High-precision linear displacement sensor

Abstract

The utility model discloses a high precision linear displacement sensor, comprising a rotating shaft rotatably arranged in a housing, one end of the rotating shaft is fixedly provided with a probe, the other end of the rotating shaft is connected with an angle encoder, and the rotating shaft between the angle encoder and the probe is also provided with a pose sensor. Compared with the prior art, the abbe error is corrected through the cooperation of the angle encoder and the pose sensor, so that the measurement result is converted from the relative variation to the absolute variation, and compared with a traditional lever meter, the measurement precision is higher, the device can be integrated into intelligent manufacturing, and the production efficiency is improved. Compared with an existing digital lever meter, the cost is lower. And secondly, the linear displacement sensor provided by the utility model has lower requirements on pose placement when in use, further reduces the learning cost of a beginner, and is helpful for improving the reliability of a measurement result and the working efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of linear displacement sensor manufacturing, in particular to a high-precision linear displacement sensor. Background Art

[0002] Lever gauges are measuring instruments widely used in mechanical production and processing scenarios such as shape inspection, tolerance control, and wear detection. Traditional lever gauges have the following drawbacks:

[0003] 1. Unable to correct Abbe error: Due to design limitations, traditional lever gauges only use a purely mechanical lever structure to amplify probe displacement and lack the structure and capability to correct Abbe error.

[0004] 2. Difficulty in data recording: Traditional leverage meters usually do not have digital functions, and data recording and analysis need to rely on manual operations, which is not conducive to large-scale data processing and modern production needs.

[0005] Existing digital lever meters also have the following defects:

[0006] 1. High cost: Digital lever meters are complex to manufacture and contain electronic components and sensors, so they are generally more expensive than traditional lever meters. This may not be feasible for small and medium-sized businesses with limited budgets.

[0007] 2. Unable to correct Abbe error: Since it uses the same design principle as the traditional lever meter, it is also unable to consider the error caused by different measurement postures on the measurement results, that is, it is unable to correct Abbe error.

[0008] Fundamentally, whether it is a traditional lever meter or an existing digital lever meter, its algorithm design still uses the measurement principle of a traditional lever meter, so it is impossible to compensate for the Abbe error. Therefore, the measurements of both can only be relative deviation measurements, not absolute deviation measurements. Utility Model Content

[0009] (1) Technical issues to be resolved

[0010] Based on this, the utility model proposes a high-precision linear displacement sensor to solve the problem that the existing lever meter cannot correct the Abbe error.

[0011] (2) Technical solution

[0012] In order to overcome the above-mentioned problems or at least partially solve the above-mentioned problems, the present utility model provides a linear displacement sensor with a measurement method for a high-precision linear displacement sensor, comprising a rotating shaft rotatably arranged in a shell, a measuring needle fixed to one end of the rotating shaft, an angle encoder connected to the other end of the rotating shaft, and a posture sensor further provided on the rotating shaft between the angle encoder and the measuring needle.

[0013] Preferably, the measuring needle is threadedly connected to the rotating shaft.

[0014] Preferably, the posture sensor is fixed on the rotating shaft by bonding.

[0015] Preferably, a plane is provided in the middle of the rotating shaft, and the posture sensor is fixed on the plane by gluing.

[0016] Preferably, the rotating shaft is provided with a connecting hole adapted to the rotating rod of the angle encoder, and the connecting hole is coaxially arranged with the rotating shaft.

[0017] Preferably, a rear end plate is fixed to the housing, a battery is provided in the rear end plate, and the angle encoder is provided between the rear end plate and the rotating shaft.

[0018] Preferably, the housing is further fixed with a front end cover, and the rotating shaft is rotatably connected to the front end cover.

[0019] Preferably, it further comprises a clamping member, which is clamped on the housing, and the clamping member and the measuring needle are respectively arranged at two ends of the housing.

[0020] Preferably, it further includes a display screen and a controller, and the controller is communicatively connected to the display screen, the angle encoder and the posture sensor respectively.

[0021] Preferably, a support arm is fixed on the rotating shaft, and a screw hole adapted to fit the measuring needle is provided on the support arm.

[0022] (3) Beneficial effects

[0023] Compared with existing technologies, the present invention corrects Abbe errors through the combination of an angle encoder and a posture sensor, converting measurement results from relative changes to absolute changes. Compared with traditional lever meters, the present invention offers higher measurement accuracy and can be integrated into intelligent manufacturing. Compared with existing digital lever meters, the present invention is also more cost-effective. Furthermore, the linear displacement sensor provided by the present invention has lower requirements for posture placement during use, further reducing the learning cost for beginners and helping to improve the reliability of measurement results and work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0025] Figure 1 Schematic diagram of the position of the stylus of the present invention;

[0026] Figure 2 This is a statistical diagram of the measured values ​​of the linear displacement sensor of the present utility model;

[0027] Figure 3 This is a statistical diagram of the measurement indications of a traditional lever meter;

[0028] Figure 4 It is a structural diagram of the utility model;

[0029] Figure 5 This is a perspective structural diagram of the utility model;

[0030] Figure 6 This is the main view of the utility model;

[0031] Figure 7 It is a partial structural diagram of the utility model.

[0032] Description of reference numerals:

[0033] 1. Housing, 2. Rotating shaft, 3. Probe, 4. Angle encoder, 5. Posture sensor, 6. Display, 7. Rear end plate, 8. Front end cover, 9. Battery, 21. Plane, 22. Connecting hole, 100. Clamp, 200. Support arm. DETAILED DESCRIPTION

[0034] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without violating the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] The measurement process of a traditional lever gauge is as follows: after placing the stylus 3 on the surface to be measured, as the workpiece / instrument moves, the height change of the surface will cause the stylus 3 to rotate, and the height change of the surface to be measured is converted into the angle change of the stylus 3.

[0036] Initially, the length of stylus 3 is assumed to be 11.2 mm (standard), and the angle P read by angle encoder 4 is 2.000°. Assuming the measurement is performed under ideal conditions (the X and Y axis pose variables of stylus 3 are both 0, that is, stylus 3 is completely horizontal, and the diameter of the ball at the tip of stylus 3 is infinitely close to 0), the measured height change is 0.390874 mm.

[0037] The effect of the tip ball diameter on the change in plane height was investigated by introducing a 0.1mm tip ball diameter, with all other conditions remaining unchanged (angle P remained at 2.000°). The measured height change was 0.390874mm, consistent with the case when the ball diameter was 0mm. Because the ball remains tangent to the measured plane, the distance between the tip center and the measured plane before and after stylus 3's rotation is always equal to the ball diameter. Subtracting the height difference before and after eliminates the ball diameter, the change in ball diameter has no effect on the measurement result.

[0038] The axial inclination angle of stylus 3's rotating shaft 2, or the X-axis inclination angle, was set to 15°, while other conditions remained unchanged (rotation angle P remained at 2.000°). The measured height change was 0.379321 mm, which is different from the X-axis inclination angle of 0°. Therefore, the measurement accuracy of the linear displacement sensor is affected by the X-axis inclination angle.

[0039] The radial inclination angle of the rotating shaft 2 of the stylus 3, that is, the Y-axis posture inclination angle, is set to 10°, and other conditions remain unchanged (the rotation angle P remains 2.000°). Under the premise of keeping the height change value at 0.379321mm, the measured rotation angle P becomes 2.0306°, which is different from when the Y-axis inclination angle is 0°. Therefore, the measurement accuracy of the linear displacement sensor is affected by the Y-axis posture inclination angle.

[0040] Refer to the attached Figure 4 and attached Figure 5 This embodiment provides a high-precision linear displacement sensor, including a rotating shaft 2 rotatably arranged in a shell 1, a measuring needle 3 is fixed to one end of the rotating shaft 2, and an angle encoder 4 is connected to the other end of the rotating shaft 2. A posture sensor 5 is also provided on the rotating shaft 2 between the angle encoder 4 and the measuring needle 3.

[0041] An implementation manner of the measuring needle 3: the measuring needle 3 is threadedly connected to the rotating shaft 2 so as to be compatible with an existing universal standard measuring needle 3.

[0042] As another embodiment of the present invention: Figure 7 The position sensor 5 is fixed to the shaft 2 by bonding. Specifically, a flat surface 21 is provided in the middle of the shaft 2, and the position sensor 5 is fixed to the flat surface 21 by gluing. Using gluing can reduce costs while ensuring stability and save internal space. Secondly, because lever gauge measurements are very sensitive to load, gluing can also prevent the shaft 2 material from being deformed or cracked by external forces. Furthermore, by gluing multiple connection points together, stress is dispersed, which can also improve the overall structural strength.

[0043] As another embodiment of the present invention, this embodiment further includes a display screen 6 and a controller, which is respectively in communication with the display screen 6, the angle encoder 4, and the posture sensor 5. Directly displaying the measurement results on the display screen 6 eliminates the time-consuming manual reading process and avoids errors caused by visual observation.

[0044] Specifically, a connecting hole 22 is provided on the rotating shaft 2 , and the connecting hole 22 is coaxially arranged with the rotating shaft 2 . The rotating rod of the angle encoder 4 is inserted into the connecting hole 22 and then fixed by bonding.

[0045] As another embodiment of the present invention: the shell 1 is fixed with a rear end plate 7, the battery 9 is installed in the rear end plate 7, the angle encoder 4 is arranged between the rear end plate 7 and the rotating shaft 2, and the tail of the angle encoder 4 is inserted into the rear end plate 7 and then fixed by bonding.

[0046] As another embodiment of the present invention: Figure 6 The housing 1 is also fixed with a front end cover 8, and the rotating shaft 2 is rotatably connected to the front end cover 8.

[0047] This embodiment further includes a clamping member 100, which is clamped on the housing 1. The clamping member 100 and the measuring needle 3 are respectively provided at two ends of the housing 1. Specifically, the clamping member 100 is clamped into the housing 1 and then fixed by bonding.

[0048] Specifically, the display screen 6 is fixed to the housing 1 by screws.

[0049] As another embodiment of the present invention: a support arm 200 is fixed on the rotating shaft 2 , a screw hole adapted to the measuring needle 3 is provided on the support arm 200 , and the measuring needle 3 is threadedly connected to the support arm 200 .

[0050] The utility model provides a method for using a high-precision linear displacement sensor, comprising the following steps:

[0051] S1: The stylus 3 is attached to the workpiece to be measured. When the workpiece to be measured moves, the controller obtains the rotation angle p° of the stylus 3, the inclination angle X° of the stylus 3 in the X direction, and the inclination angle Y° of the stylus 3 in the Y direction; refer to the attached Figure 1 The angle between the stylus 3 and the reference plane is the inclination angle X° of the stylus 3 in the X direction, and the angle between the rotation axis 2 and the reference plane is the inclination angle Y° of the stylus 3 in the Y direction.

[0052] S2: The controller then calculates the height change value H of the workpiece to be measured using the following formula (1):

[0053] H=L×sinP°×cosY°×sin(90-X)°+(LL×cosP°)×sinX° (1)

[0054] Wherein, L is the length of the measuring needle 3.

[0055] S3: The controller displays the height change value H of the workpiece to be measured on the display screen 6, so that the height change value of the workpiece to be measured can be obtained in real time, and it is also convenient to connect with other digital devices.

[0056] Dial gauge calibration experiment

[0057] The linear displacement sensor (digital lever meter) using the measurement method provided by the utility model and the traditional lever meter were used to select the same measuring area for measurement. By turning the hand wheel of the machining center to ensure the parallel movement of the worktable, the readings were taken at intervals of 0.05mm, and a total of 17 points of data were collected (the whole range is 0.8mm) and a calibration indication curve was drawn. Figure 2 The data measured by the linear displacement sensor of this utility model has a single-axis range indication error of 4μm, a double-axis range indication error of 4μm, and a return error of 1μm. Figure 3 The data is measured by a traditional lever meter, with a single-vector range indication error of 10μm, a two-vector range indication error of 10μm, and a return error of 3μm.

[0058] The correlation coefficients of the forward and reverse stroke measurement results of the two meters are calculated respectively:

[0059] R 正 =0.9108, R 反 =0.8772. The correlation coefficient shows that the trends of the indication curves of the two lever meters are highly similar, proving that the algorithm for the digital lever meter is feasible.

[0060] The present invention obtains the angle p° of rotation of the stylus 3 through the angle encoder 4, obtains the inclination X° of the stylus 3 in the X direction and the inclination Y° of the stylus 3 in the Y direction through the posture sensor 5, and corrects the Abbe error through the cooperation of the angle encoder 4 and the posture sensor 5, so that the measurement result is converted from a relative change to an absolute change. Compared with traditional lever meters, the present invention has higher measurement accuracy and can be integrated into intelligent manufacturing. Compared with existing digital lever meters, it has lower cost. Secondly, the linear displacement sensor provided by the present invention has lower requirements for posture placement when in use, further reducing the learning cost for beginners and helping to improve the reliability of measurement results and work efficiency.

[0061] Finally, the method of this application is only a preferred embodiment and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this utility model should be included in the scope of protection of this utility model.

[0062] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A high-precision linear displacement sensor, characterized in that: It comprises a rotating shaft rotatably arranged in a shell, a measuring needle is fixed to one end of the rotating shaft, an angle encoder is connected to the other end of the rotating shaft, and a posture sensor is also provided on the rotating shaft between the angle encoder and the measuring needle.

2. The high-precision linear displacement sensor according to claim 1, characterized in that: The measuring needle is threadedly connected to the rotating shaft.

3. The high-precision linear displacement sensor according to claim 1, characterized in that: The posture sensor is fixed on the rotating shaft by bonding.

4. The high-precision linear displacement sensor according to claim 3, characterized in that: A plane is provided in the middle of the rotating shaft, and the posture sensor is fixed on the plane by gluing.

5. The high-precision linear displacement sensor according to claim 4, characterized in that: The rotating shaft is provided with a connecting hole adapted to the rotating rod of the angle encoder, and the connecting hole is coaxially arranged with the rotating shaft.

6. The high-precision linear displacement sensor according to claim 1, characterized in that: A rear end plate is fixed to the shell, a battery is arranged in the rear end plate, and the angle encoder is arranged between the rear end plate and the rotating shaft.

7. The high-precision linear displacement sensor according to claim 6, characterized in that: The shell is also fixed with a front end cover, and the rotating shaft is rotatably connected to the front end cover.

8. The high-precision linear displacement sensor according to claim 1, characterized in that: It also includes a clamping piece, which is clamped on the shell, and the clamping piece and the measuring needle are respectively arranged at two ends of the shell.

9. The high-precision linear displacement sensor according to claim 1, characterized in that: It also includes a display screen and a controller, and the controller is communicatively connected with the display screen, the angle encoder and the posture sensor respectively.

10. The high-precision linear displacement sensor according to claim 2, characterized in that: A support arm is fixed on the rotating shaft, and a screw hole adapted to the measuring needle is provided on the support arm.

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