JP2007113623A - Selector valve controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make compact an electric three-way valve in an electric air pump unit 1 with the electric three-way valve integrated with an electric air pump, to reduce its cost, and to lengthen the service life for operation. <P>SOLUTION: A valve element of the two-position three-way selector valve driven at two positions by a motor torque of the electric motor 3 is structured by one valve 6, and the valve 6 and a valve shaft 7 is made as an integral component. By this structure, as a sealing component for maintaining airtightness between the valve 6 and the shaft 7 is unnecessary, and the number of components of the components structuring the electric three-way valve and assembly man-hour can be reduced, the body size of the electric three-way valve can be made small. Further, because the valve 6 does not slide on the outer periphery of the valve shaft 7, occurrence of defective sealing due to wear can be prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a switching valve control device having a two-position switching valve that selectively opens and closes two first and second fluid passage ports, and more particularly to a two-position switching valve using motor torque of an electric motor. The present invention relates to a switching valve control device that is driven to two positions, a first position and a second position.

[Conventional technology]
Conventionally, as shown in FIG. 8, two first and second fluid ports 101 and 102 inside, and a fluid flow path 103 selectively communicating with these first and second fluid ports 101 and 102. , A two-position three-way switching valve 105 housed in the housing 104 so as to be openable and closable, and a two-position three-way switching valve 105 in two positions using the motor torque of the electric motor 106. An electric three-way valve provided with a driving actuator is known (see, for example, Patent Document 1).

  Here, the two-position three-way switching valve 105 includes a first valve body 111 that opens and closes the first fluid port 101, a second valve body 112 that opens and closes the second fluid port 102, and these first and second valves. A drive shaft 113 configured separately from the bodies 111 and 112 is provided. The two first and second valve bodies 111 and 112 are slidably assembled to the outer periphery of the drive shaft 113. In addition, the two first and second valve bodies 111 and 112 are connected to each other by the urging force of the spring 114 and the two first and second stoppers 115 and 116 assembled to the drive shaft 113. The first and second fluid ports 101 and 102 are closed by being pressed against the two valve seat portions 121 and 122. The actuator includes a gear reduction mechanism 107 to which the motor torque of the electric motor 106 is transmitted, a movement direction conversion mechanism 109 that converts the rotational movement of the electric motor 106 into a linear reciprocation through the gear reduction mechanism 107, and the like. Has been. Here, FIG. 8 shows a closed state in which the two first and second fluid ports 101 and 102 are closed together by the two first and second valve bodies 111 and 112.

  When the first fluid port 101 is opened and the second fluid port 102 is closed, first, the changeover switch 124 in the gear case 123 is operated to rotate the electric motor 106 in the forward rotation direction. Then, the motion direction conversion mechanism 109 converts the forward rotation of the electric motor 106 into a linear motion in the upward direction in the figure, and the drive shaft 113 coupled to the motion direction conversion mechanism 109 moves in the upward direction in the figure. . And the 1st stopper 115 assembled | attached to the outer peripheral part of the drive shaft 113 pushes up the 1st valve body 111. FIG. At this time, the first valve body 111 is separated from the first valve seat portion 121 to open the first fluid port 101, and the second valve body 112 is pressed against the second valve seat portion 122 to form the second fluid port 101. Close fluid port 102.

  Further, when the first fluid port 101 is closed and the second fluid port 102 is opened, the changeover switch 124 is operated to rotate the electric motor 106 in the reverse direction. Then, the motion direction conversion mechanism 109 converts the rotational motion of the electric motor 106 in the reverse direction into a linear motion in the downward direction in the figure, and the drive shaft 113 moves in the downward direction in the figure. Then, the second stopper 116 pushes down the second valve body 112. At this time, the first valve body 111 is pressed against the first valve seat portion 121 to close the first fluid port 101, and the second valve body 112 is separated from the second valve seat portion 122 to be second Open fluid port 102.

[Conventional technical problems]
However, in the conventional electric three-way valve, since the two first and second valve bodies 111 and 112 are slidably assembled on the outer periphery of the drive shaft 113, the two first and second valve bodies are provided. First and second seal parts 131 and 132 such as O-rings are required to keep airtight between the inner periphery of 111 and 112 and the outer periphery of the drive shaft 113. As a result, the number of components for configuring the three-way valve is increased, and many components need to be accommodated in the housing 104. This causes a problem such as an increase in the size of the three-way valve.

Further, there is a problem that the product cost increases due to the increase in the number of assembling steps as the number of parts increases. Further, since the two first and second valve bodies 111 and 112 and the drive shaft 113 slide, the inner peripheral portion of the two first and second valve bodies 111 and 112 and the outer peripheral portion of the drive shaft 113. Between the inner peripheral part of the two first and second valve bodies 111 and 112 and the outer peripheral part of the drive shaft 113, resulting in a long service life. The problem of shortening arises.
Japanese Patent Application Laid-Open No. 64-12181 (page 1-3, FIGS. 1 to 3)

  An object of the present invention is to provide a switching valve control device capable of reducing the number of parts and the number of assembling steps and reducing the size of the physique. It is another object of the present invention to provide a switching valve control device capable of preventing the occurrence of seal failure due to wear and extending the operating durability life.

  According to the first aspect of the invention, the two-position switching valve that switches the communication state between the first fluid passage port and the fluid flow channel and the communication state between the second fluid passage port and the fluid flow channel at two positions. Is constituted by one valve body that selectively opens and closes the two first and second fluid passage ports and a drive shaft connected to the actuator, and the drive shaft is formed integrally with the valve body. . This eliminates the need for sealing parts to keep the valve body and the drive shaft hermetically sealed, so the number of parts and assembly man-hours of the components constituting the switching valve control device can be reduced, and switching The size of the valve control device can be reduced. As a result, the switching valve control device can be made compact and the cost can be reduced. In addition, since the drive shaft is formed integrally with the valve body, the valve body does not slide on the outer periphery of the drive shaft, so that it is possible to prevent the occurrence of seal failure due to wear. As a result, the operating durability life of the switching valve control device can be extended, and the durability and reliability of the switching valve control device can be improved.

  According to the invention described in claim 2, when the first seal portion of one valve body provided in the two-position switching valve is seated on the opening peripheral edge portion of the first fluid passage port, the first fluid passage port is closed, Further, when the first seal portion of one valve body is separated from the opening peripheral edge portion of the first fluid passage port, the first fluid passage port is opened. When the second seal portion of one valve body is seated on the peripheral edge of the opening of the second fluid passage port, the second fluid passage port is closed, and the second seal portion of one valve body is the second fluid. When the seat is separated from the opening peripheral edge of the passage opening, the second fluid passage opening is opened. Therefore, the two-position switching valve is driven by the driving force of the motor at the “first position” where the first seal portion of one valve body is seated on the peripheral edge of the opening of the first fluid passage port, and the first position of one valve body. The two seal portions are driven to two positions, “second position” where they are seated on the peripheral edge of the opening of the second fluid passage port, so that the communication state between the first fluid passage port and the fluid flow path and the second fluid passage The communication state between the mouth and the fluid channel can be selectively switched.

  According to the third aspect of the present invention, when the two-position switching valve is in the “first position” that closes the first fluid passage port, the “first load” applied to the two-position switching valve by the first load applying means. ”Is set larger than the“ second load ”applied to the two-position switching valve by the second load applying means, so that the first seal portion of one valve body provided in the two-position switching valve is the first fluid. The two-position switching valve is held at the “first position” by being pressed against the opening peripheral edge of the passage opening (switching valve holding function). Further, when the two-position switching valve is in the “second position” that closes the second fluid passage port, the “second load” applied to the two-position switching valve by the second load applying means is reduced by the first load applying means. Since it is set to be larger than the “first load” given to the two-position switching valve, the second seal portion of one valve body provided in the two-position switching valve is pressed against the opening peripheral edge of the second fluid passage port. Thus, the two-position switching valve is held at the “second position” (switching valve holding function). Therefore, for example, even if the supply of electric power to the motor is stopped, the two-position switching valve can be reliably held at the two positions, so that power consumption can be suppressed.

  According to the fourth aspect of the invention, the two-position switching valve is held at two positions by utilizing the repulsive force of the elastic body (the restoring force generated when the elastic body is compressed), for example, the power to the motor Since the two-position switching valve can be reliably held at the two positions even when the supply of the power is stopped, the power consumption can be suppressed. Also, by holding the two-position switching valve at two positions using elastic deformation force (repulsive force), the vibration propagates from the vibration source to the housing and further propagates from the housing to the two-position switching valve, or two-position switching. Since the vibration of the valve can be damped by the elastic body, the vibration resistance of the two-position switching valve can be improved.

  According to the fifth aspect of the invention, the impeller having a plurality of blade portions formed in the circumferential direction is also rotationally driven by the motor that drives the two-position switching valve. In addition, a two-position switching valve and an impeller are installed coaxially with the output shaft of the motor. As a result, the two-position switching valve can be driven to two positions by utilizing the rotational motion of the impeller (motor torque of the motor output shaft), so the size of the actuator that drives the two-position switching valve to two positions can be reduced. You can plan. Further, since the opening / closing operation of the two-position switching valve can be started in a short time after the rotation operation of the impeller is started, the control responsiveness of the two-position switching valve can be improved.

  Here, as an actuator (valve driving device) that drives the two-position switching valve to two positions by using the driving force (motor torque) of the motor, the rotary motion of the output shaft of the motor (or the impeller driven to rotate by the motor) A motion direction conversion mechanism for converting the rotational motion of the motion to a linear (reciprocating) motion may be provided. In addition, a centrifugal clutch or torque limiter that intermittently transmits motor torque from the motor (or impeller) to the motion direction conversion mechanism is installed between the motor output shaft (or impeller) and the motion direction conversion mechanism. Also good. Further, an impeller, a centrifugal clutch, a torque limiter, a motion direction conversion mechanism, and a two-position switching valve may be installed on the same axis as the motor output shaft.

  The best mode for carrying out the present invention is to selectively open and close the two first and second fluid passage ports for the purpose of downsizing and cost reduction, and the purpose of extending the operating durability life. This is realized by forming a two-position switching valve with a single valve body and a drive shaft connected to the actuator, and further integrally forming the valve body and the drive shaft.

[Configuration of Example 1]
FIGS. 1 to 5 show Embodiment 1 of the present invention, and FIGS. 1 and 2 are views showing the entire structure of an electric air pump unit.

  The evaporative fuel processing apparatus according to the present embodiment uses an internal combustion engine (e.g., a gasoline engine) through a canister for a fluid such as evaporative fuel (evaporated) in a fuel tank of a vehicle such as an automobile. : Evaporative fuel transpiration prevention that prevents fluid such as evaporative fuel from being released into the atmosphere by introducing (purging) it into the engine intake pipe (for example, the intake port side of the throttle valve) of the engine) Device. The fuel vapor processing apparatus includes an electric air pump unit 1 corresponding to the switching valve control device of the present invention.

  In the evaporative fuel processing device, the fuel tank and the tank side port of the canister communicate with each other via a first air flow path pipe (fluid pipe), and the canister, the engine intake pipe, and the purge port of the canister pass the second air flow. It communicates via a road pipe (fluid pipe). The fuel tank is provided with a pressure sensor (tank internal pressure sensor) for detecting the pressure in the fuel tank (tank internal pressure). An air flow path (fluid flow path) is formed in the first air flow path pipe for guiding fluid such as evaporated fuel volatilized in the fuel tank to the canister. Further, in the second air flow path, an air flow path (fluid flow path) for guiding fluid such as evaporated fuel adsorbed by the canister to the engine intake pipe via a purge VSV (vacuum switching valve) Is formed.

  The purge VSV is duty-driven by an engine control unit (hereinafter referred to as ECU), thereby adjusting a flow rate (purge amount) of a fluid such as evaporated fuel flowing through the second air passage pipe (purge control valve).・ Valve). In the canister, an adsorbent (for example, activated carbon) that adsorbs the evaporated fuel is accommodated. An air release pipe is connected to the air release hole of the canister. The electric air pump unit 1 is connected to the upstream end of the air release pipe in the air flow direction. An air flow path (fluid flow path) for guiding an air flow generated by operating the electric air pump unit 1 to the canister is formed in the atmosphere open pipe.

  The electric air pump unit 1 of the present embodiment is an electric air pump module in which an electric three-way valve is integrated with an electric air pump, and is covered by a housing 2 connected to a canister via an air release pipe. The electric air pump is a double-blade type vortex pump (vortex pump) that is rotationally driven by the driving force (motor torque) of the electric motor 3, and forcibly introduces fluid such as evaporated fuel into the engine intake pipe ( A pump impeller (impeller: hereinafter abbreviated as impeller) 5 used as a purge pump for purging) is provided.

  The electric three-way valve has a two-position three-way switching valve that is driven to two positions by the motor torque of the electric motor 3. The two-position / three-way switching valve is a single valve element that selectively opens and closes two first and second fluid passage ports (hereinafter referred to as first and second fluid ports) formed in the housing 2. An integral part (movable member) constituted by 6 (hereinafter referred to as a valve) 6 and a drive shaft (hereinafter referred to as a valve shaft) 7 formed integrally with the valve 6. The electric three-way valve has a cylindrical spring stopper 9 slidably assembled on the outer periphery of the valve shaft 7 of the two-position / three-way switching valve, and a valve 6 of the two-position / three-way switching valve in the first position (hereinafter referred to as “the first position”). There are first and second springs 11 and 12 for urging and holding at two positions, a default position and a second position (hereinafter referred to as a full lift position).

  Here, the actuator 14 that drives the valve 6 to the two positions of the default position and the full lift position using the motor torque of the electric motor 3 includes the electric motor 3 that is driven by electric power, and the motor shaft 4 of the electric motor 3. It is comprised by the motion direction conversion mechanism etc. which convert the rotational motion of this into linear motion. Further, a centrifugal clutch 15 and a torque limiter 16 are connected between the motor shaft 4 of the electric motor 3 and the movement direction conversion mechanism. In this embodiment, a two-position three-way switching valve (valve 6 and valve shaft 7), a centrifugal clutch 15, a torque limiter 16, and a motion direction conversion mechanism are arranged on the same axis as the motor shaft 4 of the electric motor 3. It is installed (configured).

  The common housing 2 for the electric air pump and the electric three-way valve is constituted by five cases (first to fourth cases 21 to 24 and a cover 25 from the right side in FIG. 1) in which components are incorporated. The first to fourth cases 21 to 24 and the cover 25 are coupled with fastening screws, clips, locking pieces, and the like. The first case 21 has an outer diameter side cylindrical portion and an inner diameter side cylindrical portion that forms an air duct (described later) between the outer diameter side cylindrical portion. This inner diameter side cylindrical portion is used as a motor housing that houses and holds the electric motor 3. A mounting stay 26 for holding the collar and the grommet is provided on the outer peripheral portion of the second case 22. The mounting stay 26 of the second case 22 is fastened and fixed to the canister using fastening bolts or the like.

  Here, the housing 2 includes a first case 21 also serving as a motor housing, a second case 22 coupled to the first case 21 with screws, and a third case 23 coupled to the second case 22 by clips. Thus, a pump housing that rotatably accommodates the impeller 5 of the electric air pump is configured. An annular vortex chamber (pump chamber) 31 that compresses air by the rotational movement of the impeller 5 is formed inside the pump housing. A C-shaped side groove having a groove bottom surface having a semicircular cross section is formed on the outer peripheral portion in the radial direction of the vortex chamber 31.

The first and second cases 21 and 22 are formed with an air duct 32 in an annular shape for sending air into the vortex chamber 31. In the air duct 32, a filter 33 for filtering air sucked by the impeller 5 is disposed. The filter 33 can pass air flowing in from the open end of the air duct 32 (the air suction port of the first case 21), but traps the foreign matter mixed in the air and enters the vortex chamber 31. Is to prevent.
The first case 21 is formed with an air inlet (not shown) for sucking air into the air duct 32.

  The air suction port of the first case 21 functions as a first air suction port (atmospheric release hole) that sucks air into the air duct 32 in which the filter 33 is built. The second case 22 is formed with a pump suction port (not shown) for sucking air from the air duct 32 into the vortex chamber 31. In addition, a pump discharge port 34 for discharging air from the vortex chamber 31 is formed in the third case 23. A partition plate (partition part) 35 is provided between the second and third cases 22 and 23 to prevent air from flowing directly from the pump suction port to the pump discharge port 34.

  Here, the housing 2 includes a third case 23 also serving as a pump housing, a fourth case 24 coupled to the third case 23 with a screw, and a cover 25 coupled to the fourth case 24 by a clip. A valve housing is configured to accommodate the valve 6 of the electric three-way valve so as to be freely opened and closed. Further, an air flow path 36 communicating with the vortex chamber 31 through the pump discharge port 34 is formed between the third and fourth cases 23 and 24. Further, a cylindrical air passage tube 38 having an air passage 37 formed therein is extended from the outer wall surface of the cover 25 so as to protrude in the left direction in the figure. The open end of the air flow path 37 functions as a second atmospheric suction port (atmospheric open hole) 39 opened to the atmosphere.

  In the valve housing, two first and second fluid ports 41 and 42 and one fluid flow path 43 selectively communicating with the first and second fluid ports 41 and 42 are formed. ing. The first fluid port 41 is disposed to face the second fluid port 42 with a predetermined gap (with the fluid flow path 43 in between). The first fluid port 41 is a circular fluid passage port (air passage port) that communicates the air flow path 36 and the fluid flow path 43, and is formed in the fourth case 24.

  The second fluid port 42 is an air passage port that communicates the air flow path 37 and the fluid flow path 43, and is formed in the cover 25. In this embodiment, a plurality of second fluid ports 42 are formed at regular intervals around an annular valve holding portion 44 connected to the cover 25 via a plurality of connecting pieces. A fitting hole that fits into the fitting portion of the valve 6 is provided in the inner peripheral portion of the valve holding portion 44. The fluid flow path 43 is a communication path communicating with the atmosphere opening hole of the canister, and is formed inside a cylindrical connection joint (air flow path pipe) constituted by the fourth case 24 and the cover 25. ing. The open end of the fluid flow path 43 functions as an air discharge port (exit port) 45.

  And the opening peripheral part of the 1st fluid port 41 is provided in the predetermined | prescribed site | part of the 4th case 24, and the opening peripheral part of this 1st fluid port 41 is the annular | circular shape in which the valve | bulb 6 can sit. The first valve seat part (first valve seat) 46 functions. In addition, an opening peripheral portion of the second fluid port 42 is provided at a predetermined portion of the cover 25, and the opening peripheral portion of the second fluid port 42 is an annular second member on which the valve 6 can be seated. It functions as a valve seat part (second valve seat) 47.

  The first and second valve seats 46 and 47 are arranged to face each other with a predetermined gap (with the fluid flow path 43 in between). The first valve seat 46 is used as a restricting portion that restricts the movement range of the valve 6 in the axial direction (the axial direction of the valve shaft 7). Thereby, when the valve 6 is seated on the first valve seat 46, the further movement of the valve 6 to the other side in the axial direction (side where the first fluid port 41 is closed) is restricted. The second valve seat 47 is used as a restricting portion that restricts the movement range of the valve 6 in the axial direction (the axial direction of the valve shaft 7). Thereby, when the valve 6 is seated on the second valve seat 47, the further movement of the valve 6 toward one side in the axial direction (the side closing the second fluid port 42) is restricted.

  Here, a reference orifice 49 is formed in parallel with the first fluid port 41 in the fourth case 24 forming a part of the valve housing of the housing 2. The reference orifice 49 is a throttle hole that allows the air flow path 36 and the fluid flow path 43 to communicate with each other, and is provided so as to penetrate the fourth case 24 in the plate thickness direction. The reference orifice 49 is a reference hole (for example, φ0.35 to 0.60 mm) provided for measuring a reference pressure (Pref) used for a leak check (leakage determination) in the closed space of the fuel vapor processing apparatus. (Preferably φ0.40 to 0.50 mm, and most preferably φ0.45 mm).

  The electric motor 3 is a direct current (DC) motor. The electric motor 3 is a motor shaft (output shaft) provided so as to protrude from the front end surface of the motor housing to one side in the rotation axis direction (the direction of the central axis of the motor shaft 4 of the electric motor 3; hereinafter referred to as the axial direction). ) 4 and a brushless DC motor comprising a stator opposed to the outer peripheral side of the rotor. The rotor is provided with a rotor core having a permanent magnet, and the stator has an armature coil (electrical machine) A stator core around which a secondary winding is wound is provided. Instead of the brushless DC motor, a direct current (DC) motor with a brush or an alternating current (AC) motor such as a three-phase induction motor may be used.

  The impeller 5 is rotatably accommodated in the vortex chamber 31 of the housing 2 (pump housing constituted by the second and third cases 22 and 23). The impeller 5 is a double-blade impeller having a plurality of blade portions (blades and fins) and a plurality of blade grooves, and pressurizes and discharges the air sucked into the vortex chamber 31. Further, the impeller 5 has a disc-shaped rotor portion (main body) that is press-fitted and fixed to the outer periphery of the motor shaft 4 of the electric motor 3 so as not to be relatively rotatable.

  A plurality of blade portions and a plurality of blade grooves are formed at a constant interval (for example, at equal intervals) alternately in the circumferential direction on the outer peripheral portion in the radial direction of the rotor portion. Between the blade portions adjacent in the plate thickness direction of the impeller 5 (axial direction of the motor shaft 4), the groove bottom surface of the blade groove adjacent in the plate thickness direction of the impeller 5 (axial direction of the motor shaft 4) is provided. An annular partition wall (rib) for partitioning is provided. The groove bottom surface shape of the plurality of blade grooves is a curved surface shape that forms an O-shaped, U-shaped, or oval space with the side groove of the vortex chamber 31.

  The centrifugal clutch 15 is installed between the motor shaft 4 and the movement direction conversion mechanism, and has a cylindrical clutch inner that performs a rotation movement integrally with the electric air pump, and a rotation movement integrally with the movement direction conversion mechanism. A cylindrical clutch outer is formed, and a plurality of clutch weights (combined bodies) 52 are swingably assembled to the clutch inner via a connecting member (for example, a pin) 51.

  The clutch inner is a motor side clutch member (drive side clutch member) integrally provided at one end portion (left end portion in the drawing) of the motor shaft 4 in the axial direction. The clutch outer is a valve-side clutch member (driven-side clutch member) that is disposed so as to face the outer peripheral surface of the clutch inner and is integrally provided at the other axial end portion (the right end portion in the drawing) of the torque limiter 16.

  The clutch outer is closed at one end side in the axial direction of the motor shaft 4 and opened at the other end side in the axial direction of the motor shaft 4. The plurality of clutch weights 52 are detachably engaged with engagement grooves formed on the inner peripheral surface of the clutch outer. These clutch weights 52 are urged toward the radially inner diameter side (centrecent direction opposite to the radial direction) of the motor shaft 4 by an elastic deformation member such as a leaf spring (not shown).

  The centrifugal clutch 15 is connected to the torque limiter 16 from the motor shaft 4 when the centrifugal force acting on the plurality of clutch weights 52 (force acting on the outer diameter side (radial direction) in the radial direction of the motor shaft 4) is a predetermined value or more. When the centrifugal force acting on the plurality of clutch weights 52 is smaller than a predetermined value, the motor torque is transmitted from the motor shaft 4 to the torque limiter 16 and the movement direction conversion mechanism. Cut off.

  In other words, the centrifugal clutch 15 is configured so that the motor torque from the motor shaft 4 to the torque limiter 16 and the movement direction changing mechanism is changed according to the magnitude of centrifugal force acting on the plurality of clutch weights 52 as the motor shaft 4 rotates. It is a centrifugal clutch mechanism that interrupts transmission. The motor side clutch member (drive side clutch member) may be a clutch outer, and the valve side clutch member (driven side clutch member) may be a clutch inner.

  The torque limiter 16 is installed between the centrifugal clutch 15 and the movement direction conversion mechanism, and is attached to the surface (circular friction surface) of the clutch outer closing portion (friction plate) 53 of the centrifugal clutch 15 and the friction plate 53. It is comprised by the surface (circular friction surface) of the friction board 54 opposingly arranged on the same axis.

  When the valve 6 moves to the full lift position and the movement of the valve 6 to one side in the axial direction (the full lift position side of the valve 6) is restricted, the torque limiter 16 receives overload torque together with the motion direction conversion mechanism. Works. At this time, the torque limiter 16 functions as a power cut-off means that cuts off transmission of motor torque from the friction plate 53 to the friction plate 54.

  Further, when no overload torque is applied, the torque limiter 16 functions as power transmission means for transmitting motor torque by frictional engagement between the friction plate 53 and the friction plate 54. In order to increase the frictional engagement force between the friction plate 53 and the friction plate 54, a coil spring, a plate spring, or a rubber-based elastic body that biases the friction plate 53 or the friction plate 54 toward the friction plate 54 or the friction plate 53 side. A friction plate urging means such as an air cushion may be installed.

  The motion direction conversion mechanism is a screw mechanism that converts the rotational motion of the motor shaft 4, that is, the rotational motion of the friction plates 53 and 54 of the centrifugal inner clutch 15 and the torque limiter 16 into linear motion of the valve 6. . Note that a ball screw mechanism or a rack and pinion mechanism may be used instead of the screw mechanism as the movement direction conversion mechanism. This movement direction conversion mechanism is constituted by a rotor sleeve 55, a valve 6, a spring stopper 9, and the like that rotate integrally with the friction plate 54 of the torque limiter 16.

  A first screw 56 is press-fitted and fixed to the inner peripheral portion of the rotor sleeve 55 of the torque limiter 16. An inner peripheral screw portion (female screw portion) that engages with an outer peripheral screw portion (male screw portion) of the valve shaft 7 that is an integral part of the valve 6 is formed on the inner peripheral portion of the first screw 56. . A first screw (female screw portion) may be integrally formed on the inner peripheral portion of the rotor sleeve 55 of the torque limiter 16.

  A second screw 57 is integrally formed on the inner peripheral portion of the rotor sleeve 55 of the torque limiter 16. The second screw 57 is an inner peripheral screw portion that engages with an outer peripheral screw portion (male screw portion) of the spring stopper 9 that can move relative to the valve 6. The lead of the second screw 57 (the distance traveled in the axial direction when making one turn around the shaft along the thread) is set larger than that of the first screw 56.

  The two-position three-way switching valve of the present embodiment is accommodated in the housing 2 so as to be openable and closable (reciprocating linear motion in the axial direction of the motor shaft 4 in the fluid flow path 43). The two-position / three-way switching valve is a poppet type valve and is driven in the axial direction by the first screw 56 of the torque limiter 16 (rotor sleeve 55) of the actuator 14. The two-position / three-way switching valve has a single valve 6 and a valve shaft 7 as described above.

  The valve 6 is a circular flange plate-shaped valve body made of a metal material or a resin material, and has a bowl shape so as to protrude from the outer peripheral surface of the valve shaft 7 toward the radially outer diameter side of the valve shaft 7. Is provided. This valve 6 is seated on and separated from the opening peripheral edge portion (first valve seat 46) of the first fluid port 41 to close and open the first fluid port 41, and the second fluid port 42 has a second seal portion that seats and separates from the opening peripheral edge portion (second valve seat 47) to close and open the second fluid port. That is, the valve 6 has first and second seal portions on both end surfaces of the valve 6 in the plate thickness direction. The first fluid port 41 is hermetically sealed on the surface of the valve 6 when seated on the first valve seat 46 of the fourth case 24, and when seated on the second valve seat 47 of the cover 25. A seal rubber 60 for hermetically sealing the second fluid port 42 is attached by baking.

  The valve shaft 7 is formed in a cylindrical shape from the same material as the valve 6 and is integrally formed so as to penetrate the central portion of the valve 6 in the plate thickness direction. The valve shaft 7 is drivingly connected to the torque limiter 16 (the rotor sleeve 55) of the actuator 14. The valve shaft 7 has a portion where the valve 6 is formed as an outermost diameter portion, and is axially more than the outermost diameter portion with respect to one side (left side in the drawing) of the axial direction from the outermost diameter portion. The other side (the right side in the figure) has a larger outer diameter. A fitting portion 61 that fits into a fitting hole of the valve holding portion 44 that is formed integrally with the cover 25 is provided on one end side in the axial direction of the valve shaft 7.

  The two-position / three-way switching valve (the valve 6 and the valve shaft 7) has a rotation preventing structure with respect to the housing 2. Specifically, as shown in FIGS. 1 to 4, two-side width portions are respectively formed on the inner periphery of the fitting hole of the valve holding portion 44 of the cover 25 and the outer periphery of the fitting portion 61 of the valve shaft 7. ing. Thereby, relative movement in the rotational direction of the valve 6 and the valve shaft 7 with respect to the housing 2 (particularly, the fourth case 24, the cover 25, the valve holding portion 44, etc.) can be prevented. Further, an outer peripheral thread portion that meshes with the first screw 56 of the torque limiter 16 is formed on the outer peripheral portion on the other end side in the axial direction of the valve shaft 7.

  Therefore, the two-position three-way switching valve (valve 6 and valve shaft 7) constituting the main component of the electric three-way valve has a default position where the first seal portion of the valve 6 is seated on the first valve seat 46 and the valve 6 The second seal portion can reciprocate between two positions with the full lift position where the second seal seat is seated on the second valve seat 47. When the valve 6 is held (or driven) in the default position, the first fluid port 41 is closed and the second fluid port 42 is opened. When the valve 6 is held (or driven) at the full lift position, the first fluid port 41 is opened and the second fluid port 42 is closed.

  The spring stopper 9 is formed in a cylindrical shape by a metal material or a resin material, and is driven in the axial direction by the second screw 57 of the torque limiter 16 (the rotor sleeve 55) of the actuator 14. The spring stopper 9 has a cylindrical portion extending in the axial direction of the valve shaft 7 and a flange-like flange portion provided on one end side of the cylindrical portion in the axial direction. Further, the spring stopper 9 applies a load in a direction in which the second seal portion of the valve 6 is pressed against the opening peripheral portion (second valve seat 47) of the second fluid port 42 via the first spring 11. It is a grant means.

  The cylindrical portion of the spring stopper 9 is slidably fitted to the outer periphery on the other end side in the axial direction of the valve shaft 7 so as to be capable of relative movement in the axial direction with respect to the valve shaft 7. Further, an outer peripheral screw portion that meshes with the second screw 57 of the torque limiter 16 is formed on the outer peripheral portion of the cylindrical portion of the spring stopper 9. The spring stopper 9 has a rotation prevention structure with respect to the housing 2. Specifically, as shown in FIG. 3 and FIG. 4, an uneven portion (locking portion, locked portion) that engages with the outer periphery of the flange portion of the spring stopper 9 and the inner periphery of the fourth case 24. 62 and 63 are provided. Thereby, relative movement in the rotation direction of the spring stopper 9 with respect to the housing 2 (particularly the fourth case 24 and the like) can be prevented.

  The first spring 11 is an elastic body that is formed in a coil shape from a metal material such as carbon steel having excellent elasticity and generates a repulsive force (restoring force) in the compression direction parallel to the axial direction of the valve shaft 7. is there. The first spring 11 is disposed so as to surround the outer periphery on the other side (the right side in the drawing) in the axial direction from the outermost diameter portion of the valve shaft 7, and as shown in the graph of FIG. An equal pitch coil (or an unequal pitch coil) having a repulsive force (load) change larger than the deflection amount than 12 is used. The first spring 11 is assembled in a state of being spanned between one end surface of the flange portion of the spring stopper 9 and the other end surface (first seal portion side end surface) of the valve 6. The first spring 11 applies a second load to the valve 6 to apply a load in a direction in which the second seal portion of the valve 6 is pressed against the opening peripheral edge portion (second valve seat 47) of the second fluid port 42. Means.

  The second spring 12 is an elastic body that is formed in a coil shape from a metal material such as carbon steel having excellent elasticity and generates a repulsive force (restoring force) in the compression direction parallel to the axial direction of the valve shaft 7. is there. The second spring 12 is disposed so as to surround the outer periphery on one side (the left side in the drawing) in the axial direction from the outermost diameter portion of the valve shaft 7, and as shown in the graph of FIG. An equal pitch coil (or an unequal pitch coil) having a smaller change in repulsive force (load) with respect to a change in the amount of deflection than 11 is used. The second spring 12 is assembled in a state of being spanned between one end surface (second seal portion side end surface) of the valve 6 and the other end surface (fluid flow channel wall surface) of the cover 25. Further, the second spring 12 applies a first load to the valve 6 in a direction in which the first seal portion of the valve 6 is pressed against the opening peripheral edge portion (first valve seat 46) of the first fluid port 41. Means.

  Here, in this embodiment, since the lead difference between the first and second screws 56 and 57 of the torque limiter 16 (the rotor sleeve 55) rotated by the electric motor 3 is different, the valve 6 and the spring stopper 9 are different. There is a difference in the amount of movement in the axial direction. For this reason, the valve 6, the spring stopper 9 and the two first and second springs 11 and 12 are two first and second springs that are generated in accordance with the difference in the amount of movement in the axial direction between the valve 6 and the spring stopper 9. The switching valve holding means is configured to hold the valve 6 at two positions using the difference (load difference) between the repulsive forces of the springs 11 and 12.

  Also, a pump connector 64 provided so as to protrude from the rear end surface of the motor housing (first case 21) for housing and holding the electric motor 3 to the other side in the axial direction is a terminal electrically connected to the armature coil. (External connection terminal, motor power supply terminal) 65 is held. The electric motor 3 is held in the motor housing hole of the first case 21, and the front end surface of the motor housing is fastened and fixed to the second case 22 using a fastening screw or the like. The terminal 65 of the electric motor 3 is electrically connected to a battery mounted on the vehicle via a pump drive circuit. The pump drive circuit includes a relay coil that is energized and controlled by the ECU, and a relay switch that is opened and closed by the magnetomotive force of the relay coil to connect and disconnect the battery and the terminal 65 of the electric motor 3.

  The ECU of the present embodiment includes functions such as a CPU for performing control processing and arithmetic processing, a storage device for storing various programs and data (nonvolatile memory such as EEPROM and volatile memory such as ROM / RAM), and the like. A microcomputer having a well-known structure is provided. When the ignition switch is turned on (IG / ON) and the engine starts operation, the ECU adjusts the power supplied to the electric motor 3 based on the control program stored in the memory, and the motor shaft 4 To control the rotational movement (eg, rotational speed or direction).

  The ECU outputs an output value (pressure signal) output from the pressure sensor 66, sensor signals from other various sensors, and a switch signal from a switch installed in a vehicle such as an automobile to the A / D converter. After A / D conversion, it is input to a microcomputer built in the ECU. The input circuit of the microcomputer includes a crank angle sensor for detecting the rotation angle (crank angle) of the crankshaft of the engine, and an accelerator opening for detecting the amount of depression of the driver's accelerator pedal (accelerator opening). Sensor, throttle opening sensor for detecting throttle valve opening (throttle opening), cooling water temperature sensor for detecting engine cooling water temperature, intake pressure sensor for detecting engine intake pipe negative pressure, etc. Is connected. The pressure sensor 66 is installed in the air flow path 36 formed between the third and fourth cases 23 and 24, and detects the air pressure in the air flow path 36.

[Operation of Example 1]
Next, the operation of the evaporative fuel processing apparatus of this embodiment will be briefly described with reference to FIGS. Here, FIG. 3A is a view showing a state where the valve is seated on the first valve seat, FIG. 3B is a view showing a state where the valve is moving, and FIG. It is the figure which showed the state currently seated on the 2nd valve seat.

  B) A purge operation using the intake pipe negative pressure is shown in FIG. 1 and FIG. The ECU opens the purge VSV when the intake pipe negative pressure (intake pressure) detected by the intake pressure sensor is higher than a predetermined value. At this time, the electric power is not supplied to the electric motor 3, and the load (P21) of the second spring 12 is set to be larger than the load (P11) of the first spring 11 as shown in FIG. Therefore, the valve 6 is urged to the right in the figure. As a result, the valve 6 is held at the default position where the first seal portion of the valve 6 is seated on the first valve seat 46, so that the first fluid port 41 is closed and the second fluid port 42 is opened. In this case, the second fluid port 42 and the fluid flow path 43 are in communication with each other (see FIGS. 1A and 3A).

  Accordingly, the intake pipe negative pressure reaches the atmosphere opening pipe and the inside of the housing 2, and the air flowing from the atmosphere opening hole 39 to the air flow path 37 → the second fluid port 42 → the fluid flow path 43 → the outlet port 45 → the air opening pipe. A flow is generated, and further an air flow is generated from the canister air opening hole to the purge port. When such an air flow occurs, desorption occurs in the evaporated fuel adsorbed by the adsorbent in the canister, and the evaporated fuel desorbed from the adsorbent flows out from the purge port of the canister. It is introduced (purged) into the combustion chamber of the engine via pipe → purge VSV → engine intake pipe → intake port.

  B) The purge operation using the operation of the electric air pump is shown in FIGS. 2, 3B and 4. FIG. When the intake pipe negative pressure (intake pressure) detected by the intake pressure sensor is lower than a predetermined value, the ECU opens the purge VSV and rotates the motor shaft 4 of the electric motor 3 in the forward rotation direction at a high speed. Thereby, the impeller 5 rotates by the motor torque. That is, as the electric air pump rotates, the atmosphere is sucked from the air suction port of the first case 21, and a pump positive pressure (a pressure higher than the intake pipe negative pressure and the atmospheric pressure) is generated inside the electric air pump. . At this time, since the motor shaft 4 rotates at high speed in the forward direction, centrifugal force acts on the plurality of clutch weights 52 and the centrifugal clutch 15 is turned on. When the centrifugal clutch 15 is turned on, the motor torque is transmitted to the torque limiter 16 and the first and second screws 56 and 57 rotate. Accordingly, the valve 6 is moved in the left direction in the figure by the first screw 56, and the spring stopper 9 is moved in the left direction in the figure by the second screw 57.

  At this time, since the lead of the second screw 57 is set to be larger than that of the first screw 56, the amount of movement of the spring stopper 9 to one side in the axial direction as shown in FIGS. Becomes larger than the amount of movement of the valve 6 toward one side in the axial direction, and the second spring 12 is bent and the first spring 11 is bent at the same time. The repulsive force with respect to the change in the deflection of the first spring 11 rather than the change in the repulsive force with respect to the change in the deflection of the second spring 12 due to the difference in the amount of movement of the valve 6 and the spring stopper 9 in one axial direction. The change of becomes larger.

  For this reason, the load (P12) of the first spring 11 becomes larger than the load (P22) of the second spring 12 due to the difference in spring load between the first spring 11 and the second spring 12, and the valve 6 is moved to the left in the figure. Be energized by. As a result, the valve 6 is held at the full lift position where the second seal portion of the valve 6 is seated on the second valve seat 47, so that the first fluid port 41 is opened and the second fluid port 42 is closed. In this case, the first fluid port 41 and the fluid flow path 43 are in a communication state (see FIGS. 2 and 4).

  When the first fluid port 41 and the fluid flow path 43 are in communication with each other (see FIGS. 2 and 4), an overload torque acts on the torque limiter 16 and the motion direction conversion mechanism. 53 slides on the friction surface of the friction plate 54. That is, the torque limiter 16 is activated (ON). At this time, the centrifugal force acting on the plurality of clutch weights 52 may be reduced by rotating the motor shaft 4 of the electric motor 3 at a low speed in the forward rotation direction, and the centrifugal clutch 15 may be turned off.

  As described above, power is supplied to the electric motor 3 to drive the valve 6 from the default position to the full lift position, and the valve 6 is held at the full lift position by the load of the first spring 11 and the impeller 5 of the electric air pump. By rotating the, the forced purge operation by the electric air pump is started. Here, when the impeller 5 is rotationally driven by the rotational movement of the motor shaft 4 of the electric motor 3, the air (air) inside the vortex chamber 31 of the pump housing is compressed by the movement of the plurality of blade portions. At this time, since a negative pressure is generated at the pump suction port of the pump housing, the air filtered by the filter 33 disposed in the air duct 32 is guided to the pump suction port via the air duct 32 and the pump of the pump housing. Since high pressure is generated at the discharge port 34, air pressurized inside the vortex chamber 31 is discharged from the pump discharge port 34.

  Therefore, the air discharged from the pump discharge port 34 of the pump housing has the valve 6 held at the full lift position and the first fluid port 41 is opened, so that the first fluid port 41 → It is sent to the atmosphere open piping via the fluid flow path 43 → the outlet port 45. As a result, an air flow from the atmosphere opening hole of the canister toward the purge port is generated. When such an air flow occurs, desorption occurs in the evaporated fuel adsorbed by the adsorbent in the canister, and the evaporated fuel desorbed from the adsorbent flows out from the purge port of the canister. It is introduced (purged) into the combustion chamber of the engine via pipe → purge VSV → engine intake pipe → intake port.

  C) Next, a method for performing a leak check in the closed space of the fuel vapor processing apparatus is shown in FIGS. When the ECU performs a leak check in the closed space of the evaporated fuel processing apparatus, the ECU first closes the purge VSV. 1 and 3A, the motor shaft 4 of the electric motor 3 is rotated in the reverse direction at a low rotational speed at which the centrifugal clutch 15 does not operate. Here, when the impeller 5 is rotationally driven by the rotational movement of the motor shaft 4 of the electric motor 3, negative pressure is generated at the pump discharge port 34 of the pump housing. Since it is led to the pump discharge port 34 via the passage 37-> the second fluid port 42-> the fluid flow path 43-> the reference orifice 49-> the air flow path 36 and a high pressure is generated at the pump suction port of the pump housing, The air pressurized inside 31 is discharged from the pump suction port.

  Next, in this state, the ECU detects the pressure in the air flow path 36 using the pressure sensor 66, and detects the reference pressure (Pref) corresponding to the reference orifice 49 having a throttle diameter of, for example, φ0.45 mm ( The reference pressure (Pref) is stored in the memory. Next, the ECU supplies electric power to the electric motor 3 to rotate the motor shaft 4 of the electric motor 3 at high speed in the normal rotation direction. As a result, the valve 6 is driven from the default position to the full lift position, and the valve 6 is held at the full lift position by the load of the first spring 11 (see FIGS. 2 and 4). 2 and 4, the motor shaft 4 of the electric motor 3 is rotated in the reverse rotation direction at a low rotation speed at which the centrifugal clutch 15 does not operate.

  Next, in this state, the ECU detects the pressure (P) in the air flow path 36 using the pressure sensor 66, and the reference pressure (Pref) stored in the memory and the pressure (P) in the air flow path 36 are detected. ) To determine the leak. Here, the ECU determines that there is no leakage when P <Pref, and that there is leakage when P> Pref. If it is determined that there is a leak, the warning lamp is turned on to alert the driver. This completes the leak check in the closed space of the evaporated fuel processing apparatus. Here, the closed space of the evaporative fuel processing device means a closed space from the fuel tank to the purge VSV through the air flow channel pipe, the canister and the air flow channel pipe when the purge VSV is closed, and the electric air pump unit 1. And a closed space from the air opening pipe, the canister and the air flow path pipe to the purge VSV, and a space upstream of the purge VSV.

[Effect of Example 1]
Here, a repulsive force (also referred to as a spring load, a spring constant, or a spring force) is applied to one valve (valve element) 6 of the two-position three-way switching valve of the present embodiment at two positions of a default position and a full lift position. The graph of FIG. 5 shows the relationship between the deflection and load of the first and second springs 11 and 12 having the switching valve holding function to be used and held.

  When the valve 6 is in the default position (when in the state shown in FIGS. 1 and 3A), the deflection and load of the first spring 11 are δ11 and P11, and the second spring 12 The deflection and load are δ21 and P21 (see the graph of FIG. 5). As a result, in the state of FIGS. 1 and 3A, the second spring 12 is caused by the load difference (P21-P11) between the load (P21) of the second spring 12 and the load (P11) of the first spring 11. The spring load becomes larger than the spring load of the first spring 11. Therefore, the valve 6 is urged rightward in the drawing by the urging force (repulsive force) of the second spring 12. As a result, the first seal portion of the valve 6 is pressed against the opening peripheral edge portion (first valve seat 46) of the first fluid port 41, so that the valve 6 is held at the default position. That is, the fully closed state of the first fluid port 41 and the fully open state of the second fluid port 42 are maintained. In this case, as described above, the second fluid port 42 and the fluid flow path 43 are in communication with each other.

  Next, when electric power is supplied to the electric motor 3 and the motor shaft 4 of the electric motor 3 is rotated at high speed in the forward direction, the motor torque is transmitted in the order of the centrifugal clutch 15 and the torque limiter 16, and the valve 6 is driven by the first screw 56. Moves to the left in the figure, and the spring stopper 9 moves to the left in the figure by the second screw 57. At this time, since the lead of the second screw 57 is set to be larger than that of the first screw 56, the amount of movement of the spring stopper 9 in the left direction of the drawing as shown in FIG. More than the amount of movement in the left direction, the gap between the valve 6 and the cover 25 is reduced and the second spring 12 is bent. At the same time, the gap between the flange portion of the spring stopper 9 and the valve 6 is increased. The gap size is reduced and the first spring 11 is also bent.

  When the second seat portion of the valve 6 is seated on the second valve seat 47 of the cover 25, the state shown in FIGS. When the valve 6 is in the full lift position (in the state shown in FIGS. 2 and 4), the deflection and load of the first spring 11 are δ12 and P12, and the deflection and load of the second spring 12 are. Is δ22 and P22 (see the graph of FIG. 5). As a result, in the state of FIGS. 2 and 4, the spring load of the first spring 11 is caused by the load difference (P12−P22) between the load of the first spring 11 (P12) and the load of the second spring 12 (P22). Becomes larger than the spring load of the second spring 12. Therefore, the valve 6 is urged in the left direction in the figure by the urging force (repulsive force) of the first spring 11. As a result, the second seal portion of the valve 6 is pressed against the opening peripheral edge (second valve seat 47) of the second fluid port 42, so that the valve 6 is held at the full lift position. That is, the fully opened state of the first fluid port 41 and the fully closed state of the second fluid port 42 are maintained. In this case, as described above, the first fluid port 41 and the fluid flow path 43 are in communication with each other.

  Therefore, the valve 6 can be reliably held at the default position and the full lift position by the load difference between the two first and second springs 11 and 12 without continuing to supply power to the electric motor 3. Power consumption can be reduced. Further, since the valve 6 is held using the elastic deformation force (repulsive force) of the two first and second springs 11 and 12 at the two positions of the default position and the full lift position, the vibration source (engine) The vibration propagated from the housing 2 to the housing 2 and further propagated from the housing 2 to the valve 6 or the vibration of the valve 6 can be damped by the two first and second springs 11 and 12. Thereby, the vibration resistance of the valve 6 can be improved.

  Further, in the electric air pump unit 1 in which the electric three-way valve is integrated with the electric air pump, the valve body of the two-position three-way switching valve driven to the two positions by the motor torque of the motor shaft 4 of the electric motor 3 is used as one valve 6. In addition, the valve shaft 7 is formed integrally with the valve 6 and the valve 6 and the valve shaft 7 are formed as an integral part, so that the valve 6 and the valve shaft 7 are kept airtight. No seal parts are required. As a result, the number of components and the number of assembling steps of the components constituting the electric air pump unit 1 can be reduced, and the size of the electric air pump unit 1 can be reduced. As a result, the electric air pump unit 1 can be made compact and the cost can be reduced.

  In particular, it is possible to reduce the number of parts and the number of assembling steps of the components constituting the electric three-way valve, and it is possible to reduce the size of the electric three-way valve. As a result, the electric three-way valve can be made compact and the cost can be reduced. Further, since the valve shaft 7 is formed integrally with the valve 6 and the valve 6 and the valve shaft 7 are formed as an integral part, the valve 6 does not slide on the outer periphery of the valve shaft 7. Occurrence of a sealing failure can be prevented. As a result, the operating durability life of the electric air pump unit 1 can be extended, and the durability and reliability of the electric air pump unit 1 can be improved. In particular, the operating durability life of the electric three-way valve can be extended, and the durability and reliability of the electric three-way valve can be improved.

  Further, in the electric air pump unit 1 of the present embodiment, the purge operation and the leak check operation can be performed by the single impeller 5, so that the size of the evaporated fuel processing apparatus as a whole can be reduced, and the vehicle such as an automobile Can be installed in the engine room. In addition, by maintaining the valve 6 at the default position during the leak check operation, the canister air opening hole can be closed, so that the canister opening / closing valve necessary for the conventional evaporative fuel processing apparatus can be eliminated, and the parts It is possible to reduce the number of points and assembly man-hours, and to reduce the cost of the entire evaporated fuel processing apparatus.

  In addition, since the electric motor 3, the impeller 5, the centrifugal clutch 15, the torque limiter 16, the motion direction conversion mechanism (first and second screws 56 and 57) and the valve 6 are integrated, power supply to the electric motor 3 is performed. , That is, the opening operation of the valve 6 can be started in a short time after the impeller 5 starts rotating. Thereby, since the response time from supplying electric power to the electric motor 3 until the valve 6 moves to the second position can be shortened, the control responsiveness of the valve 6 can be improved. Further, since the electric motor 3, the impeller 5, the centrifugal clutch 15, the torque limiter 16, the movement direction changing mechanism (first and second screws 56 and 57) and the valve 6 are integrated, the weight of the electric air pump unit 1 as a whole is increased. It is possible to reduce the number of parts and the number of assembling steps as well as improving the mounting property on a vehicle such as an automobile.

  6 and 7 show a second embodiment of the present invention, and FIGS. 6 and 7 show the entire structure of the electric air pump unit.

  The electric air pump unit 1 according to the present embodiment is incorporated in the evaporated fuel processing apparatus as in the first embodiment. The electric air pump unit 1 has an electric air pump and an electric three-way valve integrated with each other, and has five cases (first to fourth cases 21 to 24 and a cover 25 from the right side in FIG. 6) in which components are incorporated. The first to fourth cases 21 to 24 and the cover 25 are coupled with fastening screws, clips, locking pieces, and the like. The electric air pump is a double-blade type vortex pump (vortex pump) as in the first embodiment, and includes a housing 2, an electric motor 3, an impeller 5, and the like. The electric three-way valve includes a housing 2, a valve 6, a valve shaft 7, and a holding spring 13 having a switching valve holding function for holding the valve 6 at two positions of a default position and a full lift position.

  A plurality of screws 59 are press-fitted and fixed to the inner peripheral portion of the rotor sleeve 55 of the torque limiter 16 of this embodiment. An inner peripheral screw portion (female screw portion) formed integrally with the torque limiter 16 is integrally formed on the inner peripheral portion of these screws 59. Note that at least one screw 59 is sufficient. Further, a screw (female screw portion) may be integrally formed on the inner peripheral portion of the rotor sleeve 55 of the torque limiter 16.

  In addition, a valve shaft 7 extending in the axial direction is integrally formed with the valve 6, and an outer peripheral screw meshing with the screw 59 of the torque limiter 16 is provided at the outer peripheral portion on the other end side in the axial direction of the valve shaft 7. A portion (male screw portion) is formed. Further, as shown in FIGS. 6 and 7, first and second recesses that mesh with the holding spring 13 at the two positions of the default position and the full lift position are formed on the outer peripheral portion on one end side in the axial direction of the valve shaft 7. (Groove parts) 71 and 72 are formed at regular intervals in the axial direction. The first and second recesses 71 and 72 are provided so as to make one round continuously in the circumferential direction of the valve shaft 7.

  The holding spring 13 is formed in a cylindrical shape by a metal material such as carbon steel having excellent elasticity, and serves as an elastic body that generates a repulsive force (restoring force) in the compression direction parallel to the radial direction of the valve shaft 7. A plurality of bent portions 73 are provided. As shown in FIGS. 6 and 7, these bent portions 73 are provided at three locations at regular intervals in the circumferential direction of the cylindrical portion of the holding spring 13. The cylindrical portion of the holding spring 13 is disposed so as to surround the outer periphery on one side (left side in the drawing) in the axial direction with respect to the outermost diameter portion of the valve shaft 7, and protrudes from the outer wall surface of the cover 25. The air passage tube 38 is press-fitted and fixed to the inner periphery.

  As shown in FIG. 6, in the holding spring 13, each convex portion of the plurality of bent portions 73 (a substantially square-shaped portion having the smallest inner diameter among the bent portions 73) is the first of the valve shaft 7. When engaged with the recess 71, the valve 6 and the valve shaft 7 are in the first position (default position) where the first seal portion of the valve 6 is seated on the opening peripheral edge portion (first valve seat 46) of the first fluid port 41. Is a first switching valve holding means for elastically holding the valve. In addition, as shown in FIG. 7, the holding spring 13 has a second seal portion of the valve 6 that is second when the convex portions of the plurality of bent portions 73 are engaged with the second concave portions 72 of the valve shaft 7. Second switching valve holding means for elastically holding the valve 6 and the valve shaft 7 at a second position (full lift position) where the fluid port 42 is seated on the peripheral edge of the opening (second valve seat 47).

  As described above, also in the electric air pump unit 1 in which the electric three-way valve is integrated with the electric air pump according to this embodiment, the two-position three-way switching valve is driven to two positions by the motor torque of the motor shaft 4 of the electric motor 3. The valve body is composed of a single valve 6, and the valve shaft 7 is formed integrally with the valve 6 so that the valve 6 and the valve shaft 7 are an integral part. The effect can be achieved.

[Modification]
In this embodiment, the impeller 5 is directly assembled to the motor shaft 4 of the electric motor 3, but the motor shaft 4 and the rotation shaft of the impeller 5 may be configured separately. A reduction mechanism that reduces the motor rotation speed to a predetermined reduction ratio may be installed between the motor shaft 4 and the rotation shaft of the impeller 5. Further, a reduction mechanism that reduces the motor rotation speed to a predetermined reduction ratio may be installed between the rotation shaft of the impeller 5 and the centrifugal clutch 15 or the torque limiter 16 or the movement direction conversion mechanism.

  In the present embodiment, a valve (a valve body of a two-position three-way switching valve) 6 is formed integrally with the motor shaft 4 of the electric motor 3 through the impeller 5, the centrifugal clutch 15, the torque limiter 16, and the movement direction conversion mechanism. However, one or more or all of the impeller 5, the centrifugal clutch 15, and the torque limiter 16 are abolished, and the electric motor 3 (motor shaft 4) rotates. A valve shaft (integrated with a valve (valve body of a two-position / three-way switching valve) 6) is formed on the motor shaft 4 of the electric motor 3 through a motion direction conversion mechanism that converts the motion into a linear motion (of the valve 6). (Drive shaft) 7 may be assembled. A reduction mechanism that reduces the motor rotation speed to a predetermined reduction ratio may be installed between the motor shaft 4 and the valve shaft 7 of the electric motor 3.

  In the present embodiment, the example in which the switching valve control device of the present invention is applied to the electric air pump unit 1 in which the double-blade type electric air pump and the electric three-way valve are integrated has been described. Alternatively, an electric air pump unit in which a single-blade type electric air pump and an electric three-way valve are integrated may be used. Further, the switching valve control device of the present invention may be used for an electric three-way valve (or an electric valve opening / closing device) provided with a two-position switching valve such as a two-position two-way switching valve or a two-position three-way switching valve. Further, although evaporative fuel or air such as the atmosphere is used as the fluid, secondary fluid or gas such as gas phase refrigerant, liquid such as water, fuel, oil or liquid phase refrigerant may be used as the fluid.

(A) is sectional drawing which showed the whole structure of the electric air pump unit, (b) is AA sectional drawing of (a) (Example 1). It is sectional drawing which showed the whole structure of the electric air pump unit (Example 1). (A) is the enlarged view which showed the state in which the valve | bulb was seated on the 1st valve seat, (b) is the enlarged view which showed the state in which the valve is moving (Example 1). (Example 1) which was the enlarged view which showed the state in which the valve | bulb was seated on the 2nd valve seat. It is the graph which showed the relationship between the load of a 1st, 2nd spring, and bending (Example 1). (A) is sectional drawing which showed the whole structure of the electric air pump unit, (b) is BB sectional drawing of (a) (Example 2). (Example 2) which is sectional drawing which showed the whole structure of the electric air pump unit. It is sectional drawing which showed the electric three-way valve (prior art).

Explanation of symbols

1 Electric air pump unit (switching valve control device)
2 Housing 3 Electric motor 4 Motor shaft (output shaft) of electric motor
5 Impeller (impeller)
6 2-position 3-way valve (valve)
7 Valve shaft (drive shaft) of 2-position 3-way switching valve
9 Spring stopper (second load applying means)
11 First spring (elastic body, second load applying means)
12 Second spring (elastic body, first load applying means)
13 Holding spring (elastic body)
14 Actuator 15 Centrifugal clutch (actuator)
16 Torque limiter (actuator)
41 First fluid port (first fluid passage port)
42 Second fluid port (second fluid passage port)
43 Fluid passage 46 First valve seat (opening peripheral edge of first fluid port, first valve seat)
47 2nd valve seat (opening peripheral part of 2nd fluid port, 2nd valve seat part)
56 Torque limiter first screw (motion direction conversion mechanism)
57 Torque limiter second screw (motion direction conversion mechanism)
59 Torque limiter screw (motion direction conversion mechanism)

Claims (5)

(A) a housing in which two first and second fluid passage ports and at least one fluid flow channel selectively communicating with the first and second fluid passage ports are formed;
(B) a two-position switching valve that switches a communication state between the first fluid passage port and the fluid channel and a communication state between the second fluid passage port and the fluid channel at two positions;
(C) having a motor that receives a supply of electric power and generates a driving force;
A switching valve control device comprising an actuator for driving the two-position switching valve to two positions using the driving force of the motor;
The two-position switching valve has one valve body that selectively opens and closes the two first and second fluid passage ports, and a drive shaft connected to the actuator,
The switching valve control device, wherein the drive shaft is formed integrally with the valve body. In the switching valve control device according to claim 1,
The one valve body is seated on and separated from an opening peripheral edge of the first fluid passage opening to close and open the first fluid passage opening, and the second fluid passage opening. A switching valve control device comprising: a second seal portion that seats and separates from the opening peripheral edge portion to close and open the second fluid passage port. In the switching valve control device according to claim 2,
A first load applying means for applying a first load to the two-position switching valve in a direction in which the first seal portion of the one valve body is pressed against the opening peripheral edge of the first fluid passage port;
A second load applying means for applying a second load to the two-position switching valve in a direction in which the second seal portion of the one valve body is pressed against the opening peripheral edge of the second fluid passage port;
When the two-position switching valve is in a first position for closing the first fluid passage port, the first load is set to be larger than the second load,
The switching valve control device, wherein the second load is set to be larger than the first load when the two-position switching valve is in a second position where the second fluid passage port is closed. In the switching valve control device according to any one of claims 1 to 3,
It has an elastic body that generates a repulsive force in the compression direction,
A switching valve control device comprising switching valve holding means for holding the two-position switching valve at two positions using the repulsive force of the elastic body. In the switching valve control device according to any one of claims 1 to 4,
It is driven by the motor and includes an impeller having a plurality of blade portions formed in the circumferential direction,
The two-position switching valve and the impeller are installed coaxially with the output shaft of the motor.

Images