WO2003071180A1

WO2003071180A1 - Metal tube end connection structure

Info

Publication number: WO2003071180A1
Application number: PCT/JP2003/001570
Authority: WO
Inventors: Shinichi Endou; Satoshi Matsubara
Original assignee: Sanoh Kogyo Kabushiki Kaisha
Priority date: 2002-02-21
Filing date: 2003-02-14
Publication date: 2003-08-28
Also published as: JP2003247684A; JP3970633B2

Abstract

A metal tube end connection structure capable of remarkably increasing a connection strength by preventing the connection strength from being lowered by heat, wherein a cylindrical connection member (26) having a step part with an outer diameter larger than the inner diameter of a resin tube (21) formed therein is fitted to the end connection part (22) of a metal tube (10), and the resin tube (21) is press-fitted to the end connection part (22) of the metal tube (10) for connecting these tubes to each other.

Description

Details

Technical field

The present invention relates to a connection structure of a metal tube terminal connected to a resin tube. The present invention relates to a metal tube terminal connection structure.

^ 冃景. Technology

For piping of hydraulic and pneumatic circuits, fuel supply piping, and cooling piping for automobiles, etc., assemble the main piping into the vehicle as a collective piping, constructing the piping in an orderly manner, and assembling man-hours on the line. Reduction and improvement of workability. In general, durable metal pipes are used for this type of collective piping, and a resin tube (hereinafter referred to as a resin tube) is connected to the end of each metal pipe. By taking advantage of the easy-to-bend nature of the pipe, piping can be piped with a reasonable and efficient layout to the receiving part of the fluid destination.

Therefore, FIG. 7 is a diagram illustrating a pipe in which a resin tube is connected to a collective pipe of a metal pipe. The plurality of metal tubes 10 are fixed to a vehicle body or the like through a stay 11 as a bundled collective pipe, and one end of a resin tube 14 is connected to both terminal connection portions 12 of the metal tube 10. Unit is connected. At the other end of each of the resin tubes 14, a joint for connecting to another pipe or a receiving part, in this case, a quick connector 15 is attached.

Next, FIG. 8 is an enlarged view showing the structure of the terminal connecting portion 12 of the metal tube 10. The terminal connection unit 12 basically employs a connection structure proposed by the present applicant in Japanese Patent Application Laid-Open No. Hei 8-75069.

In FIG. 8, a first spool portion 16 is formed at a position near the distal end of the terminal connection portion 12 of the metal tube 10. A second spool portion 17 is formed at a position separated from the first spool portion 16 by a predetermined distance. Metal tube 10 terminal connection A pilot cap 18 is coaxially attached to the distal end of 12 as a member for guiding the press fit of the resin tube 14. An O-ring 19 is mounted between the pilot cap 18 and the first spool 16. When the resin tube 1'4 is press-fitted into the terminal connection part 12 with the pilot cap 18 as a guide, the resin tube 14 is pressed against the first spool part 16 and the second spool part 17 and does not get caught. Can be connected as follows.

However, although the conventional connection structure has the advantage that it can be easily connected without press-fitting just by press-fitting the resin tube, there was a problem that the connection strength was weaker than that of a pipe connector such as a quick connector. . In addition, there is a problem in that the resin tube disposed at a site where the ambient temperature is high and is constantly exposed to heat is softened by heat, and a reduction in connection strength is inevitable. Disclosure of the invention

Therefore, an object of the present invention is to provide a connection structure for a metal tube terminal that solves the problems of the conventional technology, prevents a decrease in connection strength due to heat, and can significantly improve connection strength. It is in.

In order to achieve the above object, a connection structure for a metal tube terminal of the present invention is a connection structure for connecting a resin tube to a terminal connection portion of a metal tube. A cylindrical connecting member having a stepped portion having an outer diameter larger than the inner diameter of the resin tube is attached, and the resin tube is press-fitted into the terminal connecting portion of the metal tube.

According to the present invention, when the connection member is attached to the terminal connection portion of the metal tube and the resin tube is press-fitted, the resin tube is hooked on the step of the connection member, and the connection strength is increased only by adding the connection member. It can be greatly improved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a longitudinal sectional view showing a connection structure of a metal tube terminal according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a longitudinal sectional view showing a connection structure of a metal tube terminal according to a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a connection structure of a metal tube terminal according to a third embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a connection structure of a metal tube terminal according to a fourth embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing an example of a method of connecting a metal tube and a resin tube in the fourth embodiment.

FIG. 7 is a diagram showing a collective pipe composed of a metal tube and a resin tube according to the related art. FIG. 8 is a longitudinal sectional view showing details of a connection structure between the metal tube and the resin tube in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a metal tube terminal connection structure according to the present invention will be described with reference to the accompanying drawings.

First embodiment

FIG. 1 shows a connection structure of a metal tube terminal according to a first embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a metal tube, and 21 denotes a resin tube, which is a somewhat hard and rigid tube made of nylon or the like. The terminal of the metal tube 10 is a terminal connection part 22 into which the resin tube 21 is press-fitted.

A first spool portion 23 is formed at a position near the distal end of the terminal connection portion 22 of the metal tube 10. A second spool portion 24 is formed at a position separated from the first spool portion 23 by a predetermined distance.

A connection member 26 is arranged between the first spool portion 23 and the second spool portion 24. In this embodiment, as shown in FIG. 2, the connecting member 26 is a cylindrical member made of resin having a C-shaped cross section, and the inner diameter is substantially equal to the outer diameter of the metal tube 10. Therefore, the length is set substantially equal to the interval between the first spool portion 23 and the second spool portion 24. Since the connecting member 26 has a C-shaped cross section, it can be easily attached by pressing the terminal connecting portion 22 from the open side, and also in the axial direction. Is restricted by the first spool portion 23 and the second spool portion 24 so that the position in the axial direction is fixed.

On the outer peripheral surface of the connecting member 26, two step portions 28 extending in the circumferential direction are formed. The stepped portion 28 has a surface 28a that rises outward in the radial direction and a tapered surface 28b that slopes while gradually reducing the diameter toward the tip. A step is formed between the outer peripheral surface of the step 26 and the stepped part 28 as a whole, so that the stepped part 28 has a multi-stage bamboo-shaped press-fit connection part. A pilot cap 30 is coaxially attached to a distal end portion of the terminal connecting portion 22 of the metal tube 10 as a member for guiding the press fitting of the resin tube 21. The pyro-cap 30 is a semi-circular cone-shaped cap having a tapered surface whose outer diameter gradually increases from the tip thereof. The maximum outer diameter is the outer diameter of the first spool portion 23. It is almost the same.

When the pilot cap 30 is attached to the terminal connecting portion 22 of the metal tube 10, a groove for interposing the O-ring 32 is provided between the end face of the pilot cap 30 and the first spool portion 23. Are formed.

The terminal structure of the metal tube according to the present embodiment is configured as described above. Next, the operation and effects thereof will be described.

First, the terminal of the resin tube 21 faces the pilot cap 30 of the metal tube 10, and then the resin tube 21 is press-fitted into the terminal connection portion 22. In the first stage of press-fitting, the tapered surface of the pilot cap 30 serves as a guide, and when it is gradually inserted, as shown in Fig. 1, the end of the resin tube 21 becomes the second spool part. You can press-in until you get over 24.

When the resin tube 21 has been press-fitted, the resin tube 21 is hooked on the four steps in all of the first spool section 23, the step sections 28, 28, and the second spool section 24. Therefore, the resin tube 21 does not come off in a normal environment and does not come off easily even in an environment where the resin tube 21 is exposed to heat. As shown in FIG. Although the structure itself is the same, the connection strength can be greatly improved only by adding the connection member 26. Second embodiment

Next, a connection structure of a metal tube terminal according to a second embodiment of the present invention will be described with reference to FIG.

The second embodiment is an embodiment in which the terminal connecting part 22 of the metal tube 10 shown in the first embodiment is the same element and the shape of the connecting member 34 is different from that of the first embodiment. The same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the embodiment shown in FIG. 3A, the connecting member 34 is shorter than the connecting member 26 in FIG. 1, and terminates at the second step 28. When the connecting member 34 is fitted into the terminal connecting portion 22 of the metal tube 10, the second step portion 28 and the second spool portion 24 are arranged adjacent to each other.

In the embodiment shown in FIG. 3 (b), a reinforcing angular step 37 is added to the connecting member 34, and the step 37 is arranged so as to be adjacent to the first spool 23. Has become. By adding such a stepped portion 37, the buckling strength of the connection member 34 is increased as compared with the embodiment of FIG. 3A, and the connection strength can be further increased.

On the other hand, in the embodiment shown in FIG. 3 (c), the connecting member 34 itself is basically the same as that in FIG. 3 (b). However, the connecting member 34 in FIG. 3 (b) is terminated at the second step portion 28, whereas the connecting member 34 in FIG. 3 (c) is terminated at the second step portion 2. It has a portion further extending from 8. In the terminal connection portion 22 of the metal tube 10, only the first spool portion 23 is formed. Instead of providing the second spool part 24, when the metal tube 10 is gripped by the chuck 38 used for automatic press-fitting or manual press-fitting, the end face of the connecting member 34 is held by the chuck 38. Since the position of the connecting member 34 can be regulated so as not to be shifted, the resin tube 21 can be smoothly press-fitted. After the press-fitting, the distal end surface of the connection member 34 comes into contact with the first spool portion 23, so that the connection member 34 can be restricted from moving in the tube removal direction.

Third embodiment

FIG. 4 is a diagram showing a connection structure of a metal tube terminal according to a third embodiment of the present invention. The third embodiment is different from the first and second embodiments described above in that the terminal connection portion 22 of the metal tube 10 has the first spool portion 23 and the second spool portion 24 both. The outer peripheral surface of the terminal connecting portion 22 of the metal tube 10 has an uneven shape in which the connecting member 40 engages with the connecting member 40. This is a type of embodiment having in common the feature of being fixed to the connection part 22.

First, in the embodiment shown in FIG. 4 (a), a concave portion 41 is formed on the outer peripheral surface of the metal tube 10 so as to be able to fit the connecting member 40 completely, over the entire circumferential direction. ing. The connection member 40 has spool portions 42 and 43 at both ends. The inner diameter of the connecting member 40 is substantially equal to the outer diameter of the concave portion 41. When the connecting member 40 is pressed against the terminal connecting portion 22 from the side and fitted, the concave portion is formed. 4 It can be mounted so that it does not move in the axial direction by regulating at the step of 1.

Next, in the embodiment shown in FIG. 4B, the concave portion 44 formed on the outer peripheral surface of the terminal connecting portion 22 of the metal tube 10 has a concave portion smaller than the concave portion 41 of FIG. 4B. It is. In addition, a bulging portion 45 is formed on the inner peripheral surface of the connecting member 40 so as to fit the concave portion 44.

In the embodiment shown in FIG. 4 (c), the outer peripheral surface of the terminal connecting portion 22 of the metal tube 10 is formed with two circumferentially extending grooves 46 at two locations. On the peripheral surface, a convex portion 48 engaging with the groove portion 46 is formed in the circumferential direction.

In the embodiment of FIG. 4 (c), when the connecting member 40 is pressed from the side so that the convex portion 48 is aligned with the groove portion 46 and fitted to the terminal connecting portion 22, the convex portion of the groove portion 46 is formed. Since the part 48 is engaged, the connecting member 40 can be attached so as not to move in the axial direction.

In the embodiment shown in FIG. 4 (d), the relationship between the groove and the projection is exactly the same as that of the embodiment in FIG. 4 (c), and the outer peripheral surface of the terminal connection portion 22 of the metal tube 10 is provided. The protrusion 49 is formed in the circumferential direction, and the groove 50 is formed in the inner circumferential surface of the connecting member 40 in the circumferential direction.

In the embodiments of FIGS. 4 (a) to 4 (d), the concave portions 42, 44, the groove portions 46, and the convex portions 48, 49 are not part of the entire circumference but part of the circumference. Is also good.

The operation and effect of the third embodiment as described above are basically the same as those of the first embodiment. In particular, a special advantage common to each example of the third embodiment is that the metal tube 10 Unlike the first and second embodiments, the terminal connection part 22 does not need to form the first spool part 23 and the second spool part 24, so the terminal connection part 22 is narrowed down. This method has the advantage that processing costs can be reduced because processing can be easily performed by using such a method.

When the connecting member 40 is made of a resin material, it is possible to form an integral structure with the terminal connecting portion 22 of the metal tube 10 by applying a direct molding method such as insert molding.

Fourth embodiment

FIG. 5 is a cross-sectional view showing a connection structure of a metal tube terminal according to a fourth embodiment of the present invention. In the embodiment described so far, the connecting member 2 having a C-shaped cross-sectional shape is used.

Although 6, 34, and 40 were used, the connection structure of the metal tube terminal according to the fourth embodiment uses connection members 52a and 52b that are divided into two in the axial direction. Other structures may be any of the structures of the first to third embodiments.

In order to press-fit the resin tube 21, for example, when the connecting member 34 shown in FIG. 3 (c) is configured into two divided connecting members 52 a and 52 b, as shown in FIG. The resin tube 21 may be press-fitted while keeping the connection member 52 a 52 b attached to the terminal connection part 22 of the metal tube 10 with the chuck 38. Note that chuck 3

Even without using 8, the metal tube 10 can be fixed to the terminal connection portion 22 with an adhesive or the like.ο

Although the present invention has been described with reference to the preferred embodiment, the number of steps of the connecting member is two in the above embodiment, but may be one or three. As is clear from the above description, according to the present invention, by simply adding a connecting member to the terminal connecting portion of a conventional metal pipe, a decrease in the connection strength due to heat is prevented, and the connection strength is significantly improved. Can be done.

In addition, a larger connection strength can be obtained while having the same shape as the conventional bamboo-shaped connection portion.

In addition, the connecting member can be positioned between the first spool portion and the second spool portion, and the resin tube is caught by all the steps of the first spool portion, the step portion, and the second spool portion. As a result, the connection strength is remarkably improved, and the resin tube can be prevented from coming off even when heated.

Furthermore, the same connection strength can be obtained without forming the first spool section and the second spool section. Since the terminal connection can be easily processed by drawing, etc., the processing cost can be reduced.

Claims

The scope of the claims

1. A connection structure for connecting a resin tube to a terminal connection portion of a metal tube, wherein a step portion having an outer diameter larger than the inner diameter of the resin tube is formed at the terminal connection portion of the metal tube. A connection structure for a metal tube end, wherein a cylindrical connection member is attached, and a resin tube is press-fitted into the terminal connection portion of the metal tube.

2. The connection structure for a metal tube terminal according to claim 1, wherein the connection member has a bamboo shoot shape in which the step portion is formed in a plurality on an outer peripheral surface of the connection member.

3. The terminal connection portion of the metal tube has a first spool portion formed at a position near the terminal of the terminal connection portion, the first spool portion being capable of locking the connection member. The connection structure of the metal tube terminal as described.

4. A second spool portion is formed in the terminal connection portion of the metal tube at a position separated from the first spool portion by a distance corresponding to the length of the connection member, and the connection member is 4. The metal tube terminal connecting structure according to claim 3, wherein the metal tube terminal is disposed between the first spool portion and the second spool portion.

5. A guide member for guiding the press-fitting of the resin tube is attached to a tip of the terminal connecting portion of the metal tube, and an O-ring is provided between the guide member and the first spool portion. 4. The connection structure for a metal tube terminal according to claim 3, wherein:

6. The terminal connection portion of the metal tube is formed with only the first spool portion capable of locking the connection member at a position near the terminal of the terminal connection portion. Item 3. The connection structure for a metal tube terminal according to item 3.

7. An outer peripheral surface of the terminal connecting portion of the metal tube and the connecting member are formed with concave and convex shapes that engage with each other, and the connecting member is connected to the terminal connecting portion using the concave and convex shape. 2. The connection structure for a metal tube terminal according to claim 1, wherein the metal tube terminal is fixed to a terminal.

8. A guide member for guiding the press-fitting of the resin tube is attached to a tip of the terminal connection portion of the metal tube, and an O-ring is provided between the guide member and a tip of the connection member. The connection structure for a metal tube terminal according to claim 7, wherein:

9. The connection structure for metal tube ends according to claim 1, wherein the connecting member has a C-shaped cross section.

10. The metal tube terminal connection structure according to claim 1, wherein the connection member is a divided type obtained by dividing a cylindrical body into two in an axial direction.

11. The connection structure for a metal tube end according to claim 1, wherein the connection member has an integral structure with the metal tube by insert molding of a resin.