JPH0727275A - Tube connecting structure - Google Patents

Abstract

PURPOSE:To excellently connect a blow-molded tube to the prescribed connection tube by forming the blow-molded tube without defects even when the height of a stopper part to be integrated with the blow-molded tube is increased. CONSTITUTION:A blow-molded tube 12 consists of a tube body 14 and a stopper member 16, and the tube body is blow-molded with the stopper member as an insert member. This constitution allows the stopper member to be integratedly fixed to the tube body at its base, and also allows the stopper member to be projected from the outer circumferential surface of the tube body to make a stopper part, and the movement of a rubber hose 28 to be fitted to the blow-molded tube to the blow-molded tube side is prevented by the stopper part.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a tube connecting structure, and particularly to a blow molding tube side of a predetermined connection tube fitted to the blow molding tube by a stopper portion integrally provided on the blow molding tube. The present invention relates to a tube connection structure that prevents movement.

[0002]

2. Description of the Related Art Conventionally, metal, synthetic resin,
Tubes made of various materials such as rubber are used. In order to reduce the weight of pipes for vehicles, etc., a tube made of synthetic resin is used as disclosed in Japanese Utility Model Publication No. 3-27224. Blow molded tubes are used.

When connecting a predetermined connecting tube to such a blow-molded tube, conventionally, a connecting structure as shown in FIG. 5 has been advantageously used. There, there is shown a tube connection structure in a pipe for air circulation that connects an intercooler of an automobile and an engine. One end of a blow molding tube 2 connected to the intercooler side is connected to the engine side. The rubber hose 4 (connection tube) is fitted and connected.

On the outer peripheral surface of one end of the blow-molded tube 2, a stopper portion 6 is provided so as to project by integral molding, and the rubber hose 4 is brought into contact with the stopper portion 6. The blow-molded tube 2 is fitted into the blow-molded tube 2. In addition, 8 is a tightening band attached to prevent the rubber hose 4 from coming off, and 10 is
In order to prevent the deformation of the blow-molded tube 2, it is a collar fitted inside the end of the tube. In such a connection structure, the stopper portion 6 prevents the rubber hose 4 from moving toward the blow-molded tube 2 side, and the fitting amount of both tubes can be confirmed. .

By the way, in such a tube connecting structure, when the thickness of the rubber hose 4 becomes thick, it is necessary to increase the height of the stopper portion 6 of the blow-molded tube 2 so as to effectively function as a stopper. Occurs. However, when the height of the stopper portion 6 is increased, it is difficult to form the stopper portion 6 because the stopper portion 6 bulges a part of the wall portion of the tube and is integrally formed. Alternatively, there is a problem that the blow molding tube 2 itself becomes difficult to mold.

More specifically, (1) when the parison that gives the blow-molded tube 2 is blown up, the resin becomes thin at the tip of the stopper portion 6 and expands and bursts, resulting in air leakage. ,
It will not be possible to blow up to the specified shape. (2) However, if the wall thickness of the tip portion of the stopper portion 6 is to be increased, the tube main body portion also has to be increased in thickness, resulting in an increase in the weight of the product and an increase in the amount of material used, resulting in an increase in cost. Furthermore, the reduction of the inner diameter of the tube will reduce the amount of fluid flow,
As a result, for example, in the air flow path that connects the intercooler of the automobile and the engine, the performance of the engine deteriorates due to the decrease in the air flow rate. (3) Also, if the parison that gives the blow-molded tube 2 is cooled when it is set in the mold, the resin reaches the tip in a small recess of the mold that gives the shape of the stopper portion 6. Since it cannot be stretched and cannot be molded to the designed height, it cannot effectively function as a stopper. Further, if it is attempted to prevent this, there arises a problem that setting of molding conditions and molding work become troublesome.

[0007]

The present invention has been made against the background of the above circumstances, and the problem to be solved is to:
The blow-molded tube can be molded without defects regardless of the height of the stopper portion so that the blow-molded tube and a predetermined connecting tube can be satisfactorily connected.

[0008]

In order to solve the above-mentioned problems, in the present invention, a blow-molded tube having a tube connecting structure for connecting a blow-molded tube made of a synthetic resin and a predetermined connection tube is provided. , A tube body obtained by blow molding and a stopper member which is a member separate from the tube body, and the stopper member is integrally fixed to the tube body at its base, while the stopper member is provided on the tube body. Of the connecting tube fitted to the blow-molded tube is prevented from moving to the blow-molded tube side. The connection structure of the tube is the gist thereof.

In the present invention, the blow molded tube is composed of a tube body and a stopper member,
Further, by blow molding the tube body using the stopper member as an insert member, the stopper member is integrally fixed to the tube body at the base thereof, while the stopper member is projected from the outer peripheral surface of the tube body. Therefore, the configuration of the stopper portion is advantageously adopted.

[0010]

In summary, in the present invention, the stopper portion provided on the blow-molded tube is configured as a stopper member that is separate from the tube body, and is integrated with the tube body.

By adopting such a constitution, the parison which gives the blow-molded tube is blown up so as to form only the tube body, and the stopper portion is not locally thinned. Therefore, at the tip of the stopper part, the resin expands completely and bursts,
Air is prevented from leaking, and the blow-molded tube can be blown up well to a predetermined shape. In addition, since there is no concern that the wall thickness of the tube will locally thin at the stopper portion, it is possible to advantageously reduce the thickness of the tube main body, thereby reducing the weight of the product and the cost of the material by reducing the amount of material used. Further, there is an advantage that the inner diameter of the tube can be advantageously secured and the fluid flow rate can be secured.

Further, even if the parison that gives the blow-molded tube is cooled when it is set in the mold, it does not hinder the molding of the tube body, and the stopper part is formed as a separate member, so that Since the shape of the portion is accurately given, the blow-molded tube as designed can be obtained, and the molding conditions can be set and the molding operation can be easily performed.

Thus, according to the present invention, the blow-molded tube as designed can be molded without defects regardless of the height of the stopper portion. Then, by connecting a predetermined connection tube to the blow-molded tube, the stopper portion effectively prevents the connection tube from moving toward the blow-molded tube, and the fitting amount of both tubes is confirmed. As a result, a stable tube connection structure can be realized.

In order to fix the stopper member to the tube body, various methods such as welding (heat welding etc.) and heat caulking can be adopted. Particularly, the stopper member is used as an insert member and A method of fixing at the time of blow molding is advantageously adopted. Thereby,
The blow molded tube can be molded extremely easily.

[0015]

EXAMPLES In order to clarify the present invention more specifically, representative examples of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 show an example of a tube connecting structure according to the present invention. In these drawings, reference numeral 12 is a blow molded tube, which is composed of a synthetic resin tube body 14 having a cylindrical shape and a small piece-shaped synthetic resin stopper member 16. A collar 18 for preventing the deformation of the tube is fitted inside the end of the tube body 14.

By the way, this blow molded tube 12
Is molded by a known blow molding method. At this time, for example, the stopper member 16 is used as an insert member as shown in FIG.
That is, the stopper member 16 is previously arranged as an insert member in the recess 23 provided in the lower mold 22 of the mold.
On top of that, a parison 24 giving the tube body 14
Are placed. Then, the upper mold 20 and the lower mold 22 are closed, the mold is further clamped, and then the parison 24 is blown up, so that the stopper member 16 is closed as shown in FIG.
Since the fixing portion (base portion) 26 of the is formed as a peripheral surface which is inclined inward toward the upper side, it bites into the tube body 14 in a wedge shape, and the stopper member 16 is integrally fixed to the tube body 14. The stopper member 16 is erected so as to project from the outer peripheral surface of the tube body 14 to form a stopper portion.

The blow-molded tube 12 having such a structure
In this case, since the stopper portion is provided by the stopper member 16 which is separate from the tube body 14, the resin is not locally thinned in the stopper portion, and air leakage due to the rupture of the parison 24 is prevented. Good molding can be performed. Further, since it is possible to advantageously reduce the thickness of the tube body 14, it is possible to reduce the weight of the product and the cost by reducing the amount of material used, and also it is possible to advantageously secure the inner diameter of the tube and to distribute the fluid. The quantity can be secured.

Further, when the parison 24 is set in the lower mold 22 of the molding die, even if the parison 24 is cooled, there is no problem in molding the tube body 14, and the shape of the stopper portion is more accurate by the stopper member 16. Therefore, the blow-molded tube 12 as designed can be obtained, and the molding conditions can be set and the molding operation can be easily performed.

Therefore, regardless of the height of the stopper,
Occurrence of defective molding in the blow-molded tube 12 can be prevented, and the rubber hose 28 (connection tube) is fitted to the blow-molded tube 12 so as to abut against the stopper portion thereof, and is fixed by the tightening band 30. By doing so, both tubes are connected. In such a tube connection structure, the stopper portion of the blow-molded tube 12 effectively prevents the rubber hose 28 from moving to the blow-molded tube 12 side, and the fitting amount of both tubes can be confirmed. Of.

Although the representative embodiments of the present invention have been described in detail above, it is needless to say that the present invention is not limited by the above description. Further, it is understood that various changes, modifications, improvements, and the like can be added to the present invention in addition to the above-described embodiments without departing from the spirit of the present invention. It should be.

For example, the stopper member may be fixed to the tube body by insert molding, or may be fixed to the tube body by a method such as welding (heat welding) or heat caulking.

Further, the material of the stopper member is not limited to that of the above embodiment, and a metallic stopper member or the like can be used. Further, the shape of the stopper member is not limited at all,
It may be an annular stopper member that is attached to the outer peripheral surface of the tube main body over the entire circumference.

Further, as the connection tube, in addition to the rubber hose, tubes made of various materials such as metal and resin can be used. Depending on the material of the connection tube, a seal member may be provided between the blow-molded tube and the connection tube in order to ensure the sealing property at the connection site.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing an example of a tube connection structure according to the present invention.

FIG. 2 is a perspective view showing a tube connection structure of FIG.

FIG. 3 is a cross-sectional explanatory view showing a state in which a parison is set in a molding die in a step of molding a blow molding tube.

FIG. 4 is a cross-sectional explanatory view showing a state in which a parison is blown up in a blow molding tube forming step.

FIG. 5 is a cross-sectional explanatory view showing an example of a conventional tube connection structure.

[Explanation of symbols]

 12 Blow Molded Tube 14 Tube Main Body 16 Stopper Member 20 Upper Mold 22 Lower Mold 24 Parison 26 Fixed Part 28 Rubber Hose 30 Tightening Band

Claims (2)

[Claims] 1. A tube connecting structure for connecting a blow molding tube made of synthetic resin and a predetermined connecting tube to each other, and a tube body obtained by blow molding the blow molding tube and a member different from the tube body. The stopper member is integrally fixed to the tube main body at its base portion, while the stopper member is projected from the outer peripheral surface of the tube main body to form a stopper portion. The tube connection structure is characterized in that the connection tube fitted into the blow-molded tube is prevented from moving toward the blow-molded tube. 2. A tube connecting structure for connecting a blow molding tube made of synthetic resin and a predetermined connecting tube, wherein the blow molding tube comprises a tube body and a stopper member, and the stopper member is inserted. As a member, by blow molding the tube body, the stopper member is integrally fixed to the tube body at its base portion, while the stopper member is projected from the outer peripheral surface of the tube body to form a stopper portion. The stopper structure prevents the connection tube fitted in the blow-molded tube from moving toward the blow-molded tube side.