JP2592526Y2 - Plastic branch branch - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic branch pipe, and more particularly to a plastic branch pipe that can be securely and air-tightly joined without using a joint.

[0002]

2. Description of the Related Art In a piping system through which a fluid such as a gas or a liquid flows, it is necessary to provide a branch joint in order to branch or merge the liquid.

[0003] Conventionally, in order to provide a branch joint in a plastic pipe, a T-shaped joint has been used and inserted into the plastic pipe. For example, in the case of a pipe for supplying gasoline to an engine, conventionally, a pipe made of a branched metal joint and a rubber pipe for joining the joint has been used. However, since such a gasoline supply pipe has a complicated structure, there has been a problem that the production cost is high and a gasoline leak occurs due to a crack in a rubber pipe portion. In some cases, an opening is provided in the side wall of the main pipe, and an end of the branch pipe is brought into contact with the opening and bonded with an adhesive, or a welding method using a welding rod made of the same material is used.

However, in the joining method using a T-shaped joint, the space occupied by the joint is large, and it is difficult to pipe several pipes in a narrow place such as an engine room of an automobile. Further, since the flow path changes rapidly, it becomes difficult to control the flow velocity and flow rate of the fluid. In addition, such joints are generally expensive and require a lot of man-hours for joining, so that there is a disadvantage that joining costs are high. In addition, in the joining method by abutting, the joining strength is low, the reliability of the confidentiality is low, and gas or liquid may leak from the joining portion. In addition, when the diameter of the pipe to be joined is small, there is a problem that it is almost impossible to form a joint part in an airtight manner.

Accordingly, the present inventor has previously formed a saddle-shaped flare portion integrally at the end of the plastic branch pipe, and abuts on the main pipe so as to surround the opening provided on the outer surface of the plastic main pipe. An apparatus and a method for firmly fusing a branch pipe to a main pipe by using a vibration welding method for applying vibration in a longitudinal direction of the main pipe have been previously proposed (Japanese Patent Application No. 4-19 / 1992).
No. 1654). This apparatus is for connecting a plastic branch branch pipe 2 having the same outer diameter of the tip and the body as shown in FIG. 8 to a plastic main pipe 6, and as shown in FIG. A lower mold 10 having a groove for partially accommodating therein, a concave portion 12a having an inner surface shape substantially corresponding to an outer surface shape of the flare portion of the branch pipe 2, and a hole 12b having a diameter communicating with the concave section and accommodating the branch pipe 2; And a vibration source (not shown) for giving a lateral vibration to the upper mold 11. The plastic main pipe 6 is accommodated in the groove of the lower mold 10 and The branch pipe 2 is housed in the cavity 12 of the mold 11, and the upper mold 11 is vibrated in the lateral direction by operating the vibration source while the flare portion 4 is pressed against the periphery of the opening 7 of the plastic main pipe 6. The contact portion is welded by frictional heat.

[0006]

Although such a device is effective when connecting branch pipes having the same outer diameter, FIG.
As shown in FIG. 7, when a plastic branch branch having an enlarged portion at the tip is used, only the enlarged portion 3 of the branch branch comes into contact with the upper die 11 as shown in FIG. (Longitudinal direction of the main pipe 6), so that it was found that there was a problem that vibration welding was not effectively performed.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a plastic branch branch pipe for branch joining with a plastic main pipe, which can be securely fixed at the time of vibration welding even if there is an enlarged diameter portion at the tip.

[0008]

In view of the above object, as a result of intensive research, the present inventor has provided a projecting portion having an outer diameter equal to or larger than the enlarged diameter portion at the tip at the lower portion of the body of the plastic branch pipe. It was discovered that the provision of the jig ensures that the jig is fixed during vibration welding.

That is, the plastic branch branch pipe of the present invention is joined to a plastic main pipe having an opening in a side wall by a vibration welding method, and includes a trunk having an enlarged diameter portion at a tip end;
It is an integrally formed body having a saddle-shaped flare portion formed at a joint end portion with the plastic main pipe, and a protrusion formed at a lower portion of the body portion and protruding at least in a longitudinal direction of the flare portion. The outer diameter of the protrusion is equal to or larger than the outer diameter of the enlarged diameter portion.

[0010]

In the case of a plastic branch branch having a saddle-shaped flare integrally formed at the end abutting against the plastic main pipe and having a large-diameter portion at the tip, the outer diameter of the large-diameter portion is formed at the lower portion of the main pipe body. When the protrusion having the above outer diameter is integrally formed,
The plastic branch pipe is securely fixed in the lateral direction (longitudinal direction of the main pipe) in the hole of the jig, and the vibration energy at the time of vibration welding sufficiently acts.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a plastic branch branch according to the present invention; FIG. 1 is an exploded perspective view showing a state where a plastic branch branch pipe according to an embodiment of the present invention is joined to a plastic main pipe. The plastic branch branch pipe 1 according to the present invention comprises a trunk portion 2, an enlarged diameter portion 3 having an outer diameter larger than the trunk portion 2, and a saddle-shaped flare integrally provided at a distal end portion for joining to the plastic main pipe 6. It has a portion 4 and a protruding portion 5 provided at a lower portion of the body portion 2. In this embodiment, the protrusion 5 has the shape of an annular protrusion integrally formed with the body 2 and the saddle-shaped flare 4. The outer diameter of the projecting portion 5 needs to be equal to or larger than the outer diameter of the enlarged diameter portion 1. When the outer diameter of the protrusion 5 is equal to the outer diameter of the enlarged diameter portion 1, the plastic branch tube 1 is fixed in the hole of the joining jig by both the enlarged diameter portion 3 and the protrusion 5. When the outer diameter of the protruding portion 5 is larger than the outer diameter of the enlarged-diameter portion 1, even if only the lower part of the plastic branch tube 1 is fixed to the jig, vibration energy can be sufficiently transmitted to the joint.

An opening 7 having a diameter substantially equal to the inner diameter of the plastic branch pipe 1 is formed in the side wall of the plastic main pipe 6, and the end face of the saddle-shaped flare portion 4 of the plastic branch pipe 1 is formed on the outer surface of the plastic main pipe 6. Is partially wrapped around. Therefore, when the plastic branch pipe 1 is brought into contact with the side wall of the plastic main pipe 6, the saddle-shaped flare portion 4 is tightly engaged with the outer surface of the plastic main pipe 6.

In the embodiment shown in FIG. 1, the cross section of the protrusion 5 is annular, but the present invention is not limited to this, and the protrusion 5 can have various shapes. For example, as shown in FIG. 2, the saddle-shaped flare portion 4 is not provided on the entire circumference of the body portion 2.
The object of the present invention can be achieved by providing a pair of protrusions 5 only in the longitudinal direction of the present invention. In this case, the outer diameter of the protrusion 5 in the longitudinal direction of the flare 5 indicates a horizontal distance from one protrusion to the other protrusion.

As shown in FIG. 3, a plastic branch branch according to another embodiment of the present invention has an annular protrusion 5 integrally provided at a position slightly below the body 2. Other parts are essentially the same as those in FIG. The position of the annular protrusion 5 is not strictly limited, but is preferably closer to the flare 5. The outer diameter of the annular projection 5 is equal to or larger than the outer diameter of the enlarged diameter portion 3.

The object of the present invention can be achieved by providing a pair of protrusions 5 which protrude only in the longitudinal direction of the saddle-shaped flare portion 4 as shown in FIG. 4 instead of the annular protrusion 5 in FIG. can do. As above, other parts are the same as those in FIG. The outer diameter in the longitudinal direction of the protrusion 5 indicates a horizontal distance between the protrusions.

Plastics which can be used for the branch tube of the present invention include polyolefins such as polyethylene and polypropylene, polyamides such as nylon, polystyrene, polyvinyl chloride, polybutylene terephthalate, modified polyphenylene oxide, polycarbonate, polyacetal and the like. It is a thermoplastic. Particularly, in the case of a plastic pipe for automobiles which requires chemical resistance in a high temperature state, polyamide such as nylon 11 or nylon 12 is preferable.

The plastic branch tube 1 can be formed by a molding method such as injection molding. Alternatively, the enlarged diameter portion 3, the saddle-shaped flare portion 4, and the protruding portion 5 can be formed by a known method using a plastic pipe having a uniform diameter.

The plastic branch branch pipe 1 of the present invention comprises a main pipe 6.
Is joined to the peripheral portion of the opening 7 by the vibration welding method. The apparatus shown in FIG. 5 can be used for the vibration welding method.
The apparatus comprises a lower mold 10 having a groove for accommodating the plastic main pipe 6 lying down, and an upper mold 11 having a cavity 12 for accommodating the body 2 of the plastic branch pipe 1 having the flare section 4 in the axial direction. Have. A vibration source (not shown) for vibration welding is fixed to the upper mold 11.

In order to perform vibration welding, as shown in FIG.
The plastic main pipe 6 is placed in the groove of the lower mold 10 with the opening facing upward, and the body 2 of the plastic branch pipe 1 is inserted into the cavity 12 of the upper mold 11. At this time, the main pipe 6 is positioned so that the opening of the main pipe 6 installed in the lower die 10 and the flare portion 4 of the trunk 2 of the branch pipe 1 inserted into the upper die 11 are aligned. In order to prevent deformation of the main pipe 6, it is preferable to insert a round bar into the main pipe 6. In this state, the plastic branch tube 1 is firmly fixed in the cavity 12 of the upper mold 11 by the enlarged diameter portion 3 and the protrusion 5 or only by the protrusion 5.

Either the lower mold 10 or the upper mold 11 is moved up and down, and the flare portion 4 of the branch pipe 1 is pressed around the opening of the main pipe 6. The pressing force is generally 20 to 600 kg / cm ²
It is preferred that In this state, vibration is applied to the upper mold 11 from a vibration source (not shown). The vibration source is of an electromagnetic drive type, the vibration frequency is 100 to 500 Hz, and the amplitude is 0.2 to 3 mm. The vibration direction is a direction in which the joining interface slides, and specifically, is a longitudinal direction of the main pipe 6 due to the shape of the flare portion 4. Under such conditions, the vibration welding time is generally 0.5 to 5 seconds.

The branch pipe according to the present invention can be applied to a plastic pipe having an arbitrary diameter, but is particularly effective for a plastic pipe having a small diameter, where it is not preferable to use a joint or abut. Specifically, the effect is large for a plastic pipe having an outer diameter of about 3 to 20 mm.

The present invention will be described in more detail with reference to the following specific examples. Example 1 Outer diameter of nylon 11 formed by extrusion molding
An opening having a diameter of 4.4 mm was formed in the side wall of the main pipe by machining in order to branch-join a branch pipe of the same dimensions and the same material to a main pipe of 4 mm and an inner diameter of 4.4 mm. And the branch branch pipe 1 of the shape shown in FIG. 1 was shape | molded with the same material by injection molding. The outer diameter of the enlarged diameter portion 3 of the branch branch pipe 1 is 7.4 mm, and the protrusion 5
Was 7.8 mm in outer diameter, and the diameter of the saddle-shaped flare was about 12 mm.

A 4.2 mm round bar was placed inside the main pipe, and the main pipe and the branch pipe were accommodated in a lower mold and an upper mold of a vibration welding device, respectively, and pressed against each other at a pressure of 160 kg / cm ² . The pressing force was calculated by calculating the load applied to the pipe from the gauge pressure of the air cylinder used and the cylinder diameter, and dividing the load by the area of the flare portion. In that state, the frequency is 240 Hz, the amplitude is 1.
A 2 mm slide was applied for 1.2 seconds and vibration welding was performed.

When the joining strength of the plastic main pipe with branch pipe thus obtained was measured, the welding strength was 40 kg or more.

Example 2 Using the same main pipe as in Example 1, a branch pipe 1 having the shape shown in FIG. 2 was formed in the same manner as in Example 1. The outer diameter of the enlarged diameter portion 3 of the branch branch pipe 1 is 7.4 mm, and the projection 5 in the longitudinal direction of the main pipe is provided.
Was 7.8 mm in outer diameter, and the diameter of the saddle-shaped flare was about 12 mm.

A branch pipe was vibration welded to the main pipe under the same conditions as in Example 1. When the joining strength of the obtained plastic main pipe with branch pipe was measured, the welding strength was 40 kg or more.

Example 3 Using the same main pipe as in Example 1, a branch pipe 1 having the shape shown in FIG. The outer diameter of the enlarged diameter portion 3 of the branch branch pipe 1 is 7.4 mm, and the projection 5 in the longitudinal direction of the main pipe is provided.
Was 7.6 mm in outer diameter, and the diameter of the saddle-shaped flare was about 12 mm.

A branch branch pipe was vibration welded to the main pipe under the same conditions as in Example 1. When the joining strength of the obtained plastic main pipe with branch pipe was measured, the welding strength was 40 kg or more.

Example 4 The same main pipe as in Example 1 was used to form a branch pipe 1 having the shape shown in FIG. The outer diameter of the enlarged diameter portion 3 of the branch branch pipe 1 is 7.4 mm, and the projection 5 in the longitudinal direction of the main pipe is provided.
Was 7.6 mm in outer diameter, and the diameter of the saddle-shaped flare was about 12 mm.

The branch pipe was vibration welded to the main pipe under the same conditions as in Example 1. When the joining strength of the obtained plastic main pipe with branch pipe was measured, the welding strength was 40 kg or more.

Comparative Example 1 Using the same main pipe as in Example 1, a branch branch pipe 1 having the shape shown in FIG. The outer diameter of the enlarged diameter portion 3 of the branch branch pipe 1 is 7.4 mm, and the diameter of the saddle-shaped flare portion is approximately 12 mm.
mm.

An attempt was made to vibrate weld the branch branch to the main pipe under the same conditions as in Example 1, but the branch branch moved,
No welding, or even if welding, welding strength is 20
kg or less.

The present invention has been described with reference to the above embodiments.
The present invention is not limited thereto, and various changes can be made within the scope of the idea of the present invention.

[0034]

As described above, even in the case of a plastic branch branch having an enlarged diameter portion at the tip, a protrusion having an outer diameter equal to or larger than the enlarged diameter portion is securely fixed in the vibration welding apparatus. Therefore, reliable welding by the vibration welding method can be performed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a state of branch joining of a plastic pipe using a plastic branch branch pipe according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a state of branch joining of a plastic pipe using a plastic branch branch pipe according to another embodiment of the present invention.

FIG. 3 is an exploded perspective view showing a state of branch joining of a plastic pipe using a plastic branch branch pipe according to still another embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a state of branch joining of a plastic pipe using a plastic branch branch pipe according to still another embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a state in which the plastic branch pipe of the present invention is set in the vibration welding device.

FIG. 6 is an exploded perspective view showing a state of branch joining of a plastic pipe using a plastic branch branch pipe having no protrusion.

FIG. 7 is a cross-sectional view showing a state in which a plastic tube having no protrusion is set in a vibration welding device.

FIG. 8 is an exploded perspective view showing a state of branch joining of a plastic tube using a plastic tube having no enlarged portion and no protruding portion.

FIG. 9 is a cross-sectional view showing a state in which a plastic branch tube having no enlarged diameter portion and no protruding portion is set in a vibration welding device.

[Explanation of symbols]

 1 ··· Plastic branch pipe 2 ··· Body 3 ··· Expanded part 4 ··· Saddle-shaped flare 5 ··· Projection 6 ··· Plastic main pipe 7・ ・ ・ Opening part 10 ・ ・ ・ ・ Lower die of vibration welding device 11 ・ ・ ・ ・ Upper die of vibration welding device 12 ・ ・ ・ ・ Cavity

Claims (2)

(57) [Scope of request for utility model registration] 1. A plastic main pipe having an opening in a side wall.
In plastic branch branch pipe joined by vibration welding method ,
A trunk portion having an enlarged diameter portion at a tip end, a saddle-shaped flare portion formed at a joint end portion with the plastic main pipe, and a lower portion of the trunk portion, which protrudes at least in a longitudinal direction of the flare portion. Consisting of an integrally formed body having
An outer diameter of the protruding portion is equal to or larger than an outer diameter of the enlarged diameter portion. 2. The plastic branch branch pipe according to claim 1, wherein the plastic branch branch pipe is an injection molded article.