JP6996814B2 - Radome assembly structure - Google Patents

Description

The present invention relates to a radome assembly structure that protects an antenna for a flying object, and more particularly to a radome assembly structure that relieves thermal stress due to a difference in thermal expansion rate between materials to be assembled.

The tip of the projectile is equipped with a radome that protects the radar antenna, and the projectile flies toward the target while transmitting and receiving radio waves with the radar antenna. Further, although the radome has a shape in which air resistance is reduced, when it flies at high speed, it is heated by aerodynamic heating and exposed to a high temperature.

Therefore, the radome needs to transmit radio waves transmitted and received by the radar antenna and has heat resistance, and is formed of, for example, a dielectric material having excellent heat resistance such as ceramics.

On the other hand, it is common to use a highly rigid material such as iron or aluminum for the housing (main body) of the flying object, and the joint between the radome and the housing has a difference in thermal expansion rate. Because it bonds large dissimilar materials, when it flies at high speed, a large thermal stress is generated and it may break from the joint.

In Japanese Patent Application Laid-Open No. 2016-174200 of Patent Document 1, the strength of the adhesive for adhering and fixing the radome and the radome ring is lowered by providing a groove for fitting with the protrusion of the radome ring on the inner surface of the radome. It is also disclosed that the radome and the radome ring can be prevented from coming off.

Further, Japanese Patent Application Laid-Open No. 2016-161270 of Patent Document 2 discloses that the thermal stress generated at the portion where the radome and the radome ring are joined can be alleviated by providing a slit in the radome ring to be joined to the main body portion. There is.

Japanese Unexamined Patent Publication No. 2016-174200 Japanese Unexamined Patent Publication No. 2016-161270

However, since these radomes use resin materials such as fiber reinforced plastics and adhesives for the joints, the heat resistant temperature of the above resin is the standard, and they can be applied to flying objects that fly at ultra-high speed for a long time. Can not.
In particular, bonding with an adhesive is vulnerable to strain in addition to the tendency for variations in adhesive strength. Furthermore, since the adhesive tends to deteriorate over time and the reliability of bonding is low, the design must be set with a low heat resistant temperature.

The present invention has been made in view of the problems of the prior art, and an object thereof is to provide a radome assembly structure capable of relaxing thermal stress, having a high heat resistant temperature, and having high reliability. To do.

As a result of diligent studies to achieve the above object, the present inventor assembles the redome and the main body without using a resin material such as fiber reinforced plastic or an adhesive, and provides an elastic member at the joint to provide thermal stress. We have found that the above object can be achieved by alleviating the above, and have completed the present invention.

That is, the above problem is solved by the following invention of the present invention.
(1) A radome, a radome ring, and a housing fixed to the radome via the radome ring are provided.
At least a part of the end face of the radome and the end face of the housing are arranged so as to face each other.
An elastic member is provided between the facing end faces, and the elastic member is provided .
The radome has a recess in the joint with the radome ring.
A radome assembly structure characterized in that the split ring and the radome ring arranged in the recess are fixed with screws, the movement of the radome ring is restricted, and the radome and the radome ring are connected . ..
(2) The radome ring and the housing have screws on the joint surface.
The radome assembly structure according to item (1), wherein the radome ring and the housing are fastened to compress the elastic member.
(3) The radome assembly structure according to item (1) or item (2) above, wherein the elastic member is a disc spring.

According to the present invention, the radome and the main body are assembled without using a resin material such as a fiber reinforced plastic or an adhesive, and an elastic member is used to relieve the thermal stress. Therefore, the radome has excellent heat resistance and reliability. A tall radome assembly structure can be provided.

It is a schematic diagram explaining the structure of a flying object. It is a schematic sectional drawing of the assembly structure of the radome of this invention. It is a schematic diagram of a split ring. It is a schematic sectional drawing of a split ring.

The radome assembly structure of the present invention will be described in detail.
FIG. 1 is a diagram illustrating a configuration of a flying object including the radome assembly structure of the present invention, and FIG. 2 is an enlarged cross-sectional view of a portion surrounded by A in FIG. 1.
The flying object includes a radome 1 for protecting a radar antenna provided at the tip of the flying object, a housing 3 for connecting to the flying object fuselage 100, and a radome ring 2 for connecting the radome and the housing.

Here, the radome is formed of a dielectric material such as ceramic having a small coefficient of thermal expansion. Further, the radome ring and the housing are made of a highly rigid metal material, and in particular, the thermal expansion rate of Invar, titanium alloy, etc. is compared with the fixing members such as the radome ring and the split ring for fixing the radome ring and the radome. A small metal material is used.
A heat-resistant cover 9 formed of a heat-resistant material and capable of reducing a temperature rise due to aerodynamic heating is provided on the outer surface of the radome ring and the housing made of the metal material.

In the radome assembly structure of the present invention, at least a part of the end face of the radome 1 and the end face of the housing 3 are arranged so as to face each other. The radome ring 2 has a cylindrical shape with an open upper surface and a lower surface, straddles the opposite radome 1 and the end face of the housing 3, and covers the end face in the circumferential direction with the side surface of the radome and the housing. It is provided on the side of the.

The radome 1 and the housing 3 each have a joint portion with the radome ring 2 on the side surface covered with the radome ring 2, and are fixed to the inside of the radome ring 2 with the radome 1 via the radome ring 2. It is coupled to the housing 3.

An elastic member 4 is provided between the radome 1, the housing 3, and the radome ring 2, that is, between the end face of the radome and the end face of the housing, and the elastic member 4 is the radome 1. It is sandwiched between the housing 3 and the housing 3 and compressed.
A flat washer 5 may be provided between the radome 1 and the elastic member 4.

In the assembled structure, the radome ring 2 thermally expands in the axial direction due to aerodynamic heating, and even if the distance between the radome 1 and the housing 3 increases, the compressed elastic member 4 expands, so that the radome 1 The end face of the housing 3 and the end face of the housing 3 are in contact with each other via the elastic member 4.
Therefore, since there is no gap between the radome and the housing, it is possible to prevent a decrease in assembly strength due to thermal expansion.

Further, even if the fixing member such as the radome ring 2 and the split ring for fixing the radome ring and the radome expands in the outer peripheral direction due to aerodynamic heating, the metal parts are elastic at the contact points with the housing. Since it spreads within the range of deformation, it does not lead to destruction. Further, since the radome 1 and the housing 3 are not directly fixed and the elastic member 4 is provided between the end faces facing each other, the respective end faces of the radome 1 and the housing 3 and the elastic member 4 are in contact with each other. The contact points can be displaced, and the thermal stress can be relaxed.

The elastic member 4 is not limited as long as it can expand in response to the thermal expansion of the radome ring and press the end face of the radome and the end face of the housing. For example, a metal or ceramic disc spring or coil spring can be used. ..
Among them, the disc spring can give a large load in a small space between the facing end faces of the radome and the housing, and can be preferably used.

The radome ring 2 and the housing 3 have a screw thread (groove) 6 on the joint surface. Specifically, threads (grooves) 6 are formed on the inner surface of the radome ring and the outer surface of the housing, and the radome ring is tightened to the housing to compress the elastic member 4 between the radome and the housing. , The radome ring 2 and the housing 3 are prevented from loosening, and the radome ring and the housing can be firmly coupled.

Further, the radome 1 and the radome ring 2 are connected by the split ring 8 and the fixing screw 7. Specifically, a groove-shaped recess 11 is formed on the side surface of the radome over the entire circumference, a split ring 8 is arranged in the recess 11, and a plurality of screw holes provided in the circumferential direction of the split ring 8. Screw the countersunk screw 7 into 81.

As a result, the radome ring 2 and the split ring 8 are fixed, the movement of the split ring 8 in the recess 11 in the flight plane axial direction is restricted, and the radome ring 2 and the split ring 8 by the screw thread (groove) 6 are restricted. In combination with the connection with the housing 3, the radome 1 and the housing 3 can be reliably connected.

FIG. 3 shows a schematic cross-sectional view of the split ring 8 in the axial direction of the flying object (in the same direction as in FIG. 2), and FIG. 4 shows a cross-sectional view taken along the line AA'in FIG.
Although FIG. 3 shows an example of a split ring divided into two, it may be divided into three or more.

According to the above fixing method, it is not necessary to make a through hole in the radome, and the radome and the radome ring can be fixed without lowering the strength of a material such as ceramic which is easily broken by brittleness.

Further, a heat-resistant cover 9 can be provided on the outer periphery of the radome ring and the housing. The heat-resistant cover is made of a heat-resistant material having heat insulating properties and covers the radome ring and the housing to provide heat protection from aerodynamic heating.

In the radome assembly structure of the present invention, the heat-resistant cover 9 is not a strength member that connects the radome and the housing, so that it does not need to be firmly bonded by adhesion or screws.
Therefore, the heat-resistant cover 9 can be sandwiched and fixed between the body joint 12 and the radome 1 along with the connection between the housing 3 fixed to the body 100 and the radome 1 via the body joint 12, and the heat-resistant cover 9 can be fixed. Since the radome is not firmly bonded, the joint is not broken by thermal stress.
A heat-resistant gasket 10 may be inserted between the heat-resistant cover 9 and the radome 1 to fill the gap.

According to the assembled structure of the redome, the thermal stress due to the difference in thermal expansion between the redome and the housing can be relaxed, and since no resin material such as an adhesive or fiber reinforced plastic is used for the joint, the heat resistant temperature is reached. Can be set high, and since it is bonded without using an adhesive, it is not affected by variations in adhesive strength or deterioration, so that the reliability of bonding is high.
Therefore, according to the assembled structure of the present invention, it is possible to fly at ultra-high speed for a long time.

1 Radome (made of ceramic)
11 Recess 2 Redome ring (made of metal)
3 Housing (metal)
4 Elastic member (disc spring: made of metal or ceramics)
5 Flat washer (made of metal)
6 Thread (groove)
7 Fixing screw 80% ring (2 divisions: made of metal)
81 Screw holes 9 Heat-resistant cover (heat-resistant material)
10 Gasket (heat resistant material)
12 fuselage joint 13 fixing bolt 100 fuselage F flying object

Claims (3)

It comprises a radome, a radome ring, and a housing fixed to the radome via the radome ring.
At least a part of the end face of the radome and the end face of the housing are arranged so as to face each other.
An elastic member is provided between the facing end faces, and the elastic member is provided.
The radome has a recess in the joint with the radome ring.
A radome assembly structure characterized in that the split ring and the radome ring arranged in the recess are fixed with screws, the movement of the radome ring is restricted, and the radome and the radome ring are connected . .. The radome ring and the housing have screws on the joint surface.
The radome assembly structure according to claim 1, wherein the radome ring is tightened into a housing to compress the elastic member. The radome assembly structure according to claim 1 or 2, wherein the elastic member is a disc spring.

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