Calibration device of caliper

Abstract

The utility model provides a calibration device of a caliper. The calibration device comprises a linear motor, a controller, a sensor, a guide rail, a slide block and a calibration positioning assembly. The linear motor provides power for the sliding block to slide along the guide rail. The calibration positioning assembly is provided with two parts which are in linear contact with the measuring surface of the caliper, and the two parts are respectively mounted at the fixed ends of the sliding block and the linear motor; the sensor is used for detecting parameters of the linear motor for controlling the sliding block and feeding back the parameters to the controller, and the controller is used for controlling the linear motor to control sliding of the sliding block. The calibration device provided by the utility model can realize caliper calibration with low cost, high efficiency, high precision and any calibration point.

Description

Technical Field

[0001] The utility model relates to the field of measurement detection and calibration, and in particular to a caliper binding device which realizes caliper calibration through line contact based on a linear motor module. Background Art

[0002] Currently, metrological calibration of calipers (e.g., vernier calipers, dial calipers, and digital calipers) is performed using a method consistent with their operating principles. Specifically, a series of standard length dimensions (including internal and external dimensions) are measured using a caliper. The measured caliper readings are then compared with the standard length dimensions to determine the caliper's indication error at that calibration point. During the calibration process, the standard length dimensions are typically generated using a gauge block or length measuring machine, and then a series of measurements are performed by an operator holding the caliper. This results in a low degree of automation, low calibration efficiency, and high metrological costs.

[0003] There are two main methods for caliper calibration:

[0004] 1. Use gauge blocks to provide a range of standard lengths (see Figure 1 and Figure 2 ):

[0005] A gauge block is a standard end-face measuring tool without scales, which is made according to a certain value size. It is widely used in existing caliper calibration, that is, the two measuring surfaces of the caliper are in surface contact with the two end faces of the gauge block to implement the measurement. The advantage of this method is that the gauge block has high accuracy and high reproducibility of standard length dimensions. However, its disadvantage is that it can only measure the calibration point of the corresponding gauge block size, and cannot measure the indication error of any calibration point according to requirements, and can only provide the standard external dimension length ( Figure 1 ), the calibration of the inner dimension indication error of the caliper requires the use of a special inspection tool to convert the outer dimension into the inner dimension (see Figure 2 ), the manual operation in this process was extremely cumbersome and inefficient. Furthermore, surface contact measurement is not recommended under the principle of optimal geometric measurement. Imperfections in the contact surface further introduced certain measurement errors during the indication error calibration.

[0006] 2. Use a length measuring machine to provide a series of standard lengths (see Figure 3 ):

[0007] A length measuring machine is a length measuring instrument that uses a grating pitch, a linear scale scale, or a lightwave wavelength as a known length, and a mechanical probe for contact measurement. This method has been increasingly adopted in caliper calibration in recent years. Its advantage is that it can generate any standard length, thus meeting the need to measure the indication error at any calibration point. However, its disadvantage is that the tailstock of the length measuring machine must be moved manually to generate the standard length dimension; it cannot be moved automatically. Due to the instrument's high resolution, it is difficult to find the correct length in one go. Furthermore, the length measuring machine itself is very expensive, making its use in calibrating calipers very costly. In reality, the accuracy of grating measurements far exceeds the error transfer requirements for caliper calibration, making it unsuitable for caliper calibration from an economical perspective. Utility Model Content

[0008] In response to the aforementioned current situation and problems in the existing technology, the present invention provides a caliper calibration device based on a linear motor. Its core concept is to control the linear motor driver through a PLC controller, forming a servo drive mechanism. The linear motor automatically generates any standard length displacement, providing a standard length at any calibration position with sufficient accuracy for calibrating the caliper. This method achieves high efficiency, low cost, reliable accuracy, and can calibrate at any calibration point. The calibration device provided by this utility model can achieve low-cost, high-efficiency, high-precision caliper calibration at any calibration point.

[0009] Specifically, the present invention provides a caliper calibration device comprising a controller, a linear motor, a sensor, a guide rail, a slider, and a calibration and positioning assembly. The linear motor's movable end is connected to the slider and provides power for the slider to slide along the guide rail. The calibration and positioning assembly comprises two parts that make linear contact with the caliper's measuring surface, and are mounted on the slider and the fixed end of the linear motor, respectively. The sensor detects the parameters of the linear motor's control slider and feeds them back to the controller, which controls the linear motor to control the slider's sliding.

[0010] Furthermore, the calibration and positioning component is a component that makes line contact with the measuring surface of the caliper, and adopts a pair of first-class precision pin-type plug gauges of the same diameter. Preferably, the dimensional deviation thereof does not exceed ±0.001mm, and the busbar straightness does not exceed 0.001mm. It is installed in the mounting holes of the slider and the fixed end of the motor respectively by tight fit. There is no special range for the diameter D of the plug gauge here, as long as the diameter is the same and the accuracy meets the standard. It is generally considered that although a too small diameter is convenient for measurement, the plug gauge has low rigidity and is prone to deformation, which affects the measurement results; and a too large diameter makes installation inconvenient. Therefore, in practical applications, a plug gauge with a diameter D range of 1-5mm can be used, preferably 5mm.

[0011] The controller, preferably a PLC programmable controller, is used to control the motion of the linear motor. The current and voltage generated by the controller can control the position, speed, acceleration and other parameters of the linear motor.

[0012] The linear motor is the core part of the device. Its working principle is realized through the electromagnetic principle and is responsible for providing driving force. This device preferably uses an iron core linear motor, which is a transmission device that can directly convert electrical energy into mechanical energy and generate linear motion without the need for any intermediate conversion mechanism. The linear motor has two important parts: the stator and the moving part. The stator is composed of an iron core and a coil, and the current is provided by the power supply to generate a magnetic field. The moving part is composed of a magnet and a conductor. When the stator generates a magnetic field, the moving part will move under the action of the magnetic force. The movement direction of the linear motor module is related to the direction of the stator coil. When the current is reversed, the movement direction of the moving part will also reverse. The moving part is used to connect the slider to provide power to the slider. The linear motor used in this utility model has the advantages of simple structure, convenient long stroke, high acceleration, fast response and high precision. The positioning accuracy can reach up to ±0.001mm and the repeatability positioning accuracy can reach 0.001mm.

[0013] The sensor detects the linear motor's position, speed, acceleration, and other parameters and feeds these parameters back to the controller for control. This device uses an encoder for position feedback, enabling high-precision position control. Furthermore, the controller can adjust the speed and acceleration of the movement by varying the magnitude and direction of the current. The distance between the two parts of the calibration positioning assembly is measured by the sensor and fed back to the controller.

[0014] The slider is the moving component of this device, its primary function being to cooperate with the guide rail to achieve linear motion. The distance between its movement and the fixed end of the linear motor defines the device's standard length (i.e., the calibration length). Multiple mounting holes are located above the slider and on the fixed end of the motor for mounting the calibration and positioning assembly. Before activating the linear motor, the two feeler gauges of the calibration and positioning assembly are preferably in contact and set to zero.

[0015] The guide rails in this device primarily support and guide the movement of the slider. GCr15 steel is the preferred material for this design, as it offers excellent rigidity and wear resistance, providing reliable and stable movement. The guide rails are precision-ground to a straightness of 0.003mm, ensuring accurate calibration.

[0016] When the device calibrates the caliper, the position where the two calibration positioning components (both with a diameter of D) touch is set as the zero point. When the caliper A point indicates an error, the controller sets the linear motor running distance L so that L=A, and the slide moves to produce the standard length dimension.

[0017] When the slide has completed its movement, the caliper measuring surface contacts the calibration positioning assembly:

[0018] ① When measuring the error of the caliper's external dimension indication, if Figure 7 As shown, make the outer claw contact the outer busbar of the positioning device and read the caliper indication A 外 , then the error of the external claw indication at this point is: E 外 =A 外 -L-2D

[0019] ② When measuring the error of the caliper's internal dimension indication, if Figure 8 As shown, make the inner claw contact the inner busbar of the positioning device and read the caliper indication A 内 , then the error of the external claw indication at this point is: E 内 =A 内 -L.

[0020] The advantages of the utility model are as follows: (1) the application of the linear motor module in the field of caliper calibration is a brand-new design, which can automatically generate any standard length through the control device, solves the calibration problem of the indication error of any calibration point, meets the calibrator calibration requirements in special occasions, and combines the low cost, low energy consumption, high accuracy and other characteristics of the linear motor module with the field of geometric measurement, thus saving costs;

[0021] (2) The standard length is automatically generated by the linear motor, and the operation speed is fast, the positioning is accurate and reliable, which reduces the tedious manual operations and greatly improves the efficiency;

[0022] (3) The contact method for caliper calibration is designed to be line contact, which is more in line with the principle of contact method optimization in geometric measurement than the current surface contact method, reduces the measurement error introduced by contact defects in the calibration of indication error, and improves the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the principle of using gauge blocks to achieve external dimension measurement and calibration in the existing technology.

[0024] Figure 2 It is a schematic diagram of the principle of using gauge blocks to achieve internal dimension measurement and calibration in the existing technology (with the help of special inspection tools).

[0025] Figure 3 The present invention is a schematic diagram of the principle of using a length measuring machine to calibrate a caliper in the prior art.

[0026] Figure 4 It is a three-dimensional schematic diagram of a caliper calibration device of the present utility model.

[0027] Figure 5 It is a top schematic diagram of a caliper calibration device of the present invention.

[0028] Figure 6 It is a side view schematic diagram of a caliper calibration device of the present utility model.

[0029] Figure 7 The utility model is a schematic diagram of a guide rail of a caliper calibration device.

[0030] Figure 8 It is a schematic diagram of a calibration and positioning assembly of a caliper calibration device of the present invention.

[0031] Figure 9 The utility model is a schematic diagram of a caliper calibration device for measuring the indication error of the caliper's external dimensions.

[0032] Figure 10 The utility model is a schematic diagram of a caliper calibration device for measuring the error of the inner dimension indication of the caliper.

[0033] In the figure, 1. linear motor; 2. sensor; 3. controller; 4. slider; 5. slide rail; 6. calibration and positioning assembly; 11. fixed end; 12. mounting hole; 13. feeler gauge. DETAILED DESCRIPTION

[0034] The "calibration device for a caliper" of the present utility model is further described with reference to the accompanying drawings.

[0035] See also Figure 4-10 The utility model provides a calibration device for a caliper, which includes: a controller 3, a linear motor 1, a sensor 2, a guide rail 5, a slider 4 and a calibration positioning component 6.

[0036] Linear motor 1 is preferably an iron-core linear motor, generating linear motion. Under the influence of a magnetic field, the motor's moving components drive slider 4 in linear motion to achieve the desired distance / length L. The linear motor employed in this utility model has the advantages of a simple structure, convenient long travel, high acceleration, fast response, and high precision. Positioning accuracy can reach up to ±0.001mm, and repeatability can reach 0.001mm.

[0037] The controller 3 may preferably be a PLC programmable controller. The current and voltage generated by the controller 3 may control parameters such as the position, speed, and acceleration of the linear motor 1 .

[0038] Sensor 2 is used to detect the position, speed, acceleration and other parameters of linear motor 1 and feed these parameters back to controller 3 for control. This device uses encoder for position feedback to achieve high-precision position control.

[0039] The slider 4 is the moving part of the device, and its main function is to cooperate with the guide rail 5 to achieve linear motion. The distance L generated by its movement and the fixed end 11 of the linear motor 1 is the standard length dimension (i.e., the calibration length) provided by the device. There are multiple mounting holes 12 above the slider 4 and on the motor fixed end 11 for installing the calibration positioning assembly 6. The proximal mounting hole 12 is preferably used for calibrating the caliper so that the feeler gauge 13 can be contacted and set to zero; the distal and other mounting holes can be used as extended applications, for example, by utilizing the high load capacity of the linear motor and adding a force sensor, a mechanical tensile test of the material can be performed.

[0040] The guide rail 5 in this device primarily supports and guides the movement of the slider 4. The preferred material is GCr15 steel, which has excellent rigidity and wear resistance, providing reliable and stable motion support for the slider 4. The guide rail 5 is precision ground to a straightness of 0.003mm, ensuring calibration accuracy.

[0041] When calibrating the caliper, the position where the two calibration positioning components 6 (both with diameters D) touch is set as the zero point. When calibrating the indication error of point A of the caliper, the controller 3 sets the running distance L of the linear motor 1 so that L=A, and the slide 4 moves to produce the standard length dimension.

[0042] When the slider 4 completes its movement, the caliper measuring surface contacts the calibration positioning component 6:

[0043] ① When measuring the error of the caliper's external dimension indication, if Figure 9 As shown, make the outer jaws contact the outer busbar of the plug gauge 13 of the positioning device 6, and read the caliper indication A 外 , then the error of the external claw indication at this point is: E 外 =A 外 -L-2D

[0044] ② When measuring the error of the caliper's internal dimension indication, if Figure 10 As shown, make the inner claw contact the inner busbar of the plug gauge 13 of the positioning device 6, and read the caliper indication A 内 , then the error of the external claw indication at this point is: E 内 =A 内 -L. As mentioned above, the current caliper calibration methods have more or less problems such as the inability to measure arbitrary calibration points, low measurement efficiency, high measurement cost, and limited measurement accuracy. Moreover, they cannot simultaneously achieve the four requirements of arbitrary calibration point measurement, high efficiency, low cost, and high accuracy.

[0045] However, the caliper calibration device based on the linear motor module proposed in this paper has the following advantages: ① The application of the linear motor module in the field of caliper calibration is a brand-new design. It can automatically generate any standard length through the control device, solve the problem of calibration of the indication error of any calibration point, meet the calibrator calibration requirements in special occasions, and combine the low cost, low energy consumption, and high accuracy of the linear motor module with the field of geometric measurement to save costs; ② The standard length is automatically generated by the linear motor, and the running speed is fast, the positioning is accurate and reliable, which reduces the tedious manual operations and greatly improves the efficiency; ③ The caliper calibration contact method is designed to be line contact, which is more in line with the contact method optimization principle in geometric measurement than the current surface contact method, reduces the measurement error introduced by contact defects in the indication error calibration, and improves the measurement accuracy.

[0046] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with this patent can make some changes or modifications to equivalent embodiments using the above-mentioned technical content without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the solution of the present invention.

Claims

1. A caliper calibration device, characterized in that: The calibration device includes: a linear motor, a controller, a sensor, a guide rail, a slider and a calibration positioning assembly; wherein, the movable end of the linear motor is connected to the slider and provides power for the slider to slide along the guide rail; the calibration positioning assembly has two parts that are in line contact with the measuring surface of the caliper, and the two parts are respectively installed on the slider and the fixed end of the linear motor; the sensor is used to detect the parameters of the linear motor controlling the slider and feed them back to the controller, and the controller is used to control the linear motor to control the sliding of the slider.

2. The caliper calibration device according to claim 1, characterized in that: The calibration and positioning assembly includes two precision pin-type plug gauges.

3. The caliper calibration device according to claim 2, characterized in that: The two precision pin-type plug gauges have the same diameter, a dimensional deviation of no more than ±0.001 mm, and a generatrix straightness of no more than 0.001 mm.

4. The caliper calibration device according to any one of claims 1 to 3, characterized in that: The fixed ends of the slider and the linear motor are respectively provided with at least one mounting hole for mounting the calibration and positioning assembly.

5. The caliper calibration device according to any one of claims 1 to 3, characterized in that: The distance between the two parts of the calibration positioning assembly is measured by a sensor and fed back to the controller.

6. The caliper calibration device according to claim 4, characterized in that: The controller is a PLC programmable controller.

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