A special auxiliary reading device for a large-scale length measuring machine and its application

Abstract

The present invention provides a special auxiliary reading device for a large-scale length measuring machine, comprising: a fixed base, a damping rotating shaft and a plane mirror, wherein the damping rotating shaft is installed at the bottom end of the plane mirror; wherein: the fixed base is of a U-shaped open structure and is provided with a set of relatively positioned round holes and a set of relatively positioned arc grooves, the plane mirror is located inside the fixed base, wherein the bottom end of the plane mirror is fixed on the round hole of the fixed base through the damping rotating shaft, and the top end of the plane mirror is installed on the arc groove of the fixed base and can move along the trajectory of the arc groove. At the same time, a JD21 type projection two-meter length measuring machine adopting the above special auxiliary reading device is provided. Through the reflection principle of the plane mirror, the present invention enables the reading device that originally needed to be perpendicular to the window to now read the value in the horizontal position, improving the work efficiency and accuracy of inspection.

Description

Technical Field

[0001] The present invention relates to the technical field of indication accuracy detection of large length measuring machines. Specifically, it relates to a special auxiliary reading device for large length measuring machines and its application, which is used to improve the accuracy when measuring the dimensions of ultra-long workpieces with a large length measuring machine. Background Art

[0002] The JD21 type projection two-meter length measuring machine is a large-scale precision length measuring and metering instrument. Through the principle of optical projection, it can accurately measure and read the internal and external dimensions of some ultra-long workpieces. By using the comparison method to calibrate grade-four and grade-five gauge blocks with dimensions greater than 100 mm, and directly measuring the calibration rods of outside micrometers, inside micrometers and self-made rods, it is used to measure the internal dimensions of various clamping plates, inner diameters and pitch diameters of external threads, etc., and is widely used in various departments such as major machinery manufacturing industries, scientific research institutes, and metrology verification institutes.

[0003] To make the measurement results accurate and reliable, in the measurement, efforts should be made to minimize the deformation caused by various reasons, which is the minimum deformation principle of measurement. There are usually three reasons for workpiece deformation: contact deformation, self-weight deformation and thermal deformation. Among them, the magnitude of the self-weight deformation of the workpiece to be measured is related to the support method and the position of the support points of the part. Therefore, in the measurement, it is necessary to select an appropriate position of the support points to reduce the influence of the self-weight deformation of the workpiece to be measured on the measurement results. For uniform materials (round bar stock, rectangular stock) with a length of L (L>100 mm), the support point positions with the smallest deformation are of the following types: Bessel points and Airy points, as Figure 1 shown. The Airy point is the position at 0.211L from each end face. The Airy point is to keep the two end faces of a horizontally placed object still parallel under the action of gravity. The support of the Airy point is mainly used in the measurement of gauge blocks. The Bessel point is that the distance between the two support points is about 0.559L, that is, the position at 0.2203L from each end face. This kind of support is to make the dimensional change of the neutral plane of the object the smallest after being affected by the gravity deformation. For example, when the line scale is supported at the Bessel point, the change in the length measurement caused by the self-weight of the scale on the neutral plane of the engraved scale is the smallest. The Bessel point is mainly used for the verification of gauge rods and line scales. The former international prototype meter was supported by Bessel points.

[0004] When the JD21 type projection two-meter length measuring machine measures the object to be measured, it is necessary to adjust the upper and lower and front and rear position adjusters of the main and auxiliary support frames, and find the inflection point of the object to be measured through the reading window, as Figure 2As shown in the figure. Since reasonable support is required to improve the measurement accuracy and obtain the best measurement uncertainty. However, when the object to be measured is too long, due to the large distance between the support position and the reading window, it is impossible for a single person to read the measurement while adjusting the position of the object to be measured. At this time, two people need to cooperate. One person adjusts the position of the object to be measured, and the other person reads the measurement at the projection window position of the length measuring machine. When two people cooperate, there will be a phenomenon of lag in the adjustment of the workpiece position and the display of the real-time reading device. During the measurement process, the adjustment of the workpiece position and the display of the reading device cannot be synchronized, resulting in an increase in measurement error. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a special auxiliary reading device for a large-scale length measuring machine and its application. This device solves the problem that when measuring large workpieces with a length measuring machine, the optical reading mechanism can only be perpendicular to the window, and it is impossible for a single person to complete the reading during work, and two people need to cooperate to read the measurement.

[0006] The present invention is achieved through the following technical solutions.

[0007] According to one aspect of the present invention, a special auxiliary reading device for a large-scale length measuring machine is provided, including: a fixed base, a damping rotating shaft, and a plane mirror, and the damping rotating shaft is installed at the bottom end of the plane mirror; wherein:

[0008] The fixed base is of a U-shaped open structure, and is provided with a set of circular holes and a set of arc grooves that are opposite to each other in position. The plane mirror is located inside the fixed base. Among them, the bottom end of the plane mirror is fixed to the circular hole of the fixed base through a damping rotating shaft, and the top end of the plane mirror is installed on the arc groove of the fixed base and can move along the trajectory of the arc groove.

[0009] Preferably, the circular holes are located at the bottom corners of the side walls of the fixed base, and the arc grooves are located at the top corners of the side walls of the fixed base and are arranged diagonally with respect to the circular holes.

[0010] Preferably, the diameter of each circular hole is 4 mm.

[0011] Preferably, the radius of each arc groove is 122 mm.

[0012] Preferably, the back plate of the plane mirror is made of a metal material, and a radial through hole for installing the damping rotating shaft is provided at the bottom end of the plane mirror.

[0013] Preferably, the dimensions of the fixed base in length × width × height are: 200 mm × 66 mm × 150 mm.

[0014] Preferably, the distance from the center point of the circular hole to the bottom edge of the fixed base is 50 mm, and the distance from the center point of the circular hole to the side edge of the fixed base is 30 mm.

[0015] Preferably, the distance from the top end of the arc groove to the top end of the fixed base is 15 mm, and the distance from the bottom end of the arc groove to the bottom edge of the fixed base is 60 mm.

[0016] According to another aspect of the present invention, as an application of the above-mentioned special auxiliary reading device for large measuring machines, a large measuring machine is provided. The reading window position of the large measuring machine is provided with the above-mentioned special auxiliary reading device for large measuring machines corresponding to its size.

[0017] Furthermore, a JD21 type projection two-meter measuring machine is provided. The reading window position of the JD21 type projection two-meter measuring machine is provided with the above-mentioned special auxiliary reading device for large measuring machines corresponding to its size.

[0018] The special auxiliary reading device for large measuring machines provided by the present invention is a detection auxiliary device manufactured according to the reading window size of the JD21 type projection two-meter measuring machine. Through the reflection principle of the plane mirror, the reading device that originally needed to be perpendicular to the window can now read the value in the horizontal position.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The special auxiliary reading device for large measuring machines provided by the present invention can realize single-person measurement, and while adjusting the position of the workpiece, it can observe the change of the pointer position on the reading disk in real time, improving the detection work efficiency and consistency.

[0021] 2. The special auxiliary reading device for large measuring machines provided by the present invention has the advantages of simple structure, easy use, low cost, and obvious effect of improving measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] By reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, other features, objects, and advantages of the present invention will become more apparent:

[0023] Figure 1 It is a schematic diagram of Bessel points and Airy points in the background technology;

[0024] Figure 2 It is a schematic diagram of the fixed base structure of the special auxiliary reading device for large measuring machines provided in the embodiment of the present invention;

[0025] Figure 3 It is a schematic diagram of the plane mirror and damping rotating shaft structure of the special auxiliary reading device for large measuring machines provided in the embodiment of the present invention.

[0026] Figure 4These are the three - view dimensions of the fixed base of the special auxiliary reading device for large - scale length measuring machines provided in the embodiments of the present invention. Among them, (a) is the front view, (b) is the left - hand view, and (c) is the top view.

[0027] Figure 5 This is the dimension diagram of the plane - mirror bottom plate of the special auxiliary reading device for large - scale length measuring machines provided in the embodiments of the present invention;

[0028] Figure 6 This is the overall structure schematic diagram of the special auxiliary reading device for large - scale length measuring machines provided in the embodiments of the present invention.

[0029] In the figure, 1 is the fixed base, 2 is the plane mirror, 3 is the damping rotating shaft, 4 is the round hole, and 5 is the arc groove. Detailed implementation mode

[0030] The following is a detailed description of the embodiments of the present invention: These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

[0031] The embodiments of the present invention provide a special auxiliary reading device for large - scale length measuring machines, as Figure 6 shown, including: a fixed base 1, a damping rotating shaft 3, and a plane mirror 2. The damping rotating shaft 3 is installed at the bottom end of the plane mirror 2; among them:

[0032] The fixed base 1 is of a U - shaped open - ended structure, and is provided with a set of relatively - positioned round holes 4 and a set of relatively - positioned arc grooves 5, as Figure 2 shown. The plane mirror 2 is located inside the fixed base 1. Among them, the bottom end of the plane mirror 2 is fixed on the round hole 4 of the fixed base through the damping rotating shaft 3, and the top end of the plane mirror 2 is installed on the arc groove 5 of the fixed base 1 and can move along the trajectory of the arc groove.

[0033] Furthermore, the round holes are located at the bottom corners of the side walls of the fixed base, and the arc grooves are located at the top corners of the side walls of the fixed base and are arranged diagonally with respect to the round holes.

[0034] Furthermore, the diameter of each round hole is 4 mm.

[0035] Furthermore, the radius of each arc groove is 122 mm.

[0036] Furthermore, the dimensions of the length × width × height of the fixed base are: 200 mm × 66 mm × 150 mm.

[0037] Further, the distance from the center point of the round hole to the bottom edge of the fixed base is 50 mm, and the distance from the center point of the round hole to the side edge of the fixed base is 30 mm.

[0038] Further, the distance from the top end of the arc groove to the top end of the fixed base is 15 mm, and the distance from the bottom end of the arc groove to the bottom edge of the fixed base is 60 mm.

[0039] Further, the back plate of the plane mirror is made of metal, and a radial through hole for installing a damping rotating shaft is provided at the bottom end of the plane mirror, as Figure 3 shown.

[0040] Based on the large length measuring machine special auxiliary reading device provided in the embodiments of the present invention, the embodiments of the present invention also provide a large length measuring machine, and the reading window position of the large length measuring machine is provided with the above-mentioned large length measuring machine special auxiliary reading device corresponding to its size.

[0041] Further, a JD21 type projection two-meter length measuring machine is provided, and the reading window position of the JD21 type projection two-meter length measuring machine is provided with the above-mentioned large length measuring machine special auxiliary reading device corresponding to its size.

[0042] In the embodiments of the present invention, the provided large length measuring machine special auxiliary reading device can be manufactured accordingly according to the reading window size of the large length measuring machine (such as the JD21 type projection two-meter length measuring machine). Through the reflection principle of the plane mirror, the reading device that originally needed to be perpendicular to the window can now read the value in the horizontal position. This improves the work efficiency and accuracy of the inspection.

[0043] The following further details the technical solutions provided in the above embodiments of the present invention with reference to the accompanying drawings.

[0044] I. Design: Determine the main dimensions of the special auxiliary reading device

[0045] 1. For the reading window of the large length measuring machine (such as the JD21 type projection two-meter length measuring machine), design an open-type fixed base with corresponding dimensions. A set of round holes with a diameter of 4 mm are opened at the corresponding positions of the fixed base to fix the damping rotating shaft, and a set of arc grooves with a radius of 122 mm are opened above the round holes to adjust and fix the angle of the plane mirror. The three-view drawing of its dimensions is as Figure 4 shown.

[0046] 2. The back plate of the plane mirror is made of metal, and a radial through hole for installing a damping rotating shaft is provided at the bottom of the plane mirror. The dimension drawing of it is as Figure 5 shown.

[0047] II. Verification:

[0048] Select four equal - value blocks with L = 800 mm for verification. Since the stability and accuracy of 4 - equal - value blocks are much higher than those of the JD21 type projection two - meter length measuring machine, only the estimated reading error generated by this device is considered during measurement. Under the condition of repeated measurement, use the special auxiliary reading device provided by the embodiment of the present invention to measure 10 times. Take the average value of the 10 measurements as the final measurement result, and calculate the standard deviation of the single - measurement result. The measurement results are 800.0010 mm, 800.0015 mm, 800.0010 mm, 800.0020 mm, 800.0010 mm, 800.0015 mm, 800.0020 mm, 800.0010 mm, 800.0015 mm, 800.0015 mm respectively. Its arithmetic mean is 800.0014 mm, and the standard deviation of single - measurement is 0.4 μm. The minimum scale value of the JD21 type projection two - meter length measuring machine is 1 μm, and its resolution is 0.5 μm. After using the special auxiliary reading device provided by the embodiment of the present invention, the standard deviation of single - measurement of the measurement result is less than its resolution, which proves that this device meets the requirements.

[0049] III. Conclusion:

[0050] After using the special auxiliary reading device provided by the embodiment of the present invention, the working efficiency of measuring large - size workpieces can be significantly improved, the error generated during the cooperation of inspectors can be reduced, the influence of human factors on the accuracy of the detection result can be minimized, and the measurement accuracy can be improved.

[0051] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above - mentioned specific embodiments, and those skilled in the art can make various deformations or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. An auxiliary reading device dedicated to a large-scale length measuring machine, characterized in that, Including: A fixed base, a damping rotating shaft, and a plane mirror, where the damping rotating shaft is installed at the bottom end of the plane mirror; wherein: The fixed base is of a U-shaped open structure and is provided with a set of relatively positioned round holes and a set of relatively positioned arc grooves. The plane mirror is located inside the fixed base. Among them, the bottom end of the plane mirror is fixed on the round hole of the fixed base through the damping rotating shaft, and the top end of the plane mirror is installed on the arc groove of the fixed base and can move along the trajectory of the arc groove.

2. The auxiliary reading device dedicated to a large-scale length measuring machine according to claim 1, characterized in that, The round holes are located at the bottom corners of the side wall of the fixed base, and the arc grooves are located at the top corners of the side wall of the fixed base and are arranged diagonally with respect to the round holes.

3. The auxiliary reading device dedicated to a large-scale length measuring machine according to claim 1, characterized in that, The diameter of each round hole is 4 mm.

4. The auxiliary reading device dedicated to a large-scale length measuring machine according to claim 1, characterized in that, The radius of each arc groove is 122 mm.

5. The auxiliary reading device dedicated to a large-scale length measuring machine according to claim 1, characterized in that, The dimensions of the fixed base in terms of length × width × height are: 200 mm × 66 mm × 150 mm.

6. The auxiliary reading device dedicated to a large-scale length measuring machine according to claim 2, characterized in that, The distance from the center point of the round hole to the bottom edge of the fixed base is 50 mm, and the distance from the center point of the round hole to the side edge of the fixed base is 30 mm.

7. The auxiliary reading device dedicated to a large-scale length measuring machine according to claim 2, characterized in that, The distance from the top end of the arc groove to the top end of the fixed base is 15 mm, and the distance from the bottom end of the arc groove to the bottom edge of the fixed base is 60 mm.

8. The auxiliary reading device dedicated to a large-scale length measuring machine according to claim 1, characterized in that, The back plate of the plane mirror is made of a metal material, and a radial through hole for installing the damping rotating shaft is provided at the bottom end of the plane mirror.

9. A large-scale length measuring machine, characterized in that, At the reading window position of the large length measuring machine, there is a special auxiliary reading device for the large length measuring machine according to any one of claims 1 to 8 corresponding to its size.

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