JPH09112775A - Resin tube connecting structural body and resin tube pressing method therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a resin tube from being deformed and prevent the surface thereof from being damaged by locking and supporting axial press-in thrust generated when a coupling member is pressed into, by an annular projection arranged on the peripheral surface of the resin tube. SOLUTION: A resin tube 1 is formed of an end part 1a positioned at one axial end, a projection 1b provided in vicinity of the axial direction of the end part 1a and a resin tube main body 1c provided in vicinity of the projection 1b and axially extended. A coupling member 2 is formed of a nipple 2a pressed into and fitted to the end part 1a of the resin tube 1, and a main body part 2b continuously connected to the nipple 2a. A press-in method for the resin tube 1 is such that the rear surface of the projection 1b of the resin tube 1 is brought in contact with the side surface of the holding part of a clamping device, and the holding part is closed so as to hold the resin tube 1. The end of the nipple 2a is fitted in the hole of the end part 1a of the resin tube 1, and the coupling member 2 is pressed into the axial direction by a press-in jig or press. At this time, press-in thrust is supported by the projection 1b and the side surface of the holding part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin tube connection structure composed of a resin tube having a relatively small diameter and a joint member connected to the resin tube, and a method of press-fitting the resin tube.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9, a resin tube 101 having a relatively small diameter used in a low pressure region has its end portion 101a and a nipple portion 102a of a joint member 102 connected by press fitting. It was Although the joint member 102 is the joint itself or may be a part of the device, the connection work can be completed by simply press-fitting the nipple portion 102a into the end portion 101a. Since the nipple portion 102a has a simple structure, it can be processed at a low cost, and since it does not require much connection work to the end portion 101a, this connection structure has been widely used. As the method of press fitting the resin tube,
As shown in FIG. 10, the end portion 101 of the resin tube 101
The clamp device 104 is clamped so as to protrude from the end surface of the clamp portion 105 by a length that allows the insertion of a. The holding portion 105 has a holding width of about 100 mm, and is arranged with a sufficient length so that the resin tube 101 does not slip. The nipple portion 102a of the joint member 102 is the resin tube 1
01 is press-fitted and connected to the protruding end portion 101a. On the other hand, a metal tube has been conventionally used in a piping system from a medium pressure region to a high pressure region used in a hydraulic circuit of a vehicle brake circuit, a machine tool, a construction machine or the like. However, the resin tube does not have the lightness and flexibility that metal tubes have, and the rubber tube hose that was necessary for vibration absorption in the metal tube piping system is no longer necessary due to the vibration absorption of the resin tube itself. Due to its own properties, piping circuits can be more simply put together and their use has been reviewed in this area as well.

[0003]

However, when the resin tube is used in a medium or high pressure region, the resin tube has a large wall thickness, for example, an inner diameter of 4 mm, an outer diameter of 8 mm, and a wall thickness of 2 mm. The above method, which was possible with about 1 mm, has caused a problem that press-fitting cannot be performed. That is,
When press-fitting the nipple portion 102a, the nipple portion 102a
Penetrates while expanding the hole of the resin tube 101, but the force that resists the expansion of the resin tube 101 is
01 becomes thicker, the axial press-fitting thrust force for overcoming and press-fitting 01 becomes very large, and it becomes very difficult to support the resin tube 101 so as not to move axially against it. Become. For example, the clamping force of the clamp device 104 is increased in order to clamp the device so as not to slip, and the clamping unit 1 of the clamp device 104 is used.
It was attempted to make the surface of No. 05 rough and to lengthen the holding length in the axial direction.
4, the resin tube 101 is deformed by the increase of the clamping force, the surface of the resin tube 101 is damaged by the roughening of the clamping portion 105 of the clamp device 104, and the clamping device 104 is increased by the extension of the clamping length in the axial direction. Is inconvenient to handle, and when a curved resin tube is used in addition to a straight resin tube, there is the inconvenience that the straight portion of the curved resin tube cannot be clamped unless it is made longer than necessary. Then, it was not possible to exert the effect sufficiently.

The present invention has been invented in view of the above problems. According to the present invention, even if the resin tube has a large wall thickness and the axial press-fitting thrust force required for press-fitting the resin tube increases, The resin tube can be supported without deformation of the resin tube and damage to the surface of the resin tube. Also, the resin tube can be clamped with a narrow width, and it can also support resin tubes with a curved straight part. An object of the present invention is to provide a resin tube connection structure formed by press-fitting tubes and a method for press-fitting the resin tube.

[0005]

In order to solve the above-mentioned problems, the invention of the present application is characterized in that the invention according to claim 1 has an end portion having a predetermined length in the axial direction from an end face, A resin tube having an annular protrusion formed adjacent to the end, a joint member having a nipple portion connected to the end of the resin tube, an end of the resin tube and the joint member It is provided with a fitting portion press-fitted to the nipple portion.

Further, the structural feature of the invention according to claim 2 is that an annular protrusion is formed on the outer peripheral surface of the resin tube adjacent to the end having a predetermined length in the axial direction from the end, It is provided that the resin tube is supported in the axial direction, and the nipple portion of the joint member is press-fitted to the end portion of the resin tube.

[0007]

In the invention according to claim 1 configured as described above, the annular projection disposed on the outer peripheral surface of the resin tube is used to control the axial press-fitting thrust force generated when the joint member is press-fitted into the resin tube. Since it can be stopped and supported, even a thick resin tube can be configured by press fitting without slipping the resin tube.

In the invention according to claim 2 configured as described above, the axial press-fitting thrust force generated when the joint member is press-fitted into the resin tube is engaged by the annular projection portion provided on the outer peripheral surface of the resin tube. Since it can be stopped and supported, it is easy to press-in thick resin tubes.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, claim 1 of the present invention will be described.
An embodiment according to the present invention will be described with reference to FIGS. 1 and 3. The resin tube connection structure according to this example is the resin tube 1
And a joint member 2 press-fitted into the resin tube 1,
It is configured by including a fitting portion 3 configured by both.

As shown in FIG. 1, the resin tube 1 has an end portion 1a located at one end in the axial direction, a protrusion portion 1b adjacent to the end portion 1a in the axial direction, and an axial portion connected to the protrusion portion 1b. It is composed of an extending resin tube body 1c. Although the resin tube 1 is a hard resin, a polyamide resin (nylon 11, nylon 12, nylon 6) is adopted in consideration of flexibility, pressure resistance, and workability required for piping. Also, the resin tube has a large wall thickness, for example, an inner diameter of 4
mm, outer diameter 8 mm, wall thickness 2 mm. The fitting portion 3 is formed by press-fitting the nipple portion 2a of the joint member 2 into the end portion 1a.

As shown in FIG. 3, the protrusion 1b of the resin tube 1 is added to the linear resin tube, and the resin tube 1 is formed before the fitting member 2 is press-fitted. There are various methods of forming, but basically, the protrusion 1
The part to be molded of b is locally heated by electric heat, high frequency, ultrasonic waves, etc., is pressed in the axial direction and bulges the protrusion 1b in the direction perpendicular to the axis. The protruding portion 1b does not have a specific function as a piping circuit, but is indispensable for forming the resin tube connection structure by press-fitting and connecting the joint member 2 to the resin tube 1.

As shown in FIG. 1, the joint member 2 is formed of a nipple portion 2a press-fitted into the end portion 1a of the resin tube 1 and a main body portion 2b connected to the nipple portion 2a. The joint member 2 is generally made of metal, but may be made of hard resin such as polyamide resin. The nipple portion 2a has an end portion 1
The fitting portion 3 is formed by press-fitting and fitting into a. The nipple portion 2a has a tubular shape, and its tip has a small diameter and has a resin tube body 1
An outer diameter dimension of approximately the same as the inner diameter of c, for example, 4 mm, is adopted, and the outer diameter dimension is tapered toward the main body portion 2b to a large diameter, for example, 5.5 mm. A corrugation having a small diameter is formed, and the outer peripheral contour of the nipple portion 2a is formed with at least two corrugations. The seal between the resin tube 1 and the joint member 2 is designed so that the fluid flowing inside the resin tube 1 does not leak due to the corrugation, but if necessary, the nipple portion 2a and the end portion 1a of the fitting portion 3 can be prevented. A sealant may be applied to the contact surface of.

Next, an embodiment according to claim 2 of the present invention will be described with reference to FIG. The resin tube connection structure according to the above-described claim 1 shown in FIG. 1 can be formed by the resin tube press-fitting method according to this example. For this reason, the method of press-fitting the resin tube is deeply related to the resin tube connection structure, and therefore the description will be made based on the above description as a supplementary form.

In the method of press fitting the resin tube, the fitting portion 3 is formed by press fitting the nipple portion 2a of the joint member 2 into the end portion 1a of the resin tube 1. The clamp device 4 for gripping the resin tube 1 is provided with a pair of half-clamping sandwiching parts 5, and a semi-circular groove having an outer radius slightly smaller than the outer radius of the resin tube is parallel to the half-cut surface. The resin tube 1 can be attached and detached by symmetrically arranging the pair of holding portions 5 and by vertically opening and closing the holding portion 5 (the operating mechanism is not shown).

When press-fitting the nipple portion 2a into the end portion 1a, first, the nipping portion 5 is arranged so that the end surface 1a projects from the side surface 5a side, and the back surface of the protruding portion 1b is brought into contact with the nipping portion 5 side surface. 5 is closed and the resin tube 1 is clamped. In the joint member 2, the tip of the nipple portion 2a is applied to the hole of the end surface 1a of the resin tube 1, and the joint member 2 is pressed in the axial direction by a press-fitting jig or a press (not shown). Since the tip of the nipple portion 2a has a small diameter and is almost the same as the inner diameter of the resin tube 1, there is no insertion resistance at first, but as the taper becomes larger,
For example, in the above example, the diameter is larger than the inner diameter of the resin tube 1 by 1.5 mm, and the resin tube 1 has a large wall thickness of 2 mm.
Since there is also mm, insertion resistance increases with insertion.
The effect of the present invention can be clearly seen here. This large press-fitting thrust force tries to move the resin tube 1 in the axial direction, but the projection 1b of the resin tube 1 abuts against the holding portion 5 and is locked. Therefore, the protrusion portion 1 b supports the press-fitting thrust force on the side surface of the holding portion 5. That is, unlike the prior art, since the clamping portion 5 is not simply clamped by the frictional resistance on the outer peripheral surface of the resin tube 1, the clamping force by the clamping portion 5 can be supported with a degree of grasping such that the resin tube 1 does not move, The width of the sandwiching portion 5 could be supported up to 40 mm as compared with the conventional width of 100 mm.

Regarding the formation of the protruding portion 1b of the resin tube 1, only the protruding portion 1b formed by swelling the protruding portion 1b in the direction perpendicular to the axis by pressing in the axial direction, which is the first example of the protruding portion shown in FIG. Instead, various variations can be applied. More specifically, the protrusion 11b shown in FIG. 4 in the second example of the protrusion and the protrusion 2 shown in FIG. 5 in the third example of the protrusion.
1b, the protrusion 31b shown in FIG. 6 in the fourth example of the protrusion
And so on. The protrusions 11b and 21b are capable of coping with a large thrust by providing a width of the bulged portion which is wider than that of the protrusion 1b in the axial direction. The protrusion 31b is not formed by bulging from the resin tube, but the annular body 31b shown in FIG. 7 or the grooved annular body 31b shown in FIG. 8 is fitted on the outer peripheral surface of the resin tube 31. The resin tube 31
It is formed by being fixedly attached to the outer peripheral surface of. for that reason,
The inner peripheral surface of the resin tube 31 can be expected to have a smooth inner surface state without a stepped portion.

Needless to say, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the scope of the claims based on the spirit of the present invention. For example, in this embodiment, the resin tube 1 is made of polyamide resin and has an inner diameter of 4 mm, an outer diameter of 8 mm, and a wall thickness of 2 mm.
Is made of metal or resin and has a small diameter dimension of 4 mm and a large diameter dimension of 5.5 mm. However, the material of the resin tube 1 and the joint member 2 or the dimension and shape of each part are not limited to those described above. The resin tube connection structure can be appropriately changed depending on the application, the use conditions and the like.

[0018]

As described above, in the invention according to claim 1, the annular projection provided on the outer peripheral surface of the resin tube locks the axial press-fitting thrust force generated when the joint member is press-fitted. Since the resin tube is thick, the resin tube can be supported without causing deformation of the resin tube or damage to the resin tube surface even if the axial press-in thrust force required to press-fit the resin tube increases. In addition, since the width of the pinching part of the resin tube can be made narrower, it is possible to carry out the resin tube with a bent part with a short straight part.
It was possible to provide a resin tube connection structure configured by press-fitting and fitting a thick resin tube.

In addition, in the invention according to claim 2, the same effect as that of the invention according to claim 1 is obtained, and at the same time,
Axial press-fitting thrust force generated when the fitting member is press-fitted into the resin tube can be supported by being locked by the annular projection provided on the outer peripheral surface of the resin tube, so that press-fitting of a thick resin tube can be facilitated

[0020]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an outline of an embodiment according to claim 1 of the present invention.

FIG. 2 is an explanatory diagram showing an outline of an embodiment according to claim 2 of the present invention.

FIG. 3 is an explanatory diagram showing a first example of a protrusion of the present invention.

FIG. 4 is an explanatory view showing a second example of the protrusion of the present invention.

FIG. 5 is an explanatory diagram showing a third example of the protrusion of the present invention.

FIG. 6 is an explanatory diagram showing a fourth example of the protrusion of the present invention.

FIG. 7 is a detailed view of the fourth protrusion 31b of the present invention.
FIG. 7 is an example of a side view of the protrusion as viewed from the direction A in FIG. 6.

FIG. 8 is a detailed view of a fourth protrusion 31b of the present invention.
FIG. 7 is another example of a side view of the protrusion viewed from the direction A in FIG. 6.

[Explanation of symbols]

 1a End part 1b Projection part 1 Resin tube 2a Nipple part 2 Joint member 3 Fitting part

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[Procedure amendment]

[Submission date] February 29, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an outline of an embodiment according to claim 1 of the present invention.

FIG. 2 is an explanatory diagram showing an outline of an embodiment according to claim 2 of the present invention.

FIG. 3 is an explanatory diagram showing a first example of a protrusion of the present invention.

FIG. 4 is an explanatory view showing a second example of the protrusion of the present invention.

FIG. 5 is an explanatory diagram showing a third example of the protrusion of the present invention.

FIG. 6 is an explanatory diagram showing a fourth example of the protrusion of the present invention.

FIG. 7 is a detailed view of the fourth protrusion 31b of the present invention.
FIG. 7 is an example of a side view of the protrusion as viewed from the direction A in FIG. 6.

FIG. 8 is a detailed view of a fourth protrusion 31b of the present invention.
FIG. 7 is another example of a side view of the protrusion viewed from the direction A in FIG. 6.

FIG. 9 is a view showing an outline of a conventional resin tube connection structure.
FIG.

FIG. 10 shows an outline of a conventional resin tube press-fitting method.
FIG.

[Explanation of Codes] 1a End portion 1b Projection portion 1 Resin tube 2a Nipple portion 2 Joint member 3 Fitting portion

Claims (2)

[Claims] 1. A resin tube having an end portion having a predetermined length in the axial direction from an end surface, and an annular protrusion formed adjacent to the end portion, and connected to the end portion of the resin tube. A resin tube connection structure comprising a joint member having a nipple portion, and a fitting portion in which an end portion of the resin tube and a nipple portion of the joint member are press-fitted and connected. 2. An annular protrusion is formed on an outer peripheral surface of a resin tube adjacent to an end having a predetermined length in the axial direction from the end surface, the resin tube is axially supported, and the end of the resin tube is formed. A method of press-fitting a resin tube, characterized in that a nipple portion of a joint member is press-fitted into the portion.