KR20010022193A - Regulated linear purge solenoid valve - Google Patents

Abstract

The pressure regulator is associated with a solenoid operated valve which can be operated by a pulse waveform whose fundamental frequency is substantially greater than the frequency response of the valve mechanism. The pressure regulator causes a certain pressure difference across the valve mechanism that is independent of both the outlet pressure of the regulator and the inlet pressure of the valve, thereby providing improved flow control accuracy. The present invention is particularly advantageous for purging fuel vapor generated in a fuel tank to an intake manifold of an automobile internal combustion engine.

Description

Regulated Linear Purge Solenoid Valve {REGULATED LINEAR PURGE SOLENOID VALVE}

Known on-board steam emission control systems include a vapor integrated canister that accumulates volatile fuel vapor generated in the upper space of the fuel tank by volatilization of fluid fuel in the tank and a canister that periodically purges the vapor accumulated in the intake manifold of the engine. Includes a purge solenoid (CPS) valve. The CPS valve includes a solenoid actuator under control of an engine control system based on a microprocessor.

While assisting in purging the conditions as scheduled by the engine control system based on various inputs to the engine control system, a steam exhaust space defined by the tank top space and the canister's cooperation is provided through the CPS valve. Purged into the manifold, the CPS valve is fluidly connected between the canister and the engine intake manifold. To the signal from the engine control computer in an amount sufficient to allow the intake manifold vacuum to draw volatile fuel vapor from the canister to entrain with the combustible mixture entering the engine's combustion chamber space at a rate consistent with engine operation. Thereby opening the CPS valve to provide acceptable vehicle driveability and acceptable levels of exhaust emissions.

Known CPS valves include movable valve components that are elastically pressurized by compression springs against the valve seat to close the valve against fluid flow when no current is supplied to the solenoid. As the current applied to the solenoid begins to increase, an increasing electromagnetic force acts to remove the valve component, thereby opening the valve to fluid flow. These electromagnetic forces include various forces acting on the mechanical mechanism before the valve component can begin to be removed, including overcoming opposing spring bias forces as well as any static friction forces present between the valve component and the seat. You must overcome it. Once the valve component is removed, the valve component / valve seat coupling structure also serves to define the functional relationship of fluid flow rate through the valve to the current supplied to the solenoid coil. Furthermore, the degree of hysteresis of a given valve may also be reflected in the functional relationship.

When the valve component comprises a tapered pintle selectively positioned axially within a circular orifice surrounded by a valve seat, a well defined flow rate versus pintle position characteristic can be obtained. However, any coupling structural factors present at the valve component / valve seat interface can prevent these properties from becoming effective until the valve component is removed from the valve seat at a certain minimum distance. Therefore, each graph of fluid flow rate through the valve versus current supplied to the solenoid coil can be considered to include a characteristic span: a short initial span occurring between the valve closing position and a constant minimum valve opening position; And wider subsequent spans that occur beyond a certain minimum valve opening position.

One particular type of CPS valve includes a linear solenoid and a linear compression spring that is increasingly compressed as the valve is gradually opened. It is often referred to as a linear solenoid purge valve, namely LSPV. Such valves can provide certain desirable properties for flow control. Independently, linear solenoids have essentially linear force-to-current characteristics over a range of constant currents. When a linear solenoid is incorporated into an electromechanical device, such as a valve, the entire electromechanical device has an output-to-current characteristic that is a function of not only the solenoid but also the solenoid force applied mechanical device, such as the valve device. As a result of the following, the output-to-current characteristic of the entire apparatus is slightly modified from the characteristic of the linear solenoid alone.

Whereas CPS valves incorporating both tapered pintle valve components that can be selectively positioned axially within a circular orifice surrounded by a linear solenoid and valve seat can exhibit desirable fluid flow rate versus pintle position characteristics, Such characteristics may not be effective until the pintle is opened by a certain minimum amount due to the coupling structural factors at the pintle / sheet interface as mentioned above. Thus, each graph of fluid flow rate through the valve versus the current applied to the solenoid coil is above the span described above, i.e. the short initial span that occurs between the valve closing position and the constant minimum valve opening position, and beyond the constant minimum valve opening position. The resulting can be considered to include a wider subsequent span.

Generally speaking, a linear solenoid purge valve can be characterized graphically by a series of graphs of fluid flow rate versus current, with each graph correlated to a particular pressure differential across the valve. Each graph can be characterized by the short initial span and the broader subsequent span described above. One particularly desirable characteristic within the latter span of each graph is that the substantially constant relationship between the change in the increase in electrical control current applied to the solenoid and the change in the increase in flow rate through the valve is a valve component / valve. It can be obtained by proper design of the seat interface coupling structure. However, the change in the increase rate of the fluid flow rate through the valve within the span of the electron can maintain a substantially different relationship with the change in the increase amount of the electric control current applied to the solenoid.

In one such linear solenoid purge valve, a constant minimum current is obtained before the valve starts to open. For a given pressure difference across the valve, the graph of the corresponding fluid flow rate versus current is a flow that is significantly different from the change in increase that occurs when a small change in current increases beyond a certain minimum open position and beyond the subsequent span where the valve is opened. It can be expressed as including a relatively short initial span that can result in a change in the amount of increase in and the change in the amount of increase in flow through the valve remains substantially constant with the change in the amount of increase in current.

The current flowing to the solenoid coil of any solenoid operated device can be supplied in a variety of ways. One known scheme is by applying a pulse width variable tissue flow voltage across the solenoid coil. In selecting the pulse frequency of the applied voltage, careful consideration should be given to the frequency response characteristics of the combined solenoids and mechanical instruments actuated by the solenoids. If an appropriate pulse frequency is used within the combined solenoid and instrument frequency response range, the instrument will faithfully follow the pulse width signal. On the other hand, if an appropriate pulse frequency is used beyond the frequency response range of the combined solenoid and mechanical instrument, the instrument will be positioned according to the time average value of the applied voltage pulse. The latter technique may be preferred over the former because the mechanical mechanism will not reciprocate at higher frequency pulse width modulation waveforms, but instead will take a position corresponding to the time average current flow of the solenoid coil. Under the former technique, the instrument may experience relatively pronounced reciprocation as it follows a lower frequency waveform, and may cause unacceptable characteristics. In the case of CPS valves, such characteristics may limit limiting devices that limit unpleasant noise and / or maximum valve movement caused by undesirable pulsations in the purge flow and repeated collisions of valve components and valve seats. It may include. Such valves may experience unacceptable variations in duty cycle from start to flow.

In order to solve pulsation, it is known to associate a mechanical pressure regulator with a CPS valve. The pressure regulator mechanically reduces the purge flow pulse, but does not solve the underlying reason due to the pulsating solenoid.

Known mechanical pressure regulators include an inlet through which the fluid flow through the valve mechanism enters the pressure regulator flow passage and a flow passage with an outlet through which the fluid flow into the pressure regulator flow passage exits the pressure regulator flow passage. The pressure regulator includes a pressure regulator that regulates the pressure at the inlet of the pressure regulator flow passage to a pressure essentially independent of the pressure at the outlet of the pressure regulator flow passage. The pressure regulating mechanism includes a fluid-impermeable movable wall that divides the internal space of the pressure regulator into two variable volume chamber spaces. The first chamber space is in communication with the atmosphere so that the pressure in the chamber space is maintained at atmospheric pressure. The second chamber space defines a portion of the flow passage extending between the pressure regulator inlet and the pressure regulator outlet. The movable wall is provided with a component that selectively restricts the flow passage such that the pressure in the second chamber space is adjusted to a predetermined magnitude substantially independent of the pressure at the pressure regulator outlet. In this way, the vacuum in the first chamber space is adjusted with respect to atmospheric pressure to a predetermined size that is substantially independent of the size of the intake manifold vacuum in communication with the pressure regulator outlet.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to automotive exhaust control valves. In one aspect, the present invention relates to a solenoid operated fluid valve for purging volatile fuel vapor from a fuel tank and a vapor storage canister to an internal combustion engine powering a vehicle.

1 is a schematic diagram of a mounted vapor exhaust control system, including an enlarged longitudinal cross-sectional view of a canister purge solenoid valve.

FIG. 2 is a representative graph relating to FIG. 1.

3 is a longitudinal cross-sectional view of another canister purge solenoid valve.

4 is a cross-sectional view in the longitudinal direction of the canister purge solenoid valve of FIG. 3 and an associated pressure regulator in accordance with the principles of the present invention.

5 is a series of graphs useful for illustrating the principles of the present invention with respect to FIG.

FIG. 6 is a view in longitudinal section, partially in cross section, for another embodiment according to the principles of the present invention;

FIG. 7 is a longitudinal view of the embodiment of FIG. 6 with another portion in cross section; FIG.

One aspect of the present invention relates to an improvement in the way in which the pressure regulating function is carried out.

In a fuel vapor integrated system with a regulated canister purge valve, the inlet port of the canister purge valve is communicated to the fuel tank headspace through the canister such that the pressure of the purge valve inlet port is essentially the pressure present in the tank steam headspace. . It is known that certain conditions can cause vapor pressure in the tank overhead space to deviate from atmospheric pressure such that the pressure applied to the purge valve inlet port deviates from atmospheric pressure. Since the pressure in the intake manifold vacuum applied to the purge valve outlet port and the pressure in the first chamber space of the pressure regulator are related to atmospheric pressure, the deviation of the tank overhead space pressure from atmospheric pressure can degrade the intended control strategy.

One general aspect of the present invention is directed to a pressure regulated purge valve that neutralizes the effect of deviating from the tank steam overhead space pressure from atmospheric pressure in accordance with the intended control strategy. This is achieved by making a dedicated communication path directly to the tank overhead space or by communicating the first chamber space of the pressure regulator to the tank vapor overhead pressure through any passage in communication with the tank overhead, such as through a canister. Can be.

The other side is a valve mechanism positioned within the valve body by an electric control signal to control the flow of fluid through the valve body, and an inlet and a regulator of the fluid flow through the valve mechanism enter the pressure regulator flow passage. An electrically operated pressure regulating fluid flow control valve comprising a pressure regulator including a flow passage with an outlet exiting the pressure regulator flow passage, wherein the pressure regulator regulates the inlet pressure of the pressure regulator flow passage. And a pressure regulator which regulates to a pressure essentially independent of the outlet pressure of the flow passage and causes the flow through the valve to be essentially independent of the pressure change at the valve inlet.

Another common aspect is a valve mechanism positioned within the valve body by an electrical control signal to control the flow through the valve body, and an inlet and pressure regulator flow passage through which the flow through the valve mechanism enters the pressure regulator flow passage. An electrically operated pressure regulating fuel vapor purge valve for purging fuel vapor from a fuel tank including a pressure regulator including a flow passage with an outlet communicating with a manifold to an intake manifold of an internal combustion engine, the pressure regulator And a pressure regulator which regulates the inlet pressure of the pressure regulator flow passage to a pressure essentially independent of the outlet pressure of the pressure regulator flow passage and causes the flow through the valve to be essentially independent of the pressure change at the valve inlet.

Another aspect is that when the valve mechanism is applied to the control of the valve mechanism so that the valve mechanism does not faithfully follow the fundamental frequency of the electrical control signal whose fundamental frequency is greater than the predetermined frequency, the signal causes the valve mechanism to cause any noticeable pulsation of the valve mechanism. The present invention relates to a valve mechanism having a frequency response characteristic for positioning at a position corresponding to the most recent time average value of an electric control signal.

Another aspect relates to an LSPV comprising a pressure regulator, which is believed to provide further improvements in purge flow control accuracy under a substantial range of valve operation and under various operating conditions.

Another aspect relates to CPS valves, in which pressure regulators are believed to provide improved purge flow control accuracy by significantly diminishing the effects of conditions that may otherwise occur in reducing purge flow control for a given valve opening. It relates to the provision of structural features.

The foregoing, additional features, and other advantages and advantages of the present invention will be described in the following description and claims appended to the drawings. The figures disclose a preferred embodiment of the invention in accordance with the best mode presently contemplated for carrying out the invention.

1 shows a canister purge solenoid (CPS) valve 14 connected in series in a known fashion between a steam integrated canister (carbon canister) 12 and a fuel tank 16 and an intake manifold 18 of an internal combustion engine 20. A steam emission control system 10 of a motor vehicle is shown. The engine adjustment computer 22 supplies the valve control signal as an input to the pulse width modulation (PWM) circuit 24 and is amplified by the drive circuit 26 and applied to the electric terminal 14et of the valve 14. Generate a modulated signal.

The valve 14 is an inlet port 14i fluidly connected to the purge port 12p of the canister 12 by the conduit 30 and an outlet port fluidly connected to the intake manifold 18 by the conduit 32. And a housing 28 with 14o). The conduit 34 communicates the canister tank port 12t with the upper space of the fuel tank 16. An actuator including solenoid actuator 14sa is disposed in housing 28 to open and close an inner passage extending between ports 14i and 14o. The mechanism includes a bias spring 14bs that acts to close the valve component 14ve relative to the valve seat 14vs to close the internal passage for flow. When the solenoid actuator is gradually energized by the engine control computer 22, electromagnetic force is applied to the armature 14a in the opposite direction to the bias spring force to remove the valve component 14ve from the valve seat 14vs. This may open the inner passage so that flow may occur between the ports 26, 30.

The canister 12 also includes a vent port 12v through which the vapor discharge space containing the fuel vapor is vented to the atmosphere. Such aeration may be done by an atmospheric pressure vent valve (not shown) which is operated in a closed state at a certain time, such as during an OBDII test period.

2 shows representative control characteristics for the valve 14 in which the fluid flow rate through the valve is related to the duty cycle of the pulse width modulation voltage applied across the terminal 14et. As an example about 10%, a constant minimum duty cycle is required before the valve begins to open. As the duty cycle increases above 10%, the flow rate generally remains linear to the duty cycle. At a duty cycle of 100%, a constant direct current voltage is applied across the entirety of the terminal 14et. The frequency of the pulse waveform to perform this type of operation is relatively low, so that the representative frequency is in the range of about 5 Hz to about 20 Hz, but may be as high as about 50 Hz. For valve mechanisms whose frequency response extends beyond this range, the mechanism will experience a pronounced reciprocation as it follows the pulse waveform.

Since the valve is not pressure regulated, the flow rate will also be a function of the pressure difference across the valve ports. Temperature and voltage variations can also affect the relationship.

It is known that the use of a linear solenoid can improve control accuracy, and FIG. 3 shows an example of a linear solenoid purge valve 14 ', the constant parts of which are already mentioned parts of the valve 14. And a reference number with the corresponding prime (').

The valve 14 'includes two-piece bodies B1 and B2 having an inlet port 14i' and an outlet port 14o '. The valve 14 'has a longitudinal axis AX, and the body B1 is coaxial with the axis AX and is open at the upper axial end of the body B1 assembled with the body B2. Cylindrical sidewall 40. Sidewall 40 includes upper and lower sidewall portions 40A, 40B connected by shoulders 42; While the latter is cylindrical except for the area crossed radially by the port 14o ', the sidewall portion of the former is completely cylindrical. The port 14i 'is in an elbow portion extending from the lower axial end of the side wall 40. On its own, the body B1 is surrounded except its open upper shaft end and two ports 14o ', 14i'.

The linear solenoid S is introduced through the open upper end of the body B1 at the time of manufacture of the valve and is arranged in the body B1. The solenoid includes a stator structure associated with a bobbin 44, a magnet wire wound on the bobbin 44 to form a bobbin mounted electromagnetic coil 46, and a bobbin-coil. The stator structure includes an upper stator piece 48 disposed at the upper end of the bobbin mounting coil, a cylindrical side stator piece 50 disposed around the outside of the bobbin mounting coil, and a lower stator piece 52 disposed at the lower end of the bobbin mounting coil. It includes.

The upper stator piece 48 includes a flat circular disc portion whose outer periphery fits into the upper end of the side piece 50 and includes a hole therein so that the bush 54 is coaxially with the axis AX. The disc portion also includes other holes to allow upward passage of a pair of bobbin-mounted electrical terminals 56 to which the ends of the magnet wire 46 are connected. The fragment 48 further comprises a cylindrical neck 58 extending downward from the disc portion at a constant distance into the central through hole in the bobbin 44 which is coaxial with the axis AX. The inner surface of the neck 58 is cylindrical while the outer surface of the neck is truncated conical to provide a radially thick portion with tapered processing that gradually decreases as the neck extends into the through hole of the bobbin.

The lower stator piece 52 includes a flat circular disk portion whose outer periphery fits into the lower end of the side piece 50 and includes a hole therein and the bush 60 is pressed into coaxial with the axis AX. The fragment 52 further includes an upper cylindrical neck 62 extending upwardly from the disk portion at a constant distance into the central through hole in the bobbin 44 and coaxial with the axis AX. The neck 62 has a constant radial thick portion. Fragment 52 further includes a lower cylindrical neck 64 extending downwards from the disk portion by a distance such that its bottom end is tightly fitted within the lower sidewall portion 40B. The valve seat component 66 is narrowed to fit into the open lower end of the neck 64 and is sealed into the interior of the wall portion 40B by the O-ring 67. On the lowest end, which fits into the side wall 40, the neck 64 is arranged through the port 14o 'and several seating holes 68 and provides communication between the space delimited by the neck 64. It includes. The side wall 40 allows such communication by not restricting the through hole 68.

The bushes 54, 60 serve to guide the valve shaft 70 with respect to the linear travel movement along the axis AX. The central portion of the shaft 70 is slightly enlarged for the pressure fit of the tubular armature 72 against the shaft 70. The lower end of the shaft 70 includes a valve 74 that cooperates with the valve seat component 66. The valve 74 is a head with a rounded tip 74A, integrally formed with the shaft 70 and having the general shape of a tapered pintle, a truncated conical tapered portion 74B extending from the tip 74A. ), A recessed cylindrical portion 74C extending from portion 74B and an integral backup flange 74D that partially defines the upper axial end of the groove of portion 74C. A suitable elastomeric O-ring seal 76 that is resistant to fuel is disposed in the groove of the portion 74c.

The sheet component 66 includes an inwardly facing shoulder 66A that includes a portion of the through hole extending axially through the sheet component. This portion of the through hole comprises a straight cylindrical portion 78 and a truncated conical sheet surface 80 extending from the upper end of the portion 78 and opening into the interior space bounded by the neck 64. The remainder of the through hole in the axial direction of the portion 78 is indicated by reference numeral 81.

The upper end of the shaft 70 is formed to protrude a certain distance above the bush 54 and provide for attachment of the spring sheet 79 to the upper end of the shaft 70. By means of a piece B2 attached to the piece B1 by a clinch ring 82 which clamps the opposite paired flanges and sandwiches the seal 84 therebetween, the spiral coil linear compression spring 86 is seated. Is caught between 79 and another spring seat 87 housed in a suitably formed pocket of piece B2. Calibrating screw 88 is threaded into a hole in the end wall of the pocket that is coaxial with axis AX, and setting the extent to which spring seat 87 is positioned axially with respect to the pocket. Externally accessible by means of suitable rotating tools (not shown). As the screw 88 gradually progresses into the hole, the sheet 87 gradually moves in the direction of the springsheet 79, during which the spring 86 is gradually compressed. Terminal 56 is also connected to terminal 90 mounted in piece B2 to form an electrical connector 92 for male and female engagement with another connector (not shown) connecting to drive circuit 26.

In the valve closing position shown in FIG. 3, the rounded surface portion of the seal 76 has a sealing contact with the seat surface 80 in a continuous circumferential direction such that the valve is between the ports 14o ', 14i'. Close the flow passage. In this position, the upper portion of the amateur 72 partially covers the air gap existing between the upper end of the neck 62 and the lower end of the neck 58 in the axial direction, but there is a slight radial gap so that the amateur 72 ) Does not actually contact the necks and thereby avoids magnetic shorts.

Generally speaking, the degree of valve opening depends on the magnitude of the current passing through the solenoid coil 46 so that the purge flow through the valve is effectively controlled by controlling the current passing through the coil. As the magnitude of current from zero increases, a value sufficient to exceed any static friction present between the sheeted O-ring 76 and the seat surface 80 reaches. At that point the valve mechanism begins to open against the opposing force of the spring 86. As soon as the o-ring seal 76 breaks contact with the seat surface 80, the valve begins to open.

The constant initial axis of the pintle, which removes the O-ring seal 76 from the seat surface 80 because it depends on the special mating structural relationship that exists between the valve pintle, its O-ring seal and the angle of the valve seat surface. Directional travel must occur before the tapered portion 74B can be executed independently to set the effective flow area through the sheet component through-holes. In other words, it is only after the valve has traveled above a certain minimum mileage that the tapered portion can run independently to control the area open to flow. Beyond this initial minimum, the open area gradually increases as the pintle is positioned further away from the seat component.

A representative graph of fluid flow rate versus current shows three characteristic spans: a first span in which the current increases without any valve opening; A second span where the valve starts to open but the tapered portion 74B has not yet been fully executed to independently control flow; And a third span that opens the valve sufficiently to allow the portion 74B to control the flow alone. The second span is related to the fact that the small increase in average current in the solenoid S causes a change in the increase in fluid flow rate that is substantially different from the result of the increase in change when the valve is operated in place of the range of the third span. Can be characterized by.

The coil 46 of the solenoid S is connected to a source of DC voltage pulses, such as a pulse width modulator circuit operating at a selected frequency. The current flowing to the coil can be controlled by a semiconductor driver in response to a control output signal from the engine control computer, and the circuit controls the ability to compensate for constant environmentally induced changes that could otherwise compromise control accuracy. A feedback loop may be included to feed back a representative signal of the current passing through the solenoid coil to impart to. For example, the feedback loop essentially negates the effect of changes in ambient conditions, such as temperature and direct current supply voltage to the circuit, thereby causing the valve to be commanded by the circuit substantially without such effects. The current through the coil 46 can be automatically adjusted to operate in position.

4 shows a mechanical pressure regulator 200 operating in conjunction with valve 14 ′. The pressure regulator 200 includes a two-piece body 202 having a base 202b and a cover 202c made of a suitable material such as injection molded plastic that is resistant to fuel. The base 202b includes an inlet port 204 and an outlet port 206, each in the form of a nipple. The conduit 208 fluid connects the port 204 with the outlet port 14o 'of the valve 14', and the outlet port 206 is connected to the engine intake manifold by other conduits not specifically shown in the figure. Fluid connection.

The nipple forming the outlet port 206 includes a radial portion extending inwardly of the body 202 to form an axial portion coaxial with the axis 210 of the pressure regulator 200. This axial portion is bounded by a circular rim that forms the seal sheet 212. Base 202b includes a cylindrical walled cup with a circular annular radial shoulder 214. The cup is bounded in a circular rim 216 coaxial with the axis 210.

The cover 202c has a catch 218 on its outer periphery that attaches the cover to the other open end of the cup of the base 202b at the rim 216 by grasping the lip of the rim as shown. It generally has a circular shape, including more. The outer circumferential bead of the impermeable flexible member 220 is held in a sealed form between the cover 202c and the outer edge of the rim 216. Located at the center of the member 220 and coaxial with the axis 210 is a rigid circular disk 222. Fixed centrally to the disk 222 facing the rim 216 is the circular seal component 224. In the illustrated embodiment, the component 224 has a portion of molded material passing from the component through a small hole in the center of the disk and is secured to the disk by being molded on the disk, so that it is on the opposite side of the disk. To form a circular forming portion 226 to connect.

It can be seen that the outer edge of disk 222 includes an annular area without shaped material. One end of the helical coil compression spring 228 bears against the annular area. The opposite end of the spring bears under the rim 212 against the wall of the base 202b which extends partially around the axial portion of the outlet port nipple.

The cover 202c is formed with a central recess 230, and under the conditions shown in FIG. 4, the spring 228 has a flat cross section of the formation 226 deflected with respect to the flat cross section of the recess 230. It can be seen that the disk 222 is as far away from the rim 212 as possible.

The assembled portions 220, 222, 224 form a fluid impermeable wall 232 that divides the interior of the body 202 into first and second chamber spaces 234, 236. In the position shown in the figure, chamber 236 provides free communication between ports 204 and 206. The flow passage thus provided represents a purge flow from the valve 14 'through the inlet port 202, through the chamber space 236 and through the outlet port 204 to the engine intake manifold. It is indicated by an arrow with no number.

The chamber space 234 communicates with the fuel tank steam upper space via the vapor accumulation canister 237. Cover 202c includes nipple 202n and one end of tubular conduit 238 fits sealingly on the nipple. The opposite end of the conduit 238 fits on a tee 14t formed with a nipple forming a sealing inlet port 14i '. Although not explicitly shown in the figures, 202n may alternatively be directly communicated directly to the tank overhead space by a dedicated conduit, making the tee 14t unnecessary.

The pressure regulator 200 operates in the following manner. For the purpose of explanation, it is assumed that the pressure regulator is in the position illustrated in the figure, there is an equal air pressure in the two chamber spaces 234 and 236 and the valve 14 'is open. The generation of increasing intake manifold vacuum in the chamber space 236 will begin to generate an increasing pressure differential on the wall 232. At some difference, the biasing force of the spring begins to overcome, and the center of the wall 232 begins to move towards the rim 212. As the wall 232 moves toward the rim 212, the steam overhead pressure is drawn into the chamber as steam is drawn through the canister 237, the inlet port 14i ', the tee 14t and the conduit 238. Held in space 234. When the vacuum is increased to a constant larger size, the seal component 224 will approach the rim 212 sufficiently to create a restriction of purge flow. The seal component, although only momentary, can actually access the rim 212. Such a restriction or closure tends to reduce the air pressure differential acting on the wall 232 such that the spring 228 then tends to move the central portion of the wall away from the rim 212. The tank vapor pressure in the chamber space 234 is maintained because the steam flows out in the opposite direction to the inflow direction.

The overall effect is that the sealing component 224 causes the vacuum in the chamber space 236 to be adjusted to a predetermined size that is substantially independent of the size of the intake manifold vacuum and the flow through the valve to the change in valve inlet pressure. In essence, it will occupy an average position that is irrelevant. Thus, a substantially constant pressure differential is maintained throughout the valve 14 '. As the valve 14 'now operates in another position as commanded by the signal applied to the solenoid, the commanded position is substantially correspondingly intended without substantially changing the intake manifold vacuum and the tank overhead pressure. Will produce a purge flow rate. Since the flexible member 220 has a vortex, the flexible member 220 imposes a restriction on the movement of the central portion of the movable wall with respect to the open end of the walled axial conduit portion including the rim 212. I never do that.

In the characterization of the previous use of the pressure regulator in connection with a pulsating purge valve, the disclosed embodiment, when operated at a fundamental pulse waveform frequency substantially greater than the frequency response of the valve mechanism, provides a means for reducing the purge artery flow. Do not use the regulator. Rather, the generation of a predetermined pressure differential acting throughout the valve 14 'is a given command signal, which makes it possible to directly provide the intended flow rate without variation of the manifold vacuum and variation of the space pressure above the tank. . This is an engine control computer which is used to process a map for processing the input indicating the intake manifold vacuum and an input for the upper tank pressure when calculating that the computer should have a command signal to the solenoid coil of the valve. It is believed that the need to include a map can be eliminated.

FIG. 5 shows a series of representative graphs of purge flow rate through the valve 14 ′ versus time average direct current of the solenoid coil. Each graph corresponds to different values of intake manifold vacuum as shown in FIG. 5, but the significant effect of the pressure regulator 200 is on the substantial agreement of the graphs for the 200, 300, 400, 500 and 600 mmHg intake manifold vacuum. Can be seen by. In the example of FIG. 5, purge flow starts at approximately 183 milliampere current for a substantially matching graph.

6 and 7 illustrate another embodiment in which the LSPV and the pressure regulator are integrated into a single assembly. Although, in comparison, some parts differ in some details of the structure, like reference numerals in the previous drawings indicate the same parts. 6 and 7 show that the pressure regulator 200 is integrated into the lower end of the LSPV 14 '. The nipples forming the valve outlet port 14o 'and the regulator inlet port 208 were removed. The flow passage downstream of the valve pintle communicates directly with the chamber space 236 within the body of the assembly.

The flexible member 220, the seal component 224 and the forming portion 226 are integrated as a unit made by insert molding on the disk 222. The interior of the cover 202c includes a circular ridge 202r and the central annular portion of the wall 232 when the spring 228 deflects the seal component 224 as far as possible from the rim 212. Bear against that circular ridge.

The flow passage connecting the chamber space 234 to the nipple forming the inlet port 14 'includes an inner trough 14t' extending from the nipple passage. An annular seal 241 formed integrally with the flexible member 220 seals around the outside of the trough passage through which the annular seal 241 communicates with the chamber space 234. The pressure regulator 200 and the valve 14 ′ of the FIGS. 6 and 7 function in the same manner as described for the previous embodiment described above.

While the solenoid S shown in FIG. 6 functions in the same way as the solenoids shown in FIGS. 3 and 4, it differs in certain structural aspects. The coils and stator portions 48, 50, 52 comprising the bobbins 44, 46 are encased in an overmold 300 to form an assembly that also includes the body portion B2 as part of the overmold. . The overmold includes features forming a shell of the connector 92. A facility for receiving the spring 86 and its associated adjustment mechanism is provided by the stator portion 48.

The stator portion 48 is a threaded portion. The stator portion 50 is a strap, rather than a complete cylindrical tube. The two parts 48, 50 are connected together. The portion 48 has a head end that passes through a hole in the radial portion of the strap 50. The portion 48 is staked over the edge of the hole in the strap 50 to coalesce the two portions. The axial portion of the strap 50 extends axially over the outside of the coil 44 and contacts the stator portion 52, extending radially from the outer end of the radial portion of the strap.

The parts to be overmolded are located in suitably formed mold cavities in the machine which form the overmolded around them. As the overmolded material flows, the overmolded material covers the coil / bobbins 44 and 46 and stator portions as shown, but leaves the outer head end of the stator portion 48 exposed. This allows access to the adjusting screw 88, which is threaded into the stator portion 48 and formed into a polygonal socket 88 'for engagement by a correspondingly formed adjusting tool (not shown). It includes. Stator portion 48 also includes a hollow interior space for spring 86. One end of the spring 86 is located on the inner shaft end of the screw 88 and centered by a nose in the shaft end. The opposite end of the spring 86 is located in the counterbore of the armature 72.

The overmold material integrates the inlet port 14i ', the outlet 206 and the regulator base 202b to form a perimeter 399 of the molded plastic portion that engages the overmold with the portion 400. As soon as the overmolding material has cured, the overmolding takes on the final form as shown.

Valve seat configuration with a lower cylindrical wall fitted in a sealed manner by an O-ring 402 to the open inner end of the nipple (coaxial with the axis AX) forming the inlet port 14i '. Element 66 is assembled to portion 400. On the lateral wall of the valve seat component including the through hole controlled by the valve 74, the cylindrical wall of the seat component includes several windows spaced about the circumference and controlled through the valve 74. Steam passing through the holes is provided to flow into the interior space of the portion 400 to enter the regulator chamber space 236. In Figs. 6 and 7, the steam flow passage is indicated by an unnumbered arrow. At the far end, the sheet component includes an annular flange located on the perimeter 399 of the portion 400 and a circular rim that fits into the stator portion 52 for a short distance. The amateur is guided by the thin walled non-ferromagnetic sleeve 408 while the pintle shaft is guided by the bush 60.

Embodiments using the principles of the present invention can be constructed in various ways. Since automatic electronic technology generally uses an electronic processor, the development of electrical control signals for the solenoid can be accomplished by using conventional software to program techniques to develop the intended waveform or waveform for any particular control strategy. Can be.

Although the present invention has been described with respect to the presently preferred embodiments, it should be understood that the present invention is not intended to be limited to the above embodiments. Accordingly, the present invention is intended to embrace various modifications and arrangements within the scope of the claims.

Claims (37)

An inlet through which the fluid flow enters the valve body, a valve mechanism positioned within the valve body by an electric control signal to control the fluid flow through the valve body, and an inlet through which the fluid flow through the valve mechanism enters the pressure regulator flow passage; The fluid flow entering the pressure regulator flow passage includes a pressure regulator including a flow passage having an outlet exiting the pressure regulator flow passage, the pressure regulator is the pressure of the pressure regulator flow passage inlet and the pressure of the pressure regulator flow passage outlet An electrically operated pressure regulated fluid flow control valve, comprising a pressure regulating mechanism that is essentially irrelevant to regulate and causes the flow through the valve to be essentially independent of the change in valve inlet pressure. 2. The pressure regulator of claim 1, wherein the pressure regulator includes a body surrounding an inner space, and the pressure regulator includes a movable wall dividing the inner space into a first chamber space and a second chamber space. Wherein the chamber space forms part of the pressure regulator flow passage, and wherein the first chamber space is in communication with the pressure at the valve inlet. 3. The valve mechanism of claim 2, wherein the valve mechanism has a frequency response characteristic that prevents the valve mechanism from faithfully following the fundamental frequency of the electrical control signal, and when applied under the control of the valve mechanism, the fundamental frequency of the electrical control signal is A fluid flow control valve, characterized in that it is greater than a predetermined frequency of positioning the valve mechanism at a position corresponding to the most recent time average of the electrical control signal without any noticeable pulsation. 3. The fluid flow control valve of claim 2, wherein the outlet of the pressure regulator flow passage is in communication with a changing vacuum. 3. The fluid flow control valve of claim 2, wherein the pressure regulator inlet further comprises an outer nipple and a conduit fitted to the nipple to transfer fluid from the valve body to the nipple. 3. The fluid flow control valve of claim 2, wherein the valve body and the pressure regulator body are assembled together to form a seal and fluid flow passes through the seal from the valve mechanism to the pressure regulator. 2. The pressure regulator of claim 1, wherein the pressure regulator includes a movable wall separating the variable volume first chamber space from the variable volume second chamber space, the second chamber space forming a portion of the pressure regulator flow passage, and And the first chamber space is in communication with the pressure at the valve inlet. 8. The movable wall of claim 7, wherein the movable wall comprises a rigid disk disposed centrally on the movable wall and a flexible member surrounding the disk, and further comprising a seal component disposed centrally on the disk. Fluid flow control valve, characterized in that. 9. The fluid flow control valve of claim 8, wherein the pressure regulating mechanism includes a helical coil spring having an axial end that bears against the disk and surrounds the seal component. 9. The fluid flow control valve of claim 8, wherein the helical coil spring and the seal component are disposed in the second chamber space. 8. The pressure regulator of claim 7, wherein the pressure regulator further comprises a wall conduit having an open end disposed in the second chamber space in parallel at the center of the movable wall and leading to the pressure regulator flow passage outlet. And a flexible vortex member surrounding the central portion of the movable wall to permit unrestricted movement of the central portion relative to the open end of the walled conduit. 12. The fluid flow control valve of claim 11, wherein the pressure regulating mechanism includes a spring that bears against the center of the movable wall and acts away from the open end of the walled conduit. 13. The fluid flow control valve of claim 12, wherein the spring includes a helical coil spring having an axial end that bears about a central portion of the movable wall, wherein the spring is disposed in the second chamber space. 14. The fluid flow control valve of claim 13, wherein the central portion of the movable wall comprises a rigid disk and the shaft end of the spring bears against the rigid disk. 15. The fluid flow control valve of claim 14, wherein the central portion of the movable wall includes a seal component disposed on the central portion of the rigid disk in parallel to the open end of the walled conduit and surrounded by the axial end of the spring. . 2. The fluid flow control valve of claim 1, wherein the valve mechanism includes a linear solenoid actuator to which an electric control signal is applied. 17. The linear solenoid actuator of claim 16, wherein the linear solenoid actuator comprises a bobbin, a coil on the bobbin to which an electric control signal is applied, a stator structure associated with the coil, and an overmold that assembles and connects the bobbin and stator structure and covers the coil. Fluid flow control valve. 17. The fluid flow control valve of claim 16, further comprising an electrical control circuit for applying an electrical signal to the linear solenoid actuator at a fundamental frequency substantially greater than the frequency response of the valve mechanism. The valve mechanism positioned in the valve body by the electric control signal to control the flow through the valve body, and the inlet and pressure regulator flow passage through which the flow through the valve mechanism enters the pressure regulator flow passage communicate with the engine intake manifold. And a pressure regulator including a flow passage having an outlet to control the pressure of the pressure regulator flow passage inlet to a pressure essentially independent of the pressure of the pressure regulator flow passage outlet and regulating the flow through the valve. An electrically operated pressure regulated fuel vapor purge valve for purging fuel vapor from a fuel tank to an intake manifold of an internal combustion engine, the pressure regulator comprising an essentially independent of the change in inlet pressure. 20. The apparatus of claim 19, wherein the pressure regulator includes a body surrounding an interior space, and the pressure regulator includes a movable wall dividing the interior space into a first chamber space and a second chamber space. Wherein the chamber space forms part of the pressure regulator flow passage, and the first chamber space communicates with the tank upper space. 21. The fuel vapor purge valve according to claim 20, wherein the first chamber space communicates with the tank upper space through the fuel vapor integrated canister. 21. The fuel vapor purge valve of claim 20, wherein the pressure regulator inlet further comprises an outer nipple and a conduit fitted to the nipple to transfer flow from the valve body to the nipple. 21. The fuel vapor purge valve according to claim 20, wherein the valve body and the pressure regulator body are assembled together to form a seal and the flow passes through the seal from the valve mechanism to the pressure regulator. 20. The method of claim 19, wherein the pressure regulating mechanism is variable volume first chamber space variable volume And a movable wall separating from the second chamber space, wherein the second chamber space forms part of the pressure regulator flow passage, and the first chamber space communicates with the tank upper space. . 25. The movable wall of claim 24, wherein the movable wall includes a rigid disk disposed centrally on the movable wall and a flexible member surrounding the disk, and further comprising a seal component disposed centrally on the disk. A fuel vapor purge valve, characterized in that. 26. The fuel vapor purge valve of claim 25, wherein the pressure regulating mechanism includes a helical coil spring having an axial end that bears against the disk and surrounds the seal component. 27. The fuel vapor purge valve of claim 26, wherein the spiral coil spring and the seal component are disposed in a second chamber space. 25. The pressure regulator of claim 24, wherein the pressure regulator further comprises a walled conduit having an open end disposed in the second chamber space in parallel at the center of the movable wall and leading to the pressure regulator flow passage outlet, the movable wall being movable And a flexible vortex member surrounding the center of the wall to allow unrestricted movement of the center relative to the open end of the walled conduit. 29. The fuel vapor purge valve of claim 28, wherein the pressure regulating mechanism includes a spring that bears against a central portion of the movable wall and acts away from the open end of the walled conduit. 30. The fuel vapor purge valve of claim 29, wherein the spring includes a helical coil spring having an axial end that bears about a central portion of the movable wall, wherein the spring is disposed in the second chamber space. 31. The fuel vapor purge valve according to claim 30, wherein the central portion of the movable wall includes a rigid disk and the shaft end of the spring bears against the rigid disk. 32. The fuel vapor purge valve according to claim 31, wherein the central portion of the movable wall includes a seal component disposed on the central portion of the rigid disk in parallel to the open end of the walled conduit and surrounded by the axial end of the spring. . 20. The fuel vapor purge valve according to claim 19, wherein the valve mechanism comprises a linear solenoid actuator to which an electric control signal is applied. 34. The fuel according to claim 33, wherein the linear solenoid actuator includes a bobbin, a coil on the bobbin to which an electric control signal is applied, a stator structure associated with the coil, and an overmold for assembling and connecting the bobbin and stator structure to cover the coil. Steam Purge Valve. 35. The fuel vapor purge valve of claim 34, further comprising an electrical control circuit for applying an electrical signal to the linear solenoid actuator at a fundamental frequency substantially greater than the frequency response of the valve mechanism. Inlet and pressure in which fluid flow enters the body, a valve mechanism positioned within the body by an electrical control signal to control the fluid flow through the body, and the fluid flow through the valve mechanism enters the pressure regulator flow passage. The fluid flow entering the regulator flow passage comprises a pressure regulator comprising a flow passage having an outlet exiting the pressure regulator flow passage, the pressure regulator being movable wall separating the variable volume first chamber space from the variable volume second chamber space. And wherein the second chamber space forms part of a pressure regulator flow passage, and wherein the first chamber space is in communication with the inlet pressure. A valve mechanism positioned within the body by an electrical control signal to control the flow through the body, and an inlet and pressure regulator flow passage through which the flow through the valve mechanism enters the pressure regulator flow passage communicates with the engine intake manifold. And a pressure regulator including a flow passage having an outlet for discharging, wherein the pressure regulator includes a movable wall separating the variable volume first chamber space from the variable volume second chamber space, wherein the second chamber space is a pressure regulator flow. And a first chamber space in communication with the body inlet pressure, wherein the first chamber space communicates with the inlet manifold of the internal combustion engine.