Angle encoder calibration device and calibration method

Abstract

The invention discloses an angle encoder calibration device and calibration method in the field of encoder calibration, and the device comprises a flexible clamping mechanism which is used for installing a stator on an encoder and buffering the stress generated when a rotor on the encoder jumps relative to the stator; the mounting and adjusting mechanism comprises a mounting mechanism and an adjusting mechanism, the mounting mechanism is used for mounting a rotor on the encoder, and the adjusting mechanism is arranged on the mounting mechanism and used for adjusting the overlap ratio of the central axis of the mounting mechanism and an upper shaft system of the rotary table; the rotary table is used for driving the rotor to rotate together. According to the angle encoder calibration device, the flexible clamping mechanism is arranged to buffer the influence of stress when a rotor on the encoder jumps relative to a stator, the encoder is connected with the mounting mechanism and is consistent with the daily working state of the encoder, the coaxiality of the mounting mechanism and a shaft system of a rotary table is adjusted through the adjusting mechanism, and the calibration precision is improved. The shaft system coaxiality of the rotor and the rotary table is ensured, and the test precision of the encoder is improved.

Description

Technical Field

[0001] The present invention relates to the field of encoder calibration, and particularly to an angle encoder calibration device and a calibration method. Background Art

[0002] At present, the methods for calibrating angle encoders mainly include the direct measurement method using a turntable and the comparative measurement method using a multi-faceted prism. As the method of combining a multi-faceted prism and an autocollimator for comparative measurement, due to its complex structure, complicated implementation steps, and poor operability, it is rarely used in actual applications.

[0003] The measuring devices for direct measurement using a turntable mainly include: a platform, a bracket, a coupling, a turntable, etc. Among them, the accuracy of the turntable and the performance of the coupling directly affect the detection accuracy of the entire angle encoder.

[0004] Currently, when domestic testing institutions detect angle encoders, the rotating shaft of the encoder to be tested is connected to the rotating shaft of the turntable through a coupling to test the angle indication value of the encoder. The stator of the encoder is fixed on a rigid bracket. Due to manufacturing accuracy, there is a deviation between the encoder shafting and the turntable rotating shafting. After being connected through a coupling, a constraint relationship is formed. During the testing process, the stress generated will damage the turntable and the encoder shafting, and there are errors in the test data. Summary of the Invention

[0005] The purpose of the present invention is to provide an angle encoder calibration device and a calibration method, which use a flexible clamping mechanism to install the stator, thereby buffering the stress when the rotor jumps relative to the stator and improving the measurement accuracy.

[0006] To solve the above technical problems, the following technical solutions are adopted: In a first aspect, the present invention provides an angle encoder calibration device, including: A flexible clamping mechanism for installing the stator on the encoder and buffering the stress when the rotor on the encoder jumps relative to the stator; An installation and adjustment mechanism including an installation mechanism and an adjustment mechanism. The installation mechanism is used to install the rotor on the encoder, and the adjustment mechanism is arranged on the installation mechanism and used to adjust the coincidence degree of the central axis of the installation mechanism and the shafting on the turntable; A turntable for installing the installation and adjustment mechanism and driving the rotor to rotate together; Wherein, before installing the rotor, the coaxiality between the turntable and the installation mechanism is calibrated using a calibration mandrel, and the installation mechanism is adjusted through the adjustment mechanism until the central axis of the installation mechanism coincides with the shafting on the turntable.

[0007] Optionally, the rotor of the encoder is a shaft or a circular hole, and the stator is of any shape.

[0008] Optionally, the installation mechanism includes a three-jaw chuck, and the adjustment mechanism includes a radial fine-tuning screw. The three-jaw chuck is installed on the chuck mounting seat through a chuck tightening nut. The radial fine-tuning screw is arranged on the outer side wall of the chuck mounting seat for adjusting the radial position of the three-jaw chuck.

[0009] Optionally, an installation shaft is further provided on the chuck mounting seat. The installation shaft is fitted and installed with an inner conical hole bushing on the turntable through a bushing tightening nut.

[0010] Optionally, the radial fine-tuning screws are arranged on the outer side wall of the chuck mounting seat at an interval of 90 degrees.

[0011] Optionally, the flexible clamping mechanism includes an annular bracket and a plurality of adjustable pressing shafts on the annular bracket. The adjustable pressing shafts are movably connected to the annular bracket, and the plurality of adjustable pressing shafts are circumferentially and evenly spaced on the annular bracket.

[0012] Optionally, the annular bracket is installed on the base through a column. The column is a structure with adjustable height, and a column tightening nut for locking the height of the column is provided on the column.

[0013] Optionally, an elastic mechanism for buffering the stress when the rotor jumps relative to the stator is provided at the front end of the adjustable pressing shaft. The elastic mechanism contacts and presses the stator on the encoder.

[0014] Optionally, the elastic mechanism includes a rubber column, a fastening bolt, and a spring coil. The rubber column is installed on the end face of the adjustable pressing shaft through the fastening bolt. The spring coil is sleeved on the fastening bolt and is located between the rubber column and the adjustable pressing shaft.

[0015] In a second aspect, the present invention provides a calibration method for an angle encoder, including the following steps: The turntable is restored to the zero-position working position. The installation and adjustment mechanism is installed on the turntable, the calibration mandrel is installed on the installation mechanism, and the deviation amount between the calibration mandrel and the turntable is collected. When the deviation amount is greater than the ideal value, the adjustment mechanism is adjusted until the collected deviation amount is less than or equal to the ideal value, and then the calibration mandrel is removed; The rotor on the encoder is installed on the installation mechanism, and the stator on the encoder is installed on the flexible clamping mechanism; The turntable rotates a standard angle, and the encoder collects the encoder angle. The difference between the standard angle and the encoder angle is the accuracy of the encoder.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention: 1. The angle encoder calibration device provided by the present invention buffers the influence of stress when the rotor on the encoder jumps relative to the stator by setting a flexible clamping mechanism. The encoder is connected to the installation mechanism, which is consistent with the daily working state of the encoder. The coaxiality of the installation mechanism and the shaft system of the turntable is adjusted through an adjustment mechanism to ensure the coaxiality of the rotor and the shaft system of the turntable, thereby improving the test accuracy of the encoder.

[0017] 2. The structure of the present invention is simple and easy to operate. The adjustment mechanism provided is a radial fine-tuning screw. The radial position of the three-jaw chuck is adjusted through the radial fine-tuning screw to ensure the coaxiality of the three-jaw chuck and the turntable, thereby ensuring the coaxiality of the rotor and the turntable. The stator is installed by setting an adjustable pressing shaft and an annular bracket. A rubber column is provided at one end of the adjustable pressing shaft in contact with the stator. Multiple adjustable pressing shafts press the stator against each other to fix the position of the stator, and the elastic force of the rubber column is used to buffer the stress when the rotor and the stator jump relative to each other.

[0018] 3. For the calibration method provided by the present invention, first, the coaxiality of the installation mechanism is calibrated through a calibration mandrel to ensure that the coaxiality of the installation mechanism and the turntable meets the preset test requirements. Then, the encoder is installed for testing. During the testing process, the turntable operation program is compiled according to the encoder standard. After the testing is completed, the encoder angle value is read to calculate the encoder accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of the installation and adjustment mechanism in the embodiment of the present invention; Figure 2 is a schematic structural diagram of the flexible clamping mechanism in the embodiment of the present invention; Figure 3 is a schematic structural diagram of the elastic mechanism in the embodiment of the present invention.

[0020] DESCRIPTION OF THE REFERENCE NUMERALS: 1. Turntable; 2. Inner tapered hole bushing; 3. Chuck mounting seat; 4. Three-jaw chuck; 5. Mounting shaft; 6. Bushing tightening nut; 7. Radial fine-tuning screw; 8. Chuck tightening nut; 9. Annular bracket; 10. Adjustable pressing shaft; 11. Rubber column; 12. Column; 13. Base; 14. Column tightening nut; 15. Fastening bolt; 16. Spring ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use.

[0022] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances. Embodiment 1

[0023] This embodiment provides an angle encoder calibration device, including a flexible clamping mechanism, an installation and adjustment mechanism, and a turntable 1. The installation and adjustment mechanism is connected to the turntable 1. The installation and adjustment mechanism mounts the rotor on the encoder. The turntable 1 drives the rotor to rotate. After the turntable 1 rotates by an angle, the encoder collects the rotor angle, and the difference between the two angles is the measurable accuracy of the encoder.

[0024] The flexible clamping mechanism is used to mount the stator on the encoder. The flexible clamping mechanism can buffer the stress when the rotor jumps relative to the stator, avoiding the influence on the stress measurement accuracy between the rotor and the stator.

[0025] The installation and adjustment mechanism includes an installation mechanism and an adjustment mechanism. The rotor is mounted on the installation mechanism. The adjustment mechanism is used to adjust the shaft alignment of the installation mechanism and the turntable 1, so that the shaft alignment of the rotor mounted on the installation mechanism and the stator meets the experimental preset requirements.

[0026] Before measuring the encoder accuracy, first calibrate the coaxiality of the installation and adjustment mechanism and the turntable 1 through a calibration mandrel. Install the calibration mandrel on the installation mechanism, use an inductive micrometer to contact the outer diameter of the calibration mandrel, collect the deviation of the calibration mandrel and the axis system of the turntable 1 within the angular range of 0 - 360°, then compare the deviation with the set ideal value. When the deviation is greater than the ideal value, adjust the radial position of the installation mechanism through the adjustment mechanism, thereby adjusting the radial position of the calibration mandrel, and then measure the deviation until the measured deviation is less than or equal to the ideal value. Then remove the calibration mandrel and test the encoder. Among them, the rotor on the encoder is connected to the installation mechanism, the stator is installed on the flexible clamping mechanism, the turntable 1 drives the rotor to rotate, and the difference between the rotation angle output by the turntable 1 and the rotation angle measured by the encoder is the accuracy of the encoder. Example 2

[0027] The difference between this embodiment and Embodiment 1 is as follows: As Figure 1 shown, in this embodiment, the installation mechanism is a three-jaw chuck 4, and the adjustment mechanism is a radial fine-tuning screw 7. The three-jaw chuck 4 is installed on the chuck mounting seat 3 through a chuck tightening nut 8. The radial fine-tuning screw 7 is installed on the outer side wall of the chuck mounting seat 3. One end of the radial fine-tuning screw 7 penetrates from the outer side wall of the chuck mounting seat 3 to the three-jaw chuck 4, and the end of the radial fine-tuning screw 7 acts on the three-jaw chuck 4. Four radial fine-tuning screws 7 are arranged at 90-degree intervals on the outer side wall of the chuck mounting seat 3. The radial position of the three-jaw chuck is adjusted through the four radial fine-tuning screws 7, so that the central axis of the three-jaw chuck 4 coincides with the axis system on the turntable 1.

[0028] Install the three-jaw chuck 4 on one end face of the chuck mounting seat 3, and an installation shaft 5 is provided on the other end face. The installation shaft 5 is fitted and installed with the inner cone hole bushing 2 on the turntable 1 through a bushing tightening nut 6, so that the chuck mounting seat 3 and the three-jaw chuck 4 are driven to rotate together, thereby driving the encoder rotor on the three-jaw chuck.

[0029] The rotor of the encoder can be a shaft or a round hole. When the rotor is a shaft, the rotor is clamped outside the shaft by the jaws of the three-jaw chuck 4. When the rotor is a round hole, the rotor is clamped inside the round hole by the jaws of the three-jaw chuck 4. Select a three-jaw chuck 4 with a suitable specification size according to the size of the measured encoder. Among them, a three-jaw chuck 4 of the SE-02 series can be selected.

[0030] As Figure 2As shown in the figure, the flexible clamping mechanism includes an annular bracket 9 and four adjustable pressing shafts 10. The annular bracket 9 is installed on the base 13 through an adjustable column 12. An adjustable column fixing nut 14 for locking the height is provided on the adjustable column 12. The column 12 includes an upper section and a lower section. One end of the upper section is arranged on the annular base 13, and one end of the lower section is arranged on the base 13. The other end of the upper section is arranged inside the other end of the lower section and can move. A thread is provided on the other end of the upper section. The height is locked by the column fixing nut 14 and the thread. When the height needs to be adjusted, loosen the column fixing nut 14, adjust the relative position of the upper section and the lower section, and then tighten the column fixing nut 14 on the thread to lock the height.

[0031] The four adjustable pressing shafts 10 are evenly spaced on the annular bracket 9. Through holes penetrating from the outer wall to the inside are provided on the annular bracket 9 for installing the adjustable pressing shafts 10. One end of the adjustable pressing shaft 10 extends from the annular bracket 9 through the through hole to the inside. The adjustable pressing shaft 10 can be telescopic in the through hole and is stably installed. When installing the stator of the encoder, the stator is located at the center position of the annular bracket 9. The end of the adjustable pressing shaft 10 presses against the outer wall of the stator of the encoder, and the position of the stator is fixed by the four adjustable pressing shafts 10.

[0032] As Figure 2 、 Figure 3 As shown in the figure, an elastic mechanism is provided on the end face of the adjustable pressing shaft 10 in contact with the outer wall of the stator. In this embodiment, the elastic mechanism is a rubber column 11. An installation hole is provided on the end face of the adjustable pressing shaft 10. A through hole communicating with both ends is provided on the rubber column 11. One end of the rubber column 11 extends into the installation hole. The fastening bolt 15 extends into the adjustable pressing shaft 10 from the through hole on the rubber column 11 to install the rubber column 11 on the end face of the adjustable pressing shaft 10. In the installation hole, a spring washer 16 is also provided. The spring washer 16 is sleeved on the fastening bolt 15 and is located between the rubber column 11 and the adjustable pressing shaft 10. The spring washer 16 is used for the rebounding effect after the rubber column is used. When installing the stator of the encoder, the rubber column 11 at the end of the adjustable pressing shaft 10 is closely attached to the outer wall of the stator. The stator is stably installed on the outer wall of the stator through the rebounding effect of the rubber column 11, and the stress during the jumping of the rotor relative to the stator can be buffered by the elastic force of the rubber column 11.

[0033] During use, first, after calibrating the coaxiality of the spindle system of the three-jaw chuck 4 and the rotating shaft through a calibration mandrel, adjust the column 12 so that the annular bracket 9 is at an appropriate height. Install the rotor on the encoder on the three-jaw chuck 4, and install the stator on the encoder at the central position of the annular bracket 9 through the adjustable pressing shaft 10. Compile the operation program of the turntable 1 according to the encoder test standard (the turntable 1 outputs different rotation angles). The turntable 1 drives the encoder to operate according to the operation program. After the operation of the turntable 1 is completed, read the angle value of the encoder during the operation of the turntable 1 (the measured angle of the encoder corresponding to the rotation angle output by the turntable 1), so as to determine the accuracy of the encoder.

[0034] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. An angle encoder calibration device, characterized in that, Comprising: A flexible clamping mechanism for installing the stator on the encoder and buffering the stress when the rotor on the buffer encoder jumps relative to the stator; An installation and adjustment mechanism, including an installation mechanism and an adjustment mechanism. The installation mechanism is used to install the rotor on the encoder, and the adjustment mechanism is arranged on the installation mechanism and used to adjust the coincidence degree between the central axis of the installation mechanism and the shafting on the turntable; A turntable for installing the installation and adjustment mechanism and driving the rotor to rotate together; Wherein, before installing the rotor, the coaxiality between the turntable and the installation mechanism is calibrated using a calibration mandrel, and the installation mechanism is adjusted through the adjustment mechanism until the central axis of the installation mechanism coincides with the shafting on the turntable.

2. The angle encoder calibration device according to claim 1, characterized in that The rotor of the encoder is a shaft or a round hole, and the stator can be of any shape.

3. The angle encoder calibration device according to claim 1, wherein The installation mechanism includes a three-jaw chuck, and the adjustment mechanism includes a radial fine-tuning screw. The three-jaw chuck is installed on the chuck mounting seat through a chuck tightening nut, and the radial fine-tuning screw is arranged on the outer side wall of the chuck mounting seat and used to adjust the radial position of the three-jaw chuck.

4. The angle encoder calibration device according to claim 3, characterized in that, An installation shaft is further provided on the chuck mounting seat, and the installation shaft is installed in cooperation with the inner tapered hole bushing on the turntable through a bushing tightening nut.

5. The angle encoder calibration device according to claim 3, characterized in that, The radial fine-tuning screws are arranged at intervals of 90 degrees on the outer side wall of the chuck mounting seat.

6. The angle encoder calibration device according to claim 1, wherein, The flexible clamping mechanism includes an annular bracket and a plurality of adjustable pressing shafts on the annular bracket. The adjustable pressing shafts are movably connected to the annular bracket, and the plurality of adjustable pressing shafts are circumferentially and evenly spaced on the annular bracket.

7. The angle encoder calibration device according to claim 6, characterized in that, The annular bracket is installed on the base through a column, the column is a structure with adjustable height, and a column tightening nut for locking the height of the column is provided on the column.

8. The angle encoder calibration device according to claim 6, wherein, An elastic mechanism for buffering the stress when the rotor jumps relative to the stator is provided at the front end of the adjustable pressing shaft, and the elastic mechanism contacts and presses the stator on the encoder.

9. The angle encoder calibration device according to claim 8, wherein, The elastic mechanism includes a rubber column, a fastening bolt and a spring ring. The rubber column is installed on the end face of the adjustable pressing shaft through the fastening bolt, and the spring ring is sleeved on the fastening bolt and is located between the rubber column and the adjustable pressing shaft.

10. A calibration method for an angle encoder, characterized in that, Realized by using the angular encoder calibration device according to any one of claims 1-9, including the following steps: The turntable returns to the zero position working position, the installation and adjustment mechanism is installed on the turntable, the calibration mandrel is installed on the installation mechanism, the deviation amount between the calibration mandrel and the turntable is collected. When the deviation amount is greater than the ideal value, the adjustment mechanism is adjusted until the collected deviation amount is less than or equal to the ideal value, and then the calibration mandrel is removed; The rotor on the encoder is installed on the installation mechanism, and the stator on the encoder is installed on the flexible clamping mechanism; The turntable rotates a standard angle, the encoder collects the encoder angle, and the difference between the standard angle and the encoder angle is the accuracy of the encoder.

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