1. Field of the Invention
The present invention relates to an integral vacuum generator system for an internal combustion engine in which the vacuum generator is integrated with an air induction throttle body and intake manifold.
2. Disclosure Information
Vehicles having vacuum operated brake boosters require a significant vacuum signal to provide the desired pedal assist. Under some operating conditions, and with certain engines, engine vacuum may be insufficient to meet the required level of brake boost without a vacuum enhancer or external vacuum source. US Patent Publication 2006/0016477 A1, which is assigned to the assignee of the present invention, discloses a vacuum enhancing check valve which is intended to provide additional vacuum with a unit which is mounted externally of a brake booster. The system shown in the '477 publication presents a potential issue, concerning packaging space, in crowded engine compartments. Other known types of vacuum intensifiers are positioned between an automotive brake booster and an internal combustion engine intake. Such intensifiers are connected with hoses to the brake booster and intake. Such devices however, suffer from increased vacuum leak paths, which are troublesome to diagnose and correct.
It would be desirable to provide an integral vacuum generator for a vehicular engine which is packaged efficiently upon the engine by integrating the vacuum generator with existing engine hardware, while simultaneously minimizing the number of potential vacuum leak paths.
According to an aspect of the present invention, an internal combustion engine includes an intake manifold and a throttle body having a main passage connected with the intake manifold. The throttle body has a throttle plate for controlling airflow through the main passage and the intake manifold. A bypass passage has a first portion formed in the throttle body, and a second portion formed integrally with the intake manifold. A venturi formed in the second portion of the bypass passage has a vacuum passage extending into a vacuum manifold. A direct vacuum supply passage extends from the second portion of the bypass passage into the vacuum manifold. According to another aspect of the present invention, a first check valve is positioned in a valve chamber formed in the venturi vacuum passage between the venturi and the vacuum manifold, and a second check valve is positioned in a valve chamber formed in the direct vacuum supply passage between the second portion of the bypass passage and the vacuum manifold.
According to another aspect of the present invention, the intake manifold and the bypass passage are preferably molded integrally into a first assembly, and the vacuum manifold, the venturi vacuum passage, and the direct vacuum supply passage are molded integrally as a second assembly, with the first and second assemblies being joined after molding.
It is an advantage of a system according to the present invention that the potential for vacuum leaks is greatly mitigated, as compared with known vacuum intensifier devices.
It is another advantage of a system according to the present invention that the present integral vacuum generator requires very little package space within the underhood environment of a vehicle.
Other advantages, as well as features of the present invention, will become apparent to the reader of this specification.
As shown in
As further shown in
Direct vacuum supply passage 42 extends radially into valve chamber 46, which is occupied in part by check valve disc 44, which controls flow from vacuum manifold 50 into passage 42.
Valve discs 36 and 44 are not spring loaded. Rather, the discs float in their respective valve chambers and when not adhering to the portions of the chambers adjoining vacuum manifold 50, remain poised upon serrated pedestals 54 and 58. These pedestals allow airflow past valve discs 36 and 44, respectively, when the discs are positioned upon their individual pedestals.
When the present integral vacuum generator is being operated with throttle plate 22 in the closed position of
In the configuration of
In a preferred embodiment, intake manifold 14, including bypass passages 26c and 26d are molded integrally from resin. This allows valve chambers 38 and 46, which may be formed integrally with vacuum manifold 50, to be friction or solvent welded to intake manifold 14. Those skilled in the art will appreciate however, that the present vacuum generator system could be configured as a single casting combining the vacuum generator with the throttle body and intake manifold.
Although the present invention has been described in connection with particular embodiments thereof, it is to be understood that various modifications, alterations, and adaptations may be made by those skilled in the art without departing from the spirit and scope of the invention set forth in the following claims.
Number | Name | Date | Kind |
---|---|---|---|
3827414 | Sarto | Aug 1974 | A |
3872845 | Schultz | Mar 1975 | A |
3875918 | Loynd | Apr 1975 | A |
3977374 | August | Aug 1976 | A |
4231337 | Kuwahara et al. | Nov 1980 | A |
4249503 | Noguchi et al. | Feb 1981 | A |
4426968 | Onuki et al. | Jan 1984 | A |
4430982 | Ramirez Diaz | Feb 1984 | A |
4637366 | Cowles | Jan 1987 | A |
4817889 | Henry | Apr 1989 | A |
4895125 | Geiger | Jan 1990 | A |
5108266 | Hewitt | Apr 1992 | A |
5611204 | Radovanovic et al. | Mar 1997 | A |
6041754 | Mori et al. | Mar 2000 | A |
RE37090 | Kloosterman et al. | Mar 2001 | E |
6585547 | Tsubouchi et al. | Jul 2003 | B2 |
6634334 | Hwang et al. | Oct 2003 | B1 |
6655392 | Erwin et al. | Dec 2003 | B2 |
6739313 | Watanabe | May 2004 | B2 |
6843224 | Ha | Jan 2005 | B2 |
6883506 | Shin | Apr 2005 | B2 |
6951199 | Suzuki | Oct 2005 | B2 |
7076952 | Vetrovec | Jul 2006 | B1 |
7174883 | Sonoda et al. | Feb 2007 | B2 |
20010007250 | Hattori et al. | Jul 2001 | A1 |
20060016477 | Zaparackas | Jan 2006 | A1 |
Number | Date | Country |
---|---|---|
1020030033157 | May 2003 | KR |