JP3256654B2 - Joint structure for flexible tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure for connecting a flexible tube to a flexible tube.

[0002]

2. Description of the Related Art Conventionally, a bamboo shoot-shaped joint has been inserted into a flexible tube, and the outer peripheral surface of the flexible tube at the insertion site has been firmly tightened with a band, and connected to another pipe so as to prevent liquid leakage and air inflow. I was

[0003]

However, it is difficult and troublesome to insert a bamboo shoot type joint into a flexible tube (particularly a thick flexible tube having a helical wire for reinforcement). In addition, a protruding stepped portion is formed in the flow path in order to insert the joint into the tube, and when a fluid to be fed containing granular solids is caused to flow into the tube, the solids hit the stepped portion and the wound is damaged. The solids were caught on the stepped portion and clogged.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a joint structure for a flexible tube that allows quick and easy connection of the flexible tube and does not cause clogging of the fluid to be fed.

[0005]

In order to achieve the above-mentioned object, a joint structure for a flexible tube according to the present invention comprises a flexible tube which is fitted to an end of an outer peripheral surface of a flexible tube to be connected. An elastic thin short cylindrical member, a joint body having a male thread portion at an end of an outer peripheral surface and a tapered portion at an opening edge of a hole, a cap nut member screwed into the male thread portion of the joint body, and the bag; A ring-shaped elastic packing interposed between the nut member and the tapered portion of the joint main body, and the bag nut member is wound around the end of the elastic thin-walled short cylindrical material via the packing into the tapered portion. It is configured to be pressed.

In addition, a plurality of elastic thin short cylindrical members are stacked and externally fitted to the flexible tube. In addition, a plurality of elastic thin-walled short cylindrical members having various thickness dimensions are arranged and used alternatively.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments.

FIG. 1 shows an exploded state of a joint structure for a flexible tube according to an embodiment of the present invention. The joint structure for a flexible tube includes a soft elastic thin short cylindrical member 3 fitted externally to an end 7 on the connection side of an outer peripheral surface 2 of a flexible tube 1 to be connected, and an end 8 of an outer peripheral surface 4a. A joint body 4 having an external thread portion 9, a cap nut member 5 (an outer peripheral surface having a polygonal shape) screwed to the external thread portion 9 of the joint body 4, and a ring interposed between the cap nut member 5 and the joint body 4 Elastic packing 6,
It has.

The flexible tube 1 includes a soft tube main body 10.
Has a hard reinforcing wire 11 spirally wound at a predetermined pitch inside the tube. For example, the tube main body 10 and the wire 11 are made of soft and hard polyvinyl chloride (PV), respectively.
It was molded in C). Further, the outer peripheral surface 2 of the flexible tube 1 has an uneven shape (or bellows shape) due to the wire 11 and the inner surface 12 is smooth.

The elastic thin short cylindrical member 3 serves as a sealing material and adjusts the outer diameter of the flexible tube 1. For example, the elastic thin short cylindrical member 3 is made of natural rubber or synthetic rubber so as to be stretchable and stretchable. I have. Assuming that the thickness of the elastic thin short cylindrical member 3 before being fitted to the flexible tube 1 is t, 0.3 mm ≦ t ≦
It is set to 3.0mm. This will be described later in detail.

The joint body 4 is made of stainless steel or the like.
An annular projection 16 for stopping the tube is provided on the inner surface 15 of the inner surface 15 so as to protrude in the circumferential direction. In addition, the cap nut member 5
Is made of stainless steel or the like, and the inner surface 21a of the inner flange portion 21 provided at the edge of the peripheral wall 18 is orthogonal to the axis.

The elastic packing 6 is formed in a ring shape from an elastic plastic or hard rubber having a relatively high hardness. The cross-sectional shape is a mountain shape, a trapezoidal shape, or the like, and has folded guide surfaces 19, 19 inclined on the outer peripheral surface. Note that a thin ring 20 is provided between the cap nut member 5 and the elastic packing 6 to prevent the elastic packing 6 from being twisted when the cap nut member 5 is screwed.

Thus, as shown in the connection state of FIG.
The joint structure for a flexible tube according to the present invention includes a cap nut member 5.
Is the end 23 of the elastic thin short cylindrical member 3 via the elastic packing 6.
Is pressed into the tapered portion 14 of the joint main body 4 in a roll-up manner.

The connection procedure will be described in detail. As shown in FIG.
And the cap nut member 5, the ring 20, and the elastic packing 6 are passed through the end 7. The end surface 24 of the end portion 7 of the flexible tube 1 is connected to the annular convex portion 16 inside the joint body 4.
The flexible tube 1 is inserted until it comes into contact with, and the cap nut member 5 is screwed into the joint body 4. Then, the elastic packing 6 pressed against the inner surface 21 a of the inner flange portion 21 of the cap nut member 5 via the ring 20 abuts the inclined return guide surface 19 on the end 23 of the elastic thin short cylindrical member 3.

Then, as the cap nut member 5 advances, as shown in FIG. 2B, the folding guide surface 19 of the elastic packing 6 scoops up the end 23 of the elastic thin-walled short cylindrical member 3 and folds it. As shown in FIG. 3C, the end portion 23 is pressed into the tapered portion 14 of the joint main body 4 in a wrapped manner.

At this time, the end 7 of the flexible tube 1 externally fitted with the elastic thin-walled short cylindrical member 3 is stopped by the tube fixing annular convex portion 16 of the joint main body 4 so as not to go any further. Because of this, the folding guide surface 19 can reliably press the end portion 23 in a roll-up manner while scooping up and folding it.

As a result, the elastic thin short cylindrical member 3 compressed in a wrapped state closely adheres to the tapered portion 14, the folded guide surface 19, and the outer peripheral surface 2 of the flexible tube 1 without any gap, and serves as a seal. Liquid leakage from inside the tube 1 and inflow of air into the tube 1 from outside are prevented. In addition, since the outer peripheral surface 2 of the tube 1 is elastically covered with the elastic thin short cylindrical member 3, the elastic thin short cylindrical member 3 in which the irregularities of the outer peripheral surface 2 are alleviated partially adheres to the inner surface 15 of the joint body 4. The wobble of the tube 1 end 7 is prevented.

When flowing a fluid through the flexible tube 1,
In order to prevent the fluid from being clogged, the inner diameter of the annular projection 16 is made larger than the inner diameter of the flexible tube 1.

FIG. 3 shows a case where two flexible tubes 1 and 1 of the same size are connected. This joint body 4
Have tapered portions 14, 14 at the opening edges of the holes 13 on both sides, and male screw portions 9, 9 at both ends 8, 8 of the outer peripheral surface 4a.
And an annular projection 16 at the center of the inner surface 15.

In this case, two cap nut members 5 and 5 are screwed into the external thread portions 9 and 9 of the joint body 4, and two elastic packings 6 and two rings 20 are provided. The inner flange portion 21 of the cap nut member 5 is provided obliquely from the peripheral wall 18, and when the cap nut member 5 is tightened to the joint body 4, the inner surface 21 a of the inner collar portion 21 (via the ring 20). A pressing force is applied perpendicularly (in the direction of the arrow) to the outer peripheral slope 25 (the folded guide surface 19) of the elastic packing 6. Thereby, the elastic thin short cylindrical member 3 can be more strongly pressed against the tapered portion 14 of the joint body 4.

FIG. 4 shows that a plurality of (two in the illustrated example) elastic thin short cylindrical members 3 are stacked on the end portion 7 of the flexible tube 1 in order to cope with variations in the outer diameter of the flexible tube 1. This shows a case where the external fitting is performed. Further, as shown in FIG. 5, one elastic thin short cylindrical member 3 may be folded plural times (in the illustrated example, folded three times) and fitted to the end 7 of the flexible tube 1.

Returning to FIG. 1, a plurality of elastic thin short tube members 3 having different thicknesses t are arranged in a plurality, and the alternative is thin, that is, the elastic thin short tube member 3 having an appropriate thickness is selected. ─
It is preferable to use it for ──. The thickness t is set to 0.3 mm ≦ t ≦ 3.0 mm (as described above). If the thickness is less than 0.3 mm, the thickness is too thin, and there is a risk of breakage during use. If the thickness exceeds 3.0 mm, the thickness is too large. In this case, it becomes difficult to press the end 23 of the elastic thin-walled short cylindrical member 3 into the tapered portion 14 of the joint body 4 in a roll-like manner, which causes a problem in sealing performance.

[0023] Next Figure 6, the flexible tube 1 of the inner diameter D _1, shows the case of connecting the metal pipe 29 having a substantially equal inner diameter d ₁ to the inner diameter D _1. Specifically, the metal pipe 29 (male screw 26) is connected to the flange 30
And is connected to the cylindrical joint member 27 (female screw 28) having a seal with a seal tape or the like. Further, the flexible tube 1 has its end 7 fitted with the elastic thin short cylindrical member 3 and connected to the joint body 4 (in the connection procedure described above).

The joint body 4 is provided with an outer flange 31 corresponding to the flange 30 of the joint member 27, and with holes 33 corresponding to a plurality of through holes 32 provided in the flange 30. ing. The annular convex portion 16 of the joint main body 4 has a mountain shape, and the inner diameter at the apex thereof is larger than the inner diameter D ₁ of the flexible tube 1. As described above, the tapered portion 14 is provided at the opening edge of the hole, and the male screw portion 9 is provided on the outer peripheral surface 4a.

In the connection procedure, the joint body 4 is connected to the joint member 27 to which the metal pipe 29 is connected via the ring-shaped seal member 34. At this time, the outer flange 31 of the joint body 4
And the respective holes 33 of the flange member 30 and the through-hole
Pass the bolts 35 through 32 and tighten them with nuts 36 to connect them. The sealing member 34 is provided with a hole for inserting a bolt. Then, the cap nut member 5, the ring 20, and the elastic packing 6 are sequentially passed through the end portion 7 of the flexible tube 1 externally fitted with the elastic thin short cylindrical member 3, and the flexible tube 1 is connected to the joint body 4 in the same manner as described above. I do.

Further, FIG. 7, the metal pipe 37 having a flexible tube 1 of the inner diameter D _2, a tapered male thread 38 on the end portion 37a which has a substantially equal inner diameter d ₃ to an inner diameter D ₂
And when they are connected.

The joint main body 4 has a stepped portion 41 for stopping the tube on the inner surface 15 with which the end surface 24 of the flexible tube 1 abuts, and a tapered male screw portion on the outer peripheral surface 4a on the connection side of the metal pipe 37. 42 are provided. The inner diameter d ₂ of the inner surface 15 inside the stepped portion 41 is set substantially equal to the inner diameter D ₂ of the flexible tube 1. As described above, the tapered portion 14 is provided at the opening edge of the hole, and the male screw portion 9 is provided on the outer peripheral surface 4a.

Thus, as a connection procedure, the joint body 4 is connected to the joint member 39 to which the metal pipe 29 is connected.
At this time, the connecting portions of the metal pipe 29 and the joint body 4 to the joint member 39 are sealed with a seal tape or the like. And
End portion 7 of flexible tube 1 externally fitted with elastic thin-walled short tube member 3
Then, the cap nut member 5, the ring 20, and the elastic packing 6 are sequentially passed through, and the flexible tube 1 is connected to the joint body 4 in the same manner as described above.

The present invention is not limited to the above-described embodiment, and the design can be freely changed without departing from the gist of the present invention. For example, the annular convex portion 16 of the joint body 4 may be intermittent. Also, if the annular convex portion 16 is omitted and the elastic thin short cylindrical member 3 is folded back in advance and the stepped portion is provided at the time of fastening the cap nut member 5, the stepped portion hits the tapered portion 14 and the tube 1 enters. Can be prevented.

[0030]

Since the present invention is configured as described above, the following effects can be obtained.

(According to the joint structure for a flexible tube according to the first aspect) The end 7 is externally fitted with the elastic thin short cylindrical member 3.
By {through the elastic thin short cylindrical member 3}, not only the flexible tube whose outer peripheral surface is smooth, but also the flexible tube 1
Even if the outer peripheral surface 2 has a bellows shape having irregularities, it is possible to obtain close contact with the inner surface 15 of the joint main body 4 and to connect the flexible tube 1 to the joint main body 4 firmly without shaking. Furthermore, since a tightly sealed state can be obtained at the end portion 23 of the elastic thin-walled short cylindrical member 3 compressed in a wrapped state, troubles such as liquid leakage and air inflow do not occur. Therefore, the fluid to be sent can be reliably sent by both the pressurized type and the vacuum siphon.

Further, the flexible tube 1 can be easily and quickly connected to another flexible tube 1 or a metal pipe 29 or the like. In particular, at the time of remodeling of a factory or the like, work can be easily performed when connecting another pipe to the existing flexible tube 1. The joint body 4 connects the flexible tube 1 to be connected in an external fitting manner. That is, the inner diameter of the inner surface of the flow path of the joint body is larger than the inner diameter of the flexible tube 1 to be connected. Since it does not become small, the fluid to be fed containing granular solids and the like does not become clogged by the joint body 4.

(According to the joint structure for a flexible tube according to the second or third aspect) Even if the outer peripheral surface 2 of the flexible tube 1 has large irregularities and the outer diameter varies, the sealing performance is ensured. Flexible tube 1
Can be linked.

The outer diameter of the flexible tube 1 can be adjusted using one elastic thin short tube member 3 (according to the joint structure for a flexible tube according to the second aspect).

(According to the joint structure for a flexible tube according to the third aspect) Since the elastic thin short cylindrical member 3 corresponding to the outer diameter of the flexible tube 1 can be quickly selected and used, it is convenient. It is.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an exploded state of an embodiment of the present invention.

FIG. 2 is a configuration explanatory diagram showing a connection state.

FIG. 3 is a cross-sectional view showing another embodiment.

FIG. 4 is a cross-sectional view of a main part showing a connecting portion.

FIG. 5 is a sectional view of a main part showing a connecting portion.

FIG. 6 is a cross-sectional view showing another embodiment.

FIG. 7 is a sectional view showing still another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible tube 2 Outer peripheral surface 3 Elastic thin short cylindrical material 4 Joint body 4a Outer peripheral surface 5 Cap nut member 6 Elastic packing 7 End part 8 End part 9 Male thread part 13 Hole 14 Taper part 23 End part t Thickness

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16L 33/00-33/26 F16L 11/08 F16L 19/03 F16L 21/00 F16L 35/00

Claims (3)

(57) [Claims] 1. A flexible elastic thin-walled short cylindrical member 3 fitted externally to an end 7 of an outer peripheral surface 2 of a flexible tube 1 to be connected, and a male screw portion 9 at an end 8 of an outer peripheral surface 4a. A joint body 4 having a tapered portion 14 at the opening edge of the hole 13, a cap nut member 5 screwed into the male screw portion 9 of the joint body 4, a tapered portion 14 of the cap nut member 5 and the joint body 4 And a ring-shaped elastic packing 6 interposed therebetween. The cap nut member 5 presses the end portion 23 of the elastic thin-walled short cylindrical member 3 via the packing 6 against the tapered portion 14 in a roll-up manner. A joint structure for a flexible tube, characterized in that: 2. A joint structure for a flexible tube according to claim 1, wherein a plurality of elastic thin-walled short cylindrical members are overlapped and fitted to the flexible tube. 3. The joint structure for a flexible tube according to claim 1, wherein a plurality of elastic thin short cylindrical members 3 having various thicknesses t are arranged and used alternatively.