Fluid coupling
A pulsation absorber is provided in a fluid channel formed in a body of a fluid coupling. Fluid flows through the fluid channel in an assembled state. The pulsation absorber is arranged to deform in a same direction as the fluid to flow in the fluid channel pulsates. The pulsation absorber thereby absorbs pulsation of the fluid.
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The present invention generally relates to a fluid coupling, and more particularly, to a fluid coupling for use in a fuel supply system of a vehicle.
Japanese Patent Application Publication No. H09(1997)-195885 discloses a fuel supply system of a fuel returnless type.
SUMMARY OF THE INVENTIONIt is an object of the present invention to provide a fluid coupling capable of damping pulsation of fluid effectively, while using a limited space and being small in size and low in cost.
According to one aspect of the present invention, a fluid coupling includes: a body formed with a fluid channel; and a pulsation absorber provided in the fluid channel, and arranged to deform in a same direction as fluid to flow in the fluid channel pulsates, and thereby to absorb pulsation of the fluid.
The other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
First, in order to facilitate understanding of the present invention, a description will be given of fuel supply systems for a vehicle.
In the fuel supply system of
Recently, improvements have been required for vehicles to be reduced further in weight and cost. Therefore, such vehicles have employed an increasing number of fuel supply systems of the returnless type which has a smaller number of elements than the return type.
However, in the fuel supply system of the returnless type, pulsation of the fuel is likely to occur on the part of delivery pipe 103, compared with the return type. For this reason, delivery pipe 103 of the returnless type is equipped with pulsation damper 108. Therefore, the fuel supply system of the returnless type requires an attaching portion, such as a flange, for joining pulsation damper 108 to delivery pipe 103, and an arrangement for sealing the joining part. Thus, the fuel supply system of the returnless type may have a complex structure, and cannot easily be reduced in cost. Besides, such fuel supply system of the returnless type cannot easily be laid out in a small space in an engine room.
Fluid coupling A1 of
The body of fluid coupling A1 is formed by material resistant to fuel. In this example, the body of fluid coupling A1 is formed by material composed mainly of a resin selected from a group consisting of polyamide, polyolefin, polysulfide, fluorocarbon resin, polyester, polyacetal and polyketone.
The body of fluid coupling A1 is formed with a fluid channel 5 extending through the body of fluid coupling A1. Fluid coupling A1 includes a support 6, and a pulsation absorber provided in fluid channel 5. The pulsation absorber of this embodiment is a bellows 7. Specifically, support 6 is fixed in fluid channel 5, and bellows 7 is supported by support 6. Pulsation absorber or bellows 7 is arranged to deform in a same direction as fluid to flow in fluid channel 5 pulsates, and thereby absorb the pulsation of the fluid. A part or first part of fluid channel 5 at which bellows 7 is provided has a section smaller than a section of other part or second part of fluid channel 5.
Support 6 is formed by material of the same kind as the material forming the body of fluid coupling A1. In this example, support 6 is formed by material composed mainly of glass fiber reinforced polyamide 12. Support 6 is formed with at least one opening to pass the fluid through the opening. Support 6 is fixed to the body of fluid coupling A1 by rotary welding.
Bellows 7 is formed by resin or rubber. In this example, bellows 7 is formed by polyamide 12, and molded by blow molding. Bellows 7 is joined to support 6 air-tightly by welding, and is arranged to act as an air spring. Besides the above-mentioned polyamide 12, bellows 7 may be formed by a thermoplastic resin, such as a polyamide-based thermoplastic resin, a polyolefin-based thermoplastic resin, a fluorocarbon-based thermoplastic resin, a polyester-based thermoplastic resin, or a polysulfide-based thermoplastic resin. Bellows 7 may also be formed by a thermoplastic elastomer, or a rubber, such as a fluorocarbon-based rubber, a nitrile-based rubber, or an acrylic-based rubber.
In fluid coupling A1 of this embodiment, pulsation absorber or bellows 7 is provided in fluid channel 5, and is arranged to deform in the same direction as the pulsation of the fluid to flow in fluid channel 5, and thereby absorb the pulsation of the fluid effectively. Thus, pulsation absorber or bellows 7 confronts a propagation direction of the pulsation of the fluid, in an assembled state in the fuel supply system or fluid delivery system. Specifically, in the fuel supply system, when the fuel is supplied from the fuel tank to metal pipe P, and pulsation of the fuel originating from the fuel injection action of fuel injectors 104 occurs on the part of metal pipe P, bellows 7 confronting the propagation direction of the pulsation deforms springily or elastically, or expand and contract, to absorb the pulsation of the fuel effectively.
Thus, fluid coupling A1 of this embodiment includes pulsation absorber or bellows 7 provided in fluid channel 5. Hence, fluid coupling A1 of this embodiment does not require an additional space for a pulsation absorber. In fluid channel 5, pulsation absorber or bellows 7 is arranged to act as air spring. Therefore, fluid coupling A1 has a simple structure having a small size and a small number of elements, and is capable of damping the pulsation of the fluid occurring in the fuel supply system. With fluid coupling A1 of this embodiment, the fuel supply system of the returnless type of
Besides, pulsation absorber or bellows 7 of fluid coupling A1 of this embodiment is formed by resin or rubber. Thus, bellows 7 is light in weight and low in cost, and has a property of deforming efficiently to absorb the pulsation of the fluid effectively. Additionally, since resin or rubber exhibits an excellent formability, bellows 7 can be formed easily to have a desired spring constant.
Further, support 6 of fluid coupling A1 of this embodiment is fixed to the body of fluid coupling A1 by rotary welding, and bellows 7 is joined to support 6 by welding. Thus, these elements can be joined to one another easily and securely without using joining parts. Therefore, the structure of fluid coupling A1 can be further simplified and reduced in weight.
Besides, fluid coupling A1 of this embodiment may be applicable between supply line 101 and supply tube 102 in the fuel supply system of the returnless type of
Further, fluid coupling A1 of this embodiment is formed with fluid channel 5, and the section of the part of fluid channel 5 at which bellows 7 is provided is smaller than the section of the other part of fluid channel 5. The thus-narrowed part of fluid channel 5 acts as an orifice, and thereby is capable of reducing the propagation of the pulsation of the fuel.
Fluid coupling A2 of
Support 11 of this embodiment is a plate member formed by glass fiber reinforced polyamide 12. The pulsation absorber of this embodiment is attached to support 11, and support 11 is fixed to the open end of extension portion E by rotary welding so as to block up the open end of extension portion E.
The pulsation absorber of this embodiment includes bellows 7 and an elastic member. Bellows 7 of this embodiment is formed by resin or rubber, as in the foregoing embodiment. The elastic member of this embodiment is provided inside bellows 7, and is arranged to deform springily or elastically, or expand and contract, together with bellows 7. The elastic member of this embodiment is a molded member 12 formed by resin or rubber. Molded member 12 of this embodiment is made of fluoro rubber compression-molded in a cylindrical form, and is provided coaxially with bellows 7.
Besides the above-mentioned fluoro rubber, molded member 12 may be made of rubber of various types, such as nitrile rubber, acrylic rubber, silicone rubber, fluorinated silicone rubber, hydrin rubber, urethane rubber, ethylene-propylene rubber, or butyl rubber. Molded member 12 may also be made of resin of various types, such as polyolefin, polysulfide, fluorocarbon resin, polyester, polyacetal, polyketone, polyvinyl chloride, or thermoplastic elastomer.
Thus, in fluid coupling A2 of this embodiment, the pulsation absorber is composed of bellows 7 and molded member 12 arranged to act respectively as air spring and a rubber spring by deforming springily or elastically, or expanding and contracting together. Additionally, bellows 7 and molded member 12 each formed by resin or rubber exhibit high damping effects. Therefore, the pulsation absorber of this embodiment can absorb the pulsation of the fluid highly effectively even when pressure of the fluid is relatively high.
Besides, since the pulsation absorber of this embodiment is composed of bellows 7 and molded member 12 each formed by resin or rubber, the pulsation absorber can be formed to have a desired spring constant with an increased degree of freedom, and thereby can adapt to various intensities of pressure and pressure pulsation in the fluid. Additionally, fluid coupling A2 of this embodiment has a simple structure having a small size and a small number of elements, as in the foregoing embodiment, and the fuel supply system adopting fluid coupling A2 of this embodiment can be reduced in weight and cost, and can be easily laid out in a limited space in an engine room.
The pulsation absorbers of FIGS. 3˜7 are applicable to fluid couplings A1 and A2 of
The pulsation absorbers of
Fluid coupling A3 of
Damping chamber F communicates with fluid channel 5 via a communicating passage 8, and is formed with an open end opening in opposite direction from communicating passage 8. Communicating passage 8 is formed narrower than fluid channel 5, or is formed to have an internal sectional size smaller than fluid channel 5. Bellows 7 is attached to support 11, and support 11 is fixed to the open end of damping chamber F, as in the foregoing embodiment.
Thus, fluid coupling A3 of this embodiment is arranged to absorb the pulsation of the fluid effectively by bellows 7 deforming, or expanding and contracting, springily or elastically, and damping chamber F acting as a Helmholtz resonating chamber. Damping chamber F branches off perpendicularly from fluid channel 5, and pulsation absorber or bellows 7 is disposed in thus-branched damping chamber F. Thus, the pulsation absorber of this embodiment does not hamper the flow of the fluid, and therefore can avoid pressure loss of the fluid.
Additionally, fluid coupling A3 of this embodiment has a simple structure having a small size and a small number of elements, as in the foregoing embodiments, and the fuel supply system adopting fluid coupling A3 of this embodiment can be reduced in weight and cost, and can be easily laid out in a limited space in an engine room. Besides, the pulsation absorbers of FIGS. 2˜7 are applicable to fluid coupling A3 of
The fluid coupling adopting the pulsation absorber of this embodiment can obtain similar effects and advantages as in the foregoing embodiments. The pulsation absorber of
According to another aspect of the present invention, the fluid coupling includes: means (5) for passing fluid; and means (7; 7, 12; 7, 13; 7, 14; 7, 15, 16; 7, 17, 16; 18, 19) for absorbing pulsation of the fluid by deforming in a same direction as the fluid pulsates.
This application is based on a prior Japanese Patent Application No. 2004-163141 filed on Jun. 1, 2004. The entire contents of this Japanese Patent Application No. 2004-163141 are hereby incorporated by reference.
Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art in light of the above teachings. The scope of the invention is defined with reference to the following claims.
Claims
1. A fluid coupling comprising:
- a body formed with a fluid channel; and
- a pulsation absorber provided in the fluid channel, and arranged to deform in a same direction as fluid to flow in the fluid channel pulsates, and thereby to absorb pulsation of the fluid.
2. The fluid coupling as claimed in claim 1, wherein the pulsation absorber is provided at a first part of the fluid channel, and the first part of the fluid channel has a section smaller than a section of a second part of the fluid channel.
3. A fluid coupling comprising:
- a pulsation absorber provided in a fluid channel, and arranged to absorb pulsation of fluid to flow in the fluid channel, the pulsation absorber including:
- a bellows formed by resin or rubber; and
- an elastic member provided inside the bellows, including a molded member formed by resin or rubber, and arranged to deform elastically together with the bellows.
4. A fluid coupling comprising:
- a body formed with a fluid channel of a straight type, and a damping chamber branching off from the fluid channel; and
- a pulsation absorber provided in the damping chamber, and arranged to absorb pulsation of fluid to flow in the fluid channel.
5. The fluid coupling as claimed in claim 4, wherein the pulsation absorber includes a diaphragm formed by resin or rubber, and an elastic member arranged to deform elastically in conjunction with deformation of the diaphragm.
6. The fluid coupling as claimed in claim 1, wherein the pulsation absorber includes a bellows formed by resin or rubber.
7. The fluid coupling as claimed in claim 6, wherein the pulsation absorber includes an elastic member provided inside the bellows, and arranged to deform elastically together with the bellows.
8. The fluid coupling as claimed in claim 7, wherein the elastic member includes at least one of a molded member formed by resin or rubber and a coil spring.
9. The fluid coupling as claimed in claim 3, wherein the molded member is resin or rubber containing numerous bubbles.
10. The fluid coupling as claimed in claim 8, further comprising a support fixed in the fluid channel, wherein the pulsation absorber is supported by the support.
11. The fluid coupling as claimed in claim 3, wherein the fluid coupling is an elbow type including an elbow portion and an extension portion extending from the elbow portion, the extension portion having an open end opening in opposite direction from the elbow portion; and the fluid coupling further comprises a support fixed to the open end of the extension portion, wherein the pulsation absorber is supported by the support in the extension portion.
12. The fluid coupling as claimed in claim 11, wherein the support is formed with an air hole arranged to expose an inside part of the bellows to open air.
13. The fluid coupling as claimed in claim 3, wherein the molded member is formed in a cylindrical form, and is provided coaxially with the bellows.
14. The fluid coupling as claimed in claim 3, wherein the molded member is a hollow-molded member formed in a bellows form.
15. The fluid coupling as claimed in claim 3, wherein the molded member is formed in a thin cylindrical form; and the elastic member further includes a coil spring disposed concentrically outside the molded member.
16. The fluid coupling as claimed in claim 3, wherein the molded member is a composite-molded member including a coil spring insert-molded in the resin or rubber forming the molded member.
17. A fluid coupling comprising:
- means for passing fluid; and
- means for absorbing pulsation of the fluid by deforming in a same direction as the fluid pulsates.
Type: Application
Filed: Jun 1, 2005
Publication Date: Dec 1, 2005
Applicant:
Inventors: Seiji Kamada (Yokohama), Hiroshi Kumagai (Kanagawa)
Application Number: 11/141,384