Patent Publication Number: US-11028790-B2

Title: Purge control valve device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of priority from Japanese Patent Application No. 2019-156095 filed on Aug. 28, 2019 and Japanese Patent Application No, 2020-026491 filed on Feb. 19, 2020. The entire disclosures of the above applications are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a purge control valve device. 
     BACKGROUND 
     A purge control valve device controls a flow rate of evaporative fuel from a canister to an engine. 
     SUMMARY 
     According to at least one embodiment of the present disclosure, a purge control valve device includes: an inflow port into which the evaporative fuel flowing out of a canister flows; an outlet port through which the evaporative fuel flows out toward an engine; a housing having an in-housing passage connecting the inflow port and the outflow port; a first electromagnetic valve provided inside the housing and having a first valve body opening and closing a first internal passage included in the in-housing passage to control a flow rate of the evaporative fuel; and a second electromagnetic valve provided inside the housing and having a second valve body opening and closing a second internal passage included in the in-housing passage to control a flow rate of the evaporative fuel. The first internal passage and the second internal passage are arranged in series in the in-housing passage The first electromagnetic valve and the second electromagnetic valve are controlled to operate individually. The first electromagnetic valve is switched between a seated state in which the first valve body contacts a first valve seat and an unseated state in which the first valve body is separated from the first valve seat. The purge control valve device further includes a narrowed passage in which a flow rate of the evaporative fuel is smaller in one of the seated state and the unseated state than in another of the seated state and the unseated state. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims. 
         FIG. 1  is a schematic diagram illustrating an evaporative fuel processing apparatus including a purge control valve device according to at least one embodiment. 
         FIG. 2  is a sectional view illustrating an operation of the purge control valve device at a first increase rate, according to at least one embodiment. 
         FIG. 3  is a sectional view illustrating an operation of the purge control valve device at a second increase rate, according to at least one embodiment. 
         FIG. 4  is a flowchart illustrating a control of the purge control valve device. 
         FIG. 5  is a diagram illustrating a flow rate control of the purge control valve device. 
         FIG. 6  is a sectional view illustrating an operation of the purge control valve device at a first increase rate, according to at least one embodiment. 
         FIG. 7  is a sectional view illustrating an operation of the purge control valve device at a second increase rate, according to at least one embodiment. 
         FIG. 8  is a flowchart illustrating a control of the purge control valve device. 
         FIG. 9  is a sectional view illustrating an operation of the purge control valve device at a first increase rate, according to at least one embodiment. 
         FIG. 10  is a sectional view illustrating an operation of the purge control valve device at a second increase rate, according to at least one embodiment. 
         FIG. 11  is a sectional view illustrating an operation of the purge control valve device at a first increase rate, according to at least one embodiment. 
         FIG. 12  is a sectional view illustrating an operation of the purge control valve device at a first increase rate, according to at least one embodiment, 
         FIG. 13  is a sectional view illustrating an operation of the purge control valve device at a first increase rate, according to at least one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     As negative pressure of a low-fuel-consumption engine decreases, and operating time of an engine of a vehicle such as a hybrid vehicle decreases, a purge valve is required to have a large flow capacity. For example, a column member may be positioned to face a housing entrance so as to reduce pulsation entering an input port and reduce decrease in flow rate. However, there is room for improvement. A purge control valve device of the present disclosure has a specific flow characteristic in order to improve the flow characteristics. 
     According to one aspect of the present disclosure, a purge control valve device includes: an inflow port into which the evaporative fuel flowing out of a canister flows; an outlet port through which the evaporative fuel flows out toward an engine; a housing having an in-housing passage connecting the inflow port and the outflow port; a first electromagnetic valve provided inside the housing and having a first valve body opening and closing a first internal passage included in the in-housing passage to control a flow rate of the evaporative fuel; and a second electromagnetic valve provided inside the housing and having a second valve body opening and closing a second internal passage included in the in-housing passage to control a flow rate of the evaporative fuel. The first internal passage and the second internal passage are arranged in series in the in-housing passage The first electromagnetic valve and the second electromagnetic valve are controlled to operate individually. The first electromagnetic valve is switched between a seated state in which the first valve body contacts a first valve seat and an unseated state in which the first valve body is separated from the first valve seat. The purge control valve device further includes a narrowed passage in which a flow rate of the evaporative fuel is smaller in one of the seated state and the unseated state than in another of the seated state and the unseated state. 
     Accordingly, the evaporative fuel flowing through the narrowed passage has a small flow rate in the one state and a large flow rate in the other state. The seated state and the unseated state can be switched such that the one state is selected when it is desired to obtain a small flow rate characteristic or to suppress pulsation, and the other state is selected when it is desired to secure a flow rate. Thus, the purge control valve device can improve flow characteristics. 
     According to another aspect of the present disclosure, a purge control valve device includes: an inflow port into which the evaporative fuel flowing out of a canister flows; an outlet port through which the evaporative fuel flows out toward an engine; a housing having an in-housing passage connecting the inflow port and the outflow port; a first electromagnetic valve provided inside the housing and having a first valve body opening and closing a first internal passage included in the in-housing passage to control a flow rate of the evaporative fuel; and a second electromagnetic valve provided inside the housing and having a second valve body opening and closing a second internal passage included in the in-housing passage to control a flow rate of the evaporative fuel. The first internal passage and the second internal passage are arranged in series in the in-housing passage. The first electromagnetic valve and the second electromagnetic valve are controlled to operate individually. The first electromagnetic valve is switched between a seated state in which the first valve body contacts a first valve seat and an unseated state in which the first valve body is separated from the first valve seat. The purge control valve device further includes a narrowed passage in the first internal passage such that a passage cross-sectional area of the first internal passage is smaller in one of the seated state and the unseated state than in another of the seated state and the unseated state. 
     Accordingly, a flow rate of the evaporative fuel can be made smaller in the one state than in the other state by the narrowed passage that reduces the passage cross-sectional area of the first internal passage. Therefore, the one state is selected when it is desired to obtain a small flow rate characteristic or to suppress pulsation while the other state is selected when it is desired to secure a flow rate. Accordingly, the passage cross-sectional area of the first internal passage can be switched, Thus, the purge control valve device can improve flow characteristics. Hereinafter, embodiments for implementing the present disclosure will be described referring to drawings. In each embodiment, portions corresponding to the elements described in the preceding embodiments are denoted by the same reference numerals, and redundant explanation may be omitted. When only a part of the configuration is described in each form, the other forms described above can be applied to the other parts of the configuration. It may be possible not only to combine parts the combination of which is explicitly described in an embodiment, but also to combine parts of respective embodiments the combination of which is not explicitly described if any obstacle does not especially occur in combining the parts of the respective embodiments. 
     First Embodiment 
     A first embodiment will be described with reference to  FIGS. 1-5 . A purge control valve device is used in an evaporative fuel processing apparatus  1  which is an evaporative fuel purge system mounted on a vehicle. A purge valve  3  is an example of the purge control valve device. As shown in  FIG. 1 , the evaporative fuel processing apparatus  1  supplies gas, such as HC gas; in fuel adsorbed by a canister  13  to an intake passage of an engine  2 . Accordingly, evaporative fuel is prevented from being released from a fuel tank  10  to an outside air. The evaporative fuel processing apparatus  1  includes an intake system of the engine  2  which constitutes the intake passage of the engine  2  that is an internal combustion engine, and an evaporative fuel purge system which supplies evaporative fuel to the intake system of the engine  2 . 
     Evaporative fuel introduced by an intake pressure into the intake passage of the engine  2  is mixed with combustion fuel supplied from an injector or the like to the engine  2  and burned in a combustion chamber of the engine  2 . The engine  2  mixes at least the combustion fuel and the evaporative fuel desorbed from the canister  13 , and burns the mixture. In the intake system of the engine  2 , an intake pipe  21  forming the intake passage is connected to an intake manifold  20 . In this intake system, a throttle valve  25  and an air filter  24  are provided in the intake pipe  21 . 
     The fuel tank  10  and the canister  13  in the evaporative fuel purge system are connected to each other through a pipe  11  that forms a vapor passage. The canister  13  and the intake pipe  21  in the evaporative fuel purge system are connected to each other through and the purge valve  3  and a pipe  14  forming a purge passage. A purge pump may be provided in the purge passage. The air filter  24  is provided in an upstream portion of the intake pipe  21  and captures dust, dirt, etc. in intake air. The throttle valve  25  is an intake amount adjustment valve that adjusts an amount of intake air flowing into the intake manifold  20  by adjusting an opening degree of an inlet of the intake manifold  20 . Intake air passes through the intake passage, and flows into the intake manifold  20 . Then, the intake air is mixed with the combustion fuel injected from the injector or the like at a predetermined air-fuel ratio to be burned in the combustion chamber. 
     The fuel tank  10  is a container for storing fuel such as gasoline. The fuel tank  10  is connected to an inflow portion of the canister  13  by the pipe  11  forming the vapor passage. An ORVR valve  15  is provided in the fuel tank  10 , The ORVR valve  15  prevents evaporative fuel in the fuel tank  10  from being discharged to the outside air from a fuel filler opening during fueling. The ORVR valve  15  is a float valve which is displaced in accordance with a fuel level. When an amount of fuel in the fuel tank  10  is small, the ORVR valve  15  is opened, and vapor is discharged from the fuel tank  10  to the canister  13  by pressure at the time of fueling. When a predetermined amount or more of fuel is present in the fuel tank  10 , the ORVR valve  15  closes due to the buoyancy of the fuel, thereby preventing the evaporative fuel from flowing out toward the canister  13 . 
     The canister  13  is a container in which an adsorbent such as activated carbon is sealed. The canister  13  takes in evaporative fuel generated in the fuel tank  10  through the vapor passage and temporarily adsorbs the evaporative fuel to the adsorbent. The canister  13  is provided with a valve module  12  integrally or through a duct. The valve module  12  includes a canister close valve and an inner pump. The canister close valve opens and closes a suction portion for drawing fresh air from the outside. Since the canister  13  includes the canister close valve, atmospheric pressure can be introduced in the canister  13 . The canister  13  can easily release (i.e. purge) the evaporative fuel adsorbed to the adsorbent by the drawn fresh air. 
     The purge valve  3  is a purge control valve device including multiple valve bodies that open and close an in-housing passage in a housing that is a part of the purge passage. The purge control valve device has therein multiple electromagnetic valves. The purge valve  3  can permit and prevent supply of the evaporative fuel from the canister  13  to the engine  2 . 
     During running of the vehicle, when a controller  50  performs a control such that an inflow port  31   a  communicates with an outflow port  33   a , a pressure difference is generated between an atmospheric pressure in the canister  13  and a negative pressure in the intake manifold  20  generated by a suction action of a piston. This pressure difference makes the vaporfuel adsorbed to the canister  13  be sucked into the intake manifold  20  through the purge passage, the purge valve  3  and the intake pipe  21 . 
     Evaporative fuel sucked into the intake manifold  20  is mixed with original combustion fuel supplied from the injector or the like to the engine  2  and burned in a cylinder of the engine  2 , In the cylinder of the engine  2 , the air-fuel ratio which is the mixing ratio of the combustion fuel and the intake air is controlled to be a predetermined air-fuel ratio set in advance. The controller  50  controls a first electromagnetic valve  34  by energization and de-energization thereof. The controller  50  controls a second electromagnetic valve  35  by controlling duty cycle of energization. Appropriate control of the first electromagnetic valve  34  and the second electromagnetic valve  35  by the controller  50  achieves adjustment of a purge amount of evaporative fuel so that the predetermined air-fuel ratio is maintained. 
     The controller  50  includes at least one processing unit (CPU) and at least one memory unit as a storage medium which stores a program and data. The controller  50  is provided by a microcontroller including a computer-readable storage medium. The storage medium is a non-transitional substantive storage medium that stores a computer-readable program in a non-temporary fashion. A semiconductor memory, a magnetic disk, or the like can serve as the storage medium. The controller  50  may be provided by a set of computer resources linked by a computer or data communication device. When executed by the controller  50 , the program causes the controller  50  to function according to the description provided herein and causes the controller  50  to perform the methods described herein. 
     Means and/or functions provided by the controller  50  may be provided by software recorded in a substantive memory device and a computer that can execute the software, software only, hardware only, or some combination of them. For example, when the controller  50  is provided by an electronic circuit being hardware, it may be possible to provide by a digital circuit including multiple logic circuits or analog circuits. 
     In recent years, a negative pressure in the engine tends to decrease due to reduction in fuel consumption, and an operating time of the engine of a vehicle such as a hybrid vehicle tends to decrease. Thus, the purge valve  3  may have a performance capable of adjusting fuel at a large flow rate. If an attempt is made to increase a flow capacity of the purge valve  3 , a fluctuation range of pressure in a flow path connecting the purge valve  3  and the canister  13  may increase. The increase in pressure fluctuation range may cause the pipe to vibrate due to pulsation and generate noise in the vehicle. Further, such large flow capacity of the purge valve  3  may lead to a fluttering sound of the ORVR valve  15 . The pipe  14  connecting the purge valve  3  and the canister  13  is provided, for example, below a floor in a vehicle compartment. Hence, the noise due to the vibration of the pipe and the fluttering sound of the ORVR valve  15  are easily transmitted to the vehicle compartment. The evaporative fuel processing apparatus  1  has an effect of reducing the pressure fluctuation range in the flow path leading to the canister  13  and reducing the fluttering sound of the ORVR valve  15 . When the purge valve  3  is increased in flow capacity, an accuracy of flow rate control is reduced, and thereby an accuracy of concentration learning of the evaporative fuel tends to be reduced. The evaporative fuel processing apparatus  1  has an effect of securing the accuracy of evaporative fuel concentration learning. 
     Next, configurations of the purge valve  3  will be described. The purge valve  3  includes the first electromagnetic valve  34  and the second electromagnetic valve  35  which are provided inside the housing. The first electromagnetic valve  34  and the second electromagnetic valve  35  are arranged inside the purge valve  3  in a direction from an upstream side to a downstream side. The upstream side is indicated by “US” in the drawings. The downstream side is indicated by “DS” in the drawings. The first electromagnetic valve  34  and the second electromagnetic valve  35  are arranged in a direction of displacement of a valve body of the purge valve  3  or in an axial direction of the valve body. The axial direction is indicated by “AD” in the drawings. The first electromagnetic valve  34  is located upstream of the second electromagnetic valve  35 . The first electromagnetic valve  34  opens and closes a first internal passage in the purge valve  3  and adjusts a passage cross-sectional area of the first internal passage. The second electromagnetic valve  35  opens and closes a second internal passage in the purge valve  3  and adjusts a passage cross-sectional area of the second internal passage. The passage cross-sectional area is a sectional area of a passage cut along a plane orthogonal to a flow direction of fluid in the passage. 
     The first internal passage and the second internal passage are passages included in the in-housing passage. The first internal passage and the second internal passage are arranged in series, not in parallel, in the internal passage in the housing. In the present embodiment, the first internal passage is an upstream passage in the in-housing passage, and the second internal passage is a downstream passage in the in-housing passage. Hereinafter, the first internal passage is replaced with the upstream passage, and the second internal passage is replaced with the downstream passage. 
     The purge valve  3  includes, as the housing, an inflow housing  31 , an outflow housing  33 , and an intermediate housing  32 . The inflow housing  31 , the intermediate housing  32 , and the outflow housing  33  are formed of, for example, a resin material. The inflow housing  31  includes the inflow port  31   a  into which evaporative fuel flows from the canister  13 . The inflow port  31   a  is connected to the pipe  14  forming the purge passage of the evaporative fuel processing apparatus  1 . The inflow port  31   a  communicates with the canister  13  through the pipe  14  connected to the inflow port  31   a . The inflow housing  31  includes a flange  31   b  which is joined to a flange  32   b  of the intermediate housing  32  by welding or bonding. 
     The inflow port  31   a  is a part of a tubular portion that has a fluid inflow passage  31   a   1  therein, and is located at an upstream end of the inflow housing  31 . A downstream portion of the tubular portion has a pipe diameter that increases in a direction toward the downstream side, and an inflow chamber is formed inside the downstream portion. The inflow chamber has a passage cross-sectional area larger than a passage in the inflow port  31   a  located upstream of the inflow chamber. The passage cross-sectional area of the inflow chamber increases in the direction toward the downstream side. A downstream end of the tubular portion is integrally formed with the flange  31   b  that protrudes radially outward. 
     The flange  31   b  has a first valve seat  31   b   1  on a downstream surface of the flange  31   b . A first valve body  34   b  contacts the first valve seat  31   b   1  in a seated state of the first electromagnetic valve  34 . The flange  31   b  is provided with a flow path narrowing wall  31   c  protruding downstream from the downstream surface of the flange  31   b . The flow path narrowing wall  31   c  is located radially outward of a plate  34   b   1 , and a gap is formed between the flow path narrowing wall  31   c  and an outer peripheral edge of the plate  34   b   1 . The flow path narrowing wall  31   c  may surround an entire or part of the outer peripheral edge of the plate  34   b   1 . 
     As shown in  FIG. 2 , the gap between the outer peripheral edge of the plate  34   b   1  and the flow path narrowing wall  31   c  forms a narrowed passage  31   c   1  through which fluid flows when the first valve body  34   b  is in an unseated state. The purge valve  3  includes the narrowed passage  31   c   1  that reduces the passage cross-sectional area of the first internal passage to be smaller than that in the seated state of the first valve body  34   b.    
     The narrowed passage  31   c   1  forms a passage having a passage cross-sectional area smaller than a through-hole  34   b   2 . The narrowed passage  31   c   1  is configured such that fluid does not flow therethrough in the seated state of the first valve body  34   b . When fluid flows at a first increase rate shown in  FIG. 5 , the narrowed passage  31   c   1  corresponds to the upstream passage of the purge valve  3  through which the fluid flows. When the fluid flows at the first increase rate in the unseated state illustrated in  FIG. 2 , the first valve body  34   b  is in contact with a fixed core  343 . The unseated state shown in  FIG. 2  can be said to be a state in which the first valve body  34   b  is seated on the fixed core  343 . Accordingly, the fluid flows through the narrowed passage  31   c   1  and does not flow through the through-hole  34   b   2 . 
     The intermediate housing  32  includes a cylindrical portion  32   a  extending in the axial direction, and flanges  32   b  and  32   c  provided at different ends of the cylindrical portion  32   a  in the axial direction. The flange  32   b  is a portion radially protruding from the upstream end of the cylindrical portion  32   a . The flange  32   c  is a portion radially protruding from the downstream end of the cylindrical portion  32   a.    
     The intermediate housing  32  houses the first electromagnetic valve  34  and the second electromagnetic valve  35 . Inside the intermediate housing  32 , the first electromagnetic valve  34  is provided in an upstream region, and the second electromagnetic valve  35  is provided in a downstream region. An inner peripheral surface of the intermediate housing  32  and an outer peripheral surface of the first electromagnetic valve  34  or the second electromagnetic valve  35  define an intermediate passage  32   a   1  therebetween. The intermediate passage  32   a   1  is a cylindrical passage located between the upstream passage and the downstream passage in the purge valve  3  and located outside the first electromagnetic valve  34  and the second electromagnetic valve  35 . The intermediate passage  32   a   1  is larger in passage cross-sectional area than the upstream passage and the downstream passage in the purge valve  3 . 
     The outflow housing  33  is provided with an outflow port  33   a  through which the evaporative fuel flows out toward the intake pipe  21 , and a tubular portion  33   c  located upstream of the outflow port  33   a . The outflow port  33   a  and the tubular portion  33   c  are provided coaxially. The outflow port  33   a  communicates with an inside of the intake pipe  21  through the pipe connected to the outflow port  33   a . The outflow housing  33  includes a flange  33   b  which is joined to the flange  32   c  of the intermediate housing  32  by welding or bonding. The flange  33   b  is a portion radially protruding from the upstream end of the outflow port  33   a.    
     The outflow port  33   a  is a tubular portion that has a fluid outflow passage  33   a   1  therein, and is located at a downstream end of the outflow housing  33 . The outflow port  33   a  and the tubular portion  33   c  are connected by the flange  33   b . A second valve seat  33   c   1  is provided at an upstream end of the tubular portion  33   c . A space between the second valve seat  33   c   1  and a second valve body  35   b  corresponds to the downstream passage of the purge valve  3  through which the fluid flows toward the outflow passage  33   a   1 . An upstream end of the passage in the tubular portion  33   c  communicates with the downstream passage of the purge valve  3 . A downstream end of the passage in the tubular portion  33   c  communicates with the outflow passage  33   a   1 , The tubular portion  33   c  has a tube diameter that decreases in a direction toward its upstream end. The passage in the tubular portion  33   c  decreases in passage cross-sectional area in the direction toward the upstream end. 
     The purge valve  3  has one inflow port  31   a  into which fluid flows in from outside and one outflow port  33   a  from which fluid flows out to the outside. All the fluid that has flowed into the inflow passage  31   a   1  flows through the upstream passage, the intermediate passage  32   a   1 , and the downstream passage, in this order, and then flows out to the outflow passage  33   a   1 , The first electromagnetic valve  34  and the second electromagnetic valve  35  each include a solenoid and a valve body, and individually form a magnetic circuit. The first electromagnetic valve  34  and the second electromagnetic valve  35  are configured such that energization of their coils are individually controlled by the controller  50 . 
     The first electromagnetic valve  34  includes the first valve body  34   b , and a first solenoid  34   a  that generates an electromagnetic force for displacing the first valve body  34   b . The first valve body  34   b  is capable of adjusting a flow path resistance in the upstream passage in the purge valve  3 . The first electromagnetic valve  34  shown in  FIG. 2  is controlled in the unseated state in which the first valve body  34   b  is separated from the first valve seat  31   b   1 . In the unseated state of the first valve body  34   b , a flow rate of fluid increases at a small increase rate that is the first increase rate shown in the graph of  FIG. 5 . The first valve body  34   b  is maintained in the unseated state while the mode of the first increase rate is being performed. 
     The first electromagnetic valve  34  shown in  FIG. 3  is controlled in the seated state in which the first valve body  34   b  is in contact with the first valve seat  31   b   1 . In the seated state of the first valve body  34   b , the flow rate of fluid increases at the second increase rate that is larger than the first increase rate as shown in the graph of  FIG. 5 . The first valve body  34   b  is maintained in the seated state while the mode of the second increase rate is being performed. The first electromagnetic valve  34  is controlled in the seated state when no voltage is applied, and is controlled in the unseated state when voltage is applied. The first electromagnetic valve  34  is a normally open valve that controls small flow by narrowing the upstream passage when voltage is applied, and controls large flow by fully opening the upstream passage when no voltage is applied. The flow increase rate is, for example, an increase of the flow rate per unit time or an increase of the flow rate per unit displacement of the valve body. 
     The first solenoid  34   a  includes a coil  340 , a bobbin  341 , a movable core  342 , the fixed core  343 , a yoke  36 , a shaft  353   b  and a spring  344 , The central axis of the first solenoid  34   a  corresponds to the central axis of the first electromagnetic valve  34  and the central axis of the purge valve  3 . The shaft  353   b  is a part of an axial support  353 . The axial support  353  includes an annular plate  353   a  located at a downstream end of the axial support  353 , and the shaft  353   b  that extends in the axial direction from an inner circumferential edge of the annular plate  353   a  toward the upstream side. The axial support  353  coaxially supports the first solenoid  34   a  and a second solenoid  35   a.    
     The movable core  342  is made of a material through which magnetism passes, for example, a magnetic material. The movable core  342  has a cup-shaped body with a bottom. The movable core  342  is provided so as to surround the spring  344 , and the spring  344  is disposed inside the movable core  342 . The spring  344  is provided between the shaft  353   b  and the movable core  342 . The spring  344  provides an urging force for moving the movable core  342  in a direction away from the shaft  353   b . The spring  344  provides an urging force for moving the movable core  342  toward the first valve seat  31   b   1 . 
     The first valve body  34   b  has a valve element formed of an elastically deformable material such as rubber. The valve element of the first valve body  34   b  has an annular shape surrounding both entire circumferences of an upstream surface and a downstream surface of the plate  34   b   1 , The plate  34   b   1  is provided integrally with an upstream end of the movable core  342 . The upstream surface of the plate  34   b   1  faces the first valve seat  31   b   1  in the axial direction. The second valve body  35   b  is provided at a downstream end of a movable core  352  and is integral with the movable core  352 . The plate  34   b   1  is provided with multiple or one through-hole  34   b   2 , As shown in  FIG. 3 , when the first valve body  34   b  is in the seated state, the through-hole  34   b   2  forms an open passage through which the fluid can flow. The purge valve  3  includes the open passage that increases the passage cross-sectional area of the first internal passage to be larger than that in the unseated state of the first valve body  34   b , As shown in  FIG. 2 , when the first valve body  34   b  is in the unseated state, the through-hole  34   b   2  forms a passage through which the fluid does not flow. When fluid flows at the second increase rate shown in  FIG. 5 , the through-hole  34   b   2  corresponds to the upstream passage of the purge valve  3  through which the fluid flows. 
     The fixed core  343  slidably supports the movable core  342  that is being moved by the electromagnetic force in the axial direction against the urging force of the spring  344 . The fixed core  343  is provided integrally with the bobbin  341 , the coil  340 , the yoke  36 , and the axial support  353 . The fixed core  343 , the movable core  342 , the first valve body  34   b , the coil  340 , and the yoke  36  are coaxial. 
     The bobbin  341  is formed of an insulating material and has a function of insulating the coil  340  from other parts. The fixed core  343 , the movable core  342 , the shaft  353   b , and the yoke  36  are made of a material that transmits magnetism. The yoke  36  includes a cylindrical portion  361  having opposite open ends in the axial direction, and an annular plate  362  having an annular shape and provided on an inner peripheral surface of the cylindrical portion  361 . The annular plate  362  is located between the coil  340  and another coil  350 . When the coil  340  is energized, a magnetic circuit indicated by dash lines around the coil  340  in  FIG. 2  is formed. This magnetic circuit generates an electromagnetic force that attracts the movable core  342  toward the shaft  353   b . The electromagnetic force switches the first valve body  34   b  from the seated state to the unseated state. The magnetic circuit in the first electromagnetic valve  34  is formed by magnetism passing through the fixed core  343 , the movable core  342 , the shaft  353   b , the annular plate  362 , and the cylindrical portion  361 . The first valve body  34   b  is driven in accordance with a balance between the electromagnetic force generated upon energization of the coil  340  and the urging force of the spring  344 , and is thereby switched between the seated state and the unseated state. 
     The housing is provided with a first connector having a terminal for energization of the coil  340  of the first electromagnetic valve  34 . The terminal built in the first connector is a current-carrying terminal electrically connected to the coil  340 . The first connector is connected to a power supply connector for power supply from a power source unit or a current controller. The first connector and the power supply connector are connected, and the terminal is electrically connected to the controller  50 . Accordingly, current supplied to the coil  340  can be controlled. 
     The second electromagnetic valve  35  includes the second valve body  35   b , and the second solenoid  35   a  that generates an electromagnetic force for displacing the second valve body  35   b . The second valve body  35   b  is capable of opening and closing the downstream passage of the purge valve  3 . In  FIGS. 2 and 3 , the second electromagnetic valve  35  is controlled in an unseated state in which the second valve body  35   b  is separated from the second valve seat  33   c   1 . 
     The second electromagnetic valve  35  is a normally closed valve that is controlled to be in a closed state in which the downstream passage is closed when no voltage is applied, and is controlled to be in an open state in which the downstream passage is open when voltage is applied. The controller  50  performs energization of the coil  350  of the second electromagnetic valve  35  by controlling a duty cycle, that is, a ratio of an energization turned-on period to a period of one cycle. The controller  50  controls the duty cycle in a range of 0% to 100%. According to the duty-cycle energization control, the flow rate of the evaporative fuel flowing through the downstream passage in the purge valve  3  changes in proportion to the duty cycle. The second electromagnetic valve  35  is controlled so that the duty cycle gradually increases from 0% to 100% when the mode of the first increase rate shown in the graph of  FIG. 5  is being implemented. The second electromagnetic valve  35  is controlled so that the duty cycle gradually increases from a predetermined percentage: X % to 100% when the mode of the second increase rate shown in the graph of  FIG. 5  is being implemented. X % is an arbitrary value set between 0% and 100%. X % may be set to a value that can ensure the continuity of the flow rate change from the first increase rate mode to the second increase rate mode as shown in  FIG. 5 . 
     The second solenoid  35   a  includes the coil  350 , a bobbin  351 , the movable core  352 , the yoke  36 , the annular plate  353   a , the shaft  353   b  and a spring  354 . The annular plate  353   a  is a component corresponding to the fixed core  343  in the first solenoid  34   a . The central axis of the second solenoid  35   a  corresponds to the central axis of the second electromagnetic valve  35  and the central axis of the purge valve  3 . 
     The movable core  352  is made of a material through which magnetism passes, for example, a magnetic material. The movable core  352  has a cup-shaped body with a bottom. The movable core  352  is provided so as to surround the spring  354 , and the spring  354  is disposed inside the movable core  352 . The spring  354  is provided between a shaft member  355  and the movable core  352 . The shaft member  355  is fixed and press-fitted into the axial support  353 . The spring  354  provides an urging force for moving the movable core  352  in a direction away from the shaft member  355 . The spring  354  provides an urging force for moving the movable core  352  toward the second valve seat  33   c   1 . The second valve body  35   b  is formed of an elastically deformable material such as rubber. The second valve body  35   b  is provided integrally with a downstream end of the movable core  352 . 
     The axial support  353  slidably supports the movable core  352  that is being moved by the electromagnetic force in the axial direction against the urging force of the spring  354 . The axial support  353  is provided integrally with the bobbin  351 , the coil  350 , the yoke  36 , and the shaft member  355 . The axial support  353 , the movable core  352 , the second valve body  35   b , the coil  350 , and the yoke  36  are coaxial. 
     The bobbin  351  is formed of an insulating material and has a function of insulating the coil  350  from other parts. The axial support  353 , the movable core  352 , and the yoke  36  are made of a material that transmits magnetism. When the coil  340  is energized, a magnetic circuit indicated by dash lines around the coil  350  in  FIGS. 2 and 3  is formed. This magnetic circuit generates an electromagnetic force that attracts the movable core  352  toward the shaft member  355 . The electromagnetic force switches the second valve body  35   b  from the seated state to the unseated state. The magnetic circuit in the second electromagnetic valve  35  is formed by magnetism passing through the annular plate  353   a , the movable core  352 , the shaft  353   b , the annular plate  362 , and the cylindrical portion  361 . The second valve body  35   b  is driven in accordance with a balance between the electromagnetic force generated upon energization of the coil  350  and the urging force of the spring  354 , and is thereby switched between the seated state and the unseated state. 
     The housing is provided with a second connector having a terminal for energization of the coil  350  of the second electromagnetic valve  35 . The terminal built in the second connector is a current-carrying terminal electrically connected to the coil  350 . The second connector is connected to a power supply connector for power supply from a power source unit or a current controller. The second connector and the power supply connector are connected, and the terminal is electrically connected to the controller  50 . Accordingly, current supplied to the coil  350  can be controlled. 
     Next, an operation of a purge valve controller will be described with reference to a flowchart of  FIG. 4 . The controller  50  executes a process according to the flowchart of  FIG. 4 . This flowchart starts when the evaporative fuel is made to flow to the engine  2 . The second electromagnetic valve  35  is controlled by duty-cycle energization in which the duty cycle gradually increases from 0%. 
     When this flowchart starts, the controller  50  determines at step S 100  whether it is in a state of learning concentration of evaporative fuel. When it is determined at step S 100  that it is in the state of learning concentration, the controller  50  determines at step S 120  whether the first electromagnetic valve  34  is energized. When it is determined at step S 120  that the first electromagnetic valve  34  is in the energized state, the process returns to step S 100 , and the determination process of step S 100  is performed. When it is determined at step S 120  that the first electromagnetic valve  34  is not in the energized state, the first electromagnetic valve  34  is controlled to be in the energized state at step S 125 , and then the determination process of step S 100  is performed. 
     When it is determined at step S 100  that it is not in the state of learning concentration, the controller  50  determines at step S 110  whether a noise generation condition is met. The noise generation condition is a preset condition under which noise is expected to be generated due to pressure fluctuation in the passage of the evaporative fuel or a fluttering sound of the ORVR valve  15 . For example, the noise generation condition can be set to be met when a current vehicle speed is equal to or lower than a predetermined speed. In this case, the controller  50  acquires the current vehicle speed based on vehicle speed information detected by a vehicle speed sensor  61 . The vehicle speed sensor  61  outputs the vehicle speed information to a vehicle ECU  60  that controls traveling of the vehicle and controls a cooling system necessary for traveling of the vehicle, and the vehicle speed information is output from the vehicle ECU  60  to the controller  50 . The predetermined speed is preferably set based on an experimental result or an empirical rule, and is set to a vehicle speed at which the noise is drowned out by the traveling sound and is difficult for an occupant in the vehicle compartment to recognize. Accordingly, the noise generation condition is met when the current vehicle speed is lower than the predetermined speed. Therefore, it is possible to suppress noise that is likely to be generated when the vehicle speed is low and the traveling sound is low. 
     For example, when the vehicle is stopped, running at a low speed, or in an idling state of the engine  2 , the controller  50  determines that the noise generation condition is met at step S 110 . When it is determined at step S 110  that the noise generation condition is met, the process proceeds to step S 120 , and the determination process of step S 120  is performed. 
     In the flow of returning from step S 120  to step S 100 , and in the flow of returning to step S 100  after executing step S 125 , the mode of the first increase rate in  FIG. 5  is performed. In the mode of the first increase rate, since the rate of increase in flow rate of fluid is small, the accuracy of learning the concentration of the evaporative fuel can be improved. According to the mode of the first increase rate, the change in flow rate in the small flow rate range can be reduced as compared with the electromagnetic valve in which the flow rate increase rate is constant. Furthermore, in the mode of the first increase rate, a small flow rate can be implemented, so that pulsation can be reduced and an effect of suppressing noise can be obtained. Further, in the mode of the first increase rate, since the fluid flow rate is reduced, the fluttering of the ORVR valve  15  is reduced, and the effect of suppressing noise is obtained. 
     When it is determined at step S 110  that the noise generation condition is not met, the controller  50  determines at step S 130  whether the duty cycle of the second electromagnetic valve  35  has reached 100%. When it is determined at step S 130  that the duty cycle has not reached 100%, the process returns to step S 100 , and the determination process of step S 100  is performed. When it is determined at step S 130  that the duty cycle has reached 100%, it is determined at step S 140  whether the first electromagnetic valve  34  is in the energized state. 
     When it is determined at step S 140  that the first electromagnetic valve  34  is not in the energized state, the process returns to step S 100 , and the determination process of step S 100  is performed. When it is determined at step S 140  that the first electromagnetic valve  34  is in the energized state, the controller  50  at step S 150  controls the first electromagnetic valve  34  to be in a de-energized state. At step S 160 , the controller  50  reduces the duty cycle of second electromagnetic valve  35  to the predetermined value of X %, and returns to step S 100 . The controller  50  executes a control to gradually increase the duty cycle of the second electromagnetic valve  35  from the predetermined value toward 100%. The processes of steps S 150  and S 160  can smoothly shift the fluid flow rate controlled by the purge valve  3  from the mode of the first increase rate to the mode of the second increase rate as shown in  FIG. 5 . 
     In the flowchart, when the first electromagnetic valve  34  is not in the energized state, the mode of the second increase rate illustrated in  FIG. 5  is performed. In the mode of the second increasing rate, enlargement of the flow rate is promoted in order to reduce a flow rate resistance of the upstream passage. According to the mode of the second increase rate, the change in flow rate in the large flow rate range can be increased as compared with the electromagnetic valve in which the flow rate increase rate is constant. For this reason, the fluid flow rate can be rapidly increased in a state where noise is unlikely to be generated, so that an output demand from the engine  2  can be satisfied. According to the control in accordance with the flowchart of  FIG. 4 , it is possible to provide a flow control capable of suppressing noise caused by pulsation while achieving a large flow rate, as shown in  FIG. 5 . 
     Further, the controller  50  may determine at step S 110  that the noise generation condition is met when a current rotation speed of the engine  2  is lower than a predetermined rotation speed. If such determination process is employed, the predetermined rotation speed is preferably set based on an experimental result or an empirical rule, and is set to a rotation speed at which the noise is drowned out by the engine sound and is difficult for the occupant to recognize. The noise generation condition is met when the current rotation speed of the engine  2  is lower than the predetermined rotation speed. Therefore, it is possible to reduce noise caused by pressure fluctuation and the like when the engine rotation speed is small and quiet. 
     Operational effects of the purge control valve device exemplified by the purge valve  3  of the first embodiment will be described. The purge control valve device includes the housing having the in-housing passage connecting the inflow port  31   a  and the outflow port  33   a . The purge control valve device includes the first electromagnetic valve  34  that opens and closes the first internal passage to control the flow rate of evaporative fuel, and the second electromagnetic valve  35  that opens and closes the second internal passage to control the flow rate of evaporative fuel. The first internal passage and the second internal passage are arranged in series in the in-housing passage. The first electromagnetic valve  34  and the second electromagnetic valve  35  are controlled to operate individually. The first electromagnetic valve  34  switches between the seated state in which the first valve body  34   b  contacts the first valve seat  31   b   1  and the unseated state in which the first valve body  34   b  is separated from the first valve seat  31   b   1 . The purge control valve device has the narrowed passage  31   c   1  in which the flow rate of the evaporative fuel is smaller in one of the seated state and the unseated state than another of the seated state and the unseated state. 
     Accordingly, it is possible to provide the purge control valve device including the narrowed passage  31   c   1  in which the evaporative fuel flowing through the first internal passage has a large flow rate in the other state and a small flow rate in the one state. The purge control valve device can be switched between the seated state and the unseated state such that the purge control valve device is set to the one state when it is desired to obtain a small flow rate characteristic or to suppress pulsation, and the purge control valve device is set to the other state when it is desired to secure a flow rate. As described above, both a small flow characteristic and a large flow characteristic can be obtained, and the purge control valve device capable of improving the flow characteristic can be obtained. 
     The purge control valve device includes the narrowed passage  31   c   1  such that the passage cross-sectional area of the first internal passage is smaller in one of the seated state and the unseated state of the first valve body than in the other state. Accordingly, it is possible to provide the purge control valve device including the narrowed passage  31   c   1  in which the passage cross-sectional area of the first internal passage is large in the other state and small in the one state. The purge control valve device can switch the passage cross-sectional area of the first internal passage such that the purge control valve device is set to the one state when it is desired to obtain a small flow rate characteristic or to suppress pulsation, and the purge control valve device is set to the other state when it is desired to secure a flow rate. In the purge control valve device, both a small flow characteristic and a large flow characteristic can be obtained, and the purge control valve device is capable of improving the flow characteristic. 
     In the purge control valve device, the first internal passage is disposed upstream of the second internal passage. According to this configuration, in the in-housing passage, an opening degree of the upstream passage can be varied, and the downstream passage can be opened and closed. Accordingly, it is possible to provide the purge control valve device in which pressure loss can be reduced and the configuration and control of the second electromagnetic valve  35  can be simplified. 
     The purge valve  3  includes a passage that functions as a narrowed passage in the unseated state, and an open passage which is larger in passage cross-sectional area than the narrowed passage and through which the evaporative fuel flows in the seated state. According to the purge valve  3 , it is possible to provide the purge control valve device in which the evaporative fuel flowing through the narrowed passage in the unseated state has a small flow rate in the unseated state while the evaporative fuel flows through the open passage at a large flow rate in the seated state. The purge valve  3  can be switched between the seated state and the unseated state such that the purge valve  3  is set to the unseated state when it is desired to suppress pulsation, and the purge valve  3  is set to the seated state when it is desired to secure a flow rate. The purge valve  3  provides the purge control valve device that can achieve both pulsation suppression and flow rate securing. 
     When increasing a flow rate of evaporative fuel, the controller  50  individually controls the first electromagnetic valve  34  and the second electromagnetic valve  35  so as to separately perform the mode of the first increase rate and the mode of the second increase rate that is larger in increase rate than the first increase rate. The controller  50  controls the first electromagnetic valve  34  and the second electromagnetic valve  35  in the mode of the first increase rate so that the evaporative fuel flows through the narrowed passage. The controller  50  controls the first electromagnetic valve  34  and the second electromagnetic valve  35  in the mode of the second increase rate so that the evaporative fuel flows through the open passage which is larger in passage cross-sectional area than the narrowed passage. According to this control, it is possible to provide the purge control valve device that can achieve both pulsation suppression and flow rate securing by switching the mode of the first increase rate and the mode of the second increase rate at appropriate timing. The purge valve  3  can obtain a wide range of flow rate and can improve flow rate characteristics. 
     In the flow rate increase control in which the flow rate of the evaporative fuel flowing out from the outflow port  33   a  increases from zero, the controller  50  executes the mode of the first increase rate and then executes the mode of the second increase rate. According to this control, it is possible to provide the purge control valve device capable of suppressing pulsation of fluid and fluttering of the ORVR valve  15  from the start of purge and capable of exhibiting a large purge performance. 
     The controller  50  controls the first electromagnetic valve  34  by turning on and off its energization, and controls the second electromagnetic valve  35  by controlling the duty cycle of the applied voltage. The controller  50  controls the second electromagnetic valve so as to increase the duty cycle of the applied voltage in the mode of the first increase rate. The controller  50  reduces the duty cycle of the applied voltage once at the time of shifting from the mode of the first increase rate to the mode of the second increase rate. Then, the controller  50  controls the second electromagnetic valve  35  so as to increase the duty cycle in the mode of the second increase rate. Accordingly, at the time of shifting from the mode of the first increase rate to the mode of the second increase rate, it is possible to perform the purge control in which the flow rate of the evaporative fuel flowing out from the outflow port  33   a  does not largely change. 
     The controller  50  individually controls the first electromagnetic valve  34  and the second electromagnetic valve  35  so as to perform the mode of the first increase rate when learning the concentration of evaporative fuel. According to this control, the evaporative-fuel concentration learning can be performed with a small change in flow rate. Thus, it is possible to provide the purge control valve device that can achieve both pulsation suppression and flow rate securing, and that can further improve the accuracy of concentration learning. 
     The controller  50  individually controls the first electromagnetic valve  34  and the second electromagnetic valve  35  so as to perform the mode of the first increase rate when the noise generation condition which can be expected is met. According to this control, the mode of the first increase rate can be performed in a state where noise due to pulsation or fluttering of the ORVR valve  15  can occur. Accordingly, it is possible to provide the purge control valve device that can more efficiently suppress noise and realize a sufficient flow rate. 
     Second Embodiment 
     A second embodiment will be described with reference to  FIGS. 6 to 8 . A purge valve  103  according to the second embodiment is different from the first embodiment in first electromagnetic valve  134 . The first electromagnetic valve  134  is a normally closed valve that controls small flow by narrowing an upstream passage when no voltage is applied, and controls large flow by fully opening the upstream passage when voltage is applied. A second electromagnetic valve  135  has the same configuration and the same operation as the second electromagnetic valve  35 . Configurations, actions, and effects not specifically described in the second embodiment are the same as those in the first embodiment, and only points different from the first embodiment will be described below. The descriptions about the first electromagnetic valve  34  in the first embodiment can be used in the second embodiment by replacing the first electromagnetic valve  34  with the first electromagnetic valve  134 . The descriptions about the second electromagnetic valve  35  in the first embodiment can be used in the second embodiment by replacing the second electromagnetic valve  35  with the second electromagnetic valve  135 . 
     Next, configurations of the purge valve  103  will be described. The purge valve  103  includes the first electromagnetic valve  134  and the second electromagnetic valve  135  which are provided inside the housing. The first electromagnetic valve  134  and the second electromagnetic valve  135  are arranged inside the purge valve  103  in a direction from an upstream side to a downstream side. The first electromagnetic valve  134  and the second electromagnetic valve  135  are arranged in a direction of displacement of a valve body of the purge valve  103  or in an axial direction of the valve body. The first electromagnetic valve  134  is located upstream of the second electromagnetic valve  135 . The first electromagnetic valve  134  adjusts a passage cross-sectional area of the upstream passage in the purge valve  103 . The second electromagnetic valve  135  adjusts a passage cross-sectional area of a downstream passage in the purge valve  103 . 
     A first valve body  34   b  contacts a first valve seat  31   b   1  in a seated state of the first electromagnetic valve  134 . The flow path narrowing wall  31   c  of the first embodiment is not provided on a flange  31   b  of an inflow housing  131 . Therefore, the purge valve  103  does not include the narrowed passage  31   c   1  of the first embodiment. 
     A plate  134   b   1  is provided integrally with an upstream end of a movable core  342 . The upstream surface of the plate  134   b   1  faces the first valve seat  31   b   1  in the axial direction. The plate  134   b   1  is provided with multiple or one through-hole  134   b   2 . As shown in  FIG. 6 , when the first valve body  34   b  is in the seated state, the through-hole  134   b   2  forms a flow passage through which the fluid can flow. As shown in  FIG. 7 , when the first valve body  34   b  is in an unseated state, the through-hole  134   b   2  forms a passage through which the fluid does not flow. When fluid flows at a first increase rate shown in  FIG. 5 , the through-hole  134   b   2  corresponds to the upstream passage of the purge valve  103  through which the fluid flows. 
     The through-hole  134   b   2  forms a passage smaller in passage cross-sectional area than a passage  31   b   2  formed between the first valve body  34   b  and the first valve seat  31   b   1  in the unseated state shown in  FIG. 7 . When the first valve body  34   b  is in the seated state, the through-hole  134   b   2  forms a narrowed passage through which the fluid flows. The purge valve  103  includes the narrowed passage that reduces a passage cross-sectional area of a first internal passage to be smaller than that in the unseated state of the first valve body  34   b . The through-hole  134   b   2  is configured such that fluid does not flow therethrough in the unseated state of the first valve body  34   b . When fluid flows at a first increase rate shown in  FIG. 5 , the through-hole  134   b   2  corresponds to the upstream passage of the purge valve  103  through which the fluid flows. The through-hole  134   b   2  functions as a narrowed passage through which the evaporative fuel flows in the mode of the first increase rate. The passage  31   b   2  forms an open passage through which the evaporative fuel flows when the first valve body  34   b  is in the unseated state. The purge valve  103  includes the open passage that increases the passage cross-sectional area of the first internal passage to be larger than that in the seated state of the first valve body  34   b . The passage  31   b   2  functions as an open passage through which the evaporative fuel flows in the mode of the second increase rate. 
     The first electromagnetic valve  134  and the second electromagnetic valve  135  each include a solenoid and a valve body, and individually form a magnetic circuit. The first electromagnetic valve  134  and the second electromagnetic valve  135  are configured such that energization of their coils are individually controlled by the controller  50 . 
     The first electromagnetic valve  134  includes the first valve body  34   b , and a first solenoid  34   a  that generates an electromagnetic force for displacing the first valve body  34   b . The first valve body  34   b  is capable of adjusting a flow path resistance in the upstream passage in the purge valve  103 . The first electromagnetic valve  134  shown in  FIG. 6  is controlled in the seated state in which the first valve body  34   b  is in contact with the first valve seat  31   b   1 . In the seated state of the first valve body  34   b , a flow rate of fluid increases at a small increase rate that is the first increase rate shown in the graph of  FIG. 5 . The first electromagnetic valve  134  shown in  FIG. 7  is controlled in the unseated state in which the first valve body  34   b  is separated from the first valve seat  31   b   1 . In the unseated state of the first valve body  34   b , the flow rate of fluid increases at the second increase rate that is larger than the first increase rate as shown in the graph of  FIG. 5 . The first electromagnetic valve  134  is controlled in the unseated state when voltage is applied, and is controlled in the seated state when no voltage is applied. 
     In  FIGS. 6 and 7 , the second electromagnetic valve  135  is controlled in an unseated state in which the second valve body  35   b  is separated from the second valve seat  33   c   1 . The second electromagnetic valve  135  is a normally closed valve that is controlled to be in a closed state in which the downstream passage is closed when no voltage is applied, and is controlled to be in an open state in which the downstream passage is open when voltage is applied. The controller  50  controls a duty cycle to energize the coil  350  of the second electromagnetic valve  135 . 
     Next, an operation of a purge valve controller will be described with reference to a flowchart of  FIG. 8 . The controller  50  executes a process according to the flowchart of  FIG. 8 . The second electromagnetic valve  135  is controlled by duty-cycle energization in which the duty cycle gradually increases from 0%. S 200 , S 210 , S 230 , and S 260  shown in  FIG. 8  are the same processes as S 100 , S 110 , S 130 , and S 160  shown in  FIG. 4 , and their descriptions of the first embodiment is incorporated herein. 
     When it is determined at step S 200  that it is in the state of learning concentration, the controller  50  determines at step S 220  whether the first electromagnetic valve  134  is not energized, i.e., in a de-energized state. When it is determined at step S 220  that the first electromagnetic valve  134  is in the de-energized state, the process returns to step S 200 , and the determination process of step S 200  is performed. When it is determined at step S 220  that the first electromagnetic valve  134  is in the energized state, the first electromagnetic valve  134  is controlled to be in the de-energized state at step S 225 , and then the determination process of step S 200  is performed. 
     When it is determined at step S 200  that it is not in the state of learning concentration, and a noise generation condition is determined to be met at step S 210 , the determination process of S 220  is performed. In the flow of returning from step S 220  to step S 200 , and in the flow of returning to step S 200  after executing step S 225 , the mode of the first increase rate in  FIG. 5  is performed. In the mode of the first increase rate, since the rate of increase in flow rate of fluid is small, the accuracy of learning the concentration of the evaporative fuel can be improved. In the mode of the first increase rate, a flow rate of fluid can be reduced, so that pulsation can be reduced and an effect of suppressing noise can be obtained. In the mode of the first increase rate, since the fluid flow rate is reduced, the fluttering of the ORVR valve  15  is reduced, and the effect of suppressing noise is obtained. 
     When it is determined at step S 230  that the duty cycle has reached 100%, it is determined at step S 240  whether the first electromagnetic valve  134  is in the de-energized state. When it is determined at step S 240  that the first electromagnetic valve  134  is not in the de-energized state, the process returns to step S 200 , and the determination process of step S 200  is performed. When it is determined at step S 240  that the first electromagnetic valve  134  is in the de-energized state, the controller  50  at step S 250  controls the first electromagnetic valve  134  to be in the energized state. At step S 260 , the controller  50  reduces the duty cycle of second electromagnetic valve  135  to the predetermined value of X %, and returns to step S 200 . The controller  50  executes a control to gradually increase the duty cycle of the second electromagnetic valve  135  from the predetermined value toward 100%. The processes of steps S 250  and S 260  can smoothly shift the fluid flow rate controlled by the purge valve  103  from the mode of the first increase rate to the mode of the second increase rate as shown in  FIG. 5 . 
     In the flowchart, when the first electromagnetic valve  134  is not in the de-energized state, the mode of the second increase rate illustrated in  FIG. 5  is performed. In the mode of the second increase rate, for promoting large capacity control, a change in flow rate within a large flow rate range can be increased as compared with the electromagnetic valve in which the flow rate increase rate is constant. According to the control in accordance with the flowchart of  FIG. 8 , it is possible to provide a flow control capable of suppressing noise caused by pulsation while achieving a large flow rate, as shown in  FIG. 5 . 
     The device of the second embodiment includes a passage that functions as a narrowed passage in the seated state, and an open passage which is larger in passage cross-sectional area than the narrowed passage and through which the evaporative fuel flows in the unseated state. According to the purge valve  103 , it is possible to provide the purge control valve device in which the evaporative fuel flowing through the narrowed passage in the seated state has a small flow rate in the unseated state while the evaporative fuel flows through the open passage at a large flow rate in the unseated state. The purge valve  103  can be switched between the seated state and the unseated state such that the purge valve  3  is set to the seated state when it is desired to suppress pulsation, and the purge valve  3  is set to the unseated state when it is desired to secure a flow rate. The purge valve  103  provides the purge control valve device that can achieve improvements of small flow characteristic, pulsation suppression and securing of large flow rate. The purge valve  103  can obtain a wide range of flow rate and can improve flow rate characteristics. 
     Third Embodiment 
     A purge valve  203  of a third embodiment will be described with reference to  FIGS. 9 to 10 . The purge valve  203  is different from the first embodiment in that the purge valve  203  includes a second valve regulator  345  that moves in an axial direction together with a first valve body  34   b . The second valve regulator  345  is coupled to a movable core  342  of a first electromagnetic valve  234 , and is displaced in the axial direction together with the movable core  342 . The second valve regulator  345  can limit a movable distance of a movable core  352  of a second electromagnetic valve  235  in a direction away from a seat. The second valve regulator  345  moves integrally with the first valve body  34   b  in response to an electromagnetic force, and has a function to change a displaceable range of the second valve body  35   b . Further, the second valve regulator  345  and the movable core  342  may be configured as a single component. 
     The first electromagnetic valve  234  is a normally open valve that controls small flow by narrowing the upstream passage when voltage is applied, and controls large flow by fully opening the upstream passage when no voltage is applied. The second electromagnetic valve  235  is a normally closed valve, similar to the second electromagnetic valve  35 . Configurations, actions, and effects not specifically described in the third embodiment are the same as those in the first embodiment, and only points different from the first embodiment will be described below. 
     Next, configurations of the purge valve  203  will be described. The purge valve  203  includes the first electromagnetic valve  234  and the second electromagnetic valve  235  which are provided inside the housing. The first electromagnetic valve  234  and the second electromagnetic valve  235  are arranged inside the purge valve  203  in a direction from an upstream side to a downstream side. The first electromagnetic valve  234  and the second electromagnetic valve  235  are arranged in a direction of displacement of a valve body of the purge valve  203  or in an axial direction of the valve body. The first electromagnetic valve  234  is located upstream of the second electromagnetic valve  235 . The first electromagnetic valve  234  adjusts a passage cross-sectional area of the upstream passage in the purge valve  203 . The second electromagnetic valve  235  adjusts a passage cross-sectional area of a downstream passage in the purge valve  203 . 
     The first electromagnetic valve  234  and the second electromagnetic valve  235  each include a solenoid and a valve body, and individually form a magnetic circuit. The first electromagnetic valve  234  and the second electromagnetic valve  235  are configured such that energization of their coils are individually controlled by the controller  50 . The first electromagnetic valve  234  includes the first valve body  34   b , and a first solenoid  234   a  that generates an electromagnetic force for displacing the first valve body  34   b . The first valve body  34   b  is capable of adjusting a flow path resistance in the upstream passage in the purge valve  203 . 
     The first electromagnetic valve  234  shown in  FIG. 9  is controlled in the unseated state in which the first valve body  34   b  is separated from the first valve seat  31   b   1 . The first valve body  34   b  is controlled to be in the unseated state in order to implement a mode of a first increase rate. The state shown in  FIG. 9  shows a state in which the mode of the first increase rate shown in  FIG. 5  starts. The first electromagnetic valve  234  shown in  FIG. 10  is controlled in the seated state in which the first valve body  34   b  is in contact with the first valve seat  31   b   1 . The first valve body  34   b  is controlled to be in the seated state in order to implement a mode of a second increase rate. The state shown in  FIG. 10  shows a state in which the mode of the second increase rate shown in  FIG. 5  starts. The first electromagnetic valve  234  is controlled in the unseated state when voltage is applied, and is controlled in the seated state when no voltage is applied. 
     In the unseated state of the first valve body  34   b , the second valve regulator  345  together with the movable core  342  is located closer to a second valve seat  33   c   1  than in the seated state shown in  FIG. 10 . Thus, the movable core  352  is located closer to the second valve seat  33   c   1  in the unseated state of the first valve body  34   b  than in the seated state shown in  FIG. 10 . The displaceable range in which the second valve body  35   b  can be displaced by action of electromagnetic force is smaller in the unseated state of the first valve body  34   b  than in the seated state of the first valve body  34   b . In the unseated state of the first valve body  34   b  where the mode of the first increase rate is performed, a stroke amount in which the second valve body  35   b  is displaceable to be seated is shorter than in the seated state in which the mode of the second increase rate is performed. The passage cross-sectional area of a second internal passage in the purge valve  203  is larger in FIG.  10  than in  FIG. 9 . The second valve regulator  345  brings the second valve body  35   b  closer to the second valve seat  33   c   1  in one state where the narrowed passage  31   c   1  is formed than in the other state. 
     In  FIGS. 9 and 10 , the second electromagnetic valve  235  is controlled in the unseated state in which the second valve body  35   b  is separated from the second valve seat  33   c   1 . The second electromagnetic valve  235  is a normally closed valve that is controlled to be in a closed state in which the downstream passage is closed when no voltage is applied, and is controlled to be in an open state in which the downstream passage is open when voltage is applied. The controller  50  controls a duty cycle to energize the coil  350  of the second electromagnetic valve  235 . 
     The first solenoid  234   a  includes a coil  340 , a bobbin  341 , a movable core  342 , the fixed core  346 , a yoke  347 , a shaft  37   c  and a spring  344 . The central axis of the first solenoid  234   a  corresponds to the central axis of the first electromagnetic valve  234  and the central axis of the purge valve  203 . The central axis of the first solenoid  234   a  is also the central axis of the second valve regulator  345 . The shaft  37   c  supports the second valve regulator  345  to be slidable in the axial direction. The shaft  37   c  has a cylindrical body. The shaft  37   c  supports the second valve regulator  345  to be slidable in the axial direction such that an inner peripheral surface of the shaft  37   c  slides on an outer peripheral surface of the second valve regulator  345 . The second valve regulator  345  is formed of, for example, metal, resin, or the like. 
     The shaft  37   c  is a part of an axial support  37 . The axial support  37  includes the shaft  37   c , an outer cylindrical portion  37   a  having a larger outer diameter than the shaft  37   c , and an annular plate  37   b  connecting the shaft  37   c  and the outer cylindrical portion  37   a . The outer cylindrical portion  37   a  coaxially supports the first solenoid  234   a  and a second solenoid  235   a . The axial support  37  is fixed to, for example, a housing in the purge valve  203 . An inner peripheral surface of an intermediate housing  32  and an outer peripheral surface of the outer cylindrical portion  37   a  define an intermediate passage  32   a   1  therebetween. 
     The spring  344  is provided between the shaft  37   c  and the movable core  342 . The spring  344  provides an urging force for moving the movable core  342  in a direction away from the shaft  37   c . The axial support  37  is formed of, for example, metal, resin, or the like. 
     The fixed core  346  slidably supports the movable core  342  that is being moved by the electromagnetic force in the axial direction against the urging force of the spring  344 . The fixed core  346  includes a cylindrical portion  346   b  having opposite open ends in the axial direction, and an annular plate  346   a  having a flange shape and provided at an upstream end of the cylindrical portion  346   b . An inner peripheral surface of the cylindrical portion  346   b  slidably supports the movable core  342 , The coil  340  is wound around an outer peripheral surface of the cylindrical portion  346   b  via the bobbin  341 . The annular plate  346   a  is engaged with the outer cylindrical portion  37   a  of the axial support  37 . The fixed core  346  is provided integrally with the bobbin  341 , the coil  340 , the yoke  347 , and the axial support  37 . The yoke  347  includes a cylindrical portion  347   b  and an annular plate  347   a  extending from an inner peripheral surface of a downstream end of the cylindrical portion  347   b  toward the center. The fixed core  346 , the movable core  342 , the first valve body  34   b , the coil  340 , and the yoke  347  are coaxial. 
     The fixed core  346 , the movable core  342 , and the yoke  347  are made of a material that transmits magnetism. When the coil  340  is energized, a magnetic circuit indicated by dash lines around the coil  340  in  FIG. 9  is formed. This magnetic circuit generates an electromagnetic force that attracts the movable core  342  toward the shaft  37   c . The electromagnetic force switches the first valve body  34   b  of the first electromagnetic valve  234  from the seated state to the unseated state. The magnetic circuit in the first electromagnetic valve  234  is formed by magnetism passing through the annular plate  346   a , the movable core  342 , the cylindrical portion  346   b , the annular plate  347   a , and the cylindrical portion  347   b . The first valve body  34   b , the movable core  342 , and the second valve regulator  345  are driven in the axial direction according to a balance between the electromagnetic force generated at the time of energization and the urging force of the spring  344 . 
     The second electromagnetic valve  235  includes the second valve body  35   b , and a second solenoid  235   a  that generates an electromagnetic force for displacing the second valve body  35   b . The controller  50  controls a duty cycle to energize the coil  350  of the second electromagnetic valve  235 . The second electromagnetic valve  235  is controlled so that the duty cycle gradually increases from 0% to 100% when the mode of the first increase rate is being implemented. The second electromagnetic valve  235  is controlled so that the duty cycle gradually increases from a predetermined percentage X % to 100% when the mode of the second increase rate is being implemented. 
     The second solenoid  235   a  includes the coil  350 , a bobbin  351 , the movable core  352 , a fixed core  356 , a yoke  357 , the shaft  37   c  and a spring  354 . The central axis of the second solenoid  235   a  corresponds to the central axis of the second electromagnetic valve  235  and the central axis of the purge valve  203 . The central axis of the second solenoid  235   a  is also the central axis of the second valve regulator  345 . The spring  354  is provided between the shaft  37   c  and the movable core  352 . The spring  354  provides an urging force for moving the movable core  352  in a direction away from the shaft  37   c.    
     The fixed core  356  slidably supports the movable core  352  that is being moved by the electromagnetic force in the axial direction against the urging force of the spring  354 . The fixed core  356  includes a cylindrical portion  356   b  having opposite open ends in the axial direction, and an annular plate  356   a  having a flange shape and provided at an upstream end of the cylindrical portion  356   b . An inner peripheral surface of the cylindrical portion  356   b  slidably supports the movable core  352 . The coil  350  is wound around an outer peripheral surface of the cylindrical portion  356   b  via the bobbin  351 . The annular plate  356   a  is engaged with the outer cylindrical portion  37   a  of the axial support  37 . The fixed core  356  is provided integrally with the bobbin  351 , the coil  350 , the yoke  357 , and the axial support  37 . The yoke  357  includes a cylindrical portion  357   b  and an annular plate  357   a  extending from an inner peripheral surface of a downstream end of the cylindrical portion  357   b  toward the center. The fixed core  356 , the movable core  352 , the second valve body  35   b , the coil  350 , and the yoke  357  are coaxial. 
     The fixed core  356 , the movable core  352 , and the yoke  357  are made of a material that transmits magnetism. When the coil  340  is energized, a magnetic circuit indicated by dash lines around the coil  350  in  FIGS. 9 and 10  is formed. This magnetic circuit generates an electromagnetic force that attracts the movable core  352  toward the shaft  37   c . The electromagnetic force switches the second valve body  35   b  of the second electromagnetic valve  235  from the seated state to the unseated state. The magnetic circuit in the second electromagnetic valve  235  is formed by magnetism passing through the annular plate  356   a , the movable core  352 , the cylindrical portion  356   b , the annular plate  357   a , and the cylindrical portion  357   b . The second valve body  35   b  and the movable core  352  are driven in the axial direction according to a balance between the electromagnetic force generated at the time of energization and the urging force of the spring  354 . 
     The controller  50  controls the purge valve  203  by executing the processing according to the flowchart of  FIG. 4 , similar to the first embodiment. The descriptions of the processing according to the flowchart of  FIG. 4  in the first embodiment are incorporated herein by replacing the first electromagnetic valve  34  and the second electromagnetic valve  35  with the first electromagnetic valve  234  and the second electromagnetic valve  235 . 
     Operational effects of the purge control valve device exemplified by the purge valve  203  of the third embodiment will be described. The purge valve  203  includes a passage that functions as a narrowed passage in the unseated state, and an open passage which is larger in passage cross-sectional area than the narrowed passage and through which the evaporative fuel flows in the seated state. According to the purge valve  203 , it is possible to provide the purge control valve device in which the evaporative fuel flowing through the narrowed passage in the unseated state has a small flow rate in the unseated state while the evaporative fuel flows through the open passage at a large flow rate in the seated state. The purge valve  203  can be switched between the seated state and the unseated state such that the purge control valve device is set to the one state when it is desired to obtain a small flow rate characteristic or to suppress pulsation, and the purge control valve device is set to the other state when it is desired to secure a flow rate. As described above, the purge valve  203  can obtain both a small flow characteristic and a large flow characteristic, and the purge valve  203  provides a purge control valve device capable of improving the flow characteristic can be obtained. 
     The purge valve  203  includes the second valve regulator  345  that changes the axial distance between the second valve body  35   b  and the second valve seat  33   c   1  according to the seated state and the unseated state of the first valve body  34   b . According to this configuration, the stroke amount in which the second valve body  35   b  can move to be seated can be smaller in the mode of first increase rate than in the mode of the second increase rate. Accordingly, a precise flow rate change and a smooth flow rate change can be realized in the mode of the first increase rate. The purge valve  203  contributes to smooth shifting of the fluid flow rate from the mode of the first increase rate to the mode of the second increase rate, and contributes to increasing linearity of the flow rate change. The effects can contribute reducing the pressure fluctuation range in the flow path leading to the canister  13  and reducing the fluttering sound of the ORVR valve  15 . 
     Fourth Embodiment 
     A purge valve  303  of a fourth embodiment will be described with reference to  FIG. 11 . The purge valve  303  is different from the purge valve  3  of the first embodiment in that a flow direction of fluid inside the apparatus is opposite. 
     With respect to the purge valve  303 , configurations, actions, and effects not specifically described in the fourth embodiment are the same as those in the first embodiment, and only points different from the first embodiment will be described below. In the purge valve  303 , the second electromagnetic valve  35  and the first electromagnetic valve  34  are arranged inside the apparatus in a direction from an upstream side to a downstream side. In the purge valve  303 , the outflow port  33   a  of the first embodiment functions as an inflow port, and the inflow port  31   a  of the first embodiment functions as an outflow port. In the fourth embodiment, a second internal passage is an upstream passage in the in-housing passage, and a first internal passage is a downstream passage in the in-housing passage. 
     Fifth Embodiment 
     A purge valve  403  of a fifth embodiment will be described with reference to  FIG. 12 . The purge valve  403  is different from the purge valve  103  of the second embodiment in that a flow direction of fluid inside the apparatus is opposite. 
     With respect to the purge valve  403 , configurations, actions, and effects not specifically described in the fifth embodiment are the same as those in the second embodiment, and only points different from the first embodiment will be described below. In the purge valve  403 , the second electromagnetic valve  135  and the first electromagnetic valve  134  are arranged inside the apparatus in a direction from an upstream side to a downstream side. In the purge valve  403 , the outflow port  33   a  of the second embodiment functions as an inflow port, and the inflow port  31   a  of the second embodiment functions as an outflow port. In the fifth embodiment, a second internal passage is an upstream passage in the in-housing passage, and a first internal passage is a downstream passage in the in-housing passage. 
     Sixth Embodiment 
     A purge valve  503  of a sixth embodiment will be described with reference to  FIG. 13 . The purge valve  503  is different from the purge valve  203  of the third embodiment in that a flow direction of fluid inside the apparatus is opposite. 
     With respect to the purge valve  503 , configurations, actions, and effects not specifically described in the sixth embodiment are the same as those in the third embodiment, and only points different from the first embodiment will be described below. In the purge valve  503 , the second electromagnetic valve  235  and the first electromagnetic valve  234  are arranged inside the apparatus in a direction from an upstream side to a downstream side. In the purge valve  503 , the outflow port  33   a  of the third embodiment functions as an inflow port, and the inflow port  31   a  of the third embodiment functions as an outflow port. In the sixth embodiment, a second internal passage is an upstream passage in the in-housing passage, and a first internal passage is a downstream passage in the in-housing passage. 
     OTHER EMBODIMENTS 
     The disclosure in the present specification is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and variations based on the embodiments by those skilled in the art. For example, the disclosure is not limited to the combinations of components and elements shown in the embodiments, and can be implemented with various modifications. The disclosure may be implemented in various combinations. The disclosure may have additional portions that may be added to the embodiments. The disclosure encompasses the omission of parts and elements of the embodiments. The disclosure encompasses the replacement or combination of components, elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiment. Technical scopes disclosed are indicated by descriptions in the claims and should be understood to include all modifications within the meaning and scope equivalent to the descriptions in the claims. 
     The purge control valve device in the specification includes a first electromagnetic valve that controls flow on the upstream side and a second electromagnetic valve that controls flow on the downstream side in a passage connecting the inflow port and the outflow port. The purge control valve device is not limited to the configuration having one inflow port and one outflow port. The purge control valve device may have a configuration including multiple inflow ports and multiple outflow ports. The purge control valve device may have a configuration having one inflow port and multiple outflow ports. The purge control valve device may have a configuration having multiple inflow ports and one outflow port. 
     As described in the fourth to sixth embodiments, the purge control valve device in the specification is configured such that the first electromagnetic valve forming the narrowed passage is located downstream of the second electromagnetic valve. In this configuration, the first internal passage connected in series with the second internal passage is arranged downstream of the second internal passage. 
     While the present disclosure has been described with reference to various exemplary embodiments thereof, it is to be understood that the disclosure is not limited to the disclosed embodiments and constructions. To the contrary, the disclosure is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the disclosure are shown in various combinations and configurations, which are exemplary, other various combinations and configurations, including more, less or only a single element, are also within the spirit of the disclosure.