KR100446547B1 - Synthetic resin pipe joint with metal connecting member and manufacturing method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin pipe joint in which a metal connecting member for connecting a metal pipe is connected and molded on one side and a synthetic resin pipe is inserted and fused on the other, and a method for manufacturing a pipe joint in which the connecting member is firmly coupled. Synthetic resin pipe joint with metal connection member has a cavity formed in the direction of tube axis and orthogonal to tube axis, groove notch is formed to prevent rotation, and the metal connection member is covered with viscous modified polyethylene. And crosslinked polyethylene is then injected and molded. The metal connecting member and the synthetic resin are prevented from being separated from each other in the tube axis direction, the direction orthogonal to the tube axis, and the rotation direction by the cavity and the notch. After insertion and molding, the core support metal member is inserted into the inside, outside, or inside and outside of the synthetic resin portion. Thereafter, the inserted supporting metal member is heated with a heater or the like, and the modified polyethylene layer is heated and fused. This layer is then firmly attached to the metal connecting member by the resin pressure due to the expansion of the resin.

Description

Synthetic resin pipe joint with metal connecting member and manufacturing method

BACKGROUND OF THE INVENTION Field of the Invention The present invention generally relates to pipe joints, in particular synthetic resin pipe joints having a metal connection member for connecting metal pipes and a method of manufacturing the same.

In recent years, lightweight and flexible synthetic resin pipes have been widely used in fields such as water pipes, drain pipes, and gas pipes. However, a metal tube is also used in a portion where pressure resistance is required, and a method of using a combination of a metal tube and a synthetic resin tube is performed.

In the case of using a combination of a metal tube and a synthetic resin tube, a joint connecting two tubes is required. Therefore, in the conventional pipe joint, there is also a synthetic resin pipe joint having a metal connecting member in which a metal connecting member having a connecting means composed of outer or inner screws is inserted and molded on one side of the synthetic resin pipe joint and a synthetic resin tube is inserted and fused on the other side. However, metals and synthetic resins are difficult to bond with each other and are easily separated at the contact surface between metals and synthetic resins. Japanese Utility Model Laid-Open Publication No. 57-48388 is configured to improve the adhesion between the metal connecting member and the synthetic resin of the above-described synthetic resin pipe joint by forming a modified polyolefin layer on the contact surface where the metal connecting member is in contact with the synthetic resin. Synthetic resin pipe joints are disclosed.

When the metal portion is bonded to the synthetic resin portion through the modified polyolefin layer, the adhesive force increases to some extent, but it is not sufficient. When external pressure such as bending or twisting is applied, the metal part and the synthetic resin part are easily separated.

It is a main object of the present invention to provide a synthetic resin pipe joint having a metal connecting member which can prevent the metal connecting member and the synthetic resin from being separated from each other, and a manufacturing method thereof.

According to the present invention, the above object is to form a cavity in the metal connecting member of the synthetic resin pipe joint, and to configure the resin portion filling the cavity to have a load resistance (resistance), thereby preventing the metal connecting member and the synthetic resin from being separated from each other. Is achieved. Therefore, a synthetic resin pipe joint with a metal connecting member is basically composed of a resin molding portion formed by inserting and molding a metal connecting member having a connecting means for fixing the metal pipe. Specifically, a metal pipe is connected to one side of the synthetic resin pipe joint having a metal connection member, and a synthetic resin pipe is connected to the other side, and a cavity for preventing separation of the metal connection member and the synthetic resin is connected to the metal connection member in the tube axis direction. It is characterized in that it is formed to be inclined with respect to the installation and covered with synthetic resin when inserting and molding the inner side of the metal connecting member.

A cavity is formed in the tube axis direction to prevent the metal connecting member and the synthetic resin from being separated from each other in a direction perpendicular to the tube axis, that is, in a radial direction. Or a cavity is formed in a radial direction perpendicular to the tube axis to prevent the metal connecting member and the synthetic resin from being separated from each other in the tube axis direction. It is preferable to form a cavity in both directions of the tube axis direction and the direction orthogonal to the tube axis to prevent the metal connecting member and the synthetic resin from separating in the tube axis direction and the radial direction.

In order to prevent the metal connecting member and the synthetic resin from separating in the tube axis direction and the radial direction at the same time, there is a configuration in which the cavities are formed to be inclined, and components are formed in these cavities to fill the cavities in the tube direction and the radial direction.

The cavity as described above prevents the metal connecting member and the synthetic resin from separating in the tube axis direction and / or in the radial direction perpendicular to the tube axis. In order to more reliably prevent such separation, it is preferable to form a hook portion protruding roughly on the contact surface between the metal connecting member and the synthetic resin in addition to the cavity to be entangled with the synthetic resin.

In order to prevent separation of the rotational direction caused by the torsion, it is more preferable to form a rotation preventing member having a rough shape (such as irregularities) in addition to the cavity in the metal connecting member.

As described above, in order to prevent separation of the metal connecting member and the synthetic resin, it is effective to form a cavity or a rotation preventing member in the metal connecting member. However, the cavity or the anti-rotation member prevents the resin from flowing smoothly during injection and molding. In particular, as shown in FIG. 8, when holes are formed in the metal connecting member to prevent rotation, a weld is generated to cause layered peeling of the synthetic resin layer, and cracks as shown in FIG. It is prone to occurrence and can recognize that a fluid leaks.

The present inventors conducted various tests to solve such a problem, and as a result, the chamfering of some or preferably all of the plurality of angular portions of the metal connecting member existing on the contact surface between the metal connecting member and the synthetic resin, It has been found that by forming a grooved notch as the anti-rotation member, it is possible to avoid the occurrence of wounds and delamination without causing the resin to flow smoothly or evenly to the notches.

On the basis of this finding, a part of the plurality of angular portions of the metal connecting member formed on the contact surface between the metal connecting member and the synthetic resin is formed in the cavity or together with the cavity in the metal connecting member of the synthetic resin pipe joint. Or preferably, the invention of the structure which chamfers about all is invented. According to still another aspect of the present invention, the synthetic resin pipe joint having the metal connecting member having the cavity and the anti-rotation member is formed to form a notch with a groove to form the anti-rotation member.

According to another invention combining each of the above-described inventions, a plurality of angular portions of the metal connecting member in which the synthetic resin pipe joint having the metal connecting member having the cavity and the anti-rotation member are present on the contact surface between the metal connecting member and the synthetic resin is present. To chamfer a part or all of the, and to prevent the rotating member is formed to have a grooved notch.

According to each invention described above, in order to increase the adhesive force between the metal connecting member and the synthetic resin, it is preferable to form a modified polyolefin layer on the contact surface between the metal connecting member and the synthetic resin, or to mix the modified polyolefin with the synthetic resin.

In order to achieve the above object, another invention is also configured to insert and mold a metal connecting member having a connecting means for fixing a metal tube, and to heat the contact surface between the metal connecting member and the synthetic resin above the softening point of the synthetic resin.

From the tests conducted by the present inventors, it was recognized that when the contact surface between the metal connecting member and the synthetic resin was heated above the softening point of the synthetic resin, the metal connecting member was firmly bonded to the synthetic resin. In other words, it can be considered that the resin pressure increases due to the volume expansion caused by fusion by heating, and the pressure input to the connecting member increases.

In order to increase the coupling characteristics between the metal connecting member and the synthetic resin, it is preferable to insert a support member made of metal, ceramic or wood from the inside, the outside, or the inside and the outside to the synthetic resin joined to the connecting member. Next, the support member is fused by heating in a state in which the support member is brought into close contact with the resin part or pressed. When the volume of the resin on the adhesive surface expands, the expansion of the resin portion is adjusted by the support member, so that the resin can be pressed into the connection member more firmly.

As described above, in order to increase the bonding property between the metal connecting member and the synthetic resin, it is preferable to form a modified polyolefin layer on the contact surface between the metal connecting member and the synthetic resin or to mix the modified polyolefin with the injected synthetic resin. A synthetic resin pipe joint having a metal connecting member having a modified polyolefin layer formed therein can be obtained by placing a metal connecting member coated with a modified polyolefin in a molding die, and inserting and molding the molded resin connecting member.

The method of coating the modified polyolefin on the metal connection member includes various conventionally known methods, for example, a method of heat fusion of a modified polyolefin by an electrostatic coating method or a fluidization dipping method, and heat fusion of a modified polyolefin film. Or a method of heat fusion of a metal connecting member, a method of immersing the modified polyolefin in an emulsifying liquid or a solution. In the case of coating with a modified polyolefin, the surface of the metal connecting member is washed with a strong acid solution, a strong alkali solution or a detergent in advance, and immediately after or without cleaning using a bonding modifying agent such as alkoxy titanium. It is preferable to perform primer treatment. In this way, a more robust coupling characteristic can be obtained.

The modified polyolefin coated on the metal connecting member is preferably heat-treated in the presence of alcohol. In this way, the deterioration of the bonding force with respect to the metal connecting member of the resin portion over time can be suppressed. Examples of the alcohol used for leisure include aliphatic alcohols such as isobutyl alcohol and dihydric alcohols such as ethylene glycol. But ethylene glycol is preferred.

The heat treatment for bringing the modified polyolefin coated on the metal connecting member into contact with alcohol is usually performed at about 200 ° C. for 30 minutes and over several hours. The coating thickness of the modified polyolefin coated on the metal connecting member is usually in the range of 1 to 10 ⁴ m, more preferably in the range of 5 to 5 x 10 ² m. Examples of the modified polyolefin include at least one of modified monomers such as unsaturated carboxylic acids such as acrylic acid and maleic acid, unsaturated anhydrides such as maleic anhydride, unsaturated carboxylic acid amides and unsaturated epoxides such as glycidyl methacrylate. And polyolefins modified by graft copolymerization.

The content of the modified monomer in the modified polyolefin is preferably in the range of 0.001 to 5% by weight based on the modified polyolefin. As a modified polyolefin, the composite material which mix | blended all the polyolefin modified with the said modified monomer and the polyolefin which is not modified yet can also be used.

On the other hand, a synthetic resin pipe joint having a metal connecting member mixed with a modified polyolefin can be obtained by placing a metal connecting member in a molding die, mixing the modified polyolefin with a synthetic resin, and injection molding the synthetic resin mixed with the modified polyolefin. The heating temperature of the connection surface between the metal connecting member and the synthetic resin is usually preferably 120 ° C. to 350 ° C. sufficient to fuse at least a part of the synthetic resin. If the heating temperature is much lower than this range, the efficiency is reduced. If the heating temperature is much higher than this range, thermal deterioration of the resin is caused and the bonding force is also reduced.

The heating time depends on the size of the pipe joint and is not particularly limited. However, if it is too short, the fusion of the resin will be incomplete. On the other hand, if it is too long, high productivity cannot be obtained, which also leads to deterioration of the resin. Therefore, the heating time is usually 5 to 500 seconds, preferably 20 to 100 seconds. As a method of heating the resin on the contact surface, for example, a method of heating a heater by contacting the metal connecting member, a method of heating the metal connecting member using electromagnetic waves such as microwave or ultrasonic wave, and immersing the metal connecting member in a high temperature oil tank to And a method of heating the connecting member. According to such a method, since only the metal connection member needs to be heated, it is simple and preferable. However, after the insertion and molding, it is preferable to heat the whole pipe joint again in the molding die.

In addition, by increasing the resin pressure at the time of insertion and molding, the injection time is set longer than the usual molding time, and the molten resin is continued while the injection pressure is continued until the molten resin fills the molding die. Therefore, according to this method, the insert molding can be performed longer than the usual molding time, and the temperature of the contact surface between the metal connecting member and the synthetic resin can be maintained above the softening point of the resin even after the molding die is filled with the resin.

According to each of the inventions described above, iron, copper, aluminum or alloys thereof can be used as the metal material for the metal connection member, but there is no particular limitation. As a connecting means for fixing a metal pipe, a screw, welding, union nut, etc. can be used, for example. The synthetic resin used for the pipe joint according to the above-described inventions is not particularly limited as long as the synthetic resin is classified as a thermoplastic resin. Examples of the thermoplastic resin include polyolefins such as polyethylene, polypropylene, polybutene-1, crosslinked polyethylene, polyvinyl chloride, polyester, polyamide, polyacetyl, and the like.

The method according to the invention can be carried out not only on synthetic resin pipe joints for connecting metal pipes to synthetic resin pipes, but also on synthetic resin pipe joints for connecting metal pipes to each other.

1 is a front view showing a synthetic resin pipe joint having a metal connecting member.

2 is a cross-sectional view showing the main portion of a synthetic resin pipe joint having a metal connecting member according to the present invention.

3 is an enlarged cross-sectional view showing a state in which a primer layer and a modified polyethylene layer are interposed between a metal connection member and a crosslinked polyethylene;

4 is a cross-sectional view showing a heating method of a synthetic resin pipe joint and a metal connecting member using a heater.

Fig. 5 is a sectional view of a synthetic resin pipe joint having a union seam metal connecting member.

6 is a cross-sectional view showing another example of a synthetic resin pipe joint having a metal connecting member.

7 is a cross-sectional view showing an embodiment of a synthetic resin pipe joint having a metal connecting member.

Fig. 8 is a cross-sectional view showing a comparative example of a synthetic resin pipe joint having a metal connecting member.

Example

Fig. 1 shows an example of a synthetic resin pipe joint 12 having a metal connecting member 11 inserted and molded. The pipe joint body is formed of crosslinked polyethylene, and is called a so-called electrofusion joint, and a heating wire (not shown) is embedded on one side thereof, and after the polyethylene pipe 13 is inserted, a current is passed through the heating wire for a predetermined time. It is a structure joined by fusion.

The metal connecting member 11 has an outer screw 15 which is a connecting means for fixing a metal pipe (not shown). A cavity 17 extending in the viewing direction is formed at the contact portion with the crosslinked polyethylene 16, and as shown in FIG. 2, the metal connecting member 11 and the crosslinked polyethylene 16 are separated from each other in a radial direction perpendicular to the tube axis. To prevent it. It also has a cavity 18 extending in the radial direction orthogonal to the tube axis to prevent the metal connecting member 11 and the crosslinked polyethylene 16 from being separated from each other. And the projection part 19 and the recessed part 20 are formed in the metal connection member 11, and the separation of the metal connection member 11 is reliably prevented. The metal connecting member 11 is further formed with a notch with a shallow groove at the end in the tube axis direction.

Insertion molding of the metal connection member 11 consists of a process of apply | coating a primer to a metal connection member, immersing in a viscous modified polyolefin, covering it with a modified polyolefin, and then setting in a shaping | molding die and injection molding a crosslinked polyethylene. As a result, the metal connecting member 11 is covered with the crosslinked polyethylene layer 16 through the primer layer 23 and the viscous-modified polyolefin layer 24, as shown in FIG.

Next, as shown in Fig. 4, the synthetic resin pipe joint with the metal connecting member in which the core-type supporting metal member 27 is inserted inside the screw connecting the metal connecting member 11 into the heater 28. Then, it heats with the heater 28, and the modified polyolefin layer 24 (not shown in FIG. 4) interposed between the connection member 11 and the crosslinked polyethylene 16 is fused by heating. Accordingly, the modified polyolefin layer 24 is thermally expanded and supported so as to be press-fitted into the metal connecting member 11 by the resin pressure.

Fig. 5 shows a synthetic resin pipe joint having a union joint metal connecting member. The metal connecting member 31 having the collar 31a is inserted and molded in the state where the union nut 33 with the inner screw 33 is placed, as in the case of the metal connecting member 11 described above. A radially extending cavity 35 orthogonal to the tube axis is formed in contact with the crosslinked polyethylene 34 and a grooved notch 36 is formed to prevent rotation. Next, all the angular portions of the proximal face in contact with the crosslinked polyethylene are chamfered.

The union nut 32 is screwed into the union screw fixed to the metal pipe (not shown), and the metal pipe is connected to the metal connection member 31. The connecting means includes the union screw and union nut 32. Referring to FIG. 5, a seal 0 ring 30 is interposed between the metal tube and the metal connecting member 31.

6 shows another example of a synthetic resin pipe joint having a metal connecting member. A metal connecting member 39 having an inner screw 38 functioning as a connecting means is inserted and molded in the same manner as in the case of the metal connecting member 11 described above. In the contact portion with the crosslinked polyethylene, a cavity 41 extending in the radial direction orthogonal to the tube axis, a cavity 42 extending in the tube axis direction, and a notch 43 with grooves for preventing rotation are formed. Next, all the angular portions in contact with the crosslinked polyethylene are chamfered.

Each embodiment described above relates to a synthetic resin pipe joint connecting a synthetic resin pipe to a metal tube. However, according to another invention, the connecting members are inserted and molded on both sides of the joint body so that the metal tubes are connected to each other.

(Example 1)

The surface of the brass connection member 45 having the structure as shown in Fig. 7 was treated with titanium salt to form a titanium oxide film. Thereafter, the brass connection member was coated with a fluidized immersion method with a powder of viscous modified polyolefin (trade name "ADMER") manufactured by Mitsui Petrochemical Industries, Ltd. Next, the powder-coated connection member was brought into contact with steam of ethylene glycol and heat-treated at 200 ° C for 1 hour. Next, this was placed in a mold for molding and injection molded into crosslinked polyethylene to obtain a synthetic resin pipe joint shown in FIG. 7. Visual inspection of the inside and outside of the synthetic resin pipe joint obtained in this way revealed no cracking.

Next, the following cold / hot hammering test was conducted on the joint of the synthetic resin pipe.

Cold water with a temperature of 7 ° C. was flowed for 3.5 minutes, and a cold water blow test of about 17.5 kg / cm ² was performed three times for 2 seconds. Subsequently, the same hot water blow test was performed three times by flowing hot water at 85 ° C. for 2.5 minutes. As a result of performing a cold / hot water striking test using cold water and hot water for a total of 6 minutes in a cycle of 100,000 cycles or more, no leakage occurred.

(Example 2)

The synthetic resin pipe joint having the metal connecting member obtained by the method of Example 1 shown in FIG. 7 was heated at a heater temperature of 320 ° C. for 60 seconds using the heater 28 shown in FIG. 4. After 60 seconds had elapsed, the joint was removed from the heater 28 and immersed in 20 ° C water for cooling.

As described above, the contact surface between the metal connecting member 45 of the synthetic resin pipe joint having the metal connecting member heated by the heater 28 and the resin was cut with a knife. Next, an attempt was made to remove the metal connecting member by the cutting pliers, but the connecting member was not separated.

(Comparative Example 1)

A metal connection having the same structure as the metal connection member 45 shown in FIG. 7 except that the hole 47 is formed instead of the notch 46 shown in FIG. 7 in the radially extending cavity 48 perpendicular to the tube axis. The member 49 was used to insert and mold in the same manner as in Example 1 to obtain a synthetic resin pipe joint with a metal connecting member as shown in FIG.

As a result of performing the same cold / hot water hit test as that of Example 1, leakage began to occur as soon as 5,000 cycles were reached.

At this time, when the inside and the outside of the synthetic resin pipe joint were visually inspected, a wound occurred, and as shown in FIG. 8, a layered peeling was likely to occur in the resin layer on the inner surface of the joint.

(Comparative Example 2)

The separation test was carried out in the same manner as in Example 2 without performing heat treatment by a heater on the metal connecting member 45 of the synthetic resin pipe joint with the metal connecting member obtained by the method of Example 1 shown in FIG. . As a result, the metal connecting member was separated even with a slight force.

As described above, according to the synthetic resin pipe joint having the metal connecting member of the present invention, the following excellent effects can be obtained.

Specifically, the synthetic resin pipe joint with the metal connection member of the present invention forms a cavity in the metal connection portion, and fills the resin with the cavity according to insertion and molding, thereby creating a strength to prevent the metal connection member and the synthetic resin from being separated from each other. There is a number.

In addition, the synthetic resin pipe joint having the metal connecting member according to the present invention forms a cavity in the tube axis direction, whereby the metal connecting member and the synthetic resin can be prevented from being separated from each other in the radial direction perpendicular to the tube axis.

Further, the synthetic resin pipe joint having the metal connecting member according to the present invention can form a cavity in the radial direction, thereby preventing the metal connecting member and the synthetic resin from being separated from each other in the tube axis direction.

In addition, the synthetic resin pipe joint having the metal connecting member of the present invention is formed by forming a cavity in the radial direction orthogonal to the tube axis direction and the tube axis, or by forming a cavity obliquely, the metal connecting member and the synthetic resin separated from each other in the tube axis direction or radial direction Can be prevented.

In addition, the synthetic resin pipe joint having the metal connecting member according to the present invention can be entangled by roughly protruding the contact surface with the synthetic resin, thereby preventing the two kinds of members from being separated from each other.

Then, by chamfering a plurality of angular portions of the metal connecting member present on the contact surface between the metal connecting member and the synthetic resin of the synthetic resin pipe joint having the metal connecting member according to the present invention, the resin flow during injection molding is smooth, and a wound is formed. Can be prevented.

Further, by forming the anti-rotation member on the metal connecting member of the synthetic resin pipe joint with the metal connecting member according to the present invention, the metal connecting member and the synthetic resin can be prevented from being separated from each other in the rotational direction.

In this case, when the notch with grooves is formed in the rotation preventing member, cracks, layered peeling and scratches can be prevented without disturbing the flow of the resin smoothly during injection molding due to this notch.

Further, by forming a modified polyolefin between the metal connecting member of the synthetic resin pipe joint having the metal connecting member and the synthetic resin according to the present invention, the adhesive force to the metal connecting member of the synthetic resin can be enhanced.

Next, according to the method of manufacturing a synthetic resin pipe joint having a metal connecting member of the present invention, the metal connecting member having a connecting means for fixing the metal pipe is inserted and molded, and then heated, and the resin is pressed into the metal connecting member. . As a result, the metal connecting member can be firmly engaged.

In addition, according to the method for producing a synthetic resin pipe joint having a metal connecting member of the present invention, the metal connecting member is coated with a modified polyolefin, followed by injection molding or by mixing the modified polyolefin with a synthetic resin to perform injection molding. The adhesion of the synthetic resin to the member can be significantly enhanced.

In addition, according to the method for manufacturing a synthetic resin pipe joint having a metal connecting member of the present invention, the above-described heat treatment after the insertion is carried out in a state in which a supporting member is inserted from the inside and / or the outside into the synthetic resin portion, whereby the resin is supported by this supporting member. Can suppress the expansion. Therefore, the resin can be pressed into the metal connecting member more firmly.

In addition, according to the method for producing a synthetic resin pipe joint having a metal connecting member of the present invention, only the metal connecting member can be easily heated by performing heat treatment using a heater, electromagnetic waves, or immersion in a high temperature oil tank.

Further, according to the method for producing a synthetic resin pipe joint having a metal connecting member of the present invention, the contact surface where the metal connecting member and the synthetic resin contact each other is formed of a modified polyolefin, or mixed with a synthetic resin that injects the modified polyolefin, and inserted and molded. By continuously applying the injection pressure even after the molding die is filled with the resin, the molding machine can be heated with high efficiency without requiring a heater or heating step.

Further, according to the method for producing a synthetic resin pipe joint having a metal connecting member of the present invention, by forming a cavity or an anti-rotation member in the metal connecting member, the metal connecting member and the synthetic resin are mutually in the tube axis direction and the radial direction and / or the rotation direction. It can prevent the separation.

In addition, according to the method of manufacturing a synthetic resin pipe joint having a metal connecting member of the present invention, after washing the metal connecting member with a strong acid aqueous solution or a strong alkaline aqueous solution or detergent, or after the metal connecting member is primed with a binder modifier, Cover with modified polyolefin. Therefore, the metal connecting member is more firmly coupled.

In addition, according to the method for producing a synthetic resin pipe joint with a metal connecting member of the present invention, the modified polyolefin coated on the metal connecting member is subjected to heat treatment in the presence of alcohol, thereby deteriorating with time the bonding force to the metal part of the resin portion. Can be suppressed.

It is apparent that the present invention can be applied in a wide variety of embodiments without departing from the spirit and scope thereof. The present invention is not limited to the specific embodiments unless limited by the scope of the following claims.

Claims (19)

In a synthetic resin pipe joint comprising a molded article formed by inserting and molding a metal connecting member having a connecting means for fixing a metal pipe, wherein the metal pipe is connected to one side and the synthetic resin pipe is connected to the other. Cavity for preventing separation of the metal connecting member and the synthetic resin is formed to be inclined with respect to the tube axis direction while the metal connecting member is coated with a synthetic resin when inserting and molding the inside of the metal connecting member. A synthetic resin pipe joint having a metal connecting member. The joint of claim 1, wherein the cavity is installed inside or outside the metal connecting member. The synthetic resin pipe joint according to claim 1 or 2, wherein the metal connecting member has a concave-convex shape, a protrusion or a hook shape in contact with the synthetic resin. The joint of claim 1 or 2, wherein at least a part of the plurality of angular portions of the metal connecting member on the contact surface between the metal connecting member and the synthetic resin is chamfered. . In a synthetic resin pipe joint comprising a molded article formed by inserting and molding a metal connecting member having a connecting means for fixing a metal pipe, wherein the metal pipe is connected to one side and the synthetic resin pipe is connected to the other. At the same time as the cavity for preventing separation of the metal connecting member and the synthetic resin in the metal connecting member, at the same time the rotation preventing means consisting of a grooved notch (grooved notch) in the side end surface of the metal connecting member to be inserted, A synthetic resin pipe joint having a metal connecting member, wherein the inside of the metal connecting member is inserted and molded to be covered with a synthetic resin. The synthetic resin pipe joint according to claim 4, wherein a modified polyolefin layer is provided between the metal connecting member and the synthetic resin. In the manufacturing method of a synthetic resin pipe joint having a metal connecting member obtained by inserting and molding the metal connecting member having a connecting means for fixing a metal pipe, A method of manufacturing a synthetic resin pipe joint having a metal connecting member, wherein the contact surface between the metal connecting member and the synthetic resin is heated above the softening point of the synthetic resin after insertion and molding. The method of manufacturing a synthetic resin pipe joint having a metal connecting member according to claim 7, wherein the metal connecting member coated with the modified polyolefin is inserted and molded. 10. The method of manufacturing a synthetic resin pipe joint having a metal connecting member according to claim 9, wherein the modified polyolefin is mixed in the synthetic resin injected by insert molding. 10. The method of manufacturing a synthetic resin pipe joint according to any one of claims 7 to 9, wherein the heating is performed while the support member is inserted into the synthetic resin portion from the inside or the outside. 10. The method of manufacturing a synthetic resin pipe joint according to any one of claims 7 to 9, wherein the heating is performed by bringing the heater into contact with the metal connecting member. The method of manufacturing a synthetic resin pipe joint according to any one of claims 7 to 9, wherein the heating is performed by applying ultrasonic waves or microwaves to the metal connecting member. 10. The method of manufacturing a synthetic resin pipe joint according to any one of claims 7 to 9, wherein the heating is performed by immersing the metal connecting member in a high temperature oil bath. Inserting and molding a metal connecting member having a connecting means for fixing the metal pipe; And Forming a modified polyolefin layer on the contact surface between the metal connection member and the synthetic resin or mixing the modified polyolefin in the synthetic resin injected; A method of manufacturing a synthetic resin pipe joint having a metal connecting member, wherein the injection pressure is continuously applied even after the mold is filled with a synthetic resin during insertion and molding. The method of manufacturing a synthetic resin pipe joint according to claim 7 or 14, wherein the metal connecting member is provided with a cavity or a rotation preventing member. The method of manufacturing a synthetic resin pipe joint having a metal connecting member according to claim 8, wherein the modified polyolefin is coated on the metal connecting member after the metal surface is washed with a strong acid solution, a strong alkaline aqueous solution or a detergent in advance. The method of manufacturing a synthetic resin pipe joint having a metal connecting member according to claim 8, wherein the coating of the modified polyolefin on the metal connecting member is performed after the metal connecting member is primed with a binding modifier. 18. The method of manufacturing a synthetic resin pipe joint according to any one of claims 8, 16 and 17, wherein the modified polyolefin coated on the metal connecting member is heat-treated in the presence of alcohol. The synthetic resin pipe joint according to any one of claims 1, 2 and 5, wherein a modified polyolefin layer is provided between the metal connecting member and the synthetic resin.