JPH028190B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe with a socket and a method for forming the same.
More specifically, the present invention relates to a pipe with a socket having a structure in which a short pipe is joined to the end of the straight pipe via a bonding material, and a method for forming the same.

Conventionally, as the bonding material, rubber packing coated with an adhesive has been generally used, as disclosed in Japanese Patent Publication No. 52-50069. However, when rubber packing is used, it is difficult to insert the short port pipe into the end of the straight pipe, and workability is poor.On the other hand, if workability is to be improved, the cost of the product will increase and performance will be degraded. This results in disadvantages such as a decrease in bonding strength and deterioration of bonding strength. In other words, in order to improve the workability, it is necessary to improve the accuracy of the gap between the straight pipe end and the socket short pipe, and to make the thickness of the rubber packing less than that gap. In order to improve the gap accuracy of the short tube, it is necessary to perform secondary processing such as cutting the tube, which increases the product cost, and also reduces the wall thickness of the tube, which impairs product performance, especially physical properties. This will lead to a deterioration in the strength of the target. Furthermore, if the thickness of the rubber packing is less than the gap size, the rubber packing will be interposed between the straight pipe and the short pipe in an uncompressed state, resulting in poor bonding strength.

In addition, as a method for forming a pipe with a socket, which allows the use of rubber packing with a thickness greater than the above-mentioned gap size and does not require secondary processing of the pipe, rubber packing is performed on the short socket pipe in an uncured state. The above-mentioned known document discloses a molding method in which a mantle is placed on a bonded straight pipe, a contracted mold is pressed, etc. to press an uncured socket short pipe onto the straight pipe, and the product is cured in that state.
In this method, the socket short tube must be used in an uncured state, so it is not possible to mass produce the short tube and store it in stock for storage and management. This method is not preferred as a molding method because it requires a large mold and the equipment costs are correspondingly high.

In view of the above points, the present invention has been devised as a novel method that can be formed with good workability by inserting a short pipe into a straight pipe, does not require secondary processing of the pipe, and has a large joining force. The present invention provides a useful pipe with a socket and a method for forming the same.

Therefore, in the pipe with a socket according to the present invention, a short socket pipe having an inner diameter larger than the outer diameter of the straight pipe is inserted into the end of the straight pipe, and the gap between the straight pipe and the short socket pipe is The gist is that a thicker foam material impregnated with a curable resin is interposed in a compressed state, and the curable resin is cured and joined.

In addition, the method for forming a pipe with a socket according to the present invention involves bonding a foam material that is thicker than the gap between the outer diameter of the straight pipe and the inner diameter of the short socket pipe to either the outer surface of the straight pipe end or the inner surface of the short socket pipe. The gist of the method is to impregnate the foam material with a curable resin after adhesion or before adhesion, and after impregnating and in an uncured state, the short socket pipe is inserted over the end of the straight pipe, and the short pipe is hardened and molded. do.

Next, one embodiment of the present invention will be described based on the drawings. FIG. 1 is a diagram showing a cross section of a pipe with a socket,
In the figure, 1 is a straight pipe with an appropriate length and a circular cross section, and 2 is a short socket with an inner diameter D ₂ larger than the outer diameter D ₁ of the straight pipe and a cross-sectional shape similar to that of the straight pipe 1. tube,
Reference numeral 3 denotes a foam material interposed in a compressed state in the gap between the overlapping tubes 1 and 2. This foam material 3 is impregnated with a curable resin, and by curing this resin, the straight pipe 1 and the short socket pipe 2 are joined. As the foam material 3, urethane, polyethylene, or other material having open cells is used. Further, as the curable resin, epoxy, vinyl ester, polyester, urethane, etc., which have excellent adhesion to the tubes 1 and 2, are used. The straight pipe 1 and the short socket pipe 2 are both reinforced plastic pipes formed by wrapping a paper band around a mandrel and continuously forming it by feeding material onto it while rotating it. etc. can be used. Further, as the short socket pipe 2, one having the shape shown in FIG. 2 can also be used.

Next, the procedure for forming the socket-equipped pipe will be explained based on FIGS. 3 and 4. First, insert the socket short pipe 2 into the outer mold 4
and the insertion inner mold 5 to set it. Next, the foam material 3 is impregnated with a curable resin and bonded to the end of the straight pipe 1 with an adhesive or the like. This foam material 3 is thicker than the gap between the outside diameter of the straight pipe 1 and the inside diameter of the short socket pipe. Subsequently, while the curable resin is in an uncured state, the straight pipe 1 is inserted from above the insertion inner diameter 5 and brought into contact with the stepped portion 5a of the inner diameter 5. In this case, the thickness of the foam material 5 is larger than the gap between the straight pipe and the short port pipe 2, but the foam material 3 is soft and has the property of deforming into any shape, so it can be inserted lightly and easily. be able to. After being inserted in this manner, the curable resin is heated in that state or cured at room temperature, and once cured, the insertion molds 4 and 5 are demolded. In this way, a pipe with a socket is obtained. In the above procedure, the foam material 3 is impregnated with a curable resin and then bonded to the straight pipe 1, but the procedure may be reversed.
In addition, although the foam material 3 is glued to the straight pipe 1,
Conversely, it may be adhered to the inner surface of the short socket pipe 2.

As explained above, the pipe with a socket and the method for forming the same according to the present invention provide the following advantages.
In other words, since a foam material impregnated with curable resin is used as the bonding material, even if the thickness is thicker than the gap between the straight pipe and the short socket pipe, the short pipe can be easily connected to the straight pipe and the workability is improved. Can be inserted well. Since the foam material is compressed in the inserted state, even if there is an error in the gap size between the straight pipe and the short socket tube, the foam material elastically expands and reliably absorbs the error. Therefore, the outer surface of the straight pipe and the inner surface of the short pipe are in close contact with the foam material, and a large bonding force is obtained.
On the other hand, the dimensional accuracy of the tube can be made relatively easy, and secondary processing is not necessary. Therefore, it is possible to reduce product cost and improve product performance. In addition, since there is no need to use uncured short socket tubes, product management is easy as the short socket tubes can be mass-produced and stocked in an independent molding process.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of a pipe with a socket according to the present invention, FIG. 2 is a sectional view showing another embodiment,
FIGS. 3 and 4 are diagrams showing the procedure for forming a pipe with a socket. 1... Straight pipe, 2... Short pipe at the socket, 3... Foam material.

Claims (1)

[Scope of Claims] 1. A short socket pipe having an inner diameter larger than the outer diameter of the straight pipe is inserted into the end of the straight pipe, and a gap between the straight pipe and the short socket pipe is thicker than that gap. A pipe with a socket, in which a foam material impregnated with a curable resin is interposed in a compressed state, and the curable resin is cured and joined. 2. Glue a foam material that is thicker than the gap between the outer diameter of the straight pipe and the inner diameter of the short socket pipe to either the outer surface of the straight pipe end or the inner surface of the short socket pipe, and then attach the foam material to either the outer surface of the straight pipe end or the inner surface of the short socket pipe. A method for forming a pipe with a socket, comprising: impregnating the pipe with a curable resin, inserting the short socket pipe onto the end of the straight pipe in an uncured state after impregnation, and hardening the pipe to form the pipe.