JPH0647812U - Inspection device for long metal objects with circular cross section - Google Patents

Abstract

(57) [Summary] [Purpose] To enable comprehensive management by detecting the outer diameter and surface appearance of a long metal object of circular cross section such as a mandrel bar over its entire length and visualizing it. . [Structure] Conveying means for transporting a long metal object around its axis in the axial direction while rotating about its axis, and an outer diameter measuring device for measuring the outer diameter of the long metal object and a surface flaw, which are attached to the conveying means. A crack detection measuring instrument and a display device for inputting detection signals from these measuring instruments and displaying a change in outer diameter of the entire length of the elongated metal object in the axial direction and a state of occurrence of a surface flaw are provided. The outer diameter of the metal elongated object is continuously scanned and detected by the outer diameter measuring device, and at the same time, the occurrence state of the surface flaw is scanned and detected by the crack detecting and measuring device, and these detection results are visualized by the display device. Enables online measurement and inspection of inspection targets.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a surface texture inspection device for detecting and visualizing an outer diameter and a surface crack of a mandrel bar used for rolling a small diameter seamless steel pipe, for example.

[0002]

[Prior art]

 For the mandrel bar, it is important to control the accuracy of the outer diameter and to evaluate the surface roughness after rolling during maintenance and inspection during the manufacturing and operation of the mandrel bar from the viewpoint of controlling the accuracy of the product.

Regarding the outer diameter management, a method of measuring several points with a micrometer is adopted because the length of the mandrel bar is about 30 m. Regarding surface roughness and cracks, only the damaged part is photographed and recorded.

[0004]

[Problems to be solved by the device]

 However, regarding the outside diameter control, it is not possible to know the aspect of the total length of the mandrel bar, because only a few points are measured.

Further, since the rough surface and the crack are not visualized for the entire length, it is not possible to grasp the overall appearance in the same manner.

Since the correlation between the variation of the outer diameter and the crack generation position cannot be collected as data, there is a limit to the analysis of the deformation of the mandrel bar due to rolling.

As described above, conventionally, in the maintenance and management of the mandrel bar, the outer diameter, cracks and the like cannot be inspected over the entire length and are not visualized.

The problem to be solved in the present invention is to comprehensively detect an outer diameter and a surface aspect of a long metal object having a circular cross section, such as a mandrel bar, along its entire length and visualize it. It is to enable management.

[0009]

[Means for Solving the Problems]

 The present invention is an apparatus for inspecting the outer diameter of a metal elongated object having a circular cross section and the occurrence state of surface flaws thereof, which conveys the metal elongated object in the axial direction while rotating about the axis thereof. And an outer diameter measuring instrument that is provided alongside the conveying means to measure the outer diameter of the metal elongated object and a crack detection measuring instrument that inspects surface flaws, and the detection signals from these measuring instruments are input to the metal. A display device for displaying a change in the outer diameter of the entire length of the long object in the axial direction and the occurrence of surface defects.

[0010]

[Action]

 The outer diameter measuring device continuously scans and detects the outer diameter of the long metal object transferred by the conveying means, and at the same time, the crack detecting and measuring device scans and detects the occurrence of surface defects. Then, these detection results are displayed and visualized by the display device, and it becomes possible to measure and inspect the inspection target online.

Further, since the data in which the change of the outer diameter and the distribution of the occurrence of cracks are displayed at the same time, the correlation between the change of the outer diameter and the occurrence of cracks can be analyzed and comprehensive management can be performed.

[0012]

【Example】

 FIG. 1 is a schematic view showing an inspection device and a mandrel bar of the present invention applied when detecting the outer diameter and surface appearance of a mandrel bar.

In the figure, the mandrel bar 5 has its axis supported substantially horizontally by a roller 6 which constitutes a conveying means, and is movable while being rotated around the axis by a driving device (not shown).

The inspection device 1 is provided with an outer diameter measuring device 2 and a crack detecting measuring device 3 each having a shape through which a mandrel bar 5 passes, and further receives signals from these measuring devices 2 and 3 for visualization. The display device 4 is provided. Then, when the total length of the mandrel bar 5 is inspected by the display device 4 and the data thereof is displayed, the transfer speed of the mandrel bar 5 by the roller 6 is adjusted so as to correspond to the position of the mandrel bar 5 in the axial direction. To enter.

As shown in FIG. 2, the outer diameter measuring device 2 has a path line of the mandrel bar 5 inside, and an outer diameter can be detected by a difference method by an optical system using a laser. The outline of the detection system is shown in FIG.

The outer diameter measuring device 2 projects the light from the laser light source 2a in the direction orthogonal to the pass line of the mandrel bar 5 by the tuning fork polarizer 2b, and the light is received by the light receiver 2e via the pair of lenses 2c and 2d. It is a system to receive. The tuning fork polarizer 2b is driven by the driver 2f, and the phase signal from the driver 2f and the detection signal from the light receiver 2e are input to the signal processing circuit 2g. On the other hand, a clock signal is input to the signal processing circuit 2g from the clock pulse generator 2h.

With such an optical system, a logical product is produced by the signal processing circuit 2g based on the phase signal in the laser scanning direction by the laser light source 2a, the detection signal from the light receiver 2e, and the clock signal from the clock pulse generator 2h. Is input to the display device 4 as an outer diameter signal of the mandrel bar 5.

As the crack detecting / measuring device 3, for example, a magnetic balance type sensor described in Japanese Patent Publication No. 56-29202 can be used. As shown in FIG. 4, this is composed of two exciting coils 3a and 3b, and a magnetic detector 3c arranged at a position where the exciting magnetic fields of these exciting coils 3a and 3b are balanced. An outline of the detection system is shown in FIG.

The exciting coils 3a and 3b are each connected to an exciting power source 3d, and a signal processing unit 3e is connected to the magnetic detection unit 3c to input a signal to it. The output signal from the signal processing unit 3e is input to the voltage phase difference comparison circuit unit 3f, and the voltage signal detected by this is input to the display unit 4 and displayed. In the voltage phase difference comparison circuit section 3f, the voltage signal when detecting a normal portion of the mandrel bar 5 is set to, for example, "0", and a positive or negative voltage signal is generated by disturbance of electromagnetic balance when a crack or the like passes. It is displayed on the display device 4.

Various types of display devices can be applied as the display device 4, and in the embodiment, a pen recorder is used.

FIG. 6 is an example of data obtained by the display device 4 obtained when the outer diameter and surface properties of the mandrel bar 5 are controlled.

FIG. 2A shows data on the change of the outer diameter of the mandrel bar 5 in the axial direction by the outer diameter measuring device 2.

In the outer diameter measuring device 2, the outer diameter of the mandrel bar 5 is measured by the optical system shown in FIG. Since the mandrel bar 5 advances in the optical system while rotating around its axis, this data shows that the horizontal axis direction corresponds to the longitudinal direction of the mandrel bar 5 and the outside of the peripheral surface of the spiral with a small twist angle. The diameter is displayed vertically. Then, since the optical system measures by the difference method, the display amount is such that the difference between the maximum diameter and the minimum diameter appears in the vertical direction.

Further, (b) of the figure is data of the measurement result of the crack generation state by the crack detection measuring device 3.

The detection signal from the crack detecting and measuring device 3 utilizes the disturbance of the equilibrium magnetic field described above, and therefore the display device 4 has a pattern whose amplitude increases in proportion to the depth of the surface flaw of the mandrel bar 5. Displayed by. Then, like the data of the outer diameter measurement, the horizontal axis coincides with the longitudinal direction of the mandrel bar 5, and the degree of the depth of the surface flaw and the crack occurrence state can be known for the entire length.

In the above configuration, when the mandrel bar 5 is placed on the roller 6 and moved while rotating around the axis as shown in FIG. 1, the mandrel bar 5 is moved by the outer diameter measuring device 2 and the crack detecting measuring device 3. The outer diameter and surface appearance of the are simultaneously measured. Then, this measurement is performed over the entire length of the mandrel bar 5, and the measurement result is displayed and recorded by the display device 4.

As described above, since the outer diameter of the entire length of the mandrel bar 5 can be measured, the outer diameter of the entire mandrel bar 5 can be grasped as compared with the conventional measurement at several points using a micrometer or the like. . Therefore, it is possible to know how the outer diameter changes depending on the number of rolled products and the aspect of the distribution of the outer diameter change in the axial direction.

Similarly, the crack detection and measurement device 3 can also measure the surface texture of the mandrel bar 5 over the entire length, and can know the size and distribution of cracks.

Then, as shown in FIG. 6, it is possible to simultaneously examine the change of the outer diameter and the surface property of one inspection object, and it is also possible to analyze the correlation between the outer diameter and the occurrence of cracks due to rolling. Becomes For this reason, if statistical changes are accumulated and analyzed as statistical data that shows changes that occur depending on the size of the outer diameter of the mandrel bar 5, the axial length, etc., the mandrel bar 5 design Optimization can also be achieved.

In the examples, the mandrel bar for manufacturing seamless steel pipes was inspected, but it is also used for inspecting various large tools having other circular cross sections or long metal products having circular cross sections. The devised inspection device can be used.

[0031]

[Effect of device]

 According to the present invention, even if the object to be inspected is large, its outer diameter and surface appearance can be inspected at the same time. For this reason, it is possible to perform inspection management with much higher accuracy than the conventional method of extrapolating the outer diameter by multipoint inspection. In addition, since it is equipped with a means for displaying inspection data, it is possible to synthesize and analyze changes in the outer diameter of the entire length of the object to be inspected and the distribution of crack occurrences, etc. Can be diversified.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an inspection device of an example in which a mandrel bar for seamless steel pipe production is inspected.

FIG. 2 is a schematic view of an outer diameter measuring device as viewed in a pass direction of a mandrel bar.

FIG. 3 is a schematic diagram of an optical measurement system of an outer diameter measuring device.

FIG. 4 is a schematic view showing an arrangement example of a crack detection measuring device with respect to a mandrel bar.

FIG. 5 is a schematic diagram showing a detection system of a crack detection measuring device.

FIG. 6 is an example of the detection data of the surface texture of the mandrel bar, in which (a) of the figure is a change in outer diameter and (b) of the figure.
Indicates the distribution of surface defects and their depth.

[Explanation of symbols]

 1 Inspection device 2 Outer diameter measuring device 3 Crack detection measuring device 4 Display device 5 Mandrel bar (long metal object) 6 Roller (conveying means)

Claims (1)

[Scope of utility model registration request] 1. An apparatus for inspecting the outer diameter of a metal elongated object having a circular cross section and the occurrence of surface defects thereof, which conveys the metal elongated object in the axial direction while rotating about the axis thereof. Means, an outer diameter measuring device that is provided in parallel with the conveying means to measure the outer diameter of the metal elongated object and a crack detection measuring device that inspects a surface flaw, and a detection signal from these measuring devices is input to the metal. A device for inspecting a long metal object having a circular cross section, comprising: a display device for displaying a change in the outer diameter of the long object in the axial direction and the occurrence of surface defects.