JP2012163017A - Butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress generation of wear by suppressing vibration or displacement of a valve element and by reducing the weight of a movable part including the valve element, and to achieve low valve leak for a long period of time.SOLUTION: One end of a shaft 4 is fixed to a housing 3, and a valve pipe 5a provided at a valve element 5 is slidably supported relative to the shaft 4. An amount of eccentricity of the valve element 5 relative to an EGR flow channel 2 is thereby suppressed so as to be small, and the vibration or displacement of the valve element 5 is suppressed so as to be extremely small. The movable part including the valve element 5 is a separate body from the shaft 4, and the weight of the movable part including the valve element 5 is provided so as to be light. Accordingly, even when vibration is generated in the movable part including the valve element 5, wear due to vibration is suppressed, and low valve leak is achieved for a long period of time. The valve pipe 5a is slidably supported by the shaft 4, so that a ball bearing or metal bearing used in the prior arts may be eliminated, and thereby the costs are suppressed.

Description

  The present invention relates to a butterfly valve that opens and closes a fluid passage or adjusts an opening thereof. For example, an EGR valve that returns a part of exhaust gas discharged from an engine (an internal combustion engine that generates power by combustion of fuel) to an intake passage as EGR gas. The present invention relates to a technique suitable for use.

(Conventional technology)
As an example of the butterfly valve, the prior art will be described using an EGR valve.
An engine mounted on a vehicle is equipped with an EGR device (exhaust gas recirculation device) that returns EGR gas to the intake side.
EGR equipment
An EGR flow path for guiding a part of the exhaust gas from the exhaust passage of the engine to the intake passage;
An EGR valve that controls the amount of EGR gas returned to the intake side by adjusting the opening of the EGR flow path;
An ECU (abbreviation for engine control unit) that performs opening control of the EGR valve (specifically, energization control of an electric actuator mounted on the EGR valve);
Is provided.

A specific example of the EGR valve in the prior art will be described with reference to a schematic diagram shown in FIG. In addition, the same code | symbol as the [form for inventing] mentioned later and [Example] shows the same function thing.
The EGR valve 1 in FIG.
A housing 3 in which a part of the EGR flow path 2 is formed;
A shaft 4 rotatably supported with respect to the housing 3;
A valve body 5 fixed to the shaft 4 for opening and closing the EGR flow path 2 and adjusting the opening;
An electric actuator 6 that drives the valve body 5 via the shaft 4;
(For example, refer to Patent Document 1).

(Problems of conventional technology)
The valve body 5 that adjusts the opening degree of the EGR flow path 2 is fixed to the shaft 4 by welding.
Further, the shaft 4 is fixed by a final gear 10 and a caulking (marked by X in the figure) of a gear reducer 9 used for the electric actuator 6.
For this reason, the movable part (specifically, the valve body 5 + the shaft 4 + the final gear 10) including the valve body 5 becomes very heavy.

The means for supporting the heavy movable part is a ball bearing J1 disposed between the housing 3 and the shaft 4.
Since the distance from the ball bearing J1 to the valve body 5 is long, even if the metal bearing J2 and the oil seal J3 are disposed between the ball bearing J1 and the valve body 5, the swing width of the valve body 5 becomes very large. The welding variation of the shaft 4 and the valve body 5 is added to this.
For this reason, the seal ring 14 is arrange | positioned in the outer periphery of the valve body 5, and the initial valve closing performance is ensured by obstruct | occluding the clearance gap around the valve body 5 at the time of full closure.

However, if a very heavy movable part (valve body 5 + shaft 4 + final gear 10 etc.) vibrates due to engine vibration, vehicle vibration, or exhaust pulsation, “between valve body 5 and seal ring 14”. In addition, heavy movable energy vibration occurs “between the seal ring 14 and the inner wall (such as the inner wall of the nozzle) of the EGR flow path 2”, and wear progresses at the vibration absorption point (contact point). In other words, wear is likely to occur due to vibrations of heavy objects.
For this reason, when the EGR valve 1 is used for a long period of time, the seal portion is worn, and EGR gas may leak through the worn portion when fully closed.

  If EGR gas leaks when fully closed, the EGR gas is returned to the intake side in an operation state in which the EGR gas is not returned to the intake side (for example, an operation state where the engine load is heavy), and the specified fresh air There is a concern that the amount (the amount of air required by the ECU) cannot be secured, leading to a decrease in engine output or a deterioration in exhaust gas emission.

JP 2007-285111 A

  The present invention has been made in view of the above circumstances, and its purpose is to suppress the deflection and displacement of the valve body and lighten the movable part including the valve body to suppress the occurrence of wear for a long period of time. Another object of the present invention is to provide a butterfly valve capable of realizing low valve leakage.

[Means of Claim 1]
According to the first aspect of the present invention, since the shaft is fixed and the valve pipe of the valve body is slidably supported with respect to the outer peripheral surface of the shaft, the amount of eccentricity of the valve body with respect to the fluid passage can be kept small. it can. That is, it is possible to suppress the deflection and positional deviation of the valve body to be extremely small.
Furthermore, since the movable part including the valve body is rotatably supported with respect to the shaft, the weight of the movable part including the valve body can be reduced.
For this reason, even if a vibration arises, wear can be suppressed and the occurrence of leakage due to wear can be prevented even when used for a long time. That is, low valve leakage can be realized over a long period of time, and high reliability can be obtained.

  Further, since the valve pipe of the valve body is slidably supported with respect to the outer peripheral surface of the shaft, the means of claim 1 is “an independent bearing for rotatably supporting the shaft in the prior art ( Independent bearings such as ball bearings and metal bearings) ”can be abolished, and costs can be reduced.

[Means of claim 2]
The butterfly valve according to claim 2 is provided with a seal ring on the outer peripheral edge of the valve body.
As shown in the means of claim 1 above, it is possible to minimize the deflection and displacement of the valve body, but by providing the seal ring, the valve body directly vibrates against the inner wall of the fluid passage. The vibration absorption points can be distributed “between the valve body and the seal ring” and “between the seal ring and the inner wall of the fluid passage”.
Thereby, since vibration energy generated in the valve body can be dispersed, the occurrence of wear can be further suppressed, and low valve leakage can be realized over a long period of time.

[Means of claim 3]
A butterfly valve according to a third aspect is applied to an EGR valve of an exhaust gas recirculation device, and is provided with a cooling water passage inside a shaft.
Thereby, it can suppress that the heat | fever of an EGR flow path is transmitted to a valve drive means. For this reason, the distance from the EGR flow path to the valve driving means (for example, the distance from the EGR flow path to the final gear provided with resin or the like) can be shortened, and the EGR valve can be downsized.
Further, since the valve pipe can be cooled via the shaft, grease or oil can be used as a lubricating means between the shaft and the valve pipe without considering heat.
Furthermore, since the valve body can be cooled via the valve pipe, it is possible to change the valve body from a conventional metal to a resin excellent in moldability.

[Means of claim 4]
The valve drive means of claim 4 is an electric actuator comprising an electric motor that generates a rotational output when energized, and a gear reducer that decelerates the rotational output of the electric motor and transmits it to the valve pipe.
The final gear of the gear reducer has a gear pipe that is rotatably supported around the shaft.

[Means of claim 5]
The power transmission part of the gear pipe and the valve pipe in claim 5 is provided by a meshing part meshing in the axial direction.

[Means of claim 6]
A seal fitting portion that covers the periphery of the valve pipe is provided on the valve pipe side of the gear pipe in claim 6.
By this seal fitting portion, foreign matter (such as deposit in the case of being used for an EGR valve) can be prevented from entering between the shaft and the valve pipe.

[Means of Claim 7]
According to a seventh aspect of the present invention, the shaft includes a shoulder portion with which one end of the valve pipe abuts. And a butterfly valve is provided with the urging means which presses a valve pipe to a level | step-difference shoulder part via the last gear.
When the valve pipe is pressed against the shoulder of the step, the play of the valve body can be eliminated.
Further, since the movable part including the valve body is urged by the urging means, it is possible to suppress the vibration of the movable part that causes wear.
Further, when a meshing portion is provided in the power transmission portion of the gear pipe and the valve pipe (refer to the means of claim 5), the gear pipe is pressed against the valve pipe, and the backlash of the meshing portion can be eliminated. Thereby, the output torque of the electric actuator can be directly transmitted to the valve body without causing hysteresis between the electric actuator and the valve body.

[Means of Claim 8]
A seal ring sandwiched between the valve pipe and the shoulder of the step is disposed between the valve pipe and the shoulder of the step.
This seal ring can prevent foreign matters (such as deposits when used for EGR valves) from entering between the shaft and the valve pipe.
Further, by providing this seal ring with a “low μ material having a small friction coefficient”, the sliding resistance of the valve pipe with respect to the shaft can be reduced, and the driving load of the electric actuator can be reduced.

[Means of Claim 9]
A seal ring sandwiched between the final gear and the housing is disposed between the final gear and the housing.
By this seal ring, it is possible to prevent the fluid flowing through the fluid passage (exhaust gas or the like when used for the EGR valve) or foreign matter (deposit or the like when used for the EGR valve) from entering the accommodation chamber of the electric actuator. .

[Means of Claim 10]
A seal ring for closing the sliding clearance between the housing and the gear pipe is disposed between the housing and the gear pipe.
By this seal ring, it is possible to prevent the fluid flowing through the fluid passage (exhaust gas or the like when used for the EGR valve) or foreign matter (deposit or the like when used for the EGR valve) from entering the accommodation chamber of the electric actuator. .

[Means of Claim 11]
The shaft of the eleventh aspect has a grease holding groove for holding the grease for lubrication in the central portion of the range where the shaft is arranged in the valve pipe.
By providing the grease holding groove, grease can be stored inside the valve pipe, and the sliding performance of the valve pipe can be maintained high over a long period of time.

[Means of Claim 12]
According to a twelfth aspect of the present invention, a labyrinth groove is provided on both sides of the range where the shaft is disposed in the valve pipe to hold the grease for lubrication or to contain foreign matter.
Since the grease is held in the labyrinth groove, the sliding performance of both end portions (stepped shoulder portions, etc.) of the valve pipe can be enhanced.
Even if foreign matter (such as deposit in the case of EGR valve) enters between the shaft and the valve pipe, the foreign matter is accommodated in the labyrinth groove, and the sliding performance of the shaft and the valve pipe due to the foreign matter is deteriorated. Can be prevented.

[Means of Claim 13]
According to a thirteenth aspect of the present invention, there is provided a seal groove into which a seal ring for closing a gap between the shaft and the valve pipe is fitted on both sides of the range where the shaft is arranged in the valve pipe.
The seal ring disposed in the seal groove can prevent foreign matters (such as deposits when used for EGR valves) from entering between the shaft and the valve pipe.
Further, when used in combination with the grease holding groove (see the means of claim 11), the grease stored in the grease holding groove can be prevented from flowing out to the outside by the seal ring arranged in the seal groove. , Stable lubricating performance can be exhibited over a long period of time.

It is a schematic sectional drawing of an EGR valve | bulb (Example 1). (Example 1) which is explanatory drawing of the power transmission part of the gear pipe in a gear reducer, and the valve pipe in a valve body. (Example 2) which is a schematic sectional drawing of an EGR valve | bulb. (Example 2) which is sectional drawing of a valve body. (Example 3) which is a schematic sectional drawing of an EGR valve | bulb. It is principal part sectional drawing of an EGR valve | bulb (Example 4). (Example 5) which is sectional drawing which shows the support structure of a valve body. (Example 6) which is sectional drawing which shows the support structure of a valve body. (Example 7) which is sectional drawing of the principal part of EGR valve, and sectional drawing of a seal fitting part. It is principal part sectional drawing of an EGR valve | bulb (Example 8). It is a schematic sectional drawing of an EGR valve (conventional example).

[Description of Embodiments] [Mode for carrying out the invention] will be described with reference to the drawings.
EGR valve 1 (an example of a butterfly valve)
(A) a housing 3 in which an EGR flow path 2 (an example of a fluid path) is formed;
(B) a shaft 4 disposed across the EGR flow path 2 and having a rod shape that is fixed directly or indirectly to the housing 3;
(C) a valve body 5 having a cylindrical shape that has a cylindrical pipe pipe 5a that is slidably supported on the outer peripheral surface of the shaft 4 and that has a substantially disk shape for opening and closing the EGR flow path 2 and adjusting the opening;
(D) an electric actuator 6 (an example of a valve driving unit) that opens and closes the EGR flow path 2 and adjusts the opening thereof by rotating and displacing the valve body 5 by driving the valve pipe 5a;
It is comprised and comprises.

A specific example (example) in which the present invention is applied to an EGR valve 1 of an EGR device mounted on a vehicle engine will be described below with reference to the drawings. The following examples disclose specific examples, and it goes without saying that the present invention is not limited to the examples.
In the following embodiments, the same reference numerals as those in the above-mentioned [Mode for Carrying Out the Invention] denote the same functional objects.

[Example 1]
A first embodiment will be described with reference to FIGS.
The EGR device is a well-known technique in which part of exhaust gas discharged from the engine is returned to the intake side of the engine as EGR gas, thereby mixing EGR gas that is non-combustible gas into a part of the intake air.
The EGR device includes at least an EGR passage 2 for returning a part of the exhaust gas flowing through the exhaust passage to the intake passage, and an EGR valve 1 for opening / closing and adjusting the opening of the EGR passage 2. The opening degree is controlled by the ECU according to the traveling state of the vehicle.

  The EGR valve 1 may be a high-pressure EGR valve 1 mounted on a high-pressure EGR device that returns EGR gas to the intake downstream side of the throttle valve in the intake passage, or an intake upstream side (for example, a turbocharger) of the throttle valve in the intake passage. The low pressure EGR valve 1 mounted on the low pressure EGR device that returns the EGR gas to the intake upstream side of the compressor in the case of a mounted vehicle may be used.

A specific example of the EGR valve 1 will be described with reference to FIG.
In the following description, the left side of FIG. 1 is referred to as left, and the right side of FIG. 1 is referred to as right. However, the left and right directions are directions for explaining the embodiment and are not limited.
The EGR valve 1 is
A housing 3 in which an EGR flow path 2 (specifically, a part of the EGR flow path 2) is formed, and a housing 3 that is arranged across the center in the EGR flow path 2 are fixed to the housing 3 on the right side. A shaft 4;
A valve body 5 having a cylindrical pipe pipe 5a that is slidably supported on the outer peripheral surface of the shaft 4, and that opens and closes the EGR flow path 2 and adjusts the opening;
An electric actuator 6 that drives the valve pipe 5a to rotate and displace the valve body 5 in the EGR flow path 2;
It comprises.

The housing 3 is made of, for example, aluminum, and an EGR channel 2 is formed inside the housing 3.
A cylindrical nozzle (not shown) made of a material having excellent heat resistance and wear resistance (for example, stainless steel) is press-fitted into the inner wall of the EGR flow path 2 at the portion opened and closed by the valve body 5. Etc. are fixedly arranged.

The shaft 4 has a cylindrical bar shape made of a material having excellent heat resistance and wear resistance (for example, stainless steel), and the right side of the shaft 4 (the range indicated by the symbol A in FIG. 1) is press-fitted and fixed to the housing 3. ing.
The housing 3 on the left side of the shaft 4 is provided with a through hole (shaft insertion hole) that communicates the inside of the EGR flow path 2 with the left side of the housing 3, and the left side of the shaft 4 has a clearance ( An assembly gap (to be described later) of the gear pipe 10a, which will be described later, is inserted and arranged.
The left end of the shaft 4 is provided so as to reach the inside of the accommodation chamber (a space formed between the housing 3 and the cover 7) of the electric actuator 6.

The valve body 5 is disposed inside the EGR flow path 2 and rotates inside the EGR flow path 2 (specifically, inside the nozzle), thereby opening and closing the EGR flow path 2 and adjusting the opening degree. The amount of EGR gas returned to the intake passage is adjusted.
The valve body 5 has a substantially disk shape and is provided by a material (for example, stainless steel) having excellent heat resistance and corrosion resistance.

  The valve pipe 5 a has a pipe shape provided integrally with the valve body 5, is fitted around the shaft 4 in the EGR flow path 2, and is slidably supported with respect to the shaft 4. That is, the valve body 5 is slidably supported around the shaft 4 via the valve pipe 5a.

  Here, the EGR flow path 2 formed in the housing 3 is provided to be inclined with respect to the axis of the shaft 4. For this reason, the valve body 5 has a disk surface (with respect to the axis of the shaft 4) so that the valve body 5 is arranged perpendicular to the central axis of the EGR flow path 2 (EGR gas flow direction) when fully closed. The direction perpendicular to the thickness direction of the valve body 5 is inclined.

The electric actuator 6 is disposed on the left side of the housing 3 and rotationally drives the valve body 5 fitted on the shaft 4.
An electric motor 8 that generates rotational power when energized (for example, a well-known DC motor that generates rotational torque in accordance with the energization amount);
A gear reducer 9 that combines a plurality of gears, amplifies the output torque of the electric motor 8 and transmits the amplified output torque to the valve body 5;
A return spring that applies a biasing force in the valve closing direction to the final gear 10 (large-diameter final gear) of the gear reducer 9;
A rotation angle sensor that detects the opening of the valve body 5 (for example, a magnetic rotation angle sensor that detects the angle of the final gear 10 in a non-contact manner; not shown);
Is provided.

The electric motor 8 is energized and controlled by the ECU. When the electric motor 8 is energized and controlled by the ECU, the opening degree of the valve body 5 is controlled and the amount of EGR gas returned to the engine is adjusted. Is done.
Specifically, the ECU is a known electronic control device equipped with a microcomputer, and the actual opening of the valve body 5 detected by the rotation angle sensor is a target opening calculated in accordance with the vehicle running state. Thus, the ECU controls the energization of the electric motor 8.

Next, power transmission means for driving the valve body 5 by the output of the electric actuator 6 will be described with reference to FIG.
The EGR valve 1 includes a gear pipe 10 a that applies the output torque of the final gear 10 to the valve pipe 5 a of the valve body 5.
The gear pipe 10a is provided integrally with the final gear 10 of the gear reducer 9, and is inserted into a through hole (shaft insertion hole) formed on the left side of the housing 3 as shown in FIG. The shaft 4 and the housing 3 are supported rotatably.
The gear pipe 10a may be provided separately from the final gear 10 and fixed to the final gear 10.

The power transmission part for transmitting the rotational torque of the gear pipe 10a to the valve pipe 5a is performed by the meshing part 11 provided at the axially opposed part of the gear pipe 10a and the valve pipe 5a.
As shown in FIG. 2B, a convex portion 11a protruding in the axial direction and a concave portion 11b recessed in the axial direction are provided at the opposing portion of the gear pipe 10a and the valve pipe 5a. The meshing portion 11 is configured by meshing the recess 11b in the axial direction, and the final gear 10 and the valve body 5 are coupled in a state where high torque can be transmitted.

A specific example of the meshing part 11 will be described with reference to FIG.
The convex part 11a and the concave part 11b of this embodiment are each provided in a tapered shape.
The relationship between the root tooth width L1 of the convex portion 11a and the hole width L2 of the opening portion of the concave portion 11b is provided as “L1 ≧ L2”. 11b is pressed and fitted in the axial direction so that the play in the rotational direction is surely eliminated.

Here, on the right side of the shaft 4, a step shoulder 12 is formed with which the right end of the valve pipe 5 a abuts. The step shoulder 12 is an annular step having a diameter larger than the inner diameter of the valve pipe 5a.
On the other hand, as shown in FIG. 2A, the EGR valve 1 is provided with a biasing means 13 that biases the final gear 10 to the right without hindering the rotation of the final gear 10. This urging means 13 may be the same as the return spring that urges the valve body 5 in the valve closing direction, or may be provided separately.
The urging means 13 of this embodiment is a compression coil spring that is compressed between the cover 7 and the final gear 10, and urges the final gear 10 to the right side.
(I) While the right end of the gear pipe 10a is pressed against the left end of the valve pipe 5a,
(Ii) The right end of the valve pipe 5 a is pressed against the shoulder shoulder 12.
In addition, the level | step difference surface of the level | step-difference shoulder part 12 is formed smoothly, and the valve pipe 5a pressed against the level | step-difference shoulder part 12 is provided so that rotation is easy.

(Effect 1 of Example 1)
In the EGR valve 1 of this embodiment, the shaft 4 is fixed and the valve pipe 5a is slidably supported with respect to the shaft 4 as described above. The amount can be kept small. In other words, the deflection and positional deviation of the valve body 5 can be suppressed extremely small.
Further, the movable part (valve body 5 + final gear 10) including the valve body 5 is separate from the shaft 4, and the movable part including the valve body 5 is rotatably supported with respect to the shaft 4. The movable part including 5 is lightly provided.

For this reason, even if vibration occurs in the movable part including the valve body 5, vibration energy is reduced and wear due to vibration can be suppressed. Even if the EGR valve 1 is used over a long period of time, leakage of EGR gas due to wear. Can be prevented. That is, even when the EGR valve 1 is used over a long period of time, low valve leakage can be realized, and high reliability can be obtained.
Further, since the valve pipe 5a is slidably supported on the shaft 4, "independent bearings for supporting the shaft 4 rotatably in the prior art (independent bearings such as a ball bearing J1 and a metal bearing J2). Etc .: see FIG. 11) ”can be eliminated, and the cost of the EGR valve 1 can be reduced.

(Effect 2 of Example 1)
In the EGR valve 1 of this embodiment, the urging means 13 urges the final gear 10 to the right, the right end of the gear pipe 10a provided on the final gear 10 urges the valve pipe 5a to the right, and the valve pipe 5a Is pushed against the shoulder 12.
Thus, the back end of the valve body 5 can be eliminated by pressing the right end of the valve pipe 5a against the step shoulder 12 by the urging means 13.
In addition, since the movable part including the valve body 5 is urged by the urging means 13, vibration of the movable part including the valve body 5 can be suppressed. That is, it is possible to suppress vibration of the movable part that causes wear.
Furthermore, when the right end of the gear pipe 10a is pressed against the valve pipe 5a by the urging means 13, the backlash of the meshing portion 11 can be eliminated, and hysteresis is not generated between the electric actuator 6 and the valve body 5, so The output torque of the actuator 6 can be directly transmitted to the valve body 5.

[Example 2]
A second embodiment will be described with reference to FIGS. In the following embodiments, the same reference numerals as those in the first embodiment denote the same functions.
In the EGR valve 1 of Example 2, a seal ring 14 is provided on the outer peripheral edge of the valve body 5.
The seal ring 14 closes the gap around the valve body 5 (between the valve body 5 and the inner wall of the EGR flow path 2) when the EGR flow path 2 is fully closed. It is inserted into the inside of the seal fitting groove 14a formed over the circumference.

Thus, by providing the seal ring 14 on the outer peripheral edge of the valve body 5, it is possible to prevent the valve body 5 from directly touching the inner wall of the EGR flow path 2 and to vibrate. 5 ”and“ between the seal ring 14 ”and“ between the seal ring 14 and the inner wall of the EGR flow path 2 ”.
As a result, vibration energy generated in the valve body 5 can be dispersed, so that the occurrence of wear can be further suppressed, and the low valve leakage of the EGR valve 1 can be realized over a long period of time.

[Example 3]
Embodiment 3 will be described with reference to FIG.
A cooling water passage 15 through which cooling water is circulated and supplied is provided inside the shaft 4.
The cooling water in this embodiment is engine cooling water. The engine cooling water is radiated by heat exchange with the outside air by the radiator, and is maintained at about 80 ° C. (100 ° C. or less) by the operation of the thermostat. The cooling water is not limited to engine cooling water, and cooling water for other uses may be used, for example, cooling water for a water cooling intercooler.

  Both ends of the shaft 4 are disposed so as to protrude to the outside of the cover 7 and the outside of the housing 3 and are connected to the circulation path of the engine cooling water. A part of the engine coolant is circulated and supplied to the coolant passage 15 formed in the shaft 4 by the operation of the water pump accompanying the operation of the engine.

  Since “the heat energy of water is several tens of times that of air”, the cooling effect by the cooling water is very large, and the exhaust heat of the EGR flow path 2 can be prevented from being transmitted to the electric actuator 6 side. For this reason, the distance from the EGR flow path 2 to the final gear 10 of the electric actuator 6 can be set short (the thickness of the housing 3 on the left side of the EGR flow path 2 can be set thin), and the EGR valve 1 can be made compact. It becomes possible to become.

  Further, since the valve pipe 5a is cooled via the shaft 4, grease or oil can be used as a lubricating means between the shaft 4 and the valve pipe 5a without considering heat. That is, since it is not necessary to use expensive heat-resistant grease, the cost can be suppressed.

  Furthermore, since the valve body 5 can be cooled via the valve pipe 5a, it is possible to manufacture the valve body 5 from a resin excellent in moldability. That is, the complicated shape of the valve body 5 having the valve pipe 5a can be easily manufactured, and the cost can be suppressed.

[Example 4]
Embodiment 4 will be described with reference to FIG.
In the shaft 4 of this embodiment, a wide grease holding groove 16 is formed in the central portion of the range where the valve pipe 5a is arranged, and the valve pipe 5a is slid on the outer peripheral surface of the shaft 4 on both sides of the grease holding groove 16. It supports freely.
The valve pipe 5 a is fitted on the inside of the grease holding groove 16 with the lubricating grease applied, and the lubricating grease is held inside the grease holding groove 16.
Thus, by providing the grease retaining groove 16 for retaining the grease inside the valve pipe 5a, the grease can be stored inside the valve pipe 5a for a long period of time, and the sliding of the valve pipe 5a for a long period of time. High dynamic performance can be maintained.
The grease holding groove 16 is also provided in the first embodiment described above.

Further, in the EGR valve 1 of this embodiment, a seal ring 17 sandwiched between the final gear 10 and the housing 3 is disposed between the final gear 10 and the housing 3.
The seal ring 17 can prevent exhaust gas and the like flowing through the EGR flow path 2 from entering the accommodation chamber of the electric actuator 6.

[Example 5]
Embodiment 5 will be described with reference to FIG.
In the shaft 4 of this embodiment, labyrinth grooves 18 are formed on both sides of the range where the valve pipe 5a is disposed to hold lubricating grease or to contain foreign matter.
7A shows that one labyrinth groove 18 is provided on each side of the grease holding groove 16, and FIG. 7B shows a plurality of (3 in the drawing) on both sides of the grease holding groove 16. The labyrinth groove 18 is provided.

By holding the grease inside the labyrinth groove 18, the sliding performance of both end portions (the right end is the stepped shoulder portion 12) of the valve pipe 5a can be enhanced.
Even if a deposit enters between the shaft 4 and the valve pipe 5a from the end of the valve pipe 5a, the deposited deposit is accommodated in the labyrinth groove 18 and the shaft 4 and the valve pipe 5a slide by the deposit. It is possible to avoid problems that degrade performance.

[Example 6]
Example 6 will be described with reference to FIG.
The shaft 4 of this embodiment is formed with seal grooves 19a into which seal rings 19 for closing the gap between the shaft 4 and the valve pipe 5a are fitted on both sides of the range arranged in the valve pipe 5a.
The seal ring 19 disposed in the seal groove 19a can prevent the deposit from entering between the shaft 4 and the valve pipe 5a, and the deposit causes a problem that the sliding performance of the shaft 4 and the valve pipe 5a deteriorates. It can be avoided.

  Further, as shown in FIG. 8, by using in combination with the grease holding groove 16, the grease stored in the grease holding groove 16 is prevented from flowing out to the outside by the seal ring 19 disposed in the seal groove 19a. The sliding performance of the valve pipe 5a can be maintained high over a long period.

[Example 7]
Embodiment 7 will be described with reference to FIG.
As shown in FIG. 9A, the EGR valve 1 of this embodiment is provided with a seal fitting portion 20 that covers the periphery of the valve pipe 5a on the valve pipe 5a side of the gear pipe 10a.
The seal fitting portion 20 is a cylindrical portion that covers the entire outer periphery of the left end of the valve pipe 5a. In this embodiment, the left end of the valve pipe 5a is press-fitted and fixed inside the seal fitting portion 20. Is.
The seal fitting portion 20 can prevent the deposit from entering between the shaft 4 and the valve pipe 5a.

In this embodiment, the power transmission portion for transmitting the rotational torque of the gear pipe 10a to the valve pipe 5a is performed by press-fitting the seal fitting portion 20 of the gear pipe 10a and the valve pipe 5a.
Specifically, the press-fitting portion of the seal fitting portion 20 and the valve pipe 5a is provided with a meshing portion that meshes in the radial direction {formed on the inner peripheral surface of the seal fitting portion 20 shown in FIG. 9B. The axial spline fitting portion 20a is connected}, and the final gear 10 and the valve body 5 are coupled in a state capable of transmitting high torque.

In the EGR valve 1 of this embodiment, a seal ring 21 sandwiched between the valve pipe 5a and the step shoulder 12 is disposed between the valve pipe 5a and the step shoulder 12.
The seal ring 21 can prevent a deposit from entering between the shaft 4 and the valve pipe 5a from the right end of the valve pipe 5a.
Further, by providing this seal ring 21 with a “low μ material having a small friction coefficient (for example, ethylene tetrafluoride resin)”, the sliding resistance of the valve pipe 5a with respect to the shaft 4 can be reduced, and electric The driving load of the actuator 6 can be reduced.

Further, in the EGR valve 1 of this embodiment, a seal ring 22 that closes the sliding clearance between the housing 3 and the gear pipe 10a is disposed between the housing 3 and the gear pipe 10a.
The seal ring 22 can prevent the exhaust gas and deposit flowing through the EGR flow path 2 from entering the accommodation chamber of the electric actuator 6.

[Example 8]
Embodiment 8 will be described with reference to FIG.
In each of the above embodiments, as an example of the EGR valve 1, the example in which the valve body 5 is inclined with respect to the shaft 4 is shown.
On the other hand, in the EGR valve 1 of this embodiment, the valve body 5 is arranged in parallel with the shaft 4. Specifically, in the EGR valve 1 of this embodiment, the valve element 5 is offset from the axis of the shaft 4.

You may use combining said each Example.
In the above embodiment, the example in which the present invention is applied to the EGR valve 1 is shown. However, the fluid is not limited to the exhaust gas, and other gas fluids and liquid fluids are opened and closed, and the flow rate or pressure is adjusted. You may apply this invention to a butterfly valve (for example, throttle valve etc.).

  In the above embodiment, an example in which the electric actuator 6 is used as an example of the valve driving means has been described. However, the means for applying the rotational force to the valve body 5 is not limited, and a fluid pressure actuator (for example, a negative pressure actuator) Other valve driving means such as a hydraulic actuator or manual operation may be used.

1 EGR valve (butterfly valve)
2 EGR flow path (fluid path)
3 Housing 4 Shaft 5 Valve body 5a Valve pipe 6 Electric actuator (valve driving means)
DESCRIPTION OF SYMBOLS 8 Electric motor 9 Gear reducer 10 Final gear 10a Gear pipe 11 Engagement part 12 Step shoulder part 13 Energizing means 14 Seal ring 14a provided in the outer periphery of a valve body Seal fitting groove 15 Cooling water path 16 Grease holding groove 17 Final gear Seal ring 18 sandwiched between housing and labyrinth groove 19 Seal ring 19a disposed in seal groove of shaft 20 Seal groove 20 of shaft Seal fitting portion 21 Seal ring 22 sandwiched between valve pipe and shoulder of stepped portion Between housing and gear pipe Seal ring arranged

Claims (13)

A housing (3) in which a fluid passage (2) is formed;
A shaft (4) disposed across the fluid passage (2) and secured to the housing (3);
A valve body (5) that includes a valve pipe (5a) that is slidably supported with respect to the outer peripheral surface of the shaft (4), and that opens / closes or adjusts the opening of the fluid passage (2);
Valve driving means (6) for applying a driving force in the rotational direction to the valve pipe (5a);
A butterfly valve. The butterfly valve (1) according to claim 1,
The butterfly valve (1) is fitted into a seal fitting groove (14a) formed in the outer peripheral edge of the valve body (5), and the valve body (5) when the fluid passage (2) is fully closed. A butterfly valve comprising a seal ring (14) for closing a gap around The butterfly valve (1) according to claim 1 or claim 2,
This butterfly valve (1) is applied to an EGR valve of an exhaust gas recirculation device,
A butterfly valve characterized in that a cooling water passage (15) through which cooling water is circulated and supplied is provided in the shaft (4). In the butterfly valve (1) according to claims 1-3,
The valve drive means (6) includes an electric motor (8) that generates a rotational output when energized, and a gear reducer (9) that decelerates the rotational output of the electric motor (8) and transmits it to the valve pipe (5a). An electric actuator comprising:
The butterfly valve characterized in that the final gear (10) of the gear reducer (9) has a gear pipe (10a) supported rotatably around the shaft (4). The butterfly valve (1) according to claim 4,
The butterfly valve characterized in that the power transmission part of the gear pipe (10a) and the valve pipe (5a) is provided by a meshing part (11) meshing in the axial direction. In the butterfly valve (1) according to claim 4 or 5,
A butterfly valve characterized in that a seal fitting portion (20) for covering the periphery of the valve pipe (5a) is provided on the side of the valve pipe (5a) of the gear pipe (10a). In the butterfly valve (1) according to any one of claims 4 to 6,
The shaft (4) includes a step shoulder (12) with which one end of the valve pipe (5a) abuts.
The butterfly valve (1) includes a biasing means (13) for pressing the valve pipe (5a) against the step shoulder (12) through the final gear (10). The butterfly valve (1) according to claim 7,
A seal ring (21) sandwiched between the valve pipe (5a) and the step shoulder (12) is disposed between the valve pipe (5a) and the step shoulder (12). Butterfly valve. In the butterfly valve (1) according to claim 7 or claim 8,
A butterfly valve characterized in that a seal ring (17) sandwiched between the final gear (10) and the housing (3) is disposed between the final gear (10) and the housing (3). In the butterfly valve (1) according to any one of claims 4 to 9,
A butterfly valve characterized in that a seal ring (22) for closing a sliding clearance between the housing (3) and the gear pipe (10a) is disposed between the housing (3) and the gear pipe (10a). . In the butterfly valve (1) according to any of claims 1 to 10,
The said shaft (4) has a grease holding groove (16) which hold | maintains the grease for lubrication in the center part of the range arrange | positioned in the said valve pipe (5a), The butterfly valve characterized by the above-mentioned. In the butterfly valve (1) according to any one of claims 1 to 11,
The said shaft (4) has the labyrinth groove | channel (18) which hold | maintains the grease for lubrication or accommodates a foreign material on both sides of the range arrange | positioned in the said valve pipe (5a), The butterfly valve characterized by the above-mentioned. In the butterfly valve (1) according to any one of claims 1 to 11,
The shaft (4) is a seal in which a seal ring (19) for closing a gap between the shaft (4) and the valve pipe (5a) is fitted on both sides of the range in which the shaft (4a) is disposed. A butterfly valve having a groove (19a).

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