JP5845488B2 - Butterfly valve - Google Patents

Description

  The present invention relates to a butterfly valve. Specifically, the assembly and disassembly work of a valve body and a valve stem is remarkably simplified, the fine members and special tools required for the work are unnecessary, and maintenance work such as cleaning is easy. It is related with the butterfly valve which can be made.

  A conventional butterfly valve has a configuration in which a pair of holes are formed in a cylindrical valve box formed of a tube having a size of about 250 A, and a rubber sheet is attached to the inner surface of the valve box. The disc-shaped valve body is provided with a through hole, a handle is attached to the valve stem, the valve body is inserted into the valve box, and the valve is inserted into the hole from the outside of the valve box. The rod is passed through the through hole of the valve body, and the valve body is fixed to the valve rod with two pins.

  In the above configuration, the size of the through hole formed in the valve body is, for example, as long as φ25 and a length of 250 mm, and there is a problem that it is very difficult to clean the through hole. Further, since the total weight of the butterfly valve is about 20 kg and the length of the valve stem is 300 mm, there is a problem that the assembling and disassembling work of the butterfly valve is very difficult. Furthermore, the rubber sheet is generally bonded to the inner surface of the valve box with a bond, and when used for a long time, the adhesive surface is peeled off, and cleaning water or powder is formed in the gap between the rubber sheet and the inner surface of the valve box. Intrusions and cannot be removed. In general, neoprene of 60 ° is used as the material of the conventional rubber sheet. However, since the neoprene is hard, there is a problem that a great deal of labor is required for detaching the rubber sheet. In addition, there is a problem that metal scrap is generated during a short period of use due to friction between the holes formed in the valve box and the valve stem due to friction between the metals.

  In order to solve such a problem, for example, Japanese Patent Laid-Open No. 7-293711 (Patent Document 1) discloses a butterfly valve that opens and closes a passage by rotating a flat valve body in a cylindrical valve box. Is disclosed. In the butterfly valve, a pair of recesses is formed in the valve body, a pressing tool is detachably attached to one of the pair of holes formed in the valve box, and the tip of the pressing tool is connected to one of the recesses of the valve body. Insert into. Then, a handle is detachably attached to the other of the pair of holes, and a distal end portion of the handle is removably inserted into the other concave portion of the valve body. Thereby, the above-mentioned problems such as cleaning and assembly / disassembly operations being remarkably facilitated can be solved.

  Japanese Patent Laid-Open No. 2000-257726 (Patent Document 2) discloses a case main body formed of a ferrule ring-shaped wall at both ends, and a fluid such as powder, particles, and the like that is rotatably supported by the case main body. There is disclosed a butterfly valve device including a circular butterfly valve that intermittently passes. The butterfly valve includes, as a circular butterfly valve, a disc-shaped butterfly valve main body and a packing-like elastic ring that fits into a concave groove on the outer periphery of the main body and that can slide on the inner surface of the case main body. In addition, the case main body is provided with a left-right symmetrical through hole, a pair of ferrule bearings located on the outside thereof, and a pair of valve rods that are inserted into and supported from the outside. And on the left and right sides of the butterfly valve main body, a thin flat portion that has the same thickness as the elastic ring and matches the tip shape of the valve stem, and a notch space portion are formed outside thereof, and the valve stem tip portion In this case, a slit portion capable of closely sandwiching the thin flat portion and the elastic ring located in the notch space portion is formed. Thereby, the sealing property at the time of shielding is good, the raw materials are not clogged and remain, and the assembly / disassembly operation can be performed quickly. In the butterfly valve device, a blind ferrule is positioned outside the one ferrule bearing, and an operating ferrule is positioned outside the other ferrule bearing. These two adjacent ferrules are clamped by clamps, respectively. An actuating body that is coupled and transmits a rotational motion to the valve rod that penetrates the actuating ferrule is detachably fitted. As a result, even an unskilled person can quickly perform assembly and disassembly operations manually without using jigs and tools. It can be prevented.

Japanese Patent Laid-Open No. 7-293711 JP 2000-257726 A

  However, in the invention described in Patent Document 1, it is necessary to perform an advanced welding process and a casting process when creating the recess of the valve body to which the tip of the valve stem is attached, and the cost required for the creation is expensive. In addition, there is a problem that the process is time-consuming.

  Further, in the invention described in Patent Document 2, similarly to Patent Document 1, when a thin flat portion of the valve body is created, there is a problem that it is necessary to perform an advanced welding process and a casting process.

  Further, in the conventional butterfly valve, as described above, a predetermined screw is used when the valve stem is attached to the valve body. In the conventional butterfly valve 110, as shown in FIG. 11, the valve body is connected to the tips 112a1 and 112b1 of a pair of valve rods 112a and 112b attached to both ends (left and right ends) 111a and 111b of the outer periphery of the valve body 111. A slit (not shown) is cut in advance with a thickness equivalent to the thickness of 111. Further, the slits at the tips 112a1 and 112b1 of the pair of valve rods 112a and 112b are configured to be able to sandwich both ends 111a and 111b on the outer periphery of the valve body 111. Next, a predetermined screw penetrating from one direction (front view direction) of the tips 112a1 and 112b1 of the pair of valve rods 112a and 112b to the other direction (rear view direction) of the tips 112a1 and 112b1 through the slit. Two holes 112a2 and 112b2 are provided. On the other hand, corresponding to the screw holes 112a2 and 112b2 of the pair of valve rods 112a and 112b, two insertion holes (not shown) are provided at both ends 111a and 111b on the outer periphery of the valve body 111, respectively. With such a configuration, the valve body 111 is disposed inside the valve box 113, and the distal ends of the pair of valve rods 112a and 112b through a through hole (not shown) provided in advance in the valve box 113. The slits in 112a1 and 112b1 are fitted into both ends 111a and 111b on the outer periphery of the valve body 111 from both sides. Thereby, the valve body 111 is supported by the pair of valve rods 112a and 112b. Next, a predetermined screw 114 prepared in advance is inserted into the screw holes 112a2 and 112b2 provided at the tips 112a1 and 112b1 of the pair of valve rods 112a and 112b. Further, after the screw 114 is passed through the insertion hole of the valve body 111, the screw 114 is fixed with a nut prepared in advance, and the screw 114 and the nut are plug welded. Thereby, the valve rods 112a and 112b and the valve body 111 are securely fixed, and the screw 114 is prevented from dropping.

  However, in the conventional butterfly valve 110, once the valve rods 112a and 112b are attached to the valve body 111, both cannot be easily removed by the above-described welding process. When doing this, there is a problem that it takes much time and effort. Further, since the screw 114 is used, a predetermined catching part (protrusion part) is generated, and powder or the like remains and aggregates in the catching part, so that there is a problem that maintenance work such as cleaning is troublesome. Furthermore, when the conventional butterfly valve 110 is used for a long period of time, the welded screw 114 may drop due to some cause, and there is a problem that foreign matter resulting from the drop of the screw 114 is generated.

  Therefore, the present invention has been made to solve the above-described problem, remarkably simplifies the assembly and disassembly work of the valve body and the valve stem, eliminates the need for fine members and special tools required for the work, An object of the present invention is to provide a butterfly valve capable of facilitating maintenance work such as cleaning.

  As a result of intensive studies, the present inventor has completed a novel butterfly valve according to the present invention.

  That is, the butterfly valve according to the present invention is configured by attaching a pair of substantially cylindrical valve rods to both ends of the outer periphery of a valve element disposed in the valve box, respectively, through the rotation of the valve rod. A butterfly valve for rotating a valve body in the valve box, the following configuration is adopted.

The butterfly valve is a part of a valve rod attached to the valve body, and is arranged at a tip peripheral portion from a predetermined position on one side surface to a predetermined position on the other side surface through the front end surface. All are provided with a peripheral groove cut into a concave shape at a predetermined depth from the outer periphery of the peripheral portion of the tip and with a thickness equivalent to the thickness of the valve body. Further, the butterfly valve is directed to both end surfaces of the tip periphery corresponding to the vicinity of both ends of the bottom surface of the peripheral groove at a predetermined acute angle with respect to the axial direction of the valve stem toward the tip surface of the tip periphery. A first tapered surface that is gently inclined is provided. Further, the butterfly valve has an opening cut into a shape equivalent to a shape drawn by the bottom surface of the peripheral groove at both ends of the outer periphery of the valve body attached to the valve stem, and both sides of the opening. And a second tapered surface that is gently inclined toward the center of the valve body at an acute angle equivalent to the acute angle of the first tapered surface with respect to the radial direction of the valve body. The diameter of the valve body is configured to be reduced by a predetermined size from the inner diameter of the valve box, and the butterfly valve is applied to a valve through which powder passes.

  As a result, it becomes possible to mount the valve stem and the valve body by the static frictional force generated on the contact surface between the first tapered surface and the second tapered surface, and the assembly / disassembly operation of both is remarkably simplified. Can be realized. In addition, since the assembly / disassembly work does not require particularly fine members or special tools, even an ordinary worker who is not a skilled worker can easily perform the assembly / disassembly work. It is possible to reliably prevent the generation of foreign matters due to the member. Further, since the hooked portion (projection) such as a screw does not occur in the mounting of the valve stem and the valve body, maintenance work such as cleaning becomes extremely easy.

As a result, the powder is aggregated in a gap between the outer periphery of the valve body and the inner diameter of the valve box, and a seal (material seal) made of the aggregated powder is naturally formed. Normally, the seal does not need to be provided separately to increase the airtightness when the valve is closed (when shut off) like an elastic ring made of a rubber elastic body provided in the gap, thus reducing the cost. And it is possible to reliably prevent the generation of foreign matter due to wear of the elastic ring.
The acute angle of the first taper surface and the acute angle of the second taper surface are preferably in the range of 0.5 degrees to 30.0 degrees, respectively. More preferably, it is in the range of degrees.

  Further, end portions of both side surfaces of the tip peripheral portion corresponding to both end portions of the bottom surface of the peripheral groove are formed in a curved shape with a predetermined curvature radius so as to be recessed toward the inside of the valve rod, and the opening portion Are formed in a curved shape with the radius of curvature so as to protrude toward the outside of the valve body.

  The butterfly valve according to the present invention greatly simplifies the assembly and disassembly work of the valve body and the valve stem, eliminates the need for fine members and special tools required for the work, and can reliably prevent the generation of foreign matter. Become.

It is a perspective view of the butterfly valve concerning the present invention. It is a top view of the state which assembled the valve body and valve stem of the butterfly valve which concerns on this invention. It is a front view of the state which assembled the valve body and valve stem of the butterfly valve concerning this invention. It is a left view of the state which assembled the valve body and valve stem of the butterfly valve which concern on this invention. It is a right view of the state which assembled the valve body and valve stem of the butterfly valve which concern on this invention. It is a top view of the state which decomposed | disassembled the valve body and valve stem of the butterfly valve which concerns on this invention. It is a front view of the state which decomposed | disassembled the valve body and valve stem of the butterfly valve which concern on this invention. It is an expanded AA line section plane view, an enlarged front view, and an enlarged side view of a valve stem of a butterfly valve concerning the present invention. FIG. 4 is an enlarged plan view, an enlarged front view, and an enlarged side view of one end portion of the valve body of the butterfly valve according to the present invention. It is an enlarged plan view in the case of mounting the valve stem of the butterfly valve according to the present invention on the valve body. It is a perspective view of the conventional butterfly valve.

  Below, with reference to an accompanying drawing, an embodiment of a butterfly valve concerning the present invention is described, and it serves for an understanding of the present invention. In addition, the following embodiment is an example which actualized this invention, Comprising: The thing of the character which limits the technical scope of this invention is not.

  FIG. 1 is a perspective view of a butterfly valve according to the present invention.

  The butterfly valve 10 according to the present invention is mainly composed of a hollow cylindrical valve box 11 serving as an exterior, a disc-shaped valve body 12, and a pair of substantially cylindrical valve shafts 13a and 13b.

  The valve box 11 is a valve-shaped hollow cylinder that can be attached to a predetermined valve, and through holes 11a and 11b that can penetrate the valve shafts 13a and 13b are provided on both left and right sides.

  The pair of valve rods 13a and 13b have predetermined peripheral grooves cut in the vicinity of their front end surfaces, and the peripheral grooves are attached to the left and right ends of the outer periphery of the valve body 12. The opening to be fitted (cut) is cut (described later).

  Here, in a state where the valve body 12 is disposed inside the valve box 11, the peripheral grooves on the front end surfaces of the pair of valve rods 13a and 13b are formed through the through holes 11a and 11b of the valve box 11, The valve rods 13a and 13b are fixed to the valve body 12 when mounted on the openings at both ends of the valve body 12 from both sides. The valve body 12 is rotatable inside the valve box 11 by the rotation of one valve rod 13a.

  Further, the end 13a1 of one valve stem 13a is formed in a shape that can be attached to an end portion (not shown) of a handle portion provided outside, for example, a substantially rectangular parallelepiped shape. When the end of the handle portion is attached and the handle portion is rotated, the rotation is transmitted to the valve body 12 via the valve rod 13a, and the valve body 12 is rotated.

  By the way, the diameter (dimension) of the valve body 12 is configured to be smaller than the inner diameter of the valve box 11 by a predetermined size (for example, several μm to several tens of μm). With such a configuration, when the butterfly valve 10 according to the present invention is applied to a valve through which powder such as noodle flour and bread crumb passes, for example, the outer periphery of the valve body 12 and the inner diameter of the valve box 11 The powder is agglomerated in a clearance (clearance) between the two and a seal (also referred to as a material seal) made of the agglomerated powder is naturally formed. The seal usually enhances the airtightness when the valve is closed (when shut off) like an elastic ring made of a rubber elastic body provided in the gap. Therefore, when the butterfly valve 10 according to the present invention is applied to a predetermined valve, it is not necessary to separately provide the elastic ring, and it is possible to reduce the cost and to reliably generate foreign matter due to wear of the elastic ring. To prevent. In particular, when the powder is a crystal system such as sugar, wear of the elastic ring becomes remarkable. However, when the valve is configured as described above, the generation of foreign matters due to the wear can be reliably prevented.

  Next, the valve body and the valve stem of the butterfly valve according to the present invention will be described.

  FIG. 2 is a plan view of the butterfly valve according to the present invention assembled with the valve body and the valve stem. FIG. 3 is a front view of the butterfly valve according to the present invention assembled with the valve body and the valve stem. is there. FIG. 4 is a left side view of the assembled butterfly valve body and valve stem of the butterfly valve according to the present invention, and FIG. 5 shows the assembled butterfly valve body and valve stem of the present invention. It is a right view. In addition, the bottom view of the state which assembled the valve body and valve stem of the butterfly valve which concerns on this invention is symmetrical with the said top view, The rear view of the state which assembled the valve body and valve stem of the butterfly valve which concerns on this invention Is omitted since it is symmetric with the front view.

  FIG. 6 is a plan view of the butterfly valve according to the present invention in a disassembled state, and FIG. 7 is a front view of the butterfly valve according to the present invention in a disassembled state. FIG.

  As shown in FIGS. 2 to 7, the valve rods 13 a and 13 b of the butterfly valve 10 according to the present invention are provided with a predetermined portion on one side surface, which is a portion of the valve rods 13 a and 13 b attached to the valve body 12. From the positions 14a1 and 14b1 to the tip peripheral portions 14a and 14b passing through the tip surfaces 14a2 and 14b2 to the predetermined positions 14a3 and 14b3 on the other side, the tip peripheral portions 14a and 14b are spread over all of the tip peripheral portions 14a and 14b. , 14b are provided with peripheral grooves 15a, 15b cut into a concave shape at a predetermined depth t1 from the outer periphery of 14b.

  Here, the predetermined positions 14a3 and 14b3 on the other side face the predetermined positions 14a1 and 14b1 on one side. Further, the tip surfaces 14a2 and 14b2 of the tip peripheral portions 14a and 14b correspond to the cylindrical bottom surfaces of the valve rods 13a and 13b.

  Further, the peripheral grooves 15a and 15b are cut into a concave shape with a thickness t2 equivalent to the thickness of the valve body 12 in a front view. Here, the term “equivalent” means including the same and means substantially the same. The same applies hereinafter.

  Next, the configuration of the tip peripheral portion 14a (the peripheral groove 15a) of the one valve rod 13a will be described in detail.

  FIG. 8 is an enlarged cross-sectional plan view, an enlarged front view, and an enlarged side view of one valve stem of the butterfly valve according to the present invention.

  As shown in FIG. 8, in one valve stem 13a, on both side surfaces of the tip peripheral portion 14a corresponding to the vicinity of both ends of the bottom surface of the peripheral groove 15a, at a predetermined acute angle α1 with respect to the axial direction of the valve stem 13a. A first tapered surface 16a that is gently inclined toward the distal end surface 14a2 of the distal end peripheral portion 14a is provided.

  Here, the first taper surface 16a is a range from the predetermined positions 14a1 and 14a3 to the front surface of the front end surface 14a2 from the predetermined positions 14a1 and 14a3 to the front surface of the front end surface 14a2, in other words, in other words. In addition, the peripheral groove 15a is provided over a range from the vicinity 14a4 at both ends of the bottom surface to the front of the central vicinity surface 15a1.

  Both ends of the bottom surface of the peripheral groove 15a correspond to the end of the side surface of the tip peripheral portion 14a, and the surface near the center of the bottom surface of the peripheral groove 15a corresponds to the tip surface of the tip peripheral portion 14a. expressing.

  Even in the other valve stem 13a, the same first tapered surface 16b as that of the one valve stem 13a is provided on both side surfaces of the tip peripheral portion 14a.

  By the way, in the valve body 12 of the butterfly valve 10 according to the present invention, as shown in FIGS. 2 to 7, the both ends 17 a and 17 b on the outer periphery of the valve body 12 attached to the valve rods 13 a and 13 b are connected to the valve body 12. Openings 18a and 18b cut into a shape equivalent to the shape drawn by the bottom surfaces of the peripheral grooves 15a and 15b (equivalent side shape) are provided.

  Next, the configuration of the opening 18a of the valve body 12 will be described in detail.

  FIG. 9 is an enlarged plan view, an enlarged front view, and an enlarged side view of one end portion of the valve element of the butterfly valve according to the present invention.

  As shown in FIG. 9, the acute angle α1 of the first tapered surface 16a is formed on both side surfaces of one opening 18a of the valve body 12 to which the one valve rod 13a is mounted with respect to the radial direction of the valve body 12. Is provided with a second taper surface 19a that is gently inclined toward the center of the valve body 12 at the same acute angle α2. Here, the fact that the acute angle α2 of the second tapered surface 19a is equivalent to the acute angle α1 of the first tapered surface 16a includes the same, because the second tapered surface 19a and the second tapered surface 19a This is because when one tapered surface 16a is cut (formed), it may not always be the same due to internal residual stress, cutting error, and the like.

  Here, the second tapered surface 19a is provided over the range from the outer periphery of the valve body 12 to a predetermined position 18a1 from the inside to the front of the inner surface 18a2 of both side surfaces of the opening 18a. .

  The second opening 18b is also provided with a second tapered surface 19b similar to the one opening 18a.

  Now, the case where the valve rods 13a and 13b of the butterfly valve 10 according to the present invention are attached to the valve body 12 will be described in detail.

  FIG. 10 is an enlarged plan view when the valve stem of the butterfly valve according to the present invention is attached to the valve body.

  As shown in FIG. 10, when the peripheral groove 15a of the one valve stem 13a is fitted into the one opening 18a of the valve body 12, the shape formed by the bottom surface of the peripheral groove 15a (the tip after cutting) The shape formed by both side surfaces and the front end surface of the peripheral portion 14a is a convex portion, and the shape formed by the side surface of the opening 18a is a concave portion. And while the 1st taper surface 16a of the said surrounding groove 15a contact | abuts to the 2nd taper surface 19a of the said opening part 18a, the said 1st taper surface 16a (both side surfaces of the said surrounding groove 15a) is just, A predetermined force (referred to as vertical drag) is applied so as to expand the second tapered surface 19a (both side surfaces of the opening 18a). As a result, the one valve rod 13 a is attached to the one opening 18 a of the valve body 12.

  Here, if one of the valve stems 13a is to be pulled out from the valve body 12, the first taper surface 16a is placed on the second taper surface 19a in the axial direction of the valve stem 13a (the valve body 12). ), That is, in contact with the drawing direction at a predetermined acute angle α1 (α2), and the normal force acts, the stationary surface is stationary in the direction opposite to the drawing direction. A frictional force will be generated.

  Here, the static friction force F (N) is expressed by the following equation, for example.

  F = tan α * N

  F is the static friction force (N), α (corresponding to α1, α2) is the acute angle (degree), and N is the normal drag (N). It is understood that F becomes larger as α is smaller or N is larger.

  When the static friction force F of the above formula is generated, the valve rod 13a cannot be detached from the valve body 12 unless the force for pulling out the one valve rod 13a exceeds the static friction force F. That is, the valve stem 13a can be attached (assembled) to the valve body 12 with the static frictional force F without the fine members and special tools required for the attachment.

  On the other hand, for example, if a predetermined impact is applied to the one valve stem 13a so as to remove the one valve stem 13a from the valve body 12 at the end portion of a predetermined driver (in the pulling direction), the one valve stem 13 When the force for pulling out 13a exceeds the static friction force F, the one valve rod 13a is easily detached from the valve body 12. That is, even when the valve stem 13a is removed from the valve body 12 (disassembly), it is not necessary to use a special tool, and the disassembly work can be easily performed. The same applies to the other valve stem 13b.

  In general, the assembly / disassembly operation of the valve rods 13a, 13b and the valve body 12 can be greatly simplified.

  In addition, the above-mentioned assembly / disassembly work does not require fine members (such as screws in the prior art) or welding work as described above, so that even a normal worker who is not a skilled worker can perform the above-mentioned assembly / disassembly. The work can be easily performed, and the generation of foreign matters due to the member can be reliably prevented.

  Further, since the valve rods 13a and 13b and the valve body 12 are not fitted with a hook (projection) such as a screw, for example, when applied to a butterfly valve through which powder passes. The powder does not remain in the hooked portion and agglomerate. Further, for example, even in maintenance work such as cleaning, the member of the maintenance work is not caught by the catch portion and becomes an obstacle. Therefore, the maintenance work becomes extremely easy.

  When the peripheral grooves 15a and 15b of the valve rods 13a and 13b are mounted in the openings 18a and 18b of the valve body 12, the thickness of the peripheral grooves 15a and 15b is equal to the thickness of the valve body 12. Therefore, both side surfaces sandwiching the bottom surfaces of the peripheral grooves 15a and 15b, that is, the upper and lower members of the valve rods 13a and 13b are just rubbed with the upper and lower surfaces of the openings 18a and 18b. Therefore, when the valve stems 13a and 13b are rotated, the sandwiching of the peripheral grooves 15a and 15b of the valve stems 13a and 13b with respect to the openings 18a and 18b of the valve body 12 appropriately transmits the rotation. The valve body 12 is rotated.

  Here, in the butterfly valve 10 according to the present invention, the acute angle α1 of the first tapered surfaces 16a and 16b and the acute angle α2 of the second tapered surfaces 19a and 19b are 0.5 degrees to 30.0 degrees, respectively. It is preferable that it is in the range. This range is a range in which the necessary static frictional force F is generated on the contact surface between the first tapered surfaces 16a and 16b and the second tapered surfaces 19a and 19b. It is possible to reduce the possibility that the valve rods 13a and 13b easily fall off from the valve body 12. Even if the acute angle α1 of the first tapered surfaces 16a and 16b and the acute angle α2 of the second tapered surfaces 19a and 19b are within the above range, they are still equivalent. The range of the acute angles α1 and α2 corresponds to the range of the acute angle of the taper surface of the taper pin of the pin to be fixed using the static frictional force of the predetermined taper surface.

  On the other hand, when the acute angle α1 of the first tapered surfaces 16a and 16b and the acute angle α2 of the second tapered surfaces 19a and 19b are each less than 0.5 degrees or more than 30.0 degrees, Since the static frictional force F acting on the contact surface between the one tapered surface 16a, 16b and the second tapered surface 19a, 19b becomes small, the valve rods 13a, 13b may fall off the valve body 12. It is not preferable.

  Further, in order to obtain a strong static frictional force F, the acute angle α1 of the first tapered surfaces 16a and 16b and the acute angle α2 of the second tapered surfaces 19a and 19b are 0.5 degrees to 3. A range of 0 degrees is particularly preferable because tan α approaches 1 and the static friction force F increases according to the above-described formula.

  The acute angle α1 of the first tapered surfaces 16a and 16b and the acute angle α2 of the second tapered surfaces 19a and 19b shown in FIGS. 1 to 10 are the same and are 1.0 degree. This is just an example.

  In the butterfly valve 10 according to the present invention, the acute angle α1 of the first tapered surfaces 16a and 16b and the acute angle α2 of the second tapered surfaces 19a and 19b are the same as the first tapered surfaces 16a and 16b and the It is preferable to be equivalent within a range where the static friction force F is generated on the contact surface with the second tapered surfaces 19a and 19b (for example, within a range of less than 1.0 degree).

  In particular, if the acute angle α1 of the first tapered surfaces 16a, 16b and the acute angle α2 of the second tapered surfaces 19a, 19b are the same, the first tapered surfaces 16a, 16b and the second tapered surface. Since 19a and 19b are in full contact (contact), a sufficient static friction force F is generated, which is most preferable. Here, when manufacturing the butterfly valve 10 according to the present invention, as described above, the peripheral grooves 15a and 15b of the valve rods 13a and 13b including the first tapered surfaces 16a and 16b, and the second taper. When the openings 18a and 18b of the valve body 12 including the surfaces 19a and 19b are cut, an internal residual stress, a cutting error, and the like are always generated, and thus may not always be the same. Actually, if the acute angle α1 of the first tapered surfaces 16a and 16b and the acute angle α2 of the second tapered surfaces 19a and 19b are equal in the range where the static frictional force F is generated, the valve stem 13a. , 13b, the bottom surfaces (inner side surfaces) of the peripheral grooves 15a and 15b and the inner side surfaces of the openings 18a and 18b of the valve body 12 are in contact with each other within a predetermined area, and the generation of the static friction force F is ensured. So no problem.

  Further, in the butterfly valve 10 according to the present invention, as shown in FIG. 8, the end portions 14a1 and 14a3 on both side surfaces of the tip peripheral portion 14a corresponding to both end portions 15a2 of the bottom surface of the peripheral groove 15a are connected to the valve stem. As shown in FIG. 9, the end portions 18a3 on both side surfaces of the opening 18a are directed toward the outside of the valve body 12 so as to be recessed toward the inside of the valve body 13a. It is preferable to form a curve with the radius of curvature R so as to be convex (protruding or protruding). The gap between both end portions 15a2 on the bottom surface of the peripheral groove 15a and the end portions 18a3 on both side surfaces of the opening 18a is a place where foreign substances are most likely to enter. Since it does not become linear, it becomes difficult for foreign matter to enter the gap.

  On the other hand, for example, when both end portions 15a2 of the bottom surface of the peripheral groove 15a are formed linearly and the end portions 18a3 of both side surfaces of the opening portion 18a are formed linearly, the gap between the two becomes linear and foreign matter is removed. It is easy to enter, and maintenance work such as cleaning needs to be performed frequently, which is not preferable.

  The radius of curvature R may be any value as long as the gap is not linear. For example, the radius of curvature R shown in FIGS. 8 and 9 is 16 mm.

  Further, in the butterfly valve 10 according to the present invention, as shown in FIG. 10, the depth t3 of the tip surface 14a2 of the tip peripheral portion 14a corresponding to the central vicinity surface 15a1 of the bottom surface of the peripheral groove 15a When the valve body 12 is mounted on the valve body 12, a predetermined gap t4 is generated between the central vicinity surface 15a1 of the bottom surface of the peripheral groove 15a of the valve rod 13a and the inner surface 18a2 of the opening 18a of the valve body 12. The depth is preferable. With this configuration, when the valve stem 13a is mounted on the valve body 12, the static friction force F is applied to the contact surface between the first tapered surface 16a and the second tapered surface 19a. The valve rod 13a can be inserted into the valve body 13. The gap t4 absorbs (includes) a cutting error that occurs in the peripheral groove 15a and the opening 18a, and makes the first tapered surface 16a and the second tapered surface 19a fully contact each other. (Contact) and sufficient static friction force F can be generated. Therefore, when removing the valve stem 13a from the valve body 12, it becomes easy to remove. The gap t4 is 0. Within a range of several mm (for example, 0.1 mm, 0.2 mm, etc.).

  On the other hand, when the valve stem 13a is attached to the valve body 12, a predetermined gap t4 does not occur between the center vicinity surface 15a1 of the bottom surface of the peripheral groove 15a and the inner side surface 18a2 of the opening 18a. The cutting error is not absorbed, and there is a possibility that the first tapered surface 16a and the second tapered surface 19a do not come into full contact with each other, which is not preferable.

  In the butterfly valve 10 according to the present invention, the depth t1 of the peripheral grooves 15a and 15b is set to a depth necessary for the valve body 12 to rotate when the valve rods 13a and 13b are rotated. For example, it can be set to a range of 1/3 to 1/6 with respect to the width direction (direction perpendicular to the axial direction) of the tip peripheral portions 14a, 14b of the valve rods 13a, 13b. With this configuration, the peripheral grooves 15a and 15b are fitted into the openings 18a and 18b with appropriate strength, and the peripheral grooves 15a and 15b are firmly inserted into the openings 18a and 18b. The rotation of the valve rods 13a and 13b is appropriately transmitted to the valve body 12. If the dimension in the width direction of the tip peripheral portions 14a and 14b of the valve rods 13a and 13b is 30 mm, for example, the depth t1 of the peripheral grooves 15a and 15b is 5 mm.

  In the butterfly valve 10 according to the present invention, the axial dimensions of the tip peripheral portions 14a and 14b of the valve rods 13a and 13b are in the range of 1/8 to 1/10 with respect to the diameter of the valve body 12. I can do it. With this configuration, when the openings 18a and 18b of the valve body 12 are mounted in the peripheral grooves 15a and 15b of the valve rods 13a and 13b, the valve rods 13a and 13b reliably support the valve body 12. It becomes possible to do.

  In the butterfly valve 10 according to the present invention, the valve rods 13a and 13b and the valve body 12 may be made of a normal material such as hard stainless steel. Further, if the surfaces of the valve rods 13a and 13b and the valve body 12 are processed with chrome plating as necessary, rubbing powder is hardly generated when both are mounted, and foreign matter generation (galling) is prevented. Is possible.

  Thus, in the butterfly valve 10 according to the present invention, the valve rods 13a and 13b include the peripheral grooves 15a and 15b and the first tapered surfaces 16a and 16b, and the valve body 12 includes the opening. 18a, 18b and the second tapered surfaces 19a, 19b.

  As a result, the valve rods 13a and 13b and the valve body 12 can be mounted by the static friction force generated on the contact surface between the first tapered surfaces 16a and 16b and the second tapered surfaces 19a and 19b. Thus, the assembly / disassembly work of both can be remarkably simplified. In addition, since the assembly / disassembly work does not require particularly fine members or special tools, even an ordinary worker who is not a skilled worker can easily perform the assembly / disassembly work. It is possible to reliably prevent the generation of foreign matters due to the member.

  The butterfly valve according to the present invention can be manufactured by a person skilled in the art using a normal cutting blade, for example, a disk-shaped cutting blade or a rod-shaped cutting blade, based on FIGS. Needless to say.

  As described above, the butterfly valve according to the present invention remarkably simplifies the assembly and disassembly work of the valve body and the valve stem, eliminates the need for fine members and special tools required for the work, and reliably prevents the generation of foreign matters. It is effective as a butterfly valve that can be used.

DESCRIPTION OF SYMBOLS 10 Butterfly valve 11 Valve box 12 Valve body 13a, 13b A pair of valve axis | shaft 14a, 14b Front-end | tip surrounding part 15a, 15b Peripheral groove 16a, 16b First taper surface 17a, 17b Both ends 18a, 18b of the outer periphery of a valve body 19a, 19b Second tapered surface

Claims (4)

By attaching a pair of substantially cylindrical valve rods to both ends of the outer periphery of the valve body arranged in the valve box, the valve body is rotated in the valve box through the rotation of the valve stem. A butterfly valve,
A part of a valve stem attached to the valve body, from a predetermined position on one side surface to a front end peripheral part through a front end surface to a predetermined position on the other side surface, over the entire front end peripheral part, A peripheral groove cut into a concave shape with a predetermined depth from the outer periphery of the peripheral portion of the tip and a thickness equivalent to the thickness of the valve body;
A first slope that is gently inclined toward the front end surface of the front end peripheral portion at a predetermined acute angle with respect to the axial direction of the valve stem on both side surfaces of the front end peripheral portion corresponding to the vicinity of both ends of the bottom surface of the peripheral groove. A tapered surface;
At both ends of the outer periphery of the valve body attached to the valve stem, openings cut into a shape equivalent to the shape drawn by the bottom surface of the peripheral groove;
A second taper surface that is gently inclined toward the center of the valve body at an acute angle equivalent to the acute angle of the first taper surface with respect to the radial direction of the valve body on both side surfaces of the opening. Prepared ,
The diameter of the valve body is configured to have a diameter reduced by a predetermined size from the inner diameter of the valve box,
This butterfly valve is a butterfly valve applied to a valve through which powder passes . The butterfly valve according to claim 1, wherein an acute angle of the first tapered surface and an acute angle of the second tapered surface are in a range of 0.5 degrees to 30.0 degrees, respectively. The butterfly valve according to claim 1 or 2 , wherein an acute angle of the first tapered surface and an acute angle of the second tapered surface are in a range of 0.5 degrees to 3.0 degrees, respectively. The end portions of both side surfaces of the tip periphery corresponding to both ends of the bottom surface of the peripheral groove are formed in a curved shape with a predetermined curvature radius so as to be recessed toward the inside of the valve stem,
The butterfly valve according to any one of claims 1 to 3 , wherein end portions of both side surfaces of the opening are formed in a curved shape with the curvature radius so as to protrude toward the outside of the valve body.