Light irradiation device and light irradiation system

Abstract

The objective is to provide a light irradiation device and light irradiation system that exhibits minimal degradation even in high-temperature and high-humidity environments and can be used repeatedly for extended periods. The light irradiation device 10 comprises a heat dissipation section, a plurality of LED substrates 29 arranged on the outer surface of the heat dissipation section and each substrate having multiple LEDs 28 that emit light of a specific wavelength, a synthetic quartz glass cylinder 30 that functions as a window material when the plurality of LED substrates 29 are sealed, and a sealing section 35 that seals the ends of the heat dissipation section and the synthetic quartz glass cylinder 30.

Description

Technical Field

[0001] The present disclosure relates to a light irradiation device and a light irradiation system that irradiate light from an LED.

Background Art

[0002] In recent years, as a method for extending the life and repairing sewer pipes that have developed defects and cracks due to long-term use, a reinforcing member impregnated with a photocurable resin is arranged along the inner wall of the sewer pipe, and light is irradiated from a light source such as an LED to cure the resin and regenerate the sewer pipe (see, for example, Patent Document 1). Further, a light irradiation device that irradiates light toward the inner wall of the sewer pipe while moving inside the sewer pipe and is used in this regeneration method has been proposed. Patent Document 1 discloses a device (light irradiation device) in which a plurality of LEDs that irradiate light outward are arranged on the outer periphery of an octagonal cylindrical or cylindrical housing element.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the prior art including Patent Document 1, since the inside of the sewer pipe is an environment with high temperature and very high humidity, there is a problem that the LEDs of the light irradiation device and the LED substrate on which the LEDs are arranged deteriorate quickly. There was room for further improvement in order to reduce the frequency of repair and replacement of the light irradiation device and improve convenience.

[0005] Therefore, an object of the present disclosure is to provide a light irradiation device and a light irradiation system that have little deterioration even in a high-temperature and high-humidity environment and can be repeatedly used for a long period of time.

Means for Solving the Problems

[0006] The light irradiation device disclosed herein comprises: a heat dissipation section; a plurality of LED substrates arranged on the outer circumferential surface of the heat dissipation section, each substrate having a plurality of LEDs that emit light of a specific wavelength; a synthetic quartz glass cylinder that functions as a window material when the plurality of LED substrates are sealed; and a sealing section that seals the ends of the heat dissipation section and the synthetic quartz glass cylinder, and hermetically seals the space surrounded by the heat dissipation section and the synthetic quartz glass cylinder to prevent air from entering from the outside. The synthetic quartz glass tube is a polygonal tube formed by joining multiple synthetic quartz glass plates with an adhesive, and the roundness of the polygonal synthetic quartz glass tube is within 1 mm on any face. ru 。 Other light irradiation devices of the present disclosure include: a heat dissipation section; a plurality of LED substrates arranged on the outer circumferential surface of the heat dissipation section, each substrate having a plurality of LEDs that emit light of a specific wavelength; a synthetic quartz glass cylinder that functions as a window material when the plurality of LED substrates are sealed; a sealing section that seals the ends of the heat dissipation section and the synthetic quartz glass cylinder, and hermetically seals the space surrounded by the heat dissipation section and the synthetic quartz glass cylinder to prevent air from entering from the outside; a control circuit section that supplies power to the LED substrates; and a separation member that separates air drawn in from the outside into air that cools the control circuit section and air that is blown into the heat dissipation section without cooling the control circuit section. .

[0007] The light irradiation system of this disclosure is as described in claim 1 to 8 This is a combination of multiple light irradiation devices described in any one of the items. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a light irradiation device and light irradiation system that can be used in pipe rehabilitation technology by photocuring, and which exhibit minimal degradation even in high-temperature and high-humidity environments and can be used repeatedly for a long period of time. Furthermore, economic benefits such as improved work efficiency of the light irradiation device and light irradiation system and a reduction in the frequency of LED replacement can also be obtained simultaneously. [Brief explanation of the drawing]

[0009] [Figure 1] A side view showing the configuration of the main components of a light irradiation system according to one embodiment of the present disclosure. [Figure 2] A side view showing the configuration of a light irradiation device according to one embodiment of the present disclosure. [Figure 3] A side cross-sectional view showing the configuration of the main part of a light irradiation device according to one embodiment of the present disclosure. [Figure 4] A front view of a light irradiation device according to one embodiment of the present disclosure. [Figure 5] A cross-sectional view of a light irradiation device according to one embodiment of the present disclosure, taken along the line V1-V1 in Figure 3. [Figure 6] A cross-sectional view of a light irradiation device according to one embodiment of the present disclosure, taken along the line V2-V2 in Figure 3. [Figure 7]Cross-sectional view taken along the arrow V3-V3 in FIG. 3 of the light irradiation device according to an embodiment of the present disclosure. [Figure 8] Cross-sectional view taken along the arrow V4-V4 in FIG. 3 of the light irradiation device according to an embodiment of the present disclosure. [Figure 9] Explanatory diagram of the air flow inside the light irradiation device according to an embodiment of the present disclosure. [Figure 10] Explanatory diagram of the synthetic quartz glass plate constituting the polygonal synthetic quartz glass cylinder of the light irradiation device according to an embodiment of the present disclosure. [Figure 11] Explanatory diagram of the manufacturing method of the polygonal synthetic quartz glass cylinder of the light irradiation device according to an embodiment of the present disclosure. [Figure 12] Explanatory diagram of the roundness of the polygonal synthetic quartz glass cylinder of the light irradiation device according to an embodiment of the present disclosure. [Figure 13] Explanatory diagram of the relationship between the LED and the polygonal synthetic quartz glass cylinder of the light irradiation device according to an embodiment of the present disclosure. [Figure 14] Explanatory diagram of the method for rehabilitating a sewer pipe using the light irradiation device according to an embodiment of the present disclosure. [Figure 15] Explanatory diagram of the method for rehabilitating a sewer pipe using the light irradiation system according to an embodiment of the present disclosure. [Figure 16] Explanatory diagram of the method for rehabilitating a sewer pipe using the light irradiation system according to an embodiment of the present disclosure.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. The configurations, shapes, etc. described below are examples for explanation, and can be appropriately changed according to the specifications of the light irradiation system, light irradiation device, sewer pipe, and reinforcing member. Hereinafter, corresponding elements in all the drawings are denoted by the same reference numerals, and redundant explanations are omitted. In FIG. 1 and a part described later, as two axes orthogonal to each other in the horizontal plane, the X-axis (the left-right direction in FIG. 1) in the moving direction of the light irradiation device and the Y-axis (the direction perpendicular to the paper surface in FIG. 1) orthogonal to the moving direction are shown. In FIG. 1 and a part described later, the Z-axis (the up-down direction in FIG. 1) is shown as the height direction orthogonal to the horizontal plane.

[0011] First, referring to FIG. 1, the configuration of the light irradiation system 1 will be described. The light irradiation system 1 includes a plurality of light irradiation devices 10. The plurality of light irradiation devices 10 connect the front connection part 2 and the rear connection part 3 provided in the front and rear light irradiation devices 10. That is, in the light irradiation system 1, a plurality of light irradiation devices 10 are connected. In the example shown in FIG. 1, in the light irradiation system 1, four light irradiation devices 10A to 10D are connected in series.

[0012] The first light irradiation device 10A and the second light irradiation device 10B are connected by the rear connection part 3 of the light irradiation device 10A and the front connection part 2 of the light irradiation device 10B. The second light irradiation device 10B and the third light irradiation device 10C are connected by the rear connection part 3 of the light irradiation device 10B and the front connection part 2 of the light irradiation device 10C. The third light irradiation device 10C and the fourth light irradiation device 10D are connected by the rear connection part 3 of the light irradiation device 10C and the front connection part 2 of the light irradiation device 10D.

[0013] The connected front connection part 2 and rear connection part 3 are relatively rotatable about the central axis CL (see FIGS. 2 and 4) in the moving direction (X-axis direction) of the light irradiation devices 10A to 10D as the rotation axis. Further, the light irradiation devices 10A to 10D are relatively bendable in the directions (Y-axis direction, Z-axis direction) orthogonal to the moving direction. Thereby, when moving the light irradiation devices 10A to 10D connected by the front connection part 2 and the rear connection part 3 inside the reinforcing member 8 (see FIGS. 14 to 16) laid inside the sewer pipe 7, even at a location where the sewer pipe 7 is curved (not shown), they can move along the inner surface of the reinforcing member 8.

[0014] In Figure 1, a camera 4 is positioned in front of the leading light irradiation device 10A to capture images of the front. Camera 4 captures images of the inner surface of the reinforcing member 8 laid inside the sewer pipe 7 as the light irradiation devices 10A to 10D move through the reinforcing member 8 laid inside the sewer pipe 7 during pipe rehabilitation. A camera 5 is positioned behind the last light irradiation device 10D to capture images of the rear. Camera 5 captures images of the inner surface of the reinforcing member 8 laid behind the light irradiation device 10A to 10D as the light irradiation devices 10A to 10D move through the reinforcing member 8 laid inside the sewer pipe 7 during pipe rehabilitation. Thus, of the multiple light irradiation devices 10A to 10D provided in the light irradiation system 1, the leading and last light irradiation devices 10A and 10D have cameras 4 and 5.

[0015] Each of the leading light illuminator 10A and the last light illuminator 10D is connected to a cable 6 that transmits power and commands from an operating device (not shown) to the light illuminators 10A-10D. Furthermore, the image data captured by cameras 4 and 5 is transmitted to the operating device via cable 6. With the light illuminators 10A-10D installed inside the reinforcing member 8 laid within the sewer pipe 7, workers or a cable winding machine (not shown) pull on the front or rear cable 6 (arrows a1 and a2), causing the light illuminators 10A-10D to move back and forth inside the reinforcing member 8.

[0016] In the following, unless otherwise necessary, the light irradiation devices 10A to 10D may simply be referred to as "light irradiation device 10".

[0017] Next, the configuration of the light irradiation device 10 will be described with reference to Figures 1 to 9. The light irradiation devices 10A to 10D have similar configurations, and the second light irradiation device 10B will be used as an example below. In Figure 2, the light irradiation device 10 (light irradiation device 10B) is configured with a control unit 11 on the front side in the direction of movement (X-axis direction) and an irradiation unit 12 on the rear side. In addition, wheels 13 are arranged at 90° intervals on a circle centered on the central axis CL on both the front and rear sides of the light irradiation device 10 (see Figure 14).

[0018] Each wheel 13 is connected via a wheel connection part 14 to the control unit housing 15 of the control unit 11, or to the irradiation unit housing 16 located behind the irradiation unit 12. The wheel connection part 14 allows for changes in the distance to the wheel 13 and the angle with respect to the central axis CL. By changing the distance to the wheel 13 and the angle with respect to the central axis CL, the distance from the central axis CL to the wheel 13 can be changed. This allows the light irradiation device 10 to be used in sewer pipes 7 of different diameters. Thus, the light irradiation device 10 is equipped with multiple wheels 13 on its exterior.

[0019] In Figures 1 to 4 and Figure 9, the control unit housing 15 of the control unit 11 is substantially cylindrical. A front side plate 17 is positioned at the front end of the control unit housing 15. Multiple intake openings 17a are formed in the front side plate 17 for introducing air F1 into the interior of the light irradiation device 10. The multiple intake openings 17a are formed to penetrate the front side plate 17. A front connecting portion 2 is positioned in the center of the front side of the front side plate 17.

[0020] The irradiation unit housing 16 of the irradiation unit 12 is substantially cylindrical. A rear side plate 18 is positioned at the rear end of the irradiation unit housing 16. The rear side plate 18 has the same shape as the front side plate 17, and multiple discharge openings 18a are formed in the rear side plate 18 for discharging air F6 from inside the light irradiation device 10. The multiple discharge openings 18a are formed to penetrate the rear side plate 18. A rear connecting part 3 is positioned in the center of the rear side of the rear side plate 18.

[0021] In Figures 3 and 9, a cooling fan 19 is positioned behind the front plate 17 inside the control unit housing 15. The cooling fan 19 generates an airflow of F1 to F6, which is drawn in through the intake opening 17a and discharged through the exhaust opening 18a. A fan mounting plate 20 is positioned behind the cooling fan 19. The cooling fan 19 is fixed inside the control unit housing 15 by the fan mounting plate 20. A fan opening 20a is formed in the center of the fan mounting plate 20 to blow the air F1 drawn in through the intake opening 17a to the rear. The fan opening 20a is formed by penetrating the fan mounting plate 20.

[0022] In Figures 3, 5, and 9, a separation member 21 is positioned behind the fan mounting plate 20 inside the control unit housing 15. The separation member 21 has the function of separating the air F1, which is drawn in from the intake opening 17a and blown into the interior through the fan opening 20a, into air F2, which cools the control circuit unit 22 located inside the separation member 21 and is blown to the irradiation unit 12, and air F3, which is blown to the irradiation unit 12 without cooling the control circuit unit 22. The separation member 21 is composed of a rear plate 21a located behind the control circuit unit 22, and a first extension plate 21b and a second extension plate 21c extending forward from two opposing ends of the rear plate 21a. A rear plate opening 21d is formed in the center of the rear plate 21a for blowing the air F4 that has cooled the control circuit unit 22 to the rear. The rear plate opening 21d is formed by penetrating the rear plate 21a.

[0023] The remaining two opposing ends of the rear plate 21a, where the first extension plate 21b and the second extension plate 21c do not extend, extend to the inner wall 15a of the control unit housing 15. Similarly, the two ends of the first extension plate 21b and the second extension plate 21c on the side facing the inner wall 15a of the control unit housing 15 extend to the inner wall 15a of the control unit housing 15. The control circuit unit 22 is located in the space enclosed by the first extension plate 21b, the rear plate 21a, the second extension plate 21c, and the inner wall 15a of the control unit housing 15.

[0024] In Figures 1, 3, 5, and 9, the control circuit unit 22 includes a power conversion circuit, a control circuit, and the like. The power conversion circuit converts the power supplied through the cable 6 into a voltage that is supplied to the cameras 4 and 5, the cooling fan 19, the LED board 29 (described later), and the like. The control circuit controls the cameras 4 and 5, the cooling fan 19, the LED board 29, and the like according to commands transmitted from the operating device. The air F2 that has cooled the control circuit unit 22 is blown backward through the rear plate opening 21d (air F4).

[0025] The portion enclosed by the first extension plate 21b and the inner wall 15a of the control unit housing 15 constitutes the first passage 23a. The portion enclosed by the second extension plate 21c and the inner wall 15a of the control unit housing 15 constitutes the second passage 23b. Air F3, which is blown through the fan opening 20a and supplied to the irradiation unit 12 without cooling the control circuit unit 22, passes through the first passage 23a and the second passage 23b. In this way, a portion of the air F1 (air F3) that is drawn in from the intake opening 17a and supplied to the interior through the fan opening 20a passes through the first passage 23a or the second passage 23b and is supplied to the rear without cooling the control circuit unit 22.

[0026] In Figures 3, 5, 6, and 9, a front partition plate 24 is positioned at the rear end of the control unit housing 15. The front partition plate 24 has multiple front openings 24a formed therein for introducing air F3 that is not used to cool the control circuit unit 22 into the interior of the irradiation unit 12. The multiple front openings 24a are formed to penetrate the front partition plate 24. In addition, a front communication opening 24b is formed in the center of the front partition plate 24, which penetrates the front partition plate 24.

[0027] In Figures 3, 8, and 9, a rear partition plate 25 is positioned at the front end (the end on the irradiation unit 12 side) of the irradiation unit housing 16. The rear partition plate 25 has multiple rear openings 25a formed therein for blowing air F5, which has cooled the fins 27d (described later), to the rear. The multiple rear openings 25a are formed to penetrate the rear partition plate 25. In addition, a rear communication opening 25b is formed in the center of the rear partition plate 25, which penetrates the rear partition plate 25.

[0028] In Figures 3 and 6-9, a cylindrical communication tube 26, made of a material with high thermal conductivity such as copper or aluminum, is positioned in the center of the irradiation unit 12 along the central axis CL (X-axis direction). The tip of the communication tube 26 (the end on the control unit 11 side) is inserted into the front communication opening 24b of the front partition plate 24 and communicates with the rear plate opening 21d of the rear plate 21a. The rear end of the communication tube 26 is inserted into the rear communication opening 25b of the rear partition plate 25 and communicates with the inside of the irradiation unit housing 16. The air F4 that has cooled the control circuit unit 22 enters the inside of the communication tube 26 from the rear plate opening 21d and is blown through the communication tube 26 to the inside of the irradiation unit housing 16.

[0029] In Figures 3 and 7, a heat dissipation section 27, made of a material with high thermal conductivity such as copper or aluminum, is arranged around the connecting pipe section 26 in the irradiation section 12 along the central axis CL (X-axis direction). The heat dissipation section 27 is composed of a cylindrical inner cylinder section 27a and an outer cylinder section 27b with a larger diameter than the inner cylinder section 27a. The inner wall of the inner cylinder section 27a of the heat dissipation section 27 is in contact with the outer surface of the connecting pipe section 26, allowing heat to be conducted from the heat dissipation section 27 to the connecting pipe section 26. The outer circumference of the outer cylinder section 27b, i.e., the outer shape of the heat dissipation section 27, is approximately the shape of a polygonal prism. In this example, the outer shape of the heat dissipation section 27 is the shape of a 24-sided prism.

[0030] LED substrates 29 are arranged on each outer circumferential surface 27c of the heat dissipation section 27. Multiple LEDs 28 are arranged on the LED substrates 29 in the direction of movement of the light irradiation device 10 (along the central axis CL). In this example, 24 LED substrates 29 are arranged at equal intervals on the outer circumferential surface 27c of the heat dissipation section 27, which has a shape of 24-sided prism. As a result, multiple LEDs 28 are arranged on the same circumference centered on the central axis CL. With this configuration, the light irradiation device 10 can irradiate light R uniformly outward from the central axis CL (see Figure 14). The LEDs 28 used irradiate light R of a specific wavelength selected from the wavelength range of 350 to 500 nm, for example.

[0031] In Figures 3, 7, and 9, the LED substrate 29 is positioned on the outer circumferential surface 27c of the heat dissipation section 27 so that the heat generated when the LED 28 irradiates light R can be conducted to the outer cylindrical portion 27b of the heat dissipation section 27. Between the outer cylindrical portion 27b and the inner cylindrical portion 27a of the heat dissipation section 27, a plurality of fins 27d extending along the central axis CL (X-axis direction) are arranged.

[0032] The heat generated from the LED 28 is conducted to the connecting pipe 26 through the LED substrate 29, outer cylinder 27b, fins 27d, and inner cylinder 27a. The heat conducted up to the fins 27d is carried by air F5 and F6 introduced from the front opening 24a and discharged through the rear connecting opening 25b to the discharge opening 18a. The heat conducted up to the connecting pipe 26 is carried by air F4 and F6 passing through the inside of the connecting pipe 26 and discharged through the discharge opening 18a.

[0033] In this manner, the cooling fan 19 of the light irradiation device 10 supplies air F4, F5, and F6 into the heat dissipation section 27 and discharges it from the discharge opening 18a of the rear plate 18. Furthermore, by separating the air F2 and F3 supplied from the cooling fan 19 by the separation member 21 into air F2 which mainly cools the control circuit section 22 and air F3 which cools the LED substrate 29, the control circuit section 22 and the LED substrate 29 can be cooled efficiently. As a result, the control circuit section 22 and the LEDs 28 and LED substrate 29 can be cooled efficiently so that they do not exceed a predetermined upper temperature limit. The upper temperature limit for the LEDs 28 and LED substrate 29 is preferably 80°C or less, and more preferably 60°C or less.

[0034] In Figures 2, 3, and 7, multiple LED substrates 29 arranged in the irradiation unit 12 are surrounded by polygonal synthetic quartz glass tubes 30 arranged rotationally symmetrically around the central axis CL. In this example, the synthetic quartz glass tubes 30 have an octagonal cylindrical shape. The synthetic quartz glass tubes 30 are made of synthetic quartz glass. Synthetic quartz glass has high transmittance to light R with a wavelength of 350 to 500 nm irradiated by the LEDs 28, and exhibits minimal degradation over time even when exposed to light R with a wavelength of 350 to 500 nm irradiated from the LEDs 28 for a long period of time.

[0035] In Figures 2, 3, 7, and 8, the synthetic quartz glass cylinder 30 is held by a front holding member 31 positioned behind the front partition plate 24 and a rear holding member 32 positioned in front of the rear partition plate 25. Specifically, the front end portion 30c of the synthetic quartz glass cylinder 30 is sealed by a packing 33 held by the front vertical plate 31a of the front holding member 31, which is in contact with the front partition plate 24, and the front holding portion 31b, which extends rearward from the middle of the front vertical plate 31a. The rear end portion 30d of the synthetic quartz glass cylinder 30 is sealed by a packing 33 held by the rear vertical plate 32a of the rear holding member 32, which is in contact with the rear partition plate 25, and the rear holding portion 32b, which extends forward from the middle of the rear vertical plate 32a. Examples of materials that make up the packing 33 include rubber and silicone. The front holding portion 31b and the rear holding portion 32b are formed in the same polygonal shape as the synthetic quartz glass cylinder 30.

[0036] A front extension 31c extending to the rear is formed at the lower end of the front vertical plate 31a of the front retaining member 31. A front groove 31d is formed at the rear end of the front extension 31c. An O-ring 34 is placed in the front groove 31d. A rear extension 32c extending to the front is formed at the lower end of the rear vertical plate 32a of the rear retaining member 32. A rear groove 32d is formed at the tip of the rear extension 32c. An O-ring 34 is placed in the rear groove 32d. Examples of materials that make up the O-ring 34 include rubber and silicone. The rear end of the front extension 31c and the tip of the rear extension 32c are formed in the same shape (polygon) as the outer cylinder portion 27b of the heat dissipation portion 27.

[0037] In Figures 2, 3, 7, and 8, the rear end of the front extension 31c of the front retaining member 31 and the front end of the outer cylinder portion 27b of the heat dissipation portion 27 are sealed by an O-ring 34 located in the front groove 31d. Similarly, the front end of the rear extension 32c of the rear retaining member 32 and the rear end of the outer cylinder portion 27b of the heat dissipation portion 27 are sealed by an O-ring 34 located in the rear groove 32d.

[0038] In this way, the front holding member 31, the rear holding member 32, the packing 33, and the O-ring 34 seal the heat dissipation section 27 and the ends (front end 30c, rear end 30d) of the synthetic quartz glass cylinder 30, forming a sealing section 35 that hermetically seals the irradiation space 36 surrounded by the heat dissipation section 27, the synthetic quartz glass cylinder 30, the front holding member 31, and the rear holding member 32 to prevent air from entering from the outside. The synthetic quartz glass cylinder 30 also functions as a window material when multiple LED substrates 29 are sealed. The sealing section 35 (front holding member 31, rear holding member 32, packing 33) prevents air from entering the irradiation space 36 from outside the light irradiation device 10. The sealing section 35 (front holding member 31, rear holding member 32, O-ring 34) also prevents the air F3 and F5 that cool the heat dissipation section 27 from entering the irradiation space 36. This prevents the LED substrate 29 and LEDs 28 from deteriorating due to the high temperature and humidity inside the sewer pipe 7, even if the light irradiation device 10 is installed inside the sewer pipe 7.

[0039] Next, the details of the synthetic quartz glass cylinder 30 will be described with reference to Figures 10 to 12. The synthetic quartz glass cylinder 30 is formed by joining together strip-shaped synthetic quartz glass plates 30a as shown in Figure 10. In this example, the synthetic quartz glass cylinder 30 is formed by joining eight synthetic quartz glass plates 30a with adhesive G. The synthetic quartz glass plates 30a are processed so that the side end faces 30e to be joined are at a predetermined angle.

[0040] The light irradiation system 1, using the light irradiation device 10, is used for pipe rehabilitation of sewer pipes 7, etc. Therefore, the synthetic quartz glass cylinder 30 may be damaged due to impacts such as pebbles kicked up during construction. In the case of a cylindrical synthetic quartz glass cylinder 30, the entire cylinder needs to be replaced because it is a single piece. On the other hand, in the case of a polygonal cylinder formed by bonding synthetic quartz glass plates 30a, only the damaged synthetic quartz glass plate 30a needs to be replaced. Considering that synthetic quartz glass is expensive, a synthetic quartz glass cylinder 30 made by bonding synthetic quartz glass plates 30a is economically advantageous.

[0041] In Figures 10 to 12, it is preferable that the synthetic quartz glass used in the synthetic quartz glass cylinder 30, which is the window material of the light irradiation device 10, has an arithmetic mean roughness Ra of 2 nm or less on the surface through which light R passes. If the arithmetic mean roughness Ra is greater than 2 nm, there is a possibility that the surface of the synthetic quartz glass has many fine scratches. Scratches on the surface of the synthetic quartz glass with an arithmetic mean roughness Ra greater than 2 nm can induce diffuse reflection on the surface of the synthetic quartz glass, which may reduce the efficiency of light R extraction.

[0042] Furthermore, the arithmetic mean roughness Ra of the side end surface 30e of the synthetic quartz glass plate 30a is preferably 1 to 5 μm, and more preferably 1 to 3 μm. If the arithmetic mean roughness Ra is less than 1 μm, a sufficient amount of adhesive G may not be able to penetrate the uneven parts of the side end surface 30e, potentially resulting in weaker bonding strength. Also, if the arithmetic mean roughness Ra is greater than 5 μm, lifting may occur in the joint 30b, potentially resulting in weaker bonding strength.

[0043] The adhesive G used to bond the synthetic quartz glass plates 30a needs to be transparent at the time of bonding completion, from the viewpoint of uniformly irradiating them with light R. For this reason, the adhesive G is preferably transparent. The refractive index of the synthetic quartz glass plates 30a at a wavelength of 350 to 500 nm is approximately 1.4. Therefore, a transparent adhesive G with a refractive index of around 1.4 is preferable because it does not produce stray light due to the difference in refractive index between the synthetic quartz glass at the bonding point 30b and the adhesive G. Specifically, a silicone-based adhesive with SiO2 as its main component, the same as synthetic quartz glass, is preferred.

[0044] In Figures 10 to 12, the synthetic quartz glass constituting the synthetic quartz glass plate 30a has a high theoretical transmittance of approximately 92% for light R with a wavelength of 350 to 500 nm, making it suitable as a window material for hermetically sealing the LED 28 that irradiates light R with a wavelength of 350 to 500 nm. Furthermore, to further improve transmittance, an anti-reflective film can be formed on the surface of the synthetic quartz glass cylinder 30.

[0045] When light R with a wavelength of 350-500 nm, emitted from LED 28, strikes metal impurities present in the glass of the window material, the metal is excited, causing solarization and resulting in discoloration of the glass and a decrease in transmittance. However, synthetic quartz glass is an amorphous material made of high-purity silicon dioxide (SiO2) and contains very few metal impurities, so there is no decrease in transmittance due to discoloration. The concentration of metal impurities in the synthetic quartz glass used in the synthetic quartz glass cylinder 30, which is the window material of the light irradiation device 10, is preferably less than 5 ppb, and more preferably less than 1 ppb.

[0046] Examples of metallic elements that can be impurities include lithium, sodium, magnesium, aluminum, potassium, calcium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, germanium, zirconium, molybdenum, cadmium, tin, antimony, lead, and phosphorus.

[0047] In Figures 12 and 14, it is desirable that the light R emitted from the light irradiation device 10 is uniformly irradiated onto the photocurable resin contained in the reinforcing member 8 laid on the inner wall of the sewer pipe 7. Therefore, it is desirable that the optical path length of the light R emitted from the LED 28 of the light irradiation device 10 be the same in all 360° directions. Accordingly, when a polygonal synthetic quartz glass cylinder 30 is used in the light irradiation device 10, the roundness of the polygonal synthetic quartz glass cylinder 30 is preferably within 1.0 mm, and more preferably within 0.5 mm, on any face.

[0048] Here, roundness is defined according to the Japanese Industrial Standard JIS B 0682-1:2017 as half the difference between the maximum diameter Dmax of the circumscribed circle Cmax that circumscribes the surface of the synthetic quartz glass cylinder 30 centered on the central axis CL, and the minimum diameter Dmin of the inscribed circle Cmin that circumscribes the surface of the synthetic quartz glass cylinder 30 (roundness = (Dmax - Dmin) / 2). The diameter of the circumscribed circle Cmax is largest at the joint 30b. If there are parts of the synthetic quartz glass plate 30a that do not overlap at the joint 30b, or if there are excess adhesive G parts, the roundness will be greater than 1.0 mm. If the roundness is greater than 1.0 mm, problems such as deviations in optical path length and diffuse reflection may occur.

[0049] As described above, the synthetic quartz glass cylinder 30 of this embodiment is a polygonal cylinder formed by joining multiple synthetic quartz glass plates 30a with an adhesive G. Light R irradiated by the LED 28 is transmitted through the joint 30b where the synthetic quartz glass plates 30a are joined with the adhesive G.

[0050] Next, referring to Figure 13, the relationship between the LEDs 28 of the LED substrate 29, which is arranged on the outer peripheral surface 27c of the heat dissipation section 27, and the polygonal synthetic quartz glass cylinder 30 will be explained. In this example, an LED substrate 29 is arranged on each of the outer peripheral surfaces 27c of the 24-sided heat dissipation section 27. Hereafter, the LEDs 28 arranged on each outer peripheral surface 27c will be referred to as LED28(1) to 28(24), etc.

[0051] The shorter the minimum distance Lg1 to Lg24 from each LED 28(1) to 28(24) to the synthetic quartz glass cylinder 30, the smaller the diameter of the light irradiation device 10 can be. On the other hand, if the minimum distance Lg1 to Lg24 is too short, the space surrounded by the synthetic quartz glass cylinder 30 and the LEDs 28 will not be sufficiently cooled due to the heat generated by the LEDs 28(1) to 28(24), causing the temperature of the LEDs 28(1) to 28(24) and the LED substrate 29 to rise, which may reduce the lifespan of the LEDs 28(1) to 28(24) and the LED substrate 29. Therefore, the minimum distance Lg1 to Lg24 from the LEDs 28(1) to 28(24) to the synthetic quartz glass cylinder 30 is preferably 10 to 25 mm.

[0052] Furthermore, if the density of LEDs 28(1) to 28(24) is high, cooling by air F4 and F5 may not be sufficient, causing the temperature of LEDs 28(1) to 28(24) and the LED substrate 29 to rise, which may reduce the lifespan of LEDs 28(1) to 28(24) and the LED substrate 29. On the other hand, if the number of LEDs 28(1) to 28(24) is small, the amount of light R emitted from the light irradiation device 10 will be small, and it may not be possible to obtain the amount of light necessary for photocuring. Therefore, the shortest distance Ll between adjacent LEDs 28(1) to 28(24) is preferably 5 mm to 15 mm.

[0053] In Figure 13, in regions where the angle between LEDs 28(1) to 28(24) and the surface of the synthetic quartz glass cylinder 30 is greater than the critical angle, the light R emitted from LEDs 28(1) to 28(24) is totally internalized and does not reach the outside. For example, if the angle θ2 between LED 28(2), which is closest to the joint 30b of the polygonal synthetic quartz glass cylinder 30, and the surface of the synthetic quartz glass cylinder 30 is greater than the critical angle, the light R emitted from LED 28(2) will not be extracted to the outside from near the joint 30b. In the example shown in Figure 13, LEDs 28(2), 28(3), 28(23), and 28(24) are the LEDs closest to the joint 30b of the polygonal synthetic quartz glass cylinder 30. Therefore, LEDs 28(1) to 28(24) are arranged such that the angle between LEDs 28(1) to 28(24) and the surface of the synthetic quartz glass cylinder 30 is smaller than the critical angle.

[0054] Next, with reference to Figures 14 to 16, a rehabilitation method for rehabilitating a deteriorated sewer pipe 7 using a light irradiation system 1 in which multiple light irradiation devices 10 (light irradiation devices 10A to 10D) are connected will be described. In the sewer pipe 7 rehabilitation method, first, the worker inserts a cylindrical reinforcing member 8 containing a photocurable resin into the sewer pipe 7 and lays the reinforcing member 8 along the inner wall of the sewer pipe 7 (reinforcing member laying process). The reinforcing member 8 has a three-layer structure, for example, in which glass fibers containing a photocurable resin are sandwiched between an inner film and an outer film. At the stage of laying it in the sewer pipe 7, the photocurable resin contained in the reinforcing member 8 is soft and flexible. Therefore, the worker can easily lay the reinforcing member 8 along the inner wall of the sewer pipe 7.

[0055] In this example, the photohardening resin contained in the reinforcing member 8 is assumed to have the property of curing with light R (ultraviolet light) with a wavelength of 350 nm to 500 nm. Furthermore, the multiple light irradiation devices 10 provided in the light irradiation system 1 can be combined to include LEDs 28 that emit light R of different wavelengths. For example, the LEDs 28 in the first light irradiation device 10A and the second light irradiation device 10B from the front in the direction of movement of the light irradiation device 10 may emit light R1 with a wavelength of 420 nm, while the third light irradiation device 10C and the fourth light irradiation device 10D from the front may emit light R2 with a wavelength of 380 nm.

[0056] In other words, the light irradiation system 1 is composed of at least two or more light irradiation devices 10A to 10D connected together, each irradiating light R1 and R2 of different wavelengths (420 nm and 380 nm). The wavelength of light R1 (420 nm) emitted by the front light irradiation devices 10A to 10B of the light irradiation system 1 is assumed to be longer than the wavelength of light R2 (380 nm) emitted by the rear light irradiation devices 10C to 10D. Furthermore, the cable 6 connected to the leading light irradiation device 10A is assumed to be retractable into a cable winding machine (not shown) provided by the light irradiation system 1.

[0057] In Figures 15 and 16, once the reinforcing member 8 is laid in the sewer pipe 7, the worker inserts the light irradiation devices 10A to 10D of the light irradiation system 1 into the reinforcing member 8 laid in the sewer pipe 7 (light irradiation device insertion process). For example, the worker pulls the cable 6 connected to the last light irradiation device 10D to move the light irradiation devices 10A to 10D to the work start position. At this time, the position of the wheels 13 of the light irradiation devices 10A to 10D from the central axis CL is adjusted to an appropriate position according to the diameter of the sewer pipe 7 or the reinforcing member 8 to be rehabilitated. Next, the cable winding machine pulls the cable 6 connected to the first light irradiation device 10A at a predetermined speed. This moves the light irradiation devices 10A to 10D inside the reinforcing member 8 laid in the sewer pipe 7 (light irradiation device movement process) (arrows b1, b2).

[0058] In the light irradiation device movement process, first, light R1 with a wavelength of 420 nm is irradiated onto the reinforcing member 8 (hereinafter referred to as "pre-irradiation reinforcing member 8A") before it is irradiated with light R1 and R2 by light irradiation devices 10A and 10B (first irradiation process). When the pre-irradiation reinforcing member 8A is irradiated with light R1 with a wavelength of 420 nm, the photocurable resin in the deep part (on the inner wall side of the sewer pipe 7) contained in the reinforcing member 8 is cured. Hereinafter, the reinforcing member 8 in which the photocurable resin in the deep part has been cured will be referred to as the deep-cured reinforcing member 8B.

[0059] In Figures 12 and 13, the deep-cured reinforcing member 8B is then irradiated with 380 nm light R2 by light irradiation devices 10C and 10D (second irradiation step). When the deep-cured reinforcing member 8B is irradiated with 380 nm light R2, the uncured photocurable resin on the surface side (inside the sewer pipe 7) of the reinforcing member 8 is cured. Hereinafter, the reinforcing member 8 in which the entire photocurable resin has been cured will be referred to as the cured reinforcing member 8C. In this way, the entire reinforcing member 8 can be uniformly cured by first irradiating the pre-irradiation reinforcing member 8A with long-wavelength light R1 to change it into a deep-cured reinforcing member 8B in which the deep part has been cured, and then irradiating it with short-wavelength light R2 to change it into a cured reinforcing member 8C in which the surface layer has also been cured.

[0060] Camera 4, positioned in front of the light irradiation device 10A, captures images of the reinforcing member 8 before curing (reinforcing member 8A before irradiation) while it is moving. Camera 5, positioned behind the light irradiation device 10D, captures images of the reinforcing member 8 after curing (reinforcing member 8C after curing) while it is moving. The operator can visually confirm from the captured images whether the reinforcing member 8 has cured properly.

[0061] In this manner, by irradiating the reinforcing member 8 laid along the inner wall of the sewer pipe 7 with light R1 and R2 using light irradiation devices 10A to 10D, a hard and durable hardened reinforcing member 8C is laid on the inner wall of the sewer pipe 7. After rehabilitation, sewage flows through the inside of the hardened reinforcing member 8C. In this rehabilitation method, the deteriorated sewer pipe 7 can be rehabilitated without replacement.

[0062] In Figures 15 and 16, the speed at which the cable winder pulls the cable 6 to move the light irradiation device 10 is set to an appropriate value determined by the intensity of the light R emitted by the light irradiation device 10 and the properties of the photocurable resin contained in the reinforcing member 8. Furthermore, the number of light irradiation devices 10 in the light irradiation system 1 is not limited to four. The number of light irradiation devices 10 in the light irradiation system 1 is set to an appropriate number determined by the properties of the photocurable resin contained in the reinforcing member 8, the intensity of the light R emitted by the light irradiation device 10, and the moving speed of the light irradiation device 10. For example, the light irradiation system 1 may be configured by linking one light irradiation device 10A that emits light R1 with a wavelength of 420 nm and one light irradiation device 10D that emits light R2 with a wavelength of 380 nm.

[0063] Furthermore, each of the light irradiation devices 10A to 10D may be equipped with an LED 28 that emits light R1 with a wavelength of 420 nm and an LED 28 that emits light R2 with a wavelength of 380 nm, with the front light irradiation devices 10A to 10B controlled to emit light R1 with a wavelength of 420 nm and the rear light irradiation devices 10C to 10D controlled to emit light R2 with a wavelength of 380 nm. Alternatively, the light irradiation devices 10A to 10D may emit three different wavelengths of light R. Also, the wavelength of light R that cures the photocurable resin contained in the reinforcing member 8 is not limited to 350 nm to 500 nm, but can be changed as appropriate.

[0064] As described above, the light irradiation device 10 of this embodiment includes a heat dissipation unit 27, a plurality of LED substrates 29 arranged on the outer peripheral surface 27c of the heat dissipation unit 27 and each substrate having multiple LEDs 28 that irradiate light R of a specific wavelength, a synthetic quartz glass cylinder 30 that functions as a window material when the plurality of LED substrates 29 are sealed, and a sealing unit 35 that seals the ends of the heat dissipation unit 27 and the synthetic quartz glass cylinder 30. This allows for long-term use with minimal degradation even in high-temperature and high-humidity environments. This also provides economic benefits such as improved work efficiency and reduced frequency of LED replacement. [Industrial applicability]

[0065] The light irradiation device and light irradiation system disclosed herein exhibit minimal degradation even in high-temperature and high-humidity environments and can be used repeatedly for extended periods. [Explanation of symbols]

[0066] 1. Light irradiation system 4, 5 Cameras 10, 10A~10D Light irradiation device 13 wheels 19 Cooling fan 27 Heat dissipation part 27c Outer surface 28 LED 29 LED boards 30 Synthetic quartz glass tubes 30a Synthetic quartz glass plate 35 Sealing part F1~F6 Air G Adhesive R, R1, R2 light

Claims

1. Heat dissipation section, Multiple LED substrates are arranged on the outer surface of the heat dissipation section, each substrate having multiple LEDs that emit light of a specific wavelength. A synthetic quartz glass cylinder that functions as a window material when multiple LED substrates are sealed, The heat dissipation section and the end of the synthetic quartz glass cylinder are sealed, and the sealing section is provided to airtightly seal the space surrounded by the heat dissipation section and the synthetic quartz glass cylinder so that air cannot enter from the outside. The aforementioned synthetic quartz glass cylinder is a polygonal cylinder formed by joining multiple synthetic quartz glass plates with an adhesive. A light irradiation device wherein the roundness of the polygonal synthetic quartz glass cylinder is within 1 mm on any of its surfaces.

2. The shortest distance from the LED to the synthetic quartz glass tube is 10 to 25 mm. The light irradiation device according to claim 1, wherein the shortest distance between adjacent LEDs is 5 mm to 15 mm.

3. The light irradiation device according to claim 1, wherein the wavelength of the light emitted by the LED used is selected from the range of 350 to 500 nm.

4. The light irradiation device according to claim 1, further comprising a cooling fan that supplies air drawn in from the outside into the heat dissipation section.

5. The light irradiation device according to claim 1, wherein the synthetic quartz glass cylinder has an anti-reflective coating formed on its surface.

6. The light irradiation device according to claim 1, wherein the adhesive is transparent after bonding.

7. Heat dissipation section, Multiple LED substrates are arranged on the outer surface of the heat dissipation section, each substrate having multiple LEDs that emit light of a specific wavelength. A synthetic quartz glass cylinder that functions as a window material when multiple LED substrates are sealed, A sealing portion that seals the end of the heat dissipation portion and the synthetic quartz glass cylinder, and airtightly seals the space surrounded by the heat dissipation portion and the synthetic quartz glass cylinder so that air cannot enter from the outside, A control circuit unit that supplies power to the LED substrate, A light irradiation device comprising a separation member that separates air drawn in from the outside into air for cooling the control circuit section and air that is blown into the heat dissipation section without cooling the control circuit section.

8. The light irradiation device according to claim 7, further comprising a cooling fan that supplies air drawn in from the outside to the inside of the heat dissipation section and the control circuit section.

9. A light irradiation system comprising a plurality of light irradiation devices according to any one of claims 1 to 8, connected together.

10. The light irradiation system according to claim 9, wherein the leading and trailing light irradiation devices among the plurality of light irradiation devices have cameras.

Images