JPS63149135A - Manufacture of bellows cylinder made of fiber-reinforced plastics - Google Patents

Abstract

PURPOSE:To enable mass production of a bellows cylinder made of FRP, by a method wherein fitting of a reinforcing ring and adhesion process are not required by forming directly a reinforcement part of both ends of the bellows cylinder on the uncured bellows cylinder, and therefore, operation efficiency is improved. CONSTITUTION:A split mold 1, which has been split into a plurality of parts and combined shuntably inwardly in a radial direction, is inserted into a molding part 1a of a crest and trough parts of bellows, round which continuous fiber impregnated with resin is wound at a winding angle and a fiber winding layer 3 is formed. Then a rubber mold 2 having a molding surface 2a of the crest and trough parts is put over the outer circumference of the crest and trough parts of the layer 3 by making use of an insertion jig. After fitting over of the rubber mold 2, the split mold 1 is pulled out of the jig along with the rubber mold 2 and a second fiber winding layer 4 is formed on the fiber winding layer 3. Then a pressurizing jig is put over the split mold where the fiber winding layers 3, 4 have been formed. The same is introduced into a heating furnace and impregnating resin is cured. Then the jig and rubber mold 2 are removed in the reverse order of the above and demolded by dismantling the split mold 1.

Description

Detailed Description of the Invention [Field of Industrial Application] This invention relates to a bellows tube made of fiber reinforced plastics (hereinafter abbreviated as FRP), particularly a bellows tube having reinforcing portions at both ends for connection with a straight cylinder. This invention relates to a method for efficiently manufacturing cylinders.

[Conventional technology and its problems]

Cylindrical bodies made from FRP such as carbon fiber reinforced plastics are lightweight, high strength, and have excellent corrosion resistance, so they are used for gas and liquid transfer pipes, etc. Because it exhibits excellent properties in many applications, it is also used in high-speed rotating cylinders, etc., and has a wide range of uses.

Providing a bellows on such a cylindrical body, for example,
Benefits include making the transfer tube easier to bend and absorbing the elastic bending vibrations of a high-speed rotating cylinder to make rotation easier.

However, unlike a uniform material, FRP exhibits extremely different methods, so the bellows part and the straight cylinder part cannot be integrally molded because it is necessary to change the orientation and density of the fibers and the structure of the mold used. Therefore, when making a cylindrical body with bellows, the filament winding method (hereinafter F
The most commonly used method is to fabricate a straight cylinder and a bellows cylinder separately based on the W method, and then glue and fit them together. Reinforcements shall be provided at both ends of the bellows to provide the necessary strength for the connection.

Conventionally, the reinforcing portion has been formed by separately manufacturing a reinforcing ring and adhesively fitting it to the outer periphery of both ends of the bellows tube, but this method is inefficient and does not allow mass production of bellows tubes.

This invention aims to solve this problem.

[Means for solving problems]

As shown in FIG. 1, the method of the present invention for achieving the above object is such that at least the molded portion 1a of the peak and valley portions of the bellows is divided into a plurality of parts in the circumferential direction and combined so as to be retractable inward in the radial direction. After winding the resin-impregnated continuous fibers onto the mold 1 at a predetermined winding angle, a rubber mold 2 having the peaks and troughs of the bellows and the molding surface 2a in the vicinity is wrapped around a part of the outer periphery of the fiber-wrapped layer 3 (the part of the bellows part). Then, the resin-impregnated continuous fibers are supplied from the eye part (not shown) of a carre sod traverse that reciprocates in the axial direction of the split mold while rotating the split mold 1 in a fixed position. A supply section that revolves around the split mold while moving 1 non-rotatingly in the axial direction (for this -
An example will be described later) supplies resin-impregnated continuous fibers to form a second fiber-wrapped layer 4 for the reinforcing portion on the outer periphery of the fiber-wrapped layer located outside both end surfaces of the rubber mold 2, and then It is characterized in that it is inserted into the entire pressure jig, passed through a heating furnace together with the jig to harden the impregnated resin, and then extracted from the pressure jig and demolded.

[Effect]

In the method of the present invention, the reinforcing part is formed by winding the resin-impregnated connection directly onto the uncured bellows part, thereby eliminating the need for fitting and gluing the reinforcing ring, which were conventionally necessary.

Furthermore, the heat curing process for fiber wrapping N1.4, which conventionally required twice due to the fact that the reinforcing ring and the bellows tube are molded separately, can now be done once.

Furthermore, in the conventional method, it was necessary to grind the mutually fitting surfaces of the reinforcing ring and the bellows cylinder in order to fit the reinforcing ring, but this step is also no longer necessary.

In addition, in the method of the present invention, productivity can be further improved by using split molds that can be connected in the longitudinal direction. This point will be explained in detail later.

〔Example〕

FIG. 2 shows an example of a split mold used in the present invention. 1st
The split mold 1 in the figure is the same as the one in Figure 2, so
FIG. 1 will also be used for explanation. This split mold 1 has the same cylindrical molding part 1 on both sides of the mountain and valley (uneven parts) molding part 1a divided in the circumferential direction.
It has a structure in which the core body 1C is held and fixed on the core body 1C, and when the core body 1C is extracted, each divided body of the molded part 1a can be moved inward in the radial direction, and after this movement, the cylindrical part 1b is extracted. This is done so that it can be removed from the mold. 1d and 1e are a pair of connecting means provided on one end surface and the other end surface of the core body 1C as necessary. This connection means has a plug 1d and a socket hole 1e, but is not limited thereto. Any material that can connect the split molds 1 while aligning their axes in the longitudinal direction may be used.

The following two methods can be considered for forming the fiber-wound layer 3 shown in FIG. 1 on the split mold 1. One method is to insert a single split mold or several split molds connected to each other as shown in Fig. 2 in place of the conventional mandrel, and split the molds while rotating them in a fixed position. Continuous fibers impregnated with resin (this can be either a fiber bundle or prepreg tape) are fed out from the eye of the Carere Sodji traverse, which reciprocates in the axial direction of the mold, and wound at a predetermined winding angle. This is a well-known method.

Another method is to use a winding machine 10 as shown in FIG.
This method is performed using The wrapping machine 10 has a main body 11
A rotating body 12 supported by a rotating body 12 and rotated by the force of a driving source (not shown) includes a supply bobbin 13a, a guide roll 13b,
A supply section 13 for resin-impregnated continuous fibers 5 consisting of an eye 13C and the like is provided, and a through hole 14 for passing the split mold 1 through the main body and the rotating body is provided concentrically with the pass line L along which the split mold runs. Although the fiber supply section 1 is shown in the figure, in reality, the fiber supply section 1
3 are provided at a plurality of locations on the rotating body 12 at fixed intervals in the circumferential direction. If at least two of these winding machines are used as a set, although the winding direction of the fibers is opposite, the split mold 1 can be moved along the horizontal or vertical pass line L (horizontal line shown in the figure).
The fiber-wound layer 3 can be formed by paying out the resin-impregnated fibers 5 from the supply section 13 that circulates around the split mold while traveling in the longitudinal direction without rotating upwards. This winding method is suitable for split types with pair of connecting means at both ends.
Since a plurality of molds can be sequentially connected in the longitudinal direction and flowed continuously on a pass line, and a connected winding layer can be continuously formed on the connected split molds, work efficiency is dramatically improved.

Furthermore, if the ratio between the rotational speed of the rotating body 120 and the traveling speed of the split mold 1 is kept constant, a constant winding angle can be maintained continuously.

Therefore, in the method of supplying fibers from Carrenoge traverse, there is no disturbance in the fiber orientation near both ends of the split mold, which is unavoidable due to turn winding of the fibers, and disturbance in fiber density at any cross section, which is impossible to avoid. There is no loss of materials and product quality is improved.

Next, after the fiber wrapping N3 is formed on the split mold 1 in this manner, the outer periphery of the peaks and troughs of N3 is covered with a rubber mold 2 having a forming surface 2a of the bellows peaks and troughs shown in FIG. 4. Before starting this operation, the fiber wrapping layer 3 formed on the connecting split molds is preferably cut over the entire circumference for each joining purpose of the split molds. Rubber mold 2 is used to bring the fibers that float up from the molding surface into close contact with the molding surface at the peaks and troughs of the bellows, but if the fibers of multiple uncured bellows tubes are connected, the fibers will become tense between the bellows. There may be cases where molding using a rubber mold does not work properly.

Furthermore, in order to allow the rubber mold to be inserted without any trouble, the connected split molds are preferably uncoupled individually or in units of several pieces after cutting the fibers.

FIG. 5 shows an example of an insertion jig for the rubber mold 2.

This insertion jig 20 has a main body 21 with a hole 22 having approximately the same diameter as the outer diameter of the rubber mold 2, and an annular groove 23 located in the middle of the large surface.
A small hole 24 is provided that communicates with the outside from the groove 23.The inside of 123 is evacuated from the small hole 24, and the diameter of the rubber mold 2 fitted into the opening of the groove 23 is expanded.Under this condition, the fiber-wrapped N3 is The molded split mold 1 is passed through the hole 22, and when the vacuum is released, the rubber mold 2 is placed over the surface to be molded.

After fitting the rubber mold 2, the split mold is removed from the jig together with the rubber mold, and a second fiber wrapping layer 4 is formed on the fiber wrapping layer 3 located outside both end surfaces of the rubber mold.

The winding work at this time is the same as that for layer 3, with the difference that layer 3 is mainly helical winding, whereas layer 3 is mainly hoop winding. It can be carried out in

Thereafter, the split mold 1 on which the fiber-wound layer 3.4 has been formed is covered with a pressing jig 30 as shown in FIG. The pressure jig shown in the figure consists of a main body 31 and a rubber mold 32 provided in the center hole of the main body. The rubber mold 32 may have a storage groove 33 for the rubber mold 2 on its inner surface, and the rubber mold 32 may be evacuated and fitted after expanding the diameter in the same way as the rubber mold 2, but the pressure jig used is not particularly limited to this. It's not something you can do.

Once the pressure jig 30 is covered, it is introduced into a heating furnace to harden the impregnated resin. After that, the jig 30 and the rubber mold 2 are removed in the reverse order, and the split mold 1 is further dismantled and demolded. The above work is completed, and an FRP bellows tube of approximately 100 mL is obtained.

〔effect〕

As described above, according to the present invention, the reinforcing parts at both ends of the bellows tube are formed directly on the unhardened bellows parts, so there is no need for fitting or bonding processes for the reinforcing ring, and there is no need for heat curing until completion. Only one process is required, and there is no need for a grinding process for fitting the reinforcing ring, which greatly improves work efficiency and enables mass production of FRP bellows tubes.

In particular, when winding fibers is carried out by connecting split molds, the effect of improving productivity is remarkable, and additional effects such as reducing material loss and further improving product quality are also obtained, making it possible to increase mass. In terms of degree, the contribution will be greater.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the method of the present invention, Fig. 2 is a perspective view showing an example of a split mold used in the invention, and Fig. 3 is a simplified perspective view showing an example of the fiber winding machine used. , 4th
5 is a partially cutaway perspective view showing an example of the rubber mold insertion jig, and FIG. 6 is a perspective view showing an example of the whole pressing jig. 1...Split mold, 1a...Mountain and valley forming part,
1b... Same cylindrical molded part, 1C... Core body,
1d, 1e...pair connection means, 2...
Rubber mold, 2a...Molding surface, 3.4...
Connection winding layer, 5...Resin-impregnated continuous fiber, 10
...Fiber wrapping machine, 20...Rubber mold insertion jig, 30...Overall pressure jig.

Claims (1)

[Claims] After winding the resin-impregnated continuous fiber at a predetermined winding angle on a split mold in which at least the molded portions of the peaks and valleys of the bellows are divided into a plurality of parts in the circumferential direction and combined so as to be retractable inward in the radial direction,
A rubber mold having a molding surface corresponding to the peaks and troughs of the bellows and the vicinity thereof is placed over the outer periphery of a part of the fiber-wrapped layer, and then the carriage moves reciprocally in the axial direction of the split mold while rotating the split mold in a fixed position. Either the resin-impregnated continuous fibers are supplied from the eye part of the traverse, or the resin-impregnated continuous fibers are supplied from the supply part that moves around the split mold while moving the split mold in the axial direction without rotating, and the resin-impregnated continuous fibers are supplied from the both end faces of the rubber mold. A second fiber wrapping layer for a reinforcing portion is formed on the outer periphery of the fiber wrapping layer located on the outer side, and then,
A fiber-reinforced plastic characterized by inserting this into a whole pressure jig, passing it through a heating furnace together with the jig to harden the impregnated resin, and then removing it from the pressure jig and demolding. A method of manufacturing a bellows tube made of stainless steel.