Patent Application
20180128287
This application relates to Venturi devices for producing vacuum using the Venturi effect, and more particularly to dual Venturi systems that produce increased suction mass flow rate for a given motive flow rate.
Engines, for example vehicle engines, have included aspirators or ejectors for producing vacuum, and/or check valves. Typically, the aspirators are used to generate a vacuum that is lower than engine manifold vacuum by inducing some of the engine air to travel through a Venturi gap. The aspirators may include check valves therein or the system may include separate check valves. When the check valves are separate, they are typically included downstream between the source of vacuum and the device using the vacuum.
During most operating conditions of an aspirator or check valve, the flow is classified as turbulent. This means that in addition to the bulk motion of the air, there are eddies superimposed. These eddies are well known in the field of fluid mechanics. Depending on the operating conditions, the number, physical size and location of these eddies are continuously varying. One result of these eddies being present on a transient basis is that they generate pressure waves in the fluid. These pressure waves are generated over a range of frequencies and magnitudes. When these pressure waves travel through the connecting holes to the devices using this vacuum, different natural frequencies can become excited. These natural frequencies are oscillations of either the air or the surrounding structure. If these natural frequencies are in the audible range and of sufficient magnitude, then the turbulence generated noise can become heard, either under the hood and/or in the passenger compartment. Such noise is undesirable and new aspirators and/or check valves are needed to eliminate or reduce the noise resulting from the turbulent air flow.
Venturi devices may be constructed with one or more suction ports mounted and operatively connected via a Venturi gap to a lower housing with a motive port and discharge port, such as disclosed in co-pending U.S. patent application Ser. No. 14/294,727, filed Jun. 3, 2014, the entirety of which is incorporated by reference herein. However, improvements to generate maximum suction are desirable. Further, manufacturing requirements tend to yield Venturi gaps that taper from the suction port toward the flow path, which creates more turbulence and noise than an aspirator with a symmetrical Venturi gap.
Thus, there is a need to design Venturi devices that more efficiently utilize the suction-producing capabilities of the motive flow, and to design Venturi gaps that generate less turbulence and noise.
In one aspect, Venturi devices having a body that defines a passageway having a motive section and a discharge section spaced a distance apart from one another to define a Venturi gap and converging toward the Venturi gap and that defines a first suction port and a second suction port generally opposite one another, and each in fluid communication with the Venturi gap, are disclosed. The Venturi gap is generally wider proximate both the first suction port and the second suction port than at a generally central point therebetween.
In one embodiment, the body further defines a chamber spacing the first suction port and the second suction port apart from one another by a distance. An outlet end of the motive section extends into the chamber at a position where the chamber provides fluid flow around the entire outer surface of the outlet end and an inlet end of the discharge section extends into the chamber at a position where the chamber provides fluid flow around the entire outer surface of the inlet end of the discharge section.
In one embodiment, the body further defines a bypass port downstream of the first and second suction ports, and at least one of the first suction port, the second suction port, or the bypass port defines an outlet of a check valve. In another embodiment, the first suction port defines an outlet of a check valve, and the second suction port is in fluid communication with the same check valve through one or more bifurcation passages extending from the check valve to the second suction port. The one or more bifurcation passages are generally parallel to the Venturi gap.
In another embodiment, the fluid flow proximate the first suction port is bifurcated for a portion of the fluid flow to flow through secondary passages to the second suction port, and the Venturi gap is generally wider proximate both the first suction port and the second suction port than at a generally central point therebetween. In this embodiment, the body further defines a chamber spacing the first suction port and the second suction port apart from one another by a distance, and an outlet end of the motive section extends into the chamber at a position where the chamber provides fluid flow around the entire outer surface of the outlet end. Likewise, an inlet end of the discharge section may extend into the chamber at a position where the chamber provides fluid flow around the entire outer surface of the inlet end of the discharge section. In this embodiment, the second suction port includes a cap connected thereto.
In another aspect, systems are disclosed herein in which the Venturi devices described herein are incorporated to generate suction to provide vacuum to a device requiring vacuum, which includes a vacuum reservoir. The system includes the Venturi device, a source of motive flow fluidly connected to the motive section of the Venturi device, and a first device requiring vacuum connected to the first suction port and/or the second suction port of the Venturi device. The system may also include a second device requiring vacuum, and if so, the first device requiring vacuum can be in fluid communication with the first suction port and the second device requiring vacuum can be in fluid communication with the second suction port.
The Venturi device in the system may have a first suction housing connected to the body with a fluid-tight seal to define a first suction passageway for the first suction port, which may be fluidly connected to the first device requiring vacuum. The Venturi device in the system may also have a second suction housing connected to the body with a fluid-tight seal to define a second suction passageway for the second suction port, which may be fluidly connected to the first device requiring vacuum or a second device requiring vacuum.
In one embodiment, the Venturi device includes a cap covering the second suction port, and, proximate the first suction port, the fluid flow is bifurcated through secondary passages to the second suction port.
In another embodiment of the system, at least one of the first suction port, the second suction port, or a bypass port downstream of the first and second suction ports of the Venturi device defines an outlet of a check valve.
The following detailed description will illustrate the general principles of the invention, examples of which are additionally illustrated in the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.
As used herein, “fluid” means any liquid, suspension, colloid, gas, plasma, or combinations thereof.
Referring to
The aspirator-check valve assembly 100 includes the body 106 connected to the upper suction housing 107a and connected to the lower suction housing 107b. In the illustrated embodiment, upper housing portion 107a and lower housing portion 107b are identical aside from their attachment locations relative to the body 106, but suction housings 107a, 107b need not be identical nor are they required to include all of the same components (for example, in an embodiment with only one bypass port 114, the pertinent features of one of the suction housings 107a, 107b, and the corresponding connective features of body 106, are omitted). The designations of upper, lower, and middle portions are relative to the drawings as oriented on the page, for descriptive purposes, and are not limited to the illustrated orientation when utilized in an engine system. The upper and lower suction housings are joined to the body 106, for example by sonic welding, heating, or other conventional methods for forming an airtight or fluidtight seal therebetween.
Still referring to
The check valves 120a, 120b each include a first valve seat 124, 126 as part of the body 106. The first valve seat 124 defines the first suction port 110a, and the second valve seat 126 defines the second suction port 110b, which both allow for air flow communication with air passageway 104. In
The body 106 defines passageway 104 along a central longitudinal axis B bisected by the suction ports 110a, 110b. The inner passageway 104 includes a first tapering portion 128 (also referred to herein as the motive cone) in the motive section 116 of the body 106 coupled to a second tapering portion 129 (also referred to herein as the discharge cone) in the discharge section 146 of the body 106. Here, the first tapering portion 128 and the second tapering portion 129 are aligned end to end having the motive outlet end 132 facing the discharge inlet end 134 and defining a Venturi gap 152 therebetween (shown in greater detail in
The bypass ports 114a, 114b may intersect the second tapering section 129 adjacent to, but downstream of, the discharge outlet end 136. The body 106 may thereafter, i.e., downstream of this intersection of the bypass port 114, continue with a cylindrically uniform inner diameter until it terminates at the aspirator outlet 112. In another embodiment (not shown), the bypass ports 114a, 114b and/or the suction ports 110a, 110b may be canted relative to axis B and/or to one another. In the embodiment of
Referring now to
The disclosed system, incorporating a pair of suction ports 110a, 110b on either side of the Venturi gap 152, also provides improved suction flow rate for a given motive flow and discharge pressure as compared to a system incorporating a single suction port 110 because the disclosed system provides greater capacity to utilize the Venturi effect created by the motive flow through passageway 104. With continued reference to
In contrast, in an aspirator system incorporating only one suction port at the Venturi gap (e.g., only suction port 110a or only suction port 110b), only the Venturi forces generated on the half 157, 159 of the passageway 104 in which the suction port is located can be efficiently harnessed to create suction, because the suction port does not have sufficient access to the motive flow through the opposite half 157, 159 of the passageway 104 due to interference by the motive flow itself as it crosses the Venturi gap 152. For example, in an aspirator system with suction port 110a but not 110b, the motive flow through upper half 157 of passageway 154 contributing to flow path 153 is fully utilized, but the motive flow through lower half 159 cannot be efficiently harnessed due to its distance from the suction port 110a. Thus, the disclosed system 100 provides increased total suction flow rate (adding the flow rates of the suction ports 110a, 110b together) for a given motive flow by providing more access points about the perimeter of the motive outlet end 132 at which to utilize the Venturi effect. In an alternate embodiment, additional suction ports may be added to further increase efficiencies, such as an additional two suction ports orthogonal to both the passageway 104 and the suction ports 110a, 110b.
Because aspirators and aspirator-check valve assemblies are often manufactured via injection molding, formation of a symmetrical Venturi gap in prior art aspirator systems as presently disclosed is difficult and/or not economically feasible due to limitations of the manufacturing process. To form the Venturi gap, a core pin must be employed to preserve the void in the completed product, and the core pin must be subsequently removed. To ensure the strength and integrity of the finished product, the core pin should be inserted and removed through openings intended to be present in the completed product. Extra holes should not be formed and subsequently patched expressly for the purpose of inserting and removing a core pin because this would introduce weak points in the product and limit its useful life. And, to facilitate removal of the core pin, the core pin should be slightly conical in shape, tapering toward the interior of the product.
Thus, in existing aspirator systems incorporating only one suction port which communicates with the passageway 104 on only one side of the longitudinal axis B of the Venturi gap, there is only one natural opening in passageway 104 at the Venturi gap region through which a core pin may be inserted. Thus, the conical shape of the core pin used to create the void yields an asymmetrical Venturi gap that is tapered along its entire height from upper portion 133 to lower portion 135 as labeled in
Referring now to
The body 206 defines passageway 104 along a central longitudinal axis B bisected by the suction ports 110a, 110b. The inner passageway 104 includes a first tapering portion 128 in the motive section 116 of the body 206 coupled to a second tapering portion 129 in the discharge section 146 of the body 206. The first tapering portion 128 and the second tapering portion 129 are aligned end to end having the motive outlet end 132 facing the discharge inlet end 134 and defining a Venturi gap 152 therebetween which has the same basic symmetrical shape and functionality as earlier described with respect to the aspirator-check valve assembly 100. The details and benefits shown and described above with respect to the aspirator-check valve assembly 100, including the manufacturing advantages and the discussion of
Referring now to
As illustrated, passages 208 are cylindrical tubes that are integrated into the body 206 itself, but passages 208 may alternately be formed into any shape and may be provided as external components, for example in the form of hoses that link the suction ports 110a, 110b via ports therein provided for this purpose. Passages 208 may be generally parallel to the Venturi gap. The passages 208 do not directly fluidly communicate with the motive section 116 or the discharge section 146. Instead, the passages 208 fluidly communicate with the second suction port 110b, which fluidly communicates with the Venturi gap 152. Passages 208 provide a flow path 210 (or a plurality of flow paths 210) from port 154 (in communication with the device 102), through the suction housing 207, to the second suction port 110b for suction generation as a result of the fluid flow through the lower half 159 of passageway 104, in addition to the conventional flow path 212 for suction generated by suction port 110a as a result of fluid flow through the upper half 157 of passageway 104. As a result, for a given motive flow through the Venturi gap 152, the device requiring vacuum 102 can efficiently harness the suction generated by both suction ports 110a, 110b.
Also, this design allows a single check valve 120a proximate to suction port 110a to control the flow through both suction ports 110a, 110b, thereby eliminating the need for a dedicated check valve for suction port 110b, saving space and manufacturing costs.
Further, if desired, the passages 208 may be sealed (selectively or permanently) to block flow path 210, and the cap 209 may be replaced with additional components (including, for example, an additional check valve) to redirect suction generated at suction port 110b to a different device 102, thereby yielding a configuration similar to that of the aspirator-check valve assembly 100. In one embodiment, both the passages 208 and the cap 206 may be selectively openable and closeable to allow a user to selectively apply generated suction to a variety of devices 102.
Referring now to
The body 306 defines passageway 304 along a central longitudinal axis bisected by the suction ports 310a, 310b. The inner passageway 304 includes a first tapering portion 328 and the second tapering portion 329 aligned end to end having the motive outlet end 332 facing the discharge inlet end 334 and defining a Venturi gap 352 therebetween which has the same basic symmetrical shape and functionality as earlier described with respect to the aspirator-check valve assembly 100, in particular the structure and benefits shown and described above with respect to
The body 306 of
The chamber 356 defined by the body 306 includes a plurality of fingers 342 extending radially inward and axially away (upward in the figures) from the passageway 304 of the body 306. The plurality of fingers 342 are arranged radially as protrusion from an inner wall of the chamber 356 in an orientation where immediately adjacent neighboring fingers are spaced a distance apart from one another. The plurality of fingers 342 define a seat for the sealing member 311a as part of check valve 320a. Similarly, the check valve 321a, if the bypass port(s) 314a is present, has a chamber 366 defined by the body 306 that includes a plurality of fingers 342′ extending radially inward and radially away (upward in the drawings) from the passageway 304 of the body 306 that collectively define a seat for the sealing member 311c. The plurality of fingers 342′ are arranged radially as protrusion from an inner wall of the chamber 366 in an orientation where immediately adjacent neighboring fingers are spaced a distance apart from one another. Each of the plurality of fingers 342, 342′ has a base that is wider than at an apex thereof.
The apexes of the plurality of fingers 342 collectively define the seat for the sealing member 311a for an open position, and the apexes of fingers 342′ define the seat for sealing member 311c for an open position. In the embodiment of
Referring now to
The body 406 defines passageway 404 along a central longitudinal axis bisected by the suction ports 410a, 410b. The inner passageway 404 includes a first tapering portion 428 and the second tapering portion 429 aligned end to end with the motive outlet end 432 facing the discharge inlet end 434 and defining a Venturi gap 452 therebetween. The Venturi gap 452 has the same basic symmetrical shape and functionality as earlier described with respect to the aspirator-check valve assembly 100, in particular the structure and benefits shown and described above with respect to
The body 406 of
The chamber 456 defined by the body 306 includes a plurality of fingers 442 extending radially inward and axially away (upward in the figures) from the passageway 404 of the body 406. The plurality of fingers 442 are arranged radially as protrusion from an inner wall of the chamber 456 in an orientation where immediately adjacent neighboring fingers are spaced a distance apart from one another. The plurality of fingers 442 define a seat for the sealing member 411 as part of check valve 420. Similarly, the check valve 421, if the bypass port(s) 414a, 414b are present, has a chamber 466 defined by the body 406 that includes a plurality of fingers 442′ extending radially inward and radially away (upward in the drawings) from the passageway 404 of the body 406 that collectively define a seat for the sealing member 411′. The plurality of fingers 442′ are arranged radially as protrusion from an inner wall of the chamber 466 in an orientation where immediately adjacent neighboring fingers are spaced a distance apart from one another. Each of the plurality of fingers 442, 442′ has a base that is wider than at an apex thereof. The apexes of the plurality of fingers 442 collectively define the seat for the sealing member 411 for an open position, and the apexes of fingers 442′ define the seat for sealing member 411′ for an open position.
Having described the invention in detail and by reference to preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention which is defined in the appended claims.
This application is a continuation of U.S. application Ser. No. 14/734,228, filed Jun. 9, 2015, which claims the benefit of U.S. Provisional Application No. 62/009,655, filed Jun. 9, 2014, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62009655 | Jun 2014 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14734228 | Jun 2015 | US |
| Child | 15865595 | US |
