JP2562934B2 - Seal joint method between pipes - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a seal joint method for pipes which has a sealing property when connecting the pipes by inserting the pipes in and out.

[Conventional technology and its problems]

When fitting pipes inside and outside, it is often necessary to provide a sealing property at this point. For this reason, in the past, it was fitted with tight fitting tolerances at this point. Therefore, the dimensional accuracy is required to be high, and the sealability is still insufficient by itself. Therefore, it is necessary to attach a sealing member such as an O-ring and various auxiliary members between them.

[Means for solving the problem]

Therefore, according to the present invention, when a molten resin material is adhered to the periphery of a certain object, that is, the object is adhered to the periphery of the object if a so-called overinjection operation is performed, and when the resin material is cooled and solidified, it shrinks. In addition to utilizing the property of tightening the inner object, and taking into consideration the material and order of the injection material, the physical properties of the molded product can be formed in a stratified manner, and the following measures were taken. It is a thing.

That is, an overinjection operation is performed in which the pipes are fitted inside and outside and a lock sleeve made of a resin material in a molten state is injected into a predetermined mold provided according to the shape so that the pipes come into close contact with each other on the outer circumferences. At this time, by injecting the soft resin material first and then injecting the hard resin material, the surface layer portion of the lock sleeve is a soft elastic body layer, and the deep portion is a hard rigid body layer. And a sealing member such as an O-ring or the like on the contact surfaces of both the pipe and the lock sleeve. The solution is to intervene.

[Action]

As a result, since the surface layer of the over-injected lock sleeve is the soft elastic layer, this portion elastically contacts the outer circumferences of both pipes to maintain the sealing property. On the other hand, since the deep layer is a hard and rigid layer, it exerts strength such as tightening force, and the synergistic effect of the two exerts the intended effect.

〔Example〕

Embodiments of the present invention will now be described with reference to the drawings. Fig. 1 is a process diagram showing a method of overinjecting a lock sleeve, Fig. 2 is a cross-sectional view of a lock sleeve fitted to a pipe, FIG. 3 is a sectional view when the present invention is applied to an automobile fuel hose.

First, a case where the pipe 1 and the pipe 2 are fitted in and out of each other and the lock sleeve 3 is overinjected over the outer circumferences of the pipes 1 and 2 will be described with reference to FIG. That is, a mold 4 having a predetermined shape is exteriorly packaged at a place where the lock sleeve 3 is to be fitted, and a molten resin material 7 is injected into a molding space 5 in the mold 4 through an injection passage 6. At this time, by appropriately considering the material of the resin material 7 and the injection sequence, the material of the lock sleeve 3,
As described above, the characteristics and the like can be configured in a stratified manner. Therefore, several hoppers 8a, 8b for storing the resin materials 7 having different characteristics are prepared, and the respective discharge paths 9a, 9b are provided.
Are allowed to join the injection path 6. A hydraulic pump 10 is used as a power source for injection, and the timing is controlled by the control valve 11
a, 11b (12a, 12b are check valves to prevent backflow).

As described above, first, the resin material 7 forming the surface layer portion of the lock sleeve 3 is injected, and then the resin material 7 forming the deep layer portion is injected.
Is injected into the molding space 5 while pushing the resin material 7 injected earlier to the outer peripheral side of the molding space 5 with a substantially uniform thickness. It will take a structure. By the way, here, the surface layer needs to be a soft elastic body layer that elastically contacts the outer circumference of the pipes 1 and 2 to exert sealing performance, and the deep layer needs to be a hard rigid body layer that shares the tightening function with a strong winding force. Therefore, it is natural that the characteristics and the like of each resin material 7 correspond to these.

On the other hand, at this time, even if the concavo-convex shape 13 or the like is formed on the outer peripheral surfaces of the pipes 1 and 2, over-injection of the lock sleeve 3 can be performed without any trouble. The pipes 1 and 2 and the lock sleeve 3 are improved.
As a result, a special structure for preventing the pipes 1 and 2 from falling out is unnecessary. Although the lock sleeve 3 is limited to resin in the above, the material of the pipes 1 and 2 may be metal, resin, rubber or the like.

Next, such a seal joint method can be applied to seal connection of all pipes, but is suitable for application to a fuel hose of an automobile shown in FIG. That is,
Since these parts are extremely reluctant to leak fuel, etc., the mouthpiece 16 is attached to the oil filler pipe 15 attached to the oil filler side of the vehicle body 14.
The fuel hose 17 and the fuel hose 17 and the like must be securely connected, but here, as described above, the lock sleeves 3 (18, 19) may be overinjected at the respective connection points. In this example, the sealing member 22 such as the O-rings 20 and 21 is interposed between the oil inlet pipe 15 and the mouthpiece 16, and between the oil inlet pipe 15 and the fuel hose 17 as well. The sealability between the inside of the oil inlet pipe 15 and the mouthpiece 16 and the fuel hose 17 becomes more reliable.

〔The invention's effect〕

As described above, since the present invention has been described above, it is possible to connect the pipes 1 and 2 which are required to have a sealing property without requiring a complicated sealing structure or an O-ring. Therefore, the cost is reduced by that much, but in this case, the fitting of the pipes 1 and 2 may be loose, so that the effect is further promoted by relaxing the working precision of these pipes. In addition, as for the sealing function, the entire sealing surface between the lock sleeve 3 and the pipes 1 and 2 is the sealing surface, so a wider surface seal can be realized compared to a simple line seal with an O-ring or the like interposed. The sealing property is improved accordingly.

[Brief description of drawings]

FIG. 1 is a process diagram showing an overinjection method of a lock sleeve, FIG. 2 is a sectional view when a lock sleeve is fitted to a pipe, and FIG. 3 is a sectional view when the present invention is applied to an automobile fuel hose. Is. 1 …… Pipe 2 …… Pipe 3 …… Lock sleeve 4 …… Type 7 …… Resin material 13 …… Uneven shape 22 …… Seal member

Claims (3)

(57) [Claims] 1. A lock sleeve made of a resin material (7) in a molten state so that the pipes (1) and (2) are fitted inside and outside, and the pipes (1) and (2) are closely contacted over their outer circumferences. An overinjection operation of injecting (3) into a predetermined mold (4) provided in accordance with its shape is performed, and at this time, injection of the soft resin material (7) is performed first, and then the hard resin material ( A seal joint method for pipes, in which the surface layer portion of the lock sleeve (3) is formed into a soft elastic body layer and the deep portion is formed into a hard rigid body layer by injecting 7) later. 2. A seal joint method for pipes, wherein a concavo-convex shape (13) or the like is formed on the close contact surfaces of the lock sleeve (3) and the pipes (1), (2) according to claim 2. . 3. Both pipes (1) according to the claim or claim,
A seal joint method for pipes in which a seal member (22) such as an O-ring is appropriately interposed between the close contact surfaces of (2) and the lock sleeve (3).