JP6776849B2 - Manufacturing method and manufacturing equipment for carbon fiber reinforced plastic structure - Google Patents

Description

The present invention relates to a method and an apparatus for manufacturing a carbon fiber reinforced plastic structure.

Carbon fiber reinforced plastic (CFRP) is used in various fields such as aircraft, automobile materials, and sports equipment.

An example of a CFRP structure is a high-pressure tank that stores a high-pressure gas or liquid inside. For example, Patent Document 1 proposes a method for manufacturing a high-pressure tank (hydrogen tank) as a CFRP structure mounted on a fuel cell vehicle. In the manufacturing method of Patent Document 1, carbon fibers are impregnated with a thermosetting resin, wrapped around a liner made of resin or the like, and the thermosetting resin is cured to reinforce the outside of the liner with CFRP. Manufacture hydrogen tanks.

In Patent Document 1, when impregnating carbon fibers with a thermosetting resin, a carbon fiber bundle (roving) formed by assembling a plurality of carbon fibers at a predetermined density is pulled out by rotation of a roller and moved in the fiber length direction. A so-called filament winding method is performed in which a carbon fiber bundle is impregnated with a thermosetting resin.

Japanese Unexamined Patent Publication No. 2014-124864

In the filament winding method, in order to maintain the strength of the CFRP structure, it is important to appropriately impregnate each carbon fiber constituting the carbon fiber bundle with a resin, but in the conventional method such as Patent Document 1 described above, it is important. Since the resin is impregnated while moving the carbon fiber bundle, it is not always possible to sufficiently impregnate the resin depending on the conditions such as the feed rate of the roller and the thickness of the carbon fiber bundle, and the strength of the manufactured CFRP structure. It is possible to affect.

Further, in a hydrogen tank or the like as a CFRP structure mounted on a fuel cell vehicle, hydrogen gas is filled inside in a high pressure state, so that it is desired to increase the strength as much as possible.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a manufacturing method and a manufacturing apparatus capable of manufacturing a carbon fiber reinforced plastic structure with higher strength.

According to an aspect of the present invention, a method for producing a carbon fiber reinforced plastic structure in which a carbon fiber bundle composed of a plurality of single fibers is impregnated with a resin while being conveyed in the fiber length direction, and the impregnated resin is cured and molded. Is provided. In this production method, a fiber opening step of performing fiber opening on the carbon fiber bundle, a plasma treatment step of applying plasma treatment to the opened carbon fiber bundle, and impregnation of the plasma-treated carbon fiber bundle with resin. It has a resin impregnation step. Then, the opening width, which is the width of the carbon fiber bundle after opening in the fiber opening step, is adjusted according to the transport speed of the carbon fiber bundle.

According to the present invention, a carbon fiber reinforced plastic structure can be produced with higher strength by performing fiber opening and subsequent plasma treatment.

FIG. 1 is a diagram illustrating a configuration of a high-pressure tank manufacturing apparatus according to the present embodiment. FIG. 2 is a diagram illustrating changes in the carbon fiber bundle before and after opening the fiber. FIG. 3 is a diagram illustrating a configuration of a plasma processing apparatus. FIG. 4 is a flowchart illustrating a flow of the high-pressure tank manufacturing method of the present embodiment. FIG. 5A is a diagram illustrating an mode of plasma irradiation on the unopened carbon fiber bundle. FIG. 5B is a diagram illustrating an mode of plasma irradiation on the carbon fiber bundle after opening. FIG. 6 is a graph showing the relationship between the spread width, the plasma intensity, and the plasma irradiation amount according to the transport speed in the second embodiment. FIG. 7 is a graph showing the relationship between the spread width, the plasma intensity, the plasma irradiation amount, the tension, and the resin impregnation amount according to the transport speed in the third embodiment.

(First Embodiment)
Hereinafter, the first embodiment of the present invention will be described with reference to the drawings and the like. In this embodiment, a method for manufacturing a high-pressure tank, which is an example of a CFRP structure, will be described, but the method for manufacturing a CFRP structure according to the present invention is not limited to the method for manufacturing a high-pressure tank.

FIG. 1 is a diagram illustrating a configuration of a high-pressure tank manufacturing apparatus according to the present embodiment.

As shown in the figure, the high-pressure tank manufacturing apparatus 10 includes a roving 12, a tension adjusting apparatus 14, a fiber opening apparatus 16, a plasma processing apparatus 18, a resin impregnation apparatus 20, a liner 22, and a controller 24. ..

The roving 12 is configured by winding a carbon fiber bundle Cfb around a bobbin. The carbon fiber bundle Cfb is configured by bundling a large number (for example, 10,000 to 20,000 or more) of single fiber Cf having a predetermined fiber diameter (for example, about 7 μm). As the carbon fiber, for example, rayon-based carbon fiber, polyacrylic nitrile-based carbon fiber, pitch-based carbon fiber, or the like can be used.

The roving 12 is supported by a brake roller 14a whose rolling resistance can be arbitrarily adjusted, and is configured to be rotatable in a direction (clockwise in the figure) for transporting the carbon fiber bundle Cfb. That is, in the present embodiment, the brake roller 14a functions as a part of the tension adjusting device 14.

The tension adjusting device 14 is a device that adjusts the tension of the carbon fiber bundle Cfb to be conveyed. Specifically, the tension adjusting device 14 has a brake roller 14a and a plurality of guide rollers 14b. The rolling resistance (brake force) of the brake roller 14a can be adjusted based on a command signal from the controller 24, and the tension on the carbon fiber bundle Cfb by adjusting the rolling resistance (hereinafter, simply "tension F" is used. ”) Can be adjusted. The guide roller 14b guides the carbon fiber bundle Cfb in the direction of transporting it to the fiber opening device 16.

The fiber-spreading device 16 has an air injection unit 16a such as an air gun that blows air onto the carbon fiber bundle Cfb being conveyed. By blowing air through the single fibers C constituting the carbon fiber bundle Cfb, the carbon fiber bundle Cfb can be expanded to a predetermined width and the thickness of the carbon fiber bundle Cfb can be reduced.

FIG. 2 is a diagram illustrating a change in the carbon fiber bundle Cfb before and after opening the fiber by the fiber opening device 16. Note that FIG. 2 shows a schematic cross section of the carbon fiber bundle Cfb in the direction orthogonal to the transport direction. By opening the fibers by the opening device 16 shown in the figure, the width of the carbon fiber bundle Cfb is widened and the thickness is reduced. For example, by opening the fibers with the fiber opening device 16, the carbon fiber bundle Cfb having a width of about 10 mm and a thickness of about 0.2 mm becomes 30 to 50 mm in width and about 0.05 mm in thickness. In the following, the carbon fiber bundle Cfb after the fiber opening by the fiber opening device 16 will be referred to as “opening width Ow”.

That is, the mutual distance (hereinafter, also referred to as "interfiber distance L") of the single fibers Cf constituting the carbon fiber bundle Cfb by opening the fibers by the fiber opening device 16 is widened.

Further, in the present embodiment, the opening width Ow can be adjusted by the transport speed V of the carbon fiber bundle Cfb and the flow velocity of the injected air by the air injection unit 16a. In particular, the air injection unit 16a is configured so that the flow velocity of the injected air can be arbitrarily adjusted based on the command signal from the controller 24. That is, the controller 24 corresponds to the desired opening width Ow according to various conditions such as the number, thickness, width, and transport speed V of the single fibers Cf constituting the carbon fiber bundle Cfb before opening. By calculating the target flow velocity of the injected air by the air injection unit 16a and controlling the flow velocity of the injected air accordingly, the fiber opening width Ow of the carbon fiber bundle Cfb can be adjusted to a desired fiber opening width Ow. ..

It should be noted that, for example, in order to efficiently blow air at a desired flow velocity to the carbon fiber bundle Cfb from the opposite side of the carbon fiber bundle Cfb with respect to the air injection unit 16a, it is arbitrary in response to a command from the controller 24. An air suction device such as an intake pump that can suck air with the suction force of the above may be arranged.

The plasma processing device 18 irradiates the opened carbon fiber bundle Cfb with plasma.

FIG. 3 is a diagram illustrating the configuration of the plasma processing device 18. As shown in the figure, the plasma processing device 18 includes a plurality of (three in the figure) discharge electrodes 26 and counter electrodes 28, an AC power supply 25 provided on each of the discharge electrodes 26 and the counter electrode 28, and each discharge electrode 26. An inert gas injection unit 30 for injecting an inert gas such as nitrogen is provided between the counter electrode 28 and the counter electrode 28.

In the plasma processing apparatus 18 shown in the figure, by applying a high-frequency voltage from the AC power supply 25 to the discharge electrode 26, molecules such as oxygen and ozone contained in the air between the discharge electrode 26 and the counter electrode 28 on the ground side Is ionized plasma (oxygen plasma, etc.) is generated.

Then, the generated plasma is guided to the plasma injection port 34 by the inert gas injected from the inert gas injection unit 30 through the fine hole portion 32 having a plurality of fine through holes, and carbon from the plasma injection port 34. The fiber bundle Cfb is irradiated.

The plasma injection port 34 extends over a predetermined width (for example, 25 mm) along the width direction of the carbon fiber bundle Cfb. Hereinafter, the width of the carbon fiber bundle Cfb of the plasma injection port 34 along the width direction is also referred to as “plasma width”.

In this plasma processing apparatus 18, when oxygen plasma (oxygen radical) is irradiated to the carbon fiber bundle Cfb, the oxygen radical is bonded to hydrogen atoms and carbon atoms on the surface of the carbon fiber bundle Cfb to form a hydroxyl group, an aldehyde group, etc. Produces carbon-derived functional groups. As a result, the surface of the carbon fiber bundle Cfb is modified.

By modifying the physical properties of the carbon fiber bundle Cfb by plasma irradiation in this way, the chemical bond with the resin impregnated by the resin impregnation device 20 is promoted. As a result, the strength of the carbon fiber bundle Cfb after curing the resin is improved.

Further, the intensity of the plasma (hereinafter, also simply referred to as “plasma intensity Cp”) irradiated to the carbon fiber bundle Cfb by the plasma processing device 18 is controlled by the controller 24. Specifically, the controller 24 controls the magnitude and frequency of the voltage applied from the AC power supply 25 to the discharge electrode 26, the flow velocity of the inert gas from the inert gas injection unit 30, and the like, thereby controlling the plasma intensity Cp. Can be controlled arbitrarily.

The resin impregnation device 20 is a device for impregnating the carbon fiber bundle Cfb plasma-treated by the plasma processing device 18 with a thermosetting resin.

Specifically, the resin impregnation device 20 uses the resin container 40, the main roller 42 that brings the resin solution in the resin container 40 into contact with the carbon fiber bundle Cfb, and the resin leveling that makes the resin adhering to the main roller 42 uniform. It has a plastic container 43 and guide rollers 44a and 44b.

The resin container 40 stores a solution of the matrix resin to be impregnated in the carbon fiber bundle Cfb. This matrix resin is an epoxy resin that is a thermosetting resin. As the epoxy resin, for example, an epoxy resin containing tetraphenylborones such as tetraphenylphosphonium tetraphenylborate and triethylammonium tetraphenylborate as active ingredients is used.

The main roller 42 is arranged so that a part of the main roller 42 is immersed in the resin solution in the resin container 40, and rotates along the transport direction of the carbon fiber bundle Cfb while contacting the carbon fiber bundle Cfb (clockwise in FIG. 1). It is configured to do.

The resin leveling machine 43 is configured to come into contact with the surface of the main roller 42 upstream of the portion where the carbon fiber bundle Cfb and the main roller 42 come into contact with each other. That is, the resin leveling machine 43 is a device in which the main roller 42 is immersed in the resin solution and the resin adhering to the surface thereof is made uniform before the main roller 42 comes into contact with the carbon fiber bundle Cfb.

The guide rollers 44a and 44b are rollers that guide the carbon fiber bundle Cfb in the transport direction so that the main roller 42 and the carbon fiber bundle Cfb are in suitable contact with each other.

The liner 22 is supported by a shaft 23 that can rotate at an arbitrary rotation speed in the winding direction (clockwise in FIG. 1) along the transport direction of the carbon fiber bundle Cfb, and rotates with the rotation of the shaft 23. Therefore, the carbon fiber bundle Cfb can be wound around the liner by the rotation of the shaft 23, and the basic structure of the high-pressure tank can be obtained.

The liner 22 is made of a resin material such as a thermoplastic resin or a thermosetting resin. Examples of the thermoplastic resin constituting the liner 22 include polyethylene, polypropylene, polyvinyl chloride, ABS resin, polystyrene, polyamide, polycarbonate, polyimide, and fluororesin. Examples of the thermosetting resin constituting the liner 22 include epoxy resin and polyurethane.

Further, in the present embodiment, the rotation speed of the shaft 23 is adjusted based on the command signal of the controller 24. Then, the rotation of the shaft 23 drives the carbon fiber bundle Cfb in the transport direction. That is, the rotation speed of the shaft 23 corresponds to the transport speed V of the carbon fiber bundle Cfb, and the transport speed V can be adjusted by the controller 24.

The controller 24 is composed of a computer having a central arithmetic unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface), particularly a microcomputer.

Then, the controller 24 uses each hardware element such as the CPU to determine the braking force (tension F) of the brake roller 14a of the tension adjusting device 14, the flow velocity of air from the air injection unit 16a of the fiber opening device 16, and the like (fiber opening). Width Ow), the magnitude and frequency of the voltage of the AC power supply 25 of the plasma processing device 18, the injection flow velocity of the inert gas (plasma intensity Cp), and the rotation speed of the shaft 23 (conveyance speed V) can be controlled. It is programmed in.

The flow of the high-pressure tank manufacturing method executed by using the high-pressure tank manufacturing apparatus 10 having each of the above configurations will be described.

FIG. 4 is a flowchart illustrating a flow of the high-pressure tank manufacturing method of the present embodiment. In this embodiment, the transport speed V is set to a fixed value in advance by the controller 24.

As shown in the figure, in step S101, the fiber-spreading device 16 executes the fiber-spreading step on the carbon fiber bundle Cfb. Specifically, the controller 24 controls the fiber opening device 16 so as to obtain a desired fiber opening width Ow according to the transfer speed V to perform the fiber opening. The spread width Ow is determined from the viewpoint of appropriately performing plasma irradiation and resin impregnation.

In step S102, a plasma treatment step of applying plasma treatment to the opened carbon fiber bundle Cfb is executed.

In step S103, a resin impregnation step of impregnating the plasma-treated carbon fiber bundle Cfb with the resin is performed. Specifically, as described above, the carbon fiber bundle Cfb is impregnated with the resin by the resin impregnation device 20.

In step S104, the carbon fiber bundle Cfb impregnated with the resin is wound around the liner 22 and laminated, and a predetermined curing treatment such as heat treatment is performed. As a result, a high-pressure tank as a CFRP structure in which a carbon fiber layer as a reinforcing layer is wound around the liner 22 is formed.

Therefore, in the method for manufacturing a high-pressure tank of the present embodiment, by opening the carbon fiber bundle Cfb in the fiber opening step of step S101, the mutual distance between the plurality of single fibers Cf constituting the carbon fiber bundle Cfb is increased. It spreads and the thickness of the carbon fiber bundle Cfb is also reduced. This makes it easier for the resin to permeate between the single fibers Cf in the resin impregnation step of step S103, so that each single fiber Cf can be more reliably impregnated with the resin. Therefore, it is possible to prevent the strength of the high-pressure tank, which is a finished product, from being lowered due to the generation of voids due to insufficient impregnation of the resin.

Further, in the plasma treatment step of step S102, plasma treatment is performed on the carbon fiber bundle Cfb in a state where the mutual distance between the single fibers Cf is widened by opening the fibers and the thickness of the carbon fiber bundle Cfb is reduced. As a result, the plasma irradiation efficiency of the plasma treatment can also be increased. This will be described more specifically.

FIG. 5A is a diagram illustrating an mode of plasma irradiation on the unopened carbon fiber bundle. Further, FIG. 5B is a diagram illustrating an mode of plasma irradiation of the carbon fiber bundle after opening.

First, the unopened carbon fiber bundles Cfb shown in FIG. 5A are densely packed so that the single fibers Cf are grouped together to form a substantially circular cross section.

Therefore, the plasma irradiated by the plasma treatment (indicated by the arrow in the figure) irradiates a certain amount of the single fiber Cf existing in the surface portion corresponding to the circumference of the circular circle, particularly the region A corresponding to the surface portion on the plasma injection port 34 side. However, a sufficient amount of irradiation is not secured in other parts.

In particular, the single fiber Cf existing near the center of the substantially circular carbon fiber bundle Cfb can secure a sufficient irradiation amount because the plasma is blocked by the single fiber Cf on the surface portion of the carbon fiber bundle Cfb. More difficult.

On the other hand, the carbon fiber bundle Cfb after opening shown in FIG. 5B has a thinner and wider shape as compared with the unopened state, and the mutual distance between the single fibers Cf is widened and the thickness is reduced. Therefore, in the carbon fiber bundle Cfb after opening, the irradiated plasma (indicated by the arrow in the figure) passes between the surface single fibers Cf while being sufficiently irradiated to the surface single fibers Cf. The single fiber Cf existing on the opposite side of the plasma injection port 34 is also sufficiently irradiated. This improves the plasma irradiation efficiency. As a result, the efficiency of plasma processing is improved, and the strength of the finished high-pressure tank can be increased. Further, as described above, since the mutual distance between the single fibers Cf is widened, the resin impregnation by the resin impregnation device 20 can be preferably performed.

Therefore, in the method for manufacturing the high-pressure tank of the present embodiment, the carbon fiber bundle Cfb can be suitably impregnated with the resin by opening the carbon fiber bundle Cfb in the fiber opening step, and the plasma irradiation efficiency of the subsequent plasma treatment is achieved. Can also be increased, so that the strength of the obtained high-pressure tank can be improved.

Further, in the present embodiment, since the thickness of the carbon fiber bundle Cfb is reduced by opening the fibers, the number of turns of the carbon fiber bundle Cfb with respect to the liner 22 is obtained in order to obtain the thickness required as the reinforcing layer of the high pressure tank. Will increase. That is, in the finally obtained high-pressure tank, even if the reinforcing layer has the same thickness, a wide and thin carbon fiber bundle Cfb is wound more around the liner 22. Thereby, for example, even when some event that can cause a crack occurs in the reinforcing layer of the high-pressure tank, the growth of the crack can be stopped at the boundary of each carbon fiber bundle Cfb. As a result, even if a crack occurs, its length can be kept short, which further contributes to improving the strength of the high-pressure tank.

According to the method for manufacturing a high-pressure tank as a carbon fiber reinforced plastic structure in the present embodiment described above, the following effects are obtained.

According to the present embodiment, high pressure as a carbon fiber reinforced plastic structure formed by impregnating a resin while transporting a carbon fiber bundle Cfb composed of a plurality of single fibers Cf in the fiber length direction and curing the impregnated resin. A method of manufacturing the tank is provided.

The method for manufacturing this high-pressure tank includes a fiber-spreading step (step S101 in FIG. 4) for performing fiber opening on the carbon fiber bundle Cfb and a plasma processing step (FIG. 4) for plasma-treating the opened carbon fiber bundle Cfb. Step S102) of step 4 and a resin impregnation step (step S103) of impregnating the plasma-treated carbon fiber bundle Cfb with the resin.

According to this, by opening the carbon fiber bundle Cfb in the fiber opening step, it is possible to more preferably impregnate the carbon fiber bundle Cfb with the resin in the resin impregnation step, and plasma irradiation in the subsequent plasma treatment. Efficiency can also be increased.

Therefore, it is possible to suppress a decrease in the strength of the high-pressure tank due to the generation of voids due to insufficient impregnation of the resin, and it is possible to reliably irradiate plasma with each single fiber Cf constituting the carbon fiber bundle Cfb. .. As a result, the strength of the obtained high-pressure tank can be further improved.

Further, in the present embodiment, the thickness of the carbon fiber bundle Cfb is reduced by the opening of the fiber, so that the number of turns of the carbon fiber bundle Cfb is increased in order to obtain the thickness required as the reinforcing layer of the high pressure tank. It will be. That is, in the finally obtained high-pressure tank, even if the carbon fiber layers have the same thickness, the wide and thin carbon fiber bundle Cfb is wound more, so that the strength of the high-pressure tank is increased. Will be improved further.

Further, in the method for manufacturing a high-pressure tank of the present embodiment, a high-pressure tank is manufactured by impregnating a resin while transporting a carbon fiber bundle Cfb composed of a plurality of single fibers Cf in the fiber length direction and molding after the resin impregnation. It is executed by the tank manufacturing apparatus 10.

The high-pressure tank manufacturing apparatus 10 includes a tension adjusting device 14 as a tension adjusting device for adjusting the tension F of the carbon fiber bundle Cfb to be conveyed, a fiber opening device 16 for executing fiber opening on the carbon fiber bundle Cfb, and the fiber opening device 16. Depending on the plasma processing device 18 that executes plasma treatment on the opened carbon fiber bundle Cfb, the resin impregnation device 20 that impregnates the plasma-treated carbon fiber bundle Cfb with resin, and the transport speed V of the carbon fiber bundle Cfb. , A tension adjusting device 14, a fiber opening device 16, a plasma processing device 18, and a controller 24 for controlling a resin impregnation device 20.

As a result, the high-pressure tank manufacturing apparatus 10 adjusts the tension F, the opening width Ow, and the plasma intensity Cp to appropriately control the plasma irradiation amount P and the resin impregnation amount I on the carbon fiber bundle Cfb. The method of manufacturing a high pressure tank of the embodiment can be carried out.

Therefore, for example, even if the transport speed V is set relatively high in order to improve the productivity of the high-pressure tank, the plasma irradiation amount P and the resin impregnation amount I can be appropriately secured according to the transport speed V. Therefore, a high-pressure tank having a certain level of strength can be manufactured at low cost.

(Second Embodiment)
Hereinafter, the second embodiment will be described. The same elements as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the present embodiment, the controller 24 sets (fixes) the transport speed V, and the spread width Ow and the fiber opening width Ow so that the plasma irradiation amount P applied to the carbon fiber bundle Cfb becomes constant with respect to the transport speed V. The plasma intensity Cp is controlled.

ただし、Ｃｐはプラズマ強度、Ｌは繊維間距離、ｔｐはプラズマ照射時間、及びＤｆは繊維径を意味する。 Here, the plasma irradiation amount P is determined by the following formula (1).

However, Cp means plasma intensity, L means interfiber distance, tp means plasma irradiation time, and Df means fiber diameter.

Here, the interfiber distance L means an average distance between adjacent single fibers Cf in the width direction. The interfiber distance L can be calculated from the number N of single fibers Cf, the thickness Bb of the carbon fiber bundle Cfb after opening, and the width (opening width Ow).

The interfiber distance L is, for example, assuming that the single fibers Cf are in contact with each other in the thickness direction of the carbon fiber bundle Cfb and the distance between adjacent single fibers Cf in the thickness direction is zero. It can be calculated according to (2).

Further, the plasma irradiation time tp of the formula (1) can be obtained based on the transport speed V. That is, since the time for the carbon fiber bundle Cfb to pass through the plasma irradiation region (cover region of the plasma injection port 34) in the plasma processing apparatus 18 is determined according to the transport speed V, this can be set as the plasma irradiation time tp. .. Therefore, as the transport speed V increases, the plasma irradiation time tp becomes shorter.

Therefore, in the present embodiment, the controller 24 has the spread width Ow so that the plasma irradiation amount P determined by the above equations (1) and (2) takes a substantially constant value with respect to the predetermined transfer speed V. , And the plasma intensity Cp is adjusted.

More specifically, the controller 24 also includes a target value of the spread width Ow (hereinafter, "target spread width Ow_t") so that the plasma irradiation amount P becomes a substantially constant value based on a predetermined transfer speed V. ) And the target value of plasma intensity Cp (hereinafter, also referred to as "target plasma intensity Cp_t") are determined. Then, the controller 24 controls the plasma processing device 18 and the resin impregnation device 20 so that the spread width Ow and the plasma intensity Cp approach the target spread width Ow_t and the target plasma intensity Cp_t, respectively.

FIG. 6 is a graph showing the relationship between the spread width Ow, the plasma intensity Cp, and the plasma irradiation amount P with respect to the set transport speed V. In particular, FIG. 6A shows the spread width Ow, FIG. 6B shows the plasma intensity Cp, and FIG. 6C shows the plasma irradiation amount P.

In the control of the present embodiment, the two control modes I and the control mode II are switched according to the set transfer speed V. The controller 24 switches between the control mode I and the control mode II based on the magnitude relationship between the transport speed V and the predetermined threshold value Vth.

In the present embodiment, the threshold Vth is set larger as the transport speed V increases in order to keep the plasma irradiation amount P constant in the control mode I. The target fiber opening width Ow_t is set to the plasma injection port of the plasma processing apparatus 18. It is defined as the value of the transport speed V when the opening width upper limit value Owmax corresponding to the width of 34 (the width capable of irradiating plasma) is reached.

Therefore, the controller 24 executes the control of the control mode I when the transfer speed V is less than the threshold value Vth, and selects the control mode of the control mode II when the transfer speed V is equal to or more than the threshold value Vth. .. The details of the control mode I and the control mode II will be described below.

(I) Control mode I
The controller 24 sets the target spread width Ow_t larger and increases the spread width Ow as the set transport speed V increases (see FIG. 6A). This is because, as described above, the larger the transport speed V, the shorter the plasma irradiation time tp. Therefore, the spread width Ow is increased to widen the plasma irradiation region for the carbon fiber bundle Cfb, and the plasma irradiation amount P is substantially constant. This is to maintain the temperature (see FIG. 6 (c)). In this case, the target plasma intensity Cp_t is set to a substantially constant value, and the plasma intensity Cp is kept substantially constant (see FIG. 6B).

(Ii) Control mode II
The controller 24 calculates the target opening width Ow_t as the opening width upper limit value Owmax regardless of the magnitude of the transport speed V. That is, the spread width Ow is fixed to a constant value of the spread width upper limit value Owmax (see FIG. 6A).

Here, in the control mode II, if the spread width Ow is increased as the transport speed V set as in the control mode I is larger, the spread width Ow exceeds the spread width upper limit value Owmax. .. That is, since the opening width Ow exceeds the width of the plasma injection port 34 of the plasma processing apparatus 18, the carbon fiber bundle Cfb extends beyond the plasma irradiation capable region in the width direction.

Therefore, in the present embodiment, in the control mode II, the controller 24 opens the fiber opening width Ow regardless of the change in the transport speed V in order to keep the width of the carbon fiber bundle Cfb within the range of the plasma irradiation width. The fiber width upper limit value is fixed to Owmax.

On the other hand, when the spread width Ow is fixed in this way, the plasma irradiation time tp decreases and the plasma irradiation amount P decreases as the set transport speed V increases. Therefore, in this embodiment as well, in order to keep the plasma irradiation amount P constant without decreasing it, the plasma intensity Cp is increased as the set transfer speed V is larger (see FIG. 6B).

By the control in the control mode I and the control mode II described above, the plasma irradiation amount P can be adjusted to a desired constant value regardless of the magnitude of the transport speed V (see FIG. 6C).

According to the method for manufacturing a high-pressure tank as a carbon fiber reinforced plastic structure in the present embodiment described above, the following effects are obtained.

In the present embodiment, the opening width Ow, which is the width of the carbon fiber bundle after opening in the fiber opening step, is adjusted according to the transport speed V of the carbon fiber bundle Cfb. As a result, even when the plasma irradiation time in the plasma processing step changes, the plasma irradiation amount P can be appropriately adjusted by adjusting the spread width Ow according to the change.

In particular, in the present embodiment, the opening width Ow is increased as the transport speed V is increased. As a result, even when the transport speed V is relatively large and the plasma irradiation time is relatively short, the plasma irradiation region for the carbon fiber bundle Cfb can be widened. As a result, the desired plasma irradiation amount can be secured even if the transport speed V is relatively increased.

Further, in the present embodiment, the plasma intensity Cp, which is the intensity of the plasma irradiated to the carbon fiber bundle Cfb in the plasma treatment step, is adjusted according to the transport speed V of the carbon fiber bundle Cfb. As a result, even when the transport speed V is relatively large and the plasma irradiation time tp is relatively short, the plasma intensity Cp can be increased and the plasma irradiation amount P can be increased (Equation (1). )reference). As a result, the desired plasma irradiation amount P can be secured even if the transport speed V is relatively increased.

More specifically, the plasma intensity Cp is adjusted so that the amount of plasma (plasma irradiation amount P) irradiated to the carbon fiber bundle Cfb is kept substantially constant regardless of the magnitude of the transport speed V. That is, the plasma intensity Cp can be controlled to adjust the plasma irradiation amount P to a substantially constant value regardless of the transport speed V.

More specifically, in the present embodiment, when the transport speed V of the carbon fiber bundle Cfb is less than a predetermined threshold value Vth, the larger the transport speed V, the larger the opening width Ow, and the transport of the carbon fiber bundle Cfb. When the velocity V is equal to or higher than the threshold value Vth, the plasma intensity Cp increases as the transport velocity V increases (see FIG. 6B).

Therefore, when the transport speed V is less than the threshold value Vth, that is, when the spread width Ow is less than the spread width upper limit value Owmax (control mode I in FIG. 6), the larger the set transport speed V, the larger the spread width Ow. Therefore, the plasma irradiation region can be widened, and a desired plasma irradiation amount P can be secured without changing the plasma intensity Cp (FIG. 6 (c)). On the other hand, when the transport speed V is equal to or higher than the threshold value Vth, that is, when the spread width Ow reaches the spread width upper limit value Owmax (control mode II in FIG. 6), the larger the set transport speed V, the more plasma By increasing the intensity Cp (FIG. 6 (b)), it is possible to secure the desired plasma irradiation amount P while fixing the spread width Ow to the upper limit value Owmax of the spread width (FIG. 6 (c)). ..

As a result, the desired plasma irradiation amount P can be more reliably secured according to the transport speed V arbitrarily set, which contributes to the production of a high-intensity high-pressure tank. In particular, since the spread width Ow and the plasma intensity Cp are adjusted so that the plasma irradiation amount P is kept substantially constant, the conveyed carbon fiber bundle Cfb can be uniformly subjected to plasma treatment, and as a result, the plasma treatment can be performed uniformly. It is possible to suppress product variations on the strength of the high-pressure tank and to manufacture a more stable and high-quality high-pressure tank.

The threshold value Vth of the present embodiment is based on the upper limit value of the opening width Ow (the upper limit value of the opening width Owmax) determined by the size of the region where plasma can be irradiated in the plasma treatment. Set. As a result, it is permissible to increase the spread width Ow to the maximum size at which plasma irradiation is possible according to the transport speed V arbitrarily set, so that the effect of increasing the plasma irradiation region by spread is maximized. It can be used for a limited time.

(Third Embodiment)
Hereinafter, the third embodiment will be described. The same elements as those in the second embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the present embodiment, the controller 24 sets (fixes) the transport speed V, and the plasma irradiation amount P applied to the carbon fiber bundle Cfb and the resin impregnation amount I to the carbon fiber bundle Cfb are set with respect to the transport speed V. The fiber opening width Ow, plasma intensity Cp, and tension F are controlled so as to be constant.

ただし、Ｆはテンション、Ｌは繊維間距離、ｔｉは樹脂接触時間、μは樹脂の粘度、及びＤｆは繊維径を意味する。 Here, the resin impregnation amount I is determined by the following formula (3).

However, F is tension, L is the distance between fibers, ti is the resin contact time, μ is the viscosity of the resin, and Df is the fiber diameter.

Here, the resin contact time ti is the time during which the main roller 42 of the resin impregnation device 20 comes into contact with the carbon fiber bundle Cfb. The resin contact time ti can be obtained based on the transport speed V. That is, since the time for the main roller 42 to contact the carbon fiber bundle Cfb is determined according to the transport speed V, this can be set as the resin contact time ti. The larger the transport speed V, the shorter the resin contact time ti.

Therefore, in the present embodiment, the controller 24 appropriately adjusts the tension F according to the spread width Ow adjusted to keep the plasma irradiation amount P constant according to the transport speed V predetermined in the second embodiment. The resin impregnation amount I is adjusted to be substantially constant by adjusting.

More specifically, the controller 24 determines the target value of the tension F (hereinafter, also referred to as “target tension F_t”) so that the resin impregnation amount I becomes substantially constant based on the transfer speed V. Then, the controller 24 controls the tension adjusting device 14 so that the tension F approaches the target tension F_t.

FIG. 7 is a graph showing the relationship between the spread width Ow, the plasma intensity Cp, the plasma irradiation amount P, the tension F, and the resin impregnation amount I with respect to the set transport speed V. In particular, FIG. 7 (a) represents the spread width Ow, FIG. 7 (b) represents the plasma intensity Cp, FIG. 7 (c) represents the plasma irradiation amount P, and FIG. 7 (d) represents the tension F. , FIG. 7 (e) shows the resin impregnation amount I.

As shown in the figure, similarly to the second embodiment, when the transfer speed V is less than the threshold value Vth, the control of the control mode I is executed, and when the transfer speed V is equal to or more than the threshold value Vth. Performs control of control mode II. The details of the control mode I and the control mode II will be described below.

(I) Control mode I
From the viewpoint of maintaining the plasma irradiation amount P substantially constant in the controller 24 as in the second embodiment, the larger the set transport speed V, the larger the target opening width Ow_t is set and the larger the opening width Ow is. (See FIG. 7 (a)), the target plasma intensity Cp_t is set to a substantially constant value to keep the plasma intensity Cp substantially constant (see FIG. 7 (b)).

Here, in the present embodiment, as the set transfer speed V increases, the resin contact time ti also decreases. However, since the fiber opening width Ow is increased from the viewpoint of maintaining the plasma irradiation amount P substantially constant as described above, the area in contact with the main roller 42 of the resin impregnation device 20 is widened. Therefore, even if the resin contact time ti is shortened, the resin impregnation amount I can be kept substantially constant (see FIG. 7E).

That is, in the present embodiment, not only the plasma irradiation amount P but also the resin impregnation amount I is controlled by increasing the opening width Ow according to the increase in the transport speed V with the intention of keeping the plasma irradiation amount P substantially constant. Can be kept almost constant. In this case, the target tension F_t is set to a substantially constant value, and the tension F is controlled to be constant (see FIG. 7B).

(Ii) Control mode II
Similar to the second embodiment, the controller 24 fixes the spread width Ow to the spread width upper limit value Owmax regardless of the change in the transfer speed V (see FIG. 7A), while the transfer is set. As the velocity V increases, the plasma intensity Cp is increased to adjust the plasma irradiation amount P to a desired constant value (see FIG. 7C).

Further, in the present embodiment, if the spread width Ow is fixed regardless of the transport speed V, the resin contact time ti becomes shorter and the resin impregnation amount I decreases as the set transport speed V increases. Therefore, in this embodiment as well, in order to keep the resin impregnation amount I constant without reducing it, the tension F is increased as the set transport speed V is larger (FIG. 7 (d)).

By the control in the control mode I and the control mode II described above, both the plasma irradiation amount P and the resin impregnation amount I can be adjusted to their respective predetermined constant values regardless of the magnitude of the transport speed V.

According to the method for manufacturing a high-pressure tank as a carbon fiber reinforced plastic structure in the present embodiment described above, the following effects are obtained.

In the present embodiment, the tension (tension F) of the carbon fiber bundle Cfb to be transported is adjusted according to the transport speed V. As a result, even when the transport speed V is relatively large and the resin contact time ti in the resin impregnation step is relatively short, the tension F can be increased and the resin impregnation amount I can be increased (formula). (See (3)). As a result, the desired resin impregnation amount I can be secured even if the transport speed V is relatively increased.

Further, in the present embodiment, when the transport speed V of the carbon fiber bundle Cfb is less than a predetermined threshold value Vth, the tension F of the carbon fiber bundle Cfb is maintained substantially constant (control mode of FIG. 7D). I) When the transport speed V is equal to or higher than the threshold value Vth, the tension F is increased as the transport speed V is larger (control mode II in FIG. 7D).

Therefore, in the present embodiment, when the transport speed V is less than the threshold value Vth, that is, when the spread width Ow is less than the spread width upper limit value Owmax (control mode I in FIG. 7), the magnitude of the set transport speed V is set. Regardless, the tension F of the carbon fiber bundle Cfb is maintained substantially constant. On the other hand, when the transport speed V is equal to or higher than the threshold value Vth, that is, when the spread width Ow reaches the spread width upper limit value Owmax (control mode II in FIG. 7), the larger the set transport speed V, the more the tension F. Is increased (FIG. 7 (d)).

As a result, the desired resin impregnation amount I can be more reliably secured according to the transport speed V arbitrarily set, which contributes to the production of a high-strength high-pressure tank in which the generation of voids and the like is suppressed. Become. In particular, since the tension F is adjusted so as to keep the resin impregnation amount I substantially constant, it is possible to more preferably impregnate the conveyed carbon fiber bundle Cfb with the resin, and as a result, the high-pressure tank. It is possible to manufacture a more stable and high-quality high-pressure tank by suppressing product variations related to the strength of the resin.

Further, in the present embodiment, when the transport speed V is less than the threshold value Vth (control mode I in FIG. 7), the fiber opening width Ow increases as the transport speed V increases from the viewpoint of keeping the plasma irradiation amount P substantially constant. Is controlled to be large (see FIG. 7A). Therefore, in this case, the resin impregnation amount I can be kept substantially constant by simply adjusting the tension F to be constant without performing special control on the tension F (FIGS. 7 (d) and 7). (E)). That is, in the present embodiment, the effect of making the resin impregnation amount I substantially constant can be obtained by controlling the fiber opening width Ow from the viewpoint of keeping the plasma irradiation amount P substantially constant.

On the other hand, when the transport speed V is equal to or higher than the threshold value Vth (control mode II in FIG. 7), the spread width Ow is fixed to the spread width upper limit value Owmax (FIG. 7 (a)), but the transport speed By increasing the tension F as V increases, the resin impregnation amount I can be kept constant even when the spread width Ow is maintained at the spread width upper limit value Owmax (FIG. 7 (e). )).

It is clear that the present invention is not limited to the above-described embodiment, and various changes can be made within the scope of its technical idea.

For example, the counter electrode 28 of the plasma processing device 18 may be arranged on the opposite side of the discharge electrode 26 with the carbon fiber bundle Cfb, which is the object to be irradiated with plasma, interposed therebetween. Further, the fiber opening is not limited to the blowing of air by the fiber opening device 16 of the present embodiment, and various other methods such as fiber opening using a predetermined fiber opening roller may be adopted.

Further, in the method for producing a carbon fiber reinforced plastic structure in the present embodiment, a carbon fiber bundle Cfb in which single fibers Cf are assembled in a substantially circular cross section is conveyed, and plasma treatment or fiber opening is performed on the carbon fiber bundle Cfb. .. However, a carbon fiber bundle Cfb in which single fibers Cf are assembled in a substantially rectangular cross section may be conveyed to perform plasma treatment or fiber opening. As a result, the flat surface portion forming the rectangle of the carbon fiber bundle Cfb can be irradiated with plasma and brought into contact with the resin, so that the plasma irradiation efficiency and the resin impregnation efficiency can be improved.

Further, the adjustment of the tension F, the spread width Ow, and the plasma intensity Cp according to the transport speed V is not limited to the examples described in the second embodiment and the third embodiment. For example, in the control mode I in which the transport speed V is less than the threshold value Vth, the plasma intensity Cp itself is changed in place of the configuration in which the spread width Ow is adjusted so that the plasma irradiation amount P is a desired value. You can do it.

Further, instead of the control of the second embodiment and the third embodiment, for example, at least one of the tension F, the spread width Ow, and the plasma intensity Cp is set to a fixed value, and the transfer speed V is set by the controller 24. The plasma irradiation amount P and the resin impregnation amount I may be controlled to desired values by adjusting.

Further, the control is not limited to the control that keeps the plasma irradiation amount P and the resin impregnation amount I described in the present embodiment constant, and the plasma irradiation amount P and the resin impregnation amount I that fluctuate according to the value of the transport speed V depending on the situation. In order to set the target value of the above and control the plasma irradiation amount P and the resin impregnation amount I to the fluctuating target value, at least one of the tension F, the spread width Ow, and the plasma intensity Cp is adjusted. Is also good.

Further, in the third embodiment, the tension F is adjusted to adjust the resin impregnation amount I to a desired value based on the spread width Ow adjusted to obtain the desired plasma irradiation amount P according to the control of the second embodiment. Was adjusted. However, conversely, the spread width Ow is adjusted so that the resin impregnation amount I is a desired value, and the plasma intensity Cp is adjusted to obtain a desired plasma irradiation amount P based on the adjusted spread width Ow. You may.

Further, in the second embodiment and the third embodiment, the threshold value Vth of the transport speed V (see FIG. 6 or 7) is set to the opening width upper limit value Owmax in which the opening width Ow corresponds to the width of the plasma injection port 34. Is defined as the transport speed V when reaching. However, the threshold value Vth may be set by other criteria. For example, as described above, the spread width Ow is adjusted so as to obtain the desired resin impregnation amount I, and the upper limit of the width at which the spread width Ow can come into contact with the resin in the resin impregnation device 20 ( The transport speed V when reaching the width of the main roller 42, etc.) may be set as the threshold value Vth.

Further, in the second embodiment and the third embodiment, the opening width upper limit value Owmax is set to a value corresponding to the width of the plasma injection port 34, but from the viewpoint of reliably irradiating the plasma from the entire region of the carbon fiber bundle Cfb. Therefore, the opening width upper limit value Owmax may be set to be smaller than the width of the plasma injection port 34 by a predetermined amount.

Further, the manufacturing method and manufacturing apparatus of the present invention are not limited to the manufacturing of the high-pressure tank of the above embodiment, and are applied to the manufacturing of CFRP structures used in various other applications such as aircraft, automobile materials, and sports equipment. can do.

10 High-pressure tank manufacturing equipment 12 Robbing 14 Tension adjustment device 14a Brake roller 14b Guide roller 16 Fiber opening device 16a Air injection unit 18 Plasma processing device 20 Resin impregnation device 22 Winding bobbin 24 Controller 25 AC power supply 26 Discharge electrode 28 Opposite electrode 30 Active gas injection part 32 Fine hole part 34 Plasma injection port 40 Resin container 42 Main roller 43 Resin leveling machine 44a, 44b Guide roller

Claims (9)

A method for producing a carbon fiber reinforced plastic structure, which is formed by impregnating a resin while transporting a carbon fiber bundle composed of a plurality of single fibers in the fiber length direction and curing the impregnated resin.
A fiber opening step of performing fiber opening on the carbon fiber bundle and
A plasma treatment step of applying plasma treatment to the opened carbon fiber bundle, and
A resin impregnation step of impregnating the plasma-treated carbon fiber bundle with the resin,
Have a,
The opening width, which is the width of the carbon fiber bundle after opening in the opening step, is adjusted according to the transport speed of the carbon fiber bundle.
A method for manufacturing a carbon fiber reinforced plastic structure. The method for producing a carbon fiber reinforced plastic structure according to claim 1 .
The opening width is increased as the transport speed of the carbon fiber bundle increases.
A method for manufacturing a carbon fiber reinforced plastic structure. The method for producing a carbon fiber reinforced plastic structure according to claim 1 or 2 .
The plasma intensity, which is the intensity of the plasma irradiating the carbon fiber bundle in the plasma treatment step, is adjusted according to the transport speed of the carbon fiber bundle.
A method for manufacturing a carbon fiber reinforced plastic structure. The method for producing a carbon fiber reinforced plastic structure according to claim 3 .
The plasma intensity is adjusted so that the amount of plasma irradiation applied to the carbon fiber bundle is kept substantially constant regardless of the magnitude of the transport speed of the carbon fiber bundle.
A method for manufacturing a carbon fiber reinforced plastic structure. The method for producing a carbon fiber reinforced plastic structure according to claim 4 .
When the transport speed of the carbon fiber bundle is less than a predetermined threshold value, the larger the transport speed of the carbon fiber bundle, the larger the spread width.
When the transport speed of the carbon fiber bundle is equal to or higher than the threshold value, the higher the transport speed of the carbon fiber bundle, the higher the plasma intensity.
A method for manufacturing a carbon fiber reinforced plastic structure. The method for producing a carbon fiber reinforced plastic structure according to claim 5 .
The threshold value is set based on the upper limit value of the spread width determined from the size of the region where plasma can be irradiated in the plasma treatment.
A method for manufacturing a carbon fiber reinforced plastic structure. The method for producing a carbon fiber reinforced plastic structure according to any one of claims 2 to 6 .
The tension of the carbon fiber bundle to be transported is adjusted according to the transport speed of the carbon fiber bundle.
A method for manufacturing a carbon fiber reinforced plastic structure. The method for producing a carbon fiber reinforced plastic structure according to claim 7 .
When the transport speed of the carbon fiber bundle is less than a predetermined threshold value, the tension of the carbon fiber bundle is maintained substantially constant.
When the transport speed of the carbon fiber bundle is equal to or higher than the threshold value, the higher the transport speed of the carbon fiber bundle, the greater the tension of the carbon fiber bundle.
A method for manufacturing a carbon fiber reinforced plastic structure. Manufacture of a carbon fiber reinforced plastic structure for producing a carbon fiber reinforced plastic structure formed by impregnating a resin while transporting a carbon fiber bundle composed of a plurality of single fibers in the fiber length direction and curing the impregnated resin. It ’s a device,
A tension adjusting device that adjusts the tension of the carbon fiber bundle to be transported, and
A fiber opening device that performs fiber opening on the carbon fiber bundle,
A plasma processing apparatus that executes plasma processing on the opened carbon fiber bundle, and
A resin impregnation device for impregnating the plasma-treated carbon fiber bundle with the resin,
A controller that controls the tension adjusting device, the fiber opening device, and the plasma processing device according to the transport speed of the carbon fiber bundle.
Have,
Manufacturing equipment for carbon fiber reinforced plastic structures.

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