Precision length measuring device

Abstract

To provide a precision length measuring device that can automatically measure the dimensions of thin plate workpieces with a repeatability of ±1 μm while using relatively inexpensive components. [Solution] The precision length measuring device is equipped with a multi-axis closed-loop stepping motor, a timing belt drive mechanism, a Z-axis feed mechanism using a trapezoidal screw, and a software control system using a focus score and linear scale.It integrates focus score evaluation using image processing with timing belt drive, linear scale correction, and automatic tension mechanisms, and is highly accurate and portable.

Description

[Technical Field]

[0001] This invention relates to a precision measuring device that measures the length of thin plates with high accuracy, and in particular to a device that is highly expandable and portable, and that achieves high-accuracy and labor-saving length measurements by linking image processing and mechanical correction. [Background technology]

[0002] Conventionally, precise length measuring devices have been able to perform precise measurements by using expensive linear scales and specialized jigs, but there have been issues with equipment costs, grounding compatibility, and operability. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-123456 [Non-patent literature]

[0004] [Non-Patent Document 1] BRECOflex Co., LLC “Timing Belt Factors When Designing a Linear Drive”, Technical Blog, 2021. https: / / www.brecoflex.com / blog / timing-belt-factors-when-designing-a-linear-drive [Non-patent document 2] JLCMC technical paper, “Design Guide for Precision Matching of Timing Belts and Pulleys,” 2020. https: / / jlcmc.com / blog / timing-belt-and-pulleys-precision-matching-and-replacement-guide Summary of the Invention [Problem to be solved by the invention]

[0005] The purpose of this invention is to provide a device that can achieve measurement accuracy on the order of μm while maintaining portability and expandability by combining relatively inexpensive parts. [Means for solving the problem]

[0006] This device combines a multi-axis closed-loop stepping motor, a timing belt drive mechanism, Z-axis feed using a trapezoidal screw, and a correction mechanism linked to a focus score based on AI image processing, correcting for misalignment and temperature fluctuations. Achieves repeatability measurement accuracy of within ±1μm. The timing belt is equipped with an automatic tensioning mechanism, with the 2GT belt using a torsion spring and the EV8YU belt using a slide tensioner to maintain tension at all times. [Effects of the Invention]

[0007] This device enables highly accurate length measurement using inexpensive components, and the entire device weighs less than 30 kg, making it highly portable. This allows for flexible adaptation to changes and future expansion. [Brief explanation of the drawings]

[0008] [Figure 1] Overall configuration of the device DETAILED DESCRIPTION OF THE INVENTION

[0009] Once the workpiece to be measured is installed and an automatic measurement command is issued, recognition of the workpiece end face begins. End face recognition is performed by an image recognition algorithm. In addition, the tilt of the workpiece and the tilt of the installation surface are detected and corrected using the focus score. It consists of four axes: X-axis coarse movement, X-axis fine movement, Y-axis, and Z-axis, and all axes except Z-axis are controlled by μ-steps using a timing belt and a closed-loop stepping motor. The Z-axis uses a trapezoidal screw, and pressure is applied to the screw shaft and trapezoidal screw nut. The timing belt is also equipped with an automatic tensioning mechanism to ensure that it is always tensioned appropriately. The above configuration brings backlash close to zero, ensuring stable dimensional measurement. If necessary, manual axis control is also possible on the software. [Example]

[0010] An embodiment will be explained below with reference to the attached drawings. 1 is a full view of the device housing made of an appropriate material such as aluminum, 2 is a YZ axis ASSY equipped with a Y axis for tilt detection and a Z axis for focus score detection, 3 is a cable carrier with control signal lines for the moving part housed inside, and operates by following the movement of the axis. 4 is a linear encoder, and the control signal line is housed inside the cable of 3. The wiring that passes through the cable carrier is connected to a control device in the housing indicated by 5, and then to a main control device indicated by 6. The main control device is compatible with the Bluetooth standard, and operations are performed using a general-purpose mouse and keyboard, with the user interface displayed on a general-purpose monitor via HDMI. Furthermore, when the main control device is connected to a Windows PC via USB, control is performed on the PC, enabling faster control. Since it is controlled by software, the above control mechanism can be automatically executed with one click.

[0011] Since one embodiment of the present invention has the above-mentioned configuration, extremely high scalability can be expected by optimizing the software to improve control speed and add functions, and since the wiring is guided by a cable carrier, it is possible to avoid damage to the wiring and drive belt due to interference and continuous expansion and contraction. Furthermore, by changing the design of the housing, it is possible to flexibly implement functions that meet user requests. [Industrial Applicability]

[0012] By expanding the functionality, three-dimensional measurement is also possible, such as high-precision measurement required in the process and confirmation of punching dimensions in precision sheet metal processing. [Explanation of symbols]

[0013] 1. Device housing 2 YZ axis assembly 3 Cable Carriers 4 Linear Encoders 5. Control device inside the enclosure 6 Main control device

Claims

1. Software control system using a focus score and linear scale to ensure the accuracy of the precision length measuring device

2. Split-open chassis structure that combines portability, maintainability, and ventilation for equipment cooling

Images