Valve fixing structure and valve

Abstract

To provide a valve fixing structure and a valve, capable of connecting a body and a cap of a valve by using a common fixing bolt, being attached to a predetermined position only by fastening the fixing bolt, and precisely fixing the body and the cap through the bolt.SOLUTION: Female screws 26 are communicated at plural positions of an implanting side flange 25 on a body 21 side. A part of the female screws are extended and formed on a thick wall portion 30 provided on a side which the tip end 23a side of all screw bolts 23 of the implanting side flange faces. All screw bolts are screwed in the female screws to lock the tip end side thereof to the thick wall portion side to be positioned. A cap side flange 33 is butted on the implanting side flange. Nuts 24 are screwed with rear end side of all screw bolts projecting out from the cap side flange through through-holes 34 of the cap side flange, thereby connecting the implanting side flange and the cap side flange.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fixing structure for a valve such as a ball valve, and more particularly to a fixing structure for a valve for connecting a body and a cap that are provided separately, and to a valve. [Background technology]

[0002] Conventionally, in valves such as ball valves, a body and a cap are provided separately to accommodate a valve element such as a ball valve body within the valve, and after the valve element with a stem attached is accommodated within the body, the cap is sometimes connected to the body to form an integrated unit.

[0003] An example of this type of ball valve is disclosed in Patent Document 1. In this ball valve, the body and cap are connected by fastening a plurality of stud bolts and fixing nuts, and typically, in ball valves with such a structure in which the body and cap are separate, they are often fixed together by fastening the stud bolts and fixing nuts.

[0004] Figure 5 shows a typical fixing structure between the body and cap of a ball valve. This ball valve 1 has a body portion 2 and a cap portion 3, and a flange portion 4 provided on the body portion 2 side and a flange portion 5 provided on the cap portion 3 side are connected by a stud bolt 6 and a fixing nut 7.

[0005] The stud bolt 6 has an installation-side male thread 8 on the attachment side to the body-side flange 4, a cylindrical portion 9 connected to the installation-side male thread 8, and a nut-side male thread 10 connected to the cylindrical portion 9. The installation-side male thread 8 is formed to be longer than the thickness of the body-side flange 4, and when the installation-side male thread 8 is threaded into the female thread 11 formed on the body-side flange 4, a limit to the tightening of the installation side is set at a locking portion 6a at the boundary between the installation-side male thread 8 and the cylindrical portion 9. The length of the nut-side male thread 10 is set to a length that allows the fixing nut 7 to be screwed and tightened from the outside of the cap-side flange 5 when the cap-side flange 5 is butted against the body-side flange 4 into which the stud bolt 6 is threaded.

[0006] The stud bolt 6 is used to connect the body 2 and the cap 3 with the body flange 4 and the cap flange 5 aligned. When connecting these, the stud bolt 6 is first inserted into the body 2, and then the cap 3 is temporarily assembled to the body 2 through the stud bolt 6 with the valve body and stem installed inside the body 2. With these assembled in the specified state, the fixing nut 7 is tightened onto the stud bolt 6 to integrate them.

[0007] On the other hand, when flange-connecting the body and cap of a valve other than a ball valve, or when flange-connecting pipe fittings to each other, a structure in which a stud bolt and a fixing nut are used to fix the fitting is generally known. Furthermore, in order to connect such piping components to each other via flanges, one fastening point is often fixed with a fully threaded bolt (threaded bolt) and two fixing nuts. In this case, multiple through holes that communicate with each other are provided in both flanges, and fully threaded bolts are inserted into both through holes while these flanges are butted together, and fixing nuts are tightened on both sides of the fully threaded bolt from the outside of the flanges to fix them. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Jikko No. 63-26612 Summary of the Invention [Problem to be solved by the invention]

[0009] When flange connections are made using a stud and a fixing nut, as in the ball valve of Patent Document 1, the stud 6 is positioned by the locking portion 6a at the base of the stud 6 engaging the opening of the female thread 11 on the body flange 4, as shown in Figure 5. Therefore, depending on the thickness of the flanges (body flange 4, cap flange 5), which differ depending on the valve size and pressure class, different lengths of stud-side male thread 8, nut-side male thread 10, and cylindrical portion 9 must be used. In this case, studs 6 with various specifications must be prepared in advance. Furthermore, if an appropriate stud 6 is not available, a new stud 6 may need to be machined. In this case, the stud-side male thread 8, nut-side male thread 10, and cylindrical portion 9 must be manufactured according to the dimensions of the flanges 4 and 5 to be connected, which can be tedious.

[0010] On the other hand, when the components constituting a valve are fastened together using a threaded bolt and two fixing nuts, the threaded bolt cannot be positioned on the flange portion alone, and must be positioned and fixed by tightening the fixing nuts on both sides. Because the position of the threaded bolt must be adjusted at both tightening points while the fixing nuts are tightened to connect the flanges, it becomes difficult to evenly tighten the threaded bolts at multiple points around the entire circumference of the flange. If the threaded bolts are significantly misaligned, the flange portions will be connected at an angle, resulting in an uneven seal and the risk of internal fluid leaking from the flange connection surface.

[0011] The present invention was developed to solve the problems of the past, and its purpose is to provide a valve fixing structure and a valve that can connect the body and cap of a valve using a standardized fixing bolt, can be installed in the specified position simply by tightening this fixing bolt, and can accurately fix the body and cap through the bolt. [Means for solving the problem]

[0012] In order to achieve the above object, the invention of claim 1 is a fixing structure for connecting a body and a cap of a valve, in which an implantation side flange provided on the body side has female threads formed in a plurality of locations to be threaded with male threads of implantation fully threaded bolts, and a part of the female threads extends into a thick portion provided on the side of the implantation side flange facing the tip side of the fully threaded bolt, and in a state in which the fully threaded bolt is threaded into the female threads and its tip side is engaged with the thick portion and positioned, a cap side flange provided on the cap side is butted against the implantation side flange, and a nut is screwed into the rear end of the fully threaded bolt protruding from the cap side flange through a through hole formed in the cap side flange, connecting the implantation side flange and the cap side flange, In addition, the thickened portion is provided near the base of the body on the side where the tip side of the fully threaded bolt of the implant side flange faces. A fixing structure for a valve.

[0013] The invention according to claim 2 is a fixing structure for a valve in which an incomplete female thread portion is provided in the thick-wall portion, and the tip side of the male thread of the fully threaded bolt is engaged with this incomplete female thread portion.

[0014] The invention of claim 3 is a fixing structure for a valve in which a claw portion is provided on the thick portion that protrudes toward the inner diameter of the female thread, and the tip side of the fully threaded bolt abuts and engages with this claw portion.

[0016] Claim 4 The invention relates to a valve in which a body and a cap are connected by a valve fixing structure. [Effects of the Invention]

[0017] According to the invention of claim 1, a standardized threaded bolt can be used to connect the valve body and cap, eliminating the need for different stud bolt specifications depending on the valve size and pressure class. When connecting, the fastening threaded bolt can be easily installed in the desired position by tightening the fastening threaded bolt so that its tip engages the thick portion. In this state, the cap flange is butted against the stud flange, and a nut is threaded through the through-hole in the cap flange and threaded from the rear end of the threaded bolt to connect the stud flange and cap flange. This allows for easy assembly, and the body and cap can be evenly tightened and accurately fixed using the threaded bolt. This prevents tilting between the body and cap flanges, improving sealing performance. Because the thick portion can be formed during molding, such as casting, there is no need to separately process the thick portion; it can be easily formed using excess material during manufacturing. Since stud bolts with various specifications are not required, costs are reduced. Furthermore, if a long, fully threaded bolt member with a male thread is formed in advance and then cut according to the length of the flange portion to be fixed, there is no need to prepare fully threaded bolts with different specifications for each flange portion length, which allows for significant cost reductions. By providing the thick portion near the base of the implant flange where the tip of the fully threaded bolt faces the body, the thick portion can be provided between the implant flange and the body at the same time as the molding process, such as casting.

[0018] According to the invention of claim 2, by engaging a portion of the tip side of the male thread of the fully threaded bolt with the incomplete thread portion, the fully threaded bolt can be easily attached to a predetermined position on the installation flange. By tightening nuts on each fully threaded bolt, the fully threaded bolt is prevented from coming loose from the thick-walled portion, and the installation flange and the cap flange are crimped with equal force around the entire circumference, improving the sealing of the joining surfaces and providing a stable and strong connection. At the same time as forming the female thread on the thick-walled portion, the incomplete thread portion can be easily processed so that it continues from the female thread.

[0019] According to the invention of claim 3, the tip of the fully threaded bolt can be abutted against the claw portion and locked, allowing the fully threaded bolt to be easily attached to the specified position of the stud-side flange. By tightening nuts on each fully threaded bolt, the fully threaded bolt is prevented from coming loose from the thick portion, and the stud-side flange and the cap-side flange are crimped with equal force around the entire circumference, improving the sealing of the joining surfaces and providing a stable and strong connection. By machining a female thread partway through the thick portion, the claw portion can be easily formed on the body at the same time as forming the female thread.

[0021] Claim 4 According to the invention, the body and cap can be connected using a standardized fully threaded bolt, without using stud bolts with different specifications depending on the size and pressure class. When connecting, the fully threaded bolt for fixing can be easily installed in the specified position simply by tightening the fully threaded bolt. In this state, the body and cap can be evenly tightened and accurately fixed through the fully threaded bolt, resulting in excellent assembly. This improves sealing performance by connecting the flange portions of the body and cap while preventing tilt. It is possible to easily create a thick portion by utilizing excess material during manufacturing, without separately processing the thick portion. Since stud bolts with various specifications are not required, costs are reduced, and further, it is possible to avoid the need to prepare fully threaded bolts with different specifications for each flange length, thereby significantly reducing costs. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a perspective view showing an example of a valve using the valve fixing structure of the present invention. FIG. [Figure 2] 1(a) is a side view showing an example of a valve using the valve fixing structure of the present invention, and FIG. 1(b) is a cross-sectional view taken along the line AA in FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view of part B in FIG. [Figure 4]1(a) is a cross-sectional view showing another example of a valve using the valve fixing structure of the present invention, and FIG. 1(b) is an enlarged cross-sectional view of part C in FIG. [Figure 5] FIG. 10 is a partially enlarged cross-sectional view showing a fixing structure of a conventional ball valve. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A valve fixing structure and a valve according to the present invention will be described in detail below based on embodiments. Fig. 1 shows an example of a valve to which the valve fixing structure of the present invention is applied, Fig. 2(a) is a side view showing an example of a valve using the valve fixing structure of the present invention, Fig. 2(b) is a cross-sectional view taken along line AA in Fig. 2(a), and Fig. 3 shows an enlarged cross-sectional view of part B in Fig. 2(b). In the figure, the valve (hereinafter referred to as valve body 20) is, for example, a ball valve, and includes a body 21, a cap 22, a fully threaded bolt 23 for installation, and a nut 24. Inside, it has a valve seat consisting of a stem, a valve disc, and a seat ring (not shown). The valve body 20 is rotatably mounted on the valve seat via the stem within the body 21, and the flow path can be opened and closed by rotating the stem.

[0024] An implantation flange 25 is provided on the body 21 on the side where it connects to the cap 22, and a fully threaded bolt 23 is implanted into this implantation flange 25. Female threads 26 are formed at approximately equal intervals and communicate with each other at multiple locations (four locations in this embodiment) where the fully threaded bolts 23 are implanted into the implantation flange 25, and male threads 27 formed on the fully threaded bolt 23 are provided so as to be able to be threaded into these female threads 26.

[0025] A thick portion 30 protruding in the circumferential direction is provided on the implantation-side flange 25 near the base where the tip 23a of the fully threaded bolt 23 meets the body 21, and the female threads 26 are formed by extending from this thick portion 30, with this thick portion 30 being provided for all four female threads 26. The thick portion 30 does not need to be provided over the entire circumferential direction of the female threads 26, as long as it is large enough to overlap a portion of the female threads 26. Here, "to overlap a portion of the female threads 26" refers to a state in which the thick portion 30 overlaps the projected area of ​​the female threads 26 provided on the implantation-side flange 25.

[0026] In this way, at least a part of the female thread 26 is formed in the thick portion 30, and an incomplete thread portion 31 of the female thread 26 is formed on the tip side of this thick portion 30. A tip portion 32 of the male thread 27 of the fully threaded bolt 23 can be engaged with the incomplete thread portion 31.

[0027] Conventionally, the body 21 and the implantation-side flange 25 are connected by simply extending the body outer peripheral surface 21a and the implantation-side flange surface 25a and intersecting, or the connection is provided with a slight taper or a curved surface, and the thickness of these does not overlap the female thread 26. In this embodiment, as shown in Fig. 3, by providing a thick-walled portion 30 at the boundary between the outer peripheral surface 21a of the body 21 and the implantation-side flange surface 25a so as to overlap the female thread 26, it is possible to provide an extension of the female thread 26 to this thick-walled portion 30.

[0028] In the example of Figure 3, the thickness of the thick portion 30 gradually decreases from the implantation side flange surface 25a toward the outer peripheral surface 21a of the body 21, but the extension portion of the female thread 26 is not arranged so as to penetrate to a position where the thick portion 30 does not engage with the female thread 26, but rather is arranged so as to stop at a position where the thick portion 30 has a thickness that engages with the female thread 26, making it possible to make the tip of the thick portion 30 an incomplete thread portion 31.

[0029] On the other hand, the cap 22 has a cap-side flange 33 on the side connected to the body 21, and this cap-side flange 33 is provided so as to be connectable to the implantation-side flange 25. In the cap-side flange 33, through holes 34 are formed at equal intervals at four positions where the female screws 26 face each other.

[0030] When flange-connecting the body 21 and the cap 22, first, the male threads 27 are screwed into the four female threads 26, respectively, to fix the fully threaded bolts 23. At this time, the tip 32 of the fully threaded bolt 23 is engaged with the incomplete thread portion 31 on the thick-wall portion 30 side, and the fully threaded bolt 23 is attached with the tip 23a side positioned on the implant-side flange 25. As a result, the four fully threaded bolts 23 protrude by a substantially constant length from the implant-side flange 25 toward the side where the cap 22 is attached.

[0031] In this state, the rear ends of the fully threaded bolts 23 are inserted into the through holes 34 of the cap-side flange 33, and the cap-side flange 33 is butted against the implant-side flange 25, thereby temporarily assembling the cap 22 in an aligned state to the body 21. At this time, the fully threaded bolts 23 are set in advance to a length that allows the nuts 24 to be threaded onto the rear ends thereof through the implant-side flange 25 and the cap-side flange 33.

[0032] Next, a nut 24 is screwed onto the rear end of the fully threaded bolt 23 that protrudes from the cap side flange 33 through the through hole 34, and by tightening this nut 24 and the fully threaded bolt 23, the implantation side flange 25 and the cap side flange 33 are connected, thereby forming the valve fixing structure for the valve body 20 of the present invention.

[0033] In the above embodiment, a ball valve is used as the valve body 20, but the body and cap of a valve other than a ball valve can also be connected by the above valve fixing structure.

[0034] There are four female screws 26 on the implantation side flange 25 and four through holes 34 on the cap side flange 33, but the number of these is arbitrary and may be changed as appropriate depending on the flange diameter of the implantation side flange 25 and the cap side flange 33, the valve size, etc.

[0035] The thick-walled portion 30 is the side of the implantation flange 25 facing the tip 23a of the fully threaded bolt 23, and may be provided in a location other than near the base of the body 21, as long as it is at least partially engaged with the female thread 26 and allows the female thread 26 to be extended. Alternatively, the thick-walled portion may be formed to protrude circumferentially from the implantation flange 25, and an incomplete thread portion may be provided along the entire inner periphery of this thick-walled portion. However, it is more preferable to provide the thick-walled portion near the base because the base of the body 21 is often originally built up with a radius or taper, making it easier to form a thick wall during casting, and strength is easier to maintain near the base.

[0036] Next, the operation of the valve fixing structure and the valve of the present invention in the above embodiment will be described. The above-mentioned valve fixing structure is a fixing structure that connects the body 21 and cap 22 of the valve main body 20, and in order to flange-connect them, a fully threaded bolt 23 is applied to the flange connection portion (body mounting portion).

[0037] Female threads 26 are formed in communication at multiple locations on the implantation side flange 25 provided on the body 21 side, and a thickened portion 30 is provided near the base of the implantation side flange 25 where the tip side of the fully threaded bolt 23 meets the body 21, and a portion of the female thread 26 is extended to form this thickened portion 30, so that the thickened portion 30 can be formed at the same time as the body 21 is processed by casting or the like.

[0038] Furthermore, an incomplete thread portion 31 of the female thread can be formed at the same time as the female thread 26 is machined in the thick-walled portion 30. In this case, when the female thread 26 is formed by thread cutting from the outside of the implantation-side flange 25, the incomplete thread portion 31 can be easily formed by inserting the tip side of a thread cutting tool (not shown) into the thick-walled portion 30 and cutting into it.

[0039] The fully threaded bolt 23 can connect the implant flange 25 and the cap flange 33, allowing a common use of this fully threaded bolt 23. Furthermore, it is also possible to prepare a long fully threaded bolt in advance and cut it according to the thickness of the flanges 25, 33 to be connected.

[0040] When assembling the fully threaded bolt 23 into the body 21, the fully threaded bolt 23 is threaded into the female thread 26, and when the tip 32 of the male thread 27 reaches the incomplete thread portion 31 that forms part of the female thread formed in the thick-wall portion 30, the fully threaded bolt 23 can be continued to advance. In this case, when the tip 32 of the male thread 27 reaches the incomplete thread portion 31 of the female thread 26, the fully threaded bolt 23 can be threaded in loosely enough that it stops at the incomplete thread portion 31. This allows four fully threaded bolts 23 with approximately the same overall length to be threaded into the female thread 26 to the same depth, and the lengths of protrusion toward the cap-side flange 33 can be approximately the same.

[0041] When connecting the body 21 and the cap 22, the valve body is assembled into the body 21 via the stem while the fully threaded bolts 23 are attached, and the rear end of the fully threaded bolts 23 is inserted into the through hole 34, while the cap side flange 33 is butted against the implant side flange 25, so that the cap 22 can be temporarily assembled to the body 21 while being guided by the four fully threaded bolts 23.

[0042] Furthermore, with the body 21 and cap 22 aligned using the fully threaded bolt 23, a nut 24 is screwed onto the rear end of the fully threaded bolt 23 protruding from the cap-side flange 33 through the through-hole 34. By tightening the nut 24, the fully threaded bolt is pressed into the body 21, firmly connecting the implant-side flange 25 and the cap-side flange 33. At this time, the tip 32 of the male thread 27 engages with the incomplete thread portion 31 of the female thread 26, and the incomplete thread portion 31 and tip 32 function as stoppers, fastening the fully threaded bolt 23 in a positioned state.

[0043] As mentioned above, by positioning and restricting the tip of the fully threaded bolt 23 and making the length of the protruding side toward the cap 22 approximately the same, the nuts 24 can be evenly tightened to the rear ends of the fully threaded bolts 23 while preventing the flanges 25, 33 from tilting relative to each other, reliably preventing leakage of internal fluid from the flange joint surfaces. Because the tip of the fully threaded bolt 23 is screwed in until it protrudes from the installation-side flange 25, it is possible to connect the body 21 and cap 22 even if the thickness of the casting that makes up the installation-side flange 25 is different.

[0044] 4 shows another example of a valve using the valve fixing structure of the present invention. In this embodiment, the same parts as those in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0045] In the valve body 40 of this embodiment, a thick portion 30 is provided near the base of the body 21 on the side of the implantation side flange 25 where the tip side of the fully threaded bolt 23 faces, and a claw portion 41 is provided that protrudes toward the inner diameter of the female thread 26 provided in this thick portion 30.

[0046] When the fully threaded bolt 23 is screwed into the implantation flange 25, the tip 23a of the fully threaded bolt 23 abuts against the claw portion 41, whereby the fully threaded bolt 23 is engaged with the female thread 26 and positioned.

[0047] This makes it possible to connect the body 21 and the cap 22 using the fully threaded bolt 23 and nut 24 without using a stud bolt, just as in the case where the incomplete thread portion 31 is provided in the thick-walled portion 30 described above. When connecting these, the claw portion 41 acts as a stopper for the fully threaded bolt 23, thereby strengthening the nut 24 and preventing tilting or misalignment when it is tightened, and preventing the fully threaded bolt 23 and nut 24 from loosening, thereby maintaining the connected state.

[0048] The above describes in detail the embodiments of the present invention, but the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the spirit of the invention described in the claims of the present invention. For example, if the structure uses fully threaded bolts to connect flanges, it can be used for connection points other than the valve body and cap, and can also be applied to various piping equipment other than valves. [Explanation of symbols]

[0049] 20, 40 valve body 21 Body 22 Cap 23 Fully threaded bolt 23a tip 24 Nut 25 Planting side flange 26 female thread 27 Male thread 30 Thick part 31 Incomplete thread on the female thread side 32 Male thread tip 33 Cap side flange 34 through holes 41 Claw

Claims

1. a cap flange provided on the cap side butts against the implant-side flange with a through hole formed in the cap flange, and a nut threaded onto the rear end of the threaded bolt protruding from the cap flange through a through hole formed in the cap flange, thereby connecting the implant-side flange and the cap flange; and the thick portion is provided near the base of the implant-side flange on the side facing the tip of the threaded bolt.

2. 2. The valve fixing structure according to claim 1, wherein the thick portion is provided with an incomplete thread portion of the female screw, and the tip side of the male screw of the fully threaded bolt is engaged with this incomplete thread portion.

3. 2. The valve fixing structure according to claim 1, wherein the thick-walled portion is provided with a claw portion that protrudes toward the inner diameter of the female thread, and the tip side of the fully threaded bolt abuts and is locked onto this claw portion.

4. A valve characterized in that the body and cap are connected by a valve fixing structure of any one of claims 1 to 3.

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