JP2021055715A - Constraint structure of structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a restraint structure of a structure capable of suppressing compressive fracture in a curved portion of a CFRP belt.
SOLUTION: A restraining structure of a structure circulates along an axial direction of a body portion 20 so as to hang a body portion 20, a pair of bases 30 provided at both ends of the body portion 20, and a pair of bases 30. A circumferential layer around which a belt is wound is provided, and in the circumferential layer, the radius of the curved portion 40C connected to the straight portion 40A along the body portion 20 and provided on the outer periphery of the base 30 is R, and the body portion 20 is sandwiched between them. Assuming that the distance between the outer surfaces of the opposing straight line portions 40A is H, R> H / 3 is satisfied.
[Selection diagram] Fig. 3

Description

The present invention relates to a restraint structure of a structure including a tubular body or a laminated body.

Patent Document 1 below discloses a restraint structure of a high-pressure tank in which a sheet-shaped CFRP (carbon fiber reinforced resin) belt is wound along the axial direction of a body portion constituting the high-pressure tank. Such a restraint structure can also be applied when restraining a battery composed of a plurality of cells.

JP-A-2018-119578

However, in the above-mentioned restraint structure, when the tension applied to the CFRP belt increases due to the expansion of the structure or the like, compressive fracture may occur at the curved portion of the CFRP belt.

In consideration of the above facts, an object of the present invention is to obtain a restraint structure of a structure capable of suppressing compressive fracture at a curved portion of a CFRP belt.

The restraint structure of the structure according to claim 1 is such that a restrained portion which is a tubular body or a laminated body, a pair of holding portions provided at both ends of the restrained portion, and the pair of holding portions are hung. A restraint portion around which a CFRP belt is wound along the axial direction of the restrained portion is provided, and the restraint portion is connected to a straight line portion along the restrained portion and is provided on the outer periphery of the holding portion. Assuming that the radius of the curved portion is R and the distance between the outer surfaces of the straight portions facing each other across the restrained portion is H, the following relational expression (a) is satisfied.
R> H / 3 ... Equation (a)

In the restraint structure of the structure according to claim 1, the restrained portion which is a cylinder or a laminated body is held from both sides by a pair of holding portions, and the shaft of the restrained portion is hung so as to hang the pair of holding portions. A CFRP belt is wrapped along the direction. Here, the restraint portion formed by winding the CFRP belt has a straight portion along the restrained portion and a curved portion connected to the straight portion and provided on the outer periphery of the holding portion. There is. Then, according to the restraint structure of the structure, when the radius of the curved portion is R and the distance between the outer surfaces of the opposing straight portions is H, R> H / 3 is satisfied, so that the curved portion of the CFRP belt is satisfied. It is possible to reduce the surface pressure that the belt receives, and thereby suppress the compressive fracture.

According to the present invention, compressive fracture at the curved portion of the CFRP belt can be suppressed.

It is a perspective view of the tank module which combined the high pressure tank which concerns on 1st Embodiment. It is a side sectional view of the high pressure tank which concerns on 1st Embodiment. It is a side sectional view (enlarged view of FIG. 2) of the vicinity of the base of the high pressure tank which concerns on 1st Embodiment. It is a side view of the vicinity of the base of the high pressure tank which concerns on 1st Embodiment, and is the schematic diagram of the resultant force acting on the R end. FIG. 5 is an enlarged side sectional view of a high-pressure tank according to the first embodiment, in which a part of a fixed belt is enlarged. It is a high pressure tank which concerns on 1st Embodiment, is a plan view of a fixed belt, and is a schematic view which shows the direction of carbon fiber. It is a perspective view of the battery module which combined the battery unit which concerns on 2nd Embodiment.

[First Embodiment]
Hereinafter, the high-pressure tank 10 of the first embodiment to which the restraint structure of the structure is applied will be described with reference to FIGS. 1 to 6.

As shown in FIG. 1, the high-pressure tank 10 as a structure constitutes a part of the tank module 12. That is, the tank module 12 is configured by arranging and connecting a plurality of high-pressure tanks 10. As an example, the tank module 12 is housed on the lower side of the floor panel of the fuel cell vehicle. The high-pressure tank 10 of the present embodiment contains hydrogen, which is a fluid, as an example.

The high-pressure tank 10 is formed in a columnar shape with the vehicle front-rear direction as the axial direction (longitudinal direction). The high-pressure tank 10 is wound along the axial direction of the body portion 20 so as to hang a tubular body portion 20, a base portion 30 provided at both ends of the body portion 20 in the axial direction, and a pair of base portions 30. It is configured to include the fixed belt 40 and the fixed belt 40. The body portion 20 is an example of a restrained portion which is a tubular body, and the base 30 is an example of a holding portion. Hereinafter, unless otherwise specified, the axial direction of the body portion 20 is simply the axial direction, and the radial direction of the body portion 20 is simply the radial direction.

As shown in FIGS. 2 and 3, the body portion 20 has, for example, a cylindrical liner 24 formed of an aluminum alloy and a reinforcing layer made of CFRP (carbon fiber reinforced resin) provided on the outer peripheral surface of the liner 24. It has 26 and. The reinforcing layer 26 is formed by wrapping a sheet-shaped CFRP impregnated with resin in advance around the outer peripheral surface of the liner 24, or by wrapping carbon fiber around the outer peripheral surface of the liner 24 and then impregnating with the resin. .. On the inner peripheral surface side of the reinforcing layer 26, carbon fibers (not shown) in the fiber reinforced resin are arranged along the circumferential direction of the liner 24 and the body portion 20.

The base 30 is formed in a substantially semi-cylindrical shape in which the outer portion in the axial direction is convex toward the outer side in the axial direction. The mouthpiece 30 has an insertion portion 32 and a communication flow path 34. The insertion portion 32 is a portion to be inserted into the opening 22 of the high-pressure tank 10, and is formed in a substantially columnar shape protruding inward in the axial direction. The outer peripheral surface of the insertion portion 32 is in contact with the inner peripheral surface of the body portion 20. Further, a packing accommodating portion 36 formed by cutting out an outer edge portion is provided at the tip end portion of the insertion portion 32, and the O-ring 38 is housed inside the packing accommodating portion 36. The O-ring 38 is elastically deformed along the radial direction. The body portion 20 is closed by the insertion portion 32 at one end in the axial direction and at the other end.

The communication flow path 34 is formed inside the base 30. The communication flow path 34 extends in the width direction and connects to the first communication flow path 34A which is opened inside the insertion portion 32 along the axial direction and inward in the axial direction. It is configured to include a second communication flow path 34B (see FIG. 4). In the adjacent high-pressure tanks 10, the insides of the body portions 20 of the plurality of high-pressure tanks 10 are communicated with each other by connecting the second communication flow paths 34B to each other. A plurality of body portions 20 may be connected to a base having a plurality of insertion portions 32.

The communication flow path 34 in the mouthpiece 30 is provided with a valve (not shown) as a valve member, whereby the amount of fluid flowing in the communication flow path 34 can be controlled. The communication flow path 34 is connected to a fuel cell stack, a supply pipe, or the like (not shown).

The fixing belt 40 is provided on the outer side in the radial direction of the body portion 20 and the outer side of the pair of bases 30. Specifically, the fixed belt 40 is wound around the outer surfaces of the pair of bases 30 so as to be bridged along the axial direction. The fixed belt 40 has an orbiting belt 42 that orbits the body portion 20 along the axial direction, and an interlayer belt 44 that is included between the layers of the orbiting belt 42. As shown in FIG. 5, the fixed belts 40 are laminated over 20 layers in the AA line, and the interlayer belts 44 are present in the second and 18th layers from the inside in the radial direction, and the other layers have the interlayer belts 44. There is a circuit belt 42.

As shown in FIG. 3, the fixed belt 40 includes a pair of straight portions 40A along the axial direction of the body portion 20, a pair of outer peripheral portions 40B along the outer outer surface of the base 30 in the axial direction, and a straight portion. It has a curved portion 40C connecting the 40A and the outer peripheral portion 40B. The outer peripheral portion 40B and the curved portion 40C are examples of curved portions. Here, assuming that the radius of the curved portion 40C is R and the height of the high-pressure tank 10 (in other words, the distance between the outer surfaces of the straight portions 40A facing each other across the body portion 20) is H, then R> H / 3. It is formed to be. Further, assuming that the radius of the outer peripheral portion 40B is r, the outer peripheral portion 40B is formed so that r> H / 2.

As shown in FIG. 6, the circumferential belt 42, which is a CFRP belt, is a CFRP belt and is a UD (Uni Direction) tape having carbon fiber CF in the 0 ° direction along the axial direction. The 0 ° direction along the axial direction includes an error in the direction of the carbon fiber CF during the manufacture of the circuit belt 42 and an error in the direction of the carbon fiber CF that occurs when the circuit belt 42 is wound. Further, the circumferential belt 42 is a so-called prepreg in which the carbon fiber CF is pre-impregnated with a resin, and is cured after being wound. In the circumferential belt 42, the radial inner end E1 is adhesively fixed to the outer surface of the base 30 (see FIG. 3), and after 17 laps around the body 20 to form an orbital layer CL as a restraining portion, the circumferential belt 42 is radial. The outer end portion E2 is adhesively fixed to the interlayer belt 44 in the vicinity of the connecting portion between the straight portion 40A and the curved portion 40C (see FIG. 5).

As shown in FIG. 6, the interlayer belt 44 is a CFRP belt, which is a UD tape having carbon fiber CF in the 90 ° direction along the width direction of the body portion 20. The 90 ° direction along the axial direction includes an error in the direction of the carbon fiber CF during the manufacture of the interlayer belt 44 and an error in the direction of the carbon fiber CF that occurs when the interlayer belt 44 is wound. Further, the interlayer belt 44 is a so-called prepreg in which the carbon fiber CF is pre-impregnated with a resin, and is cured after being wound. Here, in the present embodiment, the carbon fiber CF of the interlayer belt 44 accounts for 10% of the entire fixed belt 40.

As shown in FIG. 5, the interlayer belt 44 is laminated adjacent to the peripheral belt 42 of the uppermost layer TL, which is the outermost layer. Specifically, the interlayer belt 44 is wound once between the circulation belt 42 of the uppermost layer TL of the fixed belt 40 and the circulation belt 42 one lap before the uppermost layer TL.

The interlayer belt 44 is laminated adjacent to the peripheral belt 42 of the lowermost layer BL. Specifically, the interlayer belt 44 is wound around once between the circulation belt 42 of the lowermost layer BL of the fixed belt 40 and the circulation belt 42 one rotation after the lowermost layer BL.

(Production method)
The high pressure tank 10 is manufactured as follows. First, the operator prepares a base 30 in which the O-ring 38 is housed in the packing housing part 36 in advance. Subsequently, the operator inserts the insertion portion 32 of the base portion 30 into the opening 22 of the body portion 20, and attaches the base cap 30 to both ends of the body portion 20 in the axial direction.

Next, the operator brings the end portion E1 of the circumferential belt 42 into contact with the outer peripheral surface of the base 30, and winds the peripheral portion 20 about one circumference along the axial direction. After the resin is cured, the end portion E1 of the circumferential belt 42 is adhered to the base 30. Here, the operator winds the interlayer belt 44 around the first layer of the peripheral belt 42 and cuts it. It is desirable that the starting point (end) and the ending point (end) of the interlayer belt 44, which is the second layer, avoid the curved portion 40C, respectively.

Then, the operator winds the circumferential belt 42 from above the interlayer belt 44 until about 16 laps, that is, the 18th layer is formed. Here, the operator winds the interlayer belt 44 around the 17th layer of the peripheral belt 42 and cuts it. It is desirable that the starting point (end) and the ending point (end) of the interlayer belt 44, which is the 18th to 19th layers, are provided in the straight portion 40A, respectively.

Further, the operator winds the circumferential belt 42 from the top of the interlayer belt 44 about one round, that is, until the 20th layer is formed. Then, the 20th layer circular belt 42 is wound from the outer peripheral portion 40B through the curved portion 40C to the straight portion 40A. Then, the operator cuts the excess peripheral belt 42 so that the end portion E2 of the circumferential belt 42 is located near the connection portion between the straight portion 40A and the curved portion 40C.

The high-pressure tank 10 is completed by curing the resin impregnated in the circulation belt 42 and the interlayer belt 44.
The above process is premised on being performed by an operator, but the present invention is not limited to this, and the process may be mechanized by a manufacturing apparatus.

(Action effect)
Next, the operation and effect of this embodiment will be described.

In the high-pressure tank 10 of the present embodiment, when the internal pressure rises due to the contained fluid, the base 30 is pressed outward in the axial direction, and tension is generated on the fixed belt 40. On the other hand, the fixed belt 40 receives a compression force in the thickness direction, that is, a surface pressure at the contact portion with the base 30.

On the other hand, in the high pressure tank 10, the length in the axial direction is shortened as r is increased in the outer peripheral portion 40B, that is, as the outer peripheral radius of the base 30 is increased, but the straight portion 40A and the outer peripheral portion 40B are connected. The angle to be made approaches a right angle. The smaller the radius R of the curved portion 40C, which is the connecting portion between the straight portion 40A and the outer peripheral portion 40B, the greater the surface pressure acts on the fixed belt 40. Here, assuming that the surface pressure acting on the fixed belt 40 is P and the tension acting on the fixed belt 40 is F, it becomes P∝F / R. That is, the larger the tension F and the smaller the radius R, the greater the surface pressure acts.

The high-pressure tank 10 of the present embodiment is formed so that the curved portion 40C of the fixed belt 40 satisfies R> H / 3. As a result, the surface pressure in the thickness direction acting on the fixed belt 40 can be reduced, and compression fracture can be suppressed. The R of the curved portion 40C does not have to be constant, and the closer to the R end (the connecting portion between the straight portion 40A and the curved portion 40C) having bending and a large tensile stress, the slower the R. By enlarging, the strength of the fixed belt 40 against compression can be further improved.

Further, in the present embodiment, the ratio of the carbon fiber CF in the 90 ° direction to the entire fixed belt 40 is formed to be 10%. It is difficult for the circumferential belt 42 having the carbon fiber CF in the 0 ° direction with respect to the axial direction to secure the strength in the thickness direction when tension acts in the 0 ° direction. Here, in the UD tape constituting the fixed belt 40, the performance of the resin contributes more to the force in the 90 ° direction than the carbon fiber CF. Therefore, the interlayer belt 44 having the carbon fiber CF in the 90 ° direction with respect to the axial direction is not easily affected by the tension in the 0 ° direction, and the elasticity in the thickness direction can be ensured. Therefore, in the present embodiment, the fixed belt 40 includes the interlayer belt 44 having the carbon fiber CF in the 90 ° direction in a certain ratio, so that the fixed belt 40 is formed in the thickness direction as compared with the case where all the fixed belts 40 are composed of the circumferential belt 42. It can give elasticity. Therefore, according to the present embodiment, in the curved portion 40C where the surface pressure is high, compressive fracture can be suppressed while ensuring the strength of the fixed belt 40 in the tensile direction.

In order to reduce the influence of the compressive force (surface pressure) that the fixed belt 40 receives from the base 30 in the curved portion 40C, it is desirable to provide the interlayer belt 44 in the lower layer, specifically, the second layer as much as possible.

Further, in the fixed belt 40 of the present embodiment, the interlayer belt 44 is laminated adjacent to the uppermost layer TL near the end E2 where the circumferential belt 42 ends winding. Here, stress acts evenly on both sides in the axial direction in the lower layer orbital belt 42 having no end E2, whereas in the end E2, stress is concentrated between layers on the side where the orbital belt 42 is interrupted. Therefore, when the interlayer belt 44 does not exist and the circumferential belt 42 is simply wound, the shear stress acts in a concentrated manner at the end E2, so that there is a concern that peeling may occur between the interlayers.

On the other hand, in the present embodiment, the end portion E2 of the circumferential belt 42 is adhered to the interlayer belt 44. Here, in the UD tape constituting the fixed belt 40, the performance of the carbon fiber CF greatly contributes to the force in the 0 ° direction, and the performance of the resin greatly contributes to the force in the 90 ° direction. That is, the CFRP in which the carbon fiber CF is arranged in the 0 ° direction can secure the tensile strength in the 0 ° direction, and the CFRP in which the carbon fiber CF is arranged in the 90 ° direction can give elasticity in the 0 ° direction. Then, as in the present embodiment, the interlayer belt 44 in which the carbon fiber CF is arranged in the direction orthogonal to the tension can give elasticity in the axial direction. According to the present embodiment, even if shear stress is concentrated and acts on the end portion E2 of the circumferential belt 42, it is relaxed by the elasticity of the interlayer belt 44, so that peeling between layers can be suppressed.

Further, in the present embodiment, the end portion E2 of the circumferential belt 42 is arranged near the connection portion between the straight portion 40A and the curved portion 40C. As shown in FIG. 4, at the R end where the curved portion 40C is switched to the straight portion 40A, both bending stress and tensile stress act on the fixed belt 40. The bending stress acting on the R end is the stress on the upper layer side of the circumferential belt 42 in the axial direction and the stress on the lower layer side in the axial direction. Therefore, the resultant force of the bending stress and the tensile stress cancels out on the upper layer side. That is, the tensile stress of the circumferential belt 42 is relaxed toward the upper layer at the R end, which is the connecting portion between the straight portion 40A and the curved portion 40C. Therefore, by providing the end portion E2 of the circumferential belt 42 near the R end, peeling between layers can be further suppressed.

[Second Embodiment]
The second embodiment is an example in which the restraint structure of the structure is applied to the battery unit 50. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 7, the battery unit 50 as a structure constitutes a part of the battery module 52. That is, the battery module 52 is configured by arranging and connecting a plurality of battery units 50. As an example, the battery module 52 is housed on the lower side of the floor panel of an electric vehicle. The battery unit 50 of this embodiment is an example of an all-solid-state battery.

The battery unit 50 is formed in a prismatic shape with the vehicle front-rear direction as the stacking direction. Here, in the present embodiment, the stacking direction of the cells 60 and the longitudinal direction of the case 70 are the axial directions, and the direction orthogonal to the stacking direction of the cells 60 is the radial direction. The battery unit 50 includes a plurality of cells 60 arranged in the axial direction, a tubular case 70 covering the cells 60, fixing portions 80 provided at both ends in the axial direction of the case 70, and a pair of fixing portions 80. A fixed belt 40, which is wound along the axial direction of the case 70 so as to be hung, is included. The cell 60 is an example of a restrained portion which is a laminated body, and the fixing portion 80 is an example of a holding portion.

The cells 60 are stacked in the axial direction, and adjacent cells 60 are connected in series. The cell 60 is sandwiched by the fixing portion 80 in the axial direction. The case 70 is a square tubular member that covers the radial outside of the stacked cells 60.

In the present embodiment, the cells 60 laminated by the fixed belt 40 are constrained in the axial direction. Therefore, if the cell 60 expands in the charge / discharge cycle, an axial tension F is generated in the fixed belt 40. Therefore, this embodiment also has the same effect as that of the first embodiment.

[Remarks]
In each embodiment, the angle of the carbon fiber CF of the interlayer belt 44 does not necessarily have to be 90 °, and may be 45 ° or more and 90 or less with respect to the axial direction. Further, the angle of the carbon fiber CF in the interlayer belt 44 may be different between the interlayer belt 44 on the lower layer side and the interlayer belt 44 on the upper layer side.

Further, in each embodiment, the ratio of the carbon fiber CF in the 90 ° direction to the entire fixed belt 40 is formed to be 10%, but the present invention is not limited to this, and the fixed belt 40 is formed in the 45 ° to 90 ° direction. It suffices to have 10% or more and 50% or less of carbon fiber CF.

In each embodiment, the end portion E1 of the circumferential belt 42 is adhered to the outer peripheral surface of the base 30, but the present invention is not limited to this, and the end portion E1 may be adhered to the body portion 20 or the fixed belt 40. When it is adhered to the fixing belt 40, it is preferable that the end portion E1 of the circumferential belt 42 is adhered and fixed to the interlayer belt 44 provided adjacent to the end portion E2, similarly to the end portion E2. As a result, even if shear stress is concentrated and acts on the end portion E1, it is relaxed by the elasticity of the interlayer belt 44, so that peeling between layers can be suppressed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above, and it is possible to carry out various modifications other than the above within a range not deviating from the gist thereof. Of course.

10 High-pressure tank (structure)
20 Body part (cylinder body, restrained part)
30 base (holding part)
40A Straight part 40C Curved part 42 Circular belt (CFRP belt)
50 Battery unit (structure)
60 cells (laminated body, restrained part)
80 Fixed part (holding part)
CL circuit layer (restraint part)

Claims (1)

With the restrained part which is a cylinder or a laminated body,
A pair of holding portions provided at both ends of the restrained portion,
A restraining portion in which a CFRP belt is wound along the axial direction of the restrained portion so as to hang the pair of holding portions is provided.
In the restraint portion, the radius of the curved portion connected to the straight line portion along the restrained portion and provided on the outer periphery of the holding portion is R, and the outer surfaces of the straight portions facing each other across the restrained portion are opposed to each other. If the distance is H,
A restraint structure of a structure satisfying the following relational expression (a).
R> H / 3 ... Equation (a)

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