阅读说明：本技术 储罐的制造方法 (Method for manufacturing storage tank ) 是由 饭田康博 于 2019-06-03 设计创作，主要内容包括：本发明涉及储罐的制造方法,是通过在内衬的外周卷绕多层含浸有树脂的纤维来制造储罐的方法,包括：环状卷绕含浸有所述树脂的所述纤维来层叠多个环状层；以及以覆盖环状层的方式螺旋卷绕含浸有树脂的纤维来层叠多个螺旋层。在层叠多个螺旋层时,将含浸有所述树脂的所述纤维的温度调整为40℃以上且60℃以下。(The present invention relates to a method for manufacturing a tank by winding a plurality of layers of resin-impregnated fibers around the outer periphery of a liner, the method including: winding the fiber impregnated with the resin in a ring shape to laminate a plurality of ring-shaped layers; and spirally winding a resin-impregnated fiber so as to cover the annular layer, thereby laminating a plurality of spiral layers. When a plurality of spiral layers are laminated, the temperature of the fibers impregnated with the resin is adjusted to 40 ℃ to 60 ℃.)

1. A method for manufacturing a tank by winding a plurality of layers of resin-impregnated fibers around the outer periphery of a liner, the method comprising:

winding the fiber impregnated with the resin in a ring shape to laminate a plurality of ring-shaped layers; and

spirally winding the fiber impregnated with the resin so as to cover the annular layer to laminate a plurality of spiral layers;

wherein the temperature of the fibers impregnated with the resin is adjusted to 40 ℃ to 60 ℃ when the spiral layers are laminated.

2. The method of manufacturing a storage tank of claim 1,

in the case of manufacturing the tank by using a manufacturing apparatus having a resin fiber conveying roller for conveying the fiber impregnated with the resin,

the temperature of the fibers impregnated with the resin is adjusted by controlling frictional heat generated by rotation of the resin fiber conveying roller when the spiral layers are laminated.

3. The method of manufacturing a storage tank according to claim 1 or 2,

in the case of manufacturing the storage tank using the manufacturing apparatus having the heater,

the temperature of the fibers impregnated with the resin is adjusted by the heater when the spiral layers are laminated.

4. A method of manufacturing a tank according to any one of claims 1 to 3,

the temperature of the fibers impregnated with the resin is adjusted to 40 ℃ to 50 ℃ when the spiral layers are laminated.

5. The method of manufacturing a storage tank of claim 2,

controlling the rotation of the resin fiber conveying roller includes:

rotating the resin fiber feed roller in the same direction as the rotation direction of the liner;

rotating the resin fiber feed roller in a direction opposite to the rotation direction of the liner; and

the rotation of the resin fiber feed roller is stopped.

Technical Field

The present invention relates to a method for manufacturing a tank (tank) by winding a plurality of layers of resin-impregnated fibers around the outer periphery of a liner (liner).

Background

Storage tanks such as hydrogen storage tanks mounted on fuel cell vehicles require high strength and the like in order to ensure safety. As a method for manufacturing such a tank, for example, a Fiber Winding (FW) method described in international publication No. 2010/116526 is known. Namely, the following production method: the fiber impregnated with the uncured thermosetting resin is repeatedly wound around the outer periphery of the liner to form the annular layer and the spiral layer on the outer side of the annular layer, respectively, and then the thermosetting resin is thermally cured.

Disclosure of Invention

However, in the above-described manufacturing method, when the formation of the annular layer is switched to the formation of the spiral layer, the orientation of the fibers is changed, and therefore, permeation (penetration) of the resin impregnated into the fibers is deteriorated, and voids are likely to be generated. When a void is generated, the initial strength and fatigue strength of the tank are reduced.

The invention provides a method for manufacturing a storage tank, which can inhibit the generation of voids and improve the strength.

A method for manufacturing a tank according to an aspect of the present invention is a method for manufacturing a tank by winding a plurality of layers of resin-impregnated fibers around an outer periphery of a liner, the method including: winding the fiber impregnated with the resin in a ring shape to laminate a plurality of ring-shaped layers; and spirally winding the fiber impregnated with the resin so as to cover the annular layer to laminate a plurality of spiral layers; the temperature of the fibers impregnated with the resin is adjusted to 40 ℃ to 60 ℃ at least when the spiral layers are laminated.

In the method for manufacturing a tank according to one aspect of the present invention, the temperature of the resin-impregnated fiber is adjusted to 40 ℃ or higher and 60 ℃ or lower at least when the spiral layers are laminated, whereby the viscosity of the resin impregnated into the fiber can be reduced and the permeability of the resin can be improved. Therefore, even when the orientation of the fibers is changed as in the case of switching from the formation of the annular layer to the formation of the spiral layer, the epoxy resin can be impregnated, and therefore, the generation of voids can be suppressed and the strength of the tank can be improved.

In the method of manufacturing a pitcher according to one aspect of the present invention, when the pitcher is manufactured using a manufacturing apparatus including a resin fiber conveying roller for conveying the fibers impregnated with the resin, the temperature of the fibers impregnated with the resin may be adjusted by controlling frictional heat generated by rotation of the resin fiber conveying roller when the spiral layers are laminated. In this way, the temperature adjustment of the fiber can be performed only by the existing equipment without adding equipment, and therefore, the cost can be kept low.

In the method of manufacturing a tank according to one aspect of the present invention, when the tank is manufactured using a manufacturing apparatus having a heater, the temperature of the resin-impregnated fiber may be adjusted by the heater when the spiral layers are laminated. This makes it possible to cope with temperature adjustment only by existing equipment and prevent damage to the resin-impregnated fiber.

In the method of manufacturing a tank according to one aspect of the present invention, the temperature of the fibers impregnated with the resin may be adjusted to 40 ℃ or higher and 50 ℃ or lower when the spiral layers are laminated.

In the method for manufacturing a tank according to one aspect of the present invention, the controlling of the rotation of the resin fiber feed roller may include: rotating the resin fiber feed roller in the same direction as the rotation direction of the liner; rotating the resin fiber feed roller in a direction opposite to the rotation direction of the liner; and stopping the rotation of the resin fiber conveying roller.

According to the above aspect, the strength can be improved by suppressing the generation of voids.

Drawings

Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described with reference to the accompanying drawings, in which like reference numerals refer to like parts.

Fig. 1 is a sectional view showing the structure of the tank.

Fig. 2 is a schematic diagram for explaining formation of a hoop layer by hoop winding.

Fig. 3 is a schematic diagram for explaining formation of a spiral layer by spiral winding.

Fig. 4 is a graph showing the relationship between the temperature of the epoxy resin impregnated fiber and Vf (fiber volume content) of the tank.

Detailed Description

Hereinafter, embodiments of the method for manufacturing the storage tank will be described with reference to the drawings. In the following description, an example of the resin-impregnated fiber is described as an example of the fiber impregnated with an epoxy resin, but the fiber may be impregnated with a polyester resin, a polyamide resin, or the like. In the following description, the "epoxy resin-impregnated fiber" may be omitted as the "fiber" in order to avoid the complexity of the description.

First, the structure of the tank will be described with reference to fig. 1. Fig. 1 is a sectional view showing the structure of the tank. The tank 1 is a high-pressure tank mounted on a fuel cell vehicle, for example, and can store high-pressure hydrogen therein. The tank 1 has: a liner 10 having a fluid storage space, and a reinforcing layer (i.e., a fiber-reinforced resin layer) 20 closely attached to the outer periphery of the liner 10.

The liner 10 has a gas barrier property against hydrogen gas. The liner 10 is a hollow container having a substantially cylindrical body portion 11 and substantially hemispherical dome portions 12 provided at both left and right ends of the body portion 11. Openings are formed in the top portions of the 2 dome portions 12, respectively, and a valve side bayonet (joint) 13 is inserted into one of the openings and an end side bayonet 14 is inserted into the other.

The liner 10 is integrally formed by a rotational blow molding method using a resin member such as polyethylene or nylon. The liner 10 may be formed of a light metal such as aluminum instead of the resin member. Instead of the integral molding manufacturing method such as the rotational blow molding method, the liner 10 may be formed by joining a plurality of divided members formed by injection/extrusion molding or the like.

The reinforcing layer 20 includes a plurality of loop (hop) layers 21 laminated to cover the outer periphery of the body portion 11 of the liner 10, and a plurality of spiral layers 22 covering the entire liner 10 so as to surround the plurality of loop layers 21 and the dome portion 12.

As shown in fig. 2, the annular layer 21 is a fiber layer formed by annularly winding the epoxy resin-impregnated fiber 15 in the circumferential direction of the main body 11 at a winding angle substantially perpendicular to the central axis L of the liner 10. Here, "substantially perpendicular" includes both 90 ° and angles around 90 ° that are generated by shifting the winding positions of the fibers 15 so that the fibers 15 do not overlap each other.

On the other hand, as shown in fig. 3, the spiral layer 22 is formed by spirally winding the fibers 15 in the circumferential direction of the main body portion 11 and the dome portion 12 at a winding angle of more than 0 ° and less than 90 ° with respect to the central axis L of the liner 10. In addition, the spiral winding is further classified into low-angle spiral winding and high-angle spiral winding according to the winding angle. The low-angle helical winding is a helical winding when the winding angle is small (for example, greater than 0 ° and 30 ° or less), and is a winding method in which the fiber 15 is folded back in the winding direction at the dome portion 12 before the fiber 15 makes one turn around the center axis L. The high-angle helical winding is a helical winding when the winding angle is large (for example, larger than 30 ° and smaller than 90 °), and is a winding method in which the fiber 15 is wound around the central axis L at least once in the main body portion 11 until the fiber 15 is folded back in the winding direction at the dome portion 12. Further, fig. 3 shows a low-angle helical winding.

Next, a method for manufacturing the accumulator 1 will be explained. The method for manufacturing the storage tank 1 of the present embodiment mainly includes: the method for manufacturing the liner 10 includes a ring layer laminating step of laminating a plurality of ring layers 21 on the outer periphery of the body portion 11, a spiral layer laminating step of laminating a plurality of spiral layers 22 covering the entire liner 10, and a thermosetting step of thermosetting the laminated ring layers 21 and spiral layers 22 in this order.

In the annular layer laminating step, as shown in fig. 2, the fibers 15 impregnated with the epoxy resin are wound in an annular shape from the side close to the outer periphery of the main body portion 11 of the liner 10 toward the side away from the outer periphery, and a plurality of annular layers 21 are sequentially laminated. Specifically, the liner 10 is rotated about its center axis L in a state where the liner 10 is attached to a rotation driving unit (not shown) provided in the tank manufacturing apparatus.

At the same time, the resin fiber feed roller 30 around which the epoxy resin-impregnated fiber 15 is wound is reciprocated along the central axis L direction, and feeds the fiber 15 to the liner 10 side. At this time, the resin fiber feed roller 30 rotates in the same direction as the rotation direction of the liner 10.

The fiber 15 is wound in a loop from one end (left end in fig. 2) of the body 11 toward the other end (right end in fig. 2) to form a 1 st loop layer 21 on the outer periphery of the body 11. Next, the fiber 15 is wound in a loop from the other end of the body 11 toward one end, whereby the loop layer 21 of the 2 nd layer is laminated outside the loop layer 21 of the 1 st layer. Next, the annular layer 21 of the 3 rd layer, the annular layers 21 and … of the 4 th layer, and the annular layer 21 of the N +1 th layer are sequentially stacked outside the annular layer 21 of the 2 nd layer, outside the annular layer 21 of the 3 rd layer, and outside the annular layer 21 of the N +1 th layer.

Here, in order to reduce the step difference at the boundary between the main body portion 11 and the crown portion 12, it is preferable that the plurality of annular layers 21 are laminated such that both right and left end portions of the laminated annular layers 21 are inclined so as to be shifted inward in a stepwise manner in the direction of the central axis L. That is, the length of the cross section of the N +1 th annular layer 21 taken along the central axis L is shorter than the length of the cross section of the N-th annular layer 21 taken along the central axis L.

In the spiral layer laminating step following the annular layer laminating step, the fibers 15 impregnated with the epoxy resin are spirally wound so as to cover the laminated annular layer 21 and dome portion 12, thereby laminating a plurality of spiral layers 22. In the spiral layer laminating step of the present embodiment, the temperature of the epoxy resin impregnated fiber 15 is adjusted to 40 to 60 ℃.

Here, the reason why the temperature of the epoxy resin impregnated fiber 15 is set to 40 to 60 ℃.

By setting the temperature of the epoxy resin-impregnated fiber 15 higher than the normal temperature, the generation of voids can be suppressed. This is because the viscosity of the epoxy resin impregnated into the fibers 15 is lowered by increasing the temperature to be higher than the normal temperature, and the permeability of the epoxy resin can be improved.

In addition, the initial strength (also referred to as rupture strength) of the tank 1 greatly depends on Vf (fiber volume content). Vf is the proportion of fibers in a predetermined area of the radial cross section of the tank 1, and is calculated by Vf (fiber area/total area) × 100%. The total area is the cross section of the reinforcement layer 20 and is formed by fibers, epoxy and voids. Further, when Vf is large, the fiber content is high, and therefore the initial strength is also high.

Fig. 4 is a graph showing the relationship between the temperature of the epoxy resin impregnated fiber 15 and Vf of the tank 1. As shown in fig. 4, Vf increases as the temperature increases, and therefore the initial strength of the tank 1 also increases. However, if Vf is too large, there is a problem that the fatigue strength of the tank 1 is reduced. In order to increase the strength of the tank 1, both the initial strength and the fatigue strength need to be satisfied.

Accordingly, the inventors of the present invention have made extensive studies and found that the initial strength and the fatigue strength of the tank 1 can be satisfied at the same time when the temperature of the fiber 15 is 40 to 60 ℃. Specifically, the inventors of the present application prepared samples under various temperature conditions, and examined the relationship between temperature and Vf, and the influence of temperature on the initial strength and fatigue strength of the prepared samples. In addition, the relationship between the temperature and Vf shown in fig. 4 is a result of actual investigation by the inventors of the present application.

On the other hand, with respect to the influence of temperature on the initial strength and the fatigue strength, a fracture test and a cycle fatigue test were performed under the following conditions. In the burst test, the pressure of the storage tank was increased to 126MPa at an increasing rate of 0.35MPa/s using the water pressure, and kept in this state for 4 minutes. Then, the pressure increase was continued until the tank was ruptured, and the pressure at rupture (i.e., initial strength) was measured. In the cyclic fatigue test, the expansion and contraction under a pressure of 2 to 87.5MPa are repeated at normal temperature, and the number of times of expansion and contraction until the tank is ruptured or leaked is evaluated. The results of the test are shown in table 1.

[ TABLE 1 ]

Temperature (. degree.C.)	Initial Strength (MPa)	Can you go 45000 times?
			15	185	NO (35000 times)
45	205	Can be used for
			80	220	NO (30000 times)

According to table 1, the initial strength of the sample of the tank prepared by adjusting the temperature of the fiber 15 to 15 ℃ was 185MPa, and the number of times until fracture and leakage was 35000 times. The initial strength of the sample of the tank prepared by adjusting the temperature of the fiber 15 to 45 ℃ was 205MPa, and the number of times until rupture and leakage was 45000 or more. The initial strength of the sample of the tank prepared by adjusting the temperature of the fiber 15 to 80 ℃ was 220MPa, and the number of times until rupture and leakage was 30000.

Based on these test results and the like, it was found that the initial strength of the tank can be improved and the fatigue strength of the tank can be maintained by adjusting the temperature of the epoxy resin-impregnated fiber to 40 to 60 ℃. Here, it is more preferable that the temperature of the fiber containing the impregnated epoxy resin is 40 to 50 ℃. This can effectively achieve both the initial strength and the fatigue strength of the tank 1.

In addition, as a method of adjusting the temperature of the epoxy resin impregnated fiber 15 to 40 to 60 ℃ in the spiral layer laminating step of the present embodiment, for example, the following 2 methods are exemplified.

The first is a method of adjusting the temperature of the epoxy resin-impregnated fiber 15 using frictional heat generated by controlling the rotation of the resin fiber conveying roller 30. Normally, the resin fiber feed roller 30 rotates in the same direction as the rotation direction of the liner 10 while applying a constant tension to the fibers 15 wound therearound, and discharges the fibers 15 toward the liner 10. In the spiral layer laminating step of the present embodiment, by stopping the rotation of the resin fiber feed roller 30 or rotating the resin fiber feed roller 30 in the direction opposite to the rotation direction of the liner 10, frictional heat is generated between the fibers 15 and the resin fiber feed roller 30, and the fibers 15 are heated by the frictional heat.

The temperature control for heating is performed by measuring the surface temperature of the liner 10 using a non-contact thermometer, for example.

When the measured temperature is less than 40 ℃, the rotation of the resin fiber feed roller 30 is stopped, for example, and the fibers 15 are heated by the frictional heat between the fibers 15 and the resin fiber feed roller 30. When the temperature of the fibers 15 cannot be sufficiently raised by merely stopping the rotation of the resin fiber feed roller 30, the fibers 15 are heated by increasing the frictional heat by rotating the resin fiber feed roller 30 in the reverse direction (i.e., in the direction opposite to the rotation direction of the liner 10). On the other hand, when the measured temperature exceeds 60 ℃, the resin fiber conveying roller 30 is rotated in the normal direction (i.e., rotated in the same direction as the rotation direction of the liner 10) to reduce the frictional heat, thereby adjusting the temperature.

By adjusting the temperature of the fibers 15 by controlling the frictional heat generated by the rotation of the resin fiber conveying roller 30 in this way, the temperature adjustment of the fibers 15 can be dealt with only by existing equipment without adding equipment, and therefore, the cost can be kept low.

The 2 nd is a method of heating the temperature of the fiber 15 by a heater (not shown) in the case where the manufacturing apparatus has the heater. At this time, the entire liner 10 may be heated to 40 to 60 ℃ by a heater, or only the portion of the fiber 15 to be wound may be heated. This makes it possible to adjust the temperature of the fiber 15 only by using conventional equipment, and prevent damage to the fiber 15.

In the thermosetting step following the spiral layer laminating step, the liner 10 having the laminated annular layer 21 and spiral layer 22 is placed in a thermostatic bath, and heated at a temperature of, for example, about 85 ℃. Thereby, the tank 1 is completed.

In the method of manufacturing the tank 1 according to the present embodiment, the temperature of the epoxy resin-impregnated fiber 15 is adjusted to 40 to 60 ℃ in the spiral layer laminating step, whereby the viscosity of the epoxy resin impregnated in the fiber 15 can be reduced and the permeability of the epoxy resin can be improved. Therefore, even when the orientation of the fibers 15 is changed as in the case of switching from the formation of the annular layer 21 to the formation of the spiral layer 22, the epoxy resin can be impregnated, and therefore, the generation of voids can be suppressed.

Further, the initial strength and the fatigue strength of the tank 1 can be satisfied by adjusting the temperature of the epoxy resin impregnated fiber 15 to 40 to 60 ℃, and therefore, the strength of the tank 1 can be improved.

While the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the spirit of the present invention described in the claims.

For example, although the temperature of the fibers 15 is adjusted to 40 to 60 ℃ in the case of the spiral layer lamination in the above embodiment, the temperature of the fibers 15 may be adjusted to 40 to 50 ℃ in the case of the annular layer lamination, if necessary. In the above-described embodiment, as a method of adjusting the temperature of the epoxy resin impregnated fiber 15, a method of using frictional heat generated by controlling the rotation of the resin fiber conveying roller 30 or a method of using a heater is described, but these methods may be used in combination as needed, or a device such as a heating nozzle may be used.