Engagement control mechanism and joint

Abstract

To solve the problem that development of a technology capable of controlling an amount of screwing of a screw part without using a torque wrench is required.SOLUTION: An engagement control mechanism includes: a screw regulation member supported movably in an axial direction of a first female screw part with respect to a first member; a lock mechanism which can lock the screw regulation member at a lock position with respect to the first member until a second member reaches a first position and can release the lock of the screw regulation member when the second member reaches the first position; an engagement mechanism which allows the second member to move to the screw regulation member until the second member reaches the first position and engages the second member and the screw regulation member so that they can integrally move in the axial direction after the second member reaches the first position; and a stopper part which is provided for the screw regulation member and contacts the first member when the screw regulation member is screwed from the lock position by a specified amount.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present disclosure relates to a thread management mechanism used to manage threading. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a technique using a torque wrench for controlling the amount of tightening of a screw portion has been widely used (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-71278 (paragraph

[0007] , Figures 1, 2, etc.) Summary of the Invention [Problem to be solved by the invention]

[0004] In contrast to conventional techniques, there is a demand for the development of a technique that can control the amount of tightening of a screw portion without using a torque wrench. [Means for solving the problem]

[0005] One aspect of the invention is a screwing management mechanism that screws a male screw portion of a second member into a first female screw portion of a first member, and manages screwing so that when a first position is reached where screwing resistance increases, the second member is further screwed from that point by a specified amount. The screwing management mechanism includes a screwing control member supported on the first member so as to be movable in the axial direction of the first female screw portion, a locking mechanism that locks the screwing control member at an locking position with respect to the first member until the second member reaches the first position, and is capable of releasing the lock of the screwing control member when the second member reaches the first position, an engagement mechanism that allows movement of the second member relative to the screwing control member until the second member reaches the first position, and engages the second member and the screwing control member so as to move together in the axial direction after the second member reaches the first position, and a stopper portion provided on the screwing control member that abuts against the first member when the screwing control member is screwed from the locking position by the specified amount. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a side cross-sectional view of a joint according to a first embodiment. [Diagram 2] Figure 2 is a cross-sectional view of the joint taken along line AA in Figure 1. [Diagram 3] FIG. 3 is a perspective view of a screw-restricting member. [Figure 4] Figure 4 is an enlarged cross-sectional side view of the regulating protrusion of the joint. [Diagram 5] FIG. 5 is a side cross-sectional view of the fitting when the first pipe is inserted. [Figure 6] FIG. 6 is a side cross-sectional view of the joint when the second pipe is screwed into the joint and enters the joint. [Figure 7] FIG. 7 is a side cross-sectional view of the joint when the second pipe abuts against the inner sleeve and reaches the first position. [Figure 8] FIG. 8 is a side cross-sectional view of the first position when the second pipe is further screwed into the joint and the stopper portion comes into contact with the joint. [Figure 9]FIG. 9A is a schematic cross-sectional front view of the joint when the second pipe is screwed onto the second pipe and enters the joint; FIG. 9B is a schematic cross-sectional front view of the joint when the second pipe abuts against the inner sleeve and reaches a first position; and FIG. 9C is a schematic cross-sectional front view of the joint when the second pipe reaches the first position and the locking mechanism is released. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] [First embodiment] 1 shows a threading management mechanism 10 according to a first embodiment of the invention. The threading management mechanism 10 is used to manage the threading of a male thread portion 12N (see FIG. 6) of a second member into a female thread portion (small diameter female thread portion 24S described below) of a first member. In this embodiment, the first member is a member provided in a joint 90 (specifically, the outer sleeve 20 described below), and the second member is a second pipe 12 connected to the joint 90.

[0008] In the following, first, a structure of the joint 90 will be described. In this embodiment, the joint 90 has a cylindrical structure in which the inner sleeve 60 is fitted inside the outer sleeve 20. In this embodiment, the inner sleeve 60 is housed midway through the outer sleeve 20 in the axial direction of the joint 90.

[0009] The joint 90 (specifically, the outer sleeve 20) has a first insertion opening 21 at one axial end (the right end in FIG. 1) and a second insertion opening 22 at the other axial end (the left end in FIG. 1). The joint 90 is connected to the first pipe 11 (see FIG. 5) from the first insertion opening 21 side, and is connected to the second pipe 12 (see FIG. 6) from the second insertion opening 22 side. For example, the outer peripheral surface of the outer sleeve 20 has a shape (for example, a substantially regular hexagonal cross-sectional shape) that allows a tool (for example, a wrench or the like) for tightening the outer sleeve 20 to be hooked thereon. Hereinafter, one end of the joint 90, the outer sleeve 20, the inner sleeve 60, etc. will be referred to as the "tip end" and the other end as the "base end" as appropriate.

[0010] As shown in FIG. 1, in the example of this embodiment, the inside (internal flow passage R) of the outer sleeve 20 is provided with a small diameter portion 23 with the smallest inner diameter at a midpoint in the axial direction (in the example of this embodiment, at a position closer to the tip). For example, a ring member 70 (see FIG. 5) is attached to a portion of the internal flow passage R of the outer sleeve 20 closer to the first insertion opening 21 than the small diameter portion 23, and is interposed between the outer sleeve 20 and the first pipe 11 when the first pipe 11 is inserted into the first insertion opening 21. For example, the ring member 70 is formed of an insulating material such as resin (for example, rubber). For example, the ring member 70 is configured to prevent the outer sleeve 20 and the first pipe 11 from coming into direct contact with each other, and when the outer sleeve 20 and the first pipe 11 are made of different metals, it is possible to prevent corrosion due to contact between the different metals.

[0011] In this embodiment, the internal flow passage R of the outer sleeve 20 is configured to be gradually reduced in diameter from the base end side to the small diameter section 23. A large diameter female screw section 24D is formed in the outer sleeve 20 from the base end of the internal flow passage R to a position closer to the base end on the inner side (tip side). A small diameter female screw section 24S having an inner diameter smaller than the inner diameter of the large diameter female screw section 24D is formed in the internal flow passage R from the large diameter female screw section 24D to the tip side. The large diameter female screw section 24D and the small diameter female screw section 24S are coaxially arranged and connected by a step section 20D.

[0012] The small diameter female screw portion 24S is screwed into the male screw portion 12N of the second pipe 12 (see FIG. 6). In this embodiment, an annular groove 25U is formed on the inner peripheral surface of the outer sleeve 20 on the tip side of the small diameter female screw portion 24S, and an O-ring 25 (see FIG. 5) is received therein. In this embodiment, a large diameter portion 26 having approximately the same inner diameter as the small diameter female screw portion 24S is provided on the tip side of the inner flow passage R of the outer sleeve 20 from the annular groove 25U. In this embodiment, a medium diameter portion 27 is formed by reducing the diameter from the large diameter portion 26 to the tip side by a step portion 26D, and a taper portion 28 is formed from the medium diameter portion 27, which is tapered toward the tip side and is connected to the small diameter portion 23.

[0013] In the present embodiment, the inner sleeve 60 is fitted over the large diameter portion 26, the medium diameter portion 27, and the tapered portion 28 of the outer sleeve 20, and is disposed so as to be accommodated therein. A tapered portion 61 is formed at the axial tip of the inner sleeve 60. The tapered portion 61 has an outer diameter smaller than that of the base end side portion of the inner sleeve 60 due to a step portion 60D, and is fitted over the medium diameter portion 27 and the tapered portion 28 of the outer sleeve 20. As will be described later, when the inner sleeve 60 is pushed from the base end side, the tapered portion 61 is pressed against the tapered portion 28 on the inner circumferential surface of the outer sleeve 20, and is capable of being deformed to reduce in diameter (see the change from FIG. 7 to FIG. 8). In detail, in the present embodiment, the tapered portion 61 has a claw portion 61T that extends to the tip side and protrudes inward at the tip, and the tapered portion 61 is deformed (for example, elastically deformed) so that the claw portion 61T moves inward.

[0014] In this embodiment, an abutment surface 62 that is tapered toward the tip side (i.e., female tapered) is formed on the inside of the opening edge on the base end side of the inner sleeve 60. As described later, the tapered portion 13 provided at the tip of the second pipe 12 abuts against the abutment surface 62, and a gap between the abutment surface 62 and the tapered portion 13 is sealed (see FIG. 8). The tapered portion 13 is shaped on the outside of the tip of the second pipe 12 that is tapered toward the tip side (i.e., male tapered). For example, when at least a portion of the inner sleeve 60 including the abutment surface 62 is made of metal and a portion of the second pipe 12 including the tapered portion 13 is made of metal, the abutment surface 62 and the tapered portion 13 are metal sealed. For example, the entire inner sleeve 60 may be made of metal, and the entire second pipe 12 may be made of metal.

[0015] Inside the inner sleeve 60 (internal flow path), an expanded diameter section 64 expanded by a step section 63 extends from the rear (tip side) end of the abutment surface 62 toward the tip side and is connected to the throttle section 61. In this embodiment, the inner diameter of the expanded diameter section 64 is approximately the same as the inner diameter of the small diameter section 23 of the outer sleeve 20 and is larger (for example, slightly larger) than the outer diameter of the first pipe 11 inserted from the first insertion port 21. An annular groove 65U is formed on the inner circumferential surface midway through the expanded diameter section 64 of the inner sleeve 60, and an O-ring 65 is received therein (see FIG. 5).

[0016] As shown in FIG. 1, in the joint 90, a screwing restriction member 40 is screwed and supported at the base end of the outer sleeve 20. The screwing restriction member 40 has an outer screw portion 43 that screws into the large diameter female screw portion 24D of the outer sleeve 20, and is movable in the axial direction of the outer sleeve 20 by screwing. In this embodiment, the screwing restriction member 40 has a cylindrical portion 41 and a stopper portion 42 that protrudes outward from the base end of the cylindrical portion 41. The outer screw portion 43 is formed on the outer peripheral surface of the cylindrical portion 41 at a portion on the tip side of the stopper portion 42. In this embodiment, the stopper portion 42 protrudes from the entire circumferential direction of the cylindrical portion 41, and has, for example, a regular polygonal shape.

[0017] An inner screw portion 44 is formed on the inner peripheral surface of the cylindrical portion 41 of the screwing restriction member 40. The inner screw portion 44 has the same thread shape and phase as the small diameter female screw portion 24S of the outer sleeve 20, and is shaped to extend from the small diameter female screw portion 24S when supported at the base end of the outer sleeve 20. That is, the male screw portion 12N of the second pipe 12 screws into the small diameter female screw portion 24S and also screws into the inner screw portion 44 (see Figs. 6 and 7). For example, the inner screw portion 44 is provided on the inner peripheral surface of the cylindrical portion 41 over the entire axial direction.

[0018] In the screwing management mechanism 10, the screwing restriction member 40 is attached to the outer sleeve 20 in a state where the second pipe 12 is not connected to the joint 90, and is locked to the outer sleeve 20 at the locking position shown in Figs. 1 and 4 by the locking mechanism 50. The locking mechanism 50 has a protrusion that protrudes from one of the screwing restriction member 40 or the outer sleeve 20 to the other. In the example of this embodiment, this protrusion has a protrusion 51 in a valley between the threads of the outer screw portion 43 of the screwing restriction member 40 (see Figs. 2 and 3). The protrusion 51 is locked to a locking portion 29 on the inner peripheral surface of the outer sleeve 20 at the locking position (see Fig. 2). In the example of this embodiment, this locking portion 29 is a protrusion that protrudes from the inner peripheral surface of the outer sleeve 20, but may be a flat surface on the cylindrical inner peripheral surface of the outer sleeve 20.

[0019] The joint 90 of this embodiment is connected to the first pipe 11 and the second pipe 12 as follows. First, the joint 90 is assembled. Specifically, the inner sleeve 60 is housed in the outer sleeve 20, the screwing restriction member 40 is screwed onto the base end of the outer sleeve 20, and the protrusion 51 of the locking mechanism 50 is locked into the locking portion 29 to lock the screwing restriction member 40 into the locking position relative to the outer sleeve 20 (see FIGS. 4 and 5).

[0020] 5, the first pipe 11 is inserted from the first insertion port 21 of the fitting 90. The first pipe 11 passes through the outer sleeve 20 and is further inserted into the inside of the inner sleeve 60 until it abuts against the stepped portion 63, for example. At this time, in this embodiment, the gap between the first pipe 11 and the inner sleeve 60 is sealed by an O-ring 65.

[0021] Next, as shown in FIG. 6, the base end of the joint 90 is screwed into the second pipe 12. Specifically, the inner screw portion 44 of the screwing restriction member 40 is screwed into the male screw portion 12N of the second pipe 12, and further into the small diameter female screw portion 24S of the outer sleeve 20. At this time, the screwing restriction member 40 is maintained in a locking position with respect to the outer sleeve 20 by the locking mechanism 50 (by locking between the protrusion 51 and the locking portion 29). In the example of this embodiment, since the second pipe 12 is fixed to the fluid device, an operation of screwing into the second pipe 12 while rotating the outer sleeve 20 is performed. At this time, the screwing restriction member 40 is disposed in the locking position and rotates integrally with the outer sleeve 20 (see FIG. 9A).

[0022] When the joint 90 and the second pipe 12 are further screwed together, the second pipe 12 reaches a first position where it abuts against the abutment surface 62 of the inner sleeve 60, as shown in Fig. 7. At this first position, the tip portion (tapered portion 13) of the male thread portion 12N of the second pipe 12 abuts against the abutment surface 62 of the inner sleeve 60, so that the screwing resistance between the male thread portion 12N of the second pipe 12 and the small diameter female thread portion 24S of the outer sleeve 20 increases. Note that, until the second pipe 12 reaches the first position, the joint 90 is screwed into the second pipe 12 by hand tightening, for example.

[0023] Here, in the locking mechanism 50, the lock of the screwing restriction member 40 can be released when the second pipe 12 reaches the first position. This release can be performed, for example, by screwing the joint 90 to the second pipe 12 stronger than hand tightening in a state in which the screwing restriction member 40 is locked to the second pipe 12. This release releases the lock between the protrusion 51 and the locking portion 29 (see the change from FIG. 9B to FIG. 9C). For example, this release may be capable of destroying the locking mechanism 50 (for example, the locking mechanism 50 may be configured so that at least one of the protrusion 51 and the locking portion 29 is deformed).

[0024] The locking mechanism 50 can be released at the first position by configuring the screwing management mechanism 10 as follows. For example, the shape of the thread of the male screw portion 12N of the second pipe 12 is configured so that the screwing resistance between the male screw portion 12N and the inner screw portion 44 of the screwing restriction member 40 is smaller than the locking force of the locking mechanism 50 at the tip side of the intermediate position in the axial direction of the second pipe 12, and is larger than the locking force of the locking mechanism 50 at the base end side of the intermediate position in the axial direction of the second pipe 12. In this way, if the intermediate position of the second pipe 12 reaches the position of the screwing restriction member 40 when the second pipe 12 reaches the first position, the locking of the locking mechanism 50 can be released at that time. The above configuration can be realized, for example, by making the male screw portion 12N of the second pipe 12 a tapered screw tapered toward the tip side.

[0025] In addition, when the second pipe 12 reaches the first position, the sliding resistance between the second pipe 12 and the inner sleeve 60 makes the threading resistance between the male screw portion 12N and the small diameter female screw portion 24S of the outer sleeve 20 greater than the locking force of the locking mechanism 50, making it possible to release the lock of the locking mechanism 50.

[0026] From the first position shown in FIG. 7, the outer sleeve 20 and the second pipe 12 are tightened by, for example, a tool, to further deepen their screwing. Then, as shown in FIG. 8, the drawn portion 61 of the inner sleeve 60 is pressed against the tapered portion 28 of the outer sleeve 20 and deformed to reduce its diameter, and the claw portion 61T of the drawn portion 61 abuts (for example, bites into) the outer peripheral surface of the first pipe 11. As a result, the first pipe 11 is prevented from coming off the joint 90 (inner sleeve 60), and the first pipe 11 is connected to the joint 90. In addition, the tapered portion 13 at the tip of the second pipe 12 is pressed against the abutment surface 62 of the inner sleeve 60, and these are metal-sealed. As a result, the second pipe 12 is connected to the joint 90 (inner sleeve 60). At this time, in the example of this embodiment, the O-ring 25 also seals between the outer sleeve 20 and the second pipe 12.

[0027] Here, when the second pipe 12 is further screwed into the outer sleeve 20 from the first position, the locking mechanism 50 releases the locking of the screwing restriction member 40, and the second pipe 12 is engaged with the screwing restriction member 40 by the engagement mechanism 55 and moves together (see the changes shown in Figs. 7 to 8). Then, as shown in Fig. 8, when the narrowing portion 61 is reduced in diameter and the first pipe 11 is connected to the joint 90 (i.e., when the second pipe 12 is screwed into the outer sleeve 20 from the first position by an appropriate amount of screwing), the stopper portion 42 of the screwing restriction member 40 abuts against the base end surface of the outer sleeve 20. At this time, the tip surface of the screwing restriction member 40 and the step portion 20D of the outer sleeve 20 may abut. Also, either one of these two points may abut when screwed by the above-mentioned appropriate amount of screwing.

[0028] In this embodiment, a clearance C1 is provided in the first screwing S1, which is the screwing between the outer sleeve 20 (small diameter female screw portion 24S) and the second pipe 12 (male screw portion 12N). A clearance C2 is provided in the second screwing S2, which is the screwing between the outer sleeve 20 (large diameter female screw portion 24D) and the screwing restriction member 40 (outer screw portion 43). A clearance C3 is provided in the third screwing S3, which is the screwing between the screwing restriction member 40 (inner screw portion 44) and the second pipe 12 (male screw portion 12N). In this embodiment, the engagement mechanism 55 is capable of engaging the second pipe 12 and the screwing restriction member 40 because the clearance C3 is smaller than the clearances C1 and C2. As a result, when the outer sleeve 20 and the second pipe 12 are fastened, the dyne 2 pipe 12 and the screwing restriction member 40 move together in the axial direction and can rotate together with respect to the outer sleeve 20. Note that the engagement mechanism 55 allows the second pipe 12 to move with respect to the outer sleeve 20 and the screwing restriction member 40 locked by the locking mechanism 50 until the second pipe 12 reaches the first position (see FIG. 7).

[0029] The screwing management mechanism 10 of this embodiment can manage the screwing so that the male screw portion 12N of the second pipe 12 (second member) is screwed into the small diameter female screw portion 24N of the outer sleeve 20 (first member) and the second pipe 12 approaches the outer sleeve 20 by a specified amount (screwed by an appropriate screwing amount) when the first position is reached where the screwing resistance increases. Specifically, when the second pipe 12 moves by a specified amount from the first position, the stopper portion 42 of the screwing restriction member 40 abuts against the outer sleeve 20. This makes it possible to manage the tightening amount of the screw portion without using a torque wrench, and makes it possible to suppress the occurrence of problems caused by an excessive or insufficient screwing amount.

[0030] [Other embodiments] The first member having a female screw portion used for screw management by the screw management mechanism 10 and the second member having a male screw portion are not limited to the configurations in the above embodiment. The first member does not have to be one provided in the joint 90, and the second member does not have to be a pipe.

[0031] In the above embodiment, the locking mechanism 50 may be configured, instead of having the protrusion 51 and the locking portion 29, to have, for example, a penetrating member that penetrates the outer sleeve 20 and locks onto the outer peripheral surface of the screwing control member 40, and when the second pipe 12 reaches the first position, the penetrating member is moved away from the screwing control member 40 to release the locking.

[0032] In the above embodiment, the engagement mechanism 55 may be configured to include a penetrating member that penetrates the screwing limiting member 40 and engages with the outer peripheral surface of the second pipe 12, and when the second pipe 12 reaches the first position, the engagement begins, causing the screwing limiting member 40 and the second pipe to move together.

[0033] <Additional Notes> The following describes the feature groups extracted from the above-described embodiments, while indicating their effects, etc., as necessary. Note that, in the following, for ease of understanding, the corresponding configurations in the above-described embodiments are appropriately indicated in parentheses, but these feature groups are not limited to the specific configurations indicated in parentheses.

[0034] For example, the following group of features can be considered to have been conceived in response to the problem that "there is a demand for the development of a technology that can manage the tightening amount of a screw portion without using a torque wrench, in contrast to the conventional technology," in relation to the background technology that "conventionally, a technology that uses a torque wrench to manage the tightening amount of a screw portion has been widespread (see, for example, JP 2001-71278 (paragraph

[0007] , Figures 1, 2, etc.))." There is also a demand for the development of a new screw management mechanism and a new joint.

[0035] [Feature 1] a screwing management mechanism that screws a male screw portion of a second member into a first female screw portion of a first member, and when the first position where a screwing resistance increases is reached, manages the screwing so that the second member is further screwed from that position by a specified amount, a screwing restriction member supported so as to be movable in an axial direction of the first female screw portion relative to the first member; a locking mechanism that locks the screwing restriction member at a locking position relative to the first member until the second member reaches the first position and releases the locking of the screwing restriction member when the second member reaches the first position; an engagement mechanism that allows the second member to move relative to the screwing restriction member until the second member reaches the first position, and engages the second member and the screwing restriction member so as to move together in the axial direction after the second member reaches the first position; a stopper portion provided on the screwing restricting member and coming into contact with the first member when the screwing restricting member is screwed by the specified amount from the locking position.

[0036] [Feature 2] The first member is provided with a second female screw portion that is formed coaxially with the first female screw portion and has an inner diameter larger than that of the first female screw portion, the screwing restriction member has a cylindrical portion, and the stopper portion projects outward from the cylindrical portion, An outer circumferential surface of the cylindrical portion is provided with an outer screw portion that screws into the second female screw portion, An inner circumferential surface of the cylindrical portion is provided with an inner screw portion that screws into the male screw portion, The screwing management mechanism described in feature 1, wherein the internal screw portion is configured so that the male screw portion can be screwed into the first female screw portion and the internal screw portion when the screwing control member is positioned in the engagement position.

[0037] [Feature 3] The engagement mechanism is a screwing management mechanism described in feature 2, which engages the second member with the screwing control member by making a clearance of a third screwing, which is an engagement between the inner screw portion and the male screw portion, smaller than a clearance of a first screwing, which is an engagement between the first female screw portion and the male screw portion, and a clearance of a second screwing, which is an engagement between the second female screw portion and the outer screw portion.

[0038] [Feature 4] a pressed part that comes into contact with the male screw portion when the second member reaches the first position is provided on the inner side of the first female screw portion; The locking mechanism has a protrusion that protrudes from one of the screwing control member or the first member to the other, and prohibits rotation of the first female screw portion and the outer screw portion with an locking force greater than the screwing resistance of the third screwing until the second member reaches the first position, and releases the lock of the screwing control member due to the sliding resistance with the pressed part when the second member reaches the first position.

[0039] [Feature 5] A joint including an outer sleeve that is the first member of the screwing management mechanism according to feature 4 and an inner sleeve that is the pressed part, the outer sleeve has a first insertion opening at one end in the axial direction and a second insertion opening at the other end, and has a tapered portion therein that reduces in diameter toward the first insertion opening, and has a female thread portion for pipe as the first female thread portion at the other end of the interior, the inner sleeve is made of metal, is fitted into the outer sleeve, and has a tapered portion at one end in the axial direction that can be pressed against the tapered portion to reduce its diameter, and has a tapered abutment surface at the inside of an opening edge at the other end that reduces in diameter toward the one end, The reduced diameter of the constriction portion connects a first pipe inserted into the inner sleeve through the first insertion port to the inner sleeve, and a second metal pipe as the second member having the male thread portion on its outer surface is screwed into the female pipe thread portion and pressed against the abutment surface, thereby connecting the second pipe to the inner sleeve.

[0040] According to the above features 1 to 5, it becomes possible to control the tightening amount of the screw portion without using a torque wrench.

[0041] In addition, although this specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but includes various modifications and variations of the specific examples, as well as parts of the specific examples taken alone. [Explanation of symbols]

[0042] 10 Screw management mechanism 11 First Pipe 12 Second Pipe 12N Male thread 13 Tapered section 20 Outer Sleeve 21 First insertion slot 22 Second insertion slot 24D Large diameter female thread 24S small diameter female screw part 28 Tapered section 29 Locking part 29T protrusion 40 Screw-in restriction member 41 Cylindrical part 42 Stopper part 43 Outer thread 44 Internal thread 50 Locking mechanism 51 Protrusion 55 Engagement mechanism 60 Inner Sleeve 61 Squeezing section 62 Contact surface 90 Joint S1 First screw connection S2 Second screw connection S3 3rd screw connection

Claims

1. a screwing management mechanism that screws a male screw portion of a second member into a first female screw portion of a first member, and when the first position where a screwing resistance increases is reached, manages the screwing so that the second member is further screwed from that position by a specified amount, a screwing restriction member supported on the first member so as to be movable in an axial direction of the first female screw portion; a locking mechanism that locks the screwing restriction member at a locking position relative to the first member until the second member reaches the first position and releases the locking of the screwing restriction member when the second member reaches the first position; an engagement mechanism that allows movement of the second member relative to the screwing restriction member until the second member reaches the first position, and engages the second member and the screwing restriction member so as to move together in the axial direction after the second member reaches the first position; a stopper portion provided on the screwing restriction member and coming into contact with the first member when the screwing restriction member is screwed by the specified amount from the locking position.

2. The first member is provided with a second female screw portion formed coaxially with the first female screw portion and having an inner diameter larger than that of the first female screw portion, the screwing restriction member has a cylindrical portion, and the stopper portion projects outward from the cylindrical portion, An outer circumferential surface of the cylindrical portion is provided with an outer screw portion that screws into the second female screw portion, An inner circumferential surface of the cylindrical portion is provided with an inner screw portion that screws into the male screw portion, The screwing management mechanism according to claim 1 , wherein the internal screw portion is configured so that the male screw portion can be screwed into the first female screw portion and the internal screw portion when the screwing control member is disposed in the locking position.

3. 3. The screwing management mechanism according to claim 2, wherein the engagement mechanism engages the second member with the screwing control member by making a clearance of a third screwing, which is the screwing of the inner screw portion with the male screw portion, smaller than a clearance of a first screwing, which is the screwing of the first female screw portion with the male screw portion, and a clearance of a second screwing, which is the screwing of the second female screw portion with the outer screw portion.

4. a pressed part that comes into contact with the male screw portion when the second member reaches the first position is provided on the inner side of the first female screw portion; The screwing management mechanism according to claim 3, wherein the locking mechanism has a protrusion that protrudes from one of the screwing control member or the first member to the other, and prohibits rotation of the first female screw portion and the outer screw portion with an locking force greater than the screwing resistance of the third screwing until the second member reaches the first position, and releases the lock of the screwing control member due to the sliding resistance with the pressed part when the second member reaches the first position.

5. A joint including an outer sleeve that is the first member of the screwing management mechanism according to claim 4 and an inner sleeve that is the pressed part, the outer sleeve has a first insertion opening at one end in the axial direction and a second insertion opening at the other end, and has a tapered portion therein that reduces in diameter toward the first insertion opening, and has a female thread portion for pipe as the first female thread portion at the other end of the interior, the inner sleeve is made of metal, is fitted into the outer sleeve, and has a tapered portion at one end in the axial direction that can be pressed against the tapered portion to reduce its diameter, and has a tapered abutment surface at the inside of an opening edge at the other end that reduces in diameter toward the one end, The reduced diameter of the constriction portion connects a first pipe inserted into the inner sleeve through the first insertion port to the inner sleeve, and a second pipe made of metal as the second member having the male thread portion on its outer surface is screwed into the female thread portion for pipe and pressed against the abutment surface, thereby connecting the second pipe to the inner sleeve.

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