JPH09257186A - Joint for pipe with orifice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the noise of a joint caused by the pulsation pressure of fluid supplied from a pump or the like at low cost. SOLUTION: A through hole 14 is coaxially formed in a joint 10, and the diameter of a third hole part in the intermediate part of the through hole is made smaller than the inner diameters of the hole parts on both sides to constitute an orifice. Or a cylindrical bushing member is fixed to the through hole of the joint, and the orifice is constituted with the through hole of the bushing member. Pulsation pressure propagating from a pump is damped with the orifice, and noise generating from the joint can be reduced. Since the orifice is simply formed, noise reducing effect is obtained at low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piping joint used in a piping system for transporting fluid such as fuel, and more particularly to a piping joint with an orifice suitable for use in a piping system of an automobile.

[0002]

2. Description of the Related Art Fuel pipes and other fluid pipes used in automobiles are provided with pumps, fuel injectors, and flow pipes for supplying fuel and other fluids. A route switching valve or the like is connected. These generate minute pulsation during operation in the pipeline, this pulsation is transmitted to the tube and joint of the piping system, and by resonance with the tube and joint,
Generates abnormal sounds such as pulsating sounds and flowing sounds, and these abnormal sounds
It is transmitted to the passenger compartment and makes passengers uncomfortable.

Various measures have been attempted against this. For example, although it is an improvement of a pulsation generation source such as a pump or an injector, it is difficult to suppress the generation of pulsation due to its performance and cost. Further, it may be considered to install a damper, an accumulator or the like in the piping system to reduce the pulsating pressure, but it has the drawbacks that it is expensive, the space for installing the parts is large, and the weight is large. Furthermore, although there is a method of suppressing the transmission of abnormal noise into the vehicle compartment by disposing a soundproof material between the tube and the vehicle compartment, the cost increase due to the use of a large amount of soundproof material is a problem. Further, it is conceivable to elastically support the tube on the vehicle body with a rubber bush or the like, but depending on the supporting position, the reduction effect is small and the cost is increased.

By the way, it is generally known that the propagating sound can be attenuated by providing an orifice having a layout as shown in FIG. Assuming that there is no transmission of vibration energy from the tube wall or energy loss due to the viscosity of the medium for this orifice, the attenuation amount of the propagating sound is evaluated by the transmission loss, and the transmission loss TL is expressed by the following formula 1. It

[0005]

[Number 1] TL = 10 log {1 + m 2 (k × l d) 2 /
4}

However, m = S / Sd, S is the sectional area of the conduit, and Sd is the opening area of the orifice. Also, k
= 2πf / c, f is the frequency of the sound wave, and c is the speed of sound in the medium. l _d is the length of the orifice.

Actually, since there is energy permeation from the tube wall and the like, the equation 1 cannot be obtained, but if the transmission loss TL is large, the propagation sound is greatly attenuated, so that the sound generated from the tube is suppressed, If the transmission loss TL is small, the attenuation of the propagating sound is small, and the sound generated from the tube tends to be loud. It is also known that by using an elastic material for the orifice and the pipe, the propagation sound is attenuated by the vibration loss due to being absorbed by the elastic body. Based on the above facts, the inventor of the present invention uses a simple means to suppress pulsation that is transmitted from a pulsation source such as a pump or an injector to a joint of a piping system and causes abnormal noise introduced into a vehicle interior. Devised. That is, the present invention is intended to solve the above problems, and an object of the present invention is to provide a pipe joint that can reduce the generation of abnormal noise due to pulsating pressure transmitted from a pump or the like at low cost.

[0008]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, a structural feature of the invention according to claim 1 is a joint for fitting and fixing a piping tube, This is because an orifice that coaxially narrows the cross section of the flow hole in the direction perpendicular to the axis is provided in part of the flow hole.

In the invention according to claim 1 configured as described above, fluids containing various pulsating pressures flow into the joint in the pipe and pass through the orifice portion. Due to the orifice effect as shown, the propagating pulsating pressure can be attenuated. Therefore, abnormal noise generated from the joint due to the pulsating pressure can be reduced. As a result, for example, in a joint used for a piping system of an automobile, it is possible to reduce abnormal noise transmitted to the passenger compartment and improve the riding comfort of the vehicle.
Further, according to the present invention, since the orifice can be provided only in the joint itself or the member can be attached to the flow hole of the joint, the noise reduction effect can be obtained at low cost. The degree of reduction of the pulsating pressure can be adjusted by changing the diameter and length of the orifice.

Further, a structural feature of the invention according to claim 2 is that in the piping joint with an orifice according to claim 1, the orifice has a through hole having a diameter smaller than an inner diameter of the through hole. Is provided by being coaxially mounted in the through hole. In the invention according to claim 2 configured as described above, the orifice can be easily provided in the joint by mounting the bush member. By selecting and using bush members having different inner diameters and lengths of the through holes, it is possible to adjust the amount of abnormal noise generated by the orifice.
In addition, a joint with various orifice sizes can be configured by simply preparing a bush for each orifice size and assembling it into the joint without preparing a joint for each orifice size, so that the joint storage management can be simplified. .

Further, a structural feature of the invention according to claim 3 is that in the piping joint with an orifice according to claim 2, the bush member is formed of a rubber-like elastic material. . In the invention according to claim 3 configured as described above, the pulsating pressure is absorbed and weakened by the elasticity of the rubber-like elastic material. As a result, in addition to the effect of the invention described in claim 2, it is possible to further reduce the pulsating pressure, and it is possible to further suppress the transmission of abnormal noise into the vehicle interior or the like.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a joint 10 interposed in a fuel supply pipe of an automobile according to the first embodiment. It is shown schematically. The joint 10 is a tubular body made of metal, and is provided with a step 11 for flange alignment in the middle portion in the longitudinal direction, and is divided into a small diameter portion 12a and a large diameter portion 12b having a slightly larger diameter by the step 11. There is.
A ring-shaped groove portion 1 is coaxially provided near the tip of the small diameter portion 12a.
3 is provided and the O-ring 13a is attached.

A through hole 14 is coaxially provided in the joint 10. The through hole 14 is a first hole located in the small diameter portion 12a.
The hole 14a and the second hole 14 having a diameter slightly larger than that of the first part 14a extending from the tip of the large diameter part 12b to the intermediate position.
b and a third hole portion 14c having a small diameter between them are provided as different diameter holes. The third hole portion 14c is formed smaller than the first hole portion 14a, and this portion constitutes an orifice. The small diameter portion 12a is attached to a flange member 15 for fixing the joint 10 to the vehicle body, and is fixed at the step 11 position. The metal tube 1 is provided in the second hole portion 14b.
The tip portion of 6 is inserted and fixed. Small diameter part 12a
One end of the hose H is externally fitted to the shaft by press fitting.

When gasoline flows from a pump (not shown) into the joint 10 constructed as described above, the third hole 1
The 4c orifice damps the pulsating pressure from the pump. Therefore, due to pulsation, the joint 10
It is possible to reduce the abnormal noise generated from. As a result, it is possible to reduce abnormal noise in the passenger compartment of the automobile and improve the riding comfort. Further, since the joint 10 is formed with the third hole portion 14c that forms an orifice at the same time when the through hole 14 is formed, no extra member or the like is required to reduce pulsation, and thus the noise reduction effect can be obtained at low cost. Obtainable. The degree of reduction of the pulsating pressure can be adjusted by changing the diameter and length of the orifice.

As a modification of the first embodiment, as shown in FIG. 2, the present invention can be similarly applied to the joint 17 in which the through hole 19 is L-shaped.
Also in this case, the first hole portion 19a provided in the small diameter portion 18a
The third hole 19c provided between the second hole 19b and the second hole 19b penetrating from the outer peripheral surface of the large diameter part 18b toward the axis.
The orifice can be formed by reducing the diameter smaller than that of the hole 19a. Also in the modified example configured in this way, the same effect as that of the first embodiment can be obtained.

Next, a second embodiment of the present invention will be described. FIG. 3 is a schematic cross-sectional view of a fuel supply joint 20 provided in a fuel supply pipe of an automobile according to the second embodiment. The joint 20 is a metal tubular body, and is provided with a flange alignment step 21 in the middle portion in the longitudinal direction, and is divided by the step 21 into a small diameter portion 22a and a large diameter portion 22b having a slightly larger diameter. . A ring-shaped groove portion 23 is coaxially provided near the tip of the small diameter portion 22a.
Is provided and an O-ring (not shown) is attached. A through hole 24 is coaxially provided in the joint 20. The through hole 24 has a first hole portion 24a extending from the end surface of the small diameter portion 22a to a position near the end surface of the large diameter portion 22b.
And a second hole portion 24b having a diameter slightly larger than the first hole portion 24a reaching the end surface of the large diameter portion 22b.

In the first hole portion 24a, as shown in FIG.
A sleeve-shaped bush member 25, which is cylindrical from the end face and has a thread on the outer periphery, is screwed. However, the bush member 25 may be attached by means of shrink fitting, adhesion, crimping, or the like. The bush member 25 has a through hole 25.
The diameter of a is smaller than the diameter of the through hole 24, and this portion constitutes an orifice. Small diameter part 22
The fixing flange (not shown) shown in the first embodiment is fixed to a. The tip portion of the metal tube 26 is inserted and fixed to the second hole portion 24b. A hose (not shown) on the small diameter portion 22a
Is fitted by press fitting.

When gasoline flows into the joint 20 constructed as described above, the through hole 25a of the orifice causes
The pulsating pressure from the gasoline source pump is reduced. As a result, the abnormal noise generated from the joint 20 is reduced, the abnormal noise in the passenger compartment of the automobile can be reduced, and the riding comfort of the automobile can be improved. Also, joint 2
In No. 0, the orifice is formed by screwing the bush member 25 into the through hole 24, and the noise reduction effect can be obtained at low cost. Then, by changing the length and diameter of the through hole 25a of the bush member 25, the degree of reduction of the pulsating pressure can be adjusted.

Next, a third embodiment of the present invention will be described. FIG. 4 is a schematic cross-sectional view of the joint 30 according to the third embodiment. The joint 30 has substantially the same structure as the joint 20 shown in the second embodiment,
It is divided into a small diameter portion 32a and a large diameter portion 32b by a step 31, and the through hole 33 also has a first hole portion 33a and a second hole portion 33.
b. However, the through hole 33 is the first hole portion 3
Instead of providing a thread groove on the inner wall of 3a, a ring-shaped groove portion 33a1 is coaxially provided on the inner peripheral surface of the small diameter portion 32a at a substantially intermediate position in the axial direction. Others
It is similar to the joint 20 of the second embodiment.

A cylindrical container-shaped bush member 34 having one end closed is attached to the first hole 33a. As shown in FIG. 5, the bush member 34 is provided with an engaging portion 34a that spreads outward in a brim shape on the open end side, and a through hole 34b1 at the center position of the closing surface 34b. The closed surface 34b provided with the through hole 34b1 constitutes an orifice. In addition, the cylindrical surface 3 of the bush member 34
4c has a plurality of slits 3 parallel to the axis from the open end side.
4c1 are provided at equal intervals, and the bush member 34
However, it can be deformed in the diameter reducing direction at the open end side. Then, in a state where the open end side of the bush member 34 is contracted,
By being inserted into the first hole portion 33a, the open end side of the groove portion 33a1 returns to its original state and is engaged with the groove portion 33a1, whereby the bush member 34 is fixed.

Also in the joint 30 constructed as described above, when gasoline flows into the joint 30, the pulsating pressure from the pump (not shown) of the gasoline supply source is attenuated at the closing surface 34b of the orifice. As a result, the abnormal noise generated from the joint 30 is reduced, the abnormal noise in the vehicle interior can be reduced, and the riding comfort of the automobile can be improved. Further, the joint 30 has an orifice formed by fitting the bush member 34 into the first hole portion 33a, so that the noise reduction effect can be obtained at low cost. Then, the through hole 34b1 of the bush member 34
The degree of reduction of the pulsating pressure can be adjusted by changing the length and diameter of the.

As a modified example of the third embodiment, as shown in FIG. 6A, the first hole 33 of the joint 30 is formed.
A groove portion 33a1 is not provided in a and the bush member 36 is an engaging portion 36a having the same shape as the bush member 34, a closing surface 36b, a cylindrical surface 36c and a closing surface 36b.
Has a through hole 36b1 formed in it and has a slit 34c1
Is not provided. This bush member 36 is connected to the joint 3
It can be inserted from the side of the second hole 33b of No. 0 and fitted into the first hole 33a. In this case, the brim-shaped engaging portion 36a of the bush member 36 is brought into contact with the step portion between the first hole portion 33a and the second hole portion 33b and positioned. Further, the bush member 36 is fixed to the joint 30 by mounting and fixing the metal tube 35 in the second hole 33b.

Further, as shown in FIG. 6 (b), the bush member 37 may be formed in a disk shape, and the through hole 37b may be coaxially provided in the main body 37a. The bush member 37 of this form is characterized in that it is not necessary to provide a slit. As described above, the bush member 3
Even if the orifices are formed in the first hole portion 33a and the second hole portion 33b by using Nos. 6 and 37, the same effect as that of the third embodiment can be obtained.

Next, a fourth embodiment of the present invention will be described. FIG. 7 schematically shows a joint 50 according to the fourth embodiment in a partially broken sectional view. Joint 50
Is a nipple portion 41 which bulges in a chevron section in the radial direction by subjecting the tip of the metal tube 40 to bulging.
It was formed with. The other end of the tube 40 is joined to the joint member main body 51. Nipple part 4
As shown in FIG. 7, a bush member 42 is fitted inside 1 in a close contact state.

The bush member 42 is provided with an engaging portion 42a which has a mountain-shaped cross section from the open end side toward the outer peripheral side in the axial direction, and the through hole 42b1 is formed at the center position of the closing surface 42b.
Is provided. This through hole 42b1 constitutes an orifice. Further, a plurality of slits 42a1 are provided in the engaging portion 42a and the cylindrical surface 42c of the bush member 42 in parallel with the axis from the open end side at equal intervals. It can be transformed into. Then, by inserting the bush member 42 into the joint 50 of the tube 40 in a state where the open end side of the bush member 42 is contracted, the contracted tip end side of the bush member 42 returns to the original state, and the inner wall surface of the nipple portion 41. It is fixed in the tube 40 by being fitted to. As described above, by forming the orifice in the joint 50 by using the bush member 42, the same effect as that of the third embodiment can be obtained.

In the second to fourth embodiments and modifications, each bush member 25, 34, 36, 3 is used.
7, 42 are formed by using metal, resin, or rubber-like elastic material. Iron, brass, copper, aluminum or the like is used as the metal material, and polyamide, polyester, polyvinyl chloride, polyacetal, PPS, olefin or the like is used as the resin. Further, as the rubber-like elastic material, rubber, thermoplastic elastomer and foamable polymer material are used, and as the rubber, NBR, N
BR and PVC blends, FKM, EPDM, EP
M, IIR, etc., and as the thermoplastic elastomer,
Olefin-based, urethane-based, polyester-based, polyvinyl chloride-based, etc.
Polyamide type, polyacetal type, polyvinyl chloride type and the like.

Of the above materials, the bush members 25, 34,
When a rubber-like elastic material is used as the material of 36, 37 and 42, a part of the pulsating pressure propagating from the pump can be absorbed and the strength thereof can be weakened by the vibration absorbing effect of the elastic body. As a result, the bush members 25, 34, 36, 42
In addition to the effect of the orifice, the generation of abnormal noise from the joint is further suppressed, the abnormal noise transmitted to the vehicle interior is reduced, and the riding comfort of the vehicle can be further improved.

Further, in each of the above embodiments, the case where the joint is applied to the fuel pipe system of the automobile has been described, but it is also applied to the cooling liquid pipe and the like. further,
The joint can be applied to various pipes other than automobiles, and noise generated from the tube and the joint can be suppressed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a joint which is a first embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing a joint which is a modified example of the first embodiment.

FIG. 3 is a cross sectional view schematically showing a joint according to a second embodiment.

FIG. 4 is a cross-sectional view schematically showing a joint which is a third embodiment.

FIG. 5 is a front view schematically showing another bush member attached to the joint.

FIG. 6 is a sectional view schematically showing a joint which is a modified example of the third embodiment.

FIG. 7 is a sectional view schematically showing a joint according to a fourth embodiment.

FIG. 8 is an explanatory diagram for explaining the effect of the orifice.

[Explanation of symbols]

10 ... Joint, 12a ... Small diameter part, 12b ... Large diameter part, 13 ...
Groove, 14 ... Through hole, 14a ... First hole, 14b ... Second
Hole portion, 14c ... Third hole portion, 16 ... Metal tube, 17 ...
Joint, 19 ... Through hole, 20 ... Joint, 24 ... Through hole, 24
a ... 1st hole part, 24a1 ... Attachment part, 25 ... Bush member, 25a ... Through hole, 30 ... Joint, 33 ... Through hole, 33
a ... 1st hole part, 33a1 ... groove part, 33b ... 2nd hole part, 3
4 ... Bushing member, 34a ... Engaging portion, 34b1 ... Through hole, 36 ... Bushing member, 36a ... Engaging portion, 36b1 ...
Through hole, 37 ... Bush member, 37b ... Through hole, 40 ...
Metal tube, 41 ... Nipple part, 42 Bushing member,
42a ... engaging portion, 42b1 ... through hole, 50 ... joint, H ...
hose.

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[Procedure amendment]

[Submission date] August 8, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

A through hole 14 is coaxially provided in the joint 10. The through hole 14 is a first hole located in the small diameter portion 12a.
The hole 14a and the second hole 14 having a diameter slightly larger than that of the first part 14a extending from the tip of the large diameter part 12b to the intermediate position.
b and a third hole portion 14c having a small diameter between them are provided as different diameter holes. The third hole portion 14c is formed smaller than the first hole portion 14a, and this portion constitutes an orifice. The small diameter portion 12a is attached to a flange member 15 for fixing the joint 10 to the vehicle body side, and is fixed at the position of the step 11. The tip portion of the metal tube 16 is inserted and fixed to the second hole portion 14b. Small diameter part 12
One end of the vehicle body side H is fitted onto a by press fitting.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Change

[Correction contents]

[Explanation of Codes] 10 ... Joint, 12a ... Small diameter portion, 12b ... Large diameter portion, 13 ...
Groove, 14 ... Through hole, 14a ... First hole, 14b ... Second
Hole portion, 14c ... Third hole portion, 16 ... Metal tube, 17 ...
Joint, 19 ... Through hole, 20 ... Joint, 24 ... Through hole, 24
a ... 1st hole part, 24a1 ... Attachment part, 25 ... Bush member, 25a ... Through hole, 30 ... Joint, 33 ... Through hole, 33
a ... 1st hole part, 33a1 ... groove part, 33b ... 2nd hole part, 3
4 ... Bush member, 34a ... Engagement part, 34b1 ... Through hole, 36 ... Bush member, 36a ... Engagement part, 36b1 ...
Through hole, 37 ... Bush member, 47b ... Through hole, 40 ...
Metal tube, 41 ... Nipple portion, 42 ... Bush member, 42a ... Engaging portion, 41b1 ... Through hole, 50 ... Joint,
H ... Body side .

Claims (3)

[Claims] 1. A joint for fitting and fixing a piping tube, wherein an orifice is provided in a part of the through hole so as to coaxially narrow the cross section of the through hole in the direction perpendicular to the axis. Fitting for piping. 2. The pipe joint with an orifice according to claim 1, wherein the orifice has a bush member having a through hole having a diameter smaller than the inner diameter of the through hole coaxially mounted therein. A pipe joint with an orifice characterized in that it is provided by. 3. The pipe joint according to claim 2, wherein the bush member is formed of a rubber-like elastic material.