JP3677339B2 - Corrugate pipe joint - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe joint for connecting a metal corrugate pipe (hereinafter sometimes simply referred to as a pipe) having a corrugated outer peripheral surface.
[0002]
[Prior art]
Conventionally, for example, Japanese Patent Publication No. 3-3837 (USP 4,630,850) has been proposed and used as a joint for connecting such a corrugate pipe.
This joint is composed of a joint body having a screw on the outer periphery of one end, a cap nut screwed into the male thread of the joint body, and a sleeve having a waveform on the inner peripheral surface that engages with the corrugation of the corgate pipe. Yes.
Of these, the joint body has a tapered hole portion that is uniformly reduced in diameter toward the back at the inner periphery on the male screw side, and a smaller diameter passage than the tapered hole portion on the inner periphery of the other end portion. There is a hole, and a pipe receiving wall portion is provided at the boundary between the through hole and the tapered hole portion.
The sleeve has slits in the axial direction and has a plurality of segments. After attaching this sleeve to the outer periphery leaving several peaks from the end of the corrugate tube, insert this sleeve into the tapered hole of the joint body, and screw the cap nut into the male thread of the joint body from the outside of the sleeve. Tighten the nut.
Thus, several crests of the corrugate tube protruding from the end portion of the sleeve are crushed between the front end portion of the sleeve and the tube receiving wall portion of the joint main body to be connected and sealed.
[0003]
[Problems to be solved by the invention]
In this joint, since a sleeve having an inner peripheral surface having a waveform that engages with corrugation of the corrugate pipe is fitted on the outer circumference of the corgate pipe and this sleeve is screwed into the joint body with a cap nut, a reliable connection can be made. However, it can be assembled even if the end of the corrugate tube is put in the sleeve due to a mistake in construction. That is, since the end of the corrugate tube does not protrude from the end of the sleeve, the cap nut can be tightened as it is, and in this case, the end of the corgate tube is not crushed and the fluid leaks. is there.
[0004]
The procedure for connecting the corrugate pipe is as follows. First, disassemble the joint, pass the cap nut and sleeve through the corgate pipe, insert the corrugate pipe with the sleeve into the joint body, and then insert the cap nut into the joint body. It was relatively time consuming and laborious to screw and crush several piles at the end of the corrugate tube. Furthermore, there was a problem that the parts of the joints that were disassembled were dropped from the hand during piping work and the parts were lost. For this reason, there is a demand for a joint that can be connected simply by inserting a corrugate tube.
[0005]
Therefore, the present invention provides a joint that can be connected without trouble and with good sealing performance by inserting a corrugate pipe into a joint that has been preliminarily assembled and then tightening the nut slightly. In addition, at this time, a joint having a function of determining whether or not the corrugate pipe is correctly inserted is provided.
[0006]
[Means for Solving the Problems]
The present invention includes a joint body having a through hole and the internal thread of the axial direction, a sleeve for holding an end portion of Korugeito tube in a pre-mounted on the nut and the through hole, advance a provisional internal thread of the joint body includes a nut which is screwed into the clamped state, the scan Bae Saringu and to hold the mounting and tightening amount between the fitting body and the nut,
Wherein the joint body has a shoulder portion having a gas-tight surface in the through hole, circle and the tapered inner peripheral surface fitting one end of the sleeve next to the shoulder portion is reduced in diameter, circle next to the tapered inner surface an annular recess, and a small-diameter female screw from recess is formed next to the recess,
The sleeve includes a synthetic resin ring body having a protrusion that engages with a groove on the nut side on an outer periphery of an end portion, and a plurality of sleeves formed integrally with the ring body and formed in an axial direction at a front portion. Consisting of multiple segments separated by slits
When the corrugate pipe is inserted into the joint, the segment abuts against the first peak of the corgate pipe and elastically expands with the ring body as a base point , and the first peak from the tip of the corgate pipe. A protrusion is provided at the end of the corrugate tube that shrinks and enters the first valley from the tip of the corrugate tube, and the other end is formed with a contact surface against which the pressing surface of the nut hits.
Said nut includes a male screw to the female screw screwed in the joint body at one end, a groove portion for pushing surface and engaging said sleeve-side of the protrusion strikes the abutment surface of the sleeve is formed,
The spacer ring is set to a length of about one mountain of a corrugate tube to connect the distance between the protrusion of the sleeve and the airtight surface of the joint body,
When the corrugate tube was pushed into the joint, the protruding portion of the sleeve was located in the annular recess of the joint body, and allowed to expand, and climbed over the first peak from the tip of the corgate tube . After shrinking and entering the first valley from the tip of the corrugate tube, when trying to pull out the corgate tube, the sleeve retreats with the corgate tube, and the outer peripheral surface of the rear part of the segment is the female thread portion of the joint body The joint for connecting a corgate pipe is characterized in that the expansion of the protruding portion of the sleeve is restrained to prevent the corrugate pipe from being pulled out.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the joint of the present invention, a sleeve having a protrusion at the tip that can be expanded and contracted is attached to the nut, and the nut is temporarily attached to the joint body so that the distance between the protrusion and the airtight surface is about one mountain of the corrugate pipe to be connected. The spacer ring is clamped between the nut and the joint body, and this position (tightening amount) is held by the spacer ring and temporarily assembled. Therefore, when the corrugate pipe is inserted from the nut opening side of the joint, the first peak hits the protrusion of the sleeve, and at this time, the protrusion of the sleeve is positioned in the recess of the joint body, so that the protrusion is elastically expanded. Is possible. When the tube is further pushed in, the protrusion spreads outward and expands with the other end side (engagement portion side) of the sleeve as a fulcrum. At this time, since there is nothing to prevent this expansion, the protrusion expands along the crest of the tube, gets over it, shrinks as it is, and fits into the first valley from the tip. (A movement in which the front protruding portion elastically expands and climbs over the top of the tube with the rear portion of the sleeve as a fulcrum is referred to as an elastic pivot motion in the present invention.) It is impossible to push the tube any further by hitting the airtight surface.
[0008]
Next, when the tube is pulled out for confirmation of engagement insertion, the sleeve is retracted while being fitted in the valley of the tube, but the outer peripheral surface of the rear portion of the sleeve is fitted into the female thread portion of the joint body and the outer surface is constrained. As a result, the protrusion of the sleeve is prevented from spreading outward and the tube cannot be pulled out.
After that, when the nut is screwed in and tightened by about one thread, the pressing surface of the nut hits the contact surface of the sleeve and pushes the sleeve forward. Since the inner surface to which the sleeve is fitted has a tapered surface that is reduced in diameter, the sleeve is narrowed to the inner diameter side while the tip of the tube is closed to the shoulder airtight surface (this is a gasket, O-ring or a simple metal surface. It is also good).
[0009]
【Example】
FIG. 1 is a partial cross-sectional front view showing an embodiment of the joint of the present invention, where a nut and a joint body are temporarily assembled and a corrugate pipe is inserted. FIG. 2 is a front view showing a partial cross-section in a state where the nut of the joint of FIG. 1 is tightened. FIG. 3 is a perspective view of a sleeve used in the joint of the present invention.
[0010]
Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a joint body in which a through hole 11 is opened in its axial direction, and a shoulder portion 14 having an airtight surface facing one side (left in the drawing) is formed in the through hole 11. In this example, a heat-resistant gasket 12 is attached to the shoulder, and a packing 13 containing expanded graphite is provided almost in contact therewith. A taper inner peripheral surface 15 that is reduced in diameter toward the shoulder is provided next to it (the taper surface may be provided on a part of the inner surface), and an annular concave groove 16 and a female screw 17 are provided next thereto. Are provided side by side, and a notch 18 for accommodating the O-ring 36 is provided at an end thereof. On the other side (right side) of the joint main body, a male screw 19 for attaching the joint main body to other pipes or instruments is provided. In the present invention, since the screw into which the nut is screwed is the female screw 17, the nut side enters into the through hole 11 of the joint body, and as a result, the radial dimension of the joint can be suppressed and the size can be reduced.
[0011]
A sleeve 2 that holds the free end of the flexible corrugate tube 4 is positioned in the through hole 11 of the joint body 1 in a state in which the sleeve 2 is attached to the nut in advance. As shown in FIG. 3, the sleeve 2 has a ring 21 made of synthetic resin at the rear, and the front is divided into segments 22 by a plurality of axial slits (here, five). At the tip of each segment, that is, the portion facing the shoulder portion 14 in the through hole 11 of the joint body, there is a projection 23 protruding toward the inside in the radial direction. The circle formed by the tip of the projection 23 is smaller than the diameter of the peak of the corrugated tube to be inserted and slightly larger than the diameter of the valley. The sleeve 2 is a composite member in which a synthetic resin body and a metal segment are integrally formed. That is, a resin body 27 is formed from the ring body 21 of the sleeve to the inner peripheral portion of the segment 22 so that the projection 23 can easily perform an elastic pivoting motion that elastically expands with the ring body 21 as a fulcrum. . The projection 23 and the outer peripheral portion 26 of the segment 22 are embedded so as to wrap the brass plate with a resin material to increase the rigidity, and the projection 23 can crush the crest portion of the tube, and the end surface of the sleeve segment 22 contacts the nut It becomes the surface 24 so that a strong force from the nut 3 can be received. A plurality of protrusions, for example, claws 25 are attached to the outer periphery of the rear end portion of the ring body 21 of the sleeve 2, and these claws are hung on a groove portion on the nut 3 side and held.
[0012]
The nut 3 has an opening through which the corrugate pipe passes, and has a male screw 31 to be screwed into the female screw 17 of the joint body 1 on the outer periphery of one end. An annular groove is provided at the inner end of the male screw 31. This may be formed as a protrusion 32 by forming an inner circumferential groove at the inner end. Then, the projection claw 25 of the sleeve is elastically fitted and rotatably mounted here, and the sleeve 2 is allowed to move in the axial direction with respect to the nut 3 and is prevented from being separated. The tip of the nut 3 is a pressing surface 33 that presses against the contact surface 24 of the sleeve. The groove portion may be provided by forming a concave groove on the outer peripheral end portion on the male screw 31 side. In this case, the sleeve-side protrusion portion is provided on the inner peripheral side of the rear end portion of the ring body 21. . At this time, the concave / convex engagement between the groove and the protrusion may be in a form of fitting so as to hardly move in the axial direction. Further, an E-shaped packing 37 is attached to a portion of the nut 3 and the resin cover 41 of the corrugate tube facing each other, thereby preventing moisture from entering the joint.
[0013]
Next, a procedure for connecting a corrugate tube will be described. First, a spacer ring or the like is attached, leaving a tightening amount of about 1 mountain of the corrugate pipe to be connected to the nut 3 and the joint body 1 to obtain a joint assembled in a temporarily tightened state. On the other hand, since the corgate pipe 4 is often provided with a resin cover 41 such as vinyl chloride in order to improve weather resistance and prevent trauma, a cover for a length of 4 to 5 from the end of the corgate pipe 4 is provided. And is inserted into the joint from the opening of the nut 3 (from the left side of the drawing). Then, the tip of the corrugate tube 4 or the crest 42 of the tip pushes the projection 23 of the sleeve 2 to the back, and the sleeve 2 advances to the back until the hook of the projection claw 25 of the sleeve and the projection 32 of the groove of the nut allow. An annular concave groove 16 of the joint main body is located on the outer periphery of the tip protrusion 23 of the sleeve when it reaches the innermost position. When the tube is further pushed in, a force is applied to the projection 23 of the sleeve further from the tip of the corrugate tube, and the segment portion 22 at the front portion of the sleeve performs an elastic pivot motion with the ring body 21 at the rear portion as a fulcrum. Then, the protrusion 23 at the end of the sleeve opens, climbs over the peak 42 at the end of the corrugate tube, and then returns to its original state while shrinking, and the protrusion 23 enters and locks into the first valley 43 (state shown in the figure). Here, since the distance from the protrusion 23 at the sleeve tip to the shoulder (in this example, the gasket 12) inside the main body is a length corresponding to about one mountain of the corrugate tube, the protrusion 23 of the sleeve is one of the corgate tubes. The tip of the corrugate tube hits the heat-resistant gasket 12 in the state where it enters the eye valley 43, so that no further insertion is possible.
[0014]
Here, a structure in which only one mountain can be inserted is more preferable than a structure in which several tubes can be inserted because it can be determined whether the tube has been normally inserted deeply or not. Because, as described above, the sleeve projection 23 enters the first valley 43 of the corrugate tube and cannot be inserted any more. Therefore, once the corrugate tube is pulled out in this state, the sleeve is retracted together with the tube. The protrusion 23 is also retracted from the position of the groove 16. In addition, since the rear outer peripheral surface 26 of the segment fits into the female thread 17 portion of the joint body, the projection 23 cannot be opened and the tube cannot be pulled out and pulled out. In addition, in the case where the outer peripheral groove at the end of the male thread 31 of the nut and the protrusion on the inner peripheral side of the ring body 21 of the sleeve 2 are engaged, the protrusion of the sleeve is already positioned in the concave groove portion in the temporarily tightened state. Elastic pivoting is possible. Even in this state, the outer peripheral surface of the engaging portion is constrained by the threaded portion because the joint body is narrow, and when attempting to pull out the corgate tube, the elastic pivot motion is prevented and the tube does not come off. . As described above, it can be confirmed that the corrugate tube has been normally inserted by preventing the tube from coming off. On the other hand, when the corrugate tube is pulled out, it means that the projection 23 has not climbed over the peak 42 at the tip of the corrugate tube, and it can be seen that it is not properly connected. And this tells you that you need to push the tube further. At this time, if the structure can be inserted into two or three ridges, even if only one ridge is inserted, there is an inconvenience that the tube does not come out but there is no crushing cost of the tube, and insertion confirmation and normal sealing can be performed. There is no problem. In addition, the above-mentioned about 1 mountain means that it may be in the range of 0.5 mountain to 1.5 mountain.
[0015]
In addition to the connection confirmation, a force for pulling out the corrugate tube 4 from the sleeve 2 may act on the corgate tube 4. At this time, both the sleeve and the corrugate tube are pulled in the direction of the nut 3 and the sleeve 2 stops when the abutting surface 24 of the sleeve hits the pressing surface 33 of the nut. When the sleeve 2 returns to this position, the outer peripheral portion 26 (especially the rear side) of the sleeve segment moves away from the annular concave groove 16 of the main body to the female screw 17 having a narrow inner diameter of the main body 1. It will be in a state of fitting. In this case, even if a force for pulling out the corrugate tube is applied, the outer peripheral portion 26 of the segment is fitted and restrained by the female screw portion on the main body side, so that the elastic pivot movement cannot be performed and the protrusion 23 at the end of the sleeve is expanded. This prevents the Colgate tube 4 from coming off.
[0016]
Thereafter, the nut 3 is turned and the male screw 31 of the nut is tightened along the female screw 17 of the main body. The nut 3 rotates slightly until the pressing surface 33 of the nut hits the contact surface 24 of the sleeve. However, after the pressing surface 33 of the nut hits the contact surface 24 of the sleeve, the sleeve 2 rotates the nut 3. On the other hand, since the tube is rotatable, the sleeve 2 is pushed toward the back of the through hole portion 11 of the main body as the nut 3 is tightened without twisting the tube. There is a tapered inner peripheral surface 15 at the back of the through-hole portion 11 of the main body, and the inner diameter of the tapered inner peripheral surface 15 becomes smaller as it goes deeper, so that the outer periphery of the tip of the sleeve is narrowed by the tapered surface. On the other hand, since the protrusion 23 in the inner diameter direction at the tip of the sleeve is in the first valley 43 of the corrugate tube 4, the sleeve 43 tightens the valley 43 in the radial direction with the protrusion 23 of the sleeve as the sleeve 2 goes deeper. One pile 42 is pressed against the gasket 12 of the shoulder portion 14 and crushed to obtain a complete airtight connection. As shown in the figure, a heat-resistant gasket 12 is put on the shoulder portion of the main body to improve the airtight performance. Further, a rubber packing 13 containing expanded graphite is put on the outer peripheral side of the heat-resistant gasket 12 to ensure safety in the event of a fire. It is desirable to improve the property. Further, the shoulder 14 of the main body may be only a flat metal surface, or may be a surface having an annular protrusion.
[0017]
In the joint of the present invention, when assembled in the temporarily tightened state, a spacer ring 5 is inserted between the end face of the nut and the end face of the body in order to determine the distance between the projection 23 of the sleeve and the shoulder airtight face of the joint body 1. The tightening amount between the nut 3 and the joint body 1 is maintained. The size of the spacer ring 5 is, for example, a length obtained by adding a distance between the protruding portion of the sleeve and the shoulder gasket surface of the main body and a crushing margin, and is set on the basis of the length of about one mountain of the corrugate tube. The spacer ring 5 is made of an elastic plastic or the like, and has a substantially C-shape with a notch in the axial direction at a part of the circumference. In this way, when the nut is weakly tightened to the main body (temporary tightening state), the spacer ring 5 is sandwiched between the nut and the end surface of the main body, so that the nut can be positioned. However, when the nut is strongly tightened, the spacer ring 5 is broken at the notch and is detached from between the end surface of the nut and the main body and attached to the outer periphery of the main body. In addition, after inserting the corrugate tube, the spacer ring 5 between the nut and the end face of the main body can be removed by hand.
[0018]
【The invention's effect】
The joint of the present invention can be connected by inserting a corrugate pipe into the joint body and tightening the nut without disassembling joint parts such as the joint body and nut. Moreover, the sealing property at the contact portion with the corgate pipe is good. In addition, since it is known whether or not the corrugate tube is correctly inserted, a correct connection can always be made.
[Brief description of the drawings]
FIG. 1 is a front view showing a partial cross section of an embodiment of the joint of the present invention, showing a state where a flexible corrugate tube is inserted after provisional assembly.
FIG. 2 is a partial cross-sectional view showing a state in which a nut is tightened.
FIG. 3 is a perspective view of a sleeve used in the joint of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Joint body 2 Sleeve 3 Nut 4 Colgate pipe 5 Spacer ring 11 Through-hole 12 Heat-resistant gasket 13 Rubber packing 14 with expanded graphite 14 Shoulder part 15 Tapered inner peripheral surface 16 Annular groove 17 Female thread 18 Notch 19 Male thread 21 Ring Body 22 Segment 23 Sleeve 2 projection 24 Abutment surface 25 Claw 26 Segment outer periphery 27 Resin body 31 Male thread 32 Nut 3 projection 33 Pushing surface 36 O-ring 37 E-shaped packing 41 Resin cover of Colgate tube 4 Colgate tube mountain 43 Korugeito tube first one of the valley of the tip

Claims (1)

Screwed a fitting body having an axial through hole and internal thread, a sleeve for holding an end portion of Korugeito tube in a pre-mounted on the nut and the through hole, the advance temporarily fastened state with the female screw of the joint body includes a nut that is, a scan Bae Saringu for holding and tightening amount mounted between the joint body and the nut,
Wherein the joint body has a shoulder portion having a gas-tight surface in the through hole, circle and the tapered inner peripheral surface fitting one end of the sleeve next to the shoulder portion is reduced in diameter, circle next to the tapered inner surface an annular recess, and a small-diameter female screw from recess is formed next to the recess,
The sleeve includes a synthetic resin ring body having a protrusion that engages with a groove on the nut side on an outer periphery of an end portion, and a plurality of sleeves formed integrally with the ring body and formed in an axial direction at a front portion. Consisting of multiple segments separated by slits
When the corrugate pipe is inserted into the joint, the segment abuts against the first peak of the corgate pipe and elastically expands with the ring body as a base point , and the first peak from the tip of the corgate pipe. A protrusion is provided at the end of the corrugate tube that shrinks and enters the first valley from the tip of the corrugate tube, and the other end is formed with a contact surface against which the pressing surface of the nut hits.
Said nut includes a male screw to the female screw screwed in the joint body at one end, a groove portion for pushing surface and engaging said sleeve-side of the protrusion strikes the abutment surface of the sleeve is formed,
The spacer ring is set to a length of about one mountain of a corrugate tube to connect the distance between the protrusion of the sleeve and the airtight surface of the joint body,
When the corrugate tube was pushed into the joint, the protruding portion of the sleeve was located in the annular recess of the joint body, and allowed to expand, and climbed over the first peak from the tip of the corgate tube . After shrinking and entering the first valley from the tip of the corrugate tube, when trying to pull out the corgate tube, the sleeve retreats with the corgate tube, and the outer peripheral surface of the rear part of the segment is the female thread portion of the joint body A joint for connecting a corrugate pipe, wherein the expansion of the protruding portion of the sleeve is prevented and the corrugate pipe is prevented from being pulled out.

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