JP5619327B2 - Valve for fluid control - Google Patents

Description

  The present invention relates to a fluid control valve such as an exhaust gas recirculation (EGR) valve.

  Conventionally, fluid control valves (butterfly type, poppet type, flap type, etc.) have been used to scrape off foreign matter such as fluid and exhaust gas deposits around the valve shaft and prevent fluid and foreign matter from entering the bearing. For example, a filter such as a mesh filter is used, and a holder is installed to hold the filter. On the other hand, in order to support the bearing portion, for example, the bearing portion is pressurized in the axial direction with an O-ring as in Patent Document 1, and is brought into contact with the stepped end surface of the housing. Can be pressed in the axial direction with a coil spring and brought into contact with the stepped end surface of the valve shaft, or the bearing part can be pressed in the axial direction with a ring seal part and brought into contact with the labyrinth seal part as in Patent Document 3. It was.

JP 2005-120932 A JP 2005-291129 A JP 2007-32301 A

  Since the conventional fluid control valve is configured as described above, separate parts (O-ring, coil spring, ring seal part, etc.) for generating a pressurization are required to support the bearing part. It was. For this reason, there is a problem that the number of parts increases and the space required for the configuration increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to eliminate the need for a pressurizing member for supporting the bearing portion and to reduce the number of parts.

The fluid control valve according to the present invention includes a fluid passage through which a fluid flows, a through hole communicating with the fluid passage, a housing having a reduced diameter portion obtained by reducing a part of the through hole, and a large diameter inserted into the through hole. A holder having a cylindrical portion, a small-diameter cylindrical portion press-fitted or inserted into the reduced-diameter portion, a shoulder portion connecting the large-diameter cylindrical portion and the small-diameter cylindrical portion, a filter accommodated in the large-diameter cylindrical portion of the holder, and a shoulder portion Is supported by the axially applied pressure generated at a position in contact with the stepped portion between the through hole and the reduced diameter portion, and a bearing portion that is supported in contact with the predetermined support portion, and the fluid passage from the through hole. The valve shaft is inserted and supported by the bearing portion, and the valve body operates integrally with the valve shaft to open and close the fluid passage.

  According to this invention, the pressurizing member for supporting the bearing portion is generated by generating the axial pressurization with the holder for holding the filter and supporting the bearing portion in a state in contact with the predetermined support portion. It becomes unnecessary. Therefore, the number of parts constituting the fluid control valve can be reduced.

It is a longitudinal cross-sectional view which shows the structure of the valve for fluid control which concerns on Embodiment 1 of this invention. It is an enlarged view of the holder periphery of the valve for fluid control shown in FIG. 6 is an enlarged view showing a holder modification of the fluid control valve according to Embodiment 1. FIG. 6 is an enlarged view showing a holder modification of the fluid control valve according to Embodiment 1. FIG. 6 is an enlarged view showing a holder modification of the fluid control valve according to Embodiment 1. FIG.

Embodiment 1 FIG.
The EGR valve 1 shown in FIG. 1 transmits the rotational driving force generated by the motor 2 to the valve shaft 4 by gears (not shown) housed in the gear box 3, and is fixed to the valve shaft 4 with screws 5 or the like. In this configuration, the butterfly type valve element 6 is rotated to open and close the fluid passage 8 formed in the housing 7 and control the flow rate of the exhaust gas flowing through the fluid passage 8.

  The housing 7 is provided with a through hole 9 that communicates the outside with the fluid passage 8. The valve shaft 4 is inserted into the through hole 9. Further, a reduced diameter portion 10 having a reduced inner diameter is formed on the end side of the through hole 9 that opens to the fluid passage 8. The through-hole 9 is provided with a filter 11 such as a mesh filter, a holder 12 that holds the filter 11, a ring-shaped plate 13, and a bearing portion 14 that rotatably supports the valve shaft 4. Further, a plug (supporting portion) 15 is press-fitted to the end of the through hole 9 that opens to the outside, and the through hole 9 is closed.

Next, details of the holder 12 will be described using the enlarged view of FIG.
The metal holder 12 includes a cylindrical large-diameter cylindrical portion 12a having substantially the same diameter as the through-hole 9, and a cylindrical small-diameter tube having a smaller diameter than the large-diameter cylindrical portion 12a and substantially the same diameter as the reduced diameter portion 10. It is comprised from the part 12b and the shoulder part 12c which connects the large diameter cylinder part 12a and the small diameter cylinder part 12b. The large diameter cylindrical portion 12a houses the filter 11 therein. The small-diameter cylindrical portion 12b has a length in the axial direction of the small-diameter cylindrical portion 12b longer than the axial length of the reduced-diameter portion 10 to form a protruding portion 12d that protrudes into the fluid passage 8. The shoulder portion 12c includes a planar straight portion 12c-1 bent vertically from the small diameter cylindrical portion 12b, and a tapered portion 12c inclined from the end of the straight portion 12c-1 toward the end of the large diameter cylindrical portion 12a. -2.

When assembling the EGR valve 1, the holder 12 is inserted into the through hole 9 of the housing 7, and the small diameter cylindrical portion 12 b is press-fitted into the reduced diameter portion 10. The holder 12 is installed in the through hole 9 by press-fitting the small diameter cylindrical portion 12 b into the reduced diameter portion 10. At this time, the holder 12 is positioned by bringing the straight portion 12c-1 into contact with the stepped portion 10a. On the other hand, since a gap is formed between the tapered portion 12c-2 and the stepped portion 10a, the tapered portion 12c-2 can be elastically deformed in this gap so that the spring property in the axial direction of the holder 12 can be secured. Become.
Alternatively, the holder 12 may be fixed by abutting the straight portion 12c-1 and the stepped portion 10a instead of pressing the small diameter cylindrical portion 12b into the reduced diameter portion 10 and fixing the holder 12. In this case, the small diameter cylindrical portion 12b may be inserted into the reduced diameter portion 10.

  Subsequently, the filter 11 and the plate 13 are inserted into the through hole 9, the filter 11 is accommodated in the large diameter cylindrical portion 12a, and the plate 13 is brought into contact with the end of the large diameter cylindrical portion 12a. Subsequently, the bearing portion 14 is press-fitted into the through hole 9. Finally, a plug 15 (not shown in FIG. 2) is press-fitted into the through hole 9 to press the holder 12 through the bearing portion 14 and the plate 13. In response to this pressing force, the tapered portion 12c-2 of the holder 12 is compressed, and a pressure is generated in the axial direction indicated by an arrow in FIG. Then, the holder 12 pressurizes the bearing portion 14 in the axial direction via the plate 13 and abuts against the plug 15 to support it. Therefore, it is necessary to assemble the plug 15 with a pressure input that does not detach even when this pressure is applied.

  As a result, it is possible to omit a separate pressurizing member such as an O-ring, a coil spring, a lip seal, and a wave washer, which has conventionally been required to pressurize and support the bearing portion 14, and to reduce the number of components. Can be reduced. Conventionally, a space for installing a separate pressurizing member has been required. However, by adopting the holder 12 having this structure, such a space becomes unnecessary, and the EGR valve 1 can be downsized. be able to.

  Although not visible in FIG. 1, the filter 11, the holder 12, the plate 13, and the bearing portion 14 can be installed in the through hole 9 on the opposite side across the fluid passage 8. When assembling the EGR valve 1, the holder 12, the filter 11, the plate 13 and the bearing portion 14 are inserted or press-fitted from the end of the through hole 9 opened to the gear box 3 side, and finally the valve shaft 4 is inserted into the gear box It is only necessary to press-fit the holder 12 by press-fitting a plate or the like (corresponding to the plug 15) having a hole for passing through 3.

  During operation of the EGR valve 1, exhaust gas flowing through the fluid passage 8, deposits contained in the exhaust gas, condensed water condensed with water vapor contained in the exhaust gas, and the like are filtered from the gap between the valve shaft 4 and the through hole 9. And it penetrates into the bearing part 14. This intrusion is suppressed by the filter 11. Further, the filter 11 scrapes off the exhaust gas and the like adhering to the outer peripheral surface of the valve shaft 4.

  At this time, the protrusion 12 d of the holder 12 protrudes into the fluid passage 8, whereby invasion of exhaust gas or the like into the holder 12 can be suppressed. Further, the tip of the projecting portion 12d is bent toward the valve shaft 4 to reduce the distance between the tip and the valve shaft 4 to narrow the opening, thereby further suppressing the intrusion of exhaust gas or the like into the holder 12. It has a structure to do. Further, by making the bent shape of the projecting portion 12d into a smooth R shape, it is possible to obtain a structure in which the flow of exhaust gas in the fluid passage 8 is hardly obstructed (vortices are not easily generated). However, the bent shape of the protruding portion 12d is not limited to the R shape.

  Further, a space may be provided between the small-diameter cylindrical portion 12b and the valve shaft 4 to form a reservoir portion 12e, which may be structured to accumulate in the reservoir portion 12e even if an exhaust gas deposit or the like enters the holder 12 to some extent. Thus, while the protrusion 12d is bent to narrow the opening to the fluid passage 8 and suppress the intrusion of exhaust gas deposits or the like, the reservoir 12e is provided in the space inside the small diameter cylindrical portion 12b to widen the intrusion. It is possible to collect exhaust gas deposits and the like. Therefore, clogging between the small-diameter cylindrical portion 12b and the valve shaft 4 due to accumulation of substances such as exhaust gas deposits and sticking of the valve shaft 4 can be suppressed.

  In consideration of cost, when a material such as aluminum or cast iron is used as a material constituting the housing 7, the reduced diameter portion 10 opened to the fluid passage 8 and the through hole 9 around the reduced diameter portion 10 are used. Corrosion is likely to occur because the flow of exhaust gas tends to stagnate. If the holder 12 is not installed between the valve shaft 4 and the housing 7, the surface of the reduced diameter portion 10 and the through hole 9 around the reduced diameter portion 10 is unevenly roughened when aluminum, cast iron, or the like corrodes. Since exhaust gas deposits and the like are easily deposited and fixed, the concern that the valve shaft 4 is fixed increases.

  Thus, for example, the holder 12 is made of a corrosion-resistant material such as stainless steel to prevent corrosion of the holder 12 itself. Further, since the holder 12 covers the reduced diameter portion 10 opened to the fluid passage 8 and the through hole 9 around the reduced diameter portion 10 so as not to contact the exhaust gas, corrosion on the housing 7 side can also be suppressed. Furthermore, since the small-diameter cylindrical portion 12b of the holder 12 is press-fitted into the reduced-diameter portion 10 of the through hole 9, a gap between the two can be eliminated and corrosion of the press-fitted portion can be prevented.

  As described above, according to the first embodiment, the EGR valve 1 includes the fluid passage 8 through which the exhaust gas flows, the through hole 9 communicating with the fluid passage 8, and the reduced diameter portion 10 in which a part of the through hole 9 is reduced in diameter. A housing 7 having a large-diameter cylindrical portion 12a inserted into the through-hole 9, a small-diameter cylindrical portion 12b press-fitted or inserted into the reduced-diameter portion 10, and the large-diameter cylindrical portion 12a and the small-diameter cylindrical portion 12b. A holder 12 having a shoulder 12c that generates axial pressure at a position in contact with a stepped portion 10a between 9 and the reduced diameter portion 10, a filter 11 housed in the large diameter cylindrical portion 12a of the holder 12, and a shaft A bearing portion 14 that is supported in contact with the plug 15 by the pressure applied in the direction, a valve shaft 4 that is inserted into the fluid passage 8 through the through hole 9 and is supported by the bearing portion 14, and a valve shaft 4. And a valve body 6 that opens and closes the fluid passage 8. It was constructed to so that. For this reason, the pressurizing member for supporting the bearing part 14 becomes unnecessary, and the number of parts constituting the EGR valve 1 can be reduced.

  Moreover, according to Embodiment 1, the holder 12 forms the taper part 12c-2 in at least one part of the shoulder part 12c, and is elastic by the clearance gap formed between the taper part 12c-2 and the level | step-difference part 10a. It was configured to generate a preload by deformation. For this reason, the taper part 12c-2 which received the pressing force of the plug 15 is compressed, whereby the spring property of the holder 12 can be easily ensured.

  Further, according to the first embodiment, the holder 12 is configured to form the straight portion 12c-1 in contact with the stepped portion 10a on at least a part of the shoulder portion 12c. For this reason, the holder 12 can be positioned by the straight portion 12c-1, and the holder 12 can be easily installed. In addition, since the tapered portion 12c-2 is elastically deformed with the straight portion 12c-1 as a fulcrum, a more stable spring property can be ensured.

  Further, according to the first embodiment, the holder 12 is configured to have the protruding portion 12d having a shape in which the end portion of the small diameter cylindrical portion 12b protrudes into the fluid passage 8. For this reason, exhaust gas, exhaust gas deposit, condensed water and the like can be prevented from entering the filter 11 and the bearing portion 14 in the holder 12.

  In addition, according to the first embodiment, the holder 12 is made of a corrosion-resistant material such as stainless steel, so that not only corrosion of the holder 12 is prevented, but also the housing 7 covered with the holder 12 Corrosion can also be prevented.

  Further, according to the first embodiment, the holder 12 is configured to have the reservoir portion 12e that accumulates foreign matter such as exhaust gas deposit between the small-diameter cylindrical portion 12b and the valve shaft 4. For this reason, there is a space between the small-diameter cylindrical portion 12b and the valve shaft 4, and clogging and sticking are less likely to occur even if substances such as exhaust gas deposits accumulate.

Note that the holder 12 is not limited to the shape shown in FIG. 2 as long as it has a shape that can ensure the spring property and generate the axial pressure. Hereinafter, modified examples will be described.
For example, in the holder 12 shown in FIG. 3, the entire shoulder portion 12c is tapered, and the straight portion 12c-1 as shown in FIG. 2 is omitted. Even in this configuration, when the holder 12 receives a pressing force from the plug 15 (not shown) via the bearing portion 14 and the plate 13, the tapered shoulder portion 12 c is compressed in the gap between the reduced diameter portion 10. Thus, axial pressure is generated, and the bearing portion 14 can be supported by being brought into contact with the plug 15.

  For example, in the holder 12 shown in FIG. 4, the whole shoulder part 12c is made into the straight shape, and the taper part 12c-2 like FIG. 2 is abbreviate | omitted. Further, a convex portion 10b that protrudes toward the shoulder portion 12c is formed at a position of the housing 7 facing the shoulder portion 12c, that is, the reduced diameter portion 10. In the case of this configuration, a part of the shoulder portion 12c comes into contact with the convex portion 10b to become a fulcrum, and the remaining portion is elastically deformed, and the spring property of the holder 12 is ensured. Therefore, the holder 12 can support the bearing portion 14 by preloading it in the axial direction and abutting against a plug 15 (not shown).

  Further, for example, in the holder 12 shown in FIG. 5, the entire shoulder portion 12c is formed in a straight shape, and the tapered portion 12c-2 as shown in FIG. 2 is omitted. Further, the shoulder portion 12c is formed with a convex portion 12f protruding toward the reduced diameter portion 10 side. In the case of this configuration, the convex portion 12f abuts on the stepped portion 10a to become a fulcrum, the shoulder portion 12c is elastically deformed, and the spring property of the holder 12 is ensured. Therefore, the holder 12 can support the bearing portion 14 by pressurizing it in the axial direction and abutting against the plug 15 (not shown).

  1 to 5, the plate 13 is interposed between the holder 12 and the bearing portion 14, but the plate 13 may be omitted. In addition, the plug 15 is used as a support portion of the bearing portion 14 and the bearing portion 14 is supported by contacting the plug 15. However, the support portion is not limited to the plug 15. Further, another component such as a plate may be interposed between the bearing portion 14 and the plug 15.

  1 to 5, the holder 12 is applied to the butterfly type fluid control valve that opens and closes the fluid passage 8 when the valve shaft 4 rotates around the central axis, but is limited to the butterfly type. However, the holder 12 may be applied to a fluid control valve such as a flap type. The holder 12 can also be applied to a fluid control valve, such as a poppet type, that opens and closes the fluid passage 8 by reciprocating the valve shaft 4 in the axial direction. Moreover, it can be used for uses other than an EGR valve.

  In addition to the above, within the scope of the invention, the invention of the present application can be modified with any component of the embodiment or omitted with any component of the embodiment.

  1 EGR valve, 2 motor, 3 gear box, 4 valve shaft, 5 screw, 6 valve body, 7 housing, 8 fluid passage, 9 through hole, 10 reduced diameter portion, 10a stepped portion, 10b convex portion, 11 filter, 12 Holder, 12a Large diameter cylindrical part, 12b Small diameter cylindrical part, 12c Shoulder part, 12c-1 Straight part, 12c-2 Tapered part, 12d Projection part, 12e Reservoir part, 12f Convex part, 13 Plate, 14 Bearing part, 15 Plug (Support part).

Claims (6)

A fluid passage through which a fluid flows, a through hole communicating with the fluid passage, and a housing having a reduced diameter portion obtained by reducing a diameter of a part of the through hole;
A holder having a large-diameter cylindrical portion inserted into the through-hole, a small-diameter cylindrical portion press-fitted or inserted into the reduced-diameter portion, and a shoulder portion connecting the large-diameter cylindrical portion and the small-diameter cylindrical portion;
A filter accommodated in the large-diameter cylindrical portion of the holder;
A bearing portion supported in a state in which the shoulder portion is in contact with a predetermined support portion by the action of axial pressure generated at a position where the shoulder portion contacts a step portion between the through hole and the reduced diameter portion ;
A valve shaft inserted into the fluid passage from the through hole and supported by the bearing portion;
A fluid control valve comprising: a valve body that operates integrally with the valve shaft and opens and closes the fluid passage.   The holder has a tapered surface formed on at least a part of the shoulder portion, and elastically deforms in a gap formed between the tapered surface and the stepped portion to generate the pressurization. Item 2. The fluid control valve according to Item 1.   The fluid control valve according to claim 1, wherein the holder has a shape in which at least a part of the shoulder is in contact with the stepped portion.   The fluid control valve according to claim 1, wherein the holder has a shape in which an end portion of the small-diameter cylindrical portion protrudes into the fluid passage.   The fluid control valve according to claim 1, wherein the holder is made of a corrosion-resistant material.   2. The fluid control valve according to claim 1, wherein the holder has a reservoir for collecting foreign matter contained in the fluid between the small-diameter cylindrical portion and the valve shaft.

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