WO2018199365A1 - Method for manufacturing carbon fiber-reinforced composite material spring, and carbon fiber-reinforced composite material spring manufactured thereby - Google Patents

Abstract

A method for manufacturing a carbon fiber-reinforced composite material spring, according to the present invention, may comprise the steps of: forming a first carbon fiber layer by winding, around a mandrel, a carbon fiber prepreg that is gelled by impregnating a carbon fiber with a resin; forming a second carbon fiber layer by winding, on the first carbon fiber layer, a second carbon fiber prepreg of a knitted fabric shape that is gelled by impregnating a carbon fiber with a resin; forming a third carbon fiber layer by winding, on the second carbon fiber layer, a third carbon fiber prepreg of a knitted fabric shape that is gelled by impregnating a carbon fiber with a resin; obtaining a first spring material of a tubular shape by removing the mandrel when the first to third carbon fiber layers are partially cured; injecting the first spring material into a mold having a forming space of a helical shape; curing the first spring material into a third spring material of a helical shape by injecting high pressure air into a hollow of the first spring material inserted into the mold so that the first to third carbon fiber layers are expanded and integrated with each other; separating the cured third spring material of a helical shape from the mold; and producing a finished product of a carbon fiber-reinforced composite material spring by cutting the third spring material of a helical shape by a predetermined length.

Description

Carbon fiber reinforced composite spring production method and carbon fiber reinforced composite spring produced by the method

The present invention relates to a carbon fiber-reinforced composite spring, and more particularly, to manufacture a spring material using a gelled prepreg and a knitted prepreg produced by impregnating the carbon fiber with a resin, and then mold it. It relates to a carbon fiber-reinforced composite spring production method and a carbon fiber-reinforced composite spring produced by the manufacturing method thereof can be molded into a helical spring material to be added to.

In general, nanoparticles including carbon nanotubes (CNT) have excellent electrical conductivity, thermal conductivity, and strength, so that even if a small amount is added to the polymer, a nanocomposite material having much improved characteristics than the structure / functional properties of the original polymer can be obtained. In particular, research into the development of composite materials that have the improved physical properties required by adding CNT to various materials has been actively conducted in recent years.

However, since the CNT-containing composite material described above has a mechanical property of about 10 to 20% compared to the conventional micro fiber reinforced composite material, microfibers and CNTs are used to use the nanocomposite for structural and multifunctional use. Is inevitably bound to hybridize or significantly increase the amount of CNT added.

Further, as disclosed in Patent Document 1, a composite material containing CNTs is a lightweight high strength material, and many studies have been conducted for wide application in the aerospace and defense industries.

However, due to the low structural / functional properties of the polymer material, the thickness direction is weak, which hinders the wide application of the composite material, and the material properties database is insufficient, resulting in poor reliability and stability. Accordingly, many studies have been conducted to produce a structural composite material requiring high strength and high rigidity by impregnating a resin mixed with CNTs in carbon fiber.

The present invention is to solve the above-mentioned problems of the prior art, carbon fiber reinforced composite material spring that can improve the mechanical, thermal, electrical / electronic, chemical / physical and chemical properties of the spring produced by the carbon fiber reinforced composite material It is an object of the present invention to provide a carbon fiber-reinforced composite spring prepared by the manufacturing method and the manufacturing method thereof.

The present invention configured to achieve the above object is as follows. That is, the carbon fiber reinforced composite spring manufacturing method according to the present invention (a) carbon fiber impregnated with a CNT resin mixed in a ratio of 1 to 5 parts by weight of CNT (Carbon Nano Tube) with respect to 100 parts by weight of resin (gel) The first carbon fiber prepreg is wound around the mandrel, and the first carbon fiber prepreg is wound in a plurality of layers so as to have a thickness of 7/10 to 9/10 with respect to the diameter of the spring material to be manufactured. Forming a; (b) Impregnating a carbonized knitted second carbon fiber prepreg on the first carbon fiber layer by impregnating CNT resin mixed in carbon fiber at a ratio of 1 to 5 parts by weight of CNT (Carbon Nano Tube) to 100 parts by weight of resin. Winding the layer to form a second carbon fiber layer; (c) Carbon fiber knitted CNT resin impregnated with CNT resin mixed at a ratio of 1 to 5 parts by weight with respect to 100 parts by weight of resin, and a gelled knitted third carbon fiber prepreg on the second carbon fiber layer Winding the layer to form a third carbon fiber layer; (d) removing the mandrel during curing of the first to third carbon fiber layers formed through steps (a) to (c) to obtain a tubular first spring material; (e) Inner molds with helical grooves formed on the outer circumference and outer molds with helical grooves formed on the inner circumference corresponding to the first spring material obtained in step (d) are assembled into a mold having a helical shape space. step; (f) Injecting high-pressure air into the hollow of the first spring material introduced into the mold through the step (e), the first spring material is helical shape by expanding and integrating three first to third carbon fiber layers. Hardening to a third spring material; (g) separating the hardened helical third spring material from the mold through the step (f); And (h) cutting the helical shape of the third spring material separated from the mold in the step (g) to a predetermined length to complete the carbon fiber reinforced composite material spring.

In the step (a), step (b) and step (c) of the configuration according to the present invention as described above may be made of one selected from the epoxy resin, phenol resin, unsaturated polyester resin and vinyl ester resin as the thermosetting resin. have.

In addition, the first carbon fiber prepreg may be made of UD tape (Uni-Direction tape) in the step (a) of the configuration according to the present invention.

In the steps (b) and (c) of the configuration according to the present invention as described above, the carbon fiber is one carbon fiber selected from 1K carbon fiber, 3K carbon fiber, 6K carbon fiber, 12K carbon fiber and 24K carbon fiber Can be configured.

Carbon fiber reinforced composite spring according to the present invention is produced through the carbon fiber reinforced composite spring manufacturing method as described above.

On the other hand, the carbon fiber reinforced composite spring manufacturing method according to another embodiment of the present invention (A) carbon fiber impregnated CNT resin mixed in a ratio of 1 to 5 parts by weight of CNT (Carbon Nano Tube) to 100 parts by weight of resin The gel-formed first carbon fiber prepreg is wound around the mandrel, and the first carbon fiber prepreg is wound in a plurality of layers so as to have a thickness of 7/10 to 9/10 with respect to the diameter of the spring material to be manufactured. Forming a first carbon fiber layer forming a first carbon fiber layer; (B) Impregnating CNT resin mixed with carbon fiber at a ratio of 1 to 5 parts by weight of carbon nanotubes (CNT) to 100 parts by weight of resin, and gelling the second carbon fiber prepreg of a knitted shape onto a first carbon fiber layer. Winding the layer to form a second carbon fiber layer; (C) The carbon fiber knitted third carbon fiber prepreg was impregnated onto the second carbon fiber layer by impregnating CNT resin mixed with carbon fiber at a ratio of 1 to 5 parts by weight of carbon nanotubes (CNT) based on 100 parts by weight of the resin. Winding the layer to form a third carbon fiber layer; (D) removing the mandrel during curing of the first to third carbon fiber layers formed through steps (A) to (C) to obtain a tubular first spring material; (E) inserting the first spring material obtained in step (D) into a mold having a rod-shaped molding space; (F) While injecting high pressure air into the hollow of the first spring material introduced into the mold through the step (E), the first spring material is tubular by expanding and integrating three first to third carbon fiber layers. Hardening to a second spring material; (G) separating the tubular second spring material cured through the step (F) from the mold; (H) forming a tubular second spring material separated from the mold through the step (G) into a helical third spring material; And (I) cutting the third spring material formed into a helical shape through the step (H) to a predetermined length and completing the carbon fiber reinforced composite material spring.

In the steps (A), (B) and (C) of the configuration according to the present invention as described above, the resin may be one selected from epoxy resins, phenol resins, unsaturated polyester resins and vinyl ester resins as thermosetting resins. have.

In addition, the first carbon fiber prepreg may be made of a UD tape (Uni-Direction tape) in the step (A) of the configuration according to the present invention.

In addition, the carbon fiber in the step (B) and step (C) of the configuration according to the present invention will be composed of one carbon fiber selected from 1K carbon fiber, 3K carbon fiber, 6K carbon fiber, 12K carbon fiber and 24K carbon fiber Can be.

Carbon fiber reinforced composite spring according to another embodiment of the present invention is manufactured through the carbon fiber reinforced composite spring manufacturing method according to another embodiment as described above.

According to the technique of the present invention, the spring of the carbon fiber-reinforced composite material is molded into the mold after the spring material is formed by using the carbonized carbon fiber prepreg and the knitted carbon fiber prepreg manufactured by impregnating the resin into the carbon fiber. It is formed into a helical spring material to form a carbon fiber-reinforced composite spring, which has low density, high tensile strength and tensile elasticity, strong resistance to fatigue / strength, and excellent mechanical and wear characteristics. .

In addition, according to the technique of the present invention, the spring of the carbon fiber reinforced composite material has a small linear expansion coefficient, good dimensional stability, strong mechanical properties by heat, and strong resistance to fracture / deterioration, that is, mechanical properties are destroyed by heat. It has a thermal property of low thermal conductivity at extremely low temperatures.

In addition, the technology according to the present invention has the electrical and electronic properties that the spring of the carbon fiber reinforced composite material is also excellent in electrical conductivity (rate), electromagnetic wave prevention, X-ray transmittance.

In addition, the technique according to the present invention has a chemical physicochemical property that the spring of the carbon fiber reinforced composite material is chemically stable and excellent in resistance to various solvents such as acid and alkali.

1 is a block diagram showing the manufacturing process of the carbon fiber reinforced composite spring according to the first embodiment of the present invention.

Figure 2 is a perspective configuration showing the state before the winding of the first carbon fiber prepreg on the mandrel in the manufacturing process of the carbon fiber reinforced composite spring according to the first embodiment of the present invention.

Figure 3 is a perspective configuration showing the state before the winding of the second carbon fiber prepreg on the first carbon fiber layer on the mandrel in the manufacturing process of the carbon fiber reinforced composite spring according to the first embodiment of the present invention.

Figure 4 is a perspective configuration showing the state before the winding of the third carbon fiber prepreg to the second carbon fiber layer in the manufacturing process of the carbon fiber reinforced composite spring according to the first embodiment of the present invention.

Figure 5 is a perspective configuration showing the separation of the mandrel from the first spring material consisting of the first to third carbon fiber layer in the process of manufacturing the carbon fiber reinforced composite material spring according to the first embodiment of the present invention.

Figure 6 is a cross-sectional view showing a cross-section of the first spring material in the manufacturing process of the carbon fiber reinforced composite spring according to the first embodiment of the present invention.

Figure 7 is a cross-sectional view showing a state in which the first spring material is injected into the mold of the helical shape in the manufacturing process of the carbon fiber reinforced composite spring according to the first embodiment of the present invention.

FIG. 8 is a view illustrating a third spring material in a state of being hardened in a spring shape through a helical mold in a process of manufacturing a carbon fiber reinforced composite spring according to a first embodiment of the present invention. FIG.

Figure 9 is a block diagram showing the manufacturing process of the carbon fiber reinforced composite spring according to the second embodiment of the present invention.

10 is a schematic diagram showing a process of molding by injecting a high-pressure air into the hollow of the spring material in which the mandrel is removed in the process of the carbon fiber reinforced composite material spring according to the second embodiment of the present invention.

The best method for producing a carbon fiber reinforced composite spring according to the present invention is to impregnate the carbon fiber resin to the carbon fiber in a state in which the first carbon fiber layer is formed by winding the gelled first carbon fiber prepreg on the mandrel Impregnated to form a second carbon fiber layer and a third carbon fiber layer by winding the second carbon fiber prepreg and the third carbon fiber prepreg of the knitted shape on the first carbon fiber layer in order to cure the first to third carbon fiber layers. After removing the mandrel to obtain a tubular first spring material, the first spring material is put into a mold having a helical shape space, and high pressure air is injected into the hollow of the first spring material. Expanding and integrating the third carbon fiber layer so that the first spring material is cured into a helical third spring material, and the cured helical third thread After separating the spring material from the mold, the helical third spring material is cut to a set length to complete the carbon fiber reinforced composite spring.

Hereinafter, a preferred embodiment of a carbon fiber reinforced composite spring prepared by the method and a method of manufacturing the carbon fiber reinforced composite spring according to the present invention will be described in detail with reference to the accompanying drawings.

First, the carbon fiber reinforced composite spring according to the present invention can be manufactured by two methods, most of the manufacturing process is the same and the process of molding the shape of the carbon fiber reinforced composite spring in the mold and the helical shape Different embodiments of the present invention show a difference in the process of forming the helical shape of the spring material formed in a separate molding process. The two carbon fiber reinforced composite spring manufacturing method as described above will be described in detail.

1 is a block diagram showing the manufacturing process of the carbon fiber reinforced composite spring according to the first embodiment of the present invention, Figure 2 is a mandrel in the manufacturing process of the carbon fiber reinforced composite spring according to the first embodiment of the present invention 3 is a perspective view showing a pre-wound state of the first carbon fiber prepreg, FIG. 3 is a second carbon fiber prep on the first carbon fiber layer on the mandrel during the manufacturing process of the carbon fiber reinforced composite spring according to the first embodiment of the present invention; 4 is a perspective view showing the pre-winding state of the leg, Figure 4 shows the pre-winding state of the third carbon fiber prepreg to the second carbon fiber layer in the process of manufacturing the carbon fiber reinforced composite spring according to the first embodiment of the present invention 5 is a perspective view of the mandrel from the first spring material consisting of the first to third carbon fiber layer in the manufacturing process of the carbon fiber reinforced composite material spring according to the first embodiment of the present invention 6 is a cross-sectional configuration view showing a cross-section of the first spring material in the manufacturing process of the carbon fiber reinforced composite spring according to the first embodiment of the present invention, Figure 7 is a first embodiment of the present invention Sectional view showing a state in which the first spring material is injected into the helical shape mold in the manufacturing process of the carbon fiber reinforced composite material spring according to FIG. 8 is a cross-sectional view of the carbon fiber reinforced composite material spring according to the first embodiment In the manufacturing process is a configuration diagram showing a third spring material in the state of the spring hardened through the helical mold.

1 to 8, the process of manufacturing the carbon fiber-reinforced composite spring according to the first embodiment of the present invention will be described as shown in (a) the first carbonized gel (gel) by impregnating the resin to the carbon fiber The process of forming the first carbon fiber layer 21a by winding the fiber prepreg 21 on the mandrel 11 (S100), (b) impregnating a carbon fiber with a resin to form a gelled knit second carbon fiber prepreg ( The process of forming a second carbon fiber layer 22a by winding 22) on the first carbon fiber layer 21a (S110), and (c) a third carbon fiber prepreg of a knitted shape, gelled by impregnating carbon fiber with resin ) Is wound on the second carbon fiber layer 22a to form a third carbon fiber layer 23a (S120), and the first to third carbons formed through (d) step (a) to step (c) Removing the mandrel 11 during curing of the fibrous layers 21a, 22a, and 23a to obtain a tubular first spring material 20a (S130), (e) step (d) The inner spring 31 of which the helical groove 31a is formed on the outer circumferential surface of the first spring material 20a obtained therefrom and the outer mold 32 having the helical groove 32a formed on the inner circumferential surface are assembled to form a helical shape space. High pressure air in the hollow (20) of the first spring material 20a introduced into the mold (31, 32) through the process (S140), (f) step (e) of the branch (31, 32) Process to expand the first to third carbon fiber layers (21a, 22a, 23a) of the three layers while integrating with each other to integrate the first spring material (20a) into a helical third spring material (20) (S150), (g) in the process (S160) and (h) step (g) of separating the third spring material 20 of the helical shape cured through the step (f) process from the mold (31, 32) Cutting the helical shape third spring material 20 separated from the mold (31, 32) to a set length to complete the carbon fiber reinforced composite material spring It consists of a structure of a forward (S170).

In other words, the technique of manufacturing a carbon fiber reinforced composite spring according to the first embodiment of the present invention configured as described above, first, as shown in Figs. The first carbon fiber prepreg 21 is wound around the mandrel 11 to form a first carbon fiber layer 21a (S100). At this time, the resin impregnated in the carbon fiber refers to the CNT resin mixed in a ratio of 1 to 5 parts by weight of carbon nanotubes (CNT) with respect to 100 parts by weight of the resin.

On the other hand, as described above, the carbon fiber is impregnated with CNT resin mixed in a ratio of 1 to 5 parts by weight of carbon nanotubes (CNT) to 100 parts by weight of resin to mandrel the first carbonized fiber prepreg 21, When the first carbon fiber layer 21a is wound around the first carbon fiber layer 21a, the first carbon fiber prep is formed to have a diameter of 7/10 to 9/10 of the diameter of the spring material 20a to be manufactured. The leg 21 is wound up and formed in several layers.

Next, as described above, after the first carbon fiber prepreg 21 is wound around the mandrel 11 to form the first carbon fiber layer 21a, a resin is added to the carbon fiber as shown in FIGS. 1 and 3. The impregnated gel-like knitted second carbon fiber prepreg 22 is wound on the first carbon fiber layer 21a to form a second carbon fiber layer 22a (S110). At this time, the resin impregnated in the carbon fiber refers to the CNT resin mixed in a ratio of 1 to 5 parts by weight of carbon nanotubes (CNT) with respect to 100 parts by weight of the resin.

As described above, the second carbon fiber prepreg 22 having a gelled knit shape is impregnated by impregnating CNT resin mixed in carbon fiber at a ratio of 1 to 5 parts by weight of carbon nanotubes (CNT) with respect to 100 parts by weight of the resin. When the second carbon fiber layer 22a is formed on the carbon fiber layer 21a, the second carbon fiber prepreg 22 is wound in a single layer to form the second carbon fiber layer 22a.

Next, as described above, after the second carbon fiber prepreg 22 is wound on the first carbon fiber layer 21a to form the second carbon fiber layer 22a, the carbon fiber is shown in FIGS. 1 and 4. The third carbon fiber layer 23a is formed by winding the gelled knitted third carbon fiber prepreg 23 on the second carbon fiber layer 22a by impregnating the resin (S120). At this time, the resin impregnated in the carbon fiber refers to the CNT resin mixed in a ratio of 1 to 5 parts by weight of carbon nanotubes (CNT) with respect to 100 parts by weight of the resin.

As described above, the third carbon fiber prepreg 23 having a gelled knit shape is impregnated by impregnating CNT resin mixed in carbon fiber at a ratio of 1 to 5 parts by weight of carbon nanotubes (CNT) with respect to 100 parts by weight of the resin. When the third carbon fiber layer 23a is formed on the carbon fiber layer 22a, the third carbon fiber prepreg 23 is wound in a single layer to form the third carbon fiber layer 23a.

Next, as described above, after the third carbon fiber prepreg 23 is wound on the second carbon fiber layer 22a to form the third carbon fiber layer 23a, as shown in FIGS. 1, 5, and 6. As described above, when the first carbon fiber layer 21a, the second carbon fiber layer 22a, and the third carbon fiber layer 23a are hardened, the mandrel 11 is removed to obtain a tubular first spring material 20a (S130). .

Meanwhile, as described above, when the mandrel 11 is removed from the first carbon fiber layer 21a when the first carbon fiber layer 21a, the second carbon fiber layer 22a, and the third carbon fiber layer 23a are cured, the first When the carbon fiber layer 21a is completely cured, it is difficult to separate the mandrel 11 from the first carbon fiber layer 21a. Therefore, when the carbon fiber layer 21a is hardened to some extent and the tubular shape is maintained, the mandrel (mandrel) is removed from the first carbon fiber layer 21a. It would be better to remove 11).

Next, as described above, when the first carbon fiber layer 21a, the second carbon fiber layer 22a, and the third carbon fiber layer 23a are hardened, the mandrel 11 is removed to form a tubular first spring material 20a. After obtaining the first spring material 20a as shown in Figures 1 and 7 is injected into the mold (31, 32) having a helical shape of the molding space (S140).

In the process as described above, the molds 31 and 32 having a helical shape space have a helical groove on the inner mold 31 and an inner circumferential surface in which the helical groove 31a is formed on the outer circumferential surface corresponding to the first spring material 20a. The outer mold 32 having the 32a) formed thereon is assembled to form a shape having a helical shape molding space.

Next, as described above, after the first spring material 20a is introduced into the molds 31 and 32 having the helical shape space, the first spring material 20a is illustrated in FIGS. 1 and 7. The first spring material 20a is a helical third spring material 20 by expanding and integrating the first to third carbon fiber layers 21a, 22a, and 23a while injecting high pressure air into the hollow 20c. To be cured to (S150).

When the high-pressure air is injected into the hollow 20c of the first spring material 20a fixed and inserted into the molds 31 and 32 having the helical shape space in the above-described process, the first spring material 20a While there is no change in the outer diameter, the hollow 20c of the first spring material 20a is expanded while the first to third carbon fiber layers 21a, 22a, and 23a are integrated together.

In other words, the process as described above is the second carbon line oil layer (22a) and the third carbon fiber layer to the inner diameter surface of the first carbon fiber layer (21a) of the hollow 20c of the first spring material (20a) is a high pressure air pressure Since the pressure is applied in the (23a) direction, the first to third carbon fiber layers 21a, 22a, and 23a are mutually integrated through the resin.

On the other hand, in the state that the impregnated CNT resin is not completely cured as described above, the first spring material 20a is introduced into the molds 31 and 32 so that high-pressure air is blown out of the first spring material 20a. 20c) is hardened in the middle of forming in the form of a spring.

Next, as described above, the high-pressure air is injected into the hollow 20c of the first spring material 20a to harden the third spring material 20 having a helical shape, and then shown in FIGS. 1 and 8. As described above, the hardened helical third spring material 20 is separated from the molds 31 and 32 (S160).

When the helical third spring material 20 is separated from the molds 31 and 32, as in the above-described process, the first spring material 20 a is completely helical in the molds 31 and 32. It may be more preferable to separate in the state of being molded into a third spring material 20 and cured.

Next, the helical shape of the third spring material 20, which has been cured as described above, is separated from the molds 31 and 32, and then the helical shape of the third spring material, as shown in FIGS. By cutting 20 to a set length, the carbon fiber reinforced composite material spring to be manufactured in the present invention is completed.

The carbon fiber-reinforced composite spring produced through the process as described above has a lower density than the metal, high tensile strength and tensile elasticity, strong resistance to fatigue strength, and excellent mechanical and wear characteristics. There is this.

Hereinafter, the carbon fiber reinforced composite spring according to the first embodiment of the present invention will be described in detail.

As shown in Figure 1 and 2 to prepare a gelled first carbon fiber prepreg 21 by impregnating a resin (thermosetting resin or thermoplastic resin) to the carbon fiber for a predetermined time through step (a) process (S100) and This is wound around the rod-shaped mandrel 11 to a uniform thickness to form a first carbon fiber layer 21a. In this case, the length of the first carbon fiber layer 21a formed by the first carbon fiber prepreg 21 may vary depending on the length of the carbon fiber reinforced composite material spring to be manufactured.

The first carbon fiber prepreg 21 wound around the mandrel 11 to form the first carbon fiber layer 21 a as in step (a) (S100) is a UD tape (Uni-Direction tape). The first carbon fiber prepreg 21 is wound in a plurality of layers to form a first carbon fiber layer 21a until it is 7/10 to 9/10 diameter with respect to the diameter of the first spring material 20a.

And, the yarn (filament) is the initial product of the carbon fiber as in the step (a) step (S100) described above, one strand of carbon fiber is 1K carbon fiber, 3K carbon fiber, 6K carbon fiber, 12K carbon fiber and 24K carbon fiber One of the selected carbon fibers is used.

Meanwhile, as described above, after forming the first carbon fiber layer 21a by winding the first carbon fiber prepreg 21 gelled on the mandrel 11 to a uniform thickness, as shown in FIGS. 1 and 3. The second carbon fiber layer was wound by winding the second carbon fiber prepreg 22 having a gelled knit shape by impregnating carbon fibers with a thermosetting resin or a thermoplastic resin on the first carbon fiber layer 21a through step (b). 22a).

The length of the second carbon fiber prepreg 22 forming the second carbon fiber layer 22a in the step (b) process (S110) as described above is shown in FIG. 3 of the first carbon fiber layer 21a. The second carbon fiber layer 22a is formed of a single layer when the second carbon fiber prepreg 22 is wound on the first carbon fiber layer 21a and formed to have a length corresponding to the circumference.

Subsequently, as illustrated in FIGS. 1 and 4, the third carbon of the knitted carbon shape is formed by impregnating the carbon fiber with the thermosetting or thermosetting resin on the second carbon fiber layer 22a through the step (c) (S120). The fiber prepreg 23 is wound to form a third carbon fiber layer 23a. The length of the third carbon fiber prepreg 23 is the length corresponding to the circumference of the second carbon fiber layer 22a as shown in FIG. 6, the third carbon fiber layer 23a is formed of a single layer as shown in FIG. 6.

In other words, each of the second carbon fiber prepreg 22 forming the second carbon fiber layer 22a and the third carbon fiber prepreg 23 forming the third carbon fiber layer 23a may be the first carbon fiber. Unlike the first carbon fiber layer 21a, in which the prepreg 21 is formed by winding several layers, the prepreg 21 is formed in a single layer structure formed by winding in one layer. At this time, the second carbon fiber prepreg 22 and the third carbon fiber prepreg 23 may be different depending on the characteristics of the carbon fiber-reinforced composite spring to be manufactured or the like.

Meanwhile, the gelled first carbon fiber prepreg 21, the knitted second carbon fiber prepreg 22, and the third carbon fiber prepreg 23 wound on the mandrel 11 in the above-described process are used. As the constituent resin, any one selected from an epoxy resin, a phenol resin, an unsaturated polyester resin, and a vinyl ester resin may be used among thermosetting resins.

The resin constituting the first carbon fiber prepreg 21, the second carbon fiber prepreg 22, and the third carbon fiber prepreg 23 is 1 to 5 parts by weight of CNT (Carbon) based on 100 parts by weight of the resin. By adding Nano Tube, adhesive strength is improved by 30% or more than general epoxy resin, and spring elasticity is increased by 20% or more. That is, the resin constituting the first carbon fiber prepreg 21, the second carbon fiber prepreg 22, and the third carbon fiber prepreg 23 is in the ratio of 1 to 5 parts by weight of CNTs relative to 100 parts by weight of the resin. It may be referred to as a mixed composition CNT resin.

As described above, the first carbon fiber prepreg 21 gelled on the mandrel 11, the second carbon fiber prepreg 22, and the third carbon fiber prepreg 23 are sequentially wound to form the first to third carbons. After the fiber layers 21a, 22a, and 23a are formed, a predetermined time has elapsed to form the first carbon fiber prepreg 21 and the second carbon fiber prepreg constituting the first to third carbon fiber layers 21a, 22a, and 23a. When the 22 and the third carbon fiber prepreg 23 is hardened to some extent, the mandrel 11 is removed as shown in FIGS. 1, 5 and 6 through the step (d) (S130) of the present invention. The tubular first spring material 20a for molding the carbon fiber reinforced composite material spring is obtained.

In addition, the first spring material 20a obtained through the steps (a) to (d) as described above is formed in the helical shape through the step (e) process S140 as shown in FIG. 1. After the injection into the mold (31, 32) having a high pressure air is injected into the hollow (20c) of the first spring material (20a) through the step (f) process (S150) as shown in Figure 1 and 7 The first to third carbon fiber layers 21a, 22a, and 23a of the three layers are expanded to be in close contact with the molding spaces of the molds 31 and 32, respectively, and are integrated with each other so that the first spring material 20a is a helical third spring. The material 20 is to be cured.

In the above description that the inner mold 31 and the outer mold 32 are vertically separated as an example, the present invention is not limited thereto, and two or more molds may be separated and coupled in a vertical or horizontal direction. In addition, the third spring material 20 formed in the inner mold 31 and the outer mold 32 may be deformed to fit the use of the spring to be manufactured other than the circle or square. To this end, a helical groove 31a is formed on the outer circumferential surface of the inner mold 31, and a helical groove 32a is formed on the inner circumferential surface of the outer mold 32 so that the inner mold 31 and the outer mold 32 are mutually assembled. In this state, a helical space is provided inside the mold.

In addition, as described above, in order to secure the time required when the first spring material 20a is molded into the helical shape of the third spring material 20, the molds 31 and 32 may be separately heated or cooled. It may be provided.

As described above, the helical third spring material 20 cured through the step (f) process (S150) as described above with respect to the mold (31) through the step (g) process (S160) as shown in FIGS. 1 and 8. , 32) and then cut the helical shape of the third spring material 20 to the length set according to the purpose through the step (h) process (S170) as shown in Figure 1 to complete the carbon fiber reinforced composite material spring do.

Figure 9 is a block diagram showing the manufacturing process of the carbon fiber reinforced composite spring according to the second embodiment of the present invention, Figure 10 is a mandrel removed in the process of the carbon fiber reinforced composite spring according to the second embodiment of the present invention It is a schematic diagram showing the process of molding by injecting a high pressure air into the hollow of the spring material.

9 and 10, the same process as the embodiment of FIGS. 1 to 8 will be described with reference to FIGS. 1 to 6 and 8, and FIGS. 1 to 8 will be described. Processes different from those of the embodiment will be described with reference to FIGS. 9 and 10.

9 and 2, first, impregnated carbon fibers with a thermosetting or thermoplastic resin for a predetermined time through step (A) (S200) to prepare a gelled first carbon fiber prepreg 11, and The first carbon fiber layer 21 a is wound around the rod-shaped mandrel 11 with a uniform thickness. In this case, the length of the first carbon fiber layer 21a formed by the first carbon fiber prepreg 21 may vary depending on the length of the carbon fiber reinforced composite material spring to be manufactured.

As described above, the first carbon fiber prepreg 21 wound around the mandrel 11 to form the first carbon fiber layer 21a is made of UD tape and has a diameter of the carbon fiber reinforced composite spring material to be manufactured. It is desirable to have a thickness of 7/10 to 9/10.

Here, the initial product of the above-described carbon fiber (filament) of the fiber (filament) one strand of carbon fiber is one carbon fiber selected from 1K carbon fiber, 3K carbon fiber, 6K carbon fiber, 12K carbon fiber, 24K carbon fiber.

As described above, after the first carbon fiber prepreg 21 gelled on the mandrel 11 is wound to a uniform thickness to form the first carbon fiber layer 21a, step (B) as shown in FIGS. 9 and 3. By impregnating carbon fibers with a thermosetting or thermoplastic resin on the first carbon fiber layer 21a through the process (S210), the second carbon fiber layer 22a is formed by winding the gelled knit second carbon fiber prepreg 22. The length of the second carbon fiber prepreg 22 wound on the first carbon fiber layer 21a is formed to have a length corresponding to the circumference of the first carbon fiber layer 21a as shown in FIG. The first carbon fiber layer 22a is made of a single layer.

Subsequently, once again, as illustrated in FIGS. 9 and 4, the third carbon fiber prepreg of the knitted shape gelled by impregnating a thermosetting resin to the carbon fiber on the second carbon fiber layer 22a through the step (C) process S120. The legs 23 are wound to form a third carbon fiber layer 23a, and the length of the third carbon fiber prepreg 23 is formed to a length corresponding to the circumference of the second carbon fiber layer 22a as shown in FIG. As a result, as shown in FIG. 6, the third carbon fiber layer 23a is formed as a single layer.

In other words, each of the second carbon fiber prepreg 22 forming the second carbon fiber layer 22a and the third carbon fiber prepreg 23 forming the third carbon fiber layer 23a may be the first carbon fiber. Unlike the first carbon fiber layer 21a, in which the prepreg 21 is formed by winding several layers, the prepreg 21 is formed of a single layer wound and formed in one layer. In addition, the second carbon fiber prepreg 22 and the third carbon fiber prepreg 23 may vary depending on the characteristics of the carbon fiber-reinforced composite spring to be manufactured or the like.

Here, the resin constituting the gelled first carbon fiber prepreg 21 wound on the mandrel 11, the second carbon fiber prepreg 22 and the third carbon fiber prepreg 23 having a knitted shape are thermosetting. It is preferable that resin is used. In this case, any one selected from an epoxy resin, a phenol resin, an unsaturated polyester resin, and a vinyl ester resin may be used as the thermosetting resin.

In addition, the resin constituting the above-described first carbon fiber prepreg 21, second carbon fiber prepreg 22, and third carbon fiber prepreg 23 is 1 to 5 parts by weight of CNTs based on 100 parts by weight of the resin. By adding, the adhesive strength is improved by 30% or more than the general epoxy resin, and the elastic modulus of the spring is increased by 20% or more. That is, the resin constituting the first carbon fiber prepreg 21 and the second and third carbon fiber prepregs 22 and 23 is the number of CNTs mixed and mixed at a ratio of 1 to 5 parts by weight of CNTs relative to 100 parts by weight of the resin. It can be called.

As described above, the first carbon fiber prepreg 21 gelled on the mandrel 11, the second carbon fiber prepreg 22, and the third carbon fiber prepreg 23 are sequentially wound to form the first to third carbons. The first carbon fiber prepreg 21 and the second carbon fiber prepreg constituting each of the first to third carbon fiber layers 21a, 22a, and 23a after a predetermined time has elapsed after the fiber layers 21a, 22a and 23a are formed. When the 22 and the third carbon fiber prepreg 23 is partially cured, the carbon according to the present invention is removed by removing the mandrel 11 through the step S230 as shown in FIGS. 9, 5, and 6. A tubular first spring material 20a for molding the fiber reinforced composite spring can be obtained.

Then, the first spring material (20a) obtained through the above process as shown in Figure 9 and Figure 10 and the mold (33, 34) having a rod-shaped forming space through the step (E) step (S240). After the addition, the high-pressure air is injected into the hollow 20c of the first spring material 20a through the step (F) process (S250) to form the first to third carbon fiber layers 21a, 22a, and 23a. ) Are expanded so as to be in close contact with the molding spaces of the molds 33 and 34, and are integrated with each other so that the first spring material 20a is cured into a tubular second spring material 20b. .

In the above, the upper mold 33 and the lower mold 34 have been described as an example of separating up and down, but the present invention is not limited thereto, and two or more molds may be separated and combined up, down, front, rear, left, and right. In addition, the second spring material 20b formed in the molds 33 and 34 may be deformed to fit the use of a spring to be manufactured in addition to a circle or a square.

In addition, in order to secure a time required when the first spring material 20a as described above is molded into the tubular second spring material 20b, the molds 33 and 34 are provided with a separate heating device or a cooling device. Or the like.

Then, as shown in FIG. 9, the tubular second spring material 20b is separated from the mold 31. 32 through step G), step S260, and then, step H, step S270). After the cured tubular second spring material 20b is formed into a helical third spring material 20 through a separate process, the helical third spring is formed through step (I) (S280). The material 20 is cut to a length set according to the use to complete the carbon fiber reinforced composite material spring to be manufactured in the present invention.

In the above embodiment, only the carbon fiber as the fiber impregnated with the thermosetting resin has been described as an example, but the present invention is not limited thereto and at least one selected from carbon fiber, glass fiber, aramid fiber, high toughness PE fiber, acrylic fiber and nylon fiber. Can be used.

In addition, the amount of CNT added to the carbon fiber impregnated in the thermosetting resin also uses carbon fibers, glass fibers, aramid fibers, high toughness PE fibers, acrylic fibers, and nylon fibers in place of the carbon fibers as described above. can be changed.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above-described embodiments, which can be variously modified and modified by those skilled in the art to which the present invention pertains. Modifications are possible. Accordingly, the spirit of the present invention should be understood only by the claims set forth below, and all equivalent or equivalent modifications thereof will belong to the scope of the present invention.

The carbon fiber-reinforced composite spring produced by the manufacturing method according to the present invention has a low density, high tensile strength and high tensile elasticity, as well as strong resistance to fatigue strength, mechanical properties excellent in wear and lubricity compared to metals. It can be used as a spring to absorb the shock generated when driving a train or car.

On the other hand, the technique according to the present invention as described above is a mechanical element through a feature that prevents the mechanical properties are destroyed by heat because the linear expansion coefficient is small, the dimensional stability is good, and the mechanical properties due to heat and the resistance to fracture deterioration is strong Field, electrical conductivity (rate) and excellent in the electromagnetic wave prevention and X-ray transmittance, it can be used in various fields in the electric and electronic fields.

In addition, the technology according to the present invention can be utilized in a variety of chemical fields through the chemical physicochemical properties that the spring of the carbon fiber reinforced composite material is chemically stable and excellent resistance to various solvents such as acid and alkali.

Claims (10)

1. (a) Impregnating CNT resin mixed in carbon fiber at a ratio of 1 to 5 parts by weight of CNT (Carbon Nano Tube) with respect to 100 parts by weight of resin to form a gelled first carbon fiber prepreg wound on a mandrel Forming a first carbon fiber layer by winding the first carbon fiber prepreg in a plurality of layers so as to have a thickness of 7/10 to 9/10 with respect to the diameter of the spring material to be formed;

   (b) Impregnating a carbonized knitted second carbon fiber prepreg on the first carbon fiber layer by impregnating CNT resin mixed in carbon fiber at a ratio of 1 to 5 parts by weight of CNT (Carbon Nano Tube) to 100 parts by weight of resin. Winding the layer to form a second carbon fiber layer;

   (c) Carbon fiber knitted CNT resin impregnated with CNT resin mixed at a ratio of 1 to 5 parts by weight with respect to 100 parts by weight of resin, and a gelled knitted third carbon fiber prepreg on the second carbon fiber layer Winding the layer to form a third carbon fiber layer;

   (d) removing the mandrel during curing of the first to third carbon fiber layers formed through steps (a) to (c) to obtain a tubular first spring material;

   (e) Inner molds with helical grooves formed on the outer circumference and outer molds with helical grooves formed on the inner circumference corresponding to the first spring material obtained in step (d) are assembled into a mold having a helical shape space. step;

   (f) Injecting high-pressure air into the hollow of the first spring material introduced into the mold through the step (e), the first spring material is helical shape by expanding and integrating three first to third carbon fiber layers. Hardening to a third spring material;

   (g) separating the hardened helical third spring material from the mold through the step (f); And

   (h) cutting the helical shape of the third spring material separated from the mold in the step (g) to a predetermined length, the carbon fiber reinforced composite spring manufacturing method comprising the step of completing the carbon fiber reinforced composite material spring.
2. According to claim 1, wherein the resin in the step (a), step (b) and step (c) is a thermosetting resin, characterized in that selected from one of the epoxy resin, phenol resin, unsaturated polyester resin and vinyl ester resin. Carbon fiber reinforced composite spring manufacturing method.
3. The method of claim 1, wherein the first carbon fiber prepreg is a UD tape (Uni-Direction tape) in the step (a).
4. According to claim 1, wherein the carbon fibers in the step (b) and step (c) is composed of one carbon fiber selected from 1K carbon fiber, 3K carbon fiber, 6K carbon fiber, 12K carbon fiber and 24K carbon fiber Carbon fiber reinforced composite material spring manufacturing method characterized in that.
5. Carbon fiber reinforced composite spring prepared by the carbon fiber reinforced composite spring manufacturing method of any one of claims 1 to 4.
6. (A) Impregnating CNT resin mixed in carbon fiber at a ratio of 1 to 5 parts by weight of CNT (Carbon Nano Tube) to 100 parts by weight of resin to form a gelled first carbon fiber prepreg wound on a mandrel Forming a first carbon fiber layer forming a first carbon fiber layer by winding the first carbon fiber prepreg in a plurality of layers so as to have a thickness of 7/10 to 9/10 with respect to a diameter of a spring material to be formed;

   (B) Impregnating CNT resin mixed with carbon fiber at a ratio of 1 to 5 parts by weight of carbon nanotubes (CNT) to 100 parts by weight of resin, and gelling the second carbon fiber prepreg of a knitted shape onto a first carbon fiber layer. Winding the layer to form a second carbon fiber layer;

   (C) The carbon fiber knitted third carbon fiber prepreg was impregnated onto the second carbon fiber layer by impregnating CNT resin mixed with carbon fiber at a ratio of 1 to 5 parts by weight of carbon nanotubes (CNT) based on 100 parts by weight of the resin. Winding the layer to form a third carbon fiber layer;

   (D) removing the mandrel during curing of the first to third carbon fiber layers formed through steps (A) to (C) to obtain a tubular first spring material;

   (E) inserting the first spring material obtained in step (D) into a mold having a rod-shaped molding space;

   (F) While injecting high pressure air into the hollow of the first spring material introduced into the mold through the step (E), the first spring material is tubular by expanding and integrating three first to third carbon fiber layers. Hardening to a second spring material;

   (G) separating the tubular second spring material cured through the step (F) from the mold;

   (H) forming a tubular second spring material separated from the mold through the step (G) into a helical third spring material; And

   (I) a method of manufacturing a carbon fiber reinforced composite spring comprising a step of cutting the third spring material formed into a helical shape through the step (H) to a predetermined length and completing the carbon fiber reinforced composite material spring.
7. The method of claim 6, wherein the resin in the step (A), step (B) and step (C) is a thermosetting resin, characterized in that selected from the epoxy resin, phenol resin, unsaturated polyester resin and vinyl ester resin Carbon fiber reinforced composite spring manufacturing method.
8. The method of claim 6, wherein the first carbon fiber prepreg is a UD tape (Uni-Direction tape) in the step (A).
9. According to claim 6, wherein the carbon fiber in the step (B) and step (C) is composed of one carbon fiber selected from 1K carbon fiber, 3K carbon fiber, 6K carbon fiber, 12K carbon fiber and 24K carbon fiber Carbon fiber reinforced composite material spring manufacturing method characterized in that.
10. Carbon fiber reinforced composite spring prepared by the method of any one of claims 6 to 9 carbon fiber reinforced composite spring.

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