate one circle. Specifically, before the toothed part of the incomplete gear 17 is engaged with the teeth of the complete gear 18, the position changing mechanism is triggered to drive the follower plate 10 to slide on the two guide shafts 9, so that the horizontal position of the lever gauge 13 is changed, and the contact state of the measuring head of the lever gauge 13 with the inner wall of the workpiece is converted into a separation state. After the toothed part of the incomplete gear 17 is engaged with the teeth of the complete gear 18, the incomplete gear 17 can start to drive the rotating shaft 14 to rotate through the complete gear 18, so that the three-jaw chuck 15 is rotated to realize the turning of the workpiece and the switching of the measuring point. After the toothed part of the incomplete gear 17 is disengaged from the teeth of the complete gear 18, the turning process of the workpiece is completed, and then the position changing mechanism drives the follower plate 10 to slide reversely on the two guide shafts 9 to reset, and the measuring head of the lever gauge 13 recontacts the inner wall of the workpiece to measure the switched measuring point; The present application adopts the multi-point height difference measurement method to measure the concentricity of the workpiece. The lever gauge 13 needs to measure multiple points distributed equidistantly along the circumference on the inner wall of the lower end and the upper end of the workpiece, respectively. Taking four points as an example: The turning angle of the workpiece each time is 90°, that is, during the engagement of the toothed part of the incomplete gear 17 with the teeth of the complete gear 18, the rotating shaft 14 and the three-jaw chuck 15 can be driven to rotate 90°. Therefore, on each height of the workpiece, four points distributed equidistantly along the circumference can be measured, including the starting point of measurement. Further, after the toothed part of the incomplete gear 17 is disengaged from the complete gear 18, in order to avoid excessive rotation of the three-jaw chuck 15 due to inertia, so that the distribution of the selected points is uneven, a series of problems are caused, for example: If multiple measurement points are selected and distributed along the circumference but not at equal intervals, it may lead to increased measurement errors, reduced reliability of measurement results, and an inability to comprehensively assess concentricity. Equally distributed measurement points can more evenly cover all positions of the workpiece's inner hole, thus reflecting the concentricity situation more comprehensively. If the measurement points are not evenly distributed, some areas may be over-measured while other areas may be ignored, causing the measurement results to be biased towards specific areas and unable to accurately reflect the overall concentricity of the workpiece. In practical implementation, preferably, the housing 2 is also equipped with an electromagnetic brake, which uses electromagnetic principles to generate braking torque. Whenever the toothed part on the incomplete gear 17 separates from the teeth on the complete gear 18, that is, after the rotating shaft 14 and the three-jaw chuck 15 have completed a 90° rotation, the coil of the electromagnetic brake is energized, generating a magnetic field, which causes the armature of the brake and the friction plate and other components to attract or repel each other, thereby generating friction to prevent the rotating shaft 14 from continuing to rotate. The electromagnetic brake has a fast response speed and high control precision, and can achieve a fast and accurate locking function, thereby effectively ensuring the accuracy of the measurement point switching and more comprehensively reflecting the concentricity of the workpiece.

[0037] Please refer to it again. Figures 7-10 The switching mechanism includes a guide arm 21 fixed in the housing 2, a telescopic arm 22 slidably fitted with the guide arm 21, and a disc 23 fixed with the telescopic arm 22. The disc 23 has a sliding fit structure with the output shaft of the second drive motor 16. The telescopic arm 22 is connected to the follower plate 10 via a transmission component. The sliding fit structure includes a follower arm 19 fixed to the end of the output shaft of the second drive motor 16 and a protrusion 20 fixed to the follower arm 19. The disc 23 is D-shaped and has a D-groove adapted to the protrusion 20. The protrusion 20 extends into the D-groove and is slidably connected to the disc 23. The D-groove includes a first groove 2301 with an arc shape and a second groove 2302 connecting the two ends of the first groove 2301 and arranged in a straight line.

[0038] In detail, the first groove 2301 is concentric with the output shaft of the second drive motor 16; Assuming the end of the second groove 2302 closest to the support 1 is the beginning end, and the end furthest from the support 1 is the end, so as to attach... Figure 7 Taking the state shown as an example, at this time, the toothed part of the incomplete gear 17 is separated from the teeth on the complete gear 18 (which can be understood as the measuring head of the lever gauge 13 being in contact with the inner wall), and the protrusion 20 is located at the end of the first groove 2301 near the beginning of the second groove 2302. When the measuring point is switched, the second driving motor 16 works, the follower arm 19 rotates synchronously with the incomplete gear 17, before the toothed part on the incomplete gear 17 meshes with the teeth on the complete gear 18, the convex column 20 deflects into the second groove 2302, and then the convex column 20 is in sliding fit with the disc 23 through the second groove 2302. Specifically, before the follower arm 19 is perpendicular to the second groove 2302, the disc 23 drives the telescopic arm 22 to slide towards the outside of the guide arm 21, the telescopic arm 22 drives the follower plate 10 to slide on the two guide shafts 9 through the transmission member, so that the measuring head of the lever meter 13 gradually moves towards the center of the workpiece, after the follower arm 19 is perpendicular to the second groove 2302, with the continuous rotation of the follower arm 19, the disc 23 reversely moves to reset, correspondingly, the follower plate 10 reversely slides on the guide shaft 9, and the measuring head of the lever meter 13 gradually approaches the inner wall of the workpiece. After the convex column 20 enters the first groove 2301, because the first groove 2301 is concentric with the output shaft of the second driving motor 16, during the movement of the convex column 20 along the first groove 2301, the disc 23 remains stationary, and the measuring head of the lever meter 13 remains in contact with the inner wall of the workpiece. Through the analysis of the above movement process, when the convex column 20 is in the second groove 2302, the measuring head of the lever meter 13 is separated from the inner wall of the workpiece, therefore, the turning of the workpiece with the three-jaw chuck 15 is adapted to occur in this process, and in this process, the toothed part on the incomplete gear 17 meshes with the teeth on the complete gear 18, so as to complete the turning of the workpiece and switch the measuring point. It is emphasized that the time when the convex column 20 is in the second groove 2302 is longer than the meshing time of the toothed part on the incomplete gear 17 with the teeth on the complete gear 18, and before the convex column 20 enters the second groove 2302, the toothed part on the incomplete gear 17 meshes with the teeth on the complete gear 18, and before the convex column 20 is separated from the second groove 2302, the toothed part on the incomplete gear 17 is separated from the teeth on the complete gear 18.

[0039] Please refer to Figure 6 and Figure 8 The transmission member includes a vertical arm 25 fixedly connected with the telescopic arm 22, a gap is reserved between the follower plate 10 and the mounting seat 8, the vertical arm 25 extends into the gap and is in sliding connection with a connecting member 24 fixed to the follower plate 10, and the upper part of the box body 2 is provided with a strip-shaped through groove 201 for the movement of the vertical arm 25.

[0040] In operation, the vertical arm 25 can move synchronously with the telescopic arm 22, and correspondingly, the vertical arm 25 can drive the follower plate 10 to slide horizontally on the two guide shafts 9 through the connecting piece 24, so that the follower plate 10 can drive the lever gauge 13 to move horizontally through the assembling mechanism, so that the measuring head of the lever gauge 13 can be separated from or contacted with the inner wall of the workpiece. The connecting piece 24 is arranged and slidably connected between the vertical arm 25, so as to meet the height adjustment function of the lever gauge 13. In operation, the mounting seat 8 needs to be lifted and lowered by the height adjustment mechanism to change the measurement height, and the connecting piece 24 slides on the vertical arm 25 when the height adjustment mechanism drives the mounting seat 8 to lift and lower.

[0041] Please refer again to Figure 4 and Figure 6 The assembling mechanism comprises a bottom plate 11 arranged on the follower plate 10 and a dovetail clamp 12 mounted on the bottom plate 11, and the dovetail clamp 12 is used to fix the lever gauge 13.

[0042] The dovetail clamp 12 is a clamp designed by dovetail structure, which has strong clamping force and stability. The clamp uniformly distributes clamping force by downward force, avoids lateral pressure, and ensures the stability and repeatability of the workpiece. In this application, the lever gauge 13 is clamped and fixed by the dovetail clamp 12, which can effectively ensure the position stability of the lever gauge 13 during measurement, avoid measurement error caused by position deviation of the lever gauge 13, and provide guarantee for the accuracy of measurement. In addition, it should be noted that in order to facilitate the preparation work of measurement, i.e. to determine the starting point of measurement, in operation, the workpiece to be measured is first fixed by the three-jaw chuck 15, and then the height of the mounting seat 8 is adjusted by the height adjustment mechanism, and then the lever gauge 13 is fixed by the dovetail clamp 12, and then the bottom plate 11 is fixed to the follower plate 10. The follower plate 10 is provided with a plurality of mounting holes, so that the installation position of the bottom plate 11 on the follower plate 10 can be finely adjusted until the measuring head of the lever gauge 13 is contacted with the inner wall of the workpiece, so as to determine the starting point of measurement.

[0043] Please refer again to Figure 5 and Figure 6The height adjusting mechanism comprises two guide rails 3 fixed on the support 1 and two sliding seats 4 respectively slidingly fitted on the two guide rails 3, the mounting seat 8 is fixed with the two sliding seats 4, and the mounting seat 8 is further connected with a servo driving assembly arranged on the support 1. The servo driving assembly comprises a screw rod 7 rotatably arranged on the support 1 and a first driving motor 6 arranged on the top of the support 1, the screw rod 7 is connected with the output end of the first driving motor 6, and a driving block 5 threadedly connected with the screw rod 7 is arranged on the screw rod 7, and the driving block 5 is fixed with the mounting seat 8.

[0044] The first driving motor 6 is a servo motor with a bidirectional output end, when working, the first driving motor 6 drives the screw rod 7 to rotate forward, under the accurate guidance of the guide rails 3 and the sliding seats 4, the driving block 5 can be threadedly matched with the screw rod 7 to move downward, correspondingly, the height of the lever gauge 13 is lowered to adjust the appropriate measuring height, on the contrary, when the first driving motor 6 drives the screw rod 7 to rotate reversely, the height of the lever gauge 13 is increased, the adjustment of the measuring height is realized by the thread matching between the driving block 5 and the screw rod 7, and the driving stability and the precision are high.

[0045] As another embodiment of the present application, a workpiece inner hole concentricity measuring method is further provided, and the measuring device is used, and the method comprises the following steps. Step one, the workpiece to be measured is fixed by the three-jaw chuck 15, the mounting seat 8 is driven to descend by the height adjusting mechanism, and the lever gauge 13 is mounted on the follower plate 10 by the assembling mechanism; Step two, the position of the lever gauge 13 is finely adjusted, the measuring head of the lever gauge 13 contacts the inner wall of the lower end of the workpiece, and the value of the lever gauge 13 is recorded as a; Step three, the three-jaw chuck 15 drives the workpiece to intermittently rotate by 90° by the power mechanism, and the values of the lever gauge 13 at the respective measuring points are recorded as b, c and d respectively; Step four, the three-jaw chuck 15 continues to rotate, at the same time, the mounting seat 8 is driven to ascend by the height adjusting mechanism, so that the measuring head of the lever gauge 13 reaches the upper end of the workpiece and contacts the inner wall of the upper end of the workpiece, and the value of the lever gauge 13 is recorded as a1; Step five, step three is repeated, and the values of the lever gauge 13 are recorded as b1, c1 and d1; Step six, the lower end cross-section center coordinates (X 下 , Y 下 ) and the upper end cross-section center coordinates (X 上 , Y 上): Set the center of the three-jaw chuck as the reference origin (0, 0), at this time, the lower end readings a, b, c, d and the upper end readings a1, b1, c1, d1 represent the radial distance of the hole wall in each angle direction to the reference center, the calculation formula of the lower end center coordinates (X 下 , Y 下 ) is: , ; the calculation formula of the upper end section center coordinates (X 上 , Y 上 ) is: , ; therefore, the concentricity error is the radial distance between the upper and lower center: ; if the concentricity error is within the tolerance, the workpiece is qualified; if the concentricity error is out of the tolerance, the workpiece is unqualified.

[0046] It is apparent to those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the present application being defined by the appended claims rather than the foregoing description, and it is intended that all changes which come within the meaning and range of equivalency of the claims are embraced therein. Any reference signs in the claims should not be construed as limiting the claims to the figures in which the reference signs are used.

[0047] In addition, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A workpiece inner hole concentricity measuring device, comprising a support and a box body arranged on the support; characterized in that Further comprising: a mounting seat movably arranged on the support and capable of being driven to rise and fall by a height adjusting mechanism arranged on the support, two guide shafts being fixed on the mounting seat, a follower plate being slidably arranged on the two guide shafts, and a lever table being arranged on the follower plate through an assembly mechanism, the lever table being used for fixing a measuring head; a three-jaw chuck arranged on the box body and used for clamping a workpiece to be measured, a power mechanism capable of driving the three-jaw chuck to rotate being arranged in the box body, and a transposition mechanism cooperating with the power mechanism also being arranged in the box body, the transposition mechanism being capable of separating the measuring head of the lever table from the inner wall of the workpiece before and after the three-jaw chuck performs a rotating action.

2. The device for measuring the concentricity of the inner hole of a workpiece according to claim 1, wherein A rotating shaft is rotatably arranged in the box body, the three-jaw chuck is fixed with the rotating shaft, and a complete gear is fixed at an end of the rotating shaft away from the three-jaw chuck, the complete gear cooperating with the power mechanism.

3. The device of claim 2, wherein, The power mechanism comprises a second driving motor arranged in the box body and an incomplete gear fixed on an output shaft of the second driving motor, the toothed part of the incomplete gear cooperating with the complete gear.

4. The device of claim 3, wherein, The transposition mechanism comprises a guide arm fixed in the box body, a telescopic arm slidably sleeved with the guide arm, and a disc body fixed with the telescopic arm, a sliding cooperation structure being arranged between the disc body and the output shaft of the second driving motor, and the telescopic arm being connected with the follower plate through a transmission member.

5. The device of claim 4, wherein, The sliding cooperation structure comprises a follower arm fixed at the end of the output shaft of the second driving motor and a convex column fixed with the follower arm, the disc body being arranged in a "D" shape and having a D-shaped groove adapted to the convex column; wherein the convex column extends into the D-shaped groove and is slidably connected with the disc body, the D-shaped groove comprising a first groove arranged in an arc shape and a second groove arranged in a straight line and connecting two ends of the first groove.

6. The device of claim 5, wherein, The transmission member comprises a vertical arm fixedly connected with the telescopic arm, a gap being reserved between the follower plate and the mounting seat, the vertical arm extending into the gap and being slidably connected with a connecting member fixed on the follower plate, and a strip-shaped through groove being arranged on the upper part of the box body for the vertical arm to move.

7. The device of claim 1, wherein, The assembly mechanism comprises a bottom plate arranged on the follower plate and a dovetail clamp arranged on the bottom plate, the dovetail clamp being used for fixing the lever table.

8. The device of claim 1, wherein, The height adjusting mechanism comprises two guide rails fixed on the support and two sliding seats slidably embedded in the two guide rails, respectively, the mounting seat being fixed with the two sliding seats, and the mounting seat further being connected with a servo driving assembly arranged on the support.

9. The device of claim 8, wherein, The servo driving assembly comprises a lead screw rotatably arranged on the support and a first driving motor arranged on the top of the support, the lead screw being connected with the output end of the first driving motor, and a driving block being arranged on the lead screw and threadedly connected with the lead screw, the driving block being fixed with the mounting seat.

10. A method of measuring the concentricity of a bore of a workpiece using the measuring device of claim 1, characterized by, The method comprises the following steps: Step one, use three jaw chuck to fix the workpiece, drive the mounting seat down through height adjustment mechanism, install the lever gauge on the follow-up plate through assembly mechanism; Step two, fine-tune the position of the lever gauge, make the measuring head of the lever gauge contact the inner wall of the lower end of the workpiece, the value of the lever gauge is recorded as a; Step three, drive the three jaw chuck to rotate intermittently 90° with the workpiece through power mechanism, the value of the lever gauge at each measuring point is recorded as b, c, d respectively; Step four, continue to rotate the three jaw chuck, at the same time, drive the mounting seat to rise through the height adjustment mechanism, make the measuring head of the lever gauge reach the upper end of the workpiece, contact the inner wall of the upper end of the workpiece, the value of the lever gauge is recorded as a1; Step five, repeat step three, the value of the lever gauge is recorded as b1, c1, d1; Step six, calculate the lower end section circle center coordinates (X 下 , Y 下 ) and the upper end section circle center coordinates (X 上 , Y 上 ): Set the three-jaw chuck center as the reference origin (0, 0), at this time, the lower end readings a, b, c, d and the upper end readings a1, b1, c1, d1 represent the radial distance of the hole wall in each angle direction to the reference center, the calculation formula of the lower end circle center coordinates (X 下 , Y 下 ) is: , ; the calculation formula of the upper end section circle center coordinates (X 上 , Y 上 ) is: , ; therefore, the concentricity error is the radial distance between the upper and lower circle centers: ; if the concentricity error is within the tolerance, the workpiece is qualified; if the concentricity error is not within the tolerance, the workpiece is unqualified.

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