Patent Application
20230417365
The present invention relates to and asserts priority from Japanese patent application No. 2022-102775 filed on Jun. 27, 2022, and incorporates entirety of the contents and subject matter of all the above application herein by reference.
The present invention relates to a member for manufacturing a high-pressure tank liner and a method for manufacturing a high-pressure tank liner.
Conventionally, so-called high-pressure tanks for filling high-pressure gas is known as having a fiber-reinforced resin layer formed on an outside of a liner (high-pressure tank liner) made of thermoplastic resin (see, for example, PTL 1). This type of liner is manufactured by welding together a pair of bottomed cylindrical liner halves each having a bottom. Specifically, a liner half has a communication tube at one end and a circular opening at the other end, which tube communicates an inside and outside of the liner. The liner is manufactured by heating and melting end surfaces forming the circular openings of the liner halves to weld the liner halves together.
However, with the conventional liner manufacturing device (see, for example, PTL 1), it is difficult to heat and melt the end surface forming the circular opening of the liner half uniformly along its circumferential line, resulting in irregular melting on the end surface of the liner half. Therefore, the conventional liner manufacturing device might cause a risk of an insufficient quality of welding between the liner halves.
An object of the present invention is to provide a member and a method for manufacturing a high-pressure tank liner with better welding quality between liner halves than conventional liners.
The present invention that solves the aforementioned problem provides a member for manufacturing a high-pressure tank liner that is produced by welding together a pair of liner halves having cylindrical bodies on their one ends having openings to connect them, each of the members including the liner half and a cap member that is easily attached to and removed from a communication tube of the liner half that is formed on another end opposite to a joint that is the one end between the liner halves and communicates an inside and an outside of the high-pressure tank liner.
Further, the method for manufacturing the high-pressure tank liner is characterized to include: preparing the pair of members for manufacturing the high-pressure tank liner; heating and melting each of end surfaces having the openings of the pair of members for manufacturing the high-pressure tank liner with a preset heating source, which members are placed to face each other at each of the openings of the liner halves; and welding together the end surfaces of the liner halves melted with each other to form the high-pressure tank liner.
Next, a detailed description is given of an embodiment of implementing the present invention referring to the drawings as appropriate.
First, a description is given of a high-pressure tank using high-pressure tank liners obtained by a manufacturing method according to the embodiment of the present invention
The high-pressure tank 1 is supposed, for example, to be installed in a fuel cell vehicle to store hydrogen gas supplied for a fuel cell system. However, the high-pressure tank 1 is not limited to this usage and may be used for high-pressure gas for other applications.
As shown in
The mouthpiece 3 is assumed to be formed of a metallic material such as, for example, aluminum alloy. The mouthpiece 3 includes a cylindrical mouth body 18 having inside a fill and drain hole 21, and a flange 19 formed at one end of the mouth body 18 in axial directions. The fill and drain hole 21 is connected to an inside of the high-pressure tank 1 at the one end of the mouth body 18 where the flange 19 is formed. A pipe (omitted in the figures), which is to be connected to the aforementioned fuel cell system or the like, is connected to the other end of the fill and drain hole 21.
On an inner circumferential surface of the fill and drain hole 21 at the one end of the mouth body 18, a threaded portion 21a is formed to engage with a threaded portion 17a formed in a communication tube 17 of the liner 2, which is described below. An O-ring 3a is attached between a tip of the communication tube 17 of liner 2 and the inner circumferential surface of the fill and drain hole 21. Note that the O-ring 3a corresponds to a “seal member” as defined in CLAIMS. As explained below, an O-ring contact surface 17b (see
The fill and drain hole 21 has in its inside a cylindrical collar 22 made of metallic material disposed. This collar 22 extends from one end supported by the inner circumferential surface of the fill and drain hole 21 toward the liner 2 to be fitted into the communication tube 17 of the liner 2.
The fiber-reinforced resin layer 4 in the present embodiment is assumed to be obtained by winding a prepreg, in which the reinforcing fibers are pre-impregnated with a matrix resin, around the outer circumferential surfaces of the liner 2 and the mouthpiece 3, and then curing this matrix resin.
The reinforcing fiber in the present embodiment is assumed to be a strip like roving (omitted in the figures) that is formed by further bundling together a plurality of strands each formed of a plurality of carbon fiber filaments. Note that the reinforcing fibers are not limited to the above material, and for example, aramid fiber, boron fiber, alumina fiber, silicon carbide fiber, and the like may also be used.
The matrix resin in the present embodiment is assumed to be made of cured thermosetting resin, such as epoxy resin, phenol resin, unsaturated polyester resin, polyimide resin, and the like.
Note that a method of forming the fiber-reinforced resin layer 4 is not limited to a method using the prepreg described above. Thus, the fiber-reinforced resin layer 4 may be made, for example, by impregnating matrix resin into reinforcing fibers that is resin-unimpregnated and wound around the liner 2 and then curing the reinforcing fibers.
Next, description is given of the liner 2 (see
The liner 2 is a hollow body made of thermoplastic resin. Thermoplastic resin includes, but are not limited to, polyamide resin, polyethylene resin, and the like.
The liner 2 according to the present embodiment includes a body part 5 made of a cylindrical body and a mirror part 6 that is integrally molded at each end of the body part 5.
The body part 5 includes a major portion 8 that is formed with a predetermined outer diameter and occupies most of the body part 5 along the axis Ax, and a diameter-expanded portion 9 that is formed in a center along the axis Ax of the body part 5 and has a larger diameter than the major portion 8.
The diameter-expanded portion 9 is formed by cutting a joint 36 (see
As shown in
The radially central portion of the mirror part 6 is provided with a recess portion 16 that is recessed to match a shape of the flange 19 of the mouthpiece 3.
A center of the recess portion 16 is provided with the aforementioned communication tube 17 formed to protrude toward an inside of the fill and drain hole 21 of the mouthpiece 3, which communication tube 17 communicates an inside and outside of the liner 2.
The threaded portion 17a that engages with the threaded portion 21a of the fill and drain hole 21 described above is formed on an outer circumferential surface of the communication tube 17.
Next, a member for manufacturing a high-pressure tank liner is described.
This member for manufacturing a high-pressure tank liner is a member that is placed in a manufacturing device A (see
The manufacturing device A is configured to weld together a pair of members 60 for manufacturing a high-pressure tank liner (hereinafter simply referred to as “liner manufacturing member 60”) to form a single unit.
The liner manufacturing member 60 is configured to have a cap member 61 attached to the communication tube 17 of the liner half 31, as shown in
As shown in
The cap member 61 is attached to the communication tube 17 to restrain a flow of air that tends to pass from inside to outside or from outside to inside of the liner half 31 (see
The O-ring contact surface 17b (seal member contact surface) shown in
The cap member 61 is attached to the communication tube 17 having the collar 22 attached thereto as shown in
The cap member 61 in the present embodiment is assumed to be made of elastic material such as synthetic rubber or elastic porous material such as sponge to be held onto the communication tube 17 by a contracting force. Further, the cap member 61 is capable of releasing an internal pressure of the united liner halves 31 when the internal pressure increases in the welding step of the manufacturing method of the liner 2 (see
However, note that the material of the cap member 61 is not limited to the above materials.
Next description is given of the liner half 31. The liner half 31 is substantially the same in its shape as that when the liner 2 shown in
As shown in
The flange 32 is an annulus that is coaxial with and integrally molded into the body part 5 to extend radially outward (the right direction on the sheet of
The flange 32 has a circumferential groove 32a formed thereon.
This circumferential groove 32a extends along a circumference of the flange 32 so as to open upward.
A bottom surface 32a1 of the circumferential groove 32a is formed with a flat surface and is parallel to an end surface 34a of the protruding end 34 that is also formed with a flat surface similarly to the bottom surface 32a1.
The protruding end 34 is an annulus that is coaxial with the body part 5 that is integrally molded onto an end surface of the opening 33 of the liner half 31, as shown in
An outer diameter of the protruding end 34 is configured to be larger than the outer diameter of the body part 5 of the liner half 31 and smaller than the outer diameter of the flange 32.
Further, an inner diameter of the protruding end 34 is set as the same as the inner diameter of the liner half 31.
Furthermore, a thickness of the protruding end 34 along the axis Ax of the liner half 31 is thicker than the melting allowance 35 for welding together the liner halves 31 as described below.
The above description with reference to
Next, a manufacturing device for the liner 2 (see
Returning to
The manufacturing device A at which the liner manufacturing members 60 are arranged includes mainly a casing 41 placed on a grounding surface such as the ground, an upper support 42a supporting the liner half 31 of the upper liner manufacturing member 60 of the pair of the liner manufacturing members 60 at an upper part of the casing 41 via a support jig 46; a lower support 42b supporting the liner half 31 of the lower liner manufacturing member 60 at a lower part of the casing 41 via a support jig 46; and a heater 40 for heating and melting ends of the liner halves 31 of the respective liner manufacturing members 60.
A lower end of the upper support 42a has a support jig 46 attached thereto to support the liner half 31 with the opening 33 facing downward of the liner manufacturing member 60.
An upper end of the lower support 42b has a support jig 46 attached thereto to support the liner half 31 with the opening 33 facing upward of the liner manufacturing member 60.
Each of the upper and lower pair of the support jigs 46 is arranged to engage the flange 32 (see
The support jig 46 has an inner claw 46a and an outer claw 46b that engage the flange 32, as shown in
The inner claw 46a contacts the outer circumferential surface of the body part 5 of the liner half 31 and is fitted into the peripheral groove 32a of the flange 32.
A tip surface 46a1 of the inner claw 46a is formed with a flat surface and is parallel to the bottom surface 32a1 of the peripheral groove 32a.
The outer claw 46b is disposed outside from the outer circumference of the inner claw 46a and contacts with the outer circumferential surface of the flange 32. Specifically, the outer claw 46b clamps a radially outer wall of the circumferential groove 32a of the flange 32 with the inner claw 46a fitted into the circumferential groove 32a.
The lower support jig 46 shown in
Next is a description of the heater 40 (see
As shown in
As shown in
As shown in
In other words, the surface 44a1 of the heating source 44a is set within a recess 39 that is recessed from the surface 44b1 of the base member 44b.
However, the surface 44a1 of the heating source 44a can be flush with the surface 44b1 of the base member 44b, as described below.
The surface 44a1 of the heating source 44a is flat over the circumferential and radial direction of the ring shape and parallel to the surface 44b1 of the base member 44b.
The step (distance) between the surface 44b1 of the base member 44b and the surface 44a1 of the heating source 44a is represented by the depth of the recess 39, indicated by a sign D1 in
The heating source 44a in the present embodiment is assumed to be, but not limited to, one that uses Joule heat from an electric heating wire or the like, or one that uses radiant heat from far-infrared radiation.
The heating source 44a in the present embodiment is positioned opposite the end surface 34a of the protruding end 34 of the liner half 31, as shown in
The surface 44a1 of the heating source 44a is positioned so that it is parallel to the end surface 34a of the protruding end 34.
A distance D2 from the end surface 34a of the protruding end 34 to the surface 44b1 of the base member 44b is shorter than a distance Dp2 (see
The distance D2 satisfies the following equation (1), where a distance of the surface 44a1 from the heating source 44a to the end surface 34a of the protruding end 34 is indicated by a sign Ds, which is a design criterion.
[Math. 1]
D2=Ds−D1 (1)
The distance Ds as the design criterion is a value that is set in advance assuming that the surface 44b1 of the base member 44b and the surface 44a1 of the heating source 44a are flush. This distance Ds as the design criterion may be set by a well-known method that takes into account of conditions such as, for example, an output capacity of the heater 40 (heating source 44a), a material character of the liner half 31, a radial width of the end surface 34a, and the like.
To give an example, the distance Ds as the design criterion can be set at 0.3 to 2 mm, under the following conditions: a temperature of the heating source 44a: 500 to 700° C., a material of the liner half 31: polyamide resin, radial width of the end surface 34a: 3 to 5 mm, and the depth D1 from the surface 44a1 of the heating source 44a to the surface 44b1 of the base member 44b: 3.5 to 5 mm. However, the distance Ds is not limited to this example.
Preferably, the ring-shaped radial width W1 of the heating source 44a in the present embodiment is assumed to be set to be at least 3 times the radial width W2 of the protruding end 34 of the liner half 31. And the width W1 of the heating source 44a is preferably larger than the radial width W2 of the protruding end 34 of the liner half 31 by 5 mm or more in the inward and out ward radial directions respectively.
An outer diameter of the heating source 44a is preferably at least 5 mm larger than the outer diameter of the protruding end 34 of the liner half 31, and more preferably larger than the outer diameter of the flange 32 of the liner half 31.
Next, the manufacturing method of the liner 2 according to the present embodiment is described.
The present manufacturing method includes the following steps: heating the protruding ends 34 (see
In the heating, a pair of the liner manufacturing members 60 (see
The liner half 31 included in the liner manufacturing member 60 in the present embodiment is assumed to be obtained by an injection molding or blow molding using thermoplastic resin.
The cap member 61 (see
The liner manufacturing member 60 of the present embodiment is formed by attaching the cap member 61 to the communication tube 17 of the liner half 31.
In the heating step, as shown in
As shown in
In such a heating, the recess 39 restrains air flow between the end surface 34a of the protruding end 34 and the surface 44a1 of the heating source 44a (opposing surfaces), while the heating source 44a heats and melts the melting allowance 35 of the protruding end 34.
Next, the welding step of the liner halves 31 of the liner manufacturing member 60 is described.
This welding step welds together an end of the upper liner half 31 and an end of the lower liner half 31, as shown in
Specifically, in the welding, the liner halves 31 are pressed against each other by the support jig 46 shown in
As shown in
In the above-described welding, the liner halves 31 may be vibrated by a vibrating device to accelerate the welding of the liner halves 31 when they are united at the welding surface 36a.
Next, the cutting step of the integrated liner halves 31 is described.
As shown in
The root portions 32c being left are used to form the diameter-expanded portion 9 of the liner 2 described above. This completes a series of manufacturing steps for the liner 2 of the present embodiment (see
The cap member 61 attached to the communication tube 17 of the liner 2 is removed from the communication tube 17 when the mouthpiece 3 is attached to the liner 2 (see
Next, description is given of effects provided by the manufacturing method of liner 2 and the liner manufacturing member 60 (member for manufacturing the high-pressure tank liner) used for this method according to the present embodiment.
First, here is a description given of the manufacturing method of the comparative example.
As shown in
As shown in
The above escaping of the air causes a portion heated by the heating source 44a in the outer circumference of the protruding end 34 (right side of the sheet of
This results uneven forming of the molten portion 38 that is one-side distributed toward the outer circumference of the protruding end 34 (left side of the sheet in
On the other hand, as shown in
The above escaping of the air causes a portion heated by the heating source 44a in the outer circumference of the protruding end 34 (left side of the sheet of
This results uneven forming of the molten portion 38 of the protruding end 34 one-side distributed toward the inner circumference (right side of the sheet in
In other words, the conventional manufacturing method causes uneven melting on the respective end surfaces 34a of the upper and lower liner halves 31, resulting in insufficient welding quality between the liner halves 31.
On contrast, in the manufacturing method of the liner 2 and the liner manufacturing member 60 (member for manufacturing a high pressure tank liner) used in this manufacturing method according to the present embodiment, the cap members 61 are attached to the respective communication tubes 17 of the upper and lower liner halves 31, as shown in
As shown in
As shown in
The end surface 34a of the liner half 31 (protruding end 34) in this configuration is heated substantially evenly by the upward airflow Fa rising from the heating source 44a.
As a result, the molten portion 38 of the protruding end 34, indicated by shade in
As shown in
This allows the manufacturing method and the liner manufacturing member 60 (member for manufacturing the high-pressure tank liner) used in this manufacturing method to produce the liner 2 (see
In the liner manufacturing member 60 (member for manufacturing the high-pressure tank liner) of the present embodiment, the cap member 61 has the peripheral wall 62 (protective portion) that covers to protect the O-ring contact surface 17b (seal member contact surface) formed on the communication tube 17 of the liner half 31.
The above liner manufacturing member 60 (member for manufacturing the high-pressure tank liner) and the liner 2 manufacturing method using the liner manufacturing member 60 is able to prevent the O-ring contact surface 17b from being scratched or stained until the liner 2 is obtained from the liner manufacturing member 60 and the mouthpiece 3 is attached to this liner 2.
In the liner manufacturing member 60 (member for manufacturing the high-pressure tank liner) of the present embodiment, the cap member 61 is formed of a bottomed cylindrical body that is externally fitted onto the communication tube 17 of the liner half 31.
Such a liner manufacturing member 60 (member for manufacturing the high-pressure tank liner) and the liner 2 manufacturing method using the liner manufacturing member 60 allows the liner half 31 to be easily attached to the communication tube 17.
According to such a liner manufacturing member 60 (member for manufacturing the high-pressure tank liner) and a method of manufacturing liner 2 using the liner manufacturing member 60, the communication tube 17 can be sealed more securely while reducing a wall thickness of the cap member 61.
In the manufacturing method and manufacturing device A of the liner 2 of the present embodiment, as shown in
The end surface 34a of the liner half 31 (protruding end 34) in the present embodiment is heated approximately evenly by the airflow Fa rising from the heating source 44a.
As a result, the molten portion 38 of the protruding end 34 indicated by shade in
This allows the manufacturing device A and manufacturing method of the present embodiment to obtain the liner 2 (see
In the manufacturing device A of the present embodiment, it is assumed that a width W1 of the heating source 44a is set to be at least three times a width W2 of the end surface 34a of the liner half 31 (protruding end 34).
The above manufacturing device A allows more uniform melting of the protruding end 34, leading further improvement in the welding quality between the liner halves 31.
In the manufacturing device A of the present embodiment, the distance (D2) between the end surface 34a of the liner half 31 (protruding end 34) and the surface 44b1 of the base member 44b is set at a value (D2=Ds−D1) obtained by subtracting the distance (D1) between the surface 44b1 of the base member 44b1 and the surface 44a1 of the heating source 44a from the distance (Ds) between the end surface 34a of the liner half 31 (protruding end 34) and the surface 44a1 of the heating source 44a as the design criterion.
According to such a manufacturing device A, because the surface 44a1 of the heating source 44a faces the end surface 34a of the liner half 31 (protruding end 34) at the distance (Ds) as a design criterion, the end surface 34a of the protruding end 34 is able to be melted in a stable manner.
Further, according to the manufacturing device A, the end surface 34a of the liner half 31 (protruding end 34) can be brought closer to the surface 44b1 of the base member 44b, depending on the depth (distance (D1)) of the recess 39 of the base member 44b. Specifically, the distance D2 between the end surface 34a of the protruding end 34 and the surface 44b1 of the base member 44b can be shorter than the distance Dp2 (see
This further improves the airflow suppression effect of the airflow suppression mechanism 50, which includes the recesses 39, in this form of manufacturing device A.
The above is a description of the present embodiments. However, the present invention is not limited to the aforementioned embodiments, but can be implemented in various embodiments.
For example, the cap member 61 included in the liner manufacturing member 60 (see
However, a material and shape of the cap member 61 in the present invention is not limited to those described above, as long as air circulation into and out of the liner half 31 via the communication tube 17 is inhibited during the above-described heating step.
As shown in
The cap member 61 of the liner manufacturing member 60 according to the modification of the present invention allows a contact area of the cap member 61 with the communication tube 17 to be increased by the peripheral wall 62 and the plug portion 63, and thereby improving a holding force of the cap member 61 against the communication tube 17.
Further, the cap member 61 is attached to the communication tube 17 with the collar 22 attached as shown in
Further, the cylindrical plug portion 63 of the cap member 61 has a pressure-release hole 63a formed therein. This pressure-release hole 63a is designed to release an internal pressure of the united liner halves 31 when the internal pressure increases in the welding step of the liner halves 31.
A material of this cap member 61 is assumed to be synthetic rubber, but is not limited to this type and can be an elastic porous material such as sponge. The cap member 61 made of such an elastic porous material can omit the pressure-release hole 63a.
Further, in the above embodiment, the surface 44a1 of the heating source 44a is set within the recess 39 that is recessed from the surface 44b1 of the base member 44b (see
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-102775 | Jun 2022 | JP | national |
