JP2019132340A - High pressure tank - Google Patents

Abstract

To suppress occurrence of damage at a welded part of a liner.SOLUTION: A high-pressure tank comprises: a liner in which a plurality of resin parts are joined at a thermally welded part; a reinforcing layer formed on the liner; and a release film arranged between the liner and the reinforcing layer, and preventing fastening between the liner and the reinforcing layer. The release film has at least a surface formed of any one of polyimide, polytetrafluoroethylene, polyphenylene sulfide, and silicon, and is arranged only on the thermally welded part and a thermally welded part region including a peripheral edge of the thermally welded part in the liner.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for a high-pressure tank.

  In Patent Document 1, in a high-pressure tank, a release agent layer is disposed between a resinous liner and a reinforcing layer formed on the liner to prevent the liner and the reinforcing layer from sticking. In addition, it is disclosed that local stress concentration is prevented from occurring in the liner due to adhesion between the liner and the reinforcing layer. Further, it is disclosed that the release agent layer is preferably disposed at least in the dome portion of the liner where stress concentration is likely to occur, and may be disposed so as to cover the entire liner.

Japanese Patent Application Laid-Open No. 2015-017641

  Here, the liner may be formed by joining a plurality of parts by thermal welding. It was found that the heat-welded portion (hereinafter also referred to as “welded portion”) has high crystallinity and may have a reduced elongation at break. Even in this welded portion, it is possible to suppress the adhesion between the reinforcing layer and the liner to some extent by the release agent layer formed by applying the release agent. However, because the welded part has a higher possibility of fixing than other parts, and the welded part has low elongation at break, stress concentration occurs in the welded part when the liner is stretched in the surface direction. As a result, it has been found that there is a high possibility of damage from the welded portion.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.
(1) According to one aspect of the present invention, a high-pressure tank is provided. The high-pressure tank includes: a liner in which a plurality of resin parts are bonded at a heat-welded portion; a reinforcing layer formed on the liner; and disposed between the liner and the reinforcing layer, A release film for preventing adhesion between the liner and the reinforcing layer. The release film is; at least the surface thereof is formed of any one of polyimide, polytetrafluoroethylene, polyphenylene sulfide, and silicon; only on the welded portion region including the welded portion and the peripheral portion of the liner. Is arranged.
In this type of high-pressure tank, a release film having at least a surface formed of polyimide, polytetrafluoroethylene, polyphenylene sulfide, or silicon is disposed between the welded region of the liner and the reinforcing layer. Therefore, it becomes possible to prevent the adhesion between the welded portion and the reinforcing layer more effectively than when a release agent is applied. Thereby, when a liner is extended in the surface direction, it can suppress that stress concentration generate | occur | produces in a welding part, and it can suppress that a damage | wound generate | occur | produces from a welding part. Moreover, since the release film is arrange | positioned only on the welding part area | region, cost can be reduced compared with the case where a release film is arrange | positioned over the whole surface of a liner.

  Note that the present invention can be realized in various modes. For example, it is realizable with various forms, such as a manufacturing method of a high-pressure tank and a high-pressure tank.

Explanatory drawing which shows the structure of the high pressure tank as one Embodiment of this invention. Explanatory drawing which expands and shows the area | region where a release film is arrange | positioned. Explanatory drawing shown about the problem which generate | occur | produces in the welding part when there is no release film. Process drawing which shows the manufacturing method of a high pressure tank. Explanatory drawing shown about the sticking suppression effect by a release film. Explanatory drawing which shows an example of a shear peeling strength test. The graph which shows an example of the measurement result of the peeling strength according to the kind of peeling member.

A. Embodiment:
FIG. 1 is an explanatory view showing the structure of a high-pressure tank 10 as an embodiment of the present invention. In FIG. 1, the upper half is a sectional view and the lower half is a front view. In FIG. 1, the central axis AX of the high-pressure tank 10 is indicated by a two-dot chain line. The high-pressure tank 10 is used, for example, for storing hydrogen as a fuel gas used in an in-vehicle fuel cell system.

  As illustrated, the high-pressure tank 10 includes a liner 110, caps 120 and 130, release films 156 and 157, and a reinforcing layer 140. The liner 110 is provided with caps 120 and 130 around the central axis AX at both ends in a direction along the central axis AX (hereinafter also referred to as “longitudinal direction”). A configuration in which the bases 120 and 130 are provided on the liner 110 is also referred to as “liner with base 100”.

  The liner 110 is a resin-made hollow container having a gas barrier property against hydrogen gas such as polyamide resin. The liner 110 is formed in a curved shape in the vicinity of both ends in the longitudinal direction. The liner 110 is provided at a plurality of resin parts, in this example, the cylinder portion 111 that is a cylindrical portion at the center portion in the longitudinal direction, and both ends in the longitudinal direction of the cylinder portion 111, and has the curved surface shape described above. It is comprised from three parts of the dome parts 112 and 113 including the formed part. The cylinder part 111 and the dome parts 112 and 113 are joined by heat welding at the welding parts 114 and 115.

  The reinforcing layer 140 is formed on the outer surface of the liner with a base 100. The reinforcing layer 140 is formed by winding a fiber (or fiber bundle) impregnated with a thermosetting resin in advance by a filament winding method (hereinafter also referred to as FW method) around the liner 100 with a cap, and then heating the thermosetting resin by heating. It is a fiber reinforced resin layer formed by curing.

  The release films 156 and 157 are disposed only between the welded portion regions 116 and 117 including the welded portions 114 and 115 of the liner 110 and the reinforcing layer 140 as described below. The release films 156 and 157 are members for preventing the thermosetting resin of the reinforcing layer 140 from adhering to the welded portions 114 and 115 when the thermosetting resin of the reinforcing layer 140 is cured by heating. .

  FIG. 2 is an explanatory view showing, in an enlarged manner, a region where the release film 156 is disposed. When the cylinder part 111 and the dome part 112 are thermally welded to the welded part 114, heating is performed while pressing the cylinder part 111 and the dome part 112. As a result, as shown in FIG. Occur. Note that burrs on the outer surface side (burrs on the outer surface side are indicated by broken lines) are cut after welding. The welding part 114 has a region having a width Dw1 [mm] on the dome part 112 side from the joining boundary (welding boundary) 110b and a region having a width Dw2 [mm] on the cylinder part 111 side from the joining boundary 110b. The widths Dw1 and Dw2 depend on the pressing force applied to the dome part 112 and the cylinder part 111, the width of the heating region, and the heating temperature during heat welding. In this example, the widths Dw1 and Dw2 are assumed to be in the range of 4 mm to 6 mm.

  As will be described later, the release film 156 is used to prevent the welded portion 114 and the thermosetting resin of the reinforcing layer 140 from being fixed when the reinforcing layer 140 is formed by curing the thermosetting resin. The welded part 114 and the peripheral part of the welded part 114 are disposed on the welded part region 116. The welded region 116 has a region having a width Dwr1 [mm] (> Dw1) on the dome portion 112 side from the joining boundary 110b and a region having a width Dwr2 [mm] on the cylinder portion 111 side from the joining boundary 110b. .

  In addition, although illustration and description are omitted, the welded portion 115 is the same as the welded portion 114, and the release film 157 disposed only on the welded portion region 117 including the welded portion 115 and the peripheral portion of the welded portion 115 is also included. The same as the release film 156.

  FIG. 3 is an explanatory diagram showing problems that occur in the welded portion 114 when there is no release film 156. FIG. 3 omits the reinforcing layer 140 for easy understanding of the drawing.

  As described above, the welded portion 114 is a portion in which the end region where the cylinder portion 111 and the dome portion 112 are overlapped with each other is melted and pressed. Accordingly, the crystallinity is higher than that of other portions outside the welded portion 114 (hereinafter also referred to as “non-welded portion”), and the elongation at break Ebwp [%] in the surface direction of the welded portion 114 is The breaking elongation Ebn [%] of the non-welded portion is about 1/3 to 1/5.

  For this reason, in a state where the thermosetting resin of the reinforcing layer 140 and the welded portion 114 are fixed by thermosetting, the liner 110 is stretched along the surface direction by, for example, expansion of the liner 110 by filling with hydrogen gas. In this case, stress concentrates on a local part (for example, a part indicated by a broken-line arrow in FIG. 3) of the welded portion 114, and damage may occur from the part. This problem also applies to other welds (in this example, weld 115).

  Therefore, in the present embodiment, release films 156 and 157 are arranged on the welded portion regions 116 and 117 so that the reinforcing layer 140 does not come into contact with and adhere to the welded portions 114 and 115 (FIGS. 1 and 2). reference).

  Note that the widths Dwr1 and Dwr2 of the welded part region 116 shown in FIG. 2 depend on the widths Dw1 and Dw2 of the welded part 114. Therefore, it is preferable that the lower limit of the widths Dwr1 and Dwr2 is set to a value larger than the maximum value of the dimensional errors of the widths Dw1 and Dw2. Moreover, it is preferable that the lower limit of the widths Dwr1 and Dwr2 is set to be large in consideration of a margin in consideration of a dimensional error of the release film, a displacement of the release film, and the like. On the other hand, the upper limit of the widths Dwr1 and Dwr2 is not particularly limited considering only the viewpoint of preventing the liner 110 and the reinforcing layer 140 from sticking. However, the elongation at break at the non-welded portion is much larger than the elongation at break at the welded portion as described above. Even if the liner 110 and the reinforcing layer 140 are fixed at the non-welded portion, the stress due to the fixation The possibility of breakage due to concentration is low. Therefore, in view of the cost of the release film, it is preferable that it is as small as possible. For these reasons, the widths Dwr1 and Dwr2 of the welded portion region 116 may be set in consideration of the maximum value due to the dimensional error of the widths Dw1 and Dw2 of the welded portion 114 and a margin covering the welded portion 114. For example, when the maximum value due to the dimensional error of the widths Dw1 and Dw2 is 6 mm, if the margin is 2 mm, for example, the widths Dwr1 and Dwr2 of the welded region 116 may be 8 mm. However, the present invention is not limited to this, and the extent of the margin may be appropriately determined in consideration of manufacturing errors and the like. Although illustration and description are omitted, the welding part 115 and the welding part region 117 are the same as the welding part 114 and the welding part region 116.

  As the release films 156 and 157, as will be described later, release films made of any member of polyimide, polytetrafluoroethylene, polyphenylene sulfide, and silicon are used. The release films 156 and 157 may have a thickness of at least about 50 μm to 150 μm.

  FIG. 4 is a process diagram showing a method for manufacturing the high-pressure tank 10. First, a liner 100 with a base is prepared (step T12). For example, one resin (for example, polyamide) dome part 112 to which one base 120 is attached, the other resinous dome part 113 to which the other base 130 is attached, and the resinous cylinder part 111. Prepare three parts. And the liner 100 with a nozzle | cap | die with which the nozzle | cap | die 120,130 was attached to the liner 110 can be prepared by heat-welding each by the welding part 114,115 (refer FIG. 1, FIG. 2).

  Next, the release films 156 and 157 are disposed on the welded part regions 116 and 117 (see FIGS. 1 and 2) including the welded parts 114 and 115 of the liner with base 100 (step T14). The release films 156 and 157 have heat resistance that hardly causes alteration and liquid softening in an environment of a thermosetting resin heating temperature Th (for example, 120 ° C. to 160 ° C.) described later. A material having sufficient releasability (non-adhesiveness) between the thermosetting resin of the reinforcing layer 140 and the welded portion regions 116 and 117 is applicable. As will be described later, polyimide (PI), poly A release film made of any member of tetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), and silicon is applicable. The release films 156 and 157 may have a thickness of at least about 50 μm to 150 μm.

  Then, the fiber or fiber bundle (resin-impregnated fiber) impregnated with the uncured thermosetting resin is wound around the liner 100 with the die by the FW method (step T16). In this embodiment, an epoxy resin is employed as the thermosetting resin. Moreover, a carbon fiber (carbon fiber bundle) is adopted as a fiber (fiber bundle) to be wound. However, it is not limited to this, and glass fiber, aramid fiber, etc. may be adopted. Further, the winding of the carbon fiber and the winding of the fiber other than the carbon fiber may be performed in combination. As a fiber winding mode, hoop winding, low-angle / high-angle helical winding, or the like is employed.

  Thereafter, an uncured thermosetting resin (in this example, an epoxy resin) is thermally cured (step T18). Specifically, the liner 100 with the cap around which the carbon fiber impregnated with the epoxy resin is wound is heated to a predetermined heating temperature Th (for example, 120 ° C. to 160 ° C.) in a heating furnace, and uncured heat is applied. The curable resin is thermally cured to form the reinforcing layer 140. The high-pressure tank 10 can be manufactured through the steps described above.

  FIG. 5 is an explanatory view showing the sticking suppression effect by the release film. FIG. 5 shows the anti-adhesion effect for the seven types of S1 to S7 high-pressure tanks, the peelability and heat resistance according to the type of release member (release member: none, release agent, release film), and the high-pressure tank. Shows the adhesion of the liner at the welded portion (adhesion of the welded portion) and liner breakage (possibility of breakage at low temperature) when the high-pressure tank is filled with low-temperature gas. Type S1 is when no release agent is used, type S2 is when a fluorine-based release agent is used, type S3 is when a polyimide (PI) release film is used, and type S4 is polytetrafluoroethylene (PTFE) When using a mold release film, type S5 is a polyphenylene sulfide (PPS) mold release film, type S6 is a silicon mold release film, type S7 is a polyethylene (PE) mold release film The case where is used is shown.

  For the release agent of type S2 and the release film of types S3 to S6, members having a melting temperature (melting point) higher than the heating temperature Th described above are used, and each heat resistance is good (◯). Since the release film of type S7 is a member that softens considerably at the heating temperature Th, the shape of the release film cannot be maintained during heat curing of the thermosetting resin (epoxy resin), and heat resistance is not possible (× ). For this reason, in the release film of type S7, confirmation of peelability, adhesion of the welded portion and possibility of breakage at low temperature has not been made.

  FIG. 6 is an explanatory diagram showing an example of a shear peel strength test. The peelability can be determined to be higher as the peel strength measured by the shear peel strength test shown in FIG. 6 is smaller, for example. As the test members TP1 and TP2, plate members of the same member (polyamide resin in this example) as the liner 110 having a length (D) of 10 mm, a width (W) of 50 mm, and a thickness (H) of 2 mm are used. An uncured thermosetting resin (epoxy resin in this example) Tr and a release member Ts corresponding to each type S1 to S7 are sandwiched between the test members TP1 and TP2, and the heating temperature Th (this In the example, it is hot-pressed at 150 ° C. to cure the uncured thermosetting resin Tr. Then, the test members TP1 and TP2 are pulled in the direction of the arrows to measure the peel strength of the test members TP1 and TP2. The thermosetting resin Tr is applied to the test member TP1 in a pressed state so that the length (D) is 10 mm, the width (W) is 10 mm, and the thickness (H) is 100 μm. Further, as the release member Ts, a member having a length (D): 10 mm, a width (W): 10 mm, a thickness (H): 100 μm is used for a release film, and a length (D) is used for a release agent. ): 10 mm, width (W): 10 mm, and thickness (H): 100 μm.

  FIG. 7 is a graph showing an example of measurement results of peel strength according to the type of peel member. In the case of no release agent corresponding to type S1, a peel strength of 5 MPa to 9 MPa (representative value 6 MPa) was measured as shown in FIG. For this reason, as shown in FIG. 5, the peelability at the test member is low (x), sticking occurs at the welded portions 114 and 115 (see FIG. 1) of the liner 110, and the high-pressure tank is damaged during low-temperature filling. There was concern about the possibility of this.

  In the case of a release agent (fluorine type) corresponding to the type S2, a peel strength of 3 MPa to 6 MPa (representative value 4 MPa) was measured as shown in FIG. For this reason, as shown in FIG. 5, compared with the case where a peeling agent is not used, peelability becomes high ((circle)). However, depending on the state of application of the release agent at the welded portions 114 and 115 (see FIG. 1) of the liner 110 and the surface state (irregularity state) of the welded portions 114 and 115, a part of the release agent is not obtained. There is a possibility that the sticking may occur, and it is assumed that the high-pressure tank is damaged at the time of low-temperature filling.

  In the case of the release film corresponding to the types S3 to S6, as shown in FIG. 7, none of them was fixed, and the peel strength could not be measured. For this reason, as shown in FIG. 5, the peelability was very high (◎), and no sticking occurred at the welded portions 114 and 115 of the liner 110 (see FIG. 1).

  As described above, in the high-pressure tank 10 of the present embodiment, the release film made of any one of polyimide (PI), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), and silicon is used as the liner 110. It arrange | positions only on the welding part area | regions 116 and 117 containing the welding parts 114 and 115 and its peripheral part. Thereby, compared with the case where a mold release agent is used, it can suppress effectively that the thermosetting resin of the reinforcement layer 140 and the welding parts 114 and 115 adhere, and it becomes a liner from the welding parts 114 and 115. It is possible to effectively suppress the occurrence of damage to 110.

B. Other embodiments:
(1) In the said embodiment, although the mold release film which consists of any member of a polyimide, polytetrafluoroethylene, polyphenylene sulfide, and silicon was demonstrated as an example, a mold release film is not limited to this. Absent. As the release film, a film having at least a surface formed of any one of polyimide, polytetrafluoroethylene, polyphenylene sulfide, and silicon may be used. Even in such a release film, similarly, it is possible to effectively suppress the fixing of the thermosetting resin of the reinforcing layer 140 and the welded portions 114 and 115 as compared with the case where a release agent is used. It is possible to effectively prevent the liner 110 from being damaged from the welded portions 114 and 115.

  In the above description, in the embodiment, at least the surface of the release film is formed of any one of polyimide, polytetrafluoroethylene, polyphenylene sulfide, and silicon. However, the present invention is not limited to this, and has heat resistance against the heating temperature for thermosetting the thermosetting resin in order to prevent adhesion between the reinforcing layer and the welded portion, and the heat of the reinforcing layer. It is also possible to apply a release film using various members having a releasing property (non-adhering property) that does not adhere to the curable resin and the welded portion.

(2) In the above-described embodiment, the liner 110 in which three resin parts such as the resin dome parts 112 and 113 and the resin cylinder part are joined together by the two welding parts 114 and 115 is exemplified. However, the present invention is not limited to this. For example, a liner in which two resinous dome parts are joined by thermal welding at one welded part, and two resinous dome parts and two cylinder parts have three welded parts. It may be a liner bonded by thermal welding, and can be applied to various liners in which a plurality of resin parts are bonded at the heat-welded welded portion.

(3) In the said embodiment, although the fiber reinforced resin layer was demonstrated as an example as a reinforcement layer, it is not limited to this, You may form a reinforcement layer with various materials. For example, the reinforcing layer may be formed of only a thermosetting resin. In this case, the release films 156 and 157 are disposed only on the welded portion regions 116 and 117 of the liner 100 with a base, and thereafter, a thermosetting resin layer as a reinforcing layer is formed by application of thermosetting resin and thermosetting. It is good as well. Even if it does in this way, it can suppress that a thermosetting resin layer (reinforcement layer) and the welding parts 114 and 115 adhere, and it suppresses that the liner 110 is damaged from the welding parts 114 and 115. Is possible.

(4) In the above embodiment, the high-pressure tank filled with hydrogen has been described as an example of the high-pressure tank. However, it can be applied to a high-pressure tank for filling various substances such as oxygen and liquid nitrogen. is there.

  The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features of the embodiments corresponding to the technical features in each embodiment described in the summary section of the invention are intended to solve part or all of the above-described problems, or part of the above-described effects. Or, in order to achieve the whole, it is possible to replace or combine as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... High pressure tank 100 ... Liner with cap 110 ... Liner 110b ... Joining boundary 111 ... Cylinder part 112 ... Dome part 113 ... Dome part 114 ... Weld part 115 ... Weld part 116 ... Weld part area 117 ... Weld part area 120 ... Base 130 ... Base 140 ... Reinforcing layer 156 ... Release film 157 ... Release film AX ... Central axis TP1 ... Test member TP2 ... Test member Tr ... Thermosetting resin Ts ... Release member Th ... Heating temperature

Claims (1)

A high pressure tank,
A liner in which a plurality of resin parts are joined at a heat-welded welded portion;
A reinforcing layer formed on the liner;
A release film disposed between the liner and the reinforcing layer, for preventing sticking between the liner and the reinforcing layer;
With
The release film is
At least the surface thereof is formed of any one of polyimide, polytetrafluoroethylene, polyphenylene sulfide, and silicon,
It is arranged only on the welded part region including the welded part and the peripheral part of the liner,
High pressure tank.

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