A method for monitoring the level of a numerically controlled rotary table

Abstract

This invention provides a method for monitoring the levelness of a CNC rotary table, belonging to the field of CNC rotary table technology. The method includes a CNC rotary table, an accelerometer, a mounting plate, and a support. The upper surface of the support is a slope, and the CNC rotary table is placed on the slope. The mounting plate is located on top of the CNC rotary table, and its upper surface is the mounting surface, which forms an angle with the horizontal plane. The accelerometer is mounted on the mounting surface. During detection, the CNC rotary table is driven to run at a constant speed ω. The levelness of the CNC rotary table is determined by whether the output of the accelerometer is a constant value. When the output of the accelerometer is not a constant value, the CNC rotary table surface is not a horizontal surface. In this invention, the accelerometer can be installed at any position on the mounting surface, as long as it can sensitively detect the rotational angular velocity information of the CNC rotary table. This invention has low requirements for the zero point of the accelerometer, and with the use of a high-bandwidth and large-range accelerometer, the measurement efficiency can be greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of CNC rotary table technology, and particularly relates to a method for monitoring the level of a CNC rotary table surface. Background Technology

[0002] A CNC rotary table is a mechanical rotary motion device widely used in industrial manufacturing, metrology verification, and national defense. It is also a commonly used experimental device in electromechanical laboratories, playing a significant role in improving the laboratory's scientific and technological level. Besides its inherent high bandwidth, ultra-low speed, and high precision, the verticality of the rotary axis is crucial in certain applications with specific requirements for the axis, directly affecting whether the carrier rotates along the horizontal plane.

[0003] There are several methods for monitoring the verticality of a CNC rotary table. Among them, the optical method uses the principle of optical autocollimation to measure the tilt angle of the rotation axis. This method has strict requirements for the installation of the plane mirror and the alignment of the optical axis with the axis being measured, which directly affects the measurement accuracy of verticality, and the system is complex. The level method involves placing two levels perpendicular to each other or placing one level perpendicular to each other twice at a certain position on the worktable. The readings of the axis being measured at each corresponding angle are recorded according to the same testing process as the optical method. However, since the position of the level is uncertain and the measurement is only performed at a few fixed angles, it introduces measurement errors in verticality and is inefficient. Summary of the Invention

[0004] The purpose of this invention is to provide a method for monitoring the level of a CNC rotary table. The method comprises a CNC rotary table, an accelerometer, a mounting plate, and a support. The upper surface of the support is a slope, the CNC rotary table is placed on the slope, the mounting plate is placed on top of the CNC rotary table, and the upper surface of the mounting plate is a mounting surface. The mounting surface forms an angle with the horizontal plane, and the accelerometer is placed on the mounting surface. During detection, the CNC rotary table is driven to run at a constant speed ω, and the output value of the accelerometer is calculated.

[0005] When the accelerometer output is constant, the CNC rotary table surface is a horizontal surface; when the accelerometer output is not constant, the CNC rotary table surface is not a horizontal surface.

[0006] Furthermore, the formula for calculating the output value of the accelerometer is as follows:

[0007] a α =gsinθ α +ω 2 R

[0008] Where a is the accelerometer output; θ is the angle between the upper surface of the mounting plate and the horizontal plane; the subscript α is the azimuth angle of the CNC turntable; ω is the turntable rotation speed; and R is the distance between the accelerometer mounting position and the CNC turntable axis. For the output of the accelerometer's sensitive tilt angle, ω 2 R is the centrifugal acceleration generated by the rotation of the turntable.

[0009] Furthermore, the accelerometer includes a sensing unit and a reading unit connected by signals. The sensing unit is used to sense acceleration information from the outside world, and the reading unit is used for signal processing of the acceleration information and outputs a physical quantity representing the acceleration signal. The reading unit is connected to a host computer, which is used to display the physical quantity.

[0010] Furthermore, the magnitude of the rotational speed ω is determined by the bandwidth and range of the accelerometer.

[0011] Furthermore, the accelerometer is positioned at any location on the upper surface of the mounting plate.

[0012] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in:

[0013] 1. This invention detects the level of the CNC rotary table surface. The accelerometer can be installed at any position on the mounting surface, as long as the accelerometer can sensitively detect the rotational angular velocity information of the CNC rotary table.

[0014] 2. This invention utilizes the change in the CNC turntable during rotation, i.e. the relative change in the accelerometer, which reduces the requirement for the zero position of the accelerometer.

[0015] 3. The measurement method of the present invention is a continuous measurement method. When combined with an accelerometer with high bandwidth and large range, the measurement efficiency can be greatly improved. Attached Figure Description

[0016] Figure 1 A schematic diagram illustrating the principle of using an accelerometer to measure tilt angle;

[0017] Figure 2 This is a schematic diagram of the structure of the CNC rotary table of the present invention when it rotates 0° and 180°;

[0018] Figure 3 This is a schematic diagram of the accelerometer.

[0019] Figure 4 This is a schematic diagram showing the installation location of the accelerometer. Detailed Implementation

[0020] The following will describe in more detail a method for monitoring the level of a CNC rotary table according to the present invention, with reference to the schematic diagrams, which illustrate preferred embodiments of the invention. It should be understood that those skilled in the art can modify the invention described herein while still achieving the advantageous effects of the invention. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the invention.

[0021] like Figure 2As shown, a method for monitoring the level of a CNC rotary table mainly includes an accelerometer, a mounting plate, a CNC rotary table, and a support.

[0022] like Figure 3 As shown, accelerometer 1 generally consists of a sensing unit 1-1 and a reading unit 1-2 connected to each other. Sensing unit 1-1 is used to sense external acceleration information, and reading unit 1-2 is used for signal processing of the acceleration information and outputs a physical quantity representing the acceleration signal. This physical quantity can be displayed by a host computer connected to the reading unit. The principle of accelerometer measurement of tilt angle is as follows... Figure 1 As shown, the angle between mounting surface 2 and the horizontal plane is θ. At this time, the sensitive axis output of the accelerometer is gsinθ, which shows that the accelerometer output includes tilt information.

[0023] like Figure 4 As shown, the CNC rotary table 4 is mounted on the support 5, and the mounting plate 3 is mounted on the CNC rotary table 4. Various loads can be placed on the mounting plate 3. Figure 2 Two special cases are listed, namely the case where the CNC rotary table rotates 180°. It can be seen that due to the tilt of support 5, the deviation of the vertical axis of the CNC rotary table 4 itself, and the tilt of mounting plate 3, the mounting surface 2 has an angle with the horizontal plane, and the angle is different in different positions.

[0024] like Figure 4 As shown, during monitoring, accelerometer 1 is installed at any position on mounting plate 3 (A / B represent different positions, used for illustration; it can actually be installed at any position). The CNC turntable is set to run at a constant speed ω according to the accelerometer's bandwidth and range. At this time, the accelerometer's output is a. α =gsinθ α +ω 2 R, where the subscript α represents the different angles at which the CNC rotary table is located; θ is the angle between the upper surface of the mounting plate and the horizontal plane; At angle α, the angular velocity sensor outputs its sensitive axis, and R is the distance between the accelerometer mounting position and the CNC rotary table axis. Within the CNC rotary table's rotation cycle, here, the rotation cycle is at least one revolution, via a... α Whether a value is constant determines whether the CNC rotary table is level. Specifically: when a... α When a is a constant value, the CNC table is horizontal. α When the value is not constant, the CNC table is not horizontal.

[0025] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A method for monitoring the levelness of a CNC rotary table, characterized in that, The system includes a CNC rotary table, an accelerometer, a mounting plate, and a support. The upper surface of the support is a slope, and the CNC rotary table is mounted on the slope. The mounting plate is located on top of the CNC rotary table, and its upper surface is a mounting surface that forms an angle with the horizontal plane. The accelerometer is mounted on the mounting surface. During testing, the CNC rotary table is driven at a rotational speed... The accelerometer is run at a constant speed, and its output value is calculated using the following formula: ； in, For accelerometer output; The angle between the upper surface of the mounting plate and the horizontal plane; subscript The azimuth angle of the CNC rotary table; The rotational speed of the turntable. This refers to the distance between the accelerometer mounting position and the CNC rotary table axis; The output of the accelerometer is sensitive to the tilt angle. This refers to the centrifugal acceleration generated by the rotation of the turntable. When the accelerometer output value When the CNC rotary table remains constant during one revolution, the table surface is a horizontal platform; when the accelerometer output... When changes occur during one revolution of the CNC rotary table, the table surface of the CNC rotary table is not a horizontal platform.

2. The method for monitoring the level of a CNC rotary table according to claim 1, characterized in that, The accelerometer includes a sensing unit and a reading unit connected by a signal. The sensing unit is used to sense acceleration information from the outside world, and the reading unit is used for signal processing of the acceleration information and outputs a physical quantity representing the acceleration signal. The reading unit is connected to a host computer, which is used to display the physical quantity.

3. The method for monitoring the level of a CNC rotary table according to claim 1, characterized in that, The speed The magnitude is determined by the bandwidth and range of the accelerometer.

4. The method for monitoring the level of a CNC rotary table according to claim 1, characterized in that, The accelerometer is located at any position on the upper surface of the mounting plate.

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