Tube connecting structure

• US 6,199,919 B1
• Filed: 03/31/1999
• Issued: 03/13/2001
• Est. Priority Date: 03/31/1998
• Status: Expired due to Fees

• Current Assignee: Tokai Rubber Industries Limited
• Original Assignee: Tokai Rubber Industries Limited
• Inventors: Kawasaki, Minoru, Kasahara, Kazuhito
• Primary Examiner(s): Nicholson, Eric K.
• Application Number:
  US09/281,957
• Time in Patent Office: 713 Days
• Field of Search: 285/319, 285/331, 285/256
• US Class Current: 285/319
• CPC Class Codes: F16L 37/0985 the flexible hook extending radially inwardly from an outer part and engaging a bead, recess or the like on an inner part F16L37/0982 takes precedence

Abstract

A tube connecting structure for connecting a resin tube and a tubular mating member. The structure includes an engagement member having a cylindrical base that is attached onto the outer peripheral surface of an end portion of the resin tube and is fixed to the resin tube by a cylindrical press-fitted member. The cylindrical press-fitted member is press-fitted into the inner peripheral surface of the end portion, thereby expanding the diameter of the end portion of the resin tube and fixing the cylindrical base to the resin tube. The engagement member has a plurality of arm portions radially extending from the cylindrical base. First engagement portions, in the form of ratchets, are provided to protrude from tip end portions of the arm portions, such that the first engagement portions can be snap-engaged with a second engagement portion on the tubular mating member. The tubular mating member and the resin tube are directly connected to each other with a ring-shaped elastic seal member positioned therebetween.

Claims

1. A tube connecting structure comprising:

a resin tube having at least one end portion extending straight;

a ring-shaped elastic seal member abutting an outer peripheral surface or an inner peripheral surface of said one end portion of the resin tube;

an engagement member including a cylindrical base fitted onto the outer peripheral surface of said one end portion of the resin tube and a first engagement portion formed integrally with the cylindrical base;

a cylindrical press-fitted member having a cylindrical body, said body press-fitted into the inner peripheral surface of the end portion of the resin tube, expanding a diameter of the end portion and fixing said engagement member to said resin tube; and

a tubular mating member having an insertion end portion, said insertion end portion provided with a second engagement portion, said second engagement portion engaged with the first engagement portion of said engagement member, wherein

said ring-shaped seal member is disposed in a radial annular groove defined by one end portion of said cylindrical press-fitted member and said engagement member such that said seal member contacts said tubular mating member and said one end portion of the resin tube when the insertion end portion of said tubular mating member is inserted into the outer peripheral surface or inner peripheral surface of the end portion of said resin tube, said second engagement portion engaged with said first engagement portion of said engagement member;

thereby sealing the insertion end portion of said tubular mating member and said one end portion of said resin tube.

2. The tube connecting structure according to claim 1, wherein

said tube connecting structure comprises a cap-shaped outer cylindrical portion returned outward of said cylindrical body to cover an end face of the resin tube and said outer peripheral surface of said one end portion of the resin tube at an one end of said cylindrical press-fitted member,

said ring-shaped elastic seal member is axially retained on the outer peripheral surface of the resin tube between said cap-shaped outer cylindrical portion of said cylindrical body of said cylindrical press-fitted member and said cylindrical base of said engagement member, and

when the insertion end portion of said tubular mating member is inserted into the outer peripheral surface side of the end portion of said resin tube, the inner peripheral surface of the insertion end portion is engaged with the outer peripheral surface of the cylindrical base and with the outer peripheral surface of said cap-shaped outer cylindrical portion.

3. The tube connecting structure according to claim 1, wherein

said tube connecting structure comprises said cap-shaped inner cylindrical portion returned inner ward of said cylindrical body to cover an end face of said resin tube and said inner peripheral surface of said one end portion of the resin tube at an one end of the cylindrical base of said engagement member,

said ring-shaped elastic seal member is axially retained on the inner peripheral surface of the resin tube between said cap-shaped inner cylindrical portion of the engagement member and said body of said cylindrical press-fitted member, and

when the insertion end portion of said tubular mating member is inserted into the inner peripheral surface side of the end portion of said resin tube, said outer peripheral surface of said insertion end portion is engaged with both of said inner peripheral surface of said cylindrical body of said cylindrical press-fitted member and the inner peripheral surface of said cap-shaped inner cylindrical portion.

4. The tube connecting structure according to claim 3, wherein

the tube connecting structure comprises a retaining member fitted into said inner peripheral surface of the end portion of said resin tube instead of said cap-shaped inner cylindrical portion, and

said ring-shaped elastic seal member is axially retained on said inner peripheral surface of the resin tube between said retaining member and said cylindrical body of said cylindrical press-fitted member.

5. The tube connecting structure according to one of claims 1 through 4, wherein

said engagement member comprises a plurality of arm portions axially extending from the cylindrical base toward said end surface of said one end portion of the resin tube, and said arm portions defined a radial space between said arm portions and said outer peripheral surface of both of said outer peripheral surface of said cylindrical base and said cap-shaped outer cylindrical portion and said cylindrical base, said arm portions circumferentially spaced from one another;

and ratcheted first engagement portions provided to protrude radially inwardly on tip end portions of said arm portions, respectively, and

said annular first engagement portions are snap-engaged with said second engagement portion of said tubular mating member inserted into a radial space of the plural arm portions.

6. The tube connecting structure according to one of claims 1 through 4, wherein

said engagement member comprises two arm portions axially extending from the cylindrical base toward axial one end direction, said two arm portions opposite to each other and circumferentially spaced from one another furthermore said two arm portions radially spaced from said cylindrical base each other;

a circular ring portion integrally connected with a tip end portion of said two arm portions and provided coaxially with the cylindrical base; and

a pair of ratcheted first engagement portions provided, opposite to each other, to protrude radially inwardly on an inner peripheral surface of the ring portion, and

the first engagement portions are snap-engaged with the second engagement portion of said tubular mating member inserted into interiors of said ring portion.

7. The tube connecting structure according to one of claims 1 through 4, wherein

said engagement member comprises two arm portions axially extending from the cylindrical base toward an axial one end direction, said two arm portions opposite to each other and circumferentially spaced from one another furthermore said two arm portions radially spaced from said cylindrical base each other;

an elliptical or oval ring portion integrally connected with a tip end portion of said two arm portions and provided coaxially with the cylindrical base; and

a pair of ratcheted first engagement portions provided, opposite to each other, to protrude radially inwardly on an axially inner peripheral surface of said ring portion on which the ring has a smallest inner diameter, and

the first engagement portions are snap-engaged with the second engagement portion of said tubular mating member inserted into interiors of said ring portion.

8. The tube connecting structure according to claim 1, wherein said tube connecting structure comprises a nipple portion smoothly protruding radially outwardly provided on the insertion end portion of said cylindrical press-fitted member.

9. The tube connecting structure according to claim 1, wherein said tube connecting structure includes an annular projection portion protruding from both edge portions of the cylindrical base of said engagement member radially inwardly or an irregular portion provided on the inner peripheral surface of the cylindrical base of said engagement member to bite into the outer peripheral surface of the resin tube.

10. A tube connecting structure for a resin tube and a tubular mating member comprising:

a resin tube having at least one end portion extending straight;

an engagement member including a cylindrical base fitted into an outer peripheral surface of the one end portion of said resin tube and first engagement means formed integrally with the cylindrical base and engaged with said tubular mating member;

a ring-shaped elastic seal member directly contacting with and attached onto the outer peripheral surface or inner peripheral surface on an axial intermediate portion of the one end portion of said resin tube;

a cylindrical press-fitted means having at least one cylindrical body, said body press-fitted into the inner peripheral surface of the one end portion of said resin tube and fixing said engagement member to an outer peripheral surface on the other side of the one end portion of said resin tube, said body including a retaining means for preventing disassembly of said elastic seal member from said resin tube, said retaining means including a radially extending circular surface opposed to said elastic seal member, said circular surface extending outwardly beyond the outer peripheral surface or extending inwardly beyond the inner peripheral surface of the one end portion of said resin tube; and

a tubular mating member having an insertion end portion, which can be relatively inserted into the outer peripheral surface of one end portion of the base of said engagement member by fluid tight-engaging an inner peripheral surface of said tubular mating member with the outer peripheral portion of said ring-shaped elastic seal member attached to the outer peripheral surface of the one end portion of said resin tube;

or an insertion end portion, which can be relatively inserted into the inner peripheral surface of said press-fitted means by fluid tight-engaging an outer peripheral surface of said tubular mating member with the inner peripheral portion of said seal member attached to the inner peripheral surface of the one end of said resin tube;

and second engagement means provided on the outer peripheral surface of one of the insertion end portions of said mating member so as to be extended outward radially, said second engagement means being engaged with the first engagement means when one of the insertion end portions is relatively inserted into the one end portion of said resin tube, wherein

when the insertion end portion of said tubular mating member is inserted into the outer peripheral surface or the inner peripheral surface of the end portion of said resin tube, the second engagement means of said tubular mating member is engaged with the first engagement means of said resin tube, said seal member directly contacting with and interposed between said tubular mating member and said resin tube, thereby sealing the insertion end portion of said tubular mating member and the end portion of said resin tube.

11. The tube connecting structure according to claim 10, wherein

said ring-shaped elastic seal member directly contacts with and is attached to the inner peripheral surface on the axial intermediate portion of the one end portion of said resin tube,

the retaining means composing the ring-shaped surface of said cylindrical press-fitted means is composed of an inner cylindrical portion as one end portion of the body which is extended from the one end portion of the base of said engagement member and is turned so as to be cover the inner peripheral surface of said resin tube,

said ring-shaped elastic seal member is attached to and held on the inner peripheral surface of the end portion of said resin tube corresponding to a space between the other end portion of said cylindrical press-fitted means and the inner cylindrical portion, and

said tubular mating member has the insertion end portion which can be relatively inserted into the inner peripheral surface of said press-fitted means by fluidtight-engaging the outer peripheral surf ace of said tubular mating member with the inner peripheral portion of said seal member attached to the inner peripheral surface of the one end of said resin tube.

12. The tube connecting structure according to claim 10, wherein

said engagement member comprises a plurality of arm portions axially extending from the outer peripheral surface of the cylindrical base toward a tip end of said resin tube, and said arm portions circumferential spaced from one another furthermore said arm portions radially spaced from the outer peripheral surface of said cylindrical base;

and ratcheted first engagement portions integrally provided to protrude radially inwardly on tip ends of said arm portions, respectively, and

the first engagement portions are snap-engaged with the second engagement portion of said tubular mating member inserted into the plural arm portions.

13. The tube connecting structure according to claim 10, wherein

said engagement member comprises a pair of arm portions axially extending from the cylindrical base toward a tip end of said resin tube, said arm portions opposite to each other and circumferential spaced from one another furthermore said arm portions radially spaced from the outer peripheral surface of the cylindrical base each other;

a circular ring portion integrally connected with a tip end portion of the arm portions and provided coaxially with the cylindrical base; and

a pair of ratcheted first engagement portions provided, opposite to each other, to protrude radially inwardly on an inner peripheral surface of the ring portion, and

the first engagement portions are snap-engaged with the second engagement portion of said tubular mating member inserted into the ring portion because an inner diameter of the circular ring portion is larger than an outer diameter of the insertion end portion of said tubular mating member.

14. The tube connecting structure according to claim 10, wherein

said engagement member comprises a pair of arm portions axially extending from the cylindrical base toward a tip end of said resin tube, said arm portions opposite to each other and circumferentially spaced from one another furthermore said arm portions radially spaced from a cap-shaped outer cylindrical portion and the outer peripheral surface of the cylindrical base each other;

an elliptical or oval ring portion integrally connected with a tip end portion of the arm portions and provided coaxially with the cylindrical base; and

a pair of ratcheted first engagement portions provided, opposite to each other, said first engagement portions protruded radially inwardly on an axially inner peripheral surface of said ring portion on which the ring has a smallest inner diameter; and

the first engagement portions are snap-engaged with the second engagement portion of said tubular mating member inserted into the ring portion.

15. A tube connecting structure for a resin tube and a tubular mating member comprising:

a resin tube having at least one end portion extending straight;

an engagement member including a cylindrical base fitted into an outer peripheral surface of the one end portion of said resin tube and first engagement means formed integrally with the cylindrical base and engaged with said tubular mating member;

a cylindrical press-fitted means having a cylindrical body, said body press-fitted into an inner peripheral surface of the end portion of said resin tube, expanding a diameter of the end portion and fixing said engagement member to the outer peripheral surface of the other end side of the one end portion of said resin tube;

a ring-shaped extended portion extending from an outer peripheral surface on one end of the body outward radially to exceed an outer peripheral surface on one end of the expanded diameter end portion;

a ring-shaped elastic seal member attached to and held on the outer periphery of the one end portion of said resin tube corresponding to a space between an one end portion of the base of said engagement member and the ring-shaped extended portion of said cylindrical press-fitted means; and

a tubular mating member having an insertion end portion, an inner peripheral surf ace of the insertion end portion capable of being relatively inserted into the outer peripheral surface of the one end portion of the base of said engagement member by fluidtight-engaging said tubular mating member with an outer peripheral surface of said attached and held ring-shaped elastic seal member;

protruded second engagement means provided on an outer peripheral surface of the insertion end portion, said second engagement means capable of being engaged with the first engagement means when the insertion end portion is relatively inserted into the one end portion of said resin tube, wherein

when the insertion end portion of said tubular mating member is inserted into the outer peripheral surf ace on the end portion of said resin tube, the second engagement means of said tubular mating member is engaged with the first engagement means of said resin tube, said seal member directly contacting and interposed between said tubular mating member and said resin tube, thereby sealing the insertion end portion of said tubular mating member and the end portion of said resin tube.

16. The tube connecting structure according to claim 15, wherein

said engagement member comprises a pair of arm portions axially extending from the cylindrical base toward a tip end of said resin tube, said arm portions opposite to each other and circumferentially spaced from one another furthermore said arm portions radially spaced from a cap-shaped outer cylindrical portion and the outer peripheral surface of the cylindrical base each other; an elliptical or oval ring portion integrally connected with a tip end portion of the arm portions and provided coaxially with the cylindrical base; and

a pair of ratcheted first engagement portions provided, opposite to each other, said first engagement portions protruded radially inwardly on an axially inner peripheral surface of said ring portion on which the ring has a smallest inner diameter; and

the first engagement portions are snap-engaged with the second engagement portion of said tubular mating member inserted into the ring portion.