JPS58114919A - Manufacture of article through filament winding - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to a method of manufacturing an article by filament winding, and more particularly to a method of manufacturing an article by filament winding, and more particularly, by winding filament so that there are almost no voids in the article formed by winding the filament. It pertains to a method of manufacturing an article.

Current manufacturing methods for producing articles with high strength often employ filament winding methods. The filament winding process involves winding high-strength filaments disposed in a matrix of binder material around a mold or mandrel having the desired shape, i.e., a shape that approximately corresponds to the shape of the finished article, and then allowing the matrix to solidify. Contains. When manufacturing elongated articles such as airfoil blades by such filament winding methods, the mold and the filament are reciprocated relative to each other along the longitudinal axis of the mold, i.e., the winding axis. , it is common practice to wrap the filament around the mold. According to this method, a plurality of plies of filaments are placed on a mold, and the filaments of each ply are angularly (offset) from the winding shaft and the filaments of the adjacent ply. , a diverter or winding ring is used at the end of the mold or at the end of a segment of the mold to continuously reciprocate the filament along the mold, and directs the filament past the edge of the winding ring and onto its outer surface. By traversing the filament and reversing the direction of the relative longitudinal displacement of the filament and the mold, the various ends are formed once.

The filament bands of each ply intersect the filament bands of the previous ply at a particular crossing angle equal to twice the winding angle. During the wrapping of the filament, the plies of the upper filament band are crossed, as the load acting perpendicular to the surface of the mold may be insufficient to substantially compress the filament. This creates voids within the layer formed by the two plies. The surface of the article formed by winding the refilament becomes irregular due to such voids, the article formed by winding the filament becomes weak, and furthermore, the article formed by winding the filament becomes irregular. The actual shape of will no longer match the desired design shape.

The above-mentioned filament winding method, in which the filament band and the mold are relatively reciprocated in the longitudinal direction of the mold, and the filament band is wound around the rotating mold, was initially used to wind a cylindrical body by filament winding. It was also used to form regular geometric shapes such as spheres. When such regular geometric shapes are manufactured by the filament winding method, the filament essentially follows a geodesic path, i.e. the shortest distance between two mutually spaced points on the surface of the article. It is wrapped along the path to be used. However, when forming a complicated irregularly shaped object such as the airfoil blade of a large wind turbine with a curved and tapered shape by filament winding, it is necessary to use filament winding to maintain a constant winding angle. Often the filament must be rolled along a path other than a geodesic path, which imposes lateral loads on the filament band as the filament is rolled onto the mold or adjacent filament layer. This lateral loading of the filament band causes separation of the rovings within the filament band, which often creates voids due to separation of the rovings.

Since each filament lay intersects the previously laid filament ply, the void caused by the separation of the rovings is not filled by the filament fly laid over it.

As previously mentioned, the filaments are impregnated with a binder or adhesive, such as an epoxy resin, and the binder is solidified after the filament winding step. The 'voids' formed in the article by the crossing of the flies and the voids formed in the article by filament separation due to the filament being wound along a path other than the geodesic path are filled by the flow of binder. However, when the blades of a large wind turbine are formed by filament winding as described above, the filament content is relatively high (the binder content is relatively small) because of the need to improve the strength. Further, due to the capillary action and wicking action which tend to bring substantially all of the unsolidified binder into close contact with the roving, the binder does not flow as described above.

Accordingly, a primary object of the present invention is to provide a method for manufacturing articles by improved filament winding such that the formation of voids within the article is minimized. According to the invention, the voids in the filament cabinet caused by the filament being wrapped over a path other than the geodesic path are filled by the filaments of the ply wound over it! According to the invention, the above-mentioned object is to wrap all the flies of one layer in one direction, thereby eliminating the occurrence of ply crossings in one cabinet of assignment, and also to This is achieved by allowing the filaments to fill the voids formed in the underlying ply within that layer. Further, according to the present invention, arranging the filament around the mold causes the mold to which the filament is wrapped and the band of the filament wound around the mold to undergo reciprocating linear motion and reciprocating rotational motion, respectively. It can be obtained by According to such reciprocating linear motion and reciprocating rotational motion, the filament band is wrapped around the mold along the winding axis of the mold, and when the filament band reaches the end of the mold, its direction of movement is reversed and the filament band is wound around the mold along the winding axis. moves in a straight line in the opposite direction along. At about the same time as this reversal of the direction of movement of the filament band, the direction of relative rotation of the filament and mold is also reversed.

By simultaneously reversing the direction of linear movement of the filament band along the winding axis and the direction of rotational movement of the mold about the winding axis, each roving in an adjacent ply is wrapped around the mold at a constant winding angle. This ensures that filament crossings and resulting voids are eliminated. Also, by keeping the winding angle constant, the rovings of the upper ply can fill the voids created by the rovings of the lower ply.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

1 of the accompanying drawings, an article having a non-circular elongated cross-sectional shape is illustrated as being manufactured by the known filament winding process.

In this case the article is an elongated Aerofoil blade used in large wind turbines. The filament winding process is carried out in a winding machine 10 which includes a spindle 13 and on which the die 16 is mounted such that the die 16 rotates with the axis of rotation about the longitudinal axis or winding angle of the die. Implemented. The winding machine 10 includes a carriage or winding head 19 that reciprocates along the length of the winding machine by reciprocating linear motion along a track 22. The winding head 19 receives a plurality of continuous filaments (rovings) 25 of glass fiber from a suitable source (not shown), each filament being attached to a matrix in a manner well known in the art. The filaments are coated with a suitable binder, such as an epoxy resin or other suitable material, such that the filaments are collectively disposed within a binder. The filament is wrapped around the mold 16 as a band or a strand or bundle of rovings comprising one or more layers of rovings oriented parallel to each other. The airfoil blade formed by this method includes a plurality of wrapped volleys of filament. In this case rllJ
refers to a state in which the roving is continuously and completely laid on the am of the mold or on the adjacent inner layer. As shown, each turn is angularly offset relative to the winding axis of the mold 16, and thus orienting each turn at an angle to the winding axis means that the winding head 19 relative to the mold 16 is aligned with the longitudinal axis of the mold. The relative speed of the winding head to the rotational speed of the mold determines the angular direction of each turn. When winding the first or innermost fly shown in FIG. The mold 16 is rotated about its longitudinal axis while moving longitudinally from right to left in the figure.

As the winding head 19 approaches the turning section 30, an end turn 32 of the filament is placed. As the winding head 19 passes the end of the mold 16, the filament is captured by one or more spikes projecting from the edge of the diverter 30. The winding head 19 reverses its direction of movement after passing the deflection section 30, thereby winding the filament across the outer surface of the deflection section 30, after which the filament returns to the spike in which it was originally captured. It is captured by a number of spikes located at more distant locations. When the winding head 19 begins to move linearly in the opposite direction along the mold 16, an end 8B1# turn 37 is placed on the end turn 32 to intersect therewith. As the winding head 19 continuously moves linearly along the mold 16 from left to right in the figure while rotating the mold 16, a second ply of mutually spaced turns of filament is formed. The winding head 19 moves the mold 16 in the direction shown in FIG.
The winding head 1 moves linearly along the winding head 1.
When the direction of movement of 9 is reversed, a third fly is formed. It is understood that the roving turns of the third ply are generally parallel to and proximate to the turns of the first ply, and intersect therewith on the turns of the second ply. Good morning. By sliding the winding five heads in the same direction along the mold, each invasive ply is placed parallel to the ply that is placed diagonally to the mold. By successively repeating this process, a complete mausoleum of roving is placed on the mold in one piece of construction having a thickness of two plies.

Three plies are shown enlarged in FIGS. 2 and 3. Roving 40 represents a first ply wrapped onto mold 16 angularly offset from the winding axis of the mold. For purposes of explanation, assuming that FIG. 2 is taken in substantially the same direction as FIG. It can be seen that it is wrapped when moving in a straight line along the . The winding head 19 reaches the end of the mold 16 and turns toward its original position.
That is, when the direction of movement is changed from left to right, the ply containing the filament 45 is wedged. When the winding head 19 moves linearly in this direction along the mold 1-6 to its end, the winding head changes its direction and moves from the right in FIG. intersects the roving 40 and is parallel to the roving 40.
(Place a third ply containing rovings 50 in close proximity to this).

Rovings 40 and 45 as shown in FIG.
roving 45 cooperates with the surface of mold 16 to contact the edge of the band formed by roving 40 and mold 16.
A gap 55 is formed between the two parts. Similar voids are created by the intersection of each roving, such as the intersection of rovings 40 and 45, and many such voids are formed in one layer of a large article formed by traversing filaments. will be understood.

Considering that large articles formed by winding filaments contain a large number of such layers, 1
It can be seen that such voids are formed in such articles.

As mentioned in the description of the prior art herein, when an article with a complex shape is formed by filament winding, it is not always possible to wind the filament along a geodesic path. It is therefore necessary to wind the filament along a path other than a geodesic path, and as will be appreciated by those skilled in the art, such winding of the filament separates the filaments within a filament band from each other and causes the filaments within the band to Stresses are induced that form elongated voids. The gap in the band to be bent is the gap 5
As in case 5, winding the filament reduces the inherent strength of the article formed.

According to the present invention, the above-mentioned voids inherent in known filament winding processes are substantially eliminated by uniformly orienting all plies in ten layers of rovings. .

FIG. 4 depicts a winding machine substantially identical to that shown in FIG. As also shown in FIG. 4, the mold 16 is, for purposes of illustration, substantially in the shape of a neef oil blade. The mold 16 is connected to the rotating shaft 13
By reciprocating and linearly moving the winding head 19 while rotating it above, the binder-treated filament (low pink) is wound and pulled onto the mold. However, in contrast to the above-mentioned known filament winding method, in the method according to the invention, the winding head, and therefore the filament band, is reciprocated relative to the mold 16 in the longitudinal direction of the winding machine, while the winding is carried out. The mold 16 is caused to reciprocate and rotate with respect to the filament band that is not in use.

According to the invention, the reversal of the direction of rotation of the mold 16 takes place substantially simultaneously with the reversal of the direction of the linear movement of the winding head 19. In the fourth cause, the winding head 19 of the first ply moves from the right to the left in the track 2 in FIG.
The mold 16 is rotated in the direction of the arrow to attach the mold 16 to the mold 1 which is moving linearly along the arrow 2. When the winding head 19 reaches the left end in the drawing of the mold, the rovings are caught by the spikes provided at the direction changing part in the manner described above, the winding head and the mold change their respective directions of movement, and the mold moves in the direction of the arrow 65. , the winding head moves from left to right in FIG. 4, so that none of the turns of the second ply intersect the turns of the first ply. A second ply is wrapped onto the mold parallel to and aligned with the first ply. By continuing the process, the roving bands are arranged parallel to each other, thereby forming a complete filament layer having a thickness equal to that of one roving. Therefore, it can be seen that no crossing of filament bands occurs within one layer, and thus voids caused by crossing of filament bands are eliminated. It can also be seen that, according to the method according to the invention, a layer is formed whose thickness is equal to twice the diameter of the filament and whose turns are parallel to each other. Even if winding the filament along a path other than the geodesic path results in an intraband void, the filament winding will continue as the process continues with the rolls wound parallel to it. Pink easily fills the intraband voids.

The method according to the invention has various other advantages. For example, since the thickness of successive filament layers is equal to the diameter of one filament, a conventional filament winding method in which each layer has a thickness equal to twice the diameter of one filament and has a sieve structure as described above The thickness of the filament layer can be controlled to more precise dimensions than would otherwise be the case. The parallel plies of the top layer are brought into close contact with each other without excessive tension to provide further compressive forces (such excessive tension risks breaking the filaments and thus interrupting the winding process). Can be wrapped.

FIG. 5 shows a portion corresponding to the left end of the mold shown in FIG. 4 regarding another embodiment of the present invention. In this embodiment of FIG. 4, the wrapping is such that the rovings are captured on the deflection section so that the rovings are wrapped around the axis of rotation across the surface of the deflection section before the direction is reversed. Ru.

However, in the embodiment shown in FIG. 5, immediately after the roving is captured on the turning section, the roving is reversed parallel to the first ply and adjacent to the turn of the second ply. It is possible to wrap the second ply so that it is wrapped in the direction. This eliminates the placement of rovings around the axis of rotation across the surface of the redirection, thereby improving the economics of article manufacture.

In practicing the present invention, it will be appreciated that adjacent intestinal filaments may be parallel to each other, or may be angularly offset from each other. In order to eliminate the formation of voids in the article formed by winding the filaments, it is only necessary to form each layer from filaments that are parallel to each other. Adjacent 1 filaments may be angularly offset, for example, to meet the required strength requirements without creating voids within the article.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to such embodiments, and it is understood that various embodiments are possible within the scope of the present invention. It will be clear to those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a state in which an article is manufactured by a known filament winding method. FIG. 2 is an illustrative partial view showing a part of the article shown in FIG. 1 on an enlarged scale. FIG. 3 is an illustrative sectional view taken along line 3-3 of FIG. 2. Fourth! ! 1 is a perspective view similar to FIG. 1 showing an article being formed by the method according to the invention; FIG. FIG. 5 is a partial perspective view showing a portion of an article formed by filament winding according to another embodiment of the present invention. 10... Winding machine, 13... Rotating shaft. 16... type, 19... winding head, 22
...Truck, 25...Roving, 30...Direction change section. 32.37...End winding, 40,45.50...Roving, 55...Void Patent Applicant: United Chiknoroses Corporation

Claims (1)

[Claims] A method of manufacturing an article by filament winding comprising wrapping a band (25) of filament impregnated with an adhesive around a mold (16), the method comprising: Simultaneously with the reciprocating linear movement of the target, the mold (16) and the band (25) are caused to make a single reciprocating motion relative to each other, and the change in the direction of the relative rotational movement of the mold (16) and the band (25) is controlled by the mold (16) and the band (25). (16
) and said band (25) substantially simultaneously with the change in direction of the relative reciprocating linear motion of said band (25), whereby substantially all of the filaments deposited in one layer on said mold pass through said mold. A method characterized in that it is oriented in each direction uniformly with respect to an axis.