JP4452977B2 - Ultraviolet irradiation device and gas releasing method thereof - Google Patents

Description

  The present invention relates to an ultraviolet irradiation device that irradiates ultraviolet rays while releasing a gas to a workpiece to be conveyed.

As this type of ultraviolet irradiation device, for example, as shown in Patent Document 1 below, in order to cure the UV resin by irradiating ultraviolet rays toward the workpiece that is conveyed and moved, as shown in Patent Document 1 below Some are used. By the way, when UV resin is exposed to an air atmosphere containing oxygen even if it is irradiated with ultraviolet rays, surface curing failure is caused by so-called oxygen inhibition. Therefore, the UV resin is usually in a gas atmosphere such as nitrogen or carbon dioxide. It is desirable to irradiate with ultraviolet rays. FIG. 6 shows a conventional configuration in which the workpiece 1 is irradiated with ultraviolet rays while releasing nitrogen. As shown in the figure, the housing 3 that accommodates the ultraviolet lamp 2 is provided with an irradiation window 4 in which the opening on the lower surface is sealed with a glass plate, from which ultraviolet rays emitted from the ultraviolet lamp 2 (see FIG. Then, the dotted line arrow 7) is irradiated toward the machining part of the workpiece 1. Then, the same amount of nitrogen is released toward both ends of the housing 3 (upstream and downstream of the transfer path) toward the area irradiated with the ultraviolet rays (hereinafter referred to as “ultraviolet irradiation area”) on the transfer path of the workpiece 1. A pair of nozzles 5 and 5 are extended so that the UV resin 6 applied to the workpiece 1 is irradiated with ultraviolet rays in a nitrogen atmosphere.
Japanese Patent Laid-Open No. 55-1815

  However, when the work 1 is transported and moved at a relatively high speed, the nitrogen supplied from the nozzles 5 and 5 is discharged in the above-described conventional configuration in which the same amount of gas is discharged from the upstream side and the downstream side toward the ultraviolet irradiation region. Is dragged downstream of the transport path by the work 1 (solid arrow 8 in FIG. 3). That is, the upstream nitrogen concentration in the ultraviolet irradiation region is lower than the downstream nitrogen concentration. Therefore, there is a possibility that the ultraviolet irradiation cannot be performed in a state where the oxygen concentration is sufficiently lowered with respect to the workpiece 1 passing through the ultraviolet irradiation region from the upstream side to the downstream side. Certainly, it is possible to increase the upstream nitrogen concentration by increasing the amount of nitrogen released from each nozzle 5, 5, but this requires a large amount of nitrogen as well as the large amount of nitrogen to the outside. In order to prevent leakage, a structure with higher sealing performance is required, which may cause a problem of increased cost.

  The present invention has been completed based on the above circumstances, and an object of the present invention is to provide an ultraviolet irradiation device capable of irradiating ultraviolet rays while supplying gas evenly to a workpiece to be conveyed and moved.

As means for achieving the above object, an ultraviolet irradiation apparatus according to the invention of claim 1 includes an ultraviolet lamp that irradiates ultraviolet rays toward a conveyance path through which a workpiece passes, and ultraviolet rays from the ultraviolet lamp on the conveyance path. in the ultraviolet irradiation system provided with a releasing means for releasing the gas in the area to be irradiated, the release means, than the irradiation center of the ultraviolet rays from the ultraviolet lamp is provided upstream and downstream side of the conveying path, the downstream the was to release much gas from the discharge means upstream of the discharge means with the features.
The gas emission method of the ultraviolet irradiation device according to the invention of claim 2 is a gas emission method for releasing gas to an area irradiated with ultraviolet rays from an ultraviolet lamp on a conveyance path through which a workpiece passes, wherein the gas is discharged to the area. Are disposed on the upstream side and the downstream side of the transport path with respect to the irradiation center of ultraviolet rays from the ultraviolet lamp, and more gas is emitted from the upstream emission unit than the downstream emission unit. It is characterized in that it is released.
The “workpiece” may be a member in which an ultraviolet curable resin is applied to a certain member, may be an ultraviolet curable resin itself, or may be any material that is treated by irradiating ultraviolet rays. .

The invention of claim 3 is characterized in that, in the invention of claim 1, a prevention wall is provided around the discharge port of the discharge means to prevent the surrounding air from being caught.

<Inventions of Claims 1 and 2 >
According to this configuration, the discharge means is configured to discharge gas from the upstream side and the downstream side with respect to the irradiation center, and to discharge more gas from the upstream side than the downstream side. Then, the upstream gas is dragged by the workpiece to the downstream side where the amount of released gas is relatively small. Therefore, it is possible to efficiently supply the gas from the upstream side to the downstream side in the ultraviolet irradiation region while suppressing the amount of gas dragged further downstream from the ultraviolet irradiation region by the work as much as possible. Thereby, it is possible to irradiate ultraviolet rays while evenly supplying gas with a relatively small amount of released gas to the workpiece moving in the ultraviolet irradiation region on the conveyance path.

<Invention of Claim 3 >
For example, when the release means is configured to release gas from the opening of the nozzle tip of the annular air around the nozzle tip, there is a possibility that flow into the conveying path side is caught in the airflow of the gas released.
So, according to this structure, the prevention wall which prevents that the surrounding gas around the discharge port is caught in the gas discharged from the discharge port of the discharge means is provided. Therefore, it is possible to prevent ambient gas from being caught in the gas.

A reference example of the present invention will be described with reference to FIGS.
1. Outline of Ultraviolet Irradiation Apparatus The ultraviolet irradiation apparatus 10 according to the present reference example is transported by a transport means 52 that sequentially transports a workpiece W (for example, flooring) that has been subjected to various types of processing using an ultraviolet curable resin (hereinafter “UV resin 50”). It arrange | positions on the path | route 51, and it irradiates an ultraviolet-ray, spraying nitrogen as gas to the workpiece | work W, and hardens the UV resin 50. FIG. 3 and 4, the workpiece W is conveyed at a high speed from the right to the left of the drawing at a predetermined speed (for example, 1 to 100 m / min).

2. Configuration of Ultraviolet Irradiation Device FIGS. 1 to 3 are side views showing the entire ultraviolet irradiation device 10. As shown in the figure, the ultraviolet irradiation device 10 includes an ultraviolet emission unit 12 that accommodates an ultraviolet lamp (hereinafter “lamp 11”), and a gas supply unit 30 that is provided below and supplies nitrogen inside. And is configured.

(1) Ultraviolet emitting part The ultraviolet emitting part 12 has a rectangular parallelepiped shape as a whole, and a straight tubular lamp 11 is accommodated in a box-shaped case 13 whose one side faced toward the lower conveyance path 51 is open. The lamp 11 is held by fitting small diameter portions at both ends into through holes 14a and 14a of holding pieces 14 and 14 projecting downward from the ceiling inside the case 13 respectively. The lamp 11 is turned on when a voltage is applied from the terminal portion 15 provided on one end side of the case 13 via the cable 16 and emits ultraviolet rays radially. This ultraviolet ray is set to a wavelength suitable for UV resin curing (for example, a main wavelength of 365 nm).

  Further, a pair of reflecting mirrors 17 and 17 are disposed substantially rearward of the lamp 11 with respect to the opening direction of the case 13 (downward in FIG. 3). The reflecting mirrors 17 and 17 have a circular arc shape that covers the entire length of the upper side and the side of the lamp 11, and reflect the ultraviolet rays emitted rearward from the lamp 11 to guide them to the opening side (see FIG. In FIG. 3, the optical path of ultraviolet rays is indicated by a dotted arrow L). Each of the reflecting mirrors 17 and 17 has a lower end portion locked by grooves 13b and 13b provided inside the opening 13a of the case 13, and an upper end portion protruding downward from the ceiling surface inside the case 13. It is partially locked by the fixed fixture 20. And about the part in which the fixing tool 20 is not provided, the clearance gap S of the predetermined space | interval is formed between the upper end parts of both the reflective mirrors 17 and 17 (refer FIG. 3).

  A housing chamber 19 that houses a cooling fan 18 is provided at the center of the upper surface of the case 13. By driving the cooling fan 18, the ambient gas around the lamp 11 is changed to the pair of reflecting mirrors 17, 17. The air is drawn through a gap S between 17 and discharged to the outside from an exhaust port 19 a opened on the upper surface of the storage chamber 19.

(2) Gas Supply Unit The gas supply unit 30 has a central portion that opens in a rectangular shape corresponding to the shape of the opening 13a of the case 13 and sandwiches the sealing member 32 between the pair of frame bodies 31 and 31. In this state, both frame bodies 31, 31 are screwed with screws 33. And the opening part 31a of each frame 31 is sealed with the two translucent plates 34 and 34. As shown in FIG. Specifically, each of the translucent plates 34, 34 is made of, for example, quartz glass and has a rectangular shape that is slightly larger than the opening 31a of the frame 31, 31 as a whole. In this reference example , for example, four rectangular plates are used. The glass plates 35 are arranged side by side. On each translucent plate 34, a pressing plate 36 having an opening 36a having the same shape as the opening 31a of each frame 31 is covered. Each of the translucent plates 34 is sandwiched between a peripheral portion of the opening 31a of each frame 31 and a peripheral portion of the opening 36a of each pressing plate 36. Are fixed by positioning with screws 37.

  In addition, two conduction holes 32a are formed through both short side portions of the sealing member 32, and a connecting pipe 38 is provided so as to project from these through the connecting pipe 38 from a nitrogen supply means (not shown). Of nitrogen is supplied into the space M surrounded by the pair of translucent plates 34 and 34 and the sealing member 32.

As shown in FIGS. 1 and 3, the gas supply unit 30 includes a pair of translucent plates 34 arranged vertically in front of the emission direction of ultraviolet rays from the ultraviolet emission unit 12 (downward in the drawing in the drawing). , 34 are arranged. The gas supply unit 30 is attached to the case 13 via a fixture 40 that protrudes downward from both longitudinal ends of the case 13.
Further, of the pair of translucent plates 34, 34, the translucent plate (hereinafter referred to as “work side translucent plate 34 a”) directed toward the workpiece W conveyance path 51 side is one of the pair of long side ends. A plurality of discharge holes 39 are formed in a line along the long side end at a position near the long side end. This constitutes the “release means” of the present invention.

In the present reference example , cooling means arranged along the pair of light-transmitting plates 34 and 34 is provided. Specifically, the sealing member 32 is formed of a member having high heat conductivity, and as shown in FIG. 2, a U-shape in which a cooling liquid flows along the longitudinal direction on both long side portions thereof. The cooling pipe 42 is inserted so as to suppress the temperature rise of the gas supply unit 30 due to ultraviolet irradiation or nitrogen supply.
Further, in the present reference example , as shown in FIG. 3, the regulation wall 41 surrounds the periphery of the opening 13 a of the ultraviolet light emitting unit 12 at the periphery of the upper surfaces of the frame bodies 31, 31 located in the upper part of the gas supply unit 30. Is formed upright.

This restriction wall 41 is provided for the following reason. That is, if the restriction wall 41 is not provided, the cooling fan 18 is driven, and the surrounding gas containing oxygen on the side of the gas supply unit 30 (two-dot broken line arrow G2 in FIG. 3) is drawn. There is a possibility that a part flows into the transport path 51 side of the workpiece W and raises the oxygen concentration. However, in this reference example , when the cooling fan 18 is driven, the restriction wall 41 restricts the drawing of the surrounding gas on the side of the gas supply unit 30, and the surrounding air is drawn from above the restriction wall 41, so that the lamp 11, a circulation path is formed through the periphery and discharged from the exhaust port 19a. Therefore, it is possible to avoid the problem that the oxygen concentration on the conveyance path 51 side increases due to the drawing of the cooling fan 18.

3. Operational Effects of the Reference Example In the ultraviolet irradiation device 10 described above, the discharge hole 39 of the workpiece-side translucent plate 34a comes to the upstream side of the conveyance path 51 above the conveyance path 51 of the workpiece W, as shown in FIG. Arranged in this way. In other words, the discharge hole 39 is positioned on the upstream side of the transport path 51 from the irradiation center X of the ultraviolet rays emitted from the ultraviolet lamp 11. When the ultraviolet irradiation device 10 is activated, the ultraviolet rays emitted from the lamp 11 are reflected downward by the pair of reflecting mirrors 17 and 17 and emitted from the opening 13 a of the case 13 toward the gas supply unit 30. The workpiece W on the transport path 51 is irradiated through the pair of translucent plates 34, 34 of the gas supply unit 30.

  Further, nitrogen (solid arrow G1 in FIG. 3) is supplied from the connecting pipe 38 into the gas supply unit 30 and is discharged from the discharge hole 39 of the work-side light transmitting plate 34a. Thereby, it is possible to irradiate the processing part of the workpiece W with ultraviolet rays in a nitrogen atmosphere by blowing nitrogen to the workpiece W conveyed through the conveyance path 51.

Here, since the workpiece | work W is conveyed at high speed, as shown to FIG. 4 (A) (B), the nitrogen from the discharge | release hole 39 will be dragged downstream by the workpiece | work W. FIG. Therefore, in the present reference example , the discharge hole 39 is provided at a position closer to the upstream side than the irradiation center X in the ultraviolet light transmitting portion of the work side light transmitting plate 34a. Then, nitrogen released from the upstream side is dragged downstream by the workpiece W, spreads over the entire area below the workpiece-side translucent plate 34a, and efficiently reduces the oxygen concentration at the ultraviolet irradiation site of the workpiece W that is conveyed at high speed. Can do.

In addition, in this reference example , the discharge hole 39 is formed through the work-side light transmitting plate 34a through which the ultraviolet light from the ultraviolet light emitting part 12 is transmitted, and the periphery of the work-side opening of the discharge hole 39 is the work-side light transmitting plate. It is a wall by 34a (or work side translucent board 34a and frame 31). That is, it is a prevention wall that prevents (suppresses) surrounding air from being entrained around the discharge hole 39. Therefore, unlike the configuration in which gas is discharged from the opening at the tip of the annular nozzle (see the column of the effect of the invention), surrounding air can be prevented from being caught. In addition, the nitrogen stream released from the discharge hole 39 spreads laterally along the surface of the workpiece W, and the nitrogen stream can push out the atmosphere containing oxygen in the vicinity of the workpiece W. The upper UV resin 50 can be efficiently cured. Note that a greater effect can be obtained by shortening the distance between the gas supply unit 30 and the workpiece W as much as possible (for example, within 30 mm).

<Other embodiments>
(1) In the above reference example and the following embodiment , the ultraviolet curable resin is irradiated with ultraviolet rays and applied to an apparatus that supplies nitrogen as a gas. However, the present invention is not limited to nitrogen. Carbon may be used. In addition, for example, ashing or cleaning for decomposing organic substances by irradiating ultraviolet rays is performed, and the present invention can be applied to an apparatus for supplying ozone or oxygen.

(2) In the reference example , the discharge hole 39 is formed only on the upstream side of the glass plate 35 . On the other hand, in the embodiment of the present invention, a plurality of discharge holes whose diameter gradually decreases from the upstream side to the downstream side may be formed. Alternatively, the number of discharge holes on the upstream side may be larger than that on the downstream side.
Even in such a configuration, the workpiece W is irradiated with ultraviolet rays in a state where the oxygen concentration is efficiently reduced from the upstream side to the downstream side in the ultraviolet irradiation region from the ultraviolet ray emitting unit 12 in the conveyance path 51. Can do.

(3) Furthermore, the configuration shown in FIG. 5 may be used as another reference example . This has a configuration in which a nozzle 61 that discharges the gas G3 is extended to the side of the upstream side of the transmission window 60 that transmits the ultraviolet rays from the ultraviolet emitting portion. Even if it is such a structure, the effect similar to the said reference example can be acquired. In addition, the structure which provided the "prevention wall" of this invention may be sufficient. Specifically, a configuration may be adopted in which a plate-like member 62 (shown by a dotted line in the figure) is fitted to the tip of the nozzle.

(4) Further, as another embodiment of the present invention, a configuration in which the amount of nitrogen released from the upstream nozzle 5 is larger than that of the downstream nozzle 5 as compared to the configuration shown in FIG. In addition, you may provide the prevention wall by a plate-shaped member etc. in the front-end | tip of each nozzle 5 and 5 similarly to said (3).

The partial sectional view of the whole ultraviolet irradiation device concerning one reference example of the present invention Bottom view as seen from workpiece transfer path Sectional drawing in the XX fracture surface of FIG. Cross-sectional view of an ultraviolet irradiation device showing the flow of nitrogen sprayed onto a workpiece being conveyed at high speed Cross-sectional view of an ultraviolet irradiation device showing another reference example Cross-sectional view of a conventional ultraviolet irradiation device

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Ultraviolet irradiation apparatus 11 ... Ultraviolet lamp 34a ... Work side translucent board (prevention wall)
39 ... Release hole (release means)
51 ... Conveying path 61 ... Nozzle (discharge means)
62 ... Plate-shaped member (prevention wall)
G1, G3 ... Nitrogen (gas)
G2 ... Ambient gas L ... Ultraviolet light W ... Workpiece

Claims (3)

An ultraviolet lamp that irradiates ultraviolet rays toward the transport path through which the workpiece passes;
In the ultraviolet irradiation apparatus and a release means for releasing the gas in the region where ultraviolet rays are irradiated from the ultraviolet lamp on the transport path,
It said release means, than the irradiation center of the ultraviolet rays from the ultraviolet lamp provided on the upstream side and the downstream side of the transport path, emits a lot of gas from the discharge means of the upstream side of the release means of the downstream An ultraviolet irradiation device characterized by being made as described above. A gas discharge method for discharging gas to an area irradiated with ultraviolet rays from an ultraviolet lamp on a conveyance path through which a workpiece passes,
  Discharge means for releasing the gas to the region is disposed on the upstream side and the downstream side of the transport path from the irradiation center of the ultraviolet light from the ultraviolet lamp, and the upstream discharge means than the discharge means on the downstream side. A method for releasing a gas from an ultraviolet irradiation device, wherein a large amount of gas is released from the ultraviolet ray irradiation apparatus. 2. The ultraviolet irradiation apparatus according to claim 1, wherein a prevention wall capable of preventing air around the discharge port of the discharge means is provided.

Images