Internal-combustion engines – Combustion chamber means having fuel injection only – Using multiple injectors or injections
Reexamination Certificate
1999-02-01
2001-03-13
Kamen, Noah P. (Department: 3747)
Internal-combustion engines
Combustion chamber means having fuel injection only
Using multiple injectors or injections
C123S472000, C137S627500, C251S129150
Reexamination Certificate
active
06199533
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a solenoid operated three-way valve for high pressure fuel systems which effectively minimizes valve response time and transition flow losses while accurately controlling the timing and quantity of fuel injection.
BACKGROUND OF THE INVENTION
Three-way solenoid valves have long been used for controlling fluid flow in a variety of air and hydraulic systems, particularly fuel systems. Such three-way solenoid valves often control the passage of fluid under high pressure from a source to a load device and selectively interrupt the flow of pressurized fluid while simultaneously connecting the load device to a substantially unpressurized drain. Typically, a three-way valve includes a valve housing having first, second and third valve passages interconnected by an internal valve chamber containing two valve seats and a valve element movable to control fluid flow among the three valve passages by moving between
(1) a first position in which the movable valve member engages a first one of the valve seats to isolate a first one of the valve passages from the internal chamber while allowing fluid communication between the second and third valve passages through the second valve seat and internal chamber, and
(2) a second position in which the movable valve member engages the second valve seat to isolate a second one of the valve passages while allowing fluid communication between the first and third valve passages through the first valve seat and internal chamber.
Recent and upcoming legislation resulting from a concern to improve fuel economy and reduce emissions continues to place strict emissions standards on engine manufacturers. In order for new engines to meet these standards, it is necessary to produce fuel injection systems capable of achieving higher injection pressures while maintaining accurate and reliable control of the metering and timing functions. Three-way valves have been particularly useful in achieving new levels of operation by effectively controlling the flow of fuel in high pressure fuel systems, such as disclosed in PCT patent publication WO 94/27041, entitled
Compact High Performance Fuel System With Accumulator.
A “pin-within-a-sleeve” type three-way solenoid operated valve, such as disclosed in U.S. Pat. No. 5,396,926 issued to Pataki et al., is especially effective in handling very high fuel pressures while providing extremely fast response time. This pin-within-a-sleeve type three-way valve includes a hollow movable valve member having an armature connected to one end thereof for direct operation by a solenoid actuator assembly. A three-way valve also includes a floating inner pin telescopingly received within the hollow movable valve member. In an advanced position, the hollow movable valve member is biased into engagement with a first valve seat formed in the surrounding valve housing. In a solenoid retracted position, the movable valve member is biased against the floating inner pin to open the first valve seat and close a second valve seat located within the hollow movable valve member and positioned to be engaged by one end of the floating inner pin. This particular pin-within-a-sleeve design has been found to be especially advantageous in controlling relatively high pressure fuel flow due to its pressure balanced design. Moreover, the components of this particular valve are packaged to form a more compact assembly.
Although the pin-within-a-sleeve three-way valve disclosed in Pataki et al. functions to effectively control the timing and quantity of fuel injection, valve designers continually strive to increase pressure capability and minimize the response time, transition flow losses, leakage flow and complexity of valve assemblies, including the Pataki et al. valve.
Consequently, there exists a need for a three-way fuel injection control valve capable of effectively increasing the pressure capability and reducing valve response time, transition flow loss and leakage flow.
SUMMARY OF THE INVENTION
It is an object of the present invention, therefore, to overcome the disadvantages of the prior art and to provide a simple, low cost three-way fuel injection control valve capable efficiently and effectively controlling the timing and quantity of fuel injection.
Another object of the present invention is to provide a three-way fuel injection control valve capable of minimizing valve response time.
Yet another object of the present invention is to provide a three-way fuel injection control valve including a solenoid actuator wherein minimal electromagnetic forces are required for fast, effective operation.
Still another object of the present invention is to provide a compact, inexpensive three-way fuel injection control valve designed to reduce manufacturing costs while achieving accurate reliable control of fuel flow at extremely high fuel pressures.
Another object of the present invention is to provide a compact, inexpensive three-way fuel injection control valve capable of effectively controlling fuel injection timing and metering at very high engine speeds.
It is yet another object of the present invention is to provide a three-way fuel injection control valve capable of providing multiple injections.
It is a further object of the present invention is to provide a three-way fuel injection control valve capable of minimizing fuel leakage to drain.
A still further object of the present invention is to provide a three-way fuel injection control valve capable of minimizing transition flow losses as the valve moves between closed and open positions.
Another object of the present invention is to provide a three-way fuel injection control valve capable of minimizing the heat transferred to the fuel drain.
Yet another object of the present invention is to provide a three-way fuel injection control valve including a servo-controlled valve element having a control volume wherein the volume of the control volume is minimized.
Still another object of the present invention is to provide a three-way fuel injection control valve assembly having a minimum number of high pressure joints and passages.
These and other objects of the present invention are achieved by providing a three-way fuel injection control valve assembly comprising a valve housing containing at least one valve chamber, a high pressure supply circuit, a drain circuit and an outlet circuit communicating with the valve chamber. The valve assembly also includes a first valve member mounted for reciprocal movement within the valve chamber between a closed position in which the high pressure supply circuit is isolated from the outlet circuit and an open position in which the high pressure supply circuit is in fluid communication with the outlet circuit. The valve assembly also includes a second valve member mounted for reciprocal movement within the valve chamber between an open position in which the outlet circuit is in fluid communication with the drain circuit and a closed position in which the outlet circuit is isolated from the drain circuit. Moreover, the valve assembly includes a valve control device for controlling the movement of the first and the second valve members between respective open and closed positions wherein the valve control device includes a control volume positioned adjacent outer ends of the first valve member and the second valve member for receiving high pressure fuel from the high pressure supply circuit and an electronically controlled injection control valve positioned along the drain circuit for controlling the flow of fuel from the high pressure supply circuit through the drain circuit so as to cause the movement of the first and the second valve members between respective open and closed positions. The movement of the first valve member from the closed position to the open position and subsequently from the open position to the closed position defines a supply period.
The valve control device may further include a transition flow loss limiting feature for causing the second valve member to be positioned in the closed position t
Doszpoly Bela
Gant Gary L.
Morris Corydon Edward
Muntean George L.
Pataki Arpad M.
Brackett, Jr. Tim L.
Cummins Engine Company, Inc.
Gimie Mahmoud M
Kamen Noah P.
Leedom Jr. Charles M.
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