Fastener, male screw side member, and female screw side member

Abstract

To provide a fastener capable of reducing a time required for fastening.SOLUTION: A fastener comprises: a male screw side member 10 having a screw part 11 including male screw surfaces 12A and 12B on which male screw side threads 12 extending so as to be substantially orthogonal to an axial direction in an outer peripheral direction are formed, and outer peripheral segments 13A and 13B on which the male screw side threads 12 are not formed, the male screw surfaces and the outer peripheral segments being alternately arranged; and a female screw side member 20 having a screw hole 21 including female screw surfaces 22A and 22B on which female screw side threads 22 extending so as to be substantially orthogonal to the axial direction in an inner peripheral direction are formed, and inner peripheral segments 23A and 23B on which the female screw side threads 22 are not formed, the female screw surfaces and the inner peripheral segments being alternately arranged. The screw part 11 and the screw hole 21 are relatively rotated in one direction, so that the male screw side threads 12 and the female screw side threads 22 are brought into threaded engagement, and the screw part 11 and the screw hole 21 are relatively rotated in the other direction, so that the male screw side threads 12 and the female screw side threads 22 are brought into threaded engagement.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fastener, a male threaded member, and a female threaded member. [Background technology]

[0002] A fastener is a fastener that fastens a male screw and a female screw by screwing them together. For example, Patent Document 1 listed below discloses a technique for preventing loosening of this fastener after the male screw and the female screw are fastened together. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-112204 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional fasteners such as those in Patent Document 1, the threads of the male screw and the female screw are screwed together by rotating them relative to each other by the length of each other, so if the threads are long, it takes a long time to fasten them.

[0005] Therefore, an object of the present invention is to provide a fastener, a male thread side member, and a female thread side member that can shorten the time required for fastening. [Means for solving the problem]

[0006] In order to solve the above problems, a fastener according to a first aspect of the present invention comprises: a male thread-side member having a threaded portion in which, in an outer circumferential direction, male thread surfaces on which male thread-side threads extending perpendicular to the axial direction are formed and outer circumferential pieces on which the male thread-side threads are not formed are alternately arranged; and a female thread-side member having a threaded hole in which, in an inner circumferential direction, female thread surfaces on which female thread-side threads extending perpendicular to the axial direction are formed and inner circumferential pieces on which the female thread-side threads are not formed are alternately arranged; The radial width of the male thread is formed so as to narrow from approximately the center in the extension direction of the thread on the male thread toward both ends, and / or the female thread is formed so that the radial width of the screw hole narrows from approximately the center in the extension direction of the thread on the female thread toward both ends, and by rotating the threaded portion and the screw hole relative to each other in one direction, the male thread and the female thread become threadedly engaged, and by rotating the threaded portion and the screw hole relative to each other in the other direction, the male thread and the female thread become threadedly engaged.

[0007] In addition, in a second aspect of the present invention, the screw thread further includes locking portions formed on the screw thread and the screw hole to lock the screw thread and the screw hole against relative rotation in the screwed state.

[0008] In addition, in a third aspect of the present invention, the engaging portion comprises a first convex portion formed on one of the male thread thread and the female thread thread between approximately the center in the extension direction and one end, and a second convex portion formed on the other of the male thread thread and the female thread thread between approximately the center in the extension direction and the other end, and a first recess formed on the other of the male thread thread and the female thread thread at a position that engages with the first convex portion when the male thread thread and the female thread thread are rotated relative to each other in the one direction to reach the screwed state, and a second recess formed at a position that engages with the second convex portion when the male thread thread and the female thread thread are rotated relative to each other in the other direction to reach the screwed state.

[0009] In a fourth aspect of the present invention, the first recess is equal to or larger than the first protrusion, and the second recess is smaller than the second protrusion.

[0010] In a fifth aspect of the present invention, the threaded portion is cylindrical and has a through hole formed therein that communicates with the threaded hole in the threaded state.

[0011] In a sixth aspect of the present invention, there is provided a male-thread-side piping that is provided radially outward from the axis of the through hole, and that has one end branched in two directions, one of the branches being a first male-thread-side branch portion facing the one direction, and the other of the branches being a second male-thread-side branch portion facing the other direction; and a female-thread-side piping that is provided radially outward from the axis of the threaded hole, and that has one end branched in two directions, one of the branches being a first female-thread-side branch portion facing the other direction, and the other of the branches being a second female-thread-side branch portion facing the one direction, and in the threaded state, the first female-thread-side branch portion engages with the first male-thread-side branch portion, and the second female-thread-side branch portion engages with the second male-thread-side branch portion.

[0012] In addition, the male thread side member according to a seventh aspect of the present invention comprises a male thread surface that is arranged on a part of the outer periphery of the threaded portion and on which a male thread side thread is formed, extending approximately perpendicular to the axial direction of the threaded portion, and a peripheral piece that is arranged alternately with the male thread surface in the outer periphery direction to form the outer periphery of the threaded portion and on which the male thread side thread is not formed, and the male thread side thread is formed so that the radial width of the threaded portion narrows from approximately the center in the extension direction of the male thread side thread towards both ends.

[0013] Furthermore, the female thread side member according to an eighth aspect of the present invention comprises a female thread surface that is arranged in a portion of the inner circumferential direction of the threaded hole and on which a female thread side thread is provided that extends approximately perpendicular to the axial direction of the threaded hole, and inner peripheral pieces that are arranged alternately with the female thread surface in the inner circumferential direction to form the inner circumference of the threaded hole and on which the female thread side thread is not provided, and the female thread side thread is formed so that the radial width of the threaded hole narrows from approximately the center in the extension direction of the female thread side thread towards both ends. [Effects of the Invention]

[0014] The fastener, male thread side member, and female thread side member according to the present invention can reduce the time required for fastening. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view of a fastener according to a first embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. [Figure 4] FIG. 3 is an enlarged perspective view of a first protrusion shown in FIG. 2. [Figure 5] FIG. 3 is an enlarged perspective view of a second protrusion shown in FIG. 2. [Figure 6] FIG. 4 is an enlarged perspective view of a first recess shown in FIG. 3. [Figure 7] FIG. 4 is an enlarged perspective view of a second recess shown in FIG. 3. [Figure 8] FIG. 4 is a cross-sectional view corresponding to FIG. 2 of a male-thread-side member according to a second embodiment of the present invention. [Figure 9] FIG. 4 is a cross-sectional view corresponding to FIG. 3 of a female-threaded member according to a second embodiment of the present invention. [Figure 10] FIG. 4 is a cross-sectional view corresponding to FIG. 3 of a female-threaded member according to a third embodiment of the present invention. [Figure 11] FIG. 10 is a cross-sectional view corresponding to FIG. 2 of a male-thread-side member according to a fourth embodiment of the present invention. [Figure 12] FIG. 10 is a cross-sectional view corresponding to FIG. 3 of a female-threaded member according to a fourth embodiment of the present invention. [Figure 13] FIG. 10 is a cross-sectional view corresponding to FIG. 2 of a male-threaded member according to a fifth embodiment of the present invention. [Figure 14] FIG. 10 is a cross-sectional view corresponding to FIG. 3 of a female-threaded member according to a fifth embodiment of the present invention. [Figure 15] 15 is an axial cross-sectional view that schematically illustrates a state in which the male thread surface shown in FIG. 13 and the female thread surface shown in FIG. 14 are threadedly engaged with each other. [Figure 16A]16 is an enlarged view showing a first male thread-side branch portion of the male thread-side piping shown in FIG. 15 and a first female thread-side branch portion of the female thread-side piping shown in FIG. 15. FIG. [Figure 16B] 16 is an enlarged view showing a state in which a first male thread-side branch portion of the male thread-side piping shown in FIG. 15 is fitted to a first female thread-side branch portion of the female thread-side piping shown in FIG. 15. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicate descriptions will be omitted where appropriate.

[0017] ==First Embodiment== A first embodiment of the present invention will be described below.

[0018] <Configuration> First, the configuration of a fastener 1 according to a first embodiment of the present invention (hereinafter referred to as "this embodiment") will be described.

[0019] FIG. 1 is a perspective view of a fastener 1 according to this embodiment. As shown in FIG. 1, the fastener 1 includes a male thread side member 10 and a female thread side member 20 as main parts.

[0020] The male threaded member 10 has, as its main part, a cylindrical threaded portion 11 having a through hole 14 on the inside.

[0021] The threaded portion 11 extends in the axial direction such that male thread surfaces 12A and 12B on which male thread threads 12 are formed and outer peripheral pieces 13A and 13B on which no thread threads 12 are formed are alternately arranged in the outer circumferential direction. The male thread threads 12 extend perpendicular to the axial direction of the threaded portion 11.

[0022] The outer peripheral pieces 13A and 13B are roughly shaped such that a part of the outer peripheral surface of a cylindrical shape is cut away in the circumferential direction.

[0023] FIG. 2 is a cross-sectional view taken along line II-II of FIG. 2 shows that the threaded portion 11 is formed such that the male thread surface 12A, outer peripheral piece 13A, male thread surface 12B, and outer peripheral piece 13B are arranged in this order in the outer circumferential direction. The dashed double-headed arrows in FIG. 2 indicate the relative rotation directions when the threads 12 formed on the male thread surface 12A and the male thread surface 12B are screwed into the threads 22 provided on the female thread surface 22A and the female thread surface 22B, which will be described later.

[0024] As shown in FIG. 2, the outer diameter of the thread 12 (indicated by the dashed-dotted arrow) is larger than the outer diameters of the outer peripheral pieces 13A and 13B (indicated by the dashed-dotted arrow).

[0025] Furthermore, the thread 12 is formed so that the width in the radial direction of the thread portion 11 (hereinafter simply referred to as "width") narrows from approximately the center 12CA in the extension direction of the thread 12 toward both ends 12CB, 12CC in the extension direction. In other words, as shown in Fig. 2, the width of the thread 12 is maximum at approximately the center 12CA in the extension direction and minimum at both ends 12CB, 12CC in the extension direction.

[0026] However, the radial width of the thread 12 may be narrowed from approximately the center in the extension direction toward both ends 12CB, 12CC. Note that this "approximate center" includes a range in which the distance from the approximately center in the extension direction of the thread 12 is 3% of the length of the thread 12 in the extension direction.

[0027] On the other hand, the female thread side member 20 shown in FIG. 1 has a threaded hole 21 as a main part.

[0028] The threaded hole 21 extends in the axial direction of the threaded hole 21 such that the female thread surfaces 22A and 22B on which the female thread 22 is formed (attached) and the inner peripheral pieces 23A and 23B on which the thread 22 is not formed are alternately arranged in the inner circumferential direction. The female thread 22 extends perpendicular to the axial direction of the threaded hole 21.

[0029] The inner peripheral piece 23A and the inner peripheral piece 23B are roughly shaped such that a part of the inner peripheral surface of a cylindrical shape is cut away in the circumferential direction.

[0030] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 3 shows that the threaded hole 21 is formed such that the female thread surface 22A, the inner peripheral piece 23A, the female thread surface 22B, and the inner peripheral piece 23B are arranged in this order in the circumferential direction. The dashed double-headed arrows in FIG. 3 indicate the relative rotation directions when the threads 22 formed on the female thread surface 22A and the female thread surface 22B are screwed into the threads 22 formed on the male thread surface 12A and the male thread surface 12B, respectively.

[0031] As shown in FIG. 3, the diameter of the thread 22 of the screw hole 21 (indicated by the dashed-dotted arrow) is smaller than the diameter of the inner peripheral pieces 23A and 23B (indicated by the dashed-dotted arrow).

[0032] Furthermore, the thread 22 is formed so that the width in the radial direction of the threaded hole 21 (hereinafter simply referred to as "width") narrows from the center toward both ends in the extension direction of the thread 22. In other words, as shown in Fig. 3, the width of the thread 22 is greatest at approximately the center 22CA in the extension direction and is smallest at both ends 22CB, 22CC in the extension direction. However, the diameter of the threaded hole 21 in the thread 22 portion (indicated by the dashed-dotted arrow) is constant regardless of the position in the extension direction.

[0033] The width of the thread 22 may be narrowed from the approximate center 22CA in the extension direction toward both ends. Note that the "approximate center" here includes a range in which the distance from the center of the thread 22 in the extension direction is 3% of the length of the thread 22 in the extension direction.

[0034] The thread 22 is fixed to the female thread surface 22A or 22B on the outer circumferential side around the widest portion (approximately the center 22CA in the extension direction).

[0035] As will be described in detail later, by rotating the threaded portion 11 and the threaded hole 21 relative to each other in one direction, the threads 12 and 22 become threadedly engaged with each other, and by rotating the threaded portion 11 and the threaded hole 21 relative to each other in the other direction, the threads 12 and 22 become threadedly engaged with each other. At this time, the threads 12 and 22 are engaged with each other so that they overlap in a radial cross-sectional view (cross-sectional views of FIGS. 2 and 3). By engaging these, the threaded portion 11 can be fastened to the threaded hole 21.

[0036] Furthermore, in the above-mentioned screwed state, the through hole 14 of the cylindrical threaded portion 11 communicates with the threaded hole 21. This allows the male threaded member 10 and the female threaded member 20 to be used as a flow path for, for example, water pipes.

[0037] Here, the fastener 1 according to this embodiment further includes first convex portions 31AA, 31BA and second convex portions 31AB, 31BB shown in FIG. 2, and first recessed portions 32AA, 32BA and second recessed portions 32AB, 32BB shown in FIG.

[0038] 2, the first convex portion 31AA is formed between approximately the center 12CA in the extension direction of the thread 12 (on the male thread surface 12A side) and one end 12CB. Similarly, the first convex portion 31BA is formed between approximately the center 12CA in the extension direction of the thread 12 (on the male thread surface 12B side) and one end 12CB.

[0039] 2, the second convex portion 31AB is formed between approximately the center 12CA in the extension direction of the thread 12 (on the male thread surface 12A side) and the other end 12CC. Similarly, the second convex portion 31BB is formed between approximately the center 12CA in the extension direction of the thread 12 (on the male thread surface 12B side) and the other end 12CC.

[0040] 3, the first recess 32AA is formed at a position between approximately the center 22CA in the extension direction of the thread 22 (on the female thread surface 22B side) and one end 22CB. This position is the position where the first recess 32AA fits into the first protrusion 31AA when the threaded portion 11 and the threaded hole 21 are rotated relative to each other in one direction and the thread 12 and the thread 22 are threadedly engaged with each other.

[0041] Similarly, the first recess 32BA is formed between the approximate center 22CA in the extension direction of the thread 22 (on the female thread surface 22A side) and one end 22CB. This position is the position where the first recess 32BA fits into the first protrusion 31BA when the threaded portion 11 and the screw hole 21 are rotated relative to each other in one direction and the thread 12 and the thread 22 are threadedly engaged with each other.

[0042] 3, the second recess 32AB is formed at a position between the approximate center 22CA in the extension direction of the thread 22 (on the female thread surface 22A side) and the other end 22CC. This position is the position where the second recess 32AB fits into the second protrusion 31AB when the threaded portion 11 and the screw hole 21 are rotated relative to each other in the other direction and the thread 12 and the thread 22 are threadedly engaged with each other.

[0043] Similarly, the second recess 32BB is formed between the approximate center 22CA in the extension direction of the thread 22 (on the female thread surface 22B side) and the other end 22CC. This position is the position where the second recess 32BB fits into the second protrusion 31BB when the threaded portion 11 and the screw hole 21 are rotated relative to each other in the other direction and the thread 12 and the thread 22 are threadedly engaged with each other.

[0044] The above-mentioned first convex portions 31AA, 31BA, second convex portions 31AB, 31BB, first recesses 32AA, 32BA, and second recesses 32AB, 32BB are examples of locking portions formed on the threaded portion 11 and the threaded hole 21 so as to lock the relative rotation between the threaded portion 11 and the threaded hole 21 when the male threaded surfaces 12A and 12B are threadedly engaged with the female threaded surfaces 22A and 22B.

[0045] The first convex portions 31AA, 31BA and the second convex portions 31AB, 31BB are not shown in Fig. 4. However, the first convex portions 31AA, 31BA and the second convex portions 31AB, 31BB are each formed on one or more of the multiple threads 12 arranged in the axial direction as shown in Fig. 4.

[0046] Moreover, the first recesses 32AA, 32BA and the second recesses 32AB, 32BB are not shown in Fig. 5. However, the first recesses 32AA, 32BA and the second recesses 32AB, 32BB are each formed in one or more of the multiple threads 22 arranged in the axial direction as shown in Fig. 5.

[0047] FIG. 4 is an enlarged view of the first convex portion 31AA shown in FIG. 4, the first convex portion 31AA is arch-shaped and is formed on the face (slope) of the thread 12. The first convex portion 31BA also has the same shape as the first convex portion 31AA.

[0048] FIG. 5 is an enlarged view of the second protrusion 31AB shown in FIG. 5, the second convex portion 31AB is arch-shaped and is formed on the face (slope) of the thread 12. The second convex portion 31BB also has the same shape as the second convex portion 31AB.

[0049] Note that the first convex portion 31AA shown in Fig. 4 and the second convex portion 31AB shown in Fig. 5 are shown to have the same shape. That is, the first convex portions 31AA, 31BA and the second convex portions 31AB, 31BB all have the same shape. However, these may have slightly different shapes.

[0050] FIG. 6 is an enlarged view of the first recess 32AA shown in FIG. 6, the first recess 32AA has an arch-shaped hollowed-out shape and is formed on the face (slope) of the thread 22. The same applies to the first recess 32BA.

[0051] FIG. 7 is an enlarged view of the second recess 32AB shown in FIG. 7, the second recess 32AB has an arch-shaped hollowed-out shape and is formed on the face (slope) of the thread 22. The same applies to the second recess 32BB.

[0052] However, as shown in FIGS. 4 to 7, the first recesses 32AA, 32BA are larger than or equal to the first protrusions 31AA, 31BA, and the second recesses 32AB, 32BB are smaller than the second protrusions 31AB, 31BB.

[0053] 2, the male thread surface 12A, the male thread surface 12B, the outer peripheral piece 13A, and the outer peripheral piece 13B are all assumed to have the same length in the circumferential direction. However, in the threaded portion 11, it is preferable that the outer peripheral piece 13A and the outer peripheral piece 13B are longer (in the circumferential direction) than the male thread surface 12A and the male thread surface 12B, respectively.

[0054] 3, the female thread surface 22A, the female thread surface 22B, the inner peripheral piece 23A, and the inner peripheral piece 23B are all the same length in the inner circumferential direction. However, in the threaded hole 21, the inner peripheral piece 23A and the inner peripheral piece 23B are preferably longer (in the inner circumferential direction) than the female thread surface 22A and the female thread surface 22B, respectively.

[0055] In particular, it is preferable that the outer peripheral pieces 13A and 13B have a length of more than 1 / 2 to 2 / 3 or less of the entire circumference in the circumferential direction of the threaded portion 11. It is also preferable that the inner peripheral pieces 23A and 23B have a length of more than 1 / 2 to 2 / 3 or less of the entire circumference in the circumferential direction of the threaded hole 21. By making these lengths more than 1 / 2, it becomes easier to insert the threaded portion 11 into the threaded hole 21. Furthermore, by making these lengths 2 / 3 or less, it is possible to improve the fastening force between the threaded portion 11 and the threaded hole 21.

[0056] More preferably, in the threaded portion 11, the outer peripheral pieces 13A and 13B are respectively about 1% longer than the male thread surfaces 12A and 12B, and in the threaded hole 21, the inner peripheral pieces 23A and 23B are respectively about 1% longer than the female thread surfaces 22A and 22B. The above is a description of the configuration of the fastener 1 according to this embodiment.

[0057] <<Operation when rotating relative to one direction>> First, as shown in Figure 1, the threaded portion 11 is linearly inserted into the threaded hole 21 at an angle such that the male thread surface 12A and the inner peripheral piece 23B, the male thread surface 12B and the inner peripheral piece 23A, the outer peripheral piece 13A and the female thread surface 22A, and the outer peripheral piece 13B and the female thread surface 22B are opposed to each other.

[0058] The screw portion 11 is inserted linearly into the screw hole 21, and then the screw portion 11 and the screw hole 21 are rotated relative to each other by approximately 45° in one direction (clockwise in Figure 2, counterclockwise in Figure 3) so that the screw threads 12 and 22 thread together, thereby fastening the screw portion 11 and the screw hole 21 together.

[0059] In the above-mentioned screw engagement, first, the narrowest end 12CB of the thread 12 of the male thread surface 12A is inserted into the narrowest end 22CB of the thread 22 of the female thread surface 22B.

[0060] If the relative rotation continues from there, eventually, the thread 12 and the thread 22 will be screwed together in such a manner that one end 12CB of the thread 12 on the male thread surface 12A coincides with approximately the center 22CA in the extension direction of the thread 22 on the female thread surface 22B or its vicinity in a radial cross-sectional view, and the approximate center 12CA in the extension direction of the thread 12 on the male thread surface 12A coincides with one end 22CB of the thread 22 on the female thread surface 22B in a radial cross-sectional view.

[0061] The above description of the engagement between the thread 12 on the male thread surface 12A and the thread 22 on the female thread surface 22B also applies to the engagement between the thread 12 on the male thread surface 12B and the thread 22 on the female thread surface 22A.

[0062] Furthermore, when the male thread surfaces 12A and 12B are threadedly engaged with the female thread surfaces 22A and 22B as described above, the first convex portions 31AA and 31BA are fitted into the first concave portions 32AA and 32BA, thereby preventing relative rotation between the screw portion 11 and the screw hole 21.

[0063] Since the first recesses 32AA and 32BA are larger than the first protrusions 31AA and 31BA, this locking is deep and the locking is completely fixed (cannot be released).

[0064] <<Operation when rotating relative to other directions>> First, as shown in Figure 1, the threaded portion 11 is linearly inserted into the threaded hole 21 at an angle such that the male thread surface 12A and the inner peripheral piece 23B, the male thread surface 12B and the inner peripheral piece 23A, the outer peripheral piece 13A and the female thread surface 22A, and the outer peripheral piece 13B and the female thread surface 22B are opposed to each other.

[0065] From the state in which the screw portion 11 is linearly inserted into the screw hole 21, the screw portion 11 and the screw hole 21 are rotated relative to each other by approximately 45° in another direction (left rotation in Figure 2, right rotation in Figure 3) so that the screw threads 12 and 22 thread together, thereby fastening the screw portion 11 and the screw hole 21 together.

[0066] In the above-mentioned screw engagement, first, the narrowest end 12CC of the thread 12 on the male thread surface 12A is inserted into the narrowest end 22CC of the thread 22 on the female thread surface 22A.

[0067] If the relative rotation continues from there, eventually, the other end 12CC of the thread 12 on the male thread surface 12A will coincide with or around the center 22CA in the extension direction of the thread 22 on the female thread surface 22A in a radial cross-sectional view, and the approximate center 12CA in the extension direction of the thread 12 on the male thread surface 12A will coincide with the other end 22CC of the thread 22 on the female thread surface 22A in a radial cross-sectional view, so that the thread 12 and the thread 22 are in sliding contact and screwed together.

[0068] The above description of the engagement between the thread 12 on the male thread surface 12A and the thread 22 on the female thread surface 22A also applies to the engagement between the thread 12 on the male thread surface 12B and the thread 22 on the female thread surface 22B.

[0069] When the male thread surfaces 12A and 12B are threadedly engaged with the female thread surfaces 22A and 22B as described above, the second convex portions 31AB and 31BB are fitted into the second concave portions 32AB and 32BB, thereby preventing the relative rotation between the screw portion 11 and the screw hole 21.

[0070] However, since the second recesses 32AB, 32BB are smaller than the second protrusions 31AB, 31BB, this locking is shallow and is a temporary fastening that can be released by applying a force of a certain level or more in one direction.

[0071] Effect The fastener 1 according to this embodiment comprises a male-threaded member 10 having a threaded portion 11 in which, in the outer circumferential direction, male-threaded surfaces 12A, 12B on which male-threaded threads 12 extending generally orthogonally to the axial direction are formed and outer circumferential pieces 13A, 13B on which male-threaded threads 12 are not formed are alternately arranged; and a female-threaded member 20 having a threaded hole 21 in which, in the inner circumferential direction, female-threaded surfaces 22A, 22B on which female-threaded threads 22 extending generally orthogonally to the axial direction are formed and inner circumferential pieces 23A, 23B on which female-threaded threads 22 are not formed are alternately arranged. The male-threaded threads 12 are The radial width of the screw portion 11 is formed so as to narrow from approximately the center in the extension direction of the male thread 12 towards both ends 12CB, 12CC, and / or the female thread 22 is formed so as to narrow from approximately the center in the extension direction of the female thread 22 towards both ends 22CB, 22CC. By rotating the screw portion 11 and the screw hole 21 relative to each other in one direction, the male thread 12 and the female thread 22 become threadedly engaged with each other, and by rotating the screw portion 11 and the screw hole 21 relative to each other in the other direction, the male thread 12 and the female thread 22 become threadedly engaged with each other. While conventional threaded portions have continuous threads, threaded portion 11 has outer peripheral pieces 13A and 13B, resulting in short thread 12. Similarly, conventional threaded holes have continuous threads, but threaded hole 21 has inner peripheral pieces 23A and 23B, resulting in short thread 22. That is, conventional fasteners require multiple rotations to thread the threaded portion into the threaded hole.In contrast, fastener 1 according to the present embodiment inserts threaded portion 11 linearly into threaded hole 21, and then rotates threaded portion 11 and threaded hole 21 relative to each other, allowing for threading in less than one rotation, thereby reducing the time required for fastening compared to conventional fasteners. Furthermore, the fastener 1 according to this embodiment can be fastened by rotating the threaded portion 11 and the screw hole 21 relative to each other in either one direction or the other, thereby improving convenience. Furthermore, in this embodiment, when the male thread surfaces 12A, 12B and the female thread surfaces 22A, 22B are threaded together, the threads are first inserted into the thread 22 from the narrowest side of the thread 12, which reduces friction at the start of insertion and makes threading easier. As the threads are threaded together, the widths of the threads 12 and 22 that slide against each other increase, allowing the area of ​​the sliding contact to be increased, preventing the threaded state from loosening.

[0072] In addition, this embodiment further includes locking portions formed on the screw portion 11 and the screw hole 21 to lock the relative rotation between the screw portion 11 and the screw hole 21 when the screw threads 12 and 22 are in a screwed state. This makes it possible to prevent the threaded engagement between the thread 12 and the thread 22 from loosening in this embodiment.

[0073] In this embodiment, the first recess 32A is shorter than the protrusion 31 in the axial direction of the threaded portion 11 and the threaded hole 21, and the second recess 32B is longer than the protrusion 31. In this embodiment, therefore, temporary locking and completely fixed locking can be selected by changing the direction of relative rotation.

[0074] In this embodiment, the convex portion 31 is formed approximately in the center of the thread 12 in the extension direction, and the first recessed portion 32A and the second recessed portion 32B are formed approximately in the center of the thread 22 in the extension direction. As a result, regardless of the direction in which the screw portion 11 and the screw hole 21 are rotated relative to each other, the distance over which the convex portion slides against the thread 22 is the same, i.e., the ease of turning is the same, improving convenience.

[0075] In addition, in this embodiment, the locking portion may include a convex portion 31 formed on the female thread 22 and a concave portion 32 formed on the male thread 12 into which the convex portion 31 is fitted when in a screwed state. As a result, in this embodiment, the screw engagement between the male thread surfaces 12A, 12B and the female thread surfaces 22A, 22B can be prevented from loosening with a simple structure.

[0076] In this embodiment, the threaded portion 11 is cylindrical and has a through hole 14 formed therein that communicates with the threaded hole 21 when the male threaded surfaces 12A, 12B and the female threaded surfaces 22A, 22B are screwed together. As a result, in this embodiment, the male thread side member 10 and the female thread side member 20 can be used as flow paths for water pipes or the like, thereby improving convenience.

[0077] In addition, the male thread side member 10 of this embodiment comprises male thread surfaces 12A, 12B that are arranged in a portion of the outer circumferential direction of the threaded portion 11 and on which male thread side threads 12 extending approximately perpendicular to the axial direction of the threaded portion 11 are formed, and outer circumferential pieces 13A, 13B that are arranged alternately with the male thread surfaces 12A, 12B in the outer circumferential direction to form the outer periphery of the threaded portion 11 and on which the male thread side threads 12 are not formed, and the male thread side threads 12 are formed so that the width in the radial direction of the threaded portion 11 narrows from approximately the center in the extension direction of the male thread side threads 12 towards both ends. While conventional screw parts have continuous threads, screw part 11 has outer peripheral pieces 13A and 13B, which means that thread 12 is short, thereby reducing the time required for fastening compared to conventional screw parts. Furthermore, since the thread 12 is inserted between the threads on the female thread side from the narrowest side, there is little friction at the beginning of insertion, making it easy to screw in. Then, since the thread 12 is inserted up to the widest part in the screw-engaged state, the area of ​​the sliding contact with the female thread side thread can be made large, and loosening of the screw-engaged state can be prevented. Furthermore, since fastening is possible by rotating the fasteners relative to each other in either one direction or the other, convenience is improved.

[0078] In addition, the female thread side member 20 of this embodiment comprises female thread surfaces 22A, 22B which are arranged in a portion of the inner circumferential direction of the screw hole 21 and on which female thread side threads 22 extending approximately perpendicular to the axial direction of the screw hole are provided, and inner peripheral pieces 23A, 23B which are arranged alternately with the female thread surfaces 22A, 22B in the inner circumferential direction to form the inner circumference of the screw hole 21 and on which female thread side threads 22 are not provided, and the female thread side threads 22 are formed so that the width in the radial direction of the screw hole 21 narrows from approximately the center in the extension direction of the female thread side threads 22 towards both ends. While conventional screw holes have continuous threads, screw hole 21 has inner peripheral pieces 23A and 23B, and therefore has short threads 22, making it possible to shorten the time required for fastening compared to conventional screw holes. Furthermore, since the threads 22 are inserted between the threads on the male screw side from the narrowest side, there is little friction at the beginning of insertion, making it easier to screw in. Then, since the threads 22 are inserted up to the widest part in the screw-engaged state, the area of ​​the sliding contact with the threads on the male screw side can be made large, and loosening of the screw-engaged state can be prevented. Furthermore, since fastening is possible by rotating the fasteners relative to each other in either one direction or the other, convenience is improved.

[0079] == Second Embodiment == The second embodiment of the present invention will be described below, focusing on the differences from the first embodiment.

[0080] Fig. 8 is a cross-sectional view of a male-thread-side member 10 according to a second embodiment of the present invention (hereinafter referred to as "this embodiment"), corresponding to Fig. 2. Fig. 9 is a cross-sectional view of a female-thread-side member 20 according to this embodiment, corresponding to Fig. 3.

[0081] As shown in Figures 8 and 9, in this embodiment, contrary to the first embodiment, first convex portions 31AA, 31BA and second convex portions 31AB, 31BB are formed on the thread 22, and first recesses 32AA, 32BA and second recesses 32AB, 32BB are formed on the thread 12.

[0082] In the first embodiment and the present embodiment, the locking portion comprises a first convex portion 31AA, 31BA formed on one of the male thread 12 and the female thread 22, between approximately the center 12CA (22CA) in the extension direction and one end 12CB (22CB), and a second convex portion 31AB, 31BB formed on the other of the male thread 12 and the female thread 22, between approximately the center 12CA (22CA) in the extension direction and the other end 12CC (22CC); and a first recess 32AA, 32BA formed on the other of the male thread 12 and the female thread 22, at a position where it engages with the first convex portion 31AA, 31BA when the male thread 12 and the female thread 22 are rotated relative to each other in one direction to become screwed, and a second recess 32AB, 32BB formed on the other of the male thread 12 and the female thread 22, at a position where it engages with the second convex portion 31AB, 31BB when the male thread 12 and the female thread 22 are rotated relative to each other in the other direction to become screwed. As a result, in this embodiment, with a simple structure, even if relative rotation occurs in either direction, once the screw threads 12 and 22 are in a threaded engagement state, further relative rotation can be prevented.

[0083] ==Third Embodiment== Hereinafter, a third embodiment of the present invention (hereinafter referred to as "this embodiment") will be described, focusing on the differences from the first embodiment.

[0084] FIG. 10 is a cross-sectional view of the female-threaded member 20 according to this embodiment, which corresponds to FIG. As shown in FIG. 10, in the female-threaded member 20, the width of the thread 22 in the radial direction of the threaded hole 21 may be constant or approximately constant in the direction in which the thread 22 extends.

[0085] However, in this embodiment, the male thread side member 10 is the same as the male thread side member 10 shown in FIG. 2 of the first embodiment.

[0086] Furthermore, the positions of the first convex portions 31AA, 31BA and second convex portions 31AB, 31BB shown in FIG. 10 and the first recessed portions 32AA, 32BA and second recessed portions 32AB, 32BB shown in FIG. 2 may be interchanged as in the second embodiment.

[0087] As a result, in this embodiment, when the male thread surfaces 12A, 12B and the female thread surfaces 22A, 22B are threaded together, the thread is first inserted into the thread 22 from the narrowest side of the thread 12, which reduces friction at the start of insertion and makes threading easier. As the threads are threaded together, the width of the thread 12 that is in sliding contact with the thread 22 increases, allowing for a larger area for the sliding contact portion and preventing loosening of the threaded state. Furthermore, the strength of the screw thread 22 can be ensured.

[0088] ==Fourth Embodiment== The fourth embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described below, focusing on the differences from the first embodiment.

[0089] FIG. 12 is a cross-sectional view of the female-threaded member 20 according to this embodiment, which corresponds to FIG. The shape of the thread 22 of the female-threaded member 20 may be as shown in FIG.

[0090] That is, the thread 22 is formed so that the width of the threaded hole 21 narrows from the center toward both ends in the extension direction of the thread 22. In other words, as shown in Fig. 3, the width of the thread 22 is maximum at approximately the center 22CA in the extension direction and minimum at both ends 22CB and 22CC in the extension direction.

[0091] Furthermore, in the female screw side member 20 of the first embodiment, only the vicinity of the approximate center 22CA in the extension direction of the thread 22 is in contact with (fixed to) the screw hole 21, whereas in the female screw side member 20 of this embodiment, the thread 22 is formed without being separated from the screw hole 21.

[0092] FIG. 11 is a cross-sectional view of the male-threaded member 10 according to this embodiment, corresponding to FIG. As shown in FIG. 11, in the male-threaded member 10 according to this embodiment, the width of the thread 12 in the radial direction of the threaded portion 11 is constant or approximately constant in the extension direction of the thread 12.

[0093] As a result, in this embodiment, when the male thread surfaces 12A, 12B and the female thread surfaces 22A, 22B are threaded together, the thread 12 is first inserted into the narrowest side of the thread 22, which reduces friction at the start of insertion and makes threading easier. As the threads are threaded together, the width of the thread 22 that slides against the thread 12 increases, allowing for a larger area for the sliding contact portion and preventing loosening of the threaded connection.

[0094] == Fifth Embodiment == The fifth embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described below, focusing on the differences from the first embodiment.

[0095] <Configuration> FIG. 13 is a cross-sectional view of the male-threaded member 10 according to this embodiment, corresponding to FIG. As shown in FIG. 13, the male thread side member 10 includes a first male thread side piping 41A and a second male thread side piping 41B in addition to the configuration described in the first embodiment.

[0096] The first male thread side piping 41A and the second male thread side piping 41B are piping provided radially outward of the axis O1 of the through hole 14.

[0097] The first male thread side piping 41A and the second male thread side piping 41B each have one end 43 that branches in two directions. One of the branches, a first male thread side branch portion 43A, faces in one direction, and the other of the branches, a second male thread side branch portion 43B, faces in the other direction.

[0098] FIG. 14 is a cross-sectional view of the female-threaded member 20 according to this embodiment, which corresponds to FIG. As shown in FIG. 14, the female thread side member 20 includes a first female thread side piping 42A and a second female thread side piping 42B in addition to the configuration described in the first embodiment.

[0099] The first female thread side piping 42A and the second female thread side piping 42B are piping provided radially outward of the axis O2 of the threaded hole 21.

[0100] The first female-thread-side piping 42A and the second female-thread-side piping 42B each have one end 44 branched in two directions. One of the branches, the first female-thread-side branch portion 44A, faces in another direction, and the other of the branches, the second female-thread-side branch portion 44B, faces in one direction.

[0101] FIG. 15 is an axial cross-sectional view that schematically illustrates a state in which the thread 12 shown in FIG. 13 and the thread 22 shown in FIG. 14 are relatively rotated in the other direction and are screwed together. 15, the second female-thread-side branch 44B is engaged with the second male-thread-side branch 43B. Although not shown, when the thread 12 and the thread 22 are rotated relative to each other in one direction and engaged with each other, the first female-thread-side branch 44A is engaged with the first male-thread-side branch 43A.

[0102] To explain the above-mentioned fitting in more detail, the first female thread side branch 44A and the second female thread side branch 44B have larger diameters than the first male thread side branch 43A and the second male thread side branch 43B, and the first male thread side branch 43A is inserted into the first female thread side branch 44A to fit, and the second male thread side branch 43B is inserted into the second female thread side branch 44B to fit.

[0103] As a result, the first male thread side piping 41A and the first female thread side piping 42A communicate with each other, and the second male thread side piping 41B and the second female thread side piping 42B communicate with each other.

[0104] FIG. 16A is an enlarged view showing the first male thread side branch portion 43A and the first female thread side branch portion 44A. As shown in Fig. 16A, a male-threaded flat valve 45 is provided at the first male-threaded branch 43A, and a female-threaded flat valve 46 is provided at the first female-threaded branch 44A. The flat valves 45, 46 are closed in their natural state, but in Fig. 16A they are shown in a slightly open state to make the opening and closing operation of the flat valves easier to understand.

[0105] Furthermore, FIG. 16A shows, as an example, a state in which an electric cable 47 is arranged inside the first female thread side piping 42A, and an electric cable 48 is arranged inside the second female thread side piping 42B.

[0106] FIG. 16B is an enlarged view showing the fitted state of the first male-thread-side branch portion 43A and the first female-thread-side branch portion 44A. As shown in FIG. 16B, the first male thread side branch portion 43A is inserted into the first female thread side branch portion 44A, the flat valves 45 and 46 are opened, and the electric cables 47 and 48 are connected.

[0107] Although not shown in FIGS. 16A and 16B, the second male thread side branch portion 43B and the second female thread side branch portion 44B also have the same configuration.

[0108] Furthermore, each configuration described in this embodiment can be applied to the first and second embodiments.

[0109] Furthermore, inside the first male thread side piping 41A and the first female thread side piping 42A, something other than the electric cables 47, 48 (for example, a fluid flow path) may be arranged. The same applies to the second male thread side piping 41B and the second female thread side piping 42B.

[0110] Effect The fastener 1 according to this embodiment comprises male-thread-side pipes 41A, 41B, which are pipes arranged radially outward from the axis O1 of the through hole 14 and have one end 43 branched in two directions, with one branch, a first male-thread-side branch 43A, facing in one direction, and the other branch, a second male-thread-side branch 43B, facing in the other direction; and female-thread-side pipes 42A, 42B, which are pipes arranged radially outward from the axis O2 of the threaded hole 21 and have one end 44 branched in two directions, with one branch, a first female-thread-side branch 44A, facing in the other direction, and the other branch, a second female-thread-side branch 44B, facing in one direction, and in a threaded state, the first female-thread-side branch 44A engages with the first male-thread-side branch 43A, and the second female-thread-side branch 44B engages with the second male-thread-side branch 43B. As a result, in this embodiment, when the male thread surfaces 12A, 12B and the female thread surfaces 22A, 22B are threaded together, the male thread side piping 41A, 41B and the female thread side piping 42A, 42B are respectively connected, and therefore these can be used as piping for purposes independent of the male thread side member 10 (through hole 14) and the female thread side member 20 (threaded hole 21), further improving convenience.

[0111] == Variations == The present invention is not limited to the above-described embodiments. In other words, designs that are produced by those skilled in the art with appropriate design modifications to the above-described specific examples are also included within the scope of the present invention as long as they include the features of the present invention. Furthermore, the elements of the above-described embodiments and the following modifications can be combined to the extent technically possible, and such combinations are also included within the scope of the present invention as long as they include the features of the present invention.

[0112] For example, in each embodiment, the threaded portion 11 has two male thread surfaces 12A, 12B and two outer peripheral pieces 13A, 13B, and the threaded hole 21 has two female thread surfaces 22A, 22B and two inner peripheral pieces 23A, 23B. However, the present invention does not limit the number of these surfaces. In other words, it is sufficient for the threaded portion 11 to have multiple male thread surfaces and multiple outer peripheral pieces in the outer circumferential direction, and it is sufficient for the threaded hole 21 to have the same number of female thread surfaces and multiple inner peripheral pieces in the inner circumferential direction as the number of male thread surfaces or outer peripheral pieces.

[0113] The angle of relative rotation (in one direction or another) between the threaded portion 11 and the threaded hole 21 required to thread the threads 12 and 22 varies depending on the number of male and female thread surfaces. For example, if the circumferential lengths of the male thread surface, outer peripheral piece, female thread surface, and inner peripheral piece are the same, and there is one male thread surface, one outer peripheral piece, one female thread surface, and one inner peripheral piece, the angle of relative rotation will be 90°. Alternatively, if there are two each of male thread surfaces, outer peripheral pieces, female thread surfaces, and inner peripheral pieces, the angle of relative rotation will be 45° (the above embodiment takes this shape as an example). Alternatively, if there are three male thread surfaces, three outer peripheral pieces, three female thread surfaces, and three inner peripheral pieces, the angle of relative rotation is 30°. Alternatively, if there are four male thread surfaces, four outer peripheral pieces, four female thread surfaces, and four inner peripheral pieces, the angle of relative rotation is 22.5°. That is, the greater the number of each surface, the smaller the angle of relative rotation between the threaded portion 11 and the screw hole 21, and the shorter the time required for fastening.

[0114] Regardless of the number of surfaces, it is preferable that the outer peripheral piece be longer in the circumferential direction than the male thread surface and the inner peripheral piece be longer in the circumferential direction than the female thread surface. In this case, the angle of relative rotation will naturally change.

[0115] Alternatively, the outer peripheral piece may be shorter than the male thread surface in the circumferential direction, and the inner peripheral piece may be shorter than the female thread surface in the circumferential direction, thereby improving the fastening force between the threaded portion 11 and the screw hole 21.

[0116] The male-threaded member 10 may have a head like a normal male screw. Furthermore, in the first and second embodiments, the threaded portion 11 may be dense like a normal threaded portion without having a through-hole 14 on the inside. The female-threaded member 20 may have a bottom surface on the side opposite to the entrance side of the screw hole 21 (i.e., the insertion side of the male-threaded member 10).

[0117] Regardless of the number of surfaces, it is preferable that the outer peripheral piece be longer in the circumferential direction than the male thread surface and the inner peripheral piece be longer in the circumferential direction than the female thread surface. In this case, the angle of relative rotation will naturally change.

[0118] Alternatively, the outer peripheral piece may be shorter than the male thread surface in the circumferential direction, and the inner peripheral piece may be shorter than the female thread surface in the circumferential direction, thereby improving the fastening force between the threaded portion 11 and the screw hole 21.

[0119] Furthermore, in the first embodiment, the first convex portion 31AA and the second convex portion 31AB are described as being formed on some of the threads 12 among the plurality of threads 12 lined up in the circumferential direction, but regardless of the number of male thread flanks, the first convex portion 31AA and the second convex portion 31AB may be formed on only one of the threads 12 that are adjacent in the circumferential direction. Alternatively, they may be formed on only some of the threads 12 of that one of the threads 12. For example, when the number of male thread flanks is four, the first convex portion 31AA and the second convex portion 31AB are formed on the threads 12 of two non-adjacent male thread flanks, or the first convex portion 31AA and the second convex portion 31AB are formed on the threads 12 of one male thread flank.

[0120] Similarly, in the second embodiment described above, the first convex portion 31AA and the second convex portion 31AB are formed on some of the threads 22 among the plurality of threads 22 arranged in the inner circumferential direction, but regardless of the number of female thread flanks, the first convex portion 31AA and the second convex portion 31AB may be formed on only one of the threads 22 adjacent to each other in the inner circumferential direction. Alternatively, they may be formed on only some of the threads 22 of that one of the threads 22. For example, when the number of female thread flanks is four, the first convex portion 31AA and the second convex portion 31AB are formed on the threads 22 of two non-adjacent female thread flanks, or the first convex portion 31AA and the second convex portion 31AB1 are formed on the threads 22 of one female thread flank.

[0121] The male-threaded member 10 may have a head like a normal male screw. Furthermore, in the first and second embodiments, the threaded portion 11 may be dense like a normal threaded portion without having a through-hole 14 on the inside. The female-threaded member 20 may have a bottom surface on the side opposite to the entrance side of the screw hole 21 (i.e., the insertion side of the male-threaded member 10).

[0122] The fastener 1 can be used for diameters ranging from several centimeters to several tens of meters. Various materials are also applicable, including metal, PVC, glass, and others. [Explanation of symbols]

[0123] 1: fastener, 10: male thread side member, 11: threaded portion, 12: (male thread side) thread, 12A, 12B... male thread surface, 13A, 13B... outer peripheral piece, 14... through hole, 20... female thread side member, 21... threaded hole, 22... (female thread side) thread, 22A, 22B... female thread surface, 23A, 23B... inner peripheral piece, 31... convex portion, 32A... first recess, 32B: second recess

Claims

1. a male-threaded member having a threaded portion in which male-threaded surfaces on which male-threaded threads extending substantially perpendicular to the axial direction are formed and peripheral pieces on which the male-threaded threads are not formed are alternately arranged in the outer circumferential direction; A female thread side member having a threaded hole in which female thread surfaces on which female thread side threads extending approximately perpendicular to the axial direction are provided and inner peripheral pieces on which the female thread side threads are not provided are alternately arranged in the inner circumferential direction; Equipped with The male thread is formed so that the radial width of the threaded portion narrows from approximately the center in the extension direction of the male thread toward both ends, and / or the female thread is formed so that the radial width of the screw hole narrows from approximately the center in the extension direction of the female thread toward both ends, and by rotating the screw portion and the screw hole relatively in one direction, the male thread and the female thread become threadedly engaged, and by rotating the screw portion and the screw hole relatively in the other direction, the male thread and the female thread become threadedly engaged. Fasteners.

2. The screw hole may further include a locking portion formed on the screw portion and the screw hole to lock the screw portion and the screw hole against relative rotation in the screwed state. The fastener of claim 1 .

3. The locking portion is A first convex portion formed between approximately the center in the extension direction and one end of one of the male thread side thread and the female thread side thread, and a second convex portion formed between approximately the center in the extension direction and the other end, a first recess formed in the other of the male thread and the female thread at a position that engages with the first convex portion when the threads are rotated relatively in the one direction to enter the screwed state, and a second recess formed in a position that engages with the second convex portion when the threads are rotated relatively in the other direction to enter the screwed state; The fastener of claim 2 comprising:

4. The first recess is equal to or larger than the first protrusion, and the second recess is smaller than the second protrusion. The fastener of claim 3.

5. The threaded portion is cylindrical and has a through hole therein that communicates with the threaded hole in the threaded state. A fastener according to any one of claims 1 to 4.

6. a male thread-side pipe that is provided radially outward from the axis of the through hole, one end of which is branched in two directions, one of which is a first male thread-side branch portion facing the one direction, and the other of which is a second male thread-side branch portion facing the other direction; a female-thread-side piping that is provided radially outward from the axis of the threaded hole, one end of which branches in two directions, one of which is a first female-thread-side branch portion facing the other direction, and the other of which is a second female-thread-side branch portion facing the one direction, and in the threaded state, the first female-thread-side branch portion engages with the first male-thread-side branch portion, and the second female-thread-side branch portion engages with the second male-thread-side branch portion; The fastener of claim 5 comprising:

7. a male thread surface that is disposed in a portion of the outer circumferential direction of the threaded portion and has a male thread extending generally perpendicular to the axial direction of the threaded portion; An outer circumferential piece that is arranged alternately with the male thread surface in the outer circumferential direction to form the outer periphery of the threaded portion, and on which the male thread side thread is not formed; Equipped with The thread on the male screw side is formed so that the radial width of the thread portion narrows from approximately the center in the extension direction of the thread on the male screw side toward both ends. Male thread side component.

8. A female thread surface is disposed in a portion of the inner circumferential direction of the screw hole and has a female thread extending substantially perpendicular to the axial direction of the screw hole; An inner peripheral piece that is arranged alternately with the female thread surface in the inner circumferential direction to form the inner periphery of the screw hole and is not provided with a thread on the female thread side; Equipped with The female thread is formed so that the radial width of the screw hole narrows from approximately the center in the extension direction of the female thread toward both ends. Female thread side component.

Images