JP2892309B2 - Metal fittings for resin tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal pipe joint for a resin tube.

[0002]

2. Description of the Related Art In recent years, resin tubes such as polybutene tubes, PVC tubes, and polyethylene tubes have been used in place of metal tubes used as water supply or hot water supply tubes.

[0003] That is, conventionally, when connecting a steel pipe to a faucet, it was necessary to bend, bend, or braze the pipe into a predetermined shape and connect it. It is said that the work becomes unnecessary, and that interference with other members on the pipe can be avoided, and that the pipe work can be extremely easily performed (for example, Japanese Utility Model Publication No. 7-26451, Japanese Utility Model Publication No. -21664).

By the way, even a resin tube having such a characteristic cannot be used for a hot water supply pipe requiring heat resistance.
Recently, polybutene tubes (polyolefin-based resin, which is ultra-high molecular weight, but has high flexibility, heat creep properties, and stress crack resistance) that have high strength even at high temperatures, as well as corrosion resistance, have been used for water supply and water supply. It was standardized so that it could be used for hot water supply pipes (see JIS K6778).

Therefore, this polybutene tube is
It has become widely used, including heating pipes for greenhouses and vinyl houses, and floor heating and cooling pipes for houses and livestock sheds.

[0006] By the way, in order to connect a polybutene tube to another pipe type or a metal device, a metal pipe joint is required. At that time, unlike the steel pipe, the polybutene tube is free after the construction. It is also very convenient because it can be made to be able to swing positively in response to an earthquake, but it is necessary to give consideration to water leakage and escape at the joint with the pipe joint.

On the other hand, various proposals have been made for metal pipe joints for joining general resin tubes (for example, Japanese Utility Model Application Laid-Open No. 58-172178 and Japanese Utility Model Application Laid-Open No. 61-6).
6288, JP-A-2-163592, etc.).

[0008] One of such proposals is the above-mentioned Shokai 61
The pipe joint described in JP-A-66288 will be described.

In FIG. 4 (A), a tube insertion having a fitting groove 52 on one end and a circumferential groove 54 with a coarse pitch having a saw tooth 53 on the other end is inserted into a joint body 51 of the pipe joint 50. And a part 55 are formed integrally with each other, and a nut part 56 is formed substantially in the middle of these parts.

On the other hand, in FIG. 1B, a C-shaped tightening member 57 which is externally fitted to the joint body 51 and tightened has a C-shaped opening 58 formed parallel to the axial direction. A pair of flange portions 59, 59 constituting the portion 58 are formed thick. Also, a plurality of grooves 60 are formed on the inner surface of the fastening member 57, and a split ring 61 is mounted in these grooves 60. The concave groove 60 is formed in the peripheral groove
Are formed at a pitch opposed to.

A screw hole 63 for screwing a bolt 62 is formed in a pair of flange portions 59 of the fastening member 57, and a counterbore hole 64 is provided on the outer periphery of one of the screw holes 63. The head of the bolt 62 is fitted.

Because of the above-described pipe joint 50, the resin tube 65 is externally fitted to the tube insertion portion 55, and the fastening member 5 is inserted into the tube insertion portion 55 with the resin tube 65 interposed therebetween.
7 is externally fitted and tightened with bolts 62 so that the tightening member 57 is reduced in diameter.
5 is evenly tightened to improve its sealing performance.
The resin tube 65 is prevented from coming off.

In particular, since the split ring 61 slides on the inner circumference of the concave groove 60 and the outer circumference of the resin tube 65, the tightening force acting on the outer circumference of the resin tube 65 becomes uniform over the entire circumference. It is said that it does not give deformation to the thickness of 65, that is, does not generate wrinkles,
In addition, since each of the pair of flange portions 59 is formed gradually thicker toward the center, deformation of the flange portion 59 is prevented by the tightening force of the bolt 62, and loosening after tightening is prevented. It is said to be lost.

On the other hand, in Japanese Utility Model Laid-Open Publication No. Sho 61-66287, a split short cylinder (not shown) is used in place of the split ring 61, and the inner surface of the split short cylinder faces the circumferential groove 54. There has been proposed a pipe joint in which a ridge is integrally provided and performs the same function as the C-shaped tightening member 57.

[0015]

However, any of the above-mentioned pipe joints has the following problems. 1) Since the split ring and the split short tube are used, the number of parts is increased and the cost of the product is increased. 2) The C-shaped fastening part is made of thick brass and has a counterbore, etc., and is a brass-cut product with high raw material costs, which increases production costs and may cause cracks during use. There is. 3) Each of the pair of flange portions has a screw hole 6 for a bolt.
3, the production cost is increased. 4) Since a split ring or the like is interposed, the pair of flanges has a clearance after tightening.

Therefore, it is conceivable that the C-shaped fastening member is made of sheet metal such as stainless steel and a nut is welded to the back surface of one of the flange portions to reduce the production cost.
In this case, the split ring and split short cylinder are still required,
Therefore, a gap is required between the pair of flanges, and since the plate is made of sheet metal, there is a difference in the tightening force acting on the pair of flanges. If a split ring or the like is omitted, the sheet metal C-shaped tightening member extends in the direction orthogonal to the axial direction of the bolt, that is, in the lateral direction, and becomes entirely elliptical. Due to the deformation, another problem occurs in which an uneven clamping force acts on the resin tube. Therefore, such an idea cannot be adopted.

[0017]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to completely solve the problem of the above-mentioned proposed pipe joint, and its gist is as follows. 1) Inserting a tube having a circumferential groove Brass joint body integrally formed with the part, and directly tighten the resin tube externally fitted to the tube insertion part,
And a C-shaped tightening member integrally extending a pair of flange portions that are in close contact with each other at the time of tightening, and a bolt insertion hole slightly larger than the outer diameter of the bolt is formed in the pair of flange portions. And
A nut is welded to the back of the abutting surface of one of the flanges, and a bolt is screwed onto the nut to bring the flanges into close contact with each other. It is made of sheet metal, and a slit is formed in the tightening member main body to form a tightening band having a width smaller than the width of the circumferential groove. The deformable resin tube is pushed into the circumferential groove by the tightening band. So as to form an inner wall bent downward on both sides of one flange portion to which the nut is welded,
By forming a downwardly bent outer wall on the distal end side of the other flange portion and tightening the bolt, the distal end edge of the inner wall is brought into contact with the inner surface on the distal end side of the outer wall, so that the tightening member and the resin tube A metal pipe joint for resin tubes characterized in that the sealing property is improved without using a split ring between them, and 2) a tube insertion portion having two circumferential grooves is integrally formed. A brass joint body and a C-shaped tightening member which directly tightens a deformable resin tube externally fitted to the tube insertion portion and integrally extends a pair of flange portions which are in close contact with each other at the time of tightening; A bolt insertion hole slightly larger than the outer diameter of the bolt is formed in each of the pair of flange portions, and a nut is welded to the back of the contact surface of one of the flange portions. Bolts to make the parts close together,
In the metal tube fitting for resin tube consisting of, the fastening member is made of sheet metal, a slit is formed in the fastening member body to form two fastening bands, and these fastening bands are used. In the two peripheral grooves, the resin tube fitted to the outside is configured to be pressed into each, and the inner wall which is bent downward is formed on both sides of one flange portion to which the nut is welded, and the tip side of the other flange portion and By forming an outer wall bent downward on both sides and fitting the outer wall to the inner wall at the time of tightening the bolt, the front end edge of the inner wall is brought into contact with the inner surface on the front end side of the outer wall, so that the tightening member and the resin A metal pipe joint for a resin tube characterized in that the sealing property is improved without using a split ring between the tube and the tube.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in the accompanying drawings. FIG. 1 is a perspective view of a main part of an embodiment of the present invention, FIG. 2 shows first and second embodiments, and FIG. 1A is a partially cut side view of the first embodiment. FIG. 2B is a cross-sectional view taken along line A-A of FIG. 2A, FIG. 2C is a plan view of FIG. 2A, and FIG. 2D is a partial cutaway of the second embodiment. FIG. 3 is a detailed view of FIG. 1, and FIG. 3A is a cross-sectional view of FIG.
FIG. 3A is a cross-sectional view of FIG. 3A, FIG. 3C is a plan view of FIG. 3A, FIG. 3D is a cross-sectional view of FIG.
3 (B) is a detailed view of FIG. 3 (B), and FIG. 3 (F) is a plan view of FIG. 3 (E). Is used.

The pipe joint of the present invention has a nominal diameter of 10 mmφ to 3 mm.
0 mmφ, particularly suitable for brass pipe joints for joining 13 mmφ or 15 mmφ polybutene tubes,
For example, a polybutene tube having a nominal diameter of 15 mmφ has a thickness of 2 mm. And this polybutene tube and fittings are used for floor heating and cooling (for tap water)
It is convenient to connect to a water header, but it may be used as a branch pipe of a hot and cold water mixing faucet or a single faucet.

First, an outline of the pipe joint 1 according to the first embodiment of the present invention will be described. 2 (A) to 2 (C), this joint main body 2 has, at one end, a screw thread 3 for attachment to, for example, a header tube (not shown), and a polybutene tube 4 at the other end. And a tube insertion portion 6 composed of two circumferential grooves 5 and 5 having a coarse pitch are formed integrally with each other, and a nut portion 7 is formed integrally at a substantially intermediate portion between them.

On the other hand, the C-shaped tightening member 8 which is externally fitted to the polybutene tube 4 inserted into the joint main body 2 and is made of stainless steel, is formed of a stainless steel plate. The portion 9 is formed of a contact surface parallel to the axial direction, and a pair of flange portions 10 and 10A constituting the contact surface of the opening 9 are integrally provided. Bolt insertion holes 11, 11 slightly larger than the outer diameter of the bolt 13 (so-called stupid holes) are formed in these flange portions 10, 10 </ b> A, and a nut 12 is provided behind the contact surface of one of the flange portions 10. Welded. Therefore, these flange portions 10, 10A
When the bolt 13 is inserted into the bolt insertion hole 11 and the bolt 13 is screwed into the nut 12, the inserted polybutene tube 4 is directly tightened to the tube insertion portion 6 by the diameter reduction of the C-shaped tightening member 8. The flange portions 10 and 10A can be brought into contact with each other.

In FIG. 2A, reference numeral 14 denotes an O-ring groove formed between the two peripheral grooves 5, 5, 15 denotes an O-ring,
Reference numeral 6 denotes a spring washer.

The general structure and operation of the above-described pipe joint 1 are substantially the same as those of the conventional example shown in FIG.

Here, the above-mentioned C-shaped tightening member 8
In particular, the outer periphery of the polybutene tube 4 is uniformly tightened by the following configuration.

That is, mainly in FIGS. 1 and 3, the flange portion 10 to which the nut 12 is welded is integrally extended from the fastening member body 17 by sheet metal working, and both sides thereof (in the axial direction of the pipe joint 1). Side, also referred to as the left and right sides; the same applies hereinafter), and the inner walls 18, 18 are formed by bending downward (the head of the bolt 13 is set to the upper side; the same applies hereinafter). 12 is inside.

In FIG. 3 (F), reference numeral 19 denotes a weld metal, and the corner of the square nut 12 is welded.

The other flange portion 10A joined to the flange portion 10 is integrally extended from the tightening member main body 17, and its contact surface is formed slightly wider than that of the flange portion 10. I have. Outer walls 20, 21, 21 are bent downward at the tip side and both sides of the flange portion 10A to form a U-shaped or box-shaped piece in plan view. The outer walls 20 and 21 of the box-shaped piece are fitted to the inner wall 18 with a little space left when tightening, but in particular, as shown in FIG. ,
The distal edges 18A, 18A of the 18 are in contact with the inner surface on the distal side of the outer wall 20.

The fastening member main body 17 is provided with a slit 22.
Are formed as two integrated tightening bands 23, 23, facing the pitch of the two circumferential grooves 5, 5 and deforming the polybutene tube 4 during tightening as shown in FIG. 2 (A). In the circumferential groove 5. Therefore, the width of the fastening band 23 is smaller than the width of the circumferential groove 5 by the amount of deformation of the polybutene tube 4.

Therefore, the inner diameter of the tightening member body 17 after tightening is determined by the thickness of the polybutene tube 4 in addition to the outer diameter of the bottom of the circumferential groove 4 and the pair of flange portions 10, 10.
The respective contact surfaces of 10A are in close contact with each other. In other words, since the C-shaped opening 9 is eliminated and tightened, after the tightening, the polybutene tube 4 in the opening 9 is tightened.
There is almost no gap between the clamp member main body 17 and the gap.

Since the bolt 13 is screwed into the nut 12 and tightened, the nut 12 is welded only by the gap of the bolt insertion hole 11 which is a stupid hole. Tightening force is applied only to the flange portion 10, and the flange portion 10 attempts to extend in the lateral direction so as to escape, but the tip edge 18 </ b> A of the inner wall 18 comes into contact with the inner surface of the outer wall 20, and the extension is performed. So that
The two flange portions 10 and 10A are tightened under the same conditions, and no single tightening occurs. Therefore, the pair of flange portions 10, 1
0A is close without slipping. At this time, since the outer wall 20 is formed of a box-shaped piece, the outer wall 20 is not deformed due to the lateral extension by the distal end edge 18A of the inner wall 18 which is bent downward and prevented from being deformed. 17 uniformly tightens the entire outer periphery of the polybutene tube 4. Therefore, the sealing property is improved, and the polybutene tube 4 does not come off. In particular, since a split ring and a split short tube as in the related art are not used and made of sheet metal, a special cost reduction can be achieved.

In addition, when this pipe joint is used for the header for floor heating, even if a large number of pipe joints are required, there is no trouble such as water leakage and the reliability of the construction is particularly improved.

Next, a second embodiment of the present invention will be described. In FIG. 2D, the difference from the pipe joint 1 of the first embodiment is that the circumferential groove 5 provided in the tube insertion portion 6 is formed in a bamboo shoot groove 25 having saw teeth 24. Others are common. Therefore, the O-ring 15 is omitted (of course, the O-ring 15 may be provided), and the tightening band 23 of the tightening member main body 17A is slightly twisted so that the oblique tightening band is parallel to the bamboo groove 25. 23A, and the polybutene tube 4 is
5 is pressed well.

The C-shaped tightening member 8 of the present invention may be used for a pipe joint for connecting the polybutene tubes 4 together. Of course, the polybutene tube may be another resin tube.

[0034]

According to the present invention, the following effects can be expected. 1) Since the tightening member is constituted by a tightening band and the resin tube is directly tightened by the tightening band, a split ring or a short tube is not required, the number of parts can be reduced, the cost can be reduced, and the resin tube can be reduced. Can be pushed into the circumferential groove to improve the sealing performance. 2) Since the fastening member is made of sheet metal, raw material costs and production costs are reduced, and slits can be formed. 3) Since the leading edge of the inner wall in the flange portion is brought into contact with the inner surface on the leading end side of the outer wall, one-sided tightening does not occur, and the outer periphery of the resin tube pushed into the circumferential groove can be uniformly tightened. 4) Since the flange portion of the tightening member is tightly tightened, there is no looseness after tightening, and the clearance in the opening (9) between the tightening member and the resin tube is reduced as much as possible.
Tightening can be made uniform.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of an embodiment of the present invention.

FIGS. 2A and 2B show a first embodiment and a second embodiment. FIG. 2A is a partially cut-away side view of the first embodiment, and FIG. FIG. 2 is a sectional view taken in the direction of an arrow, and FIG.
(A) is a plan view, and (D) is a partially cut-away side view of the second embodiment.

3A is a detailed view of FIG. 1, wherein FIG. 3A is a cross-sectional view of FIG. 1 as viewed from arrows BB, FIG. 3B is a cross-sectional view of FIG. 3A as viewed from arrows C, and FIG. FIG. 3A is a plan view, FIG. 3D is a cross-sectional view of FIG. 3A taken along line D-A, FIG. 3E is a detailed view of FIG. 3B, and FIG. FIG.

FIG. 4 is a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pipe fitting, 2 ... Pipe fitting main body, 4 ... Polybutene tube, 6 ... Tube insertion part, 8 ... C-shaped fastening member, 10,
10A: flange portion, 12: nut, 13: bolt, 1
8 ... inner wall, 18A ... tip edge, 20 ... outer wall

Claims (2)

(57) [Claims] 1. A brass joint body integrally formed with a tube insertion portion having a circumferential groove , and a pair of resin tubes externally fitted to the tube insertion portion, which are directly tightened and closely contacted with each other at the time of tightening. A C-shaped fastening member integrally extending a flange portion, and a bolt insertion hole slightly larger than the outer diameter of the bolt is formed in each of the pair of flange portions . Abutment surface
The nut welded to the back, screwed into the nut In the bolt and a metal pipe fitting for the resin tube of which closely these flange portions, the member said clamping is made of sheet metal, 該締with member Slit on body
To form a tightening band having a width smaller than the width of the circumferential groove.
And the deformable resin tube is formed by the tightening band.
The flange is pressed into the circumferential groove, an inner wall bent downward is formed on both sides of one of the flange portions to which the nut is welded, and an outer wall bent downward is formed on the distal end side of the other flange portion. At the time of the bolt tightening, the distal end edge of the inner wall is brought into contact with the inner surface on the distal end side of the outer wall, so that the tightening member and
Sealability without using split ring between resin tube
A metal pipe joint for a resin tube characterized by being improved . 2. A brass joint body integrally formed with a tube insertion portion having two peripheral grooves, and a deformable resin tube externally fitted to the tube insertion portion are directly tightened and mutually tightened. A C-shaped fastening member in which a pair of closely-contacted flanges are integrally extended; and a bolt insertion hole slightly larger than the outer diameter of the bolt is formed in the pair of flanges, respectively. Contact surface of one flange
The nut welded to the back, screwed into the nut In the bolt and a metal pipe fitting for the resin tube of which closely these flange portions, the member said clamping is made of sheet metal, 該締with member Slit on body
To form two tightening bands, these tightening bands
The resin tube fitted to the two peripheral grooves by a band
The nut is welded to each of the flanges, and the nut is welded to form a downwardly bent inner wall on both sides of one of the flanges, and a distally bent outer wall is formed on the distal end and both sides of the other flange. At the time of tightening the bolt, the outer wall is fitted to the inner wall, and the front edge of the inner wall is brought into contact with the inner surface on the front side of the outer wall, so that the tightening member and the resin tube are joined.
Improved sealing without using a split ring between
A metal pipe joint for a resin tube.