UV irradiation equipment, UV irradiation system

Abstract

To provide an ultraviolet irradiation device which secures the ultraviolet intensity with a small number of LEDs, achieves a shadow-free state, and improves the accuracy of ultraviolet flaw inspection.SOLUTION: An ultraviolet irradiation device 1 includes: an ultraviolet LED light source 3; a first reflector 10; second reflectors 11, 11'; and third reflectors 12, 12', and is provided with an ultraviolet LED slit between upper end sides 22. The irradiation is performed through at least three routes in total: a route in which light is emitted from the ultraviolet LED light source 3, passes through the slit, and is directly applied to the plane to be irradiated; and two routes in which the light is reflected on the lower side surface and the reflection is made incident on the third reflectors 12, 12' and is applied the plane to be irradiated.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an ultraviolet irradiation device that irradiates ultraviolet rays, and an ultraviolet flaw detection device that irradiates ultraviolet rays onto the surface of an object to inspect the surface condition of the object, and more specifically, to an ultraviolet irradiation device and an ultraviolet irradiation system used for exciting fluorescent materials such as fluorescent magnetic particle inspection and fluorescent penetrant inspection. [Background technology]

[0002] As a type of non-destructive inspection method for inspecting the surface of an object such as a steel material, magnetic particle inspection and penetrant inspection are known. In magnetic particle inspection, magnetic particles or a magnetic particle solution containing magnetic particles is applied to the surface of the object, and the object is magnetized by applying a magnetic field to the object. Since magnetic flux is concentrated on defects such as cracks on the surface of the object, the magnetic particles are attracted to the magnetic flux and an indication pattern is formed by the magnetic particles. The defects are then inspected by observing the magnetic particle indication pattern. In magnetic particle inspection, there is a fluorescent magnetic particle inspection that uses fluorescent magnetic particles containing a phosphor in the magnetic particles to improve the accuracy of defect detection.

[0003] On the other hand, in penetrant testing, a penetrant is first applied to the surface of the test object to allow the penetrant to penetrate defects such as cracks on the surface. Next, excess penetrant adhering to the surface is removed, and developer powder is applied to the surface to suck the penetrant that has penetrated the defects to the surface by capillary action. The defects are then inspected by observing the penetration indication pattern of the sucked up penetrant. In penetrant testing, there is a fluorescent magnetic particle test that uses a fluorescent penetrant containing a phosphor to improve the accuracy of defect detection.

[0004] When using fluorescent magnetic particles or fluorescent penetrants in magnetic particle testing or penetrant testing, it is necessary to irradiate the test object with ultraviolet light to excite the fluorescent magnetic particles or fluorescent penetrants contained therein. As an ultraviolet irradiation device for irradiating ultraviolet light, one that uses an ultraviolet LED (Light Emitting Diode) as a light source is known.

[0005] Conventional UV irradiation devices using LED light sources use lenses and reflectors to focus the light emitted from the LED light source onto a certain range, but lenses cause loss due to transmission, and reflectors cause loss due to reflection. Also, because only the range of light emitted from the LED that can ensure a certain level of illuminance is used to irradiate the irradiation range, light rays that are away from the optical axis and have an illuminance below a certain level are lost.

[0006] Patent Document 1 discloses providing a reflecting mirror so as to cover the upper side of the ultraviolet lamp.

[0007] However, the technology described in Patent Document 1 only uses a reflector above the ultraviolet lamp, and does not solve the energy loss caused by the light emitted from the ultraviolet lamp irradiating areas other than the irradiated range having a certain width diagonally downward. One possible method to solve this problem is to extend the reflector to the vicinity of the irradiated surface, but this would block the line of sight of the worker during ultraviolet flaw detection, and would be too large to install. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2008-101947 A Summary of the Invention [Problem to be solved by the invention]

[0009] Conventional lenses have a transmittance of approximately 91 percent for the ultraviolet waves (UV-A) emitted by ultraviolet LEDs, and the loss of ultraviolet intensity due to lens surface reflection and lens ultraviolet transmittance is approximately 9 percent. In the case of a reduction due to lens surface reflection, the reflectance is approximately 4 percent when the angle of incidence / angle of incidence is 0 degrees, so it is calculated that when ultraviolet light from an ultraviolet LED light source passes through a lens, the ultraviolet intensity is reduced by at least approximately 8 percent. The change in transmittance due to the angle of incidence is small and has no effect. Therefore, the remaining 1 percent loss of the approximately 9 percent loss is thought to be due to ultraviolet transmittance. For this reason, the current challenge is to reduce these losses. Other challenges include the realization of a compact ultraviolet irradiation device and whether it is possible to simultaneously achieve shadowlessness.

[0010] Therefore, it is desirable to reduce energy loss on the surface irradiated with ultraviolet light by ultraviolet LEDs, thereby achieving high ultraviolet irradiance with fewer LEDs, and to eliminate shadows by irradiating from multiple directions with a compact irradiation device.

[0011] The object of the present invention is to provide a compact ultraviolet irradiation device and ultraviolet irradiation system that can achieve high ultraviolet irradiance in the irradiation area of ​​the irradiated surface with fewer LEDs and energy, and improve the accuracy of ultraviolet flaw detection inspection, in an ultraviolet irradiation device that irradiates ultraviolet rays, and an ultraviolet flaw detection device that irradiates ultraviolet rays on the surface of an object to be inspected to inspect the surface condition of the object, and that can achieve high ultraviolet irradiance in the irradiation area of ​​the irradiated surface with fewer LEDs and energy, and improve the accuracy of ultraviolet flaw detection inspection. [Means for solving the problem]

[0012] In order to solve the above problems, the ultraviolet irradiation device of the present invention is an ultraviolet irradiation device for an ultraviolet flaw detection device that irradiates ultraviolet rays onto a surface of an object to be inspected, the ultraviolet irradiation device including an ultraviolet LED light source and a reflecting device, the reflecting device includes a reflecting section and a passing section surrounded by a pair of first reflecting mirrors and a pair of second reflecting mirrors, and further includes a third reflecting mirror; the reflecting portion has an inner surface formed of the pair of first reflecting mirrors and a lower surface formed of the pair of second reflecting mirrors, the two first reflecting mirrors are formed to be plane-symmetrical with respect to a first imaginary plane defined by a line extending along the optical axis and a first line perpendicular to the first imaginary plane; Each of the inner surfaces has at least an upper end edge and an opening edge, Each of the lower sides has a top side, two lateral sides, and a bottom side; Each of the two first reflecting mirrors is inclined such that the upper end side is located inward and the opening side is located outward, The two inner surfaces are connected by the two lower surfaces, respectively; The two lower sides are formed to be plane-symmetrical with respect to a second imaginary plane perpendicular to the first imaginary plane, and are formed to be inclined inward so that the upper sides are positioned more inward than the lower sides, Further, the reflecting portion has a slit surrounded by the upper sides, Further, the ultraviolet LED light source is stored in an ultraviolet LED installation slit surrounded by the two upper end sides, and two side openings surrounded by two opening sides, The slit is located directly below the ultraviolet LED light source, The third reflecting mirror is provided on both sides of the reflecting portion so as to reflect the light emitted from the ultraviolet LED light source and reflected by the reflecting portion toward the irradiated area.

[0013] Furthermore, in the ultraviolet irradiation device of the present invention, the ultraviolet irradiation device further comprises a housing that surrounds the ultraviolet LED light source and the reflecting device and has an ultraviolet emission port through which ultraviolet light emitted from the ultraviolet LED light source is emitted, and an ultraviolet-transmitting protective filter is disposed in the ultraviolet emission port.

[0014] Furthermore, the ultraviolet irradiation device of the present invention is The ultraviolet irradiation device further includes a housing that surrounds the ultraviolet LED light source and the reflector and has an ultraviolet light outlet that emits ultraviolet light emitted from the ultraviolet LED light source, The ultraviolet ray exit port is characterized in that a bandpass filter that blocks visible light and transmits ultraviolet ray is disposed thereat.

[0015] Furthermore, the ultraviolet irradiation device of the present invention is characterized in that the housing is provided with a cover for closing the ultraviolet ray exit port.

[0016] In addition, the ultraviolet irradiation system of the present invention includes: The irradiated surface is a surface that is irradiated with ultraviolet light by the ultraviolet LED light source, The invention is characterized in that four or more ultraviolet irradiation devices according to claims 1 to 3 are arranged in the Y-axis direction, thereby connecting the irradiated surface to provide a long, band-like, uniform, shadowless light distribution. Effect of the Invention

[0017] In order to solve the above problems, the ultraviolet irradiation device of the present invention is an ultraviolet irradiation device for an ultraviolet flaw detection device that irradiates ultraviolet rays onto the surface of an object to be inspected, and is equipped with an ultraviolet LED light source and a reflecting device, the reflecting device is surrounded by a pair of first reflecting mirrors and a pair of second reflecting mirrors and is equipped with a reflecting section and a passing section, and further includes a third reflecting mirror, the reflecting section has an inner surface formed by the pair of first reflecting mirrors and a lower surface formed by the pair of second reflecting mirrors, the two first reflecting mirrors are formed in plane symmetry with respect to a first imaginary plane formed by a straight line extending along the optical axis and a first straight line perpendicular to the first straight line, and each of the inner surfaces has at least an upper end edge and an opening edge, Each of the lower sides has an upper edge, two horizontal edges, and a lower edge, and each of the two first reflecting mirrors is inclined so that the upper edge is located inward and the opening edge is located outward, and the two inner sides are connected by each of the two lower sides, and the two lower sides are formed in plane symmetry with respect to a second imaginary plane perpendicular to the first imaginary plane, and each of the upper edges is formed with an inward inclination so that it is located more inward than the lower edges, and the reflecting portion has a slit surrounded by the upper edges, and further includes an ultraviolet LED installation slit surrounded by the two upper edges in which the ultraviolet LED light source is stored, and two side openings surrounded by the two opening edges, The slit is located directly below the ultraviolet LED light source,The third reflecting mirror is arranged on both sides of the reflecting portion so as to reflect the light emitted from the ultraviolet LED light source and reflected by the reflecting portion toward the irradiated area. This makes it possible to obtain a band-shaped irradiation area without using lenses, etc., and reduces losses due to lens surface reflection and transmittance. In addition, light rays emitted from the ultraviolet LED light source with an intensity below a certain level can also be collected by the reflecting device, and the reflecting device can be formed short and compact in the vertical direction, making it possible to provide an ultraviolet irradiation device that makes it easy to ensure the operator's line of sight.

[0018] Furthermore, in the ultraviolet irradiation device of the present invention, the ultraviolet irradiation device further comprises a housing that surrounds the ultraviolet LED light source and the reflecting device and has an ultraviolet outlet through which ultraviolet light emitted from the ultraviolet LED light source is emitted, and an ultraviolet-transmitting protective filter is disposed at the ultraviolet outlet, thereby preventing dust from entering from the outside and preventing a decrease in illuminance, etc. due to dust.

[0019] Furthermore, the ultraviolet irradiation device of the present invention is The ultraviolet irradiation device further includes a housing that surrounds the ultraviolet LED light source and the reflector and has an ultraviolet light outlet that emits ultraviolet light emitted from the ultraviolet LED light source, The ultraviolet ray exit port is characterized by being equipped with a bandpass filter that blocks visible light and transmits ultraviolet ray, which prevents workers from misidentifying flaws due to visible light and contributes to more accurate inspection.

[0020] Furthermore, the ultraviolet irradiation device of the present invention is characterized in that a cover is provided on the housing to close the ultraviolet emission port, thereby further preventing the intrusion of dust and the like when not in use.

[0021] In addition, the ultraviolet irradiation system of the present invention includes: The irradiated surface is a surface that is irradiated with ultraviolet light by the ultraviolet LED light source, By arranging four or more ultraviolet irradiation devices as described in claims 1 to 3 in the Y-axis direction, the irradiated surface is connected to provide a long, band-like, uniform, shadow-free light distribution. Therefore, even if the object to be inspected is a long band-like object, the irradiated range can be made longer with uniform light distribution. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a front view of an ultraviolet irradiation device 1 according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a top view of FIG. 1 showing the ultraviolet irradiation device 1 according to the present embodiment. [Diagram 3] FIG. 2 is a right side view of FIG. 1 showing the ultraviolet irradiation device 1 according to the present embodiment. [Figure 4] FIG. 2 is a perspective explanatory view showing the inside of the ultraviolet irradiation device 1 in FIG. 1 with a first reflecting mirror 10 removed for the sake of explanation. [Diagram 5] 5 is a schematic front view showing the trajectories of light rays in the ultraviolet irradiation device 1 of FIG. 4. FIG. [Figure 6] 5(X) is a front view showing the trajectory of the light ray X in the ultraviolet irradiation device 1 of FIG. 4, and (Y) is a perspective view of (X). [Figure 7] 5(X) is a front view showing the trajectory of a light ray Y in the ultraviolet irradiation device 1 of FIG. 4, and (Y) is a perspective view of (X). [Figure 8] 4. (X) is a partial front view of the ultraviolet irradiating device 1 in FIG. 4 in which the third reflecting mirrors 12, 12' are omitted for the sake of explanation, and (Y) is a front view of (X). [Figure 9] (X) is a diagram showing an ultraviolet irradiation system 90 in which ultraviolet irradiation devices 1 according to this embodiment are arranged in series and stored in a housing 2, and (Y) is a diagram showing the layered structure of the reflectors used in the present invention. [Figure 10] FIG. 9(X) shows an ultraviolet irradiation system 90 according to this embodiment in which a plurality of ultraviolet irradiation devices 1 are arranged in series and housed in a housing 2, and these are further arranged in series. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, the details of the embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a front view showing an example of an ultraviolet irradiation device 1 according to this embodiment, and Fig. 2 is a top view of the ultraviolet irradiation device 1 of Fig. 1. Fig. 3 is a right side view of the ultraviolet irradiation device 1 of Fig. 1, Fig. 4 is an explanatory perspective view in which the first reflecting mirror 10 of the members of the ultraviolet irradiation device 1 shown in Fig. 1 has been removed for explanation to visualize the inside, and Fig. 5 is a schematic front view partially showing the trajectory of a light beam irradiated from an ultraviolet LED light source 3 to the ultraviolet irradiation device 1 from which the first reflecting mirror 10 has been removed for explanation as in Fig. 4. FIG. 6(X) is a front view showing the trajectory of light ray X in ultraviolet irradiation device 1 with first reflecting mirror 10 removed for the sake of explanation, similar to FIG. 4, and FIG. 6(Y) is a perspective view of FIG. 6(X). FIG. 7(X) is a front view showing the trajectory of light ray Y in ultraviolet irradiation device 1 with first reflecting mirror 10 removed for the sake of explanation, similar to FIG. 4, and FIG. 7(Y) is a perspective view of FIG. 7(X). FIG. 8(X) is a front view showing the trajectory of light ray Y in ultraviolet irradiation device 1 with first reflecting mirror 10 removed for the sake of explanation, similar to FIG. 4, and FIG. 9(X) is a perspective view showing an ultraviolet irradiation system 90 according to the present embodiment in which a plurality of ultraviolet irradiation devices 1 are arranged in series and housed in a housing 2, (Y) is a diagram showing a laminated structure of a reflector used in the ultraviolet irradiation device 1 according to the present embodiment, and Fig. 10 is a diagram showing another example of an ultraviolet irradiation system according to the present embodiment in which the housings 2 of Fig. 9(X) are further arranged in series. Note that, for convenience of explanation, in this disclosure, the front means the front as viewed from the front direction in Fig. 1 and the left direction in Fig. 3, the right side means the surface as viewed from the right in Figs. 1 and 2 and from the front in Fig. 3, and the left side means the surface as viewed from the opposite direction.

[0024] First, the ultraviolet irradiation device 1 irradiates the surface of an object to be inspected with ultraviolet light in order to excite the fluorescent magnetic powder or fluorescent penetrant liquid contained therein when fluorescent magnetic powder or fluorescent penetrant liquid is used in magnetic particle inspection or penetrant inspection, and is equipped with an ultraviolet LED light source 3 that irradiates the object to be inspected 5 or the irradiated surface 80 with ultraviolet light, and a reflecting device 4 consisting of multiple reflecting mirrors.

[0025] The ultraviolet irradiation device 1 may further include a housing 2 (not shown in FIG. 1) that surrounds the ultraviolet LED light source 3 and the reflector 4 and has an ultraviolet light outlet 60 that emits ultraviolet light emitted from the ultraviolet LED light source 3. As shown in FIG. 9, an ultraviolet light transmission filter 61 capable of blocking visible light may be disposed at the ultraviolet light outlet 60. The ultraviolet light transmission filter 61 may be an ultraviolet light transmission protective filter, or a bandpass filter that cuts visible light and transmits ultraviolet light may be used. The bandpass filter that cuts visible light and transmits ultraviolet light cuts a slight amount of visible light emitted from the ultraviolet LED light source 3 in the wavelength range of visible light, approximately 400 nm to 700 nm, and can improve the inspection work by preventing visible light from being reflected on the metallic glossy surface and dazzling the worker when inspecting the metallic glossy surface of the surface of the inspection object cut by a grinder or the like to detect defects from the inspection object. In addition, the ultraviolet light transmission protective filter is preferable because it can prevent dust from entering the housing 2, reducing the illuminance. Moreover, a cover (not shown) may be further provided so as to cover the ultraviolet ray exit port 60. In this way, it is possible to prevent dust and the like from entering the ultraviolet ray irradiation device 1 while it is not in use.

[0026] As shown in Fig. 1 and Fig. 2, the reflecting device 4 includes first reflecting mirrors 10, 10'. A slit 50 is provided so that light rays inclined 20 degrees to the left and right from a straight line P extending in the same position as the optical axis of the ultraviolet LED light source 3 can pass through and directly illuminate the illuminated area, which is the illuminated surface 80 or the surface to be inspected of the object 5 to be inspected. The maximum angle at which the light rays are inclined from the optical axis is appropriately designed depending on the distance to the illuminated surface. The plane formed by the straight line P in the same position as the optical axis of the light emitted from the ultraviolet LED light source 3 and the straight line N perpendicular to this is the first imaginary plane V. The first reflecting mirrors 10, 10' are formed symmetrically with respect to the first imaginary plane V. The irradiated range is set arbitrarily depending on the size and shape of the object 5 to be inspected.

[0027] Next, the ultraviolet irradiation device 1 will be described in more detail with reference to FIG. 3. The first reflecting mirrors 10, 10' are shaped like a letter V when viewed from the right side as shown in FIG. 3. The ultraviolet LED installation slit 51 is formed by being surrounded by the upper end edges 22, 22 of the first reflecting mirrors 10, 10'. The ultraviolet LED light source 3 is provided in the center of the ultraviolet LED installation slit. The second reflecting mirrors 11, 11' are provided so as to be surrounded by the first reflecting mirrors 10, 10' and to suspend them. The second reflecting mirrors 11, 11' are shaped like a letter V when viewed from the front as shown in FIG. 1. The third reflecting mirrors 12, 12' are provided so as to allow most of the light emitted from the ultraviolet LED light source 3 and reflected by the second reflecting mirrors 11, 11' to enter the third reflecting mirrors 12, 12', and are provided with a sufficient size. The size and position are appropriately designed according to the size of other members. In addition, there is a first imaginary plane V on which a straight line P passing through the optical axis of the ultraviolet LED light source 3 exists, and there is a second imaginary plane W perpendicular to the straight line P. Therefore, the straight line P also exists on the second imaginary plane W. The second reflecting mirrors 11, 11' are formed symmetrically with respect to the second imaginary plane W.

[0028] Next, the ultraviolet irradiation device 1 will be described in more detail with reference to Fig. 4. The second reflecting mirrors 11, 11' each have a lower side 30, 30'. The lower side 30, 30' each have an upper side 31, 31', horizontal sides 32, 33, 32', 33', and a lower side 34, 34'. The slit 50 is formed by being surrounded by the upper sides 31, 31'. The upper sides 31, 31' are provided on a straight line inclined by 20 degrees on a virtual plane V with O as the origin from the straight line P shown in Fig. 1. Of these, horizontal sides 32, 32' are connected to inner surface 21, and horizontal sides 33, 33' are connected to inner surface 21'. With this structure, second reflecting mirrors 11, 11' are provided so as to suspend first reflecting mirrors 10, 10'. Furthermore, the second reflecting mirror is provided so as not to be inclined in the longitudinal direction of slit 50, and first reflecting mirrors 10, 10' are provided so as not to be inclined in the lateral direction of slit 50. Inner surfaces 21, 21' each include an upper end side 22, an opening side 23, and a side opening side 24. Each of reflecting portion 20 is surrounded by two side opening sides 24 and includes side openings 52, 52'.

[0029] The slit 50 is formed surrounded by the upper sides 31, 31'. As already described, the slit 50 is located directly below the ultraviolet LED light source 3 because the light from the ultraviolet LED light source 3 directly irradiates the inspection object 5. At this time, after passing through the slit 50, the light passes through the passing section 40, which is surrounded by the second reflecting mirrors 11, 11' and located below the reflecting section 20.

[0030] Next, the path of the light emitted from the ultraviolet LED light source 3 to the object to be inspected 5 in the ultraviolet irradiation device 1 of the present invention will be described in detail with reference to Fig. 5. The light emitted from the ultraviolet LED light source 3 illuminates the irradiated surface 5 from three directions. In other words, there are roughly three paths. First, the light emitted from the ultraviolet LED light source 3 passes through the reflecting section 20, the slit 50, and the passing section 40 before being irradiated (Route 1). Route 1 is a path in which the ultraviolet LED light source 3 directly irradiates the object to be inspected 5 without going through a reflecting mirror.

[0031] As another route, the light emitted from the ultraviolet LED light source 3 passes through the reflecting portion 20, is reflected by the lower surface 30 of the second reflecting mirror 11, and the light is reflected by the third reflecting mirror 12 to irradiate the inspection object 5. (Route 2) Furthermore, as a third path, the light emitted from the ultraviolet LED light source 3 passes through the reflecting section 20, is reflected by the lower surface 30' of the second reflecting mirror 11', passes outside the reflecting section 20, is reflected by the third reflecting mirror 12', and irradiates the inspection object 5. (Route 3) With these three paths, the object 5 to be inspected is illuminated from three directions, improving the degree of shadow-free, which is preferable. In fluorescent magnetic particle testing and fluorescent penetrant testing, the object 5 to be inspected usually has many irregularities, so when light is irradiated from one direction, some parts are shaded by the irregularities. However, in the ultraviolet irradiation device 1 of the present invention, since the ultraviolet irradiation device 1 is irradiated via three paths as described above, some parts that are shaded in one direction are irradiated with light from three directions. This increases the area that is not shaded, improving the visibility of flaws in fluorescent magnetic particle testing and fluorescent penetrant testing, which is preferable.

[0032] Next, the trajectory of the light ray X when reflected by the undersides 30, 30' will be described in detail using route 2 as an example with reference to Figure 6. The light ray X emitted from the ultraviolet LED light source 3 is first reflected by the underside 30 as shown in Figure 6(X), and is further reflected by the third reflecting mirror 12. Figure 6(Y) shows this in a perspective view. The same thing happens when the light ray X is emitted in the direction of the underside 30' and is similarly reflected by the underside 30'.

[0033] Next, referring to Fig. 7, another case of the trajectory of the light ray X when reflected by the lower surfaces 30, 30' will be described in detail using route 2 as an example. As shown in Fig. 7(X), the light ray Y emitted from the ultraviolet LED light source 3 is reflected by the lower surface 30, then by the inner surface 21, and further by the third reflecting mirror 12, irradiating the inspection object 5. Fig. 7(Y) shows this in a perspective view. In addition to the case of light ray Y being reflected three times, there is also a case where the light ray emitted from the ultraviolet LED light source 3 is first reflected by the lower surface 30, then reflected by the inner surface 21', and then reflected by the third reflecting mirror 12. As described above, route 2 can be classified into a total of three cases depending on the method of reflection. The case of reflection from the ultraviolet LED light source 3 to the lower surface 30', that is, the light trajectory of route 3, can also be classified into these three cases.

[0034] In the ultraviolet irradiation device 1 of the present invention, the trajectories of the light irradiated from the ultraviolet LED light source 3 can be classified into a total of six categories by route 2 and route 3, and if route 1 is added to this, the number of categories becomes seven. When these light rays are irradiated to the inspection object 5 or the irradiated surface 80, they pass through the ultraviolet transmission filter 61 shown in FIG. 9(X). When the light rays from the ultraviolet irradiation device 1 of the present invention pass through the ultraviolet transmission filter 61, there are cases where visible light cannot be cut well unless the angle of incidence is 20 degrees or less. For this reason, it is necessary to set the angle of incidence of the light rays to 20 degrees or less. In order to control the angle of incidence of all the seven categories of light rays to the ultraviolet transmission filter 61 to 20 degrees or less, the present inventors have conducted extensive research and found that it is preferable to set the angles α and β shown in FIG. 8 to 5 to 15 degrees and 65 to 75 degrees, respectively.

[0035] First, the straight line P shown in Fig. 8 is a straight line that hangs down from the center point O of the ultraviolet LED light source 3, similar to the optical axis that is the central axis of the light emitted from the ultraviolet LED light source 3. For the sake of explanation, the first reflecting mirror 10 is omitted in Fig. 8(X) for the sake of explanation, but when viewed from the right side as in Fig. 8(X), the first reflecting mirrors 10 and 10' are symmetrical with respect to the straight line P as a reference, and are arranged in a V-shape with the upper end edge 22 side tilted inward. Similarly, when viewed from the front as in Fig. 8(Y), the second reflecting mirrors 11 and 11' are symmetrical with respect to the straight line P as a reference, and are arranged in a V-shape with the upper edges 31 and 31' tilted inward.

[0036] Next, angles α and β will be described in detail. Line Q shown in Figure 8(X) is parallel to line P. The angle between line Q and first reflecting mirror 10' is angle α. Although not shown, the angle between line Q and any line parallel to line P for first reflecting mirror 10 is similarly angle α. Next, regarding the angle β, as shown in Fig. 8(Y), the line R is parallel to the line P. The angle between the line R and the second reflecting mirror 11 is angle β. Although not shown, the angle between any line parallel to the line P in Fig. 8(Y) and the second reflecting mirror 11' is also angle β. If the angle β exceeds 75 degrees, the third reflecting mirrors 12, 12' must be installed higher, and the light reflected from the third reflecting mirrors 12, 12' is blocked by the reflecting device 4. If the angle β is less than 65 degrees, the third reflecting mirrors 12, 12' must be installed lower than the height of the reflecting device 4, and the ultraviolet irradiation device 1 becomes large. If the ultraviolet irradiation device 1 is large, it may block the view of the inspector during inspection. The angle β is preferably 65 to 75 degrees.

[0037] Furthermore, when the angle β is 65 to 75 degrees, the angle α is preferably 5 to 15 degrees. By setting the angle α in this range, the angle of incidence on the ultraviolet transmission filter 61 can be controlled to approximately 20 degrees or less for all of the seven types of light emitted from the ultraviolet irradiation device 1 of the present invention when passing through the ultraviolet transmission filter 61, which is preferable.

[0038] Next, an ultraviolet irradiation system 90 of the present invention will be described in detail with reference to Fig. 9. The ultraviolet irradiation system 90 is configured by arranging ultraviolet irradiation devices 1 according to the present invention in series. As shown in Fig. 9(X), in the ultraviolet irradiation system 90 of the present invention, the ultraviolet irradiation devices 1 are arranged in series and stored in a housing 2. The ultraviolet irradiation devices 1 are arranged in series in the longitudinal direction of the slits 50 of the ultraviolet irradiation devices 1. This arrangement allows the irradiation range of the ultraviolet irradiation system 90 to be vertically longer than that of the ultraviolet irradiation device 1 alone. The housing 2 also includes an ultraviolet ray irradiation port 60 and an ultraviolet ray transmission filter 61 . The ultraviolet transmission filter 61 may be an ultraviolet transmission protection filter or a bandpass filter that cuts visible light and transmits ultraviolet light. If it is an ultraviolet transmission protection filter, it is possible to prevent dust and the like from entering the inside of the housing 2 while transmitting ultraviolet light. If it is a bandpass filter that cuts visible light and transmits ultraviolet light, it is possible to significantly reduce the slight visible light emitted from the ultraviolet LED light source 3. It is necessary to ensure ultraviolet light intensity with a peak wavelength of about 365 nm for ultraviolet flaw detection, but if the ultraviolet light intensity is increased in the ultraviolet LED light source 3, the visible light of 400 nm or more will inevitably be mixed in proportion to the increase in ultraviolet light intensity. This is preferable because it is possible to take measures against this and reduce the number of times that an inspector overlooks flaws during inspection.

[0039] Fig. 9(Y) shows a suitable layered structure of the reflecting mirror. It is suitable to layer a metal reflective film (AL film) 72 on a substrate 73, and then form a dielectric multilayer film 71 (UV enhanced reflective film) on top of that. The surface of the dielectric multilayer film 71 is the reflective surface 70, which corresponds to the surface that reflects light from the inner surface 21, the lower surface 30, and the third reflecting mirrors 12 and 12'. The substrate 73 is made of glass or a metal with a smooth surface. It is preferable that all of the first to third reflecting mirrors have this layered structure.

[0040] Next, the ultraviolet irradiation system 90 of the present invention will be described in more detail with reference to FIG. 10. The ultraviolet irradiation system 90 shown in FIG. 10 shows ultraviolet irradiation devices 1 arranged in series in the same arrangement as in (X) of FIG. 9. The ultraviolet irradiation system 90 irradiates the irradiated surface 80. By arranging the ultraviolet irradiation devices 1 in this way, in the range T between the straight line S hanging down from the third ultraviolet irradiation device 1 on the right side and the straight line U hanging down from the third ultraviolet irradiation device 1 on the left side of the irradiated irradiated surface 80, the ultraviolet irradiation system 90 having a large number of light sources as shown in FIG. 10 is always irradiated from five ultraviolet LED light sources 3, which is preferable because it can maintain a uniform high-intensity light distribution. The number is not limited to the case shown in FIG. 10, and it is preferable to arrange four or more ultraviolet irradiation devices 1 in series in the same arrangement to create a uniform irradiation range. EXAMPLES

[0041] The ultraviolet irradiation device 1 of the embodiment had the features of the present invention. That is, it had a reflecting device 4 consisting of first to third reflecting mirrors, and the positional relationship between the first reflecting mirrors 10, 10', the second reflecting mirrors 11, 11', and the third reflecting mirrors 12, 12' was the same as in the present invention. For the first to third reflecting mirrors, an aluminum ultraviolet enhanced reflection mirror manufactured by Sigma Koki Co., Ltd. was used as a reflecting mirror having a layered structure as shown in Fig. 9(Y). The ultraviolet LED light source 3 used had a peak wavelength of 365 nm.

[0042] The comparative example used a conventional ultraviolet irradiation device simply equipped with reflecting mirrors on both sides, and therefore did not have the features of the present invention. <Evaluation method> (UV irradiance distribution test) The ultraviolet irradiance distribution on the irradiated surface was measured when the ultraviolet irradiation device 1 of the embodiment was used. The ultraviolet irradiance distribution was measured in an area of ​​200 mm irradiation width in the X-axis direction of the irradiated surface located 600 mm away from the improved linear Fresnel lens, and the degree of improvement of the ultraviolet irradiance distribution was measured. The method of measuring the degree of improvement was to compare the uniform irradiance when the ultraviolet irradiance was within ±10 percent of the average ultraviolet irradiance over the entire irradiation width and the ultraviolet irradiance was uniform.

[0043] As a result of comparing the illuminance through this ultraviolet irradiance measurement test, the following results were obtained: In other words, assuming the ultraviolet irradiance result of the comparative example to be 100%, the ultraviolet irradiance obtained on the irradiated surface of the inspection object 5 in the example was approximately 110 to 115%. [Industrial Applicability]

[0044] The present disclosure can be suitably used in an ultraviolet irradiation device that irradiates ultraviolet rays, and an ultraviolet flaw detection device equipped with an ultraviolet irradiation device. However, the present disclosure is not limited to the above-described embodiment and examples. The ultraviolet irradiation device of the present disclosure is useful for all tests and inspections that use ultraviolet rays, such as contamination checks, leakage inspections, and confirmation of degreasing and cleaning. In addition, the ultraviolet flaw detection device of the present disclosure is not limited to a fluorescent magnetic particle flaw detection device, but may be a penetrant flaw detection device that uses a fluorescent penetrant to detect defects on the surface of an object to be inspected, and can be applied to all ultraviolet flaw detection devices that use ultraviolet rays to detect defects. [Explanation of symbols]

[0045] 1 Ultraviolet irradiation device 2. Chassis 3 UV LED light source 4 Reflector 5. Inspection item 10, 10´ First reflector 11, 11´ Second reflector 12, 12´ Third reflector 20 Reflector 21 Inner surface 22 Top edge 23 Opening Edge 24 Side opening edge 30 Lower side 31, 31' top 32, 33, 32´, 33´ horizontal side 34, 34´ bottom 40 Passage section 50 Slit 51 UV LED installation slit 52, 52´ side opening 60 Ultraviolet light exit 61 UV Transmitting Filter 70 Reflective surface 71 Dielectric multilayer film 72 Metal reflective film 73 Substrate 80 Irradiated surface 90 UV irradiation system

Claims

1. An ultraviolet irradiation device for an ultraviolet flaw detection device that irradiates ultraviolet rays onto a surface of an object to be inspected, the ultraviolet irradiation device including an ultraviolet LED light source and a reflecting device, the reflecting device includes a reflecting section and a passing section surrounded by a pair of first reflecting mirrors and a pair of second reflecting mirrors, and further includes a third reflecting mirror; the reflecting portion has an inner surface formed of the pair of first reflecting mirrors and a lower surface formed of the pair of second reflecting mirrors, the two first reflecting mirrors are formed to be plane-symmetrical with respect to a first imaginary plane defined by a line extending along the optical axis and a first line perpendicular to the first imaginary plane; Each of the inner surfaces has at least an upper end edge and an opening edge, Each of the lower sides has a top side, two lateral sides, and a bottom side; Each of the two first reflecting mirrors is inclined such that the upper end side is located inward and the opening side is located outward, The two inner surfaces are connected by the two lower surfaces, respectively; The two lower side surfaces are formed to be plane-symmetrical with respect to a second imaginary plane perpendicular to the first imaginary plane, and are formed to be inclined inward so that the upper sides are positioned more inward than the lower sides, Further, the reflecting portion has a slit surrounded by the upper sides, Further, the ultraviolet LED light source is stored in an ultraviolet LED installation slit surrounded by the two upper end sides, and two side openings surrounded by two opening sides, The slit is located directly below the ultraviolet LED light source, The ultraviolet irradiation device, characterized in that the third reflecting mirror is provided on both sides of the reflecting portion so as to reflect the light emitted from the ultraviolet LED light source and reflected by the reflecting portion toward the irradiated area.

2. The ultraviolet irradiation device according to claim 1, further comprising a housing that surrounds the ultraviolet LED light source and the reflector and has an ultraviolet light outlet through which ultraviolet light emitted from the ultraviolet LED light source is emitted, and an ultraviolet light transmitting protective filter is disposed in the ultraviolet light outlet.

3. The ultraviolet irradiation device further includes a housing that surrounds the ultraviolet LED light source and the reflector and has an ultraviolet light outlet that emits ultraviolet light emitted from the ultraviolet LED light source, 2. The ultraviolet irradiation device according to claim 1, wherein a bandpass filter that blocks visible light and transmits ultraviolet light is disposed at the ultraviolet light exit port.

4. 4. The ultraviolet irradiation device according to claim 2, further comprising a cover provided on said housing for closing said ultraviolet ray exit port.

5. The irradiated surface is a surface that is irradiated with ultraviolet light by the ultraviolet LED light source, An ultraviolet irradiation system, characterized in that four or more ultraviolet irradiation devices according to claims 1 to 3 are arranged in a line in the Y-axis direction to connect the irradiated surface to form a long, band-like, uniform, shadow-free light distribution.

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