JPH0225034Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention relates to an expansion joint that can adjust the length of a pipe, and relates to a sliding structure between an elastic packing and a cap nut.

(Prior art) In a conventional expansion joint, elastic packing is fitted around the outer periphery of a connecting pipe, the connecting pipe is fitted into a cap nut, and the cap nut is screwed onto the joint body to tighten the elastic packing. , the outer circumferential surface of the elastic packing made of an elastic material such as rubber and the inner circumferential surface of the cap nut will rub against each other, deforming the elastic packing, making it difficult to perform the tightening operation smoothly, and causing the elastic packing to be tightened while being deformed. In this case, there was a problem of poor sealing. As an improvement on this point, an expansion joint is known in which a partially opened ring body made of synthetic resin is fitted around the outer periphery of the elastic packing to improve the slippage of the inner peripheral surface of the cap nut.

(Problems to be solved by the invention) However, in the structure in which synthetic resin rings are fitted together as described above, the restoring force of the elastic packing made of elastic bodies is inhibited by the fitting of the rings with low elasticity. There was a problem in that when the cap nut was loosened, the elastic packing did not restore the connecting pipe to its tightened state, making it impossible to adjust the pipe length by moving the elastic packing around the outer periphery of the connecting pipe. Another problem is that when a cap nut is strongly tightened due to the presence of a slippery ring, the elastic packing slides on the inner periphery of the ring and protrudes outward from the nut, impeding the tightening of the nut.

In view of the above-mentioned problems, the purpose of the present invention is to improve the sliding between the elastic ring and the cap nut using the sliding ring, and to ensure that the elastic ring uses its elastic restoring force when the cap nut is loosened. To provide an expansion joint which can be restored to its original state and further prevent slippage in the axial direction between the elastic ring and the sliding ring so that the elastic ring does not protrude from the tip of the nut, and which prevents the connecting pipe from coming off. be.

[Structure of the idea]

(Means for Solving the Problems) The expansion joint of the present invention includes a joint body into which a connecting pipe is fitted, a base end that is fitted to the outer periphery of the connecting pipe and is in contact with an end face of the joint body, and an elastic ring body having an outer circumference formed with a tapered surface tapered toward a tip, and a joint body that is fitted into the connecting pipe and has a tapered surface parallel to the tapered surface of the elastic ring body on its inner surface; a cap nut that is screwed onto the cap nut, and a slot that is inserted between the tapered surface of the elastic ring and the tapered surface of the cap nut and has a diameter reduced toward the tip and is cut from the tip in the axial direction to near the proximal end. In an expansion joint consisting of a synthetic resin sliding ring body having a plurality of grooves formed at equal intervals, an annular step formed on the outer periphery of the base end of the elastic ring body is engaged with the base end of the sliding ring body. The distal end of the elastic annular body is engaged with an annular protrusion formed on the inner periphery of the distal end of the sliding annular body, and the inner circumferential edge of the annular protrusion is formed into an edge shape that bites into the outer circumference of the connecting pipe. It is.

(Function) In the expansion joint of the present invention, an elastic ring body with a sliding ring fitted onto the tapered surface of the outer circumference is fitted onto the outer periphery of a connecting pipe inserted into a cap nut, the connecting pipe is inserted into the joint body, and the The joint body is connected to the connecting pipe by screwing the nut onto the joint body. At this time, frictional resistance is reduced by the sliding ring interposed between the tapered surface of the elastic ring and the tapered surface of the cap nut. Then, as the cap nut spirals, the elastic ring is moved in the direction of the smaller diameter of the cap nut via the sliding ring, and is pressed toward the axial center and strongly crimped onto the connecting pipe. At the same time, the sliding ring body is also reduced in diameter by the slotted groove, and the edge-shaped inner circumferential edge of the annular projection at the tip bites into the outer periphery of the connecting pipe at the tip of the elastic tube body to prevent it from coming off.

Also, if internal water pressure is applied to the connecting pipe when water is flowing, the connecting pipe will be affected in the direction of escaping from the joint body.
The frictional force between the outer periphery of the connecting pipe and the inner surface of the elastic ring is large, and the frictional force between the sliding ring and the tapered surface of the cap nut is much smaller, so the elastic ring is attached to the cap nut along with the connecting pipe. Since the tapered surface of the elastic ring is moved in the direction of the smaller diameter, the elastic ring further reduces in diameter and is more strongly crimped onto the connecting pipe to prevent water leakage.

Further, when the cap nut is loosened, the elastic ring expands in diameter due to its own elastic restoring force, and becomes movable in the axial direction around the outer circumference of the connecting pipe. In this case, the sliding ring fitted on the outer periphery of the elastic ring is spread out evenly by the slotted grooves at equal intervals at multiple locations.
The elastic ring body is also uniformly expanded in diameter. Furthermore, even when the cap nut is compressed, the diameter of the sliding ring body is reduced evenly by the equally spaced slotted grooves, so the diameter of the elastic ring body on the inner circumference side is also reduced evenly over the entire circumference, and only partially. There is no chance that the material will protrude from the groove.

Also, when the cap nut is tightened strongly, the elastic ring tries to slide axially outward on the inner circumference of the sliding ring. Furthermore, the tip of the elastic ring engages with the annular protrusion at the tip of the sliding ring, so when the cap nut is strongly tightened, the sliding ring causes the elastic ring to move in the axial direction. A force pushing inward acts on the
The elastic ring does not slide outward on the inner periphery of the sliding ring, and the tip of the elastic ring does not protrude from the cap nut.

(Example) An example of the present invention will be described with reference to the accompanying drawings.

Reference numeral 1 denotes a joint body made of vinyl chloride resin, with a threaded portion 2 formed on the outer periphery near the opening, and an opening end surface 3.
is formed into a tapered surface that slopes inward.

4 is a connecting pipe made of polyethylene resin or lead,
It is inserted into the joint body 1.

Reference numeral 5 denotes an elastic ring body made of rubber, which is fitted onto the outer periphery of the connecting pipe 4, and whose base end is connected to the open end surface 3 of the joint body 1.
A tapered surface 6 is formed on the outer circumferential surface, and the tapered surface 6 becomes thinner toward the distal end, and a large-diameter annular stepped portion 7 is formed at the proximal end.

8 is a bag nut made of hard vinyl chloride resin or polyacetal resin. The connecting tube 4 is fitted into the small diameter opening 9 at the distal end of the cap nut 8, and the large diameter opening 10 at the proximal end.
The inner circumferential thread part 11 is screwed into the thread part 2 of the joint body 1, and a tapered surface parallel to the tapered surface 6 of the elastic ring body 5 is provided on the inner circumference between the small diameter port 9 and the large diameter port 10. 14 is formed.

Reference numeral 12 denotes a sliding ring body, which is a thin plate-like ring body made of a synthetic resin such as polyacetal resin, polyamide resin, polypropylene resin, polyethylene resin, etc. that has a slippery relationship with the material of the cap nut 8, and is a thin plate-like ring body that fits between the tapered surface 6 of the elastic ring body 5 and the cap nut 8. It is interposed between the tapered surfaces 14 of 8 and has a diameter tapered toward the front. Furthermore, slotted grooves 13 cut in the axial direction from the distal end to near the proximal end are formed in the sliding ring body 12 at four equal intervals, and the base end of the sliding ring body 12 is located at the annular stepped portion of the elastic ring body 5. An annular protrusion 15 is formed on the inner periphery of the tip of the elastic annular member 7, and the inner circumferential edge 16 of the annular protrusion 15 engages with the tip of the elastic ring 5. It is shaped like an edge.

Next, the operation of the above embodiment will be explained.

The elastic ring body 5 with the sliding ring body 12 fitted on the tapered surface 6 of the outer surface is fitted onto the outer periphery of the connecting pipe 4 fitted into the cap nut 8, and the connecting pipe 4 is inserted into the joint body 1.
Screw the cap nut 8 onto the joint body 1. in this case,
A sliding ring 12 is interposed on the tapered surface 6 of the elastic ring 5, and when the cap nut 8 rotates, the frictional resistance between the inner tapered surface 14 and the elastic ring 5 is small.
The cap nut 8 is rotated smoothly. Also bag nut 8
When the cap nut 8 moves in the axial direction due to the rotation of the cap nut 8 and presses the elastic ring body 5 in the axial direction, the sliding ring body 12 slides on the tapered surface 14 of the cap nut 8, and the joint body 1
The elastic ring body 5 pressed by the opening end face 3 of the cap nut 8 is smoothly moved in the direction of the smaller diameter of the cap nut 8, and the elastic ring body 5 is pressed toward the axial center and is strongly crimped onto the connecting pipe 4. At the same time, the diameter of the sliding ring 12 is reduced by the slotted groove 13, and the edge-shaped inner peripheral edge 16 of the annular tip 15 bites into the outer periphery of the connecting tube 4 in the opposite direction to its exit direction to prevent it from coming off. Furthermore, when internal water pressure is applied to the connecting pipe 4 during water flow, the connecting pipe 4 is moved in the direction of being pulled out from the joint body 1, but the frictional force between the outer surface of the connecting pipe 4 and the inner surface of the elastic ring 5 is large. , compared to this, the frictional force between the sliding ring 12 on the outer surface of the elastic ring 5 and the tapered surface 14 of the cap nut 8 is much smaller, so the elastic ring 5, together with the connecting pipe 4, slides against the taper of the cap nut 8. Since the surface 14 is moved in the direction of the smaller diameter, the elastic ring 5 further reduces in diameter and is more strongly crimped onto the connecting pipe 4 to prevent water leakage.

Further, when the cap nut 8 is loosened, the diameter of the elastic ring 5 is expanded by its own elastic restoring force, and the elastic ring 5 becomes movable in the axial direction around the outer circumference of the connecting pipe 4. In this case, since the outer surface of the elastic ring 5 is fitted with a sliding ring 12 having a plurality of slotted grooves 13 deeper in the axial direction than the tip, the diameter of the elastic ring 5 can be expanded or contracted freely. , the sliding ring 12 does not interfere with the elastic recovery of the elastic ring. In addition, since the sliding ring body 12 can be expanded and contracted evenly over the entire circumference by the plurality of equally spaced slotted grooves 13, the elastic ring body 5 inscribed therein can be expanded and contracted. is also done evenly with no distortion.

Also, when the cap nut 8 is tightened strongly, the elastic ring 5
tries to slide outward on the inner periphery of the sliding ring 12, but the base end of the sliding ring 12 engages with the annular step 7 of the elastic ring 5, and the sliding ring 12 slides outward on the annular step 7. is pushed inward, and the tip of the elastic ring 5 engages with the annular protrusion 15 at the tip of the sliding ring 12 and is pushed inward, so the inner periphery of the sliding ring 12 of the elastic ring 5 It does not slip outward, and the tip of the elastic ring 5 does not protrude from the cap nut 8.

[Effect of idea]

According to the present invention, when the cap nut is screwed on, the tapered surface of the cap nut does not come into contact with the elastic ring body that has high friction, but instead comes into contact with the sliding ring provided circumscribing the elastic ring body and rotates smoothly. This allows the screwing operation of the cap nut to be performed smoothly. Furthermore, the sliding ring has multiple slotted grooves cut in the axial direction from the tip to near the proximal end, so the diameter is reduced by tightening the cap nut, and the elastic ring is firmly crimped onto the connecting pipe. This prevents water from leaking, and when the cap nut is loosened, the plurality of deep slotted grooves will not expand and interfere with the restoring force of the elastic ring. Furthermore, the sliding ring body can be expanded by multiple slotted grooves at equal intervals.
Since the contraction is performed evenly, the expansion and contraction of the elastic ring inscribed therein is also performed uniformly without distortion.

In addition, when the cap nut is strongly tightened, the annular stepped portion of the elastic ring is pushed inward in the axial direction of the cap nut by the base of the sliding ring, and the tip of the elastic ring also slides. Since the tip of the ring body is pushed inward in the axial direction of the cap nut, the elastic ring body does not slide axially toward the outside of the cap nut, and the tip of the elastic ring body protrudes from the cap nut. There's nothing to do. Furthermore, since the annular protrusion on the inner periphery of the tip of the sliding ring has an edge-shaped inner periphery, when the connecting pipe moves in the escape direction together with the elastic ring, the sliding ring moves along the tapered surface of the cap nut. Since the diameter is reduced by sliding toward the small diameter side, the edge-shaped inner peripheral edge strongly bites into the connecting pipe and prevents it from coming off.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of a joint showing an embodiment of the present invention, FIG. 2 is an enlarged front view of the same sliding ring, and FIG. 3 is a partially cutaway side view of the same. DESCRIPTION OF SYMBOLS 1... Joint body, 4... Connection pipe, 5... Elastic ring body, 6, 14... Taper surface, 7... Annular step part,
8... Cap nut, 12... Sliding ring body, 13... Slotted groove, 15... Annular projection, 16... Inner peripheral edge.

Claims (1)

[Claims for Utility Model Registration] A joint body into which a connecting pipe is inserted, and a joint body that is fitted onto the outer periphery of the connecting pipe and whose base end abuts the end face of the joint body, and whose outer periphery is tapered toward the tip. an elastic ring formed with a tapered surface having a small diameter; a cap nut that is fitted into the connecting pipe and has a tapered surface parallel to the tapered surface of the elastic ring on its inner surface and is screwed onto the joint body; A plurality of slotted grooves are formed at equal intervals between the tapered surface of the elastic ring and the tapered surface of the cap nut, the diameter of which decreases toward the tip, and is cut from the tip to the proximal end in the axial direction. In an expansion joint comprising a synthetic resin sliding ring body, an annular step formed on the outer periphery of the base end of the elastic ring body is engaged with the base end of the sliding ring body, and the inside of the distal end of the sliding ring body is An expansion joint characterized in that the tip of the elastic ring body is engaged with an annular projection formed on the periphery, and the inner peripheral edge of the annular projection is formed into an edge shape that bites into the outer periphery of the connecting pipe.