JPH03264356A - Method for internal repairing of parabolic antenna made of frp having honeycomb structure - Google Patents

Abstract

PURPOSE:To easily perform repairing in low cost by making small diameter blind holes in a damaged part at two places and evacuating the blind holes to remove moisture therein and injecting a low viscosity unsaturated polyester resin or epoxy resin in the blind holes to cure the same under pressure. CONSTITUTION:At first, the surface of blind holes reaching FRP 14 are made in the surface of the FRP of a released area 22 at two places of the upper and lower end parts thereof by an electric drill and a vacuum pump 29 is operated to remove the moisture in the released area. As an injection resin for repairing, a low viscosity solventless type unsaturated polyester resin having good adhesiveness to a honeycomb structure and FRP is selected. Next, load is applied to the plunger of an injector by the hand and the vacuum pump 29 is operated to discharge the moisture in the released area to the outside through an upper end tube 24 and the released part is filled with the synthetic resin 31 for repairing. Further, an iron plate is placed on the released area as load 36 to return the dimension expanded in the thickness direction by the injection resin to the original dimension and allowed to stand overnight at room temp. to perfectly cure the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for repairing the interior of a honeycomb-structured FRP antenna used as an antenna on a ship or on land.

[Conventional technology]

As the honeycomb structure FRP parabolic antenna shown in the perspective view of Figure 3 is exposed outdoors, it is exposed to ultraviolet rays from sunlight and moisture from rain, and when it is on the sea, it is exposed to sea salt particles from seawater. Therefore, as shown in the cross-sectional view in Figure 4, the table FiFRP11 that is in direct contact with the atmosphere
From there, moisture and salt gradually penetrate into the interior, and as a result,
For example, a portion of the upper honeycomb 13 and the FRP 14 below may peel off, creating a cavity and interfering with the function of the antenna.

However, as there is currently no suitable repair method, defective items are replaced with new ones, which in the case of ships, for example, is extremely costly and takes half a year to deliver.

[Problem to be solved by the invention]

This is because repairing internal peeling of a parabolic antenna has the following problems.

(1) How can we confirm the extent of the peeling inside the antenna from the outside? (2) Moisture is often present in the peeled area, and this moisture inhibits adhesion, so how can this moisture be removed? (3) The peeled area is - For example, the area between the upper layer honeycomb 13 and the FRP 14 below in Figure 4 is thin, about 111 m, and spreads laterally, so the peeled area must be bonded. As an injection resin for repairs, it has low viscosity and good adhesion to the honeycomb and FRP that make up the antenna.Furthermore, due to the structure of the antenna, a solvent-free type is required, so a resin with such characteristics is used. How do I get it? (4) How to inject repair injection resin into the damaged area? The present invention has been proposed in view of the above circumstances, and it is an object of the present invention to provide an economical method for repairing the inside of a honeycomb structure FRP parabolic antenna that can be easily repaired at low cost.

[Means to solve the problem]

To this end, the inventors of the present invention solved each of the above-mentioned problems by the following means.

(1) A hammer was used, and the damage area was determined by the sound produced during hammer percussion.

(2) For drying moisture, make two small diameter blind holes separated from each other, then connect a vacuum pump to one of the blind holes, draw a vacuum on the damaged area to suck out the moisture inside, and then dry under reduced pressure. The water was removed.

(3) Experiments have shown that with low viscosity, honeycomb and FRP
We selected a solvent-free resin that has good adhesion to the material.

(4) The resin injection method reuses the two blind holes drilled in (2) above, injects the resin under pressure through one blind hole, and connects the other blind hole to a vacuum pump. The injection speed is accelerated by vacuuming, and when the excess resin is discharged,
The injection of resin was completed.

[Effect]

According to such a method, the following effects are performed.

(1) Although internal damage cannot be visually confirmed from the outside, the damage area can be determined by tapping the surface of the antenna with a hammer and listening to the sound generated. According to this method, since the internal peeling part generates a lower sound when percussing than the good part, the peeling range can be determined and the repair range can be limited.

(2) FRPII that constitutes the antenna.

Since the material of No. 4 and Honeycomb No. 13.15 is organic synthetic resin such as polyester resin or epoxy resin, the method of heating and drying the antenna body in order to remove the moisture that has entered the peeled area is to use these synthetic resins. Therefore, we investigated a drying method using vacuum depressurization, which allows drying at room temperature instead of heating, and as a result, we were able to dry the moisture without any problems.

(3) When the repair injection resin is injected into the peeled part of the antenna, for example between the upper layer honeycomb 13 and the FRP 14 below it as shown in FIG. It has the effect of bonding the entire FRP 14.

(4) It was found that the vacuum method allows for faster injection of repair resin and also has higher filling accuracy.

〔Example〕

A honeycomb structure FRP parabolic antenna (bowl shape) diameter 2.
An example applied to a 5 m long product will be explained with reference to the drawings. FIG. 1 is an explanatory diagram showing a means for removing moisture from an internally damaged part, and FIG. 2 is an explanatory diagram showing a means for injecting resin into the damaged part.

In the above diagram, the same numbers as in Figures 3 and 4 are number 3.
~ Figure 4 shows the same member, and as a result of inspecting the peeled area using the hammer percussion method, the peeled area was approximately 300 mm in diameter.
m, and from the hammer percussion sound in the depth direction, the upper honeycomb 13 and the FR below it as shown in FIG.
It was also found that it was between P14.

Next, as shown in FIG. 1, the moisture in the inner peeled portion was dried by the following procedure.

First, regarding the peeling location 22, use an electric drill to drill the FR as shown in FIG.
A blind hole with a diameter of 5u reaching P14 is made, and then a polyethylene upper end tube 24. with an outer diameter of 5 fl and a length of 20 mm is inserted into these two blind holes. Insert the lower end tube 23.

The upper end tube 24 and the lower end tube 23 were each sealed with a commercially available silicone sealant around their peripheries to prevent them from coming off the antenna surface, and then bonded together.

A vinyl hose 25 is further attached to the upper end of the lower end tube 23. Transparent acrylic containers 26 filled with silica gel 27 are successively connected, and the upper end opening of the transparent acrylic containers 26 is connected to a vacuum pump 29 via a vinyl hose 28. Then, the vacuum pump 29 is operated, and the vacuum decompression method is applied. The water inside the peel was removed.

According to this method, when the silica gel 27 was first vacuum-dried, it changed color from blue to red, indicating that moisture was contained inside the antenna. Even after replacing it with a new one, it did not turn red, confirming that the moisture inside the antenna had been removed and it was dry.

Furthermore, the injection resin has a low viscosity and good adhesion to honeycomb and FRP as confirmed by the tests described below, and is a solvent-free unsaturated polyester resin such as Chemiflake Primer P-0.5M (Toyo Rubber Industries ■). The injection resin was injected using the means shown in FIG. 2 in accordance with the following procedure.

First, connect the upper end tube 24 through the vinyl hose 28,
A vacuum pump 29 is connected, and then a repair synthetic resin 31 is connected to the lower end tube 23 via a vinyl hose 33 in the vertical direction.
(e.g. 100cc syringe)
and the compressor inner cylinder 34 are connected. Next, by manually applying a load to the plunger of a 100 cc syringe as the compressor inner cylinder 34 and operating the vacuum pump 29, the air inside the peeling section is discharged to the outside via the upper end tube 24. Then, a synthetic resin 31 for repair was applied to the spot. At this time, completion of the repair synthetic resin 31 can be confirmed by the discharge of excess resin from the upper end tube 24.

Furthermore, as a load 36, a 20 kg iron plate, a bag containing sand, etc. is placed on the surface of the peeled area, and after returning the dimension in the thickness direction expanded by the injected resin to its original size, the resin is completely removed by leaving it at room temperature overnight. Hardened. Note that when the area of the peeled part is small, the repair can be performed without using the vacuum pump 29 and the load 36.

After leaving it at room temperature overnight, remove the load 36 shown in Figure 2,
As a result of investigating the peeled parts using the hammer percussion method, the entire surface was filled with resin, confirming that this construction method was satisfactory. It was also confirmed that its function as an antenna had been restored.

Finally, the results of the adhesion test between the injected resin and the antenna body resin are as follows: (1) Test standard: Adhesive test method JIS K6850 was followed.

■、Test guidelines: An adhesion test was conducted according to the following procedure.

(1) Epoxy resin of the same type as FRP used in the examples (
Bond E Cent (manufactured by Konishi ■)) and glass fiber (plain weave.

Using Nitto Boseki #@), width 12im x length 100m
x Two FRP boards with a thickness of 5 m were produced.

(2) Next, from the end face of one side to the part of length 12 + n
Both sheets were coated with unsaturated polyester resin Chemiflake Primer P-05M (manufactured by Toyo Tire & Rubber Industries, Ltd.) selected as the injection resin to a thickness of about 0.3 m, and then the two coated sheets were pasted together and heated at room temperature. This was cured for 24 hours to obtain a shear adhesive test piece. Note that three test pieces were prepared.

■, Test results: (3) Tensile testing machine (with tensile speed 5tm/5hin)
The results of measuring the shear adhesive force using Shimadzu Autograph S-500) were: 10 kgf/ad, l 2 kgf/ci, I
A value of 3 kgf/cd was obtained, indicating good adhesion.

[Effect of the invention] Conventionally, replacing with a new product was extremely expensive.
However, with the repair method of the present invention, the repair can be done in a few days, and the repair cost is only a few percent of the new price, and the antenna functions sufficiently. I was able to recover.

In short, according to the present invention, first, small-diameter blind holes are made in two separate locations in a damaged part of a honeycomb structure FRP parabolic antenna where a part of the inside has peeled off, and vacuum is drawn from one blind hole to inside the damaged part. The water is dried,
Next, inject a low-viscosity unsaturated polyester resin or epoxy resin as a repair resin through this blind hole, and after confirming that the resin has flowed out from the other blind hole, wait until the resin filled inside is cured. An economical honeycomb structure FR that can be easily repaired at low cost by applying pressure so that the reflective surface is flush with the original reflective surface.
The present invention is extremely useful industrially because it provides a method for repairing the inside of a parabolic antenna made of P.

[Brief explanation of drawings]

FIG. 1 is an explanatory view showing means for removing moisture from an internally damaged part in an embodiment in which the present invention is applied to a parabolic antenna for ships, and FIG. 2 is an explanatory view showing means for injecting resin into the damaged part. Figure 3 is an overall perspective view of a known parabolic antenna;
The figure is a partially enlarged view showing a cross section of the parabolic antenna (bowl-shaped) shown in Fig. 3. 10... Direction variable support frame, 11... Surface layer FRP,
12... Wire for receiving and transmitting, 13... Upper layer honeycomb,
14...FRP, 15...Lower honeycomb, 21...
・Antenna body, 22...Peeling part inside the antenna,
23...Lower end tube, 24...Upper end tube, 2
5... Vinyl hose, 26... Acrylic container, 2
7...Silica gel, 28...Vinyl hose, 29.
...Vacuum pump, 31...Synthetic resin for repair, 32...
- Press fitter outer cylinder, 33... Vinyl hose, 34... Press fitter inner cylinder, 35... Pressurizing means, 36... Load.

Claims (1)

[Claims] First, two parts of the damaged part of the honeycomb structure FRP parabolic antenna separated from each other are separated from each other.
A small diameter blind hole is made in each location, and the water inside the damaged part is dried by vacuuming through one blind hole. Next, a low viscosity unsaturated polyester resin or epoxy resin is injected as a repair resin through this blind hole. , after confirming the outflow of the resin from the other blind hole, pressurization is applied so that the reflective surface of the antenna becomes flush with the original reflective surface until the resin filled inside is cured.
How to repair the inside of a manufactured parabolic antenna.