JP6009974B2 - Fluid control valve - Google Patents

Description

  The present invention relates to a fluid control valve in which a bearing hole for receiving a bearing such as a ball bearing or a metal bush is opened at a wall surface of a flow path.

[Conventional technology]
Conventionally, as an example of a fluid control valve that controls exhaust gas discharged from an internal combustion engine (engine), an EGR control valve that controls the flow rate of EGR gas that recirculates from an exhaust pipe to an intake pipe through an exhaust recirculation pipe is known. is there.

  As shown in FIG. 12, the EGR control valve has a valve 103 that opens and closes a flow passage hole 102 formed in the housing 101, and a shaft 104 that is connected to the valve 103 so as to be integrally rotatable. An actuator for rotating the valve 103 to open and close the valve 103, a return spring 105 for biasing the valve 103 in the valve closing direction, bearings (metal bush 106, ball bearing 107) for rotatably supporting the shaft 104, and a housing There are provided annular oil seals 108 and 109 for sealing (sealing) between the inner periphery of 101 and the outer periphery of the shaft 104 (see, for example, Patent Document 1).

  The housing 101 is formed with a bearing hole 110 extending in the rotation axis direction of the valve 103 and the shaft 104. One end side (valve side) of the bearing hole 110 in the axial direction is opened at the wall surface of the flow path hole 102. The bearing hole 110 is the smallest of the clearance between the metal bush 106, the ball bearing 107 and the bearing housing hole 111 for housing the oil seals 108 and 109, and the inner periphery of the housing 101 and the outer periphery of the shaft 104 ( Narrow) minimum clearance 112 is provided.

By the way, a sliding hole is formed through the metal bush 106 so as to pivotally support the outer peripheral surface (sliding surface) of the shaft 104 so as to be slidable in the rotational direction. Further, the outer ring portion of the metal bush 106 is press-fitted and fixed to a press-fit hole provided in the middle of the bearing hole 110.
Further, since the metal bush 106 has a larger radial clearance (sliding clearance) with respect to the shaft 104 than the ball bearing 107, in the conventional design, the metal bush 106 is separated from the ball bearing 107 by a predetermined axial distance. The shaft 104 is configured to be prevented from being shaken by being spaced apart.

However, in the conventional EGR control valve, the metal bush 106 is disposed on the opening side of the bearing hole 110 or on the flow path hole side relative to the oil seal 109, and the bearing hole 110 is opened on the wall surface of the flow path hole 102. Since it is in communication with the flow path hole 102, there is a possibility that foreign matter contained in the EGR gas flowing through the flow path hole 102 may enter the bearing hole 110.
If foreign matter enters the bearing hole 110, the foreign matter may be caught in the sliding clearance formed between the sliding surface of the shaft 104 and the wall surface of the sliding hole of the metal bush 106. If foreign matter is caught in the sliding clearance, the sliding resistance of the shaft 104 with respect to the metal bush 106 increases. As a result, the rotational movement of the shaft 104 is hindered, and the valve 103 and the shaft 104 may become inoperable or malfunctioning.
Therefore, in the EGR control valve described in Patent Document 1, the above problem is solved by installing the oil seal 108 on the flow path hole side of the metal bush 106.

[Conventional technical problems]
By the way, a large amount of water (water vapor) is contained in the EGR gas that recirculates from the exhaust pipe to the intake pipe via the flow path hole 102 of the EGR control valve. For this reason, when the EGR cooler for cooling the EGR gas is provided upstream or downstream of the EGR control valve, the EGR gas is cooled by the EGR cooler, and moisture in the EGR gas is condensed to generate condensed water. . Further, when the EGR gas is mixed with the outside air sucked into the engine, that is, the intake air, condensed water is generated due to a temperature difference from the intake air.
At this time, the condensed water flowing into the housing 101 of the EGR control valve stays in the vicinity of the valve 103 of the EGR control valve. The condensed water staying in the vicinity of the valve 103 may enter the bearing hole 110 through the shaft 104.

Here, in a fluid control valve such as an EGR control valve, when the shaft 104 is rotationally driven by an actuator and the rotation angle of the valve 103 is within a predetermined angle range, the pressure gradient distribution (pressure difference) in the circumferential direction of the shaft 104 There exists a structure in which this occurs (see FIG. 12).
In the case of such a structure, when a large pressure difference occurs at the pressure difference generation site in the circumferential direction of the shaft 104, the condensed water flows from the higher pressure to the lower pressure, or the condensed water flows to the negative pressure side where the pressure is lower. Since it is sucked in, condensed water is sucked into the bearing hole 110 and may enter the bearing side such as the metal bush 106.
At this time, if the sealing performance of the oil seal 108 installed on the flow path side with respect to the metal bush 106 is deteriorated for some reason, the condensed water sucked into the bearing hole 110 is converted into the sliding surface of the shaft 104. And the seal lip of the oil seal 108 and reach the metal bush 106, and the metal bush 106 may be rusted. When the rust is generated in the metal bush 106 in this manner, the performance as a bearing is deteriorated, so that the shaft 104 may be inoperable or malfunction.

Therefore, for the purpose of inserting the shaft and preventing the intrusion of condensed water into the bearing hole that accommodates the bearing, it is made liquid-tight (airtight) by a PTFE seal that is excellent in water repellency as an oil (dust) seal. An EGR control valve that is hermetically sealed has been proposed (see, for example, Patent Document 2).
However, the PTFE seal is very expensive, and when the PTFE seal is assembled to the bearing hole, the PTFE seal alone cannot be assembled to the bearing hole, and multiple mounting brackets such as metal holders and attachments are required. Therefore, there is a problem that the number of assembling steps and the number of parts for the bearing hole increase.
Therefore, there exists a problem that the manufacturing cost of an EGR control valve becomes high.

JP 2012-002157 A JP 2010-065729 A

  An object of the present invention is to provide a fluid control valve that can prevent water from entering from the opening side of the bearing hole to the back side of the bearing hole or the bearing side without employing an expensive PTFE seal.

According to the invention described in claim 1, the sheet Yafuto for supporting the valve, provided in the opening side of the bearing hole than the bearing, the flooding from the opening side of the bearing hole to the far side or the bearing side of the bearing hole It has a flood prevention means to prevent it. The inundation preventing means communicates both sides of the shaft in the diametrical direction, and is provided with a communication passage for leveling (equalizing pressure) the pressure difference in the circumferential direction of the shaft at the pressure difference generation site .
This eliminates (or reduces) the pressure difference in the circumferential direction of the shaft at the pressure difference generation site. For this reason, since condensed water does not enter the bearing hole from the flow path of the housing, the expensive PTFE seal can be eliminated. Thereby , even if it does not employ | adopt an expensive PTFE seal | sticker, the water immersion from the opening side of a bearing hole to the back | inner side of a bearing hole or a bearing side can be prevented .
Also, seal between the outer periphery of the inner periphery and the shaft ball bearings, metal bush bearing for slidably supporting the shaft in the rotational direction (journalled) and in contact with the outer periphery of the shaft of the housing (sealing Provide a communication path with a predetermined axial distance between the bearing and the oil seal on the opening side of the bearing hole or on the flow path side of the contact (liquid-tight, air-tight) seal such as an oil seal Is desirable.

It is sectional drawing which showed the whole structure of the EGR control valve (Example 1). It is sectional drawing which showed the whole structure of the EGR control valve (Example 1). (Example 1) which is the top view which showed the actuator. It is sectional drawing which showed the main structures of the EGR control valve (Example 1). It is sectional drawing which showed the main structures of the EGR control valve (Example 1). It is sectional drawing which showed the main structures of the EGR control valve (Example 1). It is sectional drawing which showed the main structures of the EGR control valve ( reference example 1 ). It is sectional drawing which showed the main structures of the EGR control valve ( reference example 2 ). It is sectional drawing which showed the main structures of the EGR control valve ( reference example 3 ). It is sectional drawing which showed the main structures of the EGR control valve ( reference example 3 ). It is sectional drawing which showed the main structures of the EGR control valve ( reference example 3 ). It is sectional drawing which showed the whole structure of the EGR control valve (conventional technique).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Configuration of Example 1]
1 to 6 show an EGR control valve (Embodiment 1) to which the fluid control valve of the present invention is applied.

An exhaust system for an internal combustion engine according to the present embodiment is an exhaust circulation device that recirculates (refluxs) exhaust gas (hereinafter referred to as EGR gas) from an exhaust pipe of an internal combustion engine (engine) mounted on a vehicle such as an automobile to an intake pipe. (Hereinafter referred to as EGR system).
The EGR system includes an EGR gas pipe that recirculates EGR gas from an exhaust passage in the exhaust manifold or the exhaust pipe to an intake passage in the intake manifold or the intake pipe. In the EGR gas pipe, an EGR gas flow path is formed through which EGR gas flows from the exhaust passage to the intake passage.

The EGR gas pipe has an EGR cooler that cools the EGR gas that flows through the EGR gas flow path by exchanging heat with cooling water, and the flow rate of the EGR gas that passes through the EGR cooler or bypasses the EGR cooler. An EGR gas flow rate control valve (hereinafter referred to as an EGR control valve) that is controlled by an opening / closing operation is installed.
Here, the EGR system is used as an EGR valve control device (an EGR control device for an internal combustion engine) that controls the opening and closing of the valve 1 that is the valve body of the EGR control valve based on the operating state of the engine. The EGR valve control device includes an engine control unit (electronic control device: hereinafter referred to as ECU) that controls an actuator of the EGR control valve in conjunction with another system.

The EGR control valve includes a housing coupled in the middle of the EGR gas pipe, a metal valve 1 rotatably accommodated in the housing, and a seal ring groove (annular groove) formed on the outer peripheral end surface of the valve 1. ) 2, a metal seal ring 3 fitted in 2, a housing 4 that accommodates the valve 1 in an openable and closable manner, and an output shaft 5 that is rotatably connected to the valve 1. And an actuator for driving the valve 1.
The EGR control valve employs an electric actuator including a motor M, a speed reduction mechanism, and a return spring 6 as an actuator that rotationally drives the output shaft 5 to open and close the valve 1.

Here, the housing 4 accommodates the valve 1 in an openable and closable manner, and has a cylindrical valve body 8 that fits and holds the cylindrical nozzle 7, a gear case 9 that houses the speed reduction mechanism, the return spring 6, and the like, A motor case 10 that houses the motor M is integrally formed.
The speed reduction mechanism includes an output shaft (output gear shaft, valve shaft) 5 connected to the valve 1 so as to be integrally rotatable, and an intermediate gear shaft arranged in parallel to a motor shaft (motor shaft: hereinafter input shaft) 11 of the motor M. (Intermediate shaft: hereinafter referred to as an intermediate shaft) 12 and three first to third reduction gears that reduce the rotation of the input shaft 11 by two steps and transmit it to the output shaft 5.

The three first to third reduction gears are configured by a metal pinion gear 13, a synthetic resin or metal intermediate gear 14, a synthetic resin or metal output gear 15, and the like.
The three first to third reduction gears are rotatable in a gear housing space 17 formed between the gear case 9 of the housing 4 and a synthetic resin sensor cover 16 that is formed separately from the housing 4. Is housed in. The sensor cover 16 is provided with an EGR opening sensor 18 and an external connection connector 19 that electrically connects the motor M and an external circuit (ECU, battery, etc.).

The EGR control valve exhausts through the EGR gas channel by changing the opening area of the EGR gas channel (channel holes 21 to 23) formed in the housing 4 continuously or stepwise. This is an exhaust gas flow rate control valve (exhaust throttle valve) that variably controls the flow rate (EGR gas amount) of EGR gas recirculated (refluxed) from the passage to the intake passage.
Further, the EGR control valve includes a support mechanism (a bearing mechanism for the output shaft 5) that rotatably supports the output shaft 5 with respect to the housing 4. This bearing mechanism is constituted by an oil seal 24, double ball bearings 25, 26, and the like.

The valve 1 is rotated within the operable range from the fully closed position to the fully open position, thereby changing the opening area of the flow path holes 21 to 23 to adjust the EGR rate.
The valve 1 passes through the central portion of the valve 1 inside the housing 4 and is inclined by a predetermined inclination angle with respect to the axial direction of the output shaft 5 (rotational axis direction). A plate (disk) -shaped butterfly valve is fixed to the distal end side by welding or the like and extends radially about the central axis of the central portion of the valve 1.

An annular seal ring groove 2 is formed on the outer peripheral end surface of the valve 1. That is, the seal ring groove 2 is provided around the entire outer periphery (entire periphery) of the outer peripheral end surface of the valve 1.
The seal ring 3 is formed in a C shape from a heat-resistant metal. The seal ring 3 has an outer peripheral end projecting radially outward from the outer peripheral end surface of the valve 1 and an inner peripheral end in the seal ring groove 2 in the radial direction, axial direction and circumferential direction. The seal ring groove 2 is fitted and held so that it can move in the direction.

  Positioned on one side (one end face) of the valve 1 in the plate thickness direction, for example, downstream (or upstream) in the EGR gas flow direction when the valve 1 is fully closed (when the passage holes 21 to 23 are fully closed). On the downstream end surface (or upstream end surface), a fitting groove 27 that is a coupling portion (welding fixing portion) with the output shaft 5 is formed. The fitting groove 27 opens at one end surface of the valve 1 and extends from the opening side to the back side by being inclined with a predetermined inclination angle with respect to the surface direction of the one end surface of the valve 1 ( A mounting portion for attaching the output shaft 5 by press fitting or the like. Further, a first protrusion (described later) of the output shaft 5 is fitted in the fitting groove 27.

  The actuator includes a return spring 6 that urges the valve 1 in a valve closing (fully closed) direction, a motor M that generates rotational power (torque) that drives the valve 1 when supplied with electric power, and an input of the motor M. A reduction mechanism (pinion gear 13, intermediate gear 14, output gear 15) that reduces the rotation of shaft 11 by two steps and transmits it to output shaft 5, and a rotation angle detection device that detects the rotation angles of valve 1 and output shaft 5. I have.

The return spring 6 is a coil spring that generates a biasing force that biases the valve 1 in the valve closing (fully closed) direction with respect to the output gear 15. The return spring 6 includes a coil portion formed by winding a metal wire in a spiral shape. The coil portion is wound so as to surround the cylindrical portion (bearing holder) 31 of the gear case 9 and the intermediate cylindrical portion 32 of the output gear 15 in a spiral manner. The cylindrical portion 31 and the intermediate cylindrical portion 32 have a function as a spring inner peripheral guide that guides (holds) the coil inner diameter of the coil portion of the return spring 6.
One end side in the winding direction of the coil portion of the return spring 6 is locked or held by a fixing hook (not shown) of the gear case 9. Further, the other end side of the coil portion of the return spring 6 in the winding direction is locked or held by a movable hook (not shown) of the output gear 15.

The motor M is housed and held in a motor housing recess of a bottomed cylindrical motor case 10 formed integrally with the housing 4 and the gear case 9. The motor M is electrically connected to a battery mounted on a vehicle such as an automobile via a motor drive circuit electronically controlled by the ECU.
The ECU includes a CPU that performs control processing and arithmetic processing, a storage device (memory such as ROM and RAM) that stores control programs and various control data (such as maps), an input circuit (input unit), and an output circuit (output unit). A microcomputer having a well-known structure configured to include functions such as a power supply circuit and a timer is provided.

The ECU is configured to energize and control the actuator (motor M) of the EGR control valve based on a control program stored in the memory of the microcomputer when the ignition switch is turned on (IG / ON).
The ECU includes various sensors such as an EGR opening sensor 18, an air flow meter, a crank angle sensor, an accelerator opening sensor, a throttle opening sensor, an intake air temperature sensor, a cooling water temperature sensor, and an exhaust gas sensor (air-fuel ratio sensor, oxygen concentration sensor). The sensor output signal from the A / D converter is A / D converted by the A / D conversion circuit and then input to the microcomputer.

  The rotation angle detection device measures a rotation angle of a cylindrical magnetic circuit portion provided integrally with a cylindrical boss (inner diameter side cylindrical portion) 35 of the output gear 15 and the EGR control valve. An EGR opening degree sensor 18 for detecting the valve opening degree is provided, and a change in relative rotation angle between the magnetic circuit unit and the EGR opening degree sensor 18 is detected by a magnetic change given to the EGR opening degree sensor 18 from the magnetic circuit unit.

The magnetic circuit portion is insert-molded in the cylindrical boss 35 of the output gear 15. The magnetic circuit section includes a pair of partial cylindrical yokes 36 divided in the diameter direction of the cylindrical boss 35, and a pair of magnets arranged so that the magnetic poles are directed in the same direction to the divided parts (opposing parts) of the yoke 36. Permanent magnet) 37.
The EGR opening degree sensor 18 is installed in the sensor mounting portion of the sensor cover 16. The EGR opening degree sensor 18 is mainly composed of a Hall IC that outputs an analog voltage signal corresponding to a magnetic flux density interlinking the magnetic sensing surface of the semiconductor Hall element to the ECU. Instead of the Hall IC, a non-contact type magnetic detection element such as a Hall element alone or a magnetoresistive element may be used.

The speed reduction mechanism includes an output shaft 5 connected to the valve 1 so as to be integrally rotatable, an intermediate shaft 12 arranged in parallel with the output shaft 5 and the input shaft 11, a pinion gear (motor gear) 13 fixed to the input shaft 11, An intermediate gear (intermediate reduction gear) 14 that meshes with and rotates with the pinion gear 13 and an output gear 15 that meshes with and rotates with the intermediate gear 14 are provided.
The three reduction gears are housed rotatably in an internal space (gear housing space 17) formed between the gear housing recess of the gear case 9 and the gear housing recess of the sensor cover 16.

The output shaft 5 is accommodated in the housing 4 and the gear case 9 so as to be rotatable or slidable. The output shaft 5 includes first and second protruding shaft portions 41 and 42 on both sides in the rotation axis direction.
Between the first and second projecting shaft portions 41, 42, there are axial portions (a large-diameter shaft portion 43, a circumferential groove portion 44, a large-diameter shaft portion 45) disposed in a bearing hole (described later) of the housing 4. Is provided.
Details of the output shaft 5 of this embodiment will be described later.

One end of the intermediate shaft 12 is fixed in the axial groove of the gear case 9 by press fitting or the like. The other end side of the intermediate shaft 12 is inserted into an axial groove in the sensor cover 16.
The pinion gear 13 is fixed to the outer periphery of the tip of the input shaft 11 of the motor M by press fitting or the like.

  The intermediate gear 14 is fitted on the outer periphery of the intermediate shaft 12 so as to be relatively rotatable. The intermediate gear 14 has a cylindrical portion that rotates around the central axis of the intermediate shaft 12. A large-diameter gear (intermediate gear teeth) 46 that meshes with the pinion gear 13 is formed at one end of the cylindrical portion in the axial direction. A small-diameter gear (intermediate gear teeth) 47 that meshes with the output gear 15 is formed at the other end in the axial direction of the cylindrical portion.

  The output gear 15 is integrally formed of synthetic resin. A cylindrical boss 35 is formed integrally with the output gear 15. Further, the output gear 15 is integrally formed with an intermediate cylindrical portion 32 having the same outer diameter as the cylindrical portion 31 of the gear case 9 on the outer side in the radial direction than the cylindrical boss 35. Further, the output gear 15 has a partially cylindrical (fan-shaped) tooth forming portion 48 on the outer side in the radial direction from the intermediate cylindrical portion 32. On the outer periphery of the tooth forming portion 48, output gear teeth 49 that mesh with the small diameter gear 47 of the intermediate gear 14 are formed in a fan shape by a predetermined angle.

  On the front end side of the cylindrical boss 35 of the output gear 15, a metal insert plate (hereinafter referred to as a metal plate) 51 as an insert member is insert-molded. In the central portion of the metal plate 51, a fitting hole 52 having a two-surface width (a structure for preventing the output shaft 5 from rotating idly and a rotation preventing structure) is formed to penetrate therethrough. One end of the output shaft 5 in the rotation axis direction (fitting portion of the output shaft 5) is fitted into the fitting hole 52.

  Further, a convex fully closed stopper portion 53 protruding outward in the radial direction is integrally formed on the outer peripheral portion of the intermediate cylindrical portion 32 of the output gear 15. When the valve 1 and the output shaft 5 are closed to the fully closed opening position, the fully closed stopper portion 53 comes into contact with and is locked to the protruding portion (fully closed stopper) 54 of the gear case 9. As a result, when the fully closed stopper portion 53 of the output gear 15 contacts the fully closed stopper 54, further rotation of the valve 1, the output shaft 5 and the output gear 15 in the valve closing direction is restricted.

Next, details of the housing 4 of the present embodiment will be briefly described with reference to FIGS.
In the housing 4, EGR gas flow paths (flow path holes 21 to 23) for recirculating EGR gas from the exhaust passage to the intake passage are formed. The valve body 8 of the housing 4 is formed with a press-fitting hole 55 for press-fitting a nozzle 7 made of heat-resistant metal, for example. In the nozzle 7, a communication path (flow path hole) 22 that connects the flow path hole 21 and the flow path hole 23 is formed.

  On the other hand, the gear case 9 of the housing 4 has a cylindrical side wall portion that surrounds the periphery of the speed reduction mechanism and the return spring 6 in the circumferential direction, and opens on one end side of the side wall portion. An opening (gear insertion port) for inserting the return spring 6 and the like into the gear housing space 17 is provided. This opening is closed by the sensor cover 16.

  Further, the motor case 10 of the housing 4 has a cylindrical side wall portion that surrounds the circumference of the cylindrical yoke of the motor M in the circumferential direction, and opens at one end side of the side wall portion. It has an opening (motor insertion port) for insertion into the inside. The motor insertion port is closed by a front bracket having an external connection terminal (or relay terminal) for the motor M.

  Here, the housing 4 has a cylindrical shape that holds the outer ring portion of the oil seal 24 that supports the output shaft 5 so as to be slidable in the rotation direction and the outer periphery of each outer ring of the double ball bearings (bearings) 25 and 26. A bearing holder (hereinafter referred to as a bearing holder) 56 is provided. The bearing holder 56 is disposed so as to surround the outer ring portion of the oil seal 24 and the outer rings of the double ball bearings 25 and 26 in the circumferential direction.

The bearing holder 56 has a cylindrical cylindrical portion (protruding portion) 31 that protrudes from the bottom surface of the gear case 9 into the gear housing space 17 (on the sensor cover side).
The bearing holder 56 has a first annular step having a function as a first restricting portion for restricting the press-fit fixing position of the oil seal 24 and a second restriction for restricting the press-fit fixing position of the double ball bearings 25 and 26. An annular second step having a function as a portion is provided. Inside the bearing holder 56, a bearing hole 61 is formed that extends straight in the rotational axis direction (axial direction) of the valve 1 and the output shaft 5.

An opening (first port) that is opened at the wall surface of the EGR gas flow path (flow path holes 21 to 23) is formed on one end side (flow path hole side, opening side) of the bearing hole 61 in the axial direction. . Further, an opening (second port) opened at the wall surface of the gear housing space 17 is formed on the other end side in the axial direction of the bearing hole 61 (opposite side to the flow path hole side, reverse side). Yes.
The bearing hole 61 is the smallest (narrow) minimum clearance portion (hereinafter referred to as a clearance portion) 62 among the clearances between the inner periphery of the housing 4 and the outer periphery of the output shaft 5, a seal accommodation hole 63 for accommodating the oil seal 24, And the bearing accommodation hole 64 which accommodates the double ball bearings 25 and 26 is provided.

  The housing 4 defines an EGR gas flow path (flow path holes 21 to 23) and a seal accommodation hole 63, and an opening area of the clearance portion 62 of the bearing hole 61 is set to another bearing hole (seal accommodation hole 63. A diaphragm wall (partition wall) 65 for constricting from the bearing housing hole 64) is integrally formed. The throttle wall 65 surrounds the periphery of the bearing hole 61 on the channel hole side of the oil seal 24 and the double ball bearings 25, 26, the clearance portion 62, and the large-diameter shaft portion 43 of the output shaft 5 in the circumferential direction. It is formed in a cylindrical shape.

  The cylindrical clearance portion 62 provided on the opening side of the bearing hole 61 is a cylindrical gap formed between the throttle wall 65 of the housing 4 and the large-diameter shaft portion 43 of the output shaft 5. In addition, an intermediate hole 67 that is larger than the diameter of the bearing hole 61 on the opening side and smaller than the diameter of the seal accommodation hole 63 is formed between the clearance portion 62 and the seal accommodation hole 63.

The seal accommodation hole 63 constitutes a first press-fitting hole into which the outer ring portion of the oil seal 24 is press-fitted.
The bearing housing hole 64 constitutes a second press-fitting hole into which the outer rings (first and second outer ring portions) of the double ball bearings 25 and 26 are press-fitted.
The hole diameter of the bearing hole 61 increases stepwise from the first port toward the second port.

  The oil seal 24 is a hermetic seal reinforced by, for example, an L-shaped metal reinforcement ring, and includes a synthetic rubber seal rubber (elastic deformation portion) capable of elastic deformation in the radial direction and the thrust direction of the output shaft 5. ing. The oil seal 24 prevents outflow of lubricating grease and lubricating oil for lubricating the double ball bearings 25 and 26. The oil seal 24 is installed in the seal accommodation hole 63 of the bearing holder 56 so as to surround the periphery of the large-diameter shaft portion 43 of the output shaft 5 in the circumferential direction.

  The metal reinforcing ring has a cylindrical outer ring portion that is press-fitted and fixed to the wall surface of the first press-fitting hole (seal accommodating hole 63) of the bearing holder 56. The outer peripheral portion of the outer ring portion is used as a press-fit fixing portion that is press-fit and fixed in a liquid-tight manner into the first press-fit hole of the bearing holder 56. Further, the outer ring portion is in contact with the first step of the bearing holder 56, so that the press-fitting and fixing position of the oil seal 24 is regulated.

  The seal rubber has a seal lip that is in sliding contact with the outer peripheral surface (sliding surface) of the large-diameter shaft portion 43 of the output shaft 5, and the inner periphery of the bearing holder 56 of the housing 4 and the large-diameter shaft portion 43 of the output shaft 5. It has a dust seal function for hermetically sealing liquid-tight (and air-tight) between the outer periphery of the two. This seal rubber is installed inside the bearing holder 56 so as to surround the output shaft 5 in the circumferential direction.

The double ball bearings 25 and 26 include two inner rings, an inner ring that is press-fitted and fixed to the outer periphery of the large-diameter shaft portion 45 of the output shaft 5, an outer ring that is press-fitted and fixed to the second press-fitting hole of the bearing holder 56, and an inner ring and an outer ring. A plurality of steel balls (rolling elements) are slidably accommodated between the races.
Each inner ring of the double ball bearings 25 and 26 constitutes a press-fit fixing portion that is hermetically press-fitted and fixed to the outer periphery of the large-diameter shaft portion 45 of the output shaft 5.
Each outer ring of the double ball bearings 25, 26 is in contact with the second step of the bearing holder 56, so that the press-fitting and fixing position of the outer ring of the double ball bearings 25, 26 is regulated.

Further, the double ball bearings 25 and 26 are provided with two lip seals (seal materials) mounted between the two race rings and at both ends in the axial direction of the steel balls, and a plurality of steel balls falling off. There are two retainers for preventing the above.
A rolling element such as a roller may be used instead of the steel ball. Further, instead of the two lip seals, a metal reinforcing material (attachment ring) may be used.

[Features of Example 1]
Next, details of the output shaft 5 of this embodiment will be briefly described with reference to FIGS. As described above, the output shaft 5 includes the first and second protruding shaft portions 41 and 42 and the axial portion (the large-diameter shaft portion 43 and the large-diameter shaft portion 45).

The first protruding shaft portion 41 is provided on one end side of the output shaft 5 in the rotation axis direction, and protrudes from the clearance portion 62 on the opening side of the bearing hole 61 into the flow path holes 21 to 23. The first protruding shaft portion 41 has an outer diameter smaller than that of the second protruding shaft portion 42 and the large-diameter shaft portion 43. In addition, between the 1st protrusion shaft part 41 and the large diameter shaft part 43, the inclined surface (circular stripe surface) of truncated cone shape (taper shape) is formed.
The second protruding shaft portion 42 is provided on the other end side in the rotation axis direction of the output shaft 5 and protrudes from the large-diameter shaft portion 45 into the gear storage space 17. A metal plate 51 is fixed to the second projecting shaft portion 42 for coupling with the output gear 15 of the speed reduction mechanism.

  Here, after the second projecting shaft portion 42 of the output shaft 5 is fitted into the fitting hole 52 of the metal plate 51, the protruding portion that protrudes into the cylindrical boss 35 through the fitting hole 52 is caulked in a hook shape. Thus, the second protruding shaft portion 42 is fixed to the center portion of the metal plate 51. Thus, since the crimping | fixing part 69 is provided in the front-end | tip of the 2nd protrusion shaft part 42, the output gear 15 is fixed in the state stopped by the output shaft 5 via the metal plate 51. become.

  The second projecting shaft portion 42 is provided with a portion (base end portion) having a larger outer diameter than the fitting portion that fits into the fitting hole 52 of the metal plate 51. In addition, the chamfering of the taper shape is given to the corner | angular part (edge part) of a base end part. As a result, the oil seal 24 and the double ball bearings 25 and 26) can be easily assembled to the outer periphery of the axial portion (the large diameter shaft portion 43 and the large diameter shaft portion 45) of the output shaft 5.

  Further, on the outer periphery of the first projecting shaft portion 41 of the output shaft 5, an outer peripheral surface that forms a cylindrical clearance portion 62 is formed between the inner peripheral surface of the throttle wall 65 of the housing 4. The clearance 62 forms the narrowest (smallest) cylindrical gap among the clearances formed between the inner periphery of the housing 4 and the outer periphery of the output shaft 5. Moreover, the clearance part 62 is a clearance which cannot pass the solid foreign material more than predetermined particle size among the solid foreign materials contained in EGR gas.

By the way, in the EGR control valve, the output shaft 5 is rotationally driven by the rotational power of the motor M, and the rotational angle of the valve 1 is within a predetermined angle range (30 ° to 50 °, particularly 30 ° to 40 °). In some cases, the output shaft 5 includes a clearance portion 62 that generates a pressure gradient distribution (pressure difference) in the circumferential direction (shaft circumferential direction).
The clearance portion 62 having such a structure, as shown in FIGS. 4 to 6, that occur a large pressure difference in the pressure difference-generating portion (A point and B point, C point and the D point) in the circumferential direction of the shaft .

  When a large pressure difference occurs at the pressure difference generation site (points A and B, points C and D), condensed water flows from the higher pressure to the lower pressure, or condenses on the negative pressure side where the pressure is lower. Water is inhaled. For this reason, condensed water is sucked into the clearance portion 62 from the opening side (flow channel hole side) of the bearing hole 61, and the sliding surface of the large-diameter shaft portion 43 of the output shaft 5 and the seal lip of the oil seal 24. There is a possibility that the ball enters the double ball bearings 25, 26 disposed behind the bearing hole 61 through the gap.

  At this time, if the sealing performance of the oil seal 24 installed on the opening side (flow channel hole side) of the bearing hole 61 is lower than the double ball bearings 25 and 26 for some reason, the flow channel hole 21 The condensed water sucked into the clearance portion 62 of the bearing hole 61 from ˜23 passes between the sliding surface of the large-diameter shaft portion 43 of the output shaft 5 and the seal lip of the oil seal 24, and the double ball bearing 25. , 26 and the inside of the double ball bearings 25, 26 may be rusted. When the rust is generated inside the double ball bearings 25 and 26 as described above, the performance as the bearing is deteriorated, so that the valve 1 and the output shaft 5 may be inoperable or malfunction.

Therefore, the first projecting shaft portion 41 of the output shaft 5 of the present embodiment equalizes the pressure difference between the points A and B around the output shaft 5 or the pressure difference between the points C and D (equal pressure equalization). At least one radial hole 71, 72 is provided.
The radial holes 71 and 72 are provided in correspondence with the opening side of the bearing hole 61 relative to the seal lip of the oil seal 24, that is, the clearance portion 62, and are disposed on the back side of the bearing hole 61. An infiltration prevention means for preventing infiltration of condensed water to the 26 (bearing) side is configured .

The radial holes 71 and 72 are arranged so as not to contact the oil seal 24. That is, the radial holes 71 and 72 are arranged with a predetermined axial distance between them and the oil seal 24.
The radial holes 71 and 72 are installed corresponding to the clearance portion 62 where a pressure gradient distribution (pressure difference) is generated in the circumferential direction of the shaft.

The radial hole 71 is a first through hole that extends in the diameter direction of the first protruding shaft portion 41 of the output shaft 5 and penetrates the first protruding shaft portion 41 in the diameter direction. The radial hole 71 is formed in the diameter direction of the first protruding shaft portion 41 of the output shaft 5 when the rotation angle of the valve 1 is within a predetermined angle range (30 ° to 50 °, particularly 30 ° to 40 °). It is the 1st communicating path which connects both sides ( A point and B point).

The radial hole 72 is a second through hole that extends in the diameter direction of the large-diameter shaft portion 43 of the output shaft 5 and penetrates the large-diameter shaft portion 43 in the diameter direction. The radial holes 72 are formed on both sides of the large diameter shaft portion 43 of the output shaft 5 when the rotation angle of the valve 1 is within a predetermined angular range (30 ° to 50 °, particularly 30 ° to 40 °). It is the 2nd communicating path which connects ( C point and D point).

In the two radial holes 71 and 72, the first axis connecting the points A and B with a straight line and the second axis connecting the points C and D with a straight line intersect each other at a substantially right angle. It is provided to overlap (intersect).
The at least one or more radial holes 71 and 72 may be other than the straight through-holes as long as they are open on the outer peripheral surface of the first protruding shaft portion 41 or the large-diameter shaft portion 43 of the output shaft 5. Further, the openings (ports) on both sides of at least one of the radial holes 71 and 72 have a predetermined interval (equal interval or the like) in the circumferential direction of the first projecting shaft portion 41 or the large-diameter shaft portion 43 of the output shaft 5. ) May not be formed.

[Operation of Example 1]
Next, the operation of the EGR control valve of this embodiment will be briefly described with reference to FIGS.

The motor M that drives the valve 1 of this embodiment is configured to be energized and controlled by the ECU.
Here, when electric power is not supplied to the motor M, the valve 1 welded and fixed to the first projecting shaft portion 41 of the output shaft 5 by the biasing force (spring load) of the return spring 6 is set to the fully closed position. Is done.

At this time, the sliding portion of the seal ring 3 fitted in the seal ring groove 2 of the valve 1 is fitted and held in the press-fitting hole 55 of the housing 4 by the tension (elastic deformation force) in the diameter increasing direction of the seal ring itself. In order to stick to the inner peripheral surface of the nozzle 7, the sliding portion of the seal ring 3 comes into close contact with the inner peripheral surface of the nozzle 7.
Therefore, the annular gap between the inner peripheral surface of the nozzle 7 and the outer peripheral end surface of the valve 1 is completely sealed. That is, the channel holes 21 to 23 formed in the housing 4 are closed. Thereby, EGR gas does not mix in clean intake air (fresh air) that has passed through the air cleaner (EGR cut).

Next, when the operation state (engine operation state) is such that the EGR control valve is opened, the valve 1 is opened so that the valve 1 opens to a predetermined opening degree corresponding to the operation state.
Then, electric power is supplied to the motor M, and the input shaft 11 of the motor M is rotated in the valve opening operation direction. Thereby, the rotational power (torque) of the motor M is transmitted to the pinion gear 13, the intermediate gear 14, and the output gear 15. Then, the output shaft 5 to which the torque is transmitted from the output gear 15 rotates in the valve opening operation direction by a predetermined rotation angle (valve opening) as the output gear 15 rotates.

  As described above, the air cleaner is controlled by changing the valve opening degree of the EGR control valve by variably controlling the power (drive current value or applied voltage value) supplied to the motor M in accordance with the operating state of the engine. The amount of EGR gas introduced (mixed amount) with respect to clean intake air that has passed through is adjusted. That is, the valve 1 is controlled to open to a valve opening corresponding to the control target value. That is, the channel holes 21 to 23 are opened.

Therefore, EGR gas, which is a part of the exhaust gas flowing out from the combustion chamber for each cylinder of the engine, passes from the exhaust passage (EGR gas branching portion) formed in the exhaust pipe to the inside of the EGR gas pipe (EGR) on the exhaust pipe side. The gas is recirculated to the intake passage (EGR gas merging portion) formed in the intake pipe via the gas flow path. Therefore, EGR gas is mixed into the intake port and the intake air supplied to the combustion chamber for each cylinder of the engine.
As a result, harmful substances (for example, NOx) contained in the exhaust gas are reduced.

[Effect of Example 1]
As described above, in the EGR control valve of the present embodiment, the first protruding shaft portion 41 or the large diameter shaft portion 43 of the output shaft 5 that forms the clearance portion 62 between the inner wall of the throttle wall 65 of the housing 4. In addition, at least one or more radial holes 71 and 72 for leveling the pressure difference between the points A and B around the output shaft 5 or the pressure difference between the points C and D are provided.

  As a result, the pressure difference in the circumferential direction of the shaft in the clearance 62 formed between the inner periphery of the throttle wall 65 of the housing 4 and the outer periphery of the first protruding shaft portion 41 of the output shaft 5 is eliminated (or reduced). For this reason, since condensed water does not enter the clearance 62 from the flow path holes 21 to 23 of the housing 4, an expensive PTFE seal can be eliminated. As a result, it is possible to prevent the intrusion of condensed water into the double ball bearings 25 and 26 (bearing) without using an expensive PTFE seal, thereby reducing the cost. Therefore, the manufacturing cost of the EGR control valve can be reduced.

Here, inundation into the housing 4 is not limited to the above-mentioned condensed water, but also when the car is washed, when it rains, when it rains, and when the water on the road jumps up into the intake pipe There is inundation that flows into the EGR control valve from the junction of the EGR gas flow path and the intake passage.
In addition, moisture condensed in the intake pipe on the upstream side or the downstream side in the intake flow direction from the merging portion may flow into the EGR control valve from the merging portion as water droplets.
In addition, when a blow-by gas reduction device (PCV device) is installed in an automobile, a large amount of moisture is contained in the PCV gas. Therefore, when the PCV gas is cooled, the moisture contained in the PCV gas is condensed. As a result, condensed water is generated. This condensed water may flow into the EGR control valve from the junction.

[Configuration of Reference Example 1 ]
FIG. 7 shows an EGR control valve ( Reference Example 1) for the fluid control valve of the present invention. Here, the same reference numerals as those in the first embodiment indicate the same configuration or function, and the description thereof is omitted.

The EGR control valve of this reference example has a water repellent treatment on the inner peripheral surface (wall surface of the bearing hole 61) of the throttle wall 65 of the housing 4 for the purpose of preventing the intrusion of condensed water into the double ball bearings 25 and 26. The outer peripheral surface of the large diameter shaft portion 43 of the output shaft 5 is subjected to water repellent treatment.
Specifically, on the inner peripheral surface of the diaphragm wall 65 of the housing 4, a water-repellent polymer treatment agent, a fluororesin such as a thin-film PTFE (tetrafluoroethylene resin), or a water-repellent molybdenum disulfide is used. By applying the water repellents 81 and 82, a water repellent surface treatment is applied only to the inner peripheral surface of the throttle wall 65 of the housing 4.
Further, by applying a similar water repellent to the outer peripheral surface of the large-diameter shaft portion 43 of the output shaft 5, a water-repellent surface treatment is applied only to the outer peripheral surface of the large-diameter shaft portion 43 of the output shaft 5.

The water repellent surface treatment as described above is provided on the opening side of the bearing hole 61 with respect to the seal lip of the oil seal 24 and the double roller bearings 25 and 26 as in the first embodiment. Infiltration prevention means for preventing intrusion of condensed water to the double ball bearings 25 and 26 (bearing) side disposed on the back side of the hole 61 is configured.
Further, the water-repellent surface treatment is installed corresponding to the minimum clearance portion 62 formed between the inner periphery of the throttle wall 65 of the housing 4 and the outer periphery of the large-diameter shaft portion 43 of the output shaft 5. .

Accordingly, even when condensed water enters the bearing hole 61 from the flow path holes 21 to 23, the throttle wall 65 of the housing 4 or the large diameter shaft portion of the output shaft 5 subjected to the water repellent treatment. Since the water repellent at 43 and the flow of the condensed water is hindered by the surface tension due to the water repellency in the clearance portion 62, the intrusion of the condensed water into the clearance portion 62 can be suppressed.
As described above, the EGR control valve of this reference example has the same effects as those of the first embodiment. In addition, you may combine the water immersion prevention structure of Example 1 with this reference example .

[Configuration of Reference Example 2 ]
FIG. 8 shows an EGR control valve ( Reference Example 2) for the fluid control valve of the present invention. Here, the same reference numerals as those in the first and second embodiments indicate the same configuration or function, and the description thereof will be omitted.

The EGR control valve according to the present reference example is configured so that the throttle of the housing 4 corresponds to a clearance portion 62 formed between the inner periphery of the throttle wall 65 of the housing 4 and the outer periphery of the large-diameter shaft portion 43 of the output shaft 5. A circle that prevents intrusion of condensed water on the inner peripheral surface of the wall 65 from the bearing hole 61 that is the opening side of the bearing hole 61 to the double ball bearings 25 and 26 (bearing) side that are disposed on the inner side of the bearing hole 61. An annular weir 83 is provided.

The weir 83 is installed so as to surround the periphery of the output shaft 5 in the circumferential direction. The weir 83 is configured by an annular ridge rib that protrudes from the inner peripheral surface of the throttle wall 65 of the housing 4, that is, the wall surface of the bearing hole 61 toward the outer peripheral surface of the output shaft 5.
Further, the clearance portion 62 includes an annular minute gap 84 formed between the wall surface of the bearing hole 61 and the top portion of the weir 83. The minute gap 84 constitutes a clearance seal (infiltration prevention means) that makes it difficult for condensed water to enter from the bearing hole 61 to the double ball bearings 25 and 26 (bearing) side.

Therefore, by providing the weir 83 protruding from the wall surface of the bearing hole 61 to the outer peripheral surface side of the output shaft 5 and the minute gap 84 between the wall surface of the bearing hole 61 and the top portion of the weir 83, The flow of condensed water is obstructed.
As described above, the EGR control valve of this reference example has the same effects as those of the first and second embodiments.
In addition, you may combine the water immersion prevention structure of Example 1 with this reference example. Further, the outer peripheral surface of the large-diameter shaft portion 43 of the output shaft 5 may be slid in the rotational direction at the portion of the weir 83.

[Configuration of Reference Example 3 ]
9 to 11 show an EGR control valve ( Reference Example 3) for the fluid control valve of the present invention. Here, the same reference numerals as in the first to third embodiments indicate the same configuration or function, and the description thereof is omitted.

The EGR control valve of the present reference example has a bottomed groove 91 opened on the inner peripheral surface of the throttle wall 65 of the housing 4 or a bottomed groove opened on the outer peripheral surface of the large-diameter shaft portion 43 of the output shaft 5. 92.
The concave groove 91 is a first circumferential groove extending in the circumferential direction of the wall surface of the bearing hole 61 as shown in FIGS. 9 and 11.
As shown in FIGS. 10 and 11, the concave groove 92 is a second circumferential groove extending in the circumferential direction of the outer circumferential surface of the large-diameter shaft portion 43.
As shown in FIG. 11, the concave groove 92 is provided so as to face the bottom surface of the concave groove 91 with an annular gap 93 therebetween.

Similar to the first embodiment, the concave groove 91 or the concave groove 92 is provided on the opening side of the bearing hole 61 relative to the seal lip of the oil seal 24 and the double ball bearings 25 and 26, that is, on the bearing hole 61. Infiltration prevention means for preventing intrusion of condensed water from 61 to the double ball bearings 25 and 26 (bearing) side disposed on the back side of the bearing hole 61 is configured.
Further, the concave groove 91 or the concave groove 92 is installed corresponding to the smallest clearance portion 62 formed between the inner periphery of the diaphragm wall 65 of the housing 4 and the outer periphery of the large-diameter shaft portion 43 of the output shaft 5. ing.

Therefore, by providing the concave groove 91 on the inner peripheral surface of the throttle wall 65 of the housing 4 or providing the concave groove 92 on the outer peripheral surface of the large diameter shaft portion 43 of the output shaft 5, the flow of condensed water to the clearance portion 62. Is disturbed, and the intrusion of condensed water from the bearing hole 61 to the double ball bearings 25 and 26 (bearing) side is hindered.
As described above, the EGR control valve of this reference example has the same effects as those of the first to third embodiments.
In addition, you may combine the water immersion prevention structure of Example 1 with this reference example.

[Modification]
In this embodiment, as an actuator for driving the valve 1 that is a valve body of a fluid control valve such as an EGR control valve, a motor M that generates torque upon receipt of electric power, and a speed reduction mechanism that decelerates the rotation of the motor M ( An electric actuator equipped with a power transmission mechanism) is adopted, but as an actuator, a negative pressure actuated actuator driven by negative pressure from an electric vacuum pump via a negative pressure control valve, and an electromagnet including a coil are provided. A linear solenoid (electromagnetic actuator) may be employed.

In this embodiment, the present invention is applied to the EGR control valve. However, a low-temperature exhaust gas flow path communicating with the outlet side of the EGR cooler and a bypass flow path (high-temperature exhaust gas flow path) for bypassing the EGR gas from the EGR cooler are provided. The present invention may be applied to other exhaust control valves such as an exhaust gas flow path switching valve for switching and an exhaust gas flow rate (pressure) control valve installed in an exhaust pipe of an engine (turbine housing of a turbocharger).
Examples of the exhaust control valve include a waste gate valve, a scroll switching valve, an exhaust flow control valve, an exhaust pressure control valve, and an exhaust switching valve.

Further, the present invention may be applied to a fluid control valve such as an intake control valve instead of the exhaust control valve.
As the intake control valve, an intake throttle valve (throttle valve), a tumble valve, a swirl valve, and the like are conceivable.
In addition, although a butterfly valve is employed as a valve constituting the exhaust control valve and the intake control valve, a rotary valve such as a flap valve, a plate valve, or a rotary valve may be employed.

In the present embodiment, double ball bearings 25 and 26 having lubricating oil inside are used as bearings for supporting a shaft such as the output shaft 5 which is the valve shaft of the fluid control valve so as to be slidable in the rotational direction. However, at least one or more ball bearings or roller bearings may be used as bearings that support the shaft so as to be slidable in the rotational direction.
Further, as a bearing that supports the shaft so as to be slidable in the rotation direction, a metal bush that is a cylindrical sintered oil-impregnated bearing in which lubricating oil (lubricating grease, lubricating oil) is impregnated may be used.
Even if the bearing is not impregnated with lubricating oil, a type of bearing in which lubricating oil is supplied from the lubricating oil supply mechanism to the sliding portion (sliding clearance) between the bearing and the shaft may be used. good.

In this embodiment, the valve 1 that is the valve body of the fluid control valve is supported and fixed at one end side in the rotation axis direction of the shaft such as the output shaft 5 that is the valve shaft of the fluid control valve. The end side is rotatably supported by bearings such as double ball bearings 25, 26, etc., but a valve is supported and fixed at the central portion of the shaft in the rotation axis direction, and both sides of the shaft in the rotation axis direction are first and second. You may support by 2 bearings so that rotation is possible.
A hermetic (liquid-tight or air-tight) seal such as an oil seal may be installed on the wall surface of the bearing hole on the flow path side with respect to the first and second bearings.

1 Valve 4 Housing 5 Output Shaft 23 Channel Hole 24 Oil Seal 25 Ball Bearing (Bearing)
26 Ball bearing
61 Bearing hole 62 Clearance section

Claims (9)

(A) a housing (4, 21) having a bearing hole (61) that opens to the flow path (21-23) communicating with the internal combustion engine and a wall surface of the flow path (21-23) and extends from the opening side to the back side; 65)
(B) a valve (1) housed in the housing (4, 65) to open and close the flow path (21-23);
(C) It has a shaft (5, 41, 43) that is inserted into the bearing hole (61) and supports the valve (1),
An actuator that rotationally drives the shaft (5, 41, 43) to open and close the valve (1);
(D) In a fluid control valve provided with a bearing (25, 26) housed in the back side of the bearing hole (61) and supporting the shaft (5, 41, 43) so as to be slidable in the rotational direction. ,
Before Symbol shaft (5,41,43), said than bearings (25, 26) provided on the opening side of the bearing hole (61), wherein the bearing hole from the opening side of the bearing hole (61) (61 ) Or water immersion prevention means (71, 72, 83 , 84 , 91, 92) for preventing water from entering the bearing (25, 26) side ,
The inundation preventing means has communication passages (71, 72) communicating with both sides in the diameter direction of the shaft (5, 41, 43),
The communication path (71, 72) corresponds to a cylindrical clearance portion (62) formed between the inner periphery of the housing (4, 65) and the outer periphery of the shaft (5, 41, 43). Provided,
The clearance part (62) has a pressure difference generating part (A, B, C, D) in which a pressure difference is generated in the circumferential direction of the shaft (5, 41, 43). Control valve. The fluid control valve according to claim 1,
It is accommodated on the opening side of the bearing hole (61) with respect to the bearings (25, 26), and seals between the inner periphery of the housing (4, 65) and the outer periphery of the shaft (5, 41, 43). A fluid control valve comprising an annular seal (24). The fluid control valve according to claim 2,
The fluid control valve according to claim 1, wherein the communication passages (71, 72) are arranged so as not to contact the seal (24) or the bearings (25, 26). In the fluid control valve according to any one of claims 1 to 3,
The communication path extends in the diameter direction of the shaft (5, 41, 43) and has at least one radial hole (71, 72) penetrating the shaft (5, 41, 43) in the diameter direction. fluid control valve, characterized by that. In the fluid control valve according to any one of claims 1 to 4 ,
The flooding prevention hand stage, it has a weir that prevents flooding from the opening side of the bearing hole (61) toward the back side or the bearing (25, 26) side of said bearing hole (61) (83) A fluid control valve characterized by. The fluid control valve according to claim 5 ,
The weir (83) is installed so as to surround the periphery of the shaft (5, 41, 43) in the circumferential direction, from the inner peripheral surface of the housing (4, 65) or the wall surface of the bearing hole (61). A fluid control valve having an annular ridge rib protruding toward the outer peripheral surface of the shaft (5, 41, 43) . The fluid control valve according to claim 5 or 6 ,
The inundation preventing means has an annular minute gap (84) formed between the wall surface of the bearing hole (61) and the crest portion of the weir (83),
The minute gap (84) constitutes a clearance seal that makes it difficult for intrusion of condensed water from the opening side of the bearing hole (61) to the back side of the bearing hole (61) or the bearing (25, 26) side. A fluid control valve characterized by: The fluid control valve according to any one of claims 1 to 7,
Fluid the flooding prevention hand stage, which open at the inner peripheral surface of the housing (4,65), and characterized in that it has a groove (91) extending in the circumferential direction of the bearing hole (61) Control valve. The fluid control valve according to any one of claims 1 to 8,
The flood prevention means has a concave groove (92) that opens at the outer peripheral surface of the shaft (5, 41, 43) and extends in the circumferential direction of the shaft (5, 41, 43). Fluid control valve.