JP5689983B2 - solenoid valve - Google Patents

Description

  The present invention relates to an electromagnetic valve having two-stage valve members that can be opened and closed separately.

  In an evaporative gas processing system mounted on a vehicle, evaporative gas volatilized in a fuel tank is temporarily collected by a canister and drawn into the engine from the canister using an intake manifold (engine) negative pressure to be reburned. In recent years, the frequency of engine operation has decreased due to automobile fuel efficiency regulations and the like, and the amount of evaporative gas that can be drawn into the engine tends to decrease, and the purge balance has been limited.

  Therefore, a system that suppresses the amount of evaporative gas flowing to the canister side by using a pressure tank or the like as the fuel tank and sealing the tank is being mounted on the vehicle. In this system, an electromagnetic valve for opening and closing the fuel tank needs to securely seal the tank opening. In addition, it is necessary to release pressure to prevent the backflow of evaporative gas from the fuel tank to the fuel filler port when refueling, and to control the flow rate discharged to the canister side to adjust the fuel tank internal pressure during traveling. It is necessary to open and close with a pattern. Therefore, a two-stage valve mechanism having a two-stage valve member that can be opened and closed separately is employed as an electromagnetic valve for sealing the fuel tank, and the above drive pattern is performed with a single electromagnetic valve (for example, Patent Documents). 1 and 2).

  The electromagnetic valves according to Patent Documents 1 and 2 include a first valve member that is reciprocally driven by an electromagnetic drive unit, a second valve member having a first valve seat on which the first valve member is seated, and a second valve member. A structure having a two-stage valve mechanism composed of a seatable second valve seat, a communication path communicating with the fuel tank and the canister is formed in the second valve member, and the communication path is opened and closed by the first valve member It is. Then, the fuel valve is sealed by seating the first valve member and the second valve member, respectively. Further, the second valve member is opened and closed by the differential pressure between the fuel tank and the canister while the first valve member is opened.

JP 2005-291241 A JP 2006-258283 A

  In the electromagnetic valves according to Patent Documents 1 and 2, the shaft protected by the bellows is the first valve member, the flow passage hole into which the tip of the shaft is inserted is the first valve seat, and the return spring urges the shaft to bellows. The end face abuts on the periphery of the flow path hole to close the valve, and the electromagnetic drive unit adjusts the flow rate by controlling the amount of insertion of the shaft tip into the flow path hole, and the structure is complicated. Moreover, in order to attract the bellows having a large resistance due to the fluid, it is necessary to enlarge the coil of the electromagnetic drive unit. In addition, it is necessary to increase the size of the return spring in proportion to the increase in suction force and to ensure the sealing performance when the valve is closed. Therefore, there has been a problem that the solenoid valve is increased in size.

  Further, the electromagnetic valve according to Patent Document 2 is composed of a rubber-based elastic body in which the first valve member is coated with resin and the first valve seat is coated with a diamond-like carbon (hereinafter, DLC) film. Further, the second valve member is made of a metal coated with a DLC film, and the second valve seat is made of a rubber-based elastic body coated with a DLC film. In this way, the rubber-based elastic body is coated to ensure the durability and anti-adhesion properties, but the rubber on the sealing surface is cured by the coating, the original properties of the rubber are impaired, and the sealing performance deteriorates. End up. Therefore, the sealing performance at the time of valve closing deteriorates, and there is a problem that the sealing performance of the fuel tank is impaired.

  The present invention has been made to solve the above-described problems, and provides a solenoid valve that simplifies the structure, reduces the size and weight, and ensures the sealing performance when the valve is closed. Objective.

The electromagnetic valve of the present invention includes a first mover having a first valve body, a first port for introducing a fluid, a second port for deriving the fluid, and a flow communicating the first port and the second port. A flow path having a second valve seat formed in the path and communicating the first port and the second port on the upstream side of the second valve seat with a housing accommodating the first mover in the flow path A communication passage having a smaller diameter, a first valve seat that is formed on the first port communication side of the communication passage and that opens and closes between the first port and the communication passage, and a second of the communication passage. A second movable element that is formed on the port communication side and has a second valve body that opens and closes the flow path by contacting and separating from the second valve seat, and is movably held coaxially with the first movable element; and a first movable element A solenoid part that generates an electromagnetic force that attracts the child toward the valve opening side, and a first movable element that urges the first movable element toward the valve closing side, A biasing member for biasing the child, is slid first movable element in the inner surface of the cylindrical body, by sliding the second movable member in the outer surface, on the coaxial first mover and the second mover and a guide member for guiding the movable, first valve body and the first valve seat is a opening and closing operation characteristics of the electromagnetic force, the first valve body formed of an elastic member, a first valve body of the first valve seat The contact surface is made of a non-adhesive member, the parallelism of each surface where the first valve body and the first valve seat contact is secured by the guide member, and the second valve body and the second valve seat are opened and closed by differential pressure It is an operation characteristic, Comprising: At least one of each surface which a 2nd valve body and a 2nd valve seat contact | abut is formed with the non-adhesive member .

  According to this invention, the first movable element driven by electromagnetic force and the second movable element that opens according to the differential pressure are installed on the same axis, and the first valve body and the first valve seat having a small flow path diameter are provided. Since the opening and closing operation characteristics of the second valve body and the second valve seat having a large flow path diameter are different from each other, the structure can be simplified, and the size and weight can be reduced. Sealability can be secured.

It is sectional drawing which shows the structure of the solenoid valve for fuel tank sealing concerning Embodiment 1 of this invention, and shows the state which the flow path between a tank connection port and a canister connection port closed. It is a block diagram which shows the structure of the evaporative gas processing system to which the solenoid valve for fuel tank sealing which concerns on Embodiment 1 is applied. It is sectional drawing which shows the structure of the solenoid valve for fuel tank sealing which concerns on Embodiment 1, and shows the state which connected between the tank connection port and the canister connection port by the small diameter communicating path. It is sectional drawing which shows the structure of the solenoid valve for fuel tank sealing which concerns on Embodiment 1, and shows the state which the flow path between the tank connection port and the canister connection port connected. 3 is an enlarged cross-sectional view of a first mover and a second mover of a fuel tank sealing solenoid valve according to Embodiment 1. FIG. It is a graph which shows the example of control of the overexcitation drive which ECU performs with respect to the solenoid valve for fuel tank sealing. It is sectional drawing which shows the structure of the solenoid valve for fuel tank sealing concerning Embodiment 2 of this invention, and shows the state which the flow path between a tank connection port and a canister connection port closed.

Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing the configuration of a solenoid valve employing a two-stage valve mechanism. FIG. 2 is a block diagram showing a configuration of an evaporative gas treatment system 1 using this electromagnetic valve for sealing a fuel tank. An evaporative gas treatment system 1 mounted on a vehicle is operating a pressure-resistant fuel tank 2, a canister 3 that temporarily adsorbs evaporative gas evaporated in the fuel tank 2, and an evaporative gas released from the canister 3. And an intake manifold 4 for suctioning by using the intake system negative pressure of the engine. In addition, a purge solenoid valve 5 that purges (introduces) evaporative gas from the canister 3 to the intake manifold 4 is installed in a pipe that communicates the canister 3 and the intake manifold 4. An air release electromagnetic valve 6 and a filter 7 are installed in the pipe on the atmosphere release side of the canister 3. In addition, a solenoid valve 10 (shown in FIG. 1) for adjusting the internal pressure of the fuel tank 2 and sealing the fuel tank 2 is installed in the pipe communicating with the fuel tank 2, and further, a bypass pipe communicating with the fuel tank 2 and the atmosphere. A relief valve 8 is installed. The opening / closing operation of each solenoid valve 5, 6, 10 is controlled by an ECU (Electronic Control Unit) 9.
The bypass piping and the relief valve 8 shown in FIG. 2 will be described in detail in the second embodiment below.

Normally, the ECU 9 closes the fuel tank sealing solenoid valve 10 to close the pipe connecting the fuel tank 2 and the canister 3, and seals the fuel tank 2, thereby evaporating from the fuel tank 2 to the canister 3 side. Prevent gas inflow.
At the time of refueling, the ECU 9 opens the fuel tank sealing electromagnetic valve 10 as a pressure releasing operation, and causes the evaporated gas in the fuel tank 2 to flow toward the canister 3 to reduce the internal pressure. The flow of the evaporating gas at the time of refueling is shown by a one-dot chain line in FIG.
During traveling, the ECU 9 performs duty control by driving the purge solenoid valve 5 to perform duty control, draws evaporative gas from the canister 3 to the intake manifold 4 using engine negative pressure, and burns it. The flow of the evaporating gas at the time of purging is indicated by a broken line in FIG. The ECU 9 also controls the flow rate by driving the solenoid valve 10 for sealing the fuel tank in a Duty manner to flow evaporative gas from the fuel tank 2 to the intake manifold 4 using the engine negative pressure, thereby adjusting the internal pressure of the fuel tank 2. . The flow of the evaporating gas at the time of adjusting the internal pressure is indicated by a two-dot chain line in FIG.

  For example, in a plug-in hybrid vehicle (P-HEV), fuel gas adsorption from the fuel tank 2 to the canister 3 is performed only during refueling (the refueling route indicated by the one-dot chain line in FIG. 2). In addition to the time of refueling, purging from the canister 3 to the intake manifold 4 side (the path at the time of purge indicated by the broken line in FIG. 2 and the path at the time of adjusting the internal pressure indicated by the two-dot chain line) to adjust the internal pressure of the fuel tank 2 ( Reduce the amount of evaporation during refueling as much as possible.

  As shown in FIG. 1, a fuel tank sealing solenoid valve 10 is connected to a fuel tank 2 side pipe and a tank connection port 11 (first port) for introducing evaporative gas, and to a canister 3 side pipe. A canister connection port 12 (second port) through which evaporative gas is led out, a housing 13 in which flow paths (first flow path 31 and second flow path 32 described later) communicating with these ports are formed, and the first movable element And a solenoid portion 14 that opens and closes a flow path between the tank connection port 11 and the canister connection port 12 by moving the nozzle 20.

  The solenoid unit 14 is formed by integrally molding a resin member, a coil 15 formed by winding a conductive wire around a bobbin, a power supply terminal 16 that energizes the coil 15, a fixed iron core 17 that is excited by energization of the coil 15, The outer iron yoke portion 18 and the plate 19 that form a magnetic circuit together with the fixed iron core 17, the first mover (plunger) 20 attracted to the fixed iron core 17, and the first mover 20 fixed in the fixed iron core 17. A pin 21 that serves as a stopper and a first spring (biasing member) 22 that biases the first armature 20 in a direction (valve closing direction) opposite to the suction direction (valve opening direction) of the fixed iron core 17 are provided. . A first valve body 23 is formed at the tip of the first movable element 20.

The fuel tank sealing solenoid valve 10 according to the first embodiment is made up of a nonmagnetic member in addition to the first mover 20 made of a magnetic member that opens and closes by receiving an electromagnetic attraction force. It is set as the two-stage valve structure provided with the large diameter 2nd needle | mover 24 opened and closed in conjunction with opening and closing operation of.
The second mover 24 includes a communication passage 25 that penetrates the center of the columnar shape, and a first valve seat 26 that is one end of the communication passage 25 and that the first valve body 23 of the first mover 20 contacts and separates. The second valve element 27 is provided at the other end of the communication passage 25 and contacts and separates from a second valve seat 33 described later. Further, a concave portion 28 for inserting one end portion of a guide member 29 described later is formed on one end surface of the second mover 24.

A resin guide member 29 is integrally formed on a plate 19 sandwiched between the solenoid portion 14 and the housing 13. The guide member 29 has a cylindrical shape, and an inner peripheral surface thereof is brought into contact with an outer peripheral surface of the first movable element 20 to form a sliding guide when the first movable element 20 moves. Further, the lower end portion of the guide member 29 is inserted into the concave portion 28 of the second movable element 24, and the outer peripheral surface of the guide member 29 is brought into contact with the inner peripheral surface of the concave portion 28 of the second movable element 24. A sliding guide for moving the child 24 is used. In the illustrated example, an uneven shape is formed in the concave portion 28, and the outer peripheral surface of the guide member 29 is brought into contact with the convex portion.
By configuring the sliding guides of the first movable element 20 and the second movable element 24 with the inner peripheral surface and the outer peripheral surface of the same component (guide member 29), each movable element can move on the same axis. The positional deviation between the valve body and the valve seat can be suppressed. Further, when assembling the electromagnetic valve 10 for sealing the fuel tank, the sealing performance between the valve body and the valve seat can be stabilized without being affected by the accuracy of other components, the shaft misalignment, and the like.

A cylindrical portion 30 having a diameter larger than that of the communication passage 25 is formed inside the housing 13, and an opening end of the cylindrical portion 30 is connected to a second valve seat 33 to which the second valve body 27 of the second movable element 24 contacts and separates. Become. Further, the space between the housing 13 and the cylindrical portion 30 (the outer space of the cylindrical portion 30) communicates with the tank connection port 11 to become the first flow path 31, while the inner space of the cylindrical portion 30 communicates with the canister connection port 12. Thus, the second flow path 32 is obtained. The other side of the second flow path 32 communicates with the communication path 25. Therefore, the flow rate when the first flow channel 31 and the second flow channel 32 communicate with each other via the communication passage 25 is smaller than the flow rate when the first flow channel 31 and the second flow channel 32 communicate directly.
The first flow path 31 is provided with a second spring 34 that urges the second movable element 24 in a direction in which the second movable element 24 is pressed against the first movable element 20 (the valve opening direction). The urging directions of the first spring 22 and the second spring 34 are opposite to each other, and the urging force of the second spring 34 is smaller than the urging force of the first spring 22.

Next, the operation of the fuel tank sealing solenoid valve 10 and the flow of evaporative gas will be described.
(1) Normal time In normal times, the ECU 9 closes the fuel tank sealing electromagnetic valve 10 and closes the fuel tank 2. At this time, as shown in FIG. 1, the first movable element 20 is moved in the direction of the second movable element 24 by the urging force of the first spring 22, and the first valve body 23 comes into contact with the first valve seat 26. . Thereby, the communication between the first flow path 31 and the communication path 25 is blocked. The other second mover 24 receives a large biasing force of the first spring 22 through the contact between the first valve body 23 and the first valve seat 26, and resists the biasing force of the second spring 28. It moves in the direction of the valve seat 33, and the second valve body 27 comes into contact with the second valve seat 33. Thereby, the communication between the first flow path 31 and the second flow path 32 is blocked.
Accordingly, the communication between the tank connection port 11 and the canister connection port 12 is cut off, and the fuel tank 2 is closed.

(2) During refueling FIGS. 3 and 4 are cross-sectional views of the solenoid valve 10 for sealing the fuel tank, and FIG. 3 shows the tank connection port 11 (first flow path 31) and the canister connection port 12 (second flow path 32). Shows a state of communication through the communication path 25. FIG. 4 shows a state where the tank connection port 11 (first flow path 31) and the canister connection port 12 (second flow path 32) are in direct communication.
Before refueling, the ECU 9 opens the solenoid valve 10 for sealing the fuel tank and performs the pressure relief operation of the fuel tank 2. At this time, as shown in FIG. 3, the first movable element 20 is moved in the direction of the fixed iron core 17 against the urging force of the first spring 22 by the electromagnetic attractive force of the solenoid portion 14, and the first valve body 23 is separated from the first valve seat 26. As a result, the first flow path 31 and the second flow path 32 communicate with each other through the small-diameter communication path 25, and a small flow rate of evaporating gas flows from the tank connection port 11 to the canister connection port 12.
Therefore, the internal pressure of the fuel tank 2 can be reduced before refueling, and evaporative gas can be prevented from flowing out from the fuel tank 2 to the refueling port.

Further, when the internal pressure of the fuel tank 2 is increased by refueling in a state where the first movable element 20 is opened, the pressure received by the second movable element 24 is increased. Then, the second armature 24 is moved in the direction of the first armature 20 by the auxiliary biasing force of the second spring 34, and the first valve seat 26 is moved to the first valve body 23 as shown in FIG. At the same time, the second valve element 27 is separated from the second valve seat 33. As a result, the first flow path 31 is in direct communication with the second flow path 32, and a large flow rate of evaporating gas flows from the tank connection port 11 to the canister connection port 12.
Therefore, it is possible to prevent the fuel supply from being hindered by the internal pressure of the fuel tank 2 and to perform the fuel supply with a low pressure loss.

(3) During traveling During traveling, the ECU 9 opens the purge solenoid valve 5 to generate engine negative pressure in the pipe for adjusting the internal pressure, and opens and closes the fuel tank sealing solenoid valve 10 by duty drive. The internal pressure is adjusted by sucking the evaporated gas in the fuel tank 2 with the engine negative pressure. At this time, the first armature 20 is energized in accordance with the duty on / off state, and the solenoid portion 14 generates an intermittent electromagnetic attractive force in the valve opening direction against the urging force of the first spring 22. The first valve body 23 and the first valve seat 26 are moved away from each other (the state shown in FIG. 3) and the movement in the valve closing direction by the urging force of the first spring 22 (the state shown in FIG. 1) are repeated. repeat. As a result, the communication between the first flow path 31 and the second flow path 32 is repeatedly communicated and shut off via the small-diameter communication path 25, and evaporative gas having a flow rate substantially proportional to the communication time flows from the tank connection port 11 to the canister connection port 12. To flow.
Therefore, an excessive pressure increase in the fuel tank 2 can be suppressed, and deformation and breakage of the fuel tank 2 can be prevented.

Here, the first movable element 20 that controls the flow rate of the evaporative gas by duty driving has conventionally improved its adhesion to the first valve seat 26 by forming the first valve body 23 by an elastic member such as rubber. In order to ensure durability and adhesion resistance, a non-adhesive member was applied on the rubber surface of the first valve body 23. However, application of the non-adhesive member cures the rubber, impairs the original properties of the rubber, and deteriorates the sealing performance.
On the other hand, the solenoid valve 10 for sealing the fuel tank is mainly used to seal the evaporated gas generated in the fuel tank 2, and the first movable element 20 is in the closed state for most of the time. Therefore, the first movable element 20 of the fuel tank sealing electromagnetic valve 10 is less frequently opened and closed compared to the movable element of a normal use electromagnetic valve (for example, the purge electromagnetic valve 5 in FIG. 2). The contact / separation frequency between the body 23 and the first valve seat 26 is also small.
Therefore, the application of the non-adhesive member to the first movable element 20 that operates by duty driving is abolished. Details are shown in FIG.

FIG. 5 is an enlarged cross-sectional view of the first mover 20 and the second mover 24 in the fuel tank sealing electromagnetic valve 10 according to the first embodiment, and the upper side of the drawing is the tank connection port 11 (first flow In the state where the channel 31) and the canister connection port 12 (second flow path 32) are in direct communication, the lower side of the page is between the tank connection port 11 (first flow path 31) and the canister connection port 12 (second flow path 32). Shows the shut off state.
A first valve body 23, which is an elastic member such as rubber, is baked on the tip of the first movable element 20 that is a magnetic member such as iron. The surface of the first valve body 23 that comes into contact with the first valve seat 26 is not coated with fluororesin or the like and remains a rubber surface. On the other hand, a non-adhesive coating A is formed by applying a non-adhesive member such as a fluororesin or molybdenum having a non-adhesive function to the first valve seat 26 of the second mover 24 that is a non-magnetic member such as a resin. To do. Thereby, the surface roughness of the first valve body 23 of the first mover 20 and the amount of deflection can be improved, and the valve-closing sealability between the first valve body 23 and the first valve seat 26 can be ensured. Become.

  On the other hand, a non-adhesive member may be applied to the second valve body 27 and the second valve seat 33 to ensure durability.

In addition, the fuel tank sealing solenoid valve 10 is driven by continuous energization in order to keep the first movable element 20 in the normally open state during refueling or the like. Therefore, power consumption increases. On the other hand, when applied to a vehicle-mounted evaporative gas treatment system, power saving is required to reduce the burden on the battery.
When the first mover 20 is opened in the fuel tank sealing electromagnetic valve 10, a large electromagnetic force is required because the first mover 20 is attracted from the valve closing position to the valve opening direction as an initial operation. However, after the initial operation, while the first movable element 20 is held by the end face 1 of the pin 21, the electromagnetic force corresponding to the initial operation is not necessary and a holding current may be used. Is possible.
Therefore, in the case of the normally open state, the ECU 9 suppresses current consumption of the fuel tank sealing electromagnetic valve 10 by performing overexcitation driving and chopper driving on the fuel tank sealing electromagnetic valve 10.

FIG. 6 is a graph showing an example of overexcitation drive and chopper drive control performed by the ECU 9 for the solenoid valve 10 for sealing the fuel tank. The horizontal axis of the graph is the energization time, and the vertical axis is the current and voltage. When the solenoid valve 10 for sealing the fuel tank is normally opened, the ECU 9 applies a voltage to the coil 15 for a predetermined period to overexcite the solenoid unit 14 to quickly increase the current to the overexcitation current, and subsequently apply the applied voltage. Is chopped at a cycle shorter than the on / off cycle (several tens of Hz) at the time of duty driving, and held at a holding current lower than the overexcitation current. Therefore, current consumption of the solenoid valve 10 for blocking the fuel tank can be suppressed as compared with driving by continuous energization.
Thereby, power consumption and self-heating in the fuel tank sealing electromagnetic valve 10 can be minimized. In addition, since it is possible to suppress an increase in resistance of the coil 15 due to self-heating, an effect of improving the re-operability of the first mover 20 at the initial operation of the valve opening can be expected.

  As described above, according to the first embodiment, the fuel tank sealing solenoid valve 10 includes the first movable element 20 having the first valve body 23, the tank connection port 11 for introducing the evaporated gas, and the canister for deriving the evaporated gas. From the connection port 12, the housing 13 having the second valve seat 33 formed in the middle of the first flow path 31 and the second flow path 32 communicating the tank connection port 11 and the canister connection port 12, and the second valve seat 33. A communication path 25 that communicates between the tank connection port 11 and the canister connection port 12 on the upstream side, and is formed on the tank connection port 11 communication side of the communication path 25, is contacted and separated from the first valve body 23, and is connected to the tank connection port 11 and the communication path 25. The first valve seat 26 that opens and closes and the canister connection port 12 communication side of the communication passage 25 is formed on the communication side of the second valve seat 33 and opens and closes between the first flow path 31 and the second flow path 32. A second mover 24 that is movably held coaxially with the first mover 20, and a solenoid that generates an electromagnetic force that attracts the first mover 20 toward the valve opening side. And a first spring 22 that urges the first movable element 20 toward the valve closing side and urges the first movable element 20 to urge the second movable element 24. The seal structure and opening / closing operation characteristics of the valve seat 26 and the sealing structure and opening / closing operation characteristics of the second valve body 27 and the second valve seat 33 are different from each other. Therefore, it is not necessary to increase the size of the coil and the spring as in the conventional solenoid valve, the structure can be simplified, the size and the weight can be reduced, and the sealing performance when the valve is closed can be ensured. .

  Moreover, according to Embodiment 1, the 1st valve body 23 is formed with an elastic member, and the surface with which the 1st valve body 23 of the 1st valve seat 26 contacts forms the non-adhesive film A of a non-adhesive member. I did it. For this reason, since the surface roughness and the amount of deflection of the first valve body 23 can be maintained, the sealing performance when the valve is closed can be ensured.

  In addition, according to the first embodiment, the fuel tank sealing electromagnetic valve 10 is configured such that the first movable element 20 is slid on the inner surface of the cylinder and the second movable element 24 is slid on the outer surface. A guide member 29 for guiding the movement of the child 20 and the second mover 24 on the same axis is provided. Since the guide of the first movable element 20 and the guide of the second movable element 24 are performed by the one-piece guide member 29, the first movable element 20 and the second movable element 20 are improved by improving the dimensional accuracy of the guide member 29. It is possible to reduce the seal position shift of the mover 24 and the inclination of the seal surface, and the sealing performance when the valve is closed is improved.

  Further, according to the first embodiment, when the solenoid part 14 of the fuel tank sealing solenoid valve 10 is always opened, it is overexcited for a predetermined period under the control of the ECU 9, and is continuously overdriven by chopper driving. Since it is configured to operate with a holding current smaller than the current, current consumption can be reduced as compared with the case of driving with continuous energization. Therefore, when the fuel tank sealing electromagnetic valve 10 is applied to the vehicle-mounted evaporative gas treatment system 1, the burden on the in-vehicle battery can be reduced.

Embodiment 2. FIG.
In the evaporative gas treatment system 1 shown in FIG. 2 described in the first embodiment, when the solenoid valve 10 for sealing the fuel tank breaks down, the piping between the fuel tank 2 and the canister 3 is closed, and the fuel tank 2 The evaporating gas generated increases the internal pressure, and the tank may be deformed or damaged. Therefore, as a fail safe, a pressure sensitive relief valve 8 is installed by branching a pipe between the fuel tank 2 and the canister 3 to form a bypass pipe. For example, when excessive pressure is generated in the piping due to the inoperability of the solenoid valve 10 for sealing the fuel tank, the relief valve 8 is opened and the bypass piping is communicated. discharge.

  As described above, the pipe between the fuel tank 2 and the canister 3 may be branched to form a bypass pipe, but the number of pipes and connecting parts increases. Therefore, in the second embodiment, a branch port to the bypass pipe is provided in the solenoid valve 10 for sealing the fuel tank so that branching on the pipe side is unnecessary.

FIG. 7 is a cross-sectional view showing the configuration of the fuel tank sealing electromagnetic valve 10a according to the second embodiment, and shows a state where communication between the tank connection port 11 and the canister connection port 12 is blocked. 7 that are the same as or equivalent to those in FIG. 1 are assigned the same reference numerals, and descriptions thereof are omitted.
In the fuel tank sealing electromagnetic valve 10 a, a relief valve connection port (third port) 40 is formed in the housing 13. One end side of the relief valve connection port 40 communicates with the first flow path 31, and the other end side communicates with the atmosphere side via a bypass pipe. Since the fuel tank sealing solenoid valve 10a is of a type that always closes, if the fuel tank sealing solenoid valve 10a becomes inoperable due to a failure or the like, the evaporative gas in the fuel tank 2 is not released and the internal pressure rises. At this time, since the fuel tank 2, the tank connection port 11, the first flow path 31 and the relief valve connection port 40 are in communication, the relief valve 8 is opened by the internal pressure, and evaporative gas is released to the atmosphere side through the filter 7. Can be released.
The relief valve 8 is a pressure sensitive valve such as a check valve, and is opened by receiving a high internal pressure on the relief valve connection port 40 side, and communicates with the bypass pipe. Note that the relief valve 8 may be integrally provided inside the relief valve connection port 40.

  As described above, according to the second embodiment, the fuel tank sealing electromagnetic valve 10a is provided in the housing 13 in the first flow path 31 of the tank connection port 11 regardless of the open / closed state of the first mover 20 and the second mover 24. Relief valve connection port 40 communicating with is formed. For this reason, it is not necessary to install the branch pipe for connecting to the fail-safe bypass pipe provided with the relief valve 8 on the evaporative gas treatment system 1 side. Therefore, piping and connecting parts can be omitted, and piping can be simplified.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  1 Evaporative Gas Treatment System, 2 Fuel Tank, 3 Canister, 4 Intake Manifold, 5 Purge Solenoid Valve, 6 Air Solenoid Valve, 7 Filter, 8 Relief Valve, 9 ECU, 10, 10a Solenoid Valve for Fuel Tank Sealing, 11 Tank connection port (1st port), 12 Canister connection port (2nd port), 13 Housing, 14 Solenoid part, 15 Coil, 16 Feeding terminal, 17 Fixed iron core, 18 Outer iron yoke part, 19 Plate, 20 1st Movable element, 21 pin, 22 First spring (biasing member), 23 First valve element, 24 Second movable element, 25 Communication path, 26 First valve seat, 27 Second valve element, 28 Recessed part, 29 Guide member , 30 Cylindrical part, 31 First flow path, 32 Second flow path, 33 Second valve seat, 34 Second spring, 40 Relief valve connection port (Third port).

Claims (3)

A first mover having a first valve body;
A first port for introducing a fluid, a second port for deriving the fluid, and a second valve seat formed in a flow path communicating the first port and the second port, A housing containing the first armature;
The first port and the second port communicate with each other upstream from the second valve seat, the communication passage having a smaller diameter than the flow path, and formed on the first port communication side of the communication passage. A first valve seat that opens and closes between the first port and the communication path, and is formed on the second port communication side of the communication path to open and close the flow path by contacting and separating from the second valve seat. A second mover having a second valve body, and movably held coaxially with the first mover;
A solenoid unit for generating an electromagnetic force for attracting the first movable element toward the valve opening side;
A biasing member that biases the first armature toward the valve closing side and biases the second armature to the first armature ;
A guide member for sliding the first movable element on the inner surface of the cylindrical body and sliding the second movable element on the outer surface to guide the coaxial movement of the first movable element and the second movable element. And
The first valve body and the first valve seat have an opening / closing operation characteristic by electromagnetic force, the first valve body is formed of an elastic member, and a surface of the first valve seat on which the first valve body abuts is Formed of a non-adhesive member, the parallelism of each surface where the first valve body and the first valve seat abut is ensured by the guide member,
The second valve body and the second valve seat have an opening / closing operation characteristic due to differential pressure, and at least one of the surfaces on which the second valve body and the second valve seat abut is formed of a non-adhesive member. A solenoid valve characterized by that. 2. The solenoid valve according to claim 1, wherein when the solenoid portion is always opened, the solenoid valve is over-excited for a predetermined period, and subsequently operated with a chopper to operate with a current smaller than the current of the over-excitation drive. . Said housing, said first movable element and regardless of the open or closed state of said second movable member, the solenoid valve according to claim 1, characterized in that it has a third port communicating with the first port.

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