JP5131070B2 - Ultraviolet light source and light irradiator - Google Patents

Description

The present invention relates to an ultraviolet irradiation light source including a cooling jacket that cools a discharge lamp when a cooling fluid flows inside.
The present invention also relates to a light irradiator that uses a light source for ultraviolet irradiation with a cooling jacket.

  Using a lamp that emits light including ultraviolet rays, it is possible to carry out treatments such as curing, drying, melting, softening, and modification of protective films, adhesives, paints, inks, resists, resins, alignment films, etc. It is widely done in The lamps that emit ultraviolet rays used in these applications are, specifically, long arc type (rod-shaped) discharge lamps such as high-pressure mercury lamps and metal halide lamps that provide high light output. A pair of electrodes are disposed opposite to each other (hereinafter also referred to as a “sealed body”), and mercury, other metals, and the like are sealed as necessary.

  In order to shorten the processing time, the discharge lamp is required to irradiate the workpiece with light at a high output, and in order to increase the input power to the lamp, a cylinder composed of an inner tube and an outer tube. It is used as a light source for ultraviolet irradiation in which a discharge lamp is accommodated inside a double tube type cooling jacket having a transparent ultraviolet shape (see, for example, Patent Document 1 and Patent Document 2).

  When such a light source for ultraviolet irradiation does not use a cooling jacket, the temperature of the light emitting tube at the time of lighting reaches 1000 ° C. or more, and is overheated and devitrified. However, by using a cooling jacket, it is possible to lower the temperature of the arc tube of the lamp and to supply a large amount of power, and to realize a high UV output, compared to lighting without cooling or air cooling alone. Can do.

  FIG. 3A is a perspective view showing a schematic configuration of a conventional ultraviolet irradiation light source provided with a double-tube water-cooling jacket, and FIG. 3B is an ultraviolet irradiation light source A shown in FIG. It is -A sectional drawing. In the following description, since the cooling jacket is a water cooling type, it is simply referred to as a water cooling jacket.

  As shown in these drawings, a double tube type water cooling jacket 101 is attached to a rod-shaped lamp 100. The water cooling jacket 101 includes a cylindrical inner pipe 102 and an outer pipe 103, and a cooling medium, for example, cooling water flows between the inner pipe 102 and the outer pipe 103 from the cooling water inlet 108, and from the cooling water outlet 109. It is configured to be discharged.

As described above, the lamp 100 is a rod-shaped high-pressure mercury lamp or metal halide lamp that efficiently radiates ultraviolet rays. The lamp includes a pair of discharge electrodes 105 and 106 at both ends of the lamp, and power is supplied to both ends of the electrodes 105 and 106 via a power supply lead wire 107.

  The lamp 100 is inserted into the inner tube 102, and an air layer 110 is provided between the lamp 100 and the inner tube 102. When the lamp is lit, cooling water 104 flows between the inner tube 102 and the outer tube 103, and light from the lamp 100 is irradiated to an object (not shown) via the cooling water 104.

In such an ultraviolet light source, the water cooling jacket 101 has two main functions.
One is to cool the lit lamp 100 and keep it at an appropriate temperature. It is said that the temperature of the arc tube of the lamp 100 at the time of lighting is appropriate to be 500 ° C. to 900 ° C. in order to evaporate mercury and metal in the arc tube. When the temperature is 500 ° C. or lower, a metal such as mercury enclosed in the lamp 100 does not evaporate, resulting in non-lighting. Moreover, when it becomes 900 degreeC or more, the quartz which comprises a light-emitting tube will devitrify.

  The heat of the lamp 100 is transmitted to the water cooling jacket 101 via the air layer 108 between the lamp 100 and the inner tube 102 and is cooled by the cooling water 104 flowing between the inner tube 102 and the outer tube 103 of the water cooling jacket 101. The

  Thus, the cooling water 104 flowing in the water cooling jacket 101 prevents overheating of the lamp 100, but is indirectly cooled through the air layer 110, so that the temperature of the arc tube does not evaporate the metal inside the lamp. The temperature of the lamp 100 is kept at an appropriate temperature of 500 ° C. to 900 ° C. without being lowered to such a low temperature (500 ° C. or lower).

Another function of the water cooling jacket 101 is to reduce the influence of heat from the lamp 100 to the workpiece.
First, the cooling water 104 absorbs radiant heat from the above-described arc tube of 500 ° C. to 900 ° C. Further, it absorbs light components from visible to infrared, which are unnecessary for the ultraviolet treatment, contained in the light emitted from the lamp 100. By this function, heating to the object to be processed can be suppressed to be small.

  The thicker the gap between the inner tube 102 and the outer tube 103, that is, the thickness of the cooling water 104 layer, can reduce the influence of heating on the object to be processed. Since the rate to do this also decreases, it is set appropriately considering these factors.

As described above, the water cooling jacket 101 is provided with the cooling water inlet 108 and the cooling water outlet 109, to which the cooling water supply pipe and the drain pipe are connected, and the cooling water always flows while the lamp is lit. Yes.
However, if the flow of the cooling water 104 in the water cooling jacket 101 stops while the lamp 100 is lit for some reason such as the occurrence of clogging of the piping, the temperature of the cooling water 104 in the water cooling jacket 101 is increased by the heat from the lamp 100. It rises and boils in about 5 to 10 minutes.
When the cooling water 104 boils, the pressure in the water cooling jacket 101 increases, and if the pressure exceeds the pressure resistance of the water cooling jacket 101, water leakage or breakage may occur.

  Therefore, in an apparatus using such a light source for ultraviolet irradiation with a water cooling jacket, the flow rate of the cooling water is usually reduced in the cooling water pipe as a safety mechanism for preventing water leakage or damage of the water cooling jacket. A flow rate sensor and a pressure sensor for detecting an abnormality such as a pressure rise are attached, and an interlock mechanism for stopping the apparatus is provided based on output signals from these sensors.

However, since such an interlock mechanism is via an electrical signal or software for controlling the device, a double safety mechanism (double safety) that does not involve an electrical signal or software may be provided. desirable.
Even if a flow rate sensor or pressure sensor is installed in the cooling water supply pipe or drain pipe, the temperature of the cooling water jacket is likely to increase when the cooling water stops flowing, causing water leakage or damage. Therefore, the pressure and flow rate of the water cooling jacket can only be detected indirectly.
JP-A-61-158453 JP 56-155765 A

  The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a UV-cooling light source in which a lamp is disposed in a water-cooling jacket. Even if the internal pressure becomes high, the light source for ultraviolet irradiation that can detect the pressure of the cooling water in the water cooling jacket directly and reduce the pressure without using an electrical signal or software to prevent the water cooling jacket from being damaged. Is to provide.

  Another object of the present invention is to provide a light irradiator that uses the ultraviolet light source to prevent the water cooling jacket from being damaged and to detect an increase in pressure in the water cooling jacket and stop its operation.

In order to solve the above problems, in the present invention, a relief valve is attached to a jacket holder that supports an inner tube and an outer tube of a water-cooling jacket of a light source for ultraviolet irradiation. The relief valve attached to the jacket holder directly detects the pressure of the cooling water in the water cooling jacket, and opens to release the internal pressure when the water pressure in the water cooling jacket exceeds a preset value. This reduces the pressure in the water-cooled jacket.

Further, in the light irradiator using the ultraviolet light source, an opening is formed below the relief valve of the ultraviolet light source in the base on which the light exit port for supporting the ultraviolet light source is formed. A water storage container with a water leakage sensor is installed underneath.
When the relief valve of the UV light source is opened, the water in the water cooling jacket leaks outside, but the leaked cooling water enters the water storage container through the opening of the base, and the water leakage sensor detects the water leakage and irradiates the light. The instrument stops operating.

Since the relief valve is attached to the jacket holder of the water cooling jacket, it operates by directly detecting the pressure in the water cooling jacket and can prevent the water cooling jacket from being damaged.
In addition, the relief valve operates without an electrical signal or software, for example, even when electricity is not supplied to the control system, so that the pressure in the water cooling jacket increases as a double safety mechanism (double safety). Can be prevented.

  In addition, a water storage container with a water leakage sensor is installed below the relief valve. Detect and stop the operation of the light irradiator.

FIG. 1 is a diagram showing a configuration example of a light source for ultraviolet irradiation according to the present invention. In addition, this figure is sectional drawing along the longitudinal direction of a lamp | ramp, and attaches | subjects the same code | symbol about the same thing as FIG.
As shown in the figure, a rod-shaped ultraviolet lamp 100 is disposed in a double-tube type water cooling jacket 101. Jacket holders 200 are inserted into both ends of the inner tube 102 and the outer tube 103 of the water cooling jacket 101.

  The jacket holder 200 keeps the distance between the inner tube 102 and the outer tube 103, and the O-rings 201 and 202 mounted on the upper and lower sides of the jacket holder 200 are sealed so that the internal cooling water does not leak.

Through holes 203 and 204 are formed in the upper portion of the jacket holder 200, and a pipe joint is inserted into each of them to constitute a cooling water inlet 108 and a cooling water outlet 109.
In addition, a through-hole (drain port) 205 is formed in a lower portion of one jacket holder 200, and a relief valve 206 is connected thereto.
The relief valve is mainly used to prevent an increase in the pressure of liquid (water, oil, etc.). When the pressure of the liquid reaches a predetermined value (a preset value), it automatically opens according to the increase in the pressure. This valve has a function.

Therefore, when the pressure of the cooling water flowing in the water cooling jacket increases, the valve opens, the cooling water is pushed out, and the pressure in the water cooling jacket decreases.
The ultraviolet lamp 100 is inserted into the inner tube 102 of the water-cooling jacket 101, and from both sides so that a slight gap (for example, 1 mm to 0.5 mm) is formed between the outer surface of the arc tube of the lamp 100 and the inner tube 102. It is supported by the lamp holder 206.

The lamp 100 is supported by the lamp holder 206 by inserting the base 110 of the lamp 100 into a through hole 207 formed in the lamp holder 206. The power supply line (lead wire) 107 of the lamp 100 is led out from the through hole 207.
The lamp holder 206 is screwed to the jacket holder 200 and constitutes a light source for ultraviolet irradiation in which the water cooling jacket 101 and the lamp 100 are integrated.

Further, a leg 208 is attached to the jacket holder 200 and is fixed to the plate 209 by the leg 208. The plate 209 has an opening through which light emitted from the ultraviolet light source is passed.
The ultraviolet irradiation light source fixed to the plate 209 is placed and positioned on the base 300 of the light irradiator. The base 300 is also formed with an opening (light exit port) 301 through which light emitted from the ultraviolet light source is passed.

On the opposite side of the light emitting port 301 of the ultraviolet light source, a mirror 302 that reflects light from the ultraviolet light source to the light emitting port 301 side is provided.
In addition, an opening 303 is formed at a position immediately below the relief valve 206 of the ultraviolet irradiation light source of the base 300, and a water storage container (leakage pan) 304 to which a water leakage sensor 305 is attached is provided below the opening 303. Provided.
The cooling water that flows out when the relief valve 206 is opened flows into the water storage container 304 through the opening 303.
The pressure at which the relief valve 206 opens is set lower than the water pressure resistance of the water cooling jacket 101 and higher than the water pressure when cooling water is flowing.

FIG. 2 is a diagram showing a schematic configuration of a light irradiator using the ultraviolet irradiation light source shown in FIG.
As shown in the drawing, glass (for example, quartz) 303 that passes ultraviolet rays is provided on the light exit side of the light exit port 301, and the light that has passed through the glass 400 is irradiated on the work stage 401. (Work) Irradiated to W. Note that a mirror 302 is provided on the opposite side of the light source for ultraviolet irradiation to the light exit port 301 to reflect light from the light source for ultraviolet irradiation to the light exit port side.

Loading of the workpiece W into the workpiece stage 401 and loading of the workpiece W after light irradiation from the workpiece stage 401 are performed from a workpiece loading / unloading port 402 by a workpiece conveyance mechanism (not shown).
A piping from the cooling water circulation device 403 is connected to the cooling water inlet 108 and the cooling water outlet 109 of the water cooling jacket 101 of the ultraviolet light source, and the cooling water circulates. A flow meter 404 is attached to a pipe connecting the cooling water outlet 109 and the cooling water circulation device 403 to constantly measure the flow rate of the cooling water flowing in the water cooling jacket 101.

Further, wiring from the lamp lighting device 405 is connected to the lead wire 107 of the ultraviolet lamp 100. The ultraviolet lamp 100 is controlled to be turned on / off based on a signal from the control unit 406.
The water leakage sensor 305 is connected to the water leakage detector 307, and when the water leakage detector 307 detects water leakage, it sends a signal to the control unit 406.

When the pressure in the water cooling jacket 101 becomes high and the relief valve 206 is opened, the water in the water cooling jacket 101 flows out from the relief valve 206, and this water passes through the base 300 opening 303 directly below, and the water leakage sensor 305 is set. It collects in the attached water storage container 304.
When water accumulates in the water storage container 304, the water leakage sensor 305 operates and the water leakage detector 407 detects water leakage. The water leak detector 407 sends a water leak signal to the control unit 406 of the light irradiator. Based on this, the control unit 406 displays a water leakage alarm 408 with a buzzer, a warning light, or the like.

  In addition, the control unit 406 sends a lamp turn-off signal to the lamp lighting device 405, stops supplying power to the lamp, and turns off the lamp. Alternatively, a cooling water stop signal may be sent to the cooling water circulation device 403 to stop the supply of cooling water to the water cooling jacket 101.

The relief valve 206 opens to release the pressure when the water pressure in the water cooling jacket 101 rises, and prevents the water cooling jacket 101 from being damaged. However, not only that, the control unit 406 of the light irradiator must detect that the valve is open, that is, that the water pressure in the water cooling jacket 101 is rising, and stop the apparatus such as turning off the lamp.
Therefore, water discharged from the relief valve 206 is used, and the water leakage sensor 305 detects this as water leakage and sends a signal to the control unit 406.

Therefore, the water discharged from the relief valve 206 must be reliably accumulated in the water storage container 304 so that the water leakage sensor 305 can detect the water leakage.
Therefore, it is desirable to provide the relief valve 206 as close as possible to the water storage container 304. Since the water storage container 304 is attached to the lower side of the opening 303 of the base 300 on which the ultraviolet light source is mounted, the relief valve 206 is attached below the jacket holder 200 of the water cooling jacket 101 close to the gravity direction.

It is a figure which shows the structural example of the light source for ultraviolet irradiation of this invention. It is a schematic configuration of a light irradiator using the ultraviolet irradiation light source shown in FIG. It is a figure which shows schematic structure of the light source for ultraviolet irradiation provided with the conventional double tube | pipe type water cooling jacket.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Rod-shaped discharge lamp 101 Water cooling jacket 104 Cooling water 200 Jacket holder 206 Relief valve 300 Base plate 304 Water storage container 305 Water leakage sensor 403 Cooling water circulation device 405 Lamp lighting device 406 Control unit 407 Water leakage detector

Claims (2)

In the ultraviolet irradiation light source in which the ultraviolet discharge lamp having a pair of electrodes inside the arc tube is disposed in a water-cooling jacket in which cooling water flows between the inner tube and the outer tube,
At both ends of the water-cooling jacket, a jacket holder that holds the distance between the inner tube and the outer tube is attached,
The jacket holder is provided with a relief valve that directly detects the cooling water pressure and discharges the cooling water from the water cooling jacket when the cooling water pressure exceeds a preset value. A light source for ultraviolet irradiation. A light irradiator that supports the light source for ultraviolet irradiation according to claim 1 on a base on which a light emitting port is formed, and emits light from the light source for ultraviolet irradiation from the light emitting port formed on the base. ,
The light irradiator according to claim 1, wherein an opening is formed in the base below the relief valve of the light source for ultraviolet irradiation, and a water storage container having a water leakage sensor is provided below the opening.

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