Patent Application
20090152486
This application claims priority to, and the benefit of, Korean Patent Application No. 10-2007-0131636, filed in the Korean Intellectual Property Office on Dec. 14, 2007, the entire contents of which are incorporated herein by reference.
(a) Field of the Invention
The present invention relates to a pressure adjusting valve for a vehicle fuel line.
(b) Description of the Related Art
A typical pressure adjusting valve includes a spring-biased diaphragm in a fuel hydraulic chamber. If pressure in the fuel hydraulic chamber overcomes the elastic force of the spring, the diaphragm is pushed open, such that the fuel is free to leave the valve through a fuel outlet hole.
This valve can only be open or closed, and thus is not capable of fine-tuning the fuel pressure.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
A pressure adjusting valve for a vehicle fuel line includes a diaphragm disposed in a housing and dividing the interior of the housing into first and second compartments. A valve plate is provided in the second compartment and attached to the diaphragm. A return unit is provided in the second compartment. An elastic member provides an elastic force to the diaphragm toward the second compartment. An elastic force adjusting unit controls the elastic force of the elastic member.
The return unit may include a valve selectively contacting the valve plate, and an outlet for releasing fuel from the second compartment.
The elastic force adjusting unit may include a slider that is slidable within the first compartment and that contacts the elastic member, and a driving unit for controlling the position of the slider.
The driving unit may include a motor, a threaded control shaft connected with the motor, and a threaded portion of the housing connected with the control shaft, where the control shaft contacts the slider.
The slider may include a rotatable sphere, and the control shaft may contact the sphere.
A spring seat may be provided between the elastic member and the diaphragm.
An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings.
Referring to
Fuel pressure inside the hydraulic chamber 28 pushes the diaphragm 8. If the pressure inside of the hydraulic chamber 28 overcomes the elastic force on the diaphragm 8 as will be described below, the fuel passes through a gap between the valve plate 14 and the valve body 16. An elastic member 30, such as a coil spring, is disposed on the inner body 10 for supplying elastic force to the inner body 10. The elastic member 30 is disposed between the spring seat 12 and an elastic force adjusting unit, which includes a slider 32 that is slidably disposed within the upper housing 4. The elastic force adjusting unit also includes a driving unit that controls a position of the slider 32 according to control of an engine control unit (ECU). The driving unit includes a control motor 34, and a control shaft 36 that is connected with the control motor 34 and is screw coupled with a female thread member 38 of the upper housing 4.
An end of the control shaft 36 contacts a sphere 40 that is free to rotate within a seat 42 of the slider 32. Thus, the slider 32 moves up and down according to a rotating direction of the control motor 34.
The pressure adjusting valve 2 maintains the valve plate 14 against the valve body 16 when the pressure of the fuel inside the fuel hydraulic chamber 28 does not overcome the elastic force of the elastic member 30.
When the pressure of the fuel inside the fuel hydraulic chamber 28 does overcome the elastic force of the elastic member 30, the diaphragm 8 is pushed upward by the pressure inside the fuel hydraulic chamber 28 and a gap is formed between the valve plate 14 and the valve body 16. The fuel is returned to a fuel tank (not shown) through the gap, the valve body 16, and the fuel nipple 24, so that the pressure of a fuel line is maintained within a predetermined range.
If the pressure in the fuel line needs to be raised, the control motor 34 moves the slider 32 downwards, so that the pressure in the fuel line increases with increase of elastic force. If the pressure in the fuel line needs to be decreased, the control motor 34 moves the slider 32 upwards, so that the pressure in the fuel line decreases with decrease of elastic force.
The fuel pressure adjusting valve 2 may be applicable to both an ethanol and a gasoline engine. Because of the different air/fuel ratios in ethanol and gasoline engines, different injectors are typically used. However, the exemplary pressure adjusting valve 2 is applicable to both gasoline and ethanol engines.
As shown in
Alternatively, as shown in
While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2007-0131636 | Dec 2007 | KR | national |
