TW202516123A - Water stop structure of pipe joint - Google Patents

Abstract

The present invention provides a water stop structure of pipe joint without reducing the water tightness but improving the versatility of the parts, which includes a rubber gasket comprising: an annular first rubber member whose inner peripheral surface meets the outer peripheral surface of the pipe; an annular second rubber member stacked on the outer peripheral surface of the first rubber member along the pipe diameter direction Y of the pipe; and a lamination holding device which maintains the lamination state of the first rubber member and the second rubber member. The first rubber member is made of a rubber material that is harder than the second rubber member. When the first rubber member and the second rubber member are in a laminated state, the end of the first rubber member on the socket side protrudes further in the tube axis direction X of the pipe than the end of the second rubber member on the socket side. A part of the protruding section is arranged between the inner end of the socket part and the outer peripheral surface of the pipe, and the second rubber member faces the tapered surface of the socket part.

Description

Water-stopping structure of pipe joints

The present invention relates to a water-stopping structure for a pipe joint. More specifically, the present invention relates to a water-stopping structure for a pipe joint, comprising: a joint body having a socket portion for inserting a pipe; an annular gasket mounted on the outer peripheral surface of the pipe; and a pushing device connected to the joint body and pushing the rubber gasket toward the socket portion.

As is well known, as a water-stopping structure of the above-mentioned pipe joint, for example, there is a structure described in Japanese Patent Document 1. In this water-stopping structure, for example, in the case of an inserted pipe 100' shown by the dotted line in Figure 9, in order to ensure water tightness, a rubber gasket 3', a joint body 2' and a pressure ring 8' (pushing device 7') corresponding to the outer diameter of the pipe 100' are used. Therefore, in the case of a pipe 100" having a smaller diameter than the pipe 100', these parts cannot be directly used, and a rubber gasket, a joint body, and a pressure ring having an inner circumferential surface 31", an inner end 21"a, and an inner end 81" corresponding to the outer diameter of the pipe 100" having a smaller diameter are required. That is, various components must be prepared according to the outer diameter of the connecting pipe, which leads to an increase in the cost of the pipe joint.

Therefore, it is possible to consider making the connector body 2' universal, for example, using a rubber gasket 3''' as shown in the tenth figure. However, since the inner end 21'a of the socket part 21' is separated from the pipe 100'', the compressive force applied to the rubber gasket 3'' will escape to the connector body 2' side, so the water tightness is reduced. In addition, as shown in the ninth figure, even if the rubber gasket 3' is only thickened and used, since the inner end 21'a is separated from the small-diameter pipe 100'', the compression structure of the rubber gasket 3' cannot be formed, so the water tightness cannot be ensured.

[Patent Literature]

Patent document 1: Japanese Patent Publication No. 2003-247679.

In view of the actual situation of the above-mentioned known technology, the purpose of the present invention is to provide a water-stopping structure of a pipe joint that can improve the versatility of parts without reducing water tightness.

The above-mentioned purpose of the present invention is achieved by the following technologies:

The water-stopping structure of the pipe joint of the present invention comprises: a joint body having a socket portion into which a pipe is inserted; an annular rubber gasket mounted on the outer peripheral surface of the pipe; and a pushing device connected to the joint body and pushing the rubber gasket toward the socket portion, wherein the rubber gasket comprises: an annular first rubber component whose inner peripheral surface is connected to the outer peripheral surface of the pipe; an annular second rubber component stacked on the outer peripheral surface of the first rubber component along the pipe diameter direction of the pipe; and a pressing device for holding the first rubber component and the The stacking retaining device of the second rubber member is that the first rubber member is made of a rubber material harder than the second rubber member, and when the first rubber member and the second rubber member are in the stacking state, the end of the first rubber member on the side of the socket portion protrudes further toward the axial direction of the tube than the end of the second rubber member on the side of the socket portion, and a part of the protruding section is arranged between the inner end of the socket portion and the outer peripheral surface of the tube, and the second rubber member is opposite to the tapered surface of the socket portion.

According to the above structure, the rubber gasket has: an annular first rubber member whose inner peripheral surface contacts the outer peripheral surface of the pipe; an annular second rubber member stacked on the outer peripheral surface of the first rubber member in the pipe diameter direction of the pipe; and a stacking holding device for holding the stacked state of the first rubber member and the second rubber member. Thus, even when the outer diameters of the pipes are different, the second rubber member can be manufactured in accordance with the shape of the joint body and the first rubber member can be manufactured in accordance with the outer diameter of the pipe, so that the joint body and the second rubber member can be made common and the versatility can be improved. Furthermore, the first rubber member is made of a rubber material harder than the second rubber member. When the first rubber member and the second rubber member are in a stacked state, the end of the first rubber member on the socket side protrudes further in the axial direction of the pipe fitting than the end of the second rubber member on the socket side, and a part of the protruding section is arranged between the inner end of the socket and the outer peripheral surface of the pipe fitting. The second rubber member is opposite to the tapered surface of the socket. Thus, since a part of the protruding section and the tapered surface of the socket portion together constitute the compression structure of the second rubber member, the compression force generated by the pushing device will not escape to the inside of the connector body, and the second rubber member is partially compressed and deformed near the inner end, thereby improving water tightness.

In the above structure, in the stacked state, the end of the first rubber member on the pushing device side protrudes further toward the tube axis than the end of the second rubber member on the pushing device side, a portion of the protruding section is arranged between the inner end of the pushing device and the outer peripheral surface of the tube, and the second rubber member can be opposite to the pushing surface of the pushing device.

In any of the above structures, annular protrusions may be formed on the inner circumference of the first rubber member at appropriate intervals along the axial direction of the tube. The first rubber member can be deformed and moved smoothly in the axial direction of the tube by compression deformation of the protrusions, thereby ensuring watertightness on the outer circumference of the tube.

On the other hand, in any of the above structures, a lubricant can be applied to the inner peripheral surface of the first rubber member. Even in such a structure, the first rubber member can be smoothly deformed and moved in the pipe axis direction, and the watertightness of the outer peripheral surface of the pipe can be ensured.

In any of the above structures, the pushing device is a compression ring mounted on the outer peripheral surface of the pipe and fastened to the joint body. In this case, the rubber hardness of the second rubber member is preferably 65° to 75°, and the rubber hardness of the first rubber member is 3° to 15° greater than the rubber hardness of the second rubber member. When the difference in the rubber hardness is greater than 15°, the degree of compression deformation of the first and second rubber members will change greatly, and sometimes the first rubber member and the second rubber member cannot be kept in a stacked state. On the other hand, when the difference in rubber hardness is less than 3°, the first rubber member is soft and easily deformed in the tube axis direction, and the compressive force in the contraction direction is reduced. Therefore, watertightness cannot be ensured.

On the other hand, in any of the above structures, the pushing device is a locking nut screwed and fastened to the outer peripheral surface of the socket portion. In this case, preferably, the rubber hardness of the second rubber member is 50° to 60°, and the rubber hardness of the first rubber member is 3° to 20° greater than the rubber hardness of the second rubber member. When the difference in the rubber hardness is greater than 20°, the degree of compression deformation of the first and second rubber members will change greatly, and sometimes the first rubber member and the second rubber member cannot be kept in a stacked state. On the other hand, when the difference in rubber hardness is less than 3°, the first rubber member is soft and easily deformed in the tube axis direction, and the compressive force in the contraction direction is reduced. Therefore, watertightness cannot be ensured.

In any of the above structures, the stacking holding device may be composed of: a plurality of concave portions formed at appropriate intervals along the axial direction of the tube on the outer circumferential surface of the first rubber member; and a plurality of convex portions formed at appropriate intervals along the axial direction of the tube on the inner circumferential surface of the second rubber member. Thus, the stacking state is maintained by the engagement of the concave and convex portions.

In any of the above structures, the outer peripheral portion of the end portion of the second rubber member on the side of the socket portion presents a tapered shape opposite to the tapered surface, and a plurality of annular protrusions and annular concave strips may be arranged alternately along the tube axis direction on the outer peripheral portion. Thus, the annular protrusions are compressed and deformed to shrink the entire second rubber member and closely adhere to the socket portion, thereby ensuring stronger water tightness.

According to the characteristics of the above-mentioned water-stopping structure of the present invention, the versatility of the components can be improved without reducing the water tightness.

Other objects, structures and effects of the present invention will become apparent from the following description of the embodiments of the present invention.

Hereinafter, the first embodiment of the present invention will be described in more detail with reference to the first to fourth figures.

<First embodiment>

The water-stopping structure 1 of the pipe joint according to the first embodiment of the present invention, as shown in the first and third figures, generally comprises: a joint body 2 having a socket portion 21 for inserting a pipe 100; an annular rubber gasket 3 mounted on the outer peripheral surface 100a of the pipe 100 (hereinafter referred to as the "pipe outer surface"); and a pressing device 7 connected to the joint body 2 and pressing the rubber gasket 3 toward the socket portion 21. In this embodiment, the pressing device 7 is composed of a pressing ring 8.

The joint body 2 has a socket portion 21 of a slightly conical shape and a cavity 23 for positioning the end of the pipe 100. The end of the socket portion 21 on the side of the cavity 23 is provided with an inner end portion 21a protruding toward the pipe axis (as shown in the first, third and fourth figures). In addition, a slightly rectangular flange 22 is formed on the outer peripheral portion 21b of the socket portion 21, and a through hole 24 for inserting a T-head bolt (described later) 12a is formed on the corner 22a of the flange 22.

In the water-stopping structure 1 of the pipe joint according to the present invention, the rubber gasket 3 has: an annular first rubber component 4 whose inner peripheral surface 41 contacts the outer periphery 100a of the pipe; an annular second rubber component 5 stacked on the outer peripheral surface 42 of the first rubber component 4 along the pipe diameter direction Y of the pipe 100; and a stacking holding device 6 for holding the stacked state of the first rubber component 4 and the second rubber component 5 stacked along the pipe diameter direction Y.

In the present invention, the first rubber member 4 is made of a harder rubber material than the second rubber member 5. Moreover, in this embodiment, for example, the rubber hardness of the second rubber member 5 is 65° to 75° (70° ± 5°), and the rubber hardness of the first rubber member 4 is 3° to 15° greater than the rubber hardness of the second rubber member 5.

On the inner peripheral surface 41 of the first rubber member 4, a plurality of annular protrusions 41a (as shown in the second figure) are formed at appropriate intervals along the tube axis direction X. In addition, on the outer peripheral surface 42 of the first rubber member 4, a plurality of recesses 42a are formed at appropriate intervals along the tube axis direction X. The protrusions 41a and the recesses 42a are formed in the central portion of the width direction of the main body 40 of the first rubber member 4. In addition, in the present embodiment, the protrusions 41a and the recesses 42a are not formed near the first end 43 which is the end on the side of the socket portion 21 and the second end 44 which is the end on the side of the pressure ring 8 (pressing device 7). In addition, in the present embodiment, the rubber hardness of the first rubber member 4 is, for example, 73° to 85°. In particular, if the hardness of the first rubber member 4 is softer than that, in the case of FIG. 4 described later, the rubber overflows (flows) in the tube axis direction, and it is difficult to maintain the compression force of the rubber, so that the watertightness cannot be maintained.

Here, the inner diameter of the first rubber member 4 is larger than the outer diameter of the tube 100. Here, as shown in FIG. 3, a spacer 56 can be used for temporary fixing (temporary assembly). In addition, the outer diameter of the concave portion 42a of the outer peripheral surface 42 of the first rubber member 4 (hereinafter referred to as "the outer diameter of the first rubber member 4") is slightly larger than the inner diameter of the convex portion 51a of the inner peripheral surface 51 of the second rubber member 5 (hereinafter referred to as "the inner diameter of the second rubber member 5"). Therefore, the first rubber member 4 must be contracted when stacked, and it is difficult to come off due to the reaction force of the rubber generated by the contraction. In addition, "slightly larger than" means, for example, that the outer diameter of the first rubber member 4 is 1 to 3% larger than the inner diameter of the second rubber member 5. In addition, in this embodiment, the protrusion 41a and the recess 42a are formed on the front and back of the body 40 on the same straight line along the tube diameter direction Y (concentric circles relative to the tube axis).

A plurality of annular protrusions 51a (as shown in the third and fourth figures) are formed at appropriate intervals on the inner peripheral surface 51 of the second rubber member 5 along the tube axis direction X. In addition, a tapered surface 59 is formed on the outer peripheral portion of the first end portion 53, which is the end portion of the second rubber member 5 on the side corresponding to the socket portion 21, and is opposed to the tapered surface 21c of the socket portion 21.

A plurality of annular protrusions 58a and annular recesses 58b are alternately provided on the tapered surface 59 along the tube axis direction X. On the other hand, the second end portion 54, which is the end portion on the side of the pressure ring 8 (pressing device 7), abuts against the pressing surface 82 of the pressure ring 8. In addition, a positioning rib 55 is provided on the outer peripheral surface 52 of the second rubber member 5.

In this embodiment, the stacking holding means 6 is constituted by the recessed portion 42a of the first rubber member 4 and the convex portion 51a of the second rubber member 5. By the engagement of these recesses and convexities, the stacked state of the first rubber member 4 and the second rubber member 5 is firmly held.

Here, in the stacked state of the first rubber member 4 and the second rubber member 5 shown in the third and fourth figures, the first end 43 of the first rubber member 4 protrudes further in the tube axis direction X than the first end 53 of the second rubber member 5. Moreover, a part (front end) 43a of the protruding section is arranged between the inner end 21a and the outer surface 100a of the tube. In addition, in the present embodiment, the second end 44 of the first rubber member 4 protrudes further in the tube axis direction X than the second end 54 of the second rubber member 5. Moreover, a part (front end) 43a of the protruding section is arranged between the inner end 81 of the pressure ring 8 and the outer surface 100a of the tube. In addition, the protrusion 41a and the recess 42a are formed on the same straight line along the tube diameter direction Y (concentric circles relative to the tube axis).

In this embodiment, the pressing device 7 is a compression ring 8 mounted on the outer surface 100a of the pipe and fastened to the joint body 2. The compression ring 8 generally comprises: an annular body portion 80 covering the outer surface 100a of the pipe, an inner end portion 81 protruding from the body portion 80 toward the pipe axis, and a pressing surface 82 for pressing the second rubber member 5 (as shown in the first, third and fourth figures). A through hole 84 is provided on the flange portion 83 of the body portion 80 for passing the T-head bolt 12a fastened to the joint body 2.

The following is a description of the construction steps of the pipe joint with reference to the third and fourth figures. First, the second rubber member 5 is stacked on the outer peripheral surface 42 of the first rubber member 4. At this time, the convex portion 51a of the second rubber member 5 is engaged with the concave portion 42a of the first rubber member 4. As described above, since the outer diameter of the first rubber member 4 is slightly larger than the inner diameter of the second rubber member 5, the reaction force of the rubber caused by the shrinkage of the first rubber member 4 during stacking makes it more difficult for the concave and convex to be disengaged. Furthermore, the first rubber component 4 is harder than the second rubber component 5, and the rubber hardness of the first rubber component 4 is 3 to 15 degrees greater than the rubber hardness of the second rubber component 5. If the hardness difference is within the range, even during the compression deformation described later, the concave and convex fitting is difficult to be separated, and the stacked state can be maintained. Then, the first rubber component 4 and the second rubber component 5 in the stacked state are installed on the socket part 21.

As described above, since the inner diameter of the first rubber member 4 is larger than the outer diameter of the pipe 100, as shown in the third figure, the second end 54 of the second rubber member 5 is brought into contact with the pressing surface 82 of the pressure ring 8, and the spacer 56 is sandwiched between the flange 22 of the socket portion 21 on which the first rubber member 4 and the second rubber member 5 are mounted and the flange 83 of the pressure ring 8, and the T-head bolt 12a and the nut 12b are tightened to make it in a temporary assembly state. Therefore, the second rubber member 5 will not be pressed in when transporting to the construction site. In addition, since the inner diameter of the first rubber member 4 is larger than the outer diameter of the pipe 100, the pipe 100 can be easily inserted in a temporary assembly state as shown in the figure, and the workability is good.

Then, remove the spacer 56, and tighten the T-head bolt 12a and the nut 12b (as shown in the fourth figure). In this embodiment, since a portion 44a of the protruding section is disposed between the inner end portion 81 and the outer surface 100a of the pipe fitting, the thrust force generated by the pressure ring 8 acts on the second rubber member 5 through the thrust surface 82. Then, under the action of the thrust force, the outer peripheral portion of the second rubber member 5 abuts against the tapered surface 21c of the socket portion 21 and is deformed.

Here, the first end 43 of the first rubber member 4 protrudes further in the tube axis direction X than the first end 53 of the second rubber member 5, and a portion 43a of the protruding section is disposed between the inner end 21a and the outer surface 100a of the tube. The first rubber member 4 is made of a harder rubber material than the second rubber member 5. Therefore, the portion 43a of the protruding section together with the tapered surface 21c constitutes a compression structure of the first end 53 of the second rubber member 5. As a result, the protruding strip 58a is compressed and deformed by the tapered surface 21c, so that the second rubber member 5 as a whole moves along the tapered surface 21c toward the inner end 21a and contracts in diameter. When further pressed, the second rubber member 5 rolls along the tapered surface 21c and further contracts, and the outer periphery of the tapered surface 59 comes into close contact with the tapered surface 21c to improve watertightness.

In addition, the first rubber member 4 is pressed against the outer surface 100a of the pipe due to the compression deformation of the second rubber member 5. Here, since the first rubber member 4 is a harder rubber material than the second rubber member 5, it is not easy to deform in the axial direction of the pipe, but it is easy to be compressed and reduce the diameter in the diameter direction. The central part in the width direction of the body 40 where the recess 42a is formed mainly undergoes compression deformation (as shown in the fourth figure). In addition, the protrusion 41a is compressed and deformed, and the inner peripheral surface 41 is closely attached to the outer surface 100a of the pipe. Since the inner peripheral surface 41 is provided with the protrusion 41a, the first rubber member 4 can be easily deformed and moved in the axial direction of the tube by the compression deformation of the protrusion 41a. Therefore, as the second rubber member 5 rolls and contracts, the first rubber member 4 also moves and contracts in the axial direction of the tube, so the watertightness of the outer surface 100a of the tube can also be ensured.

<Second embodiment>

Hereinafter, the second embodiment of the present invention will be described with reference to Figures 5 to 7. In addition, in the following embodiments, the same components as those in the above-mentioned embodiments are marked with the same symbols.

In the above-mentioned first embodiment, the pushing device 7 is a pressure ring 8, while in the second embodiment, the pushing device 7 is a lock nut 9 tightened on the outer peripheral portion 21b of the socket portion 21.

The lock nut 9 generally comprises: an inner end portion 91 protruding toward the pipe axis side and a pressing surface 92 for pressing the second rubber member 5 (as shown in the fifth to seventh figures). In addition, an inner thread 93 engaging with an outer thread 25 of a socket portion 21 described later is formed on the inner peripheral surface 90a of the lock nut 9, and an annular groove portion 94 engaging with a body portion 11a of a clamping member 11 described later is provided on the outer peripheral surface 90b. In this embodiment, the inner end portion 91 is located inside the groove portion 94. Moreover, the locking nut 9 is used together with a stop ring 10 installed on the outer surface 100a of the pipe and tightened by a tightening device 13, and a snap-fit member 11 installed on the groove portion 94 of the locking nut 9 in a detachable manner and maintained connected with the stop ring 10.

In the second embodiment, for example, the rubber hardness of the second rubber member 5 is 50° to 60° (55° ± 5°), and the rubber hardness of the first rubber member 4 is 3° to 20° greater than the rubber hardness of the second rubber member 5. In addition, although the first rubber member 4, the second rubber member 5 and the stacking holding device 6 are different from the first embodiment in size, the basic structure is the same, so no detailed description is given here. In addition, in this embodiment, the rubber hardness of the first rubber member 4 is, for example, 58° to 75°.

In the second embodiment, the connector body 2 includes an external thread 25 engraved on its outer peripheral portion 21b (as shown in FIGS. 5 to 7). The external thread 25 is screwed with an internal thread 93 engraved on the inner peripheral surface 90a of the lock nut 9. By tightening the lock nut 9 on the socket portion 21, the first rubber member 4 and the second rubber member 5 are compressed and deformed.

As shown in FIGS. 5 to 7, the stop ring 10 has a main body 10a that is roughly C-shaped and a pair of protrusions 10b, 10b that protrude outward from both ends of the main body 10a. The protrusion 10b is provided with a through hole 10c through which the bolt 13a of the fastening device 13 passes. In this embodiment, a pair of supporting parts 10d, 10d are provided on the outer peripheral surface of the main body 10a, and the pair of supporting parts 10d, 10d accommodate the hook part 11c of the engaging member 11 described later. In addition, an annular tooth part 10e that suppresses the sliding of the pipe 100 is formed on the inner surface of the main body 10a.

As shown in FIGS. 5 to 7 , the engaging member 11 has a slightly horseshoe-shaped main body 11a, a pair of arm portions 11b, 11b extending from both ends of the main body 11a along the tube axis direction X, and a hook portion 11c protruding toward the center at the ends of the pair of arm portions 11b, 11b.

Here, the construction steps of the locking nut pipe fitting joint are explained with reference to the sixth and seventh figures. First, the second rubber member 5 is stacked on the outer peripheral surface 42 of the first rubber member 4. This is the same as the above-mentioned embodiment, so that even when compressed and deformed, the concave and convex fittings are difficult to disengage and the stacked state can be maintained. As shown in the sixth figure, the stop ring 10 is installed on the outer surface 100a of the pipe fitting, so that the first rubber member 4 and the second rubber member 5 in the stacked state are interposed between the socket part 21, and the locking nut 9 is screwed with the joint body 2. Then, the main body 10a of the engaging member 11 is engaged with the groove 94 of the locking nut 9, and the hook portion 11c is engaged with the supporting portion 10d of the stop ring 10.

Then, tighten the lock nut 9 (as shown in FIG. 7). In the second embodiment, since a portion 44a of the protruding section is disposed between the inner end portion 91 and the outer surface 100a of the pipe fitting, the thrust force generated by the lock nut 9 acts on the second rubber member 5 through the thrust surface 92. Then, under the action of the thrust force, the outer peripheral portion of the second rubber member 5 abuts against the tapered surface 21c of the socket portion 21 and is deformed.

In the second embodiment, a portion 43a of the protruding section is disposed between the inner end portion 21a and the outer surface 100a of the pipe, and the first rubber member 4 is made of a harder rubber material than the second rubber member 5. Therefore, in the second embodiment, the protruding strip 58a is also compressed and deformed by the tapered surface 21c, and the second rubber member 5 as a whole moves along the tapered surface 21c toward the inner end portion 21a and contracts in diameter. When further pressed, the second rubber member 5 rolls along the tapered surface 21c and further contracts in diameter, and the outer periphery of the tapered surface 59 is closely attached to the tapered surface 21c to improve watertightness.

In addition, since the structure of the first rubber member 4 is the same as that of the above-mentioned embodiment, as the second rubber member 5 rolls and contracts, the first rubber member 4 also moves and contracts in the axial direction of the tube. Therefore, in the second embodiment, the watertightness of the outer surface 100a of the tube can also be ensured.

Finally, the possibility of other embodiments of the present invention will be described. In the first embodiment described above, in the stacked state of the first rubber member 4 and the second rubber member 5, the second end 44 of the first rubber member 4 is made to protrude further in the tube axis direction X than the second end 54 of the second rubber member 5, and a portion 44a of the protruding section is arranged between the inner end 81 of the pressure ring 8 (pressing device 7) and the outer peripheral surface 100a of the tube 100. However, as shown in FIG. 8, the second end 44 of the first rubber member 4 may be arranged at the same position as the second end 54 of the second rubber member 5 and opposite to the pressing surface 82 of the pressure ring 8. This is also the same in the second embodiment, and the second ends 44 and 54 may be arranged at the same position and face the pressing surface 92 of the lock nut 9 at the same time. In the present invention, as long as the compression structure of the second rubber member 5 can be formed in the socket portion 21, at least the first end 43 of the first rubber member 4 protrudes further in the tube axis direction X than the first end 53 of the second rubber member 5, and a part 43a of the protruding section is arranged between the inner end 21a of the socket portion 21 and the outer peripheral surface 100a of the pipe 100. In addition, in the case of Figure 8, the rubber hardness of the first rubber member 4 is, for example, 70° to 85°. Different from the fourth figure of the first embodiment, in the eighth figure, the deformation (bulging) of the eleventh rubber member 4 in the tube axis direction is suppressed by the pressing surface 82 of the pressure ring 8, so that the watertightness can be maintained as long as it is within the above numerical range.

In the first and second embodiments, a plurality of annular protrusions 41a are formed on the inner circumferential surface 41 of the first rubber member 4 at appropriate intervals along the tube axial direction X. However, the protrusions 41a may be omitted, and a lubricant may be applied to the inner circumferential surface 41. When the protrusions 41a are omitted, the inner circumferential surface 41 of the first rubber member 4 is closely attached to the outer circumferential surface 100a of the tube 100 by the compression deformation of the second rubber member 5. Therefore, the first rubber member 4 cannot deform or move in the tube axial direction following the compression deformation of the second rubber member 5, and watertightness cannot be ensured. By applying the lubricant, it becomes easy for the first rubber member 4 to deform and move in the tube axis direction X, and water tightness can be ensured. In this way, it is sufficient to reduce the resistance of the contact surface between the first rubber member 4 and the tube 100, and the first rubber member 4 can also be formed of a rubber material with high lubricity.

In the first and second embodiments described above, the stacking holding means 6 is composed of the recessed portion 42a of the outer peripheral surface 42 of the first rubber member 4 and the convex portion 51a of the inner peripheral surface 51 of the second rubber member 5. However, the stacking holding means 6 is not limited thereto, and for example, a convex portion may be formed on the first rubber member 4 and a recessed portion may be formed on the second rubber member 5, and these may serve as the stacking holding means 6. The size, shape, number, etc. of the recessed portion 42a and the convex portion 51a may be appropriately set so as to maintain the stacked state.

In addition, in the above-mentioned first and second embodiments, the protrusion 41a of the inner circumferential surface 41 of the first rubber component 4 and the recess 42a of the outer circumferential surface 42 are located on the same straight line along the tube diameter direction, and the shape of the protrusion 41a is also similar to the convex portion 51a. However, the size, shape and number of the protrusion 41a can also be appropriately set. For example, the height or width of the protrusion 41a is smaller than the recess 42a or the convex portion 51a, and the number of the protrusion 41a is also smaller than the recess 42a. As a result, it is easy to remove from the mold when the rubber of the first rubber component 4 is molded. In addition, the protrusion 41a can be formed not only in the central part of the width direction of the main body 40, but also in the first end 43 on the side of the socket portion 21 to the second end 44 on the side of the pushing device 7 (the entire surface of the inner circumferential surface 41).

In the above-mentioned first embodiment, the pushing device 7 is composed of a lock nut 9, a stop ring 10 and a snap-fit member 11. The stop ring 10 and the snap-fit member 11 are not limited to the stop ring 10 and the snap-fit member 11 of the above-mentioned second embodiment, as long as they are used as a lock nut pipe fitting joint.

1, 1', 1'': Water stop structure 2, 2': Joint body 3, 3', 3''': Rubber gasket 4: First rubber component 5: Second rubber component 6: Stacking retaining device 7, 7', 7'': Pushing device 8, 8', 8'': Pressure ring 9: Locking nut 10: Stop ring 10a: Body 10b: Protrusion 10c: Through hole 10d: Support part 10e: Tooth part 11: Snap part 11a: Body 11b: Arm part 11c: Hook part 12a: T-head bolt 12b: Nut 13: Fastening device 13a: Bolt 13b: Nut 21, 21': Socket 21a, 21'a: Inner end 21b: Outer peripheral 21c: Tapered surface 22: Flange 22a: Corner 23: Cavity 24: Through hole 25: External thread 31', 31'', 31''': Inner peripheral surface 40: Body 41: Inner peripheral surface 41a: Protrusion 42: Outer peripheral surface 42a: Recess 43: First end (end on the socket side) 43a: Part of the protruding section (front end) 44: Second end (end on the push device side) 44a: Part of the protruding section 51: Inner peripheral surface 51a: convex part 52: outer peripheral surface 53: first end (end on the socket side) 54: second end (side of the push device) 55: positioning rib 56: spacer 58a: protrusion 58b: concave strip 59: tapered surface (outer peripheral part of the first end) 80: main body 81, 81', 81'': inner end 82, 82', 82'': push surface 83: flange 84: through hole 90a: inner peripheral surface 90b: outer peripheral surface 91: inner end 92: push surface 93: inner thread 94: groove part 100, 100', 100'': pipe fitting 100a: Outer circumference (outer surface of the pipe) X: Pipe axis direction Y: Pipe diameter direction

[Figure 1] A perspective view of the water-stopping structure of the pipe joint according to the first embodiment of the present invention. [Figure 2] A perspective view of the first rubber member. [Figure 3] A cross-sectional view of the state in which the pressure ring is assembled on the socket portion to which the first and second rubber members are mounted. [Figure 4] A cross-sectional view of the state in which the pressure ring is tightened with a bolt nut. [Figure 5] A perspective view of the water-stopping structure of the pipe joint according to the second embodiment of the present invention. [Figure 6] A cross-sectional view of the state in which the locking nut is screwed. [Figure 7] A cross-sectional view of the state in which the locking nut is tightened. [Figure 8] A corresponding view of Figure 3 of the modification of the rubber gasket. [Figure 9 shows a cross-sectional view of a known water-stopping structure for a pipe joint. [Figure 10] shows a cross-sectional view of a known water-stopping structure for a pipe joint.

1: Water-stop structure

2: Connector body

3: Rubber gasket

4: The first rubber component

5: Second rubber component

6: Layer holding device

7: Pushing device

8: Pressure ring

12b: Nut

21: Socket part

21a: Inner end

21b: Periphery

21c: Conical surface

22: flange

23: Cavity

24:Through hole

41: Inner circumference

41a: protrusion

42: Outer surface

42a: concave part

43: 1st end (end on the socket side)

43a: Part of the protruding segment (front end)

44: Second end (end on the pushing device side)

44a: Part of the protruding segment (front end)

51: Inner circumference

51a:convex part

52: Outer surface

53: 1st end (end on the socket side)

54: Second end (side of the pushing device)

55: Positioning ribs

56: spacer

58a: protrusion

58b: concave stripes

59: Conical surface (outer periphery of the first end)

81: Inner end

82: Pushing surface

83: flange

84:Through hole

100: Pipe fittings

100a: Outer surface (outer surface of pipe fitting)

X: tube axis direction

Y: Pipe diameter direction

Claims (10)

A water-stopping structure for a pipe joint, comprising: a joint body having a socket portion for inserting a pipe; an annular rubber gasket mounted on the outer circumference of the pipe; and a pushing device connected to the joint body and pushing the rubber gasket toward the socket portion, wherein the rubber gasket comprises: an annular first rubber component whose inner circumference is connected to the outer circumference of the pipe; an annular second rubber component stacked on the outer circumference of the first rubber component along the pipe diameter direction of the pipe; and a stacking holding device for holding the stacking state of the first rubber component and the second rubber component; The first rubber component is made of a harder rubber material than the second rubber component. When the first rubber component and the second rubber component are stacked, the end of the first rubber component on the side of the socket portion protrudes further toward the axial direction of the pipe fitting than the end of the second rubber component on the side of the socket portion. A portion of the protruding section is arranged between the inner end of the socket portion and the outer peripheral surface of the pipe fitting. The second rubber component faces the tapered surface of the socket portion. A water-stopping structure for a pipe joint as described in claim 1, wherein, in the stacked state, the end of the first rubber member on the pushing device side protrudes further toward the tube axis than the end of the second rubber member on the pushing device side, a portion of the protruding section is arranged between the inner end of the pushing device and the outer peripheral surface of the pipe, and the second rubber member is opposite to the pushing surface of the pushing device. A water-stopping structure for a pipe joint as described in claim 1 or 2, wherein annular protrusions are formed on the inner peripheral surface of the first rubber component at appropriate intervals along the axial direction of the pipe. A water-stopping structure for a pipe joint as described in claim 1 or 2, wherein a lubricant is applied to the inner peripheral surface of the first rubber component. A water-stopping structure for a pipe joint as described in claim 1 or 2, wherein the pushing device is a pressure ring installed on the outer circumference of the pipe and fastened to the joint body. A water-stopping structure for a pipe joint as described in claim 5, wherein the rubber hardness of the second rubber component is 65° to 75°, and the rubber hardness of the first rubber component is 3° to 15° greater than the rubber hardness of the second rubber component. A water-stopping structure for a pipe joint as described in claim 1 or 2, wherein the pushing device is a locking nut (union nut) that is screwed and tightened on the outer peripheral surface of the socket part. A water-stopping structure for a pipe joint as described in claim 7, wherein the rubber hardness of the second rubber component is 50° to 60°, and the rubber hardness of the first rubber component is 3° to 20° greater than the rubber hardness of the second rubber component. A water-stopping structure for a pipe joint as described in claim 1 or 2, wherein the stacked retaining device includes: a plurality of recesses formed at appropriate intervals on the outer circumferential surface of the first rubber component along the axial direction of the tube; and a plurality of protrusions formed at appropriate intervals on the inner circumferential surface of the second rubber component along the axial direction of the tube. A water-stopping structure for a pipe joint as described in claim 1 or 2, wherein the outer periphery of the end portion of the socket portion of the second rubber component presents a tapered shape opposite to the tapered surface, and a plurality of annular protrusions and annular recesses are alternately arranged on the outer periphery along the axial direction of the tube.