JPH022121Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention allows the eccentricity of the center of the valve stem with respect to the valve body to be selected from various values in the same butterfly valve, and only the valve body can be mounted independently. Regarding the removable butterfly valve.

[Conventional technology]

Conventional butterfly valves include tilting type check valves that make it easier to open the valve body by eccentrically positioning the valve stem relative to the valve body according to the operating pressure.
As such a check valve, for example, one shown in FIG. 10 is known.

This check valve 1 has a valve stem attachment part 3b having an insertion hole 3a through which a valve stem 4 is inserted on one side of a valve body 3 installed in a valve box 2, eccentrically from the center of the valve body to one side. A valve rod 4 is inserted horizontally into the valve box 2 via a bearing (not shown) placed opposite to the side wall of the box 2.
is passed through the insertion hole 3a and is rotatable together with the valve body 3 by a set pin 5, and an arm (not shown) is connected to the end of the valve stem 4 extending outside the valve body 2. A weight (not shown) is provided at the tip of this, and the valve stem 4 is rotated by the balance between the fluid pressure acting on the valve body 3 and the weight of the weight due to the fluid flowing in the direction of arrow A, whereby the valve body 3 is rotated. The peripheral edge 3c of the valve body 3 is moved away from or seated on the valve seat 2a provided around the inner surface of the valve body 2 to automatically open and close the valve body 3.

In addition, a check valve 6 shown in FIG. 11 has a valve body 7 that is constructed in substantially the same manner as the check valve 1 and has a valve stem mounting portion 7b having an insertion hole 7a eccentrically from the center of the valve body to one side. It is also known that the valve body 7 is inclined at a predetermined angle toward the upstream side of the fluid flowing in the direction of arrow A, and the valve body 7 automatically closes due to its own weight.

[Problem that the invention attempts to solve]

However, due to the relationship between the torque acting on the valve disc, it is necessary to change the amount of eccentricity of the valve stem with respect to the valve disc between high-pressure and low-pressure check valves. In order to change the valve to a low pressure type, it is necessary to increase the amount of eccentricity so that the valve body can open smoothly even at low pressure.

Therefore, when changing the amount of eccentricity, it is necessary to newly manufacture main parts such as the valve body and valve body, or to prepare main parts corresponding to various eccentricities in advance. In order to remove the body, the valve body cannot be removed from the valve box unless the butterfly valve is disassembled and the valve stem is taken out, so there is a problem in that it takes time and effort to remove the valve body.

Therefore, in the present invention, it is possible to easily change the amount of eccentricity of the valve stem with respect to the valve body without replacing the valve body or valve body in the same butterfly valve, and furthermore, it is possible to independently remove only the valve body from the valve body. The purpose of this invention is to provide a butterfly valve that can perform the following functions.

[Means for solving problems]

In this invention, in order to solve the above problems,
In a butterfly valve, a valve body is rotatably provided in a valve box, and the valve body is opened and closed by a valve stem extending to the outside via a bearing disposed opposite to the outer wall of the valve box. A valve stem mounting device in which the boss has an insertion hole through which the valve stem is inserted, which is offset from the boss axis, and both bearings are provided in the valve box so that they can be rotated around the boss axis and can be attached and detached, and the valve stem is fitted into the valve stem fitting. is removably attached to one side of the valve body using a fastener such as a bolt.

[Effect]

With the above configuration, when changing the amount of eccentricity of the valve stem with respect to the valve body, the insertion hole through which the valve stem is inserted is adjusted by rotating both bearings formed by making the insertion hole offset from the boss axis. In addition to changing the position, the attachment position of the valve stem to the valve body is also changed, thereby making the valve stem eccentric with respect to the valve body.

〔Example〕

An embodiment in which the butterfly valve of the present invention is applied to a tilting type check valve will be described below with reference to FIGS. 1 to 9.

The butterfly valve 10, which is connected to a pipe (not shown) to control the flow of fluid, has bearing mounting portions 11a, 11a provided on the outer wall of a valve box 11.
The valve stem 12 is inserted into the bearings 13, 13 that are attached to the bearings 13, 11a and horizontally supports the valve stem 12, and the valve body 15 is connected to the valve via the valve stem fittings 14, 14 into which the valve stem 12 is fitted. It is attached to the rod 12.

The valve box 11 is connected to the pipeline by connecting flanges 11b, 11b provided at the front and rear positions thereof, and as shown in FIG. 11c is provided around the valve body 11, and the bearing mounting portions 11a, 11a
The flanges 11e, 11e are disposed horizontally opposite each other slightly above the center of the flange 11e, and have a plurality of bolt holes (not shown) provided at equal intervals at the ends of the openings 11d, 11d into which the bearings 13, 13 are fitted. It is formed.

The bearing 13 that horizontally supports the valve stem 12 is designed so that the eccentricity L, which is the distance from the valve body center C _V to the valve stem center C _L , can be changed as shown in FIG. Valve body 11 with valve stem center C _L relative to C _V
Eccentricity in the front-rear direction (hereinafter referred to as primary eccentricity),
In order to change the vertical eccentricity (hereinafter referred to as secondary eccentricity), an insertion hole 13b formed in the boss 13a and through which the valve stem 12 is inserted is opened offset from the axis of the boss 13a. , a flange 1 that abuts the flange 11e of the bearing mounting portion 11a.
3c, a plurality of bolt holes 13d corresponding to the bolt holes provided in the flange 11e are provided at equal intervals, and an eccentricity L that minimizes the primary eccentricity and secondary eccentricity of the valve stem center C _L is provided. ₁ and used in a high pressure state, the insertion hole 13b is positioned downward and the boss 13a is inserted into the opening 11d of the bearing mounting portion 11a.
The flanges 11e and 13c are fastened with bolts 16 inserted into the bolt holes 13d, and are removably provided in the bearing mounting portion 11a.

A metal bushing 17 is inserted into the insertion hole 13b of the bearing 13, and an O-ring 18 is interposed between the metal bushing 17 and the valve stem 12. The valve stem 12 protrudes liquid-tightly outside the box 11, and valve stem fittings 14, 14 for attaching the valve stem 12 to the valve body 15 are fitted into the valve stem 12.

This valve stem mount 14 has a valve stem fixing part 14d integrally formed with a through hole 14c through which the valve stem 12 is inserted, in the center of one side of a flat mounting part 14b with a plurality of bolt holes 14a on both sides. and is fitted onto the valve stem 12 via a key 19. The valve stem mount 14 is removably attached to the downstream side surface of the valve body 15 with a bolt 20 inserted into a bolt hole 14a provided in the attachment part 14b, so that the valve body 15 is attached to the valve stem 12. Fixed.

The valve body 15 has a central plane parallel to the valve body 1.
The peripheral edge part 15a seated on the rubber valve seat 11c of 1 is formed into a disk shape by crossing the front and rear surfaces at an acute angle, and an arm (not shown) is connected to one end of the valve rod 12 protruding from the bearings 13, 13. A weight (not shown) is attached to the tip of this arm, and a dowel pot (not shown) provided on the outer wall of the valve box eases the opening/closing operation of the valve body 15, so that the valve body 15 is opened and closed by the fluid flowing in the pipe. The valve body 5 functions as a tilting check valve that automatically opens and closes depending on the balance between the fluid pressure acting on the valve and the weight of the weight.

Since the present embodiment is configured as described above, when high-pressure fluid is caused to flow in the pipe line, even if the eccentricity L ₁ of the valve stem 12 is the minimum, the fluid pressure acting on the valve body 15 causes the valve body 15 to become a valve. It rotates around a rod 12, and is opened and closed appropriately at the dart pot while its rotation is relaxed by the balance between the weight of the weight and the fluid pressure.

At this time, considering the torque when the valve body 15 opens or closes, the bearing torque T _B that acts as resistance to the rotation of the valve stem 12 by the bearing 13 etc.
If α is the constant of proportionality, then T _B = diameter of the valve stem × pressure difference before and after the valve body × α, and on the other hand, the fluid torque T _D that acts as a turning force due to the fluid pressure that the valve body 15 receives from the fluid is the constant of proportionality. If β is, T _D = Eccentricity (L) x Differential pressure across the valve body x β. Furthermore, other torques are so small that they can be ignored, so the total torque T acting on the valve body 15 is T = T. _D −T _B.

Therefore, if the eccentricity L is set small for high pressure use, the fluid torque T _D will be small and the total torque T acting on the valve body will be small.
The operating time can be adjusted arbitrarily. Furthermore, since the eccentricity L ₁ is minimized, the torque generated when the fluid flows backward is also reduced.

On the other hand, when the butterfly valve 10 is used in a low pressure state, it is necessary to set a large fluid torque T _D , and therefore the primary eccentricity or the secondary eccentricity of the valve stem center C _L with respect to the valve body center C _V or both of these For example, when increasing the eccentricity L by secondary eccentricity, as shown in Figs. 6 and 7.
As shown in the figure, by removing the bolt 16 that fixes the bearing 13 to the bearing mounting portion 11a, rotating the bearing 13 by 180 degrees, and positioning the insertion hole 13b above the valve body 11, the amount of eccentricity L ₂ can be reduced. can be set larger than the eccentricity _L1 .

In addition, when changing the amount of eccentricity L by performing both primary eccentricity and secondary eccentricity, the bearing 13 is rotated 90 degrees and set as shown in FIGS. 8 and 9.
3b is located downstream of the valve box 11 (on the left side in the figure). At this time, due to the primary eccentricity of the valve stem center C _L ,
The valve stem center C _L and the valve body center C _V are misaligned in the front-rear direction of the valve body 11, and a gap corresponding to the primary eccentricity is created between the valve stem fixture 14 and the valve body 15. The valve stem fitting 14 may be attached to the valve body 15 by intervening.

In addition, in this embodiment, if a large number of bolt holes are provided in the flange of the bearing and the bearing mounting part, it is possible to change the eccentricity L in small increments.
Further, for the fixed fitting between the valve stem and the valve stem fitting, means such as splines or serrations may be used instead of the key.

[Effect of idea]

As explained above, the butterfly valve of this invention has
An insertion hole through which the valve stem is inserted is formed in the boss of the bearing that is arranged opposite to the outer wall of the valve box to support the valve stem, and both bearings are set to rotate around the boss axis in the valve box. In addition to being removable, the valve stem is removably attached to one side of the valve body using a valve stem mount, so when installing the bearings in the valve box, both bearings can be rotated around their boss axes. By setting the insertion hole at the desired position and then attaching the valve stem to the specified position on the valve body using the valve stem mount, the amount of eccentricity of the valve stem relative to the valve body can be easily changed. As a result, a single butterfly valve can be used even when different working pressures are used, so the range of use of the butterfly valve can be expanded and production costs can be reduced.

In addition, the valve stem and valve body are attached via a valve stem mount, so if the valve body or valve seat needs to be replaced due to damage to the water stop area around the valve stem, the valve stem attachment By removing the tool from the valve body, only the valve body can be easily removed without disassembling the butterfly valve, and the valve body, valve seat, etc. can be easily replaced.

Furthermore, since the valve body and valve seat come into contact only when the valve is closed, wear on the valve seat is reduced and durability is improved.

[Brief explanation of drawings]

1 to 9 show an embodiment of the present invention, in which FIG. 1 is a front view of the butterfly valve, FIG. 2 is a side view, and FIG. 3 is a cross-sectional view of the butterfly valve.
Figure 4 is a front view of the bearing, and Figure 5 is the − of Figure 4.
The sectional views and FIGS. 6 to 9 are explanatory diagrams showing a state in which the center of the valve stem is eccentric with respect to the center of the valve body.
Figures 7 and 8 are sectional front views, Figures 7 and 9, respectively.
The figures are respectively side views, and Figures 10 and 11 show a conventional butterfly valve used in a tilting type check valve. Figure 10 is a cross-sectional front view of the butterfly valve with the valve body upright. FIG. 11 is a cross-sectional front view of the butterfly valve also tilted. 10...Butterfly valve, 11...Valve box, 12...
...Valve stem, 13...Bearing, 13a...Boss, 13b
...Insertion hole, 13c...Flange, 13d...Bolt hole, 14...Valve stem fitting, 14a...Bolt hole, 14b...Mounting part, 14c...Through hole, 14d
... Valve stem fixing part, 15 ... Valve body, 17 ... Metal bushing, 18 ... O-ring, 19 ... Key, 2
1... Spacer, C _V ... Valve body center, C _L ... Valve stem center, L... Eccentricity.

Claims (1)

[Scope of utility model registration request] In a butterfly valve, a valve body is rotatably provided in a valve box, and the valve body is opened and closed by a valve stem extending to the outside via a bearing disposed opposite to the outer wall of the valve box. An insertion hole through which the valve stem is inserted is formed in the boss offset from the boss axis, and both bearings are provided in the valve box so that they can be set to rotate around the boss axis and can be detached.
A butterfly valve characterized in that a valve stem fitting into which the valve stem fits is removably attached to one side of the valve body with a fastener such as a bolt.