JP3374822B2 - Tube fitting - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-assembled tube coupling which is simply adapted for tube end insertion. For example, the present invention relates to a tube joint that can be suitably used for piping such as an air brake of an automobile.

[0002]

2. Description of the Related Art Heretofore, as a tube joint of this type,
The one described in JP-A-9-133273 is known. That is, as shown in FIG. 8, a taper surface portion 4 that is reduced in diameter toward the tube insertion port side and an inner peripheral surface portion 5 that extends from the taper surface portion 4 that is reduced in diameter toward the tube insertion port side are formed on the inner periphery thereof. And a tightening member 8 housed in the joint main body 3 so as to be movable in the axial direction thereof and being in an engaged state with the tapered surface portion 4 during movement, one end of the tightening member 8 is provided. When fluid pressure and / or tension acts in the state where the tube T is inserted in the fastening member 8, the fastening member 8 engaged with the tapered surface portion 4 is pressed and the diameter of the tube T is reduced. When the tightening member 8 and the joint main body 3 are locked in the axial direction, the tightening member 8 moves to the tube insertion port side and is locked with the joint main body 3. Member 8 is the inner circumference The shrinkage diameter of the tightening member 8 so that the tube T is connected in an optimal retaining state while the tightening member 8 is moved to the inside of the portion 5 and the diameter is reduced most, and the tightening member 8 is reduced in the inner peripheral surface portion 5 most. Is set.

More specifically, a flange portion protruding in the radial direction is formed on one end of the second tubular member 2 of the tubular joint body 3 and is slid with respect to the inner peripheral locking portion 13 of the flange portion. A fastening member 8 having a movable outer peripheral surface is provided with a contacting pawl having a projecting portion 9 projecting radially outward from the outer peripheral surface and an engaging pawl 10 projecting inward on the inner peripheral surface at the other end. An annular outer peripheral engaging portion 14 that is provided and protrudes outward in the radial direction from the outer peripheral surface is provided in front of the contact claw at a distance.

When fluid pressure and / or tension acts on the one end of the fastening member 8 with the tube T inserted in the fastening member 8, the fastening member 8 engaged with the tapered surface portion 4 is pressed. The tube T is optimally tightened by decreasing the diameter, and the tightening member 8 moves to the tube insertion port side and is locked with the joint main body 3.

[0005]

However, in such a resin tube joint, a cavity is formed in the contact claw of the tightening member 8 and the annular outer peripheral locking portion 14 in the inner peripheral surface portion 5 of the joint main body portion, so that the resin tube joint is formed. When a bending force is applied to the resin tube attached to one end of the joint, the tightening member 8 tilts within the inner peripheral surface portion 5 of the joint main body, so that the engaging state of the plurality of evenly engaged engagement claws 10 is unbalanced. There is a problem that the resin tube is balanced and the resin tube is easily pulled out.

Further, for example, in a high temperature atmosphere such as around the engine when driving an automobile, the resin tube expands, and when the temperature returns to room temperature when stopped, the resin tube returns to its original diameter, while the tightening member 8 Since the abutting claws of No. 2 are formed relatively thin in the adjoining adjacent portions, there is a problem in that the abutting claws are likely to remain spread due to thermal deterioration, and thus the resin tube is easily pulled out.

The present invention has been devised in view of the above problems, and provides a tube joint which makes it difficult to pull out a resin tube not only when a bending force acts on the resin tube but also due to thermal deterioration. The purpose.

[0008]

To achieve the above object, a tube assembly of a pre-assembled type which can be connected by pulling back an inserted resin tube, wherein the tube joint is stepwise from one end to the other end. A tubular main body having an axial bore extending in the axial direction, the axial bore having a first bore, a second bore, and a third bore, and having an inner diameter that becomes smaller in diameter; and an end portion of the tube. It has an insertion hole that can be inserted, and the first portion of the main body portion.
An annular rib integrally provided in the inner part of the hole so as to project radially inward from the inner peripheral surface of the first hole toward one end side; and an inner peripheral surface and an outer peripheral surface. The inner peripheral surface has a guide inner peripheral surface that extends straight in parallel to the axis at one end side,
The other end side is provided with a restriction concave taper inner peripheral surface adjacent to the guide inner peripheral surface and gradually increasing in diameter toward the other end, and an annular recess is formed between the restriction concave tapered inner peripheral surface and the annular rib. And at least the other end of the outer peripheral surface of the first main body of the tubular body portion.
A cylindrical holder fixed in the hole; an annular elastic seal member mounted in the second hole; an outer peripheral surface slidable on the guide inner peripheral surface of the holder at one axial end side A tubular base portion having an outer diameter slightly smaller than the inner diameter of the inner circumferential surface of the guide, and cutouts extending from the tubular base portion toward the other end in the axial direction at intervals in the circumferential direction. A tubular fastening member having a plurality of elastically deformable arm portions formed and a fastening portion arranged annularly and integrally provided at the free ends of the respective arm portions; The tightening portion of the tightening member includes a head portion that projects radially outward and abuts the inner peripheral surface of the restriction concave taper, and a tube that projects inward from the head portion in the centripetal direction and is inserted into the tube. A claw portion having a tip inner diameter smaller than the outer diameter of
Each of the arm portions of the tightening member is adjacent to the tightening portion and extends in the axial direction toward one end side, and the adjacent extending portion has an outer diameter equal to or larger than the inner diameter of the guide inner peripheral surface, and the adjacent extending portion. A thin wall portion extending between the base portions and having an outer peripheral surface having a diameter smaller than the outer diameter of the base portion, and a third hole of the tubular main body is formed so that the end portion of the tube can be fitted therein. While the tightening portion and the adjacent extending portion of the tubular tightening member are housed in the annular recess so as to be movable in the axial direction, the inner peripheral surface of the tubular base portion of the tightening member is the tube. Is formed so that the tip of the end of the tube can be inserted, and the tip of the end of the tube is inserted through the tubular tightening member, the rib, and the annular elastic seal member to form the tubular main body. When the tube is fitted into the third hole, the distance between the outer peripheral surface of the tube end and the inner peripheral surface of the second hole is the same. Sealed with Jo of the elastic seal member,
When the tube is slightly pulled back, the tightening member is moved to the one end side together with the tube, the head portion of the tightening member abuts on the inner peripheral surface of the regulating concave taper, and the head portion is regulated. One end side end that moves in the centripetal direction along the inner surface of the concave taper, the claw portion is engaged with the outer peripheral surface of the end portion of the tube, and the head and the inner peripheral surface of the restricting concave taper abut. The tube joint is characterized in that adjacent extension portions of the respective arm portions are inserted into and engaged with the inner circumferential surface of the guide at positions further apart from each other in the axial direction.

[0009]

As described above, according to the present invention, the outer diameter of the tubular base portion of the tubular base portion of the tightening member is formed to be slightly smaller than the inner diameter of the guide inner peripheral surface, and The outer diameters of the adjacent extension portions that are adjacent to each other and extend in the axial direction toward the one end side are formed to be equal to or larger than the inner diameter of the guide inner peripheral surface, and the adjacent extension portions are formed to be relatively thick while the base portion and the adjacent extension portions are formed. The intermediate portion extending therebetween is formed into a thin portion having a smaller diameter than these outer diameters, and an empty portion is formed between the intermediate portion of the arm portion and the guide inner peripheral surface of the holder, so that the resin tube When inserting the tightening member from the one end inlet of the holder, the tightening part can be easily expanded in diameter and easily inserted into the third hole. Then, when the resin tube is pulled back, the tightening member is Moved together with the tube to one end side, and the arm is relatively thick The formed adjacent extension is securely inserted into the inner peripheral surface of the guide, and the claw part that is engaged with the outer peripheral surface of the end of the tube and the adjacent extended part that is relatively thick and extends in the axial direction. Thus, the inserted tube can be firmly fixed. Therefore, even if a bending force is applied to the resin tube, it is possible to suppress twisting that occurs at the base of the head in the adjacent extension and always firmly and firmly fix the end of the resin tube in the circumferential direction with the claw. The tube can be prevented from coming off. The resin tube can be evenly attached to the resin tube in the circumferential direction for a long period of time even against a temperature change acting on the resin tube, and the heat deterioration performance can be improved.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a resin tube to be inserted can be connected by a pullback operation, and the tube to be inserted is preferably made of resin such as nylon 11 or nylon 12. . On the other hand, the cylindrical main body and holder are generally made of a metal material such as brass or stainless steel, but in view of cost and weight reduction, a heat resistant resin, for example, a reinforced plastic such as glass reinforced nylon reinforced with glass fiber is used. Can be adopted. The tightening member is generally made of metal, and a copper alloy is preferably used as the metal material.

The tube joint of the present invention will be specifically described with reference to the drawings. A preferred specific example of the present invention will be described with reference to FIGS. In the figure, 10 is a cylindrical main body, and the main body 10 has an axially extending axial hole 11 having an inner diameter that gradually decreases from one end to the other end side, and sequentially has a first hole 11a. , Second hole 11b, third hole 1
1c and a fourth hole 11d are provided. First hole 11a
An annular rib 20 protruding inward in the radial direction from the inner peripheral surface of the first hole 11a is press-fitted and fixed to the inner part of the first hole 11a, and the end 91 of the resin tube 90 can be inserted into the annular rib 20. The insertion hole 21 is formed.

At one end of the tubular main body 10, a guide inner peripheral surface 31a extending straight to one end parallel to the axis.
On the other end, adjacent to the guide inner peripheral surface 31a, the restriction concave taper inner peripheral surface 31b is gradually increased in diameter toward the other end.
A cylindrical holder portion 30 having is provided. In detail, a guide inner peripheral surface 31a that extends straight in parallel with the axis is provided on one end side, and a regulating concave tapered inner peripheral surface that is adjacent to the guide inner peripheral surface 31a and gradually increases in diameter toward the other end on the other end side. The other end of the outer peripheral surface of the cylindrical holder 30 having 31b is fitted into the first hole 11a of the main body 10 to
It is firmly fixed by crimping the inlet of 0 to the outer peripheral surface. An annular recess 7 is formed between the inner peripheral surface 31b of the restricting concave taper and the annular rib 20.

More specifically, the annular rib 20 has a tapered outer peripheral surface 22a having a diameter gradually decreasing toward one end side at the center of a flange portion having an outer peripheral surface which can be fitted to the inner peripheral surface of the first hole 11a. An annular protruding portion 22 protruding in a boss shape is provided, and an insertion hole 21 through which the end 91 of the resin tube 90 can be inserted is provided concentrically with the cylindrical main body portion 10, and the annular rib 20 is The second hole 11b inside the first hole 11a is in contact with and fixed to a radially extending annular surface adjacent to the second hole 11b. The other end of the holder 30 is formed as a large-diameter inner peripheral surface 31c that extends straight from the large-diameter end of the concave tapered inner peripheral surface 31b toward the other end of the holder 30, and the annular protruding portion 22 of the rib 20 is formed. They are arranged concentrically on the outer circumference. The tubular tightening member 50 is held in the annular recess 7 and the guide inner peripheral surface 31a so as to be movable in the axial direction.

An annular elastic seal member such as an O-ring is mounted in the second hole 11b, and the third hole 11c is formed so that the tip of the end 91 of the resin tube 90 to be connected is just inserted. ing. In addition, the base end portion of the metal inner cylinder 8 into which the inner peripheral surface of the end portion 91 of the resin tube 90 can be inserted is fitted into the fourth hole 11d, and is connected to the holder 30 toward the one end side. It extends so as to be concentric. However, when a rigid inner tube made of metal or the like corresponding to the inner cylinder 8 is held in advance on the inner peripheral surface of the end portion 91 of the resin tube 90, the fourth hole 11d and the inner cylinder 8 are unnecessary. .

As shown in FIG. 3, the tubular fastening member 50 has a tubular base portion 51 at one axial end and a fastening portion 52 at the other end. Specifically, a plurality of notches that have the same inner diameter as the inner peripheral surface of the tubular base portion 51 and that extend in parallel with the axis from the tubular base portion 51 toward the other end in the axial direction at intervals in the circumferential direction. A fastening portion 52 is integrally formed with the base portion 51 and the arm portion 53 at the free ends of a plurality of axially extending deformable arm portions 53 formed by applying 54. The outer diameter of the outer peripheral surface of the cylindrical base 51 is formed to be slightly smaller than the inner diameter of the guide inner peripheral surface 31a, and the outer peripheral surface is slidably formed on the guide inner peripheral surface 31a of the holder 30. On the other hand, the inner peripheral surface of the base portion is formed so that the tip end portion of the end portion of the tube can be inserted therein. Further, the tightening portion 52 projects outward in the radial direction from the arm portion 53, and the holder 3
No. 0 restricting concave tapered inner peripheral surface 31b of the head portion 52a and the claw portion 5 protruding inward from the head portion 52a in the centripetal direction and having a tip inner diameter smaller than the outer diameter of the tube 90 to be inserted.
2b and. In addition, the plurality of arm portions 53
Is provided with an adjacent extended portion 53a which is adjacent to the tightening portion 52 and extends in the axial direction toward one end side, and a thin portion 53b which extends between the adjacent extended portion 53a and the cylindrical base portion 51. That is, the adjacent extension portion 53a has an outer diameter slightly larger than the outer diameter of the cylindrical base portion 51, and the thin portion 53b has an outer peripheral surface having a diameter smaller than the outer diameter of the base portion 51. And the cylindrical body 1
No. 3 third hole 11c is formed so that the tip portion of the end portion 91 of the tube 90 can be fitted therein, and the tubular tightening member 5 described above.
The tightening portion 52 and the adjacent extension portion 53a of
The fastening member 5 is housed inside so as to be movable in the axial direction.
The inner peripheral surface 51a of the cylindrical base 51 of 0 is formed so that the tip of the end 91 of the tube 90 can be inserted.

Next, a method for connecting the one end portion 91 of the resin tube 90 to the tube joint shown in FIG. 1 and configured as described above will be described. As shown in FIG. 2, the holder 3
The one end portion 91 of the tube 90 is inserted from the open end of the annular base portion 51 of the tightening member 50 that projects outward with respect to one end of 0, the inner peripheral surface 31a of the holder 30, the insertion hole 21 of the rib 20, and the elasticity. The seal member 4 is communicated, and preferably inserted until the tip surface 91a comes into contact with the innermost step 11d of the third hole. At this time, in order for the outer peripheral end surface of the tube to pass the claw portion 52b, it is necessary to forcibly expand the tightening portion 52 outward in the radial direction, but between the guide inner peripheral surface 31a of the holder 30 and the thin portion 53b. Since the annular space A is generated, the tightening portion 52 can be easily expanded, and the tip end surface 91a of the resin tube 90 can be easily inserted to the innermost step 11d of the third hole. On this occasion,
The tube 90 is sealed by an annular elastic seal member 4 which is interposed between the outer peripheral surface of the end portion 91 of the tube 90 and the inner peripheral surface of the second hole 11b.

After that, when the tube 90 is pulled back a little, as shown in FIG.
The head portion 52a of the tightening member 50 first comes into contact with the regulating concave taper inner peripheral surface 31b and at least a part of the thick adjacent extension portion 53a of the arm portion 53 of the holder 30. The other end of the guide inner peripheral surface 31a is weakly engaged, and the claw portion 52b is weakly engaged with the outer peripheral surface of the end 91 of the tube 90. Then, when fluid pressure acts, as shown in FIG. The tube 90 is further returned, the head portion 52a also moves in the centripetal direction along the regulation concave taper inner peripheral surface 31b, and the claw portion 52b strongly engages with the outer peripheral surface of the end portion 91 of the tube 90 and is tightened. The adjacent extension portion 53a of the arm portion 53 of the member 52 is strongly engaged and held in the guide inner peripheral surface 31a,
The tube 90 is regulated to have an appropriate bite so as not to be cut into pieces. In addition, preferably, as shown in the drawing, a convex tapered surface is chamfered at the entrance of the adjacent extension 53a so that a part of the adjacent extension 53a can be smoothly inserted into the guide inner peripheral surface 31a of the holder 30. An insertion outer peripheral surface is formed.

Further, preferably, the insertion hole 21 of the rib 20 is formed.
By applying the annular protrusion 22 having the above-mentioned tapered outer peripheral surface 22a to the inner peripheral edge portion of the, the head portion 52a of the tightening portion 52 is By moving along the taper surface 22a, the tightening portion 52 can be widened, and the resin tube 9
0 can be removed from the tightening member 50, and the resin tube 90 can be easily removed from the cylindrical main body 10.

In this embodiment, as described above, the base end portion of the inner cylinder 8 into which the inner peripheral surface of the end portion 91 of the resin tube 90 can be inserted is fitted into the fourth hole 11d, and one end While extending concentrically with the holder 30 toward the side, as another form, a rigid short tube made of metal or the like corresponding to the inner cylinder 8 is previously provided on the inner peripheral surface of the end 91 of the resin tube 90. If held, this inner cylinder 8 is unnecessary.

As another embodiment, in the tube joint shown in FIGS. 6 and 7, the outer circumference of the adjacent extension portion 53c of the arm portion 53 of the tightening member 50 is gradually reduced in diameter from the head portion 52a toward the thin portion 53b. The structure is the same as that shown in FIGS. 1 to 5 except that it is formed as a convex tapered surface. By thus forming the outer periphery of the adjacent extended portion 53c into a convex tapered surface, the head portion 52a of the tightening portion 52 is reliably brought into contact with the concave tapered inner peripheral surface 31b in the state where the resin tube 90 is pulled back, Guide the adjacent extended portion 53c of the arm portion 53 to the inner peripheral surface 3
It can be securely and strongly attached to 1a. Although the embodiments of the present invention have been described in detail above, these are merely limited examples, and the present invention can be implemented in various modified forms without departing from the spirit of the invention.

According to the present invention, not only can the resin tube 90 be regulated to an appropriate bite so as not to be broken, but also when the resin tube 90 is pulled back, the tightening member 50 and the tube 90 together. To the one end side of the arm portion 53, and the adjacent thickened portions 53a and 53c of the arm portion 53, which are formed to be relatively thick, are inserted into the guide inner peripheral surface 31a and bite into the outer peripheral surface of the end portion 91 of the tube. The adjacent claw portion 52b and the adjacent extending portions 53a, 5 formed in a relatively thick wall and extending in the axial direction
The tube inserted by 3c can be firmly fixed. Therefore, even if a bending force acts on the resin tube 90, twisting generated at the base of the head portion 52a by the adjacent extending portions 53a, 53c is suppressed, and the resin tube 9 is always kept by the claw portion 52b.
The end portion 0 of 0 can be fixed firmly and uniformly in the circumferential direction, and the tube 90 can be prevented from coming off.
Then, even if the temperature of the engine room of the automobile changes and the resin tube expands or returns to its original state due to temperature change acting on the resin tube 90, the resin tube is always made uniform in the circumferential direction. The resin tube 90 can be firmly fixed, the resin tube 90 can be prevented from coming off easily, and the resin tube 90 can be uniformly fixed in the circumferential direction for a long period of time, and the heat deterioration performance can be improved. 1

[Brief description of drawings]

FIG. 1 is a cross-sectional view in which a lower half is omitted in a specific example of the tube joint of the present invention.

FIG. 2 is a cross-sectional view in which a lower half is omitted for explaining a state in which a resin tube is inserted into one end of the tube joint shown in FIG.

FIG. 3 is a cross-sectional view in which a lower half is omitted for explaining a state in which a resin tube inserted into one end of the tube joint shown in FIG. 2 is being pulled back.

FIG. 4 is a cross-sectional view in which a lower half is omitted for explaining a state in which a resin tube inserted in one end portion of the tube joint shown in FIG. 2 is pulled back.

5 is a partially cutaway side view in which the upper half of the fastening member used in the tube joint shown in FIG. 1 is cut away in cross section.

FIG. 6 is a partially cutaway side view in which the upper half is cut away in cross section for explaining another embodiment.

7 is a cross-sectional view in which a lower half is omitted for explaining a state in which a resin tube inserted into one end of the tube joint shown in FIG. 6 is pulled back.

FIG. 8 is a partially cutaway side view in which the upper half of a conventional tube joint is cut away in cross section for explaining the conventional technique.

[Explanation of symbols]

10 Tubular body 11 shaft hole 11a first hole 11b Second hole 11c Third hole 20 annular rib 21 insertion hole 30 holder 31a Guide inner peripheral surface 31b Regulating concave taper inner peripheral surface 4 Annular elastic seal member 50 Cylindrical tightening member 51 cylindrical base 51a inner peripheral surface 52 Tightening part 52a head 52b claw 52c Tapered surface 53 Arm 53a, 53c adjacent extension 53b Thin part 7 Annular recess A void

Claims (3)

(57) [Claims] 1. A pre-assembled tube joint that can be connected by pulling back an inserted resin tube, and extends in an axial direction having an inner diameter that gradually decreases from one end to the other end. , Sequentially the first hole, the second hole and the third
A tubular body having a shaft hole with a hole;
Has an insertion hole through which the end of the sleeve can be inserted, and the inner side of the first hole of the main body portion is radially inward from the inner peripheral surface of the first hole toward one end side. An annular rib integrally provided so as to project; an inner peripheral surface and an outer peripheral surface, the inner peripheral surface having a guide inner peripheral surface extending straight in parallel to the axis on one end side, and the other end A regulating concave tapered inner peripheral surface that gradually increases in diameter toward the other end adjacent to the guide inner circumferential surface, and forms an annular concave portion between the regulating concave tapered inner peripheral surface and the annular rib; A cylindrical holder having at least the other end of the outer peripheral surface fixed in the first hole of the cylindrical main body; an annular elastic seal member mounted in the second hole; and one axial end. A cylindrical shape having an outer diameter slightly smaller than the inner diameter of the guide inner peripheral surface having an outer peripheral surface slidable on the guide inner peripheral surface of the holder A base portion, a plurality of elastically deformable arm portions formed by providing notches spaced from each other in the circumferential direction extending from the tubular base portion toward the other end in the axial direction, and arranged in an annular shape, and A tubular fastening member having a fastening portion integrally provided at the free end of each arm portion;
The tightening portion of the tightening member includes a head portion that projects radially outward and abuts the inner peripheral surface of the restriction concave taper, and a tube that projects inward from the head portion in the centripetal direction and is inserted into the tube. A claw portion having a tip inner diameter smaller than the outer diameter of
Each arm portion of the tightening member is adjacent to the tightening portion, extends in the axial direction toward one end side, and has an adjacent extension portion having an outer diameter equal to or larger than an inner diameter of the guide inner peripheral surface, and the adjacent extension portion. A thin wall portion extending between the extending portion and the base portion and having an outer peripheral surface having a diameter smaller than the outer diameter of the base portion, and the third hole of the cylindrical main body can fit the end portion of the tube. While the tightening portion and the adjacent extending portion of the cylindrical tightening member are housed in the annular recess so as to be movable in the axial direction, the inner peripheral surface of the cylindrical base of the tightening member is The tip of the end of the tube is formed so that it can be inserted, and the tip of the end of the tube is inserted through the tubular tightening member, the rib, and the annular elastic seal member to form the tube. Said third of the body
When the tube is fitted in the hole, the gap between the outer peripheral surface of the end of the tube and the inner peripheral surface of the second hole is sealed by the annular elastic seal member, and when the tube is pulled back a little, the tightening member is It is moved to the one end side together with the tube, the head of the tightening member abuts on the inner peripheral surface of the restriction concave taper, and the head moves in the centripetal direction along the inner peripheral surface of the restriction concave taper. At the position where the claw portion is engaged with the outer peripheral surface of the end portion of the tube and is separated from the one end side end portion where the head portion and the regulating concave taper inner peripheral surface contact with each other in the axial one end side, A tube joint in which adjacent extension portions of each arm portion are inserted into and engaged with the guide inner peripheral surface. 2. The one end portion where the tightening member is moved to one end side together with the resin tube when the resin tube is slightly returned, and the head portion and the inner peripheral surface of the regulation concave taper are in contact with each other. The adjacent extending portions of the respective arm portions are inserted into and engaged with the guide inner peripheral surface at a position further away from the one end in the axial direction, so that the claw portions are the end portions of the resin tube. The depth of biting into the outer peripheral surface of the tube joint is restricted. "The tube joint according to claim 1. 3. The adjacent extension portion mounted and engaged with the guide inner peripheral surface at a position separated from one end side end portion where the head portion and the regulating concave taper inner peripheral surface contact with each other to one end side in the axial direction. 3. The tube joint according to claim 1, wherein the outer periphery of the tube joint is formed into a convex taper surface whose diameter gradually decreases from the head toward the thin portion.