Spiral expansion device

Abstract

To inhibit two band materials from causing a malfunction when a cylindrical structure is formed and improve durability of the band materials.SOLUTION: A spiral expansion device includes: a first band material having a first fitting structure; a second band material having a second fitting structure in which the first fitting structure is fitted; and a band material guide device which has a guide structure for guiding the first band material and the second band material in a spiral shape, forms a cylindrical structure by spirally winding the first band material and the second band material around a common axis at positions offset in an axial direction and fitting the first fitting structure in the second fitting structure, and holds the cylindrical structure. The guide structure has: a first guide member forming a first guide surface; and a second guide member forming a second guide surface. In the first guide member, an axial length from a fitting start point where the first fitting structure of the first band material in a separated state is fitted in the second fitting structure fitted in a spiral groove to an upper end of the first guide member is formed so as to be one half of a lead of the spiral groove or longer.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a spiral telescopic device. [Background technology]

[0002] Patent Document 1 discloses a spiral telescopic device that forms a cylindrical structure by spirally winding two strips having an interlocking structure and interlocking them with each other, and that holds the cylindrical structure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-192257 Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration described in Patent Document 1, a bending moment may act on the cylindrical structure from the upper end side of the cylindrical structure. If the bending moment causes the cylindrical structure to tilt, the fit between the inner and outer band materials becomes unstable, and the fit between the inner band material and the guide member also becomes unstable, causing the band materials to malfunction. Furthermore, if the fit between the two band materials becomes misaligned, stress may become uneven in the cylindrical structure, potentially reducing the durability of the band materials.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a spiral telescopic device that can prevent malfunction of two strips when constructing a cylindrical structure and improve the durability of the strips. [Means for solving the problem]

[0006] The spiral extension device according to the present invention comprises a first band having a first fitting structure, a second band having a second fitting structure configured to be able to fit with the first fitting structure, and a guide structure for spirally guiding the first band and the second band, wherein the guide structure causes the first band and the second band to be spirally wound around a common axis at positions offset in the axial direction, and the first fitting structure is fitted into the second fitting structure in a state in which the inner surface of the first band and the outer surface of the second band partially overlap in the axial direction, thereby forming and holding a tubular structure; the band guide device is capable of transitioning the first band and the second band between a tubular state constituting the tubular structure and a separated state in which the first band and the second band are separated; and the guide structure is configured to guide the first band and the second band to be spirally wound around a common axis at positions offset in the axial direction, thereby forming and holding a tubular structure in which the first fitting structure is fitted into the second fitting structure, the second guide member is a fixed member having, on its first guide surface, a spiral groove that is a spiral guide groove formed therein, the second guide member being a fixed member disposed above the first guide member and having, on its second guide surface, a linear groove that is a linear guide groove that is a linear guide groove extending in the axial direction, the first guide member being a fixed member, the first guide member being a fixed member, the second guide member being a fixed member, the second guide member being a fixed member, the first guide member being a fixed member, the second guide member being a fixed member, the [Effects of the Invention]

[0007] In the present invention, malfunction of the two strip materials when forming the cylindrical structure can be suppressed, and the durability of the strip materials can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a spiral extension device according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a spiral cylindrical structure made up of a first strip and a second strip. [Figure 3] 10A and 10B are diagrams for explaining a state in which the first fitting structure, the second fitting structure, and the guide groove are fitted together. [Figure 4] FIG. 10 is a diagram for explaining the detailed structure of the spiral extension device. [Figure 5] 10A and 10B are diagrams for explaining the detailed structure of an inner guide member. [Figure 6] FIG. 6 is a view taken along an arrow A in FIG. 5. [Figure 7] FIG. 5 is a cross-sectional view taken along the line BB in FIG. 4. [Figure 8] 10A and 10B are diagrams for explaining the expansion and contraction operation of the cylindrical structure.

[0009] Hereinafter, a spiral telescopic device according to an embodiment of the present invention will be specifically described. However, the present invention is not limited to the embodiment described below.

[0010] 1 is a diagram showing a schematic diagram of a spiral extension device according to an embodiment. The spiral extension device 1 is a device that extends and contracts a spiral tubular structure 2 made up of a first band material 10 and a second band material 20 in the axial direction. The spiral extension device 1 includes the first band material 10, the second band material 20, and a band material guiding device 30.

[0011] The first strip 10 is an outer belt wound around the outside of the second strip 20. The second strip 20 is an inner belt wound around the inside of the first strip 10. The first strip 10 and the second strip 20 are flexible and elastic metal belts, and both are made of a metal material with relatively high rigidity.

[0012] The cylindrical structure 2 is a structure in which a first band material 10 and a second band material 20 are spirally wound around a common axis while being offset from each other in the axial direction. The cylindrical structure 2 is expandable and contractible in the axial direction. In the cylindrical structure 2, the first band material 10 is wound around the outside of the second band material 20.

[0013] As shown in FIG. 2, the cylindrical structure 2 is a structure in which a first fitting structure 11 of the first band material 10 and a second fitting structure 21 of the second band material 20 are fitted together, with the inner surface of the first band material 10 and the outer surface of the second band material 20 partially overlapping in the axial direction. The first band material 10 has the first fitting structure 11. The second band material 20 has a second fitting structure 21 into which the first fitting structure 11 can be fitted. The first fitting structure 11 is fitted into the second fitting structure 21. Note that the first fitting structure 11 and the second fitting structure 21 are partially omitted in FIG. 2.

[0014] The first fitting structure 11 includes an upper fitting structure 11a and a lower fitting structure 11b. The upper and lower fitting structures 11a, 11b are provided on the upper and lower portions of the first band 10, respectively. The fitting structures 11a, 11b are formed in two levels, upper and lower, and are provided at equal intervals in the longitudinal direction of the first band 10. As shown in FIG. 3, the first fitting structure 11 has a structure in which the opening of a through hole penetrating the first band 10 protrudes toward the inner surface. In this description, the upper fitting structure 11a and the lower fitting structure 11b will be referred to as the first fitting structure 11 unless there is any particular need to distinguish them.

[0015] The second fitting structure 21 includes an upper fitting structure 21a and a lower fitting structure 21b. The upper and lower fitting structures 21a, 21b are provided on the upper and lower edge portions of the second band material 20, respectively. The fitting structures 21a, 21b, formed in two levels, upper and lower, are provided at equal intervals in the longitudinal direction of the second band material 20. The second fitting structure 21 has a structure in which the opening of a through hole penetrating the second band material 20 protrudes toward the inner surface. In this description, the upper fitting structure 21a and the lower fitting structure 21b will be referred to as the second fitting structure 21 unless there is any particular need to distinguish them.

[0016] In the cylindrical structure 2, the first strip 10, which is the outer belt, has an upper edge portion that overlaps the lower edge portion of the second strip 20 from the outside, and the lower edge portion of the first strip 10 overlaps the upper edge portion of the second strip 20 from the outside. In the cylindrical structure 2, the second strip 20, which is the inner belt, has an upper edge portion that overlaps the lower edge portion of the first strip 10 from the inside, and the lower edge portion of the second strip 20 overlaps the upper edge portion of the first strip 10 from the inside.

[0017] In the region of the cylindrical structure 2 where the upper edge side portion of the first band 10 and the lower edge side portion of the second band 20 overlap, the upper edge side fitting structure 11a fits into the lower edge side fitting structure 21b. In the region of the cylindrical structure 2 where the lower edge side portion of the first band 10 and the upper edge side portion of the second band 20 overlap, the lower edge side fitting structure 11b fits into the upper edge side fitting structure 21a. By fitting the first fitting structure 11 into the second fitting structure 21, the first band 10 and the second band 20 are fixed to each other in all directions on the overlapping surfaces, and the shape of the cylindrical structure 2 is maintained. In the cylindrical structure 2, the adjacent first band 10 and second band 20 all partially overlap, and these overlapping surfaces are fixed by the fitting structure, so that the cylindrical structure 2 has high rigidity close to that of a single cylindrical member.

[0018] The strip guide device 30 constitutes and holds the cylindrical structure 2. As shown in Figures 1 and 4, the strip guide device 30 has an inner guide member 40 arranged inside the cylindrical structure 2 and an outer guide member 50 arranged outside the cylindrical structure 2. The inner guide member 40 and the outer guide member 50 are guide structures that guide the first strip 10 and the second strip 20 in a spiral shape.

[0019] The inner guide member 40 is a member around which the first strip 10 and the second strip 20 are spirally wound. The inner guide member 40 has a cylindrical inner guide surface 40a. The inner guide surface 40a is formed by the outer circumferential surface of the inner guide member 40.

[0020] The inner guide member 40 includes a first guide member 41 and a second guide member 42 .

[0021] The first guide member 41 is a rotating member that can rotate around an axis. As shown in Fig. 5, the first guide member 41 is a cylindrical member that extends along the axial direction and forms a first guide surface 41a. The first guide surface 41a is a lower guide surface of the inner guide surface 40a and is formed by the outer peripheral surface of the first guide member 41.

[0022] A spiral groove 43, which is a spiral guide groove, is formed on the first guide surface 41a of the first guide member 41. The first guide member 41 is a screw shaft with the spiral groove 43 formed on its outer circumferential surface. The spiral groove 43 guides the first band material 10 and the second band material 20 so that the cylindrical structure 2 expands and contracts in the axial direction. The second fitting structure 21 fits into the spiral groove 43.

[0023] As shown in Figure 5, when the first guide member 41 is viewed from the side, the spiral groove 43 extends upward to the right. The spiral groove 43 includes a first spiral groove 43a and a second spiral groove 43b. Two guide grooves including the first spiral groove 43a and the second spiral groove 43b are formed in the first guide surface 41a. The upper fitting structure 21a of the second fitting structure 21 fits into the first spiral groove 43a. The lower fitting structure 21b of the second fitting structure 21 fits into the second spiral groove 43b.

[0024] The second guide member 42 is a fixed member that is disposed above the first guide member 41 and is fixed so as not to rotate. The second guide member 42 is a cylindrical member that extends along the axial direction and forms a second guide surface 42a. The second guide surface 42a is an upper guide surface of the inner guide surface 40a and is formed by the outer peripheral surface of the second guide member 42.

[0025] The second guide member 42 is fixed to a support member 44. The support member 44 is a fixed member that is arranged inside the first guide member 41 and the second guide member 42 and is fixed so as not to rotate. The support member 44 is a cylindrical member that extends along the axial direction. The support member 44 rotatably supports the first guide member 41 and non-rotatably supports the second guide member 42. A first bearing 45 and a second bearing 46 are attached to the outer circumferential surface of the support member 44. The first bearing 45 is arranged on the lower end side of the first guide member 41 and supports the first guide member 41. The second bearing 46 is arranged on the upper end 41b side of the first guide member 41 and supports the first guide member 41.

[0026] The second guide member 42 is fitted to an area of ​​the outer peripheral surface of the support member 44 above the portion where the second bearing 46 is attached. The second guide member 42 is fitted to the support member 44 so as to be unable to rotate relative to the support member 44. As shown in FIG. 6 , a restricting groove 42c is formed in the inner peripheral surface 42b of the second guide member 42. The restricting groove 42c is a linear groove extending along the axial direction. A restricting protrusion protruding from the outer peripheral surface of the support member 44 is fitted into the restricting groove 42c. This restricting protrusion extends along the axial direction. By fitting the second guide member 42 from the upper end side of the support member 44, the inner peripheral surface 42b of the second guide member 42 is fitted to the outer peripheral surface of the support member 44. This restricts the rotation of the second guide member 42 relative to the support member 44. The lower end of the second guide member 42 abuts against a stepped portion formed on the outer peripheral portion of the support member 44. Therefore, the second guide member 42 is restricted from moving below the step portion.

[0027] A linear groove 47, which is a linear guide groove, is formed on the second guide surface 42a of the second guide member 42. The second guide member 42 is a straight shaft with the linear groove 47 formed on its outer circumferential surface. The linear groove 47 guides the first band material 10 and the second band material 20 so that the cylindrical structure 2 expands and contracts in the axial direction. A second fitting structure 21 fits into the linear groove 47.

[0028] As shown in Fig. 5, when the second guide member 42 is viewed from the side, the linear grooves 47 extend along the axial direction. As shown in Fig. 6, a plurality of linear grooves 47 and a plurality of storage grooves 48 are formed in the second guide surface 42a.

[0029] A plurality of linear grooves 47 are provided at equal intervals in the circumferential direction of the second band material 20. An upper edge fitting structure 21a and a lower edge fitting structure 21b of the second fitting structure 21 fit into the linear grooves 47. By fitting the second fitting structure 21 into the linear grooves 47, the cylindrical structure 2 is restricted from rotating. When the cylindrical structure 2 expands and contracts in the axial direction, the cylindrical structure 2 moves linearly in the axial direction without rotating.

[0030] A plurality of storage grooves 48 are provided at equal intervals in the circumferential direction of the second band material 20 and extend along the axial direction. A bearing that supports the inner surface of the cylindrical structure 2 is accommodated in the storage groove 48. This bearing has rollers that contact the inner surface of the cylindrical structure 2 and supports the cylindrical structure 2. The bearing installed in the storage groove 48 can reduce the sliding resistance between the cylindrical structure 2 and the second guide member 42.

[0031] The outer guide member 50 is a rotating member that can rotate around an axis. The outer guide member 50 is a cover member that covers the outer peripheral side of the inner guide member 40. The outer guide member 50 rotates integrally with the first guide member 41. The outer guide member 50 and the first guide member 41 are integrated by bolting or the like. The outer guide member 50 is a cylindrical member that extends along the axial direction and has a cylindrical outer guide surface. The outer guide surface is formed by the inner peripheral surface of the outer guide member 50. The outer guide surface faces the inner guide surface 40a.

[0032] For example, the outer guide member 50 is disposed outside the first guide member 41. In the strip guide device 30, the first strip 10 and the second strip 20 are guided into an opposing space where the outer guide surface of the outer guide member 50 and the first guide surface 41a of the first guide member 41 face each other. In the spiral telescopic device 1, when the first engaging structure 11 is engaged with the second engaging structure 21 and the second engaging structure 21 is engaged with the spiral groove 43, the outer guide surface of the outer guide member 50 does not come into contact with the outer surface of the first strip 10.

[0033] The outer guide member 50 has a first inlet 51 and a second inlet 52. The first inlet 51 is an opening formed in the upper section of the outer guide member 50 and is an inlet for introducing the first strip material 10 into the opposing space. The second inlet 52 is an opening formed in the lower section of the outer guide member 50 and is an inlet for introducing the second strip material 20 into the opposing space. In the circumferential direction, the first inlet 51 and the second inlet 52 are open over a predetermined range at different positions.

[0034] A case is provided outside the outer guide member 50 to store the first and second strip materials 10 and 20 in a separated state. Inside this case, the first and second strip materials 10 and 20 are stored in a spiral shape in two levels, upper and lower. A first storage chamber is formed in the upper level of the case, and the first strip material 10 in a separated state is stored in the first storage chamber in a spiral shape. A second storage chamber is formed in the lower level of the case, and the second strip material 20 in a separated state is stored in the second storage chamber in a spiral shape.

[0035] The guide structure of the web guiding device 30 allows it to transition between a cylindrical state in which the first web material 10 and the second web material 20 are spirally wound to form the cylindrical structure 2, and a separated state in which the first web material 10 and the second web material 20 are separated. The web guiding device 30 can transition between the cylindrical state and the separated state depending on the rotation direction of the first guide member 41 and the outer guide member 50. As shown in FIG. 7 , when the web guiding device 30 is viewed from above, as the outer guide member 50 and the first guide member 41 rotate clockwise, the first web material 10 and the second web material 20 transition to the cylindrical state. When transitioning from the separated state to the cylindrical state, the first web material 10 and the second web material 20 are restricted by the outer guide member 50 and pulled inward in the transition region from the separated state to the cylindrical state. On the other hand, when the outer guide member 50 and the first guide member 41 rotate counterclockwise, the first strip 10 and the second strip 20 transition to a separated state.

[0036] For example, the first guide member 41 and the outer guide member 50 are connected to a motor so that power can be transmitted. One of the first guide member 41 and the outer guide member 50 is provided with a driven part around which a drive belt is wound. A pulley is provided on the rotating shaft of the motor. The rotating shaft of the motor extends in the axial direction. A drive belt is wound around the driven part and the pulley. When the motor is driven, power is transmitted to the first guide member 41 and the outer guide member 50 via the pulley and the drive belt. By switching the rotation direction of the motor, the extension and contraction of the cylindrical structure 2 can be switched.

[0037] The upper end of the cylindrical structure 2 is fixed to a tip holding member 60. The tip holding member 60 is a fixed member arranged above the second guide member 42. The tip holding member 60 holds the upper end of the first band material 10 and the upper end of the second band material 20. The second guide member 42 and the tip holding member 60 are separate. When the cylindrical structure 2 expands and contracts in the axial direction, the second guide member 42 does not displace in the axial direction, but the tip holding member 60 rises and falls in the axial direction as the cylindrical structure 2 expands and contracts. When the cylindrical structure 2 expands in the axial direction, the tip holding member 60 displaces upward, and when the cylindrical structure 2 contracts in the axial direction, the tip holding member 60 displaces downward.

[0038] In the spiral extension device 1, when the power of the motor is transmitted to the first guide member 41 and the outer guide member 50 via the pulleys and the drive belt, the first guide member 41 and the outer guide member 50 rotate around their axes. While the first guide member 41 and the outer guide member 50 rotate, the second guide member 42, the tubular structure 2, and the tip holding member 60 do not rotate. When the first guide member 41 and the outer guide member 50 rotate, the first guide member 41 winds up the separated first and second web materials 10 and 20 housed in the respective storage chambers of the case into a tubular shape. As the separated portions of the first and second web materials 10 and 20 transition to a tubular shape, the tubular structure 2 extends in the axial direction, and the tip of the tubular structure 2 is unwound. As shown in FIG. 8 , the tip of the tubular structure 2 is located above the upper end of the second guide member 42. When the first guide member 41 and the outer guide member 50 rotate in the opposite direction, the cylindrical portions of the first web 10 and the second web 20 are unwound by the first guide member 41 and separated. As the cylindrical portions of the first web 10 and the second web 20 transition to a separated state, the cylindrical structure 2 shortens in the axial direction, and the leading end of the cylindrical structure 2 moves downward. The first web 10 and the second web 20 can move in the axial direction while being restricted by the second guide member 42 so as not to rotate around the axis. Therefore, the first web 10 and the second web 20 are wound up or unwound by the rotation of the first guide member 41 and the outer guide member 50.

[0039] The spiral extension device 1 configured in this manner can be used in a device that places a load on the tip holding member 60 and transports the load to a predetermined location. In this case, the load on the tip holding member 60 can be raised or lowered by extending or contracting the tubular structure 2 in the axial direction using the web guide device 30. If the load is placed in an offset position, a bending moment acts on the tubular structure 2 from the tip holding member 60 via the upper end of the tubular structure 2. If the bending moment causes the tubular structure 2 to tilt, the engagement between the first web 10 and the second web 20 becomes unstable, and the engagement between the second web 20 and the inner guide member 40 also becomes unstable, which may result in malfunction of the first web 10 and the second web 20. Furthermore, if the engagement between the first web 10 and the second web 20 becomes misaligned, stress imbalance occurs in the tubular structure 2, reducing the durability of the second web 20. Therefore, the spiral telescopic device 1 is configured so that the first fitting structure 11 fits stably into the second fitting structure 21 when the device is shifted from the separated state to the cylindrical state.

[0040] When the cylindrical structure 2 is formed by the guide structure of the strip guiding device 30, the second strip 20 is wound around the first guide member 41, then moves upward in the axial direction, and is wound around the second guide member 42. At this time, the first strip 10 is wound around the second strip 20 that is wound around the first guide member 41, then moves upward in the axial direction, and is wound around the second strip 20 that is wound around the second guide member 42. In other words, the first strip 10 is wound around the first guide member 41 via the second strip 20, and around the second guide member 42 via the second strip 20. The first guide member 41 is a rotating member, while the second guide member 42 is a fixed member. In the spiral extension device 1, the first fitting structure 11 is configured to stably fit into the second fitting structure 21 before the first strip material 10 transitions from being wound around the first guide member 41 to being wound around the second guide member 42.

[0041] More specifically, the first guide member 41 is formed such that the axial length Y from the engagement start point S where the first engagement structure 11 of the first strip material 10 engages with the second engagement structure 21 of the second strip material 20 to the upper end 41b of the first guide member 41 is at least 1 / 2 the lead of the lead of the spiral groove 43.

[0042] 7, the fitting start point S is the position where the first strip material 10 introduced into the opposing space from the first introduction port 51 is wound around the first guide member 41 and the first fitting structure 11 fits into the second fitting structure 21. The fitting start point S is the start point where the first fitting structure 11 of the first strip material 10 in a separated state starts to fit into the second fitting structure 21 that is fitted into the spiral groove 43.

[0043] The mating start point S can be determined by the first guide member 41. As shown in Fig. 5, in the first guide member 41, the mating start point S is a position on the second spiral groove 43b. The mating start point S is the position where the upper mating structure 11a of the first mating structure 11 fits into the lower mating structure 21b of the second mating structure 21.

[0044] The lead is the axial distance traveled when the first guide member 41 makes one rotation. As shown in FIG. 5, the first guide member 41 has two spiral grooves, so if the length of one lead is L, the lead L is the length of two pitches of the spiral groove 43. The pitch P of the spiral groove 43 is the axial distance between the bottom of the first spiral groove 43a and the bottom of the second spiral groove 43b. Using the pitch P between the first spiral groove 43a and the second spiral groove 43b, the lead L is expressed by the following formula (1): L=2P (1)

[0045] In the above formula (1), L represents the lead of the spiral groove 43, and P represents the pitch of the spiral groove 43.

[0046] In the axial direction, the axial length Y from the fitting start point S to the upper end 41b of the first guide member 41 is formed to be 1 / 2 lead or more. Using the lead L, the axial length Y from the fitting start point S to the upper end 41b is expressed by the following formula (2). Y≧L / 2 (2)

[0047] In the above formula (2), Y represents the axial length from the fitting start point S to the upper end 41b, and L represents the lead of the spiral groove 43.

[0048] In the spiral extension device 1, the axial length Y from the fitting start point S of the first band 10 to the upper end 41b of the first guide member 41 is ensured to be at least 1 / 2 the lead of the lead of the spiral groove 43. This stabilizes the fitting between the first fitting structure 11 and the second fitting structure 21. As a result, it is possible to avoid strong interference between the outer surface of the first band 10 and the outer guide surface of the outer guide member 50, so that the cylindrical structure 2 moves up and down smoothly, stress generated in the second band 20 can be suppressed, and durability is improved.

[0049] As described above, according to the embodiment, the first band material 10 and the second band material 20 can be stably fitted together, thereby preventing fitting failures and misalignment. This prevents malfunctions between the first band material 10 and the second band material 20, allowing the cylindrical structure 2 to expand and contract smoothly in the axial direction. This reduces stress generated in the second band material 20 in the cylindrical structure 2, improving the durability of the second band material 20.

[0050] Furthermore, the spiral extension device 1 makes it possible to increase the rigidity of the tubular structure 2, which allows the spiral extension device 1 to be used for a wide range of applications and ensures high driving and guiding performance. [Explanation of symbols]

[0051] 1 Spiral stretching device 2. Cylindrical structure 10 First strip material 11 First fitting structure 20 Second strip material 21 Second fitting structure 30 Strip material guide device 40 Inner guide member 41 1st guide member 42 Second guide member 43 Spiral groove 47 Straight groove 50. Exterior case interior materials 51 First Inlet 52 Second Inlet

Claims

1. a first strip having a first interlocking structure; a second strip having a second fitting structure configured to be able to fit into the first fitting structure; a strip material guide device having a guide structure that spirally guides the first strip material and the second strip material, wherein the guide structure spirally winds the first strip material and the second strip material around a common axis at positions offset in the axial direction, and the first fitting structure is fitted into the second fitting structure in a state where the inner surface of the first strip material and the outer surface of the second strip material partially overlap in the axial direction, thereby forming and holding a cylindrical structure; Equipped with the strip guide device is capable of transitioning the first strip and the second strip between a tubular state constituting the tubular structure and a separated state in which the first strip and the second strip are separated, The guide structure includes: a cylindrical inner guide surface around which the first strip material and the second strip material are wound; a guide groove formed on the inner guide surface and into which the second fitting structure is fitted; a first guide member that forms a first guide surface that is a lower guide surface of the inner guide surfaces; a second guide member that forms a second guide surface that is an upper guide surface of the inner guide surfaces, the first guide member is a rotating member having a spiral groove formed on the first guide surface as the guide groove, the second guide member is a fixed member disposed above the first guide member, and having a linear groove formed on the second guide surface as the guide groove that is linear along the axial direction, In the first guide member, the axial length from a fitting start point where the first fitting structure of the first strip material in the separated state fits into the second fitting structure in a state where the first guide member is fitted into the spiral groove to an upper end of the first guide member is formed to be 1 / 2 or more of the lead of the spiral groove. A spiral telescopic device characterized by:

2. The spiral groove is a double spiral groove consisting of a first spiral groove and a second spiral groove.

2. The spiral telescopic device according to claim 1.

3. the first fitting structure has a structure in which an opening of a through hole penetrating the first band material protrudes toward an inner surface side of the first band material, The second fitting structure has a structure in which an opening of a through hole penetrating the second band material protrudes toward the inner surface of the second band material.

3. The spiral telescopic device according to claim 2.

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