JP2500751Y2 - Pipe fitting - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint, and more particularly to a pipe joint capable of firmly connecting opposing ends of a metal pipe and a synthetic resin pipe.

[0002]

2. Description of the Related Art As a conventional pipe joint of this type, for example, those shown in FIGS. 3 and 4 are known. The pipe joint shown in FIG. 3 has a primer layer on one end surface of the metal fitting 53 that is connected to the inner and outer peripheral surfaces of the cylindrical connecting portion 54 provided on one side of the tubular metal fitting 53, the distal end surface, and the base end of the connecting portion 54. 56 and a modified thermoplastic resin layer 55 are formed, and an annular recess formed in the connecting portion 54 covered with the modified thermoplastic resin layer 55 by opening one side on the opposite side of the synthetic resin joint main body 51. The place 52 is fitted and fixedly integrated with the connecting portion 54 through the layers 55 and 56. In the case of this pipe joint, a hooking portion on which a tool such as a spanner and a pipe wrench is hooked is formed on the outer peripheral surface of the metal fitting 53.

On the other hand, in the pipe joint shown in FIG. 4, the modified thermoplastic resin layer 65 and the primer layer 66 are provided on one end surface of the inward engaging projection 64 provided on the outer peripheral surface of the cylindrical metal fitting 63 and the inner peripheral surface on one side. And the annular recess 62 formed in the inner peripheral surface of the synthetic resin joint body 61 facing the synthetic resin joint body 61 so as to cover the modified thermoplastic resin layer 65 is closely fitted to the joint body 6
1 is fixedly integrated with the tubular metal fitting 63 via the layers 65 and 66. In the case of this pipe joint, the hook portion on which the tool is hooked is formed on the outer peripheral surface of the joint body 61.

[0004]

However, in the case of the pipe joint of FIG. 3, the metal fitting 53 and the joint main body 51 are firmly connected via the modified thermoplastic resin layer 55, but on the other hand, the metal fitting 53 itself. The cost increases as the size increases. Further, it is preferable that the joint is compact, but in this case, there is a problem that the total length of the joint is increased by the amount corresponding to the connecting portion 54. Further, in the case of the pipe joint of FIG. 4, the metal fitting 63 is smaller than the pipe joint of FIG. 3 and the cost is reduced, and it is compact without the connecting portion 54, but the contact area between the metal fitting 63 and the joint body 61 is smaller than that of the pipe joint of FIG. The pipe joint is less than half of that of the pipe joint, and its reliability is poor. In addition, since the hook portion of the tool is formed directly on the outer peripheral surface of the joint body 61, there is a problem that defects such as deformation and scratches are likely to occur in the portion.

In view of the above, the present invention solves the above-mentioned conventional problems, makes it possible to strengthen the connection between the tubular metal fitting and the synthetic resin joint main body, reduce the cost, and make the contact between the metal fitting and the joint main body. An object of the present invention is to provide a pipe joint in which the area can be sufficiently maintained, the reliability can be enhanced, and the hook portion of the tool can be formed on the metal fitting.

[0006]

In order to achieve the above-mentioned object, the present invention provides a synthetic resin joint body for fitting and connecting an end portion of a synthetic resin pipe to an inner peripheral surface in the pipe joint as described above. And at least 1/2 of the axial length of this joint body
The metal fitting is formed to have the following length, and has a tubular fitting for fitting and connecting the end portion of the metal pipe to the inner peripheral surface. The cylindrical metal member has an outer peripheral surface formed in a polygonal hook portion on which a tool such as a spanner or a pipe wrench is hooked, and a thick wall portion is formed between the outer peripheral surface and the inner peripheral surface. A hollow part is formed in an annular shape in which one side is opened from one side to the other side in the thick part, and an inward engaging projection is provided on an inner peripheral surface which is an open end of the hollow part, and A female thread for connecting the end of the metal tube is formed on the inner peripheral surface other than the engaging projection. The synthetic resin joint body is provided with a tubular connecting portion that is thinner than the joint body and protrudes on the side facing the opening of the hollowed portion of the tubular metal fitting. An inward engaging protrusion is provided on the peripheral surface that closely engages with the engaging protrusion of the tubular fitting when the connecting portion fits into the hollowed portion. A heating wire for fusing and connecting the end portion of the synthetic resin pipe is embedded in the thick portion on the peripheral surface side. The modified thermoplastic resin layer is adhered by the primer layer to the inner surface and the inner end surface of the hollowed part of the tubular metal fitting including the engaging projections that are closely engaged with each other. The joint portion of the joint body is fitted and fixed to the hollow portion surrounded by the resin layer. In this case, the inner surface on the inner diameter side of the hollow portion may be formed in a circular shape, the inner surface on the outer diameter side may be formed in a polygonal shape, and the outer peripheral surface of the connection portion may be formed in a polygonal shape and the inner peripheral surface may be formed in a circular shape.

[0007]

[Operation] With the tubular connection part of the joint body fitted and fixed to the hollow part of the tubular metal fitting, the modified thermoplastic resin provided on the inner surface and the inner end surface of the hollow part of the hollow part Since the resin layer is bonded and the bonding area is increased, a strong connection can be achieved even when a strong tensile force or a twisting force acts between the metal fitting and the joint body.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention, 1 is a synthetic resin joint body for connecting the ends of a synthetic resin pipe 2, and 3 is a tubular metal fitting for connecting the ends of a metal pipe 4. As shown in FIG. 2, the outer peripheral surface of the metal fitting 3 is formed into a polygonal hooking portion 5 on which a tool such as a spanner or a pipe wrench can be hooked. The hook portion 5 may have a polygonal shape, or may have a knurled outer peripheral surface. A thick portion 6 is formed between the outer peripheral surface and the inner peripheral surface of the metal fitting 3, and the thick portion 6 is formed with a hollowed-out portion 7 that is open on one side from one side to the vicinity of the other side. In this example, the inner surface 7 of the hollow portion 7 on the inner diameter side
a is circular, and the outer diameter side inner surface 7b is formed in a polygonal shape in accordance with the shape of the hook portion 5 of the metal fitting 3. An inward engaging projection 8 is provided on the inner peripheral surface of the metal fitting 3 which is the opening end of the hollowed portion 7. A modified thermoplastic resin layer 10 is adhered by a primer layer 9 to the inner diameter side inner surface 7a, the outer diameter side inner surface 7b, the inner end surface 7c and one end surface of the engaging projection 8 of the hollow portion 7.

Reference numeral 11 denotes an internal thread for connecting the metal tube 4 formed on the inner peripheral surface of the metal fitting 3. The material of the metal fitting 3 is preferably a corrosion resistant metal material such as copper alloy or stainless steel. Further, as the material of the modified thermoplastic resin layer 10, a modified polyolefin, for example, “Admer” manufactured by Mitsui Petrochemical Co., Ltd., “Motic” manufactured by Mitsubishi Petrochemical Co., Ltd., or the like is preferable. As the primer layer 9, an epoxy type, for example, “Nippe Primer K-10” manufactured by Nippon Paint Co., Ltd. is preferable.

On the side of the joint body 1 facing the opening of the hollowed portion 7 of the metal fitting 3, a tubular connecting portion 15 that is thinner than the joint body 1 is provided so as to project, and the connecting portion is a modified thermoplastic resin layer. It is fitted in the hollow portion 7 surrounded by 10, and is fixedly integrated with the inner surface of the hollow portion through the layers 9 and 10. In this example, the outer peripheral surface of the connecting portion 15 is the hook portion 5 of the metal fitting 3.
The inner peripheral surface is formed in a circular shape in conformity with the above shape. Reference numeral 16 denotes an inward engaging protrusion provided on the inner peripheral surface of the joint body 1 which is the base end side of the connecting portion 15, and the engaging protruding portion fits the hollow portion 7 of the connecting portion 15 as described above. At this time, the engaging projection 8 of the metal fitting 3 is closely engaged. 17
Is a heating wire embedded in the thick portion on the inner peripheral surface side of the joint body 1, and is provided for fusion bonding to the outer peripheral surface of the end of the synthetic resin pipe 2 connected to the inner peripheral surface of the joint body 1. The joint body 1 is made of a synthetic resin material such as polyethylene, polybutene, or vinyl chloride, and is connected to the end of the synthetic resin pipe 2 by an electrofusion method.

With the connecting portion 15 of the joint body 1 fitted and fixed to the hollow portion 7 of the metal fitting 3, the connecting portion 15 is formed on the inner diameter side and outer diameter side of the hollow portion 7, and the modified heat formed on the inner end surface. Since it adheres to the inner surface of the hollow portion 7 via the plastic resin layer 10 and the adhesion area becomes large, even if a strong tensile force or a twisting force acts between the metal fitting 3 and the joint body 1, it is detached or relative to each other. A strong connection is possible without rotating. Moreover, since the inner surface of the hollow portion 7 on the outer diameter side is formed in a polygonal shape, and the outer peripheral surface of the connecting portion 15 fitted into the hollow portion 7 is formed in a polygonal shape so as to be in close contact with this, the twisting is particularly It is stronger than conventional one against force. In addition, there is no fear that water in the pipe will leak even when vibration occurs in a state where water pressure is applied for a long period of time or thermal expansion and contraction due to water temperature and outside temperature is repeated. The outer peripheral surface of the metal fitting 3 is the hook portion 5.
Since it is connected to the joint body 1 by the hollow portion 7 and the inner peripheral surface is a connection portion (formed on the female screw 11) with the metal pipe 4, the member is effectively used, so that it is possible to reduce the size. The weight is reduced and the member cost is reduced. In addition, the entire joint is compact. Furthermore, since the tool is hooked on the hooking portion 5 on the outer peripheral surface thereof, which is a connecting portion with the metal tube 4, the synthetic resin joint body 1 is not deformed or scratched due to tightening.

It should be understood that each of the above-described embodiments is only a preferred example, and that the detailed design such as the shape of the hollowed-out portion 7 can be variously changed or modified without changing the gist of the invention. Yes.

[0013]

According to the invention of claim 1, since the tubular metal fitting is formed to have a length of at least ½ or less of the axial length of the joint body as described above, the tubular metal fitting can be made compact and lightweight. The cost can be reduced and the joint as a whole does not become long, so it can be made compact. In addition, a thick portion is formed between the outer peripheral surface and the inner peripheral surface of the tubular metal member, and a hollow portion, which is open on one side from one side to the vicinity of the other side, is formed in the thick portion in an annular shape. Inward engaging protrusions are provided on the inner peripheral surface that is the opening end of the, and the modified thermoplastic resin layer is a primer layer on the inner surface and the inner end surface on the outer diameter side of the hollowed portion including the engaging protrusions. Since the joint body and the tubular fitting are integrated by bonding and fitting the tubular connection portion of the synthetic resin fitting body inside the hollow portion surrounded by this modified thermoplastic resin layer, the fitting body and the tubular fitting are integrated. The bonding area of the main body can be sufficiently maintained, reliability can be improved, and the connection between the tubular metal fitting and the joint main body can be strengthened. Further, since the tool hooking portion is formed on the outer peripheral surface of the tubular metal fitting outside the connection portion between the joint main body and the tubular metal fitting, it is possible to prevent the deformation or damage of the joint main body. Furthermore, the end of the metal pipe can be easily connected by screwing the end of the metal pipe into the female thread formed on the inner peripheral surface of the tubular fitting to the vicinity of the engaging projection, and the end of the synthetic resin pipe can be easily connected to the inside of the joint body. The tip can be fitted on the peripheral surface so as to come into contact with the engaging projection, and the connection can be easily made by fusion with a heating wire. Moreover, since no other connecting member is required for these connections, the radial size of the tubular metal fitting and the joint body can be suppressed to the minimum diameter, which makes it possible to realize a compact design. effective.

According to the second aspect of the present invention, the bonding area between the tubular metal member and the joint body can be made larger than that of the first aspect, and it is particularly strong against torsional force.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

2 is a vertical cross-sectional side view taken along the line AA of FIG.

FIG. 3 is a vertical sectional front view showing a conventional example.

FIG. 4 is a vertical sectional front view showing a conventional example.

[Explanation of symbols]

 1 Synthetic Resin Joint Body 2 Synthetic Resin Pipe 3 Cylindrical Metal Fitting 4 Metal Pipe 5 Hooking Part 6 Thick Part 7 Hollow Out Part 9 Primer Layer 10 Modified Thermoplastic Resin Layer 15 Connection Part

Continuation of the front page (56) References JP-A-4-107397 (JP, A) Actual development Sho-49-94224 (JP, U) Actual development Sho-53-17927 (JP, U)

Claims (2)

(57) [Scope of utility model registration request] 1. A pipe joint for connecting opposite ends of a metal pipe (4) and a synthetic resin pipe (2), in which the end of the synthetic resin pipe (2) is fitted and connected to an inner peripheral surface. The joint body (1) made of steel and at least 1 / the axial length of the joint body.
And a tubular metal fitting (3) which is formed to have a length of 2 or less and which fits and connects the end portion of the metal pipe (4) to the inner peripheral surface. The cylindrical metal fitting (3) has a spanner on the outer peripheral surface. , A polygonal hook portion (5) on which a tool such as a pipe wrench is hooked, and a thick portion (6) is formed between the outer peripheral surface and the inner peripheral surface. A hollowed-out portion (7) is formed in an annular shape from one side to the vicinity of the other side, and an inward engaging projection (8) is provided on an inner peripheral surface which is an open end of the hollowed-out portion. At the same time, the female screw (1) for connecting the end of the metal pipe (4) to the inner peripheral surface other than the engaging projections.
1) is formed, and the synthetic resin joint body (1) is thinner and tubular than the joint body (1) on the side of the tubular metal fitting (3) facing the opening of the hollow portion (7). When the connecting portion (15) is fitted to the hollowed-out portion (7) on the inner peripheral surface of the joint body (1), which is provided with the protruding portion (15), which is the base end side of the connecting portion, the tubular metal fitting ( 3) Inward engaging protrusions (16) are provided which are in close engagement with the engaging protrusions (8), and the connecting portion (15) is provided from this engaging protrusion.
The heating wire (17) for fusing and connecting the end portion of the synthetic resin pipe (2) is embedded in the thick portion on the inner peripheral surface side opposite to the above, and the engaging protrusion (16) is closely engaged. The modified thermoplastic resin layer (10) is provided on the inner surface and the inner end surface of the hollowed portion (7) of the tubular metal fitting (3) including the engaging projections (8) to be fitted with the primer layer (9). A pipe joint characterized in that the connecting portion of the joint body (1) is fitted and fixed to the hollowed portion (7) surrounded by the modified thermoplastic resin layer. 2. An inner surface on the inner diameter side of the hollow portion (7) is circular, and an inner surface on the outer diameter side is polygonal, and the connecting portion (1) is formed.
The pipe joint according to claim 1, wherein the outer peripheral surface of 5) is polygonal and the inner peripheral surface is circular.