JPH05136618A - Fixing structure for fiber reinforced film - Google Patents

Abstract

PURPOSE:To obtain the sufficient joining strength and to obtain the reliability by inserting a thin plate having many small projections between a fiber reinforced film and a synthetic rubber molded product. CONSTITUTION:Between the fiber reinforced film 1 and the synthetic rubber molded product 7, a thin plate 12 is loaded and small projections 13 are formed on the surface at the side of the reinforced film 1 of the thin plate 12. By tightening a bolt 3, the small projections 13 are bitten without forming the hole for penetrating into the reinforced film 1 and about 120 mechanical threads are formed per one bolt 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air membrane structure such as an air dome and a peripheral fixing structure for a fiber reinforced membrane used in a radome.

[0002]

2. Description of the Related Art FIG. 13 is a cross-sectional view showing a joint portion between a film material of an air dome and other structural members shown in, for example, Journal of Japan Society for Composite Materials Vol. 14, No. 1 (1988). In the above, 1 is a woven fabric of glass fiber and fluororesin
It is a fiber reinforced membrane coated with FE, tetrafluorene ethylene), and the rope 2 is woven into the end portion of the fiber reinforced membrane and heat-welded, and a hole is formed so that the bolt 3 can pass through. Reference numeral 4 denotes a mounting flange made of an aluminum alloy, and 5 denotes a presser foot made of an aluminum alloy, in which holes corresponding to the bolts 3 are processed similarly to the fiber reinforced film 1. 6 is a first synthetic rubber molded product inserted between the fiber reinforced membrane 1 and the mounting flange 4, 7
Is a second synthetic rubber molded product inserted between the fiber reinforced film 1 and the presser foot 5, 8 is a nut fitted with the bolt 3, 9 is a flat washer, and 10 is a cable.

FIG. 14 is a sectional view showing a peripheral fixing portion of a radome using, for example, a dielectric thin film.
15 is a fiber reinforced film in which a woven glass fiber cloth is coated with a fluororesin as in FIG. 15, but is simply bored so that the bolt 3 can pass through, and 11 is a spring washer.

The fixing portion of the conventional fiber reinforced membrane is constructed as described above, and the end portion of the fiber reinforced membrane 1 is fixed by fastening the scissor bolt 3 with the nut 8 in the mounting flange 4 and the presser foot 5. The first synthetic rubber molded product 6 and the second synthetic rubber molded product 7 inserted between the fiber reinforced film 1, the mounting flange 4 and the presser foot 5 prevent abrasion of the fiber reinforced film 1 and have airtightness and watertightness. Have secured. Both the air dome and the radome are normally kept in a shape by applying an air pressure of 30 to 100 kgf / m ² , but when the wind is strong, a large negative pressure acts on the fiber reinforced film 1 from the outside, and the fiber reinforced film 1 is in a large tension state. .. This tensile force is finally transmitted to the end portion, and in the air dome shown in FIG. 12, the load is transmitted to the mounting flange 4 by being caught by the rope 2. In the radome of FIG. 14, the frictional force generated by the tightening force of the bolt 3 and the nut 8 opposes the tensile force, resulting in so-called frictional joining.

Since the air dome as a membrane structure can realize a large space without pillars and walls, and the radome has excellent radio wave transmission properties of a fluororesin-coated glass fiber woven fabric, its use is expanding in recent years. ..

[0006]

The membrane structure has a long history of beginning as a nomadic tent, and the fixed part is folded back and reinforced with sutures or adhesives, or the eyelet is hit to prevent tearing due to the action of concentration. It is important to prevent. But,
Fluororesin-coated glass fiber woven fabric breaks and damages the glass fibers when stitched, and the surface of the fluororesin must be activated with a special etching agent in order to bond. For this reason, the actual condition is that reinforcement and connection are only made by heat welding or friction welding, which is less likely to exert a concentrated force, and the conventional fiber reinforced membrane fixing structure shown in FIGS. 13 and 14 is based on this.

However, in heat welding, the processing temperature exceeds 300 ° C., the workability is not good, and there is a dimensional change (reduction) due to thermal strain, so the shape of heat welding is limited to simple shapes such as straight lines. Moreover, it is necessary to assemble the assembly while applying a tensile force with a shimmer or the like to correct the dimensions during the installation.
Therefore, a radome such as a radome that does not like a curved shape or a dimensional change has no choice but to cut and hole the fiber reinforced film 1 and use friction bonding means, but the fluororesin is basically a material having a low friction coefficient. Therefore, in order to obtain a frictional force comparable to the tensile strength of the fiber reinforced film 1, it is necessary to introduce a huge tightening force, that is, a large amount of tightening bolts and strict tightening torque management. In addition to this, the first and second synthetic rubber molded products 6 and 7 inserted between the fiber reinforced membrane 1 and the mounting flange 4 and the presser foot 5
Since the tightening force causes permanent deformation to some extent and the tightening force decreases over time, a sufficient margin is required. In particular, when crystallized at a low temperature, permanent strain easily occurs and the tightening force of the bolt is reduced, so that there is a problem that the strength of the fiber reinforced film cannot be fully utilized.

The present invention has been made in order to solve the above-mentioned problems, and has sufficient bonding strength even if the fiber reinforced membrane is not subjected to any special processing, and is highly reliable and inexpensive. It is intended to provide a reinforced membrane fixing structure.

[0009]

In the fiber reinforced membrane fixing structure according to the present invention, a thin plate having a large number of small projections is provided between the fiber reinforced membrane and a synthetic rubber molded product, and the surface having the small projections is provided with a fiber reinforced membrane. It is to be inserted on the side of.

Further, when a thin plate having small protrusions is inserted and fixed with a bolt, a spring having a predetermined spring characteristic is inserted into the bolt.

Further, a predetermined small protrusion is formed on the presser foot,
The surface of the small projection is fixed to the fiber reinforced membrane.

Further, a sheet having particles of a predetermined particle size fixed is inserted between the fiber reinforced film and the synthetic rubber molded product with the surface having the particles being the side of the fiber reinforced film.

Further, when a sheet having particles is inserted and fixed with a bolt, a spring having a predetermined spring characteristic is inserted into the bolt.

Further, predetermined particles are fixed to the presser foot and the surfaces of the particles are fixed to the fiber reinforced film.

[0015]

When a tensile force acts on the fiber reinforced membrane of the fixed structure of the fiber reinforced membrane configured as described above, small projections or particles in contact with the fiber reinforced membrane cause a large number of mechanical forces between the fiber reinforced membrane and the fiber reinforced membrane. Since it has a hook, it prevents slippage of the fiber reinforced membrane and exhibits high tensile strength.

Further, the effect that the spring inserted in the bolt has on the tightening force of the permanent strain generated in the synthetic rubber molded product is mitigated.

[0017]

EXAMPLES Example 1. FIG. 1 is a sectional view showing an embodiment of the present invention, and reference numerals 1, 3 to 9 and 11 are exactly the same as the above-mentioned conventional fixing structure for a fiber reinforced membrane. Reference numeral 12 is a thin plate loaded between the fiber reinforced membrane 1 and the second synthetic rubber molded product 7, and 13 is a small projection formed on the surface of the thin plate 12 on the fiber reinforced membrane 1 side.

FIG. 2 is a view showing the thin plate 12, in which a comb-shaped blade is made to bite into the aluminum thin plate 12 and the small projection 13 is formed.
To form. The height H of the small protrusions 13 is set to 0.5 to 0.7 mm, which is slightly larger than the plate thickness 0.45 mm of the fiber reinforced membrane 1. And M10 screw bolt 3 1
About 120 small projections 13 are formed on the book so that the directions thereof are opposite.

In the fiber reinforced membrane fixing structure constructed as described above, the small protrusions 13 bite into the fiber reinforced membrane 1 by tightening the bolts 3 without producing holes penetrating the fiber reinforced membrane 1, and one bolt 3 As a result, about 120 mechanical catches are formed. FIG. 3 shows the result of measuring the tensile strength of this fiber reinforced membrane fixing structure corresponding to the tightening torque of the bolt 3. In the figure, the conventional fixing structure of the fiber-reinforced membrane (thin plate 1
The tensile strength of the sample (not loaded with 2) is shown by the broken line A. In the fixing structure of the fiber-reinforced membrane loaded with the thin plate 12, the tensile strength can be improved as shown in FIG. 3B, and the improvement is remarkable especially at low tightening torque. The tensile strength is related to the height of the small protrusions 13, but in the case of this embodiment, the same characteristics were exhibited if it was 0.3 mm or more. Further, when the height of the small protrusions 13 becomes large, there is a hole penetrating the fiber reinforced membrane 1 and the airtightness and watertightness are impaired. Therefore, the height of the small protrusions 13 is 0.6 of the plate thickness of the fiber reinforced membrane 1. About 1.6 times is practical. In this range, when a force exceeding the tensile strength shown in FIG. 3 acts, the small protrusions 13 scrape off the fluororesin coated with the fiber reinforced film 1 to cause slippage, but the glass fiber is not damaged and the airtightness / Shows high tensile strength in a wide range of tightening torque without impairing water tightness.

Example 2. FIG. 4 is a cross-sectional view showing a second embodiment of the present invention, in which 1, 3 to 9 and 11 to 13 are the same as those in FIG. 1, except that the small protrusions 13 shown in FIGS. The height H and the width W are set as follows. That is, the height of the small protrusions 13 is set to 1 mm, which is twice the plate thickness 0.45 mm of the fiber reinforced membrane, and the width of the small protrusions 13 is set to 1.4 mm which is about the same as the weaving yarn interval of the fiber reinforced membrane 1.
mm.

In the fiber reinforced membrane fixing structure constructed as described above, the small protrusion 13 penetrates the fiber reinforced membrane 1 by the tightening of the bolt 3 and bites into the first synthetic rubber molded product 6 to form one bolt. To about 120 mechanical traps are formed. FIG. 3 shows the results obtained by measuring the tensile strength of this fiber reinforced membrane fixing structure corresponding to the tightening torque of the bolt 3. As shown in the figure, the tensile strength can be improved, especially at low tightening torque. The tensile strength is related to the height of the small protrusions 13, but in the case of this embodiment, the same characteristics were exhibited if it was 0.3 mm or more. Also,
If the height and the width of the small protrusions 13 are increased, the fiber-reinforced membrane 1 is damaged. Therefore, the height of the small protrusions 13 is about twice the plate thickness of the fiber-reinforced membrane 1 or less, and the width is the weaving yarn interval of the fiber-reinforced membrane 1. The degree below is practical. In this range, when a force exceeding the tensile strength shown in FIG.

Embodiment 3. 5 (a) and 5 (b) are views showing a third embodiment of the present invention.
4 is inserted in the bolt 3. In this embodiment, three flat springs 14 are arranged in parallel, and two sets of six are arranged on the head side and the nut side of the bolt 3. According to this, the spring characteristic of the belleville spring 14 compensates for the permanent strain generated in the first and second synthetic rubber molded products, and the decrease in tightening torque is reduced, so that a high tensile strength can be stably obtained for a long period of time. ..

Example 4. In the first, second, and third embodiments, the end of the thin plate 12 having small protrusions is bent to facilitate the insertion. However, as shown in FIG. 6, the thin plate 12 is preliminarily attached to the second synthetic rubber molded product 7 by adhesion or the like. Even if you do, you can expect similar characteristics.

Example 5. 7 (a) (b), FIG. 8 (a)
(B) shows another embodiment in which the small protrusions 12 are formed. The small protrusions 1 are directly formed on the surface of the presser foot 5 on the fiber reinforced membrane 1 side.
2, the presser foot 5 is divided into two bolts 3 and is provided with a rounded periphery. This Figure 7
According to this, the second synthetic rubber molded product 7 is not required and the workability of assembly is improved.

Example 6. In the above Examples 1 to 5, the small protrusion 1
3 are arranged so that their directions face each other, but by aligning them in one direction or arranging them isotropically in the front-rear direction depending on the direction of the tensile force that acts, the characteristics are equal to or better than the facing position Can be expected.

Example 7. FIG. 9 is a cross-sectional view showing another embodiment of the present invention, and 1, 3 to 9 and 11 are exactly the same as the above conventional fiber reinforced membrane fixing structure. Reference numeral 15 is a sheet inserted between the fiber reinforced membrane 1 and the second synthetic rubber molded product 7, and 16 is particles attached to the surface of the sheet 15 on the fiber reinforced membrane 1 side. FIG. 10 is a view showing the sheet 15, which is a sheet 15 of a polyester film having a thickness of 0.1 mm in this embodiment, and a sheet 15 of a polyester film having a thickness of 0.1 mm in this embodiment.
Further, carborundum (SiC) particles 16 are fixed by a urethane adhesive. The particle size of the carborundum particles 16 is # 60.

In the structure of the fiber reinforced film constructed as described above, a high frictional force surface is formed between the particles 16 and the fiber reinforced film 1 by tightening the bolt 3, which is caused by the small protrusions in FIG. Almost the same tensile strength characteristics can be obtained. The tensile strength is related to the particle size of the carborundum particles 16. In this example, the particle size # 46 to # 100 was practical for the plate thickness 0.45 mm of the fiber reinforced membrane 1. In this range, when a force exceeding the tensile strength is applied, the particles 16 will be dispersed in the fiber-reinforced membrane 1.
Although the surface of the coated fluorocarbon resin is scraped off to cause slippage, the glass fiber is not damaged and shows high tensile strength in a wide range of tightening torque without impairing airtightness and watertightness.

Example 8. Similar to the embodiment shown in FIG. 5, the embodiment 8 shown in FIG. 7 replaces the spring washer 11 with the bevel spring 14 to compensate for the permanent strain generated in the first and second synthetic rubber molded products and to tighten the tightening torque. It is expected that a high tensile strength can be stably obtained for a long period of time by reducing the decrease in

Example 9. The sheet 15 is preliminarily attached to the second rubber molded product 7 by using a sheet 15 having a surface opposite to the surface on which the particles 16 are loaded in Examples 7 and 8 with an adhesive such as a pressure sensitive adhesive. Can be kept, and the work can be facilitated.

Example 10. FIGS. 11 and 12 show another embodiment in which particles 16 are loaded. The particles 16 are directly adhered to the surface of the presser member 5 on the side of the fiber reinforced film 1 with an adhesive such as urethane,
The presser foot 5 is divided into two bolts 3 and is provided with a rounded periphery. According to this FIG. 11, the second synthetic rubber molded product 7 is not necessary and the workability of assembly is improved.

Example 11. In the above Examples 7 to 10, the particles 16 were carborundum, but JIS R 6111 was used.
Similar hardness can be expected as long as it has an appropriate hardness and surface condition, such as the artificial abrasive specified in 1.

By the way, in the above description, the present invention has been described with respect to the fiber-reinforced membrane of the fluororesin-coated glass fiber woven cloth, but it goes without saying that it can be applied to a fixing structure in other fiber-reinforced membrane such as Hypalon-coated Tetoron cloth.

[0033]

Since the present invention is constructed as described above, it has the following effects.

By attaching a thin plate having small protrusions to the fiber reinforced film to attach it, an output piece fixing portion having a high tensile strength can be realized without special processing of the fiber reinforced film.

Furthermore, by inserting a predetermined spring into the bolt, the high tensile strength of the fixed portion can be maintained for a long period of time.

If a small protrusion is formed on the presser foot, a synthetic rubber molded product can be partially omitted and the structure can be simplified.

Further, by attaching a sheet having particles to the fiber reinforced film and attaching it, a peripheral fixing portion having high tensile strength can be realized without special processing of the fiber reinforced film.

If particles are fixed to the presser foot, a synthetic rubber molded product can be partially omitted and the structure can be simplified.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a detailed view of a thin plate showing the first embodiment of the present invention.

FIG. 3 is a diagram showing tensile strength characteristics of Example 1 of the present invention.

FIG. 4 is a sectional view showing Embodiment 2 of the present invention.

FIG. 5 is a diagram showing a third embodiment of the present invention.

FIG. 6 is a diagram showing Embodiment 4 of the present invention.

FIG. 7 is a sectional view showing Embodiment 5 of the present invention.

FIG. 8 is a perspective view showing a fifth embodiment of the present invention.

FIG. 9 is a sectional view showing Embodiment 7 of the present invention.

FIG. 10 is a sectional view of a seat showing Embodiment 7 of the present invention.

FIG. 11 is a sectional view showing Embodiment 10 of the present invention.

FIG. 12 is a perspective view showing Embodiment 10 of the present invention.

FIG. 13 is a cross-sectional view showing a conventional fiber reinforced membrane fixing structure.

FIG. 14 is a cross-sectional view showing a conventional fiber reinforced membrane fixing structure.

[Explanation of symbols]

 1 Fiber Reinforced Membrane 2 Rope 3 Bolt 4 Mounting Flange 5 Presser Plate 6 First Synthetic Rubber Molded Product 7 Second Synthetic Rubber Molded Product 8 Nut 9 Plain Washer 10 Rope 11 Spring Washer 12 Thin Plate 13 Small Protrusion 14 Belleville Spring 15 Sheet 16 particles

Claims (6)

[Claims] 1. In a fiber reinforced membrane fixing structure in which synthetic rubber moldings are arranged on both sides of a fiber reinforced membrane and fixed by sandwiching them with a mounting flange and a presser foot, a small rubber is provided between the fiber reinforced membrane and the synthetic rubber molding. A fixing structure for a fiber-reinforced membrane, wherein a thin plate having a plurality of projections is provided so that the small projections are located on the fiber-reinforced membrane side. 2. A fiber reinforced membrane fixing structure in which a synthetic rubber molded product is arranged on one side of a fiber reinforced membrane and is fixed between a mounting flange and a presser foot, and a plurality of pieces provided on the presser foot and contacting the fiber reinforced membrane are provided. A fixing structure for a fiber-reinforced membrane, characterized in that it has a small protrusion. 3. The height of the small protrusions is set to 0.
The fiber-reinforced membrane fixing structure according to claim 1 or 2, wherein the fiber-reinforced membrane fixing structure is 6 to 1.6 times. 4. The height of the small protrusions is not more than twice the plate thickness of the fiber reinforced membrane, and the width of the small protrusions is not more than the interval of the weaving yarns of the fiber reinforced membrane. The fixing structure for a fiber-reinforced membrane according to item 1 or 2. 5. In a fiber reinforced membrane fixing structure in which synthetic rubber moldings are arranged on both sides of a fiber reinforced membrane and fixed by a mounting flange and a presser foot, a predetermined distance is provided between the fiber reinforced membrane and the synthetic rubber molding. A fixed structure for a fiber reinforced membrane, comprising a sheet to which particles having a particle size are fixed, and the particles are located on the side of the fiber reinforced membrane. 6. A fiber reinforced membrane fixing structure in which a synthetic rubber molded product is arranged on one side of a fiber reinforced membrane and is fixed between a mounting flange and a presser foot, and particles of a predetermined particle size are fixed to the presser foot. A fixing structure for a fiber-reinforced membrane, characterized in that particles are located on the side of the fiber-reinforced membrane of the presser foot.