Paper kraft

Abstract

To provide a paper craft capable of turning a turning object member by link members respectively connected to a support member and the turning object member turnably connected to the support member.SOLUTION: This device has a cylindrical support member, a turning object member connected to the support member in a turnable state, and a cylindrical turning angle changing member having one end connected to the support member and the other end connected to the turning object member in a turnable state. The support member has an insertion hole in which the turning angle changing member is movable and turnable in the axial direction of the turning angle changing member with respect to the support member in a state where one end of the turning angle changing member is inserted. The rotation angle changing member rotates the rotation target member when one end portion of the rotation angle changing member is inserted into the support member from the insertion hole and the rotation angle changing member is moved in the axial direction of the rotation angle changing member so that the length of the portion exposed to the outside of the support member changes.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to paper crafts. [Background technology]

[0002] Paper crafts are known in which three-dimensional models of cars, buildings, machines, etc. are constructed by assembling multiple folded parts made from templates cut out of sheet material such as cardboard. Some paper crafts have movable parts to reproduce the movement of the machine, etc., or to achieve specific functions.

[0003] Patent Document 1 describes a freely riseable assembly decorative body in which a three-dimensional model rises from plate-like members. The freely riseable assembly decorative body rotatably supports a horizontal main support plate by a vertical main support plate. The freely riseable assembly decorative body also rotatably supports a vertical support sub-plate and a horizontal support sub-plate by the horizontal main support plate. The horizontal main support plate, horizontal support sub-plate, and horizontal support sub-plate each serve as a link to form a composite link mechanism. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-21635 Summary of the Invention [Problem to be solved by the invention]

[0005] The freely-raising and assembling decorative body described in Patent Document 1 can be made perpendicular to the vertical support main board by rotating the horizontal support main board, which is one of the horizontal support main boards, vertical support sub-boards, and horizontal support sub-boards that are stacked parallel to the vertical support main board. Meanwhile, when imitating a link mechanism in which a pivotable member rotatably supported on a support member, such as a bulldozer blade, is pivoted by the expansion and contraction of a link member (hydraulic cylinder, etc.), it was necessary to construct the link mechanism out of cardboard, in which the length in the extension direction of the support member that rotatably supports the pivotable member and the link member (rotation angle change member) connected to the pivotable member changes, and the link mechanism pivots around a rotation axis perpendicular to the extension direction of the link member.

[0006] The object of the present invention is to provide a paper craft that can rotate a rotating object member using a simple structure that combines a support member, a rotating object member that is rotatably connected to the support member, and a rotation angle change member that is a single member. [Means for solving the problem]

[0007] The inventors have studied a paper craft that can rotate a rotation target member using a simple configuration that combines a support member, a rotation target member rotatably connected to the support member, and a rotation angle change member that is a single member. After extensive research, the inventors have come up with the following configuration.

[0008] A paper craft according to an embodiment of the present invention is a paper craft constructed by assembling multiple hollow members formed by folding a sheet material. The paper craft includes a cylindrical support member, a rotation target member connected to the support member so as to be rotatable about a first rotation axis perpendicular to the axis of the support member, and a cylindrical rotation angle change member having one end connected to the support member and the other end connected to the rotation target member so as to be rotatable about a second rotation axis parallel to the first rotation axis. The support member has an insertion hole into which one end of the rotation angle change member is inserted, allowing the rotation angle change member to move in the axial direction of the rotation angle change member and rotate about the second rotation axis relative to the support member. When one end of the rotation angle change member is inserted into the inside of the support member through the insertion hole and moved in the axial direction of the rotation angle change member so that the length of the portion exposed to the outside of the support member changes, the rotation angle change member rotates around the second rotation axis while rotating the rotation target member around the first axis.

[0009] In the above-described configuration, the link mechanism is composed of a support member, a rotation target member rotatably supported on the support member, and a rotation angle change member, which is a single member connected to the support member and the rotation target member. The rotation angle change member is connected to the support member by inserting one end thereof into an insertion hole formed in the support member. In this manner, the rotation angle change member can be attached to the support member with a simple configuration using the insertion hole without using adhesive or the like. When the rotation angle change member is moved axially toward the insertion hole formed in the support member, it moves into the support member (i.e., one end of the rotation angle change member enters the interior of the support member through the insertion hole). In this manner, the length of the portion of the rotation angle change member retracted inside the support member increases, and the length of the portion exposed to the outside through the insertion hole of the support member decreases. In other words, the distance between the connection portion between the rotation target member and the rotation angle change member and the insertion hole of the support member decreases. Therefore, the rotation target member rotates toward the support member around the first rotation axis as the rotation center. At this time, the rotation angle change member rotates around the second rotation axis as the rotation of the rotation target member. In this way, the rotation angle change member follows the rotation of the rotation target member by rotating about the second rotation axis while moving in the axial direction within the insertion hole. This makes it possible to rotate the rotation target member with a simple configuration that combines the support member, the rotation target member rotatably supported on the support member, and the rotation angle change member, which is a single link member.

[0010] From another viewpoint, it is preferable that the paper craft of the present invention includes the following configuration: The support member holds the position of the rotation angle change member by bringing a pair of edges of the insertion hole, which are positioned in a direction perpendicular to the axial direction of the rotation angle change member, into contact with the rotation angle change member inserted into the insertion hole.

[0011] In the above-described configuration, when the width of the insertion hole of the support member in a direction perpendicular to the axial direction of the rotation angle change member is smaller than the width of the rotation angle change member, the rotation angle change member is positioned within the insertion hole while expanding the insertion hole. At this time, the elastic force of the paper craft material presses the edge of the insertion hole against the side of the rotation angle change member. Therefore, frictional force is generated between the edge of the insertion hole and the side of the rotation angle change member. Since the rotation angle change member is sandwiched between the opposing edges of the insertion hole in a direction perpendicular to the axial direction of the rotation angle change member, it is positioned relative to the support member in a direction perpendicular to the axial direction of the rotation angle change member and can be held at any position in the axial direction of the rotation angle change member. This allows the rotation target member to be rotated to any position with a simple configuration that combines the support member and the rotation angle change member, which is rotatably supported on the support member, with a single rotation angle change member.

[0012] From another perspective, it is preferable that the paper craft of the present invention includes the following configuration: The support member has a restricting portion that restricts the rotation angle of the rotation target member about the first rotation axis relative to the support member within a predetermined restricted range by contacting the rotation target member. One end of the rotation angle change member is located inside the support member when the rotation angle of the rotation target member about the first rotation axis relative to the support member is within the predetermined restricted range.

[0013] In the above-described configuration, the rotation target member is configured to be rotatable within a predetermined restricted range by the support member. Furthermore, one end of the rotation angle change member, the other end of which is connected to the rotation target member, is located inside the support member when the rotation target member is located within the predetermined restricted range. Therefore, in a link mechanism in which the movable range of the rotation target member is restricted to the predetermined restricted range, the one end of the rotation angle change member is configured not to slip out of the support member through the insertion hole. This allows the rotation angle change member, which is a link member connected to the support member and the rotation target member rotatably supported on the support member, to rotate the rotation target member to any position without slipping out of the insertion hole.

[0014] From another perspective, it is preferable that the paper craft of the present invention includes the following configuration. The paper craft is configured as a paper craft of a bulldozer. The rotation target member is a blade portion of the paper craft of the bulldozer. The support member is a main arm portion that supports the blade portion of the paper craft of the bulldozer. The rotation angle change member is a dump cylinder portion that changes the angle of the blade portion of the paper craft of the bulldozer.

[0015] The rotation angle change member, which can change the length of the portion located outside the support member and can rotate relative to the support member, simulates a bulldozer dump cylinder that can extend, retract, and rotate relative to the main arm. This allows the rotation target member, which simulates a bulldozer blade, to be rotated to any position by the rotation angle change members connected to the support member and the rotation target member that is rotatably supported on the support member.

[0016] The terminology used herein is for the purpose of defining particular embodiments only and is not intended to be limiting of the invention.

[0017] As used herein, the use of "including," "comprising," or "having" and variations thereof identify the presence of stated features, steps, operations, elements, components, and / or equivalents thereof, but may include one or more of the steps, operations, elements, components, and / or groups thereof.

[0018] As used herein, the terms "attached," "connected," "coupled," and / or their equivalents are used broadly to encompass both "direct and indirect" attachments, connections, and couplings. Furthermore, "connected" and "coupled" are not limited to physical or mechanical connections or couplings, but can also include direct or indirect electrical connections or couplings.

[0019] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. [Effects of the Invention]

[0020] According to one embodiment of the present invention, a paper craft comprises a cylindrical support member, a rotation target member connected to the support member in a state where it can rotate around a first rotation axis, and a cylindrical rotation angle change member having one end inserted into an insertion hole of the support member and the other end connected to the rotation target member in a state where it can rotate around a second rotation axis parallel to the first rotation axis relative to the rotation target member; when the rotation angle change member is moved in the axial direction so that the length of the part of the support member exposed to the outside changes, the rotation target member rotates around the first axis while rotating around the second rotation axis, so that the rotation target member can be rotated to any position by the rotation angle change member. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a side view of a paper craft of a bulldozer, which is a paper craft according to an embodiment of the present invention. [Figure 2] FIG. 2 is a rear view of a bulldozer, which is a paper craft according to an embodiment of the present invention. [Figure 3] FIG. 3 is a partial top view of a link mechanism of the paper craft according to the embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. [Figure 5] FIG. 5 is a cross-sectional view of the blade portion of FIG. 4 when the angle is changed. DETAILED DESCRIPTION OF THE INVENTION

[0022] The paper craft according to the present invention will be described below with reference to the drawings. In each drawing, the same parts are designated by the same reference numerals, and the description of the same parts will not be repeated. The dimensions of the components in each drawing do not faithfully represent the actual dimensions of the components and the dimensional ratios of the components.

[0023] Furthermore, in the following description, expressions such as "fixing," "connecting," "joining," "attaching," and "sticking" (hereinafter referred to as "fixing") include not only cases where members are directly fixed to each other, but also cases where members are fixed via other members. In other words, in the following description, expressions such as "fixing" include both direct and indirect fixing of members to each other.

[0024] [Embodiment 1] <Paper craft composition> A paper craft bulldozer 1, which is an embodiment including a paper craft link mechanism according to the present invention, will be described using Figures 1 and 2. Figure 1 is a side view of the paper craft bulldozer 1 according to the embodiment of the present invention. Figure 2 is a rear view of the paper craft bulldozer 1.

[0025] As shown in Figures 1 and 2, the bulldozer paper craft 1 is a paper craft modeled after a bulldozer. The bulldozer paper craft 1 has a frame section 2, which is a paper craft formed by folding members cut out of cardboard, for example, an engine room section 3, a cabin section 4, a pair of crawler frame sections 5, a pair of crawler sections 6, a pair of lift arm sections 7, a pair of dump cylinder sections 8, and a blade section 9. In the bulldozer paper craft 1, the crawler sections 6 are positioned below the cabin section 4, and the blade sections 9 are positioned forward relative to the cabin section 4, thereby defining the up-down direction, the front-rear direction, and the left-right direction.

[0026] The frame section 2 is a component that imitates the frame and the front portion of the engine room of a bulldozer in an integrated shape. The frame section 2 has a hollow box structure. A portion that imitates the front portion of the engine room is configured at the front end of the frame section 2. The engine room section 3, cabin section 4, and crawler frame section 5 are attached to the frame section 2. The upper surface of the frame section 2 has notches (not shown) into which the insertion portions of the engine room section 3 and the cabin section 4 are inserted. In addition, both left and right side surfaces of the frame section 2 each have a frame-side insertion portion 2a on the lower side that is inserted into the crawler-side notch portion 5b of the crawler frame section 5, and a frame-side notch portion 2b on the upper side that is inserted into the crawler-side insertion portion 5a of the crawler frame section 5 (see Figure 2).

[0027] The engine room section 3 is a component that resembles the rear portion of an engine room. The engine room section 3 has a hollow box structure. The engine room section 3 has an insertion section (not shown) for attaching it to the frame section 2. The engine room section 3 is attached to the rear of the front portion of the engine room included in the frame section 2 by the insertion section.

[0028] The cabin section 4 is a member that resembles a cabin that covers the driver's seat. The cabin section 4 has a hollow box structure. The cabin section 4 has a plug-in section (not shown) for attaching it to the frame section 2. The cabin section 4 is attached to the rear of the engine room section 3 by the plug-in section.

[0029] The pair of crawler frame sections 5 are members that resemble crawler frames that support crawlers. The pair of crawler frame sections 5 (hereinafter simply referred to as "crawler frame sections 5") have a hollow box structure. The crawler frame sections 5 have crawler-side through-holes 5c at approximately the center in the front-to-rear direction for attaching lift arms. The crawler frame sections 5 are located on both left-to-right side surfaces of the frame section 2.

[0030] The side of the crawler frame unit 5 facing the frame unit 2 has a crawler-side insertion portion 5a on the upper side into which the frame-side cutout 2b is inserted, and a crawler-side cutout 5b on the lower side into which the frame-side insertion portion 2a is inserted. The crawler frame unit 5 is connected to the frame unit 2 by inserting the frame-side insertion portion 2a into the crawler-side cutout 5b and then inserting the crawler-side insertion portion 5a into the frame-side cutout 2b with the crawler-side cutout 5b as the pivot axis. In this way, the crawler frame unit 5 can be positioned relative to the frame unit 2 by first inserting the frame-side insertion portion 2a into the crawler-side cutout 5b. Therefore, the crawler frame unit 5 can easily insert the crawler-side insertion portion 5a into the frame-side cutout 2b even if the frame-side cutout 2b is not visible.

[0031] The pair of crawler units 6 are members that resemble crawlers. The pair of crawler units 6 (hereinafter simply referred to as "crawler units 6") are strip-shaped members. The crawler units 6 have insertion parts (not shown) for attachment to the outer periphery of the crawler frame unit 5. The crawler units 6 are attached to the periphery of the crawler frame unit 5 by the insertion parts.

[0032] The pair of lift arm sections 7 are members simulating lift arms that lift the blade. In other words, the pair of lift arm sections 7 (hereinafter simply referred to as "lift arm sections 7") are configured as support members that support the blade section 9. The lift arm section 7 has a cylindrical structure. One end of the lift arm section 7 has an arm base-end insertion section 7a for rotatably attaching it to the crawler-side through-hole 5c of the crawler frame section 5. The other end of the lift arm section 7 has an arm tip-end insertion section 7b for rotatably connecting it to the side insertion hole 9a of the blade section 9. The arm base-end insertion section 7a is inserted into the crawler-side through-hole 5c of the crawler frame section 5. Therefore, the lift arm section 7 is connected to the crawler frame section 5 in a state where it can rotate about an axis perpendicular to the axis of the lift arm section 7 at the arm base-end insertion section 7a. The lift arm section 7 has an upper surface insertion hole 7c on its upper side, into which the dump cylinder section 8 is inserted.

[0033] The pair of dump cylinders 8 are members simulating dump cylinders that rotate the blades (rotating in one direction and the other within a predetermined angle range). In other words, the pair of dump cylinders 8 (hereinafter simply referred to as "dump cylinders 8") are configured as rotation angle change members that rotate the blades 9. The dump cylinders 8 have a cylindrical structure. One end of the dump cylinders 8 has a cylinder base-end insertion portion 8a that can be inserted into the top-surface insertion hole 7c of the lift arm 7. The other end of the dump cylinders 8 has a cylinder tip-end insertion portion 8b for rotatably connecting to the blades 9. The cylinder base-end insertion portion 8a is inserted into the top-surface insertion hole 7c of the lift arm 7. Therefore, the dump cylinders 8 are connected to the lift arm 7 in a state where they can rotate around a rotation axis perpendicular to the axis of the lift arm 7 in the top-surface insertion hole 7c and move in the axial direction of the dump cylinders 8.

[0034] The blade portion 9 is a member simulating a blade that levels earth and sand. In other words, the blade portion 9 is configured as a rotation target member that is rotated by the dump cylinder portion 8. The blade portion 9 has a hollow box structure. Both left and right side surfaces of the blade portion 9 each have a side insertion hole 9a for attachment to the lift arm portion 7. Both left and right ends of the rear surface of the blade portion 9 each have a rear insertion hole 9b above the side insertion hole 9a for attachment to the dump cylinder portion 8.

[0035] The arm tip side insertion portions 7b of the lift arm units 7 are inserted into the side insertion holes 9a, respectively. The blade units 9 are supported by the pair of lift arm units 7. The blade units 9 are connected to the arm tip side insertion portions 7b in a state where they can rotate about a first rotation axis A1. The first rotation axis A1 is an axis that is perpendicular to the axis of the lift arm units 7 and extends in the left-right direction on the plane of FIG. 1. The first rotation axis A1 passes through the arm tip side insertion portions 7b. The blade units 9 are connected to the crawler frame unit 5 by the lift arm units 7. The cylinder tip side insertion portions 8b of the dump cylinder units 8 are inserted into the rear insertion holes 9b of the blade units 9. The blade units 9 are connected to the cylinder tip side insertion portions 8b in a state where they can rotate about a second rotation axis A2. The second rotation axis A2 is an axis that passes through the cylinder tip side insertion portion 8b and extends parallel to the first rotation axis A1.

[0036] <Link mechanism> Next, the link mechanism 10 will be described in detail using Figures 3 to 5. Figure 3 is a partial top view of the papercraft link mechanism 10. Figure 4 is a cross-sectional view taken along the line IV-IV in Figure 3. Figure 5 is a cross-sectional view when the angle of the blade unit 9 in Figure 4 is changed. The bulldozer papercraft 1 is configured to have the papercraft link mechanism 10 by combining the lift arm unit 7, the dump cylinder unit 8, which is a single member, and the blade unit 9.

[0037] As shown in Figures 3 to 5, the link mechanism 10 has a lift arm section 7 that extends approximately horizontally forward from the crawler side through hole 5c (see Figure 1) of the crawler frame section 5, a blade section 9 that is rotatably connected to the arm tip side insertion section 7b of the lift arm section 7, and a dump cylinder section 8 that extends from a rear insertion hole 9b that is located above the side insertion hole 9a to which the arm tip side insertion section 7b is connected, toward the upper surface insertion hole 7c of the lift arm section 7 that is located rearward and downward.

[0038] The blade portion 9 is rotatable about a first rotation axis A1 relative to the lift arm portion 7. The dump cylinder portion 8 is rotatable about a second rotation axis A2 relative to the blade portion 9. Furthermore, the dump cylinder portion 8 is rotatable about the second rotation axis A2 relative to the lift arm portion 7. Therefore, in the link mechanism 10, the blade portion 9 is rotated about the first rotation axis A1 by moving the dump cylinder portion 8 in the axial direction of the dump cylinder portion 8 within the upper surface insertion hole 7c and rotating it about the second rotation axis A2.

[0039] 4 and 5, the link mechanism 10 restricts the rotation range of the blade unit 9 by the pair of lift arms 7. The pair of lift arms 7 have a first restriction portion 7d and a second restriction portion 7e that restrict the rotation range of the blade unit 9 to a predetermined restricted range.

[0040] The first restricting portion 7d is located at the lower end of one side end, which is below the first rotation axis A1. The second restricting portion 7e is located at the upper end of one side end, which is above the first rotation axis A1. The first restricting portion 7d restricts the rotation range of the rear insertion hole 9b of the blade portion 9 when it is rotated forward. The first restricting portion 7d comes into contact with the blade portion 9 when it is positioned at a rotation angle position P1. Therefore, the first restricting portion 7d restricts the forward rotation range of the blade portion 9 to the rotation angle position P1 (see FIG. 4). The second restricting portion 7e restricts the rotation range of the rear insertion hole 9b of the blade portion 9 when it is rotated rearward. The second restricting portion 7e comes into contact with the blade portion 9 when it is positioned at a rotation angle position P2. Therefore, the second restricting portion 7e restricts the rearward rotation range of the blade portion 9 to the rotation angle position P2 (see FIG. 5). In this way, the first restricting portion 7d and the second restricting portion 7e restrict the rotation range of the blade portion 9 to a predetermined restricted range.

[0041] The dump cylinder section 8 extends rearward from a rear insertion hole 9b located above the side insertion hole 9a in the blade section 9 toward the upper insertion hole 7c in the lift arm section 7. In other words, the dump cylinder section 8 is disposed in an inclined state so that it approaches the lift arm section 7 as it extends rearward from the blade section 9.

[0042] A cylinder base end side insertion portion 8a, which is a part of the dump cylinder portion 8, is inserted into the upper surface insertion hole 7c in a state inclined with respect to the lift arm portion 7.

[0043] The cylinder front-end insertion portion 8b, which is part of the dump cylinder portion 8, is inserted into the rear insertion hole 9b in a state inclined with respect to the lift arm portion 7. Furthermore, the cylinder front-end insertion portion 8b is engaged with a bent portion 9c, which is formed by bending a portion of the rear surface of the blade portion 9, within the rear insertion hole 9b. The bent portion 9c is folded inside the cylinder front-end insertion portion 8b. Therefore, the dump cylinder portion 8, which is a single member, is connected to the blade portion 9 so as to be rotatable about the second rotation axis A2, with the portion engaged with the bent portion 9c.

[0044] The angle of the dump cylinder 8 relative to the lift arm 7 changes as the blade 9 rotates relative to the lift arm 7. The vertical distance between the rear insertion hole 9b, to which the dump cylinder 8 is connected, and the lift arm 7 becomes largest when the rear surface of the blade 9 contacts the first restricting portion 7d. Therefore, the angle of the dump cylinder 8 relative to the lift arm 7 becomes largest at angle θ1 when the rear surface of the blade 9 contacts the first restricting portion 7d (see FIG. 4). Furthermore, the angle of the dump cylinder 8 relative to the lift arm 7 becomes smallest at angle θ2 when the rear surface of the blade 9 contacts the second restricting portion 7e (see FIG. 5).

[0045] The blade portion 9 rotates relative to the lift arm portion 7 by changing the length of the portion of the dump cylinder portion 8 that is exposed to the outside of the lift arm portion 7. The distance between the rear insertion hole 9b, to which the dump cylinder portion 8 is connected, and the upper insertion hole 7c becomes the largest when the rear surface of the blade portion 9 is in contact with the first restricting portion 7d. Therefore, the length of the portion of the dump cylinder portion 8 that is exposed to the outside of the lift arm portion 7 becomes the longest length L1 when the rear surface of the blade portion 9 is in contact with the first restricting portion 7d (see FIG. 4). The length of the portion of the dump cylinder portion 8 that is exposed to the outside of the lift arm portion 7 becomes the shortest length L2 when the rear surface of the blade portion 9 is in contact with the second restricting portion 7e.

[0046] Furthermore, the cylinder base end side insertion portion 8a of the dump cylinder portion 8 is housed inside the lift arm portion 7 within the range where the length of the portion of the dump cylinder portion 8 that is exposed to the outside of the lift arm portion 7 changes from length L1 to length L2. In other words, the dump cylinder portion 8 maintains a connected state with the lift arm portion 7 when the rotation angle of the blade portion 9 is within a predetermined regulation range.

[0047] In this way, when the dump cylinder 8 is moved in the axial direction of the dump cylinder 8 so that the length of the portion exposed to the outside of the lift arm 7 changes between length L1 and length L2, the dump cylinder 8 rotates the blade 9 about the first rotation axis while rotating about the second rotation axis A2 between angles θ1 and θ2 with respect to the lift arm 7. In other words, the dump cylinder 8 is configured to be movable in the axial direction and rotatable about the second rotation axis A2 within the upper surface insertion hole 7c.

[0048] The top surface insertion hole 7c into which the cylinder base end side insertion portion 8a of the dump cylinder portion 8 is inserted is a rectangular hole that is long in the front-to-rear direction (the axial direction of the lift arm portion 7). The horizontal cross-sectional area of ​​the portion of the dump cylinder portion 8 that passes through the top surface insertion hole 7c is largest when the angle of the dump cylinder portion 8 relative to the lift arm portion 7 is the smallest angle θ2 (see FIG. 5), and is smallest when the angle of the dump cylinder portion 8 relative to the lift arm portion 7 is the largest angle θ1 (see FIG. 4). In other words, the front-to-rear gap of the top surface insertion hole 7c into which the lift arm portion 7 is inserted is largest G1 when the angle of the dump cylinder portion 8 relative to the lift arm portion 7 is the angle θ1 (see FIG. 4), and is smallest G2 when the angle of the dump cylinder portion 8 relative to the lift arm portion 7 is the angle θ2 (see FIG. 5). Therefore, the upper surface insertion hole 7c has a length in the front-to-rear direction that allows the cylinder base end side insertion portion 8a to be inserted when the angle of the dump cylinder portion 8 relative to the lift arm portion 7 is at the smallest angle θ2 (see Figure 5).

[0049] The width of the upper surface insertion hole 7c in the left-right direction (the horizontal direction perpendicular to the axial direction of the lift arm section 7) is configured to be equal to or less than the left-right width of the dump cylinder section 8. In other words, a pair of left-right edges of the upper surface insertion hole 7c come into contact with the left-right side surfaces of the dump cylinder section 8. The edges of the upper surface insertion hole 7c press against the left-right side surfaces of the dump cylinder section 8 due to the elastic force of the cardboard. Therefore, frictional force is generated between the edges of the upper surface insertion hole 7c and the left-right complementary side surfaces of the dump cylinder section 8. The lift arm section 7 holds the dump cylinder section 8 at any axial position and any rotation angle by gripping the dump cylinder section 8 with the pair of edges of the upper surface insertion hole 7c.

[0050] In the link mechanism 10 configured in this manner, when the dump cylinder 8 is moved axially toward the blade 9, the dump cylinder 8 moves toward the outside of the lift arm 7. The length of the portion of the dump cylinder 8 housed inside the lift arm 7 becomes shorter, and the length of the portion exposed to the outside of the lift arm 7 becomes longer (see FIG. 4). In other words, the distance between the cylinder tip-side insertion portion 8b of the dump cylinder 8, which is in contact with the blade 9, and the bottom surface of the dump cylinder 8, which is in contact with the edge of the top-surface insertion hole 7c on the blade 9 side, becomes larger. Therefore, the dump cylinder 8 rotates the blade 9 about the first rotation axis A1 toward the first restriction portion 7d. At this time, the dump cylinder 8 rotates about the second rotation axis A2 in conjunction with the rotation of the blade 9.

[0051] When the dump cylinder 8 is moved axially toward the top insertion hole 7c of the lift arm 7, the dump cylinder 8 moves toward the inside of the lift arm 7. The length of the portion of the dump cylinder 8 housed inside the lift arm 7 increases, while the length of the portion exposed to the outside of the lift arm 7 decreases (see FIG. 5). In other words, the distance between the cylinder tip insertion portion 8b of the dump cylinder 8, which is in contact with the blade 9, and the underside of the dump cylinder 8, which is in contact with the edge of the top insertion hole 7c on the blade 9 side, decreases. Therefore, the dump cylinder 8 rotates the blade 9 about the first rotation axis A1 toward the second restriction portion 7e. At this time, the dump cylinder 8 rotates about the second rotation axis A2 in conjunction with the rotation of the blade 9.

[0052] In this way, the dump cylinder 8 moves axially within the top surface insertion hole 7c and rotates about the second rotation axis A2, thereby not impeding the rotation of the blade portion 9. Furthermore, the cylinder base end insertion portion 8a of the dump cylinder 8 is positioned inside the lift arm portion 7 when the blade portion 9 is positioned within a predetermined restricted range. Therefore, in the link mechanism 10, the cylinder base end insertion portion 8a is configured not to slip out of the lift arm portion 7 through the top surface insertion hole 7c. As a result, the link mechanism 10 can maintain the connection between the lift arm portion 7, the dump cylinder 8, and the blade portion 9 when the blade portion 9 is rotated within the predetermined restricted range.

[0053] The dump cylinder 8 is held in any position and any posture by the lift arm 7 due to frictional forces generated at the contact points with the edges of the upper surface insertion holes 7c. The dump cylinder 8 is sandwiched between the opposing edges of the upper surface insertion holes 7c in a direction perpendicular to the axial direction of the dump cylinder 8. Therefore, the link mechanism 10 maintains the left-right position (direction perpendicular to the axial direction) of the dump cylinder 8 relative to the lift arm 7, the axial position of the dump cylinder 8 relative to the lift arm 7, and the posture of the dump cylinder 8 relative to the lift arm 7.

[0054] As described above, the sheet-like components that make up the bulldozer paper craft 1—the frame 2, engine room 3, cabin 4, pair of crawler frame 5, pair of crawler 6, pair of lift arm 7, pair of dump cylinder 8, and blade 9—are each formed into a three-dimensional shape without adhesive by engaging the cutouts and insertion portions of each component. Furthermore, by inserting the insertion portion of one component into the cutout of the other component, one component can be assembled to the other without using adhesive. In this way, the link mechanism 10, which is composed of the lift arm 7, blade 9, and dump cylinder 8, which are assembled without adhesive, can rotate the blade 9 about the first rotation axis A1 and hold it in any position with a simple configuration.

[0055] [Other embodiments] In the above-described embodiment, the paper craft link mechanism 10 is composed of the lift arm portion 7, dump cylinder portion 8, and blade portion 9 of the bulldozer paper craft 1. However, the paper craft link mechanism may also be a link mechanism included in a paper craft other than a bulldozer.

[0056] In the above-described embodiment, the paper craft link mechanism 10 is composed of three members, namely, the lift arm portion 7, the dump cylinder portion 8, and the blade portion 9, which are included in the bulldozer paper craft 1. However, the paper craft link mechanism may be composed of four or more members.

[0057] In the above-described embodiment, the paper craft 1 connects one member to another member without using adhesive by inserting the insertion portion of the other member into the notch of the other member. However, the paper craft may also connect one member to another member using adhesive.

[0058] In the above-described embodiment, the upper surface insertion hole 7c is a rectangular through-hole, but the upper surface insertion hole may be, for example, a circular through-hole.

[0059] In the above-described embodiment, the left-right width of the upper surface insertion hole 7c is equal to or less than the left-right width of the dump cylinder portion 8. However, the left-right width of the upper surface insertion hole 7c may be equal to or greater than the left-right width of the dump cylinder portion 8.

[0060] Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiments, and it is possible to appropriately modify the above-described embodiments within the scope of the spirit of the present invention. [Explanation of symbols]

[0061] 1 Bulldozer paper craft 2 Frame section 2a Frame side insertion part 2b Frame side notch 3 Engine room 4 Cabin section 5 Crawler frame 5a Crawler side insertion part 5b Crawler side notch 5c Crawler side through hole 6 Crawler section 7 Lift arm section 7a Arm base end insertion part 7b Insertion part at the tip of the arm 7c Top insertion hole 7d 1st Regulatory Department 7e 2nd Regulatory Department 8 Dump cylinder section 8a Cylinder base end insertion part 8b Cylinder tip insertion part 9 Blade section 9a Side insertion hole 9b Rear insertion hole 10 Link mechanism A1 First rotation axis A2 Second Rotation Axis P1, P2 return angle position

Claims

1. A paper craft constructed by combining a plurality of hollow members formed by folding sheet materials, A cylindrical support member; a rotation target member connected to the support member in a state where the rotation target member can rotate about a first rotation axis perpendicular to the axis of the support member; a cylindrical rotation angle change member having one end connected to the support member and the other end connected to the rotation target member in a state where the rotation angle change member is rotatable relative to the rotation target member around a second rotation axis parallel to the first rotation axis, The support member is an insertion hole that allows the rotation angle change member to move in the axial direction of the rotation angle change member and rotate around the second rotation axis relative to the support member when one end of the rotation angle change member is inserted; The rotation angle change member is When one end of the rotation angle change member is inserted into the inside of the support member through the insertion hole and moved in the axial direction of the rotation angle change member so that the length of the portion exposed to the outside of the support member changes, the rotation target member is rotated around the first rotation axis while rotating around the second rotation axis. Paper craft.

2. The paper craft according to claim 1, The support member is a pair of edges of the insertion hole, which are positioned in a direction perpendicular to the axial direction of the rotation angle change member, are brought into contact with the rotation angle change member inserted into the insertion hole to hold the position of the rotation angle change member; Paper craft.

3. The paper craft according to claim 1, The support member is a restricting portion that restricts a rotation angle of the rotation target member about the first rotation axis relative to the support member within a predetermined restriction range by contacting the rotation target member, One end of the rotation angle change member is When a rotation angle of the rotation target member about the first rotation axis with respect to the support member is within the predetermined regulation range, the rotation target member is positioned inside the support member. Paper craft.

4. The paper craft according to claim 1, It is composed as a paper craft of a bulldozer, The rotation target member is A blade portion of the bulldozer paper craft, The support member is a main arm portion supporting the blade portion in the paper craft of the bulldozer, The rotation angle change member is A dump cylinder part that changes the angle of the blade part in the paper craft of the bulldozer. Paper craft.

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