CN1217426A

CN1217426A - Pipe adaptor

Info

Publication number: CN1217426A
Application number: CN98121359A
Authority: CN
Inventors: 杉原启之
Original assignee: Hino Jidosha Kogyo KK
Current assignee: Hino Motors Ltd
Priority date: 1997-11-11
Filing date: 1998-10-16
Publication date: 1999-05-26
Anticipated expiration: 2018-10-16
Also published as: KR19990044915A; JPH11141759A; KR100322637B1; JP3492503B2; CN1087062C

Abstract

Providing the pipe joint which can prevent an increase in resistance of a flow passage and a decrease in sealing performance by preventing the deformation of a pipe and that of a nipple even if the fastening torque of a nut is increased. The outer peripheral surface of a nipple 8 is fitted in the inner peripheral surface of a nut 6 at a restraint portion 10 by forming in the deep portion of the nut 6 the restraint portion 10 having an inner diameter nearly equal to the outer diameter of the nipple 8 interposed between an engaging surface 5 bulging out near the tip of a pipe 3 and the fastening surface 7 of the nut 6. This prevents the probable deformation of the nipple 8 when the fastening torque of the nut 6 is excessively increased.

Description

Pipe joint

The present invention relates to a kind of pipe joint, particularly relate to a kind of being applicable to and connect the pipe joint of high pressure line with pipeline.

As existing example, the pipe joint that high pressure line as the injection pipe of diesel engine is used, as shown in Figure 5, the front end of pipeline 3 be formed be formed at component 1 on the sealing surfaces 4 that closely contact of sealing surface 2, the front end of pipeline 3 is processed to form aforementioned sealing surface 4 and junction surface 5 by the enlarging of bridge shape.Like this, because the inside that is plugged in the nut 6 on the aforementioned pipeline 3 has formed axially intersect vertically fastening 7 with this pipeline 3, and connect aforementioned junction surfaces 5 and fastening 7 by the joint 8 that places nut 6 inside, and nut 6 is anchored on the component 1, make aforementioned two

sealing surfaces

2,4 keep closely contact.

In such pipe joint, owing on body, forms sealing surface 4, for example relatively rise joint brazing is had the little advantage of leak of liquid danger in the technology of pipeline front end at pipeline 3.

Because the relation of Thread Machining Process, the internal diameter of nut 6 inside of taking in joint 8 is greater than the external diameter of screw section and joint 8 in the conventional art, therefore, and the gap 9 of formation ring-type between the inner peripheral surface of the outer circumferential face of joint 8 and nut 6.

Thereby, nut 6 with special problem can not take place under the state tightened of fixed moment of torsion, but in the excessive occasion of the screw-down torque of nut 6, the wedge effect lower contact that produces between junction surface 5 and joint 8 shown in Figure 68 expansions can take place and take place damaged, simultaneously the front end gross distortion of pipeline 3 makes the slyness damage of its inner face and increases the resistance of stream, when serious, under the leverage of the joint 8 that has been out of shape, even can make fastening 7 distortion, and can not obtain the fastening force that needs, thereby the sealing reduction between the sealing surface 4 of the sealing surface 2 that may cause component 1 and pipeline 3.

In view of the foregoing, the purpose of this invention is to provide and a kind ofly also can suppress the distortion of pipeline and joint, preventing to prevent the pipe joint that sealability reduces when stream impedance that pipeline causes from increasing in the big occasion of the Tightening moment of nut.

In order to address the above problem, pipe joint of the present invention forms the sealing surface that contacts closely with the component sealing surface by the front end at pipeline, near the front end of pipeline, heave shape and form junction surface, and it is inner and be connected by the joint that is accommodated in the nut with aforementioned junction surface Jie with axially intersect vertically fastening of pipeline to be formed at the nut that is inserted on the aforementioned pipeline, and nut is anchored on the component to keep the close contact of aforementioned two sealing surfaces.In this pipe joint, in the inner roughly the same constraint portion of external diameter that forms internal diameter and aforementioned joint of nut, and outer circumferential face that should constraint portion middle joint is embedded in the inner peripheral surface of nut.

Fig. 1 is demonstration pipe joint the 1st embodiment's of the present invention sectional arrangement drawing,

Fig. 2 is the longitudinal sectional drawing of the state of nut when screw-down torque is excessive of expression pipe joint shown in Figure 1,

Fig. 3 is demonstration pipe joint the 2nd embodiment's of the present invention sectional arrangement drawing,

Fig. 4 is demonstration pipe joint the 3rd embodiment's of the present invention sectional arrangement drawing,

Fig. 5 shows the sectional arrangement drawing of pipe joint one example in the past,

Fig. 6 is the longitudinal sectional drawing of the state of nut when screw-down torque is excessive of expression pipe joint shown in Figure 5.

Below with reference to the accompanying drawings embodiments of the invention are described, Fig. 1 is pipe joint the 1st an embodiment's of the present invention sectional arrangement drawing.Wherein annotate with same-sign, omit its detailed description at this with the part that Fig. 5 and example in the past shown in Figure 6 have identical function.

In Fig. 1, the front end of pipeline 3 by the enlarging of bridge shape be processed to form with component 1 on the sealing surface 2 that the forms sealing surface 4 and the junction surfaces 5 that closely contact.Be formed with axially intersect vertically fastening 7 with this pipeline 3 in the inside that is plugged in the nut 6 on the described pipeline 3, and by the joint 8 that is accommodated in the nut 6 aforementioned junction surface 5 is connected with fastening 7, thereby nut 6 is anchored on the component 1 to keep the close contact of aforementioned two

sealing surfaces

2,4.

In the pipe joint of structure like this, in the present embodiment, the internal diameter of the nut 6 by will taking in joint 8 makes the outer circumferential face of joint 8 be embedded in the inner peripheral surface of nut 6 in this constraint portion 10 from fastening 7 beginning and be set at roughly the samely and constitute constraint portion 10 with the external diameter of joint 8 with the corresponding size of the thickness of joint 8.

Like this, even the wedge effect lower contact that produces between junction surface 5 and the joint 88 produces expansion, under the maintenance effect of restraining portion 10, also can suppress the distortion of joint 8 when nut 6 is tightened.Therefore, even in the excessive occasion of the screw-down torque of nut 6, also only joint 8 is approaching to component 1 as shown in Figure 2, and making the bridge shape enlarging of pipeline 3 front ends add the Ministry of worker has distortion slightly, but because the not infringement of the slyness of pipeline 3 inner faces, so can not increase the impedance of the stream that this pipeline 3 causes.

In addition, because of with constraint portion 10 in the packing interaction of nut 6, prevented the distortion of joint 8.Kept the sealability between the sealing surface 4 of the sealing surface 2 of component 1 and pipeline 3.

In the above-described embodiments, the internal diameter of the container universe of the joint 8 of nut 6 inside and the external diameter of this joint 8 are roughly the same, obtained the effect that prevents joint 8 distortion, but in order more effectively to suppress nut 6 and joint 8 distortion, the wall pressure that adds big nut 6 and joint 8 also is that effectively the structure of constraint portion 10 has more than and is limited to the form shown in the 1st embodiment.

Fig. 3 is the 2nd embodiment's of pipe joint of the present invention sectional arrangement drawing.In the present embodiment, in the inner end formation of the nut 6 constraint portion 10 shorter than the thickness of joint 8, simultaneously, make the minor diameter of thread of nut 6 consistent with the external diameter of joint 8, screw thread is being shared the function as constraint portion.

As shown in this embodiment, length in the contained portion 10 of the inside that is formed at nut 6 is littler than the thickness of joint 8, and obtain the occasion of the deformation effect that suppresses joint 8 jointly with the inner end of worm tooth, with aforementioned the 1st embodiment contrast, have the advantage that the screw thread effective length is strengthened.

Fig. 4 is pipe joint the 3rd an embodiment's of the present invention sectional arrangement drawing.In the present embodiment, in the scope of comparing enough weak points with the thickness of joint 8, be provided with the tool withdrawal groove 11 of nut 6 internal diameters greater than joint 8 external diameters.The minor diameter of thread by making nut 6 and the external diameter of joint 8 are roughly the same, the inside of this screw thread can be embedded on the joint 8, realize the function of constraint portion.

In the occasion of present embodiment because the screw thread opposing tabs 8 of nut 6 has been brought into play the effect that suppresses distortion, with above-mentioned shown in two embodiments same, can prevent the distortion of joint 8 in the excessive occasion of screw-down torque.Shown in the present embodiment, be provided with tool withdrawal groove 11 occasions in nut 6 inside owing to can process worm structure, have the advantage that can avoid nut 6 manufacture costs to rise with high efficiency rolling forming.

In the above-described embodiments, all be to form sealing surface 4 and junction surface 5 through bridge shape enlarging processing by front end with pipeline 3, even in the excessive occasion of the screw-down torque of nut 6, because the metamorphosis that the enlarging of bridge shape adds the Ministry of worker also can access stable sealing effect, but also the front end of pipeline 3 can be carried out single enlarging processing or two enlarging processing to form sealing surface 4 and junction surface 5.

As described above disclosed, the present invention is owing to the constraint portion and the joint tabling that are formed in the nut, even the distortion in that the excessive occasion of the screwing force of nut also can not produce joint when suppressing the distortion of pipeline front end, does not damage the sealing between pipeline and component.

Claims

1. pipe joint, be formed with the pipeline of the sealing surface that contacts closely with the sealing surface of component by front end, near its front end, bloat shape and form junction surface, in the inner formation of the nut that is plugged in described pipeline, and be connected with the joint of described junction surface in being accommodated in nut with axially intersect vertically fastening of pipeline, nut is anchored on the component to keep the close contact of described two sealing surfaces, it is characterized in that: be formed with the roughly the same constraint portion of external diameter of internal diameter and described joint in nut inside, the outer circumferential face of this constraint portion middle joint is embedded on the inner peripheral surface of nut.