JP6525272B2 - boom - Google Patents

Description

  The present invention relates to a boom used as a structural material of various structures such as space structures and ground structures such as satellite antennas, antennas of spacecraft, and solar cell panels.

As a conventional boom, for example, a stretchable member as described in Patent Document 1 is known.
That is, the boom body is formed of a long plate material having elasticity, and is bent in an open cross-sectional shape in a direction orthogonal to the longitudinal direction (hereinafter referred to as the short direction), while being cylindrically wound in the longitudinal direction It is configured to be bent to the taken-up form and to be stably held in the initial form in either the extended form or the wound form.
In the winding configuration, the boom body is linearly extended in the open cross-sectional shape in the latitudinal direction, and the elastic restoring force that attempts to return in the open cross-sectional direction is held by the rolled cylindrical rigidity . Further, in the extended mode, the boom body has an open cross-sectional shape in the crosswise direction, and the elastic restoring force in the winding direction is held by the longitudinal rigidity of the boom body in the open cross-sectional shape.
The boom main body is mechanically unstable in the state of having the two forms of the extension form and the winding form, and is shifted to the extension form or the winding form by an elastic restoring force.

For example, if it is set such that the elastic restoring force that restores to the stretched form is larger than the elastic restoring force that restores to the wound form so as to self-extend from the wound form to the extended form, the winding form is stable. When the boom main body is in the partially extended form, the winding form portion is from the boundary portion of the extended form, and the cross-sectional shape in the short direction of the boom main body is sequentially opened from the linear state by elastic restoring force. , Transition from the wound form to the extended form, and self-extend.
In addition, if the elastic restoring force that restores to the wound form is set to be larger than the elastic restoring force that restores to the extended form so as to self-contract from the extended form to the wound form, the extension form is stable. When the boom body is in a partially wound form, the extension form portion is in the winding state from the stretched state sequentially by the elastic restoring force in the cross-sectional shape in the short side direction of the boom body from the boundary portion of the wound form , And it shifts from the extended configuration to the wound configuration and self-contracts.

Japanese Patent Publication No. 2000-507890

  However, when this boom is molded with a resin material such as fiber reinforced resin, for example, if it is stored for a long time in a wound state, the cross-sectional shape in the short direction of the boom body returns to the open cross-sectional shape by stress relaxation. The elastic restoring force is reduced, and problems occur such as self-extension is not started, or even if extension starts, it stops in the middle of extension. Similarly, when held in the extended form for a long period of time, stress relaxation reduces the elastic restoring force to return to the wound form.

  The present invention has been made in view of such circumstances, and the purpose of the present invention is to ensure the transition between the winding form and the extension form even if stress relaxation occurs as the winding form or the extension form for a long period of time To provide a boom that can be advanced.

In order to achieve the above object, the present invention is
A long resin plate material having elasticity and bent in an open cross-sectional shape in a direction perpendicular to the longitudinal direction, while being taken up in a cylindrical form in the longitudinal direction. In its initial configuration, it is provided with a boom body which is stably held in either a longitudinally extending extension form or a winding form,
The boom body is mechanically unstable in a state of having two forms of an extension form and a take-up form, and is a boom that shifts to the extend form or the take-up form by elastic restoring force,
An assisting member composed of an elastic long metal plate is provided so as to be relatively movable in the longitudinal direction along the boom body,
It is characterized in that the elastic restoring force of the assisting member assists the transition of the boom body to the extension mode or the winding mode.
Even if a long period of time has passed in the winding or extending state of the boom body and stress relaxation has occurred, the elastic restoring force of the assisting member is biased in the extending direction or the winding direction to ensure that the boom body is self-extension or It can be contracted.

For example, in a state in which the boom main body has two forms of the extension form and the winding form, the boom body restores to the extension form more than the elastic restoring force that restores to the winding form so as to self-extend from the winding form to the extension form. The resiliency is set to be greater,
The assisting member can be surely self-expanded as long as the initial form is the extended form and the transition of the boom body from the winding-up form to the extended form is assisted.
Further, in a state where the boom main body has two forms of the extension form and the take-up form, the boom body restores to the take-up form more than the elastic restoring force that restores to the extension form so as to self-contract from the extension form to the take-up form. The resiliency is set to be greater,
The assisting member can be reliably self-contracted if the initial form is a take-up form and is configured to assist the transition from the extended form of the boom body to the take-up form.
In addition, the assisting member partially supports the transition from the wound form to the extended form in the initial form in the extended form, and the other part in the initial form is the wound form, the transition from the extended form to the wound form If it is configured to assist, it is also possible to take a sample or to catch an object by shifting to the partial winding mode.
If the cross-sectional shape of the assisting member in the direction orthogonal to the longitudinal direction is a curved cross-section, the elastic restoring force extending from the wound state is increased, and the reliability of self-extension is further increased.
The boom body may be provided with a holding member for slidably holding the assisting member. The provision of the holding member stabilizes the position of the assisting member with respect to the boom body.
Further, a part of the assisting member is fixed to the boom body, and the circumferential length difference between the boom body and the assisting member in the winding state and the extending state is between the assisting member and the boom body between the fixed portion and the free end. It absorbs by relative sliding.
By fixing a part, the deformation to the extended state proceeds more stably.
The assisting member can be fixed at an end position (winding start end side) on the inner diameter side of the winding portion when the boom body is wound up, or the winding portion when the boom body is wound up It can also be fixed at the end position on the outer diameter side of the (end side of winding).
The support member may be fixed at a midway portion in the longitudinal direction of the boom body, and a winding portion in a winding state of the boom body may be formed on both sides in the longitudinal direction with respect to the fixing portion.
The boom body can be made of a fiber reinforced resin obtained by impregnating a fiber base with a resin.
The fiber base material is a biaxial fabric structure, and the yarns of the first axial yarn and the second axial yarn are inclined at a predetermined angle in opposite directions with respect to the long axis along one longitudinal direction. it can.
Carbon fiber can be used for the yarn which constitutes the fiber base material.
In particular, if the yarn constituting the fiber substrate is an opened yarn, and the boom body has a laminated structure in which a plurality of fiber reinforced resin sheets obtained by impregnating the fiber substrate with resin are laminated, the number of layers is changed. The characteristics of the boom body can be changed in stages.

  According to the boom of the present invention, even if stress relaxation occurs as a wound form or extended form for a long period of time, the transition between the wound form and the extended form can be reliably advanced.

FIG. 1 shows an example of a boom according to Embodiment 1 of the present invention, where (A) is a perspective view in a partially extended state, (B) is a perspective view in a wound form, and (C) is a perspective view in an extended form. The figure, (D) is an expanded sectional view of the direction orthogonal to the longitudinal direction. (A) and (B) are perspective views in which the assisting member is fixed at the winding end side of the boom body and at the center, (C) is a perspective view showing an example in which holes for rigidity adjustment are provided in the assisting member, (D) These are perspective views which show the example which changed the width | variety of the assistance member partially. The FRP sheet which comprises the boom main body of FIG. 1 is shown, (A) is explanatory drawing of the orientation direction of the thread | yarn of a fiber base material, (B) is a perspective view which shows several FRP sheets laminated | stacked, (C) Is a schematic cross-sectional view of a laminated structure. (A), (B), (C) is explanatory drawing of the various winding-up unwinding mechanisms of the boom of FIG. (A) is a perspective view of a partial extension state of a boom according to Embodiment 2 of the present invention, and (B) is a perspective view of an initial form of an assisting member. The boom which concerns on Embodiment 3 of this invention is shown, (A) is a perspective view of a partial extension state, (B) is an expanded sectional view of the orthogonal direction with respect to the longitudinal direction of a protective material.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.
Embodiment 1
FIG. 1 shows a boom according to a first embodiment of the present invention.
That is, as shown in FIG. 1, the boom 1 includes a long boom main body 10 made of fiber reinforced resin and a metal assisting member 20 stacked along the longitudinal direction of the boom main body 10 There is.
The boom main body 10 is made of a long elastic resin plate material, and is bent in an open cross-sectional shape in a direction orthogonal to the longitudinal direction, while it is cylindrically wound in the longitudinal direction. In the initial state where no external force is applied, it has bistability that can be stably held in either the longitudinally extending extension form or the winding form. doing. In the following description, the winding form portion of the boom body 10 is denoted by reference numeral 10A, and the extension form portion is denoted by reference numeral 10B.
In the take-up form portion 10A, the boom main body 10 is held by the rigidity of the cylindrical shape in which the elastic restoring force to return in the open cross-sectional direction is extended. It is done. Further, in the extension form portion 10B, the boom main body 10 has an open cross-sectional shape in the crosswise direction, and the elastic restoring force in the winding direction is held by the rigidity in the longitudinal direction of the boom main body 10 in the open cross-sectional shape.
In the state where the boom body 10 has two forms of the extension form and the take-up form, as shown in FIG. 1A, there is a transition region 10C in which the take-up form portion 10A transitions to the extension form portion 10B. It is unstable, and it shifts to the stretched form or the wound form by elastic restoring force.
In this embodiment, in order to self-extend from the wound-up form to the extended form, the elastic restoring force to restore to the extended form is set larger than the elastic restoring force to restore to the wound-up form. That is, from the boundary position 10D at which the extension form portion 10B and the transition area 10C transition, the cross-sectional shape in the width direction of the boom body 10 sequentially returns from the straight line state to the open cross-sectional shape by elastic restoring force. And the extension form portion 10B to self-extend.

In this embodiment, the open cross-sectional shape of the boom body 10 in the lateral direction is a cross-sectional arc shape that constitutes a part of a circle, and the opening angle α formed by the line connecting both ends of the arc and the center of curvature is about 160 ° Set to When the opening angle is large, the elastic restoring force in the case where the open cross-sectional shape is linearly deformed is small, and when it is large, the elastic restoring force is large. If it is too large, the elastic restoring force becomes excessive and it can not be wound up, so the angle is set to about 40 ° to 180 °.
The boom body 10 has a laminated structure in which a plurality of fiber reinforced resin sheets (FRP sheets) 13 are laminated as shown in FIG. Each fiber reinforced resin sheet 13 is the structure which made the fiber base material 11 impregnate the matrix resin 12 by the same structure.
The fiber substrate 11 is a biaxial fabric structure, and the first axial yarn 11a and the second axial yarn 11b have a predetermined angle θ (orientation angle) in opposite directions with respect to the long axis N1 along one longitudinal direction. It is configured to be inclined only. The orientation angle is 45 °.
In this embodiment, carbon fibers are used as the first axial yarns 11a and the second axial yarns 11b, and in particular, the first axial yarns 11a and the second axial yarns 11b are formed by spread fibers obtained by flatly bundling fiber bundles. Are set thin, and a plurality of fiber reinforced resin sheets 13 are laminated to form the boom body 10. In this example, the fiber reinforced resin sheet 13 has a three-ply structure in which three layers are laminated, but may have a two-layer structure or a four-layer structure or more.

In the present embodiment, carbon fibers are used as the base fibers of the fiber base 11, but in addition to carbon fibers, glass fibers, polyester fibers, fluorine fibers, aramid fibers, polypropylene fibers, polyethylene fibers, Metal fibers and the like can be used. When using for an antenna etc., an electroconductive fiber can also be used.
In addition, as the matrix resin, polycarbonate resin, polyester resin such as PET or PBT, engineering plastic such as PEEK or PPS, heat resistant resin such as polyimide, or the like can be used.
The base material structure of the fiber base material 11 is not limited to the woven structure, and a braided structure is also applicable. In addition, a knitted structure, a net structure and the like are also applicable.

The assisting member 20 is formed of a long thin metal plate having elasticity, and is provided so as to be relatively movable in the longitudinal direction along the boom body 10. The assisting member 20 is configured to have only extension stability which is an extended form extended linearly in an initial form (a free state in which no external force acts).
Then, it is elastically deformed along with the winding of the boom body 10, and is wound according to the winding mode of the boom body 10, and when the boom body 10 self-expands, the elastic restoring force of the assisting member 20 to the extension mode The transition to the extension form of the boom body 10, that is, self extension is assisted.
The cross-sectional shape in the direction orthogonal to the longitudinal direction of the assisting member 20 is an arc-shaped curved open cross-sectional shape. The width in the lateral direction of the assisting member 20 is narrower than the width in the lateral direction of the boom body 10, and is disposed along the central bottom portion on the concave side of the boom body 10 having an open cross-sectional shape. Further, the longitudinal length of the assisting member 20 is provided over substantially the entire length of the boom body 10.
The metal material constituting the assisting member 20 is a spring steel band, and as a type of spring steel band, SK hardened steel, stainless steel (for example, SUS301, SUS304, SUS632 etc.), copper alloy, nickel alloy, titanium alloy, shape memory Alloys, beryllium copper alloys, etc. can be used.
A tube 40 as a holding member for slidably holding the assisting member 20 is pasted and fixed to the boom body 10 along the longitudinal direction of the boom body 10, and the assisting member 20 is in sliding contact with the tube 40. It is held freely. The tube 40 is made of a resin film which slides well with the assisting member 20, a woven fabric of a bias, a braid or the like.
In this example, the assisting member 20 is fixed to the boom body 10 at the fixing portion 21 of the inner diameter side end portion on the winding start end side of the winding portion of the boom body 10, and the winding end side of the other end is free The peripheral length difference between the boom body 10 and the assisting member 20 in the winding state and the extended state is absorbed by the relative sliding between the assisting member 20 and the boom body 10. In this embodiment, the end position on the winding end side of the assisting member 20 with respect to the boom body 10 is moved.

Next, the operation of the boom of this embodiment will be described.
In the winding configuration, the boom body 10 has a linear arc-shaped open cross-sectional shape extending in the lateral direction, and the elastic restoring force to return in the open cross-sectional direction is the stiffness of the wound cylindrical shape. Is held by
In a state where all the boom body 10 is wound, the assisting member 20 is held in a winding configuration following the boom body 10 by the rigidity of the winding form portion 10A of the boom body 10. The assisting member 20 exerts an elastic restoring force to return in the longitudinal direction, but is stably held in the winding configuration by the rigidity of the winding configuration of the boom body 10.
Assuming that the boom main body 10 stable in the winding configuration is in the extension configuration, the cross-sectional shape in the lateral direction of the boom main body 10 is in the transition region 10C transitioning from the winding configuration 10A to the extension configuration 10B. The elastic restoring force that tends to bend in the short direction sequentially returns from the straight line state to the open cross-sectional shape, and the wound form portion 10A shifts to the extended form and self-expands. During self-extension, an elastic restoring force in the unwinding direction of the assisting member 20 acts on the boom body 10, and the elastic restoring force assists the self-extension of the boom body 10.

Therefore, the elastic restoring force of the metal assisting member 20 does not decrease even if stress relaxation occurs in the boom main body 10 while being wound up for a long time on a monthly basis or a yearly basis, the elasticity of the assisting member 20 The restoring force can ensure self-extension.
In the process of extension, the contact portion between the boom body 10 and the assisting member 20 slides, and changes to the extension while absorbing the circumferential difference.
In the above embodiment, the assisting member 20 is fixed at the winding start end side S (the inner diameter side end portion of the winding form) of the boom body 10, but as shown in FIG. The portion 21 may be fixed to the winding end side T (the outer diameter side end portion of the winding configuration) of the boom body 10. In this case, the free end 20F of the assisting member 20 is disposed on the winding start end side of the boom body 10, but the position of the free end 20F of the assisting member 20 is set in consideration of the circumferential length difference during winding. , And is set shorter than the end on the winding start end side of the boom body 10.
Further, as shown in FIG. 2 (B), the fixing portion 21 may be fixed to a midway portion in the longitudinal direction of the boom body 10. Also in this case, the free end on the winding start end side of the boom body 10 of the assisting member 20 is set shorter than the end portion on the winding start end side of the boom body 10 in consideration of the circumferential length difference during winding. Ru.
Moreover, in the said embodiment, although the assisting member 20 is arrange | positioned along the bottom part by the side of the concave of the boom main body 10 of extension form, you may provide along the convex side of a boom main body.
Further, as shown in FIG. 2C, a hole 22 may be provided so as to partially change the rigidity of the assisting member 20, or, as shown in FIG. You may provide the narrow part 23 with the change. For example, when transitioning to the extension form, if the rigidity of a predetermined length in the final extension area (inner diameter side) is reduced, the initial stage to shift to extension is quickly extended, and the elastic recovery force is small at the final stage And can end extension quietly. Also, conversely, the rigidity for a predetermined length of the final extension area (inner diameter side) may be increased. In this way, it can be extended reliably. For example, by making the width of the assisting member 20 reverse-tapered from the root to the tip, it is possible to start extension slowly and adjust so as to extend and cut the tip portion that is difficult to extend.
Further, the assisting member 20 has extension stability for holding an extended state, and it is advantageous that the orthogonal cross section in the longitudinal direction is arc-shaped, but in other words, it has elasticity in the rewinding direction The cross section perpendicular to the longitudinal direction may be linear.

[Winding and unwinding mechanism]
Next, with reference to FIG. 4, the unwinding mechanism of each extension system will be described.
(One end restraint tip wound and unwinding type)
In the method shown in FIG. 4A, the end on the outer diameter side of the winding form portion 10A, which is one end of the boom body 10, is pulled out to be in an extended state, and the extended form portion 10B pulled out fixes the storage tool 110. It is part 111. Further, the free end 20F of the assisting member 20 protrudes beyond the boom body 10 by the circumferential difference. Since the extension form portion 10B is fixed, a leftward self-extension force F acts on the take-up form portion 10A, and the self-extension force F is held by the holding portion 112.
Then, when the holding portion 112 is turned over and the restraint on the winding form portion 10A is released, the winding form portion 10A is continuously rewound, and continuously shifted to the extended form.

(Center restraint both ends winding release type)
In the method shown in FIG. 4 (B), the center of the boom body 10 is fixed to the storage tool 120, and partially forms an extension form portion 10B. Both sides of the extension form portion 10B are taken as winding form portions 10A and 10A which are wound in opposite directions to each other. The fixing portion 21 of the assisting member 20, which is wound on the boom body 10 in an overlapping manner, is also fixed to the central portion of the boom body 10 and restrained by the storage tool 120. Then, the retractable holding portions 122, 122 provided at both ends of the container 110 hold the winding form portions 10A, 10A on the left and right sides so as not to extend.
If both restraints of the left and right holding parts 122, 122 are released, the left and right take-up form parts 10A, 10A extend leftward and rightward, and if only one is pulled down, only one side extends.

(Take-up shaft restraint tip unwinding type)
In the method shown in FIG. 4B, the end on the inner diameter side of the winding form portion 10A of the boom body 10 is fixed to a rotatable winding shaft 131 provided in the storage tool 130 and wound up. . The assisting member 20, which is rolled up with the boom body 10, is also rolled up with the boom body 10.
In this state, when the distal end portion is pulled out to be in the extension form, the take-up form portion 10A is rotated and sequentially shifted to the extension form, and the extension form portion 10B linearly extends with the bottom surface 121 of the storage tool 120 as a guide.

Next, experimental examples of the boom of the present invention will be described.
The structure of only the boom main body 10 and having no extension assisting member is Sample 1 as a comparative example, the assisting member 20 of the present invention having a width of 6 mm is Sample 2 and the assisting member 20 is 8 mm in width Sample 3 As, self extension time was compared.
In any case, the boom diameter (diameter) is 19 mm, the opening angle α is 160 °, the thickness of the boom body is 0.25 mm, the boom width is 33.2 mm, and the boom length is 110 mm.
The winding portion of sample 1 has an inner diameter D0 of 18 mm and the outer diameter D1 of 34 mm, the winding portion of sample 2 has an inner diameter D0 of 22 mm and an outer diameter D1 of 39 mm, and the winding portion of sample 3 has an inner diameter D0 of 30 mm The outer diameter D1 is 45 mm.
The fiber base materials of the reinforcing fiber resin are all carbon fiber woven fabrics of Toray Industries, Inc., CO 6343 (using T300-3K), and the matrix resin are all NM35 manufactured by JX Energy.
As a result of conducting extension experiments, sample 3 also has bistability to stably hold the winding state and the extension state.
Although all three samples had bistability, when self-extension time was measured, it stopped in the middle of extension in sample 1 of only boom body 10 without an assisting member. Both sample 2 and sample 3 of the present invention self-extended to the end, but the time from the start of extension to the completion of extension is 0.4 [sec / m] for sample 2 and 0.33 [sample 3]. sec / m].

Second Embodiment
A second embodiment of the present invention will now be described with reference to FIG. In the following description, only differences from the above embodiment will be mainly described, and the same components will be denoted by the same reference numerals and descriptions thereof will be omitted.
In the first embodiment, the boom body is self-extending, and the assisting member 220 assists the extension. However, in the second embodiment, the boom member 10 is self-contracting in the boom body 10. It differs in that it is supposed to help winding.
That is, in this embodiment, the boom main body 10 is restored to the extended configuration so as to self-contract from the extended configuration to the wound configuration in the state having the two configurations of the extended configuration and the wound configuration shown in FIG. It is set so that the elastic restoring force for restoring to the winding configuration is larger than the elastic restoring force.
Further, as shown in FIG. 5B, the assisting member 220 is the same in structure as the assisting member 20 of the first embodiment except that the initial form is bent in the winding form, and has a length having elasticity. It is formed of a thin thin metal plate material of a scale, and is provided so as to be relatively movable in the longitudinal direction along the boom body 10. In this winding mode, the film is wound with a curvature according to the winding mode of the boom body 10.
The cross-sectional shape of the assisting member 220 in the direction perpendicular to the longitudinal direction is an arc-shaped curved open cross-sectional shape, and the width in the latitudinal direction is narrower than the width in the latitudinal direction of the boom body 10 It is disposed along the central bottom of the concave side of the boom body 10. Further, the longitudinal length of the assisting member 220 is provided over substantially the entire length of the boom body 10. As a metal material for forming the assisting member 220, a stainless steel strip for springs (for example, SUS301, SUS304, SUS632 or the like), a beryllium copper alloy or the like can be used as in the first embodiment.
In the second embodiment, in the initial form, the assisting member 220 is in a winding configuration with the boom body 10, and when extending, the elastic restoring force in the winding direction of the boom body 10 and the assisting member 220 is resisted. Keep it stretched. The extension form is held by the shape rigidity of the boom body 10. Then, when a part of the boom body 10 is in the winding state, the extension mode is sequentially shifted to the winding mode and self-contracts, and at the same time, the assisting member 220 assists the transition of the boom body 10 from the extension mode to the winding mode. And can be reliably wound up.

FIG. 6 shows Embodiment 3 of the present invention.
In this third embodiment, the entire length of the reinforcing member 30 provided with a soft resin material having rubber-like elasticity at both side edges extending along the longitudinal direction of the boom body 10 of the open cross-sectional shape of the first embodiment or the second embodiment It is something that is covered and covered. The basic configuration is the same as in the first and second embodiments, and the same components are denoted by the same reference numerals and the description thereof is omitted.
As shown in an enlarged manner in FIGS. 2A and 2B, the reinforcing material 30 is a resin material having a low friction property that covers the surface of the main body 31 made of a soft resin having rubbery elasticity and a surface of the main body 31. It has a laminated structure provided with the surface layer 32 made of.
The main body portion 31 has a U-shaped cross section with an open groove 31a into which the side edge of the boom body 10 is inserted, and is adhered to the inner side 31b bonded to the inner side surface of the side edge of the boom body 10 An outer piece 31c, and a connecting part 31d which connects the inner and outer pieces and is bonded to the end face of the side edge.
As soft resin which comprises the main-body part 31, elastomers, such as a thermoplastic polyurethane resin (TPU), are suitable. TPU is excellent in flexibility and adhesiveness, and has an effect of enhancing the tear strength of the bistable boom end portion and preventing the crack in the fiber orientation direction of the fiber reinforced resin CFRP.
Since TPU is excellent in flexibility, it can suppress adverse effects on the storage and extension characteristics of the boom. However, due to the tackiness, slippage may become worse if TPUs are in contact with each other. Therefore, in order to improve the slippage, the surface layer 32 made of a resin material having low friction characteristics is used.
The surface layer 32 is made of a resin material with low friction and wear resistance, such as tetrafluoroethylene resin (PTFE). In particular, a material having both flexibility and difficulty in peeling in addition to low friction characteristics is preferable. For example, a thin-film PTFE adhesive tape (part number: ASF-116T) manufactured by Chuko Kasei Kogyo Co., Ltd. can be used. This tape is a tape with a total thickness of 43 μm (PTFE base thickness 21 μm, adhesive thickness 22 μm). By covering the main body 31 with the low friction surface layer 32 in this manner, the frictional resistance at the end of the bistable boom can be reduced, and the storage and extension can be smooth. Moreover, since it is a thin film, it has the property that it is difficult to separate while suppressing the mass increase.
Of course, the material of the surface layer 32 is not limited to tetrafluoroethylene resin, and any material having low friction characteristics, flexibility, and difficulty in peeling may be used.

Next, the action of the reinforcing material of the boom of Embodiment 3 will be described.
In the vicinity of the boundary of the transition area from the winding state of the boom body 10 to the extending state or the extending state to the winding state, the bending stress in the short direction in the winding state is released, and a large shear force acts in the vicinity of the boundary However, the rubbery elasticity of the main body portion 31 of the reinforcing member 30 disperses and reduces the shear force, thereby preventing the occurrence of a tear. In particular, in the case where the boom body 10 has a laminated structure of the fiber reinforced resin sheet 13, when the phases of the yarns of the fiber base 11 of the respective sheets overlap, a tear tends to occur along the overlapped yarns. Can be used to prevent tears.
Furthermore, since the surface of the reinforcing member 30 is covered by the surface layer 32 with low friction, even when the reinforcing members 30 contact with each other at the time of winding, the contact surface slides and the winding form and the extension form smoothly. Form transition of
In addition, since the reinforcing material 30 only covers the side edges, resistance to deformation due to winding and stretching is small, and combined with the smoothness of the surface of the reinforcing material 30, it is in the form of the winding form and the stretching state The transition goes smoothly.

In each of the above embodiments, the assisting member 20 is slidably inserted in the entire length of the tube 40 provided at the bottom of the boom main body 10, but relative sliding relative to the boom main body 10 is possible. As long as it is held, one part may be held and the other part may be free.
Further, in the above embodiment, the assisting member 20 is only one of self-extension assistance and self-rolling and storage assistance, but a part of the assistance member 20 is in the initial form of the extension form, and the winding form The other part may be configured to support the transition from the stretched form to the wound form, with the other part being the wound form in the initial form. For example, by providing self-extension assistance from the root to near the tip and self-winding storage of the tip, it is possible to take samples or catch an object. When a sample is taken, the extended form part can be wound into a storage form by a motor or the like.
In this case, the boom main body is held in a transition state in which no transition is made to either the extension mode or the winding mode, depending on the elastic restoring force, with the extension mode and the winding mode mixed. It is desirable to set the magnitude of the elastic restoring force. In this way, the progress of the partial form transition by the assisting member is facilitated.
However, the portion of the boom main body where the initial form of the assisting member corresponds to the extension form is the take-up form rather than the elastic restoring force that restores from the extension form to the take-up form so that it self-extends from the winding form to the extension form. It is set so that the elastic restoring force to restore from the stretching form to the stretching form is larger, and the portion corresponding to the winding form to the initial form of the assisting member self-contracts from the stretching form to the winding form, from the stretching form The elastic restoring force for restoring to the winding form may be set to be larger than the elastic restoring force for restoring to the winding form.
Further, the extension structure of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 boom 10 boom main body 10A take-up form part 10B extension form part 10C transition area 11 fiber base material 11a 1st axial thread, 11b 2nd axial thread 13 fiber reinforced resin sheet 12 matrix resin 20 support member 21 fixing part, 22 hole, 23 Narrow portion 30 Reinforcement 40 Tube S Winding start end T Winding end

Claims (13)

A long resin plate material having elasticity and bent in an open cross-sectional shape in a direction perpendicular to the longitudinal direction, while being taken up in a cylindrical form in the longitudinal direction. In the initial configuration, the boom main body provided with the boom main body stably held in either the extension form extending in the longitudinal direction or the take-up form in the bent form has two forms of the extension form and the take-up form A boom which is mechanically unstable in the state of having a force, and which shifts to an extended form or a wound form by elastic restoring force,
An assisting member composed of an elastic long metal plate is provided so as to be relatively movable in the longitudinal direction along the boom body,
A boom characterized in that the elastic restoring force of the assisting member assists the transition of the boom body to the extension mode or the winding mode. In a state where the boom body has two forms of the extension form and the winding form, an elastic restoring force restores the extension form to a stretching form rather than an elastic restoring force that restores to the winding form so as to self-extend from the winding form to the extension form Is set to be larger,
The boom according to claim 1, wherein the assisting member is in an initial form in an extended form, and is configured to assist transition of the boom main body from a take-up form to an extended form. In a state where the boom body has two forms of the extension form and the take-up form, the elastic restoring force restores the take-up form more than the elastic restoring force that restores the extend form to self-contract from the extension form to the take-up form Is set to be larger,
The boom according to claim 1, wherein the assisting member is configured in an initial form in a winding form, and is configured to assist transition of the boom body from the extended form to the winding form.   The assisting member assists in the transition from the wound form to the extended form in part in the initial form in the extended form, and in the other part in the wound form in the initial form, for the transition from the extended form to the wound form The boom according to claim 1 which is configured.   The boom according to any one of claims 1 to 4, wherein a cross-sectional shape in a direction orthogonal to the longitudinal direction of the assisting member is a curved cross section.   The boom according to any one of claims 1 to 5, wherein the boom body is provided with a holding member for slidably holding the assisting member.   The assisting member is partially fixed to the boom body, and the circumferential length difference between the boom body and the assisting member in the winding state and the extending state is a relative sliding between the assisting member and the boom body between the fixed portion and the free end. The boom according to any one of claims 1 to 6, which is configured to absorb by movement.   The boom according to claim 7, wherein the assisting member is fixed at an inner diameter end position of the boom body in a winding state.   The boom according to claim 7, wherein the assisting member is fixed at an outer diameter side end position of the boom body in a winding state.   The boom according to claim 7, wherein the assisting member is fixed at a midway portion in the longitudinal direction of the boom body, and a winding portion in a winding state of the boom body is formed on both sides in the longitudinal direction with respect to the fixing portion. The boom body is constituted by a fiber reinforced resin obtained by impregnating a fiber base with a resin.
10. A boom according to any of the preceding clauses.   The fiber base material is a biaxial fabric structure, and the yarns of the first axial yarn and the second axial yarn are configured to be inclined at predetermined angles in opposite directions with respect to the long axis along one longitudinal direction. The boom according to claim 11.   The boom according to claim 12, wherein the yarn constituting the fiber base is an open fiber and has a laminated structure in which a plurality of fiber reinforced resin sheets obtained by impregnating a fiber base with a resin are laminated.

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