JPH10141897A - Infrared transmission window for airframe and its cooling mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To capture a target with high accuracy by connecting a diamond plate to a metal outer plate of a periphery via a frame material provided with a refrigerant channel connected to its end face, and feeding cooling medium to the channel in the material, thereby cooling it from the end face of the plate. SOLUTION: A diamond plate 8 is used as a window frame 9 of an infrared transmission window, and the plate 8 is connected to a metal outer plate 2 of a periphery via a frame material provided with a refrigerant channel 10 in contact with an end face of the plate 8 by using the plate 10 with a ceramic adhesive. The medium is fed through the channel 20 to cool the plate 8 at its end face. Thus, an infrared radiating noise from the frame 9 by aerodynamic heating can be prevented. And, since the refrigerant is not fed to the outer surface of the frame 9, vibration or haze of an image does not occur, and a target can be accurately captured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared transmitting window for a high-speed flying object and a cooling mechanism for the window.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view of a conventional dome provided at the head of a flying object flying at high speed.
In the figure, 1 is a dome, 2 is a metal outer plate, 3 is a conventional infrared transmitting window, and 4 is a nozzle for jetting refrigerant. As materials for infrared transmission windows, spinel, yttria,
Magnesium fluoride, zinc sulfide and the like are used.

FIG. 6 is a longitudinal sectional view showing the above-mentioned dome in a high-speed air flow. Shock wave 6 from the tip of the dome
When such a situation occurs, the surface of the infrared transmission window 3 becomes hot due to aerodynamic heating. In a flying object equipped with an infrared seeker, if the temperature of the infrared transmission window becomes high, the radiation of infrared light from this window becomes noise, and the performance of the seeker deteriorates, and the image of the target 7 can be captured with sufficient accuracy. become unable. . In order to prevent this performance deterioration, the surface of the window has conventionally been cooled by means called film cooling. That is, a coolant is ejected from the coolant ejection nozzle 4 provided at the front edge of the window 3 to the outer surface of the window, and the surface of the window is covered with the coolant flow 5 for cooling.

[0004]

In the conventional film cooling, the refrigerant flowing on the outer surface of the window causes optical development such as image vibration (jitter) and image blur (blur), resulting in a target image information. Had the disadvantage of deteriorating.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and aims to provide an infrared transmitting window capable of recognizing a target with high accuracy by modifying a window material and a cooling mechanism.

[0006]

According to the present invention, there is provided a frame member having a diamond plate as a window material of an infrared transmission window and having a coolant flow path in contact with an end surface of the diamond plate. The diamond plate of the above-mentioned window material is joined to a surrounding metal outer plate or a diamond plate of another adjacent window material through, and a cooling medium is circulated through a coolant flow path in the above-mentioned frame material to make the above-mentioned diamond plate the diamond plate. The present invention relates to an infrared transmitting window of a flying object characterized by cooling from an end face and a cooling mechanism thereof.

Since the diamond material has a very high thermal conductivity, the entire window material can be sufficiently cooled by cooling from the end face with a cooling medium (for example, water). Thus, infrared radiation noise from the window material due to aerodynamic heating can be prevented. In addition, since no refrigerant is allowed to flow on the outer surface of the window material, no image vibration or blur occurs.

[0008]

FIG. 1 is a perspective view of a dome 1 of a flying object according to a first embodiment of the present invention. In the figure, 2 is a metal outer plate and 8 is a diamond plate. This plate is the part that becomes the infrared transmission window. Diamond plates can be manufactured by vapor phase synthesis.

FIG. 2 is a view showing a connecting portion between the metal outer plate 2 and the diamond plate 8, and is a sectional view taken along the line AA of FIG. The outer plate 2 and the diamond plate 8 are joined with a ceramic adhesive via a metal window frame 9. Window frame 9
Inside the refrigerant flow path 10 in contact with the end face of the diamond plate 8.
Is formed, and a coolant is circulated inside the diamond plate 8.
Is cooled at its end face. The refrigerant flow path is provided all around the window. Since diamond has a very high thermal conductivity, the windows are completely cooled. The conventional nozzle for ejecting the refrigerant is not provided.

In this embodiment, since the refrigerant does not flow through the outer surface of the infrared transmission window, optical effects such as image vibration and image blur, which are problems in the conventional film cooling, do not occur, and image information is not deteriorated. Is prevented and an accurate image is obtained.

FIG. 3 is a perspective view of a dome 1 according to a second embodiment of the present invention. This embodiment is an example in which a diamond plate 8 is assembled via a frame 11 so that the entire dome 1 is a diamond infrared transmission window.

FIG. 4 is a sectional view taken along line BB of FIG. This figure shows a state in which the diamond plates 8 are connected to each other via a frame 11. The diamond plate and the frame are joined with a ceramic adhesive. A coolant channel 10 is formed inside the frame 11, and the diamond plate is cooled from the end face by flowing the coolant inside.

This embodiment is an example in which the entire dome is an infrared transmitting window, and is suitable as a dome of a flying object equipped with an omnidirectional infrared seeker. In the present embodiment, as in the first embodiment, no image vibration and no image blurring occur, so that an accurate image of the infrared seeker can be obtained.

Next, an experimental result of the effect of cooling the end face of the diamond plate will be described. Table 1 shows the experimental conditions.

[0015]

[Table 1]

When the diamond plate was cooled under the conditions shown in Table 1, the temperature of the diamond plate was 387 ° C. for a heat flux of 100 W / cm ² . Since this is lower than the oxidation temperature of the diamond material of 600 ° C., it is determined that there is a cooling effect. At the above temperature, a diamond material having a width of 5 cm is 0.1 mm.
Extends 02mm. However, the hook-shaped portion of the window frame or frame bends and absorbs the distortion of the diamond material, so that the airtightness of the joint is ensured.

[0017]

The infrared transmission window of the flying object of the present invention is
Using a diamond plate as a window material, the diamond plate of the above-mentioned window material is surrounded by a surrounding metal outer plate or a diamond plate of another adjacent window material through a frame material provided with a coolant flow path in contact with an end surface of the diamond plate. It is a mechanism to cool the diamond plate from its end face by flowing a cooling medium through the refrigerant flow path in the frame material, so that there is no vibration or blurring of the image captured by the infrared seeker, accurate Images can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a dome of a flying object according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view of a dome of a flying object according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a perspective view of a conventional flying object dome.

FIG. 6 is a longitudinal sectional view showing a state of a conventional dome in a high-speed airflow.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dome 2 Metal outer plate 3 Conventional infrared transmission window 4 Refrigerant ejection nozzle 5 Refrigerant flow 6 Shock wave 7 Target 8 Diamond plate 9 Window frame 10 Refrigerant channel 11 Frame

Claims (1)

[Claims] 1. A diamond plate is used as a window material of an infrared transmission window, and the diamond plate of the window material is connected to a surrounding metal outer plate or An infrared transmitting window of a flying object, which is bonded to a diamond plate of another adjacent window material, and cools the diamond plate from its end face by flowing a cooling medium through a refrigerant flow path in the frame material. Its cooling mechanism.