Inspection equipment

Abstract

To provide an inspection device easy to measure the distribution of sheath thickness in cable sheaths, etc.SOLUTION: An inspection device 100 is a device for inspecting a plate-like object 500 with flexibility, which is formed by cutting a tube. The inspection device includes: a first clamping part 110 that has a first contact face 111 contacting the object 500; a second clamping part 120 that has a second contact face 121 contacting the object 500 and sandwiches the object 500 with the first clamping part 110; and a holding part 130 that holds the first clamping part 110 and the second clamping part 120 with the object 500 sandwiched therebetween. The second clamping part 120 has the transparency to allow the inspection light used for inspecting the object 500 to pass therethrough.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an inspection apparatus.

Background Art

[0002] Sheaths and tubes for cables (hereinafter also referred to as "sheaths etc.") are extrusion-molded using a core metal 610 and a base 620 as shown in FIG. 14. When creating a cable, a sheath 510 is extruded and formed on the outer periphery of a cable core 630. The thickness of the sheath etc. 510 is determined by adjusting the sizes and positions of the core metal 610 and the base 620.

[0003] However, when the parallelism or positional deviation relationship between the core metal 610 and the base 620 is not appropriate, variations are likely to occur in the thickness of the sheath etc. 510 (hereinafter also referred to as "sheath thickness"). In terms of appearance, even if the shape of the sheath etc. appears to have a uniform circular cross-section, the inner side of the sheath is gouged by the misaligned core metal or the cable arranged inside, and the cross-section does not become a uniform circular shape, resulting in variations in the sheath thickness. When variations occur in the sheath thickness, defects such as cracks are likely to occur in the thinner parts of the sheath thickness. That is, since the mechanical strength of the thin parts is relatively weak, for example, when the sheath etc. 510 is bent and stress concentrates on the thin parts, defects such as cracks are likely to occur.

[0004] Since the above-mentioned defects are less likely to occur when the sheath thickness is uniform, confirmation of the uniformity of the sheath thickness is being carried out. As a method for confirming the uniformity of the sheath thickness, a method is known in which the sheaths etc. are cut into rings, the cut cross-sections are observed with an optical microscope, and the distribution of the sheath thickness is measured.

[0005] However, the method of measuring the sheath thickness of the above-mentioned cut cross-section is a method of measuring the sheath thickness for a narrow part in the length direction of the sheaths etc. Therefore, in order to continuously measure the distribution of the sheath thickness in the length direction, it was necessary to cut the sheaths etc. at a plurality of locations and measure the sheath thickness.

[0006] Methods involving measurements at multiple locations are undesirable due to the time and effort required. A simple method for confirming the sheath thickness distribution (for example, regions where the sheath thickness is continuous) was desired. For example, the following methods have been proposed for simply measuring the sheath thickness distribution (see, for example, Patent Documents 1 and 2).

[0007] Patent Document 1 proposes an apparatus for measuring the shape and dimensions of a workpiece by placing it on the mounting surface, which is the upper surface of a light-transmitting plate, and irradiating it with light from the lower side of the light-transmitting plate.

[0008] Patent Document 2 proposes a device that irradiates an object to be measured with a radiation beam and detects the radiation beam that has passed through the object with a detector. The thickness of the object is measured based on the signal intensity detected by the detector. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Patent No. 4469659 [Patent Document 2] Japanese Patent Publication No. 2001-201336 [Overview of the project] [Problems that the invention aims to solve]

[0010] However, the apparatus disclosed in Patent Documents 1 and 2 made it difficult to measure the longitudinal distribution of sheath thickness, such as that of a sheath, for the reasons explained below. In other words, it was difficult to measure the longitudinal sheath thickness distribution of a sheath, such as that of a cylindrical object, using the apparatus disclosed in Patent Documents 1 and 2.

[0011] Another approach is to cut open a cylindrical sheath or similar material to create a plate-like structure and measure the sheath thickness distribution along its length. However, since the cut-open sheath tends to return to its original cylindrical shape, measuring the sheath thickness distribution along its length proved difficult.

[0012] The present invention was made to solve the above problems and aims to provide an inspection device that facilitates the measurement of the sheath thickness distribution in cable sheaths and the like. [Means for solving the problem]

[0013] To achieve the above objective, the present invention provides the following means. An inspection device according to a first aspect of the present invention is an inspection device for inspecting a flexible plate-shaped object formed by cutting open a cylindrical shape, comprising: a first clamping portion having a first contact surface that contacts the object; a second clamping portion having a second contact surface that contacts the object and clamps the object between itself and the first clamping portion; and a holding portion that holds the first clamping portion and the second clamping portion while the object is clamped, wherein the second clamping portion is transparent and allows inspection light used for inspecting the object to pass through.

[0014] An inspection apparatus according to a second aspect of the present invention is an inspection apparatus for inspecting a flexible plate-shaped object formed by cutting open a cylindrical shape, comprising: a light source unit that irradiates inspection light used for inspecting the object; a first clamping unit having a first contact surface that contacts the object and is transparent to allow the inspection light to pass through; a second clamping unit having a second contact surface that contacts the object and is transparent to allow the inspection light to pass through, and clamping the object between itself and the first clamping unit; a holding unit that holds the first clamping unit and the second clamping unit while the object is clamped; and a measuring unit that measures the intensity of the inspection light irradiated from the light source unit and transmitted through the first clamping unit, the object, and the second clamping unit.

[0015] An inspection apparatus according to a third aspect of the present invention is an inspection apparatus for inspecting a flexible plate-shaped object formed by cutting open a cylindrical shape, comprising: a light source unit that irradiates inspection light used for inspecting the object; a first clamping unit having a first contact surface that contacts the object; a second clamping unit having a second contact surface that contacts the object and is transparent to allow the inspection light to pass through, and clamping the object between itself and the first clamping unit; a holding unit that holds the first and second clamping units while the object is clamped; and a measuring unit that detects the reflected light of the inspection light irradiated from the light source unit, which has passed through the second clamping unit and reflected from the surface of the object, and measures the distance to the surface.

[0016] According to the inspection apparatus according to the first, second, and third aspects of the present invention, the object is held between the first and second clamping parts, making it easier to maintain a plate-like shape. Compared to cases where the object is not maintained in a plate-like shape, it becomes easier to measure the distribution of sheath thickness in the object. [Effects of the Invention]

[0017] According to the inspection device of the present invention, since it is provided with a first clamping part and a second clamping part that clamp and hold the object, it has the effect of making it easy to measure the distribution of sheath thickness in cable sheaths and the like. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic diagram illustrating the configuration of an inspection apparatus according to the first embodiment of the present invention. [Figure 2] Figure 1 is a cross-sectional view illustrating the configuration of the inspection device. [Figure 3] This is a perspective view illustrating an object such as a cable sheath. [Figure 4] This is a perspective view illustrating an object that has been cut open from a cylindrical shape to form a plate-like structure. [Figure 5] This is a diagram illustrating another embodiment of the holding part. [Figure 6]It is a schematic diagram for explaining the configuration of an inspection apparatus provided with a spacer. [Figure 7] It is a cross-sectional view for explaining the configuration of the inspection apparatus of FIG. 6. [Figure 8] It is a cross-sectional view for explaining the configuration of an inspection apparatus according to a second embodiment of the present invention. [Figure 9] It is a cross-sectional view for explaining the configuration of an inspection apparatus according to a third embodiment of the present invention. [Figure 10] It is a diagram for explaining the direction of relative movement of a laser microscope with respect to an object. [Figure 11] It is a graph for explaining the measurement result of the distance in the relative movement direction A. [Figure 12] It is a graph for explaining the measurement result of the distance in the relative movement direction B. [Figure 13] It is a graph for explaining the measurement result of the distance in the relative movement direction C. [Figure 14] There is a schematic diagram for explaining extrusion molding of a sheath or the like.

Mode for Carrying Out the Invention

[0019] 〔First Embodiment〕 Hereinafter, an inspection apparatus 100 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 7. This embodiment is an apparatus used for inspecting the sheath thickness of an object 500 such as a sheath for a cable. The inspection apparatus 100 is an apparatus for inspecting a flexible plate-shaped object 500 formed by cutting open a cylindrical shape.

[0020] FIG. 1 is a schematic diagram for explaining the configuration of the inspection apparatus 100. FIG. 2 is a cross-sectional view for explaining the configuration of the inspection apparatus 100 of FIG. 1. FIG. 3 is a perspective view for explaining the object 500 such as a sheath for a cable. FIG. 4 is a perspective view for explaining the object 500 formed into a plate shape by cutting open a cylindrical shape.

[0021] As shown in FIGS. 1 and 2, the inspection apparatus 100 is provided with a first clamping portion 110, a second clamping portion 120, and a holding portion 130. The object 500 inspected by the inspection device 100 is a sheath for a cable, etc., which has a cylindrical shape as shown in Figure 3. The sheath, etc., is cut open along a cutting line C that extends in the longitudinal direction. The cut-open object 500 has a rectangular plate shape as shown in Figure 4. The object 500 is flexible and, when no external force is applied, it easily returns from the plate shape shown in Figure 4 to the cylindrical shape shown in Figure 3.

[0022] As shown in Figures 1 and 2, the first clamping portion 110 and the second clamping portion 120 are members that hold the object 500 between them. In other words, they are members that restrict the shape of the object 500 so that it becomes plate-like.

[0023] In this embodiment, the first clamping portion 110 and the second clamping portion 120 have the same shape. For example, they have the same shape formed in the form of a rectangular plate. Specifically, they have the same length on each side of the rectangle and the same plate thickness. However, the first clamping portion 110 and the second clamping portion 120 may have a plate shape other than a rectangle (for example, the shape of a disc). Also, the first clamping portion 110 and the second clamping portion 120 may have different shapes.

[0024] The first clamping portion 110 and the second clamping portion 120 are formed using a translucent material that transmits inspection light used to inspect the object 500. In this embodiment, visible light is used as the inspection light. Glass is used as the translucent material. Glass used as the translucent material includes commercially available transparent plate glass such as window glass, microscope slides, liquid crystal display glass, and soda glass. Other materials such as resins that transmit visible light may also be used as the translucent material.

[0025] In the first embodiment, i.e., when using the inspection device 100, and in the third embodiment described later, i.e. when using the inspection device 300, the first clamping portion 110 may be formed using a light-transmitting material or a non-light-transmitting material that does not transmit inspection light. In the second embodiment, i.e. when using the inspection device 200, the first clamping portion 110 must be made of a light-transmitting material.

[0026] As shown in Figure 2, the first clamping portion 110 is provided with a first contact surface 111 that faces the second clamping portion 120 and comes into contact with the object 500. The second clamping portion 120 is provided with a second contact surface 121 that faces the first clamping portion 110 and comes into contact with the object 500.

[0027] The first contact surface 111 and the second contact surface 121 are surfaces that restrict the shape of the object 500 so that it becomes plate-like. In this embodiment, the first contact surface 111 and the second contact surface 121 are flat surfaces.

[0028] The first contact surface 111 and the second contact surface 121 may be all of the opposing portions of the first clamping portion 110 and the second clamping portion 120, or they may be only a part of the opposing portions. In this embodiment, the first contact surface 111 and the second contact surface 121 are all of the opposing portions of the first clamping portion 110 and the second clamping portion 120, respectively.

[0029] The first contact surface 111 and the second contact surface 121 each have contact areas 112 and 122 that contact the object 500, surrounded by non-contact areas 113 and 123 that do not contact the object 500. In other words, the first contact surface 111 and the second contact surface 121 are surfaces that are wider than the object 500.

[0030] The dimensions 110L and 120L in a predetermined direction at the first contact surface 111 and the second contact surface 121 are preferably at least twice, and more preferably at least three times, the dimensions 112L and 122L in a predetermined direction at the respective contact areas 112 and 122. Examples of the predetermined direction include the longitudinal direction of the object 500 having a rectangular shape, or the width direction perpendicular to the longitudinal direction.

[0031] The holding portion 130 is a member that holds the first clamping portion 110 and the second clamping portion 120 while the object 500 is being held between them. A known configuration can be used for the holding portion 130. The holding force in the holding portion 130, in other words, the force that brings the first clamping portion 110 and the second clamping portion 120 closer together, is preferably within a predetermined range.

[0032] The lower limit of the predetermined range is the value at which the position of the first clamping part 110, the second clamping part 120, and the object 500 does not move. The upper limit of the predetermined range is the value at which the object 500 is not crushed and the sheath thickness does not become uniform. More preferably, it is the value at which the surface irregularities of the object 500 are not crushed and flattened.

[0033] In this embodiment, four holding portions 130 are provided. The four holding portions 130 are arranged on the four sides of the first clamping portion 110 and the second clamping portion 120, respectively. Preferably, the holding portions 130 are positioned in the center of the side on which they are located. The position where the holding portions 130 are placed is any position that allows force to be applied uniformly to the object 500.

[0034] Figure 5 illustrates another embodiment of the holding portion 130. The holding portion 130 may be four, more than four, or fewer than four. For example, as shown in Figure 5, there may be one holding portion 130 that surrounds the first clamping portion 110 and the second clamping portion 120.

[0035] Figure 6 is a schematic diagram illustrating the configuration of the inspection device 100 equipped with spacer 140. Figure 7 is a cross-sectional view illustrating the configuration of the inspection device 100 in Figure 6. The inspection device 100 may also be provided with a spacer 140, as shown in Figures 6 and 7. The spacer 140 is a member positioned between the first clamping portion 110 and the second clamping portion 120, but at a position different from the object 500.

[0036] Furthermore, the spacer 140 is a member that prevents the distance between the first clamping portion 110 and the second clamping portion 120 from becoming smaller than a predetermined distance. In other words, the spacer 140 has a thickness that restricts the distance between the first clamping portion 110 and the second clamping portion 120 to a predetermined distance. The specific shape of the spacer 140 is not limited.

[0037] The predetermined interval value is determined based on the sheath thickness of the object 500. For example, it is a value such that the object 500 is not crushed and the sheath thickness does not become uniform. More preferably, it is a value such that the surface irregularities of the object 500 are not crushed and flattened. The predetermined interval value can be, for example, the design thickness of the sheath of the object 500.

[0038] In this embodiment, four spacers 140 are provided. The four spacers 140 are each positioned near the four corners of the first clamping portion 110 and the second clamping portion 120. The positions in which the spacers 140 are placed are such that the spacing between the first clamping portion 110 and the second clamping portion 120 is uniform.

[0039] Next, the inspection method using the inspection device 100, which has the above configuration, will be described. The inspection using the inspection device 100 is, for example, the first inspection (hereinafter also referred to as the primary inspection) performed in the manufacturing process of a cable having a sheath, which is the object 500. This inspection can be performed in a shorter time than the inspections performed using the inspection device 200 or the inspection device 300, which will be described later.

[0040] First, the cable to be inspected is removed from the manufacturing process. The sheath and other components are taken out of the removed cable, and as shown in Figures 3 and 4, the cylindrical sheath and other components are cut open to prepare a plate-shaped object 500.

[0041] The prepared object 500 is placed between the first clamping portion 110 and the second clamping portion 120, as shown in Figure 2. The first clamping portion 110 and the second clamping portion 120, which are holding the object 500, are then held using the holding portion 130.

[0042] For example, if the surface of the object 500 facing the second contact surface 121 is uneven, that is, if the sheath thickness of the object 500 is uneven, then the parts of the sheath that are thicker and convex will come into contact with the second contact surface 121, while the parts of the sheath that are thinner and concave will not come into contact with the second contact surface 121.

[0043] An inspector performing an inspection of the object 500 can, for example, visually inspect the object 500 from the second clamping portion 120 side and confirm the distribution of convex portions where the object 500 is in contact with the second contact surface 121 and concave portions where it is not in contact. By confirming this distribution, the thickness distribution of the object 500 can be inspected.

[0044] With the inspection device 100 configured as described above, the object 500 is held between the first clamping part 110 and the second clamping part 120, making it easier to maintain a plate-like shape. Compared to when the object 500 is not maintained in a plate-like shape, it becomes easier to measure the distribution of sheath thickness in the object 500.

[0045] Furthermore, compared to methods that involve slicing the sheath or similar material crosswise and measuring the sheath thickness at the cross-section, this method allows for the measurement of the sheath thickness distribution in the object 500 without having to cut the sheath or similar material at multiple points.

[0046] Furthermore, compared to methods that involve slicing the sheath and measuring the sheath thickness in the cross-section, this method reduces the time required from extracting the cable for inspection from the manufacturing process to inspecting the sheath thickness distribution in the object 500. This makes it easier to correct the parallelism and positional misalignment of the core metal 610 and the end cap 620 used for extruding the sheath at an earlier stage (see Figure 14).

[0047] By providing non-contact areas 113 and 123 on the first contact surface 111 and the second contact surface 121, it becomes easier to make the pressure distribution applied to the object uniform compared to the case where the non-contact areas 113 and 123 are not provided. For example, it becomes less likely that there will be a difference in pressure applied to the central part and the peripheral part of the object 500. It is also easier to suppress the inaccuracy of measuring the sheath thickness distribution due to a part of the object 500 being crushed.

[0048] By making the dimensions 110L and 120L in a predetermined direction at the first contact surface 111 and the second contact surface 121 at least twice the dimensions 112L and 122L in a predetermined direction at the contact regions 112 and 122, respectively, it becomes easier to make the pressure distribution applied to the object 500 more uniform compared to the case where this is not done. It also becomes easier to further suppress inaccuracies in measuring the sheath thickness distribution of the object 500.

[0049] By making the dimensions 110L and 120L in a predetermined direction at the first contact surface 111 and the second contact surface 121 at least three times the dimensions 112L and 122L in a predetermined direction at the contact regions 112 and 122, respectively, it becomes easier to make the pressure distribution applied to the object 500 more uniform compared to the case where this is not done. It also becomes easier to further suppress inaccuracies in measuring the sheath thickness distribution of the object 500.

[0050] By providing the spacer 140, the first clamping portion 110 and the second clamping portion 120 do not come too close together. In other words, the object 500 is not crushed to the point where it becomes difficult to inspect the sheath thickness. This makes it easier to suppress inaccuracies in measuring the sheath thickness distribution of the object 500.

[0051] [Second Embodiment] Next, an inspection apparatus 200 according to a second embodiment of the present invention will be described with reference to Figure 8. The basic configuration of the inspection apparatus 200 of this embodiment is the same as that of the inspection apparatus 100 of the first embodiment, but it differs from the first embodiment in that it is provided with a light source unit and a measuring unit. In this embodiment, the explanation of the contents common to the first embodiment will be omitted.

[0052] Figure 8 is a cross-sectional view illustrating the configuration of the inspection apparatus 200 according to the second embodiment. As shown in Figure 8, the inspection device 200 of this embodiment is provided with a light source unit 210, a first clamping unit 110, a second clamping unit 120, a holding unit 130, and a measuring unit 240.

[0053] The light source unit 210 is located on the side of the first clamping unit 110 and is a device that emits inspection light used for inspecting the object 500. The inspection light emitted from the light source unit 210 is visible light, similar to that of the first embodiment.

[0054] The light source unit 210 of this embodiment has a configuration that irradiates inspection light from a surface wider than the object 500. Furthermore, it is preferable that the light source unit 210 has a configuration that irradiates inspection light with a uniform brightness distribution. As the light source used in the light source unit 210, known light sources such as fluorescent lamps and light-emitting diodes can be used.

[0055] The measuring unit 240 is located on the side of the second clamping unit 120 and is a device for measuring the brightness distribution of the inspection light. The inspection light whose brightness is measured is the inspection light that has passed through the first clamping unit 110, the object 500, and the second clamping unit 120. In other words, the measuring unit 240 is a device for measuring the brightness distribution of the inspection light that has passed through the first clamping unit 110, the object 500, and the second clamping unit 120. Alternatively, the brightness distribution of the inspection light may be measured without setting the object 500 in the inspection device 200, and the device may be calibrated to eliminate brightness unevenness and achieve uniform brightness, thereby more accurately measuring the thickness distribution of the object 500.

[0056] The measuring unit 240 of this embodiment has a configuration in which a plurality of optical sensors for detecting transmitted inspection light are arranged in a planar manner. For example, it is preferable to have a configuration that measures the inspection light transmitted through the object 500 all at once. Alternatively, the measuring unit 240 may have a configuration that measures the inspection light transmitted through the object 500 sequentially by moving relative to the object 500. Known optical sensors can be used as sensors for detecting the brightness of light used in the measuring unit 240.

[0057] Next, the inspection method for the inspection device 200 having the above configuration will be described. The inspection performed by the inspection device 200 is, for example, an inspection performed after the primary inspection by the inspection device 100 in the manufacturing process of a cable having a sheath, which is the object 500 (hereinafter also referred to as the secondary inspection).

[0058] The secondary inspection performed by the inspection device 200 is an inspection that can measure the sheath thickness distribution more accurately than the primary inspection. Furthermore, it can be performed in a shorter time than the inspection performed using the inspection device 300, which will be described later.

[0059] The secondary inspection using the inspection device 200 can be performed on objects 500 that have been determined to have non-uniform sheath thickness based on the primary inspection using the inspection device 100. Alternatively, the secondary inspection may be performed on objects 500 that have not been determined to have non-uniform sheath thickness based on the primary inspection. Furthermore, the inspection using the inspection device 200 may be performed on objects 500 that have not undergone a primary inspection.

[0060] In the secondary inspection, as shown in Figure 8, the object 500 is placed between the first clamping part 110 and the second clamping part 120. The first clamping part 110 and the second clamping part 120, which hold the object 500, are then held using the retaining part 130.

[0061] Next, inspection light is shone from the light source unit 210 toward the first clamping unit 110, the object 500, and the second clamping unit 120. The brightness distribution of the inspection light transmitted through the first clamping unit 110, the object 500, and the second clamping unit 120 is measured by the measurement unit 240.

[0062] For example, if the object 500 has uneven sheath thickness, the inspection light will be relatively less likely to pass through the thicker parts of the sheath, resulting in relatively dimmer inspection light. On the other hand, the inspection light will be relatively more likely to pass through the thinner parts of the sheath, resulting in relatively brighter inspection light.

[0063] The measuring unit 240 measures the distribution of thick and thin areas in the sheath thickness by detecting areas that are relatively bright and relatively dark in the transmitted inspection light. The measuring unit 240 may also estimate the difference in sheath thickness by measuring the difference in brightness of the transmitted inspection light.

[0064] According to the inspection device 200 with the above configuration, the distribution of sheath thickness in the object 500 can be measured. Specifically, the brightness of the inspection light after it has passed through the first clamping part 110, the object 500, and the second clamping part 120 is measured.

[0065] For example, the inspection light that passes through the thin part of the object 500's sheath shows a relatively small decrease in brightness. On the other hand, the inspection light that passes through the thick part of the object 500's sheath shows a relatively large decrease in brightness. By measuring the brightness of the inspection light with the measuring unit 240, the distribution of sheath thickness in the object 500 can be measured.

[0066] The measuring unit 240 measures the distribution of brightness and darkness of the transmitted inspection light, making it easier to accurately measure the distribution of sheath thickness in the object 500. Therefore, compared to the method of cutting the sheath into sections and measuring the sheath thickness of the cross-section, it becomes easier to accurately correct the parallelism and positional misalignment of the core metal 610 and the end cap 620 used for extruding the sheath (see Figure 14).

[0067] [Third Embodiment] Next, an inspection apparatus 300 according to a third embodiment of the present invention will be described with reference to Figures 9 to 13. The basic configuration of the inspection apparatus 300 of this embodiment is the same as that of the inspection apparatus 100 of the first embodiment, but it differs from the first embodiment in that a laser microscope is provided. In this embodiment, the explanation of the contents common to the first embodiment will be omitted.

[0068] Figure 9 is a cross-sectional view illustrating the configuration of the inspection apparatus 300 according to the third embodiment. As shown in Figure 9, the inspection apparatus 300 of this embodiment is provided with a first clamping section 110, a second clamping section 120, a holding section 130, and a laser microscope 340.

[0069] The laser microscope 340 is a device for measuring surface irregularities on the object 500, that is, the non-uniformity of the sheath thickness of the object 500. The laser microscope 340 is located on the second clamping section 120 side of the inspection device 300. The laser microscope 340 is equipped with a light source section 341, a measuring section 342, and a moving section 343.

[0070] The light source unit 341 is a device that emits inspection light used for inspecting the object 500. The inspection light emitted from the light source unit 341 is laser light. As the light source used in the light source unit 341, a known light source used in laser microscopes can be used.

[0071] The measuring unit 342 is a device that measures the distance from the laser microscope 340 to the surface of the object 500. Specifically, it is a device that measures the distance to the surface by detecting the reflected light of the inspection light that is irradiated from the light source unit 341, passes through the second clamping unit 120, and is reflected off the surface of the object 500. The configuration of the measuring unit 342 can be a known configuration used in laser microscopes.

[0072] The moving unit 343 is a device that moves the laser microscope 340 relative to the object 500. The direction of relative movement is preferably along the surface of the plate-shaped object 500. Furthermore, it is preferable that the direction is along the surface and consists of two mutually orthogonal directions. Known configurations can be used for the relative movement of the laser microscope 340.

[0073] Next, the inspection method for the inspection device 300, which has the above configuration, will be described. The inspection performed by the inspection device 300 is, for example, an inspection performed after the secondary inspection by the inspection device 200 in the manufacturing process of a cable having a sheath, which is the object 500 (hereinafter also referred to as the tertiary inspection).

[0074] The tertiary inspection performed by the inspection device 300 is an inspection that can measure the sheath thickness distribution more accurately than the secondary inspection.

[0075] The tertiary inspection using the inspection device 300 can be performed on objects 500 that have been determined to have non-uniform sheath thickness as a result of the secondary inspection using the inspection device 200. Furthermore, the tertiary inspection may also be performed on objects 500 that have not been determined to have non-uniform sheath thickness as a result of the primary or secondary inspection. Additionally, the inspection using the inspection device 300 may be performed on objects 500 that have not undergone primary or secondary inspection.

[0076] In the third inspection, as shown in Figure 9, the object 500 is placed between the first clamping part 110 and the second clamping part 120. The first clamping part 110 and the second clamping part 120, which hold the object 500, are then held using the holding part 130.

[0077] Next, measurements are taken using the laser microscope 340. Specifically, the distance from the laser microscope 340 to the surface of the object 500, in other words, the surface irregularities of the object 500 are measured. By measuring the surface irregularities, the non-uniformity of the sheath thickness of the object 500 is measured.

[0078] Figure 10 illustrates the direction of relative movement of the laser microscope 340 with respect to the object 500. Figure 11 is a graph illustrating the measurement results of the distance from the laser microscope 340 to the surface of the object 500 in relative movement direction A. Figure 12 is a graph illustrating the measurement results of the distance from the laser microscope 340 to the surface of the object 500 in relative movement direction B. Figure 13 is a graph illustrating the measurement results of the distance from the laser microscope 340 to the surface of the object 500 in relative movement direction C.

[0079] In Figures 11 to 13, the horizontal axis represents the distance traveled in each relative direction of movement, and the vertical axis represents the distance from the laser microscope 340 to the surface of the object 500, which is the displacement from a predetermined reference point.

[0080] For example, as shown in Figures 11 to 13, the distance to the surface of the object 500 is measured while the laser microscope 340 is moved in relative movement directions A, B, and C. The object 500 shown in Figures 11 to 13 has a relatively convex portion in an approximately E-shape, in other words, a portion with a relatively thick sheath. On the other hand, it has a relatively concave portion around the periphery in an approximately E-shape, in other words, a portion with a relatively thin sheath (the hatched portion).

[0081] Relative movement direction A is the direction extending along the horizontal line in the center of the approximately E-shape, in other words, the direction extending from the center of the object 500 in the longitudinal direction in the width direction. Relative movement direction B is the direction extending across the three horizontal lines in the approximately E-shape, in other words, the direction extending from one end of the object 500 in the longitudinal direction in the width direction. Relative movement direction C is the direction extending along the vertical line in the approximately E-shape, in other words, the direction extending from the other end of the object 500 in the longitudinal direction in the width direction.

[0082] The relative movement direction A shown in Figure 11 is also the direction in which the sheath and other parts were extruded. The distance measured along the relative movement direction A, i.e., the sheath thickness, is fluctuating. Therefore, it can be inferred that the parallelism between the core metal 610 and the end cap 620 changes or misalignment occurs during the extrusion process.

[0083] The relative movement direction B shown in Figure 12 is also the circumferential direction of the sheath, etc. Furthermore, it is the circumferential direction of the sheath, etc. after the positional displacement occurs following a change in the parallelism between the core metal 610 and the end cap 620. Therefore, the measured distance, i.e., the variation in sheath thickness, is larger compared to the case shown in Figure 13.

[0084] The relative movement direction C shown in Figure 13 is also the circumferential direction of the sheath, etc. It is also the circumferential direction of the sheath, etc., before the parallelism between the core metal 610 and the end cap 620 changes, and before the misalignment occurs. Therefore, the measured distance, i.e., the variation in sheath thickness, is smaller compared to the case shown in Figure 12.

[0085] The inspection apparatus with the above configuration can measure the distribution of sheath thickness in the object 500. Specifically, the distance between the laser microscope 340 and the surface of the object 500 is measured. This distance is a value that fluctuates based on the unevenness of the surface of the object 500 and also fluctuates based on the non-uniformity of the sheath thickness of the object 500. By measuring the above distance while moving the laser microscope 340 relative to the object 500, the distribution of sheath thickness in the object 500 can be measured.

[0086] Since the distance between the laser microscope 340 and the surface of the object 500 is measured, it becomes easier to accurately measure the distribution of sheath thickness in the object 500. Therefore, compared to the method of slicing the sheath and measuring the sheath thickness of the cross-section, it becomes easier to accurately correct the parallelism and positional misalignment of the mandrel 610 and die 620 used for extruding the sheath (see Figure 14).

[0087] It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, the present invention is not limited to those applied to the embodiments described above, but may also be applied to embodiments that combine these embodiments as appropriate, and is not particularly limited. [Explanation of symbols]

[0088] 100, 200, 300…Inspection device, 110…First clamping part, 120…Second clamping part, 130…Holding part, 111…First contact surface, 121…Second contact surface, 112, 122…Contact area, 113, 123…Non-contact area, 140…Spacer, 500…Object, 210, 341…Light source part, 240, 342…Measurement part

Claims

1. An inspection device for inspecting a flexible, plate-shaped object formed by cutting open a cylindrical shape, A light source unit that emits inspection light used for inspecting the aforementioned object, A first clamping portion having a first contact surface that contacts the object and having transparency through which the inspection light passes, A second clamping portion has a second contact surface that contacts the object and is transparent, allowing the inspection light to pass through, and clamps the object between itself and the first clamping portion, A holding part that holds the first clamping part and the second clamping part while the object is being held, A measuring unit measures the brightness of the inspection light that is irradiated from the light source unit and has passed through the first clamping unit, the object, and the second clamping unit, A system was established, The first contact surface and the second contact surface are surfaces that are wider than the object, The light source unit has a configuration that irradiates the inspection light from a surface wider than the object, and is calibrated to measure the brightness distribution of the inspection light without setting the object, thereby eliminating brightness unevenness and achieving uniform brightness. The inspection device is configured such that the measuring unit moves relative to the object to sequentially measure the inspection light that has passed through the object.

2. The inspection apparatus according to claim 1, wherein the first contact surface and the second contact surface have a non-contact area surrounding the contact area that contacts the object and the area that does not contact the object.

3. The inspection apparatus according to claim 2, wherein the dimensions in a predetermined direction at the first contact surface and the second contact surface are at least twice the dimensions in the predetermined direction at each of the contact regions.

4. The inspection apparatus according to claim 2, wherein the dimensions in a predetermined direction at the first contact surface and the second contact surface are three times or more the dimensions in the predetermined direction at each of the contact regions.

5. The inspection apparatus according to claim 1, further comprising a spacer positioned between the first clamping portion and the second clamping portion, at a location different from the object.

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