Direct-acting telescopic mechanism

Abstract

The present application aims to provide a direct extension mechanism which can realize structure simplification, light weight, strength improvement of the arm part and smooth extension movement of the arm part. The direct extension mechanism (1) of the present embodiment has: a direct mechanism (21, 22, 23, 24) which is composed of multiple stages, a block column (30) which is composed of multiple blocks (40) connected in a column shape, a frontmost block in the multiple blocks connected to a frontmost direct mechanism (21) in the multiple direct mechanisms, and a storage part (10) which stores the block column and is connected to a last direct mechanism (24) in the multiple direct mechanisms. The storage part has a pair of circular arc guides (13, 14) arranged on both sides of the block column, so that the block column moves along the circular arc track, and a pair of protrusions (46, 47) which respectively engage with the pair of circular arc guides are arranged on both sides of each block.

Description

TECHNICAL FIELD

[0001] The present application relates to a direct expansion mechanism. BACKGROUND

[0002] As a direct expansion mechanism of a robot device, a structure is known in which an arm portion as a columnar body is constituted by joining a first link column and a second link column, and the first link column and the second link column are housed in a column portion as a columnar body in a longitudinal direction, the first link column is constituted by a plurality of first links (flat plates) joined in a manner capable of bending by a rotation axis, and similarly, the second link column is constituted by a plurality of second links (blocks) joined in a manner capable of bending (Patent Literature 1).

[0003] This direct expansion mechanism can extend the arm portion by increasing the number of first links and second links, and since the arm portion does not protrude to the rear, it is very useful for use in a limited space.

[0004] However, in this structure, since two kinds of link columns are required, the structure becomes complicated, and an increase in weight cannot be avoided, and in addition, since the strength of the arm portion depends on the joining strength of the links and the joining strength between the two kinds of link columns, the improvement of the strength of the arm portion is limited.

[0005] In Patent Literature 2, a structure is disclosed in which a direct expansion mechanism is realized by a group of moving members. This structure can realize a simplified structure and weight reduction since it has a group of moving members. However, in a structure in which the arm portion is constituted by a group of moving members and the moving members are joined to each other by a rotation axis, the improvement of the strength of the arm portion depends on the joining strength of the structure, and thus, the problem of improving the strength of the arm portion still remains. Furthermore, the group of moving members can be bent in a rotation guide portion which is a substantially circular cylindrical shape in which the group of moving members is housed, and thus, the smooth expansion and contraction movement of the arm portion can be hindered.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: Japanese Patent No. 5435679

[0009] Patent Literature 2: Japanese Patent Application Laid-Open No. 2015-213974 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] In a direct expansion mechanism, it is desirable to realize a simplified structure, weight reduction, improvement of the strength of the arm portion, and smooth expansion and contraction movement of the arm portion.

[0012] MEANS FOR SOLVING THE PROBLEMS

[0013] The direct motion telescopic mechanism according to one aspect of the present disclosure includes a plurality of direct motion mechanisms, a block column formed of a plurality of blocks connected in a column, a first block of the plurality of blocks connected to a first direct motion mechanism of the plurality of direct motion mechanisms, and a housing connected to a last direct motion mechanism of the plurality of direct motion mechanisms and housing the block column. The housing includes a pair of circular arc guides provided on both sides of the block column, and a pair of protrusions provided on both sides of each block and engaged with the pair of circular arc guides.

[0014] Effects of the Invention

[0015] According to this aspect, the direct motion telescopic mechanism can achieve a simplified structure, a lightweight, an improved strength of the arm portion, and a smooth telescopic movement of the arm portion. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a perspective view of the direct motion telescopic mechanism during contraction according to one embodiment.

[0017] Figure 2 is a perspective view of the direct motion telescopic mechanism during extension.

[0018] Figure 3 is a side view of the internal structure of the direct motion telescopic mechanism during contraction, with the block column removed.

[0019] Figure 4 is a side view of the direct motion telescopic mechanism of Figure 3 during extension, with the housing and the arm portion separated.

[0020] Figure 5 is a side view of the internal structure of the direct motion telescopic mechanism during contraction.

[0021] Figure 6 is a side view of the internal structure of the direct motion telescopic mechanism during extension.

[0022] Figure 7 is a perspective view of a block in Figure 5 from an oblique front.

[0023] Figure 8 is a perspective view of a block in Figure 5 from an oblique back.

[0024] Figure 9 is a side view of a block of Figure 5 .

[0025] Figure 10 is a side view of a block and a pair of guides provided in the housing.

[0026] Figure 11 is a perspective view of a block inFigure 10 perspective view of the last block of the block column in

[0027] Figure 12 is shown from an oblique rear Figure 11 perspective view of the last block in

[0028] Figure 13 is shown from an oblique rear Figure 10 side view of the guide rail in

[0029] Figure 14 is shown from an oblique rear Figure 10 perspective view of the guide rail in

[0030] Figure 15 is a cross-sectional view of A-A' of Figure 13

[0031] Figure 16 is a cross-sectional view of the guide rail in Figure 15

[0032] Figure 17 is shown from an oblique rear Figure 12 side view of the guide rail in

[0033] Figure 18 is shown from an oblique rear Figure 1 side view of the guide rail in

[0034] Figure 19 is a cross-sectional view of B-B' of Figure 18

[0035] Figure 20 is a plan view showing a linear extension mechanism after a plurality of linear guide mechanisms are replaced with a telescopic structure.

[0036] Figure 21 Figure 20 is a plan view showing an extended state of the linear extension mechanism in DETAILED DESCRIPTION

[0037] Hereinafter, the linear extension mechanism of the present embodiment will be described with reference to the drawings. In the following description, the same reference numerals are assigned to the constituent elements having substantially the same function and structure, and repeated description will be made only when necessary. The linear extension mechanism of the present embodiment can be used alone or as a linear extension joint of a robot arm mechanism.

[0038] As shown in Figure 1 , Figure 2 ​​​​As shown, the direct expansion and contraction mechanism 1 has an arm portion 20 that freely expands and contracts. Typically, the arm portion 20 is composed of a plurality of direct expansion and contraction mechanisms that are composed of a plurality of stages. In the present embodiment, the arm portion 20 is composed of a plurality of cylinders that are composed of a structure that can expand and contract (a multi-stage nested structure), and here, is composed of four cylinders 21, 22, 23, 24. Further, typically, the cylinders 21, 22, 23, 24 are circular cylindrical shapes, but can also be square cylindrical shapes.

[0039] The arm portion 20 is supported by a housing 10. Typically, the housing 10 is composed of a substantially short cylindrical shape that has a substantially 1 / 4 circular range cut from the upper portion. As shown in Figure 3 、 Figure 4 shown, the cut portion of the upper portion of the housing 10 is blocked by a cover plate 19. The rear end of the arm portion 20, that is, the last cylinder 24 is fixed vertically to the flange of the cover plate 19. An opening 191 is provided in the cover plate 19 on which the last cylinder 24 is fixed. The opening 191 communicates the inside of the housing 10 with the hollow interiors of the cylinders 21, 22, 23, 24. The opening 191 is an entrance and exit for the block row 30 described later to enter and exit from the housing 10.

[0040] As shown in Figure 5 、 Figure 6 shown, the cut portion of the upper portion of the housing 10 is blocked by a cover plate 19. The rear end of the arm portion 20, that is, the last cylinder 24 is fixed vertically to the flange of the cover plate 19. An opening 191 is provided in the cover plate 19 on which the last cylinder 24 is fixed. The opening 191 communicates the inside of the housing 10 with the hollow interiors of the cylinders 21, 22, 23, 24. The opening 191 is an entrance and exit for the block row 30 described later to enter and exit from the housing 10.

[0041] A receiving portion that receives the block row 30 along a circular arc track centered on a housing center Rc is provided in the inside of the housing 10. Details of the receiving portion will be described later. In the state in which the arm portion 20 is contracted, the block row 30 is almost entirely received in the receiving portion in the inside of the housing 10. In the inside of the housing 10, a drive mechanism that realizes the ejection and pullback actions of the block row 30 is provided. The drive mechanism can adopt any mechanism such as a rack and pinion mechanism, a ball screw mechanism, and the like. Of course, the drive mechanism can also be provided outside the housing 10.

[0042] The basic expansion and contraction action of the direct expansion and contraction mechanism 1 is as follows.

[0043] The drive mechanism delivers the block array 30 housed in the housing 10 through the opening 191 into the interior of the arm 20, thereby moving the foremost block 40 forward along the moving axis CL2. Since the foremost block 40 is connected to the foremost cylinder 21, as the foremost block 40 moves forward, other cylinders 21, 22, and 23 are pulled out one after another from the last cylinder 24 fixed to the housing 10. As a result, the arm 20 extends forward along the cylinder centerline CL1.

[0044] The drive mechanism also pulls the block array 30, which is sent out into the interior of the arm 20, back into the interior of the housing 10 through the opening 191, thereby causing the foremost block 40 to move rearward along the moving axis CL2. As the foremost block 40 moves rearward, it is sequentially retracted into the rear cylinder starting from the foremost cylinder 21, resulting in the arm 20 retracting rearward along the cylinder centerline CL1.

[0045] Thus, the block array 30 constitutes part of the actuator for driving the extension and retraction of the arm 20. The arm 20 is composed of multiple cylindrical bodies 21, 22, 23, and 24 forming a multi-level nested structure, and its actuator for extension and retraction is composed of a single block array 30, thereby simplifying the structure and achieving lightweighting, and improving the strength of the arm 20 through the multi-level nested structure and the blocks complementing each other.

[0046] like Figure 7 , Figure 8 As shown, block 40 has a block body 41. The block body 41, for example, has a cuboid shape. At the lower front end of the block body 41, two forward-protruding bearings 42 and 43 are separately provided in the width direction. At the lower rear end of the block body 41, bearings 44 and 45, integrally formed with the block body 41, are separately provided in the width direction. The bearings 42 and 43 at the front end of one of two adjacent blocks 40 are embedded between the bearings 44 and 45 at the rear end of the other block 40, and a rotating shaft (not shown) is inserted into a series of holes. Thus, the blocks 40 are rotatably connected in a row. Furthermore, the blocks 40 are connected in a row along a direction perpendicular to the rotating shaft (the connection direction). Figure 9 As shown, bearings 42, 43, 44, and 45 are all located on the bottom side of the block body 41, and the block body 41 has a cuboid shape. Therefore, when arranged in a straight line, the end faces of two adjacent blocks 40 abut against each other, thereby restricting further upward rotation but allowing downward rotation.

[0047] On two sides of the block body 41, a pair of protrusions 46 and 47 are respectively provided, which engage with the pair of arc-shaped guide rails 13 and 14 described later. Typically, the protrusions 46 and 47 can be cam followers that roll on the pair of arc-shaped guide rails 13 and 14. The rotation axis of the outer wheel of each cam follower is parallel to the rotation axis of the block 40, and the cam followers are coaxially mounted on the block body 41. Furthermore, it is undeniable that the protrusions 46 and 47 can be simply cylindrical or other shapes of protrusions. Here, the case where the protrusions 46 and 47 are cam followers will be described.

[0048] like Figure 10 As shown, in order to enable the block array 30 to move smoothly along the arc track, the relative positions of the cam follower 46, 47 and the block body 41 are as follows: when viewed from the side, the outer wheel rotation axis of the cam follower 46 (47) and the rotation axis of the connecting block 40 are arranged together on a circle CO1 concentric with the arc track (arc guide rails 13, 14 described later) centered on the housing center Rc. Thus, the block array 30 is restricted by the arc guide rails 13, 14 and housed within the housing 10 along the arc track.

[0049] The cam followers 46 and 47 of block 40 are restricted by guide rails 13 and 14. One cam follower 46 and one cam follower 47 are mounted on each of the two sides of the block body 41, and the cam followers 46 and 47 are coaxial. Therefore, block 40 can rotate slightly about the cam followers 46 and 47. Consequently, block array 30 may bend within the storage section, thus hindering smooth movement.

[0050] To suppress this situation, in this embodiment, such as Figure 11 , Figure 12As shown, in the block body 41 of the block 40 at the end of the block row 30, on one side of the block body 41, two cam followers 46, 48 are installed, and on the other side of the block body 41, two cam followers 47, 49 are installed. The two cam followers installed on the two sides of the block body 41, respectively, are positioned so as to be arranged on a circle COl with respect to the block body 41. Since two cam followers are installed on the two sides of the block body 41, respectively, the orientation of the block 40 at the end is fixed in a posture along the guide rails 13, 14. For the block 40 adjacent to the block 40 at the end, since both the cam followers 46, 47 thereof and the rotation shafts coupled to the block 40 at the end are restricted, the orientation thereof is also fixed in a posture along the guide rails 13, 14 as with the block 40 at the end. Also, for the other blocks 40 in front, since both the cam followers 46, 47 thereof and the rotation shafts coupled to the block 40 adjacent to the rear are restricted, the orientations thereof are also fixed in a posture along the guide rails 13, 14. In this way, the postures of all the blocks 40 are chained and unified to be the same as the posture of the block 40 at the end. Therefore, the block row 30 does not bend within the housing and can move smoothly along the circular arc track in a posture.

[0051] Further, the protruding bodies engaged with the guide rails 13, 14 are not limited to the cam followers, but can be any protruding bodies that enable the blocks 40 to move along the guide rails 13, 14. As the protruding bodies, rolling bodies that roll on the surfaces of the guide rails or sliding bodies that slide on the surfaces of the guide rails can be appropriately used. As the rolling bodies, various bearings of cylindrical shape, needle shape, rod shape, conical shape, spherical shape, or the like can be listed. As the sliding bodies, cylindrical bodies, rod-shaped bodies, or the like can be listed, at least the surfaces of which that contact the guide rails 13, 14 are made of self-lubricating resin.

[0052] Further, the block 40 on which two cam followers are installed on the two sides, respectively, is not limited to the block 40 at the end, but can be any of the blocks 40 that remain within the housing 10 (within the guide rails 13, 14) in the state in which the arm portion 20 is maximally extended. In addition, two cam followers can be installed on the two sides of all the blocks 40, respectively, or two cam followers can be installed on the two sides of each of a plurality of discrete blocks 40, respectively. In addition, instead of installing two cam followers on the two sides of the block 40 at the end, respectively, one cam follower 46, 47 can be installed on each of the two sides of the block 40, and the cam followers 46, 47 can be installed to the block 40 by staggering the rotation shafts of the cam followers 46, 47 in the front and the rear, whereby the orientation of the block 40 can be fixed in a posture along the guide rails 13, 14.

[0053] As Figure 13 , Figure 14As shown, to smoothly house the block array 30 along the arc-shaped track, the housing section has a pair of arc-shaped guide rails 13 and 14 that guide the cam followers 46 and 47 mounted on the block 40. The arc-shaped guide rails 13 and 14 are configured so that their arc centers Rc coincide, but have different radii, thereby guiding the cam followers 46 and 47 from their inner and outer sides, respectively. Furthermore, the arc-shaped guide rails 13 and 14 are arranged along the centerline of the housing 10 at intervals slightly wider than the width of the block 40, and are positioned on both sides of the block array 30 to prevent the cam followers 46 and 47 from reversing relative to the direction of movement. A detailed description will follow. Figure 14 The diagram shows the guide surfaces 131 and 141 of a pair of arc-shaped guide rails 13 and 14 that allow the outer wheels of the cam followers 46 and 47 to roll. The radii of the pair of arc-shaped guide rails 13 and 14 are set such that, when viewed from the side, the guide surfaces 131 and 141 are spaced apart by a distance greater than the diameter R1 of the cam followers 46 and 47 (see reference). Figure 9 The spacing is wider. That is, the distance between the radii of the guide surfaces 131 and 141 of the cam followers 46 and 47 is longer than the diameter R1 of the cam followers 46 and 47. The diameter of one arc guide rail 13 is shorter than the diameter of the other arc guide rail 14, and the cam follower 46 is guided from the inside of the cam follower 46 on one side of the block 40, thus forming the inner guide rail 13 that restricts the track of the block row 30 from the inside. The diameter of the other arc guide rail 14 is longer than the diameter of the inner guide rail 13, and the cam follower 47 is guided from the outside of the cam follower 47 on the opposite side of the block 40, thus forming the outer guide rail 14 that restricts the track of the block row 30 from the outside.

[0054] Furthermore, as described later, the sides of block 40 are restricted by guide rails 101 and 102, and block array 30 deforms with the arc track. Therefore, the rotation of block array 30 about its axis is restricted, so that block array 30 will not detach from a pair of arc guide rails 13 and 14.

[0055] The outer wheel of the cam follower 46 on one side of the block 40 rolls only on the guide surface 131 on the outer side of the inner guide rail 13, and the outer wheel of the cam follower 47 on the opposite side of the block 40 rolls only on the guide surface 141 on the inner side of the outer guide rail 14. That is, the outer wheels of the cam followers 46, 47 on both sides are rotated in opposite directions to each other as viewed from the directions of the guide surfaces 131, 141, but are positively rolled with respect to the moving direction of the block row 30. Assuming that the block row 30 is moved in a state where the cam follower on one side of the block 40 is sandwiched between the inner guide rail and the outer guide rail, the block row 30 cannot be smoothly moved because the outer wheel of the cam follower is positively rotated with respect to one rail and the outer wheel of the cam follower is reversely rotated with respect to the other rail in a manner to hinder the movement of the block row. In this embodiment, the inner guide rail 13 and the outer guide rail 14 are provided separately on both sides of the block row 30, and the outer wheels of the cam followers 46, 47 on both sides are caused to roll only on the rail of one of the inner guide rail 13 and the outer guide rail 14, respectively, so that the cam followers 46, 47 are not reversely rotated to hinder the movement of the block row 30. Thus, the block row 30 can be smoothly fed out and retracted along the circular arc track, so that the arm portion 20 can be smoothly extended and retracted.

[0056] As shown in Figure 13 , typically, the circular arc guide rails 13, 14 are configured to have a length of 3 / 4 of the circumference of a circle, but it is preferable to shorten the length by an amount of 5 to 15 degrees, and it is further preferable to shorten the length by an amount of 8 degrees. In cooperation with the shortened circular arc guide rails 13, 14, the cover plate 19 of the housing 10 also retreats by a tangent distance B0 which is the tangent distance corresponding to the shortening of the circular arc guide rails 13, 14 by 8 degrees, in a state of maintaining parallelism with the radius, in other words, in a state of maintaining the orientation perpendicular to the cylinder center line CL1. Since the rear end of the arm portion 20 is fixed to the cover plate 19, the range of movement of the hand front end can be made slightly closer to the housing 10, so that the closeness to the hand portion corresponding to the amount of the closeness is improved.

[0057] Further, the arm portion 20 is vertically installed on the cover plate 19 which is parallel to the radius, and the circular arc guide rails 13, 14 are shortened by a length corresponding to an amount of 8 degrees, so that the tangent line at the front end of the circular arc guide rails 13, 14 does not become parallel to the cylinder center line CL1 but intersects the cylinder center line CL1 to some extent. Thus, when the block row 30 is displaced from the circular arc track to the straight line track, a slightly steep angle change occurs. When the block row 30 is retracted into the housing, the block row 30 also undergoes a steep angle change. It is undeniable that this steep angle change causes the block row 30 to wobble or bend in the up-down direction. In order to suppress these wobbles or bends of the block row 30 as much as possible, the straight line guide rails 15, 16 are attached to the front ends of the circular arc guide rails 13, 14. As shown in Figure 13 , Figure 14As shown, linear guide 15 extends from the front end of arc guide 13 in an orientation parallel to the cylinder centerline CL1. Similarly, linear guide 16 also extends from the front end of arc guide 14 in an orientation parallel to the cylinder centerline CL1. Regarding the spacing of the pair of linear guides 15 and 16 in the up-down and left-right directions, in order to maintain the spacing near the front ends of the pair of arc guides 13 and 14, when viewed from the side, the guide surfaces 151 and 161 of the pair of linear guides 15 and 16 are spaced over the entire area by a distance D1 approximately equal to the diameter R1 of the cam followers 46 and 47.

[0058] like Figure 13 As shown, linear guides 15 and 16 have a length L equal to the rotation axis distance D of the cam followers 46 and 47 of the two adjacent blocks 40. When the block array 30 is sent out from or pulled back to the arc guides 13 and 14, one cam follower 46 or 47 of the block 40 will always be restricted by the linear guides 15 and 16. That is, when the cam follower 46 or 47 of a block 40 disengages from the linear guides 15 and 16, the cam follower 46 or 47 of the adjacent block 40 will be newly guided into the linear guides 15 and 16. Since one cam follower 46 or 47 of the block 40 will always be restricted by the linear guides 15 and 16, when this block 40 and the adjacent block 40 pass between the arc guides 13 and 14 and the linear guides 15 and 16, although the relative positions of these blocks 40 will change, the change will always undergo the same process. In other words, the block array 30 always traverses the same track between the circular guide rails 13 and 14 and the linear guide rails 15 and 16. Therefore, positional accuracy can be guaranteed. Furthermore, the lengths of the linear guide rails 15 and 16 only need to be greater than the rotation axis distance D of the cam followers 46 and 47. However, from the viewpoint of lightweight design and smooth vertical rotation, it is preferable that the lengths of the linear guide rails 15 and 16 are equal to the rotation axis distance D.

[0059] The arc-shaped guide rails 13 and 14 are formed as part of a circular ring. However, from the viewpoint of manufacturing efficiency, it is preferable to construct the arc-shaped guide rails 13 and 14 by forming arc-shaped grooves 111 and 121 on the disc-shaped guide rail plates 101 and 102 with a certain thickness. Figure 15 As shown, the disc-shaped guide plates 101 and 102 are arranged in parallel with a gap, such that the distance between the bottoms of a pair of grooves 111 and 121 is slightly longer than the total width of a pair of cam followers 46 and 47. The depth of the pair of grooves 111 and 121 is the same as the total length (height) of the outer wheels of the cam followers 46 and 47. The width of the pair of grooves 111 and 121 is much wider than the diameter of the outer wheels of the cam followers 46 and 47.

[0060] On one of the disc-shaped guide plates 101, an arc-shaped groove with a long diameter (outer groove 111) is formed, and on the other disc-shaped guide plate 102, an arc-shaped groove with a short diameter (inner groove 121) concentric with the outer groove 111 is formed. The width of both the outer groove 111 and the inner groove 121 is slightly wider than the diameter R1 of the cam follower members 46 and 47, and this extra width is covered when viewed from the side.

[0061] like Figure 16 As shown, the inner wall surface (guide surface) 131 of the groove 111 of the longer guide plate 101 functions as a guide surface 131 for the outer wheel of the cam follower 46 on one side of the block 40 to roll. The outer wall surface (guide surface) 141 of the groove 121 of the shorter guide plate 102 functions as a guide surface 141 for the outer wheel of the cam follower 47 on the opposite side of the block 40 to roll. That is, the inner groove side surface of the outer groove 111 guides the cam follower 46 on one side of the block 40 from the inside, which corresponds to the guide surface 131 of the inner guide rail 13 that restricts the track of the block array 30 from the inside. The inner portion of the disc-shaped guide plate 101 includes the inner groove side surface of the outer groove 111, and this inner portion functions as the aforementioned inner guide rail 13. Similarly, the outer side of the inner groove 121 guides the cam follower 47 on the opposite side of the block 40, which corresponds to the guide surface 141 of the outer guide rail 14 that restricts the track of the block array 30 from the outside. The outer portion of the disc-shaped guide plate 102 includes the outer side of the inner groove 121, which functions as the aforementioned outer guide rail 14.

[0062] In addition, such as Figure 17 As shown, in order to guide the block array 30 relative to the linear guides 15, 16, a pair of auxiliary guides 17, 18 can be connected to the front end of the linear guides 15, 16 respectively, and the pair of auxiliary guides 17, 18 expand forward in an inverted cone shape.

[0063] In addition, such as Figure 18 As shown, the overall length of the block array 30 is preferably such that when the arm 20 is extended to its maximum length and the block array 30 is extended out over the longest distance, at least half a circumference of the block array 30 remains in the receiving section. Therefore, even if an external force, i.e., a torsional force, is applied to the arm 20 around the cylinder centerline CL1, this force will propagate in a chain from the foremost block 40 connected to the arm 20 throughout the entire block array 30. To reduce the torsional error of the arm 20, it is necessary to improve the rigidity of the arm 20, the rigidity of the linear telescopic mechanism 1, and their supporting rigidity, etc. However, in this embodiment, to effectively suppress this torsional error, as described above, the block array 30 has the required overall length to allow at least half a circumference to remain in the receiving section.

[0064] The following is a detailed explanation. Figure 19 As shown, when an external force F0 is applied to the arm 20 in a clockwise direction, for example, with the cylinder centerline CL1 as the center, corresponding external forces F1 and F2 are also applied to the block array 30. On the block 40 near the opening 191, the external force F1 acts in the direction that causes the cam followers 46 and 47 to move away from the guide surfaces 131 and 141 of the arcuate guide rails 13 and 14. However, on the remaining lower block 40 on the opposite side of the upper block 40, the external force F2 acts in the direction that presses the cam followers 46 and 47 against the guide surfaces 131 and 141 of the arcuate guide rails 13 and 14. Therefore, this is true when the length of the arm 20 is shorter than its longest state, and even when the arm 20 is extended to its longest length, the block array 30, together with the guide rails 13 and 14, can effectively assist in suppressing the torsion of the arm 20. On the other hand, when an external force F0 is applied to the arm 20 in a counterclockwise direction according to the paper, on the lower block 40, the external force F2 acts in the direction that causes the cam followers 46 and 47 to move away from the guide surfaces 131 and 141 of the arc guide rails 13 and 14, while on the upper block 40 on the opposite side, the external force F1 acts in the direction that causes the cam followers 46 and 47 to be pressed against the guide surfaces 131 and 141 of the arc guide rails 13 and 14. Similarly, the block array 30 can help suppress the torsion of the arm 20.

[0065] Furthermore, the arm 20 in this embodiment is not limited to a telescopic structure. For example, such as Figure 20 , Figure 21 As shown, the arm 60 can also be composed of multiple cascaded direct-acting guide mechanisms 61, 62, and 63. The base supporting the guide rail of the last direct-acting guide mechanism 63 among the multiple direct-acting guide mechanisms 61, 62, and 63 is horizontally fixed to the cover plate 19, and the slider of the foremost direct-acting guide mechanism 61 is connected to the foremost block 40 of the block column 30 via an L-shaped connector 64. The arm 60 extends and retracts as the block column 30 moves back and forth along the moving axis CL2. Only the structure of the arm is different; even if the direct-acting telescopic mechanism of the arm 60, composed of multiple direct-acting guide mechanisms 61, 62, and 63, is used, the same effect as the direct-acting telescopic mechanism 1 when the arm 20 adopts a telescopic structure can be produced.

[0066] While some embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. In fact, the novel methods and systems described herein can be embodied in various other forms; furthermore, various omissions, substitutions, and modifications can be made to the implementation of the methods and systems described herein without departing from the spirit of the invention. The appended claims and their equivalents are intended to cover forms or modifications falling within the scope and spirit of the invention.

Claims

1. A direct-acting telescopic mechanism characterized by comprising: a plurality of direct-acting mechanisms arranged in a plurality of stages, a block row formed by a plurality of blocks connected in a row, a foremost block of the plurality of blocks being connected to a foremost direct-acting mechanism of the plurality of direct-acting mechanisms, and a housing connected to a rearmost direct-acting mechanism of the plurality of direct-acting mechanisms, the housing housing the block row; the housing having a pair of circular-arc guides provided separately on both sides of the block row, so that the block row moves along a circular-arc track, a pair of protrusions being provided on both sides of each of the blocks to engage with the pair of circular-arc guides, respectively, two protrusions being provided on both sides of at least one block of the plurality of blocks forming the block row, and one protrusion being provided on both sides of the other blocks of the plurality of blocks.

2. A direct-acting telescopic mechanism characterized by comprising: a plurality of direct-acting mechanisms arranged in a plurality of stages, a block row formed by a plurality of blocks connected in a row, a foremost block of the plurality of blocks being connected to a foremost direct-acting mechanism of the plurality of direct-acting mechanisms, and a housing connected to a rearmost direct-acting mechanism of the plurality of direct-acting mechanisms, the housing housing the block row; the housing having a pair of circular-arc guides provided separately on both sides of the block row, so that the block row moves along a circular-arc track, a pair of protrusions being provided on both sides of each of the blocks to engage with the pair of circular-arc guides, respectively, two protrusions being provided on both sides of a rearmost block of the plurality of blocks forming the block row, and one protrusion being provided on both sides of the other blocks of the plurality of blocks.

3. A direct-acting telescopic mechanism characterized by comprising: a plurality of direct-acting mechanisms arranged in a plurality of stages, a block row formed by a plurality of blocks connected in a row, a foremost block of the plurality of blocks being connected to a foremost direct-acting mechanism of the plurality of direct-acting mechanisms, and a housing connected to a rearmost direct-acting mechanism of the plurality of direct-acting mechanisms, the housing housing the block row; the housing having a pair of circular-arc guides provided separately on both sides of the block row, so that the block row moves along a circular-arc track, a pair of protrusions being provided on both sides of each of the blocks to engage with the pair of circular-arc guides, respectively, the pair of circular-arc guides being formed by an inner guide and an outer guide, the inner guide limiting a track of the protrusions from an inner side within the housing, and the outer guide limiting a track of the protrusions from an outer side within the housing, the inner guide being arranged on one side of the block row, and the outer guide being arranged on the other side of the block row.

4. The direct-acting telescopic mechanism according to any one of claims 1 to 3, characterized in that positions of the protrusions on the blocks are set so that, when viewed from a side direction, center lines of the protrusions are arranged on a circle concentric with the circular-arc guides together with rotation axes connecting the blocks within the housing. ​ ​ ​ 5. The direct-acting telescopic mechanism according to any one of claims 1 to 3, wherein the blocks are connected so as to restrict the blocks from rotating in a forward direction and allow the blocks to rotate in a reverse direction in a state in which the block row is arranged in a straight line by the abutment of the front and rear end surfaces of adjacent blocks against each other.

6. A direct-acting telescopic mechanism comprising: a plurality of direct-acting mechanisms arranged in a plurality of stages; a block row composed of a plurality of blocks connected in a row, a foremost block of the plurality of blocks being connected to a foremost direct-acting mechanism of the plurality of direct-acting mechanisms; and a housing connected to a rearmost direct-acting mechanism of the plurality of direct-acting mechanisms, the housing housing the block row; the housing having a pair of circular-arc guides provided separately on both sides of the block row, thereby causing the block row to move along a circular-arc track, a pair of protrusions being provided on both sides of each of the blocks, the protrusions engaging with the pair of circular-arc guides, respectively, the block row having a length in which the block row is housed by at least half a circumference of the circular-arc track in a state in which the plurality of direct-acting mechanisms are each elongated to a maximum length, and the positions of the protrusions on the blocks being set so that, when viewed from a side direction, the center lines of the protrusions and the axes of rotation connecting the blocks are arranged on a circle concentric with the circular-arc guides within the housing.

7. A direct-acting telescopic mechanism comprising: a plurality of direct-acting mechanisms arranged in a plurality of stages; a block row composed of a plurality of blocks connected in a row, a foremost block of the plurality of blocks being connected to a foremost direct-acting mechanism of the plurality of direct-acting mechanisms; and a housing connected to a rearmost direct-acting mechanism of the plurality of direct-acting mechanisms, the housing housing the block row; the housing having a pair of circular-arc guides provided separately on both sides of the block row, thereby causing the block row to move along a circular-arc track, a pair of protrusions being provided on both sides of each of the blocks, the protrusions engaging with the pair of circular-arc guides, respectively, the block row having a length in which the block row is housed by at least half a circumference of the circular-arc track in a state in which the plurality of direct-acting mechanisms are each elongated to a maximum length, and the blocks being connected so as to restrict the blocks from rotating in a forward direction and allow the blocks to rotate in a reverse direction in a state in which the block row is arranged in a straight line by the abutment of the front and rear end surfaces of adjacent blocks against each other. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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