High-pressure tank, method for manufacturing the same, and manufacturing apparatus therefor

Abstract

To provide a high-pressure tank that can more reliably increase a breaking strength of a reinforcing layer compared to conventional tanks.SOLUTION: A high-pressure tank 1 of the present invention has a hollow liner 2 and a reinforcing layer 4 formed on an outer surface of the liner 2, the reinforcing layer 4 having a plurality of unit layers 7 laminated on the outer surface of the liner 2, the unit layers 7 being formed by winding the liner 2 so that band-shaped fiber bundles (bands B) containing a curable resin are arranged in parallel in a width direction, and the band-shaped fiber bundles (bands B) is wider in the unit layers 7 laminated on an outer periphery side of the reinforcing layer 4 than in the unit layers 7 on the inner periphery side of the reinforcing layer 4.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a high-pressure tank, a manufacturing method thereof, and an apparatus for manufacturing the same. [Background technology]

[0002] Conventionally, a high-pressure tank is known that has a reinforcing layer formed by winding fibers containing a curable resin around the outside of a substantially cylindrical liner having dome portions at both ends (see, for example, Patent Document 1). The reinforcing layer of this high-pressure tank has a helical layer in which fibers are wound helically, and a hoop layer in which fibers are wound in a hoop shape outside the helical layer. In addition, in the manufacturing method of this high-pressure tank, the tension of the fibers when forming the hoop layer that is the outer layer is set to be greater than the tension of the fibers when forming the helical layer that is the inner layer. With a high-pressure tank manufactured in this manner, even if gas is repeatedly charged and discharged many times in a high-temperature and high-humidity environment, peeling at the interface between the helical layer (inner layer) and the hoop layer (outer layer) can be suppressed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-30873 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional manufacturing method of a high-pressure tank (see, for example, Patent Document 1), the tension of the fibers in the outer layer is greater than that of the fibers in the inner layer, which may loosen the fibers in the inner layer. If the fibers in the inner layer loosen, the breaking strength of the reinforcing layer may decrease.

[0005] An object of the present invention is to provide a high-pressure tank capable of increasing the breaking strength of a reinforcing layer more reliably than in the past, and a manufacturing method and device for the same.

Means for Solving the Problem

[0006] The high-pressure tank of the present invention that achieves the above problem has a hollow liner and a reinforcing layer formed on the outer surface of the liner. The reinforcing layer is formed by winding a belt-like fiber bundle containing a curable resin around the liner, and the belt-like fiber bundle expands on the outer peripheral side rather than the inner peripheral side of the reinforcing layer. and the reinforcing layer includes a plurality of unit layers laminated on the outer surface of the liner, the unit layer is formed by winding the liner such that the strip-shaped fiber bundles are arranged in parallel in the width direction, and the strip-shaped fiber bundles are wider for the unit layers laminated on the outer peripheral side than on the inner peripheral side of the reinforcing layer It is characterized by this.

[0007] The manufacturing method of the high-pressure tank of the present invention that achieves the above problem is a manufacturing method of a high-pressure tank having a reinforcing layer on the outer surface of a hollow liner, and includes a winding step of winding and laminating a belt-like fiber bundle containing a curable resin on the outer surface of the liner, and a reinforcing layer forming step of curing the curable resin contained in the fiber bundle wound around the outer surface to form the reinforcing layer. The winding step includes a step of expanding the belt-like fiber bundle on the outer peripheral side rather than the inner peripheral side of the reinforcing layer. and the reinforcing layer includes a plurality of unit layers laminated on the outer surface of the liner, the unit layer is formed by winding the liner such that the strip-shaped fiber bundles are arranged in parallel in the width direction, and the strip-shaped fiber bundles are wider for the unit layers laminated on the outer peripheral side than on the inner peripheral side of the reinforcing layer It is characterized by this.

[0008] The manufacturing apparatus of the high-pressure tank of the present invention that achieves the above problem is a manufacturing apparatus of a high-pressure tank having a reinforcing layer on the outer surface of a hollow liner, and includes a feeding mechanism that feeds out a plurality of fiber bundles containing a curable resin, and a winding mechanism that integrally bundles the plurality of fiber bundles fed out from the feeding mechanism and forms them into a belt-like fiber bundle and winds the belt-like fiber bundle around the liner. The winding mechanism is configured to expand the belt-like fiber bundle laminated on the outer peripheral side rather than the inner peripheral side of the reinforcing layer. and the reinforcing layer includes a plurality of unit layers laminated on the outer surface of the liner, the unit layer is formed by winding the liner such that the strip-shaped fiber bundles are arranged in parallel in the width direction, and the strip-shaped fiber bundles are wider for the unit layers laminated on the outer peripheral side than on the inner peripheral side of the reinforcing layer It is characterized by this.

Effect of the Invention

[0009] According to the manufacturing method of the high-pressure tank of the present invention, the breaking strength of the reinforcing layer can be more reliably increased compared with the conventional method.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

Figure 8A

Figure 8B

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0011] Next, embodiments (embodiments) for carrying out the present invention will be described in detail with appropriate reference to the drawings. First, the high-pressure tank of this embodiment will be described, and then its manufacturing apparatus and manufacturing method will be described. ≪High-pressure Tank≫ FIG. 1 is a longitudinal sectional view of the high-pressure tank 1. FIG. 2 is a partially enlarged transverse sectional view of the high-pressure tank 1. The high-pressure tank 1 of the present embodiment is assumed to be mounted on, for example, a fuel cell vehicle and store hydrogen gas for supplying to a fuel cell system. However, the high-pressure tank 1 is not limited thereto and may be used for other high-pressure gases.

[0012] As shown in FIG. 1, the high-pressure tank 1 includes a liner 2, a base 3 connected to the liner 2, and a reinforcing layer 4 that covers the outside of these from the liner 2 to the base 3. The base 3 is assumed to be formed of a metal material such as an aluminum alloy. The base 3 has a cylindrical base body 3a having supply / discharge holes on the inside, and a flange portion 3b formed at one end side in the axial direction of the base body 3a.

[0013] The liner 2 is a hollow body made of a thermoplastic resin. Examples of the thermoplastic resin include, but are not limited to, polyamide resin and polyethylene resin. The liner 2 of the present embodiment includes a cylindrical body portion 5 and dome portions 6 integrally formed at both ends of the body portion 5. As shown in FIG. 1, the dome portion 6 is a flat bowl-shaped body that converges so as to gradually reduce the diameter outward in the direction of the axis Ax from the side of the body portion 5. The central portion in the radial direction of the dome portion 6 is recessed so as to correspond to the shape of the flange portion 3b of the base 3.

[0014] As shown in FIG. 1, the reinforcing layer 4 is formed from the outer surface of the liner 2 to the outer surface of the base 3. As will be described in detail later, this reinforcing layer 4 is formed by curing a curable resin contained in a tow prepreg wound from the liner 2 to the base 3. Note that the tow prepreg in the present embodiment is composed of a fiber bundle (tow) of reinforcing fibers containing a curable resin and has adhesiveness. As the curable resin of the prepreg, for example, thermosetting resins such as epoxy resins, phenolic resins, unsaturated polyester resins, and polyimide resins are assumed, but it is not limited thereto. In addition, examples of the reinforcing fiber include, but are not limited to, carbon fiber, glass fiber, aramid fiber, boron fiber, alumina fiber, silicon carbide fiber, etc.

[0015] As shown in FIG. 2, the reinforcing layer 4 is composed of a plurality of unit layers 7 laminated on the outer surface of the liner 2. The reinforcing layer 4 in the present embodiment is assumed to be composed of nine unit layers 7 in the body portion 5 of the liner 2, but the number of unit layers 7 is not limited thereto. The unit layer 7 is formed by arranging the band B (see FIG. 4), which is a strip-shaped fiber bundle sent out from the band delivery head 13b (see FIG. 4) in the manufacturing apparatus 10 described later, in parallel in the axial direction of the liner 2 (the direction perpendicular to the plane of FIG. 2). The band B corresponds to the "strip-shaped fiber bundle" referred to in the claims.

[0016] FIG. 3 is a partially enlarged longitudinal sectional view schematically showing a portion corresponding to part III of FIG. 1. As shown in FIG. 3, the reinforcing layer 4 in the present embodiment has, in a longitudinal sectional view along the axial direction of the liner 2, from the outer peripheral surface side of the body portion 5 of the liner 2 in order, a first unit layer 7a, a second unit layer 7b, a third unit layer 7c, and a fourth unit layer 7d. Further, as shown by a virtual line (dashed double-dotted line), five additional unit layers 7 are laminated on the upper surface of the fourth unit layer 7d.

[0017] The first unit layer 7a in the present embodiment is formed by arranging the band B having a width W1 in parallel in the axial direction of the liner 2 (the left-right direction in the plane of FIG. 3). The second unit layer 7b in the present embodiment is formed by the band B having a width W2. The third unit layer 7c is formed by the band B having a width W3. The fourth unit layer 7d is formed by the band B having a width W4.

[0018] And in the unit layer 7 forming the reinforcing layer 4, the width of the band B (hereinafter sometimes simply referred to as "band width") becomes wider as it goes toward the radially outer side of the liner 2. Specifically, as shown in FIG. 3, the band widths of the first unit layer 7a, the second unit layer 7b, the third unit layer 7c, and the fourth unit layer 7d satisfy the relationship of "W1 < W2 < W3 < W4".

[0019] Also, although not shown, in the five unit layers 7 laminated on the upper surface of the fourth unit layer 7d, the band width also becomes wider as it goes toward the radially outer side of the liner 2. Note that the unit layer 7 shown in FIG. 3 assumes that the band B is formed around the liner 2 by hoop winding (see FIG. 7) as described later. However, the configuration in which the band width becomes wider as it goes toward the radially outer side of the liner 2 can also be applied to high helical winding (see FIG. 9), low helical winding (see FIG. 10), etc., as described later. These unit layers 7 are integrated in the reinforcing layer forming step described later in which the curable resin of the tow prepreg is cured.

[0020] ≪Manufacturing apparatus for high-pressure tank≫ Next, the manufacturing apparatus for the high-pressure tank 1 will be described. FIG. 4 is an explanatory diagram of the configuration of the manufacturing apparatus 10. As shown in FIG. 4, the manufacturing apparatus 10 mainly includes a feeding mechanism 11 for the tow prepregs P1, P2, P3, P4, and P5, a guiding mechanism 12 for guiding these tow prepregs P1 to P5 sent out from the feeding mechanism 11 to the winding mechanism 13, a winding mechanism 13 for integrally winding the tow prepregs P1 to P5 guided by the guiding mechanism 12 and press-forming them into a band B having a predetermined width and winding this band B around the liner 2, and a band width adjusting mechanism 14 for adjusting the interval (combined width) between the tow prepregs P1 to P5 in advance so that the band B press-formed by the winding mechanism 13 has a predetermined width. The band width adjusting mechanism 14 corresponds to the "combined width adjusting mechanism" referred to in the claims.

[0021] As shown in FIG. 4, the delivery mechanism 11 includes bobbins 11a1, 11a2, 11a3, 11a4, and 11a5 around which the tow pre-pregs P1 to P5 are respectively traversely wound, and a plurality of bobbin motors (not shown) that individually assist the rotation of the bobbins 11a1 to 11a5 so that the tow pre-pregs P1 to P5 are respectively drawn out from the respective bobbins 11a1 to 11a5 with a predetermined tension. In this embodiment, the delivery mechanism 11 is assumed to include five bobbins 11a1 to 11a5. However, the number of bobbins is not limited to this and can be appropriately changed as needed.

[0022] As shown in FIG. 4, the guiding mechanism 12 includes a first roller 12a1 and a second roller 12a2 over which the tow pre-pregs P1 to P5 are spanned. In this embodiment, the guiding mechanism 12 includes four first rollers 12a1 and two second rollers 12a2. However, the numbers of the first rollers 12a1 and the second rollers 12a2 are not limited to this and can be appropriately changed as needed.

[0023] FIG. 5A is an overall perspective view of the first roller 12a1. FIG. 5B is an overall perspective view of the second roller 12a2. As shown in FIG. 5A, the first roller 12a1 is a substantially cylindrical body that rotates about an axis S. As shown in FIG. 5A, the first roller 12a1 individually guides the tow pre-pregs P1 to P5 (see FIG. 4) fed out from the delivery mechanism 11 (see FIG. 4). On the circumferential surface Cc of the first roller 12a1, a plurality (five in this embodiment) of guiding circumferential grooves G arranged in the axial direction of the axis S are formed. These guiding circumferential grooves G have a flat bottom surface with a predetermined width in the groove width direction. The tow pre-pregs P1 to P5 travel while contacting the bottom surfaces of these guiding circumferential grooves G from the upstream delivery mechanism 11 (see FIG. 4) to the downstream winding mechanism 13 (see FIG. 4). Thereby, the cross-sectional shapes of the tow pre-pregs P1 to P5 are gradually flattened. Such a first roller 12a1 (see FIG. 5A) can also be configured by a split roller that individually guides each of the tow prepregs P1 to P5 (see FIG. 4).

[0024] As shown in FIG. 5B, the second roller 12a2 is a substantially cylindrical body that rotates about the axis S. On the circumferential surface Cc of the second roller 12a2, a mountain portion M and a valley portion V extending in the axis S direction are formed so as to be alternately arranged in the circumferential direction. Further, the top of the mountain portion M that comes into contact with the tow prepregs P1 to P5 (see FIG. 4) is formed as a smooth curved surface in a cross-sectional view intersecting the axis S. Note that the number of the mountain portions M in the present embodiment that are continuous in the circumferential direction is set to 12, but can be increased or decreased as appropriate according to need. Such a second roller 12a2 (see FIG. 5B) forms each of the tow prepregs P1 to P5 (see FIG. 4) in a plate shape. Note that the second roller 12a2 can also be configured by a split roller that individually corresponds to each of the tow prepregs P1 to P5 (see FIG. 4).

[0025] As shown in FIG. 4, the four first rollers 12a1 in the present embodiment guide the tow prepregs P1 to P5 fed out from the feeding mechanism 11 so as to narrow the interval between them. The two second rollers 12a2 in the present embodiment further narrow the interval between the tow prepregs P1 to P5 fed out from the first roller 12a1 side and guide them to the band width adjusting mechanism 14 (see FIG. 4).

[0026] Next, the winding mechanism 13 (see FIG. 4) will be described prior to the band width adjusting mechanism 14 (see FIG. 4). As shown in FIG. 4, the winding mechanism 13 includes a drive unit 13a (rotary motor) that rotates the liner 2 around the axis Ax, and a band delivery head 13b that delivers the band B to the rotating liner 2. The band delivery head 13b arranges and integrates a plurality (five) of tow prepregs P1 to P5 formed in a plate shape by the guiding mechanism 12 (second roller 12a2) in the width direction. Thereby, the band delivery head 13b forms the band B which is a belt-shaped tow prepreg. The band delivery head 13b is composed of a pair of pressing rollers 13b1, 13b1 that are parallel with a predetermined clearance. The five tow prepregs P1 to P5 arranged side by side upstream of the band delivery head 13b are press-formed so as to be integrated when passing between the pair of pressing rollers 13b1, 13b1 to form a band B.

[0027] Further, the band delivery head 13b is movable in the axial direction Ax of the liner 2 while sending out the band B to the rotating liner 2. Specifically, the band delivery head 13b moves in the axial direction Ax in response to the rotation operation of the liner 2 so that the unit layer 7 (see FIG. 2) is formed on the outer peripheral side of the liner 2. As the moving means of the band delivery head 13b in the present embodiment, a linear actuator 13c such as an air cylinder or a linear motor is assumed, but it is not limited thereto.

[0028] Also, the band delivery head 13b is configured to adjust the tension of the band B supplied to the liner 2. Specifically, the band delivery head 13b is adapted to adjust the load applied to the tow prepreg P in a direction intersecting the traveling direction of the tow prepreg P. As the tension adjusting means of the band B in the present embodiment, a gap adjusting actuator 13d provided between the linear actuator 13c and the band delivery head 13b is assumed. Examples of the gap adjusting actuator 13d include a rack and pinion mechanism driven by a rotary motor and an air cylinder, but it is not limited thereto.

[0029] Further, the gap adjusting actuator 13d in the present embodiment is assumed to displace the band delivery head 13b based on the detected tension of the tow prepreg P or the band B so that the detected tension becomes a preset target tension. Note that, as the means for detecting the tension of the tow prepreg P or the band B, a sensor that detects the reaction force received by the band delivery head 13b from the tow prepreg P or the band B is mentioned, but it is not limited thereto. Note that the tension of the band B supplied to the liner 2 in this embodiment is constant from the start of winding to the end of winding around the liner 2. However, the tension of the band B can also be reduced as it goes further outward in the radial direction of the liner 2.

[0030] Next, the band width adjustment mechanism 14 (see FIG. 4) will be described. As shown in FIG. 4, the band width adjustment mechanism 14 adjusts the interval between five plate-shaped tow pre-pregs P1 to P5 sent from the guide mechanism 12 (the second roller 12a2) to the band delivery head 13b, that is, the combined width of the tow pre-pregs P1 to P5 described later.

[0031] FIG. 6 is a configuration explanatory diagram of the band width adjustment mechanism 14 (see FIG. 4). FIG. 6 schematically shows the state of looking down on the band width adjustment mechanism 14 shown in FIG. 4 from above. As shown in FIG. 6, the band width adjustment mechanism 14 mainly includes five guide rollers 14a1, 14a2, 14a3, 14a4, and 14a5, an actuator 14b that adjusts the axial interval between the five guide rollers 14a1 to 14a5, and a control unit 14c that controls the movement of the actuator 14b.

[0032] The guide rollers 14a1 to 14a5 are composed of H-shaped guide rollers having flanges at both axial ends. The guide rollers 14a1 to 14a5 are arranged in the order of the guide roller 14a1, the guide roller 14a2, the guide roller 14a3, the guide roller 14a4, and the guide roller 14a5 from above to below (from the front side to the back side of the paper surface of FIG. 6).

[0033] The guide roller 14a1 guides the plate-shaped tow prepreg P1 downstream while restricting the movement in the width direction thereof. The guide roller 14a2 guides the plate-shaped tow prepreg P2 downstream while restricting the movement in the width direction thereof. The guide roller 14a3 guides the plate-shaped tow prepreg P3 downstream while restricting the movement in the width direction thereof. The guide roller 14a4 guides the plate-shaped tow prepreg P4 downstream while restricting the movement in the width direction thereof. The guide roller 14a5 guides the plate-shaped tow prepreg P5 downstream while restricting the movement in the width direction thereof.

[0034] That is, the tow prepregs P1 to P5 are arranged from above to below (from the front side to the back side of the paper surface in FIG. 6) in the order of the tow prepreg P1, the tow prepreg P2, the tow prepreg P3, the tow prepreg P4, and the tow prepreg P5. And the tow prepregs P1 to P5 are arranged with a predetermined overlap allowance when viewed in the vertical direction.

[0035] The actuator 14b relatively moves the axial intervals of the other guide rollers 14a1 to 14a4 with respect to the guide roller 14a5. As shown by the white arrows in FIG. 6, the actuator 14b relatively moves the guide rollers 14a1 to 14a4 individually. Thereby, as shown in FIG. 6, when viewed in the vertical direction, the combined width of the tow prepregs P1 to P5 is widened. Although not shown, the actuator 14b can also narrow the combined width of the tow prepregs P1 to P5 by relatively moving the guide rollers 14a1 to 14a4 in the direction opposite to the white arrows shown in FIG. 6. Examples of the actuator 14b in the present embodiment include, but are not limited to, a rack and pinion mechanism driven by a rotary motor and an air cylinder.

[0036] The control unit 14c can be configured to include a ROM (Read Only Memory) that stores a program for controlling the actuator 14b, a RAM (Random Access Memory) that reads and expands the program stored in the ROM, and a CPU (Central Processing Unit) that executes the expanded program and outputs a command to the actuator 14b. The control unit 14c widens the alignment width of the prepregs P1 to P5 as shown in FIG. 6 according to a preset program. The procedure executed by the control unit 14c will be described together with the following method for manufacturing a high-pressure tank.

[0037] ≪Method for Manufacturing High-Pressure Tank≫ Next, the method for manufacturing the high-pressure tank 1 of the present embodiment will be described. The manufacturing method of the present embodiment includes a winding step of winding a band B (see FIG. 4) in which the prepregs P1 to P5 (see FIG. 4) are in a strip shape around the outer surface of the liner 2 (see FIG. 4), and a reinforcing layer forming step of curing the curable resin contained in the band B (prepregs P1 to P5) wound around the outer surface of the liner 2 to form a reinforcing layer 4 (see FIG. 2). Here, the manufacturing method of the present embodiment will be specifically described by taking as an example the method of winding the band B around the body portion 5 (see FIG. 3) of the liner 2 (see FIG. 3) by hoop winding.

[0038] FIG. 7 is an explanatory diagram of hoop winding of the band B with respect to the liner 2. As shown in FIG. 4, hoop winding is such that the band B is wound around the body portion 5 of the liner 2 in a nested (annular) shape. That is, in hoop winding, the angle θ1 (winding angle) formed by the extending direction D of the band B with respect to the axial direction Ax is set to an angle close to 90 degrees so that the bands B are parallel in the axial direction Ax. As a result, the band B forms a unit layer 7 (see FIG. 2) having a thickness substantially the same as the thickness of the band B on the outer peripheral surface of the body portion 5 of the liner 2.

[0039] In the winding process, as shown in FIG. 3, a plurality of unit layers 7 are formed on the outer peripheral surface of the body portion 5 of the liner 2. The formation of this unit layer 7 in hoop winding is performed, as shown in FIG. 4, by reciprocating the band delivery head 13b with respect to the rotating liner 2 at a distance corresponding to the length of the body portion 5 of the liner 2. Specifically, the odd-numbered unit layers 7 (see FIG. 3) are formed on the forward path of the band delivery head 13b, and the even-numbered unit layers 7 (see FIG. 3) are formed on the return path.

[0040] Such a winding process is performed so that the band width gradually widens toward the outer peripheral side of the reinforcing layer 4 (see FIG. 2). Specifically, as shown in FIG. 3, the winding process is performed such that the band widths of the first unit layer 7a, the second unit layer 7b, the third unit layer 7c, and the fourth unit layer 7d satisfy the relationship of "W1 < W2 < W3 < W4". Also, in the five unit layers 7 laminated on the upper surface of the fourth unit layer 7d, the winding process is performed such that the band width becomes wider toward the outer side in the radial direction of the liner 2 as described above.

[0041] The widening of the band B (see FIG. 4) in such a band delivery head 13b (see FIG. 4) is performed by the band width adjusting mechanism 14 widening the above-described alignment width of the tows P1 to P5 sent from the guiding mechanism 12 to the band delivery head 13b. Specifically, it is performed by the control unit 14c of the band width adjusting mechanism 14 controlling the actuator 14b according to a predetermined procedure.

[0042] FIG. 8A is a flowchart for explaining the procedure executed by the control unit 14c (see FIG. 6). FIG. 8B is an explanatory diagram of a table referred to when the control unit 14c (see FIG. 6) executes the procedure. As shown in FIG. 8A, the control unit 14c (see FIG. 6) first detects which layer the winding of the band B (see FIG. 3) around the liner 2 is (see step S101). The control unit 14c, for example, counts the number of times the band delivery head 13b reciprocates as described above, stores this in a predetermined memory, and reads the number of times from this memory to detect which layer the winding of the band B (see FIG. 3) is on.

[0043] Next, the control unit 14c (see FIG. 6) determines the target width of the band B, that is, the target band width, with reference to the table shown in FIG. 8B (see step S102). As shown in FIG. 8, the table prescribes in advance the band widths W1, W2, W3, W4 (W1 < W2 < W3 < W4) shown in FIG. 3 and the band widths in each of the plurality of unit layers 7 that are laminated on the upper surface of the fourth unit layer 7d (not shown in FIG. 3) and become wider toward the radially outer side of the liner 2. Then, when the control unit 14c (see FIG. 6) detects that the winding is on the third layer, for example, it sets the width W3 of the band B corresponding to the third unit layer 7c whose stacking layer order in the table shown in FIG. 8 is the third layer as the target band width.

[0044] Next, as shown in FIG. 8, the control unit 14c (see FIG. 6) outputs a drive command to the actuator 14b (see FIG. 6) so that the width of the band B (see FIG. 4) becomes the determined target width (target band width) (see step S103). Thereby, the subroutine in which the control unit 14c (see FIG. 6) controls the actuator 14b (see FIG. 6) ends.

[0045] Then, as shown in FIG. 6, based on the drive command from the control unit 14c, the actuator 14b adjusts the combined width of the prepregs P1 to P5 sent from the guide mechanism 12 (see FIG. 4) to the band delivery head 13b (see FIG. 4) to the target band width. As shown in FIG. 4, the band delivery head 13b sends out the band B with the target band width to the liner 2 side by press-forming the sent prepregs P1 to P5 as described above.

[0046] On the other hand, the band feeding head 13b reciprocates at a distance corresponding to the length of the body portion 5 of the liner 2, and stacks a plurality of unit layers 7 on the body portion 5 of the liner 2 as shown in FIG. 3. The band width for forming the unit layer 7 increases as it goes toward the outer side in the radial direction of the liner 2.

[0047] And, as shown in FIG. 7, the manufacturing method of the present embodiment assumes a configuration in which, after performing hoop winding of the band B only on the body portion 5 of the liner 2, the band B is further wound by high helical winding and low helical winding.

[0048] FIG. 9 is an explanatory diagram of the high helical winding of the band B (see FIG. 4). FIG. 10 is an explanatory diagram of the low helical winding of the band B (see FIG. 4). As shown in FIG. 9, in the high helical winding, the band B (see FIG. 4) is set such that the angle θ2 (winding angle) formed by the extending direction D of the band B with respect to the axis Ax direction is approximately 75 degrees. As a result, the band B is wound across the body portion 5 of the liner 2 on which hoop winding has been performed and the peripheral edge portion of the dome portion 6 adjacent to this body portion 5. As shown in FIG. 10, in the low helical winding, the band B (see FIG. 4) is set such that the angle θ3 (winding angle) formed by the extending direction D of the band B with respect to the axis Ax direction is approximately 10 degrees. As a result, the band B is wound from the body portion 5 of the liner 2 on which hoop winding and high helical winding have been performed across the entire dome portion 6.

[0049] Note that the band width of the high helical winding and the band width of the low helical winding in the manufacturing method of the present embodiment are set to be the same as the band width of the outermost hoop winding. However, the band width of the high helical winding and the band width of the low helical winding can also be configured to widen as they go toward the outer peripheral side of the reinforcing layer 4 (see FIG. 1).

[0050] In the reinforcing layer forming step, the liner 2 (see FIG. 4) that has completed the winding step is removed from the winding mechanism 13 (see FIG. 4) and heated at a predetermined temperature in a heating furnace (not shown). As a result, the curable resin contained in the band B (see FIG. 4) wound around the liner 2 cures. In the process of the curable resin curing, the plurality of unit layers 7 (see FIG. 5) stacked together integrate and adhere to the outer surface of the liner 2. Thereby, the reinforcing layer 4 (see FIG. 1) is formed and the manufacturing process of the series of high-pressure tanks 1 is completed.

[0051] ≪Function and Effect≫ Next, the functions and effects of the high-pressure tank 1, the manufacturing method thereof, and the manufacturing apparatus 10 according to the present embodiment will be described. In the high-pressure tank 1 of the present embodiment, the band B (band-shaped fiber bundle) widens on the outer peripheral side rather than the inner peripheral side of the reinforcing layer 4. According to this high-pressure tank 1, since the band B on the outer peripheral side widens more than the band B on the inner peripheral side, the surface pressure (pressure per unit area of the band B) exerted by the band B on the outer peripheral side on the band B on the inner peripheral side is reduced. According to this high-pressure tank 1, unlike a conventional high-pressure tank (see, for example, Patent Document 1), loosening of the fibers of the band B on the inner layer side is suppressed. Thereby, the high-pressure tank 1 can more reliably increase the breaking strength of the reinforcing layer 4 as compared with the conventional one.

[0052] Further, in such a high-pressure tank 1, the reinforcing layer 4 includes a plurality of unit layers 7 laminated on the outer surface of the liner 2. Further, the unit layer 7 is formed by winding the liner 2 so that the bands B (band-shaped fiber bundles) are arranged in parallel in the width direction. And the band B widens more in the unit layer 7 laminated on the outer peripheral side than the inner peripheral side of the reinforcing layer 4. According to this high-pressure tank 1, since the band B widens for each of the laminated unit layers 7, the breaking strength of the reinforcing layer 4 can be further reliably increased.

[0053] Further, in such a high-pressure tank 1, the liner 2 is configured to have a cylindrical body portion 5 and dome portions 6 at both ends of the body portion 5. And the plurality of unit layers 7 are formed only on the body portion 5 of the liner 2. According to this high-pressure tank 1, by more intensively winding the band B around the body portion 5 rather than the dome portion 6 having a relatively high strength against the internal pressure of the high-pressure tank 1, the reinforcement layer 4 of the entire high-pressure tank 1 can be strengthened more efficiently.

[0054] The manufacturing method of the high-pressure tank 1 of this embodiment includes a winding step of winding and laminating a band B (a strip-shaped fiber bundle containing a curable resin) around the outer surface of the liner 2, and a reinforcing layer forming step of curing the curable resin contained in the band B wound around the outer surface to form a reinforcing layer 4. The winding step includes a step of widening the band B on the outer peripheral side rather than the inner peripheral side of the reinforcing layer 4. According to such a manufacturing method of the high-pressure tank 1, a high-pressure tank 1 with a higher breaking strength of the reinforcing layer 4 can be manufactured more reliably compared with the prior art.

[0055] Also, in such a manufacturing method, the winding step is performed by hoop winding of the band B (strip-shaped fiber bundle) around the body portion 5 of the liner 2. According to this manufacturing method, since the band B is wound around the body portion 5 of the liner 2 so as to form a substantially right angle with respect to the axis Ax of the liner 2, the band B can contribute more effectively to the improvement of the breaking strength of the reinforcing layer 4.

[0056] The manufacturing apparatus 10 of the high-pressure tank 1 of this embodiment includes a feeding mechanism 11 for feeding out tow prepregs P1 to P5 (a plurality of fiber bundles containing a curable resin), and a winding mechanism 13 for integrally collecting the tow prepregs P1 to P5 fed out from the feeding mechanism 11 to form a band B (strip-shaped fiber bundle) and winding the band B around the liner 2. The winding mechanism 13 is configured to widen the band B laminated on the outer peripheral side rather than the inner peripheral side of the reinforcing layer 4. According to this manufacturing apparatus, a high-pressure tank 1 with a higher breaking strength of the reinforcing layer 4 can be manufactured more reliably compared with the prior art.

[0057] In such a manufacturing apparatus 10, a guiding mechanism 12 that flattens the cross-sectional shapes of the tow pre-pregs P1 to P5 (a plurality of fiber bundles containing a curable resin) into a plate shape while guiding the tow pre-pregs P1 to P5 from a feeding mechanism 11 to a winding mechanism 13, and a band width adjusting mechanism 14 (a width adjustment mechanism) that sets the combined width of the flattened tow pre-pregs P1 to P5 to the width of a band B (a belt-like fiber bundle) that the winding mechanism 13 winds around the liner 2 are further provided. According to this manufacturing apparatus 10, the winding mechanism 13 can widen the band B that is laminated on the outer peripheral side rather than the inner peripheral side of the reinforcing layer 4 more accurately.

[0058] As described above, the embodiments of the present invention have been explained, but the present invention is not limited to the above embodiments and can be implemented in various forms. In the manufacturing method of the above embodiment, the process having steps of performing high helical winding and low helical winding following the hoop winding of the band B around the liner 2 has been explained. However, the order of hoop winding, high helical winding, and low helical winding, which are the ways of winding the band B around the liner 2, can be mutually interchanged.

[0059] Also, the widening of the band B in the above embodiment is assumed to be applied only to the hoop winding performed on the body portion 5 of the liner 2. However, for the widening of the band B, it is sufficient that the band width is wider than that of the band B in which at least a part of the band B in any of hoop winding, high helical winding, and low helical winding is wound around its inner peripheral side.

[0060] Also, in the winding process of the manufacturing method of the above embodiment, hoop winding and helical winding are combined in the layer thickness direction of the reinforcing layer 4, and the winding angles θ1, θ2, θ3 of the band B (belt-like fiber bundle) around the liner 2 (see FIGS. 7, 9, and 10) change. Assuming a manufacturing method of the high-pressure tank 1 in which the winding orders of the hoop winding, high helical winding, and low helical winding, which are the winding methods of the band B around the liner 2, are mutually interchanged, the winding angle of the band B changes from θ1 to θ2 or θ3, from θ2 to θ1 or θ3, or from θ3 to θ1 or θ2. In such a manufacturing method, prior to changing the winding angle of the band B, connector winding in which the band B is wound around the liner 2 at a winding angle between the winding angles to be changed can be interposed.

[0061] FIG. 11 is an explanatory diagram of the connector winding of the band B. In FIG. 11, the body portion 5 of the liner 2 is drawn to be longer in the axial direction of the axis Ax than the actual one for the convenience of drawing. Here, taking the case of changing from the low helical winding (see FIG. 10) to the hoop winding (see FIG. 7) as an example, the connector winding of the band B will be described. In FIG. 11, the symbol Lh indicates the end position of the low helical winding (see FIG. 10) around the liner 2. The symbol hh indicates the start position of the hoop winding (see FIG. 7) around the liner 2.

[0062] As shown in FIG. 11, when the winding method of the band B of the connector winding changes from the low helical winding (see FIG. 10) with the winding angle θ3 to the hoop winding (see FIG. 7) with the winding angle θ1, it goes from the end position Lh of the low helical winding (see FIG. 10) set on one end side of the axis Ax of the liner 2 to the start position hh of the hoop winding (see FIG. 7) set at the end of the body portion 5 at the other end and is wound around the liner 2 in one round trip. And, during one round trip, the band B of the connector winding is wound around the liner 2 so as to gradually shift from the winding angle θ3 to the winding angle θ1 at a winding angle between the winding angle θ3 (see FIG. 10) to be changed and the winding angle θ1 (see FIG. 7), that is, at a winding angle exceeding θ3 and less than θ1. According to such a connector winding (see FIG. 11), it is possible to prevent the winding slippage of the band B due to the change in the winding angle.

[0063] In addition, in the manufacturing method of this embodiment with such a connector winding (see FIG. 11) interposed, the band B of the connector winding can be configured to have a width wider than that of the band B on the inner peripheral side.

[0064] That is, in the winding process of this manufacturing method, hoop winding and helical winding are combined in the layer thickness direction of the reinforcing layer 4 so that the winding angle of the band B (band-shaped fiber bundle) with respect to the outer surface of the liner 2 changes. Prior to changing the winding angle, a connector winding is interposed in which the band B (band-shaped fiber bundle) is wound at the winding angle between the winding angles to be changed. The band B (band-shaped fiber bundle) of the connector winding is made wider compared to the band B (band-shaped fiber bundle) on the inner peripheral side of the band B (band-shaped fiber bundle) of the connector winding.

[0065] According to such a manufacturing method, even when the reinforcing layer 4 is configured by winding the band B in a manner in which the winding angle changes, the slippage of the band B is suppressed, so that a high-pressure tank 1 with an even higher breaking strength of the reinforcing layer 4 can be manufactured.

Explanation of Reference Numerals

[0066] 1 High-pressure tank 2 Liner 4 Reinforcing layer 5 Body 6 Dome part 7 Unit layer 11 Feeding mechanism 12 Guide mechanism 13 Winding mechanism 14 Band width adjusting mechanism (alignment width adjusting mechanism) B Band (band-shaped fiber bundle) P1~P5 Tow prepreg (plural fiber bundles)

Claims

1. A hollow liner, a reinforcing layer formed on an outer surface of the liner, and having, the reinforcing layer is formed by winding a strip-shaped fiber bundle containing a curable resin around the liner, the strip-shaped fiber bundle is widened on an outer peripheral side rather than an inner peripheral side of the reinforcing layer, the reinforcing layer includes a plurality of unit layers laminated on the outer surface of the liner, the unit layer is formed by winding the liner such that the strip-shaped fiber bundles are arranged in parallel in a width direction, the strip-shaped fiber bundle is widened more in the unit layer laminated on the outer peripheral side rather than the inner peripheral side of the reinforcing layer, characterized in that it is a high-pressure tank.

2. The liner is configured to have a cylindrical body portion and dome portions at both ends of the body portion, the plurality of unit layers are formed only on the body portion of the liner, characterized in that it is the high-pressure tank according to Claim 1.

3. Having a reinforcing layer on an outer surface of a hollow liner, the reinforcing layer includes a plurality of unit layers laminated on the outer surface of the liner, the unit layer is formed by winding the liner such that the strip-shaped fiber bundles are arranged in parallel in a width direction, a method for manufacturing a high-pressure tank, wherein the strip-shaped fiber bundle is widened more in the unit layer laminated on the outer peripheral side rather than the inner peripheral side of the reinforcing layer, a winding step of winding and laminating a strip-shaped fiber bundle containing a curable resin on the outer surface of the liner, a reinforcing layer forming step of curing the curable resin contained in the fiber bundle wound on the outer surface to form the reinforcing layer, and having, the winding step includes a step of widening the strip-shaped fiber bundle on an outer peripheral side rather than an inner peripheral side of the reinforcing layer, characterized in that it is a method for manufacturing a high-pressure tank.

4. The winding step is performed by hoop winding of the strip-shaped fiber bundle around the body portion of the liner, characterized in that it is the method for manufacturing a high-pressure tank according to Claim 3.

5. A method for manufacturing a high-pressure tank having a reinforcing layer on an outer surface of a hollow liner, a winding step of winding and laminating a strip-shaped fiber bundle containing a curable resin on the outer surface of the liner, a reinforcing layer forming step of curing the curable resin contained in the fiber bundle wound on the outer surface to form the reinforcing layer, and having, the winding step includes a step of widening the strip-shaped fiber bundle on an outer peripheral side rather than an inner peripheral side of the reinforcing layer, the winding step is performed such that hoop winding and helical winding are combined in a layer thickness direction of the reinforcing layer so that a winding angle of the strip-shaped fiber bundle with respect to the outer surface of the liner changes. Prior to changing the winding angle, an interposed connector winding is provided, in which the belt-like fiber bundle is wound at an angle between the winding angles to be changed. A method for manufacturing a high-pressure tank, characterized in that the belt-like fiber bundle of the connector winding is widened as compared with the belt-like fiber bundle on the inner peripheral side of the belt-like fiber bundle of the connector winding. **Claim 6** A reinforcing layer is provided on the outer surface of a hollow liner. The reinforcing layer includes a plurality of unit layers laminated on the outer surface of the liner. The unit layer is formed by winding the liner such that the belt-like fiber bundles are arranged in parallel in the width direction. A manufacturing apparatus for a high-pressure tank, wherein the belt-like fiber bundle is widened more in the unit layer laminated on the outer peripheral side than on the inner peripheral side of the reinforcing layer. The manufacturing apparatus includes: A feeding mechanism for feeding out a plurality of fiber bundles containing a curable resin; A winding mechanism for integrally bundling the plurality of fiber bundles fed out from the feeding mechanism and forming them into a belt-like fiber bundle, and winding the belt-like fiber bundle around the liner; and The winding mechanism is configured to widen the belt-like fiber bundle laminated on the outer peripheral side more than the inner peripheral side of the reinforcing layer. **Claim 7** The manufacturing apparatus for a high-pressure tank according to claim 6, further comprising: a guiding mechanism for flattening the cross-sectional shape of the fiber bundle into a plate shape while guiding the plurality of fiber bundles from the feeding mechanism to the winding mechanism; and a width adjustment mechanism for setting the combined width of the plurality of flattened fiber bundles to the width of the belt-like fiber bundle wound around the liner by the winding mechanism.

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