JP2006046358A - Valve element structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To completely prevent a liquid from oozing while enabling a seal member formed of a non-deformable material to be fitted to a recessed part. <P>SOLUTION: The recessed part 2 for mounting a valve element is formed in the tip face of a valve stem 1, and a space part 4 in which at least its tip side is tilted to a valve seat S side in a convergent wedge shape is formed between the outer peripheral surface 3a of the seal member 3 fitted into the recessed part 2 and the inner peripheral surface 2a of the recessed part 2 facing the outer peripheral surface. Accordingly, since the maximum outer diameter D1 of the seal member 3 on the fitting side is approximately equal to the inner diameter D2 of the recessed part 2 at its tip, the seal member 3 is accessible into the recessed part 2. A packing 5 is compressingly installed in the space part 4, and fitted to the wedge-like tilted surfaces 3a' and 2a'. Thus, since the sealing performance of the packing 5 with the wedge-like tilted surfaces 3a' and 2a' is increased by a wedge effect utilizing the elasticity of the packing 5, entry of a fluid from the outside to the space part 4 can be cut out. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a valve body structure such as a sanitary valve that is provided in a place where high hygiene management is required, such as a dairy / beverage and other food factories or pharmaceutical factories.
More specifically, the present invention relates to a valve body structure in which an annular seal member that comes in contact with and separates from a valve seat is fitted into and mounted on a valve body mounting recess formed in a valve stem.

Conventionally, as this type of valve body structure, a valve body mounting recess (valve rod) is formed in an annular shape on the outer periphery of the tip of a valve stem (valve shaft). Either or both of the protrusions are appropriately projected, and a Teflon (registered trademark) or other synthetic resin or rubber seal member (valve member) is attached, and the protrusion bites into the seal member, In some cases, the contact surface of the seal member is completely brought into close contact so that bacteria are not generated in the deformation of the seal member or in the gap between the recess and the seal member (for example, see Patent Document 1).
In addition, a seal member (rubber sheet) is sandwiched between a recess (sheet seat) formed on the front end surface and a sheet presser arranged substantially parallel to the recess, and the contact surfaces are fitted together. In some cases, the bolt is tightened so that the seal member is firmly locked and fixed to prevent it from coming off (for example, see Patent Document 2).

Japanese Utility Model Publication No. 52-41524 (first page, Fig. 1-2) Japanese Patent Laid-Open No. 11-201295 (page 1-3, FIG. 1)

However, in such a conventional valve body structure, in the case of Patent Document 1, when the seal member is formed of a hard and hardly deformable material such as Teflon (registered trademark), it is formed on the outer periphery of the tip of the valve stem. Therefore, there is a problem in that the use is limited because the seal member cannot be mounted in the annular recess, and the seal member is limited to a material that is easily elastically deformed.
Therefore, as in Patent Document 2, if a valve body mounting recess is formed on the tip surface of the valve stem, a sealing member is inserted therein, and then tightened with a mounting bolt in a state of being sandwiched by a sheet press, the deformation It is conceivable that even an impossible seal member can be mounted.
However, in this case, since the outer peripheral surface of the seal member and the inner peripheral surface of the recess facing the seal member are only in contact with each other or pressed against each other, fluid easily enters these gaps, and the soaked liquid is sealed. There is a problem in that the bacteria are prone to grow and become unsanitary as a result, and as a result, the bacteria are likely to grow and become unsanitary. To prevent this, it is necessary to frequently perform disassembly and cleaning, which causes a reduction in operating rate. .

The invention according to the first aspect of the present invention aims to completely prevent the liquid from penetrating while making it possible to attach a seal member made of a material that cannot be deformed to the recess.
In addition to the object of the invention described in claim 1, the invention described in claim 2 aims to simplify the structure most.
In addition to the object of the invention described in claim 1 or 2, the invention described in claim 3 is intended to easily replace and disassemble and clean the seal member.

In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention is characterized in that a recess for mounting a valve body is formed on a tip surface of a valve stem, and an outer peripheral surface of a seal member fitted in the recess; A space portion is formed between the inner peripheral surface of the concave portion facing it and at least the tip side inclined in a tapered wedge shape toward the valve seat side, and packing is compressed into the space portion to form a wedge-shaped inclined surface. Each is characterized by close contact.
The invention described in claim 2 is characterized in that the structure of the invention described in claim 1 is added with a configuration in which the cross-sectional shapes of the space and the packing are formed in a substantially triangular shape.
According to a third aspect of the present invention, the pressing member is covered from the outside of the seal member to the configuration of the first or second aspect of the invention, and tightened in the axial direction with respect to the valve stem by a fastening means that inserts both of them. Further, the present invention is characterized in that a structure in which the seal member and the packing are brought into pressure contact with the inner bottom surface of the recess is added.

According to the first aspect of the present invention, a recess for attaching a valve body is formed on the tip surface of the valve stem, and the outer peripheral surface of the seal member fitted into the recess, and the inner peripheral surface of the recess facing the recess By forming a space portion in which at least the distal end side is inclined in a tapered wedge shape toward the valve seat side, the maximum outer diameter on the insertion side of the seal member becomes substantially the same as the distal inner diameter of the concave portion. The seal member can be inserted and removed freely, and the packing is compressed and installed in the space portion, and is brought into close contact with the wedge-shaped inclined surface, so that the wedge and the wedge-shaped inclined surface are utilized by the wedge effect utilizing the elasticity of the packing. The sealing performance is improved, and the intrusion of fluid from the outside into the space is blocked.
Therefore, it is possible to completely prevent the liquid from penetrating while making it possible to attach the seal member made of a material that cannot be deformed to the recess.
As a result, not only can the seal member of the best material be selected according to the application, but also the replacement of the seal member is easy, so that it is possible to improve the maintainability, and foreign matters such as liquid wrap around the back side of the seal member. It is always hygienic because it does not occur, and it is not necessary to frequently perform disassembly and cleaning, and the operating rate can be maintained high.

In addition to the effect of the invention of claim 1, the invention of claim 2 forms the space and the cross-sectional shape of the packing in a substantially triangular shape so that the packing and the seal member can be easily molded and aligned with the seal member. Easy.
Therefore, the structure can be simplified most.

In addition to the effect of the invention of claim 1 or 2, the invention of claim 3 covers the pressing member from the outside of the seal member, and tightens it in the axial direction with respect to the valve stem by a fastening means that inserts both of them. By pressing the seal member and the packing against the inner bottom surface of the recess, the seal member and the packing can be easily positioned and disassembled only by operating the fastening means.
Therefore, replacement and disassembly cleaning of the seal member can be easily performed.

  In the valve body structure A of the present invention, as shown in FIG. 1, a concave portion 2 for mounting a disc-like valve body is formed in a cross-sectional dovetail shape (reverse taper shape) at the center of the tip surface of the valve stem 1. A seal member (stem packing) 3 formed in an annular shape with, for example, a fluororesin such as PFA or other material is inserted into the recess 2, and the base end side of the outer peripheral surface 3 a of these seal members 3, A space 4 that is inclined in a tapered wedge shape (inverted V-shape) at least at the tip side toward the valve seat S side is formed between the inner peripheral surface 2a of the concave portion 2 that gradually decreases in diameter toward the tip side. Forming.

  Then, an annular packing (fixed packing) 5 larger than the cross-sectional area of the space portion 4 formed of an elastically deformable material such as EPDM or silicone rubber is elastically deformed toward the wedge-shaped space portion 4. Then, after inserting the proximal end side of the seal member 3 and positioning them so as to be in pressure contact with the inner bottom surface 2b of the recess 2, the packing 5 is compressed and deformed to form a wedge shape. The outer peripheral surface 3a 'of the sealing member 3 and the inner peripheral surface 2a' of the recess 2 are in close contact with each other.

As a method for press-contact positioning of the seal member 3 and the packing 5 as described above, a pressing member 6 is put on the outside of the seal member 3, and tightened in the axial direction with respect to the valve stem 1 by the fastening means 7 through which both are inserted, It is preferable that the seal member 3 and the packing 5 are pressed against the inner bottom surface 2 b of the recess 2.
Embodiments of the present invention will be described below with reference to the drawings.

  In the first embodiment, as shown in FIGS. 1 and 2, the valve body structure A of the present invention is provided in a sanitary valve B, and the valve rod 1 is reciprocated in the axial direction by an actuator (not shown) of an air motor, for example. This shows the case where the front end of the seal member 3 contacts and separates from the valve seat S and the flow path C opens and closes, and the proximal end side of the outer peripheral surface 3a of the seal member 3 and the inner peripheral surface 2a of the recess 2 A space portion 4 having a triangular cross section is formed between them, and a packing 5 having a triangular cross section larger than the cross sectional area of the space portion 4 is fitted into the space portion 4 and compressed and deformed.

  In the case of the illustrated example, the cross-sectional shapes of the space portion 4 and the packing 5 are formed in a substantially isosceles triangle having an acute apex angle.

  Further, as a method of positioning the seal member 3, the inner peripheral surface 3b of the seal member 3 and the outer peripheral surface 6a of the pressing member 6 are formed in a shape that fits to each other, and the sealing member 3 and the pressing member 6 are inserted. As a means 7, a seated bolt 7 a is screwed into a screw hole 7 b formed in the valve rod 1, and a gap between the seated bolt 7 a and the pressing member 6 is sealed with an O-ring 8.

Next, the effect of the valve body structure A will be described.
First, as shown in FIGS. 1 and 2, the proximal end side of the outer peripheral surface 3a of the seal member 3 fitted in the concave portion 2 formed at the center of the front end surface of the valve stem 1, and the inner peripheral surface of the concave portion 2 facing the same. Since the space part 4 which inclines in the shape of a tapered wedge toward the valve seat S is formed between 2a and 2a, the insertion-side maximum outer diameter D1 of the seal member 3 is substantially the same as the tip inner diameter D2 of the recess 2 facing it. It becomes a diameter, and the seal member 3 can be taken in and out freely in the recess 2.

  As a result, even when the seal member 3 is formed of a non-deformable material such as a fluororesin, the seal member 3 can be easily attached to the recess 2 and the best seal material 3 can be selected according to the application.

  Then, an elastically deformable packing 5 is compressed and installed in the space portion 4 so as to be in close contact with the outer peripheral surface 3a ′ of the seal member 3 and the inner peripheral surface 2a ′ of the recess 2 inclined in a wedge shape. Due to the wedge effect utilizing elasticity, the sealing performance between the packing 5 and the wedge-shaped inclined surfaces 3a 'and 2a' is improved, and the intrusion of fluid into the space 4 from the outside is blocked.

  As a result, it is possible to completely prevent the liquid from penetrating and always keep it hygienic.

Furthermore, in the case of Example 1, since the cross-sectional shape of the space part 4 and the packing 5 was formed in a substantially triangular shape, the packing 5 and the seal member 3 can be easily formed and the alignment with the seal member 3 is easy.
As a result, there is an advantage that the penetration of the liquid can be completely prevented while simplifying the structure.

Further, the pressing member 6 is put on the outer side of the seal member 3, and is fastened in the axial direction with respect to the valve stem 1 by the fastening means 7 that inserts both of them, so that the seal member 3 and the packing 5 are attached to the inner bottom surface 2 b of the recess 2. Since they are brought into pressure contact, the sealing member 3 and the packing 5 can be easily positioned and disassembled only by operating the fastening means 7.
As a result, there is an advantage that the seal member 3 can be easily replaced and disassembled and cleaned.

  In the second embodiment, as shown in FIG. 3, the base end side of the outer peripheral surface 3a of the seal member 3 is projected outward, and the wedge-shaped angle with the inner peripheral surface 2a of the concave portion 2 facing it is further reduced. However, unlike the first embodiment shown in FIGS. 1 and 2, the other configuration is the same as that of the first embodiment shown in FIGS.

In the case of the illustrated example, the sectional shape of the space 4 and the packing 5 is formed in a substantially right triangle so that the base end side of the outer peripheral surface 3a of the seal member 3 is substantially perpendicular to the bottom surface 3c. However, the shape may be a triangle having another shape as long as the apex angle is a wedge shape (acute angle).
.
Therefore, what is shown in FIG. 3 can also obtain the same effects as those of the first embodiment described above.

  In the third embodiment, as shown in FIG. 4, the contact surface between the base end side of the outer peripheral surface 3 a of the seal member 3 and the packing 5 is formed into a shape that fits together, and the cross section of the space portion 4 and the packing 5 is formed. The configuration in which the shape is a polygonal shape is different from the first embodiment shown in FIGS. 1 and 2, and the other configuration is the same as the first embodiment shown in FIGS.

In the case of the illustrated example, the sectional shape of the space 4 and the packing 5 is formed in a substantially square shape, but is not limited thereto, and if the apex angle is a wedge shape (acute angle), a substantially pentagonal shape, a hexagonal shape, etc. But it ’s okay.
Therefore, what is shown in FIG. 4 can also obtain the same effects as those of the first embodiment described above.

  In the fourth embodiment, as shown in FIG. 5, the contact surface between the base end side of the outer peripheral surface 3 a of the seal member 3 and the packing 5 is formed into a curved surface to be fitted to each other, and the cross section of the space portion 4 and the packing 5 is formed. The configuration in which the shape is formed in a substantially triangular shape is different from the first embodiment shown in FIGS. 1 and 2, and the other configuration is the same as that of the first embodiment shown in FIGS. 1 and 2.

In the case of the illustrated example, the contact surface between the base end side of the outer peripheral surface 3a of the seal member 3 and the packing 5 is formed as an arcuate surface that fits to each other. However, the present invention is not limited to this, and the apex angle is a wedge shape. If it becomes, it may be a curved surface other than the circular arc surface.
Therefore, the function and effect similar to those of the first embodiment described above can also be obtained with the one shown in FIG.

  In the fifth embodiment, as shown in FIG. 6, the contact surface between the base end side of the outer peripheral surface 3 a of the seal member 3 and the packing 5 is formed to fit with each other, and the cross section of the space portion 4 and the packing 5 is formed. Unlike the first embodiment shown in FIG. 1 and FIG. 2, the configuration in which the shape is a polygonal shape with a part of the recess is the same as that of the first embodiment shown in FIG. 1 and FIG. is there.

In the case of the illustrated example, the cross-sectional shapes of the space 4 and the packing 5 are formed in a substantially quadrangular shape in which a part is recessed. However, the present invention is not limited to this, and if the apex angle is a wedge shape (acute angle), A substantially pentagonal or hexagonal shape with a recessed portion may be used.
Accordingly, the function and effect similar to those of the first embodiment described above can also be obtained with the one shown in FIG.

  In the first embodiment, the valve body structure A of the present invention is provided in the sanitary valve B. For example, when the valve rod 1 is reciprocated in the axial direction by an actuator of an air motor, the tip of the seal member 3 is moved to the valve seat. Although the case where the flow path C opens and closes in contact with and away from S has been shown, the present invention is not limited to this, and the valve body structure A of the present invention is provided in a valve other than the sanitary valve B, or is manually opened and closed other than the actuator, for example. The valve stem 1 may be used.

  Furthermore, although the case where the bolt 7a with a seat is screwed into the screw hole 7b formed in the valve rod 1 as the fastening means 7 for inserting the seal member 3 and the pressing member 6 is shown, it is not limited thereto. Other structures may be employed, such as inserting the seal member 3 and the pressing member 6 into the bolt continuously provided on the valve stem 1 side and tightening with a nut.

It is a vertical front view of the valve body structure which shows Example 1 of this invention. It is a decomposition | disassembly expanded sectional view of the principal part. It is an expansion vertical front view of only the valve body structure which shows Example 2 of this invention. It is an expansion vertical front view of only the valve body structure which shows Example 3 of this invention. It is an expansion vertical front view only of the valve body structure which shows Example 4 of this invention. It is an expansion vertical front view only of the valve body structure which shows Example 5 of this invention.

Explanation of symbols

A Valve body structure B Sanitary valve C Flow path D1 Sealing member insertion side maximum outer diameter D2 Recessed tip inner diameter S Valve seat 1 Valve rod 2 Recessed part 2a Inner peripheral surface 2a 'Inclined surface 2b Inner bottom surface 3 Seal member 3a Outer peripheral surface 3a ′ Inclined surface 3b Inner peripheral surface 3c Bottom surface 4 Space 5 Packing 6 Holding member 6a Outer peripheral surface 7 Fastening means 7a Seated bolt 7b Screw hole 8 O-ring

Claims (3)

In the valve body structure in which the seal member (3) that is in contact with and away from the valve seat (S) is fitted into the valve body mounting recess (2) formed in the valve stem (1).
A recess (2) for mounting a valve body is formed on the distal end surface of the valve stem (1), and an outer peripheral surface (3a) of a seal member (3) fitted into the recess (2) and a recess ( A space portion (4) is formed between the inner peripheral surface (2a) of 2) and at least the tip side is inclined in a tapered wedge shape toward the valve seat (S), and the space portion (4) is formed in the space portion (4). A valve body structure characterized in that the packing (5) is compression-fitted and brought into close contact with the wedge-shaped inclined surfaces (3a ', 2a'). The valve body structure according to claim 1, wherein the space (4) and the packing (5) have a substantially triangular cross section. The pressing member (6) is covered from the outside of the sealing member (3), and is tightened in the axial direction with respect to the valve stem (1) by the fastening means (7) through which both are inserted, and the sealing member (3) and the packing The valve body structure according to claim 1 or 2, wherein (5) is brought into pressure contact with the inner bottom surface (2b) of the recess (2).

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