Extension rod

Abstract

To provide a high-strength extension rod suitable for use in outer space, including the surface of the moon. [Solution] An extension rod having an extension structure having a long, elastic extension member and a storage section that winds up and stores the extension member, the extension section being formed as the tip of the extension member extends one-dimensionally from the storage section, forming a hollow cylindrical shape; and a telescopic boom consisting of multiple hollow cylindrical members of different diameters, such that in the stored configuration, the cylindrical member with the largest diameter contains the other cylindrical members concentrically, and in the extended configuration, the ends of the cylindrical members are connected to form a multi-stage cylindrical shape, the extension member consisting of three divided extension members, the storage section consisting of divided storage sections that store each of the divided extension members, the telescopic boom being positioned inside the hollow cylindrical shape of the extension section, the cylindrical member located at the tip of the telescopic boom in the extension direction is connected to the tip of the divided extension member, and the extension structure and telescopic boom extend in the same direction in conjunction with each other.

Description

[Technical Field]

[0001] The present invention relates to an extension rod. [Background technology]

[0002] Extension rods with a deployment mechanism that can be moved from a stowed configuration to an extended configuration are used as deployment devices for solar panel (SAP) and structural materials of space structures such as antennas used in artificial satellites and lunar probes. Known extension rods include those with a Storable Tubular Extendible Member (STEM) structure using a long, elastic extension member and those using a telescopic boom.

[0003] An extension rod with a STEM structure has a long, elastic extension member and a storage section that winds and stores the extension member. The extension member is configured so that the tip of the extension member extends one-dimensionally from the storage section, forming an extension section with a hollow cylindrical structure. Some extension rods with a STEM structure use a structure (called Tri-STEM) in which the extension member is divided into three segments so that the hollow cylindrical extension section is divided into three parts, thereby ensuring mechanical strength and straightness during extension (see Patent Document 1). In an extension rod with a Tri-STEM structure, the tips of each segment extension member are connected and a fixing means is provided to connect the sides of the segment extension members during extension, thereby giving the extension section a hollow structure with a closed cross section. The extension rod also has three segment storage sections corresponding to each segment extension member, and the base end of each segment extension member is independently wound into each segment storage section. With an extension rod with a Tri-STEM structure, the three separate extension materials are connected to each other while extending, so there is almost no change in the center of gravity as it moves from the storage form to the extension section, allowing for stable extension.

[0004] A telescopic boom is made up of multiple hollow cylindrical members of different diameters. In its stowed configuration, the largest-diameter cylindrical member houses the other multiple cylindrical members concentrically inside it. When extended, the cylindrical members are successively pulled out, starting with the smallest diameter, to form an extended configuration in which the ends of the multiple cylindrical members are connected to form a multi-stage, long rod. Extending a telescopic boom requires a drive source to pull the internal cylindrical members out. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-111203 Summary of the Invention [Problem to be solved by the invention]

[0006] The Tri-STEM extension rod has a structure in which the segmented extension members are wound around a storage section. However, if the segmented extension members are too thick, they cannot be wound up, so there is a limit to the thickness of the segmented extension members. Furthermore, although the extension section has a closed cross-sectional shape, the structure involves multiple segmented extension members being joined together, which results in anisotropy in strength, and this may be insufficient, particularly for lunar rover applications where gravity is present. On the other hand, when the telescopic boom is extended, the joints between the cylindrical members are exposed to the outside, which could allow small foreign objects such as sand to enter the joints and hinder the extension, especially for lunar rover applications.

[0007] An object of the present invention is to provide a high-strength extension rod suitable for use in outer space, including the lunar surface. [Means for solving the problem]

[0008] The present invention employs the following means to solve the above problems.

[0009] That is, the extension rod of the present invention is an extensible structure comprising: a long elastic extensible material; and a storage section for winding and storing the extensible material, wherein the extensible section formed by one-dimensionally extending the tip of the extensible material from the storage section has a hollow cylindrical shape; a telescopic boom comprising a plurality of hollow cylindrical members of different diameters, in which in a stowed configuration, the cylindrical members are concentrically housed inside the cylindrical member with the largest diameter, and in an extended configuration, the ends of the cylindrical members are connected to each other to form a multi-stage cylindrical shape; and In the extension structure, The extension member is composed of three divided extension members, and the three divided extension members have connecting portions on their sides that connect to each other when extended to form the extension member into a hollow cylindrical shape with a closed cross section; The storage section is composed of three divided storage sections that independently wind and store the base ends of the three divided extensible materials, the telescopic boom is disposed inside the hollow cylindrical shape of the extension section, The cylindrical member that is located at the tip of the extension direction in the extended form among the multiple cylindrical members that make up the telescopic boom and the tip ends of the three divided extension members of the extension structure are connected to each other, and the extension structure and the telescopic boom are linked and extend in the same direction.

[0010] With an extension rod configured in this manner, the telescopic boom is disposed inside the extension structure, and the extension structure and telescopic boom extend in the same direction in unison. Therefore, even if an external force that bends or flexes the extension section acts on a weak part of the extension section of the extension structure due to the anisotropy of its strength in the extended form, the extension section is supported by the telescopic boom disposed inside the extension section, which has excellent strength, and bending of the extension section during the extension operation or after reaching the extended form can be prevented. Therefore, sufficient strength can be ensured even in an environment where gravity is present, such as in lunar probe applications.

[0011] Furthermore, because the telescopic boom in the extended configuration is disposed inside the extension section of the extension structure in the extended configuration, most of the outer circumferential surface of the telescopic boom is covered by the outer circumferential surface of the hollow cylindrical shape of the extension section. This prevents the joints between the cylindrical members of the telescopic boom in the extended configuration from being exposed to the outside. This prevents fine foreign matter such as sand from entering the joints. This allows the telescopic boom to be extended more reliably even in an environment where foreign matter is present, such as in a lunar probe application.

[0012] In the divided extensible material in an extended form, the wound portion wound around the divided storage section has a linear cross-sectional shape perpendicular to the extension direction, and the extended portion including the tip portion has an arc-shaped or curved shape convex in the outer circumferential direction, In the extension direction, at least a portion of the telescopic boom in the stowed configuration may be configured to be in a position corresponding to a transitional configuration portion between the wound configuration portion and the extended configuration portion of the segmented extension material.

[0013] Since at least a portion of the telescopic boom in the stowed configuration is located in the transition configuration portion of the divided extension members of the extension structure, the size of the extension rod in the extension direction in the stowed configuration can be reduced.

[0014] The telescopic boom is a cylindrical member having a maximum diameter in a stored configuration. However, the segmented extension material can be configured to transition to an extended form together with the extension structure by being pulled out in the extension direction by the extending segmented extension material, starting from the cylindrical member with the smallest diameter connected to the tip of the segmented extension material.

[0015] This allows the telescopic boom to be extended in conjunction with the extension of the extension structure.

[0016] a roller that forms a nip portion with an outer peripheral surface of the cylindrical member with the largest diameter of the telescopic boom; a motor that rotates and drives the roller; Furthermore, The divided stretchable material can be configured to be sandwiched in the nip portion, stretched by the forward rotation of the roller, and wound up in the divided storage portion by the reverse rotation of the roller.

[0017] According to this configuration, the divided extension members and the telescopic boom connected thereto can be extended by the driving force of the motor.

[0018] The above configurations may be combined as much as possible. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a high-strength extension rod suitable for use in outer space, including the surface of the moon. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 10 is a perspective view showing the extension rod of the embodiment in the middle of extension. [Figure 2] 1A and 1B are side views showing the extension rod of the embodiment in a housed state and an extended state. [Figure 3] FIG. 10 is a top view of an example extension rod. [Figure 4] 1A and 1B are cross-sectional views showing the extension rod of the embodiment in a housed state and an extended state. [Figure 5] FIG. 2 is a perspective view of an extension portion of the extension structure of the embodiment. [Figure 6] FIG. 2 is a cross-sectional view of an extension portion of an extension structure according to an embodiment. [Figure 7] 1A and 1B are diagrams illustrating a telescopic boom constituting an extension rod of an embodiment in a retracted state and an extended state. DETAILED DESCRIPTION OF THE INVENTION

[0021] The following detailed description of the present invention will be given by way of example with reference to the accompanying drawings, although the dimensions, materials, shapes, relative positions, etc. of the components described in the examples are not intended to limit the scope of the present invention unless otherwise specified.

[0022] FIG. 1 is a perspective view showing an extension rod according to an embodiment of the present invention in a state midway through extension. FIG. 2(A) is a side view showing the extension rod of the embodiment in a stored state, and FIG. 2(B) is a side view showing the extension rod of the embodiment in an extended state. FIG. 3 is a top view of the extension rod of the embodiment. FIG. 4(A) is a cross-sectional view showing the extension rod of the embodiment in a stored state, and FIG. 4(B) is a cross-sectional view showing the extension rod of the embodiment in an extended state. FIG. 5 is a perspective view of an extension section of an extension structure constituting the extension rod of the embodiment. FIG. 6 is a cross-sectional view of the extension section of an extension structure constituting the extension rod of the embodiment. FIG. 7(A) is a view showing the telescopic boom constituting the extension rod of the embodiment in an extended state, and FIG. 7(B) is a view showing the telescopic boom constituting the extension rod of the embodiment in a stored state.

[0023] The extension rod 100 includes an extension structure 1 and a telescopic boom 40.

[0024] (extension structure) The extension structure 1 has a long, elastic extension material 10 and a storage section 20 for winding up and storing the extension material 10, and is configured so that the extension section 15 formed by the tip of the extension material 10 extending one-dimensionally from the storage section 20 has a hollow cylindrical shape.

[0025] The extension member 10 is made up of three divided extension members 11, 12, and 13, and the tip ends of the three divided extension members 11, 12, and 13 are each connected to a plate-shaped tip member 16. As will be described later, the tip end of the cylindrical member 44 with the smallest diameter of the telescopic boom 40 is connected to the tip member 16, and the extension structure 1 and the telescopic boom 40 are connected via the tip member 16.

[0026] Ears 14 are provided along the entire length of the extension direction of the sides of the three divided extension members 11, 12, and 13. The ears 14 are connected to each other in the circumferential direction of the hollow cylindrical extension portion 15 and protrude outward relative to the extension portion 15. The ears 14 are provided with hook-and-loop fasteners 30, which are connecting parts that connect the three divided extension members 11, 12, and 13 to each other when extended, giving the extension portion 15 a hollow cylindrical shape with a closed cross section.

[0027] As shown in Figures 3 and 5, the hollow cylindrical extension section 15 has a cylindrical shape with a circular cross section, and each of the divided extension members 11, 12, and 13 is composed of an elongated arc-shaped body obtained by dividing the circumference into three 120-degree sections. The cross-sectional shape of the extension section 15 is not limited to a circle, and may be any closed cross-sectional shape. For example, as shown in Figures 1 and 6, the cross-sectional shape of the divided extension members 11, 12, and 13 may be a curved shape that is convex toward the outer periphery, and the overall shape may not be circular.

[0028] The storage section 20 is composed of three divided storage sections 21, 22, and 23, which independently wind and store the base ends of the three divided extensible materials 11, 12, and 13. The three divided storage sections 21, 22, and 23 are arranged radially in three directions when viewed from the extension direction. In other words, the divided storage sections 21, 22, and 23 are arranged in an equilateral triangle. That is, the cross sections perpendicular to the extension direction of the divided extensible materials 11, 12, and 13 stored in the divided storage sections 21, 22, and 23 are linear, but the angles between these lines are 60 degrees. The divided storage sections 21, 22, and 23 are configured to pull out the divided extensible materials 11, 12, and 13 toward the outlet side of the storage section 20.

[0029] The segmented extensible members 11, 12, and 13 are made of fiber-reinforced plastic reinforced with a fibrous substrate, such as a triaxial woven single-layer composite material. The fibrous substrate can be a woven fabric, a knitted fabric, or a unidirectional material in which carbon fibers are aligned in only one direction. The woven fabric can be a triaxial woven fabric or a biaxial woven fabric. The substrate fibers can be high-strength, high-elasticity, low-thermal-expansion fibers such as carbon fiber, aramid fiber, high-strength, high-heat-resistant polyparaphenylenebenzoxazole (PBO) fiber, or quartz glass fiber. Furthermore, thermosetting resins such as epoxy resins and polyimide resins are suitable as the matrix resin of the fiber-reinforced plastic.

[0030] (Split extension material and split storage section) Figure 4 is a cross-sectional view taken along the line AA in Figure 5. However, to simplify the drawing, only divided extension member 12 is shown in Figure 4, and the other divided extension members are not shown. Using Figure 4, divided extension members 11, 12, and 13 and divided storage sections 21, 22, and 23 will be explained using divided extension member 12 and divided storage section 22 as examples, but the configurations of the other divided extension members and divided storage sections are similar.

[0031] The divided storage section 22 has a winding drum 25 that winds up the divided extension material 12, a wall section 26 that rotatably supports the winding drum 25, a guide roller 27 that pulls out the divided extension material 12 from the winding drum 25, an extension guide 28 that is provided at the outlet of the divided storage section 22 and extends in the extension direction, a roller 24 that forms a nip section with the outer surface of the cylindrical member 41 with the largest diameter of the telescopic boom 40, and a motor 50 that rotates and drives the roller 24.

[0032] The divided stretched material 12 is clamped in the nip between the roller 24 and the cylindrical member 41, stretched by rotating the roller 24 forward, and wound up into the divided storage section 22 by rotating the roller 24 reversely. Note that the motor 50 may be provided in each of the three divided storage sections, or the output of one motor may be transmitted to the rollers of the three divided storage sections via power transmission means such as gears.

[0033] The extension guide 28 is provided with an elastic member (not shown) that holds the hook-and-loop fastener 30. The hook-and-loop fastener 30 can have a known configuration. For example, it may be composed of a female fastener piece with many loops and a male fastener piece with many hooks that engage with the loops. The male and female fastener pieces are attached to the ears 14 on the adjacent sides of the divided extension members 11, 12, and 13, and are held down by the elastic member of the extension guide 28 to engage with each other.

[0034] In the extended form of the divided extensible material 12, the wound portion 51 wound on the winding drum 25 of the divided storage section 22 has a linear cross-sectional shape perpendicular to the extension direction, while the extended portion 53 including the tip has an arc-shaped cross-sectional shape perpendicular to the extension direction or a curved shape convex toward the periphery. The region between the extended portion 53 and the wound portion 51 is a transitional portion 52 in which the radius of curvature of the cross-sectional shape gradually decreases along the extension direction.

[0035] In the extension direction, at least a part of the telescopic boom 40 in the stowed configuration is in a position corresponding to the transition configuration portion 52 of the segmented extension member 12. In the example shown in Figure 4, the cylindrical member 41 with the largest diameter of the telescopic boom 40 is in a position corresponding to the transition configuration portion 52.

[0036] In the stored state, the split stretch material 12 is stored in a wound state on the winding drum 25 of the split storage section 22. In the stored state, the tip member 16 to which the split stretch material 12 is connected is located at the exit of the split storage section 22. When the motor 50 is rotated forward in this state, the split stretch material 12 is pulled out in the stretching direction by the rollers 24, and moves toward the exit while the outer periphery is guided by the stretching guide 28.

[0037] The ears 14 on the sides of adjacent split stretchable materials 11, 12, 13 are pressed by the elastic member of stretching guide 28, and hook-and-loop fasteners 30 engage, joining the adjacent split stretchable materials together. Therefore, when split stretchable materials 11, 12, 13 leave split storage sections 21, 22, 23, they are already in the form of hollow cylindrical stretchable section 15, and stretch one-dimensionally.

[0038] Furthermore, since the split stretchable materials are connected to each other by hook-and-loop fasteners 30, stretching and storage can be performed reversibly. When storing, the split stretchable materials 11, 12, and 13 can be wound up and stored by rotating rollers 24 in contact with the split stretchable materials 11, 12, and 13 in the reverse direction using motor 50.

[0039] (telescopic boom) As shown in Fig. 7, the telescopic boom 40 is made up of a plurality of hollow cylindrical members of different diameters. Fig. 7 shows an example in which the telescopic boom 40 is made up of four cylindrical members 41, 42, 43, and 44, but this is an example for the purpose of explanation, and the number of cylindrical members constituting the telescopic boom 40 is not limited to this example. Fig. 7(A) shows the extended form of the telescopic boom 40, and Fig. 7(B) shows the stored form of the telescopic boom 40.

[0040] In the extended configuration, the telescopic boom 40 has a multi-stage cylindrical shape with the ends of cylindrical members connected to each other, as shown in FIG. 7(A), and in the stowed configuration, as shown in FIG. 7(B), the other cylindrical members 42, 43, and 44 are concentrically housed inside the cylindrical member 41 with the largest diameter.

[0041] In the connecting portion 46, a certain cylindrical member (hereinafter referred to as the first cylindrical member) and a cylindrical member (hereinafter referred to as the second cylindrical member) having the next smallest diameter after the first cylindrical member are arranged along the extension direction, and the end of the first cylindrical member in the extension direction is connected to the end of the second cylindrical member opposite the extension direction. A known structure can be used to connect the ends of adjacent cylindrical members. For example, each cylindrical member has a tapered shape that slightly reduces in diameter along the extension direction, and the first cylindrical member and the second cylindrical member are fixed in a connected state by friction or fitting between the inner circumferential surface of the first cylindrical member and the outer circumferential surface of the second cylindrical member at the connecting portion.

[0042] Although FIG. 7(B) illustrates an example in which the lengths of the cylindrical members 41 to 44 in the extension direction are equal to each other, the lengths of the cylindrical members in the extension direction may be different.

[0043] The telescopic boom 40 is disposed inside the hollow cylindrical shape of the extension section 15 of the extension structure 1. In other words, as shown in Fig. 3, when viewed from the extension direction, the telescopic boom 40 is located inside an equilateral triangle formed by the divided extension members 11, 12, and 13.

[0044] Of the multiple cylindrical members 41 to 44 that make up the telescopic boom 40, the cylindrical member 44 with the smallest diameter that is located at the tip in the extension direction in the extended form and the tip ends of the divided extension members 11, 12, and 13 of the extension structure 1 are both fixed to the tip member 16. In other words, the cylindrical member 44 at the tip of the telescopic boom 40 and the tip ends of the divided extension members 11, 12, and 13 of the extension structure 1 are connected via the tip member 16.

[0045] As a result, the extension structure 1 and the telescopic boom 40 extend in the same direction in conjunction with each other. That is, the telescopic boom 40 extends in conjunction with the movement of the divided extension members 11, 12, and 13 being pulled out from the divided storage sections 21, 22, and 23 by the driving force of the motor 50. Specifically, the telescopic boom 40 transitions to the extension form together with the extension structure 1 as the other cylindrical members 42, 43, and 44 housed in the cylindrical member 41 with the largest diameter in the stored form are successively pulled out in the extension direction by the extending divided extension members 11, 12, and 13, starting from the cylindrical member 44 with the smallest diameter connected to the tip end of the divided extension members 11, 12, and 13.

[0046] (Advantages of the extension rod of the embodiment) According to the extension rod 100 configured as described above, the telescopic boom 40 is arranged inside the extension structure 1, and the extension structure 1 and the telescopic boom 40 extend in the same direction in conjunction with each other. Therefore, even if an external force that bends or flexes the extension section 15 of the extension structure 1 acts on a weak part due to the anisotropy of the strength of the extension section 15 in the extension form, the extension section 15 is supported by the telescopic boom 40, which has excellent strength and is arranged inside the extension section 15, and therefore bending of the extension section 15 can be prevented during the extension operation or after the extension form is reached.

[0047] Here, the extendable structure 1 itself has the following excellent features: When extended, the three divided extendable members 11, 12, and 13 extend while being connected to one another, so that the center of gravity changes very little in the process from the stored configuration to the extended configuration of the extension section 15, allowing for stable extension. In addition, the three divided extendable members 11, 12, and 13 are connected by hook-and-loop fasteners 30 in a direction that pushes them toward the center from three sides, so that they are connected in a well-balanced manner and extend stably and straight along the axial direction without tilting.

[0048] Furthermore, the hook-and-loop fasteners 30 cause the divided extension members 11, 12, and 13 to already assume the form of extension section 15 when they exit storage section 20, so the shape can be constrained at the exit of storage section 20, ensuring straightness. Furthermore, because extension section 15 has a closed cross-sectional shape due to hook-and-loop fasteners 30, it has high straightness and bending rigidity, and is resistant to bending moments. It also has high mechanical strength, such as compressive strength.

[0049] However, if the separated extensible members 11, 12, and 13 are too thick, they will not be able to be wound onto the winding drum 25 of the separated storage sections 21, 22, and 23, and so there is a limit to the thickness of the separated extensible members 11, 12, and 13. In other words, although the mechanical strength of the extension structure 1, such as bending rigidity and compressive strength, is high, there is a limit. For this reason, in an environment where gravity is present, such as a lunar mission, the extension structure 1 alone may not be strong enough.

[0050] In this regard, with the extension rod 100 of the embodiment, the strength of the extension structure 1 can be reinforced by the telescopic boom 40, and therefore sufficient strength can be ensured even in an environment where gravity is acting, such as in a lunar probe application.

[0051] Furthermore, by connecting the divided extension members 11, 12, 13 with hook-and-loop fasteners 30 at the exit of the storage section 20 of the extension structure 1, it is possible to shorten the length of the transitional configuration portion 52 from the flat wound-up configuration portion 51 to the arc-shaped extended configuration portion 53 of the divided extension members 11, 12, 13. Furthermore, since the telescopic boom 40 in the stowed configuration is located at a position corresponding to this transitional configuration portion 52, the extension rod 100 in the stowed configuration has high storage ability in the extension direction.

[0052] Furthermore, since the telescopic boom 40 in the extended configuration is disposed inside the extension section 15 of the extension structure 1 in the extended configuration, most of the outer circumferential surface of the telescopic boom 40 is covered by the hollow cylindrical outer circumferential surface of the extension section 15. This prevents the connection section 46 between the cylindrical members of the telescopic boom 40 in the extended configuration from being exposed to the outside. This prevents fine foreign matter such as sand from entering the joints between the cylindrical members at the connection section 46.

[0053] As described above, with the extension rod 100 of the embodiment, the strength of the extension structure 1 can be compensated for by the highly rigid telescopic boom 40, allowing the extension rod 100 to operate reliably even in an environment where gravity is present. Furthermore, the low resistance of the telescopic boom 40 to foreign matter such as sand and dust, which is caused by the presence of the connecting section 46, can be resolved by covering the outer circumferential surface of the telescopic boom 40 with the extension section 15 of the extension structure 1. Therefore, with the extension rod 100 of the embodiment, sufficient strength can be ensured and reliable extension operation can be performed not only in outer space but also on the surface of the moon or on Earth, where gravity is present and sand and dust is present.

[0054] (Variation) In the above embodiment, an example was described in which fiber-reinforced plastic was used as the segmented extensible members, but this is not limited to this and elastic metals such as beryllium copper alloys may also be used. Also, while an example was shown in which hook-and-loop fasteners were used as the connecting parts, this is not limited to this and any other fasteners may be used, such as wire fasteners, rail fasteners, magnets, latches, hooks, buttons, adhesives, or glue, as long as they can be used to connect three segmented extensible members to obtain an extensible part with a closed cross-section structure. [Explanation of symbols]

[0055] 1: Extension structure 10: Extension material 11, 12, 13: Split extension material 14:Ear part 15: Extension part 16: Tip member 20: Storage unit 21, 22, 23: Separate storage section 24: Laura 25: Winding drum 26: Wall part 27: Guide roller 28: Extension guide 30: Velcro 40: Telescopic boom 41, 42, 43, 44: Cylindrical members 46:Connection part 50: Motor 51: Winding form part 52: Transition form part 53: Extension form part 100: Extension rod

Claims

1. an extensible structure comprising: a long elastic extensible material; and a storage section for winding and storing the extensible material, wherein the extensible section formed by one-dimensionally extending the tip of the extensible material from the storage section has a hollow cylindrical shape; a telescopic boom comprising a plurality of hollow cylindrical members of different diameters, in which in a stowed configuration, the other cylindrical members are concentrically housed inside the cylindrical member with the largest diameter, and in an extended configuration, the ends of the cylindrical members are connected to each other to form a multi-stage cylindrical shape; An extension rod having In the extension structure, The extension member is composed of three divided extension members, and the three divided extension members have connecting portions on their sides that connect to each other when extended to form the extension member into a hollow cylindrical shape with a closed cross section; The storage section is composed of three divided storage sections that independently wind and store the base ends of the three divided extensible materials, the telescopic boom is disposed inside the hollow cylindrical shape of the extension section, an extension rod characterized in that the cylindrical member that is located at the tip of the extension direction in an extended form among the plurality of cylindrical members that constitute the telescopic boom and the tip ends of the three divided extension members of the extension structure are connected to each other, and the extension structure and the telescopic boom extend in the same direction in conjunction with each other.

2. In the divided extensible material in an extended form, the wound portion wound around the divided storage section has a linear cross-sectional shape perpendicular to the extension direction, and the extended portion including the tip portion has an arc-shaped or curved shape convex in the outer circumferential direction, 2. The extension rod according to claim 1, wherein in the extension direction, at least a portion of the telescopic boom in the stowed configuration is at a position corresponding to a transition configuration portion between the wound configuration portion and the extended configuration portion of the segmented extension member.

3. 3. The extension rod according to claim 1 or 2, wherein the telescopic boom transitions to the extended form together with the extension structure by the other cylindrical members housed in the cylindrical member with the largest diameter in the housed form being pulled out in the extension direction by the extending segment extension members, successively from the cylindrical member with the smallest diameter connected to the tip end of the segment extension member.

4. a roller that forms a nip portion with an outer peripheral surface of the cylindrical member with the largest diameter of the telescopic boom; a motor that rotates and drives the roller; Furthermore, The extension rod according to claim 1 or 2, wherein the divided extension material is held in the nip portion, extended by the forward rotation of the roller, and wound up in the divided storage portion by the reverse rotation of the roller.

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